Add QUEUE_FLAG_NOWAIT to allow a block device to advertise support for
REQ_NOWAIT. Bio-based devices may set QUEUE_FLAG_NOWAIT where
applicable.
Update QUEUE_FLAG_MQ_DEFAULT to include QUEUE_FLAG_NOWAIT. Also
update submit_bio_checks() to verify it is set for REQ_NOWAIT bios.
Reported-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
block/blk-core.c | 4 ++--
include/linux/blkdev.h | 7 +++++--
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index ca3f0f00c943..e3adfa135a20 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -817,9 +817,9 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio)
/*
* For a REQ_NOWAIT based request, return -EOPNOTSUPP
- * if queue is not a request based queue.
+ * if queue does not support NOWAIT.
*/
- if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q))
+ if ((bio->bi_opf & REQ_NOWAIT) && !blk_queue_nowait(q))
goto not_supported;
if (should_fail_bio(bio))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index be5ef6f4ba19..9723b497d435 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -618,10 +618,12 @@ struct request_queue {
#define QUEUE_FLAG_PCI_P2PDMA 25 /* device supports PCI p2p requests */
#define QUEUE_FLAG_ZONE_RESETALL 26 /* supports Zone Reset All */
#define QUEUE_FLAG_RQ_ALLOC_TIME 27 /* record rq->alloc_time_ns */
-#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */
+#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */
+#define QUEUE_FLAG_NOWAIT 29 /* device supports NOWAIT */
#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
- (1 << QUEUE_FLAG_SAME_COMP))
+ (1 << QUEUE_FLAG_SAME_COMP) | \
+ (1 << QUEUE_FLAG_NOWAIT))
void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
@@ -661,6 +663,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
#define blk_queue_pm_only(q) atomic_read(&(q)->pm_only)
#define blk_queue_fua(q) test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
#define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
+#define blk_queue_nowait(q) test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
extern void blk_set_pm_only(struct request_queue *q);
extern void blk_clear_pm_only(struct request_queue *q);
--
2.15.0
