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| author | Jonathan Brassow <jbrassow@redhat.com> | 2018-02-27 21:58:59 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2018-03-06 20:23:57 -0500 |
| commit | da1e148803e0b98961599b0295418bb7a8fc79f3 (patch) | |
| tree | cbb8d48073dab1f800dda94ca0b3b4ab87e015bc /drivers/md/dm-raid.c | |
| parent | 519049afead4f7c3e6446028c41e99fde958cc04 (diff) | |
| download | lwn-da1e148803e0b98961599b0295418bb7a8fc79f3.tar.gz lwn-da1e148803e0b98961599b0295418bb7a8fc79f3.zip | |
dm raid: fix incorrect sync_ratio when degraded
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>
Diffstat (limited to 'drivers/md/dm-raid.c')
| -rw-r--r-- | drivers/md/dm-raid.c | 7 |
1 files 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; |