diff options
| -rw-r--r-- | block/blk-core.c | 27 | ||||
| -rw-r--r-- | block/blk-merge.c | 5 | ||||
| -rw-r--r-- | block/blk-mq.c | 3 | ||||
| -rw-r--r-- | block/blk-settings.c | 20 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 12 | ||||
| -rw-r--r-- | block/blk.h | 2 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 26 | ||||
| -rw-r--r-- | include/linux/elevator.h | 1 |
8 files changed, 95 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 00e053c704a1..c0e4d41d3d33 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1483,6 +1483,30 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, return true; } +bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, + struct bio *bio) +{ + unsigned short segments = blk_rq_nr_discard_segments(req); + + if (segments >= queue_max_discard_segments(q)) + goto no_merge; + if (blk_rq_sectors(req) + bio_sectors(bio) > + blk_rq_get_max_sectors(req, blk_rq_pos(req))) + goto no_merge; + + req->biotail->bi_next = bio; + req->biotail = bio; + req->__data_len += bio->bi_iter.bi_size; + req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); + req->nr_phys_segments = segments + 1; + + blk_account_io_start(req, false); + return true; +no_merge: + req_set_nomerge(q, req); + return false; +} + /** * blk_attempt_plug_merge - try to merge with %current's plugged list * @q: request_queue new bio is being queued at @@ -1547,6 +1571,9 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, case ELEVATOR_FRONT_MERGE: merged = bio_attempt_front_merge(q, rq, bio); break; + case ELEVATOR_DISCARD_MERGE: + merged = bio_attempt_discard_merge(q, rq, bio); + break; default: break; } diff --git a/block/blk-merge.c b/block/blk-merge.c index 6cbd90ad5f90..2afa262425d1 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -803,7 +803,10 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) enum elv_merge blk_try_merge(struct request *rq, struct bio *bio) { - if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector) + if (req_op(rq) == REQ_OP_DISCARD && + queue_max_discard_segments(rq->q) > 1) + return ELEVATOR_DISCARD_MERGE; + else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector) return ELEVATOR_BACK_MERGE; else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_iter.bi_sector) return ELEVATOR_FRONT_MERGE; diff --git a/block/blk-mq.c b/block/blk-mq.c index dd9722df4afe..7412191aee57 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -780,6 +780,9 @@ static bool blk_mq_attempt_merge(struct request_queue *q, if (blk_mq_sched_allow_merge(q, rq, bio)) merged = bio_attempt_front_merge(q, rq, bio); break; + case ELEVATOR_DISCARD_MERGE: + merged = bio_attempt_discard_merge(q, rq, bio); + break; default: continue; } diff --git a/block/blk-settings.c b/block/blk-settings.c index 6eb19bcbf3cb..1e7174ffc9d4 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -88,6 +88,7 @@ EXPORT_SYMBOL_GPL(blk_queue_lld_busy); void blk_set_default_limits(struct queue_limits *lim) { lim->max_segments = BLK_MAX_SEGMENTS; + lim->max_discard_segments = 1; lim->max_integrity_segments = 0; lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; lim->virt_boundary_mask = 0; @@ -128,6 +129,7 @@ void blk_set_stacking_limits(struct queue_limits *lim) /* Inherit limits from component devices */ lim->discard_zeroes_data = 1; lim->max_segments = USHRT_MAX; + lim->max_discard_segments = 1; lim->max_hw_sectors = UINT_MAX; lim->max_segment_size = UINT_MAX; lim->max_sectors = UINT_MAX; @@ -337,6 +339,22 @@ void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments EXPORT_SYMBOL(blk_queue_max_segments); /** + * blk_queue_max_discard_segments - set max segments for discard requests + * @q: the request queue for the device + * @max_segments: max number of segments + * + * Description: + * Enables a low level driver to set an upper limit on the number of + * segments in a discard request. + **/ +void blk_queue_max_discard_segments(struct request_queue *q, + unsigned short max_segments) +{ + q->limits.max_discard_segments = max_segments; +} +EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments); + +/** * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg * @q: the request queue for the device * @max_size: max size of segment in bytes @@ -553,6 +571,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, b->virt_boundary_mask); t->max_segments = min_not_zero(t->max_segments, b->max_segments); + t->max_discard_segments = min_not_zero(t->max_discard_segments, + b->max_discard_segments); t->max_integrity_segments = min_not_zero(t->max_integrity_segments, b->max_integrity_segments); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 48032c4759a7..070d81bae1d5 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -121,6 +121,12 @@ static ssize_t queue_max_segments_show(struct request_queue *q, char *page) return queue_var_show(queue_max_segments(q), (page)); } +static ssize_t queue_max_discard_segments_show(struct request_queue *q, + char *page) +{ + return queue_var_show(queue_max_discard_segments(q), (page)); +} + static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) { return queue_var_show(q->limits.max_integrity_segments, (page)); @@ -545,6 +551,11 @@ static struct queue_sysfs_entry queue_max_segments_entry = { .show = queue_max_segments_show, }; +static struct queue_sysfs_entry queue_max_discard_segments_entry = { + .attr = {.name = "max_discard_segments", .mode = S_IRUGO }, + .show = queue_max_discard_segments_show, +}; + static struct queue_sysfs_entry queue_max_integrity_segments_entry = { .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, .show = queue_max_integrity_segments_show, @@ -697,6 +708,7 @@ static struct attribute *default_attrs[] = { &queue_max_hw_sectors_entry.attr, &queue_max_sectors_entry.attr, &queue_max_segments_entry.attr, + &queue_max_discard_segments_entry.attr, &queue_max_integrity_segments_entry.attr, &queue_max_segment_size_entry.attr, &queue_iosched_entry.attr, diff --git a/block/blk.h b/block/blk.h index ae82f2ac4019..d1ea4bd9b9a3 100644 --- a/block/blk.h +++ b/block/blk.h @@ -100,6 +100,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, struct bio *bio); bool bio_attempt_back_merge(struct request_queue *q, struct request *req, struct bio *bio); +bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, + struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int *request_count, struct request **same_queue_rq); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e0bac14347e6..aecca0e7d9ca 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -331,6 +331,7 @@ struct queue_limits { unsigned short logical_block_size; unsigned short max_segments; unsigned short max_integrity_segments; + unsigned short max_discard_segments; unsigned char misaligned; unsigned char discard_misaligned; @@ -1146,6 +1147,8 @@ extern void blk_queue_bounce_limit(struct request_queue *, u64); extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); extern void blk_queue_max_segments(struct request_queue *, unsigned short); +extern void blk_queue_max_discard_segments(struct request_queue *, + unsigned short); extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); extern void blk_queue_max_discard_sectors(struct request_queue *q, unsigned int max_discard_sectors); @@ -1189,6 +1192,15 @@ extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua); +/* + * Number of physical segments as sent to the device. + * + * Normally this is the number of discontiguous data segments sent by the + * submitter. But for data-less command like discard we might have no + * actual data segments submitted, but the driver might have to add it's + * own special payload. In that case we still return 1 here so that this + * special payload will be mapped. + */ static inline unsigned short blk_rq_nr_phys_segments(struct request *rq) { if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) @@ -1196,6 +1208,15 @@ static inline unsigned short blk_rq_nr_phys_segments(struct request *rq) return rq->nr_phys_segments; } +/* + * Number of discard segments (or ranges) the driver needs to fill in. + * Each discard bio merged into a request is counted as one segment. + */ +static inline unsigned short blk_rq_nr_discard_segments(struct request *rq) +{ + return max_t(unsigned short, rq->nr_phys_segments, 1); +} + extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); extern long nr_blockdev_pages(void); @@ -1384,6 +1405,11 @@ static inline unsigned short queue_max_segments(struct request_queue *q) return q->limits.max_segments; } +static inline unsigned short queue_max_discard_segments(struct request_queue *q) +{ + return q->limits.max_discard_segments; +} + static inline unsigned int queue_max_segment_size(struct request_queue *q) { return q->limits.max_segment_size; diff --git a/include/linux/elevator.h b/include/linux/elevator.h index b38b4e651ea6..8265b6330cc2 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -16,6 +16,7 @@ enum elv_merge { ELEVATOR_NO_MERGE = 0, ELEVATOR_FRONT_MERGE = 1, ELEVATOR_BACK_MERGE = 2, + ELEVATOR_DISCARD_MERGE = 3, }; typedef enum elv_merge (elevator_merge_fn) (struct request_queue *, struct request **, |