From: "Antonio Vargas" <windenntw@gmail.com>
To: "Trond Myklebust" <trond.myklebust@fys.uio.no>,
"Andrew Morton" <akpm@osdl.org>,
"Oleg Drokin" <green@linuxhacker.ru>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: FMODE_EXEC or alike?
Date: Tue, 21 Feb 2006 15:15:53 +0100 [thread overview]
Message-ID: <69304d110602210615m491829ccx9ba84edc8dafe1f7@mail.gmail.com> (raw)
In-Reply-To: <1140530396.7864.63.camel@lade.trondhjem.org>
On 2/21/06, Trond Myklebust <trond.myklebust@fys.uio.no> wrote:
> On Mon, 2006-02-20 at 21:51 -0800, Andrew Morton wrote:
> > Oleg Drokin <green@linuxhacker.ru> wrote:
> > >
> > > Hello!
> > >
> > > We are working on a lustre client that would not require any patches
> > > to linux kernel. And there are few things that would be nice to have
> > > that I'd like your input on.
> > >
> > > One of those is FMODE_EXEC - to correctly detect cross-node situations with
> > > executing a file that is opened for write or the other way around, we need
> > > something like this extra file mode to be present (and used as a file open
> > > mode when opening files for exection, e.g. in fs/exec.c)
> > > Do you think there is a chance this can be included into vanilla kernel,
> > > or is there a better solution I oversee?
> > > I am just thinking about something as simple as this
> > > (with some suitable FMODE_EXEC define, of course):
> > >
> > > --- linux/fs/exec.c.orig 2006-02-21 00:11:47.000000000 +0200
> > > +++ linux/fs/exec.c 2006-02-21 00:12:24.000000000 +0200
> > > @@ -127,7 +127,7 @@ asmlinkage long sys_uselib(const char __
> > > struct nameidata nd;
> > > int error;
> > >
> > > - error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ);
> > > + error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
> > > if (error)
> > > goto out;
> > >
> > > @@ -477,7 +477,7 @@ struct file *open_exec(const char *name)
> > > int err;
> > > struct file *file;
> > >
> > > - err = path_lookup_open(name, LOOKUP_FOLLOW, &nd, FMODE_READ);
> > > + err = path_lookup_open(name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
> > > file = ERR_PTR(err);
> > >
> > > if (!err) {
> > >
> >
> > Such a patch would have zero runtime cost. I'd have no problem carrying
> > that if it makes things easier for lustre, personally.
> >
> > We would need to understand whether this is needed by other distributed
> > filesystems and if so, whether the proposed implementation is suitable and
> > sufficient.
>
> Hmm.... We might possibly want to use that for NFSv4 at some point in
> order to deny write access to the file to other clients while it is in
> use.
When done with regards to failing a write if anyone has mapped the
file for executing it, or failing the execute if it's open/mmaped for
write, I can't really see the difference between local, remote and
clustered filesystems...
--
Greetz, Antonio Vargas aka winden of network
http://wind.codepixel.com/
windNOenSPAMntw@gmail.com
thesameasabove@amigascne.org
Every day, every year
you have to work
you have to study
you have to scene.
next prev parent reply other threads:[~2006-02-21 14:15 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-02-20 22:19 FMODE_EXEC or alike? Oleg Drokin
2006-02-21 5:51 ` Andrew Morton
2006-02-21 11:30 ` Oleg Drokin
2006-02-21 11:36 ` Andrew Morton
2006-02-21 11:56 ` Oleg Drokin
2006-02-21 13:59 ` Trond Myklebust
2006-02-21 14:15 ` Antonio Vargas [this message]
2006-02-21 14:21 ` Oleg Drokin
2006-02-22 9:57 ` Antonio Vargas
2006-02-21 14:42 ` Trond Myklebust
2006-02-21 23:26 ` J. Bruce Fields
2006-02-21 23:32 ` Trond Myklebust
2006-02-22 19:57 ` J. Bruce Fields
2006-02-22 21:36 ` Trond Myklebust
2006-02-22 22:04 ` J. Bruce Fields
2006-02-22 22:17 ` Trond Myklebust
2006-02-22 23:31 ` J. Bruce Fields
2006-02-21 10:39 ` Christoph Hellwig
2006-02-22 1:03 ` Chris Wedgwood
2006-02-22 8:59 ` Steven Whitehouse
2006-02-22 21:42 ` J. Bruce Fields
2006-02-22 22:02 ` Christoph Hellwig
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