Messages in this thread | | | Date | Tue, 15 Feb 2011 17:06:07 -0500 | From | Chuck Ebbert <> | Subject | Re: BUG at fs/namei.c:405 (nameidata_drop_rcu) |
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On Tue, 15 Feb 2011 18:17:08 -0200 Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> wrote:
> Em Sex, 2011-02-11 às 00:02 -0500, Chuck Ebbert escreveu: > > Apparently hit this very early in nameidata_drop_rcu(): > > > > BUG_ON(!(nd->flags & LOOKUP_RCU)); > > > > The user reports he ran "fuser /var/cache/yum" while logged in to > > an X session with his home directory mounted via NFS4. Home dirs > > are normally automounted, but manually mounting the dir still > > reproduces the problem. > > I got a similar report too, and was able to reproduce here with nfs4 > too. > > We hit it at force_reval_path > > From what I saw force_reval_path is never called with LOOKUP_RCU flag > set. Who calls force_reval_path is __do_follow_link, and > __do_follow_link is called from do_filp_open and do_follow_link. When > do_filp_open calls it, it already dropped LOOKUP_RCU (if path rcu lookup > didn't work). do_follow_link also calls it without LOOKUP_RCU set from > what I'm seeing, as before each do_follow_link call > nameidata_dentry_drop_rcu_maybe is called. > > So simply removing again nameidata_drop_rcu from force_reval_path should > do it. I'm running now on this change and didn't experience the same bug > or other problems. > > Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> > > diff --git a/fs/namei.c b/fs/namei.c > index ec4b2d0..7dcedbc 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -668,9 +668,7 @@ force_reval_path(struct path *path, struct nameidata *nd) > return 0; > > if (!status) { > - /* Don't d_invalidate in rcu-walk mode */ > - if (nameidata_drop_rcu(nd)) > - return -ECHILD; > + BUG_ON(nd->flags & LOOKUP_RCU); > d_invalidate(dentry); > status = -ESTALE; > } > >
Looks like this is fixed today by commit 844a391799c25d9ba85cbce33e4697db06083ec6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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