Re: [PATCH] eCryptfs: Delay writing 0's after llseek until write

From: Nish Aravamudan
Date: Tue May 22 2007 - 11:01:39 EST


On 5/22/07, Michael Halcrow <mhalcrow@xxxxxxxxxx> wrote:
On Mon, May 21, 2007 at 09:07:08PM -0700, Andrew Morton wrote:
> On Mon, 21 May 2007 18:00:21 -0500 Michael Halcrow <mhalcrow@xxxxxxxxxx> wrote:
>
> > Delay writing 0's out in eCryptfs after a seek past the end of the
> > file until data is actually written.
>
> a) why?

http://www.opengroup.org/onlinepubs/009695399/functions/lseek.html

``The lseek() function shall not, by itself, extend the size of a
file.''

> b) what is the impact upon a user of them not having this patch?

Applications that lseek() past the end of the file without writing
will experience unexpected behavior.

FWIW, I believe Andrew's point was that critical information for Joe
Enduser (and Joe Patch-Ho) was lacking in the original changelog.

Thanks,
Nish
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