Merge commit 'v2.6.39' into for-2.6.40/core

Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.

Also fixes up conflicts in the below files.

Conflicts:
	drivers/block/paride/pcd.c
	drivers/cdrom/viocd.c
	drivers/ide/ide-cd.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 32 insertions, 55 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 129a357..22a0ef4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -99,12 +99,9 @@ static struct kmem_cache *dentry_cache __read_mostly;
 static unsigned int d_hash_mask __read_mostly;
 static unsigned int d_hash_shift __read_mostly;
 
-struct dcache_hash_bucket {
-	struct hlist_bl_head head;
-};
-static struct dcache_hash_bucket *dentry_hashtable __read_mostly;
+static struct hlist_bl_head *dentry_hashtable __read_mostly;
 
-static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
+static inline struct hlist_bl_head *d_hash(struct dentry *parent,
 					unsigned long hash)
 {
 	hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
@@ -112,16 +109,6 @@ static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
 	return dentry_hashtable + (hash & D_HASHMASK);
 }
 
-static inline void spin_lock_bucket(struct dcache_hash_bucket *b)
-{
-	bit_spin_lock(0, (unsigned long *)&b->head.first);
-}
-
-static inline void spin_unlock_bucket(struct dcache_hash_bucket *b)
-{
-	__bit_spin_unlock(0, (unsigned long *)&b->head.first);
-}
-
 /* Statistics gathering. */
 struct dentry_stat_t dentry_stat = {
 	.age_limit = 45,
@@ -167,8 +154,8 @@ static void d_free(struct dentry *dentry)
 	if (dentry->d_op && dentry->d_op->d_release)
 		dentry->d_op->d_release(dentry);
 
-	/* if dentry was never inserted into hash, immediate free is OK */
-	if (hlist_bl_unhashed(&dentry->d_hash))
+	/* if dentry was never visible to RCU, immediate free is OK */
+	if (!(dentry->d_flags & DCACHE_RCUACCESS))
 		__d_free(&dentry->d_u.d_rcu);
 	else
 		call_rcu(&dentry->d_u.d_rcu, __d_free);
@@ -330,28 +317,19 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
  */
 void __d_drop(struct dentry *dentry)
 {
-	if (!(dentry->d_flags & DCACHE_UNHASHED)) {
-		if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
-			bit_spin_lock(0,
-				(unsigned long *)&dentry->d_sb->s_anon.first);
-			dentry->d_flags |= DCACHE_UNHASHED;
-			hlist_bl_del_init(&dentry->d_hash);
-			__bit_spin_unlock(0,
-				(unsigned long *)&dentry->d_sb->s_anon.first);
-		} else {
-			struct dcache_hash_bucket *b;
+	if (!d_unhashed(dentry)) {
+		struct hlist_bl_head *b;
+		if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED))
+			b = &dentry->d_sb->s_anon;
+		else
 			b = d_hash(dentry->d_parent, dentry->d_name.hash);
-			spin_lock_bucket(b);
-			/*
-			 * We may not actually need to put DCACHE_UNHASHED
-			 * manipulations under the hash lock, but follow
-			 * the principle of least surprise.
-			 */
-			dentry->d_flags |= DCACHE_UNHASHED;
-			hlist_bl_del_rcu(&dentry->d_hash);
-			spin_unlock_bucket(b);
-			dentry_rcuwalk_barrier(dentry);
-		}
+
+		hlist_bl_lock(b);
+		__hlist_bl_del(&dentry->d_hash);
+		dentry->d_hash.pprev = NULL;
+		hlist_bl_unlock(b);
+
+		dentry_rcuwalk_barrier(dentry);
 	}
 }
 EXPORT_SYMBOL(__d_drop);
@@ -1304,7 +1282,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 	dname[name->len] = 0;
 
