patch-2.1.66 linux/drivers/char/ftape/ftape-bsm.c

• Lines: 429
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.1.65/linux/drivers/char/ftape/ftape-bsm.c
• Orig date: Thu Mar 14 01:53:44 1996

diff -u --recursive --new-file v2.1.65/linux/drivers/char/ftape/ftape-bsm.c linux/drivers/char/ftape/ftape-bsm.c
@@ -1,428 +0,0 @@
-/*
- *      Copyright (C) 1994-1995 Bas Laarhoven.
-
- 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
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; see the file COPYING.  If not, write to
- the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Source: /home/bas/distr/ftape-2.03b/RCS/ftape-bsm.c,v $
- $Author: bas $
- *
- $Revision: 1.7 $
- $Date: 1995/04/30 13:15:14 $
- $State: Beta $
- *
- *      This file contains the bad-sector map handling code for
- *      the QIC-117 floppy tape driver for Linux.
- *      QIC-40, QIC-80, QIC-3010 and QIC-3020 maps are implemented.
- */
-
-#include <linux/ftape.h>
-#include <linux/string.h>
-
-#include "tracing.h"
-#include "ftape-bsm.h"
-#include "ftape-ctl.h"
-#include "ftape-rw.h"
-
-
-/*      Global vars.
- */
-int bad_sector_map_changed = 0;
-
-/*      Local vars.
- */
-static byte bad_sector_map[BAD_SECTOR_MAP_SIZE];
-typedef enum {
-	forward, backward
-} mode_type;
-
-#if 0
-/*  fix_tape converts a normal QIC-80 tape into a 'wide' tape.
- *  For testing purposes only !
- */
-void fix_tape(byte * buffer)
-{
-	static byte list[BAD_SECTOR_MAP_SIZE];
-	unsigned long *src_ptr = (unsigned long *) list;
-	byte *dst_ptr = bad_sector_map;
-	unsigned long map;
-	unsigned sector = 1;
-	int i;
-
-	memcpy(list, bad_sector_map, sizeof(list));
-	memset(bad_sector_map, 0, sizeof(bad_sector_map));
-	while ((byte *) src_ptr - list < sizeof(list)) {
-		map = *src_ptr++;
-		if (map == EMPTY_SEGMENT) {
-			*(unsigned long *) dst_ptr = 0x800000 + sector;
-			dst_ptr += 3;
-			sector += SECTORS_PER_SEGMENT;
-		} else {
-			for (i = 0; i < SECTORS_PER_SEGMENT; ++i) {
-				if (map & 1) {
-					*(unsigned long *) dst_ptr = sector;
-					dst_ptr += 3;
-				}
-				map >>= 1;
-				++sector;
-			}
-		}
-	}
-	bad_sector_map_changed = 1;
-	*(buffer + 4) = 4;	/* put new format code */
-	format_code = 4;
-}
-
-#endif
-
-byte *
- find_end_of_bsm_list(byte * ptr, byte * limit)
-{
-	while (ptr + 2 < limit) {
-		if (ptr[0] || ptr[1] || ptr[2]) {
-			ptr += 3;
-		} else {
-			return ptr;
-		}
-	}
-	return NULL;
-}
-
-void store_bad_sector_map(byte * buffer)
-{
-	TRACE_FUN(8, "store_bad_sector_map");
-	size_t count;
-	size_t offset;
-
-	/*  Store the bad sector map in buffer.
-	 */
-	if (format_code == 4) {
-		offset = 256;
-		count = sizeof(bad_sector_map);
-	} else {
-		offset = 2 * SECTOR_SIZE;	/* skip failed sector log */
-		count = sizeof(bad_sector_map) - (offset - 256);
-	}
-	memcpy(buffer + offset, bad_sector_map, count);
-	TRACE_EXIT;
-}
-
-void put_sector(byte ** ptr, unsigned long sector)
-{
-	*(*ptr)++ = sector & 0xff;
-	sector >>= 8;
-	*(*ptr)++ = sector & 0xff;
-	sector >>= 8;
-	*(*ptr)++ = sector & 0xff;
-}
-
-unsigned long get_sector(byte ** ptr, mode_type mode)
-{
-	unsigned long sector;
-
-	if (mode == forward) {
-		sector = *(*ptr)++;
-		sector += *(*ptr)++ << 8;
-		sector += *(*ptr)++ << 16;
-	} else {
-		sector = *--(*ptr) << 16;
-		sector += *--(*ptr) << 8;
-		sector += *--(*ptr);
-	}
-	return sector;
-}
-
-void extract_bad_sector_map(byte * buffer)
-{
-	TRACE_FUN(8, "extract_bad_sector_map");
-
-	/*  Fill the bad sector map with the contents of buffer.
-	 */
-	if (format_code == 4) {
-		/* QIC-3010/3020 and wide QIC-80 tapes no longer have a failed
-		 * sector log but use this area to extend the bad sector map.
