sa(4) driver changes available for test
Kenneth D. Merry
ken at FreeBSD.ORG
Mon Mar 2 00:18:44 UTC 2015
On Sun, Mar 01, 2015 at 17:06:24 -0500, Dan Langille wrote:
>
> > On Feb 13, 2015, at 7:32 PM, Kenneth D. Merry <ken at freebsd.org> wrote:
> >
> >
> > I have a fairly large set of changes to the sa(4) driver and mt(1) driver
> > that I'm planning to commit in the near future.
> >
> > A description of the changes is here and below in this message.
> >
> > If you have tape hardware and the inclination, I'd appreciate testing and
> > feedback.
> >
> > ============
> > Rough draft commit message:
> >
> > http://people.freebsd.org/~ken/sa_changes_commitmsg.20150213.3.txt
> >
> > The patches against FreeBSD/head as of SVN revision 278706:
> >
> > http://people.freebsd.org/~ken/sa_changes.20150213.3.txt
> >
> > And (untested) patches against FreeBSD stable/10 as of SVN revision 278721.
> >
> > http://people.freebsd.org/~ken/sa_changes.stable_10.20150213.3.txt
> > ============
> >
> > The intent is to get the tape infrastructure more up to date, so we can
> > support LTFS and more modern tape drives:
> >
> > http://www.ibm.com/systems/storage/tape/ltfs/
> >
> > I have ported IBM's LTFS Single Drive Edition to FreeBSD. The port depends
> > on the patches linked above. It isn't fully cleaned up and ready for
> > redistribution. If you're interested, though, let me know and I'll tell
> > you when it is ready to go out. You need an IBM LTO-5, LTO-6, TS1140 or
> > TS1150 tape drive. HP drives aren't supported by IBM's LTFS, and older
> > drives don't have the necessary features to support LTFS.
> >
> > The commit message below outlines most of the changes.
> >
> > A few comments:
> >
> > 1. I'm planning to commit the XPT_DEV_ADVINFO changes separately.
> >
> > 2. The XML output is similar to what GEOM and CTL do. It would be nice to
> > figure out how to put a standard schema on it so that standard tools
> > could read it. I don't know how feasible that is, since I haven't
> > time to dig into it. If anyone has suggestions on whether that is
> > feasible or advisable, I'd appreciate feedback.
> >
> > 3. I have tested with a reasonable amount of tape hardware (see below for a
> > list), but more testing and feedback would be good.
> >
> > 4. Standard 'mt status' output looks like this:
> >
> > # mt -f /dev/nsa3 status -v
> > Drive: sa3: <IBM ULTRIUM-HH6 E4J1> Serial Number: 101500520A
> > ---------------------------------
> > Mode Density Blocksize bpi Compression
> > Current: 0x5a:LTO-6 variable 384607 enabled (0xff)
> > ---------------------------------
> > Current Driver State: at rest.
> > ---------------------------------
> > Partition: 0 Calc File Number: 0 Calc Record Number: 0
> > Residual: 0 Reported File Number: 0 Reported Record Number: 0
> > Flags: BOP
> >
> > 5. 'mt status -v' looks like this:
> >
> > # mt -f /dev/nsa3 status -v
> > Drive: sa3: <IBM ULTRIUM-HH6 E4J1> Serial Number: 101500520A
> > ---------------------------------
> > Mode Density Blocksize bpi Compression
> > Current: 0x5a:LTO-6 variable 384607 enabled (0xff)
> > ---------------------------------
> > Current Driver State: at rest.
