Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

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)

- 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.

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)

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

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