Subversion Repositories or1k

/*

   The compile-time configurable defaults for the Linux SCSI tape driver.

   Copyright 1995-2003 Kai Makisara.

   Last modified: Sun Apr  6 22:45:15 2003 by makisara

*/

#ifndef _ST_OPTIONS_H

#define _ST_OPTIONS_H

/* The driver does not wait for some operations to finish before returning

   to the user program if ST_NOWAIT is non-zero. This helps if the SCSI

   adapter does not support multiple outstanding commands. However, the user

   should not give a new tape command before the previous one has finished. */

#define ST_NOWAIT 0

/* If ST_IN_FILE_POS is nonzero, the driver positions the tape after the

   record been read by the user program even if the tape has moved further

   because of buffered reads. Should be set to zero to support also drives

   that can't space backwards over records. NOTE: The tape will be

   spaced backwards over an "accidentally" crossed filemark in any case. */

#define ST_IN_FILE_POS 0

/* If ST_RECOVERED_WRITE_FATAL is non-zero, recovered errors while writing

   are considered "hard errors". */

#define ST_RECOVERED_WRITE_FATAL 0

/* The "guess" for the block size for devices that don't support MODE

   SENSE. */

#define ST_DEFAULT_BLOCK 0

/* The tape driver buffer size in kilobytes. Must be non-zero. */

#define ST_BUFFER_BLOCKS 32

/* The maximum number of tape buffers the driver tries to allocate at

   driver initialisation. The number is also constrained by the number

   of drives detected. If more buffers are needed, they are allocated

   at run time and freed after use. */

#define ST_MAX_BUFFERS 4

/* Maximum number of scatter/gather segments */

#define ST_MAX_SG      16

/* The number of scatter/gather segments to allocate at first try (must be

   smaller or equal to the maximum). */

#define ST_FIRST_SG    8

/* The size of the first scatter/gather segments (determines the maximum block

   size for SCSI adapters not supporting scatter/gather). The default is set

   to try to allocate the buffer as one chunk. */

#define ST_FIRST_ORDER  5

/* The following lines define defaults for properties that can be set

   separately for each drive using the MTSTOPTIONS ioctl. */

/* If ST_TWO_FM is non-zero, the driver writes two filemarks after a

   file being written. Some drives can't handle two filemarks at the

   end of data. */

#define ST_TWO_FM 0

/* If ST_BUFFER_WRITES is non-zero, writes in fixed block mode are

   buffered until the driver buffer is full or asynchronous write is

   triggered. May make detection of End-Of-Medium early enough fail. */

#define ST_BUFFER_WRITES 1

/* If ST_ASYNC_WRITES is non-zero, the SCSI write command may be started

   without waiting for it to finish. May cause problems in multiple

   tape backups. */

#define ST_ASYNC_WRITES 1

/* If ST_READ_AHEAD is non-zero, blocks are read ahead in fixed block

   mode. */

#define ST_READ_AHEAD 1

/* If ST_AUTO_LOCK is non-zero, the drive door is locked at the first

   read or write command after the device is opened. The door is opened

   when the device is closed. */

#define ST_AUTO_LOCK 0

/* If ST_FAST_MTEOM is non-zero, the MTEOM ioctl is done using the

   direct SCSI command. The file number status is lost but this method

   is fast with some drives. Otherwise MTEOM is done by spacing over

   files and the file number status is retained. */

#define ST_FAST_MTEOM 0

/* If ST_SCSI2LOGICAL is nonzero, the logical block addresses are used for

   MTIOCPOS and MTSEEK by default. Vendor addresses are used if ST_SCSI2LOGICAL

   is zero. */

#define ST_SCSI2LOGICAL 0

/* If ST_SYSV is non-zero, the tape behaves according to the SYS V semantics.

   The default is BSD semantics. */

#define ST_SYSV 0

/* Open without O_NONBLOCK blocks if the drive is not ready (blocking times out

   after 2 minutes) */

#define ST_BLOCKING_OPEN 0

/* Time to wait for the drive to become ready if blocking open */

#define ST_BLOCK_SECONDS     120

#endif