1 /*
2 * Copyright (c) 1995-1997 Claus-Justus Heine
3
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License as
6 published by the Free Software Foundation; either version 2, or (at
7 your option) any later version.
8
9 This program is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; see the file COPYING. If not, write to
16 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
17 USA.
18
19 *
20 * $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-vtbl.c,v $
21 * $Revision: 1.7.6.1 $
22 * $Date: 1997/11/24 13:48:31 $
23 *
24 * This file defines a volume table as defined in various QIC
25 * standards.
26 *
27 * This is a minimal implementation, just allowing ordinary DOS
28 * :( prgrams to identify the cartridge as used.
29 */
30
31 #include <linux/errno.h>
32 #include <linux/mm.h>
33 #include <linux/slab.h>
34 #include <asm/segment.h>
35
36 #include <linux/zftape.h>
37 #include "../zftape/zftape-init.h"
38 #include "../zftape/zftape-eof.h"
39 #include "../zftape/zftape-ctl.h"
40 #include "../zftape/zftape-write.h"
41 #include "../zftape/zftape-read.h"
42 #include "../zftape/zftape-rw.h"
43 #include "../zftape/zftape-vtbl.h"
44
45 #define ZFT_CMAP_HACK /* leave this defined to hide the compression map */
46
47 /*
48 * global variables
49 */
50 int zft_qic_mode = 1; /* use the vtbl */
51 int zft_old_ftape; /* prevents old ftaped tapes to be overwritten */
52 int zft_volume_table_changed; /* for write_header_segments() */
53
54 /*
55 * private variables (only exported for inline functions)
56 */
57 LIST_HEAD(zft_vtbl);
58
59 /* We could also allocate these dynamically when extracting the volume table
60 * sizeof(zft_volinfo) is about 32 or something close to that
61 */
62 static zft_volinfo tape_vtbl;
63 static zft_volinfo eot_vtbl;
64 static zft_volinfo *cur_vtbl;
65
zft_new_vtbl_entry(void)66 inline void zft_new_vtbl_entry(void)
67 {
68 struct list_head *tmp = &zft_last_vtbl->node;
69 zft_volinfo *new = zft_kmalloc(sizeof(zft_volinfo));
70
71 list_add(&new->node, tmp);
72 new->count = zft_eom_vtbl->count ++;
73 }
74
zft_free_vtbl(void)75 void zft_free_vtbl(void)
76 {
77 for (;;) {
78 struct list_head *tmp = zft_vtbl.prev;
79 zft_volinfo *vtbl;
80
81 if (tmp == &zft_vtbl)
82 break;
83 list_del(tmp);
84 vtbl = list_entry(tmp, zft_volinfo, node);
85 zft_kfree(vtbl, sizeof(zft_volinfo));
86 }
87 INIT_LIST_HEAD(&zft_vtbl);
88 cur_vtbl = NULL;
89 }
90
91 /* initialize vtbl, called by ftape_new_cartridge()
92 */
zft_init_vtbl(void)93 void zft_init_vtbl(void)
94 {
95 zft_volinfo *new;
96
97 zft_free_vtbl();
98
99 /* Create the two dummy vtbl entries
100 */
101 new = zft_kmalloc(sizeof(zft_volinfo));
102 list_add(&new->node, &zft_vtbl);
103 new = zft_kmalloc(sizeof(zft_volinfo));
104 list_add(&new->node, &zft_vtbl);
105 zft_head_vtbl->end_seg = ft_first_data_segment;
106 zft_head_vtbl->blk_sz = zft_blk_sz;
107 zft_head_vtbl->count = -1;
108 zft_eom_vtbl->start_seg = ft_first_data_segment + 1;
109 zft_eom_vtbl->end_seg = ft_last_data_segment + 1;
110 zft_eom_vtbl->blk_sz = zft_blk_sz;
111 zft_eom_vtbl->count = 0;
112
113 /* Reset the pointer for zft_find_volume()
114 */
115 cur_vtbl = zft_eom_vtbl;
116
117 /* initialize the dummy vtbl entries for zft_qic_mode == 0
118 */
119 eot_vtbl.start_seg = ft_last_data_segment + 1;
120 eot_vtbl.end_seg = ft_last_data_segment + 1;
121 eot_vtbl.blk_sz = zft_blk_sz;
122 eot_vtbl.count = -1;
123 tape_vtbl.start_seg = ft_first_data_segment;
124 tape_vtbl.end_seg = ft_last_data_segment;
125 tape_vtbl.blk_sz = zft_blk_sz;
126 tape_vtbl.size = zft_capacity;
127 tape_vtbl.count = 0;
128 }
129
130 /* check for a valid VTBL signature.
