release-notes

linux-2.6.15.6

Much improved driver interruption
---------------------------------
Most possible loops have been broken and signal detection
has been improved.
In most cases the driver can be aborted by ^C (SIGINT) and
SIGKILL (kill -9) will generate be a sure kill.
(Note that aborting a tape operation may damage the last
data written to tape)

Improved error recovery
-----------------------
Ftape now returns an error (ENODATA) to the application if
a segment proves to be unrecoverable and then skips the
bad segment.
This causes most applications to continue to work (tar
and afio) loosing only a small amount (up to 29 Kb) of data.
Retried read operations will now be done slightly off-track
to improve the chance of success. Serious head off-track
errors will be detected.

FC-10 and FC-20 controllers
---------------------------
Ftape now supports both the old CMS FC-10 and the newer FC-20
controllers.
Because the operation of these cards is still undocumented,
thus far they will only work with the default settings (See
Makefile). Any feed-back on how to use them with other settings
will be welcome !
Compilation will fail if one changes the settings to illegal
values.

Kernels and compilers
---------------------
Ftape is currently being developed using the 2.5.8 compiler.
The older 2.4.5 probably works too (Set option in Makefile!).
I have no experience with any later compilers nor Elf support.
Any information on this is welcome.
The latest kernel I have tested ftape with is 1.2.6.

Compression
-----------
An impressive collection of changes for ftape including
on-the-fly compression is still lying on my desk.
If 2.03 proves to be reliable I might start integrating these
but as usual, I'm short in time :-(

Formatting
----------
There is still no way to format tapes under Linux. As far as
I know all attempts to write such a program have died now.
Since formatted tapes are rather common now, I think all we
need is a utility that writes a worst case pattern and verifies
that with the drive put in verify mode, reducing margins.
Any takers ?

Furthermore
-----------
Cleaned up messages.
Prepared to support multiple tape drives on one fdc.
Thanks to all the people who sent bug reports and helped me
improve the driver. Without trying to be complete I'll mention
Gary Anderson (without his accurate reports and unreliable
hardware there wouldn't be a 2.03), Stefan Kneifel (FC-20),
Robert Broughton (FC-20, you were almost there ;-), Bjorn
Ekwall (for the versioned modules and buggy insmod ;-), Peter
Fox, Christopher Oliver, Ralph Whittaker and not the least
Linus Torvalds (for Linux and keeping me busy because of
changes to the kernel ;-)
Thanks to anyone I forgot, for the bug reports, the ftape
bashing and the mental support...


That's it for now. Have Fun,

Bas.


===== Release notes for ftape-2.02g, 06/05/95 =====

- Added extra test to break read-id loop with signal.
- Changed rewind code to handle negative overshoot for drives
  that take very long to start or stop.
- Let use of get/set i/o-regions depend on kernel version.
- Changed code to use a more general test for conditional
  compilations depending on kernel version.
- Improved micro-step functionality to go off-track only
  while reading (id & data).
- Added failure on tape-not-referenced bit in ftape_command.
- Added FOREVER option to read-wait routine.
- Changed read-id to use shorter timeout causing smaller
  rewinds on timeout.
- Made kernel-interface functions static.


===== Release notes for ftape-2.02f, 03/05/95 =====

- Added support for dual tape drives on my system, extended Configure
  script to detect host 'dodo'.
- Log media defect in history if ecc failed and no data was returned.
- Fixed Configure script that was failing for kernel versions with
  double digit version or revision numbers.


===== Release notes for ftape-2.02e, 01/05/95 =====

- Fixed reposition loop at logical eot (failing read_id).
- Fixed 34 segment offset when rewinding.
- Added fast seek capability for more than 255 segments.
- Fixed wrong busy result from ftape_command causing reverse
  seek to fail.
- Added breakout from infinite rewind loop (if something fails).


===== Release notes for ftape-2.02d, 30/04/95 =====

- Improved abortion on signals: Interrupt will make a graceful
  exit, Kill will be less nice and should be used if everything
  else fails.
- Included check for tape-head off track.
- Implemented exit from tape-start loop.
- Added kernel io-port registration.
- Implemented skip of failing segment (ENODATA) on ecc failure.
  This allows afio and tar to continue when the tape is damaged.
- Made distinction between drive names with different codes.


