3 * block.c -- tape block handling functions
5 * Kern Sibbald, March MMI
6 * added BB02 format October MMII
12 Copyright (C) 2000-2003 Kern Sibbald and John Walker
14 This program is free software; you can redistribute it and/or
15 modify it under the terms of the GNU General Public License as
16 published by the Free Software Foundation; either version 2 of
17 the License, or (at your option) any later version.
19 This program is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 General Public License for more details.
24 You should have received a copy of the GNU General Public
25 License along with this program; if not, write to the Free
26 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
35 extern int debug_level;
38 * Dump the block header, then walk through
39 * the block printing out the record headers.
41 void dump_block(DEV_BLOCK *b, char *msg)
45 char Id[BLKHDR_ID_LENGTH+1];
46 uint32_t CheckSum, BlockCheckSum;
49 uint32_t VolSessionId, VolSessionTime, data_len;
54 unser_begin(b->buf, BLKHDR1_LENGTH);
55 unser_uint32(CheckSum);
56 unser_uint32(block_len);
57 unser_uint32(BlockNumber);
58 unser_bytes(Id, BLKHDR_ID_LENGTH);
59 ASSERT(unser_length(b->buf) == BLKHDR1_LENGTH);
60 Id[BLKHDR_ID_LENGTH] = 0;
62 unser_uint32(VolSessionId);
63 unser_uint32(VolSessionTime);
67 VolSessionId = VolSessionTime = 0;
72 if (block_len > 100000) {
73 Dmsg3(20, "Dump block %s 0x%x blocksize too big %u\n", msg, b, block_len);
77 BlockCheckSum = bcrc32((uint8_t *)b->buf+BLKHDR_CS_LENGTH,
78 block_len-BLKHDR_CS_LENGTH);
79 Pmsg6(000, "Dump block %s %x: size=%d BlkNum=%d\n\
80 Hdrcksum=%x cksum=%x\n",
81 msg, b, block_len, BlockNumber, CheckSum, BlockCheckSum);
83 while (p < (b->buf + block_len+WRITE_RECHDR_LENGTH)) {
84 unser_begin(p, WRITE_RECHDR_LENGTH);
85 if (rhl == RECHDR1_LENGTH) {
86 unser_uint32(VolSessionId);
87 unser_uint32(VolSessionTime);
89 unser_int32(FileIndex);
91 unser_uint32(data_len);
92 Pmsg6(000, " Rec: VId=%u VT=%u FI=%s Strm=%s len=%d p=%x\n",
93 VolSessionId, VolSessionTime, FI_to_ascii(FileIndex),
94 stream_to_ascii(Stream, FileIndex), data_len, p);
100 * Create a new block structure.
101 * We pass device so that the block can inherit the
102 * min and max block sizes.
104 DEV_BLOCK *new_block(DEVICE *dev)
106 DEV_BLOCK *block = (DEV_BLOCK *)get_memory(sizeof(DEV_BLOCK));
108 memset(block, 0, sizeof(DEV_BLOCK));
110 /* If the user has specified a max_block_size, use it as the default */
111 if (dev->max_block_size == 0) {
112 block->buf_len = DEFAULT_BLOCK_SIZE;
114 block->buf_len = dev->max_block_size;
117 block->block_len = block->buf_len; /* default block size */
118 block->buf = get_memory(block->buf_len);
119 if (block->buf == NULL) {
120 Mmsg0(&dev->errmsg, _("Unable to malloc block buffer.\n"));
121 Emsg0(M_FATAL, 0, dev->errmsg);
125 block->BlockVer = BLOCK_VER; /* default write version */
126 Dmsg1(90, "Returning new block=%x\n", block);
133 void free_block(DEV_BLOCK *block)
135 Dmsg1(199, "free_block buffer %x\n", block->buf);
136 free_memory(block->buf);
137 Dmsg1(199, "free_block block %x\n", block);
138 free_memory((POOLMEM *)block);
141 /* Empty the block -- for writing */
142 void empty_block(DEV_BLOCK *block)
144 block->binbuf = WRITE_BLKHDR_LENGTH;
145 block->bufp = block->buf + block->binbuf;
147 block->write_failed = false;
148 block->block_read = false;
152 * Create block header just before write. The space
153 * in the buffer should have already been reserved by
156 static void ser_block_header(DEV_BLOCK *block)
159 uint32_t CheckSum = 0;
160 uint32_t block_len = block->binbuf;
162 Dmsg1(190, "ser_block_header: block_len=%d\n", block_len);
163 ser_begin(block->buf, BLKHDR2_LENGTH);
164 ser_uint32(CheckSum);
165 ser_uint32(block_len);
166 ser_uint32(block->BlockNumber);
167 ser_bytes(WRITE_BLKHDR_ID, BLKHDR_ID_LENGTH);
168 if (BLOCK_VER >= 2) {
169 ser_uint32(block->VolSessionId);
170 ser_uint32(block->VolSessionTime);
173 /* Checksum whole block except for the checksum */
174 CheckSum = bcrc32((uint8_t *)block->buf+BLKHDR_CS_LENGTH,
175 block_len-BLKHDR_CS_LENGTH);
176 Dmsg1(190, "ser_bloc_header: checksum=%x\n", CheckSum);
177 ser_begin(block->buf, BLKHDR2_LENGTH);
178 ser_uint32(CheckSum); /* now add checksum to block header */
182 * Unserialized the block header for reading block.
