linux-kernel - Re: [PATCH v2 3/3] [SCSI] Make LBP quirk skip lbpme checks tests

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 for Android: free password hash cracker in your pocket

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

Message-ID: <yq1iommkgkv.fsf@sermon.lab.mkp.net>
Date:	Thu, 24 Jul 2014 09:54:24 -0400
From:	"Martin K. Petersen" <martin.petersen@...cle.com>
To:	Sitsofe Wheeler <sitsofe@...il.com>
Cc:	Christoph Hellwig <hch@...radead.org>,
	"K. Y. Srinivasan" <kys@...rosoft.com>, gregkh@...uxfoundation.org,
	linux-kernel@...r.kernel.org, devel@...uxdriverproject.org,
	ohering@...e.com, apw@...onical.com, jasowang@...hat.com,
	jbottomley@...allels.com, linux-scsi@...r.kernel.org
Subject: Re: [PATCH v2 3/3] [SCSI] Make LBP quirk skip lbpme checks tests

>>>>> "Sitsofe" == Sitsofe Wheeler <sitsofe@...il.com> writes:

Sitsofe> Fix incorrectly named variable.  Some block devices (such as
Sitsofe> Hyper-V passthrough SSDs) support logical block provisioning
Sitsofe> (e.g. via UNMAP) but don't set lbpme thus disabling discard. 

The fix for an SSD that is known to support LBP but which does not claim
support for it is to use:

    echo unmap > /sys/class/scsi_disk/foo/provisioning_mode

I'm very much against short-circuiting the LBP logic in a passthrough
driver because then we might end up in the exact situation we were
trying to avoid with this patch series. Namely sending down commands
unsupported by the target device.

This kind of thing really needs to be a sysadmin decision and can be
handled with a udev rule.

-- 
Martin K. Petersen	Oracle Linux Engineering
--
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/