===== Release notes for ftape-2.02c, 22/04/95 =====

- Fixed too tight command queueing after tape stop/pause command
  issued from within interrupt service routine (Showed as timeout
  on Acknowledge errors during retries on some systems)
- Tried to fix timeouts when using 425 ft tape because the extended
  length doesn't seem to be detected by the hardware.
  We now use the format code from the header segment so adjust the
  timing after reading the header segment.
- Fixed some messages stating 'unexpected something...' being not
  unexpected anymore.
- Started preparations for merge of dynamic buffer allocation and
  compression code.
- Changed some debug messages to include relevant segment information
  at level 4.
- Included early bail-out when drive offline, preventing a lot of
  false messages.
- Moved ftape_parameter_xxx() offsets into function instead of in calls.
- Removed 'weird, drive busy but no data' error when caused by
  an error during a read-id.
- Improved 'timeout on acknowledge' diagnostics.
- Moved MODULE option into Configure.
- Reduced code size when no tracing at all was set (Claus Heine).
- No longer log error code 0 (no error) as an error.


===== Release notes for ftape-2.02b, 09/04/95 =====

- Relaxed timing for status operation and displaying
  abnormal results. Hopefully this shows what's going
  wrong with the Conner TSM850R drives.
- Created script for configuration, using version number
  of kernel source if available, otherwise /proc/version.
- Fixed conditionals in kernel-interface.c.
- Removed unavoidable TRACE output.


===== Release notes for ftape-2.02a, 01/04/95 =====

- Implemented `new-style' (versioned) modules support for new
  kernels.
- Reduced size of module by moving static data to bss.
- Now using version number of kernel source instead of running
  kernel for kernel versions >= 1.1.82
- Added feedback on drive speeds to vendor information.
- Included fixed insmod sources to distribution (Let's hope
  the modules distribution get fixed soon :-/).

Note that I haven't yet implemented any of the code extension I
received. I hope to find some time to do this soon.


===== Release notes for ftape-2.02, 15/01/95 =====


- Fixed failing repositioning when overshoot was incremented.
- Fixed rate selection: Because of a deficiency in the QIC-117
  specification one cannot distinguish between a not implemented
  and a failing command. Therefor we now try to find out if the
  drive does support this command before usage.
- Fixed error retry using wrong offset in fdc-isr.
- Improved retry code to retry only once on a single no-data
  error in a segment.
- Validate sector number extracted from eof mark because an
  invalid file mark (due to ???) could cause kernel panic.
- Split ftape-io.c into ftape-io.c and ftape-ctl.c files.
- Corrected too high media error count after writing to
  a bad tape.
- Added #include <asm/segment.h> again because old kernel versions
  need it.
- Fixed fdc not being disabled when open failed because no tape
  drive was found.
- Fixed problem with soft error in sector 32 (shift operator with
  shiftcount 32 is not defined).


===== Release notes for ftape-2.01, 08/01/95 =====


- Removed TESTING setting from distributed Makefile.
- Fixed `mt asf' failure: Rewind was deferred to close which
  overruled the fsf ioctl.
- Prevented non-interruptible commands being interrupted.
- Added missing timeout.pause setting.
- Maximum tape speed read from drive type information table.
  If the information is not in the table (0) the drive will
  determine the speed itself and put a message in the logfile.
  This information should then be added to the table in the
  vendors.h file (and reported to me).
- Added call to ftape_init_drive after soft reset for those
  (antique) drives that don't do an implicit seek_load_point
  after a reset or power up.
- Don't try to set data rate if reset failed.
- Prevent update of seek variables when starting from the
  beginning or the end of the tape.
- Fixed wrong adjustment of overshoot in seek_forward().
- Added sync to Makefile (again).
- Added code to diagnose timer problems (calibr.c).
- Replaced time differences by timediff calls.
- Removed reference to do_floppy from object for recent kernels.
- Fixed wrong display of 'failing dma controller' message.
- Removed various no longer used #include statements.
- Added max. tape speed value to vendor-struct.
- Changed ftape-command to check pre-conditions and wait
  if needed.
- Further updated qic117.h to rev G.
- Combined command name table and restrictions table to one.
  Extended this table with some new fields.
- Increased timeout on Ack timer value and included code to
  report out of spec behaviour.
- Increased rewind timeout margin to calculated + 20%.
- Improved data rate selection so it won't fail on some
  older (pre standard) drives.
- Changed initialisation code so drive will be rewound if the
  driver is reloaded and the tape is not at bot.
- Moved some of the flush operations from close to the ioctls.
- Added exit code value to failing verify area message.
- Loop until tape halted in smart-stop.
- Fast seek handled specially if located at bot or eot.
- Being more conservative on overshoot value.


===== Release notes for ftape-2.00, 31/12/94 =====

  The Install-guide is completely rewritten and now also includes
some information on how to use the driver. If you're either new
to ftape or new to Unix tape devices make sure to read it !

  If you own a pci system and experience problems with the
ftape driver make sure to read the README.PCI file. It contains
some hints on how to fix your hardware.

  For anybody who hasn't noticed: The version number of the
driver has been incremented (The latest released version has
been version 1.14d).
  This has been done for two major reasons:

  o  A new (better) error recovery scheme is implemented.
  o  Support for new drive types has been added.

  All these improvements/changes will probably include a couple
of new (and old?) bugs. If you encounter any problems that you think
I'm not yet aware of, feel free to send a report to <[e-mail]>.
  I recommend keeping a version of ftape-1.14d available, just
in case ;-)

  This version should work with all kernel versions from 1.0.9 up
to 1.1.72 (and probably earlier and later versions too).


Major new features:

- Better handling of tapes with defects: When a sector repeatedly
  (SOFT_RETRIES in ftape.h) cannot be written to or read from it is
  marked as an hard error and gets skipped.
  The error correction code can handle up to three of these hard
  errors provided there are no other errors in that segment (32 Kb).
  
- Allows writing to tapes with defects (although the risk of loosing
  data increases !)
  Look for the media-defects entry printed with the statistics when
  the tape is closed. A non-zero value here shows a bad tape.
  [the actual count is wrong (too high), this is a known bug].

- Use of backup header segment if first one is failing.

- Support for extended length tapes with QIC-80: both 425 and 1100 ft.
  0.25 inch tapes are now recognized and handled.

- Support for new QIC-80 drives with 8 mm `wide' tapes (e.g. Conner
  TSM 420).

- Support for new QIC-3010 and QIC-3020 drives (experimental) with
  both 0.25 inch and 8 mm tapes.

Some minor features were added, a couple of small bugs were fixed and
probably some new ones introduced ;-).

[lseek() didn't make it into this version]

Have fun,

Bas.
----
 LocalWords:  ftape MCONFIG mt VFS zftape resp sftape proc subdir MTIOCVOLINFO
 LocalWords:  MTIOCGETSIZE BOT EOD MTBSF zft kerneld modprobe kdtime contrib TR
 LocalWords:  MTSETBLK afio uninstall texi www EIO QIC init sft eof aka dma GB
 LocalWords:  SIGKILL MTIOCFTCMD mmap Iomega FDC fdc io gnumt mtio fc asm inb
 LocalWords:  outb ft qic frontend TeXinfo irq mach MODVERSIONS CONFIG html dvi
 LocalWords:  usr doc SMP Mb Dunno FIXME vtblc perl listtape volinfo fsf MTWEOF
 LocalWords:  amanda degaussed ComByte DoublePlay whraven njackn com MTIOC vtbl
 LocalWords:  GETBLKSZ MAKEDEV zftape's linux dif CVS Revison cp MTREW MTOFFL
 LocalWords:  MTFSF BSF Marcin Dalecki GCC Config cpio swapout Kai Harrekilde
 LocalWords:  Pederson khp dolphinics Justus claus momo rwth aachen Laarhoven