1 /* $NetBSD: tape.c,v 1.40 2003/04/02 10:39:24 fvdl Exp $ */ 2 3 /*- 4 * Copyright (c) 1980, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)tape.c 8.4 (Berkeley) 5/1/95"; 40 #else 41 __RCSID("$NetBSD: tape.c,v 1.40 2003/04/02 10:39:24 fvdl Exp $"); 42 #endif 43 #endif /* not lint */ 44 45 #include <sys/param.h> 46 #include <sys/socket.h> 47 #include <sys/time.h> 48 #include <sys/wait.h> 49 #include <ufs/ufs/dinode.h> 50 #include <sys/ioctl.h> 51 #include <sys/mtio.h> 52 53 #include <protocols/dumprestore.h> 54 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <setjmp.h> 58 #include <signal.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <time.h> 63 #include <unistd.h> 64 65 #include "dump.h" 66 #include "pathnames.h" 67 68 int writesize; /* size of malloc()ed buffer for tape */ 69 int64_t lastspclrec = -1; /* tape block number of last written header */ 70 int trecno = 0; /* next record to write in current block */ 71 extern long blocksperfile; /* number of blocks per output file */ 72 long blocksthisvol; /* number of blocks on current output file */ 73 extern int ntrec; /* blocking factor on tape */ 74 extern int cartridge; 75 extern char *host; 76 char *nexttape; 77 78 static ssize_t atomic_read(int, char *, int); 79 static ssize_t atomic_write(int, char *, int); 80 static void doslave(int, int); 81 static void enslave(void); 82 static void flushtape(void); 83 static void killall(void); 84 static void proceed(int); 85 static void rollforward(void); 86 static void sigpipe(int); 87 static void tperror(int); 88 89 /* 90 * Concurrent dump mods (Caltech) - disk block reading and tape writing 91 * are exported to several slave processes. While one slave writes the 92 * tape, the others read disk blocks; they pass control of the tape in 93 * a ring via signals. The parent process traverses the file system and 94 * sends writeheader()'s and lists of daddr's to the slaves via pipes. 95 * The following structure defines the instruction packets sent to slaves. 96 */ 97 struct req { 98 daddr_t dblk; 99 int count; 100 }; 101 int reqsiz; 102 103 #define SLAVES 3 /* 1 slave writing, 1 reading, 1 for slack */ 104 struct slave { 105 int64_t tapea; /* header number at start of this chunk */ 106 int64_t firstrec; /* record number of this block */ 107 int count; /* count to next header (used for TS_TAPE */ 108 /* after EOT) */ 109 int inode; /* inode that we are currently dealing with */ 110 int fd; /* FD for this slave */ 111 int pid; /* PID for this slave */ 112 int sent; /* 1 == we've sent this slave requests */ 113 char (*tblock)[TP_BSIZE]; /* buffer for data blocks */ 114 struct req *req; /* buffer for requests */ 115 } slaves[SLAVES+1]; 116 struct slave *slp; 117 118 char (*nextblock)[TP_BSIZE]; 119 120 static time_t tstart_volume; /* time of volume start */ 121 static int64_t tapea_volume; /* value of spcl.c_tapea at volume start */ 122 123 int master; /* pid of master, for sending error signals */ 124 int tenths; /* length of tape used per block written */ 125 static int caught; /* have we caught the signal to proceed? */ 126 static int ready; /* have we reached the lock point without having */ 127 /* received the SIGUSR2 signal from the prev slave? */ 128 static jmp_buf jmpbuf; /* where to jump to if we are ready when the */ 129 /* SIGUSR2 arrives from the previous slave */ 130 131 int 132 alloctape(void) 133 { 134 int pgoff = getpagesize() - 1; 135 char *buf; 136 int i; 137 138 writesize = ntrec * TP_BSIZE; 139 reqsiz = (ntrec + 1) * sizeof(struct req); 140 /* 141 * CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode 142 * (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require 143 * repositioning after stopping, i.e, streaming mode, where the gap is 144 * variable, 0.30" to 0.45". The gap is maximal when the tape stops. 145 */ 146 if (blocksperfile == 0 && !unlimited) 147 tenths = writesize / density + 148 (cartridge ? 16 : density == 625 ? 5 : 8); 149 /* 150 * Allocate tape buffer contiguous with the array of instruction 151 * packets, so flushtape() can write them together with one write(). 152 * Align tape buffer on page boundary to speed up tape write(). 153 */ 154 for (i = 0; i <= SLAVES; i++) { 155 buf = (char *) 156 xmalloc((unsigned)(reqsiz + writesize + pgoff + TP_BSIZE)); 157 slaves[i].tblock = (char (*)[TP_BSIZE]) 158 (((long)&buf[ntrec + 1] + pgoff) &~ pgoff); 159 slaves[i].req = (struct req *)slaves[i].tblock - ntrec - 1; 160 } 161 slp = &slaves[0]; 162 slp->count = 1; 163 slp->tapea = 0; 164 slp->firstrec = 0; 165 nextblock = slp->tblock; 166 return(1); 167 } 168 169 void 170 writerec(char *dp, int isspcl) 171 { 172 173 slp->req[trecno].dblk = (daddr_t)0; 174 slp->req[trecno].count = 1; 175 *(union u_spcl *)(*(nextblock)++) = *(union u_spcl *)dp; 176 if (isspcl) 177 lastspclrec = iswap64(spcl.c_tapea); 178 trecno++; 179 spcl.c_tapea = iswap64(iswap64(spcl.c_tapea) +1); 180 if (trecno >= ntrec) 181 flushtape(); 182 } 183 184 void 185 dumpblock(daddr_t blkno, int size) 186 { 187 int avail, tpblks; 188 daddr_t dblkno; 189 190 dblkno = fsatoda(ufsib, blkno); 191 tpblks = size >> tp_bshift; 192 while ((avail = MIN(tpblks, ntrec - trecno)) > 0) { 193 slp->req[trecno].dblk = dblkno; 194 slp->req[trecno].count = avail; 195 trecno += avail; 196 spcl.c_tapea = iswap64(iswap64(spcl.c_tapea) + avail); 197 if (trecno >= ntrec) 198 flushtape(); 199 dblkno += avail << (tp_bshift - dev_bshift); 200 tpblks -= avail; 201 } 202 } 203 204 int nogripe = 0; 205 206 static void 207 tperror(int signo) 208 { 209 210 if (pipeout) { 211 msg("write error on %s\n", tape); 212 quit("Cannot recover\n"); 213 /* NOTREACHED */ 214 } 215 msg("write error %ld blocks into volume %d\n", blocksthisvol, tapeno); 216 broadcast("DUMP WRITE ERROR!\n"); 217 if (!query("Do you want to restart?")) 218 dumpabort(0); 219 msg("Closing this volume. Prepare to restart with new media;\n"); 220 msg("this dump volume will be rewritten.