MFC sa(4) and mt(1) improvements.

MFC sa(4) and mt(1) improvements.

This includes these changes: 279219, 279229, 279261, 279534, 279570,
280230, 280231.

In addition, bump __FreeBSD_version for the addition of the new
mtio(4) / sa(4) ioctls.

Thanks to Dan Langille, Harald Schmalzbauer and Rudolf Cejka for spending
a significant amount of time and effort testing these changes.

  ------------------------------------------------------------------------
  r279219 | ken | 2015-02-23 14:59:30 -0700 (Mon, 23 Feb 2015) | 282 lines

  Significant upgrades to sa(4) and mt(1).

  The primary focus of these changes is to modernize FreeBSD's
  tape infrastructure so that we can take advantage of some of the
  features of modern tape drives and allow support for LTFS.

  Significant changes and new features include:

   o sa(4) driver status and parameter information is now exported via an
     XML structure.  This will allow for changes and improvements later
     on that will not break userland applications.  The old MTIOCGET
     status ioctl remains, so applications using the existing interface
     will not break.

   o 'mt status' now reports drive-reported tape position information
     as well as the previously available calculated tape position
     information.  These numbers will be different at times, because
     the drive-reported block numbers are relative to BOP (Beginning
     of Partition), but the block numbers calculated previously via
     sa(4) (and still provided) are relative to the last filemark.
     Both numbers are now provided.  'mt status' now also shows the
     drive INQUIRY information, serial number and any position flags
     (BOP, EOT, etc.) provided with the tape position information.
     'mt status -v' adds information on the maximum possible I/O size,
     and the underlying values used to calculate it.

   o The extra sa(4) /dev entries (/dev/saN.[0-3]) have been removed.

     The extra devices were originally added as place holders for
     density-specific device nodes.  Some OSes (NetBSD, NetApp's OnTap
     and Solaris) have had device nodes that, when you write to them,
     will automatically select a given density for particular tape drives.

     This is a convenient way of switching densities, but it was never
     implemented in FreeBSD.  Only the device nodes were there, and that
     sometimes confused users.

     For modern tape devices, the density is generally not selectable
     (e.g. with LTO) or defaults to the highest availble density when
     the tape is rewritten from BOT (e.g. TS11X0).  So, for most users,
     density selection won't be necessary.  If they do need to select
     the density, it is easy enough to use 'mt density' to change it.

   o Protection information is now supported.  This is either a
     Reed-Solomon CRC or CRC32 that is included at the end of each block
     read and written.  On write, the tape drive verifies the CRC, and
     on read, the tape drive provides a CRC for the userland application
     to verify.

   o New, extensible tape driver parameter get/set interface.

   o Density reporting information.  For drives that support it,
     'mt getdensity' will show detailed information on what formats the
     tape drive supports, and what formats the tape drive supports.

   o Some mt(1) functionality moved into a new mt(3) library so that
     external applications can reuse the code.

   o The new mt(3) library includes helper routines to aid in parsing
     the XML output of the sa(4) driver, and build a tree of driver
     metadata.

   o Support for the MTLOAD (load a tape in the drive) and MTWEOFI
     (write filemark immediate) ioctls needed by IBM's LTFS
     implementation.

   o Improve device departure behavior for the sa(4) driver.  The previous
     implementation led to hangs when the device was open.

   o This has been tested on the following types of drives:
  	IBM TS1150
  	IBM TS1140
  	IBM LTO-6
  	IBM LTO-5
  	HP LTO-2
  	Seagate DDS-4
  	Quantum DLT-4000
  	Exabyte 8505
  	Sony DDS-2

  contrib/groff/tmac/doc-syms,
  share/mk/bsd.libnames.mk,
  lib/Makefile,
  	Add libmt.

  lib/libmt/Makefile,
  lib/libmt/mt.3,
  lib/libmt/mtlib.c,
  lib/libmt/mtlib.h,
  	New mt(3) library that contains functions moved from mt(1) and
  	new functions needed to interact with the updated sa(4) driver.

