In case of shared tags and none io sched, batched completion still may
be run into, and hctx->nr_active is accounted when getting driver tag,
so it has to be updated in blk_mq_end_request_batch().
Otherwise, hctx->nr_active may become same with queue depth, then
hctx_may_queue() always return false, then io hang is caused.
Fixes the issue by updating the counter in batched way.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
Fixes: f794f3351f26 ("block: add support for blk_mq_end_request_batch()")
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 7 +++++++
block/blk-mq.h | 12 +++++++++---
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 07eb1412760b..2a2c57c98bbd 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -815,6 +815,13 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx,
{
struct request_queue *q = hctx->queue;
+ /*
+ * All requests should have been marked as RQF_MQ_INFLIGHT, so
+ * update hctx->nr_active in batch
+ */
+ if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
+ __blk_mq_sub_active_requests(hctx, nr_tags);
+
blk_mq_put_tags(hctx->tags, tag_array, nr_tags);
percpu_ref_put_many(&q->q_usage_counter, nr_tags);
}
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 28859fc5faee..cb0b5482ca5e 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -225,12 +225,18 @@ static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
atomic_inc(&hctx->nr_active);
}
-static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
+static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
+ int val)
{
if (blk_mq_is_shared_tags(hctx->flags))
- atomic_dec(&hctx->queue->nr_active_requests_shared_tags);
+ atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
else
- atomic_dec(&hctx->nr_active);
+ atomic_sub(val, &hctx->nr_active);
+}
+
+static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
+{
+ __blk_mq_sub_active_requests(hctx, 1);
}
static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
--
2.31.1
