File 1004-mdadm-super1-restore-commit-45a87c2f31335-to-fix-clu.patch of Package mdadm.24703
From 3a84e55858171f96321fa4c775fe7e4e851c6b85 Mon Sep 17 00:00:00 2001
From: Heming Zhao <heming.zhao@suse.com>
Date: Thu, 31 Mar 2022 23:30:51 +0800
Subject: [PATCH] mdadm/super1: restore commit 45a87c2f31335 to fix clustered
slot issue
To: linux-raid@vger.kernel.org,
jes@trained-monkey.org
Patch-mainline: N/A, maintainer didn't respond this patch.
References: bsc#1197158, bsc#1197571
Commit 9d67f6496c71 ("mdadm:check the nodes when operate clustered
array") modified assignment logic for st->nodes in write_bitmap1(),
which introduced bitmap slot issue:
load_super1 didn't set up supertype.nodes, which made spare disk only
have one slot info. Then it triggered kernel md_bitmap_load_sb to get
wrong bitmap slot data.
For fixing this issue, there are two methods:
1> revert the related code of commit 9d67f6496c71. and restore the code
from former commit 45a87c2f31335 ("super1: add more checks for
NodeNumUpdate option").
st->nodes value would be 0 & 1 under current code logic. i.e.
When adding a spare disk, there is no place to init st->nodes, and
the value is ZERO.
2> keep 9d67f6496c71, add additional ->nodes handling in load_super1(),
let load_super1 to set st->nodes when bitmap is BITMAP_MAJOR_CLUSTERED.
Under current mdadm code logic, load_super1 will be called many
times, any new code in load_super1 will cost mdadm running more time.
And more reason is I prefer as much as possible to limit clustered
code spreading in every corner.
So I used method <1> to fix this issue.
How to trigger:
dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda
dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb
dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdc
mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb
mdadm -a /dev/md0 /dev/sdc
mdadm /dev/md0 --fail /dev/sda
mdadm /dev/md0 --remove /dev/sda
mdadm -Ss
mdadm -A /dev/md0 /dev/sdb /dev/sdc
the output of current "mdadm -X /dev/sdc":
(there should be (by default) 4 slot info for correct output)
```
Filename : /dev/sdc
Magic : 6d746962
Version : 5
UUID : a74642f8:a6b1fba8:58e1f8db:cfe7b082
Events : 29
Events Cleared : 0
State : OK
Chunksize : 64 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 306176 (299.00 MiB 313.52 MB)
Bitmap : 5 bits (chunks), 5 dirty (100.0%)
```
And mdadm later operations will trigger kernel output error message:
(triggered by "mdadm -A /dev/md0 /dev/sdb /dev/sdc")
```
kernel: md0: invalid bitmap file superblock: bad magic
kernel: md_bitmap_copy_from_slot can't get bitmap from slot 1
kernel: md-cluster: Could not gather bitmaps from slot 1
kernel: md0: invalid bitmap file superblock: bad magic
kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2
kernel: md-cluster: Could not gather bitmaps from slot 2
kernel: md0: invalid bitmap file superblock: bad magic
kernel: md_bitmap_copy_from_slot can't get bitmap from slot 3
kernel: md-cluster: Could not gather bitmaps from slot 3
kernel: md-cluster: failed to gather all resyn infos
kernel: md0: detected capacity change from 0 to 612352
```
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
---
super1.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/super1.c b/super1.c
index a12a5bc847b9..f08d4f831319 100644
--- a/super1.c
+++ b/super1.c
@@ -2674,7 +2674,17 @@ static int write_bitmap1(struct supertype *st, int fd, enum bitmap_update update
}
if (bms->version == BITMAP_MAJOR_CLUSTERED) {
- if (__cpu_to_le32(st->nodes) < bms->nodes) {
+ if (st->nodes == 1) {
+ /* the parameter for nodes is not valid */
+ pr_err("Warning: cluster-md at least needs two nodes\n");
+ return -EINVAL;
+ } else if (st->nodes == 0) {
+ /*
+ * parameter "--nodes" is not specified, (eg, add a disk to
+ * clustered raid)
+ */
+ break;
+ } else if (__cpu_to_le32(st->nodes) < bms->nodes) {
/*
* Since the nodes num is not increased, no
* need to check the space enough or not,
--
2.33.0
