block: Fix discard alignment calculation and printing
Discard alignment reporting for partitions was incorrect. Update to
match the algorithm used elsewhere.
The alignment can be negative (misaligned). Fix format string
accordingly.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9b98173..a41bcc8 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1148,8 +1148,11 @@
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)