From 20d0189b1012a37d2533a87fb451f7852f2418d1 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 23 Nov 2013 18:21:01 -0800 Subject: 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 --- drivers/md/raid10.c | 113 ++++++++++++++++++++++------------------------------ 1 file changed, 47 insertions(+), 66 deletions(-) (limited to 'drivers/md/raid10.c') 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); -- cgit v1.2.3-59-g8ed1b