From: "Pádraig Brady" <P@draigBrady.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Theodore Tso <tytso@MIT.EDU>,
Christoph Hellwig <hch@infradead.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: fallocate vs ENOSPC
Date: Mon, 28 Nov 2011 08:55:02 +0000 [thread overview]
Message-ID: <4ED34C66.8050300@draigBrady.com> (raw)
In-Reply-To: <20111128051054.GZ2386@dastard>
On 11/28/2011 05:10 AM, Dave Chinner wrote:
> Quite frankly, if system utilities like cp and tar start to abuse
> fallocate() by default so they can get "upfront ENOSPC detection",
> then I will seriously consider making XFS use delayed allocation for
> fallocate rather than unwritten extents so we don't lose the past 15
> years worth of IO and aging optimisations that delayed allocation
> provides us with....
For the record I was considering fallocate() for these reasons.
1. Improved file layout for subsequent access
2. Immediate indication of ENOSPC
3. Efficient writing of NUL portions
You lucidly detailed issues with 1. which I suppose could be somewhat
mitigated by not fallocating < say 1MB, though I suppose file systems
could be smarter here and not preallocate small chunks (or when
otherwise not appropriate). We can already get ENOSPC from a write()
after an fallocate() in certain edge cases, so it would probably make
sense to expand those cases.
cheers,
Pádraig.
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2011-11-28 8:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-25 10:26 fallocate vs ENOSPC Pádraig Brady
2011-11-25 10:40 ` Christoph Hellwig
2011-11-27 3:14 ` Ted Ts'o
2011-11-27 23:43 ` Dave Chinner
2011-11-28 0:13 ` Pádraig Brady
2011-11-28 3:51 ` Dave Chinner
2011-11-28 0:40 ` Theodore Tso
2011-11-28 5:10 ` Dave Chinner
2011-11-28 8:55 ` Pádraig Brady [this message]
2011-11-28 10:41 ` tao.peng
2011-11-28 12:02 ` Pádraig Brady
2011-11-28 14:36 ` Theodore Tso
2011-11-28 14:51 ` Pádraig Brady
2011-11-28 20:29 ` Ted Ts'o
2011-11-28 20:49 ` Jeremy Allison
2011-11-29 22:39 ` Eric Sandeen
2011-11-29 23:04 ` Jeremy Allison
2011-11-29 23:19 ` Eric Sandeen
2011-11-28 18:49 ` Jeremy Allison
2011-11-29 0:26 ` Dave Chinner
2011-11-29 0:45 ` Jeremy Allison
2011-11-29 0:24 ` Dave Chinner
2011-11-29 14:11 ` Pádraig Brady
2011-11-29 23:37 ` Dave Chinner
2011-11-30 9:28 ` Pádraig Brady
2011-11-30 15:32 ` Ted Ts'o
2011-11-30 16:11 ` Pádraig Brady
2011-11-30 17:01 ` Ted Ts'o
2011-11-30 23:39 ` Dave Chinner
2011-12-01 0:11 ` Pádraig Brady
2011-12-07 11:42 ` Pádraig Brady
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4ED34C66.8050300@draigBrady.com \
--to=p@draigbrady.com \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=tytso@MIT.EDU \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.