From: Marco Stornelli <marco.stornelli@gmail.com>
To: Zach Brown <zab@zabbo.net>
Cc: Dave Chinner <david@fromorbit.com>,
Andreas Dilger <adilger@dilger.ca>,
Christoph Hellwig <hch@infradead.org>,
Josef Bacik <josef@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-btrfs@vger.kernel.org, xfs@oss.sgi.com,
viro@zeniv.linux.org.uk, dchinner@redhat.com
Subject: Re: [PATCH] xfstests 255: add a seek_data/seek_hole tester
Date: Sun, 28 Aug 2011 12:17:36 +0200 [thread overview]
Message-ID: <4E5A15C0.3020205@gmail.com> (raw)
In-Reply-To: <4E58AB28.1080009@gmail.com>
Il 27/08/2011 10:30, Marco Stornelli ha scritto:
> Il 26/08/2011 16:41, Zach Brown ha scritto:
>>>> Hole: a range of the file that contains no data or is made up
>>>> entirely of NULL (zero) data. Holes include preallocated ranges of
>>>> files that have not had actual data written to them.
>>
>>> No for me. A hole is made up of zero data? It's a strange definition
>>> for me.
>>
>> It's a very natural definition for me. It mirrors the behaviour of
>> read() of sparse data inside i_size that file system authors already
>> have to consider.
>>
>> It's also a reminder for people that this interface is about avoiding
>> reading zeros. Systems that track contents can do this for files that
>> had tons of zeros written. The data is there but the app is
>> specifically asking us to skip it by using SEEK_DATA.
>>
>> - z
>>
>
> I think we need to consider a hole and "data not present/not written
> yet" as two different cases even they are related. For example, if I do
> an fallocate without keep size option, then I do a read, I have the same
> behavior of sparse data inside i_size, but the blocks are allocated so
> no sparse data in this case. Simply there are no difference from app
> point of view.
>
> Marco
Please don't care about the last part, when reading in this case the app
will have a return value different from zero obviously, I was under the
effect of a beer :) However I'd add to the definition, that we consider
holes only inside i_size, as Zack said. In this way, we haven't got any
ambiguity for preallocated space beyond eof.
Marco
WARNING: multiple messages have this Message-ID (diff)
From: Marco Stornelli <marco.stornelli@gmail.com>
To: Zach Brown <zab@zabbo.net>
Cc: Andreas Dilger <adilger@dilger.ca>,
linux-kernel@vger.kernel.org, xfs@oss.sgi.com,
Christoph Hellwig <hch@infradead.org>,
linux-btrfs@vger.kernel.org, dchinner@redhat.com,
linux-fsdevel@vger.kernel.org, Josef Bacik <josef@redhat.com>,
viro@zeniv.linux.org.uk
Subject: Re: [PATCH] xfstests 255: add a seek_data/seek_hole tester
Date: Sun, 28 Aug 2011 12:17:36 +0200 [thread overview]
Message-ID: <4E5A15C0.3020205@gmail.com> (raw)
In-Reply-To: <4E58AB28.1080009@gmail.com>
Il 27/08/2011 10:30, Marco Stornelli ha scritto:
> Il 26/08/2011 16:41, Zach Brown ha scritto:
>>>> Hole: a range of the file that contains no data or is made up
>>>> entirely of NULL (zero) data. Holes include preallocated ranges of
>>>> files that have not had actual data written to them.
>>
>>> No for me. A hole is made up of zero data? It's a strange definition
>>> for me.
>>
>> It's a very natural definition for me. It mirrors the behaviour of
>> read() of sparse data inside i_size that file system authors already
>> have to consider.
>>
>> It's also a reminder for people that this interface is about avoiding
>> reading zeros. Systems that track contents can do this for files that
>> had tons of zeros written. The data is there but the app is
>> specifically asking us to skip it by using SEEK_DATA.
>>
>> - z
>>
>
> I think we need to consider a hole and "data not present/not written
> yet" as two different cases even they are related. For example, if I do
> an fallocate without keep size option, then I do a read, I have the same
> behavior of sparse data inside i_size, but the blocks are allocated so
> no sparse data in this case. Simply there are no difference from app
> point of view.
>
> Marco
Please don't care about the last part, when reading in this case the app
will have a return value different from zero obviously, I was under the
effect of a beer :) However I'd add to the definition, that we consider
holes only inside i_size, as Zack said. In this way, we haven't got any
ambiguity for preallocated space beyond eof.
