diff options
authorMikulas Patocka <>2020-01-15 08:35:25 -0500
committerJens Axboe <>2020-01-15 21:43:09 -0700
commitad6bf88a6c19a39fb3b0045d78ea880325dfcf15 (patch)
parent16c731fed6d8e5615e23d2fd59cfe62eb10d9ff4 (diff)
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: Reviewed-by: Martin K. Petersen <> Reviewed-by: Ming Lei <> Signed-off-by: Mikulas Patocka <> Signed-off-by: Jens Axboe <>
4 files changed, 7 insertions, 7 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;
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 3c50c4e4da8f..963d3774c93e 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -17,7 +17,7 @@
#include <linux/dm-bufio.h>
#define DM_MSG_PREFIX "persistent snapshot"
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index b7c20979bd19..322386ff5d22 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -87,7 +87,7 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
- unsigned short blksize = 512;
+ unsigned blksize = 512;
*private_conf = ERR_PTR(-ENOMEM);
if (!conf)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 47eb22a3b7f9..4c636c42ad68 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -328,6 +328,7 @@ struct queue_limits {
unsigned int max_sectors;
unsigned int max_segment_size;
unsigned int physical_block_size;
+ unsigned int logical_block_size;
unsigned int alignment_offset;
unsigned int io_min;
unsigned int io_opt;
@@ -338,7 +339,6 @@ struct queue_limits {
unsigned int discard_granularity;
unsigned int discard_alignment;
- unsigned short logical_block_size;
unsigned short max_segments;
unsigned short max_integrity_segments;
unsigned short max_discard_segments;
@@ -1077,7 +1077,7 @@ extern void blk_queue_max_write_same_sectors(struct request_queue *q,
unsigned int max_write_same_sectors);
extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
unsigned int max_write_same_sectors);
-extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
+extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
extern void blk_queue_alignment_offset(struct request_queue *q,
unsigned int alignment);
@@ -1291,7 +1291,7 @@ static inline unsigned int queue_max_segment_size(const struct request_queue *q)
return q->limits.max_segment_size;
-static inline unsigned short queue_logical_block_size(const struct request_queue *q)
+static inline unsigned queue_logical_block_size(const struct request_queue *q)
int retval = 512;
@@ -1301,7 +1301,7 @@ static inline unsigned short queue_logical_block_size(const struct request_queue
return retval;
-static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
+static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
return queue_logical_block_size(bdev_get_queue(bdev));