[Bug-cpio] debian mt patches

[Clint Adams]

Debian has apparently been patching cpio's mt for many years.  Here is
what I believe to be a correct forward-port; I do not know if this has
been sent upstream before.

Index: doc/mt.1
===================================================================
RCS file: /cvsroot/cpio/cpio/doc/mt.1,v
retrieving revision 1.1
diff -u -r1.1 mt.1
--- doc/mt.1    27 Feb 2004 13:28:40 -0000      1.1
+++ doc/mt.1    29 Aug 2005 21:11:52 -0000
@@ -76,9 +76,6 @@
 .IR count .
 Equivalent to rewind followed by fsf
 .IR count .
-.IP seek
-Seek to block number
-.IR count .
 .IP eom
 Space to the end of the recorded media on the tape
 (for appending files onto tapes).
@@ -93,6 +90,69 @@
 then rewind it again.
 .IP erase
 Erase the tape.
+.IP fss
+(SCSI tapes) Forward space
+.I count
+setmarks.
+.IP bss
+(SCSI tapes) Backward space
+.I count
+setmarks.
+.IP "wset"
+(SCSI tapes) Write
+.I count
+setmarks at current position (only SCSI tape).
+.IP "eod, seod"
+Space to end of valid data.  Used on streamer tape
+drives to append data to the logical and of tape.
+.IP setblk
+(SCSI tapes) Set the block size of the drive to
+.I count
+bytes per record.
+.IP setdensity
+(SCSI tapes) Set the tape density code to
+.I count.
+The proper codes to use with each drive should be looked up from the
+drive documentation.
+.IP drvbuffer
+(SCSI tapes) Set the tape drive buffer code to
+.I number.
+The proper value for unbuffered operation is zero and "normal" buffered
+operation one. The meanings of other values can be found in the drive
+documentation or, in case of a SCSI-2 drive, from the SCSI-2 standard.
+.IP stoptions
+(SCSI tapes) Set the driver options bits to
+.I count
+for the device.
+The bits can be set by oring the following values: 1 to enable write
+buffering, 2 to enable asynchronous writes, 4 to enable read ahead,
+8 to enable debugging output (if it has been compiled to the driver).
+.IP stwrthreshold
+(SCSI tapes) The write threshold for the tape device is set to
+.I count
+kilobytes. The value must be smaller than or equal to the driver
+buffer size.
+.IP seek
+(SCSI tapes) Seek to the
+.I count
+block on the tape.  This operation is available on some
+Tandberg and Wangtek streamers and some SCSI-2 tape drives.
+.IP tell
+(SCSI tapes) Tell the current block on tape.  This operation is available on 
some
+Tandberg and Wangtek streamers and some SCSI-2 tape drives.
+.IP densities
+(SCSI tapes) Write explanation of some common density codes to
+standard output.
+.IP datcompression
+(some SCSI-2 DAT tapes) Inquire or set the compression status
+(on/off). If the
+.I count
+is one the compression status is printed. If the
+.I count
+is zero, compression is disabled. Otherwise, compression is
+enabled. The command uses the SCSI ioctl to read and write the Data
+Compression Characteristics mode page (15). ONLY ROOT CAN USE THIS
+COMMAND.
 .PP
 .B mt
 exits with a status of 0 if the operation succeeded, 1 if the
@@ -117,9 +177,10 @@
 that it should use
 .I command
 to communicate with remote devices instead of
-.I /usr/bin/ssh
-or
-.IR /usr/bin/rsh .
+.IR /usr/bin/ssh ,
+.IR /usr/bin/rsh ,
+or the command specified by the environment variable
+.BR MT_RSH .
 .TP
 .I "\-V, \-\-version"
 Print the version number of
Index: src/mt.c
===================================================================
RCS file: /cvsroot/cpio/cpio/src/mt.c,v
retrieving revision 1.6
diff -u -r1.6 mt.c
--- src/mt.c    25 May 2005 11:28:48 -0000      1.6
+++ src/mt.c    29 Aug 2005 21:11:52 -0000
@@ -1,5 +1,5 @@
 /* mt -- control magnetic tape drive operation
-   Copyright (C) 1991, 1992, 1995, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -17,6 +17,10 @@
    02110-1301 USA
 */
 