Marco
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2011-08-28 10:17 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-28 15:33 [PATCH 1/4] fs: add SEEK_HOLE and SEEK_DATA flags Josef Bacik
2011-06-28 15:33 ` Josef Bacik
2011-06-28 15:33 ` [PATCH 2/4] Btrfs: implement our own ->llseek Josef Bacik
2011-06-28 15:33 ` Josef Bacik
2011-06-28 15:33 ` [PATCH 3/4] Ext4: handle SEEK_HOLE/SEEK_DATA generically Josef Bacik
2011-06-28 15:33 ` Josef Bacik
2011-06-28 16:29 ` Andreas Dilger
2011-06-28 17:34 ` Josef Bacik
2011-06-28 15:33 ` [PATCH 4/4] fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek Josef Bacik
2011-06-28 15:33 ` Josef Bacik
2011-06-28 15:33 ` [PATCH] xfstests 255: add a seek_data/seek_hole tester Josef Bacik
2011-06-28 15:33 ` Josef Bacik
2011-06-29 6:53 ` Dave Chinner
2011-06-29 6:53 ` Dave Chinner
2011-06-29 6:53 ` Dave Chinner
2011-06-29 6:53 ` Dave Chinner
2011-06-29 7:40 ` Christoph Hellwig
2011-06-29 7:40 ` Christoph Hellwig
2011-06-29 10:42 ` Pádraig Brady
2011-06-29 10:42 ` Pádraig Brady
2011-06-29 10:42 ` Pádraig Brady
2011-06-29 10:42 ` Pádraig Brady
2011-06-29 17:29 ` Sunil Mushran
2011-06-29 17:29 ` Sunil Mushran
2011-06-29 17:29 ` Sunil Mushran
2011-06-29 17:29 ` Sunil Mushran
2011-06-29 17:36 ` Christoph Hellwig
2011-06-29 17:36 ` Christoph Hellwig
2011-06-29 17:40 ` Sunil Mushran
2011-06-29 17:40 ` Sunil Mushran
2011-06-29 21:29 ` Pádraig Brady
2011-06-29 21:29 ` Pádraig Brady
2011-06-29 21:29 ` Pádraig Brady
2011-07-01 9:37 ` Christoph Hellwig
2011-07-01 9:37 ` Christoph Hellwig
2011-06-29 17:10 ` Sunil Mushran
2011-06-29 17:10 ` Sunil Mushran
2011-06-29 17:52 ` Josef Bacik
2011-06-29 17:52 ` Josef Bacik
2011-06-29 13:19 ` Josef Bacik
2011-06-29 13:19 ` Josef Bacik
2011-06-29 13:19 ` Josef Bacik
2011-08-25 6:06 ` Christoph Hellwig
2011-08-25 6:06 ` Christoph Hellwig
2011-08-25 6:40 ` Dave Chinner
2011-08-25 6:40 ` Dave Chinner
2011-08-25 6:51 ` Andreas Dilger
2011-08-25 6:51 ` Andreas Dilger
2011-08-26 1:35 ` Dave Chinner
2011-08-26 1:35 ` Dave Chinner
2011-08-26 6:24 ` Marco Stornelli
2011-08-26 6:24 ` Marco Stornelli
2011-08-26 6:24 ` Marco Stornelli
2011-08-26 14:41 ` Zach Brown
2011-08-26 14:41 ` Zach Brown
2011-08-26 14:41 ` Zach Brown
2011-08-26 14:41 ` Zach Brown
2011-08-27 8:30 ` Marco Stornelli
2011-08-27 8:30 ` Marco Stornelli
2011-08-28 10:17 ` Marco Stornelli [this message]
2011-08-28 10:17 ` Marco Stornelli
2011-08-30 17:42 ` Sunil Mushran
2011-08-30 17:42 ` Sunil Mushran
2011-08-31 1:17 ` Sunil Mushran
2011-08-31 1:17 ` Sunil Mushran
2011-08-31 3:29 ` Dave Chinner
2011-08-31 3:29 ` Dave Chinner
2011-08-31 3:53 ` david
2011-08-31 3:53 ` david
2011-08-31 4:43 ` Sunil Mushran
2011-08-31 4:43 ` Sunil Mushran
2011-08-31 9:05 ` Pádraig Brady
2011-08-31 9:05 ` Pádraig Brady
2011-08-31 9:05 ` Pádraig Brady
2011-08-31 4:48 ` Dan Merillat
2011-08-31 4:48 ` Dan Merillat
2011-07-29 9:58 ` [PATCH 1/4] fs: add SEEK_HOLE and SEEK_DATA flags Marco Stornelli
2011-07-29 9:58 ` Marco Stornelli
2011-08-20 9:41 ` Marco Stornelli
2011-08-20 9:41 ` Marco Stornelli
2011-08-20 10:03 ` Marco Stornelli
2011-08-20 10:03 ` Marco Stornelli
2011-08-20 15:36 ` Sunil Mushran
2011-08-20 15:36 ` Sunil Mushran
2011-08-20 16:32 ` Marco Stornelli
2011-08-20 16:32 ` Marco Stornelli
2011-08-22 6:08 ` Sunil Mushran
2011-08-22 6:08 ` Sunil Mushran
2011-08-22 10:56 ` Marco Stornelli
2011-08-22 10:56 ` Marco Stornelli
2011-08-22 10:56 ` Marco Stornelli
2011-08-22 10:56 ` Marco Stornelli
2011-08-22 15:57 ` Sunil Mushran
2011-08-22 15:57 ` Sunil Mushran
2011-08-22 17:56 ` Marco Stornelli
2011-08-22 17:56 ` Marco Stornelli
2011-08-22 21:22 ` Sunil Mushran
2011-08-22 21:22 ` Sunil Mushran
2011-08-23 17:44 ` Marco Stornelli
2011-08-23 17:44 ` Marco Stornelli
2011-08-31 0:35 ` Dave Chinner
2011-08-31 0:35 ` Dave Chinner
[not found] ` <CAGpXXZ+xjhadprkc_LiP3qUypLLkCxdeEmo8+K+6mOnBuNhmLg@mail.gmail.com>
2011-08-20 17:18 ` Greg Freemyer
-- strict thread matches above, loose matches on Subject: below --
2011-06-27 18:02 Josef Bacik
2011-06-27 18:02 ` [PATCH] xfstests 255: add a seek_data/seek_hole tester Josef Bacik
2011-06-27 18:32 ` Andreas Dilger
2011-06-27 18:47 ` Josef Bacik
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=4E5A15C0.3020205@gmail.com \
--to=marco.stornelli@gmail.com \
--cc=adilger@dilger.ca \
--cc=david@fromorbit.com \
--cc=dchinner@redhat.com \
--cc=hch@infradead.org \
--cc=josef@redhat.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=xfs@oss.sgi.com \
--cc=zab@zabbo.net \
/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.