From 07ea7a617d6b278fb7acedb5cbe1a81ce2de7d0c Mon Sep 17 00:00:00 2001
From: Li Lingfeng <lilingfeng3@huawei.com>
Date: Fri, 17 Jun 2022 14:25:15 +0800
Subject: [PATCH] ext4: recover csum seed of tmp_inode after migrating to
extents
Git-commit: 07ea7a617d6b278fb7acedb5cbe1a81ce2de7d0c
Patch-mainline: v6.0-rc1
References: bsc#1202713
When migrating to extents, the checksum seed of temporary inode
need to be replaced by inode's, otherwise the inode checksums
will be incorrect when swapping the inodes data.
However, the temporary inode can not match it's checksum to
itself since it has lost it's own checksum seed.
mkfs.ext4 -F /dev/sdc
mount /dev/sdc /mnt/sdc
xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/sdc/testfile
chattr -e /mnt/sdc/testfile
chattr +e /mnt/sdc/testfile
umount /dev/sdc
fsck -fn /dev/sdc
========
...
Pass 1: Checking inodes, blocks, and sizes
Inode 13 passes checks, but checksum does not match inode. Fix? no
...
========
The fix is simple, save the checksum seed of temporary inode, and
recover it after migrating to extents.
Fixes: e81c9302a6c3 ("ext4: set csum seed in tmp inode while migrating to extents")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220617062515.2113438-1-lilingfeng3@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
---
fs/ext4/migrate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 42f590518b4c..54e7d3c95fd7 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -417,7 +417,7 @@ int ext4_ext_migrate(struct inode *inode)
struct inode *tmp_inode = NULL;
struct migrate_struct lb;
unsigned long max_entries;
- __u32 goal;
+ __u32 goal, tmp_csum_seed;
uid_t owner[2];
/*
@@ -465,6 +465,7 @@ int ext4_ext_migrate(struct inode *inode)
* the migration.
*/
ei = EXT4_I(inode);
+ tmp_csum_seed = EXT4_I(tmp_inode)->i_csum_seed;
EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed;
i_size_write(tmp_inode, i_size_read(inode));
/*
@@ -575,6 +576,7 @@ int ext4_ext_migrate(struct inode *inode)
* the inode is not visible to user space.
*/
tmp_inode->i_blocks = 0;
+ EXT4_I(tmp_inode)->i_csum_seed = tmp_csum_seed;
/* Reset the extent details */
ext4_ext_tree_init(handle, tmp_inode);
--
2.35.3