| From ed048a979eeca8f2b64761adbdce56062fb37bd0 Mon Sep 17 00:00:00 2001 |
| From: ChangSyun Peng <allenpeng@synology.com> |
| Date: Fri, 31 Jul 2020 17:50:17 +0800 |
| Subject: [PATCH] md/raid5: Fix Force reconstruct-write io stuck in degraded |
| raid5 |
| |
| commit a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef upstream. |
| |
| 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: <stable@vger.kernel.org> # v4.4+ |
| Reviewed-by: Alex Wu <alexwu@synology.com> |
| Reviewed-by: BingJing Chang <bingjingc@synology.com> |
| Reviewed-by: Danny Shih <dannyshih@synology.com> |
| Signed-off-by: ChangSyun Peng <allenpeng@synology.com> |
| Signed-off-by: Song Liu <songliubraving@fb.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c |
| index 9313dc8e3389..d0af52da65af 100644 |
| --- a/drivers/md/raid5.c |
| +++ b/drivers/md/raid5.c |
| @@ -3598,6 +3598,7 @@ 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; |
| @@ -4834,7 +4835,7 @@ 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) |
| -- |
| 2.27.0 |
| |