\n"); 221 killall(); 222 nogripe = 1; 223 close_rewind(); 224 Exit(X_REWRITE); 225 } 226 227 static void 228 sigpipe(int signo) 229 { 230 231 quit("Broken pipe\n"); 232 } 233 234 /* 235 * do_stats -- 236 * Update xferrate stats 237 */ 238 time_t 239 do_stats(void) 240 { 241 time_t tnow, ttaken; 242 int64_t blocks; 243 244 (void)time(&tnow); 245 ttaken = tnow - tstart_volume; 246 blocks = iswap64(spcl.c_tapea) - tapea_volume; 247 msg("Volume %d completed at: %s", tapeno, ctime(&tnow)); 248 if (ttaken > 0) { 249 msg("Volume %d took %d:%02d:%02d\n", tapeno, 250 (int) (ttaken / 3600), (int) ((ttaken % 3600) / 60), 251 (int) (ttaken % 60)); 252 msg("Volume %d transfer rate: %d KB/s\n", tapeno, 253 (int) (blocks / ttaken)); 254 xferrate += blocks / ttaken; 255 } 256 return(tnow); 257 } 258 259 /* 260 * statussig -- 261 * information message upon receipt of SIGINFO 262 * (derived from optr.c::timeest()) 263 */ 264 void 265 statussig(int notused) 266 { 267 time_t tnow, deltat; 268 char msgbuf[128]; 269 int errno_save; 270 271 if (blockswritten < 500) 272 return; 273 errno_save = errno; 274 (void) time((time_t *) &tnow); 275 if (tnow <= tstart_volume) 276 return; 277 deltat = tstart_writing - tnow + 278 (1.0 * (tnow - tstart_writing)) / blockswritten * tapesize; 279 (void)snprintf(msgbuf, sizeof(msgbuf), 280 "%3.2f%% done at %ld KB/s, finished in %d:%02d\n", 281 (blockswritten * 100.0) / tapesize, 282 (long)((iswap64(spcl.c_tapea) - tapea_volume) / 283 (tnow - tstart_volume)), 284 (int)(deltat / 3600), (int)((deltat % 3600) / 60)); 285 write(STDERR_FILENO, msgbuf, strlen(msgbuf)); 286 errno = errno_save; 287 } 288 289 static void 290 flushtape(void) 291 { 292 int i, blks, got; 293 int64_t lastfirstrec; 294 295 int siz = (char *)nextblock - (char *)slp->req; 296 297 slp->req[trecno].count = 0; /* Sentinel */ 298 299 if (atomic_write(slp->fd, (char *)slp->req, siz) != siz) 300 quit("error writing command pipe: %s\n", strerror(errno)); 301 slp->sent = 1; /* we sent a request, read the response later */ 302 303 lastfirstrec = slp->firstrec; 304 305 if (++slp >= &slaves[SLAVES]) 306 slp = &slaves[0]; 307 308 /* Read results back from next slave */ 309 if (slp->sent) { 310 if (atomic_read(slp->fd, (char *)&got, sizeof got) 311 != sizeof got) { 312 perror(" DUMP: error reading command pipe in master"); 313 dumpabort(0); 314 } 315 slp->sent = 0; 316 317 /* Check for end of tape */ 318 if (got < writesize) { 319 msg("End of tape detected\n"); 320 321 /* 322 * Drain the results, don't care what the values were. 323 * If we read them here then trewind won't... 324 */ 325 for (i = 0; i < SLAVES; i++) { 326 if (slaves[i].sent) { 327 if (atomic_read(slaves[i].fd, 328 (char *)&got, sizeof got) 329 != sizeof got) { 330 perror(" DUMP: error reading command pipe in master"); 331 dumpabort(0); 332 } 333 slaves[i].sent = 0; 334 } 335 } 336 337 close_rewind(); 338 rollforward(); 339 return; 340 } 341 } 342 343 blks = 0; 344 if (iswap32(spcl.c_type) != TS_END) { 345 for (i = 0; i < iswap32(spcl.c_count); i++) 346 if (spcl.c_addr[i] != 0) 347 blks++; 348 } 349 slp->count = lastspclrec + blks + 1 - iswap32(spcl.c_tapea); 350 slp->tapea = iswap64(spcl.c_tapea); 351 slp->firstrec = lastfirstrec + ntrec; 352 slp->inode = curino; 353 nextblock = slp->tblock; 354 trecno = 0; 355 asize += tenths; 356 blockswritten += ntrec; 357 blocksthisvol += ntrec; 358 if (!pipeout && !unlimited && (blocksperfile ? 