block: Fix front merge check
For a front merge, the maximum number of sectors of the
request must be checked against the front merge BIO sector,
not the current sector of the request.
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-merge.c b/block/blk-merge.c
index e7c2fbc..5e4d93e 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -500,7 +500,7 @@
integrity_req_gap_back_merge(req, bio))
return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
- blk_rq_get_max_sectors(req)) {
+ blk_rq_get_max_sectors(req, blk_rq_pos(req))) {
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
@@ -524,7 +524,7 @@
integrity_req_gap_front_merge(req, bio))
return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
- blk_rq_get_max_sectors(req)) {
+ blk_rq_get_max_sectors(req, bio->bi_iter.bi_sector)) {
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
@@ -570,7 +570,7 @@
* Will it become too large?
*/
if ((blk_rq_sectors(req) + blk_rq_sectors(next)) >
- blk_rq_get_max_sectors(req))
+ blk_rq_get_max_sectors(req, blk_rq_pos(req)))
return 0;
total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9d84c98..48f05d7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -922,7 +922,8 @@
(offset & (q->limits.chunk_sectors - 1));
}
-static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
+static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
+ sector_t offset)
{
struct request_queue *q = rq->q;
@@ -932,7 +933,7 @@
if (!q->limits.chunk_sectors || (req_op(rq) == REQ_OP_DISCARD))
return blk_queue_get_max_sectors(q, req_op(rq));
- return min(blk_max_size_offset(q, blk_rq_pos(rq)),
+ return min(blk_max_size_offset(q, offset),
blk_queue_get_max_sectors(q, req_op(rq)));
}