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From: Pavel Machek <pavel@ucw.cz>
To: Mike Waychison <mikew@google.com>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [patch 1/1] Drop CAP_SYS_RAWIO requirement for FIBMAP
Date: Mon, 29 Oct 2007 19:08:13 +0000	[thread overview]
Message-ID: <20071029190813.GB7742@ucw.cz> (raw)
In-Reply-To: <20071025230758.945535769@crlf.corp.google.com>

Hi!

> Remove the need for having CAP_SYS_RAWIO when doing a FIBMAP call on an open file descriptor.
> 
> It would be nice to allow users to have permission to see where their data is landing on disk, and there really isn't a good reason to keep them from getting at this information.

I believe it is to prevent users from intentionally creating extremely
fragmented files...

You can read 60MB in a second, but fragmented 60MB file could take
10msec * 60MB/4KB = 150 seconds. That's factor 150 slowdown...

...but I agree that SYS_RAWIO may be wrong capability to cover this.

							Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  parent reply	other threads:[~2007-11-01 14:32 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-25 23:06 [patch 1/1] Drop CAP_SYS_RAWIO requirement for FIBMAP Mike Waychison
2007-10-26  0:22 ` Alan Cox
2007-10-26  0:35   ` Mike Waychison
2007-10-26  0:43     ` Alan Cox
2007-10-26 21:55   ` Jason Uhlenkott
2007-10-26 21:59     ` Mike Waychison
2007-10-26 22:40       ` Jason Uhlenkott
2007-10-26 22:53         ` Mike Waychison
2007-10-29 19:08 ` Pavel Machek [this message]
2007-11-01 14:51   ` Ric Wheeler

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