[Ocfs2-devel] configfs: Q: item leak in a failing configfs_attach_group()?
Joel Becker
Joel.Becker at oracle.com
Tue Jun 24 14:34:39 PDT 2008
On Tue, Jun 24, 2008 at 08:04:56PM +0200, Louis Rilling wrote:
> On Tue, Jun 24, 2008 at 10:10:51AM -0700, Joel Becker wrote:
> > On Tue, Jun 24, 2008 at 04:16:49PM +0200, Louis Rilling wrote:
> > > Hi,
> > >
> > > I'd like an opinion on the following scenario:
> > >
> > > process 1: process 2:
> > > configfs_mkdir("A")
> > > attach_group("A")
> > > attach_item("A")
> > > d_instantiate("A")
> > > populate_groups("A")
> > > mutex_lock("A")
> > > attach_group("A/B")
> > > attach_item("A")
> > > d_instantiate("A/B")
> > > mkdir("A/B/C")
> > > do_path_lookup("A/B/C", LOOKUP_PARENT)
> >
> > This has to sleep until
> > configfs_mkdir("A") finishes.
> > It's waiting on A->d_parent's
> > i_mutex, which is held by
> > sys_mkdirat().
>
> Can you be more precise? I don't see where do_path_lookup() locks an inode
It doesn't. It's in lookup_create(), which takes the mutex on the
parent of 'A'. Note that the end of sys_mkdirat() explicitly drops that
mutex - it couldn't do so if it hadn't been taken :-)
Joel
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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127
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