tree 5762e0620cc50f1e02b615170b62f2fa9202a863
parent 0e6e255e7a58cdf4ee4163f83deeb5ce4946051e
author Ming Lei <ming.lei@redhat.com> 1593611937 +0800
committer Jens Axboe <axboe@kernel.dk> 1594245879 -0600

blk-mq: streamline handling of q->mq_ops->queue_rq result

Current handling of q->mq_ops->queue_rq result is a bit ugly:

- two branches which needs to 'continue' have to check if the
dispatch local list is empty, otherwise one bad request may
be retrieved via 'rq = list_first_entry(list, struct request, queuelist);'

- the branch of 'if (unlikely(ret != BLK_STS_OK))' isn't easy
to follow, since it is actually one error branch.

Streamline this handling, so the code becomes more readable, meantime
potential kernel oops can be avoided in case that the last request in
local dispatch list is failed.

Fixes: fc17b6534eb8 ("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>