From: Kent Overstreet Date: Sun, 24 Nov 2013 02:21:01 +0000 (-0800) Subject: block: Introduce new bio_split() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=20d0189b1012a37d2533a87fb451f7852f2418d1;p=linux-beck.git block: Introduce new bio_split() The new bio_split() can split arbitrary bios - it's not restricted to single page bios, like the old bio_split() (previously renamed to bio_pair_split()). It also has different semantics - it doesn't allocate a struct bio_pair, leaving it up to the caller to handle completions. Then convert the existing bio_pair_split() users to the new bio_split() - and also nvme, which was open coding bio splitting. (We have to take that BUG_ON() out of bio_integrity_trim() because this bio_split() needs to use it, and there's no reason it has to be used on bios marked as cloned; BIO_CLONED doesn't seem to have clearly documented semantics anyways.) Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: Martin K. Petersen Cc: Matthew Wilcox Cc: Keith Busch Cc: Vishal Verma Cc: Jiri Kosina Cc: Neil Brown --- diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 5539d2920872..1f14ac403945 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -441,104 +441,19 @@ int nvme_setup_prps(struct nvme_dev *dev, struct nvme_common_command *cmd, return total_len; } -struct nvme_bio_pair { - struct bio b1, b2, *parent; - struct bio_vec *bv1, *bv2; - int err; - atomic_t cnt; -}; - -static void nvme_bio_pair_endio(struct bio *bio, int err) -{ - struct nvme_bio_pair *bp = bio->bi_private; - - if (err) - bp->err = err; - - if (atomic_dec_and_test(&bp->cnt)) { - bio_endio(bp->parent, bp->err); - kfree(bp->bv1); - kfree(bp->bv2); - kfree(bp); - } -} - -static struct nvme_bio_pair *nvme_bio_split(struct bio *bio, int idx, - int len, int offset) -{ - struct nvme_bio_pair *bp; - - BUG_ON(len > bio->bi_iter.bi_size); - BUG_ON(idx > bio->bi_vcnt); - - bp = kmalloc(sizeof(*bp), GFP_ATOMIC); - if (!bp) - return NULL; - bp->err = 0; - - bp->b1 = *bio; - bp->b2 = *bio; - - bp->b1.bi_iter.bi_size = len; - bp->b2.bi_iter.bi_size -= len; - bp->b1.bi_vcnt = idx; - bp->b2.bi_iter.bi_idx = idx; - bp->b2.bi_iter.bi_sector += len >> 9; - - if (offset) { - bp->bv1 = kmalloc(bio->bi_max_vecs * sizeof(struct bio_vec), - GFP_ATOMIC); - if (!bp->bv1) - goto split_fail_1; - - bp->bv2 = kmalloc(bio->bi_max_vecs * sizeof(struct bio_vec), - GFP_ATOMIC); - if (!bp->bv2) - goto split_fail_2; - - memcpy(bp->bv1, bio->bi_io_vec, - bio->bi_max_vecs * sizeof(struct bio_vec)); - memcpy(bp->bv2, bio->bi_io_vec, - bio->bi_max_vecs * sizeof(struct bio_vec)); - - bp->b1.bi_io_vec = bp->bv1; - bp->b2.bi_io_vec = bp->bv2; - bp->b2.bi_io_vec[idx].bv_offset += offset; - bp->b2.bi_io_vec[idx].bv_len -= offset; - bp->b1.bi_io_vec[idx].bv_len = offset; - bp->b1.bi_vcnt++; - } else - bp->bv1 = bp->bv2 = NULL; - - bp->b1.bi_private = bp; - bp->b2.bi_private = bp; - - bp->b1.bi_end_io = nvme_bio_pair_endio; - bp->b2.bi_end_io = nvme_bio_pair_endio; - - bp->parent = bio; - atomic_set(&bp->cnt, 2); - - return bp; - - split_fail_2: - kfree(bp->bv1); - split_fail_1: - kfree(bp); - return NULL; -} - static int nvme_split_and_submit(struct bio *bio, struct nvme_queue *nvmeq, - int idx, int len, int offset) + int len) { - struct nvme_bio_pair *bp = nvme_bio_split(bio, idx, len, offset); - if (!bp) + struct bio *split = bio_split(bio, len >> 9, GFP_ATOMIC, NULL); + if (!split) return -ENOMEM; + bio_chain(split, bio); + if (bio_list_empty(&nvmeq->sq_cong)) add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait); - bio_list_add(&nvmeq->sq_cong, &bp->b1); - bio_list_add(&nvmeq->sq_cong, &bp->b2); + bio_list_add(&nvmeq->sq_cong, split); + bio_list_add(&nvmeq->sq_cong, bio); return 