From 79eb4dde742fe2e9c9e301432b894a7410261ce7 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:24 +1100
Subject: cifs: dont overwrite dentry name in d_revalidate

Use vfat's method for dealing with negative dentries to preserve case,
rather than overwrite dentry name in d_revalidate, which is a bit ugly
and also gets in the way of doing lock-free path walking.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 fs/cifs/dir.c | 43 ++++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 19 deletions(-)

(limited to 'fs/cifs')

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 3840eddbfb7a..521d841b1fd1 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -656,22 +656,34 @@ lookup_out:
 static int
 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 {
-	int isValid = 1;
-
 	if (direntry->d_inode) {
 		if (cifs_revalidate_dentry(direntry))
 			return 0;
-	} else {
-		cFYI(1, "neg dentry 0x%p name = %s",
-			 direntry, direntry->d_name.name);
-		if (time_after(jiffies, direntry->d_time + HZ) ||
-			!lookupCacheEnabled) {
-			d_drop(direntry);
-			isValid = 0;
-		}
+		else
+			return 1;
 	}
 
-	return isValid;
+	/*
+	 * This may be nfsd (or something), anyway, we can't see the
+	 * intent of this. So, since this can be for creation, drop it.
+	 */
+	if (!nd)
+		return 0;
+
+	/*
+	 * Drop the negative dentry, in order to make sure to use the
+	 * case sensitive name which is specified by user if this is
+	 * for creation.
+	 */
+	if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
+		if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+			return 0;
+	}
+
+	if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
+		return 0;
+
+	return 1;
 }
 
 /* static int cifs_d_delete(struct dentry *direntry)
@@ -709,15 +721,8 @@ static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
 	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 
 	if ((a->len == b->len) &&
-	    (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
-		/*
-		 * To preserve case, don't let an existing negative dentry's
-		 * case take precedence.  If a is not a negative dentry, this
-		 * should have no side effects
-		 */
-		memcpy((void *)a->name, b->name, a->len);
+	    (nls_strnicmp(codepage, a->name, b->name, a->len) == 0))
 		return 0;
-	}
 	return 1;
 }
 
-- 
cgit v1.2.3


From 621e155a3591962420eacdd39f6f0aa29ceb221e Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:27 +1100
Subject: fs: change d_compare for rcu-walk

Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/Locking |  4 +-
 Documentation/filesystems/porting |  7 +++
 Documentation/filesystems/vfs.txt | 26 +++++++++--
 drivers/staging/smbfs/dir.c       | 16 ++++---
 fs/adfs/dir.c                     |  8 ++--
 fs/affs/namei.c                   | 46 ++++++++++++--------
 fs/cifs/dir.c                     | 12 ++---
 fs/dcache.c                       |  4 +-
 fs/fat/namei_msdos.c              | 14 +++---
 fs/fat/namei_vfat.c               | 33 ++++++++------
 fs/hfs/hfs_fs.h                   |  5 ++-
 fs/hfs/string.c                   | 14 +++---
 fs/hfsplus/hfsplus_fs.h           |  5 ++-
 fs/hfsplus/unicode.c              | 15 ++++---
 fs/hpfs/dentry.c                  | 22 ++++++----
 fs/isofs/inode.c                  | 92 ++++++++++++++++++++-------------------
 fs/isofs/namei.c                  |  3 +-
 fs/jfs/namei.c                    | 11 +++--
 fs/ncpfs/dir.c                    | 25 ++++++-----
 fs/ncpfs/ncplib_kernel.h          |  8 ++--
 fs/proc/proc_sysctl.c             | 13 +++---
 include/linux/dcache.h            | 12 +++--
 include/linux/ncp_fs.h            |  4 +-
 23 files changed, 242 insertions(+), 157 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 33fa3e5d38fd..9a76f8d8bf95 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -11,7 +11,9 @@ be able to use diff(1).
 prototypes:
 	int (*d_revalidate)(struct dentry *, int);
 	int (*d_hash) (struct dentry *, struct qstr *);
-	int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
+	int (*d_compare)(const struct dentry *, const struct inode *,
+			const struct dentry *, const struct inode *,
+			unsigned int, const char *, const struct qstr *);
 	int (*d_delete)(struct dentry *);
 	void (*d_release)(struct dentry *);
 	void (*d_iput)(struct dentry *, struct inode *);
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 9e71c9ad3108..d44511e20828 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -326,3 +326,10 @@ to it.
 unreferenced dentries, and is now only called when the dentry refcount goes to
 0. Even on 0 refcount transition, it must be able to tolerate being called 0,
 1, or more times (eg. constant, idempotent).
+
+---
+[mandatory]
+
+	.d_compare() calling convention and locking rules are significantly
+changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
+look at examples of other filesystems) for guidance.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 95c0a93f056c..250681b8c7cc 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -848,7 +848,9 @@ defined:
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, struct nameidata *);
 	int (*d_hash)(struct dentry *, struct qstr *);
-	int (*d_compare)(struct dentry *, struct qstr *, struct qstr *);
+	int (*d_compare)(const struct dentry *, const struct inode *,
+			const struct dentry *, const struct inode *,
+			unsigned int, const char *, const struct qstr *);
 	int (*d_delete)(const struct dentry *);
 	void (*d_release)(struct dentry *);
 	void (*d_iput)(struct dentry *, struct inode *);
@@ -860,9 +862,27 @@ struct dentry_operations {
 	dcache. Most filesystems leave this as NULL, because all their
 	dentries in the dcache are valid
 
-  d_hash: called when the VFS adds a dentry to the hash table
+  d_hash: called when the VFS adds a dentry to the hash table. The first
+	dentry passed to d_hash is the parent directory that the name is
+	to be hashed into.
 
-  d_compare: called when a dentry should be compared with another
+  d_compare: called to compare a dentry name with a given name. The first
+	dentry is the parent of the dentry to be compared, the second is
+	the parent's inode, then the dentry and inode (may be NULL) of the
+	child dentry. len and name string are properties of the dentry to be
+	compared. qstr is the name to compare it with.
+
+	Must be constant and idempotent, and should not take locks if
+	possible, and should not or store into the dentry or inodes.
+	Should not dereference pointers outside the dentry or inodes without
+	lots of care (eg.  d_parent, d_inode, d_name should not be used).
+
+	However, our vfsmount is pinned, and RCU held, so the dentries and
+	inodes won't disappear, neither will our sb or filesystem module.
+	->i_sb and ->d_sb may be used.
+
+	It is a tricky calling convention because it needs to be called under
+	"rcu-walk", ie. without any locks or references on things.
 
   d_delete: called when the last reference to a dentry is dropped and the
 	dcache is deciding whether or not to cache it. Return 1 to delete
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index 2270d4822c2f..bd63229f43f2 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -275,7 +275,10 @@ smb_dir_open(struct inode *dir, struct file *file)
  */
 static int smb_lookup_validate(struct dentry *, struct nameidata *);
 static int smb_hash_dentry(struct dentry *, struct qstr *);
-static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+static int smb_compare_dentry(const struct dentry *,
+		const struct inode *,
+		const struct dentry *, const struct inode *,
+		unsigned int, const char *, const struct qstr *);
 static int smb_delete_dentry(const struct dentry *);
 
 static const struct dentry_operations smbfs_dentry_operations =
@@ -347,14 +350,17 @@ smb_hash_dentry(struct dentry *dir, struct qstr *this)
 }
 
 static int
-smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b)
+smb_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	int i, result = 1;
 
-	if (a->len != b->len)
+	if (len != name->len)
 		goto out;
-	for (i=0; i < a->len; i++) {
-		if (tolower(a->name[i]) != tolower(b->name[i]))
+	for (i=0; i < len; i++) {
+		if (tolower(str[i]) != tolower(name->name[i]))
 			goto out;
 	}
 	result = 0;
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index f4287e4de744..c8ed66162bd4 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -237,17 +237,19 @@ adfs_hash(struct dentry *parent, struct qstr *qstr)
  * requirements of the underlying filesystem.
  */
 static int
-adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name)
+adfs_compare(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	int i;
 
-	if (entry->len != name->len)
+	if (len != name->len)
 		return 1;
 
 	for (i = 0; i < name->len; i++) {
 		char a, b;
 
-		a = entry->name[i];
+		a = str[i];
 		b = name->name[i];
 
 		if (a >= 'A' && a <= 'Z')
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 914d1c0bc07a..547d5deb0d42 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -14,10 +14,16 @@ typedef int (*toupper_t)(int);
 
 static int	 affs_toupper(int ch);
 static int	 affs_hash_dentry(struct dentry *, struct qstr *);
-static int       affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+static int       affs_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 static int	 affs_intl_toupper(int ch);
 static int	 affs_intl_hash_dentry(struct dentry *, struct qstr *);
-static int       affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+static int       affs_intl_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 
 const struct dentry_operations affs_dentry_operations = {
 	.d_hash		= affs_hash_dentry,
@@ -88,29 +94,29 @@ affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
 	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
 }
 
-static inline int
-__affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper)
+static inline int __affs_compare_dentry(unsigned int len,
+		const char *str, const struct qstr *name, toupper_t toupper)
 {
-	const u8 *aname = a->name;
-	const u8 *bname = b->name;
-	int len;
+	const u8 *aname = str;
+	const u8 *bname = name->name;
 
-	/* 'a' is the qstr of an already existing dentry, so the name
-	 * must be valid. 'b' must be validated first.
+	/*
+	 * 'str' is the name of an already existing dentry, so the name
+	 * must be valid. 'name' must be validated first.
 	 */
 
-	if (affs_check_name(b->name,b->len))
+	if (affs_check_name(name->name, name->len))
 		return 1;
 
-	/* If the names are longer than the allowed 30 chars,
+	/*
+	 * If the names are longer than the allowed 30 chars,
 	 * the excess is ignored, so their length may differ.
 	 */
-	len = a->len;
 	if (len >= 30) {
-		if (b->len < 30)
+		if (name->len < 30)
 			return 1;
 		len = 30;
-	} else if (len != b->len)
+	} else if (len != name->len)
 		return 1;
 
 	for (; len > 0; len--)
@@ -121,14 +127,18 @@ __affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, tou
 }
 
 static int
-affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+affs_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return __affs_compare_dentry(dentry, a, b, affs_toupper);
+	return __affs_compare_dentry(len, str, name, affs_toupper);
 }
 static int
-affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+affs_intl_compare_dentry(const struct dentry *parent,const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return __affs_compare_dentry(dentry, a, b, affs_intl_toupper);
+	return __affs_compare_dentry(len, str, name, affs_intl_toupper);
 }
 
 /*
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 521d841b1fd1..c60133f0d8e4 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -715,13 +715,15 @@ static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
 	return 0;
 }
 
-static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
-			   struct qstr *b)
+static int cifs_ci_compare(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+	struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls;
 
-	if ((a->len == b->len) &&
-	    (nls_strnicmp(codepage, a->name, b->name, a->len) == 0))
+	if ((name->len == len) &&
+	    (nls_strnicmp(codepage, name->name, str, len) == 0))
 		return 0;
 	return 1;
 }
diff --git a/fs/dcache.c b/fs/dcache.c
index 814e5f491e9c..7075555fbb04 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1437,7 +1437,9 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name)
 		 */
 		qstr = &dentry->d_name;
 		if (parent->d_op && parent->d_op->d_compare) {
-			if (parent->d_op->d_compare(parent, qstr, name))
+			if (parent->d_op->d_compare(parent, parent->d_inode,
+						dentry, dentry->d_inode,
+						qstr->len, qstr->name, name))
 				goto next;
 		} else {
 			if (qstr->len != len)
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 3345aabd1dd7..99d3c7ac973c 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -164,16 +164,18 @@ static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
  * Compare two msdos names. If either of the names are invalid,
  * we fall back to doing the standard name comparison.
  */
-static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int msdos_cmp(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+	struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
 	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 	int error;
 
-	error = msdos_format_name(a->name, a->len, a_msdos_name, options);
+	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
 	if (error)
 		goto old_compare;
-	error = msdos_format_name(b->name, b->len, b_msdos_name, options);
+	error = msdos_format_name(str, len, b_msdos_name, options);
 	if (error)
 		goto old_compare;
 	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
@@ -182,8 +184,8 @@ out:
 
 old_compare:
 	error = 1;
-	if (a->len == b->len)
-		error = memcmp(a->name, b->name, a->len);
+	if (name->len == len)
+		error = memcmp(name->name, str, len);
 	goto out;
 }
 
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index b936703b8924..95e00ab84c3f 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -85,15 +85,18 @@ static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
 }
 
 /* returns the length of a struct qstr, ignoring trailing dots */
-static unsigned int vfat_striptail_len(struct qstr *qstr)
+static unsigned int __vfat_striptail_len(unsigned int len, const char *name)
 {
-	unsigned int len = qstr->len;
-
-	while (len && qstr->name[len - 1] == '.')
+	while (len && name[len - 1] == '.')
 		len--;
 	return len;
 }
 
+static unsigned int vfat_striptail_len(const struct qstr *qstr)
+{
+	return __vfat_striptail_len(qstr->len, qstr->name);
+}
+
 /*
  * Compute the hash for the vfat name corresponding to the dentry.
  * Note: if the name is invalid, we leave the hash code unchanged so
@@ -133,16 +136,18 @@ static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
 /*
  * Case insensitive compare of two vfat names.
  */
-static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int vfat_cmpi(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+	struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io;
 	unsigned int alen, blen;
 
 	/* A filename cannot end in '.' or we treat it like it has none */
-	alen = vfat_striptail_len(a);
-	blen = vfat_striptail_len(b);
+	alen = vfat_striptail_len(name);
+	blen = __vfat_striptail_len(len, str);
 	if (alen == blen) {
-		if (nls_strnicmp(t, a->name, b->name, alen) == 0)
+		if (nls_strnicmp(t, name->name, str, alen) == 0)
 			return 0;
 	}
 	return 1;
@@ -151,15 +156,17 @@ static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
 /*
  * Case sensitive compare of two vfat names.
  */
-static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int vfat_cmp(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	unsigned int alen, blen;
 
 	/* A filename cannot end in '.' or we treat it like it has none */
-	alen = vfat_striptail_len(a);
-	blen = vfat_striptail_len(b);
+	alen = vfat_striptail_len(name);
+	blen = __vfat_striptail_len(len, str);
 	if (alen == blen) {
-		if (strncmp(a->name, b->name, alen) == 0)
+		if (strncmp(name->name, str, alen) == 0)
 			return 0;
 	}
 	return 1;
diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h
index c8cffb81e849..8cd876f0e961 100644
--- a/fs/hfs/hfs_fs.h
+++ b/fs/hfs/hfs_fs.h
@@ -216,7 +216,10 @@ extern const struct dentry_operations hfs_dentry_operations;
 extern int hfs_hash_dentry(struct dentry *, struct qstr *);
 extern int hfs_strcmp(const unsigned char *, unsigned int,
 		      const unsigned char *, unsigned int);
-extern int hfs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+extern int hfs_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 
 /* trans.c */
 extern void hfs_asc2mac(struct super_block *, struct hfs_name *, struct qstr *);
diff --git a/fs/hfs/string.c b/fs/hfs/string.c
index 927a5af79428..aaf90d0d6940 100644
--- a/fs/hfs/string.c
+++ b/fs/hfs/string.c
@@ -92,21 +92,21 @@ int hfs_strcmp(const unsigned char *s1, unsigned int len1,
  * Test for equality of two strings in the HFS filename character ordering.
  * return 1 on failure and 0 on success
  */
-int hfs_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
+int hfs_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	const unsigned char *n1, *n2;
-	int len;
 
-	len = s1->len;
 	if (len >= HFS_NAMELEN) {
-		if (s2->len < HFS_NAMELEN)
+		if (name->len < HFS_NAMELEN)
 			return 1;
 		len = HFS_NAMELEN;
-	} else if (len != s2->len)
+	} else if (len != name->len)
 		return 1;
 
-	n1 = s1->name;
-	n2 = s2->name;
+	n1 = str;
+	n2 = name->name;
 	while (len--) {
 		if (caseorder[*n1++] != caseorder[*n2++])
 			return 1;
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index cb3653efb57a..7aa96eefe483 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -380,7 +380,10 @@ int hfsplus_strcmp(const struct hfsplus_unistr *, const struct hfsplus_unistr *)
 int hfsplus_uni2asc(struct super_block *, const struct hfsplus_unistr *, char *, int *);
 int hfsplus_asc2uni(struct super_block *, struct hfsplus_unistr *, const char *, int);
 int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str);
-int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2);
+int hfsplus_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 
 /* wrapper.c */
 int hfsplus_read_wrapper(struct super_block *);
diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
index b66d67de882c..b178c997efa8 100644
--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c
@@ -363,9 +363,12 @@ int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str)
  * Composed unicode characters are decomposed and case-folding is performed
  * if the appropriate bits are (un)set on the superblock.
  */
-int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
+int hfsplus_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct super_block *sb = dentry->d_sb;
+	struct super_block *sb = parent->d_sb;
 	int casefold, decompose, size;
 	int dsize1, dsize2, len1, len2;
 	const u16 *dstr1, *dstr2;
@@ -375,10 +378,10 @@ int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *
 
 	casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 	decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
-	astr1 = s1->name;
-	len1 = s1->len;
-	astr2 = s2->name;
-	len2 = s2->len;
+	astr1 = str;
+	len1 = len;
+	astr2 = name->name;
+	len2 = name->len;
 	dsize1 = dsize2 = 0;
 	dstr1 = dstr2 = NULL;
 
diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c
index 67d9d36b3d5f..dd9b1e74a734 100644
--- a/fs/hpfs/dentry.c
+++ b/fs/hpfs/dentry.c
@@ -34,19 +34,25 @@ static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
 	return 0;
 }
 
-static int hpfs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int hpfs_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	unsigned al=a->len;
-	unsigned bl=b->len;
-	hpfs_adjust_length(a->name, &al);
+	unsigned al = len;
+	unsigned bl = name->len;
+
+	hpfs_adjust_length(str, &al);
 	/*hpfs_adjust_length(b->name, &bl);*/
-	/* 'a' is the qstr of an already existing dentry, so the name
-	 * must be valid. 'b' must be validated first.
+
+	/*
+	 * 'str' is the nane of an already existing dentry, so the name
+	 * must be valid. 'name' must be validated first.
 	 */
 
-	if (hpfs_chk_name(b->name, &bl))
+	if (hpfs_chk_name(name->name, &bl))
 		return 1;
-	if (hpfs_compare_names(dentry->d_sb, a->name, al, b->name, bl, 0))
+	if (hpfs_compare_names(parent->d_sb, str, al, name->name, bl, 0))
 		return 1;
 	return 0;
 }
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index bfdeb82a53be..7b0fbc61af81 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -28,14 +28,26 @@
 
 static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
 static int isofs_hash(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_dentry_cmpi(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
+static int isofs_dentry_cmp(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 
 #ifdef CONFIG_JOLIET
 static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
 static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_dentry_cmpi_ms(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
+static int isofs_dentry_cmp_ms(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name);
 #endif
 
 static void isofs_put_super(struct super_block *sb)
@@ -206,49 +218,31 @@ isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
 }
 
 /*
- * Case insensitive compare of two isofs names.
+ * Compare of two isofs names.
  */
-static int isofs_dentry_cmpi_common(struct dentry *dentry, struct qstr *a,
-				struct qstr *b, int ms)
+static int isofs_dentry_cmp_common(
+		unsigned int len, const char *str,
+		const struct qstr *name, int ms, int ci)
 {
 	int alen, blen;
 
 	/* A filename cannot end in '.' or we treat it like it has none */
-	alen = a->len;
-	blen = b->len;
+	alen = name->len;
+	blen = len;
 	if (ms) {
-		while (alen && a->name[alen-1] == '.')
+		while (alen && name->name[alen-1] == '.')
 			alen--;
-		while (blen && b->name[blen-1] == '.')
+		while (blen && str[blen-1] == '.')
 			blen--;
 	}
 	if (alen == blen) {
-		if (strnicmp(a->name, b->name, alen) == 0)
-			return 0;
-	}
-	return 1;
-}
-
-/*
- * Case sensitive compare of two isofs names.
- */
-static int isofs_dentry_cmp_common(struct dentry *dentry, struct qstr *a,
-					struct qstr *b, int ms)
-{
-	int alen, blen;
-
-	/* A filename cannot end in '.' or we treat it like it has none */
-	alen = a->len;
-	blen = b->len;
-	if (ms) {
-		while (alen && a->name[alen-1] == '.')
-			alen--;
-		while (blen && b->name[blen-1] == '.')
-			blen--;
-	}
-	if (alen == blen) {
-		if (strncmp(a->name, b->name, alen) == 0)
-			return 0;
+		if (ci) {
+			if (strnicmp(name->name, str, alen) == 0)
+				return 0;
+		} else {
+			if (strncmp(name->name, str, alen) == 0)
+				return 0;
+		}
 	}
 	return 1;
 }
@@ -266,15 +260,19 @@ isofs_hashi(struct dentry *dentry, struct qstr *qstr)
 }
 
 static int
-isofs_dentry_cmp(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return isofs_dentry_cmp_common(dentry, a, b, 0);
+	return isofs_dentry_cmp_common(len, str, name, 0, 0);
 }
 
 static int
-isofs_dentry_cmpi(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return isofs_dentry_cmpi_common(dentry, a, b, 0);
+	return isofs_dentry_cmp_common(len, str, name, 0, 1);
 }
 
 #ifdef CONFIG_JOLIET
@@ -291,15 +289,19 @@ isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr)
 }
 
 static int
-isofs_dentry_cmp_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp_ms(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return isofs_dentry_cmp_common(dentry, a, b, 1);
+	return isofs_dentry_cmp_common(len, str, name, 1, 0);
 }
 
 static int
-isofs_dentry_cmpi_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi_ms(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	return isofs_dentry_cmpi_common(dentry, a, b, 1);
+	return isofs_dentry_cmp_common(len, str, name, 1, 1);
 }
 #endif
 
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c
index 0d23abfd4280..715f7d318046 100644
--- a/fs/isofs/namei.c
+++ b/fs/isofs/namei.c
@@ -37,7 +37,8 @@ isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
 
 	qstr.name = compare;
 	qstr.len = dlen;
-	return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr);
+	return dentry->d_op->d_compare(NULL, NULL, NULL, NULL,
+			dentry->d_name.len, dentry->d_name.name, &qstr);
 }
 
 /*
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 2da1546161fa..92129016cd79 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1587,14 +1587,17 @@ static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
 	return 0;
 }
 
-static int jfs_ci_compare(struct dentry *dir, struct qstr *a, struct qstr *b)
+static int jfs_ci_compare(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	int i, result = 1;
 
-	if (a->len != b->len)
+	if (len != name->len)
 		goto out;
-	for (i=0; i < a->len; i++) {
-		if (tolower(a->name[i]) != tolower(b->name[i]))
+	for (i=0; i < len; i++) {
+		if (tolower(str[i]) != tolower(name->name[i]))
 			goto out;
 	}
 	result = 0;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index e80ea4e37c48..3bcc68aed416 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -75,7 +75,9 @@ const struct inode_operations ncp_dir_inode_operations =
  */
 static int ncp_lookup_validate(struct dentry *, struct nameidata *);
 static int ncp_hash_dentry(struct dentry *, struct qstr *);
-static int ncp_compare_dentry (struct dentry *, struct qstr *, struct qstr *);
+static int ncp_compare_dentry(const struct dentry *, const struct inode *,
+		const struct dentry *, const struct inode *,
+		unsigned int, const char *, const struct qstr *);
 static int ncp_delete_dentry(const struct dentry *);
 
 static const struct dentry_operations ncp_dentry_operations =
@@ -113,10 +115,10 @@ static inline int ncp_preserve_entry_case(struct inode *i, __u32 nscreator)
 
 #define ncp_preserve_case(i)	(ncp_namespace(i) != NW_NS_DOS)
 
-static inline int ncp_case_sensitive(struct dentry *dentry)
+static inline int ncp_case_sensitive(const struct inode *i)
 {
 #ifdef CONFIG_NCPFS_NFS_NS
-	return ncp_namespace(dentry->d_inode) == NW_NS_NFS;
+	return ncp_namespace(i) == NW_NS_NFS;
 #else
 	return 0;
 #endif /* CONFIG_NCPFS_NFS_NS */
@@ -129,12 +131,13 @@ static inline int ncp_case_sensitive(struct dentry *dentry)
 static int 
 ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
 {
-	if (!ncp_case_sensitive(dentry)) {
+	if (!ncp_case_sensitive(dentry->d_inode)) {
+		struct super_block *sb = dentry->d_sb;
 		struct nls_table *t;
 		unsigned long hash;
 		int i;
 
-		t = NCP_IO_TABLE(dentry);
+		t = NCP_IO_TABLE(sb);
 		hash = init_name_hash();
 		for (i=0; i<this->len ; i++)
 			hash = partial_name_hash(ncp_tolower(t, this->name[i]),
@@ -145,15 +148,17 @@ ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
 }
 
 static int
-ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+ncp_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	if (a->len != b->len)
+	if (len != name->len)
 		return 1;
 
-	if (ncp_case_sensitive(dentry))
-		return strncmp(a->name, b->name, a->len);
+	if (ncp_case_sensitive(pinode))
+		return strncmp(str, name->name, len);
 
-	return ncp_strnicmp(NCP_IO_TABLE(dentry), a->name, b->name, a->len);
+	return ncp_strnicmp(NCP_IO_TABLE(pinode->i_sb), str, name->name, len);
 }
 
 /*
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index 3c57eca634ce..244d1b73fda7 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -135,7 +135,7 @@ int ncp__vol2io(struct ncp_server *, unsigned char *, unsigned int *,
 				const unsigned char *, unsigned int, int);
 
 #define NCP_ESC			':'
-#define NCP_IO_TABLE(dentry)	(NCP_SERVER((dentry)->d_inode)->nls_io)
+#define NCP_IO_TABLE(sb)	(NCP_SBP(sb)->nls_io)
 #define ncp_tolower(t, c)	nls_tolower(t, c)
 #define ncp_toupper(t, c)	nls_toupper(t, c)
 #define ncp_strnicmp(t, s1, s2, len) \
@@ -150,15 +150,15 @@ int ncp__io2vol(unsigned char *, unsigned int *,
 int ncp__vol2io(unsigned char *, unsigned int *,
 				const unsigned char *, unsigned int, int);
 
-#define NCP_IO_TABLE(dentry)	NULL
+#define NCP_IO_TABLE(sb)	NULL
 #define ncp_tolower(t, c)	tolower(c)
 #define ncp_toupper(t, c)	toupper(c)
 #define ncp_io2vol(S,m,i,n,k,U)	ncp__io2vol(m,i,n,k,U)
 #define ncp_vol2io(S,m,i,n,k,U)	ncp__vol2io(m,i,n,k,U)
 
 
-static inline int ncp_strnicmp(struct nls_table *t, const unsigned char *s1,
-		const unsigned char *s2, int len)
+static inline int ncp_strnicmp(const struct nls_table *t,
+		const unsigned char *s1, const unsigned char *s2, int len)
 {
 	while (len--) {
 		if (tolower(*s1++) != tolower(*s2++))
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index a256d770ea18..ae4b0fd9033f 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -397,15 +397,16 @@ static int proc_sys_delete(const struct dentry *dentry)
 	return !!PROC_I(dentry->d_inode)->sysctl->unregistering;
 }
 
-static int proc_sys_compare(struct dentry *dir, struct qstr *qstr,
-			    struct qstr *name)
+static int proc_sys_compare(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct dentry *dentry = container_of(qstr, struct dentry, d_name);
-	if (qstr->len != name->len)
+	if (name->len != len)
 		return 1;
-	if (memcmp(qstr->name, name->name, name->len))
+	if (memcmp(name->name, str, len))
 		return 1;
-	return !sysctl_is_seen(PROC_I(dentry->d_inode)->sysctl);
+	return !sysctl_is_seen(PROC_I(inode)->sysctl);
 }
 
 static const struct dentry_operations proc_sys_dentry_operations = {
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 6cdf4995c90a..75a072bf2a34 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -134,7 +134,9 @@ enum dentry_d_lock_class
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, struct nameidata *);
 	int (*d_hash)(struct dentry *, struct qstr *);
-	int (*d_compare)(struct dentry *, struct qstr *, struct qstr *);
+	int (*d_compare)(const struct dentry *, const struct inode *,
+			const struct dentry *, const struct inode *,
+			unsigned int, const char *, const struct qstr *);
 	int (*d_delete)(const struct dentry *);
 	void (*d_release)(struct dentry *);
 	void (*d_iput)(struct dentry *, struct inode *);
@@ -145,12 +147,8 @@ struct dentry_operations {
  * Locking rules for dentry_operations callbacks are to be found in
  * Documentation/filesystems/Locking. Keep it updated!
  *
- * the dentry parameter passed to d_hash and d_compare is the parent
- * directory of the entries to be compared. It is used in case these
- * functions need any directory specific information for determining
- * equivalency classes.  Using the dentry itself might not work, as it
- * might be a negative dentry which has no information associated with
- * it.
+ * FUrther descriptions are found in Documentation/filesystems/vfs.txt.
+ * Keep it updated too!
  */
 
 /* d_flags entries */
diff --git a/include/linux/ncp_fs.h b/include/linux/ncp_fs.h
index ef663061d5ac..1c27f201c856 100644
--- a/include/linux/ncp_fs.h
+++ b/include/linux/ncp_fs.h
@@ -184,13 +184,13 @@ struct ncp_entry_info {
 	__u8			file_handle[6];
 };
 
-static inline struct ncp_server *NCP_SBP(struct super_block *sb)
+static inline struct ncp_server *NCP_SBP(const struct super_block *sb)
 {
 	return sb->s_fs_info;
 }
 
 #define NCP_SERVER(inode)	NCP_SBP((inode)->i_sb)
-static inline struct ncp_inode_info *NCP_FINFO(struct inode *inode)
+static inline struct ncp_inode_info *NCP_FINFO(const struct inode *inode)
 {
 	return container_of(inode, struct ncp_inode_info, vfs_inode);
 }
-- 
cgit v1.2.3


From b1e6a015a580ad145689ad1d6b4aa0e03e6c868b Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:28 +1100
Subject: fs: change d_hash for rcu-walk

Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/Locking |  5 +++--
 Documentation/filesystems/porting |  7 +++++++
 Documentation/filesystems/vfs.txt |  8 ++++++--
 drivers/staging/smbfs/cache.c     |  2 +-
 drivers/staging/smbfs/dir.c       |  6 ++++--
 fs/adfs/dir.c                     |  3 ++-
 fs/affs/namei.c                   | 20 ++++++++++++--------
 fs/cifs/dir.c                     |  5 +++--
 fs/cifs/readdir.c                 |  2 +-
 fs/dcache.c                       |  2 +-
 fs/ecryptfs/inode.c               |  4 ++--
 fs/fat/namei_msdos.c              |  3 ++-
 fs/fat/namei_vfat.c               |  8 +++++---
 fs/gfs2/dentry.c                  |  3 ++-
 fs/hfs/hfs_fs.h                   |  3 ++-
 fs/hfs/string.c                   |  3 ++-
 fs/hfsplus/hfsplus_fs.h           |  3 ++-
 fs/hfsplus/unicode.c              |  3 ++-
 fs/hpfs/dentry.c                  |  3 ++-
 fs/isofs/inode.c                  | 28 ++++++++++++++++++----------
 fs/jfs/namei.c                    |  3 ++-
 fs/namei.c                        |  5 +++--
 fs/ncpfs/dir.c                    | 10 ++++++----
 fs/sysv/namei.c                   |  3 ++-
 include/linux/dcache.h            |  3 ++-
 25 files changed, 94 insertions(+), 51 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 9a76f8d8bf95..a15ee207b449 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -10,7 +10,8 @@ be able to use diff(1).
 --------------------------- dentry_operations --------------------------
 prototypes:
 	int (*d_revalidate)(struct dentry *, int);
-	int (*d_hash) (struct dentry *, struct qstr *);
+	int (*d_hash)(const struct dentry *, const struct inode *,
+			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
 			const struct dentry *, const struct inode *,
 			unsigned int, const char *, const struct qstr *);
@@ -22,7 +23,7 @@ prototypes:
 locking rules:
 		dcache_lock	rename_lock	->d_lock	may block
 d_revalidate:	no		no		no		yes
-d_hash		no		no		no		yes
+d_hash		no		no		no		no
 d_compare:	no		yes		no		no 
 d_delete:	yes		no		yes		no
 d_release:	no		no		no		yes
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index d44511e20828..9fd31940a8ef 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -333,3 +333,10 @@ unreferenced dentries, and is now only called when the dentry refcount goes to
 	.d_compare() calling convention and locking rules are significantly
 changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
 look at examples of other filesystems) for guidance.
+
+---
+[mandatory]
+
+	.d_hash() calling convention and locking rules are significantly
+changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
+look at examples of other filesystems) for guidance.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 250681b8c7cc..69b10ff5ec81 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -847,7 +847,8 @@ defined:
 
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, struct nameidata *);
-	int (*d_hash)(struct dentry *, struct qstr *);
+	int (*d_hash)(const struct dentry *, const struct inode *,
+			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
 			const struct dentry *, const struct inode *,
 			unsigned int, const char *, const struct qstr *);
@@ -864,7 +865,10 @@ struct dentry_operations {
 
   d_hash: called when the VFS adds a dentry to the hash table. The first
 	dentry passed to d_hash is the parent directory that the name is
-	to be hashed into.
+	to be hashed into. The inode is the dentry's inode.
+
+	Same locking and synchronisation rules as d_compare regarding
+	what is safe to dereference etc.
 