183 * This includes setting all the buffer pointers correctly.
185 * Returns: 0 on failure (not a block)
188 static int unser_block_header(DEVICE *dev, DEV_BLOCK *block)
191 char Id[BLKHDR_ID_LENGTH+1];
192 uint32_t CheckSum, BlockCheckSum;
195 uint32_t BlockNumber;
198 unser_begin(block->buf, BLKHDR_LENGTH);
199 unser_uint32(CheckSum);
200 unser_uint32(block_len);
201 unser_uint32(BlockNumber);
202 unser_bytes(Id, BLKHDR_ID_LENGTH);
203 ASSERT(unser_length(block->buf) == BLKHDR1_LENGTH);
205 Id[BLKHDR_ID_LENGTH] = 0;
207 bhl = BLKHDR1_LENGTH;
209 block->bufp = block->buf + bhl;
210 if (strncmp(Id, BLKHDR1_ID, BLKHDR_ID_LENGTH) != 0) {
211 Mmsg2(&dev->errmsg, _("Buffer ID error. Wanted: %s, got %s. Buffer discarded.\n"),
213 Emsg0(M_ERROR, 0, dev->errmsg);
216 } else if (Id[3] == '2') {
217 unser_uint32(block->VolSessionId);
218 unser_uint32(block->VolSessionTime);
219 bhl = BLKHDR2_LENGTH;
221 block->bufp = block->buf + bhl;
222 if (strncmp(Id, BLKHDR2_ID, BLKHDR_ID_LENGTH) != 0) {
223 Mmsg2(&dev->errmsg, _("Buffer ID error. Wanted: %s, got %s. Buffer discarded.\n"),
225 Emsg0(M_ERROR, 0, dev->errmsg);
229 Mmsg1(&dev->errmsg, _("Expected block-id BB01 or BB02, got %s. Buffer discarded.\n"), Id);
230 Emsg0(M_ERROR, 0, dev->errmsg);
235 if (block_len > MAX_BLOCK_LENGTH) {
236 Mmsg1(&dev->errmsg, _("Block length %u is insane (too large), probably due to a bad archive.\n"),
238 Emsg0(M_ERROR, 0, dev->errmsg);
242 Dmsg1(190, "unser_block_header block_len=%d\n", block_len);
243 /* Find end of block or end of buffer whichever is smaller */
244 if (block_len > block->read_len) {
245 block_end = block->read_len;
247 block_end = block_len;
249 block->binbuf = block_end - bhl;
250 block->block_len = block_len;
251 block->BlockNumber = BlockNumber;
252 Dmsg3(190, "Read binbuf = %d %d block_len=%d\n", block->binbuf,
254 if (block_len <= block->read_len) {
255 BlockCheckSum = bcrc32((uint8_t *)block->buf+BLKHDR_CS_LENGTH,
256 block_len-BLKHDR_CS_LENGTH);
257 if (BlockCheckSum != CheckSum) {
258 Dmsg2(00, "Block checksum mismatch: calc=%x blk=%x\n", BlockCheckSum,
260 Mmsg3(&dev->errmsg, _("Block checksum mismatch in block %u: calc=%x blk=%x\n"),
261 (unsigned)BlockNumber, BlockCheckSum, CheckSum);
269 * Write a block to the device, with locking and unlocking
271 * Returns: 1 on success
275 int write_block_to_device(JCR *jcr, DEVICE *dev, DEV_BLOCK *block)
279 if (!write_block_to_dev(jcr, dev, block)) {
280 stat = fixup_device_block_write_error(jcr, dev, block);
287 * Write a block to the device
289 * Returns: 1 on success or EOT
292 int write_block_to_dev(JCR *jcr, DEVICE *dev, DEV_BLOCK *block)
295 uint32_t wlen; /* length to write */
296 int hit_max1, hit_max2;
299 #ifdef NO_TAPE_WRITE_TEST
303 ASSERT(block->binbuf == ((uint32_t) (block->bufp - block->buf)));
305 /* dump_block(block, "before write"); */
306 if (dev->state & ST_WEOT) {
307 Dmsg0(100, "return write_block_to_dev with ST_WEOT\n");
308 Jmsg(jcr, M_FATAL, 0, _("Cannot write block. Device at EOM.\n"));
311 wlen = block->binbuf;
312 if (wlen <= WRITE_BLKHDR_LENGTH) { /* Does block have data in it? */
313 Dmsg0(100, "return write_block_to_dev no data to write\n");
317 * Clear to the end of the buffer if it is not full,
318 * and on tape devices, apply min and fixed blocking.
