dcache-split-inode_lock

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@suse.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

16 files changed, 111 insertions, 112 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 5f89414446c4..7f0737214788 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -160,7 +160,7 @@ static void spufs_prune_dir(struct dentry *dir)
 	list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
 		spin_lock(&dentry->d_lock);
 		if (!(d_unhashed(dentry)) && dentry->d_inode) {
-			dget_locked_dlock(dentry);
+			dget_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
 			simple_unlink(dir->d_inode, dentry);
diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 39f9f1ba46f7..ba08b0e6ea5a 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -274,7 +274,7 @@ static int remove_file(struct dentry *parent, char *name)
 
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
-		dget_locked_dlock(tmp);
+		dget_dlock(tmp);
 		__d_drop(tmp);
 		spin_unlock(&tmp->d_lock);
 		simple_unlink(parent->d_inode, tmp);
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/autofs4/root.c b/fs/autofs4/root.c
index f674826cf989..9e108ae491a8 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -575,7 +575,7 @@ restart:
 
 		if (active->d_inode && IS_DEADDIR(active->d_inode)) {
 			if (!list_empty(&ino->rehash_list)) {
-				dget_locked_dlock(active);
+				dget_dlock(active);
 				spin_unlock(&active->d_lock);
 				spin_unlock(&sbi->lookup_lock);
 				spin_unlock(&autofs4_lock);
@@ -598,7 +598,7 @@ restart:
 		if (memcmp(qstr->name, str, len))
 			goto next;
 
-		dget_locked_dlock(active);
+		dget_dlock(active);
 		spin_unlock(&active->d_lock);
 		spin_unlock(&sbi->lookup_lock);
 		spin_unlock(&autofs4_lock);
@@ -651,7 +651,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
 		if (memcmp(qstr->name, str, len))
 			goto next;
 
-		dget_locked_dlock(expiring);
+		dget_dlock(expiring);
 		spin_unlock(&expiring->d_lock);
 		spin_unlock(&sbi->lookup_lock);
 		spin_unlock(&autofs4_lock);
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 52d73487f765..aa8e83ed0f0b 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -256,7 +256,7 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
 	if (dentry) {
 		spin_lock(&dentry->d_lock);
 		if (!(d_unhashed(dentry) && dentry->d_inode)) {
-			dget_locked_dlock(dentry);
+			dget_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
 			simple_unlink(parent->d_inode, dentry);
diff --git a/fs/dcache.c b/fs/dcache.c
index 4822e0d9b970..c992c5aed5d1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -37,7 +37,7 @@
 
 /*
  * Usage:
- * dcache_inode_lock protects:
+ * dcache->d_inode->i_lock protects:
  *   - the inode alias lists, d_inode
  * dcache_hash_bucket->lock protects:
  *   - the dcache hash table
@@ -51,7 +51,7 @@
  *   - d_subdirs and children's d_child
  *
  * Ordering:
- * dcache_inode_lock
+ * dcache->d_inode->i_lock
  *   dentry->d_lock
  *     dcache_lru_lock
  *     dcache_hash_bucket->lock
@@ -59,12 +59,10 @@
 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;
 
@@ -140,14 +138,13 @@ static void d_free(struct dentry *dentry)
  */
 static void dentry_iput(struct dentry * dentry)
 	__releases(dentry->d_lock)
-	__releases(dcache_inode_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)
@@ -156,7 +153,6 @@ static void dentry_iput(struct dentry * dentry)
 			iput(inode);
 	} else {
 		spin_unlock(&dentry->d_lock);
-		spin_unlock(&dcache_inode_lock);
 	}
 }
 
@@ -227,7 +223,6 @@ static void dentry_lru_del_init(struct dentry *dentry)
  */
 static struct dentry *d_kill(struct dentry *dentry)
 	__releases(dentry->d_lock)
-	__releases(dcache_inode_lock)
 {
 	struct dentry *parent;
 
@@ -265,32 +260,20 @@ void d_drop(struct dentry *dentry)
 }
 EXPORT_SYMBOL(d_drop);
 
-/* This should be called _only_ with a lock pinning the dentry */
-static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
+static inline struct dentry *__dget_dlock(struct dentry *dentry)
 {
 	dentry->d_count++;
-	dentry_lru_del_init(dentry);
 	return dentry;
 }
 
-static inline struct dentry * __dget_locked(struct dentry *dentry)
+static inline struct dentry *__dget(struct dentry *dentry)
 {
 	spin_lock(&dentry->d_lock);
-	__dget_locked_dlock(dentry);
+	__dget_dlock(dentry);
 	spin_unlock(&dentry->d_lock);
 	return dentry;
 }
 
