From: Steven Whitehouse <swhiteho@redhat.com>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dave Chinner <david@fromorbit.com>,
Chris Mason <chris.mason@fusionio.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ric Wheeler <rwheeler@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Martin Steigerwald <Martin@lichtvoll.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI
Date: Mon, 10 Dec 2012 18:05:59 +0000 [thread overview]
Message-ID: <1355162759.2704.50.camel@menhir> (raw)
In-Reply-To: <20121210173739.GA1359@thunk.org>
Hi,
On Mon, 2012-12-10 at 12:37 -0500, Theodore Ts'o wrote:
> On Sat, Dec 08, 2012 at 11:17:05AM +1100, Dave Chinner wrote:
> > I wouldn't recommend XFS_IOC_ALLOCSP as a user-friendly interface.
> > The concept, however, implemented by a new fallocate()
> > flag (say FALLOC_FL_WRITE_ZEROS) so that the filesystem knows that
> > the application considers unwritten extents undesirable is exactly
> > the sort of thing that we should be considering implementing.
>
> What's the point of using a new flag like this (or XFS's
> XFS_IOC_ALLOCSP) for writing zeros during preallocation as oppoised to
> simply doing a fallocate() followed by zeroing the data via a O_DIRECT
> write system call?
>
If the block device can zero out blocks more efficiently than just
writing zeros (i.e. via sb_issue_zeroout()) then this could be faster.
In fact GFS2 already zeros out fallocate()d extents in this way because
it has no way to mark unwritten extents in its metadata, and we did not
want to leave them uninitialised,
Steve.
next prev parent reply other threads:[~2012-12-10 18:07 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 [this message]
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
2012-11-27 13:44 ` Martin Steigerwald
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