   d_compare: called to compare a dentry name with a given name. The first
 	dentry is the parent of the dentry to be compared, the second is
diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c
index dbd2e1df3ba9..0beded260b00 100644
--- a/drivers/staging/smbfs/cache.c
+++ b/drivers/staging/smbfs/cache.c
@@ -134,7 +134,7 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
 	qname->hash = full_name_hash(qname->name, qname->len);
 
 	if (dentry->d_op && dentry->d_op->d_hash)
-		if (dentry->d_op->d_hash(dentry, qname) != 0)
+		if (dentry->d_op->d_hash(dentry, inode, qname) != 0)
 			goto end_advance;
 
 	newdent = d_lookup(dentry, qname);
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index bd63229f43f2..5f79799d5d4a 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -274,7 +274,8 @@ smb_dir_open(struct inode *dir, struct file *file)
  * Dentry operations routines
  */
 static int smb_lookup_validate(struct dentry *, struct nameidata *);
-static int smb_hash_dentry(struct dentry *, struct qstr *);
+static int smb_hash_dentry(const struct dentry *, const struct inode *,
+		struct qstr *);
 static int smb_compare_dentry(const struct dentry *,
 		const struct inode *,
 		const struct dentry *, const struct inode *,
@@ -336,7 +337,8 @@ smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
 }
 
 static int 
-smb_hash_dentry(struct dentry *dir, struct qstr *this)
+smb_hash_dentry(const struct dentry *dir, const struct inode *inode,
+		struct qstr *this)
 {
 	unsigned long hash;
 	int i;
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index c8ed66162bd4..a11e5e102716 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -201,7 +201,8 @@ const struct file_operations adfs_dir_operations = {
 };
 
 static int
-adfs_hash(struct dentry *parent, struct qstr *qstr)
+adfs_hash(const struct dentry *parent, const struct inode *inode,
+		struct qstr *qstr)
 {
 	const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
 	const unsigned char *name;
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 547d5deb0d42..5aca08c21100 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -13,13 +13,15 @@
 typedef int (*toupper_t)(int);
 
 static int	 affs_toupper(int ch);
-static int	 affs_hash_dentry(struct dentry *, struct qstr *);
+static int	 affs_hash_dentry(const struct dentry *,
+		const struct inode *, struct qstr *);
 static int       affs_compare_dentry(const struct dentry *parent,
 		const struct inode *pinode,
 		const struct dentry *dentry, const struct inode *inode,
 		unsigned int len, const char *str, const struct qstr *name);
 static int	 affs_intl_toupper(int ch);
-static int	 affs_intl_hash_dentry(struct dentry *, struct qstr *);
+static int	 affs_intl_hash_dentry(const struct dentry *,
+		const struct inode *, struct qstr *);
 static int       affs_intl_compare_dentry(const struct dentry *parent,
 		const struct inode *pinode,
 		const struct dentry *dentry, const struct inode *inode,
@@ -64,13 +66,13 @@ affs_get_toupper(struct super_block *sb)
  * Note: the dentry argument is the parent dentry.
  */
 static inline int
-__affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
+__affs_hash_dentry(struct qstr *qstr, toupper_t toupper)
 {
 	const u8 *name = qstr->name;
 	unsigned long hash;
 	int i;
 
-	i = affs_check_name(qstr->name,qstr->len);
+	i = affs_check_name(qstr->name, qstr->len);
 	if (i)
 		return i;
 
@@ -84,14 +86,16 @@ __affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
 }
 
 static int
-affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
-	return __affs_hash_dentry(dentry, qstr, affs_toupper);
+	return __affs_hash_dentry(qstr, affs_toupper);
 }
 static int
-affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_intl_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
-	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
+	return __affs_hash_dentry(qstr, affs_intl_toupper);
 }
 
 static inline int __affs_compare_dentry(unsigned int len,
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index c60133f0d8e4..88bfe686ac00 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -700,9 +700,10 @@ const struct dentry_operations cifs_dentry_ops = {
 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 };
 
-static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
+static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *q)
 {
-	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 	unsigned long hash;
 	int i;
 
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index a73eb9f4bdaf..ee463aeca0b0 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -79,7 +79,7 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
 	cFYI(1, "For %s", name->name);
 
 	if (parent->d_op && parent->d_op->d_hash)
-		parent->d_op->d_hash(parent, name);
+		parent->d_op->d_hash(parent, parent->d_inode, name);
 	else
 		name->hash = full_name_hash(name->name, name->len);
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 7075555fbb04..6f59f375ed9d 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1478,7 +1478,7 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
 	 */
 	name->hash = full_name_hash(name->name, name->len);
 	if (dir->d_op && dir->d_op->d_hash) {
-		if (dir->d_op->d_hash(dir, name) < 0)
+		if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
 			goto out;
 	}
 	dentry = d_lookup(dir, name);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 9d1a22d62765..a1ed7a7cb173 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -454,7 +454,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	lower_name.hash = ecryptfs_dentry->d_name.hash;
 	if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
 		rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
-						    &lower_name);
+				lower_dir_dentry->d_inode, &lower_name);
 		if (rc < 0)
 			goto out_d_drop;
 	}
@@ -489,7 +489,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
 	if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
 		rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
-						    &lower_name);
+				lower_dir_dentry->d_inode, &lower_name);
 		if (rc < 0)
 			goto out_d_drop;
 	}
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 99d3c7ac973c..3b3e072d8982 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -148,7 +148,8 @@ static int msdos_find(struct inode *dir, const unsigned char *name, int len,
  * that the existing dentry can be used. The msdos fs routines will
  * return ENOENT or EINVAL as appropriate.
  */
-static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
+static int msdos_hash(const struct dentry *dentry, const struct inode *inode,
+	       struct qstr *qstr)
 {
 	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 	unsigned char msdos_name[MSDOS_NAME];
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 95e00ab84c3f..4fc06278db48 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -103,7 +103,8 @@ static unsigned int vfat_striptail_len(const struct qstr *qstr)
  * that the existing dentry can be used. The vfat fs routines will
  * return ENOENT or EINVAL as appropriate.
  */
-static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hash(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
 	return 0;
@@ -115,9 +116,10 @@ static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
  * that the existing dentry can be used. The vfat fs routines will
  * return ENOENT or EINVAL as appropriate.
  */
-static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hashi(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
-	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+	struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io;
 	const unsigned char *name;
 	unsigned int len;
 	unsigned long hash;
diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c
index e80fea2f65ff..50497f65763b 100644
--- a/fs/gfs2/dentry.c
+++ b/fs/gfs2/dentry.c
@@ -100,7 +100,8 @@ fail:
 	return 0;
 }
 
-static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
+static int gfs2_dhash(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *str)
 {
 	str->hash = gfs2_disk_hash(str->name, str->len);
 	return 0;
diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h
index 8cd876f0e961..ad97c2d58287 100644
--- a/fs/hfs/hfs_fs.h
+++ b/fs/hfs/hfs_fs.h
@@ -213,7 +213,8 @@ extern int hfs_part_find(struct super_block *, sector_t *, sector_t *);
 /* string.c */
 extern const struct dentry_operations hfs_dentry_operations;
 
-extern int hfs_hash_dentry(struct dentry *, struct qstr *);
+extern int hfs_hash_dentry(const struct dentry *, const struct inode *,
+		struct qstr *);
 extern int hfs_strcmp(const unsigned char *, unsigned int,
 		      const unsigned char *, unsigned int);
 extern int hfs_compare_dentry(const struct dentry *parent,
diff --git a/fs/hfs/string.c b/fs/hfs/string.c
index aaf90d0d6940..495a976a3cc9 100644
--- a/fs/hfs/string.c
+++ b/fs/hfs/string.c
@@ -51,7 +51,8 @@ static unsigned char caseorder[256] = {
 /*
  * Hash a string to an integer in a case-independent way
  */
-int hfs_hash_dentry(struct dentry *dentry, struct qstr *this)
+int hfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *this)
 {
 	const unsigned char *name = this->name;
 	unsigned int hash, len = this->len;
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 7aa96eefe483..a5308f491e3e 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -379,7 +379,8 @@ int hfsplus_strcasecmp(const struct hfsplus_unistr *, const struct hfsplus_unist
 int hfsplus_strcmp(const struct hfsplus_unistr *, const struct hfsplus_unistr *);
 int hfsplus_uni2asc(struct super_block *, const struct hfsplus_unistr *, char *, int *);
 int hfsplus_asc2uni(struct super_block *, struct hfsplus_unistr *, const char *, int);
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str);
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *str);
 int hfsplus_compare_dentry(const struct dentry *parent,
 		const struct inode *pinode,
 		const struct dentry *dentry, const struct inode *inode,
diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
index b178c997efa8..d800aa0f2c80 100644
--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c
@@ -320,7 +320,8 @@ int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
  * Composed unicode characters are decomposed and case-folding is performed
  * if the appropriate bits are (un)set on the superblock.
  */
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str)
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *str)
 {
 	struct super_block *sb = dentry->d_sb;
 	const char *astr;
diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c
index dd9b1e74a734..35526df1fd32 100644
--- a/fs/hpfs/dentry.c
+++ b/fs/hpfs/dentry.c
@@ -12,7 +12,8 @@
  * Note: the dentry argument is the parent dentry.
  */
 
-static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+static int hpfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	unsigned long	 hash;
 	int		 i;
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 7b0fbc61af81..d204ee4235fd 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -26,8 +26,10 @@
 
 #define BEQUIET
 
-static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash(struct dentry *parent, struct qstr *qstr);
+static int isofs_hashi(const struct dentry *parent, const struct inode *inode,
+		struct qstr *qstr);
+static int isofs_hash(const struct dentry *parent, const struct inode *inode,
+		struct qstr *qstr);
 static int isofs_dentry_cmpi(const struct dentry *parent,
 		const struct inode *pinode,
 		const struct dentry *dentry, const struct inode *inode,
@@ -38,8 +40,10 @@ static int isofs_dentry_cmp(const struct dentry *parent,
 		unsigned int len, const char *str, const struct qstr *name);
 
 #ifdef CONFIG_JOLIET
-static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
+static int isofs_hashi_ms(const struct dentry *parent, const struct inode *inode,
+		struct qstr *qstr);
+static int isofs_hash_ms(const struct dentry *parent, const struct inode *inode,
+		struct qstr *qstr);
 static int isofs_dentry_cmpi_ms(const struct dentry *parent,
 		const struct inode *pinode,
 		const struct dentry *dentry, const struct inode *inode,
@@ -172,7 +176,7 @@ struct iso9660_options{
  * Compute the hash for the isofs name corresponding to the dentry.
  */
 static int
-isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
 {
 	const char *name;
 	int len;
@@ -193,7 +197,7 @@ isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
  * Compute the hash for the isofs name corresponding to the dentry.
  */
 static int
-isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
 {
 	const char *name;
 	int len;
@@ -248,13 +252,15 @@ static int isofs_dentry_cmp_common(
 }
 
 static int
-isofs_hash(struct dentry *dentry, struct qstr *qstr)
+isofs_hash(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	return isofs_hash_common(dentry, qstr, 0);
 }
 
 static int
-isofs_hashi(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	return isofs_hashi_common(dentry, qstr, 0);
 }
@@ -277,13 +283,15 @@ isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode,
 
 #ifdef CONFIG_JOLIET
 static int
-isofs_hash_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hash_ms(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	return isofs_hash_common(dentry, qstr, 1);
 }
 
 static int
-isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi_ms(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	return isofs_hashi_common(dentry, qstr, 1);
 }
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 92129016cd79..57f90dad8919 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1574,7 +1574,8 @@ const struct file_operations jfs_dir_operations = {
 	.llseek		= generic_file_llseek,
 };
 
-static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
+static int jfs_ci_hash(const struct dentry *dir, const struct inode *inode,
+		struct qstr *this)
 {
 	unsigned long hash;
 	int i;
diff --git a/fs/namei.c b/fs/namei.c
index 4ff7ca530533..f3b5ca404659 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -731,7 +731,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 	 * to use its own hash..
 	 */
 	if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) {
-		int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name);
+		int err = nd->path.dentry->d_op->d_hash(nd->path.dentry,
+				nd->path.dentry->d_inode, name);
 		if (err < 0)
 			return err;
 	}
@@ -1134,7 +1135,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 	 * to use its own hash..
 	 */
 	if (base->d_op && base->d_op->d_hash) {
-		err = base->d_op->d_hash(base, name);
+		err = base->d_op->d_hash(base, inode, name);
 		dentry = ERR_PTR(err);
 		if (err < 0)
 			goto out;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 3bcc68aed416..bbbf7922f422 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -74,7 +74,8 @@ const struct inode_operations ncp_dir_inode_operations =
  * Dentry operations routines
  */
 static int ncp_lookup_validate(struct dentry *, struct nameidata *);
-static int ncp_hash_dentry(struct dentry *, struct qstr *);
+static int ncp_hash_dentry(const struct dentry *, const struct inode *,
+		struct qstr *);
 static int ncp_compare_dentry(const struct dentry *, const struct inode *,
 		const struct dentry *, const struct inode *,
 		unsigned int, const char *, const struct qstr *);
@@ -129,9 +130,10 @@ static inline int ncp_case_sensitive(const struct inode *i)
  * is case-sensitive.
  */
 static int 
-ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
+ncp_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *this)
 {
-	if (!ncp_case_sensitive(dentry->d_inode)) {
+	if (!ncp_case_sensitive(inode)) {
 		struct super_block *sb = dentry->d_sb;
 		struct nls_table *t;
 		unsigned long hash;
@@ -597,7 +599,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
 	qname.hash = full_name_hash(qname.name, qname.len);
 
 	if (dentry->d_op && dentry->d_op->d_hash)
-		if (dentry->d_op->d_hash(dentry, &qname) != 0)
+		if (dentry->d_op->d_hash(dentry, dentry->d_inode, &qname) != 0)
 			goto end_advance;
 
 	newdent = d_lookup(dentry, &qname);
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index 11e7f7d11cd0..7507aeb4c90e 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -27,7 +27,8 @@ static int add_nondir(struct dentry *dentry, struct inode *inode)
 	return err;
 }
 
-static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
+static int sysv_hash(const struct dentry *dentry, const struct inode *inode,
+		struct qstr *qstr)
 {
 	/* Truncate the name in place, avoids having to define a compare
 	   function. */
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 75a072bf2a34..1149e706f04d 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -133,7 +133,8 @@ enum dentry_d_lock_class
 
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, struct nameidata *);
-	int (*d_hash)(struct dentry *, struct qstr *);
+	int (*d_hash)(const struct dentry *, const struct inode *,
+			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
 			const struct dentry *, const struct inode *,
 			unsigned int, const char *, const struct qstr *);
-- 
cgit v1.2.3


From b23fb0a60379a95e10c671f646b259ea2558421e Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:35 +1100
Subject: fs: scale inode alias list

Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 fs/9p/vfs_inode.c      |  2 ++
 fs/affs/amigaffs.c     |  2 ++
 fs/cifs/inode.c        |  3 +++
 fs/dcache.c            | 66 ++++++++++++++++++++++++++++++++++++++++++++------
 fs/exportfs/expfs.c    |  4 +++
 fs/nfs/getroot.c       |  4 +++
 fs/notify/fsnotify.c   |  2 ++
 fs/ocfs2/dcache.c      |  3 ++-
 include/linux/dcache.h |  1 +
 9 files changed, 78 insertions(+), 9 deletions(-)

(limited to 'fs/cifs')

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 34bf71b56542..47dfd5d29a6b 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -271,9 +271,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode)
 	struct dentry *dentry;
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	/* Directory should have only one entry. */
 	BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
 	dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	return dentry;
 }
diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c
index 7d0f0a30f7a3..2321cc92d44f 100644
--- a/fs/affs/amigaffs.c
+++ b/fs/affs/amigaffs.c
@@ -129,6 +129,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 	struct list_head *head, *next;
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	head = &inode->i_dentry;
 	next = head->next;
 	while (next != head) {
@@ -139,6 +140,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 		}
 		next = next->next;
 	}
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 }
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 589f3e3f6e00..003698365ece 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -810,12 +810,15 @@ inode_has_hashed_dentries(struct inode *inode)
 	struct dentry *dentry;
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
+			spin_unlock(&dcache_inode_lock);
 			spin_unlock(&dcache_lock);
 			return true;
 		}
 	}
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	return false;
 }
diff --git a/fs/dcache.c b/fs/dcache.c
index a661247a20d5..de38680ee0ed 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -37,6 +37,8 @@
 
 /*
  * Usage:
+ * dcache_inode_lock protects:
+ *   - i_dentry, d_alias, d_inode
  * dcache_hash_lock protects:
  *   - the dcache hash table, s_anon lists
  * dcache_lru_lock protects:
@@ -49,12 +51,14 @@
  *   - d_unhashed()
  *   - d_parent and d_subdirs
  *   - childrens' d_child and d_parent
+ *   - d_alias, d_inode
  *
  * Ordering:
  * dcache_lock
- *   dentry->d_lock
- *     dcache_lru_lock
- *     dcache_hash_lock
+ *   dcache_inode_lock
+ *     dentry->d_lock
+ *       dcache_lru_lock
+ *       dcache_hash_lock
  *
  * If there is an ancestor relationship:
  * dentry->d_parent->...->d_parent->d_lock
@@ -70,11 +74,13 @@
 int sysctl_vfs_cache_pressure __read_mostly = 100;
 EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
 __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
 
+EXPORT_SYMBOL(dcache_inode_lock);
 EXPORT_SYMBOL(dcache_lock);
 
 static struct kmem_cache *dentry_cache __read_mostly;
@@ -154,6 +160,7 @@ static void d_free(struct dentry *dentry)
  */
 static void dentry_iput(struct dentry * dentry)
 	__releases(dentry->d_lock)
+	__releases(dcache_inode_lock)
 	__releases(dcache_lock)
 {
 	struct inode *inode = dentry->d_inode;
@@ -161,6 +168,7 @@ static void dentry_iput(struct dentry * dentry)
 		dentry->d_inode = NULL;
 		list_del_init(&dentry->d_alias);
 		spin_unlock(&dentry->d_lock);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 		if (!inode->i_nlink)
 			fsnotify_inoderemove(inode);
@@ -170,6 +178,7 @@ static void dentry_iput(struct dentry * dentry)
 			iput(inode);
 	} else {
 		spin_unlock(&dentry->d_lock);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 	}
 }
@@ -231,6 +240,7 @@ static void dentry_lru_move_tail(struct dentry *dentry)
 static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
 	__releases(dentry->d_lock)
 	__releases(parent->d_lock)
+	__releases(dcache_inode_lock)
 	__releases(dcache_lock)
 {
 	list_del(&dentry->d_u.d_child);
@@ -332,13 +342,18 @@ repeat:
 			 * want to reduce dcache_lock anyway so this will
 			 * get improved.
 			 */
+drop1:
 			spin_unlock(&dentry->d_lock);
 			goto repeat;
 		}
-		if (parent && !spin_trylock(&parent->d_lock)) {
-			spin_unlock(&dentry->d_lock);
+		if (!spin_trylock(&dcache_inode_lock)) {
+drop2:
 			spin_unlock(&dcache_lock);
-			goto repeat;
+			goto drop1;
+		}
+		if (parent && !spin_trylock(&parent->d_lock)) {
+			spin_unlock(&dcache_inode_lock);
+			goto drop2;
 		}
 	}
 	dentry->d_count--;
@@ -369,6 +384,7 @@ repeat:
  	spin_unlock(&dentry->d_lock);
 	if (parent)
 		spin_unlock(&parent->d_lock);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	return;
 
@@ -558,7 +574,9 @@ struct dentry *d_find_alias(struct inode *inode)
 
 	if (!list_empty(&inode->i_dentry)) {
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
 		de = __d_find_alias(inode, 0);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 	}
 	return de;
@@ -574,18 +592,21 @@ void d_prune_aliases(struct inode *inode)
 	struct dentry *dentry;
 restart:
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		spin_lock(&dentry->d_lock);
 		if (!dentry->d_count) {
 			__dget_locked_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
+			spin_unlock(&dcache_inode_lock);
 			spin_unlock(&dcache_lock);
 			dput(dentry);
 			goto restart;
 		}
 		spin_unlock(&dentry->d_lock);
 	}
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(d_prune_aliases);
@@ -601,6 +622,7 @@ EXPORT_SYMBOL(d_prune_aliases);
 static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
 	__releases(dentry->d_lock)
 	__releases(parent->d_lock)
+	__releases(dcache_inode_lock)
 	__releases(dcache_lock)
 {
 	__d_drop(dentry);
@@ -612,6 +634,7 @@ static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
 	 */
 	while (dentry) {
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
 again:
 		spin_lock(&dentry->d_lock);
 		if (IS_ROOT(dentry))
@@ -627,6 +650,7 @@ again:
 			if (parent)
 				spin_unlock(&parent->d_lock);
 			spin_unlock(&dentry->d_lock);
+			spin_unlock(&dcache_inode_lock);
 			spin_unlock(&dcache_lock);
 			return;
 		}
@@ -676,8 +700,9 @@ relock:
 		spin_unlock(&dcache_lru_lock);
 
 		prune_one_dentry(dentry, parent);
-		/* dcache_lock and dentry->d_lock dropped */
+		/* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
 		spin_lock(&dcache_lru_lock);
 	}
 }
@@ -699,6 +724,7 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags)
 	int cnt = *count;
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 relock:
 	spin_lock(&dcache_lru_lock);
 	while (!list_empty(&sb->s_dentry_lru)) {
@@ -737,8 +763,8 @@ relock:
 	if (!list_empty(&referenced))
 		list_splice(&referenced, &sb->s_dentry_lru);
 	spin_unlock(&dcache_lru_lock);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
-
 }
 
 /**
@@ -832,12 +858,14 @@ void shrink_dcache_sb(struct super_block *sb)
 	LIST_HEAD(tmp);
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	spin_lock(&dcache_lru_lock);
 	while (!list_empty(&sb->s_dentry_lru)) {
 		list_splice_init(&sb->s_dentry_lru, &tmp);
 		shrink_dentry_list(&tmp);
 	}
 	spin_unlock(&dcache_lru_lock);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(shrink_dcache_sb);
@@ -1255,9 +1283,11 @@ EXPORT_SYMBOL(d_alloc_name);
 /* the caller must hold dcache_lock */
 static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 {
+	spin_lock(&dentry->d_lock);
 	if (inode)
 		list_add(&dentry->d_alias, &inode->i_dentry);
 	dentry->d_inode = inode;
+	spin_unlock(&dentry->d_lock);
 	fsnotify_d_instantiate(dentry, inode);
 }
 
@@ -1280,7 +1310,9 @@ void d_instantiate(struct dentry *entry, struct inode * inode)
 {
 	BUG_ON(!list_empty(&entry->d_alias));
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	__d_instantiate(entry, inode);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	security_d_instantiate(entry, inode);
 }
@@ -1341,7 +1373,9 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
 	BUG_ON(!list_empty(&entry->d_alias));
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	result = __d_instantiate_unique(entry, inode);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 
 	if (!result) {
@@ -1432,8 +1466,10 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	tmp->d_parent = tmp; /* make sure dput doesn't croak */
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	res = __d_find_alias(inode, 0);
 	if (res) {
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 		dput(tmp);
 		goto out_iput;
@@ -1450,6 +1486,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
 	spin_unlock(&dcache_hash_lock);
 	spin_unlock(&tmp->d_lock);
+	spin_unlock(&dcache_inode_lock);
 
 	spin_unlock(&dcache_lock);
 	return tmp;
@@ -1482,9 +1519,11 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 
 	if (inode && S_ISDIR(inode->i_mode)) {
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
 		new = __d_find_alias(inode, 1);
 		if (new) {
 			BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
+			spin_unlock(&dcache_inode_lock);
 			spin_unlock(&dcache_lock);
 			security_d_instantiate(new, inode);
 			d_move(new, dentry);
@@ -1492,6 +1531,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 		} else {
 			/* already taking dcache_lock, so d_add() by hand */
 			__d_instantiate(dentry, inode);
+			spin_unlock(&dcache_inode_lock);
 			spin_unlock(&dcache_lock);
 			security_d_instantiate(dentry, inode);
 			d_rehash(dentry);
@@ -1566,8 +1606,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 * already has a dentry.
 	 */
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
 		__d_instantiate(found, inode);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 		security_d_instantiate(found, inode);
 		return found;
@@ -1579,6 +1621,7 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 */
 	new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
 	dget_locked(new);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	security_d_instantiate(found, inode);
 	d_move(new, found);
@@ -1797,6 +1840,7 @@ void d_delete(struct dentry * dentry)
 	 * Are we the only user?
 	 */
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	spin_lock(&dentry->d_lock);
 	isdir = S_ISDIR(dentry->d_inode->i_mode);
 	if (dentry->d_count == 1) {
@@ -1810,6 +1854,7 @@ void d_delete(struct dentry * dentry)
 		__d_drop(dentry);
 
 	spin_unlock(&dentry->d_lock);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 
 	fsnotify_nameremove(dentry, isdir);
@@ -2067,6 +2112,7 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
  */
 static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
 	__releases(dcache_lock)
+	__releases(dcache_inode_lock)
 {
 	struct mutex *m1 = NULL, *m2 = NULL;
 	struct dentry *ret;
@@ -2092,6 +2138,7 @@ out_unalias:
 	d_move_locked(alias, dentry);
 	ret = alias;
 out_err:
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	if (m2)
 		mutex_unlock(m2);
@@ -2153,6 +2200,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 	BUG_ON(!d_unhashed(dentry));
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 
 	if (!inode) {
 		actual = dentry;
@@ -2196,6 +2244,7 @@ found:
 	_d_rehash(actual);
 	spin_unlock(&dcache_hash_lock);
 	spin_unlock(&actual->d_lock);
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 out_nolock:
 	if (actual == dentry) {
@@ -2207,6 +2256,7 @@ out_nolock:
 	return actual;
 
 shouldnt_be_hashed:
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 	BUG();
 }
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 51b304056f10..84b8c460a781 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -48,8 +48,10 @@ find_acceptable_alias(struct dentry *result,
 		return result;
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
 		dget_locked(dentry);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 		if (toput)
 			dput(toput);
@@ -58,8 +60,10 @@ find_acceptable_alias(struct dentry *result,
 			return dentry;
 		}
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
 		toput = dentry;
 	}
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 
 	if (toput)
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index ac7b814ce162..850f67d5f0ac 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -64,7 +64,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 		 * Oops, since the test for IS_ROOT() will fail.
 		 */
 		spin_lock(&dcache_lock);
+		spin_lock(&dcache_inode_lock);
+		spin_lock(&sb->s_root->d_lock);
 		list_del_init(&sb->s_root->d_alias);
+		spin_unlock(&sb->s_root->d_lock);
+		spin_unlock(&dcache_inode_lock);
 		spin_unlock(&dcache_lock);
 	}
 	return 0;
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index aa4f25e803f6..ae769fc9b66c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -60,6 +60,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 	watched = fsnotify_inode_watches_children(inode);
 
 	spin_lock(&dcache_lock);
+	spin_lock(&dcache_inode_lock);
 	/* run all of the dentries associated with this inode.  Since this is a
 	 * directory, there damn well better only be one item on this list */
 	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
@@ -82,6 +83,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 		}
 		spin_unlock(&alias->d_lock);
 	}
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 }
 
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 35e5f5a9ef59..c31b5c647ac7 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -170,7 +170,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 	struct dentry *dentry = NULL;
 
 	spin_lock(&dcache_lock);
-
+	spin_lock(&dcache_inode_lock);
 	list_for_each(p, &inode->i_dentry) {
 		dentry = list_entry(p, struct dentry, d_alias);
 
@@ -188,6 +188,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 		dentry = NULL;
 	}
 
+	spin_unlock(&dcache_inode_lock);
 	spin_unlock(&dcache_lock);
 
 	return dentry;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index ddf4f55624f7..bda5ec0b077d 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -181,6 +181,7 @@ struct dentry_operations {
 
 #define DCACHE_CANT_MOUNT	0x0100
 
+extern spinlock_t dcache_inode_lock;
 extern spinlock_t dcache_lock;
 extern seqlock_t rename_lock;
 
-- 
cgit v1.2.3


From b5c84bf6f6fa3a7dfdcb556023a62953574b60ee Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:38 +1100
Subject: fs: dcache remove dcache_lock

dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/Locking            |  16 +--
 Documentation/filesystems/dentry-locking.txt |  40 ++++---
 Documentation/filesystems/porting            |   8 +-
 arch/powerpc/platforms/cell/spufs/inode.c    |   5 +-
 drivers/infiniband/hw/ipath/ipath_fs.c       |   6 +-
 drivers/infiniband/hw/qib/qib_fs.c           |   3 -
 drivers/staging/pohmelfs/path_entry.c        |   2 -
 drivers/staging/smbfs/cache.c                |   4 -
 drivers/usb/core/inode.c                     |   3 -
 fs/9p/vfs_inode.c                            |   2 -
 fs/affs/amigaffs.c                           |   2 -
 fs/autofs4/autofs_i.h                        |   3 +
 fs/autofs4/expire.c                          |  10 +-
 fs/autofs4/root.c                            |  44 ++++----
 fs/autofs4/waitq.c                           |   7 +-
 fs/ceph/dir.c                                |   6 +-
 fs/ceph/inode.c                              |   4 -
 fs/cifs/inode.c                              |   3 -
 fs/coda/cache.c                              |   2 -
 fs/configfs/configfs_internal.h              |   2 -
 fs/configfs/inode.c                          |   6 +-
 fs/dcache.c                                  | 160 ++++-----------------------
 fs/exportfs/expfs.c                          |   4 -
 fs/libfs.c                                   |   8 --
 fs/namei.c                                   |   9 +-
 fs/ncpfs/dir.c                               |   3 -
 fs/ncpfs/ncplib_kernel.h                     |   4 -
 fs/nfs/dir.c                                 |   3 -
 fs/nfs/getroot.c                             |   2 -
 fs/nfs/namespace.c                           |   3 -
 fs/notify/fsnotify.c                         |   2 -
 fs/ocfs2/dcache.c                            |   2 -
 include/linux/dcache.h                       |   5 +-
 include/linux/fs.h                           |   6 +-
 include/linux/fsnotify.h                     |   2 -
 include/linux/fsnotify_backend.h             |  11 +-
 include/linux/namei.h                        |   1 -
 kernel/cgroup.c                              |   6 -
 mm/filemap.c                                 |   3 -
 security/selinux/selinuxfs.c                 |   4 -
 40 files changed, 109 insertions(+), 307 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index a15ee207b449..bdad6414dfa0 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -21,14 +21,14 @@ prototypes:
 	char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
 
 locking rules:
-		dcache_lock	rename_lock	->d_lock	may block
-d_revalidate:	no		no		no		yes
-d_hash		no		no		no		no
-d_compare:	no		yes		no		no 
-d_delete:	yes		no		yes		no
-d_release:	no		no		no		yes
-d_iput:		no		no		no		yes
-d_dname:	no		no		no		no
+		rename_lock	->d_lock	may block
+d_revalidate:	no		no		yes
+d_hash		no		no		no
+d_compare:	yes		no		no
+d_delete:	no		yes		no
+d_release:	no		no		yes
+d_iput:		no		no		yes
+d_dname:	no		no		no
 
 --------------------------- inode_operations --------------------------- 
 prototypes:
diff --git a/Documentation/filesystems/dentry-locking.txt b/Documentation/filesystems/dentry-locking.txt
index 79334ed5daa7..30b6a40f5650 100644
--- a/Documentation/filesystems/dentry-locking.txt
+++ b/Documentation/filesystems/dentry-locking.txt
@@ -31,6 +31,7 @@ significant change is the way d_lookup traverses the hash chain, it
 doesn't acquire the dcache_lock for this and rely on RCU to ensure
 that the dentry has not been *freed*.
 
+dcache_lock no longer exists, dentry locking is explained in fs/dcache.c
 
 Dcache locking details
 ======================
@@ -50,14 +51,12 @@ Safe lock-free look-up of dcache hash table
 
 Dcache is a complex data structure with the hash table entries also
 linked together in other lists. In 2.4 kernel, dcache_lock protected
-all the lists. We applied RCU only on hash chain walking. The rest of
-the lists are still protected by dcache_lock.  Some of the important
-changes are :
+all the lists. RCU dentry hash walking works like this:
 
 1. The deletion from hash chain is done using hlist_del_rcu() macro
    which doesn't initialize next pointer of the deleted dentry and
    this allows us to walk safely lock-free while a deletion is
-   happening.
+   happening. This is a standard hlist_rcu iteration.
 
 2. Insertion of a dentry into the hash table is done using
    hlist_add_head_rcu() which take care of ordering the writes - the
@@ -66,19 +65,18 @@ changes are :
    which has since been replaced by hlist_for_each_entry_rcu(), while
    walking the hash chain. The only requirement is that all
    initialization to the dentry must be done before
-   hlist_add_head_rcu() since we don't have dcache_lock protection
-   while traversing the hash chain. This isn't different from the
-   existing code.
-
-3. The dentry looked up without holding dcache_lock by cannot be
-   returned for walking if it is unhashed. It then may have a NULL
-   d_inode or other bogosity since RCU doesn't protect the other
-   fields in the dentry. We therefore use a flag DCACHE_UNHASHED to
-   indicate unhashed dentries and use this in conjunction with a
-   per-dentry lock (d_lock). Once looked up without the dcache_lock,
-   we acquire the per-dentry lock (d_lock) and check if the dentry is
-   unhashed. If so, the look-up is failed. If not, the reference count
-   of the dentry is increased and the dentry is returned.
+   hlist_add_head_rcu() since we don't have lock protection
+   while traversing the hash chain.
+
+3. The dentry looked up without holding locks cannot be returned for
+   walking if it is unhashed. It then may have a NULL d_inode or other
+   bogosity since RCU doesn't protect the other fields in the dentry. We
+   therefore use a flag DCACHE_UNHASHED to indicate unhashed dentries
+   and use this in conjunction with a per-dentry lock (d_lock). Once
+   looked up without locks, we acquire the per-dentry lock (d_lock) and
+   check if the dentry is unhashed. If so, the look-up is failed. If not,
+   the reference count of the dentry is increased and the dentry is
+   returned.
 
 4. Once a dentry is looked up, it must be ensured during the path walk
    for that component it doesn't go away. In pre-2.5.10 code, this was
@@ -86,10 +84,10 @@ changes are :
    In some sense, dcache_rcu path walking looks like the pre-2.5.10
    version.
 
-5. All dentry hash chain updates must take the dcache_lock as well as
-   the per-dentry lock in that order. dput() does this to ensure that
-   a dentry that has just been looked up in another CPU doesn't get
-   deleted before dget() can be done on it.
+5. All dentry hash chain updates must take the per-dentry lock (see
+   fs/dcache.c). This excludes dput() to ensure that a dentry that has
+   been looked up concurrently does not get deleted before dget() can
+   take a ref.
 
