From: Eric Paris <eparis@redhat.com>
To: David Drysdale <drysdale@google.com>
Cc: David Miller <davem@davemloft.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: sparc: Clashing values for O_PATH and FMODE_NONOTIFY?
Date: Thu, 20 Nov 2014 14:12:31 -0500 [thread overview]
Message-ID: <1416510751.3116.13.camel@localhost> (raw)
In-Reply-To: <CAHse=S-f5o3vbT+b1D5baEWCWMUnDyLSxM88+vwwymFuLrTirg@mail.gmail.com>
On Thu, 2014-11-20 at 12:12 +0000, David Drysdale wrote:
> [+linux-fsdevel, without the typo this time]
>
> On Wed, Nov 19, 2014 at 8:30 PM, David Miller <davem@davemloft.net> wrote:
> > From: David Drysdale <drysdale@google.com>
> > Date: Tue, 18 Nov 2014 13:13:51 +0000
> >
> >> Hi folks,
> >>
> >> It looks like the value for O_PATH on sparc:
> >>
> >> arch/sparc/include/uapi/asm/fcntl.h:37:#define O_PATH 0x1000000
> >>
> >> clashes with the arch-independent value for __FMODE_NONOTIFY:
> >>
> >> include/linux/fs.h:137:#define FMODE_NONOTIFY ((__force fmode_t)0x1000000)
> >> include/linux/fs.h:2764:#define __FMODE_NONOTIFY ((__force int)
> >> FMODE_NONOTIFY)
> >>
> >> and they are both in the same numbering space, as indicated by the
> >> comment at the top of include/uapi/asm-generic/fcntl.h and the use in
> >> fs/notify/fanotify/fanotify_user.c:715.
> >>
> >> Presumably this could theoretically cause problems (no notifications for
> >> O_PATH files on SPARC?), so would it be a good idea to renumber
> >> FMODE_NONOTIFY? (I *think* that value is entirely kernel-internal.)
> >>
> >> Given that this has happened before (12ed2e36c98aec6c4155 "fanotify:
> >> FMODE_NONOTIFY and __O_SYNC in sparc conflict") it would probably
> >> also be a good idea to add __FMODE_NOTIFY to the uniqueness check in
> >> fs/fcntl.c:fcntl_init().
> >>
> >> Thoughts?
> >
> > I think you will need to change the internal value, to not clash with
> > the sparc exported one, for sure.
>
> Well, I was sort of hoping someone else might volunteer to make the
> change :-) -- I don't use fanotify (or sparc for that matter), I just
> happened to notice the clash in passing.
>
> But I'm happy to have a go, although I can't test much. It would be
> good to hear from the fanotify maintainers first, though -- Eric?
It's totally internal. And was picked to not clash with anyone. I
don't know how to keep it from happening in the future.....
next prev parent reply other threads:[~2014-11-20 19:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHse=S_EY3mJ_pdZf+A46joro_uNy=6tXGG1v7Va4NX_YxJu2w@mail.gmail.com>
[not found] ` <20141119.153001.1273476178846053821.davem@davemloft.net>
2014-11-20 12:12 ` sparc: Clashing values for O_PATH and FMODE_NONOTIFY? David Drysdale
2014-11-20 19:12 ` Eric Paris [this message]
2014-11-20 19:31 ` David Drysdale
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