Re: [PATCH][RFC 1/12/1/5] SCST core's Makefile and Kconfig

[Vladislav Bolkhovitin <vst@vlnb.net>]

This patch contains SCST core's Makefile and Kconfig.

Signed-off-by: Vladislav Bolkhovitin <vst@vlnb.net>
---
 Kconfig  |  246 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Makefile |   11 ++
 2 files changed, 257 insertions(+)

diff -uprN orig/linux-2.6.33/drivers/scst/Kconfig linux-2.6.33/drivers/scst/Kconfig
--- orig/linux-2.6.33/drivers/scst/Kconfig
+++ linux-2.6.33/drivers/scst/Kconfig
@@ -0,0 +1,246 @@
+menu "SCSI target (SCST) support"
+
+config SCST
+	tristate "SCSI target (SCST) support"
+	depends on SCSI
+	help
+	  SCSI target (SCST) is designed to provide unified, consistent
+	  interface between SCSI target drivers and Linux kernel and
+	  simplify target drivers development as much as possible. Visit
+	  http://scst.sourceforge.net for more info about it.
+
+config SCST_DISK
+	tristate "SCSI target disk support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for disk device.
+
+config SCST_TAPE
+	tristate "SCSI target tape support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for tape device.
+
+config SCST_CDROM
+	tristate "SCSI target CDROM support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for CDROM device.
+
+config SCST_MODISK
+	tristate "SCSI target MO disk support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for MO disk device.
+
+config SCST_CHANGER
+	tristate "SCSI target changer support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for changer device.
+
+config SCST_PROCESSOR
+	tristate "SCSI target processor support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for processor device.
+
+config SCST_RAID
+	tristate "SCSI target storage array controller (RAID) support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST pass-through device handler for raid storage array controller (RAID) device.
+
+config SCST_VDISK
+	tristate "SCSI target virtual disk and/or CDROM support"
+	default SCST
+	depends on SCSI && SCST
+	help
+	  SCST device handler for virtual disk and/or CDROM device.
+
+config SCST_STRICT_SERIALIZING
+	bool "Strict serialization"
+	depends on SCST
+	help
+	  Enable strict SCSI command serialization. When enabled, SCST sends
+	  all SCSI commands to the underlying SCSI device synchronously, one
+	  after one. This makes task management more reliable, at the cost of
+	  a performance penalty. This is most useful for stateful SCSI devices
+	  like tapes, where the result of the execution of a command
+	  depends on the device settings configured by previous commands. Disk
+	  and RAID devices are stateless in most cases. The current SCSI core
+	  in Linux doesn't allow to abort all commands reliably if they have
+	  been sent asynchronously to a stateful device.
+	  Enable this option if you use stateful device(s) and need as much
+	  error recovery reliability as possible.
+
+	  If unsure, say "N".
+
+config SCST_STRICT_SECURITY
+	bool "Strict security"
+	depends on SCST
+	help
+	  Makes SCST clear (zero-fill) allocated data buffers. Note: this has a
+	  significant performance penalty.
+
+	  If unsure, say "N".
+
+config SCST_ALLOW_PASSTHROUGH_IO_SUBMIT_IN_SIRQ
+	bool "Allow pass-through commands to be sent from soft-IRQ context"
+	depends on SCST
+	help
+	  Allows SCST to submit SCSI pass-through commands to real SCSI devices
+	  via the SCSI middle layer using scsi_execute_async() function from
+	  soft-IRQ context (tasklets). This used to be the default, but
+	  currently it seems the SCSI middle layer starts expecting only thread
+	  context on the IO submit path, so it is disabled now by default.
+	  Enabling it will decrease amount of context switches and improve
+	  performance. It is more or less safe. In the worst case, if in your
+	  configuration the SCSI middle layer really doesn't expect SIRQ
+	  context in scsi_execute_async() function, you will get a warning
+	  message in the kernel log.
+
+	  If unsure, say "N".
+
+config SCST_ABORT_CONSIDER_FINISHED_TASKS_AS_NOT_EXISTING
+	bool "Send back UNKNOWN TASK when an already finished task is aborted"
+	depends on SCST
+	help
+	  Controls which response is sent by SCST to the initiator in case
+	  the initiator attempts to abort (ABORT TASK) an already finished
+	  request. If this option is enabled, the response UNKNOWN TASK is
+	  sent back to the initiator. However, some initiators, particularly
+	  the VMware iSCSI initiator, interpret the UNKNOWN TASK response as
+	  if the target got crazy and try to RESET it. Then sometimes the
+	  initiator gets crazy itself.
+
+	  If unsure, say "N".
+
+config SCST_USE_EXPECTED_VALUES