 6. There are several ways to do reference counting of RCU protected
    objects. One such example is in ipv4 route cache where deferred
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 9fd31940a8ef..1eb76959d096 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -216,7 +216,6 @@ had ->revalidate()) add calls in ->follow_link()/->readlink().
 ->d_parent changes are not protected by BKL anymore.  Read access is safe
 if at least one of the following is true:
 	* filesystem has no cross-directory rename()
-	* dcache_lock is held
 	* we know that parent had been locked (e.g. we are looking at
 ->d_parent of ->lookup() argument).
 	* we are called from ->rename().
@@ -340,3 +339,10 @@ look at examples of other filesystems) for guidance.
 	.d_hash() calling convention and locking rules are significantly
 changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
 look at examples of other filesystems) for guidance.
+
+---
+[mandatory]
+	dcache_lock is gone, replaced by fine grained locks. See fs/dcache.c
+for details of what locks to replace dcache_lock with in order to protect
+particular things. Most of the time, a filesystem only needs ->d_lock, which
+protects *all* the dcache state of a given dentry.
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 5aef1a7f5e4b..2662b50ea8d4 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -159,21 +159,18 @@ static void spufs_prune_dir(struct dentry *dir)
 
 	mutex_lock(&dir->d_inode->i_mutex);
 	list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
-		spin_lock(&dcache_lock);
 		spin_lock(&dentry->d_lock);
 		if (!(d_unhashed(dentry)) && dentry->d_inode) {
 			dget_locked_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
 			simple_unlink(dir->d_inode, dentry);
-			/* XXX: what is dcache_lock protecting here? Other
+			/* XXX: what was dcache_lock protecting here? Other
 			 * filesystems (IB, configfs) release dcache_lock
 			 * before unlink */
-			spin_unlock(&dcache_lock);
 			dput(dentry);
 		} else {
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 		}
 	}
 	shrink_dcache_parent(dir);
diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 18aee04a8411..925e88227ded 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -277,18 +277,14 @@ static int remove_file(struct dentry *parent, char *name)
 		goto bail;
 	}
 
-	spin_lock(&dcache_lock);
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
 		dget_locked_dlock(tmp);
 		__d_drop(tmp);
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 		simple_unlink(parent->d_inode, tmp);
-	} else {
+	} else
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
-	}
 
 	ret = 0;
 bail:
diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index fe4b242f0094..49af4a6538ba 100644
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -453,17 +453,14 @@ static int remove_file(struct dentry *parent, char *name)
 		goto bail;
 	}
 
-	spin_lock(&dcache_lock);
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
 		dget_locked_dlock(tmp);
 		__d_drop(tmp);
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 		simple_unlink(parent->d_inode, tmp);
 	} else {
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 	}
 
 	ret = 0;
diff --git a/drivers/staging/pohmelfs/path_entry.c b/drivers/staging/pohmelfs/path_entry.c
index bbe42f42ca8f..400a9fc386ad 100644
--- a/drivers/staging/pohmelfs/path_entry.c
+++ b/drivers/staging/pohmelfs/path_entry.c
@@ -101,7 +101,6 @@ rename_retry:
 	d = first;
 	seq = read_seqbegin(&rename_lock);
 	rcu_read_lock();
-	spin_lock(&dcache_lock);
 
 	if (!IS_ROOT(d) && d_unhashed(d))
 		len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */
@@ -110,7 +109,6 @@ rename_retry:
 		len += d->d_name.len + 1; /* Plus slash */
 		d = d->d_parent;
 	}
-	spin_unlock(&dcache_lock);
 	rcu_read_unlock();
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c
index 920434b6c071..75dfd403fb90 100644
--- a/drivers/staging/smbfs/cache.c
+++ b/drivers/staging/smbfs/cache.c
@@ -62,7 +62,6 @@ smb_invalidate_dircache_entries(struct dentry *parent)
 	struct list_head *next;
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
@@ -72,7 +71,6 @@ smb_invalidate_dircache_entries(struct dentry *parent)
 		next = next->next;
 	}
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /*
@@ -98,7 +96,6 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 	}
 
 	/* If a pointer is invalid, we search the dentry. */
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
@@ -115,7 +112,6 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 	dent = NULL;
 out_unlock:
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 	return dent;
 }
 
diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index 89a0e8366585..1b125c224dcf 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -343,7 +343,6 @@ static int usbfs_empty (struct dentry *dentry)
 {
 	struct list_head *list;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	list_for_each(list, &dentry->d_subdirs) {
 		struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
@@ -352,13 +351,11 @@ static int usbfs_empty (struct dentry *dentry)
 		if (usbfs_positive(de)) {
 			spin_unlock(&de->d_lock);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 			return 0;
 		}
 		spin_unlock(&de->d_lock);
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 	return 1;
 }
 
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 47dfd5d29a6b..1073bca8488c 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -270,13 +270,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode)
 {
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	/* Directory should have only one entry. */
 	BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
 	dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	return dentry;
 }
 
diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c
index 2321cc92d44f..600101a21ba2 100644
--- a/fs/affs/amigaffs.c
+++ b/fs/affs/amigaffs.c
@@ -128,7 +128,6 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 	void *data = dentry->d_fsdata;
 	struct list_head *head, *next;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	head = &inode->i_dentry;
 	next = head->next;
@@ -141,7 +140,6 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 		next = next->next;
 	}
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 }
 
 
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 9d2ae9b30d9f..0fffe1c24cec 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -16,6 +16,7 @@
 #include <linux/auto_fs4.h>
 #include <linux/auto_dev-ioctl.h>
 #include <linux/mutex.h>
+#include <linux/spinlock.h>
 #include <linux/list.h>
 
 /* This is the range of ioctl() numbers we claim as ours */
@@ -60,6 +61,8 @@ do {							\
 		current->pid, __func__, ##args);	\
 } while (0)
 
+extern spinlock_t autofs4_lock;
+
 /* Unified info structure.  This is pointed to by both the dentry and
    inode structures.  Each file in the filesystem has an instance of this
    structure.  It holds a reference to the dentry, so dentries are never
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 968c1434af62..2f7951d67d16 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -102,7 +102,7 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev,
 	if (prev == NULL)
 		return dget(prev);
 
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 relock:
 	p = prev;
 	spin_lock(&p->d_lock);
@@ -114,7 +114,7 @@ again:
 
 			if (p == root) {
 				spin_unlock(&p->d_lock);
-				spin_unlock(&dcache_lock);
+				spin_unlock(&autofs4_lock);
 				dput(prev);
 				return NULL;
 			}
@@ -144,7 +144,7 @@ again:
 	dget_dlock(ret);
 	spin_unlock(&ret->d_lock);
 	spin_unlock(&p->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	dput(prev);
 
@@ -408,13 +408,13 @@ found:
 	ino->flags |= AUTOFS_INF_EXPIRING;
 	init_completion(&ino->expire_complete);
 	spin_unlock(&sbi->fs_lock);
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&expired->d_parent->d_lock);
 	spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
 	list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
 	spin_unlock(&expired->d_lock);
 	spin_unlock(&expired->d_parent->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 	return expired;
 }
 
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 7a9ed6b88291..10ca68a96dc7 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -23,6 +23,8 @@
 
 #include "autofs_i.h"
 
+DEFINE_SPINLOCK(autofs4_lock);
+
 static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
 static int autofs4_dir_unlink(struct inode *,struct dentry *);
 static int autofs4_dir_rmdir(struct inode *,struct dentry *);
@@ -142,15 +144,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
 	 * autofs file system so just let the libfs routines handle
 	 * it.
 	 */
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&dentry->d_lock);
 	if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 		return -ENOENT;
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 out:
 	return dcache_dir_open(inode, file);
@@ -255,11 +257,11 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 	/* We trigger a mount for almost all flags */
 	lookup_type = autofs4_need_mount(nd->flags);
 	spin_lock(&sbi->fs_lock);
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&dentry->d_lock);
 	if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 		spin_unlock(&sbi->fs_lock);
 		goto follow;
 	}
@@ -272,7 +274,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 	if (ino->flags & AUTOFS_INF_PENDING ||
 	    (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 		spin_unlock(&sbi->fs_lock);
 
 		status = try_to_fill_dentry(dentry, nd->flags);
@@ -282,7 +284,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 		goto follow;
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 	spin_unlock(&sbi->fs_lock);
 follow:
 	/*
@@ -353,14 +355,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
 		return 0;
 
 	/* Check for a non-mountpoint directory with no contents */
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&dentry->d_lock);
 	if (S_ISDIR(dentry->d_inode->i_mode) &&
 	    !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
 		DPRINTK("dentry=%p %.*s, emptydir",
 			 dentry, dentry->d_name.len, dentry->d_name.name);
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 
 		/* The daemon never causes a mount to trigger */
 		if (oz_mode)
@@ -377,7 +379,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
 		return status;
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	return 1;
 }
@@ -432,7 +434,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
 	const unsigned char *str = name->name;
 	struct list_head *p, *head;
 
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&sbi->lookup_lock);
 	head = &sbi->active_list;
 	list_for_each(p, head) {
@@ -465,14 +467,14 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
 			dget_dlock(active);
 			spin_unlock(&active->d_lock);
 			spin_unlock(&sbi->lookup_lock);
-			spin_unlock(&dcache_lock);
+			spin_unlock(&autofs4_lock);
 			return active;
 		}
 next:
 		spin_unlock(&active->d_lock);
 	}
 	spin_unlock(&sbi->lookup_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	return NULL;
 }
@@ -487,7 +489,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
 	const unsigned char *str = name->name;
 	struct list_head *p, *head;
 
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&sbi->lookup_lock);
 	head = &sbi->expiring_list;
 	list_for_each(p, head) {
@@ -520,14 +522,14 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
 			dget_dlock(expiring);
 			spin_unlock(&expiring->d_lock);
 			spin_unlock(&sbi->lookup_lock);
-			spin_unlock(&dcache_lock);
+			spin_unlock(&autofs4_lock);
 			return expiring;
 		}
 next:
 		spin_unlock(&expiring->d_lock);
 	}
 	spin_unlock(&sbi->lookup_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	return NULL;
 }
@@ -763,12 +765,12 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
 
 	dir->i_mtime = CURRENT_TIME;
 
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	autofs4_add_expiring(dentry);
 	spin_lock(&dentry->d_lock);
 	__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	return 0;
 }
@@ -785,20 +787,20 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
 	if (!autofs4_oz_mode(sbi))
 		return -EACCES;
 
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	spin_lock(&sbi->lookup_lock);
 	spin_lock(&dentry->d_lock);
 	if (!list_empty(&dentry->d_subdirs)) {
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&sbi->lookup_lock);
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 		return -ENOTEMPTY;
 	}
 	__autofs4_add_expiring(dentry);
 	spin_unlock(&sbi->lookup_lock);
 	__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 
 	if (atomic_dec_and_test(&ino->count)) {
 		p_ino = autofs4_dentry_ino(dentry->d_parent);
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 4be8f778a418..c5f8459c905e 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -194,14 +194,15 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
 rename_retry:
 	buf = *name;
 	len = 0;
+
 	seq = read_seqbegin(&rename_lock);
 	rcu_read_lock();
-	spin_lock(&dcache_lock);
+	spin_lock(&autofs4_lock);
 	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
 		len += tmp->d_name.len + 1;
 
 	if (!len || --len > NAME_MAX) {
-		spin_unlock(&dcache_lock);
+		spin_unlock(&autofs4_lock);
 		rcu_read_unlock();
 		if (read_seqretry(&rename_lock, seq))
 			goto rename_retry;
@@ -217,7 +218,7 @@ rename_retry:
 		p -= tmp->d_name.len;
 		strncpy(p, tmp->d_name.name, tmp->d_name.len);
 	}
-	spin_unlock(&dcache_lock);
+	spin_unlock(&autofs4_lock);
 	rcu_read_unlock();
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 2c924e8d85fe..58abc3da6111 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -112,7 +112,6 @@ static int __dcache_readdir(struct file *filp,
 	dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
 	     last);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 
 	/* start at beginning? */
@@ -156,7 +155,6 @@ more:
 	dget_dlock(dentry);
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 
 	dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
 	     dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
@@ -182,21 +180,19 @@ more:
 
 	filp->f_pos++;
 
-	/* make sure a dentry wasn't dropped while we didn't have dcache_lock */
+	/* make sure a dentry wasn't dropped while we didn't have parent lock */
 	if (!ceph_i_test(dir, CEPH_I_COMPLETE)) {
 		dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
 		err = -EAGAIN;
 		goto out;
 	}
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	p = p->prev;	/* advance to next dentry */
 	goto more;
 
 out_unlock:
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 out:
 	if (last)
 		dput(last);
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2c6944473366..2a48cafc174b 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -841,7 +841,6 @@ static void ceph_set_dentry_offset(struct dentry *dn)
 	di->offset = ceph_inode(inode)->i_max_offset++;
 	spin_unlock(&inode->i_lock);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dir->d_lock);
 	spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
 	list_move(&dn->d_u.d_child, &dir->d_subdirs);
@@ -849,7 +848,6 @@ static void ceph_set_dentry_offset(struct dentry *dn)
 	     dn->d_u.d_child.prev, dn->d_u.d_child.next);
 	spin_unlock(&dn->d_lock);
 	spin_unlock(&dir->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /*
@@ -1233,13 +1231,11 @@ retry_lookup:
 			goto retry_lookup;
 		} else {
 			/* reorder parent's d_subdirs */
-			spin_lock(&dcache_lock);
 			spin_lock(&parent->d_lock);
 			spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
 			list_move(&dn->d_u.d_child, &parent->d_subdirs);
 			spin_unlock(&dn->d_lock);
 			spin_unlock(&parent->d_lock);
-			spin_unlock(&dcache_lock);
 		}
 
 		di = dn->d_fsdata;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 003698365ece..99b9a2cc14b7 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -809,17 +809,14 @@ inode_has_hashed_dentries(struct inode *inode)
 {
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
 			spin_unlock(&dcache_inode_lock);
-			spin_unlock(&dcache_lock);
 			return true;
 		}
 	}
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	return false;
 }
 
diff --git a/fs/coda/cache.c b/fs/coda/cache.c
index 859393fca2b7..5525e1c660fd 100644
--- a/fs/coda/cache.c
+++ b/fs/coda/cache.c
@@ -93,7 +93,6 @@ static void coda_flag_children(struct dentry *parent, int flag)
 	struct list_head *child;
 	struct dentry *de;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	list_for_each(child, &parent->d_subdirs)
 	{
@@ -104,7 +103,6 @@ static void coda_flag_children(struct dentry *parent, int flag)
 		coda_flag_inode(de->d_inode, flag);
 	}
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 	return; 
 }
 
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index e58b4c30e216..026cf68553a4 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -120,7 +120,6 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry
 {
 	struct config_item * item = NULL;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	if (!d_unhashed(dentry)) {
 		struct configfs_dirent * sd = dentry->d_fsdata;
@@ -131,7 +130,6 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry
 			item = config_item_get(sd->s_element);
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 
 	return item;
 }
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 79b37765d8ff..fb3a55fff82a 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -250,18 +250,14 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
 	struct dentry * dentry = sd->s_dentry;
 
 	if (dentry) {
-		spin_lock(&dcache_lock);
 		spin_lock(&dentry->d_lock);
 		if (!(d_unhashed(dentry) && dentry->d_inode)) {
 			dget_locked_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 			simple_unlink(parent->d_inode, dentry);
-		} else {
+		} else
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
-		}
 	}
 }
 
diff --git a/fs/dcache.c b/fs/dcache.c
index a9bc4ecc21e1..0dbae053b664 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -54,11 +54,10 @@
  *   - d_alias, d_inode
  *
  * Ordering:
- * dcache_lock
- *   dcache_inode_lock
- *     dentry->d_lock
- *       dcache_lru_lock
- *       dcache_hash_lock
+ * dcache_inode_lock
+ *   dentry->d_lock
+ *     dcache_lru_lock
+ *     dcache_hash_lock
  *
  * If there is an ancestor relationship:
  * dentry->d_parent->...->d_parent->d_lock
@@ -77,12 +76,10 @@ EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
 __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
 
 EXPORT_SYMBOL(rename_lock);
 EXPORT_SYMBOL(dcache_inode_lock);
-EXPORT_SYMBOL(dcache_lock);
 
 static struct kmem_cache *dentry_cache __read_mostly;
 
@@ -139,7 +136,7 @@ static void __d_free(struct rcu_head *head)
 }
 
 /*
- * no dcache_lock, please.
+ * no locks, please.
  */
 static void d_free(struct dentry *dentry)
 {
@@ -162,7 +159,6 @@ static void d_free(struct dentry *dentry)
 static void dentry_iput(struct dentry * dentry)
 	__releases(dentry->d_lock)
 	__releases(dcache_inode_lock)
-	__releases(dcache_lock)
 {
 	struct inode *inode = dentry->d_inode;
 	if (inode) {
@@ -170,7 +166,6 @@ static void dentry_iput(struct dentry * dentry)
 		list_del_init(&dentry->d_alias);
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 		if (!inode->i_nlink)
 			fsnotify_inoderemove(inode);
 		if (dentry->d_op && dentry->d_op->d_iput)
@@ -180,7 +175,6 @@ static void dentry_iput(struct dentry * dentry)
 	} else {
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 	}
 }
 
@@ -235,14 +229,13 @@ static void dentry_lru_move_tail(struct dentry *dentry)
  *
  * If this is the root of the dentry tree, return NULL.
  *
- * dcache_lock and d_lock and d_parent->d_lock must be held by caller, and
- * are dropped by d_kill.
+ * dentry->d_lock and parent->d_lock must be held by caller, and are dropped by
+ * d_kill.
  */
 static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
 	__releases(dentry->d_lock)
 	__releases(parent->d_lock)
 	__releases(dcache_inode_lock)
-	__releases(dcache_lock)
 {
 	dentry->d_parent = NULL;
 	list_del(&dentry->d_u.d_child);
@@ -285,11 +278,9 @@ EXPORT_SYMBOL(__d_drop);
 
 void d_drop(struct dentry *dentry)
 {
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(d_drop);
 
@@ -337,21 +328,10 @@ repeat:
 	else
 		parent = dentry->d_parent;
 	if (dentry->d_count == 1) {
-		if (!spin_trylock(&dcache_lock)) {
-			/*
-			 * Something of a livelock possibility we could avoid
-			 * by taking dcache_lock and trying again, but we
-			 * want to reduce dcache_lock anyway so this will
-			 * get improved.
-			 */
-drop1:
-			spin_unlock(&dentry->d_lock);
-			goto repeat;
-		}
 		if (!spin_trylock(&dcache_inode_lock)) {
 drop2:
-			spin_unlock(&dcache_lock);
-			goto drop1;
+			spin_unlock(&dentry->d_lock);
+			goto repeat;
 		}
 		if (parent && !spin_trylock(&parent->d_lock)) {
 			spin_unlock(&dcache_inode_lock);
@@ -363,7 +343,6 @@ drop2:
 		spin_unlock(&dentry->d_lock);
 		if (parent)
 			spin_unlock(&parent->d_lock);
-		spin_unlock(&dcache_lock);
 		return;
 	}
 
@@ -387,7 +366,6 @@ drop2:
 	if (parent)
 		spin_unlock(&parent->d_lock);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	return;
 
 unhash_it:
@@ -418,11 +396,9 @@ int d_invalidate(struct dentry * dentry)
 	/*
 	 * If it's already been dropped, return OK.
 	 */
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	if (d_unhashed(dentry)) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
 		return 0;
 	}
 	/*
@@ -431,9 +407,7 @@ int d_invalidate(struct dentry * dentry)
 	 */
 	if (!list_empty(&dentry->d_subdirs)) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
 		shrink_dcache_parent(dentry);
-		spin_lock(&dcache_lock);
 		spin_lock(&dentry->d_lock);
 	}
 
@@ -450,19 +424,17 @@ int d_invalidate(struct dentry * dentry)
 	if (dentry->d_count > 1) {
 		if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 			return -EBUSY;
 		}
 	}
 
 	__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 	return 0;
 }
 EXPORT_SYMBOL(d_invalidate);
 
-/* This must be called with dcache_lock and d_lock held */
+/* This must be called with d_lock held */
 static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
 {
 	dentry->d_count++;
@@ -470,7 +442,7 @@ static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
 	return dentry;
 }
 
-/* This should be called _only_ with dcache_lock held */
+/* This must be called with d_lock held */
 static inline struct dentry * __dget_locked(struct dentry *dentry)
 {
 	spin_lock(&dentry->d_lock);
@@ -575,11 +547,9 @@ struct dentry *d_find_alias(struct inode *inode)
 	struct dentry *de = NULL;
 
 	if (!list_empty(&inode->i_dentry)) {
-		spin_lock(&dcache_lock);
 		spin_lock(&dcache_inode_lock);
 		de = __d_find_alias(inode, 0);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 	}
 	return de;
 }
@@ -593,7 +563,6 @@ void d_prune_aliases(struct inode *inode)
 {
 	struct dentry *dentry;
 restart:
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		spin_lock(&dentry->d_lock);
@@ -602,14 +571,12 @@ restart:
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
 			spin_unlock(&dcache_inode_lock);
-			spin_unlock(&dcache_lock);
 			dput(dentry);
 			goto restart;
 		}
 		spin_unlock(&dentry->d_lock);
 	}
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(d_prune_aliases);
 
@@ -625,17 +592,14 @@ static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
 	__releases(dentry->d_lock)
 	__releases(parent->d_lock)
 	__releases(dcache_inode_lock)
-	__releases(dcache_lock)
 {
 	__d_drop(dentry);
 	dentry = d_kill(dentry, parent);
 
 	/*
-	 * Prune ancestors.  Locking is simpler than in dput(),
-	 * because dcache_lock needs to be taken anyway.
+	 * Prune ancestors.
 	 */
 	while (dentry) {
-		spin_lock(&dcache_lock);
 		spin_lock(&dcache_inode_lock);
 again:
 		spin_lock(&dentry->d_lock);
@@ -653,7 +617,6 @@ again:
 				spin_unlock(&parent->d_lock);
 			spin_unlock(&dentry->d_lock);
 			spin_unlock(&dcache_inode_lock);
-			spin_unlock(&dcache_lock);
 			return;
 		}
 
@@ -702,8 +665,7 @@ relock:
 		spin_unlock(&dcache_lru_lock);
 
 		prune_one_dentry(dentry, parent);
-		/* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */
-		spin_lock(&dcache_lock);
+		/* dcache_inode_lock and dentry->d_lock dropped */
 		spin_lock(&dcache_inode_lock);
 		spin_lock(&dcache_lru_lock);
 	}
@@ -725,7 +687,6 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags)
 	LIST_HEAD(tmp);
 	int cnt = *count;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 relock:
 	spin_lock(&dcache_lru_lock);
@@ -766,7 +727,6 @@ relock:
 		list_splice(&referenced, &sb->s_dentry_lru);
 	spin_unlock(&dcache_lru_lock);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /**
@@ -788,7 +748,6 @@ static void prune_dcache(int count)
 
 	if (unused == 0 || count == 0)
 		return;
-	spin_lock(&dcache_lock);
 	if (count >= unused)
 		prune_ratio = 1;
 	else
@@ -825,11 +784,9 @@ static void prune_dcache(int count)
 		if (down_read_trylock(&sb->s_umount)) {
 			if ((sb->s_root != NULL) &&
 			    (!list_empty(&sb->s_dentry_lru))) {
-				spin_unlock(&dcache_lock);
 				__shrink_dcache_sb(sb, &w_count,
 						DCACHE_REFERENCED);
 				pruned -= w_count;
-				spin_lock(&dcache_lock);
 			}
 			up_read(&sb->s_umount);
 		}
@@ -845,7 +802,6 @@ static void prune_dcache(int count)
 	if (p)
 		__put_super(p);
 	spin_unlock(&sb_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /**
@@ -859,7 +815,6 @@ void shrink_dcache_sb(struct super_block *sb)
 {
 	LIST_HEAD(tmp);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	spin_lock(&dcache_lru_lock);
 	while (!list_empty(&sb->s_dentry_lru)) {
@@ -868,7 +823,6 @@ void shrink_dcache_sb(struct super_block *sb)
 	}
 	spin_unlock(&dcache_lru_lock);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(shrink_dcache_sb);
 
@@ -885,12 +839,10 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 	BUG_ON(!IS_ROOT(dentry));
 
 	/* detach this root from the system */
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	dentry_lru_del(dentry);
 	__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 
 	for (;;) {
 		/* descend to the first leaf in the current subtree */
@@ -899,7 +851,6 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 
 			/* this is a branch with children - detach all of them
 			 * from the system in one go */
-			spin_lock(&dcache_lock);
 			spin_lock(&dentry->d_lock);
 			list_for_each_entry(loop, &dentry->d_subdirs,
 					    d_u.d_child) {
@@ -910,7 +861,6 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 				spin_unlock(&loop->d_lock);
 			}
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 
 			/* move to the first child */
 			dentry = list_entry(dentry->d_subdirs.next,
@@ -977,8 +927,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 
 /*
  * destroy the dentries attached to a superblock on unmounting
- * - we don't need to use dentry->d_lock, and only need dcache_lock when
- *   removing the dentry from the system lists and hashes because:
+ * - we don't need to use dentry->d_lock because:
  *   - the superblock is detached from all mountings and open files, so the
  *     dentry trees will not be rearranged by the VFS
  *   - s_umount is write-locked, so the memory pressure shrinker will ignore
@@ -1029,7 +978,6 @@ rename_retry:
 	this_parent = parent;
 	seq = read_seqbegin(&rename_lock);
 
-	spin_lock(&dcache_lock);
 	if (d_mountpoint(parent))
 		goto positive;
 	spin_lock(&this_parent->d_lock);
@@ -1075,7 +1023,6 @@ resume:
 		if (this_parent != child->d_parent ||
 				read_seqretry(&rename_lock, seq)) {
 			spin_unlock(&this_parent->d_lock);
-			spin_unlock(&dcache_lock);
 			rcu_read_unlock();
 			goto rename_retry;
 		}
@@ -1084,12 +1031,10 @@ resume:
 		goto resume;
 	}
 	spin_unlock(&this_parent->d_lock);
-	spin_unlock(&dcache_lock);
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
 	return 0; /* No mount points found in tree */
 positive:
-	spin_unlock(&dcache_lock);
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
 	return 1;
@@ -1121,7 +1066,6 @@ rename_retry:
 	this_parent = parent;
 	seq = read_seqbegin(&rename_lock);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&this_parent->d_lock);
 repeat:
 	next = this_parent->d_subdirs.next;
@@ -1185,7 +1129,6 @@ resume:
 		if (this_parent != child->d_parent ||
 				read_seqretry(&rename_lock, seq)) {
 			spin_unlock(&this_parent->d_lock);
-			spin_unlock(&dcache_lock);
 			rcu_read_unlock();
 			goto rename_retry;
 		}
@@ -1195,7 +1138,6 @@ resume:
 	}
 out:
 	spin_unlock(&this_parent->d_lock);
-	spin_unlock(&dcache_lock);
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
 	return found;
@@ -1297,7 +1239,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 	INIT_LIST_HEAD(&dentry->d_u.d_child);
 
 	if (parent) {
-		spin_lock(&dcache_lock);
 		spin_lock(&parent->d_lock);
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
 		dentry->d_parent = dget_dlock(parent);
@@ -1305,7 +1246,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 		list_add(&dentry->d_u.d_child, &parent->d_subdirs);
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&parent->d_lock);
-		spin_unlock(&dcache_lock);
 	}
 
 	this_cpu_inc(nr_dentry);
@@ -1325,7 +1265,6 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name)
 }
 EXPORT_SYMBOL(d_alloc_name);
 
-/* the caller must hold dcache_lock */
 static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 {
 	spin_lock(&dentry->d_lock);
@@ -1354,11 +1293,9 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 void d_instantiate(struct dentry *entry, struct inode * inode)
 {
 	BUG_ON(!list_empty(&entry->d_alias));
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	__d_instantiate(entry, inode);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	security_d_instantiate(entry, inode);
 }
 EXPORT_SYMBOL(d_instantiate);
@@ -1422,11 +1359,9 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
 
 	BUG_ON(!list_empty(&entry->d_alias));
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	result = __d_instantiate_unique(entry, inode);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 
 	if (!result) {
 		security_d_instantiate(entry, inode);
@@ -1515,12 +1450,11 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	}
 	tmp->d_parent = tmp; /* make sure dput doesn't croak */
 
-	spin_lock(&dcache_lock);
+
 	spin_lock(&dcache_inode_lock);
 	res = __d_find_alias(inode, 0);
 	if (res) {
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 		dput(tmp);
 		goto out_iput;
 	}
@@ -1538,7 +1472,6 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	spin_unlock(&tmp->d_lock);
 	spin_unlock(&dcache_inode_lock);
 
-	spin_unlock(&dcache_lock);
 	return tmp;
 
  out_iput:
@@ -1568,21 +1501,18 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 	struct dentry *new = NULL;
 
 	if (inode && S_ISDIR(inode->i_mode)) {
-		spin_lock(&dcache_lock);
 		spin_lock(&dcache_inode_lock);
 		new = __d_find_alias(inode, 1);
 		if (new) {
 			BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
 			spin_unlock(&dcache_inode_lock);
-			spin_unlock(&dcache_lock);
 			security_d_instantiate(new, inode);
 			d_move(new, dentry);
 			iput(inode);
 		} else {
-			/* already taking dcache_lock, so d_add() by hand */
+			/* already taking dcache_inode_lock, so d_add() by hand */
 			__d_instantiate(dentry, inode);
 			spin_unlock(&dcache_inode_lock);
-			spin_unlock(&dcache_lock);
 			security_d_instantiate(dentry, inode);
 			d_rehash(dentry);
 		}
@@ -1655,12 +1585,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 * Negative dentry: instantiate it unless the inode is a directory and
 	 * already has a dentry.
 	 */
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
 		__d_instantiate(found, inode);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 		security_d_instantiate(found, inode);
 		return found;
 	}
@@ -1672,7 +1600,6 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
 	dget_locked(new);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	security_d_instantiate(found, inode);
 	d_move(new, found);
 	iput(inode);
@@ -1843,7 +1770,6 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
 {
 	struct dentry *child;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dparent->d_lock);
 	list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
 		if (dentry == child) {
@@ -1851,12 +1777,10 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
 			__dget_locked_dlock(dentry);
 			spin_unlock(&dentry->d_lock);
 			spin_unlock(&dparent->d_lock);
-			spin_unlock(&dcache_lock);
 			return 1;
 		}
 	}
 	spin_unlock(&dparent->d_lock);
-	spin_unlock(&dcache_lock);
 
 	return 0;
 }
@@ -1889,7 +1813,6 @@ void d_delete(struct dentry * dentry)
 	/*
 	 * Are we the only user?
 	 */
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	spin_lock(&dentry->d_lock);
 	isdir = S_ISDIR(dentry->d_inode->i_mode);
@@ -1905,7 +1828,6 @@ void d_delete(struct dentry * dentry)
 
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 
 	fsnotify_nameremove(dentry, isdir);
 }
@@ -1932,13 +1854,11 @@ static void _d_rehash(struct dentry * entry)
  
 void d_rehash(struct dentry * entry)
 {
-	spin_lock(&dcache_lock);
 	spin_lock(&entry->d_lock);
 	spin_lock(&dcache_hash_lock);
 	_d_rehash(entry);
 	spin_unlock(&dcache_hash_lock);
 	spin_unlock(&entry->d_lock);
-	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(d_rehash);
 
@@ -1961,11 +1881,9 @@ void dentry_update_name_case(struct dentry *dentry, struct qstr *name)
 	BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
 	BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	memcpy((unsigned char *)dentry->d_name.name, name->name, name->len);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 }
 EXPORT_SYMBOL(dentry_update_name_case);
 
@@ -2058,14 +1976,14 @@ static void dentry_unlock_parents_for_move(struct dentry *dentry,
  * The hash value has to match the hash queue that the dentry is on..
  */
 /*
- * d_move_locked - move a dentry
+ * d_move - move a dentry
  * @dentry: entry to move
  * @target: new dentry
  *
  * Update the dcache to reflect the move of a file name. Negative
  * dcache entries should not be moved in this way.
  */
-static void d_move_locked(struct dentry * dentry, struct dentry * target)
+void d_move(struct dentry * dentry, struct dentry * target)
 {
 	if (!dentry->d_inode)
 		printk(KERN_WARNING "VFS: moving negative dcache entry\n");
@@ -2114,22 +2032,6 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target)
 	spin_unlock(&dentry->d_lock);
 	write_sequnlock(&rename_lock);
 }
-
-/**
- * d_move - move a dentry
- * @dentry: entry to move
- * @target: new dentry
- *
- * Update the dcache to reflect the move of a file name. Negative
- * dcache entries should not be moved in this way.
- */
-
-void d_move(struct dentry * dentry, struct dentry * target)
-{
-	spin_lock(&dcache_lock);
-	d_move_locked(dentry, target);
-	spin_unlock(&dcache_lock);
-}
 EXPORT_SYMBOL(d_move);
 
 /**
@@ -2155,13 +2057,12 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
  * This helper attempts to cope with remotely renamed directories
  *
  * It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex and the dcache_lock
+ * dentry->d_parent->d_inode->i_mutex and the dcache_inode_lock
  *
  * Note: If ever the locking in lock_rename() changes, then please
  * remember to update this too...
  */
 static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
-	__releases(dcache_lock)
 	__releases(dcache_inode_lock)
 {
 	struct mutex *m1 = NULL, *m2 = NULL;
@@ -2185,11 +2086,10 @@ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
 		goto out_err;
 	m2 = &alias->d_parent->d_inode->i_mutex;
 out_unalias:
-	d_move_locked(alias, dentry);
+	d_move(alias, dentry);
 	ret = alias;
 out_err:
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	if (m2)
 		mutex_unlock(m2);
 	if (m1)
@@ -2249,7 +2149,6 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 
 	BUG_ON(!d_unhashed(dentry));
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 
 	if (!inode) {
@@ -2295,7 +2194,6 @@ found:
 	spin_unlock(&dcache_hash_lock);
 	spin_unlock(&actual->d_lock);
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 out_nolock:
 	if (actual == dentry) {
 		security_d_instantiate(dentry, inode);
@@ -2307,7 +2205,6 @@ out_nolock:
 
 shouldnt_be_hashed:
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 	BUG();
 }
 EXPORT_SYMBOL_GPL(d_materialise_unique);
@@ -2421,11 +2318,9 @@ char *__d_path(const struct path *path, struct path *root,
 	int error;
 
 	prepend(&res, &buflen, "\0", 1);
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	error = prepend_path(path, root, &res, &buflen);
 	write_sequnlock(&rename_lock);
-	spin_unlock(&dcache_lock);
 
 	if (error)
 		return ERR_PTR(error);
@@ -2487,14 +2382,12 @@ char *d_path(const struct path *path, char *buf, int buflen)
 		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
 
 	get_fs_root(current->fs, &root);
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	tmp = root;
 	error = path_with_deleted(path, &tmp, &res, &buflen);
 	if (error)
 		res = ERR_PTR(error);
 	write_sequnlock(&rename_lock);
-	spin_unlock(&dcache_lock);
 	path_put(&root);
 	return res;
 }
@@ -2520,14 +2413,12 @@ char *d_path_with_unreachable(const struct path *path, char *buf, int buflen)
 		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
 
 	get_fs_root(current->fs, &root);
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	tmp = root;
 	error = path_with_deleted(path, &tmp, &res, &buflen);
 	if (!error && !path_equal(&tmp, &root))
 		error = prepend_unreachable(&res, &buflen);
 	write_sequnlock(&rename_lock);
-	spin_unlock(&dcache_lock);
 	path_put(&root);
 	if (error)
 		res =  ERR_PTR(error);
@@ -2594,11 +2485,9 @@ char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen)
 {
 	char *retval;
 
