X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=block%2Fblk-merge.c;h=6c583f9c5b65d002a6ca357c53b19799f822f512;hb=9579f10dfdd91d5a1bc77a588b630bc945d9fb95;hp=1ffc58977835ff2e581c97faa35ee85ebc9a5095;hpb=60e53a6701ca55b3399275d805d223834819d9ce;p=~andy%2Flinux diff --git a/block/blk-merge.c b/block/blk-merge.c index 1ffc5897783..6c583f9c5b6 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -12,38 +12,47 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, struct bio *bio) { - struct bio_vec *bv, *bvprv = NULL; - int cluster, i, high, highprv = 1; + struct bio_vec bv, bvprv = { NULL }; + int cluster, high, highprv = 1; unsigned int seg_size, nr_phys_segs; struct bio *fbio, *bbio; + struct bvec_iter iter; if (!bio) return 0; + /* + * This should probably be returning 0, but blk_add_request_payload() + * (Christoph!!!!) + */ + if (bio->bi_rw & REQ_DISCARD) + return 1; + + if (bio->bi_rw & REQ_WRITE_SAME) + return 1; + fbio = bio; cluster = blk_queue_cluster(q); seg_size = 0; nr_phys_segs = 0; for_each_bio(bio) { - bio_for_each_segment(bv, bio, i) { + bio_for_each_segment(bv, bio, iter) { /* * 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) - goto new_segment; - if (cluster) { - if (seg_size + bv->bv_len + high = page_to_pfn(bv.bv_page) > queue_bounce_pfn(q); + if (!high && !highprv && cluster) { + if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; - if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv)) + if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv)) goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv)) + if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv)) goto new_segment; - seg_size += bv->bv_len; + seg_size += bv.bv_len; bvprv = bv; continue; } @@ -54,7 +63,7 @@ new_segment: nr_phys_segs++; bvprv = bv; - seg_size = bv->bv_len; + seg_size = bv.bv_len; highprv = high; } bbio = bio; @@ -87,6 +96,9 @@ EXPORT_SYMBOL(blk_recount_segments); static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, struct bio *nxt) { + struct bio_vec end_bv = { NULL }, nxt_bv; + struct bvec_iter iter; + if (!blk_queue_cluster(q)) return 0; @@ -97,34 +109,40 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, if (!bio_has_data(bio)) return 1; - if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt))) + bio_for_each_segment(end_bv, bio, iter) + if (end_bv.bv_len == iter.bi_size) + break; + + nxt_bv = bio_iovec(nxt); + + if (!BIOVEC_PHYS_MERGEABLE(&end_bv, &nxt_bv)) return 0; /* * bio and nxt are contiguous in memory; check if the queue allows * these two to be merged into one */ - if (BIO_SEG_BOUNDARY(q, bio, nxt)) + if (BIOVEC_SEG_BOUNDARY(q, &end_bv, &nxt_bv)) return 1; return 0; } -static void +static inline void __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec, - struct scatterlist *sglist, struct bio_vec **bvprv, + struct scatterlist *sglist, struct bio_vec *bvprv, struct scatterlist **sg, int *nsegs, int *cluster) { int nbytes = bvec->bv_len; - if (*bvprv && *cluster) { + if (*sg && *cluster) { if ((*sg)->length + nbytes > queue_max_segment_size(q)) goto new_segment; - if (!BIOVEC_PHYS_MERGEABLE(*bvprv, bvec)) + if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, *bvprv, bvec)) + if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec)) goto new_segment; (*sg)->length += nbytes; @@ -150,7 +168,49 @@ new_segment: sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset); (*nsegs)++; } - *bvprv = bvec; + *bvprv = *bvec; +} + +static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio, + struct scatterlist *sglist, + struct scatterlist **sg) +{ + struct bio_vec bvec, bvprv = { NULL }; + struct bvec_iter iter; + int nsegs, cluster; + + nsegs = 0; + cluster = blk_queue_cluster(q); + + if (bio->bi_rw & REQ_DISCARD) { + /* + * This is a hack - drivers should be neither modifying the + * biovec, nor relying on bi_vcnt - but because of + * blk_add_request_payload(), a discard bio may or may not have + * a payload we need to set up here (thank you Christoph) and + * bi_vcnt is really the only way of telling if we need to. + */ + + if (bio->bi_vcnt) + goto single_segment; + + return 0; + } + + if (bio->bi_rw & REQ_WRITE_SAME) { +single_segment: + *sg = sglist; + bvec = bio_iovec(bio); + sg_set_page(*sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset); + return 1; + } + + for_each_bio(bio) + bio_for_each_segment(bvec, bio, iter) + __blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg, + &nsegs, &cluster); + + return nsegs; } /* @@ -160,24 +220,11 @@ new_segment: int blk_rq_map_sg(struct request_queue *q, struct request *rq, struct scatterlist *sglist) { - struct bio_vec *bvec, *bvprv; - struct req_iterator iter; - struct scatterlist *sg; - int nsegs, cluster; - - nsegs = 0; - cluster = blk_queue_cluster(q); - - /* - * for each bio in rq - */ - bvprv = NULL; - sg = NULL; - rq_for_each_segment(bvec, rq, iter) { - __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg, - &nsegs, &cluster); - } /* segments in rq */ + struct scatterlist *sg = NULL; + int nsegs = 0; + if (rq->bio) + nsegs = __blk_bios_map_sg(q, rq->bio, sglist, &sg); if (unlikely(rq->cmd_flags & REQ_COPY_USER) && (blk_rq_bytes(rq) & q->dma_pad_mask)) { @@ -223,21 +270,13 @@ EXPORT_SYMBOL(blk_rq_map_sg); int blk_bio_map_sg(struct request_queue *q, struct bio *bio, struct scatterlist *sglist) { - struct bio_vec *bvec, *bvprv; - struct scatterlist *sg; - int nsegs, cluster; - unsigned long i; - - nsegs = 0; - cluster = blk_queue_cluster(q); - - bvprv = NULL; - sg = NULL; - bio_for_each_segment(bvec, bio, i) { - __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg, - &nsegs, &cluster); - } /* segments in bio */ + struct scatterlist *sg = NULL; + int nsegs; + struct bio *next = bio->bi_next; + bio->bi_next = NULL; + nsegs = __blk_bios_map_sg(q, bio, sglist, &sg); + bio->bi_next = next; if (sg) sg_mark_end(sg); @@ -543,9 +582,9 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) int blk_try_merge(struct request *rq, struct bio *bio) { - if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_sector) + 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_sector) + else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_iter.bi_sector) return ELEVATOR_FRONT_MERGE; return ELEVATOR_NO_MERGE; }