Re: [PATCH 4/6] ubifs: Maintain a parent pointer

From: Richard Weinberger
Date: Mon May 22 2017 - 04:45:19 EST


Hyunchul,

Am 22.05.2017 um 06:30 schrieb Hyunchul Lee:
>> + if (move)
>> + old_inode_ui->parent_inum = new_dir->i_ino;
>> +
>> err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
>> new_inode, &new_nm, whiteout, sync);
>
> I think that old_inode_ui->parent_inum could point old_dir, even though old_inode
> is a child of new_dir. this could happen that there is power-cut before
> old_inode is synced. so I guess that old_inode is needed to be written with
> rename's node group in ubifs_jnl_rename. is it right?

I assumed that the journal does this already because we change old_inode->i_ctime
in this function too.
But checking the code showed the opposite.
So, if we face a power-cut the rename can succeed but we lose the ctime change.

This needs to be addressed before we can add the parent pointer.

Thanks,
//richard