move d_rcu from overlapping d_child to overlapping d_alias

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Hutchings <ben@decadent.org.uk>
[hujianyang: Backported to 3.10 refer to the work of Ben Hutchings in 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 36 insertions, 36 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 25c0a1b5f6c0..b3cb521809e9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -43,7 +43,7 @@
 /*
  * Usage:
  * dcache->d_inode->i_lock protects:
- *   - i_dentry, d_alias, d_inode of aliases
+ *   - i_dentry, d_u.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_unhashed()
  *   - d_parent and d_subdirs
  *   - childrens' d_child and d_parent
- *   - d_alias, d_inode
+ *   - d_u.d_alias, d_inode
  *
  * Ordering:
  * dentry->d_inode->i_lock
@@ -215,7 +215,6 @@ static void __d_free(struct rcu_head *head)
 {
 	struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
 
-	WARN_ON(!hlist_unhashed(&dentry->d_alias));
 	if (dname_external(dentry))
 		kfree(dentry->d_name.name);
 	kmem_cache_free(dentry_cache, dentry); 
@@ -226,6 +225,7 @@ static void __d_free(struct rcu_head *head)
  */
 static void d_free(struct dentry *dentry)
 {
+	WARN_ON(!hlist_unhashed(&dentry->d_u.d_alias));
 	BUG_ON(dentry->d_count);
 	this_cpu_dec(nr_dentry);
 	if (dentry->d_op && dentry->d_op->d_release)
@@ -264,7 +264,7 @@ static void dentry_iput(struct dentry * dentry)
 	struct inode *inode = dentry->d_inode;
 	if (inode) {
 		dentry->d_inode = NULL;
-		hlist_del_init(&dentry->d_alias);
+		hlist_del_init(&dentry->d_u.d_alias);
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&inode->i_lock);
 		if (!inode->i_nlink)
@@ -288,7 +288,7 @@ static void dentry_unlink_inode(struct dentry * dentry)
 {
 	struct inode *inode = dentry->d_inode;
 	dentry->d_inode = NULL;
-	hlist_del_init(&dentry->d_alias);
+	hlist_del_init(&dentry->d_u.d_alias);
 	dentry_rcuwalk_barrier(dentry);
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&inode->i_lock);
@@ -364,7 +364,7 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
 	__releases(parent->d_lock)
 	__releases(dentry->d_inode->i_lock)
 {
-	list_del(&dentry->d_u.d_child);
+	list_del(&dentry->d_child);
 	/*
 	 * Inform try_to_ascend() that we are no longer attached to the
 	 * dentry tree
@@ -660,7 +660,7 @@ static struct dentry *__d_find_alias(struct inode *inode, int want_discon)
 
 again:
 	discon_alias = NULL;
-	hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
+	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
 		spin_lock(&alias->d_lock);
  		if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
 			if (IS_ROOT(alias) &&
@@ -713,7 +713,7 @@ void d_prune_aliases(struct inode *inode)
 	struct dentry *dentry;
 restart:
 	spin_lock(&inode->i_lock);
-	hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+	hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
 		spin_lock(&dentry->d_lock);
 		if (!dentry->d_count) {
 			__dget_dlock(dentry);
@@ -893,7 +893,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 		/* descend to the first leaf in the current subtree */
 		while (!list_empty(&dentry->d_subdirs))
 			dentry = list_entry(dentry->d_subdirs.next,
-					    struct dentry, d_u.d_child);
+					    struct dentry, d_child);
 
 		/* consume the dentries from this leaf up through its parents
 		 * until we find one with children or run out altogether */
@@ -927,17 +927,17 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 
 			if (IS_ROOT(dentry)) {
 				parent = NULL;
-				list_del(&dentry->d_u.d_child);
+				list_del(&dentry->d_child);
 			} else {
 				parent = dentry->d_parent;
 				parent->d_count--;
-				list_del(&dentry->d_u.d_child);
+				list_del(&dentry->d_child);
 			}
 
 			inode = dentry->d_inode;
 			if (inode) {
 				dentry->d_inode = NULL;
-				hlist_del_init(&dentry->d_alias);
+				hlist_del_init(&dentry->d_u.d_alias);
 				if (dentry->d_op && dentry->d_op->d_iput)
 					dentry->d_op->d_iput(dentry, inode);
 				else
@@ -955,7 +955,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 		} while (list_empty(&dentry->d_subdirs));
 
 		dentry = list_entry(dentry->d_subdirs.next,
-				    struct dentry, d_u.d_child);
+				    struct dentry, d_child);
 	}
 }
 
@@ -1048,7 +1048,7 @@ repeat:
 resume:
 	while (next != &this_parent->d_subdirs) {
 		struct list_head *tmp = next;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
 		next = tmp->next;
 
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
@@ -1075,7 +1075,7 @@ resume:
 		this_parent = try_to_ascend(this_parent, locked, seq);
 		if (!this_parent)
 			goto rename_retry;
-		next = child->d_u.d_child.next;
+		next = child->d_child.next;
 		goto resume;
 	}
 	spin_unlock(&this_parent->d_lock);
@@ -1131,7 +1131,7 @@ repeat:
 resume:
 	while (next != &this_parent->d_subdirs) {
 		struct list_head *tmp = next;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
 		next = tmp->next;
 
