block: fix an integer overflow in logical block size

Logical block size has type unsigned short. That means that it can be at
most 32768. However, there are architectures that can run with 64k pages
(for example arm64) and on these architectures, it may be possible to
create block devices with 64k block size.

For exmaple (run this on an architecture with 64k pages):

Mount will fail with this error because it tries to read the superblock using 2-sector
access:
  device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536
  EXT4-fs (dm-0): unable to read superblock

This patch changes the logical block size from unsigned short to unsigned
int to avoid the overflow.

Cc: stable@vger.kernel.org
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 1 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 5f6dcc7a47bd..c8eda2e7b91e 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -328,7 +328,7 @@ EXPORT_SYMBOL(blk_queue_max_segment_size);
  *   storage device can address.  The default of 512 covers most
  *   hardware.
  **/
-void blk_queue_logical_block_size(struct request_queue *q, unsigned short size)
+void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
 {
 	q->limits.logical_block_size = size;