320 if (wlen != block->buf_len) {
321 uint32_t blen; /* current buffer length */
323 Dmsg2(200, "binbuf=%d buf_len=%d\n", block->binbuf, block->buf_len);
326 /* Adjust write size to min/max for tapes only */
327 if (dev->state & ST_TAPE) {
328 if (wlen < dev->min_block_size) {
329 wlen = ((dev->min_block_size + TAPE_BSIZE - 1) / TAPE_BSIZE) * TAPE_BSIZE;
331 /* check for fixed block size */
332 if (dev->min_block_size == dev->max_block_size) {
333 wlen = block->buf_len; /* fixed block size already rounded */
337 memset(block->bufp, 0, wlen-blen); /* clear garbage */
341 ser_block_header(block);
343 /* Limit maximum Volume size to value specified by user */
344 hit_max1 = (dev->max_volume_size > 0) &&
345 ((dev->VolCatInfo.VolCatBytes + block->binbuf)) >= dev->max_volume_size;
346 hit_max2 = (dev->VolCatInfo.VolCatMaxBytes > 0) &&
347 ((dev->VolCatInfo.VolCatBytes + block->binbuf)) >= dev->VolCatInfo.VolCatMaxBytes;
348 if (hit_max1 || hit_max2) {
351 Dmsg0(10, "==== Output bytes Triggered medium max capacity.\n");
353 max_cap = dev->max_volume_size;
355 max_cap = dev->VolCatInfo.VolCatMaxBytes;
357 Jmsg(jcr, M_INFO, 0, _("User defined maximum volume capacity %s exceeded on device %s.\n"),
358 edit_uint64(max_cap, ed1), dev->dev_name);
359 block->write_failed = true;
360 dev->EndBlock = dev->block_num;
361 dev->EndFile = dev->file;
362 weof_dev(dev, 1); /* end the tape */
363 weof_dev(dev, 1); /* write second eof */
364 dev->state |= (ST_EOF | ST_EOT | ST_WEOT);
368 /* Limit maximum File size on volume to user specified value */
369 if (dev->state & ST_TAPE) {
370 if ((dev->max_file_size > 0) &&
371 (dev->file_addr+block->binbuf) >= dev->max_file_size) {
372 if (weof_dev(dev, 1) != 0) { /* write eof */
373 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
374 /* Plunge on anyway -- if tape is bad we will die on write */
379 dev->VolCatInfo.VolCatWrites++;
380 Dmsg1(300, "Write block of %u bytes\n", wlen);
381 if ((uint32_t)(stat=write(dev->fd, block->buf, (size_t)wlen)) != wlen) {
382 /* We should check for errno == ENOSPC, BUT many
383 * devices simply report EIO when the volume is full.
384 * With a little more thought we may be able to check
385 * capacity and distinguish real errors and EOT
386 * conditions. In any case, we probably want to
387 * simulate an End of Medium.
