1 files changed, 21 insertions, 25 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 678d39deb60..5489b2d98a0 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -381,20 +381,17 @@ restart:
  * Throw away a dentry - free the inode, dput the parent.  This requires that
  * the LRU list has already been removed.
  *
- * If prune_parents is true, try to prune ancestors as well.
+ * Try to prune ancestors as well.  This is necessary to prevent
+ * quadratic behavior of shrink_dcache_parent(), but is also expected
+ * to be beneficial in reducing dentry cache fragmentation.
  *
  * Called with dcache_lock, drops it and then regains.
  * Called with dentry->d_lock held, drops it.
  */
-static void prune_one_dentry(struct dentry * dentry, int prune_parents)
+static void prune_one_dentry(struct dentry * dentry)
 {
 	__d_drop(dentry);
 	dentry = d_kill(dentry);
-	if (!prune_parents) {
-		dput(dentry);
-		spin_lock(&dcache_lock);
-		return;
-	}
 
 	/*
 	 * Prune ancestors.  Locking is simpler than in dput(),
@@ -422,7 +419,6 @@ static void prune_one_dentry(struct dentry * dentry, int prune_parents)
  * @count: number of entries to try and free
  * @sb: if given, ignore dentries for other superblocks
  *         which are being unmounted.
- * @prune_parents: if true, try to prune ancestors as well in one go
  *
  * Shrink the dcache. This is done when we need
  * more memory, or simply when we need to unmount
@@ -433,7 +429,7 @@ static void prune_one_dentry(struct dentry * dentry, int prune_parents)
  * all the dentries are in use.
  */
  
-static void prune_dcache(int count, struct super_block *sb, int prune_parents)
+static void prune_dcache(int count, struct super_block *sb)
 {
 	spin_lock(&dcache_lock);
 	for (; count ; count--) {
@@ -493,7 +489,7 @@ static void prune_dcache(int count, struct super_block *sb, int prune_parents)
 		 * without taking the s_umount lock (I already hold it).
 		 */
 		if (sb && dentry->d_sb == sb) {
-			prune_one_dentry(dentry, prune_parents);
+			prune_one_dentry(dentry);
 			continue;
 		}
 		/*
@@ -508,7 +504,7 @@ static void prune_dcache(int count, struct super_block *sb, int prune_parents)
 		s_umount = &dentry->d_sb->s_umount;
 		if (down_read_trylock(s_umount)) {
 			if (dentry->d_sb->s_root != NULL) {
-				prune_one_dentry(dentry, prune_parents);
+				prune_one_dentry(dentry);
 				up_read(s_umount);
 				continue;
 			}
@@ -557,18 +553,18 @@ void shrink_dcache_sb(struct super_block * sb)
 	 * superblock to the most recent end of the unused list.
 	 */
 	spin_lock(&dcache_lock);
-	list_for_each_safe(tmp, next, &dentry_unused) {
+	list_for_each_prev_safe(tmp, next, &dentry_unused) {
 		dentry = list_entry(tmp, struct dentry, d_lru);
 		if (dentry->d_sb != sb)
 			continue;
-		list_move(tmp, &dentry_unused);
+		list_move_tail(tmp, &dentry_unused);
 	}
 
 	/*
 	 * Pass two ... free the dentries for this superblock.
 	 */
 repeat:
-	list_for_each_safe(tmp, next, &dentry_unused) {
+	list_for_each_prev_safe(tmp, next, &dentry_unused) {
 		dentry = list_entry(tmp, struct dentry, d_lru);
 		if (dentry->d_sb != sb)
 			continue;
@@ -579,7 +575,7 @@ repeat:
 			spin_unlock(&dentry->d_lock);
 			continue;
 		}
-		prune_one_dentry(dentry, 1);
+		prune_one_dentry(dentry);
 		cond_resched_lock(&dcache_lock);
 		goto repeat;
 	}
@@ -858,7 +854,7 @@ void shrink_dcache_parent(struct dentry * parent)
 	int found;
 
 	while ((found = select_parent(parent)) != 0)
-		prune_dcache(found, parent->d_sb, 1);
+		prune_dcache(found, parent->d_sb);
 }
 
 /*
@@ -878,7 +874,7 @@ static int shrink_dcache_memory(int nr, gfp_t gfp_mask)
 	if (nr) {
 		if (!(gfp_mask & __GFP_FS))
 			return -1;
-		prune_dcache(nr, NULL, 1);
+		prune_dcache(nr, NULL);
 	}
 	return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
 }
@@ -903,7 +899,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 	struct dentry *dentry;
 	char *dname;
 
-	dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL); 
+	dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
 	if (!dentry)
 		return NULL;
 
@@ -1514,8 +1510,8 @@ static void switch_names(struct dentry *dentry, struct dentry *target)
  * This forceful removal will result in ugly /proc output if
  * somebody holds a file open that got deleted due to a rename.
  * We could be nicer about the deleted file, and let it show
- * up under the name it got deleted rather than the name that
- * deleted it.
+ * up under the name it had before it was deleted rather than
+ * under the original name of the file that was moved on top of it.
  */
  
 /*
@@ -1546,7 +1542,7 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target)
 	}
 
 	/* Move the dentry to the target hash queue, if on different bucket */
-	if (dentry->d_flags & DCACHE_UNHASHED)
+	if (d_unhashed(dentry))
 		goto already_unhashed;
 
 	hlist_del_rcu(&dentry->d_hash);
@@ -2108,7 +2104,7 @@ static void __init dcache_init_early(void)
 		INIT_HLIST_HEAD(&dentry_hashtable[loop]);
 }
 
-static void __init dcache_init(unsigned long mempages)
+static void __init dcache_init(void)
 {
 	int loop;
 
@@ -2170,10 +2166,10 @@ void __init vfs_caches_init(unsigned long mempages)
 	filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
 			SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 
-	dcache_init(mempages);
-	inode_init(mempages);
+	dcache_init();
+	inode_init();
 	files_init(mempages);
-	mnt_init(mempages);
+	mnt_init();
 	bdev_cache_init();
 	chrdev_init();
 }