From: Li Lingfeng lilingfeng3@huawei.com
[ Upstream commit 07ea7a617d6b278fb7acedb5cbe1a81ce2de7d0c ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7a5353a8cfd7..f2c4d9eee475 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);