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	retval = __dentry_path(dentry, buf, buflen);
 	write_sequnlock(&rename_lock);
-	spin_unlock(&dcache_lock);
 
 	return retval;
 }
@@ -2609,7 +2498,6 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen)
 	char *p = NULL;
 	char *retval;
 
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	if (d_unlinked(dentry)) {
 		p = buf + buflen;
@@ -2619,12 +2507,10 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen)
 	}
 	retval = __dentry_path(dentry, buf, buflen);
 	write_sequnlock(&rename_lock);
-	spin_unlock(&dcache_lock);
 	if (!IS_ERR(retval) && p)
 		*p = '/';	/* restore '/' overriden with '\0' */
 	return retval;
 Elong:
-	spin_unlock(&dcache_lock);
 	return ERR_PTR(-ENAMETOOLONG);
 }
 
@@ -2658,7 +2544,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
 	get_fs_root_and_pwd(current->fs, &root, &pwd);
 
 	error = -ENOENT;
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	if (!d_unlinked(pwd.dentry)) {
 		unsigned long len;
@@ -2669,7 +2554,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
 		prepend(&cwd, &buflen, "\0", 1);
 		error = prepend_path(&pwd, &tmp, &cwd, &buflen);
 		write_sequnlock(&rename_lock);
-		spin_unlock(&dcache_lock);
 
 		if (error)
 			goto out;
@@ -2690,7 +2574,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
 		}
 	} else {
 		write_sequnlock(&rename_lock);
-		spin_unlock(&dcache_lock);
 	}
 
 out:
@@ -2776,7 +2659,6 @@ void d_genocide(struct dentry *root)
 rename_retry:
 	this_parent = root;
 	seq = read_seqbegin(&rename_lock);
-	spin_lock(&dcache_lock);
 	spin_lock(&this_parent->d_lock);
 repeat:
 	next = this_parent->d_subdirs.next;
@@ -2823,7 +2705,6 @@ resume:
 		if (this_parent != child->d_parent ||
 				read_seqretry(&rename_lock, seq)) {
 			spin_unlock(&this_parent->d_lock);
-			spin_unlock(&dcache_lock);
 			rcu_read_unlock();
 			goto rename_retry;
 		}
@@ -2832,7 +2713,6 @@ resume:
 		goto resume;
 	}
 	spin_unlock(&this_parent->d_lock);
-	spin_unlock(&dcache_lock);
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
 }
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 84b8c460a781..53a5c08fb63c 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -47,24 +47,20 @@ find_acceptable_alias(struct dentry *result,
 	if (acceptable(context, result))
 		return result;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
 		dget_locked(dentry);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 		if (toput)
 			dput(toput);
 		if (dentry != result && acceptable(context, dentry)) {
 			dput(result);
 			return dentry;
 		}
-		spin_lock(&dcache_lock);
 		spin_lock(&dcache_inode_lock);
 		toput = dentry;
 	}
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 
 	if (toput)
 		dput(toput);
diff --git a/fs/libfs.c b/fs/libfs.c
index cc4794914b52..28b36663c44e 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -100,7 +100,6 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
 			struct dentry *cursor = file->private_data;
 			loff_t n = file->f_pos - 2;
 
-			spin_lock(&dcache_lock);
 			spin_lock(&dentry->d_lock);
 			/* d_lock not required for cursor */
 			list_del(&cursor->d_u.d_child);
@@ -116,7 +115,6 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
 			}
 			list_add_tail(&cursor->d_u.d_child, p);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 		}
 	}
 	mutex_unlock(&dentry->d_inode->i_mutex);
@@ -159,7 +157,6 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
 			i++;
 			/* fallthrough */
 		default:
-			spin_lock(&dcache_lock);
 			spin_lock(&dentry->d_lock);
 			if (filp->f_pos == 2)
 				list_move(q, &dentry->d_subdirs);
@@ -175,13 +172,11 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
 
 				spin_unlock(&next->d_lock);
 				spin_unlock(&dentry->d_lock);
-				spin_unlock(&dcache_lock);
 				if (filldir(dirent, next->d_name.name, 
 					    next->d_name.len, filp->f_pos, 
 					    next->d_inode->i_ino, 
 					    dt_type(next->d_inode)) < 0)
 					return 0;
-				spin_lock(&dcache_lock);
 				spin_lock(&dentry->d_lock);
 				spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
 				/* next is still alive */
@@ -191,7 +186,6 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
 				filp->f_pos++;
 			}
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 	}
 	return 0;
 }
@@ -285,7 +279,6 @@ int simple_empty(struct dentry *dentry)
 	struct dentry *child;
 	int ret = 0;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) {
 		spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
@@ -298,7 +291,6 @@ int simple_empty(struct dentry *dentry)
 	ret = 1;
 out:
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 	return ret;
 }
 
diff --git a/fs/namei.c b/fs/namei.c
index cbfa5fb31072..5642bc2be418 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -612,8 +612,8 @@ int follow_up(struct path *path)
 	return 1;
 }
 
-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
+/*
+ * serialization is taken care of in namespace.c
  */
 static int __follow_mount(struct path *path)
 {
@@ -645,9 +645,6 @@ static void follow_mount(struct path *path)
 	}
 }
 
-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
- */
 int follow_down(struct path *path)
 {
 	struct vfsmount *mounted;
@@ -2131,12 +2128,10 @@ void dentry_unhash(struct dentry *dentry)
 {
 	dget(dentry);
 	shrink_dcache_parent(dentry);
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	if (dentry->d_count == 2)
 		__d_drop(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 int vfs_rmdir(struct inode *dir, struct dentry *dentry)
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 102278ed38bd..de15c533311c 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -391,7 +391,6 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 	}
 
 	/* If a pointer is invalid, we search the dentry. */
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
@@ -402,13 +401,11 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 			else
 				dent = NULL;
 			spin_unlock(&parent->d_lock);
-			spin_unlock(&dcache_lock);
 			goto out;
 		}
 		next = next->next;
 	}
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 	return NULL;
 
 out:
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index c4b718ff9a6b..1220df75ff22 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -193,7 +193,6 @@ ncp_renew_dentries(struct dentry *parent)
 	struct list_head *next;
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
@@ -207,7 +206,6 @@ ncp_renew_dentries(struct dentry *parent)
 		next = next->next;
 	}
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 static inline void
@@ -217,7 +215,6 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
 	struct list_head *next;
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
@@ -227,7 +224,6 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
 		next = next->next;
 	}
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 struct ncp_cache_head {
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 12de824edb5c..eb77471b8823 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1718,11 +1718,9 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry)
 	dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
 		dir->i_ino, dentry->d_name.name);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	if (dentry->d_count > 1) {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_lock);
 		/* Start asynchronous writeout of the inode */
 		write_inode_now(dentry->d_inode, 0);
 		error = nfs_sillyrename(dir, dentry);
@@ -1733,7 +1731,6 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry)
 		need_rehash = 1;
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 	error = nfs_safe_remove(dentry);
 	if (!error || error == -ENOENT) {
 		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 850f67d5f0ac..b3e36c3430de 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -63,13 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 		 * This again causes shrink_dcache_for_umount_subtree() to
 		 * Oops, since the test for IS_ROOT() will fail.
 		 */
-		spin_lock(&dcache_lock);
 		spin_lock(&dcache_inode_lock);
 		spin_lock(&sb->s_root->d_lock);
 		list_del_init(&sb->s_root->d_alias);
 		spin_unlock(&sb->s_root->d_lock);
 		spin_unlock(&dcache_inode_lock);
-		spin_unlock(&dcache_lock);
 	}
 	return 0;
 }
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 78c0ebb0b07c..74aaf3963c10 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -60,7 +60,6 @@ rename_retry:
 
 	seq = read_seqbegin(&rename_lock);
 	rcu_read_lock();
-	spin_lock(&dcache_lock);
 	while (!IS_ROOT(dentry) && dentry != droot) {
 		namelen = dentry->d_name.len;
 		buflen -= namelen + 1;
@@ -71,7 +70,6 @@ rename_retry:
 		*--end = '/';
 		dentry = dentry->d_parent;
 	}
-	spin_unlock(&dcache_lock);
 	rcu_read_unlock();
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
@@ -91,7 +89,6 @@ rename_retry:
 	memcpy(end, base, namelen);
 	return end;
 Elong_unlock:
-	spin_unlock(&dcache_lock);
 	rcu_read_unlock();
 	if (read_seqretry(&rename_lock, seq))
 		goto rename_retry;
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index ae769fc9b66c..9be6ec1f36d8 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -59,7 +59,6 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 	/* determine if the children should tell inode about their events */
 	watched = fsnotify_inode_watches_children(inode);
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	/* run all of the dentries associated with this inode.  Since this is a
 	 * directory, there damn well better only be one item on this list */
@@ -84,7 +83,6 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 		spin_unlock(&alias->d_lock);
 	}
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /* Notify this dentry's parent about a child's events. */
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index c31b5c647ac7..b7de749bdd12 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -169,7 +169,6 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 	struct list_head *p;
 	struct dentry *dentry = NULL;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&dcache_inode_lock);
 	list_for_each(p, &inode->i_dentry) {
 		dentry = list_entry(p, struct dentry, d_alias);
@@ -189,7 +188,6 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 	}
 
 	spin_unlock(&dcache_inode_lock);
-	spin_unlock(&dcache_lock);
 
 	return dentry;
 }
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index c963ebada922..a2ceb94b0e38 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -183,7 +183,6 @@ struct dentry_operations {
 #define DCACHE_GENOCIDE		0x0200
 
 extern spinlock_t dcache_inode_lock;
-extern spinlock_t dcache_lock;
 extern seqlock_t rename_lock;
 
 static inline int dname_external(struct dentry *dentry)
@@ -296,8 +295,8 @@ extern char *dentry_path(struct dentry *, char *, int);
  *	destroyed when it has references. dget() should never be
  *	called for dentries with zero reference counter. For these cases
  *	(preferably none, functions in dcache.c are sufficient for normal
- *	needs and they take necessary precautions) you should hold dcache_lock
- *	and call dget_locked() instead of dget().
+ *	needs and they take necessary precautions) you should hold d_lock
+ *	and call dget_dlock() instead of dget().
  */
 static inline struct dentry *dget_dlock(struct dentry *dentry)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 090f0eacde29..296cf2fde945 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1378,7 +1378,7 @@ struct super_block {
 #else
 	struct list_head	s_files;
 #endif
-	/* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
+	/* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
 	struct list_head	s_dentry_lru;	/* unused dentry lru */
 	int			s_nr_dentry_unused;	/* # of dentry on lru */
 
@@ -2446,6 +2446,10 @@ static inline ino_t parent_ino(struct dentry *dentry)
 {
 	ino_t res;
 
+	/*
+	 * Don't strictly need d_lock here? If the parent ino could change
+	 * then surely we'd have a deeper race in the caller?
+	 */
 	spin_lock(&dentry->d_lock);
 	res = dentry->d_parent->d_inode->i_ino;
 	spin_unlock(&dentry->d_lock);
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index b10bcdeaef76..2a53f10712b3 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -17,7 +17,6 @@
 
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
  */
 static inline void fsnotify_d_instantiate(struct dentry *dentry,
 					  struct inode *inode)
@@ -62,7 +61,6 @@ static inline int fsnotify_perm(struct file *file, int mask)
 
 /*
  * fsnotify_d_move - dentry has been moved
- * Called with dcache_lock and dentry->d_lock held.
  */
 static inline void fsnotify_d_move(struct dentry *dentry)
 {
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 7380763595d3..69ad89b50489 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 {
 	struct dentry *parent;
 
-	assert_spin_locked(&dcache_lock);
 	assert_spin_locked(&dentry->d_lock);
 
+	/*
+	 * Serialisation of setting PARENT_WATCHED on the dentries is provided
+	 * by d_lock. If inotify_inode_watched changes after we have taken
+	 * d_lock, the following __fsnotify_update_child_dentry_flags call will
+	 * find our entry, so it will spin until we complete here, and update
+	 * us with the new state.
+	 */
 	parent = dentry->d_parent;
 	if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
 		dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
@@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
  */
 static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
 {
 	if (!inode)
 		return;
 
-	assert_spin_locked(&dcache_lock);
-
 	spin_lock(&dentry->d_lock);
 	__fsnotify_update_dcache_flags(dentry);
 	spin_unlock(&dentry->d_lock);
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 05b441d93642..aec730b53935 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -41,7 +41,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  *  - require a directory
  *  - ending slashes ok even for nonexistent files
  *  - internal "there are more path components" flag
- *  - locked when lookup done with dcache_lock held
  *  - dentry cache is untrusted; force a real lookup
  */
 #define LOOKUP_FOLLOW		 1
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7b4705b51d4a..1864cb6a6a59 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -876,7 +876,6 @@ static void cgroup_clear_directory(struct dentry *dentry)
 	struct list_head *node;
 
 	BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
-	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
 	node = dentry->d_subdirs.next;
 	while (node != &dentry->d_subdirs) {
@@ -891,18 +890,15 @@ static void cgroup_clear_directory(struct dentry *dentry)
 			dget_locked_dlock(d);
 			spin_unlock(&d->d_lock);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
 			d_delete(d);
 			simple_unlink(dentry->d_inode, d);
 			dput(d);
-			spin_lock(&dcache_lock);
 			spin_lock(&dentry->d_lock);
 		} else
 			spin_unlock(&d->d_lock);
 		node = dentry->d_subdirs.next;
 	}
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 /*
@@ -914,14 +910,12 @@ static void cgroup_d_remove_dir(struct dentry *dentry)
 
 	cgroup_clear_directory(dentry);
 
-	spin_lock(&dcache_lock);
 	parent = dentry->d_parent;
 	spin_lock(&parent->d_lock);
 	spin_lock(&dentry->d_lock);
 	list_del_init(&dentry->d_u.d_child);
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&parent->d_lock);
-	spin_unlock(&dcache_lock);
 	remove_dir(dentry);
 }
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 6b9aee20f242..ca389394fa2a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -102,9 +102,6 @@
  *    ->inode_lock		(zap_pte_range->set_page_dirty)
  *    ->private_lock		(zap_pte_range->__set_page_dirty_buffers)
  *
- *  ->task->proc_lock
- *    ->dcache_lock		(proc_pid_lookup)
- *
  *  (code doesn't rely on that order, so you could switch it around)
  *  ->tasklist_lock             (memory_failure, collect_procs_ao)
  *    ->i_mmap_lock
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 017ec096446e..2285d693f296 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1145,7 +1145,6 @@ static void sel_remove_entries(struct dentry *de)
 {
 	struct list_head *node;
 
-	spin_lock(&dcache_lock);
 	spin_lock(&de->d_lock);
 	node = de->d_subdirs.next;
 	while (node != &de->d_subdirs) {
@@ -1158,11 +1157,9 @@ static void sel_remove_entries(struct dentry *de)
 			dget_locked_dlock(d);
 			spin_unlock(&de->d_lock);
 			spin_unlock(&d->d_lock);
-			spin_unlock(&dcache_lock);
 			d_delete(d);
 			simple_unlink(de->d_inode, d);
 			dput(d);
-			spin_lock(&dcache_lock);
 			spin_lock(&de->d_lock);
 		} else
 			spin_unlock(&d->d_lock);
@@ -1170,7 +1167,6 @@ static void sel_remove_entries(struct dentry *de)
 	}
 
 	spin_unlock(&de->d_lock);
-	spin_unlock(&dcache_lock);
 }
 
 #define BOOL_DIR_NAME "booleans"
-- 
cgit v1.2.3


From fa0d7e3de6d6fc5004ad9dea0dd6b286af8f03e9 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:49 +1100
Subject: fs: icache RCU free inodes

RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/porting         | 14 ++++++++++++++
 arch/powerpc/platforms/cell/spufs/inode.c | 10 ++++++++--
 drivers/staging/pohmelfs/inode.c          |  9 ++++++++-
 drivers/staging/smbfs/inode.c             |  9 ++++++++-
 fs/9p/vfs_inode.c                         |  9 ++++++++-
 fs/adfs/super.c                           |  9 ++++++++-
 fs/affs/super.c                           |  9 ++++++++-
 fs/afs/super.c                            | 10 +++++++++-
 fs/befs/linuxvfs.c                        | 10 ++++++++--
 fs/bfs/inode.c                            |  9 ++++++++-
 fs/block_dev.c                            |  9 ++++++++-
 fs/btrfs/inode.c                          |  9 ++++++++-
 fs/ceph/inode.c                           | 11 ++++++++++-
 fs/cifs/cifsfs.c                          |  9 ++++++++-
 fs/coda/inode.c                           |  9 ++++++++-
 fs/ecryptfs/super.c                       | 12 +++++++++++-
 fs/efs/super.c                            |  9 ++++++++-
 fs/exofs/super.c                          |  9 ++++++++-
 fs/ext2/super.c                           |  9 ++++++++-
 fs/ext3/super.c                           |  9 ++++++++-
 fs/ext4/super.c                           |  9 ++++++++-
 fs/fat/inode.c                            |  9 ++++++++-
 fs/freevxfs/vxfs_inode.c                  |  9 ++++++++-
 fs/fuse/inode.c                           |  9 ++++++++-
 fs/gfs2/super.c                           |  9 ++++++++-
 fs/hfs/super.c                            |  9 ++++++++-
 fs/hfsplus/super.c                        | 10 +++++++++-
 fs/hostfs/hostfs_kern.c                   |  9 ++++++++-
 fs/hpfs/super.c                           |  9 ++++++++-
 fs/hppfs/hppfs.c                          |  9 ++++++++-
 fs/hugetlbfs/inode.c                      |  9 ++++++++-
 fs/inode.c                                | 10 +++++++++-
 fs/isofs/inode.c                          |  9 ++++++++-
 fs/jffs2/super.c                          |  9 ++++++++-
 fs/jfs/super.c                            | 10 +++++++++-
 fs/logfs/inode.c                          |  9 ++++++++-
 fs/minix/inode.c                          |  9 ++++++++-
 fs/ncpfs/inode.c                          |  9 ++++++++-
 fs/nfs/inode.c                            |  9 ++++++++-
 fs/nilfs2/super.c                         | 10 +++++++++-
 fs/ntfs/inode.c                           |  9 ++++++++-
 fs/ocfs2/dlmfs/dlmfs.c                    |  9 ++++++++-
 fs/ocfs2/super.c                          |  9 ++++++++-
 fs/openpromfs/inode.c                     |  9 ++++++++-
 fs/proc/inode.c                           |  9 ++++++++-
 fs/qnx4/inode.c                           |  9 ++++++++-
 fs/reiserfs/super.c                       |  9 ++++++++-
 fs/romfs/super.c                          |  9 ++++++++-
 fs/squashfs/super.c                       |  9 ++++++++-
 fs/sysv/inode.c                           |  9 ++++++++-
 fs/ubifs/super.c                          | 10 +++++++++-
 fs/udf/super.c                            |  9 ++++++++-
 fs/ufs/super.c                            |  9 ++++++++-
 fs/xfs/xfs_iget.c                         | 13 ++++++++++++-
 include/linux/fs.h                        |  5 ++++-
 include/linux/net.h                       |  1 -
 ipc/mqueue.c                              |  9 ++++++++-
 mm/shmem.c                                |  9 ++++++++-
 net/socket.c                              | 16 ++++++++--------
 net/sunrpc/rpc_pipe.c                     | 10 +++++++++-
 60 files changed, 490 insertions(+), 68 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 1eb76959d096..ccf0ce7866b9 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -346,3 +346,17 @@ look at examples of other filesystems) for guidance.
 for details of what locks to replace dcache_lock with in order to protect
 particular things. Most of the time, a filesystem only needs ->d_lock, which
 protects *all* the dcache state of a given dentry.
+
+--
+[mandatory]
+
+	Filesystems must RCU-free their inodes, if they can have been accessed
+via rcu-walk path walk (basically, if the file can have had a path name in the
+vfs namespace).
+
+	i_dentry and i_rcu share storage in a union, and the vfs expects
+i_dentry to be reinitialized before it is freed, so an:
+
+  INIT_LIST_HEAD(&inode->i_dentry);
+
+must be done in the RCU callback.
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 03185de7cd4a..856e9c398068 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -71,12 +71,18 @@ spufs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void
-spufs_destroy_inode(struct inode *inode)
+static void spufs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
 }
 
+static void spufs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, spufs_i_callback);
+}
+
 static void
 spufs_init_once(void *p)
 {
diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c
index 61685ccceda8..cc8d2840f9b6 100644
--- a/drivers/staging/pohmelfs/inode.c
+++ b/drivers/staging/pohmelfs/inode.c
@@ -826,6 +826,13 @@ const struct address_space_operations pohmelfs_aops = {
 	.set_page_dirty 	= __set_page_dirty_nobuffers,
 };
 
+static void pohmelfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(pohmelfs_inode_cache, POHMELFS_I(inode));
+}
+
 /*
  * ->detroy_inode() callback. Deletes inode from the caches
  *  and frees private data.
@@ -842,8 +849,8 @@ static void pohmelfs_destroy_inode(struct inode *inode)
 
 	dprintk("%s: pi: %p, inode: %p, ino: %llu.\n",
 		__func__, pi, &pi->vfs_inode, pi->ino);
-	kmem_cache_free(pohmelfs_inode_cache, pi);
 	atomic_long_dec(&psb->total_inodes);
+	call_rcu(&inode->i_rcu, pohmelfs_i_callback);
 }
 
 /*
diff --git a/drivers/staging/smbfs/inode.c b/drivers/staging/smbfs/inode.c
index 540a984bb516..244319dc9702 100644
--- a/drivers/staging/smbfs/inode.c
+++ b/drivers/staging/smbfs/inode.c
@@ -62,11 +62,18 @@ static struct inode *smb_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void smb_destroy_inode(struct inode *inode)
+static void smb_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(smb_inode_cachep, SMB_I(inode));
 }
 
+static void smb_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, smb_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct smb_inode_info *ei = (struct smb_inode_info *) foo;
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 1073bca8488c..f6f9081e6d2c 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -237,10 +237,17 @@ struct inode *v9fs_alloc_inode(struct super_block *sb)
  *
  */
 
-void v9fs_destroy_inode(struct inode *inode)
+static void v9fs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode));
 }
+
+void v9fs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, v9fs_i_callback);
+}
 #endif
 
 /**
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 959dbff2d42d..47dffc513a26 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -240,11 +240,18 @@ static struct inode *adfs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void adfs_destroy_inode(struct inode *inode)
+static void adfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
 }
 
+static void adfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, adfs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 0cf7f4384cbd..4c18fcfb0a19 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -95,11 +95,18 @@ static struct inode *affs_alloc_inode(struct super_block *sb)
 	return &i->vfs_inode;
 }
 
-static void affs_destroy_inode(struct inode *inode)
+static void affs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
 }
 
+static void affs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, affs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 27201cffece4..f901a9d7c111 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -498,6 +498,14 @@ static struct inode *afs_alloc_inode(struct super_block *sb)
 	return &vnode->vfs_inode;
 }
 
+static void afs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(afs_inode_cachep, vnode);
+}
+
 /*
  * destroy an AFS inode struct
  */
@@ -511,7 +519,7 @@ static void afs_destroy_inode(struct inode *inode)
 
 	ASSERTCMP(vnode->server, ==, NULL);
 
-	kmem_cache_free(afs_inode_cachep, vnode);
+	call_rcu(&inode->i_rcu, afs_i_callback);
 	atomic_dec(&afs_count_active_inodes);
 }
 
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index aa4e7c7ae3c6..de93581b79a2 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -284,12 +284,18 @@ befs_alloc_inode(struct super_block *sb)
         return &bi->vfs_inode;
 }
 
-static void
-befs_destroy_inode(struct inode *inode)
+static void befs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
 }
 
+static void befs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, befs_i_callback);
+}
+
 static void init_once(void *foo)
 {
         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 76db6d7d49bb..a8e37f81d097 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -248,11 +248,18 @@ static struct inode *bfs_alloc_inode(struct super_block *sb)
 	return &bi->vfs_inode;
 }
 
-static void bfs_destroy_inode(struct inode *inode)
+static void bfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 }
 
+static void bfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, bfs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct bfs_inode_info *bi = foo;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 4230252fd689..771f23527010 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -409,13 +409,20 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void bdev_destroy_inode(struct inode *inode)
+static void bdev_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
 	struct bdev_inode *bdi = BDEV_I(inode);
 
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(bdev_cachep, bdi);
 }
 
+static void bdev_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, bdev_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct bdev_inode *ei = (struct bdev_inode *) foo;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7ce9f8932789..f9d2994a42a2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6495,6 +6495,13 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	return inode;
 }
 
+static void btrfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
 void btrfs_destroy_inode(struct inode *inode)
 {
 	struct btrfs_ordered_extent *ordered;
@@ -6564,7 +6571,7 @@ void btrfs_destroy_inode(struct inode *inode)
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 free:
-	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+	call_rcu(&inode->i_rcu, btrfs_i_callback);
 }
 
 int btrfs_drop_inode(struct inode *inode)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2a48cafc174b..47f8c8baf3b5 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -368,6 +368,15 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	return &ci->vfs_inode;
 }
 
+static void ceph_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ceph_inode_cachep, ci);
+}
+
 void ceph_destroy_inode(struct inode *inode)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
@@ -407,7 +416,7 @@ void ceph_destroy_inode(struct inode *inode)
 	if (ci->i_xattrs.prealloc_blob)
 		ceph_buffer_put(ci->i_xattrs.prealloc_blob);
 
-	kmem_cache_free(ceph_inode_cachep, ci);
+	call_rcu(&inode->i_rcu, ceph_i_callback);
 }
 
 
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 3936aa7f2c22..223717dcc401 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -334,10 +334,17 @@ cifs_alloc_inode(struct super_block *sb)
 	return &cifs_inode->vfs_inode;
 }
 
+static void cifs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
+}
+
 static void
 cifs_destroy_inode(struct inode *inode)
 {
-	kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
+	call_rcu(&inode->i_rcu, cifs_i_callback);
 }
 
 static void
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 5ea57c8c7f97..50dc7d189f56 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -56,11 +56,18 @@ static struct inode *coda_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void coda_destroy_inode(struct inode *inode)
+static void coda_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(coda_inode_cachep, ITOC(inode));
 }
 
+static void coda_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, coda_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index 2720178b7718..3042fe123a34 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -62,6 +62,16 @@ out:
 	return inode;
 }
 
+static void ecryptfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct ecryptfs_inode_info *inode_info;
+	inode_info = ecryptfs_inode_to_private(inode);
+
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
+}
+
 /**
  * ecryptfs_destroy_inode
  * @inode: The ecryptfs inode
@@ -88,7 +98,7 @@ static void ecryptfs_destroy_inode(struct inode *inode)
 		}
 	}
 	ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
-	kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
+	call_rcu(&inode->i_rcu, ecryptfs_i_callback);
 }
 
 /**
diff --git a/fs/efs/super.c b/fs/efs/super.c
index 5073a07652cc..0f31acb0131c 100644
--- a/fs/efs/super.c
+++ b/fs/efs/super.c
@@ -65,11 +65,18 @@ static struct inode *efs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void efs_destroy_inode(struct inode *inode)
+static void efs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
 }
 
+static void efs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, efs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct efs_inode_info *ei = (struct efs_inode_info *) foo;
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index 79c3ae6e0456..8c6c4669b381 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -150,12 +150,19 @@ static struct inode *exofs_alloc_inode(struct super_block *sb)
 	return &oi->vfs_inode;
 }
 
+static void exofs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+}
+
 /*
  * Remove an inode from the cache
  */
 static void exofs_destroy_inode(struct inode *inode)
 {
-	kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+	call_rcu(&inode->i_rcu, exofs_i_callback);
 }
 
 /*
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index d89e0b6a2d78..e0c6380ff992 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -161,11 +161,18 @@ static struct inode *ext2_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void ext2_destroy_inode(struct inode *inode)
+static void ext2_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 }
 
+static void ext2_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, ext2_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index acf8695fa8f0..77ce1616f725 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -479,6 +479,13 @@ static struct inode *ext3_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
+static void ext3_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
+}
+
 static void ext3_destroy_inode(struct inode *inode)
 {
 	if (!list_empty(&(EXT3_I(inode)->i_orphan))) {
@@ -489,7 +496,7 @@ static void ext3_destroy_inode(struct inode *inode)
 				false);
 		dump_stack();
 	}
-	kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
+	call_rcu(&inode->i_rcu, ext3_i_callback);
 }
 
 static void init_once(void *foo)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index fb15c9c0be74..cd37f9d5e447 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -841,6 +841,13 @@ static int ext4_drop_inode(struct inode *inode)
 	return drop;
 }
 
+static void ext4_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
+}
+
 static void ext4_destroy_inode(struct inode *inode)
 {
 	ext4_ioend_wait(inode);
@@ -853,7 +860,7 @@ static void ext4_destroy_inode(struct inode *inode)
 				true);
 		dump_stack();
 	}
-	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
+	call_rcu(&inode->i_rcu, ext4_i_callback);
 }
 
 static void init_once(void *foo)
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ad6998a92c30..8cccfebee180 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -514,11 +514,18 @@ static struct inode *fat_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void fat_destroy_inode(struct inode *inode)
+static void fat_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
 }
 
+static void fat_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, fat_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
diff --git a/fs/freevxfs/vxfs_inode.c b/fs/freevxfs/vxfs_inode.c
index 8c04eac5079d..2ba6719ac612 100644
--- a/fs/freevxfs/vxfs_inode.c
+++ b/fs/freevxfs/vxfs_inode.c
@@ -337,6 +337,13 @@ vxfs_iget(struct super_block *sbp, ino_t ino)
 	return ip;
 }
 
+static void vxfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(vxfs_inode_cachep, inode->i_private);
+}
+
 /**
  * vxfs_evict_inode - remove inode from main memory
  * @ip:		inode to discard.
@@ -350,5 +357,5 @@ vxfs_evict_inode(struct inode *ip)
 {
 	truncate_inode_pages(&ip->i_data, 0);
 	end_writeback(ip);
-	kmem_cache_free(vxfs_inode_cachep, ip->i_private);
+	call_rcu(&ip->i_rcu, vxfs_i_callback);
 }
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index cfce3ad86a92..44e0a6c57e87 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -99,6 +99,13 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
 	return inode;
 }
 
+static void fuse_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(fuse_inode_cachep, inode);
+}
+
 static void fuse_destroy_inode(struct inode *inode)
 {
 	struct fuse_inode *fi = get_fuse_inode(inode);
@@ -106,7 +113,7 @@ static void fuse_destroy_inode(struct inode *inode)
 	BUG_ON(!list_empty(&fi->queued_writes));
 	if (fi->forget_req)
 		fuse_request_free(fi->forget_req);
-	kmem_cache_free(fuse_inode_cachep, inode);
+	call_rcu(&inode->i_rcu, fuse_i_callback);
 }
 
 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 2b2c4997430b..16c2ecac7eb7 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1405,11 +1405,18 @@ static struct inode *gfs2_alloc_inode(struct super_block *sb)
 	return &ip->i_inode;
 }
 
-static void gfs2_destroy_inode(struct inode *inode)
+static void gfs2_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(gfs2_inode_cachep, inode);
 }
 
+static void gfs2_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, gfs2_i_callback);
+}
+
 const struct super_operations gfs2_super_ops = {
 	.alloc_inode		= gfs2_alloc_inode,
 	.destroy_inode		= gfs2_destroy_inode,
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 4824c27cebb8..ef4ee5716abe 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -167,11 +167,18 @@ static struct inode *hfs_alloc_inode(struct super_block *sb)
 	return i ? &i->vfs_inode : NULL;
 }
 
-static void hfs_destroy_inode(struct inode *inode)
+static void hfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 }
 
+static void hfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, hfs_i_callback);
+}
+
 static const struct super_operations hfs_super_operations = {
 	.alloc_inode	= hfs_alloc_inode,
 	.destroy_inode	= hfs_destroy_inode,
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 52cc746d3ba3..182e83a9079e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -488,11 +488,19 @@ static struct inode *hfsplus_alloc_inode(struct super_block *sb)
 	return i ? &i->vfs_inode : NULL;
 }
 
-static void hfsplus_destroy_inode(struct inode *inode)
+static void hfsplus_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
 }
 
+static void hfsplus_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, hfsplus_i_callback);
+}
+
 #define HFSPLUS_INODE_SIZE	sizeof(struct hfsplus_inode_info)
 
 static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 39dc505ed273..861113fcfc88 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -247,11 +247,18 @@ static void hostfs_evict_inode(struct inode *inode)
 	}
 }
 
-static void hostfs_destroy_inode(struct inode *inode)
+static void hostfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kfree(HOSTFS_I(inode));
 }
 
+static void hostfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, hostfs_i_callback);
+}
+
 static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 {
 	const char *root_path = vfs->mnt_sb->s_fs_info;
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index 6c5f01597c3a..49935ba78db8 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -177,11 +177,18 @@ static struct inode *hpfs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void hpfs_destroy_inode(struct inode *inode)
+static void hpfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(hpfs_inode_cachep, hpfs_i(inode));
 }
 
+static void hpfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, hpfs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo;
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index f702b5f713fc..87ed48e0343d 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -632,11 +632,18 @@ void hppfs_evict_inode(struct inode *ino)
 	mntput(ino->i_sb->s_fs_info);
 }
 
-static void hppfs_destroy_inode(struct inode *inode)
+static void hppfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kfree(HPPFS_I(inode));
 }
 
+static void hppfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, hppfs_i_callback);
+}
+
 static const struct super_operations hppfs_sbops = {
 	.alloc_inode	= hppfs_alloc_inode,
 	.destroy_inode	= hppfs_destroy_inode,
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a5fe68189eed..9885082b470f 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -663,11 +663,18 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 	return &p->vfs_inode;
 }
 
+static void hugetlbfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
+}
+
 static void hugetlbfs_destroy_inode(struct inode *inode)
 {
 	hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
 	mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
-	kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
+	call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
 }
 
 static const struct address_space_operations hugetlbfs_aops = {
diff --git a/fs/inode.c b/fs/inode.c
index 5a0a898f55d1..6751dfe8cc06 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -272,6 +272,13 @@ void __destroy_inode(struct inode *inode)
 }
 EXPORT_SYMBOL(__destroy_inode);
 
+static void i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(inode_cachep, inode);
+}
+
 static void destroy_inode(struct inode *inode)
 {
 	BUG_ON(!list_empty(&inode->i_lru));
@@ -279,7 +286,7 @@ static void destroy_inode(struct inode *inode)
 	if (inode->i_sb->s_op->destroy_inode)
 		inode->i_sb->s_op->destroy_inode(inode);
 	else
-		kmem_cache_free(inode_cachep, (inode));
+		call_rcu(&inode->i_rcu, i_callback);
 }
 
