diff options
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r-- | block/blk-merge.c | 171 |
1 files changed, 145 insertions, 26 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 30a0d9f89017..d088cffb8105 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -9,12 +9,146 @@ #include "blk.h" +static struct bio *blk_bio_discard_split(struct request_queue *q, + struct bio *bio, + struct bio_set *bs) +{ + unsigned int max_discard_sectors, granularity; + int alignment; + sector_t tmp; + unsigned split_sectors; + + /* Zero-sector (unknown) and one-sector granularities are the same. */ + granularity = max(q->limits.discard_granularity >> 9, 1U); + + max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); + max_discard_sectors -= max_discard_sectors % granularity; + + if (unlikely(!max_discard_sectors)) { + /* XXX: warn */ + return NULL; + } + + if (bio_sectors(bio) <= max_discard_sectors) + return NULL; + + split_sectors = max_discard_sectors; + + /* + * If the next starting sector would be misaligned, stop the discard at + * the previous aligned sector. + */ + alignment = (q->limits.discard_alignment >> 9) % granularity; + + tmp = bio->bi_iter.bi_sector + split_sectors - alignment; + tmp = sector_div(tmp, granularity); + + if (split_sectors > tmp) + split_sectors -= tmp; + + return bio_split(bio, split_sectors, GFP_NOIO, bs); +} + +static struct bio *blk_bio_write_same_split(struct request_queue *q, + struct bio *bio, + struct bio_set *bs) +{ + if (!q->limits.max_write_same_sectors) + return NULL; + + if (bio_sectors(bio) <= q->limits.max_write_same_sectors) + return NULL; + + return bio_split(bio, q->limits.max_write_same_sectors, GFP_NOIO, bs); +} + +static struct bio *blk_bio_segment_split(struct request_queue *q, + struct bio *bio, + struct bio_set *bs) +{ + struct bio *split; + struct bio_vec bv, bvprv; + struct bvec_iter iter; + unsigned seg_size = 0, nsegs = 0, sectors = 0; + int prev = 0; + + bio_for_each_segment(bv, bio, iter) { + sectors += bv.bv_len >> 9; + + if (sectors > queue_max_sectors(q)) + goto split; + + /* + * If the queue doesn't support SG gaps and adding this + * offset would create a gap, disallow it. + */ + if (prev && bvec_gap_to_prev(q, &bvprv, bv.bv_offset)) + goto split; + + if (prev && blk_queue_cluster(q)) { + if (seg_size + bv.bv_len > queue_max_segment_size(q)) + goto new_segment; + if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv)) + goto new_segment; + if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv)) + goto new_segment; + + seg_size += bv.bv_len; + bvprv = bv; + prev = 1; + continue; + } +new_segment: + if (nsegs == queue_max_segments(q)) + goto split; + + nsegs++; + bvprv = bv; + prev = 1; + seg_size = bv.bv_len; + } + + return NULL; +split: + split = bio_clone_bioset(bio, GFP_NOIO, bs); + + split->bi_iter.bi_size -= iter.bi_size; + bio->bi_iter = iter; + + if (bio_integrity(bio)) { + bio_integrity_advance(bio, split->bi_iter.bi_size); + bio_integrity_trim(split, 0, bio_sectors(split)); + } + + return split; +} + +void blk_queue_split(struct request_queue *q, struct bio **bio, + struct bio_set *bs) +{ + struct bio *split; + + if ((*bio)->bi_rw & REQ_DISCARD) + split = blk_bio_discard_split(q, *bio, bs); + else if ((*bio)->bi_rw & REQ_WRITE_SAME) + split = blk_bio_write_same_split(q, *bio, bs); + else + split = blk_bio_segment_split(q, *bio, q->bio_split); + + if (split) { + bio_chain(split, *bio); + generic_make_request(*bio); + *bio = split; + } +} +EXPORT_SYMBOL(blk_queue_split); + static unsigned int __blk_recalc_rq_segments(struct request_queue *q, struct bio *bio, bool no_sg_merge) { struct bio_vec bv, bvprv = { NULL }; - int cluster, high, highprv = 1; + int cluster, prev = 0; unsigned int seg_size, nr_phys_segs; struct bio *fbio, *bbio; struct bvec_iter iter; @@ -36,7 +170,6 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, cluster = blk_queue_cluster(q); seg_size = 0; nr_phys_segs = 0; - high = 0; for_each_bio(bio) { bio_for_each_segment(bv, bio, iter) { /* @@ -46,13 +179,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, if (no_sg_merge) goto new_segment; - /* - * the trick here is making sure that a high page is - * never considered part of another segment, since - * that might change with the bounce page. - */ - high = page_to_pfn(bv.bv_page) > queue_bounce_pfn(q); - if (!high && !highprv && cluster) { + if (prev && cluster) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; @@ -72,8 +199,8 @@ new_segment: nr_phys_segs++; bvprv = bv; + prev = 1; seg_size = bv.bv_len; - highprv = high; } bbio = bio; } @@ -116,7 +243,7 @@ void blk_recount_segments(struct request_queue *q, struct bio *bio) bio->bi_next = nxt; } - bio->bi_flags |= (1 << BIO_SEG_VALID); + bio_set_flag(bio, BIO_SEG_VALID); } EXPORT_SYMBOL(blk_recount_segments); @@ -266,7 +393,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, if (rq->cmd_flags & REQ_WRITE) memset(q->dma_drain_buffer, 0, q->dma_drain_size); - sg->page_link &= ~0x02; + sg_unmark_end(sg); sg = sg_next(sg); sg_set_page(sg, virt_to_page(q->dma_drain_buffer), q->dma_drain_size, @@ -356,12 +483,12 @@ static bool req_no_special_merge(struct request *req) return !q->mq_ops && req->special; } -static int req_gap_to_prev(struct request *req, struct request *next) +static int req_gap_to_prev(struct request *req, struct bio *next) { struct bio *prev = req->biotail; - return bvec_gap_to_prev(&prev->bi_io_vec[prev->bi_vcnt - 1], - next->bio->bi_io_vec[0].bv_offset); + return bvec_gap_to_prev(req->q, &prev->bi_io_vec[prev->bi_vcnt - 1], + next->bi_io_vec[0].bv_offset); } static int ll_merge_requests_fn(struct request_queue *q, struct request *req, @@ -378,8 +505,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, if (req_no_special_merge(req) || req_no_special_merge(next)) return 0; - if (test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags) && - req_gap_to_prev(req, next)) + if (req_gap_to_prev(req, next->bio)) return 0; /* @@ -564,8 +690,6 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, bool blk_rq_merge_ok(struct request *rq, struct bio *bio) { - struct request_queue *q = rq->q; - if (!rq_mergeable(rq) || !bio_mergeable(bio)) return false; @@ -590,13 +714,8 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) return false; /* Only check gaps if the bio carries data */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && bio_has_data(bio)) { - struct bio_vec *bprev; - - bprev = &rq->biotail->bi_io_vec[rq->biotail->bi_vcnt - 1]; - if (bvec_gap_to_prev(bprev, bio->bi_io_vec[0].bv_offset)) - return false; - } + if (bio_has_data(bio) && req_gap_to_prev(rq, bio)) + return false; return true; } |