1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef lint 33 #if 0 34 static char sccsid[] = "@(#)tape.c 8.4 (Berkeley) 5/1/95"; 35 #endif 36 static const char rcsid[] = 37 "$FreeBSD$"; 38 #endif /* not lint */ 39 40 #include <sys/param.h> 41 #include <sys/socket.h> 42 #include <sys/wait.h> 43 #include <sys/stat.h> 44 45 #include <ufs/ufs/dinode.h> 46 #include <ufs/ffs/fs.h> 47 48 #include <protocols/dumprestore.h> 49 50 #include <assert.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <limits.h> 54 #include <setjmp.h> 55 #include <signal.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <time.h> 60 #include <unistd.h> 61 62 #include "dump.h" 63 64 ino_t curino; /* current inumber; used globally */ 65 int newtape; /* new tape flag */ 66 union u_spcl u_spcl; /* mapping of variables in a control block */ 67 68 static int tapefd; /* tape file descriptor */ 69 static long asize; /* number of 0.1" units written on cur tape */ 70 static int writesize; /* size of malloc()ed buffer for tape */ 71 static int64_t lastspclrec = -1; /* tape block number of last written header */ 72 static int trecno = 0; /* next record to write in current block */ 73 static long blocksthisvol; /* number of blocks on current output file */ 74 static char *nexttape; 75 static FILE *popenfp = NULL; 76 77 static int atomic_read(int, void *, int); 78 static int atomic_write(int, const void *, int); 79 static void worker(int, int); 80 static void create_workers(void); 81 static void flushtape(void); 82 static void killall(void); 83 static void rollforward(void); 84 85 /* 86 * Concurrent dump mods (Caltech) - disk block reading and tape writing 87 * are exported to several worker processes. While one worker writes the 88 * tape, the others read disk blocks; they pass control of the tape in 89 * a ring via signals. The parent process traverses the file system and 90 * sends writeheader()'s and lists of daddr's to the workers via pipes. 91 * The following structure defines the instruction packets sent to workers. 92 */ 93 struct req { 94 ufs2_daddr_t dblk; 95 int count; 96 }; 97 static int reqsiz; 98 99 #define WORKERS 3 /* 1 worker writing, 1 reading, 1 for slack */ 100 static struct worker { 101 int64_t tapea; /* header number at start of this chunk */ 102 int64_t firstrec; /* record number of this block */ 103 int count; /* count to next header (used for TS_TAPE */ 104 /* after EOT) */ 105 int inode; /* inode that we are currently dealing with */ 106 int fd; /* FD for this worker */ 107 int pid; /* PID for this worker */ 108 int sent; /* 1 == we've sent this worker requests */ 109 char (*tblock)[TP_BSIZE]; /* buffer for data blocks */ 110 struct req *req; /* buffer for requests */ 111 } workers[WORKERS+1]; 112 static struct worker *wp; 113 114 static char (*nextblock)[TP_BSIZE]; 115 116 static int master; /* pid of master, for sending error signals */ 117 static int tenths; /* length of tape used per block written */ 118 static volatile sig_atomic_t caught; /* have we caught the signal to proceed? */ 119 static volatile sig_atomic_t ready; /* reached the lock point without having */ 120 /* received the SIGUSR2 signal from the prev worker? */ 121 static jmp_buf