blk-mq: simplify flush check in blk_mq_dispatch_rq_list

1. Remove check of needs_resource and ret == BLK_STS_DEV_RESOURCE.
For busy error BLK_STS*_RESOURCE, request will always be added
back to list, so need_resource will not be true and ret will
not be == BLK_STS_DEV_RESOURCE if list is empty. We could remove
these dead check.

2. Check ret of last request instead of errors
If list is empty, we only need to explicitly commit_rqs
if error happens at last request which is stored in ret. So check
ret of last request instead of errors to remove unnecessary
commit_rqs triggered by errors returned from previous request.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions