Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Remove asserts that Giant is not held on entrance into geom KPI, which
outlived their usefulness. This allows to remove drop/pickup Giant
wrappers around GEOM calls.

Discussed with: alfred, imp, phk
Sponsored by: The FreeBSD Foundation

We have two functions from where a geom orphan method could be called:
g_orphan_register and g_resize_provider_event. Both are called from the
event queue. Also we have GEOM_DEV class, which does deferred destroy
for its consumers via g_dev_destroy (also called from the event queue).
So it is possible, that for some consumers an orphan method will be
called twice. This triggers panic in g_dev_orphan.
Check that consumer isn't already orphaned before call orphan method.

MFC after: 2 weeks

Make g_wither_washer() to not loop by itself, but only when there was some
more topology change done that may require its attention. Add few missing
g_do_wither() calls in respective places to signal it.

This fixes potential infinite loop here when some provider is withered, but
still opened or connected for some reason and so can not be destroyed. For
example, see r227009 and r227510.

Implement media change notification for DA and CD removable media devices.
It includes three parts:
1) Modifications to CAM to detect media media changes and report them to
disk(9) layer. For modern SATA (and potentially UAS) devices it utilizes
Asynchronous Notification mechanism to receive events from hardware.
Active polling with TEST UNIT READY commands with 3 seconds period is used
for incapable hardware. After that both CD and DA drivers work the same way,
detecting two conditions: "NOT READY: Medium not present" after medium was
detected previously, and "UNIT ATTENTION: Not ready to ready change, medium
may have changed". First one reported to disk(9) as media removal, second
as media insert/change. To reliably receive second event new
AC_UNIT_ATTENTION async added to make UAs broadcasted to all periphs by
generic error handling code in cam_periph_error().
2) Modifications to GEOM core to handle media remove and change events.
Media removal handled by spoiling all consumers attached to the provider.
Media change event also schedules provider retaste after spoiling to probe
new media. New flag G_CF_ORPHAN was added to consumers to reflect that
consumer is in process of destruction. It allows retaste to create new
geom instance of the same class, while previous one is still dying.
3) Modifications to some GEOM classes: DEV -- to report media change
events to devd; VFS -- to handle spoiling same as orphan to prevent
accessing replaced media. PART class already handles spoiling alike to
orphan.

Reviewed by: silence on geom@ and scsi@
Tested by: avg
Sponsored by: iXsystems, Inc. / PC-BSD
MFC after: 2 months

Workaround the problem introduced by combination of r162200 and r215687.
r162200 delays provider orphanization until all running requests complete,
to workaround broken orphan() method implementation in some classes.
r215687 removes persistent periodic (10Hz) event thread wake ups.
Together these changes can indefinitely delay orphanization until some
other event wake up the event thread. One consequence of this is inability
of CAM to destroy device disconnected when busy and, as consequence, create
new one after reconnection.

While the best solution would be to revert r162200, it is not easy, as
some classes still look broken in that way. Instead conditionally wake up
event thread if there are some providers waiting for orphanization.

MFC after: 1 week

Plumb device physical path reporting from CAM devices, through GEOM and
DEVFS, and make it accessible via the diskinfo utility.

Extend GEOM's generic attribute query mechanism into generic disk consumers.
sys/geom/geom_disk.c:
sys/geom/geom_disk.h:
sys/cam/scsi/scsi_da.c:
sys/cam/ata/ata_da.c:
- Allow disk providers to implement a new method which can override
the default BIO_GETATTR response, d_getattr(struct bio *). This
function returns -1 if not handled, otherwise it returns 0 or an
errno to be passed to g_io_deliver().

sys/cam/scsi/scsi_da.c:
sys/cam/ata/ata_da.c:
- Don't copy the serial number to dp->d_ident anymore, as the CAM XPT
is now responsible for returning this information via
d_getattr()->(a)dagetattr()->xpt_getatr().

sys/geom/geom_dev.c:
- Implement a new ioctl, DIOCGPHYSPATH, which returns the GEOM
attribute "GEOM::physpath", if possible. If the attribute request
returns a zero-length string, ENOENT is returned.

usr.sbin/diskinfo/diskinfo.c:
- If the DIOCGPHYSPATH ioctl is successful, report physical path
data when diskinfo is executed with the '-v' option.

Submitted by: will
Reviewed by: gibbs
Sponsored by: Spectra Logic Corporation

Add generic attribute change notification support to GEOM.

sys/sys/geom/geom.h:
Add a new attrchanged method field to both g_class
and g_geom.

sys/sys/geom/geom.h:
sys/geom/geom_event.c:
- Provide the g_attr_changed() function that providers
can use to advertise attribute changes.
- Perform delivery of attribute change notifications
from a thread context via the standard GEOM event
mechanism.

sys/geom/geom_subr.c:
Inherit the attrchanged method from class to geom (class instance).

sys/geom/geom_disk.c:
Provide disk_attr_changed() to provide g_attr_changed() access
to consumers of the disk API.

sys/cam/scsi/scsi_pass.c:
sys/cam/scsi/scsi_da.c:
sys/geom/geom_dev.c:
sys/geom/geom_disk.c:
Use attribute changed events to track updates to physical path
information.

sys/cam/scsi/scsi_da.c:
Add AC_ADVINFO_CHANGED to the registered asynchronous CAM
events for this driver. When this event occurs, and
the updated buffer type references our physical path
attribute, emit a GEOM attribute changed event via the
disk_attr_changed() API.

sys/cam/scsi/scsi_pass.c:
Add AC_ADVINFO_CHANGED to the registered asynchronous CAM
events for this driver. When this event occurs, update
the physical patch devfs alias for this pass instance.

