Date: Wed, 18 Feb 2015 17:13:47 -0700 From: "Kenneth D. Merry" <ken@FreeBSD.ORG> To: scsi@freebsd.org, current@freebsd.org Subject: Re: sa(4) driver changes available for test Message-ID: <20150219001347.GA57416@mithlond.kdm.org> In-Reply-To: <20150214003232.GA63990@mithlond.kdm.org> References: <20150214003232.GA63990@mithlond.kdm.org>
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I have updated the patches. I have removed the XPT_DEV_ADVINFO changes from the patches to head, since I committed those separately. I have (hopefully) fixed the build for the stable/10 patches by MFCing dependencies. (One of them mav did for me, thanks!) Rough draft commit message: http://people.freebsd.org/~ken/sa_changes_commitmsg.20150218.1.txt The patches against FreeBSD/head as of SVN revision 278975: http://people.freebsd.org/~ken/sa_changes.20150218.1.txt And (untested) patches against FreeBSD stable/10 as of SVN revision 278974: http://people.freebsd.org/~ken/sa_changes.stable_10.20150218.1.txt Thanks, Ken On Fri, Feb 13, 2015 at 17:32:32 -0700, Kenneth D. Merry 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 > > 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. > > 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@FreeBSD.ORG -- Kenneth Merry ken@FreeBSD.ORG
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