dm raid: fix discard limits for raid1 and raid10

Block core warned that discard_granularity was 0 for dm-raid with
personality of raid1.  Reason is that raid_io_hints() was incorrectly
special-casing raid1 rather than raid0.

But since commit 29efc390b9 ("md/md0: optimize raid0 discard
handling") even raid0 properly handles large discards.

Fix raid_io_hints() by removing discard limits settings for raid1.
Also, fix limits for raid10 by properly stacking underlying limits as
done in blk_stack_limits().

Depends-on: 29efc390b9 ("md/md0: optimize raid0 discard handling")
Fixes: 61697a6abd ("dm: eliminate 'split_discard_bios' flag from DM target interface")
Cc: stable@vger.kernel.org
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2020-09-24 13:14:52 -04:00
parent cd74693870
commit e0910c8e4f

View File

@ -3730,12 +3730,14 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
/*
* RAID1 and RAID10 personalities require bio splitting,
* RAID0/4/5/6 don't and process large discard bios properly.
* RAID10 personality requires bio splitting,
* RAID0/1/4/5/6 don't and process large discard bios properly.
*/
if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
limits->discard_granularity = chunk_size_bytes;
limits->max_discard_sectors = rs->md.chunk_sectors;
if (rs_is_raid10(rs)) {
limits->discard_granularity = max(chunk_size_bytes,
limits->discard_granularity);
limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
limits->max_discard_sectors);
}
}