> > ---------------------------------
> > Partition: 0 Calc File Number: 0 Calc Record Number: 0
> > Residual: 0 Reported File Number: 0 Reported Record Number: 0
> > Flags: BOP
> > ---------------------------------
> > Tape I/O parameters:
> > Maximum I/O size allowed by driver and controller (maxio): 1081344 bytes
> > Maximum I/O size reported by controller (cpi_maxio): 5197824 bytes
> > Maximum block size supported by tape drive and media (max_blk): 8388608 bytes
> > Minimum block size supported by tape drive and media (min_blk): 1 bytes
> > Block granularity supported by tape drive and media (blk_gran): 0 bytes
> > Maximum possible I/O size (max_effective_iosize): 1081344 bytes
>
>
> # mtx -f /dev/pass0 status
> Storage Changer /dev/pass0:2 Drives, 10 Slots ( 0 Import/Export )
> Data Transfer Element 0:Empty
> Data Transfer Element 1:Empty
> Storage Element 1:Empty
> Storage Element 2:Empty
> Storage Element 3:Empty
> Storage Element 4:Full :VolumeTag=FAI260
> Storage Element 5:Full :VolumeTag=FAI261
> Storage Element 6:Full :VolumeTag=FAI262
> Storage Element 7:Full :VolumeTag=FAI263
> Storage Element 8:Empty
> Storage Element 9:Empty
> Storage Element 10:Empty
>
>
> It was at this point I spent the next 90 minute trying to get the tape
> drive out of the tape library to free a stuck tape. Some of this was spent
> attempting, and failing, to undo a stripped screw. I stopped the attempt when
> I noticed the screw did need to be removed. :/
Thanks for all of the effort! Looks like it is paying off! :)
> When I do this command, I hear the drive move a bit, to read the tape:
>
> # mt -f /dev/nsa1 status
> Drive: sa1: <DEC TZ89 (C) DEC 2561> Serial Number: CXA09S1340
> ---------------------------------
> Mode Density Blocksize bpi Compression
> Current: 0x1b:DLTapeIV(35GB) variable 85937 enabled (IDRC)
> ---------------------------------
> Current Driver State: at rest.
> ---------------------------------
> Partition: 0 Calc File Number: 0 Calc Record Number: 0
> Residual: 0 Reported File Number: -1 Reported Record Number: -1
> Flags: None
Looks like the drive isn't reporting position information. It will still
be useful to try it with Bacula, though.
> # mt -f /dev/nsa1 ostatus
> Mode Density Blocksize bpi Compression
> Current: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> ---------available modes---------
> 0: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 1: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 2: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 3: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> ---------------------------------
> Current Driver State: at rest.
> ---------------------------------
> File Number: 0 Record Number: 0 Residual Count 0
>
>
> After doing a very small tar -c and tar -x, I have:
>
> # mt -f /dev/nsa1 /dev/nsa1 ostatus
> Mode Density Blocksize bpi Compression
> Current: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> ---------available modes---------
> 0: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 1: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 2: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> 3: 0x1b:DLTapeIV(35GB) variable 85937 IDRC
> ---------------------------------
> Current Driver State: at rest.
> ---------------------------------
> File Number: 0 Record Number: 7 Residual Count 0
Woohoo! It works.
> # mt -f /dev/nsa1 status -v
> Drive: sa1: <DEC TZ89 (C) DEC 2561> Serial Number: CXA09S1340
> ---------------------------------
> Mode Density Blocksize bpi Compression
> Current: 0x1b:DLTapeIV(35GB) variable 85937 enabled (IDRC)
> ---------------------------------
> Current Driver State: at rest.
> ---------------------------------
> Partition: 0 Calc File Number: 0 Calc Record Number: 7
> Residual: 0 Reported File Number: -1 Reported Record Number: -1
> Flags: None
> ---------------------------------
> Tape I/O parameters:
> Maximum I/O size allowed by driver and controller (maxio): 65536 bytes
> Maximum I/O size reported by controller (cpi_maxio): 0 bytes
> Maximum block size supported by tape drive and media (max_blk): 16777214 bytes
> Minimum block size supported by tape drive and media (min_blk): 2 bytes
> Block granularity supported by tape drive and media (blk_gran): 0 bytes
> Maximum possible I/O size (max_effective_iosize): 65536 bytes
>
> I may not get to testing Bacula today.
