#
229997 |
|
11-Jan-2012 |
ken |
Add the CAM Target Layer (CTL).
CTL is a disk and processor device emulation subsystem originally written for Copan Systems under Linux starting in 2003. It has been shipping in Copan (now SGI) products since 2005.
It was ported to FreeBSD in 2008, and thanks to an agreement between SGI (who acquired Copan's assets in 2010) and Spectra Logic in 2010, CTL is available under a BSD-style license. The intent behind the agreement was that Spectra would work to get CTL into the FreeBSD tree.
Some CTL features:
- Disk and processor device emulation. - Tagged queueing - SCSI task attribute support (ordered, head of queue, simple tags) - SCSI implicit command ordering support. (e.g. if a read follows a mode select, the read will be blocked until the mode select completes.) - Full task management support (abort, LUN reset, target reset, etc.) - Support for multiple ports - Support for multiple simultaneous initiators - Support for multiple simultaneous backing stores - Persistent reservation support - Mode sense/select support - Error injection support - High Availability support (1) - All I/O handled in-kernel, no userland context switch overhead.
(1) HA Support is just an API stub, and needs much more to be fully functional.
ctl.c: The core of CTL. Command handlers and processing, character driver, and HA support are here.
ctl.h: Basic function declarations and data structures.
ctl_backend.c, ctl_backend.h: The basic CTL backend API.
ctl_backend_block.c, ctl_backend_block.h: The block and file backend. This allows for using a disk or a file as the backing store for a LUN. Multiple threads are started to do I/O to the backing device, primarily because the VFS API requires that to get any concurrency.
ctl_backend_ramdisk.c: A "fake" ramdisk backend. It only allocates a small amount of memory to act as a source and sink for reads and writes from an initiator. Therefore it cannot be used for any real data, but it can be used to test for throughput. It can also be used to test initiators' support for extremely large LUNs.
ctl_cmd_table.c: This is a table with all 256 possible SCSI opcodes, and command handler functions defined for supported opcodes.
ctl_debug.h: Debugging support.
ctl_error.c, ctl_error.h: CTL-specific wrappers around the CAM sense building functions.
ctl_frontend.c, ctl_frontend.h: These files define the basic CTL frontend port API.
ctl_frontend_cam_sim.c: This is a CTL frontend port that is also a CAM SIM. This frontend allows for using CTL without any target-capable hardware. So any LUNs you create in CTL are visible in CAM via this port.
ctl_frontend_internal.c, ctl_frontend_internal.h: This is a frontend port written for Copan to do some system-specific tasks that required sending commands into CTL from inside the kernel. This isn't entirely relevant to FreeBSD in general, but can perhaps be repurposed.
ctl_ha.h: This is a stubbed-out High Availability API. Much more is needed for full HA support. See the comments in the header and the description of what is needed in the README.ctl.txt file for more details.
ctl_io.h: This defines most of the core CTL I/O structures. union ctl_io is conceptually very similar to CAM's union ccb.
ctl_ioctl.h: This defines all ioctls available through the CTL character device, and the data structures needed for those ioctls.
ctl_mem_pool.c, ctl_mem_pool.h: Generic memory pool implementation used by the internal frontend.
ctl_private.h: Private data structres (e.g. CTL softc) and function prototypes. This also includes the SCSI vendor and product names used by CTL.
ctl_scsi_all.c, ctl_scsi_all.h: CTL wrappers around CAM sense printing functions.
ctl_ser_table.c: Command serialization table. This defines what happens when one type of command is followed by another type of command.
ctl_util.c, ctl_util.h: CTL utility functions, primarily designed to be used from userland. See ctladm for the primary consumer of these functions. These include CDB building functions.
scsi_ctl.c: CAM target peripheral driver and CTL frontend port. This is the path into CTL for commands from target-capable hardware/SIMs.
README.ctl.txt: CTL code features, roadmap, to-do list.
usr.sbin/Makefile: Add ctladm.
ctladm/Makefile, ctladm/ctladm.8, ctladm/ctladm.c, ctladm/ctladm.h, ctladm/util.c: ctladm(8) is the CTL management utility. It fills a role similar to camcontrol(8). It allow configuring LUNs, issuing commands, injecting errors and various other control functions.
usr.bin/Makefile: Add ctlstat.
ctlstat/Makefile ctlstat/ctlstat.8, ctlstat/ctlstat.c: ctlstat(8) fills a role similar to iostat(8). It reports I/O statistics for CTL.
sys/conf/files: Add CTL files.
sys/conf/NOTES: Add device ctl.
sys/cam/scsi_all.h: To conform to more recent specs, the inquiry CDB length field is now 2 bytes long.
Add several mode page definitions for CTL.
sys/cam/scsi_all.c: Handle the new 2 byte inquiry length.
sys/dev/ciss/ciss.c, sys/dev/ata/atapi-cam.c, sys/cam/scsi/scsi_targ_bh.c, scsi_target/scsi_cmds.c, mlxcontrol/interface.c: Update for 2 byte inquiry length field.
scsi_da.h: Add versions of the format and rigid disk pages that are in a more reasonable format for CTL.
amd64/conf/GENERIC, i386/conf/GENERIC, ia64/conf/GENERIC, sparc64/conf/GENERIC: Add device ctl.
i386/conf/PAE: The CTL frontend SIM at least does not compile cleanly on PAE.
Sponsored by: Copan Systems, SGI and Spectra Logic MFC after: 1 month
|
#
225950 |
|
03-Oct-2011 |
ken |
Add descriptor sense support to CAM, and honor sense residuals properly in CAM.
