clean out unused code in dentry pruning

It looks like in the end all pruners want parents removed.

So remove unused code and function arguments.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/dcache.c b/fs/dcache.c
index 920c877..bde6057 100644 (file)
--- 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;
 }