linux-kernel - Re: [PATCH 9/9] tcm_qla2xxx: Add special case for COMPARE_AND_WRITE data

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: <1377070267.32763.26.camel@haakon3.risingtidesystems.com>
Date:	Wed, 21 Aug 2013 00:31:07 -0700
From:	"Nicholas A. Bellinger" <nab@...ux-iscsi.org>
To:	Christoph Hellwig <hch@...radead.org>
Cc:	"Nicholas A. Bellinger" <nab@...erainc.com>,
	target-devel <target-devel@...r.kernel.org>,
	lkml <linux-kernel@...r.kernel.org>,
	linux-scsi <linux-scsi@...r.kernel.org>,
	Christoph Hellwig <hch@....de>, Hannes Reinecke <hare@...e.de>,
	Martin Petersen <martin.petersen@...cle.com>,
	Chris Mason <chris.mason@...ionio.com>,
	James Bottomley <JBottomley@...allels.com>,
	Giridhar Malavali <giridhar.malavali@...gic.com>,
	Chad Dupuis <chad.dupuis@...gic.com>
Subject: Re: [PATCH 9/9] tcm_qla2xxx: Add special case for COMPARE_AND_WRITE
 data_direction

On Tue, 2013-08-20 at 23:37 -0700, Christoph Hellwig wrote:
> On Tue, Aug 20, 2013 at 08:08:00PM +0000, Nicholas A. Bellinger wrote:
> > From: Nicholas Bellinger <nab@...erainc.com>
> > 
> > Add a special case for COMPARE_AND_WRITE for the reverse data direction
> > mapping used for pci_map_sg() + friends.
> 
> A low level driver is an even worse place to hardcode a specific cdb
> opcode.  As written before this should be done by a flag on the command.
> 

Which means adding another COMPARE_AND_WRITE specific flag to
se_cmd_flags_Table, as the SCF_COMPARE_AND_WRITE_POST is ony set after
the comparsion of the verify instance data is complete..

Is it really worth having two se_cmd_flags for COMPARE_AND_WRITE..?

> Also it might make sense to lift this helper to get a dma direction from
> a command into common code.
> 

Mmm, perhaps.  I don't recall of the top of my head why tcm_qla2xxx
actually needed to reverse it's dma direction (I'm sure that Roland
knows, CC'ed), but IIRC it was a tcm_qla2xxx specific thing..?

--nab

--
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/