Submitted by: gibbs
Sponsored by: Spectra Logic Corporation

Use g_eventlock to protect against losing wakeups in the g_event process
and replace tsleep(9) with msleep(9) which doesn't use a timeout. The
previously used timeout caused the event process to wake up ten times
per second on an idle system.

one_event() is now called with the topology lock held and it returns
with both the topology and event locks held when there are no more
events in the queue.

Reported by: mav, Marius Nünnerich
Reviewed by: freebsd-geom

Extend the g_eventlock mutex coverage in one_event() to include setting
of the EV_DONE flag and use the mutex to protect against losing wakeups
in g_waitfor_event().

Reported by: davidxu
Tested by: davidxu
Discussed on: freebsd-current

Try and narrow the gap in which you act on an event that has been canceled.
Obtained from: Jaako Heinonen
MFC after: 1 month

When orphaning a provider, cancel events related to it.
Without this change the following situation was possible:

1. Provider is orphaned from within class' access() method on last write
close - orphan provider event is send.
2. GEOM detects last write close on a provider and sends new provider event.
3. g_orphan_register() is called, and calls all orphan methods of attached
consumers.
4. New provider event is executed on orphaned provider, all classes can
taste already orphaned provider, and some may attach consumers to it.
Those consumers will never go away, because the g_orphan_register()
was already called.

We end up with a zombie provider.

With this change, at step 3, we will cancel new provider event.

How to repeat this problem:

# mdconfig -a -t malloc -s 10m
# geli init -i 0 md0
# geli attach md0
# newfs -L test /dev/md0.eli
# mount /dev/ufs/test /mnt/tmp
# geli detach -l md0.eli
# umount /mnt/tmp
# glabel status
Name Status Components
ufs/test N/A N/A

Reviewed by: phk
Approved by: re (kensmith)

Delay an orphan event if provider has still in-flight I/O requests.
This way GEOM classes can safely detach from provider when an orphan
event is received. This fixes 'detach with active requests' panic for
gstripe/gconcat under load.

PR: kern/102766
Submitted by: mjacob
OK'ed by: phk
MFC after: 1 week

Remove a race condition that could result in processes being stuck
waiting for geom events to happen:

Instead of maintaining a count of outstanding events, simply look if
the queue is empty. Make sure to not remove events from the queue
until they are executed in order to not open a new race.

Much work by: pjd
Tested by: kris
MT6: yes, should be.

Correct typo.

Introduce g_waitidlelock() function which is simlar to g_waitidle(),
but should be called with the topology lock held and returns with the
topology lock held and empty event queue.

Approved by: phk (sometime ago)

Add a new per-thread private flag: TDP_GEOM.

This flag gets set whenever the thread posts an event on the GEOM
event queue, and if the flag is set when the thread is prepared
to return to userland from the kernel, g_waitidle() will be called
to make sure that the posted events have completed.

This can replace an insufficient number of g_waitidle() calls in
various other places, and has the advantage of being failsafe: Any
system call which does a VOP_OPEN()/VOP_CLOSE will now correctly
wait for any geom events it posted as part of spoils or tastes.

Assert that topology and Giant is not held in g_waitidle().

Make withering water tight.

When we orphan/wither a provider, an attached geom+consumer could
end up being withered as a result and it may be in front of us in
the normal object scanning order so we need to do multi-pass. On
the other hand, there may be withering stuff we can't get rid off
(yet), so we need to keep track of both the existence of withering
stuff and if there is more we can do at this time.

Rearrange some of the GEOM debugging tools to be more structured.

Retire g_sanity() and corresponding debugflag (0x8)

Retire g_{stall,release}_events().

Under #ifdef DIAGNOSTIC:

Make g_valid_obj() an official function and have it return an an
non-zero integer which indicates the kind of object when found.

Implement G_VALID_{CLASS,GEOM,CONSUMER,PROVIDER}() macros based
on g_valid_obj().

Sprinkle calls to these macros liberally over the infrastructure.

Always check that we do not free a live object.

Now we have g_topology_assert_not(), so use it to detect deadlocks.

Approved by: phk, scottl (mentor)

Don't mingle malloc/g_event flags.

Spotted by: pjd@

Make sure to keep track of canceled events.

Submitted by: Pawel Jakub Dawidek <nick@garage.freebsd.pl>

Prevent withering of the provider we're orphaning from happening until
we do it ourselves.