359 (blocksthisvol >= blocksperfile) : (asize > tsize))) { 360 close_rewind(); 361 startnewtape(0); 362 } 363 timeest(); 364 } 365 366 void 367 trewind(int eject) 368 { 369 int f; 370 int got; 371 372 for (f = 0; f < SLAVES; f++) { 373 /* 374 * Drain the results, but unlike EOT we DO (or should) care 375 * what the return values were, since if we detect EOT after 376 * we think we've written the last blocks to the tape anyway, 377 * we have to replay those blocks with rollforward. 378 * 379 * fixme: punt for now. 380 */ 381 if (slaves[f].sent) { 382 if (atomic_read(slaves[f].fd, (char *)&got, sizeof got) 383 != sizeof got) { 384 perror(" DUMP: error reading command pipe in master"); 385 dumpabort(0); 386 } 387 slaves[f].sent = 0; 388 if (got != writesize) { 389 msg("EOT detected in last 2 tape records!\n"); 390 msg("Use a longer tape, decrease the size estimate\n"); 391 quit("or use no size estimate at all.\n"); 392 } 393 } 394 (void) close(slaves[f].fd); 395 } 396 while (wait((int *)NULL) >= 0) /* wait for any signals from slaves */ 397 /* void */; 398 399 if (pipeout) 400 return; 401 402 msg("Closing %s\n", tape); 403 404 #ifdef RDUMP 405 if (host) { 406 rmtclose(); 407 while (rmtopen(tape, 0, 0) < 0) 408 sleep(10); 409 if (eflag && eject) { 410 msg("Ejecting %s\n", tape); 411 (void) rmtioctl(MTOFFL, 0); 412 } 413 rmtclose(); 414 return; 415 } 416 #endif 417 (void) close(tapefd); 418 while ((f = open(tape, 0)) < 0) 419 sleep (10); 420 if (eflag && eject) { 421 struct mtop offl; 422 423 msg("Ejecting %s\n", tape); 424 offl.mt_op = MTOFFL; 425 offl.mt_count = 0; 426 (void) ioctl(f, MTIOCTOP, &offl); 427 } 428 (void) close(f); 429 } 430 431 void 432 close_rewind(void) 433 { 434 int i, f; 435 436 trewind(1); 437 (void)do_stats(); 438 if (nexttape) 439 return; 440 if (!nogripe) { 441 msg("Change Volumes: Mount volume #%d\n", tapeno+1); 442 broadcast("CHANGE DUMP VOLUMES!\a\a\n"); 443 } 444 if (lflag) { 445 for (i = 0; i < lflag / 10; i++) { /* wait lflag seconds */ 446 if (host) { 447 if (rmtopen(tape, 0, 0) >= 0) { 448 rmtclose(); 449 return; 450 } 451 } else { 452 if ((f = open(tape, 0)) >= 0) { 453 close(f); 454 return; 455 } 456 } 457 sleep (10); 458 } 459 } 460 461 while (!query("Is the new volume mounted and ready to go?")) 462 if (query("Do you want to abort?")) { 463 dumpabort(0); 464 /*NOTREACHED*/ 465 } 466 } 467 468 void 469 rollforward(void) 470 { 471 struct req *p, *q, *prev; 472 struct slave *tslp; 473 int i, size, savedtapea, got; 474 union u_spcl *ntb, *otb; 475 tslp = &slaves[SLAVES]; 476 ntb = (union u_spcl *)tslp->tblock[1]; 477 478 /* 479 * Each of the N slaves should have requests that need to 480 * be replayed on the next tape. Use the extra slave buffers 481 * (slaves[SLAVES]) to construct request lists to be sent to 482 * each slave in turn. 483 */ 484 for (i = 0; i < SLAVES; i++) { 485 q = &tslp->req[1]; 486 otb = (union u_spcl *)slp->tblock; 487 488 /* 489 * For each request in the current slave, copy it to tslp. 490 */ 491 492 prev = NULL; 493 for (p = slp->req; p->count > 0; p += p->count) { 494 *q = *p; 495 if (p->dblk == 0) 496 *ntb++ = *otb++; /* copy the datablock also */ 497 prev = q; 498 q += q->count; 499 } 500 if (prev == NULL) 501 quit("rollforward: protocol botch"); 502 if (prev->dblk != 0) 503 prev->count -= 1; 504 else 505 ntb--; 506 q -= 1; 507 q->count = 0; 508 q = &tslp->req[0]; 509 if (i == 0) { 510 q->dblk = 0; 511 q->count = 1; 512 trecno = 0; 513 nextblock = tslp->tblock; 514 savedtapea = iswap32(spcl.c_tapea); 515 spcl.c_tapea = iswap32(slp->tapea); 516 startnewtape(0); 517 spcl.c_tapea = iswap32(savedtapea); 518 lastspclrec = savedtapea - 1; 519 } 520 size = (char *)ntb - (char *)q; 521 if (atomic_write(slp->fd, (char *)q, size) != size) { 522 perror(" DUMP: error writing command pipe"); 523 dumpabort(0); 524 } 525 slp->sent = 1; 526 if (++slp >= &slaves[SLAVES]) 527 slp = &slaves[0]; 528 529 q->count = 1; 530 531 if (prev->dblk != 0) { 532 /* 533 * If the last one was a disk block, make the 534 * first of this one be the last bit of that disk 535 * block... 536 */ 537 q->dblk = prev->dblk + 538 prev->count * (TP_BSIZE / DEV_BSIZE); 539 ntb = (union u_spcl *)tslp->tblock; 540 } else { 541 /* 542 * It wasn't a disk block. Copy the data to its 543 * new location in the buffer. 544 */ 545 q->dblk = 0; 546 *((union u_spcl *)tslp->tblock) = *ntb; 547 ntb = (union u_spcl *)tslp->tblock[1]; 548 } 549 } 550 slp->req[0] = *q; 551 nextblock = slp->tblock; 552 if (q->dblk == 0) 553 nextblock++; 554 trecno = 1; 555 556 /* 557 * Clear the first slaves' response. One hopes that it 558 * worked ok, otherwise the tape is much too short! 559 */ 560 if (slp->sent) { 561 if (atomic_read(slp->fd, (char *)&got, sizeof got) 562 != sizeof got) { 563 perror(" DUMP: error reading command pipe in master"); 564 dumpabort(0); 565 } 566 slp->sent = 0; 567 568 if (got != writesize) { 569 quit("EOT detected at start of the tape!\n"); 570 } 571 } 572 } 573 574 /* 575 * We implement taking and restoring checkpoints on the tape level. 576 * When each tape is opened, a new process is created by forking; this 577 * saves all of the necessary context in the parent. The child 578 * continues the dump; the parent waits around, saving the context. 579 * If the child returns X_REWRITE, then it had problems writing that tape; 580 * this causes the parent to fork again, duplicating the context, and 581 * everything continues as if nothing had happened. 582 */ 583 void 584 startnewtape(int top) 585 { 586 int parentpid; 587 int childpid; 588 int status; 589 int waitforpid; 590 char *p; 591 sig_t interrupt_save; 592 593 interrupt_save = signal(SIGINT, SIG_IGN); 594 parentpid = getpid(); 595 tapea_volume = iswap32(spcl.c_tapea); 596 (void)time(&tstart_volume); 597 598 restore_check_point: 599 (void)signal(SIGINT, interrupt_save); 600 /* 601 * All signals are inherited... 