jmpbuf; /* where to jump to if we are ready when the */ 122 /* SIGUSR2 arrives from the previous worker */ 123 124 int 125 alloctape(void) 126 { 127 int pgoff = getpagesize() - 1; 128 char *buf; 129 int i; 130 131 writesize = ntrec * TP_BSIZE; 132 reqsiz = (ntrec + 1) * sizeof(struct req); 133 /* 134 * CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode 135 * (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require 136 * repositioning after stopping, i.e, streaming mode, where the gap is 137 * variable, 0.30" to 0.45". The gap is maximal when the tape stops. 138 */ 139 if (blocksperfile == 0 && !unlimited) 140 tenths = writesize / density + 141 (cartridge ? 16 : density == 625 ? 5 : 8); 142 /* 143 * Allocate tape buffer contiguous with the array of instruction 144 * packets, so flushtape() can write them together with one write(). 145 * Align tape buffer on page boundary to speed up tape write(). 146 */ 147 for (i = 0; i <= WORKERS; i++) { 148 buf = (char *) 149 malloc((unsigned)(reqsiz + writesize + pgoff + TP_BSIZE)); 150 if (buf == NULL) 151 return(0); 152 workers[i].tblock = (char (*)[TP_BSIZE]) 153 (((long)&buf[ntrec + 1] + pgoff) &~ pgoff); 154 workers[i].req = (struct req *)workers[i].tblock - ntrec - 1; 155 } 156 wp = &workers[0]; 157 wp->count = 1; 158 wp->tapea = 0; 159 wp->firstrec = 0; 160 nextblock = wp->tblock; 161 return(1); 162 } 163 164 void 165 writerec(char *dp, int isspcl) 166 { 167 168 wp->req[trecno].dblk = (ufs2_daddr_t)0; 169 wp->req[trecno].count = 1; 170 /* Can't do a structure assignment due to alignment problems */ 171 bcopy(dp, *(nextblock)++, sizeof (union u_spcl)); 172 if (isspcl) 173 lastspclrec = spcl.c_tapea; 174 trecno++; 175 spcl.c_tapea++; 176 if (trecno >= ntrec) 177 flushtape(); 178 } 179 180 void 181 dumpblock(ufs2_daddr_t blkno, int size) 182 { 183 int avail, tpblks; 184 ufs2_daddr_t dblkno; 185 186 dblkno = fsbtodb(sblock, blkno); 187 tpblks = size >> tp_bshift; 188 while ((avail = MIN(tpblks, ntrec - trecno)) > 0) { 189 wp->req[trecno].dblk = dblkno; 190 wp->req[trecno].count = avail; 191 trecno += avail; 192 spcl.c_tapea += avail; 193 if (trecno >= ntrec) 194 flushtape(); 195 dblkno += avail << (tp_bshift - dev_bshift); 196 tpblks -= avail; 197 } 198 } 199 200 int nogripe = 0; 201 202 void 203 tperror(int signo __unused) 204 { 205 206 if (pipeout) { 207 msg("write error on %s\n", tape); 208 quit("Cannot recover\n"); 209 /* NOTREACHED */ 210 } 211 msg("write error %ld blocks into volume %d\n", blocksthisvol, tapeno); 212 broadcast("DUMP WRITE ERROR!\n"); 213 if (!query("Do you want to restart?")) 214 dumpabort(0); 215 msg("Closing this volume. Prepare to restart with new media;\n"); 216 msg("this dump volume will be rewritten.