Commit 2895f183 authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed 



Otherwise io will hung because request will only be completed if the
cmd has the flag 'NBD_CMD_INFLIGHT'.

Fixes: 07175cb1 ("nbd: make sure request completion won't concurrent")
Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-4-yukuai3@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c55b2b98

drivers/block/nbd.c

+14 −4
Original line number Diff line number Diff line
@@ -403,13 +403,14 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, 
	if (!mutex_trylock(&cmd->lock))

		return BLK_EH_RESET_TIMER;



	if (!__test_and_clear_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {

	if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {

		mutex_unlock(&cmd->lock);

		return BLK_EH_DONE;

	}



	if (!refcount_inc_not_zero(&nbd->config_refs)) {

		cmd->status = BLK_STS_TIMEOUT;

		__clear_bit(NBD_CMD_INFLIGHT, &cmd->flags);

		mutex_unlock(&cmd->lock);

		goto done;

	}
@@ -478,6 +479,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, 
	dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out\n");

	set_bit(NBD_RT_TIMEDOUT, &config->runtime_flags);

	cmd->status = BLK_STS_IOERR;

	__clear_bit(NBD_CMD_INFLIGHT, &cmd->flags);

	mutex_unlock(&cmd->lock);

	sock_shutdown(nbd);

	nbd_config_put(nbd);
@@ -745,7 +747,7 @@ static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index, 
	cmd = blk_mq_rq_to_pdu(req);



	mutex_lock(&cmd->lock);

	if (!__test_and_clear_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {

	if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {

		dev_err(disk_to_dev(nbd->disk), "Suspicious reply %d (status %u flags %lu)",

			tag, cmd->status, cmd->flags);

		ret = -ENOENT;
@@ -854,8 +856,16 @@ static void recv_work(struct work_struct *work) 
		}



		rq = blk_mq_rq_from_pdu(cmd);

		if (likely(!blk_should_fake_timeout(rq->q)))

		if (likely(!blk_should_fake_timeout(rq->q))) {

			bool complete;



			mutex_lock(&cmd->lock);

			complete = __test_and_clear_bit(NBD_CMD_INFLIGHT,

							&cmd->flags);

			mutex_unlock(&cmd->lock);

			if (complete)

				blk_mq_complete_request(rq);

		}

		percpu_ref_put(&q->q_usage_counter);

	}