+/* Modified for the Linux SCSI tape driver by Brian Mays from code
+   written by Kai Makisara.
+   Last Modified: Tue Apr 23 15:37:54 EDT 1996
+*/
 
 /* If -f is not given, the environment variable TAPE is used;
    if that is not set, a default device defined in sys/mtio.h is used.
@@ -51,6 +55,46 @@
    retension   Rewind the tape, then wind it to the end of the reel,
                then rewind it again.
    erase       Erase the tape.
+   fss         (SCSI tapes) Forward space COUNT setmarks.
+   bss         (SCSI tapes) Backward space COUNT setmarks.
+   wset                (SCSI tapes) Write COUNT setmarks at current position
+               (only SCSI tape).
+   eod, seod   Space to end of valid data.  Used on streamer tape
+               drives to append data to the logical and of tape.
+   setblk      (SCSI tapes) Set the block size of the drive to COUNT
+               bytes per record.
+   setdensity  (SCSI tapes) Set the tape density code to COUNT.  The
+               proper codes to use with each drive should be looked
+               up from the drive documentation.
+   drvbuffer   (SCSI tapes) Set the tape drive buffer code to
+               NUMBER.  The proper value for unbuffered operation is
+               zero and "normal" buffered operation one. The meanings
+               of other values can be found in the drive
+               documentation or, in case of a SCSI-2 drive, from the
+               SCSI-2 standard.
+   stoptions   (SCSI tapes) Set the driver options bits to COUNT for
+               the device.  The bits can be set by oring the
+               following values: 1 to enable write buffering, 2 to
+               enable asynchronous writes, 4 to enable read ahead, 8
+               to enable debugging output (if it has been compiled to
+               the driver).
+   stwrthreshold 
+               (SCSI tapes) The write threshold for the tape device
+               is set to COUNT kilobytes.  The value must be smaller
+               than or equal to the driver buffer size.
+   seek                (SCSI tapes) Seek to the COUNT block on the tape.
+               This operation is available on some Tandberg and
+               Wangtek streamers and some SCSI-2 tape drives.
+   tell                (SCSI tapes) Tell the current block on tape.  This
+               operation is available on some Tandberg and Wangtek
+               streamers and some SCSI-2 tape drives.
+   densities   (SCSI tapes) Write explanation of some common density
+               codes to standard output.
+   datcompression
+               (some SCSI-2 DAT tapes) Inquire or set the compression
+               status (on/off).  If the COUNT is one the compression
+               status is printed.  If the COUNT is zero, compression
+               is disabled.  Otherwise, compression is enabled.
 
