linux-kernel - Re: block: correctly fallback for zeroout

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, 6 Jun 2016 23:38:42 -0700
From:	Christoph Hellwig <hch@...radead.org>
To:	"Martin K. Petersen" <martin.petersen@...cle.com>
Cc:	Mike Snitzer <snitzer@...hat.com>,
	Christoph Hellwig <hch@...radead.org>,
	Shaohua Li <shli@...com>, linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org, sitsofe@...oo.com, axboe@...com,
	Kernel-team@...com
Subject: Re: block: correctly fallback for zeroout

On Mon, Jun 06, 2016 at 10:32:38PM -0400, Martin K. Petersen wrote:
> >>>>> "Mike" == Mike Snitzer <snitzer@...hat.com> writes:
> 
> Mike> But hch was originally in favor of _always_ dropping EOPNOTSUPP on
> Mike> the floor (that is what his commit 38f25255330 did).  Then he said
> Mike> he disagrees with these interfaces playing games with masking
> Mike> EOPNOTSUPP -- to which you seemingly really don't agree.  Unless
> Mike> I'm completely misreading you.
> 
> Userland apps rely on EOPNOTSUPP, we can't break that.

Rely on what exactly?  Current we return EOPNOTSUPP if the device
doesn't claim to support discards, but it returns 0 if the device first
claims to support it but then fails the I/O.