On 10/23/19 7:34 PM, Bart Van Assche wrote:

On 2019-10-22 10:41, André Almeida wrote:

quoted

The only usage of the label "done" is when (rq->tag != -1) at the
begging of the function. Rather than jumping to label, we can just
remove this label and execute the code at the "if". Besides that,
the code that would be executed after the label "done" is the return of
the logical expression (rq->tag != -1) but since we are already inside
the if, we now that this is true. Remove the label and replace the goto
with the proper result of the label.

Signed-off-by: André Almeida <redacted>
---
Hello,

I've used `blktest` to check if this change add any regression. I have
used `./check block` and I got the same results with and without this
patch (a bunch of "passed" and three "not run" because of the virtual
scsi capabilities). Please let me know if there would be a better way to
test changes at block stack.

This commit was rebase at linux-block/for-5.5/block.

Thanks,
	André
---
  block/blk-mq.c | 3 +--
  1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8538dc415499..1e067b78ab97 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c

@@ -1036,7 +1036,7 @@ bool blk_mq_get_driver_tag(struct request *rq)
  	bool shared;
  
  	if (rq->tag != -1)
-		goto done;
+		return true;
  
  	if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag))
  		data.flags |= BLK_MQ_REQ_RESERVED;

@@ -1051,7 +1051,6 @@ bool blk_mq_get_driver_tag(struct request *rq)
  		data.hctx->tags->rqs[rq->tag] = rq;
  	}
  
-done:
  	return rq->tag != -1;
  }

Do we really need code changes like the above? I'm not aware of any text
in the Documentation/ directory that forbids the use of goto statements.

Agree, it looks fine as-is. It's also a fast path, so I'd never get rid
of that without looking at the generated code.

-- 
Jens Axboe