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 <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Neil Brown <neilb@suse.de>
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 6b6fe93..964353c 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -901,7 +901,6 @@
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 522f957..fa028fa 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -11,84 +11,6 @@
#include <linux/blkdev.h>
-/**
- * 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 @@
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 63451c7..5878cdb 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -371,7 +371,7 @@
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 @@
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 @@
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 @@
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 e9b53e9..56f534b 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -288,65 +288,65 @@
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;
+ do {
+ rcu_read_lock();
-
- 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;
+ 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;
rcu_read_unlock();
- bp = bio_pair_split(bio, end_sector - bio->bi_iter.bi_sector);
+ if (unlikely(bio->bi_iter.bi_sector >= end_sector ||
+ bio->bi_iter.bi_sector < start_sector))
+ goto out_of_bounds;
- 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();
+ 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;
+ }
- if (unlikely((bio->bi_rw & REQ_DISCARD) &&
- !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) {
- /* Just ignore it */
- bio_endio(bio, 0);
- return;
- }
+ split->bi_iter.bi_sector = split->bi_iter.bi_sector -
+ start_sector + data_offset;
- generic_make_request(bio);
+ 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 ea754dd..407a99e 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -513,65 +513,44 @@
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;
- }
+ unsigned chunk_sects = mddev->chunk_sectors;
- 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;
+ unsigned sectors = chunk_sects -
+ (likely(is_power_of_2(chunk_sects))
+ ? (sector & (chunk_sects-1))
+ : sector_div(sector, chunk_sects));
- 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 (sectors < bio_sectors(bio)) {
+ split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);
+ bio_chain(split, bio);
+ } else {
+ split = bio;
+ }
- generic_make_request(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;
-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);
-
- bio_io_error(bio);
- return;
+ 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 69c1bc8..6d43d88 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1152,14 +1152,12 @@
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 @@
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 @@
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);
