From a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef Mon Sep 17 00:00:00 2001 From: ChangSyun Peng Date: Fri, 31 Jul 2020 17:50:17 +0800 Subject: md/raid5: Fix Force reconstruct-write io stuck in degraded raid5 In degraded raid5, we need to read parity to do reconstruct-write when data disks fail. However, we can not read parity from handle_stripe_dirtying() in force reconstruct-write mode. Reproducible Steps: 1. Create degraded raid5 mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 missing 2. Set rmw_level to 0 echo 0 > /sys/block/md2/md/rmw_level 3. IO to raid5 Now some io may be stuck in raid5. We can use handle_stripe_fill() to read the parity in this situation. Cc: # v4.4+ Reviewed-by: Alex Wu Reviewed-by: BingJing Chang Reviewed-by: Danny Shih Signed-off-by: ChangSyun Peng Signed-off-by: Song Liu --- drivers/md/raid5.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index b06edfaa73b0..9aab66fd1003 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3626,6 +3626,7 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, * is missing/faulty, then we need to read everything we can. */ if (sh->raid_conf->level != 6 && + sh->raid_conf->rmw_level != PARITY_DISABLE_RMW && sh->sector < sh->raid_conf->mddev->recovery_cp) /* reconstruct-write isn't being forced */ return 0; @@ -4862,7 +4863,7 @@ static void handle_stripe(struct stripe_head *sh) * or to load a block that is being partially written. */ if (s.to_read || s.non_overwrite - || (conf->level == 6 && s.to_write && s.failed) + || (s.to_write && s.failed) || (s.syncing && (s.uptodate + s.compute < disks)) || s.replacing || s.expanding) -- cgit