[PATCH 4/6] ubifs: Maintain a parent pointer
hyc.lee at gmail.com
Mon May 22 16:50:49 PDT 2017
On Mon, May 22, 2017 at 10:45:08AM +0200, Richard Weinberger wrote:
> 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.
Is writing old_inode->i_ctime required? I guess that it is needed only when
IS_SYNC(old_inode) is true, otherwise we don't need to guarantee that ctime
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