From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> 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 <nab@xxxxxxxxxxxxxxx> 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(-) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