 /*
@@ -432,6 +439,7 @@ void end_writeback(struct inode *inode)
 	BUG_ON(!(inode->i_state & I_FREEING));
 	BUG_ON(inode->i_state & I_CLEAR);
 	inode_sync_wait(inode);
+	/* don't need i_lock here, no concurrent mods to i_state */
 	inode->i_state = I_FREEING | I_CLEAR;
 }
 EXPORT_SYMBOL(end_writeback);
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d204ee4235fd..d8f3a652243d 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -81,11 +81,18 @@ static struct inode *isofs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void isofs_destroy_inode(struct inode *inode)
+static void isofs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
 }
 
+static void isofs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, isofs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct iso_inode_info *ei = foo;
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index c86041b866a4..853b8e300084 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -40,11 +40,18 @@ static struct inode *jffs2_alloc_inode(struct super_block *sb)
 	return &f->vfs_inode;
 }
 
-static void jffs2_destroy_inode(struct inode *inode)
+static void jffs2_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
 }
 
+static void jffs2_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, jffs2_i_callback);
+}
+
 static void jffs2_i_init_once(void *foo)
 {
 	struct jffs2_inode_info *f = foo;
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 0669fc1cc3bf..b715b0f7bdfd 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -115,6 +115,14 @@ static struct inode *jfs_alloc_inode(struct super_block *sb)
 	return &jfs_inode->vfs_inode;
 }
 
+static void jfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct jfs_inode_info *ji = JFS_IP(inode);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(jfs_inode_cachep, ji);
+}
+
 static void jfs_destroy_inode(struct inode *inode)
 {
 	struct jfs_inode_info *ji = JFS_IP(inode);
@@ -128,7 +136,7 @@ static void jfs_destroy_inode(struct inode *inode)
 		ji->active_ag = -1;
 	}
 	spin_unlock_irq(&ji->ag_lock);
-	kmem_cache_free(jfs_inode_cachep, ji);
+	call_rcu(&inode->i_rcu, jfs_i_callback);
 }
 
 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index d8c71ece098f..03b8c240aeda 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -141,13 +141,20 @@ struct inode *logfs_safe_iget(struct super_block *sb, ino_t ino, int *is_cached)
 	return __logfs_iget(sb, ino);
 }
 
+static void logfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(logfs_inode_cache, logfs_inode(inode));
+}
+
 static void __logfs_destroy_inode(struct inode *inode)
 {
 	struct logfs_inode *li = logfs_inode(inode);
 
 	BUG_ON(li->li_block);
 	list_del(&li->li_freeing_list);
-	kmem_cache_free(logfs_inode_cache, li);
+	call_rcu(&inode->i_rcu, logfs_i_callback);
 }
 
 static void logfs_destroy_inode(struct inode *inode)
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index fb2020858a34..ae0b83f476a6 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -68,11 +68,18 @@ static struct inode *minix_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void minix_destroy_inode(struct inode *inode)
+static void minix_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
 }
 
+static void minix_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, minix_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 8fb93b604e73..60047dbeb38d 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -58,11 +58,18 @@ static struct inode *ncp_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void ncp_destroy_inode(struct inode *inode)
+static void ncp_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(ncp_inode_cachep, NCP_FINFO(inode));
 }
 
+static void ncp_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, ncp_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct ncp_inode_info *ei = (struct ncp_inode_info *) foo;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e67e31c73416..017daa3bed38 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1438,11 +1438,18 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
 	return &nfsi->vfs_inode;
 }
 
-void nfs_destroy_inode(struct inode *inode)
+static void nfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
 }
 
+void nfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, nfs_i_callback);
+}
+
 static inline void nfs4_init_once(struct nfs_inode *nfsi)
 {
 #ifdef CONFIG_NFS_V4
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index d36fc7ee615f..e2dcc9c733f7 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -162,10 +162,13 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
 	return &ii->vfs_inode;
 }
 
-void nilfs_destroy_inode(struct inode *inode)
+static void nilfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
 	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
+	INIT_LIST_HEAD(&inode->i_dentry);
+
 	if (mdi) {
 		kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 		kfree(mdi);
@@ -173,6 +176,11 @@ void nilfs_destroy_inode(struct inode *inode)
 	kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 }
 
+void nilfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, nilfs_i_callback);
+}
+
 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 {
 	struct the_nilfs *nilfs = sbi->s_nilfs;
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 93622b175fc7..a627ed82c0a3 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -332,6 +332,13 @@ struct inode *ntfs_alloc_big_inode(struct super_block *sb)
 	return NULL;
 }
 
+static void ntfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode));
+}
+
 void ntfs_destroy_big_inode(struct inode *inode)
 {
 	ntfs_inode *ni = NTFS_I(inode);
@@ -340,7 +347,7 @@ void ntfs_destroy_big_inode(struct inode *inode)
 	BUG_ON(ni->page);
 	if (!atomic_dec_and_test(&ni->count))
 		BUG();
-	kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode));
+	call_rcu(&inode->i_rcu, ntfs_i_callback);
 }
 
 static inline ntfs_inode *ntfs_alloc_extent_inode(void)
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index b2df490a19ed..8c5c0eddc365 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -351,11 +351,18 @@ static struct inode *dlmfs_alloc_inode(struct super_block *sb)
 	return &ip->ip_vfs_inode;
 }
 
-static void dlmfs_destroy_inode(struct inode *inode)
+static void dlmfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
 }
 
+static void dlmfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, dlmfs_i_callback);
+}
+
 static void dlmfs_evict_inode(struct inode *inode)
 {
 	int status;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index cfeab7ce3697..17ff46fa8a10 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -569,11 +569,18 @@ static struct inode *ocfs2_alloc_inode(struct super_block *sb)
 	return &oi->vfs_inode;
 }
 
-static void ocfs2_destroy_inode(struct inode *inode)
+static void ocfs2_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(ocfs2_inode_cachep, OCFS2_I(inode));
 }
 
+static void ocfs2_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, ocfs2_i_callback);
+}
+
 static unsigned long long ocfs2_max_file_offset(unsigned int bbits,
 						unsigned int cbits)
 {
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index 911e61f348fc..a2a5bff774e3 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -343,11 +343,18 @@ static struct inode *openprom_alloc_inode(struct super_block *sb)
 	return &oi->vfs_inode;
 }
 
-static void openprom_destroy_inode(struct inode *inode)
+static void openprom_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(op_inode_cachep, OP_I(inode));
 }
 
+static void openprom_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, openprom_i_callback);
+}
+
 static struct inode *openprom_iget(struct super_block *sb, ino_t ino)
 {
 	struct inode *inode;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 3ddb6068177c..6bcb926b101b 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -65,11 +65,18 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
 	return inode;
 }
 
-static void proc_destroy_inode(struct inode *inode)
+static void proc_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
 }
 
+static void proc_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, proc_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct proc_inode *ei = (struct proc_inode *) foo;
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index fcada42f1aa3..e63b4171d583 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -425,11 +425,18 @@ static struct inode *qnx4_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void qnx4_destroy_inode(struct inode *inode)
+static void qnx4_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 }
 
+static void qnx4_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, qnx4_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index b243117b8752..2575682a9ead 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -529,11 +529,18 @@ static struct inode *reiserfs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void reiserfs_destroy_inode(struct inode *inode)
+static void reiserfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(reiserfs_inode_cachep, REISERFS_I(inode));
 }
 
+static void reiserfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, reiserfs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct reiserfs_inode_info *ei = (struct reiserfs_inode_info *)foo;
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 6647f90e55cd..2305e3121cb1 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -400,11 +400,18 @@ static struct inode *romfs_alloc_inode(struct super_block *sb)
 /*
  * return a spent inode to the slab cache
  */
-static void romfs_destroy_inode(struct inode *inode)
+static void romfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
 }
 
+static void romfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, romfs_i_callback);
+}
+
 /*
  * get filesystem statistics
  */
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 24de30ba34c1..20700b9f2b4c 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -440,11 +440,18 @@ static struct inode *squashfs_alloc_inode(struct super_block *sb)
 }
 
 
-static void squashfs_destroy_inode(struct inode *inode)
+static void squashfs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
 }
 
+static void squashfs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, squashfs_i_callback);
+}
+
 
 static struct file_system_type squashfs_fs_type = {
 	.owner = THIS_MODULE,
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index de44d067b9e6..0630eb969a28 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -333,11 +333,18 @@ static struct inode *sysv_alloc_inode(struct super_block *sb)
 	return &si->vfs_inode;
 }
 
-static void sysv_destroy_inode(struct inode *inode)
+static void sysv_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 }
 
+static void sysv_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, sysv_i_callback);
+}
+
 static void init_once(void *p)
 {
 	struct sysv_inode_info *si = (struct sysv_inode_info *)p;
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 91fac54c70e3..6e11c2975dcf 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -272,12 +272,20 @@ static struct inode *ubifs_alloc_inode(struct super_block *sb)
 	return &ui->vfs_inode;
 };
 
+static void ubifs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(ubifs_inode_slab, ui);
+}
+
 static void ubifs_destroy_inode(struct inode *inode)
 {
 	struct ubifs_inode *ui = ubifs_inode(inode);
 
 	kfree(ui->data);
-	kmem_cache_free(ubifs_inode_slab, inode);
+	call_rcu(&inode->i_rcu, ubifs_i_callback);
 }
 
 /*
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 4a5c7c61836a..b539d53320fb 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -139,11 +139,18 @@ static struct inode *udf_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void udf_destroy_inode(struct inode *inode)
+static void udf_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(udf_inode_cachep, UDF_I(inode));
 }
 
+static void udf_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, udf_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct udf_inode_info *ei = (struct udf_inode_info *)foo;
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 2c47daed56da..2c61ac5d4e48 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1412,11 +1412,18 @@ static struct inode *ufs_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void ufs_destroy_inode(struct inode *inode)
+static void ufs_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(ufs_inode_cachep, UFS_I(inode));
 }
 
+static void ufs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, ufs_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct ufs_inode_info *ei = (struct ufs_inode_info *) foo;
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index 0cdd26932d8e..d7de5a3f7867 100644
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -91,6 +91,17 @@ xfs_inode_alloc(
 	return ip;
 }
 
+STATIC void
+xfs_inode_free_callback(
+	struct rcu_head		*head)
+{
+	struct inode		*inode = container_of(head, struct inode, i_rcu);
+	struct xfs_inode	*ip = XFS_I(inode);
+
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_zone_free(xfs_inode_zone, ip);
+}
+
 void
 xfs_inode_free(
 	struct xfs_inode	*ip)
@@ -134,7 +145,7 @@ xfs_inode_free(
 	ASSERT(!spin_is_locked(&ip->i_flags_lock));
 	ASSERT(completion_done(&ip->i_flush));
 
-	kmem_zone_free(xfs_inode_zone, ip);
+	call_rcu(&ip->i_vnode.i_rcu, xfs_inode_free_callback);
 }
 
 /*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 296cf2fde945..1ff4d0a33b25 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -737,7 +737,10 @@ struct inode {
 	struct list_head	i_wb_list;	/* backing dev IO list */
 	struct list_head	i_lru;		/* inode LRU list */
 	struct list_head	i_sb_list;
-	struct list_head	i_dentry;
+	union {
+		struct list_head	i_dentry;
+		struct rcu_head		i_rcu;
+	};
 	unsigned long		i_ino;
 	atomic_t		i_count;
 	unsigned int		i_nlink;
diff --git a/include/linux/net.h b/include/linux/net.h
index 16faa130088c..06bde4908473 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -120,7 +120,6 @@ enum sock_shutdown_cmd {
 struct socket_wq {
 	wait_queue_head_t	wait;
 	struct fasync_struct	*fasync_list;
-	struct rcu_head		rcu;
 } ____cacheline_aligned_in_smp;
 
 /**
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 035f4399edbc..14fb6d67e6a3 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -237,11 +237,18 @@ static struct inode *mqueue_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void mqueue_destroy_inode(struct inode *inode)
+static void mqueue_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
 }
 
+static void mqueue_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, mqueue_i_callback);
+}
+
 static void mqueue_evict_inode(struct inode *inode)
 {
 	struct mqueue_inode_info *info;
diff --git a/mm/shmem.c b/mm/shmem.c
index 47fdeeb9d636..5ee67c990602 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2415,13 +2415,20 @@ static struct inode *shmem_alloc_inode(struct super_block *sb)
 	return &p->vfs_inode;
 }
 
+static void shmem_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+}
+
 static void shmem_destroy_inode(struct inode *inode)
 {
 	if ((inode->i_mode & S_IFMT) == S_IFREG) {
 		/* only struct inode is valid if it's an inline symlink */
 		mpol_free_shared_policy(&SHMEM_I(inode)->policy);
 	}
-	kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+	call_rcu(&inode->i_rcu, shmem_i_callback);
 }
 
 static void init_once(void *foo)
diff --git a/net/socket.c b/net/socket.c
index 088fb3fd45e0..97fff3a4e72f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -262,20 +262,20 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 }
 
 
-static void wq_free_rcu(struct rcu_head *head)
+static void sock_free_rcu(struct rcu_head *head)
 {
-	struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct socket_alloc *ei = container_of(inode, struct socket_alloc,
+								vfs_inode);
 
-	kfree(wq);
+	kfree(ei->socket.wq);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(sock_inode_cachep, ei);
 }
 
 static void sock_destroy_inode(struct inode *inode)
 {
-	struct socket_alloc *ei;
-
-	ei = container_of(inode, struct socket_alloc, vfs_inode);
-	call_rcu(&ei->socket.wq->rcu, wq_free_rcu);
-	kmem_cache_free(sock_inode_cachep, ei);
+	call_rcu(&inode->i_rcu, sock_free_rcu);
 }
 
 static void init_once(void *foo)
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index a0dc1a86fcea..2899fe27f880 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -162,11 +162,19 @@ rpc_alloc_inode(struct super_block *sb)
 }
 
 static void
-rpc_destroy_inode(struct inode *inode)
+rpc_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 }
 
+static void
+rpc_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, rpc_i_callback);
+}
+
 static int
 rpc_pipe_open(struct inode *inode, struct file *filp)
 {
-- 
cgit v1.2.3


From fb045adb99d9b7c562dc7fef834857f78249daa1 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:55 +1100
Subject: fs: dcache reduce branches in lookup path

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 arch/ia64/kernel/perfmon.c    |  2 +-
 drivers/staging/autofs/root.c |  2 +-
 drivers/staging/smbfs/dir.c   |  8 ++++----
 fs/9p/vfs_inode.c             | 26 +++++++++++++-------------
 fs/adfs/dir.c                 |  2 +-
 fs/adfs/super.c               |  2 +-
 fs/affs/namei.c               |  2 +-
 fs/affs/super.c               |  2 +-
 fs/afs/dir.c                  |  2 +-
 fs/anon_inodes.c              |  2 +-
 fs/autofs4/inode.c            |  2 +-
 fs/autofs4/root.c             | 10 +++++-----
 fs/btrfs/export.c             |  4 ++--
 fs/btrfs/inode.c              |  2 +-
 fs/ceph/dir.c                 |  6 +++---
 fs/cifs/dir.c                 | 16 ++++++++--------
 fs/cifs/inode.c               |  8 ++++----
 fs/cifs/link.c                |  4 ++--
 fs/cifs/readdir.c             |  4 ++--
 fs/coda/dir.c                 |  2 +-
 fs/configfs/dir.c             |  8 ++++----
 fs/dcache.c                   | 30 ++++++++++++++++++++++++++----
 fs/ecryptfs/inode.c           |  2 +-
 fs/ecryptfs/main.c            |  4 ++--
 fs/fat/inode.c                |  4 ++--
 fs/fat/namei_msdos.c          |  6 +++---
 fs/fat/namei_vfat.c           |  8 ++++----
 fs/fuse/dir.c                 |  2 +-
 fs/fuse/inode.c               |  4 ++--
 fs/gfs2/export.c              |  4 ++--
 fs/gfs2/ops_fstype.c          |  2 +-
 fs/gfs2/ops_inode.c           |  2 +-
 fs/hfs/dir.c                  |  2 +-
 fs/hfs/super.c                |  2 +-
 fs/hfsplus/dir.c              |  2 +-
 fs/hfsplus/super.c            |  2 +-
 fs/hostfs/hostfs_kern.c       |  2 +-
 fs/hpfs/dentry.c              |  2 +-
 fs/isofs/inode.c              |  2 +-
 fs/isofs/namei.c              |  2 +-
 fs/jfs/namei.c                |  4 ++--
 fs/jfs/super.c                |  2 +-
 fs/libfs.c                    |  2 +-
 fs/minix/namei.c              |  2 +-
 fs/namei.c                    | 31 ++++++++++++++++++++-----------
 fs/ncpfs/dir.c                |  4 ++--
 fs/ncpfs/inode.c              |  2 +-
 fs/nfs/dir.c                  |  6 +++---
 fs/nfs/getroot.c              |  4 ++--
 fs/ocfs2/export.c             |  4 ++--
 fs/ocfs2/namei.c              | 10 +++++-----
 fs/pipe.c                     |  2 +-
 fs/proc/base.c                | 12 ++++++------
 fs/proc/generic.c             |  2 +-
 fs/proc/proc_sysctl.c         |  4 ++--
 fs/reiserfs/xattr.c           |  2 +-
 fs/sysfs/dir.c                |  2 +-
 fs/sysv/namei.c               |  2 +-
 fs/sysv/super.c               |  2 +-
 include/linux/dcache.h        |  6 ++++++
 kernel/cgroup.c               |  2 +-
 net/socket.c                  |  2 +-
 net/sunrpc/rpc_pipe.c         |  2 +-
 63 files changed, 174 insertions(+), 137 deletions(-)

(limited to 'fs/cifs')

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index d39d8a53b579..5a24f40bb48e 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2233,7 +2233,7 @@ pfm_alloc_file(pfm_context_t *ctx)
 	}
 	path.mnt = mntget(pfmfs_mnt);
 
-	path.dentry->d_op = &pfmfs_dentry_operations;
+	d_set_d_op(path.dentry, &pfmfs_dentry_operations);
 	d_add(path.dentry, inode);
 
 	file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
diff --git a/drivers/staging/autofs/root.c b/drivers/staging/autofs/root.c
index 0fdec4befd84..b09adb57971f 100644
--- a/drivers/staging/autofs/root.c
+++ b/drivers/staging/autofs/root.c
@@ -237,7 +237,7 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr
 	 *
 	 * We need to do this before we release the directory semaphore.
 	 */
-	dentry->d_op = &autofs_dentry_operations;
+	d_set_d_op(dentry, &autofs_dentry_operations);
 	dentry->d_flags |= DCACHE_AUTOFS_PENDING;
 	d_add(dentry, NULL);
 
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index 5f79799d5d4a..78f09412740c 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -398,9 +398,9 @@ smb_new_dentry(struct dentry *dentry)
 	struct smb_sb_info *server = server_from_dentry(dentry);
 
 	if (server->mnt->flags & SMB_MOUNT_CASE)
-		dentry->d_op = &smbfs_dentry_operations_case;
+		d_set_d_op(dentry, &smbfs_dentry_operations_case);
 	else
-		dentry->d_op = &smbfs_dentry_operations;
+		d_set_d_op(dentry, &smbfs_dentry_operations);
 	dentry->d_time = jiffies;
 }
 
@@ -462,9 +462,9 @@ smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	add_entry:
 			server = server_from_dentry(dentry);
 			if (server->mnt->flags & SMB_MOUNT_CASE)
-				dentry->d_op = &smbfs_dentry_operations_case;
+				d_set_d_op(dentry, &smbfs_dentry_operations_case);
 			else
-				dentry->d_op = &smbfs_dentry_operations;
+				d_set_d_op(dentry, &smbfs_dentry_operations);
 
 			d_add(dentry, inode);
 			smb_renew_times(dentry);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index f6f9081e6d2c..df8bbb358d54 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -635,9 +635,9 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	}
 
 	if (v9ses->cache)
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 	else
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 
 	d_instantiate(dentry, inode);
 	err = v9fs_fid_add(dentry, fid);
@@ -749,7 +749,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
 				err);
 			goto error;
 		}
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 		d_instantiate(dentry, inode);
 		err = v9fs_fid_add(dentry, fid);
 		if (err < 0)
@@ -767,7 +767,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
 			err = PTR_ERR(inode);
 			goto error;
 		}
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 		d_instantiate(dentry, inode);
 	}
 	/* Now set the ACL based on the default value */
@@ -956,7 +956,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 				err);
 			goto error;
 		}
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 		d_instantiate(dentry, inode);
 		err = v9fs_fid_add(dentry, fid);
 		if (err < 0)
@@ -973,7 +973,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 			err = PTR_ERR(inode);
 			goto error;
 		}
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 		d_instantiate(dentry, inode);
 	}
 	/* Now set the ACL based on the default value */
@@ -1041,9 +1041,9 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 
 inst_out:
 	if (v9ses->cache)
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 	else
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 
 	d_add(dentry, inode);
 	return NULL;
@@ -1709,7 +1709,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 					err);
 			goto error;
 		}
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 		d_instantiate(dentry, inode);
 		err = v9fs_fid_add(dentry, fid);
 		if (err < 0)
@@ -1722,7 +1722,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 			err = PTR_ERR(inode);
 			goto error;
 		}
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 		d_instantiate(dentry, inode);
 	}
 
@@ -1856,7 +1856,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
 		ihold(old_dentry->d_inode);
 	}
 
-	dentry->d_op = old_dentry->d_op;
+	d_set_d_op(dentry, old_dentry->d_op);
 	d_instantiate(dentry, old_dentry->d_inode);
 
 	return err;
@@ -1980,7 +1980,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode,
 				err);
 			goto error;
 		}
-		dentry->d_op = &v9fs_cached_dentry_operations;
+		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
 		d_instantiate(dentry, inode);
 		err = v9fs_fid_add(dentry, fid);
 		if (err < 0)
@@ -1996,7 +1996,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode,
 			err = PTR_ERR(inode);
 			goto error;
 		}
-		dentry->d_op = &v9fs_dentry_operations;
+		d_set_d_op(dentry, &v9fs_dentry_operations);
 		d_instantiate(dentry, inode);
 	}
 	/* Now set the ACL based on the default value */
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index a11e5e102716..bf7693c384f9 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -276,7 +276,7 @@ adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	struct object_info obj;
 	int error;
 
-	dentry->d_op = &adfs_dentry_operations;	
+	d_set_d_op(dentry, &adfs_dentry_operations);
 	lock_kernel();
 	error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
 	if (error == 0) {
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 47dffc513a26..a4041b52fbca 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -484,7 +484,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
 		adfs_error(sb, "get root inode failed\n");
 		goto error;
 	} else
-		sb->s_root->d_op = &adfs_dentry_operations;
+		d_set_d_op(sb->s_root, &adfs_dentry_operations);
 	unlock_kernel();
 	return 0;
 
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 5aca08c21100..944a4042fb65 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -240,7 +240,7 @@ affs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 		if (IS_ERR(inode))
 			return ERR_CAST(inode);
 	}
-	dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
+	d_set_d_op(dentry, AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations);
 	d_add(dentry, inode);
 	return NULL;
 }
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 4c18fcfb0a19..d39081bbe7ce 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -482,7 +482,7 @@ got_root:
 		printk(KERN_ERR "AFFS: Get root inode failed\n");
 		goto out_error;
 	}
-	sb->s_root->d_op = &affs_dentry_operations;
+	d_set_d_op(sb->s_root, &affs_dentry_operations);
 
 	pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 	return 0;
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 2c18cde27000..b8bb7e7148d0 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -581,7 +581,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 	}
 
 success:
-	dentry->d_op = &afs_fs_dentry_operations;
+	d_set_d_op(dentry, &afs_fs_dentry_operations);
 
 	d_add(dentry, inode);
 	_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 57ce55b2564c..aca8806fa206 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -113,7 +113,7 @@ struct file *anon_inode_getfile(const char *name,
 	 */
 	ihold(anon_inode_inode);
 
-	path.dentry->d_op = &anon_inodefs_dentry_operations;
+	d_set_d_op(path.dentry, &anon_inodefs_dentry_operations);
 	d_instantiate(path.dentry, anon_inode_inode);
 
 	error = -ENFILE;
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index ac87e49fa706..a7bdb9dcac84 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -309,7 +309,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 		goto fail_iput;
 	pipe = NULL;
 
-	root->d_op = &autofs4_sb_dentry_operations;
+	d_set_d_op(root, &autofs4_sb_dentry_operations);
 	root->d_fsdata = ino;
 
 	/* Can this call block? */
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 10ca68a96dc7..bfe3f2eb684d 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -571,7 +571,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
 		 * we check for the hashed dentry and return the newly
 		 * hashed dentry.
 		 */
-		dentry->d_op = &autofs4_root_dentry_operations;
+		d_set_d_op(dentry, &autofs4_root_dentry_operations);
 
 		/*
 		 * And we need to ensure that the same dentry is used for
@@ -710,9 +710,9 @@ static int autofs4_dir_symlink(struct inode *dir,
 	d_add(dentry, inode);
 
 	if (dir == dir->i_sb->s_root->d_inode)
-		dentry->d_op = &autofs4_root_dentry_operations;
+		d_set_d_op(dentry, &autofs4_root_dentry_operations);
 	else
-		dentry->d_op = &autofs4_dentry_operations;
+		d_set_d_op(dentry, &autofs4_dentry_operations);
 
 	dentry->d_fsdata = ino;
 	ino->dentry = dget(dentry);
@@ -845,9 +845,9 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	d_add(dentry, inode);
 
 	if (dir == dir->i_sb->s_root->d_inode)
-		dentry->d_op = &autofs4_root_dentry_operations;
+		d_set_d_op(dentry, &autofs4_root_dentry_operations);
 	else
-		dentry->d_op = &autofs4_dentry_operations;
+		d_set_d_op(dentry, &autofs4_dentry_operations);
 
 	dentry->d_fsdata = ino;
 	ino->dentry = dget(dentry);
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 659f532d26a0..0ccf9a8afcdf 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -110,7 +110,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 
 	dentry = d_obtain_alias(inode);
 	if (!IS_ERR(dentry))
-		dentry->d_op = &btrfs_dentry_operations;
+		d_set_d_op(dentry, &btrfs_dentry_operations);
 	return dentry;
 fail:
 	srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -225,7 +225,7 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
 	key.offset = 0;
 	dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
 	if (!IS_ERR(dentry))
-		dentry->d_op = &btrfs_dentry_operations;
+		d_set_d_op(dentry, &btrfs_dentry_operations);
 	return dentry;
 fail:
 	btrfs_free_path(path);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f9d2994a42a2..63e4546b478a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4084,7 +4084,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 	int index;
 	int ret;
 
-	dentry->d_op = &btrfs_dentry_operations;
+	d_set_d_op(dentry, &btrfs_dentry_operations);
 
 	if (dentry->d_name.len > BTRFS_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 58abc3da6111..cc01cf826769 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -42,11 +42,11 @@ int ceph_init_dentry(struct dentry *dentry)
 
 	if (dentry->d_parent == NULL ||   /* nfs fh_to_dentry */
 	    ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
-		dentry->d_op = &ceph_dentry_ops;
+		d_set_d_op(dentry, &ceph_dentry_ops);
 	else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
-		dentry->d_op = &ceph_snapdir_dentry_ops;
+		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
 	else
-		dentry->d_op = &ceph_snap_dentry_ops;
+		d_set_d_op(dentry, &ceph_snap_dentry_ops);
 
 	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
 	if (!di)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 88bfe686ac00..e3b10ca6d453 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -135,9 +135,9 @@ static void setup_cifs_dentry(struct cifsTconInfo *tcon,
 			      struct inode *newinode)
 {
 	if (tcon->nocase)
-		direntry->d_op = &cifs_ci_dentry_ops;
+		d_set_d_op(direntry, &cifs_ci_dentry_ops);
 	else
-		direntry->d_op = &cifs_dentry_ops;
+		d_set_d_op(direntry, &cifs_dentry_ops);
 	d_instantiate(direntry, newinode);
 }
 
@@ -421,9 +421,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
 		rc = cifs_get_inode_info_unix(&newinode, full_path,
 						inode->i_sb, xid);
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 
 		if (rc == 0)
 			d_instantiate(direntry, newinode);
@@ -604,9 +604,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 
 	if ((rc == 0) && (newInode != NULL)) {
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_add(direntry, newInode);
 		if (posix_open) {
 			filp = lookup_instantiate_filp(nd, direntry,
@@ -634,9 +634,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 		rc = 0;
 		direntry->d_time = jiffies;
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_add(direntry, NULL);
 	/*	if it was once a directory (but how can we tell?) we could do
 		shrink_dcache_parent(direntry); */
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 99b9a2cc14b7..2a239d878e85 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1319,9 +1319,9 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
 	to set uid/gid */
 			inc_nlink(inode);
 			if (pTcon->nocase)
-				direntry->d_op = &cifs_ci_dentry_ops;
+				d_set_d_op(direntry, &cifs_ci_dentry_ops);
 			else
-				direntry->d_op = &cifs_dentry_ops;
+				d_set_d_op(direntry, &cifs_dentry_ops);
 
 			cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
 			cifs_fill_uniqueid(inode->i_sb, &fattr);
@@ -1363,9 +1363,9 @@ mkdir_get_info:
 						 inode->i_sb, xid, NULL);
 
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_instantiate(direntry, newinode);
 		 /* setting nlink not necessary except in cases where we
 		  * failed to get it from the server or was set bogus */
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 85cdbf831e7b..fe2f6a93c49e 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -525,9 +525,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 			      rc);
 		} else {
 			if (pTcon->nocase)
-				direntry->d_op = &cifs_ci_dentry_ops;
+				d_set_d_op(direntry, &cifs_ci_dentry_ops);
 			else
-				direntry->d_op = &cifs_dentry_ops;
+				d_set_d_op(direntry, &cifs_dentry_ops);
 			d_instantiate(direntry, newinode);
 		}
 	}
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index ee463aeca0b0..ec5b68e3b928 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -103,9 +103,9 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
 	}
 
 	if (cifs_sb_master_tcon(CIFS_SB(sb))->nocase)
-		dentry->d_op = &cifs_ci_dentry_ops;
+		d_set_d_op(dentry, &cifs_ci_dentry_ops);
 	else
-		dentry->d_op = &cifs_dentry_ops;
+		d_set_d_op(dentry, &cifs_dentry_ops);
 
 	alias = d_materialise_unique(dentry, inode);
 	if (alias != NULL) {
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 9e37e8bc9b89..aa40c811f8d2 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -125,7 +125,7 @@ static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struc
 		return ERR_PTR(error);
 
 exit:
-	entry->d_op = &coda_dentry_operations;
+	d_set_d_op(entry, &coda_dentry_operations);
 
 	if (inode && (type & CODA_NOCACHE))
 		coda_flag_inode(inode, C_VATTR | C_PURGE);
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index e9acea440ffc..36637a8c1ed3 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -442,7 +442,7 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
 		return error;
 	}
 
-	dentry->d_op = &configfs_dentry_ops;
+	d_set_d_op(dentry, &configfs_dentry_ops);
 	d_rehash(dentry);
 
 	return 0;
@@ -489,7 +489,7 @@ static struct dentry * configfs_lookup(struct inode *dir,
 		 */
 		if (dentry->d_name.len > NAME_MAX)
 			return ERR_PTR(-ENAMETOOLONG);
-		dentry->d_op = &configfs_dentry_ops;
+		d_set_d_op(dentry, &configfs_dentry_ops);
 		d_add(dentry, NULL);
 		return NULL;
 	}
@@ -683,7 +683,7 @@ static int create_default_group(struct config_group *parent_group,
 	ret = -ENOMEM;
 	child = d_alloc(parent, &name);
 	if (child) {
-		child->d_op = &configfs_dentry_ops;
+		d_set_d_op(child, &configfs_dentry_ops);
 		d_add(child, NULL);
 
 		ret = configfs_attach_group(&parent_group->cg_item,
@@ -1681,7 +1681,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 	err = -ENOMEM;
 	dentry = d_alloc(configfs_sb->s_root, &name);
 	if (dentry) {
-		dentry->d_op = &configfs_dentry_ops;
+		d_set_d_op(dentry, &configfs_dentry_ops);
 		d_add(dentry, NULL);
 
 		err = configfs_attach_group(sd->s_element, &group->cg_item,
diff --git a/fs/dcache.c b/fs/dcache.c
index 1d5cf511e1c7..f9693da3efbd 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -398,7 +398,7 @@ repeat:
 		return;
 	}
 
-	if (dentry->d_op && dentry->d_op->d_delete) {
+	if (dentry->d_flags & DCACHE_OP_DELETE) {
 		if (dentry->d_op->d_delete(dentry))
 			goto kill_it;
 	}
@@ -1301,6 +1301,28 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name)
 }
 EXPORT_SYMBOL(d_alloc_name);
 
+void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
+{
+	BUG_ON(dentry->d_op);
+	BUG_ON(dentry->d_flags & (DCACHE_OP_HASH	|
+				DCACHE_OP_COMPARE	|
+				DCACHE_OP_REVALIDATE	|
+				DCACHE_OP_DELETE ));
+	dentry->d_op = op;
+	if (!op)
+		return;
+	if (op->d_hash)
+		dentry->d_flags |= DCACHE_OP_HASH;
+	if (op->d_compare)
+		dentry->d_flags |= DCACHE_OP_COMPARE;
+	if (op->d_revalidate)
+		dentry->d_flags |= DCACHE_OP_REVALIDATE;
+	if (op->d_delete)
+		dentry->d_flags |= DCACHE_OP_DELETE;
+
+}
+EXPORT_SYMBOL(d_set_d_op);
+
 static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 {
 	spin_lock(&dentry->d_lock);
@@ -1731,7 +1753,7 @@ seqretry:
 		 */
 		if (read_seqcount_retry(&dentry->d_seq, *seq))
 			goto seqretry;
-		if (parent->d_op && parent->d_op->d_compare) {
+		if (parent->d_flags & DCACHE_OP_COMPARE) {
 			if (parent->d_op->d_compare(parent, *inode,
 						dentry, i,
 						tlen, tname, name))
@@ -1846,7 +1868,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
 		 */
 		tlen = dentry->d_name.len;
 		tname = dentry->d_name.name;
-		if (parent->d_op && parent->d_op->d_compare) {
+		if (parent->d_flags & DCACHE_OP_COMPARE) {
 			if (parent->d_op->d_compare(parent, parent->d_inode,
 						dentry, dentry->d_inode,
 						tlen, tname, name))
@@ -1887,7 +1909,7 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
 	 * routine may choose to leave the hash value unchanged.
 	 */
 	name->hash = full_name_hash(name->name, name->len);
-	if (dir->d_op && dir->d_op->d_hash) {
+	if (dir->d_flags & DCACHE_OP_HASH) {
 		if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
 			goto out;
 	}
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5e5c7ec1fc98..f91b35db4c6e 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -441,7 +441,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	struct qstr lower_name;
 	int rc = 0;
 