131 */
vtbl_signature_valid(__u8 signature[4])132 static int vtbl_signature_valid(__u8 signature[4])
133 {
134 const char *vtbl_ids[] = VTBL_IDS; /* valid signatures */
135 int j;
136
137 for (j = 0;
138 (j < NR_ITEMS(vtbl_ids)) && (memcmp(signature, vtbl_ids[j], 4) != 0);
139 j++);
140 return j < NR_ITEMS(vtbl_ids);
141 }
142
143 /* We used to store the block-size of the volume in the volume-label,
144 * using the keyword "blocksize". The blocksize written to the
145 * volume-label is in bytes.
146 *
147 * We use this now only for compatability with old zftape version. We
148 * store the blocksize directly as binary number in the vendor
149 * extension part of the volume entry.
150 */
check_volume_label(const char * label,int * blk_sz)151 static int check_volume_label(const char *label, int *blk_sz)
152 {
153 int valid_format;
154 char *blocksize;
155 TRACE_FUN(ft_t_flow);
156
157 TRACE(ft_t_noise, "called with \"%s\" / \"%s\"", label, ZFT_VOL_NAME);
158 if (strncmp(label, ZFT_VOL_NAME, strlen(ZFT_VOL_NAME)) != 0) {
159 *blk_sz = 1; /* smallest block size that we allow */
160 valid_format = 0;
161 } else {
162 TRACE(ft_t_noise, "got old style zftape vtbl entry");
163 /* get the default blocksize */
164 /* use the kernel strstr() */
165 blocksize= strstr(label, " blocksize ");
166 if (blocksize) {
167 blocksize += strlen(" blocksize ");
168 for(*blk_sz= 0;
169 *blocksize >= '0' && *blocksize <= '9';
170 blocksize++) {
171 *blk_sz *= 10;
172 *blk_sz += *blocksize - '0';
173 }
174 if (*blk_sz > ZFT_MAX_BLK_SZ) {
175 *blk_sz= 1;
176 valid_format= 0;
177 } else {
178 valid_format = 1;
179 }
180 } else {
181 *blk_sz= 1;
182 valid_format= 0;
183 }
184 }
185 TRACE_EXIT valid_format;
186 }
187
188 /* check for a zftape volume
189 */
check_volume(__u8 * entry,zft_volinfo * volume)190 static int check_volume(__u8 *entry, zft_volinfo *volume)
191 {
192 TRACE_FUN(ft_t_flow);
193
194 if(strncmp(&entry[VTBL_EXT+EXT_ZFTAPE_SIG], ZFTAPE_SIG,
195 strlen(ZFTAPE_SIG)) == 0) {
196 TRACE(ft_t_noise, "got new style zftape vtbl entry");
197 volume->blk_sz = GET2(entry, VTBL_EXT+EXT_ZFTAPE_BLKSZ);
198 volume->qic113 = entry[VTBL_EXT+EXT_ZFTAPE_QIC113];
199 TRACE_EXIT 1;
200 } else {
201 TRACE_EXIT check_volume_label(&entry[VTBL_DESC], &volume->blk_sz);
202 }
203 }
204
205
206 /* create zftape specific vtbl entry, the volume bounds are inserted
207 * in the calling function, zft_create_volume_headers()
208 */
create_zft_volume(__u8 * entry,zft_volinfo * vtbl)209 static void create_zft_volume(__u8 *entry, zft_volinfo *vtbl)
210 {
211 TRACE_FUN(ft_t_flow);
212
213 memset(entry, 0, VTBL_SIZE);
214 memcpy(&entry[VTBL_SIG], VTBL_ID, 4);
215 sprintf(&entry[VTBL_DESC], ZFT_VOL_NAME" %03d", vtbl->count);
216 entry[VTBL_FLAGS] = (VTBL_FL_NOT_VERIFIED | VTBL_FL_SEG_SPANNING);
217 entry[VTBL_M_NO] = 1; /* multi_cartridge_count */
218 strcpy(&entry[VTBL_EXT+EXT_ZFTAPE_SIG], ZFTAPE_SIG);
219 PUT2(entry, VTBL_EXT+EXT_ZFTAPE_BLKSZ, vtbl->blk_sz);
220 if (zft_qic113) {
221 PUT8(entry, VTBL_DATA_SIZE, vtbl->size);
