udf: use hardware sector size

This patch makes the UDF FS driver use the hardware sector size as the
default logical block size, which is required by the UDF specifications.
While the previous default of 2048 bytes was correct for optical disks,
it was not for hard disks or USB storage devices, and made it impossible
to use such a device with the default mount options.  (The Linux mkudffs
tool uses a default block size of 2048 bytes even on devices with
smaller hardware sectors, so this bug is unlikely to be noticed unless
UDF-formatted USB storage devices are exchanged with other OSs.)

To avoid regressions for people who use loopback optical disk images or
who used the (sometimes wrong) defaults of mkudffs, we also try with
a block size of 2048 bytes if no anchor was found with the hardware
sector size.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
index 158221ecdc42..2dd921928338 100644
--- a/fs/udf/udf_sb.h
+++ b/fs/udf/udf_sb.h
@@ -30,6 +30,7 @@
 #define UDF_FLAG_GID_SET        16
 #define UDF_FLAG_SESSION_SET    17
 #define UDF_FLAG_LASTBLOCK_SET  18
+#define UDF_FLAG_BLOCKSIZE_SET  19
 
 #define UDF_PART_FLAG_UNALLOC_BITMAP    0x0001
 #define UDF_PART_FLAG_UNALLOC_TABLE     0x0002