From: Cong Wang <amwang@redhat.com>
To: Pekka Enberg <penberg@kernel.org>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org, kay.sievers@vrfy.org
Subject: Re: [Patch] tmpfs: add fallocate support
Date: Wed, 16 Nov 2011 15:09:52 +0800 [thread overview]
Message-ID: <4EC361C0.7040309@redhat.com> (raw)
In-Reply-To: <CAOJsxLEXbWbEhqX2YfzcQhyLJrY0H2ifCJCvGkoFHZsYAZEMPA@mail.gmail.com>
ao? 2011a1'11ae??15ae?JPY 19:23, Pekka Enberg a??e??:
> Hello,
>
> On Tue, Nov 15, 2011 at 10:42 AM, Amerigo Wang<amwang@redhat.com> wrote:
>> This patch adds fallocate support to tmpfs. I tested this patch
>> with the following test case,
>>
>> % sudo mount -t tmpfs -o size=100 tmpfs /mnt
>> % touch /mnt/foobar
>> % echo hi> /mnt/foobar
>> % fallocate -o 3 -l 5000 /mnt/foobar
>> fallocate: /mnt/foobar: fallocate failed: No space left on device
>> % fallocate -o 3 -l 3000 /mnt/foobar
>> % ls -l /mnt/foobar
>> -rw-rw-r-- 1 wangcong wangcong 3003 Nov 15 16:10 /mnt/foobar
>> % dd if=/dev/zero of=/mnt/foobar seek=3 bs=1 count=3000
>> 3000+0 records in
>> 3000+0 records out
>> 3000 bytes (3.0 kB) copied, 0.0153224 s, 196 kB/s
>> % hexdump -C /mnt/foobar
>> 00000000 68 69 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 |hi..............|
>> 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
>> *
>> 00000bb0 00 00 00 00 00 00 00 00 00 00 00 |...........|
>> 00000bbb
>> % cat /mnt/foobar
>> hi
>>
>> Signed-off-by: WANG Cong<amwang@redhat.com>
>
> What's the use case for this?
>
Hi, Pekka,
Systemd needs it, see http://lkml.org/lkml/2011/10/20/275.
I am adding Kay into Cc.
Thanks.
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next prev parent reply other threads:[~2011-11-16 7:10 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-15 8:42 [Patch] tmpfs: add fallocate support Amerigo Wang
2011-11-15 10:23 ` Cong Wang
2011-11-15 17:43 ` Dave Hansen
2011-11-16 7:21 ` Cong Wang
2011-11-16 23:21 ` Dave Hansen
2011-11-15 11:23 ` Pekka Enberg
2011-11-16 7:09 ` Cong Wang [this message]
2011-11-16 7:12 ` Pekka Enberg
2011-11-16 7:16 ` Cong Wang
2011-11-17 1:31 ` Hugh Dickins
2011-11-18 10:27 ` Cong Wang
2011-11-16 1:18 ` KAMEZAWA Hiroyuki
2011-11-16 7:12 ` Cong Wang
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