partitions/msdos: Unable to mount UFS 44bsd partitions

UFS partitions from newer versions of FreeBSD 10 and 11 use relative
addressing for their subpartitions. But older versions of FreeBSD still
use absolute addressing just like OpenBSD and NetBSD.

Instead of simply testing for a FreeBSD partition, the code needs to
also test if the starting offset of the C subpartition is zero.

https://bugzilla.kernel.org/show_bug.cgi?id=197733

Signed-off-by: Richard Narron <comet.berkeley@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/partitions/msdos.c b/block/partitions/msdos.c
index 0af3a3db6fb07dab3ad72bb9e5e8431cea020370..82c44f7df91130fd7a8484f7162a110aaf875a75 100644 (file)
--- a/block/partitions/msdos.c
+++ b/block/partitions/msdos.c
@@ -301,7 +301,9 @@ static void parse_bsd(struct parsed_partitions *state,
                        continue;
                bsd_start = le32_to_cpu(p->p_offset);
                bsd_size = le32_to_cpu(p->p_size);
-               if (memcmp(flavour, "bsd\0", 4) == 0)
+               /* FreeBSD has relative offset if C partition offset is zero */
+               if (memcmp(flavour, "bsd\0", 4) == 0 &&
+                   le32_to_cpu(l->d_partitions[2].p_offset) == 0)
                        bsd_start += offset;
                if (offset == bsd_start && size == bsd_size)
                        /* full parent partition, we have it already */