partitions/msdos: Unable to mount UFS 44bsd partitions

[ Upstream commit 5f15684bd5e5ef39d4337988864fec8012471dda ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

diff --git a/block/partitions/msdos.c b/block/partitions/msdos.c
index 5610cd537da78812e2633d76ca90e5c3fb66e7cc..7d8d50c11ce779b55d55984523cf1c2ae35cc5e1 100644 (file)
--- a/block/partitions/msdos.c
+++ b/block/partitions/msdos.c
@@ -300,7 +300,9 @@ 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 */