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)

Switch to our preferred 2-clause BSD license.

Approved by: bp

Don't print out a message on loading a module. 'kldload -v' and 'kldstat
| grep <modname>' can be used instead.

Put a message behind bootverbose as

ichwd0: <Intel ICH6M watchdog timer> on isa0
ichwd0: Intel ICH6M watchdog timer (ICH6 or equivalent)

does not make a lot of sense.

MFC after: 1 week

Implement device cloning for /dev/nsmb, the netsmb control pseudo-device.
The smb library in userspace already knows how to deal with this type of
cloning.

This also corrects a leak in which the netsmb kernel module could not be
unloaded if device nodes had been stat'd but not open'd.

Discussed with: kib

Catch up with netsmb locking: explicit thread arguments no longer required.

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

Remove unit2minor() use from kernel code.

When I changed kern_conf.c three months ago I made device unit numbers
equal to (unneeded) device minor numbers. We used to require
bitshifting, because there were eight bits in the middle that were
reserved for a device major number. Not very long after I turned
dev2unit(), minor(), unit2minor() and minor2unit() into macro's.
The unit2minor() and minor2unit() macro's were no-ops.

We'd better not remove these four macro's from the kernel, because there
is a lot of (external) code that may still depend on them. For now it's
harmless to remove all invocations of unit2minor() and minor2unit().

Reviewed by: kib

Fixing the mount_smbfs(8) hanging by utilising the destroy_dev_sched() KPI.

Relevant threads:

http://lists.freebsd.org/pipermail/freebsd-current/2007-June/074329.html

Reviewed by: kib, bp (slightly different version)
Tested by: Yuri Pankov <yuri.pankov at gmail dot com>,
Jiawei Ye <leafy7382 at gmail dot com>
Approved by: re (kensmith)

Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock. This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention. All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently. Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.

- Generally eliminate the distinction between "fast" and regular
acquisisition of the filedesc lock; the plan is that they will now all
be fast. Change all locking instances to either shared or exclusive
locks.

- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
was called without the mutex held; sx_sleep() is now always called with
the sxlock held exclusively.

- Universally hold the struct file lock over changes to struct file,
rather than the filedesc lock or no lock. Always update the f_ops
field last. A further memory barrier is required here in the future
(discussed with jhb).

- Improve locking and reference management in linux_at(), which fails to
properly acquire vnode references before using vnode pointers. Annotate
improper use of vn_fullpath(), which will be replaced at a future date.

In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).

Tested by: kris
Discussed with: jhb, kris, attilio, jeff

Backing out the wrong fix which could possibly trash the memory if devfs
tries to drop the reference count after our close routine returns.

A more correct fix is to defer the destroy_dev() to a taskqueue(either
in devfs or locally).

Reminded by: jhb

It turns out that devfs_close() does a dev_refthread() before invoking
device specific d_close(), which makes subsequent destroy_dev() being
blocked in the "devdrn" loop.

This bandaid should fix the smbfs hang/crashing observed on -CURRENT since
the introduction of sys/kern/kern_conf.c:1.199:

# mount_smbfs -I server //server/share /mnt
Password:
[hang]

Reviewed by: bp
See also: http://lists.freebsd.org/pipermail/cvs-src/2006-November/071379.html

Prevent module unloading if there are active connections.

PR: kern/89085
Submitted by: Rostislav Krasny
MFC after: 1 week

Merge the dev_clone and dev_clone_cred event handlers into a single
event handler, dev_clone, which accepts a credential argument.
Implementors of the event can ignore it if they're not interested,
and most do. This avoids having multiple event handler types and
fall-back/precedence logic in devfs.

This changes the kernel API for /dev cloning, and may affect third
party packages containg cloning kernel modules.

Requested by: phk
MFC after: 3 days

Explicitly hold a reference to the cdev we have just cloned. This
closes the race where the cdev was reclaimed before it ever made it
back to devfs lookup.

/* -> /*- for license, minor formatting changes

Don't use vn_todev().

Second half of the dev_t cleanup.

The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()

Various minor adjustments including handling of userland access to kernel
space struct cdev etc.

Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.

add missing #include <sys/module.h>

Device megapatch 4/6:

Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.

Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.

Use automatic major number allocation for nsmb devices.

- Support for multibyte charsets in LIBICONV.
- CD9660_ICONV, NTFS_ICONV and MSDOSFS_ICONV kernel options
(with corresponding modules).
- kiconv(3) for loadable charset conversion tables support.

Submitted by: Ryuichiro Imura <imura@ryu16.org>

Add a f_vnode field to struct file.

Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.

By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.

At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.

Use __FBSDID().

Remove fragments of support for the FreeBSD 3.x and 4.x branches.

Gigacommit to improve device-driver source compatibility between
branches:

Initialize struct cdevsw using C99 sparse initializtion and remove
all initializations to default values.

This patch is automatically generated and has been tested by compiling
LINT with all the fields in struct cdevsw in reverse order on alpha,
sparc64 and i386.

Approved by: re(scottl)

Use noread(), nowrite() and nopoll() instead of our own stub functions.

NODEVFS cleanup: Don't call cdevsw_{add,remove}()

Back out M_* changes, per decision of the TRB.

Approved by: trb

Pass a minor number instead of a unit number to make_dev().
Devices with the wrong major were being created for units >255.

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

Bow to the whining masses and change a union back into void *. Retain
removal of unnecessary casts and throw in some minor cleanups to see if
anyone complains, just for the hell of it.

Change struct file f_data to un_data, a union of the correct struct
pointer types, and remove a huge number of casts from code using it.

Change struct xfile xf_data to xun_data (ABI is still compatible).

If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.

When compiling the kernel do not implicitly include filedesc.h from proc.h,
this was causing filedesc work to be very painful.
In order to make this work split out sigio definitions to thier own header
(sigio.h) which is included from proc.h for the time being.

Simple p_ucred -> td_ucred changes to start using the per-thread ucred
reference.

SMP Lock struct file, filedesc and the global file list.

Seigo Tanimura (tanimura) posted the initial delta.

I've polished it quite a bit reducing the need for locking and
adapting it for KSE.

Locks:

1 mutex in each filedesc
protects all the fields.
protects "struct file" initialization, while a struct file
is being changed from &badfileops -> &pipeops or something
the filedesc should be locked.

1 mutex in each struct file
protects the refcount fields.
doesn't protect anything else.
the flags used for garbage collection have been moved to
f_gcflag which was the FILLER short, this doesn't need
locking because the garbage collection is a single threaded
container.
could likely be made to use a pool mutex.

1 sx lock for the global filelist.

struct file * fhold(struct file *fp);
/* increments reference count on a file */

struct file * fhold_locked(struct file *fp);
/* like fhold but expects file to locked */

struct file * ffind_hold(struct thread *, int fd);
/* finds the struct file in thread, adds one reference and
returns it unlocked */

struct file * ffind_lock(struct thread *, int fd);
/* ffind_hold, but returns file locked */

I still have to smp-safe the fget cruft, I'll get to that asap.

Pull netsmb requester from the pre-KSE world. This update mostly based
on the patches submitted by Max Khon <fjoe@iclub.nsu.ru>

Remove unnecessary "#if __FreeBSD_version".

Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by: bde (with reservations)

Import kernel part of SMB/CIFS requester.
Add smbfs(CIFS) filesystem.

Userland part will be in the ports tree for a while.

Obtained from: smbfs-1.3.7-dev package.