Update the sa(4) man page for CAM. This was repository-copied from the

st(4) man page.

Take out most of the sd(4) and st(4) man pages and point to the new
da(4) and sa(4) man pages.

Add sa.4 to the makefile.

Reviewed by:	ken
Submitted by:	gibbs

1 files changed, 57 insertions, 260 deletions

diff --git a/share/man/man4/sa.4 b/share/man/man4/sa.4
index 0e074d5..ce16520 100644
--- a/share/man/man4/sa.4
+++ b/share/man/man4/sa.4
@@ -23,79 +23,35 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$Id$
+.\"	$Id: st.4,v 1.11 1997/03/07 02:49:34 jmg Exp $
 .\"
-.Dd January 17, 1996
-.Dt ST 4
+.Dd October 15, 1998
+.Dt SA 4
 .Os FreeBSD
 .Sh NAME
-.Nm st
-.Nd SCSI tape driver
+.Nm sa
+.Nd SCSI Sequential Access Device Driver
 .Sh SYNOPSIS
-.Cd tape st
-.Cd device st1 at scbus0 target 4 lun 0
+.Cd device sa0
+.Cd device sa1 at scbus0 target 4 lun 0
 .Sh DESCRIPTION
 The
-.Nm
-driver provides support for a 
-.Tn SCSI
-tape. It allows the tape
-to be run in up to four different modes depending on minor numbers
-and supports several different `sub-modes'.
-The device can have both a
-.Em raw
-interface
-and a
-.Em block
-interface; however, only the raw interface is usually used (or recommended).
-In general the interfaces are similar to those described by 
-.Xr wt 4 
-or
-.Xr mt 4 .
-.Pp
-Where the 
-.Xr wt 4
-device has a fairly low level interface to the system, 
+.Nm sa
+driver provides support for all
 .Tn SCSI
-devices have a much higher level interface and talk to the system via
-a 
+devices of the sequential access class that are attached to the system
+through a supported
 .Tn SCSI
-adapter and a
-.Tn SCSI
-adapter driver
-(e.g.,
-.Xr ahc 4 ) .
+Host Adapter.
+The sequential access class includes tape and other linear access devices.
+.Pp
 A
 .Tn SCSI
+Host
 adapter must also be separately configured into the system
 before a
 .Tn SCSI
-tape can be configured.
-.Pp
-As the
-.Tn SCSI
-adapter is probed during boot, the 
-.Tn SCSI
-bus is scanned for devices. Any devices found which answer as
-.Sq Em Sequential
-type devices will be attached to the 
-.Nm
-driver.
-In
-.Tn FreeBSD
-releases prior to 2.1, the first found is attached as
-.Em st0
-and the next, 
-.Em st1 ,
-etc.
-Beginning in 
-.Fx 2.1
-it is possible to specify what
-.Nm
-unit a device should
-come on line as; refer to
-.Xr scsi 4
-for details on kernel configuration.
+sequential access device can be configured.
 .Sh MOUNT SESSIONS
 The 
 .Nm
@@ -108,59 +64,18 @@ until replaced. The tape can be unmounted, bringing the session to a
 close in several ways.  These include:
 .Bl -enum
 .It
-Closing an `unmount device',
+Closing a `rewind device',
 referred to as sub-mode 00 below. An example is 
-.Pa /dev/rst0 .
+.Pa /dev/rsa0 .
 .It
 Using the MTOFFL
 .Xr ioctl 2
 command, reachable through the
 .Sq Cm offline
 command of
-.Xr st 1 .
-.It
-Opening a different mode will implicitly unmount the tape, thereby closing
-off the mode that was previously mounted.  All parameters will be loaded
-freshly from the new mode.  (See below for more on modes.)
-.El
-.Pp
-Parameters that are required to last across the unmounting of a tape
-should be set on the control device.  This is sub-mode 3 (see below) and is
-reached through a file with a name of the form
-.Sm off
-.No Xo
-.Pa /dev/st
-.Ar Y
-.Pa ctl.
-.Ar X
-.Xc ,
-.Sm on
-where
-.Ar Y
-is the drive number and
-.Ar X
-is the mode number.
-.Sh MODES AND SUB-MODES
-There are four 
-.Sq operation
-modes. These are controlled by bits 2 and 3 of the minor number and
-are designed to allow users to easily read and write different formats
-of tape on devices that allow multiple formats.  The parameters for
-each mode can be set individually by hand with the
-.Xr mt 1
-command.  When a device corresponding to a particular mode is first
