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From:   Yu Kuai <yukuai3@huawei.com>
To:     <josef@toxicpanda.com>, <axboe@kernel.dk>, <ming.lei@redhat.com>,
        <hch@infradead.org>
CC:     <linux-block@vger.kernel.org>, <nbd@other.debian.org>,
        <linux-kernel@vger.kernel.org>, <yukuai3@huawei.com>,
        <yi.zhang@huawei.com>
Subject: [patch v8 4/7] nbd: don't start request if nbd_queue_rq() failed
Date:   Thu, 16 Sep 2021 17:33:47 +0800
Message-ID: <20210916093350.1410403-5-yukuai3@huawei.com>
In-Reply-To: <20210916093350.1410403-1-yukuai3@huawei.com>
References: <20210916093350.1410403-1-yukuai3@huawei.com>
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Precedence: bulk

commit 6a468d5990ec ("nbd: don't start req until after the dead
connection logic") move blk_mq_start_request() from nbd_queue_rq()
to nbd_handle_cmd() to skip starting request if the connection is
dead. However, request is still started in other error paths.

Currently, blk_mq_end_request() will be called immediately if
nbd_queue_rq() failed, thus start request in such situation is
useless. So remove blk_mq_start_request() from error paths in
nbd_handle_cmd().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/block/nbd.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index c724a5bd7fa4..22c91d8901f6 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -934,7 +934,6 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 	if (!refcount_inc_not_zero(&nbd->config_refs)) {
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
 				    "Socks array is empty\n");
-		blk_mq_start_request(req);
 		return -EINVAL;
 	}
 	config = nbd->config;
@@ -943,7 +942,6 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
 				    "Attempted send on invalid socket\n");
 		nbd_config_put(nbd);
-		blk_mq_start_request(req);
 		return -EINVAL;
 	}
 	cmd->status = BLK_STS_OK;
@@ -967,7 +965,6 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 			 */
 			sock_shutdown(nbd);
 			nbd_config_put(nbd);
-			blk_mq_start_request(req);
 			return -EIO;
 		}
 		goto again;
-- 
2.31.1