222 entry[VTBL_CMPR] = VTBL_CMPR_UNREG;
223 if (vtbl->use_compression) { /* use compression: */
224 entry[VTBL_CMPR] |= VTBL_CMPR_USED;
225 }
226 entry[VTBL_EXT+EXT_ZFTAPE_QIC113] = 1;
227 } else {
228 PUT4(entry, VTBL_DATA_SIZE, vtbl->size);
229 entry[VTBL_K_CMPR] = VTBL_CMPR_UNREG;
230 if (vtbl->use_compression) { /* use compression: */
231 entry[VTBL_K_CMPR] |= VTBL_CMPR_USED;
232 }
233 }
234 if (ft_format_code == fmt_big) {
235 /* SCSI like vtbl, store the number of used
236 * segments as 4 byte value
237 */
238 PUT4(entry, VTBL_SCSI_SEGS, vtbl->end_seg-vtbl->start_seg + 1);
239 } else {
240 /* normal, QIC-80MC like vtbl
241 */
242 PUT2(entry, VTBL_START, vtbl->start_seg);
243 PUT2(entry, VTBL_END, vtbl->end_seg);
244 }
245 TRACE_EXIT;
246 }
247
248 /* this one creates the volume headers for each volume. It is assumed
249 * that buffer already contains the old volume-table, so that vtbl
250 * entries without the zft_volume flag set can savely be ignored.
251 */
zft_create_volume_headers(__u8 * buffer)252 void zft_create_volume_headers(__u8 *buffer)
253 {
254 __u8 *entry;
255 struct list_head *tmp;
256 zft_volinfo *vtbl;
257 TRACE_FUN(ft_t_flow);
258
259 #ifdef ZFT_CMAP_HACK
260 if((strncmp(&buffer[VTBL_EXT+EXT_ZFTAPE_SIG], ZFTAPE_SIG,
261 strlen(ZFTAPE_SIG)) == 0) &&
262 buffer[VTBL_EXT+EXT_ZFTAPE_CMAP] != 0) {
263 TRACE(ft_t_noise, "deleting cmap volume");
264 memmove(buffer, buffer + VTBL_SIZE,
265 FT_SEGMENT_SIZE - VTBL_SIZE);
266 }
267 #endif
268 entry = buffer;
269 for (tmp = zft_head_vtbl->node.next;
270 tmp != &zft_eom_vtbl->node;
271 tmp = tmp->next) {
272 vtbl = list_entry(tmp, zft_volinfo, node);
273 /* we now fill in the values only for newly created volumes.
274 */
275 if (vtbl->new_volume) {
276 create_zft_volume(entry, vtbl);
277 vtbl->new_volume = 0; /* clear the flag */
278 }
279
280 DUMP_VOLINFO(ft_t_noise, &entry[VTBL_DESC], vtbl);
281 entry += VTBL_SIZE;
282 }
283 memset(entry, 0, FT_SEGMENT_SIZE - zft_eom_vtbl->count * VTBL_SIZE);
284 TRACE_EXIT;
285 }
286
287 /* write volume table to tape. Calls zft_create_volume_headers()
288 */
zft_update_volume_table(unsigned int segment)289 int zft_update_volume_table(unsigned int segment)
290 {
291 int result = 0;
292 __u8 *verify_buf = NULL;
293 TRACE_FUN(ft_t_flow);
294
295 TRACE_CATCH(result = ftape_read_segment(ft_first_data_segment,
296 zft_deblock_buf,
297 FT_RD_SINGLE),);
298 zft_create_volume_headers(zft_deblock_buf);
299 TRACE(ft_t_noise, "writing volume table segment %d", segment);
300 if (zft_vmalloc_once(&verify_buf, FT_SEGMENT_SIZE) == 0) {
301 TRACE_CATCH(zft_verify_write_segments(segment,
302 zft_deblock_buf, result,
303 verify_buf),
304 zft_vfree(&verify_buf, FT_SEGMENT_SIZE));
305 zft_vfree(&verify_buf, FT_SEGMENT_SIZE);
306 } else {
307 TRACE_CATCH(ftape_write_segment(segment, zft_deblock_buf,
308 FT_WR_SINGLE),);
309 }
310 TRACE_EXIT 0;
311 }
312
313 /* non zftape volumes are handled in raw mode. Thus we need to
314 * calculate the raw amount of data contained in those segments.
