This is a note to let you know that I've just added the patch titled ext4: recover csum seed of tmp_inode after migrating to extents to the 5.18-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: ext4-recover-csum-seed-of-tmp_inode-after-migrating-.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 95c415efc984b5fb401b4ee8007623f0b55f69d4 Author: Li Lingfeng <lilingfeng3@xxxxxxxxxx> Date: Fri Jun 17 14:25:15 2022 +0800 ext4: recover csum seed of tmp_inode after migrating to extents [ 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@xxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Link: https://lore.kernel.org/r/20220617062515.2113438-1-lilingfeng3@xxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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);