[PATCH v2 0/1] mdrestore: fix restore_v2() superblock length check

[Pavel Reichl <preichl@redhat.com>]

Hi all,

On s390x (big-endian), running xfstests -g metadump currently fails
6 out of 9 tests. The failure is triggered by the superblock
extent-length validation in restore_v2(). The code rejects
xme_len == 1, but a length of 1 is the correct and expected value,
since the superblock fits within a single 512-byte sector.

On big-endian systems, this length decodes to 1 and the check aborts
the restore. On little-endian systems, the same on-disk bytes are
interpreted as 16777216, so the faulty logic never triggers there.

The patch removes the incorrect rejection of a valid extent length of
1 and applies proper logic so that the superblock extent length is
validated consistently across all architectures.

The outline of the fix was discussed with Chandan (thanks).

v2:
- xme.xme_len is an ondisk value so use be32_to_cpu() instead of
  cpu_to_be32()

Pavel Reichl (1):
  mdrestore: fix restore_v2() superblock length check

 mdrestore/xfs_mdrestore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.52.0