From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Pai Subject: Re: [PATCH 01/34] VFS: Make clone_mnt() and copy_tree() return error codes Date: Thu, 30 Sep 2010 17:33:42 -0700 Message-ID: <20101001003342.GI9247@ram-laptop> References: <1284675145-4391-1-git-send-email-vaurora@redhat.com> <1284675145-4391-2-git-send-email-vaurora@redhat.com> <20100930214123.GA490@shell> <20100930214418.GB490@shell> Reply-To: Ram Pai Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Miklos Szeredi , viro@zeniv.linux.org.uk, hch@infradead.org, agruen@suse.de, npiggin@kernel.dk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Valerie Aurora Return-path: Received: from e33.co.us.ibm.com ([32.97.110.151]:60315 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753122Ab0JAAdt (ORCPT ); Thu, 30 Sep 2010 20:33:49 -0400 Content-Disposition: inline In-Reply-To: <20100930214418.GB490@shell> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Sep 30, 2010 at 05:44:18PM -0400, Valerie Aurora wrote: > (Resend with correct email for Ram Pai) > > On Thu, Sep 30, 2010 at 11:51:30AM +0200, Miklos Szeredi wrote: > > On Thu, 16 Sep 2010, Valerie Aurora wrote: > > > copy_tree() can theoretically fail in a case other than ENOMEM, but > > > always returns NULL which is interpreted by callers as -ENOMEM. > > > Convert to return an explicit error. Convert clone_mnt() for > > > consistency and because union mounts will add new error cases. > > > > I think it makes sense to push this fix to 2.6.37 independently of the > > other patches. > > > > Acked-by: Miklos Szeredi > > I'm certainly not going to argue, but I spent an hour trying to > trigger the non-ENOMEM case (below) and failed - maybe it's > unreachable? > > > > @@ -1212,11 +1216,12 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry, > > > struct path path; > > > > > > if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt)) > > > - return NULL; > > > + return ERR_PTR(-EINVAL); > > Ram, do you remember how this worked? Oops. That should be a OR condition. there is one other check in that function that should also be a OR condition. BTW: the return value has to be NULL. right? because its not an error to clone a unbindable mount. Nor is it an error to not specify CL_COPY_ALL. It just means that you want nothing in return. RP