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]
Date:	Mon, 15 Mar 2010 07:47:59 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Denys Vlasenko <vda.linux@...glemail.com>
CC:	david@...g.hm, Arnd Bergmann <arnd@...db.de>,
	Tejun Heo <tj@...nel.org>,
	"linux-ide@...r.kernel.org" <linux-ide@...r.kernel.org>,
	lkml <linux-kernel@...r.kernel.org>,
	Daniel Taylor <Daniel.Taylor@....com>,
	Jeff Garzik <jeff@...zik.org>, Mark Lord <kernel@...savvy.com>,
	tytso@....edu, hirofumi@...l.parknet.co.jp,
	Andrew Morton <akpm@...ux-foundation.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>, irtiger@...il.com,
	Matthew Wilcox <matthew@....cx>, aschnell@...e.de,
	knikanth@...e.de, jdelvare@...e.de
Subject: Re: ATA 4 KiB sector issues.

On 03/15/2010 02:56 AM, Denys Vlasenko wrote:
> I think Linux already is doing this. The problem is, in many cases
> OS can't possibly do this, short of using a specially designed
> filesystem.
> 
> If you untar a Linux kernel source tarball on a seriously
> fragmented ext2 filesystem, there will be a lot of discontiguous
> and/or misaligned writes smaller than 256K.
> Only smart firmware can help in this case.

Yes, but guess what... there is a lot of stupid firmware out there, and
there are lots of RAID arrays, and so on.

"Seriously fragmented" means you have already lost in the first place.

This doesn't change the fact that this is a real issue and that that is
the major reason why aligning to 63*4K is a bad idea.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists