From: Luís Henriques <lhenriques@xxxxxxx> commit e81c9302a6c3c008f5c30beb73b38adb0170ff2d upstream. When migrating to extents, the temporary inode will have it's own checksum seed. This means that, when swapping the inodes data, the inode checksums will be incorrect. This can be fixed by recalculating the extents checksums again. Or simply by copying the seed into the temporary inode. Link: https://bugzilla.kernel.org/show_bug.cgi?id=213357 Reported-by: Jeroen van Wolffelaar <jeroen@xxxxxxxxxxxxx> Signed-off-by: Luís Henriques <lhenriques@xxxxxxx> Link: https://lore.kernel.org/r/20211214175058.19511-1-lhenriques@xxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/migrate.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -477,6 +477,17 @@ int ext4_ext_migrate(struct inode *inode ext4_journal_stop(handle); goto out_unlock; } + /* + * Use the correct seed for checksum (i.e. the seed from 'inode'). This + * is so that the metadata blocks will have the correct checksum after + * the migration. + * + * Note however that, if a crash occurs during the migration process, + * the recovery process is broken because the tmp_inode checksums will + * be wrong and the orphans cleanup will fail. + */ + ei = EXT4_I(inode); + EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed; i_size_write(tmp_inode, i_size_read(inode)); /* * Set the i_nlink to zero so it will be deleted later @@ -520,7 +531,6 @@ int ext4_ext_migrate(struct inode *inode goto out_tmp_inode; } - ei = EXT4_I(inode); i_data = ei->i_data; memset(&lb, 0, sizeof(lb));
