[PATCH 2/7] zram: Prevent overflow in logical block size

Robert Jennings
2011-01-26T17:23:27Z

On a 64K page kernel, the value PAGE_SIZE passed to
blk_queue_logical_block_size would overflow the logical block size
argument (resulting in setting it to 0).

Take the minimum of PAGE_SIZE or 4096 and use this for the block device
logical block size.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
---
drivers/staging/zram/zram_drv.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index d0e9e02..d5e0275 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -621,7 +621,8 @@ static int create_device(struct zram *zram, int device_id)
* and n*PAGE_SIZED sized I/O requests.
*/
blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE);
- blk_queue_logical_block_size(zram->disk->queue, PAGE_SIZE);
+ blk_queue_logical_block_size(zram->disk->queue,
+ (unsigned short) min_t(unsigned int, PAGE_SIZE, 4096));
blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);

--
1.6.0.2