0; } @@ -568,8 +483,7 @@ static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod, } else { if (!first && BIOVEC_NOT_VIRT_MERGEABLE(&bvprv, &bvec)) return nvme_split_and_submit(bio, nvmeq, - iter.bi_idx, - length, 0); + length); sg = sg ? sg + 1 : iod->sg; sg_set_page(sg, bvec.bv_page, @@ -578,9 +492,7 @@ static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod, } if (split_len - length < bvec.bv_len) - return nvme_split_and_submit(bio, nvmeq, iter.bi_idx, - split_len, - split_len - length); + return nvme_split_and_submit(bio, nvmeq, split_len); length += bvec.bv_len; bvprv = bvec; first = 0; diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 28789b82ae7d..3dda09a5ec41 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2338,75 +2338,29 @@ static void pkt_end_io_read_cloned(struct bio *bio, int err) pkt_bio_finished(pd); } -static void pkt_make_request(struct request_queue *q, struct bio *bio) +static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio) { - struct pktcdvd_device *pd; - char b[BDEVNAME_SIZE]; + struct bio *cloned_bio = bio_clone(bio, GFP_NOIO); + struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO); + + psd->pd = pd; + psd->bio = bio; + cloned_bio->bi_bdev = pd->bdev; + cloned_bio->bi_private = psd; + cloned_bio->bi_end_io = pkt_end_io_read_cloned; + pd->stats.secs_r += bio_sectors(bio); + pkt_queue_bio(pd, cloned_bio); +} + +static void pkt_make_request_write(struct request_queue *q, struct bio *bio) +{ + struct pktcdvd_device *pd = q->queuedata; sector_t zone; struct packet_data *pkt; int was_empty, blocked_bio; struct pkt_rb_node *node; - pd = q->queuedata; - if (!pd) { - pr_err("%s incorrect request queue\n", - bdevname(bio->bi_bdev, b)); - goto end_io; - } - - /* - * Clone READ bios so we can have our own bi_end_io callback. - */ - if (bio_data_dir(bio) == READ) { - struct bio *cloned_bio = bio_clone(bio, GFP_NOIO); - struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO); - - psd->pd = pd; - psd->bio = bio; - cloned_bio->bi_bdev = pd->bdev; - cloned_bio->bi_private = psd; - cloned_bio->bi_end_io = pkt_end_io_read_cloned; - pd->stats.secs_r += bio_sectors(bio); - pkt_queue_bio(pd, cloned_bio); - return; - } - - if (!test_bit(PACKET_WRITABLE, &pd->flags)) { - pkt_notice(pd, "WRITE for ro device (%llu)\n", - (unsigned long long)bio->bi_iter.bi_sector); - goto end_io; - } - - if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) { - pkt_err(pd, "wrong bio size\n"); - goto end_io; - } - - blk_queue_bounce(q, &bio); - zone = get_zone(bio->bi_iter.bi_sector, pd); - pkt_dbg(2, pd, "start = %6llx stop = %6llx\n", - (unsigned long long)bio->bi_iter.bi_sector, - (unsigned long long)bio_end_sector(bio)); - - /* Check if we have to split the bio */ - { - struct bio_pair *bp; - sector_t last_zone; - int first_sectors; - - last_zone = get_zone(bio_end_sector(bio) - 1, pd); - if (last_zone != zone) { - BUG_ON(last_zone != zone + pd->settings.size); - first_sectors = last_zone - bio->bi_iter.bi_sector; - bp = bio_pair_split(bio, first_sectors); - BUG_ON(!bp); - pkt_make_request(q, &bp->bio1); - pkt_make_request(q, &bp->bio2); - bio_pair_release(bp); - return; - } - } /* * If we find a matching packet in state WAITING or READ_WAIT, we can @@ -2480,6 +2434,64 @@ static void pkt_make_request(struct request_queue *q, struct bio *bio) */ wake_up(&pd->wqueue); } +} + +static void pkt_make_request(struct request_queue *q, struct bio *bio) +{ + struct pktcdvd_device *pd; + char b[BDEVNAME_SIZE]; + struct bio *split; + + pd = q->queuedata; + if (!pd) { + pr_err("%s incorrect request queue\n", + bdevname(bio->bi_bdev, b)); + goto