[PATCH v2 2/2] nbd: convert to use blk_mq_get_rq_by_tag()
From: Yu Kuai
Date: Sun Aug 08 2021 - 22:58:54 EST
blk_mq_tag_to_rq() might return freed request, use
blk_mq_get_rq_by_tag() instead.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/block/nbd.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index c38317979f74..9e56975a8eee 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -713,11 +713,10 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
tag = nbd_handle_to_tag(handle);
hwq = blk_mq_unique_tag_to_hwq(tag);
if (hwq < nbd->tag_set.nr_hw_queues)
- req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
- blk_mq_unique_tag_to_tag(tag));
- if (!req || !blk_mq_request_started(req)) {
- dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
- tag, req);
+ req = blk_mq_get_rq_by_tag(nbd->tag_set.tags[hwq],
+ blk_mq_unique_tag_to_tag(tag));
+ if (!req) {
+ dev_err(disk_to_dev(nbd->disk), "Unexpected reply %d\n", tag);
return ERR_PTR(-ENOENT);
}
trace_nbd_header_received(req, handle);
@@ -779,6 +778,8 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
}
out:
trace_nbd_payload_received(req, handle);
+ if (req)
+ blk_mq_put_rq_ref(req);
mutex_unlock(&cmd->lock);
return ret ? ERR_PTR(ret) : cmd;
}
--
2.31.1