-mounted, The operating parameters for that
-mount session
-are copied from that mode.  Further changes to the parameters during the
-session will change those in effect for the session but not those set
-in the operation mode.  To change the parameters for an operation mode, 
-one must either assign the parameters to the control device, or compile
-them into the
-.Dq Em Rogues Gallery
-table in the driver's source code.
-.Pp
-In addition to the four operating modes mentioned above, 
-bits 0 and 1 of the minor number are interpreted as
+.Xr mt 1 .
+.Sh SUB-MODES
+Bits 0 and 1 of the minor number are interpreted as
 .Sq sub-modes .
 The sub-modes differ in the action taken when the device is closed:
 .Bl -tag -width XXXX
@@ -179,24 +94,6 @@ A close will rewind the device. If the tape has been
 written, then a file mark will be written before the rewind is requested.
 On completion of the rewind an unload command will be issued.
 The device is unmounted.
-.It 11
-This is a special mode, known as the 
-.Dq control device
-for the mode.  Parameters set for the mode while in this sub-mode will
-be remembered from one mount to the next.  This allows the system
-administrator to set different characteristics (e.g., density,
-blocksize)
-.\" (and eventually compression)
-on each mode, and have the different modes keep those parameters
-independent of any parameter changes a user may invoke during a single
-mount session.  At the completion of the user's mount session, drive
-parameters will revert to those set by the administrator.  I/O
-operations cannot be performed on this device/sub-mode.  General
-.Xr scsi 4
-ioctls can
-.Em only
-be performed against the control device.
-.El
 .Sh BLOCKING MODES
 .Tn SCSI
 tapes may run in either 
@@ -238,8 +135,9 @@ and vice-versa.
 If one requests more blocks than remain in the file, the drive will
 encounter the file mark.  Because there is some data to return (unless
 there were no records before the file mark), the read will succeed,
-returning that data, The next read will return immediately with an
-EOF.  (As above, if the file mark is never read, it remains for the next process to read if in no-rewind mode.)
+returning that data, The next read will return immediately with a value
+of 0.  (As above, if the file mark is never read, it remains for the next
+process to read if in no-rewind mode.)
 .El
 .Sh FILE MARK HANDLING
 The handling of file marks on write is automatic. If the user has
@@ -255,148 +153,47 @@ last file is read.  These devices include the QIC family of devices.
 (It might be that this set of devices is the same set as that of fixed
 block devices.  This has not been determined yet, and they are treated
 as separate behaviors by the driver at this time.)
-.Sh KERNEL CONFIGURATION
-Because different tape drives behave differently, there is a mechanism 
-within the source to
-.Nm
-to quickly and conveniently recognize and deal
-with brands and models of drive that have special requirements.
-.Pp
-There is a table (called the
-.Dq Em Rogues Gallery )
-in which the identification
-strings of known errant drives can be stored.  Alongside each is
-a set of flags that allows the setting of densities and blocksizes for each 
-of the four modes, along with a set of `QUIRK' flags that can be
-used to enable or disable sections of code within the driver if a particular
-drive is recognized.
 .Sh IOCTLS
-The following 
-.Xr ioctl 2
-calls apply to
-.Tn SCSI
-tapes.  Some also apply to other tapes.  They are defined
-in the header file
-.Aq Pa /sys/mtio.h .
-.\"
-.\" Almost all of this discussion belongs in a separate mt(4)
-.\" manual page, since it is common to all magnetic tapes.
-.\"
-.Pp
-.Bl -tag -width MTIOCEEOT
-.It Dv MTIOCGET
-.Pq Li "struct mtget"
-Retrieve the status and parameters of the tape.
