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

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

MFC r255043 (by ken):
Bump up the default timeouts for move commands in the ch(4) driver
to 15 minutes, and 5 minutes for things like READ ELEMENT STATUS.

This is needed to account for the worst case scenarios on at least
some Spectra Logic tape libraries.

MFC r256552:
Unify periph invalidation and destruction reporting.
Print message containing device model and serial number on invalidation.

MFC r253274 and r253368:

r253274 | ken | 2013-07-12 11:09:50 -0600 (Fri, 12 Jul 2013) | 40 lines

Fix a problem with READ ELEMENT STATUS that occurs on some
changers that don't support the DVCID and CURDATA bits that were
introduced in the SMC spec.

These changers will return an Illegal Request type error if the
bits are set. This causes "chio status" to fail.

The fix is two-fold. First, for changers that claim to be SCSI-2
or older, don't set the DVCID and CURDATA bits for READ ELEMENT
STATUS. For newer changers (SCSI-3 and newer), we default to
setting the new bits, but back off and try the READ ELEMENT STATUS
without the bits if we get an Illegal Request type error.

This has been tested on a Qualstar TLS-8211, which is a SCSI-2
changer that does not support the new bits, and a Spectra T-380,
which is a SCSI-3 changer that does support the new bits. In the
absence of a SCSI-3 changer that does not support the bits, I
tested that with some error injection code. (The SMC spec says
that support for CURDATA is mandatory, and DVCID is optional.)

scsi_ch.c: Add a new quirk, CH_Q_NO_DVCID that gets set for
SCSI-2 and older libraries, or newer libraries that
report errors when the DVCID/CURDATA bits are set.

In chgetelemstatus(), use the new quirk to
determine whether or not to set DVCID and CURDATA.
If we get an error with the bits set, back off and
try without the bits. Set the quirk flag if the
read element status succeeds without the bits set.

Increase the READ ELEMENT STATUS timeout to 60
seconds after testing with a Spectra T-380. The
previous value was 10 seconds, and too short for
the T-380. This may be decreased later after
some additional testing and investigation.

Tested by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
Sponsored by: Spectra Logic

------------------------------------------------------------------------
r253368 | ken | 2013-07-15 10:38:48 -0600 (Mon, 15 Jul 2013) | 5 lines

Fix an argument reversal in calls to scsi_read_element_status().

Reported by: Ulrich Spoerlein <uqs@FreeBSD.org>

Approved by: re (kib)

MFC: 249658, 249701

Update chio(1) and ch(4) to support reporting element designators.

This allows mapping a tape drive in a changer (as reported by
'chio status') to a sa(4) driver instance by comparing the
serial numbers.

The designators can be ASCII (which is printed out directly), binary
(which is printed in hex format) or UTF-8, which is printed in either
native UTF-8 format if the terminal can support it, or in %XX notation
for non-ASCII characters. Thanks to Hiroki Sato <hrs@> for the
explanation and example UTF-8 printing code.

chio.h: Modify the changer_element_status structure to add new
fields and definitions from the SMC3r16 spec.

Rename the original CHIOGSTATUS ioctl to OCHIOGTATUS and
define a new CHIOGSTATUS ioctl.

Clean up some tab/space issues.

chio.c: For the 'status' subcommand, print the designator field
if it is supplied by a device.

scsi_ch.h: Add new flags for DVCID and CURDATA to the READ
ELEMENT STATUS command structure.

Add a read_element_status_device_id structure
for the data fields in the new standard. Add new
unions, dt_or_obsolete and voltage_devid, to hold
and address data from either SCSI-2 or newer devices.

scsi_ch.c: Implement support for fetching device IDs with READ
ELEMENT STATUS data.

Add new arguments to scsi_read_element_status() to
allow the user to request the DVCID and CURDATA bits.
This isn't compiled into libcam (it's only an internal
kernel interface), so we don't need any special
handling for the API change.

If the user issues the new CHIOGSTATUS ioctl, copy all of
the available element status data out. If he issues the
OCHIOGSTATUS ioctl, we don't copy the new fields in the
structure.

Fix a bug in chopen() that would result in the peripheral
never getting unheld if chgetparams() failed.

Sponsored by: Spectra Logic
Submitted by: Po-Li Soong

MFC r250792:
Added output of device QUIRKS for CAM and AHCI devices during boot.

MFC r227293 (by ed):
Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

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

MFC r244014 (by ken):

Fix a device departure bug for the the pass(4), enc(4), sg(4) and ch(4)
drivers.

