Skip to content

Commit

Permalink
btrfs: add comment about metadata_uuid in btrfs_fs_devices
Browse files Browse the repository at this point in the history
Add comment about metadata_uuid in btrfs_fs_devices.
No functional change.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
  • Loading branch information
Anand Jain authored and David Sterba committed Jun 19, 2023
1 parent c6930d7 commit f62c302
Showing 1 changed file with 12 additions and 0 deletions.
12 changes: 12 additions & 0 deletions fs/btrfs/volumes.h
Original file line number Diff line number Diff line change
Expand Up @@ -280,7 +280,19 @@ enum btrfs_read_policy {

struct btrfs_fs_devices {
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */

/*
* UUID written into the btree blocks:
*
* - If metadata_uuid != fsid then super block must have
* BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag set.
*
* - Following shall be true at all times:
* - metadata_uuid == btrfs_header::fsid
* - metadata_uuid == btrfs_dev_item::fsid
*/
u8 metadata_uuid[BTRFS_FSID_SIZE];

struct list_head fs_list;

/*
Expand Down

0 comments on commit f62c302

Please sign in to comment.