From: Michael Raskin <7c6f434c@mail.ru>
To: Edward Shishkin <edward.shishkin@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [BUG] fallocate behavior when crossing end-of-file
Date: Thu, 07 May 2009 01:07:18 +0400 [thread overview]
Message-ID: <4A01FC06.80703@mail.ru> (raw)
In-Reply-To: <4A01AE6E.1050400@gmail.com>
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Edward Shishkin wrote:
>> <<<
>> If the offset+ len is beyond the current file size, then
>> posix_fallocate() shall adjust the file size to offset+ len. Otherwise,
>> the file size shall not be changed.
>>
>
> fallocate (2) is something different from posix_fallocate:
>
> "...This default behavior closely resembles the behavior
> of the posix_fallocate(3) library function, and is intended
> as a method of optimally implementing that function."
If you overincrement file size counter, the only way for glibc to
correctly implement is to ftruncate after fallocate . It doesn't look
like an optimal implementation of posix_fallocate (2 system calls). It
also doesn't look like something glibc would do. It currently doesn't.
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prev parent reply other threads:[~2009-05-06 21:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-06 13:03 [BUG] fallocate behavior when crossing end-of-file Raskin Michael
2009-05-06 14:59 ` Edward Shishkin
2009-05-06 15:10 ` Chris Mason
2009-05-06 15:12 ` Michael Raskin
2009-05-06 15:36 ` Edward Shishkin
2009-05-06 21:07 ` Michael Raskin [this message]
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