linux/fs/udf
Jan Kara 15fb05fd28 udf: Allow writing to 'Rewritable' partitions
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: b085fbe2ef ("udf: Fix crash during mount")
Link: https://lore.kernel.org/linux-fsdevel/20200112144735.hj2emsoy4uwsouxz@pali
Signed-off-by: Jan Kara <jack@suse.cz>
2020-01-20 13:59:17 +01:00
..
balloc.c udf: prevent allocation beyond UDF partition 2019-07-31 18:41:37 +02:00
dir.c udf: Fix 64-bit sign extension issues affecting blocks > 0x7FFFFFFF 2017-10-17 11:56:45 +02:00
directory.c udf: Provide function for calculating dir entry length 2018-06-20 11:05:49 +02:00
ecma_167.h udf: Fix meaning of ENTITYID_FLAGS_* macros to be really bitwise-or flags 2020-01-13 12:38:46 +01:00
file.c udf: augment UDF permissions on new inodes 2019-08-27 15:38:46 +02:00
ialloc.c udf: augment UDF permissions on new inodes 2019-08-27 15:38:46 +02:00
inode.c udf: Fix spelling in EXT_NEXT_EXTENT_ALLOCDESCS 2020-01-08 11:11:46 +01:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
lowlevel.c udf: atomically read inode size 2017-01-10 11:57:34 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
misc.c udf: Fix signed/unsigned format specifiers 2017-10-17 12:00:58 +02:00
namei.c udf: fix an uninitialized read bug and remove dead code 2019-04-17 13:13:24 +02:00
osta_udf.h udf: Update header files to UDF 2.60 2020-01-08 11:12:20 +01:00
partition.c udf: Fix signed/unsigned format specifiers 2017-10-17 12:00:58 +02:00
super.c udf: Allow writing to 'Rewritable' partitions 2020-01-20 13:59:17 +01:00
symlink.c statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
truncate.c udf: Fix spelling in EXT_NEXT_EXTENT_ALLOCDESCS 2020-01-08 11:11:46 +01:00
udf_i.h udf: augment UDF permissions on new inodes 2019-08-27 15:38:46 +02:00
udf_sb.h udf: Drop pack pragma from udf_sb.h 2018-09-07 10:32:23 +02:00
udfdecl.h udf: augment UDF permissions on new inodes 2019-08-27 15:38:46 +02:00
udfend.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udftime.c udf: convert inode stamps to timespec64 2018-06-27 13:58:00 +02:00
unicode.c udf: Allow mounting volumes with incorrect identification strings 2018-11-19 10:27:59 +01:00