The bug occurrs when a userland process has the driver instance
open and the underlying device goes away. We get the devfs
callback that the device node has been destroyed, but not all of
the closes necessary to fully decrement the reference count on the
CAM peripheral.

The reason is that once devfs calls back and says the device has
been destroyed, it is moved off to deadfs, and devfs guarantees
that there will be no more open or close calls. So the solution
is to keep track of how many outstanding open calls there are on
the device, and just release that many references when we get the
callback from devfs.

scsi_pass.c,
scsi_enc.c,
scsi_enc_internal.h: Add an open count to the softc in these
drivers. Increment it on open and
decrement it on close.

When we get a devfs callback to say that
the device node has gone away, decrement
the peripheral reference count by the
number of still outstanding opens.

Make sure we don't access the peripheral
with cam_periph_unlock() after what might
be the final call to
cam_periph_release_locked(). The
peripheral might have been freed, and we
will be dereferencing freed memory.

scsi_ch.c,
scsi_sg.c: For the ch(4) and sg(4) drivers, add the
same changes described above, and in
addition, fix another bug that was
previously fixed in the pass(4) and enc(4)
drivers.

These drivers were calling destroy_dev()
from their cleanup routine, but that could
cause a deadlock because the cleanup
routine could be indirectly called from
the driver's close routine. This would
cause a deadlock, because the device node
is being held open by the active close
call, and can't be destroyed.

MFC r241404:
Remove 'periph == NULL' check from bunch of periph drivers.
This condition can never be true as functions are called from single place
and the checks just pollute the code and confuse Clang Static Analyzer.

MFC r238200:
Remove variables which are initialized but never used thereafter
reported by gcc46 warning

Approved by: cperciva (implicit)

MFC r236138, with the exception of scsi_enc.c:

r236138 | ken | 2012-05-27 00:11:09 -0600 (Sun, 27 May 2012) | 64 lines

Work around a race condition in devfs by changing the way closes
are handled in most CAM peripheral drivers that are not handled by
GEOM's disk class.

The usual character driver open and close semantics are that the
driver gets N open calls, but only one close, when the last caller
closes the device.

CAM peripheral drivers expect that behavior to be honored to the
letter, and the CAM peripheral driver code (specifically
cam_periph_release_locked_busses()) panics if it is done incorrectly.

Since devfs has to drop its locks while it calls a driver's close
routine, and it does not have a way to delay or prevent open calls
while it is calling the close routine, there is a race.

The sequence of events, simplified a bit, is:

- devfs acquires a lock
- devfs checks the reference count, and if it is 1, continues to close.
- devfs releases the lock

- 2nd process open call on the device happens here

- devfs calls the driver's close routine

- devfs acquires a lock
- devfs decrements the reference count
- devfs releases the lock

- 2nd process close call on the device happens here

At the second close, we get a panic in
cam_periph_release_locked_busses(), complaining that peripheral
has been released when the reference count is already 0. This is
because we have gotten two closes in a row, which should not
happen.

The fix is to add the D_TRACKCLOSE flag to the driver's cdevsw, so
that we get a close() call for each open(). That does happen
reliably, so we can make sure that our reference counts are
correct.

Note that the sa(4) and pt(4) drivers only allow one context
through the open routine. So these drivers aren't exposed to the
same race condition.

scsi_ch.c,
scsi_enc.c,
scsi_enc_internal.h,
scsi_pass.c,
scsi_sg.c:
For these drivers, change the open() routine to
increment the reference count for every open, and
just decrement the reference count in the close.

Call cam_periph_release_locked() in some scenarios
to avoid additional lock and unlock calls.

scsi_pt.c: Call cam_periph_release_locked() in some scenarios
to avoid additional lock and unlock calls.

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

Approved by: re (implicit)

Make CAM report devices with ATA/SATA transport to devstat(9) as IDE.

MFp4: Large set of CAM inprovements.

- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.

MFp4:
Fix several device freeze counting bugs.

Replace most of priority numbers with defines. No logical changes.

Separate the parallel scsi knowledge out of the core of the XPT, and
modularize it so that new transports can be created.

Add a transport for SATA

Add a periph+protocol layer for ATA

Add a driver for AHCI-compliant hardware.

Add a maxio field to CAM so that drivers can advertise their max
I/O capability. Modify various drivers so that they are insulated
from the value of MAXPHYS.

