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->failed_write = FALSE;
151 * Create block header just before write. The space
152 * in the buffer should have already been reserved by
155 static void ser_block_header(DEV_BLOCK *block)
158 uint32_t CheckSum = 0;
159 uint32_t block_len = block->binbuf;
161 Dmsg1(190, "ser_block_header: block_len=%d\n", block_len);
162 ser_begin(block->buf, BLKHDR2_LENGTH);
163 ser_uint32(CheckSum);
164 ser_uint32(block_len);
165 ser_uint32(block->BlockNumber);
166 ser_bytes(WRITE_BLKHDR_ID, BLKHDR_ID_LENGTH);
167 if (BLOCK_VER >= 2) {
168 ser_uint32(block->VolSessionId);
169 ser_uint32(block->VolSessionTime);
172 /* Checksum whole block except for the checksum */
173 CheckSum = bcrc32((uint8_t *)block->buf+BLKHDR_CS_LENGTH,
174 block_len-BLKHDR_CS_LENGTH);
175 Dmsg1(190, "ser_bloc_header: checksum=%x\n", CheckSum);
176 ser_begin(block->buf, BLKHDR2_LENGTH);
177 ser_uint32(CheckSum); /* now add checksum to block header */
181 * Unserialized the block header for reading block.
182 * This includes setting all the buffer pointers correctly.
184 * Returns: 0 on failure (not a block)
187 static int unser_block_header(DEVICE *dev, DEV_BLOCK *block)
190 char Id[BLKHDR_ID_LENGTH+1];
191 uint32_t CheckSum, BlockCheckSum;
194 uint32_t BlockNumber;
197 unser_begin(block->buf, BLKHDR_LENGTH);
198 unser_uint32(CheckSum);
199 unser_uint32(block_len);
200 unser_uint32(BlockNumber);
201 unser_bytes(Id, BLKHDR_ID_LENGTH);
202 ASSERT(unser_length(block->buf) == BLKHDR1_LENGTH);
204 Id[BLKHDR_ID_LENGTH] = 0;
206 bhl = BLKHDR1_LENGTH;
208 block->bufp = block->buf + bhl;
209 if (strncmp(Id, BLKHDR1_ID, BLKHDR_ID_LENGTH) != 0) {
210 Mmsg2(&dev->errmsg, _("Buffer ID error. Wanted: %s, got %s. Buffer discarded.\n"),
212 Emsg0(M_ERROR, 0, dev->errmsg);
215 } else if (Id[3] == '2') {
216 unser_uint32(block->VolSessionId);
217 unser_uint32(block->VolSessionTime);
218 bhl = BLKHDR2_LENGTH;
220 block->bufp = block->buf + bhl;
221 if (strncmp(Id, BLKHDR2_ID, BLKHDR_ID_LENGTH) != 0) {
222 Mmsg2(&dev->errmsg, _("Buffer ID error. Wanted: %s, got %s. Buffer discarded.\n"),
224 Emsg0(M_ERROR, 0, dev->errmsg);
228 Mmsg1(&dev->errmsg, _("Expected block-id BB01 or BB02, got %s. Buffer discarded.\n"), Id);
229 Emsg0(M_ERROR, 0, dev->errmsg);
234 if (block_len > MAX_BLOCK_LENGTH) {
235 Mmsg1(&dev->errmsg, _("Block length %u is insane (too large), probably due to a bad archive.\n"),
237 Emsg0(M_ERROR, 0, dev->errmsg);
241 Dmsg1(190, "unser_block_header block_len=%d\n", block_len);
242 /* Find end of block or end of buffer whichever is smaller */
243 if (block_len > block->read_len) {
244 block_end = block->read_len;
246 block_end = block_len;
248 block->binbuf = block_end - bhl;
249 block->block_len = block_len;
250 block->BlockNumber = BlockNumber;
251 Dmsg3(190, "Read binbuf = %d %d block_len=%d\n", block->binbuf,
253 if (block_len <= block->read_len) {
254 BlockCheckSum = bcrc32((uint8_t *)block->buf+BLKHDR_CS_LENGTH,
255 block_len-BLKHDR_CS_LENGTH);
256 if (BlockCheckSum != CheckSum) {
257 Dmsg2(00, "Block checksum mismatch: calc=%x blk=%x\n", BlockCheckSum,
259 Mmsg3(&dev->errmsg, _("Block checksum mismatch in block %u: calc=%x blk=%x\n"),
260 (unsigned)BlockNumber, BlockCheckSum, CheckSum);
268 * Write a block to the device, with locking and unlocking
270 * Returns: 1 on success
274 int write_block_to_device(JCR *jcr, DEVICE *dev, DEV_BLOCK *block)
278 if (!write_block_to_dev(jcr, dev, block)) {
279 Jmsg(jcr, M_INFO, 0, "%s", dev->errmsg);
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 Mmsg0(&dev->errmsg, _("Cannot write block. Device at EOF.\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) {
350 dev->state |= ST_WEOT;
