1 files changed, 20 insertions, 17 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index b9caf47..4d9df3c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -258,7 +258,7 @@ static void __d_free(struct rcu_head *head)
  */
 static void d_free(struct dentry *dentry)
 {
-	BUG_ON(dentry->d_lockref.count);
+	BUG_ON((int)dentry->d_lockref.count > 0);
 	this_cpu_dec(nr_dentry);
 	if (dentry->d_op && dentry->d_op->d_release)
 		dentry->d_op->d_release(dentry);
@@ -337,8 +337,9 @@ static void dentry_unlink_inode(struct dentry * dentry)
  */
 static void dentry_lru_add(struct dentry *dentry)
 {
-	if (list_empty(&dentry->d_lru)) {
+	if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) {
 		spin_lock(&dcache_lru_lock);
+		dentry->d_flags |= DCACHE_LRU_LIST;
 		list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
 		dentry->d_sb->s_nr_dentry_unused++;
 		dentry_stat.nr_unused++;
@@ -349,7 +350,7 @@ static void dentry_lru_add(struct dentry *dentry)
 static void __dentry_lru_del(struct dentry *dentry)
 {
 	list_del_init(&dentry->d_lru);
-	dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+	dentry->d_flags &= ~(DCACHE_SHRINK_LIST | DCACHE_LRU_LIST);
 	dentry->d_sb->s_nr_dentry_unused--;
 	dentry_stat.nr_unused--;
 }
@@ -370,6 +371,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
 {
 	spin_lock(&dcache_lru_lock);
 	if (list_empty(&dentry->d_lru)) {
+		dentry->d_flags |= DCACHE_LRU_LIST;
 		list_add_tail(&dentry->d_lru, list);
 		dentry->d_sb->s_nr_dentry_unused++;
 		dentry_stat.nr_unused++;
@@ -472,7 +474,7 @@ EXPORT_SYMBOL(d_drop);
  * If ref is non-zero, then decrement the refcount too.
  * Returns dentry requiring refcount drop, or NULL if we're done.
  */
-static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
+static inline struct dentry *dentry_kill(struct dentry *dentry)
 	__releases(dentry->d_lock)
 {
 	struct inode *inode;
@@ -495,8 +497,11 @@ relock:
 		goto relock;
 	}
 
-	if (ref)
-		dentry->d_lockref.count--;
+	/*
+	 * The dentry is now unrecoverably dead to the world.
+	 */
+	lockref_mark_dead(&dentry->d_lockref);
+
 	/*
 	 * inform the fs via d_prune that this dentry is about to be
 	 * unhashed and destroyed.
@@ -538,24 +543,22 @@ relock:
  */
 void dput(struct dentry *dentry)
 {
-	if (!dentry)
+	if (unlikely(!dentry))
 		return;
 
 repeat:
-	if (dentry->d_lockref.count == 1)
-		might_sleep();
 	if (lockref_put_or_lock(&dentry->d_lockref))
 		return;
 
-	if (dentry->d_flags & DCACHE_OP_DELETE) {
+	/* Unreachable? Get rid of it */
+	if (unlikely(d_unhashed(dentry)))
+		goto kill_it;
+
+	if (unlikely(dentry->d_flags & DCACHE_OP_DELETE)) {
 		if (dentry->d_op->d_delete(dentry))
 			goto kill_it;
 	}
 
-	/* Unreachable? Get rid of it */
- 	if (d_unhashed(dentry))
-		goto kill_it;
-
 	dentry->d_flags |= DCACHE_REFERENCED;
 	dentry_lru_add(dentry);
 
@@ -564,7 +567,7 @@ repeat:
 	return;
 
 kill_it:
-	dentry = dentry_kill(dentry, 1);
+	dentry = dentry_kill(dentry);
 	if (dentry)
 		goto repeat;
 }
@@ -789,7 +792,7 @@ static void try_prune_one_dentry(struct dentry *dentry)
 {
 	struct dentry *parent;
 
-	parent = dentry_kill(dentry, 0);
+	parent = dentry_kill(dentry);
 	/*
 	 * If dentry_kill returns NULL, we have nothing more to do.
 	 * if it returns the same dentry, trylocks failed. In either
@@ -810,7 +813,7 @@ static void try_prune_one_dentry(struct dentry *dentry)
 	while (dentry) {
 		if (lockref_put_or_lock(&dentry->d_lockref))
 			return;
-		dentry = dentry_kill(dentry, 1);
+		dentry = dentry_kill(dentry);
 	}
 }