315 */
extract_alien_volume(__u8 * entry,zft_volinfo * vtbl)316 static void extract_alien_volume(__u8 *entry, zft_volinfo *vtbl)
317 {
318 TRACE_FUN(ft_t_flow);
319
320 vtbl->size = (zft_calc_tape_pos(zft_last_vtbl->end_seg+1) -
321 zft_calc_tape_pos(zft_last_vtbl->start_seg));
322 vtbl->use_compression = 0;
323 vtbl->qic113 = zft_qic113;
324 if (vtbl->qic113) {
325 TRACE(ft_t_noise,
326 "Fake alien volume's size from " LL_X " to " LL_X,
327 LL(GET8(entry, VTBL_DATA_SIZE)), LL(vtbl->size));
328 } else {
329 TRACE(ft_t_noise,
330 "Fake alien volume's size from %d to " LL_X,
331 (int)GET4(entry, VTBL_DATA_SIZE), LL(vtbl->size));
332 }
333 TRACE_EXIT;
334 }
335
336
337 /* extract an zftape specific volume
338 */
extract_zft_volume(__u8 * entry,zft_volinfo * vtbl)339 static void extract_zft_volume(__u8 *entry, zft_volinfo *vtbl)
340 {
341 TRACE_FUN(ft_t_flow);
342
343 if (vtbl->qic113) {
344 vtbl->size = GET8(entry, VTBL_DATA_SIZE);
345 vtbl->use_compression =
346 (entry[VTBL_CMPR] & VTBL_CMPR_USED) != 0;
347 } else {
348 vtbl->size = GET4(entry, VTBL_DATA_SIZE);
349 if (entry[VTBL_K_CMPR] & VTBL_CMPR_UNREG) {
350 vtbl->use_compression =
351 (entry[VTBL_K_CMPR] & VTBL_CMPR_USED) != 0;
352 } else if (entry[VTBL_CMPR] & VTBL_CMPR_UNREG) {
353 vtbl->use_compression =
354 (entry[VTBL_CMPR] & VTBL_CMPR_USED) != 0;
355 } else {
356 TRACE(ft_t_warn, "Geeh! There is something wrong:\n"
357 KERN_INFO "QIC compression (Rev = K): %x\n"
358 KERN_INFO "QIC compression (Rev > K): %x",
359 entry[VTBL_K_CMPR], entry[VTBL_CMPR]);
360 }
361 }
362 TRACE_EXIT;
363 }
364
365 /* extract the volume table from buffer. "buffer" must already contain
366 * the vtbl-segment
367 */
zft_extract_volume_headers(__u8 * buffer)368 int zft_extract_volume_headers(__u8 *buffer)
369 {
370 __u8 *entry;
371 TRACE_FUN(ft_t_flow);
372
373 zft_init_vtbl();
374 entry = buffer;
375 #ifdef ZFT_CMAP_HACK
376 if ((strncmp(&entry[VTBL_EXT+EXT_ZFTAPE_SIG], ZFTAPE_SIG,
377 strlen(ZFTAPE_SIG)) == 0) &&
378 entry[VTBL_EXT+EXT_ZFTAPE_CMAP] != 0) {
379 TRACE(ft_t_noise, "ignoring cmap volume");
380 entry += VTBL_SIZE;
381 }
382 #endif
383 /* the end of the vtbl is indicated by an invalid signature
384 */
385 while (vtbl_signature_valid(&entry[VTBL_SIG]) &&
386 (entry - buffer) < FT_SEGMENT_SIZE) {
387 zft_new_vtbl_entry();
388 if (ft_format_code == fmt_big) {
389 /* SCSI like vtbl, stores only the number of
390 * segments used
391 */
392 unsigned int num_segments= GET4(entry, VTBL_SCSI_SEGS);
393 zft_last_vtbl->start_seg = zft_eom_vtbl->start_seg;
394 zft_last_vtbl->end_seg =
395 zft_last_vtbl->start_seg + num_segments - 1;
396 } else {
397 /* `normal', QIC-80 like vtbl
398 */
399 zft_last_vtbl->start_seg = GET2(entry, VTBL_START);
400 zft_last_vtbl->end_seg = GET2(entry, VTBL_END);
401 }
402 zft_eom_vtbl->start_seg = zft_last_vtbl->end_seg + 1;
403 /* check if we created this volume and get the
404 * blk_sz
405 */
406 zft_last_vtbl->zft_volume = check_volume(entry, zft_last_vtbl);
407 if (zft_last_vtbl->zft_volume == 0) {
