Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r270282:

Use proper include paths in kernel iSCSI code.

Sponsored by: The FreeBSD Foundation

MFC r270279:

Make the iSCSI stack use __FBSDID() properly.

Sponsored by: The FreeBSD Foundation

MFC r269197:

Fix potential double free that could happen after connection error.

MFC r267613 (by trasz):
Implement redirection handling in initiator.

Fix build on stable/10.

MFC r268388:
Add XPT_ABORT support to iSCSI initiator.

While CAM does not use it normally, it is useful for targets testing.

MFC r268370:
Make XPT_GET_TRAN_SETTINGS to report CAM that command queueing is enabled,
but make couple changes to handle non-queued commands too, if happen.

MFC r268326:
Make iSCSI initiator keep Initiator Session ID (ISID) across reconnects.

Previously ISID was changed every time, that made impossible correct
persistent reservation, because reconnected session was identified as
completely new one.

MFC r264355 by mav@:

Remove unused val argument value from SYSCTL_INT() calls.

MFC r264549:

Make it possible for the initiator side to operate in both proxy
and normal mode; this makes it possible to compile with the former
by default, but use it only when neccessary. That's especially
important for the userland part.

Sponsored by: The FreeBSD Foundation

MFC r264545:

Fix typo.

Sponsored by: The FreeBSD Foundation

MFC r264348 by mav@:

Improve use of socket buffer upcalls.

Use soreadable()/sowriteable() in socket upcalls to avoid extra wakeups
until we have enough data to read or space to write.

Increase partial receive len from 1K to 128K to not wake up on every
received packet.

This significantly reduces locks congestion and CPU usage and improves
throughput for large I/Os on NICs without TSO and LRO.

MFC r264552 by mav@:

Close the race in older code, that caused connection stuck after r264348.

Sponsored by: iXsystems, Inc.

MFC r264544:

Add kern.iscsi.fail_on_disconnection; this is required for gmultipath
to work.

Sponsored by: The FreeBSD Foundation

MFC r264538:

Remove useless debug.

Sponsored by: The FreeBSD Foundation

MFC r264537:

Be more strict with locking for is_waiting_for_iscsid variable.

Sponsored by: The FreeBSD Foundation

MFC r264536:

Get rid of ISCSIDCLOSE; it wasn't used and is redundant anyway,
because of ISCSIDFAIL.

Sponsored by: The FreeBSD Foundation

MFC r264530:

Properly pass the initiator address when running in proxy mode.

Sponsored by: The FreeBSD Foundation

MFC r264526:

Properly identify target portal when running in proxy mode. While here,
remove CTL_ISCSI_CLOSE, it wasn't used or implemented anyway.

Sponsored by: The FreeBSD Foundation

MFC r264525:

Add some stuff to make it easier to figure out for the system administrator
whether the ICL_KERNEL_PROXY stuff got compiled in correctly.

Sponsored by: The FreeBSD Foundation

MFC r263740:

Use a less unusual syntax in debug printfs.

Sponsored by: The FreeBSD Foundation

MFC r264163:

Remove hack to pass STAILQ to a function and do it properly instead.

Sponsored by: The FreeBSD Foundation

MFC r264122:

Rework the iSCSI PDU transmit code to avoid lock contention and coalesce
PDUs before sending.

Sponsored by: The FreeBSD Foundation

MFC r264110:

All the iSCSI sysctls are also tunables; advertise that.

Sponsored by: The FreeBSD Foundation

MFC r264109:

We don't need TAILQ for iSCSI PDUs; STAILQ is enough.

Sponsored by: The FreeBSD Foundation

MFC r264026:

Enable a KASSERT.

Sponsored by: The FreeBSD Foundation

MFC r264025:

Get rid of the "autoscaling", instead just set socket buffer sizes
in the usual way. The only thing the old code did was making things
less predictable.

MFC r264058:

Fix build, broken by r264025.

Sponsored by: The FreeBSD Foundation

MFC r264023:

Instead of "icltx" and "iclrx", use thread names with prefix from upper
layer, so that one can see which side of the stack the threads are for.

Sponsored by: The FreeBSD Foundation

MFC r264022:

Get rid of ICL lock; use upper-layer (initiator or target) lock instead.
This avoids extra locking in icl_pdu_queue(); the upper layer needs to call
it while holding its own lock anyway, to avoid sending PDUs out of order.

Sponsored by: The FreeBSD Foundation

MFC r263743:

Move the ic_outstanding_count under #ifdef DIAGNOSTIC.

Sponsored by: The FreeBSD Foundation

MFC r263742:

Fix harmless warning after reconnecting a session and not doing anything
with it.

Sponsored by: The FreeBSD Foundation

MFC r260389:

Fix a rare "truncated checksums" problem, which manifested like this:

WARNING: icl_pdu_check_data_digest: data digest check failed; got 0xf23b,
should be 0xdb7f23b

Sponsored by: The FreeBSD Foundation

MFC r260083:

Fix extremely slow operation with data digests enabled. This was caused
by receive code waiting for data digest even when the data segment was
empty. It didn't actually read it, but it waited until those four bytes
become available in the socket buffer, i.e. until any other PDU (e.g. NOP)
came in.

