linux-kernel - Re: Tux3 Report: How fast can we fail?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5565CF03.9010202@gmail.com>
Date:	Wed, 27 May 2015 10:04:51 -0400
From:	Austin S Hemmelgarn <ahferroin7@...il.com>
To:	Mosis Tembo <mosis.tembo@...il.com>, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: Tux3 Report: How fast can we fail?

On 2015-05-27 03:37, Mosis Tembo wrote:
>
> On 05/26/2015 12:03 PM, Pavel Machek wrote:
>>> We identified the following quality metrics for this algorithm:
>>>
>>>   1) Never fails to detect out of space in the front end.
>>>   2) Always fills a volume to 100% before reporting out of space.
>>>   3) Allows rm, rmdir and truncate even when a volume is full.
>
> This is definitely nonsense. You can not rm, rmdir and truncate
> when the volume is full. You will need a free space on disk to perform
> such operations. Do you know why?
>
I assume you are referring either to Tux3 specifically or COW 
filesystems in general, because you very much _can_ do any of those on 
any of the non-COW filesystems in the Linux kernel (I know from 
experience).  Also, IIRC, it was mentioned somewhere that Tux3 keeps a 
small reserve of space on the volume for internal operations; and, I 
would assume that if that is the case, it reports the volume full when 
everything *except* that reserve of space is used, in which case rm, 
rmdir, and truncate should work fine when the volume is full.



Download attachment "smime.p7s" of type "application/pkcs7-signature" (2967 bytes)