-	ecryptfs_dentry->d_op = &ecryptfs_dops;
+	d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
 	if ((ecryptfs_dentry->d_name.len == 1
 	     && !strcmp(ecryptfs_dentry->d_name.name, "."))
 	    || (ecryptfs_dentry->d_name.len == 2
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index a9dbd62518e6..351038675376 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -189,7 +189,7 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 	if (special_file(lower_inode->i_mode))
 		init_special_inode(inode, lower_inode->i_mode,
 				   lower_inode->i_rdev);
-	dentry->d_op = &ecryptfs_dops;
+	d_set_d_op(dentry, &ecryptfs_dops);
 	fsstack_copy_attr_all(inode, lower_inode);
 	/* This size will be overwritten for real files w/ headers and
 	 * other metadata */
@@ -594,7 +594,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 		deactivate_locked_super(s);
 		goto out;
 	}
-	s->s_root->d_op = &ecryptfs_dops;
+	d_set_d_op(s->s_root, &ecryptfs_dops);
 	s->s_root->d_sb = s;
 	s->s_root->d_parent = s->s_root;
 
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 8cccfebee180..206351af7c58 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -750,7 +750,7 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
 	 */
 	result = d_obtain_alias(inode);
 	if (!IS_ERR(result))
-		result->d_op = sb->s_root->d_op;
+		d_set_d_op(result, sb->s_root->d_op);
 	return result;
 }
 
@@ -800,7 +800,7 @@ static struct dentry *fat_get_parent(struct dentry *child)
 
 	parent = d_obtain_alias(inode);
 	if (!IS_ERR(parent))
-		parent->d_op = sb->s_root->d_op;
+		d_set_d_op(parent, sb->s_root->d_op);
 out:
 	unlock_super(sb);
 
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 3b3e072d8982..35ffe43afa4b 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -227,10 +227,10 @@ static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 	}
 out:
 	unlock_super(sb);
-	dentry->d_op = &msdos_dentry_operations;
+	d_set_d_op(dentry, &msdos_dentry_operations);
 	dentry = d_splice_alias(inode, dentry);
 	if (dentry)
-		dentry->d_op = &msdos_dentry_operations;
+		d_set_d_op(dentry, &msdos_dentry_operations);
 	return dentry;
 
 error:
@@ -673,7 +673,7 @@ static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	sb->s_flags |= MS_NOATIME;
-	sb->s_root->d_op = &msdos_dentry_operations;
+	d_set_d_op(sb->s_root, &msdos_dentry_operations);
 	unlock_super(sb);
 	return 0;
 }
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 4fc06278db48..3be5ed7d859f 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -766,11 +766,11 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
 
 out:
 	unlock_super(sb);
-	dentry->d_op = sb->s_root->d_op;
+	d_set_d_op(dentry, sb->s_root->d_op);
 	dentry->d_time = dentry->d_parent->d_inode->i_version;
 	dentry = d_splice_alias(inode, dentry);
 	if (dentry) {
-		dentry->d_op = sb->s_root->d_op;
+		d_set_d_op(dentry, sb->s_root->d_op);
 		dentry->d_time = dentry->d_parent->d_inode->i_version;
 	}
 	return dentry;
@@ -1072,9 +1072,9 @@ static int vfat_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	if (MSDOS_SB(sb)->options.name_check != 's')
-		sb->s_root->d_op = &vfat_ci_dentry_ops;
+		d_set_d_op(sb->s_root, &vfat_ci_dentry_ops);
 	else
-		sb->s_root->d_op = &vfat_dentry_ops;
+		d_set_d_op(sb->s_root, &vfat_dentry_ops);
 
 	unlock_super(sb);
 	return 0;
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c9627c95482d..c9a8a426a395 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -347,7 +347,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 	}
 
 	entry = newent ? newent : entry;
-	entry->d_op = &fuse_dentry_operations;
+	d_set_d_op(entry, &fuse_dentry_operations);
 	if (outarg_valid)
 		fuse_change_entry_timeout(entry, &outarg);
 	else
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 44e0a6c57e87..a8b31da19b93 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -626,7 +626,7 @@ static struct dentry *fuse_get_dentry(struct super_block *sb,
 
 	entry = d_obtain_alias(inode);
 	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
-		entry->d_op = &fuse_dentry_operations;
+		d_set_d_op(entry, &fuse_dentry_operations);
 		fuse_invalidate_entry_cache(entry);
 	}
 
@@ -728,7 +728,7 @@ static struct dentry *fuse_get_parent(struct dentry *child)
 
 	parent = d_obtain_alias(inode);
 	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
-		parent->d_op = &fuse_dentry_operations;
+		d_set_d_op(parent, &fuse_dentry_operations);
 		fuse_invalidate_entry_cache(parent);
 	}
 
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
index 5ab3839dfcb9..97012ecff560 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -130,7 +130,7 @@ static struct dentry *gfs2_get_parent(struct dentry *child)
 
 	dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
 	if (!IS_ERR(dentry))
-		dentry->d_op = &gfs2_dops;
+		d_set_d_op(dentry, &gfs2_dops);
 	return dentry;
 }
 
@@ -158,7 +158,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
 out_inode:
 	dentry = d_obtain_alias(inode);
 	if (!IS_ERR(dentry))
-		dentry->d_op = &gfs2_dops;
+		d_set_d_op(dentry, &gfs2_dops);
 	return dentry;
 }
 
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 3eb1393f7b81..2aeabd4218cc 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -440,7 +440,7 @@ static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
 		iput(inode);
 		return -ENOMEM;
 	}
-	dentry->d_op = &gfs2_dops;
+	d_set_d_op(dentry, &gfs2_dops);
 	*dptr = dentry;
 	return 0;
 }
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 12cbea7502c2..f28f89796f4d 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -106,7 +106,7 @@ static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
 {
 	struct inode *inode = NULL;
 
-	dentry->d_op = &gfs2_dops;
+	d_set_d_op(dentry, &gfs2_dops);
 
 	inode = gfs2_lookupi(dir, &dentry->d_name, 0);
 	if (inode && IS_ERR(inode))
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index 2b3b8611b41b..ea4aefe7c652 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -25,7 +25,7 @@ static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
 	struct inode *inode = NULL;
 	int res;
 
-	dentry->d_op = &hfs_dentry_operations;
+	d_set_d_op(dentry, &hfs_dentry_operations);
 
 	hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
 	hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index ef4ee5716abe..0bef62aa4f42 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -434,7 +434,7 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sb->s_root)
 		goto bail_iput;
 
-	sb->s_root->d_op = &hfs_dentry_operations;
+	d_set_d_op(sb->s_root, &hfs_dentry_operations);
 
 	/* everything's okay */
 	return 0;
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 9d59c0571f59..ccab87145f7a 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -37,7 +37,7 @@ static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
 
 	sb = dir->i_sb;
 
-	dentry->d_op = &hfsplus_dentry_operations;
+	d_set_d_op(dentry, &hfsplus_dentry_operations);
 	dentry->d_fsdata = NULL;
 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 182e83a9079e..ddf712e4700e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -419,7 +419,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 		err = -ENOMEM;
 		goto cleanup;
 	}
-	sb->s_root->d_op = &hfsplus_dentry_operations;
+	d_set_d_op(sb->s_root, &hfsplus_dentry_operations);
 
 	str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
 	str.name = HFSP_HIDDENDIR_NAME;
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 861113fcfc88..0bc81cf256b8 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -612,7 +612,7 @@ struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
 		goto out_put;
 
 	d_add(dentry, inode);
-	dentry->d_op = &hostfs_dentry_ops;
+	d_set_d_op(dentry, &hostfs_dentry_ops);
 	return NULL;
 
  out_put:
diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c
index 35526df1fd32..32c13a94e1e9 100644
--- a/fs/hpfs/dentry.c
+++ b/fs/hpfs/dentry.c
@@ -65,5 +65,5 @@ static const struct dentry_operations hpfs_dentry_operations = {
 
 void hpfs_set_dentry_operations(struct dentry *dentry)
 {
-	dentry->d_op = &hpfs_dentry_operations;
+	d_set_d_op(dentry, &hpfs_dentry_operations);
 }
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d8f3a652243d..844a7903c72f 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -949,7 +949,7 @@ root_found:
 		table += 2;
 	if (opt.check == 'r')
 		table++;
-	s->s_root->d_op = &isofs_dentry_ops[table];
+	d_set_d_op(s->s_root, &isofs_dentry_ops[table]);
 
 	kfree(opt.iocharset);
 
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c
index 715f7d318046..679a849c3b27 100644
--- a/fs/isofs/namei.c
+++ b/fs/isofs/namei.c
@@ -172,7 +172,7 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam
 	struct inode *inode;
 	struct page *page;
 
-	dentry->d_op = dir->i_sb->s_root->d_op;
+	d_set_d_op(dentry, dir->i_sb->s_root->d_op);
 
 	page = alloc_page(GFP_USER);
 	if (!page)
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 57f90dad8919..a151cbdec626 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1466,7 +1466,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
 	jfs_info("jfs_lookup: name = %s", name);
 
 	if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
-		dentry->d_op = &jfs_ci_dentry_operations;
+		d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
 	if ((name[0] == '.') && (len == 1))
 		inum = dip->i_ino;
@@ -1495,7 +1495,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
 	dentry = d_splice_alias(ip, dentry);
 
 	if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
-		dentry->d_op = &jfs_ci_dentry_operations;
+		d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
 	return dentry;
 }
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index b715b0f7bdfd..3150d766e0d4 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -525,7 +525,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 		goto out_no_root;
 
 	if (sbi->mntflag & JFS_OS2)
-		sb->s_root->d_op = &jfs_ci_dentry_operations;
+		d_set_d_op(sb->s_root, &jfs_ci_dentry_operations);
 
 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
diff --git a/fs/libfs.c b/fs/libfs.c
index 28b36663c44e..889311e3d06b 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -59,7 +59,7 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct na
 
 	if (dentry->d_name.len > NAME_MAX)
 		return ERR_PTR(-ENAMETOOLONG);
-	dentry->d_op = &simple_dentry_operations;
+	d_set_d_op(dentry, &simple_dentry_operations);
 	d_add(dentry, NULL);
 	return NULL;
 }
diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index c0d35a3accef..1b9e07728a9f 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -23,7 +23,7 @@ static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, st
 	struct inode * inode = NULL;
 	ino_t ino;
 
-	dentry->d_op = dir->i_sb->s_root->d_op;
+	d_set_d_op(dentry, dir->i_sb->s_root->d_op);
 
 	if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
 		return ERR_PTR(-ENAMETOOLONG);
diff --git a/fs/namei.c b/fs/namei.c
index c731b50a6184..90bd2873e117 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -587,6 +587,17 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
 	return dentry;
 }
 
+static inline int need_reval_dot(struct dentry *dentry)
+{
+	if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
+		return 0;
+
+	if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)))
+		return 0;
+
+	return 1;
+}
+
 /*
  * force_reval_path - force revalidation of a dentry
  *
@@ -610,10 +621,9 @@ force_reval_path(struct path *path, struct nameidata *nd)
 
 	/*
 	 * only check on filesystems where it's possible for the dentry to
-	 * become stale. It's assumed that if this flag is set then the
-	 * d_revalidate op will also be defined.
+	 * become stale.
 	 */
-	if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))
+	if (!need_reval_dot(dentry))
 		return 0;
 
 	status = dentry->d_op->d_revalidate(dentry, nd);
@@ -1003,7 +1013,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 	 * See if the low-level filesystem might want
 	 * to use its own hash..
 	 */
-	if (parent->d_op && parent->d_op->d_hash) {
+	if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
 		int err = parent->d_op->d_hash(parent, nd->inode, name);
 		if (err < 0)
 			return err;
@@ -1029,7 +1039,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 			return -ECHILD;
 
 		nd->seq = seq;
-		if (dentry->d_op && dentry->d_op->d_revalidate) {
+		if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
 			/* We commonly drop rcu-walk here */
 			if (nameidata_dentry_drop_rcu(nd, dentry))
 				return -ECHILD;
@@ -1043,7 +1053,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 		if (!dentry)
 			goto need_lookup;
 found:
-		if (dentry->d_op && dentry->d_op->d_revalidate)
+		if (dentry->d_flags & DCACHE_OP_REVALIDATE)
 			goto need_revalidate;
 done:
 		path->mnt = mnt;
@@ -1281,8 +1291,7 @@ return_reval:
 		 * We bypassed the ordinary revalidation routines.
 		 * We may need to check the cached dentry for staleness.
 		 */
-		if (nd->path.dentry && nd->path.dentry->d_sb &&
-		    (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) {
+		if (need_reval_dot(nd->path.dentry)) {
 			if (nameidata_drop_rcu_maybe(nd))
 				return -ECHILD;
 			err = -ESTALE;
@@ -1602,7 +1611,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 	 * See if the low-level filesystem might want
 	 * to use its own hash..
 	 */
-	if (base->d_op && base->d_op->d_hash) {
+	if (base->d_flags & DCACHE_OP_HASH) {
 		err = base->d_op->d_hash(base, inode, name);
 		dentry = ERR_PTR(err);
 		if (err < 0)
@@ -1616,7 +1625,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 	 */
 	dentry = d_lookup(base, name);
 
-	if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+	if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE))
 		dentry = do_revalidate(dentry, nd);
 
 	if (!dentry)
@@ -2070,7 +2079,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 		follow_dotdot(nd);
 		dir = nd->path.dentry;
 	case LAST_DOT:
-		if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
+		if (need_reval_dot(dir)) {
 			if (!dir->d_op->d_revalidate(dir, nd)) {
 				error = -ESTALE;
 				goto exit;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 0ba3cdc95a44..4b9cbb28d7fa 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -633,7 +633,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
 		entry->ino = iunique(dir->i_sb, 2);
 		inode = ncp_iget(dir->i_sb, entry);
 		if (inode) {
-			newdent->d_op = &ncp_dentry_operations;
+			d_set_d_op(newdent, &ncp_dentry_operations);
 			d_instantiate(newdent, inode);
 			if (!hashed)
 				d_rehash(newdent);
@@ -889,7 +889,7 @@ static struct dentry *ncp_lookup(struct inode *dir, struct dentry *dentry, struc
 	if (inode) {
 		ncp_new_dentry(dentry);
 add_entry:
-		dentry->d_op = &ncp_dentry_operations;
+		d_set_d_op(dentry, &ncp_dentry_operations);
 		d_add(dentry, inode);
 		error = 0;
 	}
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 60047dbeb38d..0c75a5f3cafd 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -717,7 +717,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 	sb->s_root = d_alloc_root(root_inode);
         if (!sb->s_root)
 		goto out_no_root;
-	sb->s_root->d_op = &ncp_root_dentry_operations;
+	d_set_d_op(sb->s_root, &ncp_root_dentry_operations);
 	return 0;
 
 out_no_root:
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index eb77471b8823..37e0a8bb077e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -438,7 +438,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 	if (dentry == NULL)
 		return;
 
-	dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+	d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
 	inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
 	if (IS_ERR(inode))
 		goto out;
@@ -1188,7 +1188,7 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
 	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
 		goto out;
 
-	dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+	d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
 
 	/*
 	 * If we're doing an exclusive create, optimize away the lookup
@@ -1333,7 +1333,7 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry
 		res = ERR_PTR(-ENAMETOOLONG);
 		goto out;
 	}
-	dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+	d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
 
 	/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
 	 * the dentry. */
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index b3e36c3430de..c3a5a1126833 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -121,7 +121,7 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 	security_d_instantiate(ret, inode);
 
 	if (ret->d_op == NULL)
-		ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+		d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
 out:
 	nfs_free_fattr(fsinfo.fattr);
 	return ret;
@@ -228,7 +228,7 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 	security_d_instantiate(ret, inode);
 
 	if (ret->d_op == NULL)
-		ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+		d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
 
 out:
 	nfs_free_fattr(fattr);
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
index 19ad145d2af3..6adafa576065 100644
--- a/fs/ocfs2/export.c
+++ b/fs/ocfs2/export.c
@@ -138,7 +138,7 @@ check_gen:
 
 	result = d_obtain_alias(inode);
 	if (!IS_ERR(result))
-		result->d_op = &ocfs2_dentry_ops;
+		d_set_d_op(result, &ocfs2_dentry_ops);
 	else
 		mlog_errno(PTR_ERR(result));
 
@@ -176,7 +176,7 @@ static struct dentry *ocfs2_get_parent(struct dentry *child)
 
 	parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
 	if (!IS_ERR(parent))
-		parent->d_op = &ocfs2_dentry_ops;
+		d_set_d_op(parent, &ocfs2_dentry_ops);
 
 bail_unlock:
 	ocfs2_inode_unlock(dir, 0);
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index ff5744e1e36f..d14cad6e2e41 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -147,7 +147,7 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry,
 	spin_unlock(&oi->ip_lock);
 
 bail_add:
-	dentry->d_op = &ocfs2_dentry_ops;
+	d_set_d_op(dentry, &ocfs2_dentry_ops);
 	ret = d_splice_alias(inode, dentry);
 
 	if (inode) {
@@ -415,7 +415,7 @@ static int ocfs2_mknod(struct inode *dir,
 		mlog_errno(status);
 		goto leave;
 	}
-	dentry->d_op = &ocfs2_dentry_ops;
+	d_set_d_op(dentry, &ocfs2_dentry_ops);
 
 	status = ocfs2_add_entry(handle, dentry, inode,
 				 OCFS2_I(inode)->ip_blkno, parent_fe_bh,
@@ -743,7 +743,7 @@ static int ocfs2_link(struct dentry *old_dentry,
 	}
 
 	ihold(inode);
-	dentry->d_op = &ocfs2_dentry_ops;
+	d_set_d_op(dentry, &ocfs2_dentry_ops);
 	d_instantiate(dentry, inode);
 
 out_commit:
@@ -1794,7 +1794,7 @@ static int ocfs2_symlink(struct inode *dir,
 		mlog_errno(status);
 		goto bail;
 	}
-	dentry->d_op = &ocfs2_dentry_ops;
+	d_set_d_op(dentry, &ocfs2_dentry_ops);
 
 	status = ocfs2_add_entry(handle, dentry, inode,
 				 le64_to_cpu(fe->i_blkno), parent_fe_bh,
@@ -2459,7 +2459,7 @@ int ocfs2_mv_orphaned_inode_to_new(struct inode *dir,
 		goto out_commit;
 	}
 
-	dentry->d_op = &ocfs2_dentry_ops;
+	d_set_d_op(dentry, &ocfs2_dentry_ops);
 	d_instantiate(dentry, inode);
 	status = 0;
 out_commit:
diff --git a/fs/pipe.c b/fs/pipe.c
index ae3592dcc88c..01a786567810 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1004,7 +1004,7 @@ struct file *create_write_pipe(int flags)
 		goto err_inode;
 	path.mnt = mntget(pipe_mnt);
 
-	path.dentry->d_op = &pipefs_dentry_operations;
+	d_set_d_op(path.dentry, &pipefs_dentry_operations);
 	d_instantiate(path.dentry, inode);
 
 	err = -ENFILE;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d932fdb6a245..85f0a80912aa 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1969,7 +1969,7 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
 	inode->i_op = &proc_pid_link_inode_operations;
 	inode->i_size = 64;
 	ei->op.proc_get_link = proc_fd_link;
-	dentry->d_op = &tid_fd_dentry_operations;
+	d_set_d_op(dentry, &tid_fd_dentry_operations);
 	d_add(dentry, inode);
 	/* Close the race of the process dying before we return the dentry */
 	if (tid_fd_revalidate(dentry, NULL))
@@ -2137,7 +2137,7 @@ static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
 	ei->fd = fd;
 	inode->i_mode = S_IFREG | S_IRUSR;
 	inode->i_fop = &proc_fdinfo_file_operations;
-	dentry->d_op = &tid_fd_dentry_operations;
+	d_set_d_op(dentry, &tid_fd_dentry_operations);
 	d_add(dentry, inode);
 	/* Close the race of the process dying before we return the dentry */
 	if (tid_fd_revalidate(dentry, NULL))
@@ -2196,7 +2196,7 @@ static struct dentry *proc_pident_instantiate(struct inode *dir,
 	if (p->fop)
 		inode->i_fop = p->fop;
 	ei->op = p->op;
-	dentry->d_op = &pid_dentry_operations;
+	d_set_d_op(dentry, &pid_dentry_operations);
 	d_add(dentry, inode);
 	/* Close the race of the process dying before we return the dentry */
 	if (pid_revalidate(dentry, NULL))
@@ -2615,7 +2615,7 @@ static struct dentry *proc_base_instantiate(struct inode *dir,
 	if (p->fop)
 		inode->i_fop = p->fop;
 	ei->op = p->op;
-	dentry->d_op = &proc_base_dentry_operations;
+	d_set_d_op(dentry, &proc_base_dentry_operations);
 	d_add(dentry, inode);
 	error = NULL;
 out:
@@ -2926,7 +2926,7 @@ static struct dentry *proc_pid_instantiate(struct inode *dir,
 	inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
 		ARRAY_SIZE(tgid_base_stuff));
 
-	dentry->d_op = &pid_dentry_operations;
+	d_set_d_op(dentry, &pid_dentry_operations);
 
 	d_add(dentry, inode);
 	/* Close the race of the process dying before we return the dentry */
@@ -3169,7 +3169,7 @@ static struct dentry *proc_task_instantiate(struct inode *dir,
 	inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
 		ARRAY_SIZE(tid_base_stuff));
 
-	dentry->d_op = &pid_dentry_operations;
+	d_set_d_op(dentry, &pid_dentry_operations);
 
 	d_add(dentry, inode);
 	/* Close the race of the process dying before we return the dentry */
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 1d607be36d95..f766be29d2c7 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -439,7 +439,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
 out_unlock:
 
 	if (inode) {
-		dentry->d_op = &proc_dentry_operations;
+		d_set_d_op(dentry, &proc_dentry_operations);
 		d_add(dentry, inode);
 		return NULL;
 	}
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 998e3a715bcc..35efd85a4d32 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -120,7 +120,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 		goto out;
 
 	err = NULL;
-	dentry->d_op = &proc_sys_dentry_operations;
+	d_set_d_op(dentry, &proc_sys_dentry_operations);
 	d_add(dentry, inode);
 
 out:
@@ -201,7 +201,7 @@ static int proc_sys_fill_cache(struct file *filp, void *dirent,
 				dput(child);
 				return -ENOMEM;
 			} else {
-				child->d_op = &proc_sys_dentry_operations;
+				d_set_d_op(child, &proc_sys_dentry_operations);
 				d_add(child, inode);
 			}
 		} else {
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 5d04a7828e7a..e0f0d7ea10a1 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -990,7 +990,7 @@ int reiserfs_lookup_privroot(struct super_block *s)
 				strlen(PRIVROOT_NAME));
 	if (!IS_ERR(dentry)) {
 		REISERFS_SB(s)->priv_root = dentry;
-		dentry->d_op = &xattr_lookup_poison_ops;
+		d_set_d_op(dentry, &xattr_lookup_poison_ops);
 		if (dentry->d_inode)
 			dentry->d_inode->i_flags |= S_PRIVATE;
 	} else
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 27e1102e303e..3e076caa8daf 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -701,7 +701,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 	/* instantiate and hash dentry */
 	ret = d_find_alias(inode);
 	if (!ret) {
-		dentry->d_op = &sysfs_dentry_ops;
+		d_set_d_op(dentry, &sysfs_dentry_ops);
 		dentry->d_fsdata = sysfs_get(sd);
 		d_add(dentry, inode);
 	} else {
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index 7507aeb4c90e..b5e68da2db32 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -48,7 +48,7 @@ static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, st
 	struct inode * inode = NULL;
 	ino_t ino;
 
-	dentry->d_op = dir->i_sb->s_root->d_op;
+	d_set_d_op(dentry, dir->i_sb->s_root->d_op);
 	if (dentry->d_name.len > SYSV_NAMELEN)
 		return ERR_PTR(-ENAMETOOLONG);
 	ino = sysv_inode_by_name(dentry);
diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index 3d9c62be0c10..76712aefc4ab 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -346,7 +346,7 @@ static int complete_read_super(struct super_block *sb, int silent, int size)
 	if (sbi->s_forced_ro)
 		sb->s_flags |= MS_RDONLY;
 	if (sbi->s_truncate)
-		sb->s_root->d_op = &sysv_dentry_operations;
+		d_set_d_op(sb->s_root, &sysv_dentry_operations);
 	return 1;
 }
 
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index e4414693065e..f4b40a751f09 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -183,6 +183,11 @@ struct dentry_operations {
 #define DCACHE_GENOCIDE		0x0200
 #define DCACHE_MOUNTED		0x0400	/* is a mountpoint */
 
+#define DCACHE_OP_HASH		0x1000
+#define DCACHE_OP_COMPARE	0x2000
+#define DCACHE_OP_REVALIDATE	0x4000
+#define DCACHE_OP_DELETE	0x8000
+
 
 extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
@@ -201,6 +206,7 @@ extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
 extern void __d_drop(struct dentry *dentry);
 extern void d_drop(struct dentry *dentry);
 extern void d_delete(struct dentry *);
+extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
 
 /* allocate/de-allocate */
 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 9f41470c3949..51cddc11cd85 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2222,7 +2222,7 @@ static struct dentry *cgroup_lookup(struct inode *dir,
 
 	if (dentry->d_name.len > NAME_MAX)
 		return ERR_PTR(-ENAMETOOLONG);
-	dentry->d_op = &cgroup_dentry_operations;
+	d_set_d_op(dentry, &cgroup_dentry_operations);
 	d_add(dentry, NULL);
 	return NULL;
 }
diff --git a/net/socket.c b/net/socket.c
index 817dc92e9ef8..991e266bc7ae 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -368,7 +368,7 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
 	}
 	path.mnt = mntget(sock_mnt);
 
-	path.dentry->d_op = &sockfs_dentry_operations;
+	d_set_d_op(path.dentry, &sockfs_dentry_operations);
 	d_instantiate(path.dentry, SOCK_INODE(sock));
 	SOCK_INODE(sock)->i_fop = &socket_file_ops;
 
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 2899fe27f880..09f01f41e55a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -591,7 +591,7 @@ static struct dentry *__rpc_lookup_create(struct dentry *parent,
 		}
 	}
 	if (!dentry->d_inode)
-		dentry->d_op = &rpc_dentry_operations;
+		d_set_d_op(dentry, &rpc_dentry_operations);
 out_err:
 	return dentry;
 }
-- 
cgit v1.2.3


From 34286d6662308d82aed891852d04c7c3a2649b16 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:57 +1100
Subject: fs: rcu-walk aware d_revalidate method

Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/Locking         | 18 +++++------
 Documentation/filesystems/path-lookup.txt |  5 ++-
 Documentation/filesystems/porting         | 20 ++++++++++++
 Documentation/filesystems/vfs.txt         |  9 ++++++
 drivers/staging/autofs/root.c             |  5 ++-
 drivers/staging/smbfs/dir.c               | 16 ++++++---
 fs/afs/dir.c                              |  4 +++
 fs/autofs4/root.c                         | 13 ++++++--
 fs/ceph/dir.c                             |  7 +++-
 fs/cifs/dir.c                             |  3 ++
 fs/coda/dir.c                             |  7 +++-
 fs/ecryptfs/dentry.c                      |  9 ++++--
 fs/fat/namei_vfat.c                       |  6 ++++
 fs/fuse/dir.c                             |  6 +++-
 fs/gfs2/dentry.c                          | 17 +++++++---
 fs/hfs/sysdep.c                           |  7 +++-
 fs/jfs/namei.c                            |  2 ++
 fs/namei.c                                | 54 ++++++++++++++++++++-----------
 fs/ncpfs/dir.c                            |  4 +++
 fs/ncpfs/inode.c                          |  1 +
 fs/nfs/dir.c                              |  8 +++--
 fs/ocfs2/dcache.c                         | 10 ++++--
 fs/proc/base.c                            | 33 +++++++++++++++----
 fs/proc/proc_sysctl.c                     |  3 ++
 fs/reiserfs/xattr.c                       |  2 ++
 fs/sysfs/dir.c                            |  6 +++-
 include/linux/dcache.h                    |  1 -
 27 files changed, 215 insertions(+), 61 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index bdad6414dfa0..e90ffe61eb65 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -9,7 +9,7 @@ be able to use diff(1).
 
 --------------------------- dentry_operations --------------------------
 prototypes:
-	int (*d_revalidate)(struct dentry *, int);
+	int (*d_revalidate)(struct dentry *, struct nameidata *);
 	int (*d_hash)(const struct dentry *, const struct inode *,
 			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
@@ -21,14 +21,14 @@ prototypes:
 	char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
 
 locking rules:
-		rename_lock	->d_lock	may block
-d_revalidate:	no		no		yes
-d_hash		no		no		no
-d_compare:	yes		no		no
-d_delete:	no		yes		no
-d_release:	no		no		yes
-d_iput:		no		no		yes
-d_dname:	no		no		no
+		rename_lock	->d_lock	may block	rcu-walk
+d_revalidate:	no		no		yes (ref-walk)	maybe
+d_hash		no		no		no		maybe
+d_compare:	yes		no		no		maybe
+d_delete:	no		yes		no		no
+d_release:	no		no		yes		no
+d_iput:		no		no		yes		no
+d_dname:	no		no		no		no
 
 --------------------------- inode_operations --------------------------- 
 prototypes:
diff --git a/Documentation/filesystems/path-lookup.txt b/Documentation/filesystems/path-lookup.txt
index 09b2878724a1..8789d1810bed 100644
--- a/Documentation/filesystems/path-lookup.txt
+++ b/Documentation/filesystems/path-lookup.txt
@@ -317,11 +317,10 @@ The detailed design for rcu-walk is like this:
 The cases where rcu-walk cannot continue are:
 * NULL dentry (ie. any uncached path element)
 * parent with d_inode->i_op->permission or ACLs
-* dentries with d_revalidate
 * Following links
 
-In future patches, permission checks and d_revalidate become rcu-walk aware. It
-may be possible eventually to make following links rcu-walk aware.
+In future patches, permission checks become rcu-walk aware. It may be possible
+eventually to make following links rcu-walk aware.
 