Sponsored by: The FreeBSD Foundation

MFC r259183:

Properly refuse handoff requests on already connected sessions. Previously
this would result in dropping the session.

Sponsored by: The FreeBSD Foundation

MFC r258790:

Fix hang on reboot with active iSCSI connections.

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

MFC r257061:

Don't spin with mutex hold when there is not enough room in the send socket
buffer. While here, make the code flow somewhat nicer.

Thanks to mav@ for tracking it down.

Approved by: re (glebius)

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

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

Properly handle residual count in Data-In PDUs with S bit set.

Approved by: re (gjb)
Sponsored by: FreeBSD Foundation

Be extra paranoid with values obtained from the target.

Approved by: re (glebius)
Sponsored by: FreeBSD Foundation

Fail connection upon receiving too large data segment.

Approved by: re (glebius)
Sponsored by: FreeBSD Foundation

Fix NOP-In/NOP-Out payload handling. Previous way didn't work at all; fortunately
nothing seems to actually use this feature, but it's required by standard.

Approved by: re (glebius)
Sponsored by: FreeBSD Foundation

Don't leak memory when removing an unconnected session, and remove useless
UMA_ZONE_NOFREE that caused another leak when unloading the module.

Approved by: re (glebius)
Sponsored by: FreeBSD Foundation

As it turns out, when MOD_LOAD handler returns error, kernel calls MOD_UNLOAD
handler. Make the new iSCSI initiator not panic when this happens.

Approved by: re (glebius)
Sponsored by: FreeBSD Foundation

Don't use M_WAITOK when running from context where sleeping is prohibited,
such as callout or a geom thread.

Approved by: re (marius)
Sponsored by: FreeBSD Foundation

Add some spare fields to structs used by the new iSCSI stack - some just
in case, some for future MC/S support.

This requires kernel and world rebuild.

Approved by: re (blanket)
Sponsored by: FreeBSD Foundation

Fix several problems in the new iSCSI stack; this includes interoperability
fix for LIO (Linux target), removing possibility for the target to avoid mutual
CHAP by choosing to skip authentication altogether, and fixing truncated error
messages in iscsictl(8) output. This also fixes several of the problems found
with Coverity.

Note that this change requires world rebuild.

Coverity CID: 1088038, 1087998, 1087990, 1088004, 1088044, 1088041, 1088040
Approved by: re (blanket)
Sponsored by: FreeBSD Foundation

Bring in the new iSCSI target and initiator.

Reviewed by: ken (parts)
Approved by: re (delphij)
Sponsored by: FreeBSD Foundation

Move the old iSCSI initiator source to a more appropriate place
(sys/dev/iscsi_initiator/ instead of sys/dev/iscsi/initiator/), to make
room for the new one. This is also more logical location (kernel module
being named iscsi_initiator.ko, for example). There is no ongoing work
on this I know of, so it shouldn't make life harder for anyone.

There are no functional changes, apart from "svn mv" and adjusting paths.

MFprojects/camlock r248982:
Stop abusing xpt_periph in random plases that really have no periph related
to CCB, for example, bus scanning. NULL value is fine in such cases and it
is correctly logged in debug messages as "noperiph". If at some point we
need some real XPT periphs (alike to pmpX now), quite likely they will be
per-bus, and not a single global instance as xpt_periph now.

Finish r243882: mechanically substitute flags from historic mbuf
allocator with malloc(9) flags within sys.

Sponsored by: Nginx, Inc.

Merge Capsicum overhaul:

- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.

- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.

- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.

- The cap_getrights(2) syscall is renamed to cap_rights_get(2).

- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.

- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).

- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.

- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.

- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:

CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.

Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).

Added CAP_SYMLINKAT:
- Allow for symlinkat(2).

Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).

Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.

Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.

Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.

Removed CAP_MAPEXEC.

CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.

Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).

Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.

CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).

CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).

Added convinient defines:

#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE

#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)

Added defines for backward API compatibility:

#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)

Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

Update to version 2.3.1.0

Obtained from: Daniel Braniss <danny@cs.huji.ac.il>

Remove direct access to si_name.

Code should just use the devtoname() function to obtain the name of a
character device. Also add const keywords to pieces of code that need it
to build properly.

MFC after: 2 weeks

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

Remove MALLOC_DECLAREs of nonexisting malloc-pools.

After careful grepping, it seems none of these pools can be found in our
source tree. They are not in use, nor are they defined.

Do not ignore block offsets.

PR: kern/160943
Submitted by: Craig Boston <cb severious net>
Reviewed by: Danny Braniss <danny cs huji ac il>
MFC after: 1 week

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

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc

Specify a CTLTYPE_FOO so that a future sysctl(8) change does not need
to rely on the format string.

sysctl(9) cleanup checkpoint: amd64 GENERIC builds cleanly.

