diff mbox series

[5/7] btrfs: drop redundant check to use fs_devices::metadata_uuid

Message ID 92f71226c8eb0797931eda2c92ba243113104a69.1690792823.git.anand.jain@oracle.com (mailing list archive)
State New, archived
Headers show
Series metadata_uuid misc cleanup and fixes part2 | expand

Commit Message

Anand Jain July 31, 2023, 11:16 a.m. UTC 
fs_devices::metadata_uuid value is already updated based on the
super_block::METADATA_UUID flag for either fsid or metadata_uuid as
appropriate. So, fs_devices::metadata_uuid can be used directly.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

Comments

Johannes Thumshirn Aug. 1, 2023, 1:25 p.m. UTC | #1 
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
diff mbox series

Patch

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e2fb11e89279..902dfc4aec53 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -313,21 +313,16 @@  static bool check_tree_block_fsid(struct extent_buffer *eb)
 	struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
 	u8 fsid[BTRFS_FSID_SIZE];
-	u8 *metadata_uuid;
 
 	read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
 			   BTRFS_FSID_SIZE);
+
 	/*
-	 * Checking the incompat flag is only valid for the current fs. For
-	 * seed devices it's forbidden to have their uuid changed so reading
-	 * ->fsid in this case is fine
+	 * alloc_fs_devices() copies the fsid into metadata_uuid if the
+	 * metadata_uuid is unset in the superblock, including for a seed device.
+	 * So, we can use fs_devices->metadata_uuid.
 	 */
-	if (btrfs_fs_incompat(fs_info, METADATA_UUID))
-		metadata_uuid = fs_devices->metadata_uuid;
-	else
-		metadata_uuid = fs_devices->fsid;
-
-	if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
+	if (!memcmp(fsid, fs_info->fs_devices->metadata_uuid, BTRFS_FSID_SIZE))
 		return false;
 
 	list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)