  	This includes XML parser helper functions that application writers
  	can use when writing code to query tape parameters.

  rescue/rescue/Makefile:
  	Add -lmt to CRUNCH_LIBS.

  src/share/man/man4/mtio.4
  	Clarify this man page a bit, and since it contains what is
  	essentially the mtio.h header file, add new ioctls and structure
  	definitions from mtio.h.

  src/share/man/man4/sa.4
  	Update BUGS and maintainer section.

  sys/cam/scsi/scsi_all.c,
  sys/cam/scsi/scsi_all.h:
  	Add SCSI SECURITY PROTOCOL IN/OUT CDB definitions and CDB building
  	functions.

  sys/cam/scsi/scsi_sa.c
  sys/cam/scsi/scsi_sa.h
  	Many tape driver changes, largely outlined above.

  	Increase the sa(4) driver read/write timeout from 4 to 32
  	minutes.  This is based on the recommended values for IBM LTO
  	5/6 drives.  This may also avoid timeouts for other tape
  	hardware that can take a long time to do retries and error
  	recovery.  Longer term, a better way to handle this is to ask
  	the drive for recommended timeout values using the REPORT
  	SUPPORTED OPCODES command.  Modern IBM and Oracle tape drives
  	at least support that command, and it would allow for more
  	accurate timeout values.

  	Add XML status generation.  This is done with a series of
  	macros to eliminate as much duplicate code as possible.  The
  	new XML-based status values are reported through the new
  	MTIOCEXTGET ioctl.

  	Add XML driver parameter reporting, using the new MTIOCPARAMGET
  	ioctl.

  	Add a new driver parameter setting interface, using the new
  	MTIOCPARAMSET and MTIOCSETLIST ioctls.

  	Add a new MTIOCRBLIM ioctl to get block limits information.

  	Add CCB/CDB building routines scsi_locate_16, scsi_locate_10,
  	and scsi_read_position_10().

  	scsi_locate_10 implements the LOCATE command, as does the
  	existing scsi_set_position() command.  It just supports
  	additional arguments and features.  If/when we figure out a
  	good way to provide backward compatibility for older
  	applications using the old function API, we can just revamp
  	scsi_set_position().  The same goes for
  	scsi_read_position_10() and the existing scsi_read_position()
  	function.

  	Revamp sasetpos() to take the new mtlocate structure as an
  	argument.  It now will use either scsi_locate_10() or
  	scsi_locate_16(), depending upon the arguments the user
  	supplies.  As before, once we change position we don't have a
  	clear idea of what the current logical position of the tape
  	drive is.

  	For tape drives that support long form position data, we
  	read the current position and store that for later reporting
  	after changing the position.  This should help applications
  	like Bacula speed tape access under FreeBSD once they are
  	modified to support the new ioctls.

  	Add a new quirk, SA_QUIRK_NO_LONG_POS, that is set for all
  	drives that report SCSI-2 or older, as well as drives that
  	report an Illegal Request type error for READ POSITION with
  	the long format.  So we should automatically detect drives
  	that don't support the long form and stop asking for it after
  	an initial try.

  	Add a partition number to the sa(4) softc.

  	Improve device departure handling. The previous implementation
  	led to hangs when the device was open.

  	If an application had the sa(4) driver open, and attempted to
  	close it after it went away, the cam_periph_release() call in
  	saclose() would cause the periph to get destroyed because that
  	was the last reference to it.  Because destroy_dev() was
  	called from the sa(4) driver's cleanup routine (sacleanup()),
  	and would block waiting for the close to happen, a deadlock
  	would result.

  	So instead of calling destroy_dev() from the cleanup routine,
  	call destroy_dev_sched_cb() from saoninvalidate() and wait for
  	the callback.

  	Acquire a reference for devfs in saregister(), and release it
  	in the new sadevgonecb() routine when all devfs devices for
  	the particular sa(4) driver instance are gone.