end_io; + } + + pkt_dbg(2, pd, "start = %6llx stop = %6llx\n", + (unsigned long long)bio->bi_iter.bi_sector, + (unsigned long long)bio_end_sector(bio)); + + /* + * Clone READ bios so we can have our own bi_end_io callback. + */ + if (bio_data_dir(bio) == READ) { + pkt_make_request_read(pd, bio); + return; + } + + if (!test_bit(PACKET_WRITABLE, &pd->flags)) { + pkt_notice(pd, "WRITE for ro device (%llu)\n", + (unsigned long long)bio->bi_iter.bi_sector); + goto end_io; + } + + if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) { + pkt_err(pd, "wrong bio size\n"); + goto end_io; + } + + blk_queue_bounce(q, &bio); + + do { + sector_t zone = get_zone(bio->bi_iter.bi_sector, pd); + sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd); + + if (last_zone != zone) { + BUG_ON(last_zone != zone + pd->settings.size); + + split = bio_split(bio, last_zone - + bio->bi_iter.bi_sector, + GFP_NOIO, fs_bio_set); + bio_chain(split, bio); + } else { + split = bio; + } + + pkt_make_request_write(q, split); + } while (split != bio); + return; end_io: bio_io_error(bio); diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 6b6fe935be73..964353c5329d 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -901,7 +901,6 @@ void bch_bbio_endio(struct cache_set *, struct bio *, int, const char *); void bch_bbio_free(struct bio *, struct cache_set *); struct bio *bch_bbio_alloc(struct cache_set *); -struct bio *bch_bio_split(struct bio *, int, gfp_t, struct bio_set *); void bch_generic_make_request(struct bio *, struct bio_split_pool *); void __bch_submit_bbio(struct bio *, struct cache_set *); void bch_submit_bbio(struct bio *, struct cache_set *, struct bkey *, unsigned); diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c index 522f95778443..fa028fa82df4 100644 --- a/drivers/md/bcache/io.c +++ b/drivers/md/bcache/io.c @@ -11,84 +11,6 @@ #include -/** - * bch_bio_split - split a bio - * @bio: bio to split - * @sectors: number of sectors to split from the front of @bio - * @gfp: gfp mask - * @bs: bio set to allocate from - * - * Allocates and returns a new bio which represents @sectors from the start of - * @bio, and updates @bio to represent the remaining sectors. - * - * If bio_sectors(@bio) was less than or equal to @sectors, returns @bio - * unchanged. - * - * The newly allocated bio will point to @bio's bi_io_vec, if the split was on a - * bvec boundry; it is the caller's responsibility to ensure that @bio is not - * freed before the split. - */ -struct bio *bch_bio_split(struct bio *bio, int sectors, - gfp_t gfp, struct bio_set *bs) -{ - unsigned vcnt = 0, nbytes = sectors << 9; - struct bio_vec bv; - struct bvec_iter iter; - struct bio *ret = NULL; - - BUG_ON(sectors <= 0); - - if (sectors >= bio_sectors(bio)) - return bio; - - if (bio->bi_rw & REQ_DISCARD) { - ret = bio_alloc_bioset(gfp, 1, bs); - if (!ret) - return NULL; - goto out; - } - - bio_for_each_segment(bv, bio, iter) { - vcnt++; - - if (nbytes <= bv.bv_len) - break; - - nbytes -= bv.bv_len; - } - - ret = bio_alloc_bioset(gfp, vcnt, bs); - if (!ret) - return NULL; - - bio_for_each_segment(bv, bio, iter) { - ret->bi_io_vec[ret->bi_vcnt++] = bv; - - if (ret->bi_vcnt == vcnt) - break; - } - - ret->bi_io_vec[ret->bi_vcnt - 1].bv_len = nbytes; -out: - ret->bi_bdev = bio->bi_bdev; - ret->bi_iter.bi_sector = bio->bi_iter.bi_sector; - ret->bi_iter.bi_size = sectors << 9; - ret->bi_rw = bio->bi_rw; - - if (bio_integrity(bio)) { - if (bio_integrity_clone(ret, bio, gfp)) { - bio_put(ret); - return NULL; - } - - bio_integrity_trim(ret, 0, bio_sectors(ret)); - } - - bio_advance(bio, ret->bi_iter.bi_size); - - return ret; -} - static unsigned bch_bio_max_sectors(struct bio *bio) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); @@ -172,8 +94,8 @@ void bch_generic_make_request(struct bio *bio, struct bio_split_pool *p) bio_get(bio); do { - n = bch_bio_split(bio, bch_bio_max_sectors(bio), - GFP_NOIO, s->p->bio_split); + n = bio_next_split(bio, bch_bio_max_sectors(bio), + GFP_NOIO, s->p->bio_split); n->bi_end_io = bch_bio_submit_split_endio; n->bi_private = &s->cl; diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 63451c724781..5878cdb39529 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -371,7 +371,7 @@ static void bch_data_insert_start(struct closure *cl) op->writeback)) goto err; - n = bch_bio_split(bio, KEY_SIZE(k), GFP_NOIO, split); + n = bio_next_split(bio, KEY_SIZE(k), GFP_NOIO, split); n->bi_end_io = bch_data_insert_endio; n->bi_private = cl; @@ -679,9 +679,9 @@ static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k) if (KEY_DIRTY(k)) s->read_dirty_data = true; - n = bch_bio_split(bio, min_t(uint64_t, INT_MAX, - KEY_OFFSET(k) - bio->bi_iter.bi_sector), - GFP_NOIO, s->d->bio_split); + n = bio_next_split(bio, min_t(uint64_t, INT_MAX, + KEY_OFFSET(k) - bio->bi_iter.bi_sector), + GFP_NOIO, s->d->bio_split); bio_key = &container_of(n, struct bbio, bio)->key; bch_bkey_copy_single_ptr(bio_key, k, ptr); @@ -920,7 +920,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, struct bio *miss, *cache_bio; if (s->cache_miss || s->iop.bypass) { - miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); + miss = bio_next_split(bio, sectors, GFP_NOIO, s->d->bio_split); ret = miss == bio ? MAP_DONE : MAP_CONTINUE; goto out_submit; } @@ -943,7 +943,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, s->iop.replace = true; - miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); + miss = bio_next_split(bio, sectors, GFP_NOIO, s->d->bio_split); /* btree_search_recurse()'s btree iterator is no good anymore */ ret = miss == bio ? MAP_DONE : -EINTR; diff --git a/drivers/md/linear.c b/drivers/md/linear.c index e9b53e9793bf..56f534b4a2d2 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -288,65 +288,65 @@ static int linear_stop (struct mddev *mddev) static void linear_make_request(struct mddev *mddev, struct bio *bio) { + char b[BDEVNAME_SIZE]; struct dev_info *tmp_dev; - sector_t start_sector; + struct bio *split; + sector_t start_sector, end_sector, data_offset; if (unlikely(bio->bi_rw & REQ_FLUSH)) { md_flush_request(mddev, bio); return; } - rcu_read_lock(); - tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector); - start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors; - - - if (unlikely(bio->bi_iter.bi_sector >= (tmp_dev->end_sector) - || (bio->bi_iter.bi_sector < start_sector))) { - char b[BDEVNAME_SIZE]; - - printk(KERN_ERR - "md/linear:%s: make_request: Sector %llu out of bounds on " - "dev %s: %llu sectors, offset %llu\n", - mdname(mddev), - (unsigned long long)bio->bi_iter.bi_sector, - bdevname(tmp_dev->rdev->bdev, b), - (unsigned long long)tmp_dev->rdev->sectors, - (unsigned long long)start_sector); - rcu_read_unlock(); - bio_io_error(bio); - return; - } - if (unlikely(bio_end_sector(bio) > tmp_dev->end_sector)) { - /* This bio crosses a device boundary, so we have to - * split it. - */ - struct bio_pair *bp; - sector_t end_sector = tmp_dev->end_sector; + do { + rcu_read_lock(); - rcu_read_unlock(); - - bp = bio_pair_split(bio, end_sector - bio->bi_iter.bi_sector); + tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector); + start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors; + end_sector = tmp_dev->end_sector; + data_offset = tmp_dev->rdev->data_offset; + bio->bi_bdev = tmp_dev->rdev->bdev; - linear_make_request(mddev, &bp->bio1); - linear_make_request(mddev, &bp->bio2); - bio_pair_release(bp); - return; - } - - bio->bi_bdev = tmp_dev->rdev->bdev; - bio->bi_iter.bi_sector = bio->bi_iter.bi_sector - start_sector - + tmp_dev->rdev->data_offset; - rcu_read_unlock(); + rcu_read_unlock(); - if (unlikely((bio->bi_rw & REQ_DISCARD) && - !