[PATCH] SCSI tape EOT write fixes

This contains the following changes:
 - EOT detection fixed when writing in fixed block mode
 - asynchronous writes in fixed block mode and write threshold removed
   to enable the EOT fixes (the parameter accepted for compatibility)

Documentation/scsi/st.txt

 This file contains brief information about the SCSI tape driver.
 The driver is currently maintained by Kai Mäkisara (email
-Kai.Makisara@metla.fi)
+Kai.Makisara@kolumbus.fi)
 
-Last modified: Sat Dec 14 14:35:30 2002 by makisara
+Last modified: Sun Apr  6 22:44:13 2003 by makisara
 
 
 BASICS
@@ -132,7 +132,7 @@ minimum allowable buffer size.
 Asynchronous writing. Writing the buffer contents to the tape is
 started and the write call returns immediately. The status is checked
 at the next tape operation. Asynchronous writes are not done with
-direct i/o.
+direct i/o and not in fixed block mode.
 
 Buffered writes and asynchronous writes may in some rare cases cause
 problems in multivolume operations if there is not enough space on the
@@ -143,11 +143,6 @@ attempted even if the user does not want to get all of the data at
 this read command. Should be disabled for those drives that don't like
 a filemark to truncate a read request or that don't like backspacing.
 
-The threshold for triggering asynchronous write in fixed block mode
-is defined by ST_WRITE_THRESHOLD. This may be optimized for each
-use pattern. The default triggers asynchronous write after three
-default sized writes (10 kB) from tar.
-
 Scatter/gather buffers (buffers that consist of chunks non-contiguous
 in the physical memory) are used if contiguous buffers can't be
 allocated. To support all SCSI adapters (including those not

drivers/scsi/st.h

@@ -96,7 +96,6 @@ typedef struct {
 	unsigned char c_algo;			/* compression algorithm */
 	unsigned char pos_unknown;			/* after reset position unknown */
 	int tape_type;
-	int write_threshold;
 	int timeout;		/* timeout for normal commands */
 	int long_timeout;	/* timeout for commands known to take long time */
 

drivers/scsi/st_options.h

 /*
    The compile-time configurable defaults for the Linux SCSI tape driver.
 
-   Copyright 1995-2002 Kai Makisara.
+   Copyright 1995-2003 Kai Makisara.
 
-   Last modified: Fri Jul 26 15:54:31 2002 by makisara
+   Last modified: Mon Apr  7 22:49:18 2003 by makisara
 */
 
 #ifndef _ST_OPTIONS_H
@@ -39,11 +39,6 @@
    Must be non-zero. */
 #define ST_FIXED_BUFFER_BLOCKS 32
 
-/* The number of kilobytes of data in the buffer that triggers an
-   asynchronous write in fixed block mode. See also ST_ASYNC_WRITES
-   below. */
-#define ST_WRITE_THRESHOLD_BLOCKS 30
-
 /* Maximum number of scatter/gather segments */
 #define ST_MAX_SG      256