408 extract_alien_volume(entry, zft_last_vtbl);
409 } else {
410 extract_zft_volume(entry, zft_last_vtbl);
411 }
412 DUMP_VOLINFO(ft_t_noise, &entry[VTBL_DESC], zft_last_vtbl);
413 entry +=VTBL_SIZE;
414 }
415 #if 0
416 /*
417 * undefine to test end of tape handling
418 */
419 zft_new_vtbl_entry();
420 zft_last_vtbl->start_seg = zft_eom_vtbl->start_seg;
421 zft_last_vtbl->end_seg = ft_last_data_segment - 10;
422 zft_last_vtbl->blk_sz = zft_blk_sz;
423 zft_last_vtbl->zft_volume = 1;
424 zft_last_vtbl->qic113 = zft_qic113;
425 zft_last_vtbl->size = (zft_calc_tape_pos(zft_last_vtbl->end_seg+1)
426 - zft_calc_tape_pos(zft_last_vtbl->start_seg));
427 #endif
428 TRACE_EXIT 0;
429 }
430
431 /* this functions translates the failed_sector_log, misused as
432 * EOF-marker list, into a virtual volume table. The table mustn't be
433 * written to tape, because this would occupy the first data segment,
434 * which should be the volume table, but is actually the first segment
435 * that is filled with data (when using standard ftape). We assume,
436 * that we get a non-empty failed_sector_log.
437 */
zft_fake_volume_headers(eof_mark_union * eof_map,int num_failed_sectors)438 int zft_fake_volume_headers (eof_mark_union *eof_map, int num_failed_sectors)
439 {
440 unsigned int segment, sector;
441 int have_eom = 0;
442 int vol_no;
443 TRACE_FUN(ft_t_flow);
444
445 if ((num_failed_sectors >= 2) &&
446 (GET2(&eof_map[num_failed_sectors - 1].mark.segment, 0)
447 ==
448 GET2(&eof_map[num_failed_sectors - 2].mark.segment, 0) + 1) &&
449 (GET2(&eof_map[num_failed_sectors - 1].mark.date, 0) == 1)) {
450 /* this should be eom. We keep the remainder of the
451 * tape as another volume.
452 */
453 have_eom = 1;
454 }
455 zft_init_vtbl();
456 zft_eom_vtbl->start_seg = ft_first_data_segment;
457 for(vol_no = 0; vol_no < num_failed_sectors - have_eom; vol_no ++) {
458 zft_new_vtbl_entry();
459
460 segment = GET2(&eof_map[vol_no].mark.segment, 0);
461 sector = GET2(&eof_map[vol_no].mark.date, 0);
462
463 zft_last_vtbl->start_seg = zft_eom_vtbl->start_seg;
464 zft_last_vtbl->end_seg = segment;
465 zft_eom_vtbl->start_seg = segment + 1;
466 zft_last_vtbl->blk_sz = 1;
467 zft_last_vtbl->size =
468 (zft_calc_tape_pos(zft_last_vtbl->end_seg)
469 - zft_calc_tape_pos(zft_last_vtbl->start_seg)
470 + (sector-1) * FT_SECTOR_SIZE);
471 TRACE(ft_t_noise,
472 "failed sector log: segment: %d, sector: %d",
473 segment, sector);
474 DUMP_VOLINFO(ft_t_noise, "Faked volume", zft_last_vtbl);
475 }
476 if (!have_eom) {
477 zft_new_vtbl_entry();
478 zft_last_vtbl->start_seg = zft_eom_vtbl->start_seg;
479 zft_last_vtbl->end_seg = ft_last_data_segment;
480 zft_eom_vtbl->start_seg = ft_last_data_segment + 1;
481 zft_last_vtbl->size = zft_capacity;
482 zft_last_vtbl->size -= zft_calc_tape_pos(zft_last_vtbl->start_seg);
483 zft_last_vtbl->blk_sz = 1;
484 DUMP_VOLINFO(ft_t_noise, "Faked volume",zft_last_vtbl);
485 }
486 TRACE_EXIT 0;
487 }
488
489 /* update the internal volume table
490 *