>
> Based on the above, is there any commands you'd like me to try?
Aside from making sure things work okay with Bacula, that is probably
sufficient. These drives won't support density reports or position
information.
> Read below regarding two tape drives
>
> >
> > 6. Existing applications should work without changes. If not, please let
> > me know. Hopefully they will move over time to the new interfaces.
> >
> > 7. There are lots of additional features that could be added later.
> > Append-only support, encryption, more log pages, etc.
> >
> > 8. I have SCSI READ ATTRIBUTE changes for camcontrol(8) that will go in
> > separately. These changes allow displaying the contents of the MAM
> > (Medium Auxiliary Memory) chips on LTO, TS and other modern tape drives.
> > These are good, and a future possible direction is adding attributes
> > to the status XML from the sa(4) driver.
> >
> > ============
> > 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.
>
> How does this affect a tape library with more than one tape drive?
>
> [root at cuppy:~] # camcontrol amcontrol devlist
> <DEC TL800 (C) DEC 0525> at scbus0 target 0 lun 0 (pass0,ch0)
> <DEC TZ89 (C) DEC 2561> at scbus0 target 2 lun 0 (sa1,pass2)
> <WDC WD5000AAKS-00YGA0 12.01C02> at scbus1 target 0 lun 0 (pass3,ada0)
> <WDC WD5000AAKS-00YGA0 12.01C02> at scbus2 target 0 lun 0 (pass4,ada1)
> <AHCI SGPIO Enclosure 1.00 0001> at scbus3 target 0 lun 0 (pass5,ses0)
>
> This system has two tapes drives and I can access them through the front panel but:
>
> # ls -l /dev/*sa*
> crw-rw---- 1 root operator 0x65 Feb 28 22:04 /dev/esa1
> crw-rw---- 1 root operator 0x64 Mar 1 22:43 /dev/nsa1
> crw-rw---- 1 root operator 0x63 Feb 28 22:04 /dev/sa1
> crw-rw---- 1 root operator 0x62 Feb 28 22:04 /dev/sa1.ctl
>
> ... only one tape drives shows up.
Hmm. The tape drive is listed as sa1, which implies that there may be an
sa0 that was there previously or is in the process of probing. What does
dmesg show? How about 'camcontrol devlist -v'?
I would look at cabling and termination. Is this your library?
http://manx.classiccmp.org/collections/mds-199909/cd3/tape/tl891uga.pdf
If it is close enough, there are 6 connectors on the back. You would want
to have something plugged into all 6, either a cable or a terminator.
In the manual above, the SCSI IDs are set via the front panel. If the
other drive is on the same bus as the drive above and the library device,
it should be at a separate SCSI ID.
> > 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.
> >
> > sys/cam/cam_ccb.h
> > Add a new flag value for the XPT_DEV_ADVINFO CCB, CDAI_FLAG_NONE.
> >
> > sbin/camcontrol/camcontrol.c,
> > sys/cam/scsi/scsi_da.c,
> > sys/cam/scsi/scsi_enc_ses.c,
> > sys/dev/mps/mps_sas.c:
> > Make sure the flags for the XPT_DEV_ADVINFO CCB are set correctly.
> > This prevents unintended attempts to set advanced information
> > values when XPT_DEV_ADVINFO CCBs are not pre-zeroed.
> >
> > 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
> >
> > Thanks,
> >
> > Ken
> > --
> > Kenneth Merry
> > ken at FreeBSD.ORG
> > _______________________________________________
> > freebsd-scsi at freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-scsi
> > To unsubscribe, send any mail to "freebsd-scsi-unsubscribe at freebsd.org"
>
> ?
> Dan Langille
> http://langille.org/
>
>
>
>
>
--
Kenneth Merry
ken at FreeBSD.ORG
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