2.6.24-rc8

 fs

diff --git a/fs/dcache.c b/fs/dcache.c
index 678d39d..d9ca1e5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -38,7 +38,7 @@ int sysctl_vfs_cache_pressure __read_mostly = 100;
 EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 
  __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
-static __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
 
 EXPORT_SYMBOL(dcache_lock);
 
@@ -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;
 
@@ -1483,6 +1479,8 @@ static void switch_names(struct dentry *dentry, struct dentry *target)
           * dentry:internal, target:external.  Steal target's
           * storage and make target internal.
           */
+         memcpy(target->d_iname, dentry->d_name.name,
+               dentry->d_name.len + 1);
          dentry->d_name.name = target->d_name.name;
          target->d_name.name = target->d_iname;
       }
@@ -1514,8 +1512,8 @@ 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 +1544,7 @@ 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 +2106,7 @@ 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 +2168,10 @@ 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();
 }