block: call rq_qos_done() before ref check in batch completions

We need to call rq_qos_done() regardless of whether or not we're freeing
the request or not, as the reference count doesn't cover the IO completion
tracking.

Fixes: f794f3351f26 ("block: add support for blk_mq_end_request_batch()")
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8799fa7..8874a63 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -860,13 +860,14 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob)
                if (iob->need_ts)
                        __blk_mq_end_request_acct(rq, now);
 
+               rq_qos_done(rq->q, rq);
+
                WRITE_ONCE(rq->state, MQ_RQ_IDLE);
                if (!refcount_dec_and_test(&rq->ref))
                        continue;
 
                blk_crypto_free_request(rq);
                blk_pm_mark_last_busy(rq);
-               rq_qos_done(rq->q, rq);
 
                if (nr_tags == TAG_COMP_BATCH || cur_hctx != rq->mq_hctx) {
                        if (cur_hctx)