    David MacKenzie <address@hidden> */
 
@@ -104,6 +148,57 @@
 #if !HAVE_DECL_EXIT
 void exit ();
 #endif
+#ifdef MTTELL
+void print_position ();
+#endif
+
+int do_dat_compression(char *dev, int fn, int count);
+
+#if defined(linux) || defined(__linux)
+#define MTDATCOMP 1000                /* Random unused number.  */
+#define MTDENS 1001           /* Random unused number.  */
+
+struct densities {
+  int code;
+  char *name;
+} density_tbl[] = {
+  {0x00, "default"},
+  {0x01, "NRZI (800 bpi)"},
+  {0x02, "PE (1600 bpi)"},
+  {0x03, "GCR (6250 bpi)"},
+  {0x05, "QIC-45/60 (GCR, 8000 bpi)"},
+  {0x06, "PE (3200 bpi)"},
+  {0x07, "IMFM (6400 bpi)"},
+  {0x08, "GCR (8000 bpi)"},
+  {0x09, "GCR (37871 bpi)"},
+  {0x0a, "MFM (6667 bpi)"},
+  {0x0b, "PE (1600 bpi)"},
+  {0x0c, "GCR (12960 bpi)"},
+  {0x0d, "GCR (25380 bpi)"},
+  {0x0f, "QIC-120 (GCR 10000 bpi)"},
+  {0x10, "QIC-150/250 (GCR 10000 bpi)"},
+  {0x11, "QIC-320/525 (GCR 16000 bpi)"},
+  {0x12, "QIC-1350 (RLL 51667 bpi)"},
+  {0x13, "DDS (61000 bpi)"},
+  {0x14, "EXB-8200 (RLL 43245 bpi)"},
+  {0x15, "EXB-8500 (RLL 45434 bpi)"},
+  {0x16, "MFM 10000 bpi"},
+  {0x17, "MFM 42500 bpi"},
+  {0x18, "MFM 42500 bpi, 56 track pairs"},
+  {0x19, "DLTtape III/DLTtape IIIxt (62500 bpi)"},
+  {0x1A, "DLTtape IV (81633 bpi)"},
+  {0x22, "SLR4DC"},
+  {0x24, "DDS-2"},
+  {0x45, "QIC-3095"},
+  {0x80, "DLTtape III/DLTtape IIIxt (62500 bpi)"},
+  {0x81, "DLTtape III/DLTtape IIIxt compressed (62500 bpi)"},
+  {0x82, "DLTtape IV (81633 bpi)"},
+  {0x83, "DLTtape IV compressed (81633 bpi)"},
+  {140, "EXB-8505 compressed"},
+  {144, "EXB-8205 compressed"},
+  {-1, NULL}};
+#endif
+
 
 char *opnames[] =
 {
@@ -114,6 +209,8 @@
 #endif
 #ifdef MTEOM
   "eom",
+  "eod",
+  "seod",
 #endif
 #ifdef MTRETEN
   "retension",
@@ -128,6 +225,39 @@
 #ifdef MTSEEK
   "seek",
 #endif
+#ifdef MTTELL
+  "tell",
+#endif
+#ifdef MTFSS
+  "fss",
+#endif
+#ifdef MTBSS
+  "bss",
+#endif
+#ifdef MTWSM
+  "wset",
+#endif
+#ifdef MTSETBLK
+  "setblk",
+#endif
+#ifdef MTSETDENSITY
+  "setdensity",
+#endif
+#ifdef MTSETDRVBUFFER
+  "drvbuffer",
+#ifdef MT_ST_BOOLEANS
+  "stoptions",
+#endif
+#ifdef MT_ST_WRITE_THRESHOLD
+  "stwrthreshold",
+#endif
+#endif
+#ifdef MTDATCOMP
+  "datcompression",
+#endif
+#ifdef MTDENS
+  "densities",
+#endif
   NULL
 };
 
@@ -141,6 +271,8 @@
 #endif
 #ifdef MTEOM
   MTEOM,
+  MTEOM,
+  MTEOM,
 #endif
 #ifdef MTRETEN
   MTRETEN,
@@ -155,9 +287,68 @@
 #ifdef MTSEEK
   MTSEEK,
 #endif
+#ifdef MTTELL
+  MTTELL,
+#endif
+#ifdef MTFSS
+  MTFSS,
+#endif
+#ifdef MTBSS
+  MTBSS,
+#endif
+#ifdef MTWSM
+  MTWSM,
+#endif
+#ifdef MTSETBLK
+  MTSETBLK,
+#endif
+#ifdef MTSETDENSITY
+  MTSETDENSITY,
+#endif
+#ifdef MTSETDRVBUFFER
+  MTSETDRVBUFFER,
+#ifdef MT_ST_BOOLEANS
+  MTSETDRVBUFFER,
+#endif
+#ifdef MT_ST_WRITE_THRESHOLD
+  MTSETDRVBUFFER,
+#endif
+#endif
+#ifdef MTDATCOMP
+  MTDATCOMP,
+#endif
+#ifdef MTDENS
+  MTDENS,
+#endif
   0
 };
 
