[libblkid] Why wholedisk_probe does not force GPT while gathering partition details?

[mfrydrysiak]

I patched my systemd-udevd to set BLKID_PARTS_FORCE_GPT flag on probing superblocks to recover from situations, when Protective MBR is damaged:

blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS | BLKID_PARTS_FORCE_GPT);

It seems that this flag is indeed used while partitions_probe (in the blkid_do_probe() backend, once it detects the GPT layout). However, when it passes to details gathering (details_only label) and it executes blkid_partitions_probe_partition function, it opens a new disk prober in the blkid_probe_get_wholedisk_probe function, which does not contain the mentioned BLKID_PARTS_FORCE_GPT flag. As a result, as far as I understand, the protective MBR validation is not skipped (it fails) so it does not consider this partition layout as GPT.

Is there any way to avoid such situations so the pMBR validation is skipped?

util-linux version v2.35.1

[karelzak]

It seems like a bug; the flag should be copied to the whole-disk prober. I have fixed it in commit 22769ac; it should be available in v2.39.

It would be nice if you could test the current git tree in your environment.

[mfrydrysiak]

Thanks, it did the trick :) I have applied and tested it on the v2.35.1 branch. Works as expected.

[karelzak]

And a suggestion, fix your PMBR :-)