From: Dave Chinner <david@fromorbit.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI
Date: Tue, 27 Nov 2012 08:12:00 +1100 [thread overview]
Message-ID: <20121126211200.GI6434@dastard> (raw)
In-Reply-To: <20121126115345.19977e46@pyramind.ukuu.org.uk>
On Mon, Nov 26, 2012 at 11:53:45AM +0000, Alan Cox wrote:
> > It's not like there is any shortage of flag bits, so what's the harm
> > of reserving the bit?
>
> Why not just reserve a small group of bits for fs private use in that
> case - for any fs.
Flawed - one bit, one function for all filesystems, otherwise the
same binary could behave very differently on different filesystems.
Besides, we already have a mechanism for adding filesystem specific
interfaces. It's called an ioctl. That's what it's there for - a
free-form extensible interface that can be wholly defined and
contained in the out-of-tree patch.
Most filesystems implement ioctls for their own specific
functionality, including for one-off preallocation semantics (e.g.
XFS_IOC_ZERO_RANGE). There is no reason why ext4 can't do the same
thing and we can drop the whole issue of having to modify a syscall
API with magic, undocumented flag bits with unpredictable
behaviour....
ext4 is not a special snowflake that allows developers to bend rules
whenever they want. If the ext4 developers want to support out of
tree functionality for their filesystem, then they can do it within
their filesystem via ioctls like everyone else does.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2012-11-26 21:12 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-19 23:04 [PATCH] fs: revert commit bbdd6808 to fallocate UAPI Dave Chinner
2012-11-20 16:36 ` Christoph Hellwig
2012-11-26 0:28 ` [PATCH, 3.7-rc7, RESEND] " Dave Chinner
2012-11-26 2:55 ` Theodore Ts'o
2012-11-26 6:14 ` Tao Ma
2012-11-26 9:12 ` Dave Chinner
2012-12-05 10:48 ` Martin Steigerwald
2012-12-05 15:45 ` Linus Torvalds
2012-12-05 16:18 ` Martin Steigerwald
2012-12-05 16:33 ` Theodore Ts'o
2012-12-05 17:24 ` Martin Steigerwald
2012-12-05 17:34 ` Theodore Ts'o
2012-12-05 17:55 ` Martin Steigerwald
2012-12-06 0:42 ` Dave Chinner
2012-12-06 9:24 ` Martin Steigerwald
2012-12-05 18:25 ` Linus Torvalds
2012-12-06 1:14 ` Dave Chinner
2012-12-06 3:03 ` Linus Torvalds
2012-12-06 9:37 ` Martin Steigerwald
2012-12-07 1:08 ` Ingo Molnar
2012-12-07 2:40 ` Dave Chinner
2012-12-07 10:24 ` Martin Steigerwald
2012-12-06 12:06 ` Christoph Hellwig
2012-12-06 16:50 ` Theodore Ts'o
2012-12-07 1:57 ` Dave Chinner
2012-12-06 12:05 ` Christoph Hellwig
2012-12-07 1:16 ` Ingo Molnar
2012-12-07 3:19 ` Dave Chinner
2012-12-07 17:36 ` Ric Wheeler
2012-12-07 18:18 ` Linus Torvalds
2012-12-07 19:03 ` Chris Mason
2012-12-07 20:43 ` Theodore Ts'o
2012-12-07 21:09 ` Chris Mason
2012-12-07 21:27 ` Theodore Ts'o
2012-12-07 21:43 ` Chris Mason
2012-12-07 21:49 ` Ric Wheeler
2012-12-07 21:57 ` Chris Mason
2012-12-07 22:51 ` Eric Sandeen
2012-12-07 22:52 ` Eric Sandeen
2012-12-07 21:42 ` Ric Wheeler
2012-12-07 21:57 ` Theodore Ts'o
2012-12-07 22:02 ` Ric Wheeler
2012-12-08 0:39 ` Dave Chinner
2012-12-08 2:52 ` Joel Becker
2012-12-08 4:04 ` Dave Chinner
2012-12-08 0:17 ` Dave Chinner
2012-12-08 1:39 ` Chris Mason
2012-12-10 16:02 ` Chris Mason
2012-12-10 17:37 ` Theodore Ts'o
2012-12-10 18:05 ` Steven Whitehouse
2012-12-10 18:13 ` Theodore Ts'o
2012-12-10 18:20 ` Theodore Ts'o
2012-12-11 12:16 ` Steven Whitehouse
2012-12-11 22:09 ` Dave Chinner
2012-12-10 18:52 ` Ric Wheeler
2012-12-11 0:52 ` Dave Chinner
2012-12-07 19:30 ` Steven Rostedt
2012-12-07 21:14 ` Theodore Ts'o
2012-12-07 21:47 ` Ric Wheeler
2012-12-07 23:25 ` Howard Chu
2012-12-08 0:50 ` Dave Chinner
2012-12-08 13:52 ` Howard Chu
2012-12-08 14:02 ` Ric Wheeler
2012-12-07 22:01 ` Eric Sandeen
2012-12-09 21:37 ` Ric Wheeler
2012-11-26 11:53 ` Alan Cox
2012-11-26 14:43 ` Theodore Ts'o
2012-11-26 21:12 ` Dave Chinner [this message]
2012-11-27 13:44 ` Martin Steigerwald
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