From: Andrew Bartlett <abartlet@samba.org>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Namjae Jeon <linkinjeon@gmail.com>,
linux-kernel@vger.kernel.org, Ravishankar N <cyberax82@gmail.com>,
Amit Sahrawat <amit.sahrawat83@gmail.com>,
Nam-Jae Jeon <namjae.jeon@samsung.com>,
Ravishankar N <ravi.n1@samsung.com>,
Amit Sahrawat <a.sahrawat@samsung.com>
Subject: Re: Read support for fat_fallocate()? (was [v2] fat: editions to support fat_fallocate())
Date: Tue, 19 Feb 2013 00:11:14 +1100 [thread overview]
Message-ID: <1361193074.5565.87.camel@jesse> (raw)
In-Reply-To: <87fw0t26qu.fsf@devron.myhome.or.jp>
On Mon, 2013-02-18 at 20:36 +0900, OGAWA Hirofumi wrote:
> Andrew Bartlett <abartlet@samba.org> writes:
> > Or, if we cannot make any changes to the on-disk format, what about
> > keeping such a database in memory, allocating some of the existing free
> > list to files that have had fallocate() called on them? (Naturally,
> > this makes it non-persistent, and instead more of a 'hint', but could at
> > least solve our mutual performance issues).
>
> [...]
>
> Hm. My concerns are compatibility and reliability. Although We can
> change on-disk format if need, but I don't think it can be compatible
> and reliable. If so, who wants to use it? I feel there is no reason to
> use FAT if there is no compatible.
>
> Well, anyway, possible solution would be, we can pre-allocate physical
> blocks via fallocate(2) or something, but discard pre-allocated blocks
> at ->release() (or before unmount at least). This way would have
> compatibility (no on-disk change over unmount) and possible breakage
> would be same with normal extend write patterns on kernel crash
> (i.e. Windows or fsck will truncate after i_size).
That would certainly give me what the Samba NAS with USB FAT disk use
case needs.
Thanks,
Andrew Bartlett
--
Andrew Bartlett http://samba.org/~abartlet/
Authentication Developer, Samba Team http://samba.org
next prev parent reply other threads:[~2013-02-18 13:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-13 14:31 [PATCH v2] fat: editions to support fat_fallocate() Namjae Jeon
2012-10-14 16:20 ` OGAWA Hirofumi
2012-10-16 4:12 ` Namjae Jeon
2012-10-16 10:14 ` OGAWA Hirofumi
2012-10-17 10:57 ` Namjae Jeon
2012-10-21 23:54 ` OGAWA Hirofumi
2012-10-22 15:10 ` Namjae Jeon
2012-10-23 7:19 ` OGAWA Hirofumi
2012-10-23 7:24 ` Namjae Jeon
2013-02-14 2:40 ` Read support for fat_fallocate()? (was [v2] fat: editions to support fat_fallocate()) Andrew Bartlett
2013-02-14 2:48 ` Andrew Bartlett
2013-02-14 6:44 ` Namjae Jeon
2013-02-14 7:07 ` Andrew Bartlett
2013-02-14 9:52 ` Namjae Jeon
2013-02-15 3:49 ` Andrew Bartlett
2013-02-18 11:36 ` OGAWA Hirofumi
2013-02-18 13:11 ` Andrew Bartlett [this message]
2013-02-18 14:25 ` Namjae Jeon
2013-02-18 14:59 ` OGAWA Hirofumi
2013-02-18 15:15 ` Namjae Jeon
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