-struct dentry * dget_locked_dlock(struct dentry *dentry)
-{
-	return __dget_locked_dlock(dentry);
-}
-
-struct dentry * dget_locked(struct dentry *dentry)
-{
-	return __dget_locked(dentry);
-}
-
 struct dentry *dget_parent(struct dentry *dentry)
 {
 	struct dentry *ret;
@@ -349,6 +332,7 @@ EXPORT_SYMBOL(dget_parent);
 void dput(struct dentry *dentry)
 {
 	struct dentry *parent;
+	struct inode *inode;
 
 	if (!dentry)
 		return;
@@ -384,16 +368,23 @@ repeat:
 	spin_unlock(&dentry->d_lock);
 	return;
 
-kill_it:
-	spin_unlock(&dentry->d_lock);
-	spin_lock(&dcache_inode_lock);
-relock:
+relock1:
 	spin_lock(&dentry->d_lock);
+kill_it:
+	inode = dentry->d_inode;
+	if (inode) {
+		if (!spin_trylock(&inode->i_lock)) {
+relock2:
+			spin_unlock(&dentry->d_lock);
+			goto relock1;
+		}
+	}
 	parent = dentry->d_parent;
 	if (parent && parent != dentry) {
 		if (!spin_trylock(&parent->d_lock)) {
-			spin_unlock(&dentry->d_lock);
-			goto relock;
+			if (inode)
+				spin_unlock(&inode->i_lock);
+			goto relock2;
 		}
 	}
 	dentry->d_count--;
@@ -402,7 +393,8 @@ relock:
 		spin_unlock(&dentry->d_lock);
 		if (parent && parent != dentry)
 			spin_unlock(&parent->d_lock);
-		spin_unlock(&dcache_inode_lock);
+		if (inode)
+			spin_unlock(&inode->i_lock);
 		return;
 	}
 	/* if dentry was on the d_lru list delete it from there */
@@ -501,7 +493,7 @@ static struct dentry * __d_find_alias(struct inode *inode, int want_discon)
 			    (alias->d_flags & DCACHE_DISCONNECTED))
 				discon_alias = alias;
 			else if (!want_discon) {
-				__dget_locked_dlock(alias);
+				__dget_dlock(alias);
 				spin_unlock(&alias->d_lock);
 				return alias;
 			}
@@ -509,7 +501,7 @@ static struct dentry * __d_find_alias(struct inode *inode, int want_discon)
 		spin_unlock(&alias->d_lock);
 	}
 	if (discon_alias)
-		__dget_locked(discon_alias);
+		__dget(discon_alias);
 	return discon_alias;
 }
 
@@ -518,9 +510,9 @@ 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;
 }
@@ -533,20 +525,20 @@ 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_locked_dlock(dentry);
+			__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);
 }
 
 /*
@@ -568,8 +560,10 @@ static void prune_one_dentry(struct dentry * dentry)
 	 */
 	while (dentry) {
 		struct dentry *parent = NULL;
+		struct inode *inode = dentry->d_inode;
 
-		spin_lock(&dcache_inode_lock);
+		if (inode)
+			spin_lock(&inode->i_lock);
 again:
 		spin_lock(&dentry->d_lock);
 		if (dentry->d_parent && dentry != dentry->d_parent) {
@@ -584,7 +578,8 @@ again:
 			if (parent)
 				spin_unlock(&parent->d_lock);
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_inode_lock);
+			if (inode)
+				spin_unlock(&inode->i_lock);
 			return;
 		}
 
@@ -653,10 +648,11 @@ restart:
 	}
 	spin_unlock(&dcache_lru_lock);
 
-	spin_lock(&dcache_inode_lock);
 again:
 	spin_lock(&dcache_lru_lock); /* lru_lock also protects tmp list */
 	while (!list_empty(&tmp)) {
+		struct inode *inode;
+
 		dentry = list_entry(tmp.prev, struct dentry, d_lru);
 
 		if (!spin_trylock(&dentry->d_lock)) {
@@ -674,10 +670,17 @@ again1:
 			spin_unlock(&dentry->d_lock);
 			continue;
 		}
+		inode = dentry->d_inode;
+		if (inode && !spin_trylock(&inode->i_lock)) {
+again2:
+			spin_unlock(&dentry->d_lock);
+			goto again1;
+		}
 		if (dentry->d_parent && dentry->d_parent != dentry) {
 			if (!spin_trylock(&dentry->d_parent->d_lock)) {
-				spin_unlock(&dentry->d_lock);
-				goto again1;
+				if (inode)
+					spin_unlock(&inode->i_lock);
+				goto again2;
 			}
 		}
 		__dentry_lru_del_init(dentry);
@@ -685,10 +688,8 @@ again1:
 
 		prune_one_dentry(dentry);
 		/* dentry->d_lock dropped */
-		spin_lock(&dcache_inode_lock);
 		spin_lock(&dcache_lru_lock);
 	}
-	spin_unlock(&dcache_inode_lock);
 
 	if (count == NULL && !list_empty(&sb->s_dentry_lru))
 		goto restart;
@@ -1252,9 +1253,11 @@ 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);
 }
 