 	dentry->d_count = 1;
-	dentry->d_flags = DCACHE_UNHASHED;
+	dentry->d_flags = 0;
 	spin_lock_init(&dentry->d_lock);
 	seqcount_init(&dentry->d_seq);
 	dentry->d_inode = NULL;
@@ -1606,10 +1584,9 @@ struct dentry *d_obtain_alias(struct inode *inode)
 	tmp->d_inode = inode;
 	tmp->d_flags |= DCACHE_DISCONNECTED;
 	list_add(&tmp->d_alias, &inode->i_dentry);
-	bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
-	tmp->d_flags &= ~DCACHE_UNHASHED;
+	hlist_bl_lock(&tmp->d_sb->s_anon);
 	hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
-	__bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
+	hlist_bl_unlock(&tmp->d_sb->s_anon);
 	spin_unlock(&tmp->d_lock);
 	spin_unlock(&inode->i_lock);
 	security_d_instantiate(tmp, inode);
@@ -1789,7 +1766,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
 	unsigned int len = name->len;
 	unsigned int hash = name->hash;
 	const unsigned char *str = name->name;
-	struct dcache_hash_bucket *b = d_hash(parent, hash);
+	struct hlist_bl_head *b = d_hash(parent, hash);
 	struct hlist_bl_node *node;
 	struct dentry *dentry;
 
@@ -1813,7 +1790,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
 	 *
 	 * See Documentation/filesystems/path-lookup.txt for more details.
 	 */
-	hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+	hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
 		struct inode *i;
 		const char *tname;
 		int tlen;
@@ -1908,7 +1885,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
 	unsigned int len = name->len;
 	unsigned int hash = name->hash;
 	const unsigned char *str = name->name;
-	struct dcache_hash_bucket *b = d_hash(parent, hash);
+	struct hlist_bl_head *b = d_hash(parent, hash);
 	struct hlist_bl_node *node;
 	struct dentry *found = NULL;
 	struct dentry *dentry;
@@ -1935,7 +1912,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
 	 */
 	rcu_read_lock();
 	
-	hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+	hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
 		const char *tname;
 		int tlen;
 
@@ -2086,13 +2063,13 @@ again:
 }
 EXPORT_SYMBOL(d_delete);
 
-static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b)
+static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
 {
 	BUG_ON(!d_unhashed(entry));
-	spin_lock_bucket(b);
- 	entry->d_flags &= ~DCACHE_UNHASHED;
-	hlist_bl_add_head_rcu(&entry->d_hash, &b->head);
-	spin_unlock_bucket(b);
+	hlist_bl_lock(b);
+	entry->d_flags |= DCACHE_RCUACCESS;
+	hlist_bl_add_head_rcu(&entry->d_hash, b);
+	hlist_bl_unlock(b);
 }
 
 static void _d_rehash(struct dentry * entry)
@@ -3025,7 +3002,7 @@ static void __init dcache_init_early(void)
 
 	dentry_hashtable =
 		alloc_large_system_hash("Dentry cache",
-					sizeof(struct dcache_hash_bucket),
+					sizeof(struct hlist_bl_head),
 					dhash_entries,
 					13,
 					HASH_EARLY,
@@ -3034,7 +3011,7 @@ static void __init dcache_init_early(void)
 					0);
 
 	for (loop = 0; loop < (1 << d_hash_shift); loop++)
-		INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
 }
 
 static void __init dcache_init(void)
@@ -3057,7 +3034,7 @@ static void __init dcache_init(void)
 
 	dentry_hashtable =
 		alloc_large_system_hash("Dentry cache",
-					sizeof(struct dcache_hash_bucket),
+					sizeof(struct hlist_bl_head),
 					dhash_entries,
 					13,
 					0,
@@ -3066,7 +3043,7 @@ static void __init dcache_init(void)
 					0);
 
 	for (loop = 0; loop < (1 << d_hash_shift); loop++)
-		INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
 }
 
 /* SLAB cache for __getname() consumers */