Desriptor sense is a new sense data format that originated in SPC-3. Among other things, it allows for an 8-byte info field, which is necessary to pass back block numbers larger than 4 bytes.
This change adds a number of new functions to scsi_all.c (and therefore libcam) that abstract out most access to sense data.
This includes a bump of CAM_VERSION, because the CCB ABI has changed. Userland programs that use the CAM pass(4) driver will need to be recompiled.
camcontrol.c: Change uses of scsi_extract_sense() to use scsi_extract_sense_len().
Use scsi_get_sks() instead of accessing sense key specific data directly.
scsi_modes: Update the control mode page to the latest version (SPC-4).
scsi_cmds.c, scsi_target.c: Change references to struct scsi_sense_data to struct scsi_sense_data_fixed. This should be changed to allow the user to specify fixed or descriptor sense, and then use scsi_set_sense_data() to build the sense data.
ps3cdrom.c: Use scsi_set_sense_data() instead of setting sense data manually.
cam_periph.c: Use scsi_extract_sense_len() instead of using scsi_extract_sense() or accessing sense data directly.
cam_ccb.h: Bump the CAM_VERSION from 0x15 to 0x16. The change of struct scsi_sense_data from 32 to 252 bytes changes the size of struct ccb_scsiio, but not the size of union ccb. So the version must be bumped to prevent structure mis-matches.
scsi_all.h: Lots of updated SCSI sense data and other structures.
Add function prototypes for the new sense data functions.
Take out the inline implementation of scsi_extract_sense(). It is now too large to put in a header file.
Add macros to calculate whether fields are present and filled in fixed and descriptor sense data
scsi_all.c: In scsi_op_desc(), allow the user to pass in NULL inquiry data, and we'll assume a direct access device in that case.
Changed the SCSI RESERVED sense key name and description to COMPLETED, as it is now defined in the spec.
Change the error recovery action for a number of read errors to prevent lots of retries when the drive has said that the block isn't accessible. This speeds up reconstruction of the block by any RAID software running on top of the drive (e.g. ZFS).
In scsi_sense_desc(), allow for invalid sense key numbers. This allows calling this routine without checking the input values first.
Change scsi_error_action() to use scsi_extract_sense_len(), and handle things when invalid asc/ascq values are encountered.
Add a new routine, scsi_desc_iterate(), that will call the supplied function for every descriptor in descriptor format sense data.
Add scsi_set_sense_data(), and scsi_set_sense_data_va(), which build descriptor and fixed format sense data. They currently default to fixed format sense data.
Add a number of scsi_get_*() functions, which get different types of sense data fields from either fixed or descriptor format sense data, if the data is present.
Add a number of scsi_*_sbuf() functions, which print formatted versions of various sense data fields. These functions work for either fixed or descriptor sense.
Add a number of scsi_sense_*_sbuf() functions, which have a standard calling interface and print the indicated field. These functions take descriptors only.
Add scsi_sense_desc_sbuf(), which will print a formatted version of the given sense descriptor.
Pull out a majority of the scsi_sense_sbuf() function and put it into scsi_sense_only_sbuf(). This allows callers that don't use struct ccb_scsiio to easily utilize the printing routines. Revamp that function to handle descriptor sense and use the new sense fetching and printing routines.
Move scsi_extract_sense() into scsi_all.c, and implement it in terms of the new function, scsi_extract_sense_len(). The _len() version takes a length (which should be the sense length - residual) and can indicate which fields are present and valid in the sense data.
Add a couple of new scsi_get_*() routines to get the sense key, asc, and ascq only.
mly.c: Rename struct scsi_sense_data to struct scsi_sense_data_fixed.
sbp_targ.c: Use the new sense fetching routines to get sense data instead of accessing it directly.
sbp.c: Change the firewire/SCSI sense data transformation code to use struct scsi_sense_data_fixed instead of struct scsi_sense_data. This should be changed later to use scsi_set_sense_data().
ciss.c: Calculate the sense residual properly. Use scsi_get_sense_key() to fetch the sense key.
mps_sas.c, mpt_cam.c: Set the sense residual properly.
iir.c: Use scsi_set_sense_data() instead of building sense data by hand.
iscsi_subr.c: Use scsi_extract_sense_len() instead of grabbing sense data directly.
umass.c: Use scsi_set_sense_data() to build sense data.
Grab the sense key using scsi_get_sense_key().
Calculate the sense residual properly.
isp_freebsd.h: Use scsi_get_*() routines to grab asc, ascq, and sense key values.
Calculate and set the sense residual.
MFC after: 3 days Sponsored by: Spectra Logic Corporation
|
#
107178 |
|
22-Nov-2002 |
njl |
New SCSI target emulator code
This code allows a user program to enable target mode on a SIM and then emulate any number of devices (disks, tape drives, etc.) All decisions about device behavior (UA, CA, inquiry response) are left to the usermode program and the kernel driver is merely a conduit for CCBs. This enables multiple concurrent target emulators, each using its own backing store and IO model.
Also included is a user program that emulates a disk (RBC) using a file as a backing store. This provides functionality similar to md(4) at the CAM layer.
Code has been tested on ahc(4) and should also work on isp(4) (and other SIMs that gain target mode support). It is a complete rewrite of /sys/cam/scsi_target* and /usr/share/examples/scsi_target.
Design, comments from: gibbs Supported by: Cryptography Research Approved by: re
|