1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9b98173a8184..5c8018977efa 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -938,6 +938,8 @@ extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 extern void blk_set_default_limits(struct queue_limits *lim);
 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
                             sector_t offset);
+extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
+                            sector_t offset);
 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
                               sector_t offset);
 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
@@ -1148,8 +1150,11 @@ static inline int queue_discard_alignment(struct request_queue *q)
 static inline int queue_sector_discard_alignment(struct request_queue *q,
                                                  sector_t sector)
 {
-        return ((sector << 9) - q->limits.discard_alignment)
-                & (q->limits.discard_granularity - 1);
+        struct queue_limits *lim = &q->limits;
+        unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
+
+        return (lim->discard_granularity + lim->discard_alignment - alignment)
+                & (lim->discard_granularity - 1);
 }
 
 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)