diff options
| author | yangerkun <yangerkun@huawei.com> | 2020-09-05 19:25:56 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-07 08:02:53 +0200 |
| commit | c53cd18774060d53babe8bd754f5f9dfdc022609 (patch) | |
| tree | 66d7f3efcc80ac4583c7880398e9ae4b703a76d2 | |
| parent | a6141f191d830f5437eff08816187ae077e377d7 (diff) | |
blk-mq: call commit_rqs while list empty but error happen
[ Upstream commit 632bfb6323799c087fcb4108dfe59518609667a7 ]
Blk-mq should call commit_rqs once 'bd.last != true' and no more
request will come(so virtscsi can kick the virtqueue, e.g.). We already
do that in 'blk_mq_dispatch_rq_list/blk_mq_try_issue_list_directly' while
list not empty and 'queued > 0'. However, we can seen the same scene
once the last request in list call queue_rq and return error like
BLK_STS_IOERR which will not requeue the request, and lead that list
empty but need call commit_rqs too(Or the request for virtscsi will stay
timeout until other request kick virtqueue).
We found this problem by do fsstress test with offline/online virtscsi
device repeat quickly.
Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()")
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | block/blk-mq.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index a366726094a8..8e623e028275 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1304,6 +1304,11 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, hctx->dispatched[queued_to_index(queued)]++; + /* If we didn't flush the entire list, we could have told the driver + * there was more coming, but that turned out to be a lie. + */ + if ((!list_empty(list) || errors) && q->mq_ops->commit_rqs && queued) + q->mq_ops->commit_rqs(hctx); /* * Any items that need requeuing? Stuff them into hctx->dispatch, * that is where we will continue on next queue run. @@ -1311,14 +1316,6 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, if (!list_empty(list)) { bool needs_restart; - /* - * If we didn't flush the entire list, we could have told - * the driver there was more coming, but that turned out to - * be a lie. - */ - if (q->mq_ops->commit_rqs && queued) - q->mq_ops->commit_rqs(hctx); - spin_lock(&hctx->lock); list_splice_tail_init(list, &hctx->dispatch); spin_unlock(&hctx->lock); @@ -1971,6 +1968,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, struct list_head *list) { int queued = 0; + int errors = 0; while (!list_empty(list)) { blk_status_t ret; @@ -1987,6 +1985,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, break; } blk_mq_end_request(rq, ret); + errors++; } else queued++; } @@ -1996,7 +1995,8 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, * the driver there was more coming, but that turned out to * be a lie. */ - if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs && queued) + if ((!list_empty(list) || errors) && + hctx->queue->mq_ops->commit_rqs && queued) hctx->queue->mq_ops->commit_rqs(hctx); } |