inode: convert inode_sb_list_lock to per-sb

The process of reducing contention on per-superblock inode lists
starts with moving the locking to match the per-superblock inode
list. This takes the global lock out of the picture and reduces the
contention problems to within a single filesystem. This doesn't get
rid of contention as the locks still have global CPU scope, but it
does isolate operations on different superblocks form each other.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/super.c b/fs/super.c
index b61372354f2b..c808183554a2 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -191,6 +191,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
         INIT_HLIST_NODE(&s->s_instances);
         INIT_HLIST_BL_HEAD(&s->s_anon);
         INIT_LIST_HEAD(&s->s_inodes);
+        spin_lock_init(&s->s_inode_list_lock);
 
         if (list_lru_init_memcg(&s->s_dentry_lru))
                 goto fail;
@@ -399,7 +400,7 @@ void generic_shutdown_super(struct super_block *sb)
                 sync_filesystem(sb);
                 sb->s_flags &= ~MS_ACTIVE;
 
-                fsnotify_unmount_inodes(&sb->s_inodes);
+                fsnotify_unmount_inodes(sb);
 
                 evict_inodes(sb);