390 clrerror_dev(dev, -1);
391 if (dev->dev_errno == 0) {
392 dev->dev_errno = ENOSPC; /* out of space */
394 Jmsg(jcr, M_ERROR, 0, _("Write error on device %s. ERR=%s.\n"),
395 dev->dev_name, strerror(dev->dev_errno));
397 dev->dev_errno = ENOSPC; /* out of space */
398 Jmsg3(jcr, M_INFO, 0, _("End of medium on device %s. Write of %u bytes got %d.\n"),
399 dev->dev_name, wlen, stat);
402 Dmsg4(10, "=== Write error. size=%u rtn=%d errno=%d: ERR=%s\n",
403 wlen, stat, dev->dev_errno, strerror(dev->dev_errno));
405 block->write_failed = true;
406 dev->EndBlock = dev->block_num;
407 dev->EndFile = dev->file;
408 weof_dev(dev, 1); /* end the tape */
409 weof_dev(dev, 1); /* write second eof */
410 dev->state |= (ST_EOF | ST_EOT | ST_WEOT);
413 #define CHECK_LAST_BLOCK
414 #ifdef CHECK_LAST_BLOCK
416 * If the device is a tape and it supports backspace record,
417 * we backspace over two eof marks and over the last record,
418 * then re-read it and verify that the block number is
421 if (dev->state & ST_TAPE && dev_cap(dev, CAP_BSR)) {
423 /* Now back up over what we wrote and read the last block */
424 if (bsf_dev(dev, 1) != 0 || bsf_dev(dev, 1) != 0) {
426 Jmsg(jcr, M_ERROR, 0, _("Back space file at EOT failed. ERR=%s\n"), strerror(dev->dev_errno));
428 /* Backspace over record */
429 if (ok && bsr_dev(dev, 1) != 0) {
431 Jmsg(jcr, M_ERROR, 0, _("Back space record at EOT failed. ERR=%s\n"), strerror(dev->dev_errno));
433 * On FreeBSD systems, if the user got here, it is likely that his/her
434 * tape drive is "frozen". The correct thing to do is a
435 * rewind(), but if we do that, higher levels in cleaning up, will
436 * most likely write the EOS record over the beginning of the
437 * tape. The rewind *is* done later in mount.c when another
438 * tape is requested. Note, the clrerror_dev() call in bsr_dev()
439 * calls ioctl(MTCERRSTAT), which *should* fix the problem.
443 DEV_BLOCK *lblock = new_block(dev);
444 /* Note, this can destroy dev->errmsg */
445 if (!read_block_from_dev(jcr, dev, lblock, NO_BLOCK_NUMBER_CHECK)) {
446 Jmsg(jcr, M_ERROR, 0, _("Re-read last block at EOT failed. ERR=%s"), dev->errmsg);
448 if (lblock->BlockNumber+1 == block->BlockNumber) {
449 Jmsg(jcr, M_INFO, 0, _("Re-read of last block succeeded.\n"));
451 Jmsg(jcr, M_ERROR, 0, _(
452 "Re-read of last block failed. Last block=%u Current block=%u.\n"),
453 lblock->BlockNumber, block->BlockNumber);
462 dev->VolCatInfo.VolCatBytes += block->binbuf;
463 dev->VolCatInfo.VolCatBlocks++;
464 dev->file_addr += wlen;
465 dev->EndBlock = dev->block_num;
466 dev->EndFile = dev->file;
468 block->BlockNumber++;
470 Dmsg2(190, "write_block: wrote block %d bytes=%d\n", dev->block_num,
477 * Read block with locking
480 int read_block_from_device(JCR *jcr, DEVICE *dev, DEV_BLOCK *block, bool check_block_numbers)
483 Dmsg0(90, "Enter read_block_from_device\n");
485 stat = read_block_from_dev(jcr, dev, block, check_block_numbers);
487 Dmsg0(90, "Leave read_block_from_device\n");
492 * Read the next block into the block structure and unserialize
493 * the block header. For a file, the block may be partially
494 * or completely in the current buffer.