@@ -1298,7 +1301,7 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry,
 			continue;
 		if (memcmp(qstr->name, name, len))
 			continue;
-		dget_locked(alias);
+		dget(alias);
 		return alias;
 	}
 
@@ -1312,9 +1315,11 @@ 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);
@@ -1394,10 +1399,10 @@ 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;
 	}
@@ -1411,7 +1416,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	list_add(&tmp->d_alias, &inode->i_dentry);
 	hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
 	spin_unlock(&tmp->d_lock);
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 
 	return tmp;
 
@@ -1442,19 +1447,19 @@ 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_rehash(dentry);
 			d_move(new, dentry);
 			iput(inode);
 		} else {
-			/* already taken dcache_inode_lock, d_add() by hand */
+			/* already taken inode->i_lock, 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);
 		}
@@ -1526,10 +1531,10 @@ 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;
 	}
@@ -1539,8 +1544,8 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 	 * reference to it, move it in place and use it.
 	 */
 	new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
-	dget_locked(new);
-	spin_unlock(&dcache_inode_lock);
+	dget(new);
+	spin_unlock(&inode->i_lock);
 	security_d_instantiate(found, inode);
 	d_move(new, found);
 	iput(inode);
@@ -1574,8 +1579,7 @@ err_out:
  *
  * The dentry unused LRU is not updated even if lookup finds the required dentry
  * in there. It is updated in places such as prune_dcache, shrink_dcache_sb,
- * select_parent and __dget_locked. This laziness saves lookup from LRU lock
- * acquisition.
+ * select_parent. This laziness saves lookup from LRU lock acquisition.
  *
  * d_lookup() is protected against the concurrent renames in some unrelated
  * directory using the seqlockt_t rename_lock.
@@ -1716,7 +1720,7 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
 		 */
 		if (dentry == hlist_entry(lhp, struct dentry, d_hash)) {
 			spin_unlock(&b->lock);
-			__dget_locked_dlock(dentry);
+			__dget_dlock(dentry);
 			spin_unlock(&dentry->d_lock);
 			return 1;
 		}
@@ -1750,15 +1754,17 @@ out:
  
 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);
 			goto again;
 		}
@@ -1996,6 +2002,7 @@ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
 {
 	struct mutex *m1 = NULL, *m2 = NULL;
 	struct dentry *ret;
+	struct inode *inode;
 
 	/* If alias and dentry share a parent, then no extra locks required */
 	if (alias->d_parent == dentry->d_parent)
@@ -2011,14 +2018,15 @@ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
 	if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex))
 		goto out_err;
 	m1 = &dentry->d_sb->s_vfs_rename_mutex;
-	if (!mutex_trylock(&alias->d_parent->d_inode->i_mutex))
+	inode = alias->d_parent->d_inode;
+	if (!mutex_trylock(&inode->i_mutex))
 		goto out_err;
-	m2 = &alias->d_parent->d_inode->i_mutex;
+	m2 = &inode->i_mutex;
 out_unalias:
 	d_move_locked(alias, dentry);
 	ret = alias;
 out_err:
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 	if (m2)
 		mutex_unlock(m2);
 	if (m1)
@@ -2089,7 +2097,7 @@ 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;
@@ -2125,7 +2133,7 @@ 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);
@@ -2688,7 +2696,6 @@ EXPORT_SYMBOL(d_rehash);
 EXPORT_SYMBOL(d_splice_alias);
 EXPORT_SYMBOL(d_add_ci);
 EXPORT_SYMBOL(d_validate);
-EXPORT_SYMBOL(dget_locked);
 EXPORT_SYMBOL(dput);
 EXPORT_SYMBOL(find_inode_number);
 EXPORT_SYMBOL(have_submounts);
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 61629d7ff382..b55fee07c0d9 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) {
-		dget_locked(dentry);
-		spin_unlock(&dcache_inode_lock);
+	inode = result->d_inode;
+	spin_lock(&inode->i_lock);
+	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+		dget(dentry);
+		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/ncpfs/dir.c b/fs/ncpfs/dir.c
index 02685b5f5071..0a5210802874 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -370,7 +370,7 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 		dent = list_entry(next, struct dentry, d_u.d_child);
 		if ((unsigned long)dent->d_fsdata == fpos) {
 			if (dent->d_inode)
-				dget_locked(dent);
+				dget(dent);
 			else
 				dent = NULL;
 			spin_unlock(&parent->d_lock);
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 2a31f3c83df9..f90a380a6364 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -64,11 +64,11 @@ 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 e9ba87ebf280..bdaaa5813d2c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -52,7 +52,7 @@ 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) {
@@ -75,7 +75,7 @@ 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/notify/inotify/inotify.c b/fs/notify/inotify/inotify.c
index ea87c0f0d1ed..1915a9a55252 100644
--- a/fs/notify/inotify/inotify.c
+++ b/fs/notify/inotify/inotify.c
@@ -185,7 +185,7 @@ static void set_dentry_child_flags(struct inode *inode, int watched)
 {
 	struct dentry *alias;
 