351 Dmsg0(10, "==== Output bytes Triggered medium max capacity.\n");
353 Mmsg(&dev->errmsg, _("Max. Volume capacity %s exceeded on device %s.\n"),
354 edit_uint64(dev->max_volume_size, ed1), dev->dev_name);
356 Mmsg(&dev->errmsg, _("Max. Volume capacity %s exceeded on device %s.\n"),
357 edit_uint64(dev->VolCatInfo.VolCatMaxBytes, ed1), dev->dev_name);
359 block->failed_write = 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 */
367 /* Limit maximum File size on volume to user specified value */
368 if (dev->state & ST_TAPE) {
369 if ((dev->max_file_size > 0) &&
370 (dev->file_addr+block->binbuf) >= dev->max_file_size) {
371 if (weof_dev(dev, 1) != 0) { /* write eof */
372 Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
373 /* Plunge on anyway -- if tape is bad we will die on write */
378 dev->VolCatInfo.VolCatWrites++;
379 Dmsg1(500, "Write block of %u bytes\n", wlen);
380 if ((uint32_t)(stat=write(dev->fd, block->buf, (size_t)wlen)) != wlen) {
381 /* We should check for errno == ENOSPC, BUT many
382 * devices simply report EIO when it is full.
383 * with a little more thought we may be able to check
384 * capacity and distinguish real errors and EOT
385 * conditions. In any case, we probably want to
386 * simulate an End of Medium.
388 dev->state |= ST_EOF | ST_EOT | ST_WEOT;
389 clrerror_dev(dev, -1);
391 if (dev->dev_errno == 0) {
392 dev->dev_errno = ENOSPC; /* out of space */
395 Dmsg4(10, "=== Write error. size=%u rtn=%d errno=%d: ERR=%s\n",
396 wlen, stat, dev->dev_errno, strerror(dev->dev_errno));
399 Mmsg2(&dev->errmsg, _("Write error on device %s. ERR=%s.\n"),
400 dev->dev_name, strerror(dev->dev_errno));
402 Mmsg3(&dev->errmsg, _("End of media on device %s. Write of %u bytes got %d.\n"),
403 dev->dev_name, wlen, stat);
405 block->failed_write = 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 */
412 #define CHECK_LAST_BLOCK
413 #ifdef CHECK_LAST_BLOCK
415 * If the device is a tape and it supports backspace record,
416 * we backspace over two eof marks and over the last record,
417 * then re-read it and verify that the block number is
420 if (dev->state & ST_TAPE && dev_cap(dev, CAP_BSR)) {
422 /* Now back up over what we wrote and read the last block */
423 if (bsf_dev(dev, 1) != 0 || bsf_dev(dev, 1) != 0) {
425 Jmsg(jcr, M_ERROR, 0, _("Back space file at EOT failed. ERR=%s\n"), strerror(dev->dev_errno));
427 /* Backspace over record */
428 if (ok && bsr_dev(dev, 1) != 0) {
430 Jmsg(jcr, M_ERROR, 0, _("Back space record at EOT failed. ERR=%s\n"), strerror(dev->dev_errno));
433 DEV_BLOCK *lblock = new_block(dev);
434 /* Note, this can destroy dev->errmsg */
435 if (!read_block_from_dev(dev, lblock)) {
436 Jmsg(jcr, M_ERROR, 0, _("Re-read last block at EOT failed. ERR=%s"), dev->errmsg);
438 if (lblock->BlockNumber+1 == block->BlockNumber) {
439 Jmsg(jcr, M_INFO, 0, _("Re-read of last block succeeded.\n"));
441 Jmsg(jcr, M_ERROR, 0, _(
442 "Re-read of last block failed. Last block=%u Current block=%u.\n"),
443 lblock->BlockNumber, block->BlockNumber);
452 dev->VolCatInfo.VolCatBytes += block->binbuf;
453 dev->VolCatInfo.VolCatBlocks++;
454 dev->file_addr += wlen;
455 dev->EndBlock = dev->block_num;
456 dev->EndFile = dev->file;
458 block->BlockNumber++;
461 Dmsg2(190, "write_block: wrote block %d bytes=%d\n", dev->block_num,
468 * Read block with locking
471 int read_block_from_device(DEVICE *dev, DEV_BLOCK *block)
474 Dmsg0(90, "Enter read_block_from_device\n");
476 stat = read_block_from_dev(dev, block);
478 Dmsg0(90, "Leave read_block_from_device\n");
483 * Read the next block into the block structure and unserialize
484 * the block header. For a file, the block may be partially
485 * or completely in the current buffer.
