From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Rob Browning <rlb@defaultvalue.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org,
Robert Edmonds <edmonds@debian.org>
Subject: Re: Argument type for FS_IOC_GETFLAGS/FS_IOC_SETFLAGS ioctls
Date: Thu, 19 Dec 2013 15:30:53 -0800 [thread overview]
Message-ID: <20131219233053.GA23894@birch.djwong.org> (raw)
In-Reply-To: <87zjnw1z4f.fsf@trouble.defaultvalue.org>
On Thu, Dec 19, 2013 at 12:20:32PM -0600, Rob Browning wrote:
> "Darrick J. Wong" <darrick.wong@oracle.com> writes:
>
> > On Tue, Nov 26, 2013 at 09:05:59PM +0100, Aurelien Jarno wrote:
>
> > It also causes problems with FUSE, because the kernel fuse driver expects to be
> > able to transfer a ulong to and from userspace, but chattr & friends only
> > allocate an int on the stack, so stack mashing seems to happen.
> >
> > I complained to tytso about it on linux-ext4 a while ago, he suggested
> > special-casing fuse... I haven't gotten around to doing that.
>
> So if we didn't make a mistake, we changed bup to use int as suggested
> by this thread, and now it appears to crash at least sometimes when FUSE
> is involved:
>
> https://groups.google.com/forum/#!topic/bup-list/QxcHthbLHjw
>
> Is the problem (you mentioned above) that FUSE always expects a long,
> and if so, is there a way to tell that we're talking to FUSE?
I'm still leaning towards fixing FUSE[1], and letting userland keep on using
int, like (most?) programs always have.
The interface is still in hard shape, but this at least gets us to a place
where all the Linux filesystems behave the same -- (int *) argument.
--D
[1] Look for "[PATCH] fuse: Fix IOC_[GS]ETFLAGS argument size brokenness" on
lkml/fsdevel.
>
> Thanks
> --
> Rob Browning
> rlb @defaultvalue.org and @debian.org
> GPG as of 2011-07-10 E6A9 DA3C C9FD 1FF8 C676 D2C4 C0F0 39E9 ED1B 597A
> GPG as of 2002-11-03 14DD 432F AE39 534D B592 F9A0 25C8 D377 8C7E 73A4
next prev parent reply other threads:[~2013-12-19 23:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-26 20:05 Argument type for FS_IOC_GETFLAGS/FS_IOC_SETFLAGS ioctls Aurelien Jarno
2013-11-27 1:01 ` Darrick J. Wong
2013-11-27 4:00 ` Theodore Ts'o
2013-11-27 10:03 ` Aurelien Jarno
2013-11-27 13:34 ` Theodore Ts'o
2013-11-27 18:14 ` Robert Edmonds
2013-11-27 23:14 ` Aurelien Jarno
2013-11-29 0:53 ` Andreas Dilger
2013-11-29 4:54 ` Theodore Ts'o
2013-11-29 5:27 ` Dave Chinner
2013-11-29 14:22 ` Theodore Ts'o
2013-11-29 16:32 ` Rob Browning
2013-12-01 22:20 ` Dave Chinner
2013-12-02 4:52 ` Theodore Ts'o
2013-12-02 22:30 ` Dave Chinner
2013-11-29 21:55 ` Andreas Dilger
2013-12-19 18:20 ` Rob Browning
2013-12-19 23:30 ` Darrick J. Wong [this message]
2013-11-27 10:15 ` Christoph Hellwig
2014-06-30 22:51 ` Rob Browning
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