491 * if before start of last volume: erase all following volumes if
492 * inside a volume: set end of volume to infinity
493 *
494 * this function is intended to be called every time _ftape_write() is
495 * called
496 *
497 * return: 0 if no new volume was created, 1 if a new volume was
498 * created
499 *
500 * NOTE: we don't need to check for zft_mode as ftape_write() does
501 * that already. This function gets never called without accessing
502 * zftape via the *qft* devices
503 */
504
zft_open_volume(zft_position * pos,int blk_sz,int use_compression)505 int zft_open_volume(zft_position *pos, int blk_sz, int use_compression)
506 {
507 TRACE_FUN(ft_t_flow);
508
509 if (!zft_qic_mode) {
510 TRACE_EXIT 0;
511 }
512 if (zft_tape_at_lbot(pos)) {
513 zft_init_vtbl();
514 if(zft_old_ftape) {
515 /* clear old ftape's eof marks */
516 zft_clear_ftape_file_marks();
517 zft_old_ftape = 0; /* no longer old ftape */
518 }
519 zft_reset_position(pos);
520 }
521 if (pos->seg_pos != zft_last_vtbl->end_seg + 1) {
522 TRACE_ABORT(-EIO, ft_t_bug,
523 "BUG: seg_pos: %d, zft_last_vtbl->end_seg: %d",
524 pos->seg_pos, zft_last_vtbl->end_seg);
525 }
526 TRACE(ft_t_noise, "create new volume");
527 if (zft_eom_vtbl->count >= ZFT_MAX_VOLUMES) {
528 TRACE_ABORT(-ENOSPC, ft_t_err,
529 "Error: maxmimal number of volumes exhausted "
530 "(maxmimum is %d)", ZFT_MAX_VOLUMES);
531 }
532 zft_new_vtbl_entry();
533 pos->volume_pos = pos->seg_byte_pos = 0;
534 zft_last_vtbl->start_seg = pos->seg_pos;
535 zft_last_vtbl->end_seg = ft_last_data_segment; /* infinity */
536 zft_last_vtbl->blk_sz = blk_sz;
537 zft_last_vtbl->size = zft_capacity;
538 zft_last_vtbl->zft_volume = 1;
539 zft_last_vtbl->use_compression = use_compression;
540 zft_last_vtbl->qic113 = zft_qic113;
541 zft_last_vtbl->new_volume = 1;
542 zft_last_vtbl->open = 1;
543 zft_volume_table_changed = 1;
544 zft_eom_vtbl->start_seg = ft_last_data_segment + 1;
545 TRACE_EXIT 0;
546 }
547
548 /* perform mtfsf, mtbsf, not allowed without zft_qic_mode
549 */
zft_skip_volumes(int count,zft_position * pos)550 int zft_skip_volumes(int count, zft_position *pos)
551 {
552 const zft_volinfo *vtbl;
553 TRACE_FUN(ft_t_flow);
554
555 TRACE(ft_t_noise, "count: %d", count);
556
557 vtbl= zft_find_volume(pos->seg_pos);
558 while (count > 0 && vtbl != zft_eom_vtbl) {
559 vtbl = list_entry(vtbl->node.next, zft_volinfo, node);
560 count --;
561 }
562 while (count < 0 && vtbl != zft_first_vtbl) {
563 vtbl = list_entry(vtbl->node.prev, zft_volinfo, node);
564 count ++;
565 }
566 pos->seg_pos = vtbl->start_seg;
567 pos->seg_byte_pos = 0;
568 pos->volume_pos = 0;
569 pos->tape_pos = zft_calc_tape_pos(pos->seg_pos);
570 zft_just_before_eof = vtbl->size == 0;
571 if (zft_cmpr_ops) {
572 (*zft_cmpr_ops->reset)();
573 }
574 zft_deblock_segment = -1; /* no need to keep cache */
575 TRACE(ft_t_noise, "repositioning to:\n"
576 KERN_INFO "zft_seg_pos : %d\n"
577 KERN_INFO "zft_seg_byte_pos : %d\n"
578 KERN_INFO "zft_tape_pos : " LL_X "\n"
