Re: Revert "dm raid: remove unnecessary discard limits for raid10"
From: Mike Snitzer <hidden>
Date: 2020-12-09 22:38:40
Also in:
dm-devel, lkml
On Wed, Dec 09 2020 at 4:58pm -0500, Song Liu [off-list ref] wrote:
This reverts commit f0e90b6c663a7e3b4736cb318c6c7c589f152c28. Matthew Ruffell reported data corruption in raid10 due to the changes in discard handling [1]. Revert these changes before we find a proper fix. [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1907262/ Cc: Matthew Ruffell <redacted> Cc: Xiao Ni <redacted> Cc: Mike Snitzer <redacted> Signed-off-by: Song Liu <redacted>
If you're reverting all the MD code that enabled this DM change, then obviously the DM change must be reverted too. But please do _not_ separate the DM revert from the MD reverts. Please include this in a v2 pull request to Jens. Mike
quoted hunk ↗ jump to hunk
--- drivers/md/dm-raid.c | 11 +++++++++++ 1 file changed, 11 insertions(+)diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 9c1f7c4de65b3..dc8568ab96f24 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c@@ -3728,6 +3728,17 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) blk_limits_io_min(limits, chunk_size_bytes); blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs)); + + /* + * RAID10 personality requires bio splitting, + * RAID0/1/4/5/6 don't and process large discard bios properly. + */ + 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); + } } static void raid_postsuspend(struct dm_target *ti)-- 2.24.1