[PATCH] md/raid5: reject llbitmap reshape when md chunk shrinks
Yu Kuai <[email protected]>
| Newsgroups | gmane.linux.raid,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Yu Kuai <[email protected]> llbitmap reshape keeps one live bitmap and cannot safely make an existing bitmap bit cover a smaller data range. The llbitmap chunksize itself will not shrink when mddev->chunk_sectors stays the same or grows. However, shrinking mddev->chunk_sectors shrinks sectors_per_chunk used by raid5_bitmap_sector_map(). That can shrink the effective data range covered by each bit across the old and new RAID5 geometry. Reject that reshape while llbitmap is active. Signed-off-by: Yu Kuai <[email protected]> --- drivers/md/raid5.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index ff4da82f78fe..55af1d1eec63 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -8497,10 +8497,13 @@ static int check_reshape(struct mddev *mddev) } if (!check_stripe_cache(mddev)) return -ENOSPC; + if (mddev->bitmap_id == ID_LLBITMAP && + mddev->new_chunk_sectors < mddev->chunk_sectors) + return -EOPNOTSUPP; if (mddev->new_chunk_sectors > mddev->chunk_sectors || mddev->delta_disks > 0) if (resize_chunks(conf, conf->previous_raid_disks + max(0, mddev->delta_disks), -- 2.51.0