 Uncached path elements will always require dropping to ref-walk mode, at the
 very least because i_mutex needs to be grabbed, and objects allocated.
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index ccf0ce7866b9..cd9756a2709d 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -360,3 +360,23 @@ i_dentry to be reinitialized before it is freed, so an:
   INIT_LIST_HEAD(&inode->i_dentry);
 
 must be done in the RCU callback.
+
+--
+[recommended]
+	vfs now tries to do path walking in "rcu-walk mode", which avoids
+atomic operations and scalability hazards on dentries and inodes (see
+Documentation/filesystems/path-walk.txt). d_hash and d_compare changes (above)
+are examples of the changes required to support this. For more complex
+filesystem callbacks, the vfs drops out of rcu-walk mode before the fs call, so
+no changes are required to the filesystem. However, this is costly and loses
+the benefits of rcu-walk mode. We will begin to add filesystem callbacks that
+are rcu-walk aware, shown below. Filesystems should take advantage of this
+where possible.
+
+--
+[mandatory]
+	d_revalidate is a callback that is made on every path element (if
+the filesystem provides it), which requires dropping out of rcu-walk mode. This
+may now be called in rcu-walk mode (nd->flags & LOOKUP_RCU). -ECHILD should be
+returned if the filesystem cannot handle rcu-walk. See
+Documentation/filesystems/vfs.txt for more details.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 69b10ff5ec81..c936b4912383 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -863,6 +863,15 @@ struct dentry_operations {
 	dcache. Most filesystems leave this as NULL, because all their
 	dentries in the dcache are valid
 
+	d_revalidate may be called in rcu-walk mode (nd->flags & LOOKUP_RCU).
+	If in rcu-walk mode, the filesystem must revalidate the dentry without
+	blocking or storing to the dentry, d_parent and d_inode should not be
+	used without care (because they can go NULL), instead nd->inode should
+	be used.
+
+	If a situation is encountered that rcu-walk cannot handle, return
+	-ECHILD and it will be called again in ref-walk mode.
+
   d_hash: called when the VFS adds a dentry to the hash table. The first
 	dentry passed to d_hash is the parent directory that the name is
 	to be hashed into. The inode is the dentry's inode.
diff --git a/drivers/staging/autofs/root.c b/drivers/staging/autofs/root.c
index b09adb57971f..bf0e9755da67 100644
--- a/drivers/staging/autofs/root.c
+++ b/drivers/staging/autofs/root.c
@@ -154,13 +154,16 @@ static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, str
  * yet completely filled in, and revalidate has to delay such
  * lookups..
  */
-static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int autofs_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode * dir;
 	struct autofs_sb_info *sbi;
 	struct autofs_dir_ent *ent;
 	int res;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	lock_kernel();
 	dir = dentry->d_parent->d_inode;
 	sbi = autofs_sbi(dir->i_sb);
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index 78f09412740c..dd612f50749f 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -14,6 +14,7 @@
 #include <linux/ctype.h>
 #include <linux/net.h>
 #include <linux/sched.h>
+#include <linux/namei.h>
 
 #include "smb_fs.h"
 #include "smb_mount.h"
@@ -301,13 +302,20 @@ static const struct dentry_operations smbfs_dentry_operations_case =
  * This is the callback when the dcache has a lookup hit.
  */
 static int
-smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
+smb_lookup_validate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct smb_sb_info *server = server_from_dentry(dentry);
-	struct inode * inode = dentry->d_inode;
-	unsigned long age = jiffies - dentry->d_time;
+	struct smb_sb_info *server;
+	struct inode *inode;
+	unsigned long age;
 	int valid;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	server = server_from_dentry(dentry);
+	inode = dentry->d_inode;
+	age = jiffies - dentry->d_time;
+
 	/*
 	 * The default validation is based on dentry age:
 	 * we believe in dentries for a few seconds.  (But each
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index b8bb7e7148d0..34a3263d60a4 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/fs.h>
+#include <linux/namei.h>
 #include <linux/pagemap.h>
 #include <linux/ctype.h>
 #include <linux/sched.h>
@@ -607,6 +608,9 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 	void *dir_version;
 	int ret;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	vnode = AFS_FS_I(dentry->d_inode);
 
 	if (dentry->d_inode)
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index bfe3f2eb684d..651e4ef563b1 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -315,12 +315,19 @@ out_error:
  */
 static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *dir = dentry->d_parent->d_inode;
-	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
-	int oz_mode = autofs4_oz_mode(sbi);
+	struct inode *dir;
+	struct autofs_sb_info *sbi;
+	int oz_mode;
 	int flags = nd ? nd->flags : 0;
 	int status = 1;
 
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	dir = dentry->d_parent->d_inode;
+	sbi = autofs4_sbi(dir->i_sb);
+	oz_mode = autofs4_oz_mode(sbi);
+
 	/* Pending dentry */
 	spin_lock(&sbi->fs_lock);
 	if (autofs4_ispending(dentry)) {
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index cc01cf826769..fa7ca04ee816 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -990,7 +990,12 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
  */
 static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *dir = dentry->d_parent->d_inode;
+	struct inode *dir;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	dir = dentry->d_parent->d_inode;
 
 	dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
 	     dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index e3b10ca6d453..db2a58c00f7b 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -656,6 +656,9 @@ lookup_out:
 static int
 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	if (direntry->d_inode) {
 		if (cifs_revalidate_dentry(direntry))
 			return 0;
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index aa40c811f8d2..619a8303766e 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -18,6 +18,7 @@
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/spinlock.h>
+#include <linux/namei.h>
 
 #include <asm/uaccess.h>
 
@@ -541,9 +542,13 @@ out:
 /* called when a cache lookup succeeds */
 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
 {
-	struct inode *inode = de->d_inode;
+	struct inode *inode;
 	struct coda_inode_info *cii;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = de->d_inode;
 	if (!inode || coda_isroot(inode))
 		goto out;
 	if (is_bad_inode(inode))
diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index 906e803f7f79..6fc4f319b550 100644
--- a/fs/ecryptfs/dentry.c
+++ b/fs/ecryptfs/dentry.c
@@ -44,12 +44,17 @@
  */
 static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+	struct dentry *lower_dentry;
+	struct vfsmount *lower_mnt;
 	struct dentry *dentry_save;
 	struct vfsmount *vfsmount_save;
 	int rc = 1;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
 	if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
 		goto out;
 	dentry_save = nd->path.dentry;
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 3be5ed7d859f..e3ffc5e12332 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -43,6 +43,9 @@ static int vfat_revalidate_shortname(struct dentry *dentry)
 
 static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	/* This is not negative dentry. Always valid. */
 	if (dentry->d_inode)
 		return 1;
@@ -51,6 +54,9 @@ static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
 
 static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	/*
 	 * This is not negative dentry. Always valid.
 	 *
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c9a8a426a395..07f4b5e675fc 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -156,8 +156,12 @@ u64 fuse_get_attr_version(struct fuse_conn *fc)
  */
 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
 {
-	struct inode *inode = entry->d_inode;
+	struct inode *inode;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
 
+	inode = entry->d_inode;
 	if (inode && is_bad_inode(inode))
 		return 0;
 	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c
index 50497f65763b..4a456338b873 100644
--- a/fs/gfs2/dentry.c
+++ b/fs/gfs2/dentry.c
@@ -11,6 +11,7 @@
 #include <linux/completion.h>
 #include <linux/buffer_head.h>
 #include <linux/gfs2_ondisk.h>
+#include <linux/namei.h>
 #include <linux/crc32.h>
 
 #include "gfs2.h"
@@ -34,15 +35,23 @@
 
 static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct dentry *parent = dget_parent(dentry);
-	struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
-	struct gfs2_inode *dip = GFS2_I(parent->d_inode);
-	struct inode *inode = dentry->d_inode;
+	struct dentry *parent;
+	struct gfs2_sbd *sdp;
+	struct gfs2_inode *dip;
+	struct inode *inode;
 	struct gfs2_holder d_gh;
 	struct gfs2_inode *ip = NULL;
 	int error;
 	int had_lock = 0;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	parent = dget_parent(dentry);
+	sdp = GFS2_SB(parent->d_inode);
+	dip = GFS2_I(parent->d_inode);
+	inode = dentry->d_inode;
+
 	if (inode) {
 		if (is_bad_inode(inode))
 			goto invalid;
diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
index 7478f5c219aa..19cf291eb91f 100644
--- a/fs/hfs/sysdep.c
+++ b/fs/hfs/sysdep.c
@@ -8,15 +8,20 @@
  * This file contains the code to do various system dependent things.
  */
 
+#include <linux/namei.h>
 #include "hfs_fs.h"
 
 /* dentry case-handling: just lowercase everything */
 
 static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode;
 	int diff;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
 	if(!inode)
 		return 1;
 
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index a151cbdec626..4414e3a42264 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1608,6 +1608,8 @@ out:
 
 static int jfs_ci_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
 	/*
 	 * This is not negative dentry. Always valid.
 	 *
diff --git a/fs/namei.c b/fs/namei.c
index 90bd2873e117..6e275363e89d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -563,10 +563,26 @@ void release_open_intent(struct nameidata *nd)
 		fput(nd->intent.open.file);
 }
 
+static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	int status;
+
+	status = dentry->d_op->d_revalidate(dentry, nd);
+	if (status == -ECHILD) {
+		if (nameidata_dentry_drop_rcu(nd, dentry))
+			return status;
+		status = dentry->d_op->d_revalidate(dentry, nd);
+	}
+
+	return status;
+}
+
 static inline struct dentry *
 do_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	int status = dentry->d_op->d_revalidate(dentry, nd);
+	int status;
+
+	status = d_revalidate(dentry, nd);
 	if (unlikely(status <= 0)) {
 		/*
 		 * The dentry failed validation.
@@ -574,14 +590,20 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
 		 * the dentry otherwise d_revalidate is asking us
 		 * to return a fail status.
 		 */
-		if (!status) {
+		if (status < 0) {
+			/* If we're in rcu-walk, we don't have a ref */
+			if (!(nd->flags & LOOKUP_RCU))
+				dput(dentry);
+			dentry = ERR_PTR(status);
+
+		} else {
+			/* Don't d_invalidate in rcu-walk mode */
+			if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
+				return ERR_PTR(-ECHILD);
 			if (!d_invalidate(dentry)) {
 				dput(dentry);
 				dentry = NULL;
 			}
-		} else {
-			dput(dentry);
-			dentry = ERR_PTR(status);
 		}
 	}
 	return dentry;
@@ -626,7 +648,7 @@ force_reval_path(struct path *path, struct nameidata *nd)
 	if (!need_reval_dot(dentry))
 		return 0;
 
-	status = dentry->d_op->d_revalidate(dentry, nd);
+	status = d_revalidate(dentry, nd);
 	if (status > 0)
 		return 0;
 
@@ -1039,12 +1061,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 			return -ECHILD;
 
 		nd->seq = seq;
-		if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
-			/* We commonly drop rcu-walk here */
-			if (nameidata_dentry_drop_rcu(nd, dentry))
-				return -ECHILD;
+		if (dentry->d_flags & DCACHE_OP_REVALIDATE)
 			goto need_revalidate;
-		}
 		path->mnt = mnt;
 		path->dentry = dentry;
 		__follow_mount_rcu(nd, path, inode);
@@ -1292,12 +1310,11 @@ return_reval:
 		 * We may need to check the cached dentry for staleness.
 		 */
 		if (need_reval_dot(nd->path.dentry)) {
-			if (nameidata_drop_rcu_maybe(nd))
-				return -ECHILD;
-			err = -ESTALE;
 			/* Note: we do not d_invalidate() */
-			if (!nd->path.dentry->d_op->d_revalidate(
-					nd->path.dentry, nd))
+			err = d_revalidate(nd->path.dentry, nd);
+			if (!err)
+				err = -ESTALE;
+			if (err < 0)
 				break;
 		}
 return_base:
@@ -2080,10 +2097,11 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 		dir = nd->path.dentry;
 	case LAST_DOT:
 		if (need_reval_dot(dir)) {
-			if (!dir->d_op->d_revalidate(dir, nd)) {
+			error = d_revalidate(nd->path.dentry, nd);
+			if (!error)
 				error = -ESTALE;
+			if (error < 0)
 				goto exit;
-			}
 		}
 		/* fallthrough */
 	case LAST_ROOT:
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 4b9cbb28d7fa..28f136d4aaec 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -17,6 +17,7 @@
 #include <linux/kernel.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
+#include <linux/namei.h>
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
 
@@ -308,6 +309,9 @@ ncp_lookup_validate(struct dentry *dentry, struct nameidata *nd)
 	int res, val = 0, len;
 	__u8 __name[NCP_MAXPATHLEN + 1];
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	parent = dget_parent(dentry);
 	dir = parent->d_inode;
 
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 0c75a5f3cafd..9531c052d7a4 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -29,6 +29,7 @@
 #include <linux/vfs.h>
 #include <linux/mount.h>
 #include <linux/seq_file.h>
+#include <linux/namei.h>
 
 #include <linux/ncp_fs.h>
 
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 37e0a8bb077e..58beace14b19 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -938,7 +938,8 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
  * component of the path.
  * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
  */
-static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+						unsigned int mask)
 {
 	if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
 		return 0;
@@ -1018,7 +1019,7 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
  * If the parent directory is seen to have changed, we throw out the
  * cached dentry and do a new lookup.
  */
-static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode *dir;
 	struct inode *inode;
@@ -1027,6 +1028,9 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
 	struct nfs_fattr *fattr = NULL;
 	int error;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	parent = dget_parent(dentry);
 	dir = parent->d_inode;
 	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 4d54c60ceee4..0310b16a7238 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -52,9 +52,15 @@ void ocfs2_dentry_attach_gen(struct dentry *dentry)
 static int ocfs2_dentry_revalidate(struct dentry *dentry,
 				   struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode;
 	int ret = 0;    /* if all else fails, just return false */
-	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
+	struct ocfs2_super *osb;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
+	osb = OCFS2_SB(dentry->d_sb);
 
 	mlog_entry("(0x%p, '%.*s')\n", dentry,
 		   dentry->d_name.len, dentry->d_name.name);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 85f0a80912aa..dc5b2fcadc3b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1719,10 +1719,16 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat
  */
 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *task = get_proc_task(inode);
+	struct inode *inode;
+	struct task_struct *task;
 	const struct cred *cred;
 
+	if (nd && nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
+	task = get_proc_task(inode);
+
 	if (task) {
 		if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
 		    task_dumpable(task)) {
@@ -1888,12 +1894,19 @@ static int proc_fd_link(struct inode *inode, struct path *path)
 
 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *task = get_proc_task(inode);
-	int fd = proc_fd(inode);
+	struct inode *inode;
+	struct task_struct *task;
+	int fd;
 	struct files_struct *files;
 	const struct cred *cred;
 
+	if (nd && nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
+	task = get_proc_task(inode);
+	fd = proc_fd(inode);
+
 	if (task) {
 		files = get_files_struct(task);
 		if (files) {
@@ -2563,8 +2576,14 @@ static const struct pid_entry proc_base_stuff[] = {
  */
 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *task = get_proc_task(inode);
+	struct inode *inode;
+	struct task_struct *task;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
+	task = get_proc_task(inode);
 	if (task) {
 		put_task_struct(task);
 		return 1;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 35efd85a4d32..c9097f43b425 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -5,6 +5,7 @@
 #include <linux/sysctl.h>
 #include <linux/proc_fs.h>
 #include <linux/security.h>
+#include <linux/namei.h>
 #include "internal.h"
 
 static const struct dentry_operations proc_sys_dentry_operations;
@@ -389,6 +390,8 @@ static const struct inode_operations proc_sys_dir_operations = {
 
 static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
 	return !PROC_I(dentry->d_inode)->sysctl->unregistering;
 }
 
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index e0f0d7ea10a1..9ea22a56cdf1 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -972,6 +972,8 @@ int reiserfs_permission(struct inode *inode, int mask)
 
 static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
 	return -EPERM;
 }
 
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 3e076caa8daf..ea9120a830d8 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -239,9 +239,13 @@ static int sysfs_dentry_delete(const struct dentry *dentry)
 
 static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct sysfs_dirent *sd = dentry->d_fsdata;
+	struct sysfs_dirent *sd;
 	int is_dir;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	sd = dentry->d_fsdata;
 	mutex_lock(&sysfs_mutex);
 
 	/* The sysfs dirent has been deleted */
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index b1aeda077258..8b2064d02928 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -190,7 +190,6 @@ struct dentry_operations {
 #define DCACHE_OP_REVALIDATE	0x4000
 #define DCACHE_OP_DELETE	0x8000
 
-
 extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
 
-- 
cgit v1.2.3


From b74c79e99389cd79b31fcc08f82c24e492e63c7e Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:49:58 +1100
Subject: fs: provide rcu-walk aware permission i_ops

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 Documentation/filesystems/Locking         |  6 +--
 Documentation/filesystems/path-lookup.txt | 44 ++++++++++++++++--
 Documentation/filesystems/porting         |  5 +++
 Documentation/filesystems/vfs.txt         | 10 ++++-
 drivers/staging/smbfs/file.c              |  5 ++-
 fs/9p/acl.c                               |  5 ++-
 fs/9p/acl.h                               |  2 +-
 fs/afs/internal.h                         |  2 +-
 fs/afs/security.c                         |  7 ++-
 fs/bad_inode.c                            |  5 ++-
 fs/btrfs/acl.c                            |  6 ++-
 fs/btrfs/ctree.h                          |  2 +-
 fs/btrfs/inode.c                          |  7 ++-
 fs/ceph/inode.c                           | 11 +++--
 fs/ceph/super.h                           |  2 +-
 fs/cifs/cifsfs.c                          |  7 ++-
 fs/coda/dir.c                             |  5 ++-
 fs/coda/pioctl.c                          |  6 ++-
 fs/ecryptfs/inode.c                       |  4 +-
 fs/ext2/acl.c                             |  8 +++-
 fs/ext2/acl.h                             |  2 +-
 fs/ext3/acl.c                             |  8 +++-
 fs/ext3/acl.h                             |  2 +-
 fs/ext4/acl.c                             |  8 +++-
 fs/ext4/acl.h                             |  2 +-
 fs/fuse/dir.c                             | 10 +++--
 fs/generic_acl.c                          |  8 +++-
 fs/gfs2/acl.c                             |  5 ++-
 fs/gfs2/acl.h                             |  2 +-
 fs/gfs2/file.c                            |  2 +-
 fs/gfs2/inode.c                           |  4 +-
 fs/gfs2/inode.h                           |  2 +-
 fs/gfs2/ops_inode.c                       | 18 +++++---
 fs/hostfs/hostfs_kern.c                   |  7 ++-
 fs/hpfs/namei.c                           |  2 +-
 fs/jffs2/acl.c                            |  5 ++-
 fs/jffs2/acl.h                            |  2 +-
 fs/jfs/acl.c                              |  8 +++-
 fs/jfs/jfs_acl.h                          |  2 +-
 fs/logfs/dir.c                            |  6 ++-
 fs/namei.c                                | 75 ++++++++++++-------------------
 fs/nfs/dir.c                              |  7 ++-
 fs/nilfs2/inode.c                         | 10 +++--
 fs/nilfs2/nilfs.h                         |  2 +-
 fs/ocfs2/acl.c                            |  8 +++-
 fs/ocfs2/acl.h                            |  2 +-
 fs/ocfs2/file.c                           |  7 ++-
 fs/ocfs2/file.h                           |  2 +-
 fs/proc/base.c                            |  6 ++-
 fs/proc/proc_sysctl.c                     |  5 ++-
 fs/reiserfs/xattr.c                       | 14 ++++--
 fs/sysfs/inode.c                          | 11 +++--
 fs/sysfs/sysfs.h                          |  2 +-
 fs/xfs/linux-2.6/xfs_acl.c                |  8 +++-
 fs/xfs/xfs_acl.h                          |  2 +-
 include/linux/coda_linux.h                |  2 +-
 include/linux/fs.h                        | 10 +++--
 include/linux/generic_acl.h               |  2 +-
 include/linux/nfs_fs.h                    |  2 +-
 include/linux/reiserfs_xattr.h            |  2 +-
 60 files changed, 287 insertions(+), 146 deletions(-)

(limited to 'fs/cifs')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index e90ffe61eb65..977d8919cc69 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -47,8 +47,8 @@ ata *);
 	void * (*follow_link) (struct dentry *, struct nameidata *);
 	void (*put_link) (struct dentry *, struct nameidata *, void *);
 	void (*truncate) (struct inode *);
-	int (*permission) (struct inode *, int, struct nameidata *);
-	int (*check_acl)(struct inode *, int);
+	int (*permission) (struct inode *, int, unsigned int);
+	int (*check_acl)(struct inode *, int, unsigned int);
 	int (*setattr) (struct dentry *, struct iattr *);
 	int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *);
 	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
@@ -76,7 +76,7 @@ follow_link:	no
 put_link:	no
 truncate:	yes		(see below)
 setattr:	yes
-permission:	no
+permission:	no (may not block if called in rcu-walk mode)
 check_acl:	no
 getattr:	no
 setxattr:	yes
diff --git a/Documentation/filesystems/path-lookup.txt b/Documentation/filesystems/path-lookup.txt
index 8789d1810bed..eb59c8b44be9 100644
--- a/Documentation/filesystems/path-lookup.txt
+++ b/Documentation/filesystems/path-lookup.txt
@@ -316,11 +316,9 @@ The detailed design for rcu-walk is like this:
 
 The cases where rcu-walk cannot continue are:
 * NULL dentry (ie. any uncached path element)
-* parent with d_inode->i_op->permission or ACLs
 * Following links
 
-In future patches, permission checks become rcu-walk aware. It may be possible
-eventually to make following links rcu-walk aware.
+It may be possible eventually to make following links rcu-walk aware.
 
 Uncached path elements will always require dropping to ref-walk mode, at the
 very least because i_mutex needs to be grabbed, and objects allocated.
@@ -336,9 +334,49 @@ or stored into. The result is massive improvements in performance and
 scalability of path resolution.
 
 
+Interesting statistics
+======================
+
+The following table gives rcu lookup statistics for a few simple workloads
+(2s12c24t Westmere, debian non-graphical system). Ungraceful are attempts to
+drop rcu that fail due to d_seq failure and requiring the entire path lookup
+again. Other cases are successful rcu-drops that are required before the final
+element, nodentry for missing dentry, revalidate for filesystem revalidate
+routine requiring rcu drop, permission for permission check requiring drop,
+and link for symlink traversal requiring drop.
+
+     rcu-lookups     restart  nodentry          link  revalidate  permission
+bootup     47121           0      4624          1010       10283        7852
+dbench  25386793           0   6778659(26.7%)     55         549        1156
+kbuild   2696672          10     64442(2.3%)  108764(4.0%)     1        1590
+git diff   39605           0        28             2           0         106
+vfstest 24185492        4945    708725(2.9%) 1076136(4.4%)     0        2651
+
+What this shows is that failed rcu-walk lookups, ie. ones that are restarted
+entirely with ref-walk, are quite rare. Even the "vfstest" case which
+specifically has concurrent renames/mkdir/rmdir/ creat/unlink/etc to excercise
+such races is not showing a huge amount of restarts.
+
+Dropping from rcu-walk to ref-walk mean that we have encountered a dentry where
+the reference count needs to be taken for some reason. This is either because
+we have reached the target of the path walk, or because we have encountered a
+condition that can't be resolved in rcu-walk mode.  Ideally, we drop rcu-walk
+only when we have reached the target dentry, so the other statistics show where
+this does not happen.
+
+Note that a graceful drop from rcu-walk mode due to something such as the
+dentry not existing (which can be common) is not necessarily a failure of
+rcu-walk scheme, because some elements of the path may have been walked in
+rcu-walk mode. The further we get from common path elements (such as cwd or
+root), the less contended the dentry is likely to be. The closer we are to
+common path elements, the more likely they will exist in dentry cache.
+
+
 Papers and other documentation on dcache locking
 ================================================
 
 1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124).
 
 2. http://lse.sourceforge.net/locking/dcache/dcache.html
+
+
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index cd9756a2709d..07a32b42cf9c 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -379,4 +379,9 @@ where possible.
 the filesystem provides it), which requires dropping out of rcu-walk mode. This
 may now be called in rcu-walk mode (nd->flags & LOOKUP_RCU). -ECHILD should be
 returned if the filesystem cannot handle rcu-walk. See
+Documentation/filesystems/vfs.txt for more details.
+
+	permission and check_acl are inode permission checks that are called
+on many or all directory inodes on the way down a path walk (to check for
+exec permission). These must now be rcu-walk aware (flags & IPERM_RCU). See
 Documentation/filesystems/vfs.txt for more details.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index c936b4912383..fbb324e2bd43 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -325,7 +325,8 @@ struct inode_operations {
         void * (*follow_link) (struct dentry *, struct nameidata *);
         void (*put_link) (struct dentry *, struct nameidata *, void *);
 	void (*truncate) (struct inode *);
-	int (*permission) (struct inode *, int, struct nameidata *);
+	int (*permission) (struct inode *, int, unsigned int);
+	int (*check_acl)(struct inode *, int, unsigned int);
 	int (*setattr) (struct dentry *, struct iattr *);
 	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
 	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
@@ -414,6 +415,13 @@ otherwise noted.
   permission: called by the VFS to check for access rights on a POSIX-like
   	filesystem.
 
+	May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk
+	mode, the filesystem must check the permission without blocking or
+	storing to the inode.
+
+	If a situation is encountered that rcu-walk cannot handle, return
+	-ECHILD and it will be called again in ref-walk mode.
+
   setattr: called by the VFS to set attributes for a file. This method
   	is called by chmod(2) and related system calls.
 
diff --git a/drivers/staging/smbfs/file.c b/drivers/staging/smbfs/file.c
index 5dcd19c60eb9..31372e7b12de 100644
--- a/drivers/staging/smbfs/file.c
+++ b/drivers/staging/smbfs/file.c
@@ -407,11 +407,14 @@ smb_file_release(struct inode *inode, struct file * file)
  * privileges, so we need our own check for this.
  */
 static int
-smb_file_permission(struct inode *inode, int mask)
+smb_file_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	int mode = inode->i_mode;
 	int error = 0;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	VERBOSE("mode=%x, mask=%x\n", mode, mask);
 
 	/* Look at user permissions */
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 12d602351dbe..6e58c4ca1e6e 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -91,11 +91,14 @@ static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
 	return acl;
 }
 
-int v9fs_check_acl(struct inode *inode, int mask)
+int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
 	struct posix_acl *acl;
 	struct v9fs_session_info *v9ses;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	v9ses = v9fs_inode2v9ses(inode);
 	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
 		/*
diff --git a/fs/9p/acl.h b/fs/9p/acl.h
index 59e18c2e8c7e..7ef3ac9f6d95 100644
--- a/fs/9p/acl.h
+++ b/fs/9p/acl.h
@@ -16,7 +16,7 @@
 
 #ifdef CONFIG_9P_FS_POSIX_ACL
 extern int v9fs_get_acl(struct inode *, struct p9_fid *);
-extern int v9fs_check_acl(struct inode *inode, int mask);
+extern int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags);
 extern int v9fs_acl_chmod(struct dentry *);
 extern int v9fs_set_create_acl(struct dentry *,
 			       struct posix_acl *, struct posix_acl *);
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index cca8eef736fc..6d4bc1c8ff60 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -624,7 +624,7 @@ extern void afs_clear_permits(struct afs_vnode *);
 extern void afs_cache_permit(struct afs_vnode *, struct key *, long);
 extern void afs_zap_permits(struct rcu_head *);
 extern struct key *afs_request_key(struct afs_cell *);
-extern int afs_permission(struct inode *, int);
+extern int afs_permission(struct inode *, int, unsigned int);
 
 /*
  * server.c
diff --git a/fs/afs/security.c b/fs/afs/security.c
index bb4ed144d0e4..f44b9d355377 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -285,13 +285,16 @@ static int afs_check_permit(struct afs_vnode *vnode, struct key *key,
  * - AFS ACLs are attached to directories only, and a file is controlled by its
  *   parent directory's ACL
  */
-int afs_permission(struct inode *inode, int mask)
+int afs_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	struct afs_vnode *vnode = AFS_FS_I(inode);
 	afs_access_t uninitialized_var(access);
 	struct key *key;
 	int ret;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	_enter("{{%x:%u},%lx},%x,",
 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);
 
@@ -347,7 +350,7 @@ int afs_permission(struct inode *inode, int mask)
 	}
 
 	key_put(key);
-	ret = generic_permission(inode, mask, NULL);
+	ret = generic_permission(inode, mask, flags, NULL);
 	_leave(" = %d", ret);
 	return ret;
 
diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index f024d8aaddef..9ad2369d9e35 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -229,8 +229,11 @@ static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
 	return -EIO;
 }
 
-static int bad_inode_permission(struct inode *inode, int mask)
+static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags)
 {
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	return -EIO;
 }
 
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 2222d161c7b6..cb518a4b917c 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -185,13 +185,15 @@ static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
 	return ret;
 }
 
-int btrfs_check_acl(struct inode *inode, int mask)
+int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
 	struct posix_acl *acl;
 	int error = -EAGAIN;
 
-	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index af52f6d7a4d8..a142d204b526 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2544,7 +2544,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait);
 
 /* acl.c */
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
-int btrfs_check_acl(struct inode *inode, int mask);
+int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags);
 #else
 #define btrfs_check_acl NULL
 #endif
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 63e4546b478a..5cf0db0081f9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7211,11 +7211,14 @@ static int btrfs_set_page_dirty(struct page *page)
 	return __set_page_dirty_nobuffers(page);
 }
 
-static int btrfs_permission(struct inode *inode, int mask)
+static int btrfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
 		return -EACCES;
-	return generic_permission(inode, mask, btrfs_check_acl);
+	return generic_permission(inode, mask, flags, btrfs_check_acl);
 }
 
 static const struct inode_operations btrfs_dir_inode_operations = {
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 47f8c8baf3b5..e61de4f7b99d 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1781,12 +1781,17 @@ int ceph_do_getattr(struct inode *inode, int mask)
  * Check inode permissions.  We verify we have a valid value for
  * the AUTH cap, then call the generic handler.
  */
-int ceph_permission(struct inode *inode, int mask)
+int ceph_permission(struct inode *inode, int mask, unsigned int flags)
 {
-	int err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED);
+	int err;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
+	err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED);
 
 	if (!err)
-		err = generic_permission(inode, mask, NULL);
+		err = generic_permission(inode, mask, flags, NULL);
 	return err;
 }
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 7f01728a4657..4553d8829edb 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -665,7 +665,7 @@ extern void ceph_queue_invalidate(struct inode *inode);
 extern void ceph_queue_writeback(struct inode *inode);
 
 extern int ceph_do_getattr(struct inode *inode, int mask);
-extern int ceph_permission(struct inode *inode, int mask);
+extern int ceph_permission(struct inode *inode, int mask, unsigned int flags);
 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
 			struct kstat *stat);
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 223717dcc401..8e21e0fe65d5 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -283,10 +283,13 @@ cifs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
-static int cifs_permission(struct inode *inode, int mask)
+static int cifs_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	struct cifs_sb_info *cifs_sb;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	cifs_sb = CIFS_SB(inode->i_sb);
 
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) {
@@ -298,7 +301,7 @@ static int cifs_permission(struct inode *inode, int mask)
 		on the client (above and beyond ACL on servers) for
 		servers which do not support setting and viewing mode bits,
 		so allowing client to check permissions is useful */
-		return generic_permission(inode, mask, NULL);
+		return generic_permission(inode, mask, flags, NULL);
 }
 
 static struct kmem_cache *cifs_inode_cachep;
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 619a8303766e..29badd91360f 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -135,10 +135,13 @@ exit:
 }
 
 
-int coda_permission(struct inode *inode, int mask)
+int coda_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	int error;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
  
 	if (!mask)
diff --git a/fs/coda/pioctl.c b/fs/coda/pioctl.c
index 2fd89b5c5c7b..741f0bd03918 100644
--- a/fs/coda/pioctl.c
+++ b/fs/coda/pioctl.c
@@ -24,7 +24,7 @@
 #include <linux/coda_psdev.h>
 
 /* pioctl ops */
-static int coda_ioctl_permission(struct inode *inode, int mask);
+static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags);
 static long coda_pioctl(struct file *filp, unsigned int cmd,
 			unsigned long user_data);
 
@@ -41,8 +41,10 @@ const struct file_operations coda_ioctl_operations = {
 };
 
 /* the coda pioctl inode ops */
-static int coda_ioctl_permission(struct inode *inode, int mask)
+static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags)
 {
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 	return (mask & MAY_EXEC) ? -EACCES : 0;
 }
 
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f91b35db4c6e..337352a94751 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -980,8 +980,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 }
 
 static int
-ecryptfs_permission(struct inode *inode, int mask)
+ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 	return inode_permission(ecryptfs_inode_to_lower(inode), mask);
 }
 
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index 2bcc0431bada..dd9bb3f0c8d7 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -232,10 +232,14 @@ ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 }
 
 int
-ext2_check_acl(struct inode *inode, int mask)
+ext2_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
+	struct posix_acl *acl;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h
index 3ff6cbb9ac44..c939b7b12099 100644
--- a/fs/ext2/acl.h
+++ b/fs/ext2/acl.h
@@ -54,7 +54,7 @@ static inline int ext2_acl_count(size_t size)
 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext2_check_acl (struct inode *, int);
+extern int ext2_check_acl (struct inode *, int, unsigned int);
 extern int ext2_acl_chmod (struct inode *);
 extern int ext2_init_acl (struct inode *, struct inode *);
 
diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c
index 8a11fe212183..9e49da8302d3 100644
--- a/fs/ext3/acl.c
+++ b/fs/ext3/acl.c
@@ -240,10 +240,14 @@ ext3_set_acl(handle_t *handle, struct inode *inode, int type,
 }
 
 int
-ext3_check_acl(struct inode *inode, int mask)
+ext3_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+	struct posix_acl *acl;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
diff --git a/fs/ext3/acl.h b/fs/ext3/acl.h
index 597334626de9..5faf8048e906 100644
--- a/fs/ext3/acl.h
+++ b/fs/ext3/acl.h
@@ -54,7 +54,7 @@ static inline int ext3_acl_count(size_t size)
 #ifdef CONFIG_EXT3_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext3_check_acl (struct inode *, int);
+extern int ext3_check_acl (struct inode *, int, unsigned int);
 extern int ext3_acl_chmod (struct inode *);
 extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
 
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 5e2ed4504ead..373dcaeedba9 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -238,10 +238,14 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type,
 }
 
 int
-ext4_check_acl(struct inode *inode, int mask)
+ext4_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
+	struct posix_acl *acl;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 9d843d5deac4..dec821168fd4 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -54,7 +54,7 @@ static inline int ext4_acl_count(size_t size)
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext4_check_acl(struct inode *, int);
+extern int ext4_check_acl(struct inode *, int, unsigned int);
 extern int ext4_acl_chmod(struct inode *);
 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 07f4b5e675fc..f738599fd8cd 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -985,12 +985,15 @@ static int fuse_access(struct inode *inode, int mask)
  * access request is sent.  Execute permission is still checked
  * locally based on file mode.
  */
-static int fuse_permission(struct inode *inode, int mask)
+static int fuse_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	bool refreshed = false;
 	int err = 0;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	if (!fuse_allow_task(fc, current))
 		return -EACCES;
 
@@ -1005,7 +1008,7 @@ static int fuse_permission(struct inode *inode, int mask)
 	}
 
 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
-		err = generic_permission(inode, mask, NULL);
+		err = generic_permission(inode, mask, flags, NULL);
 
 		/* If permission is denied, try to refresh file
 		   attributes.  This is also needed, because the root
@@ -1013,7 +1016,8 @@ static int fuse_permission(struct inode *inode, int mask)
 		if (err == -EACCES && !refreshed) {
 			err = fuse_do_getattr(inode, NULL, NULL);
 			if (!err)
-				err = generic_permission(inode, mask, NULL);
+				err = generic_permission(inode, mask,
+							flags, NULL);
 		}
 
 		/* Note: the opposite of the above test does not
diff --git a/fs/generic_acl.c b/fs/generic_acl.c
index 6bc9e3a5a693..628004282130 100644
--- a/fs/generic_acl.c
+++ b/fs/generic_acl.c
@@ -190,10 +190,14 @@ generic_acl_chmod(struct inode *inode)
 }
 
 int
-generic_check_acl(struct inode *inode, int mask)
+generic_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
+	struct posix_acl *acl;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
 	if (acl) {
 		int error = posix_acl_permission(inode, acl, mask);
 		posix_acl_release(acl);
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 48171f4c943d..7118f1a780a9 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -75,11 +75,14 @@ static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type)
  * Returns: errno
  */
 
-int gfs2_check_acl(struct inode *inode, int mask)
+int gfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
 	struct posix_acl *acl;
 	int error;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h
index b522b0cb39ea..a93907c8159b 100644
--- a/fs/gfs2/acl.h
+++ b/fs/gfs2/acl.h
@@ -16,7 +16,7 @@
 #define GFS2_POSIX_ACL_DEFAULT		"posix_acl_default"
 #define GFS2_ACL_MAX_ENTRIES		25
 
-extern int gfs2_check_acl(struct inode *inode, int mask);
+extern int gfs2_check_acl(struct inode *inode, int mask, unsigned int);
 extern int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode);
 extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
 extern const struct xattr_handler gfs2_xattr_system_handler;
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index aa996471ec5c..fca6689e12e6 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -241,7 +241,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 	    !capable(CAP_LINUX_IMMUTABLE))
 		goto out;
 	if (!IS_IMMUTABLE(inode)) {
-		error = gfs2_permission(inode, MAY_WRITE);
+		error = gfs2_permission(inode, MAY_WRITE, 0);
 		if (error)
 			goto out;
 	}
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index e1213f7f9217..6163be9686be 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -509,7 +509,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
 	}
 
 	if (!is_root) {
-		error = gfs2_permission(dir, MAY_EXEC);
+		error = gfs2_permission(dir, MAY_EXEC, 0);
 		if (error)
 			goto out;
 	}
@@ -539,7 +539,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
 {
 	int error;
 
-	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
+	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0);
 	if (error)
 		return error;
 
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index d8499fadcc53..732a183efdb3 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -113,7 +113,7 @@ extern struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
 extern struct inode *gfs2_createi(struct gfs2_holder *ghs,
 				  const struct qstr *name,
 				  unsigned int mode, dev_t dev);
-extern int gfs2_permission(struct inode *inode, int mask);
+extern int gfs2_permission(struct inode *inode, int mask, unsigned int flags);
 extern int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr);
 extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name);
 extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf);
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index f28f89796f4d..5c63a06fcd7c 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -166,7 +166,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 	if (error)
 		goto out_child;
 
-	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
+	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC, 0);
 	if (error)
 		goto out_gunlock;
 
@@ -289,7 +289,7 @@ static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
 	if (IS_APPEND(&dip->i_inode))
 		return -EPERM;
 
-	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
+	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0);
 	if (error)
 		return error;
 
@@ -822,7 +822,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 			}
 		}
 	} else {
-		error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC);
+		error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC, 0);
 		if (error)
 			goto out_gunlock;
 