+	bool "Prefer initiator-supplied SCSI command attributes"
+	depends on SCST
+	help
+	  When SCST receives a SCSI command from an initiator, such a SCSI
+	  command has both data transfer length and direction attributes.
+	  There are two possible sources for these attributes: either the
+	  values computed by SCST from its internal command translation table
+	  or the values supplied by the initiator. The former are used by
+	  default because of security reasons. Invalid initiator-supplied
+	  attributes can crash the target, especially in pass-through mode.
+	  Only consider enabling this option when SCST logs the following
+	  message: "Unknown opcode XX for YY. Should you update
+	  scst_scsi_op_table?" and when the initiator complains. Please
+	  report any unrecognized commands to scst-devel@lists.sourceforge.net.
+
+	  If unsure, say "N".
+
+config SCST_EXTRACHECKS
+	bool "Extra consistency checks"
+	depends on SCST
+	help
+	  Enable additional consistency checks in the SCSI middle level target
+	  code. This may be helpful for SCST developers. Enable it if you have
+	  any problems.
+
+	  If unsure, say "N".
+
+config SCST_TRACING
+	bool "Tracing support"
+	depends on SCST
+	default y
+	help
+	  Enable SCSI middle level tracing support. Tracing can be controlled
+	  dynamically via sysfs interface. The traced information
+	  is sent to the kernel log and may be very helpful when analyzing
+	  the cause of a communication problem between initiator and target.
+
+	  If unsure, say "Y".
+
+config SCST_DEBUG
+	bool "Debugging support"
+	depends on SCST
+	select DEBUG_BUGVERBOSE
+	help
+	  Enables support for debugging SCST. This may be helpful for SCST
+	  developers.
+
+	  If unsure, say "N".
+
+config SCST_DEBUG_OOM
+	bool "Out-of-memory debugging support"
+	depends on SCST
+	help
+	  Let SCST's internal memory allocation function
+	  (scst_alloc_sg_entries()) fail about once in every 10000 calls, at
+	  least if the flag __GFP_NOFAIL has not been set. This allows SCST
+	  developers to test the behavior of SCST in out-of-memory conditions.
+	  This may be helpful for SCST developers.
+
+	  If unsure, say "N".
+
+config SCST_DEBUG_RETRY
+	bool "SCSI command retry debugging support"
+	depends on SCST
+	help
+	  Let SCST's internal SCSI command transfer function
+	  (scst_rdy_to_xfer()) fail about once in every 100 calls. This allows
+	  SCST developers to test the behavior of SCST when SCSI queues fill
+	  up. This may be helpful for SCST developers.
+
+	  If unsure, say "N".
+
+config SCST_DEBUG_SN
+	bool "SCSI sequence number debugging support"
+	depends on SCST
+	help
+	  Allows to test SCSI command ordering via sequence numbers by
+	  randomly changing the type of SCSI commands into
+	  SCST_CMD_QUEUE_ORDERED, SCST_CMD_QUEUE_HEAD_OF_QUEUE or
+	  SCST_CMD_QUEUE_SIMPLE for about one in 300 SCSI commands.
+	  This may be helpful for SCST developers.
+
+	  If unsure, say "N".
+
+config SCST_DEBUG_TM
+	bool "Task management debugging support"
+	depends on SCST_DEBUG
+	help
+	  Enables support for debugging of SCST's task management functions.
+	  When enabled, some of the commands on LUN 0 in the default access
+	  control group will be delayed for about 60 seconds. This will
+	  cause the remote initiator send SCSI task management functions,
+	  e.g. ABORT TASK and TARGET RESET.
+
+	  If unsure, say "N".
+
+config SCST_TM_DBG_GO_OFFLINE
+	bool "Let devices become completely unresponsive"
+	depends on SCST_DEBUG_TM
+	help
+	  Enable this option if you want that the device eventually becomes
+	  completely unresponsive. When disabled, the device will receive
+	  ABORT and RESET commands.
+
+config SCST_MEASURE_LATENCY
+	bool "Commands processing latency measurement facility"
+	depends on SCST
+	help
+	  This option enables commands processing latency measurement
+	  facility in SCST. It will provide in the sysfs interface
+	  average commands processing latency statistics. You can clear
+	  already measured results by writing 0 in the corresponding sysfs file.
+	  Note, you need a non-preemtible kernel to have correct results.
+
+	  If unsure, say "N".
+
+source "drivers/scst/iscsi-scst/Kconfig"
+source "drivers/scst/srpt/Kconfig"
+
+endmenu
diff -uprN orig/linux-2.6.33/drivers/scst/Makefile linux-2.6.33/drivers/scst/Makefile
--- orig/linux-2.6.33/drivers/scst/Makefile
+++ linux-2.6.33/drivers/scst/Makefile
@@ -0,0 +1,11 @@
+ccflags-y += -Iinclude/scst -Wno-unused-parameter
+
+scst-y        += scst_main.o
+scst-y        += scst_targ.o
+scst-y        += scst_lib.o
+scst-y        += scst_sysfs.o
+scst-y        += scst_mem.o
+scst-y        += scst_debug.o
+
+obj-$(CONFIG_SCST)   += scst.o dev_handlers/ iscsi-scst/ srpt/
+