On Wed, 2010-10-06 at 11:36 +0900, FUJITA Tomonori wrote: > On Wed, 22 Sep 2010 15:49:23 -0700 > "Nicholas A. Bellinger" <nab@xxxxxxxxxxxxxxx> wrote: > > > From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> > > > > The patch adds core generic target engine functionality including processing of struct se_cmd > > generation of N struct se_task, control CDB emulation, sense data, memory allocation, and > > and mapping from fabric module allocated memory using linked list struct scatterlist > > style memory based on the limitiations of the underlying TCM HBA and Device backstores. > > > > The TCM layer sits is above Linux/SCSI, Linux/BLOCK and Linux/VFS subsystems, and > > communicates with these subsystems (and local RAMDISK plugins) using an API of function > > pointers in se_subsystem_api_t. It provides processing capabilties and emulation for SCSI > > logic and CDBs in a generic manner to storage object LUNs provided from Linux storage > > subsystems backend storage devices. > > > > Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx> > > --- > > drivers/target/target_core_scdb.c | 158 + > > drivers/target/target_core_scdb.h | 15 + > > drivers/target/target_core_transport.c | 8860 ++++++++++++++++++++++++++++++++ > > include/target/target_core_transport.h | 570 ++ > > 4 files changed, 9603 insertions(+), 0 deletions(-) > > create mode 100644 drivers/target/target_core_scdb.c > > create mode 100644 drivers/target/target_core_scdb.h > > create mode 100644 drivers/target/target_core_transport.c > > create mode 100644 include/target/target_core_transport.h > > Can a driver cleanly overwrite cmd->transport_emulate_cdb? ibmvscsi > target driver needs to the specific responses for INQUIRY and > REPORT_LUNS. > Hmmmmmm.. Currently the optional cmd->transport_emulate_cdb() assignment is done from TCM internal code for things like PR and ALUA CDB emulation, but I cannot see a reason why something similar could not be exported out into TCM fabric module code with a bit of work. > I guess that the driver can ignore the response buffer from tcm and > create the own but it would be nice if the driver can do cleanly. > -- <nod>, makes perfect sense to me.. Also just FYI, hch has been prodding me to unify the current per subsystem backstore logic for [iblock,fd,rd,stgt]_emulate_scsi_cdb() and make any specific CDB emulation that requires non generic code use a CDB specific struct se_subsystem_api function pointer. I will be looking at doing this in the next days, and I will see what what can be done for an patch w/ example case for TCM_Loop to allow CDB context emulation to be done via the TCM fabric module struct target_core_fabric_ops API. Thanks Tomo-san! --nab -- 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