579 KERN_INFO "zft_volume_pos : " LL_X "\n"
580 KERN_INFO "file number : %d",
581 pos->seg_pos, pos->seg_byte_pos,
582 LL(pos->tape_pos), LL(pos->volume_pos), vtbl->count);
583 zft_resid = count < 0 ? -count : count;
584 TRACE_EXIT zft_resid ? -EINVAL : 0;
585 }
586
587 /* the following simply returns the raw data position of the EOM
588 * marker, MTIOCSIZE ioctl
589 */
zft_get_eom_pos(void)590 __s64 zft_get_eom_pos(void)
591 {
592 if (zft_qic_mode) {
593 return zft_calc_tape_pos(zft_eom_vtbl->start_seg);
594 } else {
595 /* there is only one volume in raw mode */
596 return zft_capacity;
597 }
598 }
599
600 /* skip to eom, used for MTEOM
601 */
zft_skip_to_eom(zft_position * pos)602 void zft_skip_to_eom(zft_position *pos)
603 {
604 TRACE_FUN(ft_t_flow);
605 pos->seg_pos = zft_eom_vtbl->start_seg;
606 pos->seg_byte_pos =
607 pos->volume_pos =
608 zft_just_before_eof = 0;
609 pos->tape_pos = zft_calc_tape_pos(pos->seg_pos);
610 TRACE(ft_t_noise, "ftape positioned to segment %d, data pos " LL_X,
611 pos->seg_pos, LL(pos->tape_pos));
612 TRACE_EXIT;
613 }
614
615 /* write an EOF-marker by setting zft_last_vtbl->end_seg to seg_pos.
616 * NOTE: this function assumes that zft_last_vtbl points to a valid
617 * vtbl entry
618 *
619 * NOTE: this routine always positions before the EOF marker
620 */
zft_close_volume(zft_position * pos)621 int zft_close_volume(zft_position *pos)
622 {
623 TRACE_FUN(ft_t_any);
624
625 if (zft_vtbl_empty || !zft_last_vtbl->open) { /* should not happen */
626 TRACE(ft_t_noise, "There are no volumes to finish");
627 TRACE_EXIT -EIO;
628 }
629 if (pos->seg_byte_pos == 0 &&
630 pos->seg_pos != zft_last_vtbl->start_seg) {
631 pos->seg_pos --;
632 pos->seg_byte_pos = zft_get_seg_sz(pos->seg_pos);
633 }
634 zft_last_vtbl->end_seg = pos->seg_pos;
635 zft_last_vtbl->size = pos->volume_pos;
636 zft_volume_table_changed = 1;
637 zft_just_before_eof = 1;
638 zft_eom_vtbl->start_seg = zft_last_vtbl->end_seg + 1;
639 zft_last_vtbl->open = 0; /* closed */
640 TRACE_EXIT 0;
641 }
642
643 /* write count file-marks at current position.
644 *
645 * The tape is positioned after the eof-marker, that is at byte 0 of
646 * the segment following the eof-marker
647 *
648 * this function is only allowed in zft_qic_mode
649 *
650 * Only allowed when tape is at BOT or EOD.
651 */
zft_weof(unsigned int count,zft_position * pos)652 int zft_weof(unsigned int count, zft_position *pos)
653 {
654
655 TRACE_FUN(ft_t_flow);
656
657 if (!count) { /* write zero EOF marks should be a real no-op */
658 TRACE_EXIT 0;
659 }
660 zft_volume_table_changed = 1;
661 if (zft_tape_at_lbot(pos)) {
662 zft_init_vtbl();
663 if(zft_old_ftape) {
664 /* clear old ftape's eof marks */
665 zft_clear_ftape_file_marks();
666 zft_old_ftape = 0; /* no longer old ftape */
667 }
668 }
669 if (zft_last_vtbl->open) {
670 zft_close_volume(pos);
671 zft_move_past_eof(pos);
672 count --;
673 }
674 /* now it's easy, just append eof-marks, that is empty
675 * volumes, to the end of the already recorded media.