The new ATA/SATA code supports AHCI-compliant hardware, and will override
the classic ATA driver if it is loaded as a module at boot time or compiled
into the kernel. The stack now support NCQ (tagged queueing) for increased
performance on modern SATA drives. It also supports port multipliers.

ATA drives are accessed via 'ada' device nodes. ATAPI drives are
accessed via 'cd' device nodes. They can all be enumerated and manipulated
via camcontrol, just like SCSI drives. SCSI commands are not translated to
their ATA equivalents; ATA native commands are used throughout the entire
stack, including camcontrol. See the camcontrol manpage for further
details. Testing this code may require that you update your fstab, and
possibly modify your BIOS to enable AHCI functionality, if available.

This code is very experimental at the moment. The userland ABI/API has
changed, so applications will need to be recompiled. It may change
further in the near future. The 'ada' device name may also change as
more infrastructure is completed in this project. The goal is to
eventually put all CAM busses and devices until newbus, allowing for
interesting topology and management options.

Few functional changes will be seen with existing SCSI/SAS/FC drivers,
though the userland ABI has still changed. In the future, transports
specific modules for SAS and FC may appear in order to better support
the topologies and capabilities of these technologies.

The modularization of CAM and the addition of the ATA/SATA modules is
meant to break CAM out of the mold of being specific to SCSI, letting it
grow to be a framework for arbitrary transports and protocols. It also
allows drivers to be written to support discrete hardware without
jeopardizing the stability of non-related hardware. While only an AHCI
driver is provided now, a Silicon Image driver is also in the works.
Drivers for ICH1-4, ICH5-6, PIIX, classic IDE, and any other hardware
is possible and encouraged. Help with new transports is also encouraged.

Submitted by: scottl, mav
Approved by: re

Don't call destroy_dev(9) with a mutex held. While here, shuffle
things around so the periph destructors look alike. Based on a patch
by Jaakko Heinonen.

Submitted by: Jaakko Heinonen
Reviewed by: scottl
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation

Add a helper function for registering async callbacks. Besides
eliminating a lot of duplicated code, this also fixes a locking edge case.

Eliminate the use of M_TEMP.

Remove Giant from CAM. Drivers (SIMs) now register a mutex that CAM will
use to synchornize and protect all data objects that are used for that
SIM. Drivers that are not yet MPSAFE register Giant and operate as
usual. RIght now, no drivers are MPSAFE, though a few will be changed
in the coming week as this work settles down.

The driver API has changed, so all CAM drivers will need to be recompiled.
The userland API has not changed, so tools like camcontrol do not need to
be recompiled.

Add an xpt_print function to reduce most of the xpt_print_path/printf
pairs. Convert the core code to use it.

Reviewed by: scsi (various folks weighing in with good advice)
MFC after: 2 weeks

Fix a place where we were referencing a pointer after it had been freed.

Submitted by: "Henry Miller" <hank@blackhole.com>
MFC after: 3 days

Start each of the license/copyright comments with /*-

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

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.

Device megapatch 1/6:

Free approx 86 major numbers with a mostly automatically generated patch.

A number of strategic drivers have been left behind by caution, and a few
because they still (ab)use their major number.

Use __FBSDID().

Use symbolic constants instead of "4".
Use arrays instead of relying on struct packing.

Identical md5(scsi_ch.o).

Allocate the devstat structure with devstat_new_entry().

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)

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.

Be consistent about "static" functions: if the function is marked
static in its prototype, mark it static at the definition too.

Inspired by: FlexeLint warning #512

Remove usage of cam_extend.c, replace with dev->si_drv1

PR: kern/39809
Approved by: gibbs

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Check the void * argument in the AC_FOUND_DEV case against NULL. Whether
correctly or not, this sometimes is propagated up via XPT.

Rewrite of the CAM error recovery code.

Some of the major changes include:

- The SCSI error handling portion of cam_periph_error() has
been broken out into a number of subfunctions to better
modularize the code that handles the hierarchy of SCSI errors.
As a result, the code is now much easier to read.

- String handling and error printing has been significantly
revamped. We now use sbufs to do string formatting instead
of using printfs (for the kernel) and snprintf/strncat (for
userland) as before.

There is a new catchall error printing routine,
cam_error_print() and its string-based counterpart,
cam_error_string() that allow the kernel and userland
applications to pass in a CCB and have errors printed out
properly, whether or not they're SCSI errors. Among other
things, this helped eliminate a fair amount of duplicate code
in camcontrol.