496 int read_block_from_dev(JCR *jcr, DEVICE *dev, DEV_BLOCK *block, bool check_block_numbers)
500 uint32_t BlockNumber;
504 Dmsg1(100, "Full read() in read_block_from_device() len=%d\n",
508 Mmsg1(&dev->errmsg, _("Block buffer size looping problem on device %s\n"),
510 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
515 stat = read(dev->fd, block->buf, (size_t)block->buf_len);
517 dev->VolCatInfo.VolCatErrors++;
519 } while (stat == -1 && (errno == EINTR || errno == EIO) && retry++ < 11);
521 Dmsg1(90, "Read device got: ERR=%s\n", strerror(errno));
522 clrerror_dev(dev, -1);
524 Mmsg2(&dev->errmsg, _("Read error on device %s. ERR=%s.\n"),
525 dev->dev_name, strerror(dev->dev_errno));
526 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
527 if (dev->state & ST_EOF) { /* EOF just seen? */
528 dev->state |= ST_EOT; /* yes, error => EOT */
532 Dmsg1(90, "Read device got %d bytes\n", stat);
533 if (stat == 0) { /* Got EOF ! */
534 dev->block_num = block->read_len = 0;
535 Mmsg1(&dev->errmsg, _("Read zero bytes on device %s.\n"), dev->dev_name);
536 if (dev->state & ST_EOF) { /* EOF already read? */
537 dev->state |= ST_EOT; /* yes, 2 EOFs => EOT */
541 dev->file++; /* increment file */
542 dev->state |= ST_EOF; /* set EOF read */
544 return 0; /* return eof */
546 /* Continue here for successful read */
547 block->read_len = stat; /* save length read */
548 if (block->read_len < BLKHDR2_LENGTH) {
549 Mmsg2(&dev->errmsg, _("Very short block of %d bytes on device %s discarded.\n"),
550 block->read_len, dev->dev_name);
551 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
552 dev->state |= ST_SHORT; /* set short block */
553 block->read_len = block->binbuf = 0;
554 return 0; /* return error */
557 BlockNumber = block->BlockNumber + 1;
558 if (!unser_block_header(dev, block)) {
564 * If the block is bigger than the buffer, we reposition for
565 * re-reading the block, allocate a buffer of the correct size,
568 if (block->block_len > block->buf_len) {
569 Mmsg2(&dev->errmsg, _("Block length %u is greater than buffer %u. Attempting recovery.\n"),
570 block->block_len, block->buf_len);
571 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
572 Pmsg1(000, "%s", dev->errmsg);
573 /* Attempt to reposition to re-read the block */
574 if (dev->state & ST_TAPE) {
575 Dmsg0(100, "Backspace record for reread.\n");
576 if (bsr_dev(dev, 1) != 0) {
577 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
582 Dmsg0(100, "Seek to beginning of block for reread.\n");
583 off_t pos = lseek(dev->fd, (off_t)0, SEEK_CUR); /* get curr pos */
584 pos -= block->read_len;
585 lseek(dev->fd, pos, SEEK_SET);
587 Mmsg1(&dev->errmsg, _("Setting block buffer size to %u bytes.\n"), block->block_len);
588 Jmsg(jcr, M_INFO, 0, "%s", dev->errmsg);
589 Pmsg1(000, "%s", dev->errmsg);
590 /* Set new block length */
591 dev->max_block_size = block->block_len;
592 block->buf_len = block->block_len;
593 free_memory(block->buf);
594 block->buf = get_memory(block->buf_len);
597 goto reread; /* re-read block with correct block size */
600 if (block->block_len > block->read_len) {
601 Mmsg2(&dev->errmsg, _("Short block of %d bytes on device %s discarded.\n"),
602 block->read_len, dev->dev_name);
603 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
604 dev->state |= ST_SHORT; /* set short block */
605 block->read_len = block->binbuf = 0;
606 return 0; /* return error */
609 dev->state &= ~(ST_EOF|ST_SHORT); /* clear EOF and short block */
611 dev->VolCatInfo.VolCatReads++;
612 dev->VolCatInfo.VolCatRBytes += block->read_len;
615 * If we read a short block on disk,
616 * seek to beginning of next block. This saves us
617 * from shuffling blocks around in the buffer. Take a
618 * look at this from an efficiency stand point later, but
619 * it should only happen once at the end of each job.
621 * I've been lseek()ing negative relative to SEEK_CUR for 30
622 * years now. However, it seems that with the new off_t definition,
623 * it is not possible to seek negative amounts, so we use two
624 * lseek(). One to get the position, then the second to do an
625 * absolute positioning -- so much for efficiency. KES Sep 02.
627 Dmsg0(200, "At end of read block\n");
628 if (block->read_len > block->block_len && !(dev->state & ST_TAPE)) {
629 off_t pos = lseek(dev->fd, (off_t)0, SEEK_CUR); /* get curr pos */
630 pos -= (block->read_len - block->block_len);
631 lseek(dev->fd, pos, SEEK_SET);
632 Dmsg2(100, "Did lseek blk_size=%d rdlen=%d\n", block->block_len,
635 Dmsg2(200, "Exit read_block read_len=%d block_len=%d\n",
636 block->read_len, block->block_len);
637 block->block_read = true;