linux-kernel - Re: [PATCH 1/2] Add partition resize function to BLKPG ioctl

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: <4EE0E085.8000907@cfl.rr.com>
Date:	Thu, 08 Dec 2011 11:06:29 -0500
From:	Phillip Susi <psusi@....rr.com>
To:	Vivek Goyal <vgoyal@...hat.com>
CC:	Karel Zak <kzak@...hat.com>, linux-kernel@...r.kernel.org,
	Jens Axboe <jaxboe@...ionio.com>
Subject: Re: [PATCH 1/2] Add partition resize function to BLKPG ioctl

On 12/8/2011 10:58 AM, Vivek Goyal wrote:
> So, if there is an IO in flight while partition shrinking is happening,
> then IO can end up happening outside the partition?

Yes.  Of course if there was an in flight IO at the time you truncate 
the partition, then you did something wrong ( didn't shrink the fs first ).

> part->nr_sects can be 64 bits on 32bit machines and update will be
> non-atomic. I had used sequence counter to make sure read is able
> to get to intermediate value. May be it is a good idea to address
> this concenrn.

Isn't that what the mutex is for?

--
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/