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) { - /* Just ignore it */ - bio_endio(bio, 0); - return; - } + if (unlikely(bio->bi_iter.bi_sector >= end_sector || + bio->bi_iter.bi_sector < start_sector)) + goto out_of_bounds; + + if (unlikely(bio_end_sector(bio) > end_sector)) { + /* This bio crosses a device boundary, so we have to + * split it. + */ + split = bio_split(bio, end_sector - + bio->bi_iter.bi_sector, + GFP_NOIO, fs_bio_set); + bio_chain(split, bio); + } else { + split = bio; + } - generic_make_request(bio); + split->bi_iter.bi_sector = split->bi_iter.bi_sector - + start_sector + data_offset; + + if (unlikely((split->bi_rw & REQ_DISCARD) && + !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { + /* Just ignore it */ + bio_endio(split, 0); + } else + generic_make_request(split); + } while (split != bio); + return; + +out_of_bounds: + printk(KERN_ERR + "md/linear:%s: make_request: Sector %llu out of bounds on " + "dev %s: %llu sectors, offset %llu\n", + mdname(mddev), + (unsigned long long)bio->bi_iter.bi_sector, + bdevname(tmp_dev->rdev->bdev, b), + (unsigned long long)tmp_dev->rdev->sectors, + (unsigned long long)start_sector); + bio_io_error(bio); } static void linear_status (struct seq_file *seq, struct mddev *mddev) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index ea754dd1a5f5..407a99e46f69 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -513,65 +513,44 @@ static inline int is_io_in_chunk_boundary(struct mddev *mddev, static void raid0_make_request(struct mddev *mddev, struct bio *bio) { - unsigned int chunk_sects; - sector_t sector_offset; struct strip_zone *zone; struct md_rdev *tmp_dev; + struct bio *split; if (unlikely(bio->bi_rw & REQ_FLUSH)) { md_flush_request(mddev, bio); return; } - chunk_sects = mddev->chunk_sectors; - if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { + do { sector_t sector = bio->bi_iter.bi_sector; - struct bio_pair *bp; - /* Sanity check -- queue functions should prevent this happening */ - if (bio_multiple_segments(bio)) - goto bad_map; - /* This is a one page bio that upper layers - * refuse to split for us, so we need to split it. - */ - if (likely(is_power_of_2(chunk_sects))) - bp = bio_pair_split(bio, chunk_sects - (sector & - (chunk_sects-1))); - else - bp = bio_pair_split(bio, chunk_sects - - sector_div(sector, chunk_sects)); - raid0_make_request(mddev, &bp->bio1); - raid0_make_request(mddev, &bp->bio2); - bio_pair_release(bp); - return; - } - - sector_offset = bio->bi_iter.bi_sector; - zone = find_zone(mddev->private, §or_offset); - tmp_dev = map_sector(mddev, zone, bio->bi_iter.bi_sector, - §or_offset); - bio->bi_bdev = tmp_dev->bdev; - bio->bi_iter.bi_sector = sector_offset + zone->dev_start + - tmp_dev->data_offset; - - if (unlikely((bio->bi_rw & REQ_DISCARD) && - !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) { - /* Just ignore it */ - bio_endio(bio, 0); - return; - } - - generic_make_request(bio); - return; - -bad_map: - printk("md/raid0:%s: make_request bug: can't convert block across chunks" - " or bigger than %dk %llu %d\n", - mdname(mddev), chunk_sects / 2, - (unsigned long long)bio->bi_iter.bi_sector, - bio_sectors(bio) / 2); + unsigned chunk_sects = mddev->chunk_sectors; + + unsigned sectors = chunk_sects - + (likely(is_power_of_2(chunk_sects)) + ? (sector & (chunk_sects-1)) + : sector_div(sector, chunk_sects)); + + if (sectors < bio_sectors(bio)) { + split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set); + bio_chain(split, bio); + } else { + split = bio; + } - bio_io_error(bio); - return; + zone = find_zone(mddev->private, §or); + tmp_dev = map_sector(mddev, zone, sector, §or); + split->bi_bdev = tmp_dev->bdev; + split->bi_iter.bi_sector = sector + zone->dev_start + + tmp_dev->data_offset; + + if (unlikely((split->bi_rw & REQ_DISCARD) && + !