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/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);