The UUID change by btrfstune sets SUPER_FLAG_CHANGING_FSID and resets it only when changing fsid is complete. Its not a good idea to mount the device anything in between, reading metadata blocks would fail with UUID mismatch. This patch doesn't add SUPER_FLAG_CHANGING_FSID into BTRFS_SUPER_FLAG_SUPP list, so mount will fail (along with the fix in the next patch) when SUPER_FLAG_CHANGING_FSID is set.
Showing the changes to include/uapi/linux (1 of 1 file). Show all
Unified · Split
| @@ -457,6 +457,7 @@ struct btrfs_free_space_header { · 456 unmodified lines | ||
| 457 | 457 | #define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32) |
| 458 | 458 | #define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33) |
| 459 | 459 | #define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34) |
| 460 | +#define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35) | |
| 460 | 461 | |
| 461 | 462 | |
| 462 | 463 | /* |