This is a note to let you know that I've just added the patch titled
async_xor: increase src_offs when dropping destination page
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
async_xor-increase-src_offs-when-dropping-destination-page.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ceaf2966ab082bbc4d26516f97b3ca8a676e2af8 Mon Sep 17 00:00:00 2001
From: Xiao Ni <xni@xxxxxxxxxx>
Date: Sun, 25 Apr 2021 17:22:57 +0800
Subject: async_xor: increase src_offs when dropping destination page
From: Xiao Ni <xni@xxxxxxxxxx>
commit ceaf2966ab082bbc4d26516f97b3ca8a676e2af8 upstream.
Now we support sharing one page if PAGE_SIZE is not equal stripe size. To
support this, it needs to support calculating xor value with different
offsets for each r5dev. One offset array is used to record those offsets.
In RMW mode, parity page is used as a source page. It sets
ASYNC_TX_XOR_DROP_DST before calculating xor value in ops_run_prexor5.
So it needs to add src_list and src_offs at the same time. Now it only
needs src_list. So the xor value which is calculated is wrong. It can
cause data corruption problem.
I can reproduce this problem 100% on a POWER8 machine. The steps are:
mdadm -CR /dev/md0 -l5 -n3 /dev/sdb1 /dev/sdc1 /dev/sdd1 --size=3G
mkfs.xfs /dev/md0
mount /dev/md0 /mnt/test
mount: /mnt/test: mount(2) system call failed: Structure needs cleaning.
Fixes: 29bcff787a25 ("md/raid5: add new xor function to support different page offset")
Cc: stable@xxxxxxxxxxxxxxx # v5.10+
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/async_tx/async_xor.c | 1 +
1 file changed, 1 insertion(+)
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -233,6 +233,7 @@ async_xor_offs(struct page *dest, unsign
if (submit->flags & ASYNC_TX_XOR_DROP_DST) {
src_cnt--;
src_list++;
+ src_offs++;
}
/* wait for any prerequisite operations */
Patches currently in stable-queue which might be from xni@xxxxxxxxxx are
queue-5.12/async_xor-increase-src_offs-when-dropping-destination-page.patch
