From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: [PATCH 0/2] [tgt]: Add proper SG_IO struct cmd CDB passthrough Date: Mon, 17 May 2010 22:12:54 -0700 Message-ID: <1274159574-6053-1-git-send-email-nab@linux-iscsi.org> Return-path: Received: from smtp107.sbc.mail.gq1.yahoo.com ([67.195.14.110]:25495 "HELO smtp107.sbc.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753786Ab0ERC1m (ORCPT ); Mon, 17 May 2010 22:27:42 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: stgt-devel , linux-scsi , FUJITA Tomonori , Mike Christie Cc: James Bottomley , Douglas Gilbert , Nicholas Bellinger From: Nicholas Bellinger Greetings Tomo and Mike, These are two patches to allow the STGT SG_IO backstore to function using a new struct scsi_cmd->sg_iovec member with sg_io_hdr->iovec_count=1, and to update usr/scsi.c:scsi_cmd_perform() to allow for a hand off incoming descriptors into the struct device_type_template->cmd_passthrough() function pointer. I initially updated usr/sbc.c to set sbc_rw() as it's CDB passthrough function for TYPE_DISK, but the logic should apply to any device types *_rw() functions. Please let me know if this makes sense, and I will look at updating the other stgt device types. So far with this patch, I am able to successfully mkfs new iSCSI TYPE_DISK LUNS with Open-iSCSI to the userspace STGT iSCSI fabric module + SG_IO into kernel level TCM_Loop virtual iSCSI target ports on a x86 HVM, and bulk 512KB DATA_SG_IO payloads between STGT and TCM_Loop are now functioning as expected. There is one unresolved issue that I ran into while running initially with TCM_Loop and struct scsi_device->max_sectors=256. SG_IO writes larger than the struct scsi_device->max_sectors are being returned with -EINVAL, but it appears that the CHECK_CONDITION is not actually being propigated back into STGT/iSCSI. After increasing the TCM_Loop ports to struct scsi_device->max_sectors=1024 following the Open-iSCSI Initiator default, the 512KB paylods begin work as expected. I will need to have a look at the case for CDB length > max_sectors, which means that bs_sg.c getting the correct scsi_status and sense data out of the kernel might still need more work. In the mean time, please have a look at applying these patches. Best, Signed-off-by: Nicholas A. Bellinger Nicholas Bellinger (2): [tgt]: Add proper CDB passthrough for SG_IO backstores [tgt]: Add support for SG_IO CDB passthrough in scsi_cmd_perform() usr/bs_sg.c | 31 ++++++++++++++++++++++++------- usr/sbc.c | 1 + usr/scsi.c | 11 +++++++++++ usr/scsi_cmnd.h | 4 ++++ usr/tgtd.h | 2 ++ 5 files changed, 42 insertions(+), 7 deletions(-)