diff options
| author |   yangerkun <yangerkun@huawei.com> | 2020-09-05 19:25:56 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-09-29 08:10:17 -0600 |
| commit | 632bfb6323799c087fcb4108dfe59518609667a7 (patch) | |
| tree | 82a008b131427f22482b359a62434ebc77f8421d /block | |
| parent | block: remove unused BLK_QC_T_EAGAIN flag (diff) | |
| download | linux-dev-632bfb6323799c087fcb4108dfe59518609667a7.tar.xz linux-dev-632bfb6323799c087fcb4108dfe59518609667a7.zip | |
blk-mq: call commit_rqs while list empty but error happen
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>
Diffstat (limited to 'block')
| -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 b3d2785eefe9..cdced4aca2e8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1412,6 +1412,11 @@ out: 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. @@ -1425,14 +1430,6 @@ out: blk_mq_release_budgets(q, nr_budgets); - /* - * 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); @@ -2079,6 +2076,7 @@ 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; @@ -2095,6 +2093,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, break; } blk_mq_end_request(rq, ret); + errors++; } else queued++; } @@ -2104,7 +2103,8 @@ 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); } |