-		 */
-		memcpy(bad_sector_map, buffer + 256, sizeof(bad_sector_map));
-	} else {
-		/* non-wide QIC-80 tapes have a failed sector log area that
-		 * mustn't be included in the bad sector map.
-		 */
-		memcpy(bad_sector_map, buffer + 256 + FAILED_SECTOR_LOG_SIZE,
-		       sizeof(bad_sector_map) - FAILED_SECTOR_LOG_SIZE);
-	}
-#if 0
-	/* for testing of bad sector handling at end of tape
-	 */
-	((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 3] = 0x000003e0;
-	((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 2] = 0xff3fffff;
-	((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 1] = 0xffffe000;
-#endif
-#if 0
-	/*  Enable to test bad sector handling
-	 */
-	((unsigned long *) bad_sector_map)[30] = 0xfffffffe;
-	((unsigned long *) bad_sector_map)[32] = 0x7fffffff;
-	((unsigned long *) bad_sector_map)[34] = 0xfffeffff;
-	((unsigned long *) bad_sector_map)[36] = 0x55555555;
-	((unsigned long *) bad_sector_map)[38] = 0xffffffff;
-	((unsigned long *) bad_sector_map)[50] = 0xffff0000;
-	((unsigned long *) bad_sector_map)[51] = 0xffffffff;
-	((unsigned long *) bad_sector_map)[52] = 0xffffffff;
-	((unsigned long *) bad_sector_map)[53] = 0x0000ffff;
-#endif
-#if 0
-	/*  Enable when testing multiple volume tar dumps.
-	 */
-	for (i = first_data_segment; i <= ftape_last_segment.id - 7; ++i) {
-		((unsigned long *) bad_sector_map)[i] = EMPTY_SEGMENT;
-	}
-#endif
-#if 0
-	/*  Enable when testing bit positions in *_error_map
-	 */
-	for (i = first_data_segment; i <= ftape_last_segment.id; ++i) {
-		((unsigned long *) bad_sector_map)[i] |= 0x00ff00ff;
-	}
-#endif
-	if (tracing > 2) {
-		unsigned int map;
-		int good_sectors = 0;
-		int bad_sectors;
-		unsigned int total_bad = 0;
-		int i;
-
-		if (format_code == 4 || format_code == 3) {
-			byte *ptr = bad_sector_map;
-			unsigned sector;
-
-			do {
-				sector = get_sector(&ptr, forward);
-				if (sector != 0) {
-					if (format_code == 4 && sector & 0x800000) {
-						total_bad += SECTORS_PER_SEGMENT - 3;
-						TRACEx1(6, "bad segment at sector: %6d", sector & 0x7fffff);
-					} else {
-						++total_bad;
-						TRACEx1(6, "bad sector: %6d", sector);
-					}
-				}
-			} while (sector != 0);
-			/*  Display end-of-file marks
-			 */
-			do {
-				sector = *((unsigned short *) ptr)++;
-				if (sector) {
-					TRACEx2(4, "eof mark: %4d/%2d", sector,
-					    *((unsigned short *) ptr)++);
-				}
-			} while (sector);
-		} else {
-			for (i = first_data_segment;
-			 i < segments_per_track * tracks_per_tape; ++i) {
-				map = ((unsigned long *) bad_sector_map)[i];
-				bad_sectors = count_ones(map);
-				if (bad_sectors > 0) {
-					TRACEx2(6, "bsm for segment %4d: 0x%08x", i, map);
-					if (bad_sectors > SECTORS_PER_SEGMENT - 3) {
-						bad_sectors = SECTORS_PER_SEGMENT - 3;
-					}
-					total_bad += bad_sectors;
-				}
-			}
-		}
-		good_sectors = ((segments_per_track * tracks_per_tape - first_data_segment)
-				* (SECTORS_PER_SEGMENT - 3)) - total_bad;
-		TRACEx1(3, "%d Kb usable on this tape",
-			good_sectors - ftape_last_segment.free);
-		if (total_bad == 0) {
-			TRACE(1, "WARNING: this tape has no bad blocks registered !");
-		} else {
-			TRACEx1(2, "%d bad sectors", total_bad);
-		}
-	}
-	TRACE_EXIT;
-}
-
-unsigned long cvt2map(int sector)
-{
-	return 1 << (((sector & 0x7fffff) - 1) % SECTORS_PER_SEGMENT);
-}
-
-int cvt2segment(int sector)
-{
-	return ((sector & 0x7fffff) - 1) / SECTORS_PER_SEGMENT;
-}
-
-int forward_seek_entry(int segment_id, byte ** ptr, unsigned long *map)
-{
-	byte *tmp_ptr;
-	unsigned long sector;
-	int segment;
-	int count;
-
-	do {
-		sector = get_sector(ptr, forward);
-		segment = cvt2segment(sector);
-	} while (sector != 0 && segment < segment_id);
-	tmp_ptr = *ptr - 3;	/* point to first sector >= segment_id */
-	/*  Get all sectors in segment_id
-	 */
-	if (format_code == 4 && (sector & 0x800000) && segment == segment_id) {
