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authorXiao Ni <xni@redhat.com>2020-09-02 15:00:23 +0300
committerSong Liu <songliubraving@fb.com>2020-09-25 02:44:45 +0300
commitd3ee2d8415a6256c1c41e1be36e80e640c3e6359 (patch)
tree8517646317457beb0a9a3662320686ac46cfea6a /drivers/md/raid10.c
parentbcc90d280465ebd51ab8688be86e1f00c62dccf9 (diff)
downloadlinux-d3ee2d8415a6256c1c41e1be36e80e640c3e6359.tar.xz
md/raid10: improve discard request for far layout
For far layout, the discard region is not continuous on disks. So it needs far copies r10bio to cover all regions. It needs a way to know all r10bios have finish or not. Similar with raid10_sync_request, only the first r10bio master_bio records the discard bio. Other r10bios master_bio record the first r10bio. The first r10bio can finish after other r10bios finish and then return the discard bio. Signed-off-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'drivers/md/raid10.c')
-rw-r--r--drivers/md/raid10.c86
1 files changed, 63 insertions, 23 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 05773ee1b5ba..b7bca6703df8 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1534,6 +1534,28 @@ static struct bio *raid10_split_bio(struct r10conf *conf,
return bio;
}
+static void raid_end_discard_bio(struct r10bio *r10bio)
+{
+ struct r10conf *conf = r10bio->mddev->private;
+ struct r10bio *first_r10bio;
+
+ while (atomic_dec_and_test(&r10bio->remaining)) {
+
+ allow_barrier(conf);
+
+ if (!test_bit(R10BIO_Discard, &r10bio->state)) {
+ first_r10bio = (struct r10bio *)r10bio->master_bio;
+ free_r10bio(r10bio);
+ r10bio = first_r10bio;
+ } else {
+ md_write_end(r10bio->mddev);
+ bio_endio(r10bio->master_bio);
+ free_r10bio(r10bio);
+ break;
+ }
+ }
+}
+
static void raid10_end_discard_request(struct bio *bio)
{
struct r10bio *r10_bio = bio->bi_private;
@@ -1560,11 +1582,7 @@ static void raid10_end_discard_request(struct bio *bio)
rdev = conf->mirrors[dev].rdev;
}
- if (atomic_dec_and_test(&r10_bio->remaining)) {
- md_write_end(r10_bio->mddev);
- raid_end_bio_io(r10_bio);
- }
-
+ raid_end_discard_bio(r10_bio);
rdev_dec_pending(rdev, conf->mddev);
}
@@ -1577,7 +1595,9 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r10conf *conf = mddev->private;
struct geom *geo = &conf->geo;
- struct r10bio *r10_bio;
+ struct r10bio *r10_bio, *first_r10bio;
+ int far_copies = geo->far_copies;
+ bool first_copy = true;
int disk;
sector_t chunk;
@@ -1616,30 +1636,20 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
if (bio_sectors(bio) < stripe_size*2)
goto out;
- /* For far offset layout, if bio is not aligned with stripe size, it splits
- * the part that is not aligned with strip size.
+ /* For far and far offset layout, if bio is not aligned with stripe size,
+ * it splits the part that is not aligned with strip size.
*/
div_u64_rem(bio_start, stripe_size, &remainder);
- if (geo->far_offset && remainder) {
+ if ((far_copies > 1) && remainder) {
split_size = stripe_size - remainder;
bio = raid10_split_bio(conf, bio, split_size, false);
}
div_u64_rem(bio_end, stripe_size, &remainder);
- if (geo->far_offset && remainder) {
+ if ((far_copies > 1) && remainder) {
split_size = bio_sectors(bio) - remainder;
bio = raid10_split_bio(conf, bio, split_size, true);
}
- r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
- r10_bio->mddev = mddev;
- r10_bio->state = 0;
- r10_bio->sectors = 0;
- memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks);
-
- wait_blocked_dev(mddev, r10_bio);
-
- r10_bio->master_bio = bio;
-
bio_start = bio->bi_iter.bi_sector;
bio_end = bio_end_sector(bio);
@@ -1665,6 +1675,28 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
end_disk_offset = (bio_end & geo->chunk_mask) +
(last_stripe_index << geo->chunk_shift);
+retry_discard:
+ r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
+ r10_bio->mddev = mddev;
+ r10_bio->state = 0;
+ r10_bio->sectors = 0;
+ memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks);
+ wait_blocked_dev(mddev, r10_bio);
+
+ /* For far layout it needs more than one r10bio to cover all regions.
+ * Inspired by raid10_sync_request, we can use the first r10bio->master_bio
+ * to record the discard bio. Other r10bio->master_bio record the first
+ * r10bio. The first r10bio only release after all other r10bios finish.
+ * The discard bio returns only first r10bio finishes
+ */
+ if (first_copy) {
+ r10_bio->master_bio = bio;
+ set_bit(R10BIO_Discard, &r10_bio->state);
+ first_copy = false;
+ first_r10bio = r10_bio;
+ } else
+ r10_bio->master_bio = (struct bio *)first_r10bio;
+
rcu_read_lock();
for (disk = 0; disk < geo->raid_disks; disk++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev);
@@ -1755,11 +1787,19 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
}
}
- if (atomic_dec_and_test(&r10_bio->remaining)) {
- md_write_end(r10_bio->mddev);
- raid_end_bio_io(r10_bio);
+ if (!geo->far_offset && --far_copies) {
+ first_stripe_index += geo->stride >> geo->chunk_shift;
+ start_disk_offset += geo->stride;
+ last_stripe_index += geo->stride >> geo->chunk_shift;
+ end_disk_offset += geo->stride;
+ atomic_inc(&first_r10bio->remaining);
+ raid_end_discard_bio(r10_bio);
+ wait_barrier(conf);
+ goto retry_discard;
}
+ raid_end_discard_bio(r10_bio);
+
return 0;
out:
allow_barrier(conf);