linux-kernel - Re: [PATCH v2] libata: Simulate REPORT LUNS for ATAPI devices

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] [day] [month] [year] [list]

Message-ID: <45805D54.3070809@us.ibm.com>
Date:	Wed, 13 Dec 2006 12:06:44 -0800
From:	"Darrick J. Wong" <djwong@...ibm.com>
To:	Patrick Mansfield <patmans@...ibm.com>
CC:	Jeff Garzik <jeff@...zik.org>,
	linux-scsi <linux-scsi@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-ide@...r.kernel.org" <linux-ide@...r.kernel.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: Re: [PATCH v2] libata: Simulate REPORT LUNS for ATAPI devices

Patrick Mansfield wrote:
> On Mon, Dec 04, 2006 at 03:32:20PM -0800, Darrick J. Wong wrote:
>> The Quantum GoVault SATAPI removable disk device returns ATA_ERR in
>> response to a REPORT LUNS packet.  If this happens to an ATAPI device
>> that is attached to a SAS controller (this is the case with sas_ata),
>> the device does not load because SCSI won't touch a "SCSI device"
>> that won't report its LUNs.  Since most ATAPI devices don't support
>> multiple LUNs anyway, we might as well fake a response like we do for
>> ATA devices.
> 
> If the REPORT LUNS fails, we should fall back to a sequential scan.
> 
> Is (or why isn't) the error propagated back to scsi?

I believe the error is reported back to SCSI, which attempts to follow
up with TEST UNIT READY.  Unfortunately, for some reason the device then
gets dropped.  libata normally calls __scsi_add_device with lun=0, but
SAS calls scsi_scan_target with lun=SCAN_WILD_CARD, which is why SCSI
sends REPORT LUNs in the first place.

As an alternative I suppose we could detect ATA devices in sas_rphy_add
and change that SCAN_WILD_CARD to "0".

--D
-
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/