From: Jan Kara jack@suse.cz
[ Upstream commit 15fb05fd286ac57a0802d71624daeb5c1c2d5b07 ]
UDF 2.60 standard states in section 2.2.14.2:
A partition with Access Type 3 (rewritable) shall define a Freed Space Bitmap or a Freed Space Table, see 2.3.3. All other partitions shall not define a Freed Space Bitmap or a Freed Space Table.
Rewritable partitions are used on media that require some form of preprocessing before re-writing data (for example legacy MO). Such partitions shall use Access Type 3.
Overwritable partitions are used on media that do not require preprocessing before overwriting data (for example: CD-RW, DVD-RW, DVD+RW, DVD-RAM, BD-RE, HD DVD-Rewritable). Such partitions shall use Access Type 4.
however older versions of the standard didn't have this wording and there are tools out there that create UDF filesystems with rewritable partitions but that don't contain a Freed Space Bitmap or a Freed Space Table on media that does not require pre-processing before overwriting a block. So instead of forcing media with rewritable partition read-only, base this decision on presence of a Freed Space Bitmap or a Freed Space Table.
Reported-by: Pali Rohár pali.rohar@gmail.com Reviewed-by: Pali Rohár pali.rohar@gmail.com Fixes: b085fbe2ef7f ("udf: Fix crash during mount") Link: https://lore.kernel.org/linux-fsdevel/20200112144735.hj2emsoy4uwsouxz@pali Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/udf/super.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/fs/udf/super.c b/fs/udf/super.c index 7af011d..6fd0f14 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -999,7 +999,6 @@ static int check_partition_desc(struct super_block *sb, switch (le32_to_cpu(p->accessType)) { case PD_ACCESS_TYPE_READ_ONLY: case PD_ACCESS_TYPE_WRITE_ONCE: - case PD_ACCESS_TYPE_REWRITABLE: case PD_ACCESS_TYPE_NONE: goto force_ro; }