fs: move i_sb_list out from under inode_lock

Protect the per-sb inode list with a new global lock
inode_sb_list_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the list.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/internal.h b/fs/internal.h
index 8318059b42c6..7013ae0c88c1 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -125,6 +125,8 @@ extern long do_handle_open(int mountdirfd,
 /*
  * inode.c
  */
+extern spinlock_t inode_sb_list_lock;
+
 extern int get_nr_dirty_inodes(void);
 extern void evict_inodes(struct super_block *);
 extern int invalidate_inodes(struct super_block *, bool);