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
@@ -1182,7 +1182,7 @@ resume:
 		this_parent = try_to_ascend(this_parent, locked, seq);
 		if (!this_parent)
 			goto rename_retry;
-		next = child->d_u.d_child.next;
+		next = child->d_child.next;
 		goto resume;
 	}
 out:
@@ -1278,8 +1278,8 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
 	INIT_HLIST_BL_NODE(&dentry->d_hash);
 	INIT_LIST_HEAD(&dentry->d_lru);
 	INIT_LIST_HEAD(&dentry->d_subdirs);
-	INIT_HLIST_NODE(&dentry->d_alias);
-	INIT_LIST_HEAD(&dentry->d_u.d_child);
+	INIT_HLIST_NODE(&dentry->d_u.d_alias);
+	INIT_LIST_HEAD(&dentry->d_child);
 	d_set_d_op(dentry, dentry->d_sb->s_d_op);
 
 	this_cpu_inc(nr_dentry);
@@ -1309,7 +1309,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 	 */
 	__dget_dlock(parent);
 	dentry->d_parent = parent;
-	list_add(&dentry->d_u.d_child, &parent->d_subdirs);
+	list_add(&dentry->d_child, &parent->d_subdirs);
 	spin_unlock(&parent->d_lock);
 
 	return dentry;
@@ -1369,7 +1369,7 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 	if (inode) {
 		if (unlikely(IS_AUTOMOUNT(inode)))
 			dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
-		hlist_add_head(&dentry->d_alias, &inode->i_dentry);
+		hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
 	}
 	dentry->d_inode = inode;
 	dentry_rcuwalk_barrier(dentry);
@@ -1394,7 +1394,7 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
  
 void d_instantiate(struct dentry *entry, struct inode * inode)
 {
-	BUG_ON(!hlist_unhashed(&entry->d_alias));
+	BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
 	if (inode)
 		spin_lock(&inode->i_lock);
 	__d_instantiate(entry, inode);
@@ -1433,7 +1433,7 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry,
 		return NULL;
 	}
 
-	hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
+	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
 		/*
 		 * Don't need alias->d_lock here, because aliases with
 		 * d_parent == entry->d_parent are not subject to name or
@@ -1459,7 +1459,7 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
 {
 	struct dentry *result;
 
-	BUG_ON(!hlist_unhashed(&entry->d_alias));
+	BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
 
 	if (inode)
 		spin_lock(&inode->i_lock);
@@ -1502,7 +1502,7 @@ static struct dentry * __d_find_any_alias(struct inode *inode)
 
 	if (hlist_empty(&inode->i_dentry))
 		return NULL;
-	alias = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+	alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
 	__dget(alias);
 	return alias;
 }
@@ -1576,7 +1576,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	spin_lock(&tmp->d_lock);
 	tmp->d_inode = inode;
 	tmp->d_flags |= DCACHE_DISCONNECTED;
-	hlist_add_head(&tmp->d_alias, &inode->i_dentry);
+	hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry);
 	hlist_bl_lock(&tmp->d_sb->s_anon);
 	hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
 	hlist_bl_unlock(&tmp->d_sb->s_anon);
@@ -2019,7 +2019,7 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
 	struct dentry *child;
 
 	spin_lock(&dparent->d_lock);
-	list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
+	list_for_each_entry(child, &dparent->d_subdirs, d_child) {
 		if (dentry == child) {
 			spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
 			__dget_dlock(dentry);
@@ -2266,8 +2266,8 @@ static void __d_move(struct dentry * dentry, struct dentry * target)
 	/* Unhash the target: dput() will then get rid of it */
 	__d_drop(target);
 
-	list_del(&dentry->d_u.d_child);
-	list_del(&target->d_u.d_child);
+	list_del(&dentry->d_child);
+	list_del(&target->d_child);
 
 	/* Switch the names.. */
 	switch_names(dentry, target);
@@ -2277,15 +2277,15 @@ static void __d_move(struct dentry * dentry, struct dentry * target)
 	if (IS_ROOT(dentry)) {
 		dentry->d_parent = target->d_parent;
 		target->d_parent = target;
-		INIT_LIST_HEAD(&target->d_u.d_child);
+		INIT_LIST_HEAD(&target->d_child);
 	} else {
 		swap(dentry->d_parent, target->d_parent);
 
 		/* And add them back to the (new) parent lists */
-		list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
+		list_add(&target->d_child, &target->d_parent->d_subdirs);
 	}
 
-	list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+	list_add(&dentry->d_child, &dentry->d_parent->d_subdirs);
 
 	write_seqcount_end(&target->d_seq);
 	write_seqcount_end(&dentry->d_seq);
@@ -2392,9 +2392,9 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
 	swap(dentry->d_name.hash, anon->d_name.hash);
 
 	dentry->d_parent = dentry;
-	list_del_init(&dentry->d_u.d_child);
+	list_del_init(&dentry->d_child);
 	anon->d_parent = dparent;
-	list_move(&anon->d_u.d_child, &dparent->d_subdirs);
+	list_move(&anon->d_child, &dparent->d_subdirs);
 
 	write_seqcount_end(&dentry->d_seq);
 	write_seqcount_end(&anon->d_seq);
@@ -2933,7 +2933,7 @@ repeat:
 resume:
 	while (next != &this_parent->d_subdirs) {
 		struct list_head *tmp = next;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
 		next = tmp->next;
 
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
@@ -2963,7 +2963,7 @@ resume:
 		this_parent = try_to_ascend(this_parent, locked, seq);
 		if (!this_parent)
 			goto rename_retry;
-		next = child->d_u.d_child.next;
+		next = child->d_child.next;
 		goto resume;
 	}
 	spin_unlock(&this_parent->d_lock);