On Wed, Oct 26, 2016 at 03:51:01PM -0700, Linus Torvalds wrote:
> Dave: it might be a good idea to split that "WARN_ON_ONCE()" in
> blk_mq_merge_queue_io() into two, since right now it can trigger both
> for the
>
> blk_mq_bio_to_request(rq, bio);
>
> path _and_ for the
>
> if (!blk_mq_attempt_merge(q, ctx, bio)) {
> blk_mq_bio_to_request(rq, bio);
> goto insert_rq;
>
> path. If you split it into two: one before that "insert_rq:" label,
> and one before the "goto insert_rq" thing, then we could see if it is
> just one of the blk_mq_merge_queue_io() cases (or both) that is
> broken..
It's the latter of the two.
[ 12.302392] WARNING: CPU: 3 PID: 272 at block/blk-mq.c:1191
blk_sq_make_request+0x320/0x4d0
Dave
