diff options
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index e199967..7c9ca01 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -311,6 +311,36 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, return 1; } +/** + * blk_rq_set_mixed_merge - mark a request as mixed merge + * @rq: request to mark as mixed merge + * + * Description: + * @rq is about to be mixed merged. Make sure the attributes + * which can be mixed are set in each bio and mark @rq as mixed + * merged. + */ +void blk_rq_set_mixed_merge(struct request *rq) +{ + unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; + struct bio *bio; + + if (rq->cmd_flags & REQ_MIXED_MERGE) + return; + + /* + * @rq will no longer represent mixable attributes for all the + * contained bios. It will just track those of the first one. + * Distributes the attributs to each bio. + */ + for (bio = rq->bio; bio; bio = bio->bi_next) { + WARN_ON_ONCE((bio->bi_rw & REQ_FAILFAST_MASK) && + (bio->bi_rw & REQ_FAILFAST_MASK) != ff); + bio->bi_rw |= ff; + } + rq->cmd_flags |= REQ_MIXED_MERGE; +} + static void blk_account_io_merge(struct request *req) { if (blk_do_io_stat(req)) { @@ -366,6 +396,19 @@ static int attempt_merge(struct request_queue *q, struct request *req, return 0; /* + * If failfast settings disagree or any of the two is already + * a mixed merge, mark both as mixed before proceeding. This + * makes sure that all involved bios have mixable attributes + * set properly. + */ + if ((req->cmd_flags | next->cmd_flags) & REQ_MIXED_MERGE || + (req->cmd_flags & REQ_FAILFAST_MASK) != + (next->cmd_flags & REQ_FAILFAST_MASK)) { + blk_rq_set_mixed_merge(req); + blk_rq_set_mixed_merge(next); + } + + /* * At this point we have either done a back merge * or front merge. We need the smaller start_time of * the merged requests to be the current request |