602 */ 603 childpid = fork(); 604 if (childpid < 0) { 605 msg("Context save fork fails in parent %d\n", parentpid); 606 Exit(X_ABORT); 607 } 608 if (childpid != 0) { 609 /* 610 * PARENT: 611 * save the context by waiting 612 * until the child doing all of the work returns. 613 * don't catch the interrupt 614 */ 615 signal(SIGINT, SIG_IGN); 616 signal(SIGINFO, SIG_IGN); /* only want child's stats */ 617 #ifdef TDEBUG 618 msg("Tape: %d; parent process: %d child process %d\n", 619 tapeno+1, parentpid, childpid); 620 #endif /* TDEBUG */ 621 while ((waitforpid = wait(&status)) != childpid) 622 msg("Parent %d waiting for child %d has another child %d return\n", 623 parentpid, childpid, waitforpid); 624 if (status & 0xFF) { 625 msg("Child %d returns LOB status %o\n", 626 childpid, status&0xFF); 627 } 628 status = (status >> 8) & 0xFF; 629 #ifdef TDEBUG 630 switch(status) { 631 case X_FINOK: 632 msg("Child %d finishes X_FINOK\n", childpid); 633 break; 634 case X_ABORT: 635 msg("Child %d finishes X_ABORT\n", childpid); 636 break; 637 case X_REWRITE: 638 msg("Child %d finishes X_REWRITE\n", childpid); 639 break; 640 default: 641 msg("Child %d finishes unknown %d\n", 642 childpid, status); 643 break; 644 } 645 #endif /* TDEBUG */ 646 switch(status) { 647 case X_FINOK: 648 Exit(X_FINOK); 649 case X_ABORT: 650 Exit(X_ABORT); 651 case X_REWRITE: 652 goto restore_check_point; 653 default: 654 msg("Bad return code from dump: %d\n", status); 655 Exit(X_ABORT); 656 } 657 /*NOTREACHED*/ 658 } else { /* we are the child; just continue */ 659 signal(SIGINFO, statussig); /* now want child's stats */ 660 #ifdef TDEBUG 661 sleep(4); /* allow time for parent's message to get out */ 662 msg("Child on Tape %d has parent %d, my pid = %d\n", 663 tapeno+1, parentpid, getpid()); 664 #endif /* TDEBUG */ 665 /* 666 * If we have a name like "/dev/rst0,/dev/rst1", 667 * use the name before the comma first, and save 668 * the remaining names for subsequent volumes. 669 */ 670 tapeno++; /* current tape sequence */ 671 if (nexttape || strchr(tape, ',')) { 672 if (nexttape && *nexttape) 673 tape = nexttape; 674 if ((p = strchr(tape, ',')) != NULL) { 675 *p = '\0'; 676 nexttape = p + 1; 677 } else 678 nexttape = NULL; 679 msg("Dumping volume %d on %s\n", tapeno, tape); 680 } 681 #ifdef RDUMP 682 while ((tapefd = (host ? rmtopen(tape, 2, 1) : 683 pipeout ? 1 : open(tape, O_WRONLY|O_CREAT, 0666))) < 0) 684 #else 685 while ((tapefd = (pipeout ? 1 : 686 open(tape, O_WRONLY|O_CREAT, 0666))) < 0) 687 #endif 688 { 689 msg("Cannot open output \"%s\".\n", tape); 690 if (!query("Do you want to retry the open?")) 691 dumpabort(0); 692 } 693 694 enslave(); /* Share open tape file descriptor with slaves */ 695 696 asize = 0; 697 blocksthisvol = 0; 698 if (top) 699 newtape++; /* new tape signal */ 700 spcl.c_count = iswap32(slp->count); 701 /* 702 * measure firstrec in TP_BSIZE units since restore doesn't 703 * know the correct ntrec value... 