\n"); 217 killall(); 218 nogripe = 1; 219 close_rewind(); 220 Exit(X_REWRITE); 221 } 222 223 void 224 sigpipe(int signo __unused) 225 { 226 227 quit("Broken pipe\n"); 228 } 229 230 static void 231 flushtape(void) 232 { 233 int i, blks, got; 234 int64_t lastfirstrec; 235 236 int siz = (char *)nextblock - (char *)wp->req; 237 238 wp->req[trecno].count = 0; /* Sentinel */ 239 240 if (atomic_write(wp->fd, (const void *)wp->req, siz) != siz) 241 quit("error writing command pipe: %s\n", strerror(errno)); 242 wp->sent = 1; /* we sent a request, read the response later */ 243 244 lastfirstrec = wp->firstrec; 245 246 if (++wp >= &workers[WORKERS]) 247 wp = &workers[0]; 248 249 /* Read results back from next worker */ 250 if (wp->sent) { 251 if (atomic_read(wp->fd, (void *)&got, sizeof got) 252 != sizeof got) { 253 perror(" DUMP: error reading command pipe in master"); 254 dumpabort(0); 255 } 256 wp->sent = 0; 257 258 /* Check for end of tape */ 259 if (got < writesize) { 260 msg("End of tape detected\n"); 261 262 /* 263 * Drain the results, don't care what the values were. 264 * If we read them here then trewind won't... 265 */ 266 for (i = 0; i < WORKERS; i++) { 267 if (workers[i].sent) { 268 if (atomic_read(workers[i].fd, 269 (void *)&got, sizeof got) 270 != sizeof got) { 271 perror(" DUMP: error reading command pipe in master"); 272 dumpabort(0); 273 } 274 workers[i].sent = 0; 275 } 276 } 277 278 close_rewind(); 279 rollforward(); 280 return; 281 } 282 } 283 284 blks = 0; 285 if (spcl.c_type != TS_END && spcl.c_type != TS_CLRI && 286 spcl.c_type != TS_BITS) { 287 assert(spcl.c_count <= TP_NINDIR); 288 for (i = 0; i < spcl.c_count; i++) 289 if (spcl.c_addr[i] != 0) 290 blks++; 291 } 292 wp->count = lastspclrec + blks + 1 - spcl.c_tapea; 293 wp->tapea = spcl.c_tapea; 294 wp->firstrec = lastfirstrec + ntrec; 295 wp->inode = curino; 296 nextblock = wp->tblock; 297 trecno = 0; 298 asize += tenths; 299 blockswritten += ntrec; 300 blocksthisvol += ntrec; 301 if (!pipeout && !unlimited && (blocksperfile ? 302 (blocksthisvol >= blocksperfile) : (asize > tsize))) { 303 close_rewind(); 304 startnewtape(0); 305 } 306 timeest(); 307 } 308 309 void 310 trewind(void) 311 { 312 struct stat sb; 313 int f; 314 int got; 315 316 for (f = 0; f < WORKERS; f++) { 317 /* 318 * Drain the results, but unlike EOT we DO (or should) care 319 * what the return values were, since if we detect EOT after 320 * we think we've written the last blocks to the tape anyway, 321 * we have to replay those blocks with rollforward. 322 * 323 * fixme: punt for now. 324 */ 325 if (workers[f].sent) { 326 if (atomic_read(workers[f].fd, (void *)&got, sizeof got) 327 != sizeof got) { 328 perror(" DUMP: error reading command pipe in master"); 329 dumpabort(0); 330 } 331 workers[f].sent = 0; 332 if (got != writesize) { 333 msg("EOT detected in last 2 tape records!\n"); 334 msg("Use a longer tape, decrease the size estimate\n"); 335 quit("or use no size estimate at all.\n"); 336 } 337 } 338 (void) close(workers[f].fd); 339 } 340 while (wait((int *)NULL) >= 0) /* wait for any signals from workers */ 341 /* void */; 342 343 if (pipeout) 344 return; 345 346 msg("Closing %s\n", tape); 347 348 if (popenout) { 349 tapefd = -1; 350 (void)pclose(popenfp); 351 popenfp = NULL; 352 return; 353 } 354 #ifdef RDUMP 355 if (host) { 356 rmtclose(); 357 while (rmtopen(tape, 0) < 0) 358 sleep(10); 359 rmtclose(); 360 return; 361 } 362 #endif 363 if (fstat(tapefd, &sb) == 0 && S_ISFIFO(sb.st_mode)) { 364 (void)close(tapefd); 365 return; 366 } 367 (void) close(tapefd); 368 while ((f = open(tape, 0)) < 0) 369 sleep (10); 370 (void) close(f); 371 } 372 373 void 374 close_rewind() 375 { 376 time_t tstart_changevol, tend_changevol; 377 378 trewind(); 379 if (nexttape) 380 return; 381 (void)time((time_t *)&(tstart_changevol)); 382 if (!nogripe) { 383 msg("Change Volumes: Mount volume #%d\n", tapeno+1); 384 broadcast("CHANGE DUMP VOLUMES!