  	Add a new function, sasetupdev(), to centralize setting
  	per-instance devfs device parameters instead of repeating the
  	code in saregister().

  	Add an open count to the softc, so we know how many
  	peripheral driver references are a result of open
         	sessions.

  	Add the D_TRACKCLOSE flag to the cdevsw flags so
  	that we get a 1:1 mapping of open to close calls
  	instead of a N:1 mapping.

  	This should be a no-op for everything except the
  	control device, since we don't allow more than one
  	open on non-control devices.

  	However, since we do allow multiple opens on the
  	control device, the combination of the open count
  	and the D_TRACKCLOSE flag should result in an
  	accurate peripheral driver reference count, and an
  	accurate open count.

  	The accurate open count allows us to release all
  	peripheral driver references that are the result
  	of open contexts once we get the callback from devfs.

  sys/sys/mtio.h:
  	Add a number of new mt(4) ioctls and the requisite data
  	structures.  None of the existing interfaces been removed
  	or changed.

  	This includes definitions for the following new ioctls:

  	MTIOCRBLIM      /* get block limits */
  	MTIOCEXTLOCATE	/* seek to position */
  	MTIOCEXTGET     /* get tape status */
  	MTIOCPARAMGET	/* get tape params */
  	MTIOCPARAMSET	/* set tape params */
  	MTIOCSETLIST	/* set N params */

  usr.bin/mt/Makefile:
  	mt(1) now depends on libmt, libsbuf and libbsdxml.

  usr.bin/mt/mt.1:
  	Document new mt(1) features and subcommands.

  usr.bin/mt/mt.c:
  	Implement support for mt(1) subcommands that need to
  	use getopt(3) for their arguments.

  	Implement a new 'mt status' command to replace the old
  	'mt status' command.  The old status command has been
  	renamed 'ostatus'.

  	The new status function uses the MTIOCEXTGET ioctl, and
  	therefore parses the XML data to determine drive status.
  	The -x argument to 'mt status' allows the user to dump out
  	the raw XML reported by the kernel.

  	The new status display is mostly the same as the old status
  	display, except that it doesn't print the redundant density
  	mode information, and it does print the current partition
  	number and position flags.

  	Add a new command, 'mt locate', that will supersede the
  	old 'mt setspos' and 'mt sethpos' commands.  'mt locate'
  	implements all of the functionality of the MTIOCEXTLOCATE
  	ioctl, and allows the user to change the logical position
  	of the tape drive in a number of ways.  (Partition,
  	block number, file number, set mark number, end of data.)
  	The immediate bit and the explicit address bits are
  	implemented, but not documented in the man page.

  	Add a new 'mt weofi' command to use the new MTWEOFI ioctl.
  	This allows the user to ask the drive to write a filemark
  	without waiting around for the operation to complete.

  	Add a new 'mt getdensity' command that gets the XML-based
  	tape drive density report from the sa(4) driver and displays
  	it.  This uses the SCSI REPORT DENSITY SUPPORT command
  	to get comprehensive information from the tape drive about
  	what formats it is able to read and write.

  	Add a new 'mt protect' command that allows getting and setting
  	tape drive protection information.  The protection information
  	is a CRC tacked on to the end of every read/write from and to
  	the tape drive.

  Sponsored by:	Spectra Logic
  MFC after:	1 month

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r279229 | ken | 2015-02-23 22:43:16 -0700 (Mon, 23 Feb 2015) | 5 lines

  Fix printf format warnings on sparc64 and mips.

  Sponsored by:	Spectra Logic
  MFC after:	1 month

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r279261 | ken | 2015-02-24 21:30:23 -0700 (Tue, 24 Feb 2015) | 23 lines

  Fix several problems found by Coverity.

  lib/libmt/mtlib.c:
  	In mt_start_element(), make sure we don't overflow the
  	cur_sb array.  CID 1271325

  usr.bin/mt/mt.c:
  	In main(), bzero the mt_com structure so that we aren't
  	using any uninitialized stack variables.  CID 1271319

  	In mt_param(), only allow one -s and one -p argument.  This
  	will prevent a memory leak caused by overwriting the
  	param_name and/or param_value variables.  CID 1271320 and
  	CID 1271322

  	To make things simpler in mt_param(), make sure there
  	there is only one exit path for the function.  Make sure
  	the arguments are explicitly freed.

