fs-inode_lock-scale-6b

Protect i_hash, i_sb_list etc members with i_lock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 27 insertions, 3 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a0bbd3d1b41a..ab1e261738bf 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -382,6 +382,7 @@ static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
 	if (generic_detach_inode(inode)) {
 		truncate_hugepages(inode, 0);
 		clear_inode(inode);
+		/* XXX: why no wake_up_inode? */
 		destroy_inode(inode);
 	}
 }
diff --git a/fs/inode.c b/fs/inode.c
index ea96254bd490..b04e902da355 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -356,12 +356,14 @@ static void dispose_list(struct list_head *head)
 		clear_inode(inode);
 
 		spin_lock(&inode_lock);
+		spin_lock(&sb_inode_list_lock);
+		spin_lock(&inode->i_lock);
 		spin_lock(&inode_hash_lock);
 		hlist_del_init(&inode->i_hash);
 		spin_unlock(&inode_hash_lock);
-		spin_lock(&sb_inode_list_lock);
 		list_del_init(&inode->i_sb_list);
 		spin_unlock(&sb_inode_list_lock);
+		spin_unlock(&inode->i_lock);
 		spin_unlock(&inode_lock);
 
 		wake_up_inode(inode);
@@ -663,7 +665,6 @@ __inode_add_to_lists(struct super_block *sb, struct hlist_head *head,
 			struct inode *inode)
 {
 	atomic_inc(&inodes_stat.nr_inodes);
-	spin_lock(&sb_inode_list_lock);
 	list_add(&inode->i_sb_list, &sb->s_inodes);
 	spin_unlock(&sb_inode_list_lock);
 	spin_lock(&wb_inode_list_lock);
@@ -693,7 +694,10 @@ void inode_add_to_lists(struct super_block *sb, struct inode *inode)
 	struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino);
 
 	spin_lock(&inode_lock);
+	spin_lock(&sb_inode_list_lock);
+	spin_lock(&inode->i_lock);
 	__inode_add_to_lists(sb, head, inode);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 EXPORT_SYMBOL_GPL(inode_add_to_lists);
@@ -725,9 +729,12 @@ struct inode *new_inode(struct super_block *sb)
 	inode = alloc_inode(sb);
 	if (inode) {
 		spin_lock(&inode_lock);
+		spin_lock(&sb_inode_list_lock);
+		spin_lock(&inode->i_lock);
 		inode->i_ino = ++last_ino;
 		inode->i_state = 0;
 		__inode_add_to_lists(sb, NULL, inode);
+		spin_unlock(&inode->i_lock);
 		spin_unlock(&inode_lock);
 	}
 	return inode;
@@ -791,11 +798,14 @@ static struct inode *get_new_inode(struct super_block *sb,
 		/* We released the lock, so.. */
 		old = find_inode(sb, head, test, data);
 		if (!old) {
+			spin_lock(&sb_inode_list_lock);
+			spin_lock(&inode->i_lock);
 			if (set(inode, data))
 				goto set_failed;
 
 			inode->i_state = I_NEW;
 			__inode_add_to_lists(sb, head, inode);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 
 			/* Return the locked inode with I_NEW set, the
@@ -820,6 +830,7 @@ static struct inode *get_new_inode(struct super_block *sb,
 
 set_failed:
 	spin_unlock(&inode->i_lock);
+	spin_unlock(&sb_inode_list_lock);
 	spin_unlock(&inode_lock);
 	destroy_inode(inode);
 	return NULL;
@@ -842,9 +853,12 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
 		/* We released the lock, so.. */
 		old = find_inode_fast(sb, head, ino);
 		if (!old) {
+			spin_lock(&sb_inode_list_lock);
+			spin_lock(&inode->i_lock);
 			inode->i_ino = ino;
 			inode->i_state = I_NEW;
 			__inode_add_to_lists(sb, head, inode);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 
 			/* Return the locked inode with I_NEW set, the
@@ -1180,6 +1194,7 @@ repeat:
 			break;
 		}
 		if (likely(!node)) {
+			/* XXX: initialize inode->i_lock to locked? */
 			hlist_add_head(&inode->i_hash, head);
 			spin_unlock(&inode_hash_lock);
 			spin_unlock(&inode_lock);
@@ -1228,6 +1243,7 @@ repeat:
 			break;
 		}
 		if (likely(!node)) {
+			/* XXX: initialize inode->i_lock to locked? */
 			hlist_add_head(&inode->i_hash, head);
 			spin_unlock(&inode_hash_lock);
 			spin_unlock(&inode_lock);
@@ -1258,10 +1274,13 @@ EXPORT_SYMBOL(insert_inode_locked4);
 void __insert_inode_hash(struct inode *inode, unsigned long hashval)
 {
 	struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
+
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_add_head(&inode->i_hash, head);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 EXPORT_SYMBOL(__insert_inode_hash);
@@ -1275,9 +1294,11 @@ EXPORT_SYMBOL(__insert_inode_hash);
 void remove_inode_hash(struct inode *inode)
 {
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_del_init(&inode->i_hash);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 EXPORT_SYMBOL(remove_inode_hash);
@@ -1325,9 +1346,11 @@ void generic_delete_inode(struct inode *inode)
 		clear_inode(inode);
 	}
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_del_init(&inode->i_hash);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 	wake_up_inode(inode);
 	BUG_ON(inode->i_state != I_CLEAR);
@@ -1372,10 +1395,10 @@ int generic_detach_inode(struct inode *inode)
 		spin_lock(&inode->i_lock);
 		WARN_ON(inode->i_state & I_NEW);
 		inode->i_state &= ~I_WILL_FREE;
-		atomic_dec(&inodes_stat.nr_unused);
 		spin_lock(&inode_hash_lock);
 		hlist_del_init(&inode->i_hash);
 		spin_unlock(&inode_hash_lock);
+		atomic_dec(&inodes_stat.nr_unused);
 	}
 	spin_lock(&wb_inode_list_lock);
 	list_del_init(&inode->i_list);