487 int read_block_from_dev(DEVICE *dev, DEV_BLOCK *block)
493 Dmsg1(100, "Full read() in read_block_from_device() len=%d\n",
497 Mmsg1(&dev->errmsg, _("Block buffer size looping problem on device %s\n"),
502 if ((stat=read(dev->fd, block->buf, (size_t)block->buf_len)) < 0) {
503 Dmsg1(90, "Read device got: ERR=%s\n", strerror(errno));
504 clrerror_dev(dev, -1);
506 Mmsg2(&dev->errmsg, _("Read error on device %s. ERR=%s.\n"),
507 dev->dev_name, strerror(dev->dev_errno));
510 Dmsg1(90, "Read device got %d bytes\n", stat);
511 if (stat == 0) { /* Got EOF ! */
512 dev->block_num = block->read_len = 0;
513 Mmsg1(&dev->errmsg, _("Read zero bytes on device %s.\n"), dev->dev_name);
514 if (dev->state & ST_EOF) { /* EOF alread read? */
515 dev->state |= ST_EOT; /* yes, 2 EOFs => EOT */
519 dev->file++; /* increment file */
520 dev->state |= ST_EOF; /* set EOF read */
522 return 0; /* return eof */
524 /* Continue here for successful read */
525 block->read_len = stat; /* save length read */
526 if (block->read_len < BLKHDR2_LENGTH) {
527 Mmsg2(&dev->errmsg, _("Very short block of %d bytes on device %s discarded.\n"),
528 block->read_len, dev->dev_name);
529 dev->state |= ST_SHORT; /* set short block */
530 block->read_len = block->binbuf = 0;
531 return 0; /* return error */
534 if (!unser_block_header(dev, block)) {
540 * If the block is bigger than the buffer, we reposition for
541 * re-reading the block, allocate a buffer of the correct size,
544 if (block->block_len > block->buf_len) {
545 Mmsg2(&dev->errmsg, _("Block length %u is greater than buffer %u. Attempting recovery.\n"),
546 block->block_len, block->buf_len);
547 Emsg0(M_WARNING, 0, dev->errmsg);
548 Dmsg1(000, "%s", dev->errmsg);
549 /* Attempt to reposition to re-read the block */
550 if (dev->state & ST_TAPE) {
551 Dmsg0(100, "Backspace record for reread.\n");
552 if (bsf_dev(dev, 1) != 0) {
553 Emsg0(M_ERROR, 0, dev->errmsg);
558 Dmsg0(100, "Seek to beginning of block for reread.\n");
559 off_t pos = lseek(dev->fd, (off_t)0, SEEK_CUR); /* get curr pos */
560 pos -= block->read_len;
561 lseek(dev->fd, pos, SEEK_SET);
563 Mmsg1(&dev->errmsg, _("Resetting buffer size to %u bytes.\n"), block->block_len);
564 Emsg0(M_WARNING, 0, dev->errmsg);
565 Dmsg1(000, "%s", dev->errmsg);
566 /* Set new block length */
567 dev->max_block_size = block->block_len;
568 block->buf_len = block->block_len;
569 free_memory(block->buf);
570 block->buf = get_memory(block->buf_len);
573 goto reread; /* re-read block with correct block size */
576 if (block->block_len > block->read_len) {
577 Mmsg2(&dev->errmsg, _("Short block of %d bytes on device %s discarded.\n"),
578 block->read_len, dev->dev_name);
579 dev->state |= ST_SHORT; /* set short block */
580 block->read_len = block->binbuf = 0;
581 return 0; /* return error */
584 dev->state &= ~(ST_EOF|ST_SHORT); /* clear EOF and short block */
588 * If we read a short block on disk,
589 * seek to beginning of next block. This saves us
590 * from shuffling blocks around in the buffer. Take a
591 * look at this from an efficiency stand point later, but
592 * it should only happen once at the end of each job.
594 * I've been lseek()ing negative relative to SEEK_CUR for 30
595 * years now. However, it seems that with the new off_t definition,
596 * it is not possible to seek negative amounts, so we use two
597 * lseek(). One to get the position, then the second to do an
598 * absolute positioning -- so much for efficiency. KES Sep 02.
600 Dmsg0(200, "At end of read block\n");
601 if (block->read_len > block->block_len && !(dev->state & ST_TAPE)) {
602 off_t pos = lseek(dev->fd, (off_t)0, SEEK_CUR); /* get curr pos */
603 pos -= (block->read_len - block->block_len);
604 lseek(dev->fd, pos, SEEK_SET);
605 Dmsg2(100, "Did lseek blk_size=%d rdlen=%d\n", block->block_len,
608 Dmsg2(200, "Exit read_block read_len=%d block_len=%d\n",
609 block->read_len, block->block_len);