-	spin_lock(&dcache_inode_lock);
+	spin_lock(&inode->i_lock);
 	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
 		struct dentry *child;
 
@@ -203,7 +203,7 @@ static void set_dentry_child_flags(struct inode *inode, int watched)
 		}
 		spin_unlock(&alias->d_lock);
 	}
-	spin_unlock(&dcache_inode_lock);
+	spin_unlock(&inode->i_lock);
 }
 
 /*
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index ef24898e4754..d825f00eda71 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -151,7 +151,7 @@ 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);
 
@@ -160,7 +160,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
 			mlog(0, "dentry found: %.*s\n",
 			     dentry->d_name.len, dentry->d_name.name);
 
-			dget_locked_dlock(dentry);
+			dget_dlock(dentry);
 			spin_unlock(&dentry->d_lock);
 			break;
 		}
@@ -169,7 +169,7 @@ 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/fs/smbfs/cache.c b/fs/smbfs/cache.c
index 9351e1d79848..61e482123488 100644
--- a/fs/smbfs/cache.c
+++ b/fs/smbfs/cache.c
@@ -102,7 +102,7 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 		dent = list_entry(next, struct dentry, d_u.d_child);
 		if ((unsigned long)dent->d_fsdata == fpos) {
 			if (dent->d_inode)
-				dget_locked(dent);
+				dget(dent);
 			else
 				dent = NULL;
 			goto out_unlock;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index e3bec299113a..1ca2e7fb7a86 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -186,7 +186,6 @@ d_iput:		no		no       yes
 
 #define DCACHE_FSNOTIFY_PARENT_WATCHED	0x0080 /* Parent inode is watched by some fsnotify listener */
 
-extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
 
 /**
@@ -303,23 +302,17 @@ extern char *dentry_path(struct dentry *, char *, int);
 /* Allocation counts.. */
 
 /**
- *	dget, dget_locked	-	get a reference to a dentry
+ *	dget, dget_dlock -	get a reference to a dentry
  *	@dentry: dentry to get a reference to
  *
  *	Given a dentry or %NULL pointer increment the reference count
  *	if appropriate and return the dentry. A dentry will not be 
- *	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().
+ *	destroyed when it has references.
  */
 static inline struct dentry *dget_dlock(struct dentry *dentry)
 {
-	if (dentry) {
-		BUG_ON(!dentry->d_count);
+	if (dentry)
 		dentry->d_count++;
-	}
 	return dentry;
 }
 
@@ -333,9 +326,6 @@ static inline struct dentry *dget(struct dentry *dentry)
 	return dentry;
 }
 
-extern struct dentry * dget_locked(struct dentry *);
-extern struct dentry * dget_locked_dlock(struct dentry *);
-
 extern struct dentry *dget_parent(struct dentry *dentry);
 
 /**
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index bd31be20a22a..84ad27652d40 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -819,7 +819,7 @@ static void cgroup_clear_directory(struct dentry *dentry)
 			/* This should never be called on a cgroup
 			 * directory with child cgroups */
 			BUG_ON(d->d_inode->i_mode & S_IFDIR);
-			dget_locked_dlock(d);
+			dget_dlock(d);
 			spin_unlock(&d->d_lock);
 			spin_unlock(&dentry->d_lock);
 			d_delete(d);
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 7654521fced1..a016c04e5d52 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -952,7 +952,7 @@ static void sel_remove_entries(struct dentry *de)
 		list_del_init(node);
 
 		if (d->d_inode) {
-			dget_locked_dlock(d);
+			dget_dlock(d);
 			spin_unlock(&de->d_lock);
 			spin_unlock(&d->d_lock);
 			d_delete(d);