+char *cbnames[] =
+{
+#ifdef MT_ST_BOOLEANS
+  "stoptions",
+#endif
+#ifdef MT_ST_WRITE_THRESHOLD
+  "stwrthreshold",
+#endif
+  NULL
+};
+
+int count_bits[] =
+{
+#ifdef MT_ST_BOOLEANS
+  MT_ST_BOOLEANS,
+#endif
+#ifdef MT_ST_WRITE_THRESHOLD
+  MT_ST_WRITE_THRESHOLD,
+#endif
+  0
+};
+
+#ifdef MT_TAPE_INFO
+  struct mt_tape_info tapes[] = MT_TAPE_INFO;
+#endif
+
 struct option longopts[] =
 {
   {"file", 1, NULL, 'f'},
@@ -196,15 +387,58 @@
     error (2, errno, _("%s: rmtioctl failed"), dev);
 }
 
+#ifdef MTTELL
+void
+print_position (dev, desc)
+     char *dev;
+     int desc;
+{
+  struct mtpos position;
+
+  if (rmtioctl (desc, MTIOCPOS, &position) == -1)
+    error (2, errno, "%s", dev);
+  printf("At block %d.\n", (int) position.mt_blkno);
+
+}
+#endif
+
 void
 print_status (char *dev, int desc)
 {
   struct mtget status;
 
-  if (rmtioctl (desc, MTIOCGET, (char*)&status) == -1)
+  if (rmtioctl (desc, MTIOCGET, (char*)&status))
     error (2, errno, _("%s: rmtioctl failed"), dev);
 
-  printf ("drive type = %d\n", (int) status.mt_type);
+#ifdef MT_ISFTAPE_FLAG
+  if ((int) status.mt_type & MT_ISFTAPE_FLAG)
+    {
+      printf ("qic-117 drive type = 0x%05x, ", (int) status.mt_type & 0x1ffff);
+      if (GMT_DR_OPEN( (long) status.mt_gstat))
+      {
+        printf ("no tape or door open\n");
+      }
+      else
+      {
+        printf ("%s-line%s\n",
+                GMT_ONLINE( (long) status.mt_gstat) ? "on" : "off",
+                GMT_WR_PROT( (long) status.mt_gstat) ?
+                " and write-protected" : "");
+      }
+    }
+  else
+#endif
+    {
+#ifdef MT_TAPE_INFO
+      struct mt_tape_info *mt;
+      for (mt = tapes; mt->t_type; mt++)
+      if (mt->t_type == status.mt_type) break;
+      if (mt->t_type != 0)
+      printf ("drive type = %s\n", mt->t_name);
+      else
+#endif
+      printf ("drive type = %d\n", (int) status.mt_type);
+    }
 #if defined(hpux) || defined(__hpux)
   printf ("drive status (high) = %d\n", (int) status.mt_dsreg1);
   printf ("drive status (low) = %d\n", (int) status.mt_dsreg2);
@@ -217,6 +451,60 @@
   printf ("file number = %d\n", (int) status.mt_fileno);
   printf ("block number = %d\n", (int) status.mt_blkno);
 #endif
+#if defined(linux) || defined(__linux)
+  if (status.mt_type == MT_ISSCSI1 ||
+      status.mt_type == MT_ISSCSI2)
+    {
+      int dens, i;
+      char *density;
+      dens = (status.mt_dsreg & MT_ST_DENSITY_MASK) >> MT_ST_DENSITY_SHIFT;
+      density = "unknown";
+      for (i=0; density_tbl[i].code >= 0; i++)
+      if (density_tbl[i].code == dens)
+        {
+          density = density_tbl[i].name;
+          break;
+        }
+      printf("Tape block size %d bytes. Density code 0x%x (%s).\n",
+           (int)((status.mt_dsreg & MT_ST_BLKSIZE_MASK) >>
+                 MT_ST_BLKSIZE_SHIFT),
+           dens, density);
+
+      printf("Soft error count since last status=%d\n",
+           (int)(status.mt_erreg & MT_ST_SOFTERR_MASK) >>
+           MT_ST_SOFTERR_SHIFT);
+      printf("General status bits on (%x):\n", (unsigned)status.mt_gstat);
+      if (GMT_EOF(status.mt_gstat))
+      printf(" EOF");
+      if (GMT_BOT(status.mt_gstat))
+      printf(" BOT");
+      if (GMT_EOT(status.mt_gstat))
+      printf(" EOT");
+      if (GMT_SM(status.mt_gstat))
+      printf(" SM");
+      if (GMT_EOD(status.mt_gstat))
+      printf(" EOD");
+      if (GMT_WR_PROT(status.mt_gstat))
+      printf(" WR_PROT");
+      if (GMT_ONLINE(status.mt_gstat))
+      printf(" ONLINE");
+      if (GMT_D_6250(status.mt_gstat))
+      printf(" D_6250");
+      if (GMT_D_1600(status.mt_gstat))
+      printf(" D_1600");
+      if (GMT_D_800(status.mt_gstat))
+      printf(" D_800");
+      if (GMT_DR_OPEN(status.mt_gstat))
+      printf(" DR_OPEN");       
+      if (GMT_IM_REP_EN(status.mt_gstat))
+      printf(" IM_REP_EN");
+      printf("\n");
+    }
+  else
+    {
+      printf("gstat = %0x\n", (unsigned)status.mt_gstat);
+    }
+#endif
 }
 
