From da1e148803e0b98961599b0295418bb7a8fc79f3 Mon Sep 17 00:00:00 2001
From: Jonathan Brassow <jbrassow@redhat.com>
Date: Tue, 27 Feb 2018 21:58:59 +0100
Subject: [PATCH] dm raid: fix incorrect sync_ratio when degraded
Git-commit: da1e148803e0b98961599b0295418bb7a8fc79f3
Patch-mainline: v4.16-rc5
References: bsc#1093023
Upstream commit 4102d9de6d375 ("dm raid: fix rs_get_progress()
synchronization state/ratio") in combination with commit 7c29744ecce
("dm raid: simplify rs_get_progress()") introduced a regression by
incorrectly reporting a sync_ratio of 0 for degraded raid sets. This
caused lvm2 to fail to repair raid legs automatically.
Fix by identifying the degraded state by checking the MD_RECOVERY_INTR
flag and returning mddev->recovery_cp in case it is set.
MD sets recovery = [ MD_RECOVERY_RECOVER MD_RECOVERY_INTR
MD_RECOVERY_NEEDED ] when a RAID member fails. It then shuts down any
sync thread that is running and leaves us with all MD_RECOVERY_* flags
cleared. The bug occurs if a status is requested in the short time it
takes to shut down any sync thread and clear the flags, because we were
keying in on the MD_RECOVERY_NEEDED - understanding it to be the initial
phase of a “recover” sync thread. However, this is an incorrect
interpretation if MD_RECOVERY_INTR is also set.
This also explains why the bug only happened when automatic repair was
enabled and not a normal ‘manual’ method. It is impossible to react
quick enough to hit the problematic window without it being automated.
Fix passes automatic repair tests.
Fixes: 7c29744ecce ("dm raid: simplify rs_get_progress()")
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-raid.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 7ef469e902c6..c1d1034ff7b7 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3408,9 +3408,10 @@ static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
} else {
- if (test_bit(MD_RECOVERY_NEEDED, &recovery) ||
- test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
- test_bit(MD_RECOVERY_RUNNING, &recovery))
+ if (!test_bit(MD_RECOVERY_INTR, &recovery) &&
+ (test_bit(MD_RECOVERY_NEEDED, &recovery) ||
+ test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
+ test_bit(MD_RECOVERY_RUNNING, &recovery)))
r = mddev->curr_resync_completed;
else
r = mddev->recovery_cp;
--
2.16.3