diff mbox series

[15/16] btrfs-progs: recover from the failed btrfstune -m|M

Message ID 5d68db431d32f2521e6541e5a8a4ed3a14f4e674.1692018849.git.anand.jain@oracle.com (mailing list archive)
State New, archived
Headers show
Series btrfs-progs: recover from failed metadata_uuid | expand

Commit Message

Anand Jain Aug. 14, 2023, 3:28 p.m. UTC 
Currently, to fix device following the write failure of one or more devices
during btrfstune -m|M, we rely on the kernel's ability to reassemble devices,
even when they possess distinct fsids.

Kernel hinges combinations of metadata_uuid and generation number, with
additional cues taken from the fsid and the BTRFS_SUPER_FLAG_CHANGING_FSID_V2
flag. This patch adds this capability to btrfs-progs.

In complex scenarios (such as multiple fsids with the same metadata_uuid and
matching generation), user intervention becomes necessary to resolve the
situations which btrfs-prog can do better.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 tune/change-metadata-uuid.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/tune/change-metadata-uuid.c b/tune/change-metadata-uuid.c
index ada3149ad549..371f34e679b4 100644
--- a/tune/change-metadata-uuid.c
+++ b/tune/change-metadata-uuid.c
@@ -46,14 +46,23 @@  int set_metadata_uuid(struct btrfs_root *root, const char *new_fsid_string)
 	}
 
 	if (check_unfinished_fsid_change(root->fs_info, fsid, metadata_uuid)) {
-		error("UUID rewrite in progress, cannot change metadata_uuid");
-		return 1;
-	}
+		if (new_fsid_string) {
+			uuid_t tmp;
 
-	if (new_fsid_string)
-		uuid_parse(new_fsid_string, fsid);
-	else
-		uuid_generate(fsid);
+			uuid_parse(new_fsid_string, tmp);
+			if (memcmp(tmp, fsid, BTRFS_FSID_SIZE)) {
+				error(
+		"new fsid %s is not the same with unfinished fsid change",
+				      new_fsid_string);
+				return -EINVAL;
+			}
+		}
+	} else {
+		if (new_fsid_string)
+			uuid_parse(new_fsid_string, fsid);
+		else
+			uuid_generate(fsid);
+	}
 
 	new_fsid = (memcmp(fsid, disk_super->fsid, BTRFS_FSID_SIZE) != 0);