Nailed by: Simon Heath <heath@cng.fr>

KASSERT against multiple orphanings of providers.

Fix a harmless bug and add a ')' in a debugging printf.

Submitted by: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>

Destroy providers maked with G_PF_WITHER when the last consumer has detached.

Use __FBSDID().

Approved by: phk

Add missing va_end() calls.

Noticed by: tmm

Get rid of trivial function g_destroy_event().

Add a new flag, EV_CANCELED, and use it to make g_waitfor_event() return
EAGAIN if an event got canceled.

When events on a reference is cancelled, check our doorstep first,
it might be an orphan.

Introduce a g_waitfor_event() function which posts an event and waits for
it to be run (or cancelled) and use this instead of home-rolled versions.

More of the event stuff can now be private to geom_event.c

Rename g_call_me() to g_post_event(), and give it a flag
argument to determine if we can M_WAITOK in malloc.

Remove the now unused hardcoded g_post_event() event support.

Turn EV_NEW_PROVIDER into a g_call_me() event.

Convert EV_SPOILED event to use g_call_me().

Turn the hardwired NEW_CLASS event into a g_call_me() event.

Move the shutdown eventhandler stuff to a more logical place.

Time has run from the "run GEOM in userland" harness, and the new regression
test is built to test GEOM as running in the kernel.

This commit is basically "unifdef -D_KERNEL" to remove the mainly #include
related code to support the userland-harness.

Fix a bug which resulted in orphanization getting confused every now
and then.

Add handling for cancelled events in the g_call_me() methods.

Change events to have an array of "void *" references, and give the
event posting functions varargs to fill these.

Attribute g_call_me() to appropriate g_geom's where necessary.

Add a flag argument to g_call_me() methods which will be used to signal
cancellation of events in the future.

This commit should be a no-op.

Save a lock: Grab the stall_events SX lock exclusively so it also serialize
OAM reqests.

Introduce g_cancel_events() and use it a couple of places where it makes
sense.

Introduce an SX lock which allows us to stall event processing
during OAM operations.

#ifdef notyet a bit of code which needs not yet committed refcounting to
work correctly.

If we run out of consumers while orphaning them, and the provider's geom
is withering, destroy the provider when done.

This was exposed by the recent change to geom_dev's orphaning logic.

Stamp out Danglish.

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

Approved by: trb

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

Remove g_silence(). It does not do anything anymore.

Polish a bit here and there.
Reenable the geom.ctl device so people can play with gbde.

Sponsored by: DARPA & NAI Labs

Make sure we don't loose our topology lock in a call_me() handler.

Sponsored by: DARPA & NAI Labs.

Implement g_call_me() as a way for geom methods to schedule operations
to be performed in the event-thread.

To do this, we need to lock the eventlist with g_eventlock (nee g_doorlock),
since g_call_me() being called from the UP/DOWN paths will not be able to
aquire g_topology_lock.

This also means that for now these events are not referenced on any
particular consumer/provider/geom.

For UP/DOWN path use, this will not become a problem since the access()
function will make sure we drain any bio's before we dismantle.

Sponsored by: DARPA & NAI Labs.

Ok, include also the two tests which actually does effect the claims
of the last commit message.

Sponsored by: DARPA & NAI Labs.

Hook into the shutdown EVENTHANDLER and stop tasting things after we
get notified to make things settle a bit faster.

Sponsored by: DARPA & NAI Labs.

Rename the doorlock to eventlock, it gets to protect a bit more in the future.

Sponsored by: DARPA & NAI Labs.

Improve some on the naming.

Submitted by: iedowse

Only clear the spoiled flag if the class had no spoiled method, the spoiled
method may have deallocated the consumer already and modifying free()'ed
memory is bad style.

Sponsored by: DARPA & NAI Labs.

Don't grab Giant around malloc(9) and free(9).
Don't grab Giant around wakeup(9).
Don't print verbose messages about each device found in geom_dev.
Various cleanups.

Sponsored by: DARPA & NAI Labs.

Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on: i386, alpha, sparc64

Move access and orphan member functions from class to geom.

Sponsored by: DARPA & NAI Labs

s/classs/classes/ to fixup grammer after the previous global renaming.

Sponsored by: DARPA & NAI Labs

Eliminate some thread pointers which do not make sense anymore.

Split private parts of geom.h into geom_int.h. The latter should
never be included in class implemtations.

Cave in to tradition and rename "methods" to "classes".

First commit of the GEOM subsystem to make it easier for people to
test and play with this.

This is not yet production quality and should be run only on dedicated
test boxes.

For people who want to develop transformations for GEOM there exist a
set of shims to run geom in userland (ask phk@freebsd.org).

Reports of all kinds to: phk@freebsd.org
Please include in report:
dmesg
sysctl debug.geomdot
sysctl debug.geomconf

Known significant limitations:
no kernel dump facility.
ioctls severely restricted.

Sponsored by: DARPA, NAI Labs