vfs: Re-introduce s_uuid in the superblock

Gaah.  When commit be85bccaa5aa reverted the export of file system uuid
via /proc/<pid>/mountinfo, it also unintentionally removed the s_uuid
field in struct super_block.

I didn't mean to do that, since filesystems have been taught to fill it
in (and we want to keep it for future re-introduction in the mountinfo
file).

Stupid of me. This adds it back in.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5b14843..dbd860a 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1403,6 +1403,7 @@ struct super_block {
        wait_queue_head_t       s_wait_unfrozen;
 
        char s_id[32];                          /* Informational name */
+       u8 s_uuid[16];                          /* UUID */
 
        void                    *s_fs_info;     /* Filesystem private info */
        fmode_t                 s_mode;