 void
@@ -229,6 +517,118 @@
   exit (status);
 }
 
+#if defined(linux) || defined(__linux)
+/*** Get and set the DAT compression (Mode Page 15) ***/
+
+#define MODE_SENSE 0x1a
+#define MODE_SELECT 0x15
+
+int
+read_mode_page(int fn, int page, int length, unsigned char *buffer,
+             int do_mask)
+{
+  int result, *ip;
+  unsigned char tmpbuffer[30], *cmd;
+
+  memset(tmpbuffer, 0, 14);
+  ip = (int *)&(tmpbuffer[0]);
+  *ip = 0;
+  *(ip+1) = length + 4;
+
+  cmd = &(tmpbuffer[8]);
+  cmd[0] = MODE_SENSE;
+  cmd[1] = 8;
+  cmd[2] = page;
+  if (do_mask)
+    cmd[2] |= 0x40;  /* Get changeable parameter mask */
+  cmd[4] = length + 4;
+
+  result = ioctl(fn, 1, tmpbuffer);
+  if (result) {
+    fprintf(stderr, "Can't read mode page. Are you sure you are root?\n");
+    return 0;
+  }
+  memcpy(buffer, tmpbuffer + 8, length + 4);
+  return 1;
+}
+
+int
+write_mode_page(int fn, int page, int length, unsigned char *buffer)
+{
+  int result, *ip;
+  unsigned char tmpbuffer[40], *cmd;
+
+  memset(tmpbuffer, 0, 14);
+  ip = (int *)&(tmpbuffer[0]);
+  *ip = length + 4;
+  *(ip+1) = 0;
+
+  cmd = &(tmpbuffer[8]);
+  cmd[0] = MODE_SELECT;
+  cmd[1] = 0x10;
+  cmd[4] = length + 4;
+
+  memcpy(tmpbuffer + 14, buffer, length + 4);
+  tmpbuffer[14] = 0;  /* reserved data length */
+  tmpbuffer[18] &= 0x3f;  /* reserved bits in page code byte */
+
+  result = ioctl(fn, 1, tmpbuffer);
+  if (result) {
+    fprintf(stderr, "Can't write mode page.\n");
+    return 0;
+  }
+  return 1;
+}
+
+int
+do_dat_compression(char *dev, int fn, int count)
+{
+  int i;
+  unsigned char buffer[30], mask[30];
+
+  if (!read_mode_page(fn, 0x0f, 16, buffer, 0)) {
+    error (2, errno, "%s", dev);
+  }
+
+  if (count != 1) {
+    if (read_mode_page(fn, 0x0f, 16, mask, 1))
+      if (mask[4+2] & 0x80 == 0)
+        fprintf(stderr, "Device does not allow setting this parameter.\n");
+    if (count == 0)
+      buffer[4+2] &= 0x7f;
+    else {
+      buffer[4+2] |= 0x80;
+      if (buffer[4+2+1] & 0x80 == 0) {
+        fprintf(stderr, "Warning: Decompression is disabled.  Enabling.\n");
+        buffer[4+2+1] |= 0x80;
+      }
+    }
+      buffer[1] = 0;
+    if (!write_mode_page(fn, 0x0f, 16, buffer)) {
+      error (2, errno, "%s", dev);
+    }
+    if (!read_mode_page(fn, 0x0f, 16, buffer, 0)) {  /* Re-read to check */
+      error (2, errno, "%s", dev);
+    }
+  }
+
+  if (buffer[4+2] & 0x80)
+    printf("Compression on.\n");
+  else
+    printf("Compression off.\n");
+  if (buffer[4+2] & 0x40)
+    printf("Compression capable.\n");
+  else
+    printf("Compression not capable.\n");
+  if (buffer[4+2+1] & 0x80)
+    printf("Decompression capable.\n");
+  else
+    printf("Decompression not capable.\n");
+
+  return 1;
+}
+#endif
+
 int
 main (int argc, char **argv)
 {
@@ -237,7 +637,7 @@
   char *tapedev;
   int tapedesc;
   int i;
-  char *rsh_command_option = NULL;
+  char *rsh_command_option = getenv("MT_RSH");
 