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { + /* Just ignore it */ + bio_endio(split, 0); + } else + generic_make_request(split); + } while (split != bio); } static void raid0_status(struct seq_file *seq, struct mddev *mddev) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 69c1bc8da88f..6d43d88657aa 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1152,14 +1152,12 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule) kfree(plug); } -static void make_request(struct mddev *mddev, struct bio * bio) +static void __make_request(struct mddev *mddev, struct bio *bio) { struct r10conf *conf = mddev->private; struct r10bio *r10_bio; struct bio *read_bio; int i; - sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask); - int chunk_sects = chunk_mask + 1; const int rw = bio_data_dir(bio); const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); const unsigned long do_fua = (bio->bi_rw & REQ_FUA); @@ -1174,69 +1172,6 @@ static void make_request(struct mddev *mddev, struct bio * bio) int max_sectors; int sectors; - if (unlikely(bio->bi_rw & REQ_FLUSH)) { - md_flush_request(mddev, bio); - return; - } - - /* If this request crosses a chunk boundary, we need to - * split it. This will only happen for 1 PAGE (or less) requests. - */ - if (unlikely((bio->bi_iter.bi_sector & chunk_mask) + bio_sectors(bio) - > chunk_sects - && (conf->geo.near_copies < conf->geo.raid_disks - || conf->prev.near_copies < conf->prev.raid_disks))) { - struct bio_pair *bp; - /* Sanity check -- queue functions should prevent this happening */ - if (bio_multiple_segments(bio)) - goto bad_map; - /* This is a one page bio that upper layers - * refuse to split for us, so we need to split it. - */ - bp = bio_pair_split(bio, chunk_sects - - (bio->bi_iter.bi_sector & (chunk_sects - 1))); - - /* Each of these 'make_request' calls will call 'wait_barrier'. - * If the first succeeds but the second blocks due to the resync - * thread raising the barrier, we will deadlock because the - * IO to the underlying device will be queued in generic_make_request - * and will never complete, so will never reduce nr_pending. - * So increment nr_waiting here so no new raise_barriers will - * succeed, and so the second wait_barrier cannot block. - */ - spin_lock_irq(&conf->resync_lock); - conf->nr_waiting++; - spin_unlock_irq(&conf->resync_lock); - - make_request(mddev, &bp->bio1); - make_request(mddev, &bp->bio2); - - spin_lock_irq(&conf->resync_lock); - conf->nr_waiting--; - wake_up(&conf->wait_barrier); - spin_unlock_irq(&conf->resync_lock); - - bio_pair_release(bp); - return; - bad_map: - printk("md/raid10:%s: make_request bug: can't convert block across chunks" - " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2, - (unsigned long long)bio->bi_iter.bi_sector, - bio_sectors(bio) / 2); - - bio_io_error(bio); - return; - } - - md_write_start(mddev, bio); - - /* - * Register the new request and wait if the reconstruction - * thread has put up a bar for new requests. - * Continue immediately if no resync is active currently. - */ - wait_barrier(conf); - sectors = bio_sectors(bio); while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && bio->bi_iter.bi_sector < conf->reshape_progress && @@ -1600,6 +1535,52 @@ retry_write: goto retry_write; } one_write_done(r10_bio); +} + +static void make_request(struct mddev *mddev, struct bio *bio) +{ + struct r10conf *conf = mddev->private; + sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask); + int chunk_sects = chunk_mask + 1; + + struct bio *split; + + if (unlikely(bio->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bio); + return; + } + + md_write_start(mddev, bio); + + /* + * Register the new request and wait if the reconstruction + * thread has put up a bar for new requests. + * Continue immediately if no resync is active currently. + */ + wait_barrier(conf); + + do { + + /* + * If this request crosses a chunk boundary, we need to split + * it. + */ + if (unlikely((bio->bi_iter.bi_sector & chunk_mask) + + bio_sectors(bio) > chunk_sects + && (conf->geo.near_copies < conf->geo.raid_disks + || conf->prev.near_copies < + conf->prev.raid_disks))) { + split = bio_split(bio, chunk_sects - + (bio->bi_iter.bi_sector & + (chunk_sects - 1)), + GFP_NOIO, fs_bio_set); + bio_chain(split, bio); + } else { + split = bio; + } + + __make_request(mddev, split); + } while (split != bio); /* In case raid10d snuck in to freeze_array */ wake_up(&conf->wait_barrier); diff --git a/fs/bio.c b/fs/bio.c index a3e753f4d5a6..7b062befac82 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1793,6 +1793,42 @@ void bio_endio_nodec(struct bio *bio, int error) } EXPORT_SYMBOL(bio_endio_nodec); +/** + * bio_split - split a bio + * @bio: bio to split + * @sectors: number of sectors to split from the front of @bio + * @gfp: gfp mask + * @bs: bio set to allocate from + * + * Allocates and returns a new bio which represents @sectors from the start of + * @bio, and updates @bio to represent the remaining sectors. + * + * The newly allocated bio will point to @bio's bi_io_vec; it is the caller's + * responsibility to ensure that @bio is not freed before the split. + */ +struct bio *bio_split(struct bio *bio, int sectors, + gfp_t gfp, struct bio_set *bs) +{ + struct bio *split = NULL; + + BUG_ON(sectors <= 0); + BUG_ON(sectors >= bio_sectors(bio)); + + split = bio_clone_fast(bio, gfp, bs); + if (!split) + return NULL; + + split->bi_iter.bi_size = sectors << 9; + + if (bio_integrity(split)) + bio_integrity_trim(split, 0, sectors); + + bio_advance(bio, split->bi_iter.bi_size); + + return split; +} +EXPORT_SYMBOL(bio_split); + void bio_pair_release(struct bio_pair *bp) { if (atomic_dec_and_test(&bp->cnt)) { diff --git a/include/linux/bio.h b/include/linux/bio.h index aa67af0b31ac..19e31b2f5b2c 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -321,6 +321,28 @@ extern struct bio_pair *bio_pair_split(struct bio *bi, int first_sectors); extern void bio_pair_release(struct bio_pair *dbio); extern void bio_trim(struct bio *bio, int offset, int size); +extern struct bio *bio_split(struct bio *bio, int sectors, + gfp_t gfp, struct bio_set *bs); + +/** + * bio_next_split - get next @sectors from a bio, splitting if necessary + * @bio: bio to split + * @sectors: number of sectors to split from the front of @bio + * @gfp: gfp mask + * @bs: bio set to allocate from + * + * Returns a bio representing the next @sectors of @bio - if the bio is smaller + * than @sectors, returns the original bio unchanged. + */ +static inline struct bio *bio_next_split(struct bio *bio, int sectors, + gfp_t gfp, struct bio_set *bs) +{ + if (sectors >= bio_sectors(bio)) + return bio; + + return bio_split(bio, sectors, gfp, bs); +} + extern struct bio_set *bioset_create(unsigned int, unsigned int); extern void bioset_free(struct bio_set *); extern mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries);