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 4.19-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-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit edece10be14675ac1f650dd15f61816877e746b4
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 9adfe217b39d..37ce665ae1d2 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -435,7 +435,7 @@ 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];
/*
@@ -483,6 +483,7 @@ 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));
/*
@@ -593,6 +594,7 @@ 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);