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
@@ -284,6 +684,8 @@
     }
   operation = operations[i];
 
+  i = argmatch (argv[optind], cbnames);
+
   if (++optind < argc)
     /* Debian hack: Replaced the atoi function call with strtol so
        that hexidecimal values can be used for the count parameter.
@@ -296,6 +698,8 @@
 #endif
   if (++optind < argc)
     usage (stderr, 1);
+  if (i >= 0)
+    count |= count_bits[i];
 
   if (tapedev == NULL)
     {
@@ -308,10 +712,29 @@
 #endif
     }
 
+#ifdef MTDENS
+  if (operation == MTDENS)
+    {
+      printf("Some SCSI tape density codes:\ncode   explanation\n");
+      for (i=0; density_tbl[i].code >= 0; i++)
+       printf("0x%02x   %s\n", density_tbl[i].code, density_tbl[i].name);
+      exit (0);
+    }
+#endif
+
   if ( (operation == MTWEOF)
 #ifdef MTERASE
        || (operation == MTERASE)
 #endif
+#ifdef MTWSM
+       || (operation == MTWSM)
+#endif
+#ifdef MTSETDRVBUFFER
+       || (operation == MTSETDRVBUFFER)
+#endif
+#ifdef MTDATCOMP
+       || (operation == MTDATCOMP)
+#endif
        )
     tapedesc = rmtopen (tapedev, O_WRONLY, 0, rsh_command_option);
   else
@@ -320,15 +743,27 @@
     error (1, errno, _("%s: rmtopen failed"), tapedev);
   check_type (tapedev, tapedesc);
 
-  if (operation == MTASF)
-    {
-      perform_operation (tapedev, tapedesc, MTREW, 1);
-      operation = MTFSF;
-    }
-  perform_operation (tapedev, tapedesc, operation, count);
-  if (operation == MTNOP)
-    print_status (tapedev, tapedesc);
-
+#ifdef MTDATCOMP
+  if (operation == MTDATCOMP)
+    do_dat_compression(tapedev, tapedesc, count);
+  else
+#endif
+#ifdef MTTELL
+  if (operation == MTTELL)
+    print_position (tapedev, tapedesc);
+  else
+#endif
+  {
+    if (operation == MTASF)
+      {
+       perform_operation (tapedev, tapedesc, MTREW, 1);
+       operation = MTFSF;
+      }
+    perform_operation (tapedev, tapedesc, operation, count);
+    if (operation == MTNOP)
+      print_status (tapedev, tapedesc);
+  }
+  
   if (rmtclose (tapedesc) == -1)
     error (2, errno, _("%s: rmtclose failed"), tapedev);