[PATCH] blk-mq: Call bio_io_error if request returned is NULL

[PATCH] blk-mq: Call bio_io_error if request returned is NULL

[Goldwyn Rodrigues]

From: Goldwyn Rodrigues <rgoldwyn@suse.com>

If blk_mq_map_request returns NULL, bio_endio() function is not
called. Call bio_io_error() in case request returned is NULL.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 block/blk-mq.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 81caceb..7cd8912 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1286,8 +1286,10 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 		return BLK_QC_T_NONE;
 
 	rq = blk_mq_map_request(q, bio, &data);
-	if (unlikely(!rq))
+	if (unlikely(!rq)) {
+		bio_io_error(bio);
 		return BLK_QC_T_NONE;
+	}
 
 	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
 
@@ -1381,8 +1383,10 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
 		request_count = blk_plug_queued_count(q);
 
 	rq = blk_mq_map_request(q, bio, &data);
-	if (unlikely(!rq))
+	if (unlikely(!rq)) {
+		bio_io_error(bio);
 		return BLK_QC_T_NONE;
+	}
 
 	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
 
-- 
2.10.2

Re: [PATCH] blk-mq: Call bio_io_error if request returned is NULL

[Jens Axboe]

On 02/13/2017 09:04 AM, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> If blk_mq_map_request returns NULL, bio_endio() function is not
> called. Call bio_io_error() in case request returned is NULL.

That's currently not a possible condition, since the main
request mapper functions block on rq allocation. So we can
never return NULL there.

-- 
Jens Axboe