1 files changed, 10 insertions, 14 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 920c87720385..bde6057c5df6 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;
                         }
@@ -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;
 }