  Sponsored by:	Spectra Logic
  Pointed out by:	emaste
  MFC after:	1 month

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r279534 | ken | 2015-03-02 11:09:49 -0700 (Mon, 02 Mar 2015) | 18 lines

  Change the sa(4) driver to check for long position support on
  SCSI-2 devices.

  Some older tape devices claim to be SCSI-2, but actually do support
  long position information.  (Long position information includes
  the current file mark.)  For example, the COMPAQ SuperDLT1.

  So we now only disable the check on SCSI-1 and older devices.

  sys/cam/scsi/scsi_sa.c:
  	In saregister(), only disable fetching long position
  	information on SCSI-1 and older drives.  Update the
  	comment to explain why.

  Confirmed by:	dvl
  Sponsored by:	Spectra Logic
  MFC after:	3 weeks

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r279570 | ken | 2015-03-03 15:49:07 -0700 (Tue, 03 Mar 2015) | 21 lines

  Add density code for DAT-72, and notes on DAT-160.

  As it turns out, the density code for DAT-160 (0x48) is the same
  as for SDLT220.  Since the SDLT values are already in the table,
  we will leave them in place.

  Thanks to Harald Schmalzbauer for confirming the DAT-72 density code.

  lib/libmt/mtlib.c:
  	Add DAT-72 density code, and commented out DAT-160 density
  	code.  Explain why DAT-160 is commented out.  Add notes
  	explaining where the bpi values for these formats came from.

  usr.bin/mt/mt.1:
  	Add DAT-72 density code, and add a note explaining that
  	the SDLTTapeI(110) density code (0x48) is the same as
  	DAT-160.

  Sponsored by:	Spectra Logic
  MFC after:	3 weeks

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r280230 | ken | 2015-03-18 14:52:34 -0600 (Wed, 18 Mar 2015) | 25 lines

  Fix a couple of problems in the sa(4) media type reports.

  The only drives I have discovered so far that support medium type
  reports are newer HP LTO (LTO-5 and LTO-6) drives.  IBM drives
  only support the density reports.

  sys/cam/scsi/scsi_sa.h:
  	The number of possible density codes in the medium type
  	report is 9, not 8.  This caused problems parsing all of
  	the medium type report after this point in the structure.

  usr.bin/mt/mt.c:
  	Run the density codes returned in the medium type report
  	through denstostring(), just like the primary and secondary
  	density codes in the density report.  This will print the
  	density code in hex, and give a text description if it
  	is available.

  Thanks to Rudolf Cejka for doing extensive testing with HP LTO drives
  and Bacula and discovering these problems.

  Tested by:	Rudolf Cejka <cejkar at fit.vutbr.cz>
  Sponsored by:	Spectra Logic
  MFC after:	4 days

  ------------------------------------------------------------------------
  ------------------------------------------------------------------------
  r280231 | ken | 2015-03-18 14:54:54 -0600 (Wed, 18 Mar 2015) | 16 lines

  Improve the mt(1) rblim display.

  The granularity reported by READ BLOCK LIMITS is an exponent, not a
  byte value.  So a granularity of 0 means 2^0, or 1 byte.  A
  granularity of 1 means 2^1, or 2 bytes.

  Print out the individual block limits on separate lines to improve
  readability and avoid exceeding 80 columns.

  usr.bin/mt/mt.c:
  	Fix and improve the 'mt rblim' output.  Add a MT_PLURAL()
  	macro so we can print "byte" or "bytes" as appropriate.

  Sponsored by:	Spectra Logic
  MFC after:	4 days

  ------------------------------------------------------------------------

Sponsored by:	Spectra Logic

git-svn-id: svn://svn.freebsd.org/base/stable/10@280438 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f