-		*map = EMPTY_SEGMENT;
-		count = 32;
-	} else {
-		*map = 0;
-		count = 0;
-		while (sector != 0 && segment == segment_id) {
-			*map |= cvt2map(sector);
-			sector = get_sector(ptr, forward);
-			segment = cvt2segment(sector);
-			++count;
-		}
-	}
-	*ptr = tmp_ptr;
-	return count;
-}
-
-int backwards_seek_entry(int segment_id, byte ** ptr, unsigned long *map)
-{
-	unsigned long sector;
-	int segment;
-	int count;
-
-	*map = 0;
-	if (*ptr > bad_sector_map) {
-		do {
-			sector = get_sector(ptr, backward);
-			segment = cvt2segment(sector);
-		} while (*ptr > bad_sector_map && segment > segment_id);
-		count = 0;
-		if (segment > segment_id) {
-			/*  at start of list, no entry found */
-		} else if (segment < segment_id) {
-			/*  before smaller entry, adjust for overshoot */
-			*ptr += 3;
-		} else {
-			/*  get all sectors in segment_id */
-			if (format_code == 4 && (sector & 0x800000)) {
-				*map = EMPTY_SEGMENT;
-				count = 32;
-			} else {
-				do {
-					*map |= cvt2map(sector);
-					++count;
-					if (*ptr <= bad_sector_map) {
-						break;
-					}
-					sector = get_sector(ptr, backward);
-					segment = cvt2segment(sector);
-				} while (segment == segment_id);
-				if (segment < segment_id) {
-					*ptr += 3;
-				}
-			}
-		}
-	} else {
-		count = 0;
-	}
-	return count;
-}
-
-void put_bad_sector_entry(int segment_id, unsigned long new_map)
-{
-	byte *ptr = bad_sector_map;
-	int count;
-	int new_count;
-	unsigned long map;
-
-	if (format_code == 3 || format_code == 4) {
-		count = forward_seek_entry(segment_id, &ptr, &map);
-		new_count = count_ones(new_map);
-		/*  If format code == 4 put empty segment instead of 32 bad sectors.
-		 */
-		if (new_count == 32 && format_code == 4) {
-			new_count = 1;
-		}
-		if (count != new_count) {
-			/*  insert (or delete if < 0) new_count - count entries.
-			 *  Move trailing part of list including terminating 0.
-			 */
-			byte *hi_ptr = ptr;
-
-			do {
-			} while (get_sector(&hi_ptr, forward) != 0);
-			memmove(ptr + new_count, ptr + count, hi_ptr - (ptr + count));
-		}
-		if (new_count == 1 && new_map == EMPTY_SEGMENT) {
-			put_sector(&ptr, 0x800001 + segment_id * SECTORS_PER_SEGMENT);
-		} else {
-			int i = 0;
-
-			while (new_map) {
-				if (new_map & 1) {
-					put_sector(&ptr, 1 + segment_id * SECTORS_PER_SEGMENT + i);
-				}
-				++i;
-				new_map >>= 1;
-			}
-		}
-	} else {
-		((unsigned long *) bad_sector_map)[segment_id] = new_map;
-	}
-	bad_sector_map_changed = 1;
-}
-
-unsigned long get_bad_sector_entry(int segment_id)
-{
-	TRACE_FUN(8, "get_bad_sector_entry");
-	static unsigned long map = 0;
-
-	if (used_header_segment == -1) {
-		/*  When reading header segment we'll need a blank map.
-		 */
-		map = 0;
-	} else if (format_code == 3 || format_code == 4) {
-		/*  Invariants:
-		 *    map - mask value returned on last call.
-		 *    ptr - points to first sector greater or equal to
-		 *          first sector in last_referenced segment.
-		 *    last_referenced - segment id used in the last call,
-		 *                      sector and map belong to this id.
-		 *  This code is designed for sequential access and retries.
-		 *  For true random access it may have to be redesigned.
-		 */
-		static int last_reference = -1;
-		static byte *ptr = bad_sector_map;
-
-		if (segment_id > last_reference) {
-			/*  Skip all sectors before segment_id
-			 */
-			forward_seek_entry(segment_id, &ptr, &map);
-		} else if (segment_id < last_reference) {
-			/*  Skip backwards until begin of buffer or first sector in segment_id
-			 */
-			backwards_seek_entry(segment_id, &ptr, &map);
-		}		/* segment_id == last_reference : keep map */
-		last_reference = segment_id;
-	} else {
-		map = ((unsigned long *) bad_sector_map)[segment_id];
-	}
-	TRACE_EXIT;
-	return map;
-}
-
-void ftape_init_bsm(void)
-{
-	memset(bad_sector_map, 0, sizeof(bad_sector_map));
-}