From fb73b357fb985cc652a72a41541d25915c7f9635 Mon Sep 17 00:00:00 2001
From: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>
Date: Tue, 4 Sep 2018 15:08:30 +0200
Subject: [PATCH] raid5: block failing device if raid will be failed
Git-commit: fb73b357fb985cc652a72a41541d25915c7f9635
Patch-mainline: v4.20-rc1
References: bsc#1166003

Currently there is an inconsistency for failing the member drives
for arrays with different RAID levels. For RAID456 - there is a possibility
to fail all of the devices. However - for other RAID levels - kernel blocks
removing the member drive, if the operation results in array's FAIL state
(EBUSY is returned). For example - removing last drive from RAID1 is not
possible.
This kind of blocker was never implemented for raid456 and we cannot see
the reason why.

We had tested following patch and did not observe any regression, so do you
have any comments/reasons for current approach, or we can send the proper
patch for this?

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/raid5.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e4e98f47865d..4990f0319f6c 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2681,6 +2681,18 @@ static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
 	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;
+	}
+
 	set_bit(Faulty, &rdev->flags);
 	clear_bit(In_sync, &rdev->flags);
 	mddev->degraded = raid5_calc_degraded(conf);
-- 
2.25.0