b39ec0de86
3 Commits
Author | SHA1 | Message | Date | |
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Kenneth D. Merry
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beedaee94a |
Add a loader tunable, kern.cam.ctl.disable, that will disable
loading CTL. This may be useful in very low memory installations. MFC after: 3 days |
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Kenneth D. Merry
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bf8f8f340e |
Change the SCSI INQUIRY peripheral qualifier that CTL reports for LUNs
that don't exist. Anecdotal evidence indicates that it is better to return 011b (bad LUN) than 001b (LUN offline). However, this change also gives the user a sysctl/tunable, kern.cam.ctl.inquiry_pq_no_lun, to override the change and return to the previous behavior. (The previous behavior was to return 001b, or LUN offline.) ctl.c: Change the default inquiry peripheral qualifier to 011b, and add a sysctl and tunable to allow the user to change it back to 001b if needed. Don't insert a Copan copyright statement in the inquiry data. The copyright statements on the files are sufficient. ctl_private.h: Add sysctl variable context to the CTL softc. ctl_cmd_table.c, ctl_frontend_internal.c, ctl_frontend.c, ctl_backend.c, ctl_error.c: Include sys/sysctl.h. MFC after: 3 days |
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Kenneth D. Merry
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130f4520cb |
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 |