Add flag for marking bio-based queues which support REQ_NOWAIT.
Set for all request based (mq) devices.
Stacking device should set it after blk_set_stacking_limits() if method
make_request() itself doesn't delay requests or handles REQ_NOWAIT.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
block/blk-core.c | 4 ++--
block/blk-mq.c | 3 +++
block/blk-settings.c | 3 +++
include/linux/blkdev.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index c4b015004796..9139a316e6d4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -892,9 +892,9 @@ generic_make_request_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 this flag.
*/
- if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q))
+ if ((bio->bi_opf & REQ_NOWAIT) && !q->limits.nowait_requests)
goto not_supported;
if (should_fail_bio(bio))
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a7785df2c944..0c3daa0cda87 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2952,6 +2952,9 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
*/
q->poll_nsec = BLK_MQ_POLL_CLASSIC;
+ /* Request based queue always supports REQ_NOWAIT */
+ q->limits.nowait_requests = 1;
+
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
blk_mq_add_queue_tag_set(set, q);
blk_mq_map_swqueue(q);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 14397b4c4b53..8f96c7324497 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -59,6 +59,7 @@ void blk_set_default_limits(struct queue_limits *lim)
lim->io_opt = 0;
lim->misaligned = 0;
lim->zoned = BLK_ZONED_NONE;
+ lim->nowait_requests = 0;
}
EXPORT_SYMBOL(blk_set_default_limits);
@@ -486,6 +487,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
t->max_segment_size = min_not_zero(t->max_segment_size,
b->max_segment_size);
+ t->nowait_requests &= b->nowait_requests;
+
t->misaligned |= b->misaligned;
alignment = queue_limit_alignment_offset(b, start);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 32868fbedc9e..5f612dda34c2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -346,6 +346,7 @@ struct queue_limits {
unsigned char misaligned;
unsigned char discard_misaligned;
unsigned char raid_partial_stripes_expensive;
+ unsigned char nowait_requests;
enum blk_zoned_model zoned;
};
--
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