- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r289881: Give CTL support for PIM_EXTLUNS when talking to CAM.

CTL itself still lives in flat LUN space, but it can generate extended
numbers if CAM SIM reports such capability.

MFC r288348: Umplement media load/eject support for removable devices.

In case of block backend eject really closes the backing store, while
load tries to open it back. Failed store open is reported as no media.

MFC r288148: Synchronize mode pages between HA peers.

We allow to modify only few fields in mode pages now, but still it is
not good if they unexpectedly change during failover. Also this fixes
reporting of "Mode parameters changed" UAs on secondary node.

MFC r287967: Relax serseq option operation for reads.

Previously, with serseq enabled, next command was unblocked only after
previous completed. With this change, for read operations, next command
is unblocked as soon as last media read completed. This is important
for frontends that actually wait for data move completion (like camtgt),
or when data are moved through the HA link, or especially when both.

MFC r287940: Replicate initiators WWPNs and names between HA peers.

MFC r287756:
Report INQUIRY DATA HAS CHANGED for related LUNs on port on-/offline.

MFC r287621: Reimplement CTL High Availability.

CTL HA functionality was originally implemented by Copan many years ago,
but large part of the sources was never published. This change includes
clean room implementation of the missing code and fixes for many bugs.

This code supports dual-node HA with ALUA in four modes:
- Active/Unavailable without interlink between nodes;
- Active/Standby with second node handling only basic LUN discovery and
reservation, synchronizing with the first node through the interlink;
- Active/Active with both nodes processing commands and accessing the
backing storage, synchronizing with the first node through the interlink;
- Active/Active with second node working as proxy, transfering all
commands to the first node for execution through the interlink.

Unlike original Copan's implementation, depending on specific hardware,
this code uses simple custom TCP-based protocol for interlink. It has
no authentication, so it should never be enabled on public interfaces.

The code may still need some polishing, but generally it is functional.

Relnotes: yes
Sponsored by: iXsystems, Inc.

MFC r287500: Allow LUN options modification via CTL_LUNREQ_MODIFY.

Not all changes take effect, but that is a different question.

MFC r287433: Small UA cleanup.

MFC r286807: Move "ioctl" CAM frontend into separate file.

It has nothing to share with too huge ctl.c other then device descriptor,
but even that may be counted as design error that may be fixed later.
At some point we may even want to have several ioctl ports.

MFC r286406, r286414:
Wrap some unused functions with notyet, it is necessary to be able to
build the modules/ctl directly.
Remove a dead MALLOC_DEFINE.

MFC r278584: Add support for General Statistics and Performance log page.

CTL already collects most of statistics reported there, so why not.

MFC r275953: Replace ctl_min() macro with MIN().

MFC r275865:
Add configuration options to override physical and UNMAP blocks geometry.

While in most cases CTL should correctly fetch those values from backing
storages, there are some initiators (like MS SQL), that may not like large
physical block sizes, even if they are true. For such cases allow override
fetched values with supported ones (like 4K).

MFC r275474: Add GET LBA STATUS command support to CTL.

It is implemented for LUNs backed by ZVOLs in "dev" mode and files.
GEOM has no such API, so for LUNs backed by raw devices all LBAs will
be reported as mapped/unknown.

Sponsored by: iXsystems, Inc.

MFC r274154, r274163:
Add to CTL support for logical block provisioning threshold notifications.

For ZVOL-backed LUNs this allows to inform initiators if storage's used or
available spaces get above/below the configured thresholds.

Sponsored by: iXsystems, Inc.

MFC r273693: Fix printing non-terminated strings in devlist XML.

MFC r273075: Remove couple Copan's vendor-specific mode pages.

Those pages are highly system-/hardware-specific, the code is incomplete,
and so they hardly can be useful for anybody else.

MFC r271309:
Improve cache control support, including DPO/FUA flags and the mode page.

At this moment it works only for files and ZVOLs in device mode since BIOs
have no respective respective cache control flags (DPO/FUA).

MFC r272040:
When reporting some major UNIT ATTENTION condition, like POWER ON OCCURRED
or I_T NEXUS LOSS, clear all minor UAs for the LUN, redundant in this case.

All SAM specifications tell that target MAY do it, but libiscsi initiator
seems require it to be done, terminating connection with error if some more
UAs happen to be reported during iSCSI connection.

Approved by: re (gjb)

MFC r268363:
Add support for READ FULL STATUS action of PERSISTENT RESERVE IN command.

MFC r268353:
Implement ABORT TASK SET and I_T NEXUS RESET task management functions.

Use the last one to terminate active commands on iSCSI session termination.
Previous code was aborting only commands doing some data moves.

MFC r268291:
Create separate CTL port for every iSCSI target (and maybe portal group).

Having single port for all iSCSI connections makes problematic implementing
some more advanced SCSI functionality in CTL, that require proper ports
enumeration and identification.

This change extends CTL iSCSI API, making ctld daemon to control list of
iSCSI ports in CTL. When new target is defined in config fine, ctld will
create respective port in CTL. When target is removed -- port will be
also removed after all active commands through that port properly aborted.
This change require ctld to be rebuilt to match the kernel.

As a minor side effect, this allows to have iSCSI targets without LUNs.
While that may look odd and not very useful, that is not incorrect.

MFC r268280:
Make options KPI more generic to allow it to be used for ports too,
not only for LUNs.

MFC r267639:
Increase CTL_DEVID_LEN from 16 to 64 bytes.

SPC-4 recommends T10 vendor ID based LUN ID was created by concatenating
product name and serial number (and istgt follows that). But product name
is 16 bytes long by itself, so 16 bytes total length is clearly not enough
to fit both.

To keep compatibility with existing configurations, pad short device IDs
to old length of 16, same as before.

This change probably breaks CTL user-level ABI, so control tools should
be rebuilt after this change.

MFC r267643, r267873, r268391, r268398:
Introduce fine-grained CTL locking to improve SMP scalability.

Split global ctl_lock, historically protecting most of CTL context:
- remaining ctl_lock now protects lists of fronends and backends;
- per-LUN lun_lock(s) protect LUN-specific information;
- per-thread queue_lock(s) protect request queues.
This allows to radically reduce congestion on ctl_lock.

Create multiple worker threads, depending on number of CPUs, and assign
each LUN to one of them. This allows to spread load between multiple CPUs,
still avoiging congestion on queues and LUNs locks.

On 40-core server, exporting 5 LUNs, each backed by gstripe of SATA SSDs,
accessed via 6 iSCSI connections, this change improves peak request rate
from 250K to 680K IOPS.

Sponsored by: iXsystems, Inc.

MFC r267537:
Add support for VERIFY(10/12/16) and COMPARE AND WRITE SCSI commands.

Make data_submit backends method support not only read and write requests,
but also two new ones: verify and compare. Verify just checks readability
of the data in specified location without transferring them outside.
Compare reads the specified data and compares them to received data,
returning error if they are different.

VERIFY(10/12/16) commands request either verify or compare from backend,
depending on BYTCHK CDB field. COMPARE AND WRITE command executed in two
stages: first it requests compare, and then, if succeesed, requests write.
Atomicity of operation is guarantied by CTL request ordering code.

Sponsored by: iXsystems, Inc.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

CTL changes required for iSCSI target, most notably LUN remapping
and a mechanism to allow CTL frontends for retrieving LUN options.

Reviewed by: ken (earlier version)

Add LUN resizing to CTL. Also make it possible to explicitly set
size when creating file-backed or device-backed LUN.

Reviewed by: ken (earlier version)
Sponsored by: The FreeBSD Foundation

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