[PATCH 2/2] raid5: introduce MD_BROKEN
From: Mariusz Tkaczyk <hidden>
Date: 2021-09-17 15:35:21
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
Raid456 module had allowed to achieve failed state, distinct from other
redundant levels. It was fixed by fb73b357fb9 ("raid5: block failing
device if raid will be failed").
This fix introduces a bug, now if raid5 fails during IO, it may result
with a hung task without completion. Faulty flag on the device is
necessary to process all requests and is checked many times, mainly in
anaylze_stripe().
Allow to set faulty flag on drive again and set MD_BROKEN if raid is
failed.
Fixes: fb73b357fb9 ("raid5: block failing device if raid will be failed")
Signed-off-by: Mariusz Tkaczyk <redacted>
---
drivers/md/raid5.c | 34 ++++++++++++++++------------------
1 file changed, 16 insertions(+), 18 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 02ed53b20654..43e1ff43a222 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c@@ -690,6 +690,9 @@ static int has_failed(struct r5conf *conf) { int degraded; + if (test_bit(MD_BROKEN, &conf->mddev->flags)) + return 1; + if (conf->mddev->reshape_position == MaxSector) return conf->mddev->degraded > conf->max_degraded;
@@ -2877,34 +2880,29 @@ static void raid5_error(struct mddev *mddev, struct md_rdev *rdev) unsigned long flags; pr_debug("raid456: error called\n"); - spin_lock_irqsave(&conf->device_lock, flags); - - if (test_bit(In_sync, &rdev->flags) && - mddev->degraded == conf->max_degraded) { - /* - * Don't allow to achieve failed state - * Don't try to recover this device - */ - conf->recovery_disabled = mddev->recovery_disabled; - spin_unlock_irqrestore(&conf->device_lock, flags); - return; - } + pr_crit("md/raid:%s: Disk failure on %s, disabling device.\n", + mdname(mddev), bdevname(rdev->bdev, b)); + spin_lock_irqsave(&conf->device_lock, flags); set_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); mddev->degraded = raid5_calc_degraded(conf); + + if (has_failed(conf)) { + set_bit(MD_BROKEN, &mddev->flags); + conf->recovery_disabled = mddev->recovery_disabled; + pr_crit("md/raid:%s: Cannot continue on %d devices.\n", + mdname(mddev), conf->raid_disks - mddev->degraded); + } else + pr_crit("md/raid:%s: Operation continuing on %d devices.\n", + mdname(mddev), conf->raid_disks - mddev->degraded); + spin_unlock_irqrestore(&conf->device_lock, flags); set_bit(MD_RECOVERY_INTR, &mddev->recovery); set_bit(Blocked, &rdev->flags); set_mask_bits(&mddev->sb_flags, 0, BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); - pr_crit("md/raid:%s: Disk failure on %s, disabling device.\n" - "md/raid:%s: Operation continuing on %d devices.\n", - mdname(mddev), - bdevname(rdev->bdev, b), - mdname(mddev), - conf->raid_disks - mddev->degraded); r5c_update_on_rdev_error(mddev, rdev); }
--
2.26.2