704 */ 705 spcl.c_firstrec = iswap32(slp->firstrec); 706 spcl.c_volume = iswap32(iswap32(spcl.c_volume) + 1); 707 spcl.c_type = iswap32(TS_TAPE); 708 if (!is_ufs2) 709 spcl.c_flags = iswap32(iswap32(spcl.c_flags) 710 | DR_NEWHEADER); 711 writeheader((ino_t)slp->inode); 712 if (!is_ufs2) 713 spcl.c_flags = iswap32(iswap32(spcl.c_flags) & 714 ~ DR_NEWHEADER); 715 msg("Volume %d started at: %s", tapeno, ctime(&tstart_volume)); 716 if (tapeno > 1) 717 msg("Volume %d begins with blocks from inode %d\n", 718 tapeno, slp->inode); 719 } 720 } 721 722 void 723 dumpabort(int signo) 724 { 725 726 if (master != 0 && master != getpid()) 727 /* Signals master to call dumpabort */ 728 (void) kill(master, SIGTERM); 729 else { 730 killall(); 731 msg("The ENTIRE dump is aborted.\n"); 732 } 733 #ifdef RDUMP 734 rmtclose(); 735 #endif 736 Exit(X_ABORT); 737 } 738 739 void 740 Exit(int status) 741 { 742 743 #ifdef TDEBUG 744 msg("pid = %d exits with status %d\n", getpid(), status); 745 #endif /* TDEBUG */ 746 exit(status); 747 } 748 749 /* 750 * proceed - handler for SIGUSR2, used to synchronize IO between the slaves. 751 */ 752 static void 753 proceed(int signo) 754 { 755 756 if (ready) 757 longjmp(jmpbuf, 1); 758 caught++; 759 } 760 761 void 762 enslave(void) 763 { 764 int cmd[2]; 765 int i, j; 766 767 master = getpid(); 768 769 signal(SIGTERM, dumpabort); /* Slave sends SIGTERM on dumpabort() */ 770 signal(SIGPIPE, sigpipe); 771 signal(SIGUSR1, tperror); /* Slave sends SIGUSR1 on tape errors */ 772 signal(SIGUSR2, proceed); /* Slave sends SIGUSR2 to next slave */ 773 774 for (i = 0; i < SLAVES; i++) { 775 if (i == slp - &slaves[0]) { 776 caught = 1; 777 } else { 778 caught = 0; 779 } 780 781 if (socketpair(AF_LOCAL, SOCK_STREAM, 0, cmd) < 0 || 782 (slaves[i].pid = fork()) < 0) 783 quit("too many slaves, %d (recompile smaller): %s\n", 784 i, strerror(errno)); 785 786 slaves[i].fd = cmd[1]; 787 slaves[i].sent = 0; 788 if (slaves[i].pid == 0) { /* Slave starts up here */ 789 for (j = 0; j <= i; j++) 790 (void) close(slaves[j].fd); 791 signal(SIGINT, SIG_IGN); /* Master handles this */ 792 signal(SIGINFO, SIG_IGN); 793 doslave(cmd[0], i); 794 Exit(X_FINOK); 795 } 796 } 797 798 for (i = 0; i < SLAVES; i++) 799 (void) atomic_write(slaves[i].fd, 800 (char *) &slaves[(i + 1) % SLAVES].pid, 801 sizeof slaves[0].pid); 802 803 master = 0; 804 } 805 806 void 807 killall(void) 808 { 809 int i; 810 811 for (i = 0; i < SLAVES; i++) 812 if (slaves[i].pid > 0) { 813 (void) kill(slaves[i].pid, SIGKILL); 814 slaves[i].sent = 0; 815 } 816 } 817 818 /* 819 * Synchronization - each process has a lockfile, and shares file 820 * descriptors to the following process's lockfile. When our write 821 * completes, we release our lock on the following process's lock- 822 * file, allowing the following process to lock it and proceed. We 823 * get the lock back for the next cycle by swapping descriptors. 824 */ 825 static void 826 doslave(int cmd, int slave_number) 827 { 828 int nread, nextslave, size, wrote, eot_count, werror; 829 sigset_t nsigset; 830 831 /* 832 * Need our own seek pointer. 