We now print out more information than before, including
the CAM status and SCSI status and the error recovery action
taken to remedy the problem.

- sbufs are now available in userland, via libsbuf. This
change was necessary since most of the error printing code
is shared between libcam and the kernel.

- A new transfer settings interface is included in this checkin.
This code is #ifdef'ed out, and is primarily intended to aid
discussion with HBA driver authors on the final form the
interface should take. There is example code in the ahc(4)
driver that implements the HBA driver side of the new
interface. The new transfer settings code won't be enabled
until we're ready to switch all HBA drivers over to the new
interface.

src/Makefile.inc1,
lib/Makefile: Add libsbuf. It must be built before libcam,
since libcam uses sbuf routines.

libcam/Makefile: libcam now depends on libsbuf.

libsbuf/Makefile: Add a makefile for libsbuf. This pulls in the
sbuf sources from sys/kern.

bsd.libnames.mk: Add LIBSBUF.

camcontrol/Makefile: Add -lsbuf. Since camcontrol is statically
linked, we can't depend on the dynamic linker
to pull in libsbuf.

camcontrol.c: Use cam_error_print() instead of checking for
CAM_SCSI_STATUS_ERROR on every failed CCB.

sbuf.9: Change the prototypes for sbuf_cat() and
sbuf_cpy() so that the source string is now a
const char *. This is more in line wth the
standard system string functions, and helps
eliminate warnings when dealing with a const
source buffer.

Fix a typo.

cam.c: Add description strings for the various CAM
error status values, as well as routines to
look up those strings.

Add new cam_error_string() and
cam_error_print() routines for userland and
the kernel.

cam.h: Add a new CAM flag, CAM_RETRY_SELTO.

Add enumerated types for the various options
available with cam_error_print() and
cam_error_string().

cam_ccb.h: Add new transfer negotiation structures/types.

Change inq_len in the ccb_getdev structure to
be "reserved". This field has never been
filled in, and will be removed when we next
bump the CAM version.

cam_debug.h: Fix typo.

cam_periph.c: Modularize cam_periph_error(). The SCSI error
handling part of cam_periph_error() is now
in camperiphscsistatuserror() and
camperiphscsisenseerror().

In cam_periph_lock(), increase the reference
count on the periph while we wait for our lock
attempt to succeed so that the periph won't go
away while we're sleeping.

cam_xpt.c: Add new transfer negotiation code. (ifdefed
out)

Add a new function, xpt_path_string(). This
is a string/sbuf analog to xpt_print_path().

scsi_all.c: Revamp string handing and error printing code.
We now use sbufs for much of the string
formatting code. More of that code is shared
between userland the kernel.

scsi_all.h: Get rid of SS_TURSTART, it wasn't terribly
useful in the first place.

Add a new error action, SS_REQSENSE. (Send a
request sense and then retry the command.)
This is useful when the controller hasn't
performed autosense for some reason.

Change the default actions around a bit.

scsi_cd.c,
scsi_da.c,
scsi_pt.c,
scsi_ses.c: SF_RETRY_SELTO -> CAM_RETRY_SELTO. Selection
timeouts shouldn't be covered by a sense flag.

scsi_pass.[ch]: SF_RETRY_SELTO -> CAM_RETRY_SELTO.

Get rid of the last vestiges of a read/write
interface.

libkern/bsearch.c,
sys/libkern.h,
conf/files: Add bsearch.c, which is needed for some of the
new table lookup routines.

aic7xxx_freebsd.c: Define AHC_NEW_TRAN_SETTINGS if
CAM_NEW_TRAN_CODE is defined.

sbuf.h,
subr_sbuf.c: Add the appropriate #ifdefs so sbufs can
compile and run in userland.

Change sbuf_printf() to use vsnprintf()
instead of kvprintf(), which is only available
in the kernel.

Change the source string for sbuf_cpy() and
sbuf_cat() to be a const char *.

Add __BEGIN_DECLS and __END_DECLS around
function prototypes since they're now exported
to userland.

kdump/mkioctls: Include stdio.h before cam.h since cam.h now
includes a function with a FILE * argument.

Submitted by: gibbs (mostly)
Reviewed by: jdp, marcel (libsbuf makefile changes)
Reviewed by: des (sbuf changes)
Reviewed by: ken

Send the remains (such as I have located) of "block major numbers" to
the bit-bucket.

