diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 99 | ||||
| -rw-r--r-- | block/blk-merge.c | 43 | ||||
| -rw-r--r-- | block/blk.h | 1 |
3 files changed, 143 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 4daae1e..c822239 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1157,6 +1157,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) const unsigned short prio = bio_prio(bio); const int sync = bio_sync(bio); const int unplug = bio_unplug(bio); + const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK; int rw_flags; if (bio_barrier(bio) && bio_has_data(bio) && @@ -1186,6 +1187,9 @@ static int __make_request(struct request_queue *q, struct bio *bio) trace_block_bio_backmerge(q, bio); + if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) + blk_rq_set_mixed_merge(req); + req->biotail->bi_next = bio; req->biotail = bio; req->__data_len += bytes; @@ -1205,6 +1209,12 @@ static int __make_request(struct request_queue *q, struct bio *bio) trace_block_bio_frontmerge(q, bio); + if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) { + blk_rq_set_mixed_merge(req); + req->cmd_flags &= ~REQ_FAILFAST_MASK; + req->cmd_flags |= ff; + } + bio->bi_next = req->bio; req->bio = bio; @@ -1649,6 +1659,50 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) } EXPORT_SYMBOL_GPL(blk_insert_cloned_request); +/** + * blk_rq_err_bytes - determine number of bytes till the next failure boundary + * @rq: request to examine + * + * Description: + * A request could be merge of IOs which require different failure + * handling. This function determines the number of bytes which + * can be failed from the beginning of the request without + * crossing into area which need to be retried further. + * + * Return: + * The number of bytes to fail. + * + * Context: + * queue_lock must be held. + */ +unsigned int blk_rq_err_bytes(const struct request *rq) +{ + unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; + unsigned int bytes = 0; + struct bio *bio; + + if (!(rq->cmd_flags & REQ_MIXED_MERGE)) + return blk_rq_bytes(rq); + + /* + * Currently the only 'mixing' which can happen is between + * different fastfail types. We can safely fail portions + * which have all the failfast bits that the first one has - + * the ones which are at least as eager to fail as the first + * one. + */ + for (bio = rq->bio; bio; bio = bio->bi_next) { + if ((bio->bi_rw & ff) != ff) + break; + bytes += bio->bi_size; + } + + /* this could lead to infinite loop */ + BUG_ON(blk_rq_bytes(rq) && !bytes); + return bytes; +} +EXPORT_SYMBOL_GPL(blk_rq_err_bytes); + static void blk_account_io_completion(struct request *req, unsigned int bytes) { if (blk_do_io_stat(req)) { @@ -1995,6 +2049,12 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) if (blk_fs_request(req) || blk_discard_rq(req)) req->__sector += total_bytes >> 9; + /* mixed attributes always follow the first bio */ + if (req->cmd_flags & REQ_MIXED_MERGE) { + req->cmd_flags &= ~REQ_FAILFAST_MASK; + req->cmd_flags |= req->bio->bi_rw & REQ_FAILFAST_MASK; + } + /* * If total number of sectors is less than the first segment * size, something has gone terribly wrong. @@ -2174,6 +2234,25 @@ bool blk_end_request_cur(struct request *rq, int error) EXPORT_SYMBOL(blk_end_request_cur); /** + * blk_end_request_err - Finish a request till the next failure boundary. + * @rq: the request to finish till the next failure boundary for + * @error: must be negative errno + * + * Description: + * Complete @rq till the next failure boundary. + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + */ +bool blk_end_request_err(struct request *rq, int error) +{ + WARN_ON(error >= 0); + return blk_end_request(rq, error, blk_rq_err_bytes(rq)); +} +EXPORT_SYMBOL_GPL(blk_end_request_err); + +/** * __blk_end_request - Helper function for drivers to complete the request. * @rq: the request being processed * @error: %0 for success, < %0 for error @@ -2232,6 +2311,26 @@ bool __blk_end_request_cur(struct request *rq, int error) } EXPORT_SYMBOL(__blk_end_request_cur); +/** + * __blk_end_request_err - Finish a request till the next failure boundary. + * @rq: the request to finish till the next failure boundary for + * @error: must be negative errno + * + * Description: + * Complete @rq till the next failure boundary. Must be called + * with queue lock held. + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + */ +bool __blk_end_request_err(struct request *rq, int error) +{ + WARN_ON(error >= 0); + return __blk_end_request(rq, error, blk_rq_err_bytes(rq)); +} +EXPORT_SYMBOL_GPL(__blk_end_request_err); + void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio) { 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 diff --git a/block/blk.h b/block/blk.h index 3fae6ad..5ee3d7e 100644 --- a/block/blk.h +++ b/block/blk.h @@ -104,6 +104,7 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req, int attempt_back_merge(struct request_queue *q, struct request *rq); int attempt_front_merge(struct request_queue *q, struct request *rq); void blk_recalc_rq_segments(struct request *rq); +void blk_rq_set_mixed_merge(struct request *rq); void blk_queue_congestion_threshold(struct request_queue *q); |