From: Heming Zhao <heming.zhao@suse.com>
To: linux-raid <linux-raid@vger.kernel.org>
Subject: commit 480523feae581 may introduce a bug
Date: Mon, 6 Jul 2020 04:47:10 +0000 [thread overview]
Message-ID: <DB7PR04MB466640DAB67751FE3375C9C297690@DB7PR04MB4666.eurprd04.prod.outlook.com> (raw)
Hello list
In cluster-md env, after below steps, "mdadm -D /dev/md0" show state is "active"
```
mdadm -S --scan
mdadm --zero-superblock /dev/sd{a,b}
mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb
```
```
lp-clustermd1:~ # mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Mon Jul 6 12:02:23 2020
Raid Level : raid1
Array Size : 64512 (63.00 MiB 66.06 MB)
Used Dev Size : 64512 (63.00 MiB 66.06 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Jul 6 12:02:24 2020
State : active <==== this line
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : lp-clustermd1:0 (local to host lp-clustermd1)
Cluster Name : hacluster
UUID : 38ae5052:560c7d36:bb221e15:7437f460
Events : 18
Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
```
I am not sure if the active state is special on cluster-md, but before 480523feae581, The state is clean.
the related code in kernel is the value of mddev->in_sync.
with commit 480523feae581, the try_set_sync never true. so in_sync always 0.
I am not familiar with md module code and can't give a good fix for this issue.
Below is my silly solutions, there are 2 ways to fix:
- modify md_allow_write(), let "mddev->safemode = 1" also suite for cluster-md.
The safemode will change back to 0 in set_in_sync(), and never change to other value later.
or
- in mdadm, add a action like
"echo clean > /sys/devices/virtual/block/md0/md/array_state".
do it after creating a cluster-md dev.
reply other threads:[~2020-07-06 4:47 UTC|newest]
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