Subject: bug#9500: [PATCH]: use posix_fallocate where supported

From: Jim Meyering <[email-masked]>
Date: Tue, 29 Nov 2011 14:22:33 +0100

Pádraig Brady wrote:
> On 11/25/2011 10:59 AM, Pádraig Brady wrote:
>> On 11/25/2011 10:13 AM, Pádraig Brady wrote:
>>
>>> Hmm, one of your points above got me thinking.
>>> Might fallocate() fail to allocate an extent with ENOSPC,
>>> but there could be fragmented space available to write()?
>>> That would scupper benefit (2) above :(
>>> I'll ask [email-masked]
>>
>> And the response from there is that fallocate() will
>> check the free blocks first, and then try to allocate
>> as a contiguous extent, but that part is not guaranteed.
>> So we still get benefit (2).
>
> However that thread has continued, and it
> was mentioned that benefit (1) might actually
> be detrimental, at least for small files.
>
> http://thread.gmane.org/gmane.linux.file-systems/59092

Sigh, indeed.
Do you think it's even worth an option, now?