@@ -857,7 +857,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 	/* Check out the dir to be renamed */
 
 	if (dir_rename) {
-		error = gfs2_permission(odentry->d_inode, MAY_WRITE);
+		error = gfs2_permission(odentry->d_inode, MAY_WRITE, 0);
 		if (error)
 			goto out_gunlock;
 	}
@@ -1041,13 +1041,17 @@ static void gfs2_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
  * Returns: errno
  */
 
-int gfs2_permission(struct inode *inode, int mask)
+int gfs2_permission(struct inode *inode, int mask, unsigned int flags)
 {
-	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_inode *ip;
 	struct gfs2_holder i_gh;
 	int error;
 	int unlock = 0;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
+	ip = GFS2_I(inode);
 	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 		if (error)
@@ -1058,7 +1062,7 @@ int gfs2_permission(struct inode *inode, int mask)
 	if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
 		error = -EACCES;
 	else
-		error = generic_permission(inode, mask, gfs2_check_acl);
+		error = generic_permission(inode, mask, flags, gfs2_check_acl);
 	if (unlock)
 		gfs2_glock_dq_uninit(&i_gh);
 
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 0bc81cf256b8..d3244d949a4e 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -749,11 +749,14 @@ int hostfs_rename(struct inode *from_ino, struct dentry *from,
 	return err;
 }
 
-int hostfs_permission(struct inode *ino, int desired)
+int hostfs_permission(struct inode *ino, int desired, unsigned int flags)
 {
 	char *name;
 	int r = 0, w = 0, x = 0, err;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	if (desired & MAY_READ) r = 1;
 	if (desired & MAY_WRITE) w = 1;
 	if (desired & MAY_EXEC) x = 1;
@@ -768,7 +771,7 @@ int hostfs_permission(struct inode *ino, int desired)
 		err = access_file(name, r, w, x);
 	__putname(name);
 	if (!err)
-		err = generic_permission(ino, desired, NULL);
+		err = generic_permission(ino, desired, flags, NULL);
 	return err;
 }
 
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
index 11c2b4080f65..f4ad9e31ddc4 100644
--- a/fs/hpfs/namei.c
+++ b/fs/hpfs/namei.c
@@ -419,7 +419,7 @@ again:
 			unlock_kernel();
 			return -ENOSPC;
 		}
-		if (generic_permission(inode, MAY_WRITE, NULL) ||
+		if (generic_permission(inode, MAY_WRITE, 0, NULL) ||
 		    !S_ISREG(inode->i_mode) ||
 		    get_write_access(inode)) {
 			d_rehash(dentry);
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 54a92fd02bbd..95b79672150a 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -259,11 +259,14 @@ static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 	return rc;
 }
 
-int jffs2_check_acl(struct inode *inode, int mask)
+int jffs2_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
 	struct posix_acl *acl;
 	int rc;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h
index 5e42de8d9541..3119f59253d3 100644
--- a/fs/jffs2/acl.h
+++ b/fs/jffs2/acl.h
@@ -26,7 +26,7 @@ struct jffs2_acl_header {
 
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 
-extern int jffs2_check_acl(struct inode *, int);
+extern int jffs2_check_acl(struct inode *, int, unsigned int);
 extern int jffs2_acl_chmod(struct inode *);
 extern int jffs2_init_acl_pre(struct inode *, struct inode *, int *);
 extern int jffs2_init_acl_post(struct inode *);
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 1057a4998e4e..e5de9422fa32 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -114,10 +114,14 @@ out:
 	return rc;
 }
 
-int jfs_check_acl(struct inode *inode, int mask)
+int jfs_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
+	struct posix_acl *acl;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index 54e07559878d..f9285c4900fa 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -20,7 +20,7 @@
 
 #ifdef CONFIG_JFS_POSIX_ACL
 
-int jfs_check_acl(struct inode *, int);
+int jfs_check_acl(struct inode *, int, unsigned int flags);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
 int jfs_acl_chmod(struct inode *inode);
 
diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 409dfd65e9a1..f9ddf0c388c8 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -555,9 +555,11 @@ static int logfs_symlink(struct inode *dir, struct dentry *dentry,
 	return __logfs_create(dir, dentry, inode, target, destlen);
 }
 
-static int logfs_permission(struct inode *inode, int mask)
+static int logfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
-	return generic_permission(inode, mask, NULL);
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+	return generic_permission(inode, mask, flags, NULL);
 }
 
 static int logfs_link(struct dentry *old_dentry, struct inode *dir,
diff --git a/fs/namei.c b/fs/namei.c
index 6e275363e89d..4e957bf744ae 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -169,8 +169,8 @@ EXPORT_SYMBOL(putname);
 /*
  * This does basic POSIX ACL permission checking
  */
-static inline int __acl_permission_check(struct inode *inode, int mask,
-		int (*check_acl)(struct inode *inode, int mask), int rcu)
+static int acl_permission_check(struct inode *inode, int mask, unsigned int flags,
+		int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
 {
 	umode_t			mode = inode->i_mode;
 
@@ -180,13 +180,9 @@ static inline int __acl_permission_check(struct inode *inode, int mask,
 		mode >>= 6;
 	else {
 		if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
-			if (rcu) {
-				return -ECHILD;
-			} else {
-				int error = check_acl(inode, mask);
-				if (error != -EAGAIN)
-					return error;
-			}
+			int error = check_acl(inode, mask, flags);
+			if (error != -EAGAIN)
+				return error;
 		}
 
 		if (in_group_p(inode->i_gid))
@@ -201,32 +197,31 @@ static inline int __acl_permission_check(struct inode *inode, int mask,
 	return -EACCES;
 }
 
-static inline int acl_permission_check(struct inode *inode, int mask,
-		int (*check_acl)(struct inode *inode, int mask))
-{
-	return __acl_permission_check(inode, mask, check_acl, 0);
-}
-
 /**
- * generic_permission  -  check for access rights on a Posix-like filesystem
+ * generic_permission -  check for access rights on a Posix-like filesystem
  * @inode:	inode to check access rights for
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
  * @check_acl:	optional callback to check for Posix ACLs
+ * @flags	IPERM_FLAG_ flags.
  *
  * Used to check for read/write/execute permissions on a file.
  * We use "fsuid" for this, letting us set arbitrary permissions
  * for filesystem access without changing the "normal" uids which
- * are used for other things..
+ * are used for other things.
+ *
+ * generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk
+ * request cannot be satisfied (eg. requires blocking or too much complexity).
+ * It would then be called again in ref-walk mode.
  */
-int generic_permission(struct inode *inode, int mask,
-		int (*check_acl)(struct inode *inode, int mask))
+int generic_permission(struct inode *inode, int mask, unsigned int flags,
+	int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
 {
 	int ret;
 
 	/*
 	 * Do the basic POSIX ACL permission checks.
 	 */
-	ret = acl_permission_check(inode, mask, check_acl);
+	ret = acl_permission_check(inode, mask, flags, check_acl);
 	if (ret != -EACCES)
 		return ret;
 
@@ -281,9 +276,10 @@ int inode_permission(struct inode *inode, int mask)
 	}
 
 	if (inode->i_op->permission)
-		retval = inode->i_op->permission(inode, mask);
+		retval = inode->i_op->permission(inode, mask, 0);
 	else
-		retval = generic_permission(inode, mask, inode->i_op->check_acl);
+		retval = generic_permission(inode, mask, 0,
+				inode->i_op->check_acl);
 
 	if (retval)
 		return retval;
@@ -668,22 +664,19 @@ force_reval_path(struct path *path, struct nameidata *nd)
  * short-cut DAC fails, then call ->permission() to do more
  * complete permission check.
  */
-static inline int __exec_permission(struct inode *inode, int rcu)
+static inline int exec_permission(struct inode *inode, unsigned int flags)
 {
 	int ret;
 
 	if (inode->i_op->permission) {
-		if (rcu)
-			return -ECHILD;
-		ret = inode->i_op->permission(inode, MAY_EXEC);
-		if (!ret)
-			goto ok;
-		return ret;
+		ret = inode->i_op->permission(inode, MAY_EXEC, flags);
+	} else {
+		ret = acl_permission_check(inode, MAY_EXEC, flags,
+				inode->i_op->check_acl);
 	}
-	ret = __acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl, rcu);
-	if (!ret)
+	if (likely(!ret))
 		goto ok;
-	if (rcu && ret == -ECHILD)
+	if (ret == -ECHILD)
 		return ret;
 
 	if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
@@ -691,17 +684,7 @@ static inline int __exec_permission(struct inode *inode, int rcu)
 
 	return ret;
 ok:
-	return security_inode_exec_permission(inode, rcu);
-}
-
-static int exec_permission(struct inode *inode)
-{
-	return __exec_permission(inode, 0);
-}
-
-static int exec_permission_rcu(struct inode *inode)
-{
-	return __exec_permission(inode, 1);
+	return security_inode_exec_permission(inode, flags);
 }
 
 static __always_inline void set_root(struct nameidata *nd)
@@ -1165,7 +1148,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 
 		nd->flags |= LOOKUP_CONTINUE;
 		if (nd->flags & LOOKUP_RCU) {
-			err = exec_permission_rcu(nd->inode);
+			err = exec_permission(nd->inode, IPERM_FLAG_RCU);
 			if (err == -ECHILD) {
 				if (nameidata_drop_rcu(nd))
 					return -ECHILD;
@@ -1173,7 +1156,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 			}
 		} else {
 exec_again:
-			err = exec_permission(nd->inode);
+			err = exec_permission(nd->inode, 0);
 		}
  		if (err)
 			break;
@@ -1620,7 +1603,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 	struct dentry *dentry;
 	int err;
 
-	err = exec_permission(inode);
+	err = exec_permission(inode, 0);
 	if (err)
 		return ERR_PTR(err);
 
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 58beace14b19..d33da530097a 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2189,11 +2189,14 @@ int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
 	return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
 }
 
-int nfs_permission(struct inode *inode, int mask)
+int nfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	struct rpc_cred *cred;
 	int res = 0;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	nfs_inc_stats(inode, NFSIOS_VFSACCESS);
 
 	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
@@ -2241,7 +2244,7 @@ out:
 out_notsup:
 	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
 	if (res == 0)
-		res = generic_permission(inode, mask, NULL);
+		res = generic_permission(inode, mask, flags, NULL);
 	goto out;
 }
 
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 71d4bc8464e0..77b48c8fab17 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -785,15 +785,19 @@ out_err:
 	return err;
 }
 
-int nilfs_permission(struct inode *inode, int mask)
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
-	struct nilfs_root *root = NILFS_I(inode)->i_root;
+	struct nilfs_root *root;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 
+	root = NILFS_I(inode)->i_root;
 	if ((mask & MAY_WRITE) && root &&
 	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 		return -EROFS; /* snapshot is not writable */
 
-	return generic_permission(inode, mask, NULL);
+	return generic_permission(inode, mask, flags, NULL);
 }
 
 int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index f7560da5a567..0ca98823db59 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -256,7 +256,7 @@ extern void nilfs_update_inode(struct inode *, struct buffer_head *);
 extern void nilfs_truncate(struct inode *);
 extern void nilfs_evict_inode(struct inode *);
 extern int nilfs_setattr(struct dentry *, struct iattr *);
-int nilfs_permission(struct inode *inode, int mask);
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags);
 extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *,
 				  struct buffer_head **);
 extern int nilfs_inode_dirty(struct inode *);
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 391915093fe1..704f6b1742f3 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -291,13 +291,17 @@ static int ocfs2_set_acl(handle_t *handle,
 	return ret;
 }
 
-int ocfs2_check_acl(struct inode *inode, int mask)
+int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct ocfs2_super *osb;
 	struct buffer_head *di_bh = NULL;
 	struct posix_acl *acl;
 	int ret = -EAGAIN;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
+	osb = OCFS2_SB(inode->i_sb);
 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 		return ret;
 
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index 5c5d31f05853..4fe7c9cf4bfb 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -26,7 +26,7 @@ struct ocfs2_acl_entry {
 	__le32 e_id;
 };
 
-extern int ocfs2_check_acl(struct inode *, int);
+extern int ocfs2_check_acl(struct inode *, int, unsigned int);
 extern int ocfs2_acl_chmod(struct inode *);
 extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
 			  struct buffer_head *, struct buffer_head *,
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index f6cba566429d..bdadbae09094 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1307,10 +1307,13 @@ bail:
 	return err;
 }
 
-int ocfs2_permission(struct inode *inode, int mask)
+int ocfs2_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	int ret;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	mlog_entry_void();
 
 	ret = ocfs2_inode_lock(inode, NULL, 0);
@@ -1320,7 +1323,7 @@ int ocfs2_permission(struct inode *inode, int mask)
 		goto out;
 	}
 
-	ret = generic_permission(inode, mask, ocfs2_check_acl);
+	ret = generic_permission(inode, mask, flags, ocfs2_check_acl);
 
 	ocfs2_inode_unlock(inode, 0);
 out:
diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h
index 97bf761c9e7c..f5afbbef6703 100644
--- a/fs/ocfs2/file.h
+++ b/fs/ocfs2/file.h
@@ -61,7 +61,7 @@ int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh,
 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);
 int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
 		  struct kstat *stat);
-int ocfs2_permission(struct inode *inode, int mask);
+int ocfs2_permission(struct inode *inode, int mask, unsigned int flags);
 
 int ocfs2_should_update_atime(struct inode *inode,
 			      struct vfsmount *vfsmnt);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index dc5b2fcadc3b..b953d41d9abf 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2114,11 +2114,13 @@ static const struct file_operations proc_fd_operations = {
  * /proc/pid/fd needs a special permission handler so that a process can still
  * access /proc/self/fd after it has executed a setuid().
  */
-static int proc_fd_permission(struct inode *inode, int mask)
+static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	int rv;
 
-	rv = generic_permission(inode, mask, NULL);
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+	rv = generic_permission(inode, mask, flags, NULL);
 	if (rv == 0)
 		return 0;
 	if (task_pid(current) == proc_pid(inode))
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index c9097f43b425..09a1f92a34ef 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -295,7 +295,7 @@ out:
 	return ret;
 }
 
-static int proc_sys_permission(struct inode *inode, int mask)
+static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags)
 {
 	/*
 	 * sysctl entries that are not writeable,
@@ -305,6 +305,9 @@ static int proc_sys_permission(struct inode *inode, int mask)
 	struct ctl_table *table;
 	int error;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	/* Executable files are not allowed under /proc/sys/ */
 	if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))
 		return -EACCES;
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 9ea22a56cdf1..3cfb2e933644 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -870,11 +870,14 @@ out:
 	return err;
 }
 
-static int reiserfs_check_acl(struct inode *inode, int mask)
+static int reiserfs_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
 	struct posix_acl *acl;
 	int error = -EAGAIN; /* do regular unix permission checks by default */
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
 
 	if (acl) {
@@ -951,8 +954,10 @@ static int xattr_mount_check(struct super_block *s)
 	return 0;
 }
 
-int reiserfs_permission(struct inode *inode, int mask)
+int reiserfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
 	/*
 	 * We don't do permission checks on the internal objects.
 	 * Permissions are determined by the "owning" object.
@@ -965,9 +970,10 @@ int reiserfs_permission(struct inode *inode, int mask)
 	 * Stat data v1 doesn't support ACLs.
 	 */
 	if (get_inode_sd_version(inode) != STAT_DATA_V1)
-		return generic_permission(inode, mask, reiserfs_check_acl);
+		return generic_permission(inode, mask, flags,
+					reiserfs_check_acl);
 #endif
-	return generic_permission(inode, mask, NULL);
+	return generic_permission(inode, mask, flags, NULL);
 }
 
 static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd)
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index cffb1fd8ba33..30ac27345586 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -348,13 +348,18 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const cha
 		return -ENOENT;
 }
 
-int sysfs_permission(struct inode *inode, int mask)
+int sysfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
-	struct sysfs_dirent *sd = inode->i_private;
+	struct sysfs_dirent *sd;
+
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
+	sd = inode->i_private;
 
 	mutex_lock(&sysfs_mutex);
 	sysfs_refresh_inode(sd, inode);
 	mutex_unlock(&sysfs_mutex);
 
-	return generic_permission(inode, mask, NULL);
+	return generic_permission(inode, mask, flags, NULL);
 }
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index d9be60a2e956..ffaaa816bfba 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -200,7 +200,7 @@ static inline void __sysfs_put(struct sysfs_dirent *sd)
 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
 void sysfs_evict_inode(struct inode *inode);
 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
-int sysfs_permission(struct inode *inode, int mask);
+int sysfs_permission(struct inode *inode, int mask, unsigned int flags);
 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c
index b2771862fd3d..4b11eaf6a580 100644
--- a/fs/xfs/linux-2.6/xfs_acl.c
+++ b/fs/xfs/linux-2.6/xfs_acl.c
@@ -219,12 +219,16 @@ xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 }
 
 int
-xfs_check_acl(struct inode *inode, int mask)
+xfs_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-	struct xfs_inode *ip = XFS_I(inode);
+	struct xfs_inode *ip;
 	struct posix_acl *acl;
 	int error = -EAGAIN;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
+	ip = XFS_I(inode);
 	trace_xfs_check_acl(ip);
 
 	/*
diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h
index 0135e2a669d7..11dd72070cbb 100644
--- a/fs/xfs/xfs_acl.h
+++ b/fs/xfs/xfs_acl.h
@@ -42,7 +42,7 @@ struct xfs_acl {
 #define SGI_ACL_DEFAULT_SIZE	(sizeof(SGI_ACL_DEFAULT)-1)
 
 #ifdef CONFIG_XFS_POSIX_ACL
-extern int xfs_check_acl(struct inode *inode, int mask);
+extern int xfs_check_acl(struct inode *inode, int mask, unsigned int flags);
 extern struct posix_acl *xfs_get_acl(struct inode *inode, int type);
 extern int xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl);
 extern int xfs_acl_chmod(struct inode *inode);
diff --git a/include/linux/coda_linux.h b/include/linux/coda_linux.h
index 2e914d0771b9..4ccc59c1ea82 100644
--- a/include/linux/coda_linux.h
+++ b/include/linux/coda_linux.h
@@ -37,7 +37,7 @@ extern const struct file_operations coda_ioctl_operations;
 /* operations shared over more than one file */
 int coda_open(struct inode *i, struct file *f);
 int coda_release(struct inode *i, struct file *f);
-int coda_permission(struct inode *inode, int mask);
+int coda_permission(struct inode *inode, int mask, unsigned int flags);
 int coda_revalidate_inode(struct dentry *);
 int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 int coda_setattr(struct dentry *, struct iattr *);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a04aa96acb71..d5a4d42f655b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1550,11 +1550,13 @@ struct file_operations {
 	int (*setlease)(struct file *, long, struct file_lock **);
 };
 
+#define IPERM_FLAG_RCU	0x0001
+
 struct inode_operations {
 	struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
 	void * (*follow_link) (struct dentry *, struct nameidata *);
-	int (*permission) (struct inode *, int);
-	int (*check_acl)(struct inode *, int);
+	int (*permission) (struct inode *, int, unsigned int);
+	int (*check_acl)(struct inode *, int, unsigned int);
 
 	int (*readlink) (struct dentry *, char __user *,int);
 	void (*put_link) (struct dentry *, struct nameidata *, void *);
@@ -2165,8 +2167,8 @@ extern sector_t bmap(struct inode *, sector_t);
 #endif
 extern int notify_change(struct dentry *, struct iattr *);
 extern int inode_permission(struct inode *, int);
-extern int generic_permission(struct inode *, int,
-		int (*check_acl)(struct inode *, int));
+extern int generic_permission(struct inode *, int, unsigned int,
+		int (*check_acl)(struct inode *, int, unsigned int));
 
 static inline bool execute_ok(struct inode *inode)
 {
diff --git a/include/linux/generic_acl.h b/include/linux/generic_acl.h
index 574bea4013b6..0437e377b555 100644
--- a/include/linux/generic_acl.h
+++ b/include/linux/generic_acl.h
@@ -10,6 +10,6 @@ extern const struct xattr_handler generic_acl_default_handler;
 
 int generic_acl_init(struct inode *, struct inode *);
 int generic_acl_chmod(struct inode *);
-int generic_check_acl(struct inode *inode, int mask);
+int generic_check_acl(struct inode *inode, int mask, unsigned int flags);
 
 #endif /* LINUX_GENERIC_ACL_H */
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 29d504d5d1c3..0779bb8f95be 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -351,7 +351,7 @@ extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
-extern int nfs_permission(struct inode *, int);
+extern int nfs_permission(struct inode *, int, unsigned int);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
 extern int nfs_attribute_timeout(struct inode *inode);
diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h
index b2cf2089769b..3b94c91f20a6 100644
--- a/include/linux/reiserfs_xattr.h
+++ b/include/linux/reiserfs_xattr.h
@@ -41,7 +41,7 @@ int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
 int reiserfs_lookup_privroot(struct super_block *sb);
 int reiserfs_delete_xattrs(struct inode *inode);
 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);
-int reiserfs_permission(struct inode *inode, int mask);
+int reiserfs_permission(struct inode *inode, int mask, unsigned int flags);
 
 #ifdef CONFIG_REISERFS_FS_XATTR
 #define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir)
-- 
cgit v1.2.3


From 873feea09ebc980cbd3631b767356ce1eee65ec1 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 7 Jan 2011 17:50:06 +1100
Subject: fs: dcache per-inode inode alias locking

dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
 fs/9p/vfs_inode.c      |  4 +--
 fs/affs/amigaffs.c     |  4 +--
 fs/cifs/inode.c        |  6 ++--
 fs/dcache.c            | 88 +++++++++++++++++++++++++++-----------------------
 fs/exportfs/expfs.c    | 12 ++++---
 fs/nfs/getroot.c       |  4 +--
 fs/notify/fsnotify.c   |  4 +--
 fs/ocfs2/dcache.c      |  4 +--
 include/linux/dcache.h |  1 -
 9 files changed, 67 insertions(+), 60 deletions(-)

(limited to 'fs/cifs')

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index df8bbb358d54..59782981b225 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -277,11 +277,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode)
 {
 	struct dentry *dentry;
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	/* Directory should have only one entry. */
 	BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
 	dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	return dentry;
 }
 
diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c
index 600101a21ba2..3a4557e8325c 100644
--- a/fs/affs/amigaffs.c
+++ b/fs/affs/amigaffs.c
@@ -128,7 +128,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 	void *data = dentry->d_fsdata;
 	struct list_head *head, *next;
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	head = &inode->i_dentry;
 	next = head->next;
 	while (next != head) {
@@ -139,7 +139,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 		}
 		next = next->next;
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 }
 
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 2a239d878e85..a853a89857a5 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -809,14 +809,14 @@ inode_has_hashed_dentries(struct inode *inode)
 {
 	struct dentry *dentry;
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
-			spin_unlock(&dcache_inode_lock);
+			spin_unlock(&inode->i_lock);
 			return true;
 		}
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	return false;
 }
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 9f04e1ba75b7..09ec945f3c98 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -39,8 +39,8 @@
 
 /*
  * Usage:
- * dcache_inode_lock protects:
- *   - i_dentry, d_alias, d_inode
+ * dcache->d_inode->i_lock protects:
+ *   - i_dentry, d_alias, d_inode of aliases
  * dcache_hash_bucket lock protects:
  *   - the dcache hash table
  * s_anon bl list spinlock protects:
@@ -58,7 +58,7 @@
  *   - d_alias, d_inode
  *
  * Ordering:
- * dcache_inode_lock
+ * dentry->d_inode->i_lock
  *   dentry->d_lock
  *     dcache_lru_lock
  *     dcache_hash_bucket lock
@@ -78,12 +78,10 @@
 int sysctl_vfs_cache_pressure __read_mostly = 100;
 EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
 __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
 
 EXPORT_SYMBOL(rename_lock);
-EXPORT_SYMBOL(dcache_inode_lock);
 
 static struct kmem_cache *dentry_cache __read_mostly;
 
@@ -196,14 +194,14 @@ static inline void dentry_rcuwalk_barrier(struct dentry *dentry)
  */
 static void dentry_iput(struct dentry * dentry)
 	__releases(dentry->d_lock)
-	__releases(dcache_inode_lock)
+	__releases(dentry->d_inode->i_lock)
 {
 	struct inode *inode = dentry->d_inode;
 	if (inode) {
 		dentry->d_inode = NULL;
 		list_del_init(&dentry->d_alias);
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&inode->i_lock);
 		if (!inode->i_nlink)
 			fsnotify_inoderemove(inode);
 		if (dentry->d_op && dentry->d_op->d_iput)
@@ -212,7 +210,6 @@ static void dentry_iput(struct dentry * dentry)
 			iput(inode);
 	} else {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_inode_lock);
 	}
 }
 
@@ -222,14 +219,14 @@ static void dentry_iput(struct dentry * dentry)
  */
 static void dentry_unlink_inode(struct dentry * dentry)
 	__releases(dentry->d_lock)
-	__releases(dcache_inode_lock)
+	__releases(dentry->d_inode->i_lock)
 {
 	struct inode *inode = dentry->d_inode;
 	dentry->d_inode = NULL;
 	list_del_init(&dentry->d_alias);
 	dentry_rcuwalk_barrier(dentry);
 	spin_unlock(&dentry->d_lock);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	if (!inode->i_nlink)
 		fsnotify_inoderemove(inode);
 	if (dentry->d_op && dentry->d_op->d_iput)
@@ -295,7 +292,7 @@ static void dentry_lru_move_tail(struct dentry *dentry)
 static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
 	__releases(dentry->d_lock)
 	__releases(parent->d_lock)
-	__releases(dcache_inode_lock)
+	__releases(dentry->d_inode->i_lock)
 {
 	dentry->d_parent = NULL;
 	list_del(&dentry->d_u.d_child);
@@ -370,9 +367,11 @@ EXPORT_SYMBOL(d_drop);
 static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
 	__releases(dentry->d_lock)
 {
+	struct inode *inode;
 	struct dentry *parent;
 
-	if (!spin_trylock(&dcache_inode_lock)) {
+	inode = dentry->d_inode;
+	if (inode && !spin_trylock(&inode->i_lock)) {
 relock:
 		spin_unlock(&dentry->d_lock);
 		cpu_relax();
@@ -383,7 +382,8 @@ relock:
 	else
 		parent = dentry->d_parent;
 	if (parent && !spin_trylock(&parent->d_lock)) {
-		spin_unlock(&dcache_inode_lock);
+		if (inode)
+			spin_unlock(&inode->i_lock);
 		goto relock;
 	}
 
@@ -618,9 +618,9 @@ struct dentry *d_find_alias(struct inode *inode)
 	struct dentry *de = NULL;
 
 	if (!list_empty(&inode->i_dentry)) {
-		spin_lock(&dcache_inode_lock);
+		spin_lock(&inode->i_lock);
 		de = __d_find_alias(inode, 0);
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&inode->i_lock);
 	}
 	return de;
 }
@@ -634,20 +634,20 @@ void d_prune_aliases(struct inode *inode)
 {
 	struct dentry *dentry;
 restart:
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		spin_lock(&dentry->d_lock);
 		if (!dentry->d_count) {
 			__dget_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_inode_lock);
+			spin_unlock(&inode->i_lock);
 			dput(dentry);
 			goto restart;
 		}
 		spin_unlock(&dentry->d_lock);
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 }
 EXPORT_SYMBOL(d_prune_aliases);
 
@@ -1392,9 +1392,11 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 void d_instantiate(struct dentry *entry, struct inode * inode)
 {
 	BUG_ON(!list_empty(&entry->d_alias));
-	spin_lock(&dcache_inode_lock);
+	if (inode)
+		spin_lock(&inode->i_lock);
 	__d_instantiate(entry, inode);
-	spin_unlock(&dcache_inode_lock);
+	if (inode)
+		spin_unlock(&inode->i_lock);
 	security_d_instantiate(entry, inode);
 }
 EXPORT_SYMBOL(d_instantiate);
@@ -1458,9 +1460,11 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
 
 	BUG_ON(!list_empty(&entry->d_alias));
 
-	spin_lock(&dcache_inode_lock);
+	if (inode)
+		spin_lock(&inode->i_lock);
 	result = __d_instantiate_unique(entry, inode);
-	spin_unlock(&dcache_inode_lock);
+	if (inode)
+		spin_unlock(&inode->i_lock);
 
 	if (!result) {
 		security_d_instantiate(entry, inode);
@@ -1542,10 +1546,10 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	tmp->d_parent = tmp; /* make sure dput doesn't croak */
 
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	res = __d_find_alias(inode, 0);
 	if (res) {
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&inode->i_lock);
 		dput(tmp);
 		goto out_iput;
 	}
@@ -1561,7 +1565,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
 	__bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
 	spin_unlock(&tmp->d_lock);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 
 	return tmp;
 
@@ -1592,18 +1596,18 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 	struct dentry *new = NULL;
 
 	if (inode && S_ISDIR(inode->i_mode)) {
-		spin_lock(&dcache_inode_lock);
+		spin_lock(&inode->i_lock);
 		new = __d_find_alias(inode, 1);
 		if (new) {
 			BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
-			spin_unlock(&dcache_inode_lock);
+			spin_unlock(&inode->i_lock);
 			security_d_instantiate(new, inode);
 			d_move(new, dentry);
 			iput(inode);
 		} else {
-			/* already got dcache_inode_lock, so d_add() by hand */
+			/* already taking inode->i_lock, so d_add() by hand */
 			__d_instantiate(dentry, inode);
-			spin_unlock(&dcache_inode_lock);
+			spin_unlock(&inode->i_lock);
 			security_d_instantiate(dentry, inode);
 			d_rehash(dentry);
 		}
@@ -1676,10 +1680,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 * Negative dentry: instantiate it unless the inode is a directory and
 	 * already has a dentry.
 	 */
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
 		__d_instantiate(found, inode);
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&inode->i_lock);
 		security_d_instantiate(found, inode);
 		return found;
 	}
@@ -1690,7 +1694,7 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 */
 	new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
 	__dget(new);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	security_d_instantiate(found, inode);
 	d_move(new, found);
 	iput(inode);
@@ -2004,15 +2008,17 @@ EXPORT_SYMBOL(d_validate);
  
 void d_delete(struct dentry * dentry)
 {
+	struct inode *inode;
 	int isdir = 0;
 	/*
 	 * Are we the only user?
 	 */
 again:
 	spin_lock(&dentry->d_lock);
-	isdir = S_ISDIR(dentry->d_inode->i_mode);
+	inode = dentry->d_inode;
+	isdir = S_ISDIR(inode->i_mode);
 	if (dentry->d_count == 1) {
-		if (!spin_trylock(&dcache_inode_lock)) {
+		if (inode && !spin_trylock(&inode->i_lock)) {
 			spin_unlock(&dentry->d_lock);
 			cpu_relax();
 			goto again;
@@ -2266,13 +2272,13 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
  * This helper attempts to cope with remotely renamed directories
  *
  * It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex and the dcache_inode_lock
+ * dentry->d_parent->d_inode->i_mutex and the inode->i_lock
  *
  * Note: If ever the locking in lock_rename() changes, then please
  * remember to update this too...
  */
-static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
-	__releases(dcache_inode_lock)
+static struct dentry *__d_unalias(struct inode *inode,
+		struct dentry *dentry, struct dentry *alias)
 {
 	struct mutex *m1 = NULL, *m2 = NULL;
 	struct dentry *ret;
@@ -2298,7 +2304,7 @@ out_unalias:
 	d_move(alias, dentry);
 	ret = alias;
 out_err:
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	if (m2)
 		mutex_unlock(m2);
 	if (m1)
@@ -2371,7 +2377,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 		goto out_nolock;
 	}
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 
 	if (S_ISDIR(inode->i_mode)) {
 		struct dentry *alias;
@@ -2388,7 +2394,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 				goto found;
 			}
 			/* Nope, but we must(!) avoid directory aliasing */
-			actual = __d_unalias(dentry, alias);
+			actual = __d_unalias(inode, dentry, alias);
 			if (IS_ERR(actual))
 				dput(alias);
 			goto out_nolock;
@@ -2406,7 +2412,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 found:
 	_d_rehash(actual);
 	spin_unlock(&actual->d_lock);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 out_nolock:
 	if (actual == dentry) {
 		security_d_instantiate(dentry, inode);
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index f06a940065f6..4b6825740dd5 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -43,24 +43,26 @@ find_acceptable_alias(struct dentry *result,
 		void *context)
 {
 	struct dentry *dentry, *toput = NULL;
+	struct inode *inode;
 
 	if (acceptable(context, result))
 		return result;
 
-	spin_lock(&dcache_inode_lock);
-	list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
+	inode = result->d_inode;
+	spin_lock(&inode->i_lock);
+	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		dget(dentry);
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&inode->i_lock);
 		if (toput)
 			dput(toput);
 		if (dentry != result && acceptable(context, dentry)) {
 			dput(result);
 			return dentry;
 		}
-		spin_lock(&dcache_inode_lock);
+		spin_lock(&inode->i_lock);
 		toput = dentry;
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 
 	if (toput)
 		dput(toput);
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index c3a5a1126833..5596c6a2881e 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -63,11 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 		 * This again causes shrink_dcache_for_umount_subtree() to
 		 * Oops, since the test for IS_ROOT() will fail.
 		 */
-		spin_lock(&dcache_inode_lock);
+		spin_lock(&sb->s_root->d_inode->i_lock);
 		spin_lock(&sb->s_root->d_lock);
 		list_del_init(&sb->s_root->d_alias);
 		spin_unlock(&sb->s_root->d_lock);
-		spin_unlock(&dcache_inode_lock);
+		spin_unlock(&sb->s_root->d_inode->i_lock);
 	}
 	return 0;
 }
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 9be6ec1f36d8..79b47cbb5cd8 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -59,7 +59,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 	/* determine if the children should tell inode about their events */
 	watched = fsnotify_inode_watches_children(inode);
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	/* run all of the dentries associated with this inode.  Since this is a
 	 * directory, there damn well better only be one item on this list */
 	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
@@ -82,7 +82,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 		}
 		spin_unlock(&alias->d_lock);
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 }
 
 /* Notify this dentry's parent about a child's events. */
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 0310b16a7238..6d80ecc7834f 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -175,7 +175,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 	struct list_head *p;
 	struct dentry *dentry = NULL;
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	list_for_each(p, &inode->i_dentry) {
 		dentry = list_entry(p, struct dentry, d_alias);
 
@@ -193,7 +193,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 		dentry = NULL;
 	}
 
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 
 	return dentry;
 }
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 5f0392ef759b..d719e4de8046 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -191,7 +191,6 @@ struct dentry_operations {
 #define DCACHE_OP_REVALIDATE	0x4000
 #define DCACHE_OP_DELETE	0x8000
 
-extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
 
 static inline int dname_external(struct dentry *dentry)
-- 
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