diff --git a/[refs] b/[refs]
index 235611b522c6..9dddc2ff0970 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 390192b300570b2bc721d77067ca133f58015ae8
+refs/heads/master: 0f79960391a5a1e3679956024e18aeeb0369ac44
diff --git a/trunk/block/blk-lib.c b/trunk/block/blk-lib.c
index 78e627e2581d..64974b1c7cca 100644
--- a/trunk/block/blk-lib.c
+++ b/trunk/block/blk-lib.c
@@ -59,7 +59,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	 * granularity
 	 */
 	max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
-	if (q->limits.discard_granularity) {
+	if (!unlikely(!max_discard_sectors)) {
+		/* Avoid infinite loop below. Being cautious never hurts. */
+		return -EOPNOTSUPP;
+	} else if (q->limits.discard_granularity) {
 		unsigned int disc_sects = q->limits.discard_granularity >> 9;
 
 		max_discard_sectors &= ~(disc_sects - 1);