[PATCH 2/4] Limit max_discard_sectors to UINT_MAX>>9

[Gwendal Grignou]

max_discard_sectors can not be larger than UINT_MAX>>9,
otherwise, there is a risk that discard requests would be merged
into a request larger than 4GB.

Signed-off-by: Gwendal Grignou <gwendal at chromium.org>
---
 block/blk-lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9b5b561..67bb0e7 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -64,7 +64,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	 * Ensure that max_discard_sectors is of the proper
 	 * granularity, so that requests stay aligned after a split.
 	 */
-	max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+	max_discard_sectors = q->limits.max_discard_sectors;
 	max_discard_sectors -= max_discard_sectors % granularity;
 	if (unlikely(!max_discard_sectors)) {
 		/* Avoid infinite loop below. Being cautious never hurts. */
-- 
1.9.1.423.g4596e3a