833 */ 834 (void) close(diskfd); 835 if ((diskfd = open(disk, O_RDONLY)) < 0) 836 quit("slave couldn't reopen disk: %s\n", strerror(errno)); 837 838 /* 839 * Need the pid of the next slave in the loop... 840 */ 841 if ((nread = atomic_read(cmd, (char *)&nextslave, sizeof nextslave)) 842 != sizeof nextslave) { 843 quit("master/slave protocol botched - didn't get pid of next slave.\n"); 844 } 845 846 /* 847 * Get list of blocks to dump, read the blocks into tape buffer 848 */ 849 while ((nread = atomic_read(cmd, (char *)slp->req, reqsiz)) == reqsiz) { 850 struct req *p = slp->req; 851 852 for (trecno = 0; trecno < ntrec; 853 trecno += p->count, p += p->count) { 854 if (p->dblk) { 855 bread(p->dblk, slp->tblock[trecno], 856 p->count * TP_BSIZE); 857 } else { 858 if (p->count != 1 || atomic_read(cmd, 859 (char *)slp->tblock[trecno], 860 TP_BSIZE) != TP_BSIZE) 861 quit("master/slave protocol botched.\n"); 862 } 863 } 864 if (setjmp(jmpbuf) == 0) { 865 ready = 1; 866 if (!caught) 867 (void) pause(); 868 } 869 ready = 0; 870 caught = 0; 871 872 /* Try to write the data... */ 873 eot_count = 0; 874 size = 0; 875 werror = 0; 876 877 while (eot_count < 10 && size < writesize) { 878 #ifdef RDUMP 879 if (host) 880 wrote = rmtwrite(slp->tblock[0]+size, 881 writesize-size); 882 else 883 #endif 884 wrote = write(tapefd, slp->tblock[0]+size, 885 writesize-size); 886 werror = errno; 887 #ifdef WRITEDEBUG 888 fprintf(stderr, "slave %d wrote %d werror %d\n", 889 slave_number, wrote, werror); 890 #endif 891 if (wrote < 0) 892 break; 893 if (wrote == 0) 894 eot_count++; 895 size += wrote; 896 } 897 898 #ifdef WRITEDEBUG 899 if (size != writesize) 900 fprintf(stderr, 901 "slave %d only wrote %d out of %d bytes and gave up.\n", 902 slave_number, size, writesize); 903 #endif 904 905 /* 906 * Handle ENOSPC as an EOT condition. 907 */ 908 if (wrote < 0 && werror == ENOSPC) { 909 wrote = 0; 910 eot_count++; 911 } 912 913 if (eot_count > 0) 914 size = 0; 915 916 if (wrote < 0) { 917 (void) kill(master, SIGUSR1); 918 sigemptyset(&nsigset); 919 for (;;) 920 sigsuspend(&nsigset); 921 } else { 922 /* 923 * pass size of write back to master 924 * (for EOT handling) 925 */ 926 (void) atomic_write(cmd, (char *)&size, sizeof size); 927 } 928 929 /* 930 * If partial write, don't want next slave to go. 931 * Also jolts him awake. 932 */ 933 (void) kill(nextslave, SIGUSR2); 934 } 935 printcachestats(); 936 if (nread != 0) 937 quit("error reading command pipe: %s\n", strerror(errno)); 938 } 939 940 /* 941 * Since a read from a pipe may not return all we asked for, 942 * loop until the count is satisfied (or error). 943 */ 944 static ssize_t 945 atomic_read(int fd, char *buf, int count) 946 { 947 ssize_t got, need = count; 948 949 while ((got = read(fd, buf, need)) > 0 && (need -= got) > 0) 950 buf += got; 951 return (got < 0 ? got : count - need); 952 } 953 954 /* 955 * Since a write may not write all we ask if we get a signal, 956 * loop until the count is satisfied (or error). 957 */ 958 static ssize_t 959 atomic_write(int fd, char *buf, int count) 960 { 961 ssize_t got, need = count; 962 963 while ((got = write(fd, buf, need)) > 0 && (need -= got) > 0) 964 buf += got; 965 return (got < 0 ? got : count - need); 966 } 967