Change the peripheral driver list from a linker set to module driven
driver registration. This should allow things like da, sa, cd etc to be
in seperate KLD's to the cam core and make them preloadable.

Remove unused #includes

Reviewed by: ken

Add the use of M_ZERO to some malloc calls.

Submitted by: josh@zipperup.org
Submitted by: Robert Drehmel <robd@gmx.net>
Approved by: gibbs

Remove unneeded <sys/buf.h> includes.

Due to some interesting cpp tricks in lockmgr, the LINT kernel shrinks
by 924 bytes.

Fix two problems in the ch(4) driver.

- Mike Smith discovered a panic in the changer probe code if the probe
command (mode sense) fails. So we need to release the CCB used in the
probe before we unlock the peripheral. (i.e. the same fix mjacob put in
the CD and DA drivers)

- A newline was missing in a warning message. (PR kern/17512)

PR: kern/17512
Submitted by: Louis Mamakos <louie@uu.net> (newline fix)

Do the minor changes needed because of change to ccb_getdev structure.
JKH Trading Stamps applied.

Reviewed by: gibbs@freebsd.org, ken@freebsd.org

Add make_dev functions. Tested with only one changer (sigh- all my others
are broken).
Submitted by: ken@freebsd.org

Remove five now unused fields from struct cdevsw. They should never
have been there in the first place. A GENERIC kernel shrinks almost 1k.

Add a slightly different safetybelt under nostop for tty drivers.

Add some missing FreeBSD tags

Remove unneeded disk-related includes.

$Id$ -> $FreeBSD$

Cast pointers to uintptr_t instead of casting them to u_long. Don't
depend on gcc's feature of casting lvalues. Cosmetic.

Simplify cdevsw registration.

The cdevsw_add() function now finds the major number(s) in the
struct cdevsw passed to it. cdevsw_add_generic() is no longer
needed, cdevsw_add() does the same thing.

cdevsw_add() will print an message if the d_maj field looks bogus.

Remove nblkdev and nchrdev variables. Most places they were used
bogusly. Instead check a dev_t for validity by seeing if devsw()
or bdevsw() returns NULL.

Move bdevsw() and devsw() functions to kern/kern_conf.c

Bump __FreeBSD_version to 400006

This commit removes:
72 bogus makedev() calls
26 bogus SYSINIT functions

if_xe.c bogusly accessed cdevsw[], author/maintainer please fix.

I4b and vinum not changed. Patches emailed to authors. LINT
probably broken until they catch up.

This commit should be a extensive NO-OP:

Reformat and initialize correctly all "struct cdevsw".

Initialize the d_maj and d_bmaj fields.

The d_reset field was not removed, although it is never used.

I used a program to do most of this, so all the files now use the
same consistent format. Please keep it that way.

Vinum and i4b not modified, patches emailed to respective authors.

Add a default async handler funstion to cam_periph.c to remove duplicated
code in all initiator type peripheral drivers.

scsi_target.c:
Release ATIO structures that wind up in the 'unkown command queue'
for consumption by our userland counterpart, back to the controller
when the exception for that command is cleared.

Add a facility in the CAM error handling code to retry selection timeouts.
If the client requests that the error recovery code retry a selection
timeout, it will be retried after half a second. The delay is to give the
device time to recover.

For most of these drivers, I only added selection timeout retries where
they were also retrying unit attention type errors. The sa(4) driver calls
saerror() in a number of places, but most of them don't request retrying
unit attentions.

Also, bump the default minimum CD changer timeout from 2 to 5 seconds and
the maximum timeout from 10 to 15 seconds. Some Pioneer changers seem to
have trouble with the shorter timeout.

Reviewed by: gibbs

Add a prioritization field to the devstat_add_entry() call so that
peripheral drivers can determine where in the devstat(9) list they are
inserted.

This requires recompilation of libdevstat, systat, vmstat, rpc.rstatd, and
any ports that depend on the devstat code, since the size of the devstat
structure has changed. The devstat version number has been incremented as
well to reflect the change.

This sorts devices in the devstat list in "more interesting" to "less
interesting" order. So, for instance, da devices are now more important
than floppy drives, and so will appear before floppy drives in the default
output from systat, iostat, vmstat, etc.

The order of devices is, for now, kept in a central table in devicestat.h.
If individual drivers were able to make a meaningful decision on what
priority they should be at attach time, we could consider splitting the
priority information out into the various drivers. For now, though, they
have no way of knowing that, so it's easier to put them in an easy to find
table.