-.It Dv MTIOCTOP
-.Pq Li "struct mtop"
-Perform a multiplexed operation.  The argument structure is as follows:
-.Bd -literal -offset indent
-struct mtop {
-	short	mt_op;
-	daddr_t	mt_count;
-};
-.Ed
-.Pp
-The following operation values are defined for
-.Va mt_op :
-.Bl -tag -width MTSELDNSTY
-.It Dv MTWEOF
-Write
-.Va mt_count
-end of file marks at the present head position.
-.It Dv MTFSF
-Skip over
-.Va mt_count
-file marks. Leave the head on the EOM side of the last skipped
-file mark.
-.It Dv MTBSF
-Skip
-.Em backwards
-over
-.Va mt_count
-file marks. Leave the head on the BOM (beginning of media)
-side of the last skipped file mark.
-.It Dv MTFSR
-Skip forwards over 
-.Va mt_count
-records.
-.It Dv MTBSR
-Skip backwards over
-.Va mt_count
-records.
-.It Dv MTREW
-Rewind the device to the beginning of the media.
-.It Dv MTOFFL
-Rewind the media (and, if possible, eject). Even if the device cannot
-eject the media it will often no longer respond to normal requests.
-.It Dv MTNOP
-No-op; set status only.
-.It Dv MTCACHE
-Enable controller buffering.
-.It Dv MTNOCACHE
-Disable controller buffering.
-.It Dv MTSETBSIZ
-Set the blocksize to use for the device/mode. If the device is capable of
-variable blocksize operation, and the blocksize is set to 0, then the drive
-will be driven in variable mode. This parameter is in effect for the present
-mount session only, unless set on the control device.
-.It Dv MTSETDNSTY
-Set the density value (see 
-.Xr mt 1 )
-to use when running in the mode opened (minor bits 2 and 3).
-This parameter is in effect for the present
-mount session only, unless set on the control device.
-.El
-.It Dv MTIOCIEOT
-Set end-of-tape processing (not presently supported for
-.Nm
-devices).
-.It Dv MTIOCEEOT
-Set end-of-tape processing (not presently supported for
-.Nm
-devices).
-.El
-.Pp
-In addition, the 
-.Nm
-driver will allow the use of any of the general 
-.Xr scsi 4
-.Fn ioctl
-commands, on the control device only.
+The
+.Nm sa
+driver supports all of the ioctls of
+.Xr mtio 4 .
 .Sh FILES
-.Bl -tag -width /dev/[n][e]rst[0-9].[0-3] -compact
-.It Pa /dev/[n][e]rst[0-9].[0-3]
+.Bl -tag -width /dev/[n][e]rsa[0-9] -compact
+.It Pa /dev/[n][e]rsa[0-9]
 general form:
-.It Pa /dev/rst0.0	
-Mode 0, rewind on close
-.It Pa /dev/nrst0.2	
-Mode 2, No rewind on close
-.It Pa /dev/erst0.3
-Mode 3, Eject on close (if capable)
-.It Pa /dev/rst0	
-Another name for rst0.0
-.It Pa /dev/nrst0	
-Another name for nrst0.0
-.It Pa /dev/st0ctl.0	
-Parameters set to this device become the default parameters for [en]rst0.0
-.It Pa /dev/st0ctl.1	
-Parameters set to this device become the default parameters for [en]rst0.1
-.It Pa /dev/st0ctl.2	
-Parameters set to this device become the default parameters for [en]rst0.2
-.It Pa /dev/st0ctl.3	
-Parameters set to this device become the default parameters for [en]rst0.3
-.El
+.It Pa /dev/rsa0
+Rewind on close
+.It Pa /dev/nrsa0
+No rewind on close
+.It Pa /dev/erst0
+Eject on close (if capable)
+.Sh BUGS
+This driver lacks many of the hacks required to deal with older devices.
+Many older
+.Tn SCSI-1
+devices may not work properly with this driver yet.
+.Pp
+The device node interface for different tape formats and modes should
+be rethought after considering the strategies employed by other vendors.
+.Pp
+Support for fast indexing and tape status reporting is lacking.
 .Sh DIAGNOSTICS
 None.
 .Sh SEE ALSO
 .Xr mt 1 ,
 .Xr scsi 4 ,
-.Xr st 9
+.Xr sa 9
 .Sh HISTORY
-This
-.Nm
-driver was originally written for
+The
+.Nm sa
+driver was written for the
+.Tn CAM
+.Tn SCSI
+subsystem by Justin T. Gibbs and Kenneth Merry.
+Many ideas were gleaned from the
+.Nm st
+device driver written and ported from
 .Tn Mach
-2.5, and was ported to 
-.Tn FreeBSD
+2.5
 by Julian Elischer.