Commit the rest of the devices.

Remove the freelist, which simply duplicates some of the zone allocator's
functionality.

Submitted by: Daniel Braniss <danny@cs.huji.ac.il>
MFC after: 3 weeks

Do not use %z to print a time_t. Fixes build on architectures where time_t
and size_t are different types.

- Add full support for header / data digests.
- Increase target limit from 4 to 64; this limit will be removed entirely
at a later time.
- Improve recovery from lost network connections.
- Fix some potential deadlocks and a serious memory leak.
- Fix incorrect use of MH_ALIGN (instead of M_ALIGN), which makes no
practical difference, but triggers a KASSERT with INVARIANTS.
- Fix some warnings in iscontrol(8) and improve the man page somewhat.

Submitted by: Daniel Braniss <danny@cs.huji.ac.il>
Sponsored by: Dansk Scanning A/S, Data Robotics Inc.

Remove extraneous semicolons, no functional changes.

Submitted by: Marc Balmer <marc@msys.ch>
MFC after: 1 week

Fix iSCSI initiator and vpo driver operation, broken by CAM changes.

Reviewed by: scottl, Danny Braniss
Approved by: re (rwatson)

Change the type of uio_resid member of struct uio from int to ssize_t.
Note that this does not actually enable full-range i/o requests for
64 architectures, and is done now to update KBI only.

Tested by: pho
Reviewed by: jhb, bde (as part of the review of the bigger patch)

This commit fixes the issue with alias_sctp.c. No
longer do we require SCTP to be in the kernel for the
lib to be able to handle SCTP. We do this by moving
the CRC32c checksum into libkern/crc32.c and then adjusting
all routines to use the common methods. Note that this
will improve the performance of iSCSI since they were
using the old single 256 bit table lookup versus the
slicing 8 algorithm (which gives a 4x speed up in
CRC32c calculation :-D)

Reviewed by:rwatson, gnn, scottl, paolo
MFC after: 4 week? (assuming we MFC the alias_sctp changes)

Big update to the iSCSI initiator code. Highlights include IPv6 support,
many bugs fixes, many more performance improvements.

Submitted by: Danny Braniss

M sbin/iscontrol/iscsi.conf.5
M sbin/iscontrol/iscontrol.8
M sbin/iscontrol/iscontrol.h
M sbin/iscontrol/config.c
M sbin/iscontrol/fsm.c
M sbin/iscontrol/login.c
M sbin/iscontrol/pdu.c
M sbin/iscontrol/misc.c
M sbin/iscontrol/auth_subr.c
M sbin/iscontrol/iscontrol.c
M sys/dev/iscsi/initiator/isc_cam.c
M sys/dev/iscsi/initiator/iscsi.h
M sys/dev/iscsi/initiator/isc_soc.c
M sys/dev/iscsi/initiator/iscsi_subr.c
M sys/dev/iscsi/initiator/iscsivar.h
M sys/dev/iscsi/initiator/isc_subr.c
M sys/dev/iscsi/initiator/iscsi.c
M sys/dev/iscsi/initiator/isc_sm.c

Replace all calls to minor() with dev2unit().

After I removed all the unit2minor()/minor2unit() calls from the kernel
yesterday, I realised calling minor() everywhere is quite confusing.
Character devices now only have the ability to store a unit number, not
a minor number. Remove the confusion by using dev2unit() everywhere.

This commit could also be considered as a bug fix. A lot of drivers call
minor(), while they should actually be calling dev2unit(). In -CURRENT
this isn't a problem, but it turns out we never had any problem reports
related to that issue in the past. I suspect not many people connect
more than 256 pieces of the same hardware.

Reviewed by: kib

Record the dependency of the iscsi initiator on cam.

PR: 116745
Submitted by: OISHI Masakuni
Approved by: rwatson (mentor)
MFC after: 1 month

Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by: arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.

Give MEXTADD() another argument to make both void pointers to the
free function controlable, instead of passing the KVA of the buffer
storage as the first argument.

Fix all conventional users of the API to pass the KVA of the buffer
as the first argument, to make this a no-op commit.

Likely break the only non-convetional user of the API, after informing
the relevant committer.

Update the mbuf(9) manual page, which was already out of sync on
this point.

Bump __FreeBSD_version to 800016 as there is no way to tell how
many arguments a CPP macro needs any other way.

This paves the way for giving sendfile(9) a way to wait for the
passed storage to have been accessed before returning.

This does not affect the memory layout or size of mbufs.

Parental oversight by: sam and rwatson.

No MFC is anticipated.

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

Introduce Danny Braniss' iSCSI initiator, version 2.0.99. Please read the
included man pages on how to use it. This code is still somewhat experimental
but has been successfully tested on a number of targets. Many thanks to
Danny for contributing this.

Approved by: re