Also, move the checkversion() call in vmstat(8) to a more logical place.

Thanks to Bruce and David O'Brien for suggestions, for reviewing this, and
for putting up with the long time it has taken me to commit it. Bruce did
object somewhat to the central priority table (he would rather the
priorities be distributed in each driver), so his objection is duly noted
here.

Reviewed by: bde, obrien

Staticize.

Reviewed by: gibbs

Return ENODEV instead of EINVAL when a particular exchange or move
operation exceeds the capabilities of the changer device.

Examine all occurrences of sprintf(), strcat(), and str[n]cpy()
for possible buffer overflow problems. Replaced most sprintf()'s
with snprintf(); for others cases, added terminating NUL bytes where
appropriate, replaced constants like "16" with sizeof(), etc.

These changes include several bug fixes, but most changes are for
maintainability's sake. Any instance where it wasn't "immediately
obvious" that a buffer overflow could not occur was made safer.

Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Mike Spengler <mks@networkcs.com>

Fix a few problems that Bruce noticed about a month ago, and fix oup one
other problem.

- Hold onto splsoftcam() in the peripheral driver open routines until we
have locked the periph. This eliminates a race condition.

- Disallow opening the pass driver when securelevel > 1.

- If a user tries to open the pass driver with O_NONBLOCK set, return
EINVAL instead of ENODEV. (noticed by gibbs)

Fix a problem with the way we handled device invalidation when attaching
to a device failed.

In theory, the same steps that happen when we get an AC_LOST_DEVICE async
notification should have been taken when a driver fails to attach. In
practice, that wasn't the case.

This only affected the da, cd and ch drivers, but the fix affects all
peripheral drivers.

There were several possible problems:
- In the da driver, we didn't remove the peripheral's softc from the da
driver's linked list of softcs. Once the peripheral and softc got
removed, we'd get a kernel panic the next time the timeout routine
called dasendorderedtag().
- In the da, cd and possibly ch drivers, we didn't remove the
peripheral's devstat structure from the devstat queue. Once the
peripheral and softc were removed, this could cause a panic if anyone
tried to access device statistics. (one component of the linked list
wouldn't exist anymore)
- In the cd driver, we didn't take the peripheral off the changer run
queue if it was scheduled to run. In practice, it's highly unlikely,
and maybe impossible that the peripheral would have been on the
changer run queue at that stage of the probe process.

The fix is:
- Add a new peripheral callback function (the "oninvalidate" function)
that is called the first time cam_periph_invalidate() is called for a
peripheral.

- Create new foooninvalidate() routines for each peripheral driver. This
routine is always called at splsoftcam(), and contains all the stuff
that used to be in the AC_LOST_DEVICE case of the async callback
handler.

- Move the devstat cleanup call to the destructor/cleanup routines, since
some of the drivers do I/O in their close routines.

- Make sure that when we're flushing the buffer queue, we traverse it at
splbio().

- Add a check for the invalid flag in the pt driver's open routine.

Reviewed by: gibbs

Clean up some unused variables.

Reviewed by: ken
Submitted by: phk

Fix a printf format warning that shows up when CAMDEBUG is defined.

Modify the changer driver so it can handle (hopefully!) changers that need
block descriptors enabled on mode sense commands.

Basically, we try sending a mode sense with block descriptors disabled (the
previous default), and if it fails, we try sending the mode sense with
block descriptors enabled. If that works, we note that in a runtime quirk
entry, so we don't bother disabling block descriptors again for the device.

This problem was first reported by Chris Jones <cjones@honors.montana.edu>
on one of the NetBSD lists, but I'd imagine that some FreeBSD users would
have run into it eventually as well, since our changer driver is derived
form the NetBSD changer driver.

Also, change some of the probe logic so that we do the right thing in the
case of a failure to attach.

Fix a memory leak in chgetparams().

Add a couple of inline helper functions to scsi_all.h to correctly return
the start of a mode page.

NetBSD PR: kern/6214
Reviewed by: gibbs

SCSI Peripheral drivers for CAM:

da - Direct Access Devices (disks, optical devices, SS disks)
cd - CDROM (or devices that can act like them, WORM, CD-RW, etc)
ch - Medium Changer devices.
sa - Sequential Access Devices (tape drives)
pass - Application pass-thru driver
targ - Target Mode "Processor Target" Emulator
pt - Processor Target Devices (scanners, cpus, etc.)

Submitted by: The CAM Team