Re: [BUG] fs: ocfs2: possible ABBA deadlock in ocfs2_dio_end_io_write() and ocfs2_move_extents()

[Jia-Ju Bai]

On 2021/12/14 15:08, Joseph Qi wrote:
> Hi,
>
> Thanks for the report. But I don't think this is a possible deadlock in
> practice. Please see my comments below.
>
> On 12/10/21 4:38 PM, Jia-Ju Bai wrote:
> > Hello,
> >
> > My static analysis tool reports a possible ABBA deadlock in the ocfs2 module in Linux 5.10:
> >
> > ocfs2_dio_end_io_write()
> >    down_write(&oi->ip_alloc_sem); --> Line 2322 (Lock A)
> >    ocfs2_del_inode_from_orphan()
> >      inode_lock(orphan_dir_inode);  --> Line 2701 (Lock B)
> Just as the variable name indicates, it is orphan dir inode, which is a
> system file (something hidden inside the filesystem) and not visible for
> end user.
>
> > ocfs2_move_extents()
> >    inode_lock(inode); --> Line 916 (Lock B)
> This is called from a ioctl from user, it a normal file inode.

Okay, thanks for the explanation :)


Best wishes,
Jia-Ju Bai