From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen)
To: Lars Noschinski <lklml@ml.noschinski.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: How does ext2 implement sparse files?
Date: Thu, 31 Jan 2008 11:51:17 -0500 [thread overview]
Message-ID: <20080131165117.GC26259@csclub.uwaterloo.ca> (raw)
In-Reply-To: <20080131152823.GA29422@lars.home.noschinski.de>
On Thu, Jan 31, 2008 at 04:28:23PM +0100, Lars Noschinski wrote:
> For an university project, we had to write a toy filesystem (ext2-like),
> for which I would like to implement sparse file support. For this, I
> digged through the ext2 source code; but I could not find the point,
> where ext2 detects holes.
>
> As far as I can see from fs/buffer.c, an hole is a buffer_head which is
> not mapped, but uptodate. But I cannot find a relevant source line,
> where ext2 makes usage of this information.
>
> Any hints would be greatly appreciated,
While I don't actually know, I always thought it was up to the
application to create files with holes by seeking over the holes before
writing data. That seems like the simplest way to me.
--
Len Sorensen
next prev parent reply other threads:[~2008-01-31 16:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-31 15:28 Lars Noschinski
2008-01-31 16:51 ` Lennart Sorensen [this message]
2008-01-31 17:18 ` Chris Snook
2008-01-31 18:14 ` Andi Kleen
2008-02-01 10:34 ` Shuduo Sang
2008-02-01 11:08 ` Eric Dumazet
2008-02-01 11:55 ` Lars Noschinski
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