Hi,
在 2025/03/04 14:12, Wu Guanghao 写道:
When testing the raid1, I found that adding disk to raid1 fails.
Here's how to reproduce it:
1. modprobe brd rd_nr=3 rd_size=524288
2. mdadm -Cv /dev/md0 -l1 -n2 -e1.0 /dev/ram0 /dev/ram1
3. mdadm /dev/md0 -f /dev/ram0
4. mdadm /dev/md0 -r /dev/ram0
5. echo "10000 100" > /sys/block/md0/md/dev-ram1/bad_blocks
6. echo "write_error" > /sys/block/md0/md/dev-ram1/state
7. mkfs.xfs /dev/md0
8. mdadm --examine-badblocks /dev/ram1 # Bad block records can be seen
Bad-blocks on /dev/ram1:
10000 for 100 sectors
9. mdadm /dev/md0 -a /dev/ram2
mdadm: add new device failed for /dev/ram2 as 2: Invalid argument
Can you add a new regression test as well?
When adding a disk to a RAID1 array, the metadata is read from the existing
member disks for synchronization. However, only the bad_blocks flag are copied,
the bad_blocks records are not copied, so the bad_blocks records are all zeros.
The kernel function super_1_load() detects bad_blocks flag and reads the
bad_blocks record, then sets the bad block using badblocks_set().
After the kernel commit 1726c7746("badblocks: improve badblocks_set() for
multiple ranges handling"), if the length of a bad_blocks record is 0, it will
return a failure. Therefore the device addition will fail.
So, don't set the bad_blocks flag when initializing the metadata, kernel can
handle it.
Signed-off-by: Wu Guanghao <wuguanghao3@xxxxxxxxxx>
---
super1.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/super1.c b/super1.c
index fe3c4c64..03578e5b 100644
--- a/super1.c
+++ b/super1.c
@@ -2139,6 +2139,9 @@ static int write_init_super1(struct supertype *st)
if (raid0_need_layout)
sb->feature_map |= __cpu_to_le32(MD_FEATURE_RAID0_LAYOUT);
+ if (sb->feature_map & MD_FEATURE_BAD_BLOCKS)
+ sb->feature_map &= ~__cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
There are also other flags that is per rdev, like MD_FEATURE_REPLACEMENT
and MD_FEATURE_JOURNAL, they should be excluded as well.
Thanks,
Kuai
+
sb->sb_csum = calc_sb_1_csum(sb);
rv = store_super1(st, di->fd);