676 */
677 while (count > 0 &&
678 pos->seg_pos <= ft_last_data_segment &&
679 zft_eom_vtbl->count < ZFT_MAX_VOLUMES) {
680 TRACE(ft_t_noise,
681 "Writing zero sized file at segment %d", pos->seg_pos);
682 zft_new_vtbl_entry();
683 zft_last_vtbl->start_seg = pos->seg_pos;
684 zft_last_vtbl->end_seg = pos->seg_pos;
685 zft_last_vtbl->size = 0;
686 zft_last_vtbl->blk_sz = zft_blk_sz;
687 zft_last_vtbl->zft_volume = 1;
688 zft_last_vtbl->use_compression = 0;
689 pos->tape_pos += zft_get_seg_sz(pos->seg_pos);
690 zft_eom_vtbl->start_seg = ++ pos->seg_pos;
691 count --;
692 }
693 if (count > 0) {
694 /* there are two possibilities: end of tape, or the
695 * maximum number of files is exhausted.
696 */
697 zft_resid = count;
698 TRACE(ft_t_noise,"Number of marks NOT written: %d", zft_resid);
699 if (zft_eom_vtbl->count == ZFT_MAX_VOLUMES) {
700 TRACE_ABORT(-EINVAL, ft_t_warn,
701 "maximum allowed number of files "
702 "exhausted: %d", ZFT_MAX_VOLUMES);
703 } else {
704 TRACE_ABORT(-ENOSPC,
705 ft_t_noise, "reached end of tape");
706 }
707 }
708 TRACE_EXIT 0;
709 }
710
zft_find_volume(unsigned int seg_pos)711 const zft_volinfo *zft_find_volume(unsigned int seg_pos)
712 {
713 TRACE_FUN(ft_t_flow);
714
715 TRACE(ft_t_any, "called with seg_pos %d",seg_pos);
716 if (!zft_qic_mode) {
717 if (seg_pos > ft_last_data_segment) {
718 TRACE_EXIT &eot_vtbl;
719 }
720 tape_vtbl.blk_sz = zft_blk_sz;
721 TRACE_EXIT &tape_vtbl;
722 }
723 if (seg_pos < zft_first_vtbl->start_seg) {
724 TRACE_EXIT (cur_vtbl = zft_first_vtbl);
725 }
726 while (seg_pos > cur_vtbl->end_seg) {
727 cur_vtbl = list_entry(cur_vtbl->node.next, zft_volinfo, node);
728 TRACE(ft_t_noise, "%d - %d", cur_vtbl->start_seg, cur_vtbl->end_seg);
729 }
730 while (seg_pos < cur_vtbl->start_seg) {
731 cur_vtbl = list_entry(cur_vtbl->node.prev, zft_volinfo, node);
732 TRACE(ft_t_noise, "%d - %d", cur_vtbl->start_seg, cur_vtbl->end_seg);
733 }
734 if (seg_pos > cur_vtbl->end_seg || seg_pos < cur_vtbl->start_seg) {
735 TRACE(ft_t_bug, "This cannot happen");
736 }
737 DUMP_VOLINFO(ft_t_noise, "", cur_vtbl);
738 TRACE_EXIT cur_vtbl;
739 }
740
741 /* this function really assumes that we are just before eof
742 */
zft_move_past_eof(zft_position * pos)743 void zft_move_past_eof(zft_position *pos)
744 {
745 TRACE_FUN(ft_t_flow);
746
747 TRACE(ft_t_noise, "old seg. pos: %d", pos->seg_pos);
748 pos->tape_pos += zft_get_seg_sz(pos->seg_pos++) - pos->seg_byte_pos;
749 pos->seg_byte_pos = 0;
750 pos->volume_pos = 0;
751 if (zft_cmpr_ops) {
752 (*zft_cmpr_ops->reset)();
753 }
754 zft_just_before_eof = 0;
755 zft_deblock_segment = -1; /* no need to cache it anymore */
756 TRACE(ft_t_noise, "new seg. pos: %d", pos->seg_pos);
757 TRACE_EXIT;
758 }
759