\a\a\n"); 385 } 386 while (!query("Is the new volume mounted and ready to go?")) 387 if (query("Do you want to abort?")) { 388 dumpabort(0); 389 /*NOTREACHED*/ 390 } 391 (void)time((time_t *)&(tend_changevol)); 392 if ((tstart_changevol != (time_t)-1) && (tend_changevol != (time_t)-1)) 393 tstart_writing += (tend_changevol - tstart_changevol); 394 } 395 396 void 397 rollforward(void) 398 { 399 struct req *p, *q, *prev; 400 struct worker *twp; 401 int i, size, got; 402 int64_t savedtapea; 403 union u_spcl *ntb, *otb; 404 twp = &workers[WORKERS]; 405 ntb = (union u_spcl *)twp->tblock[1]; 406 407 /* 408 * Each of the N workers should have requests that need to 409 * be replayed on the next tape. Use the extra worker buffers 410 * (workers[WORKERS]) to construct request lists to be sent to 411 * each worker in turn. 412 */ 413 for (i = 0; i < WORKERS; i++) { 414 q = &twp->req[1]; 415 otb = (union u_spcl *)wp->tblock; 416 417 /* 418 * For each request in the current worker, copy it to twp. 419 */ 420 421 prev = NULL; 422 for (p = wp->req; p->count > 0; p += p->count) { 423 *q = *p; 424 if (p->dblk == 0) 425 *ntb++ = *otb++; /* copy the datablock also */ 426 prev = q; 427 q += q->count; 428 } 429 if (prev == NULL) 430 quit("rollforward: protocol botch"); 431 if (prev->dblk != 0) 432 prev->count -= 1; 433 else 434 ntb--; 435 q -= 1; 436 q->count = 0; 437 q = &twp->req[0]; 438 if (i == 0) { 439 q->dblk = 0; 440 q->count = 1; 441 trecno = 0; 442 nextblock = twp->tblock; 443 savedtapea = spcl.c_tapea; 444 spcl.c_tapea = wp->tapea; 445 startnewtape(0); 446 spcl.c_tapea = savedtapea; 447 lastspclrec = savedtapea - 1; 448 } 449 size = (char *)ntb - (char *)q; 450 if (atomic_write(wp->fd, (const void *)q, size) != size) { 451 perror(" DUMP: error writing command pipe"); 452 dumpabort(0); 453 } 454 wp->sent = 1; 455 if (++wp >= &workers[WORKERS]) 456 wp = &workers[0]; 457 458 q->count = 1; 459 460 if (prev->dblk != 0) { 461 /* 462 * If the last one was a disk block, make the 463 * first of this one be the last bit of that disk 464 * block... 465 */ 466 q->dblk = prev->dblk + 467 prev->count * (TP_BSIZE / DEV_BSIZE); 468 ntb = (union u_spcl *)twp->tblock; 469 } else { 470 /* 471 * It wasn't a disk block. Copy the data to its 472 * new location in the buffer. 473 */ 474 q->dblk = 0; 475 *((union u_spcl *)twp->tblock) = *ntb; 476 ntb = (union u_spcl *)twp->tblock[1]; 477 } 478 } 479 wp->req[0] = *q; 480 nextblock = wp->tblock; 481 if (q->dblk == 0) 482 nextblock++; 483 trecno = 1; 484 485 /* 486 * Clear the first workers' response. One hopes that it 487 * worked ok, otherwise the tape is much too short! 488 */ 489 if (wp->sent) { 490 if (atomic_read(wp->fd, (void *)&got, sizeof got) 491 != sizeof got) { 492 perror(" DUMP: error reading command pipe in master"); 493 dumpabort(0); 494 } 495 wp->sent = 0; 496 497 if (got != writesize) { 498 quit("EOT detected at start of the tape!\n"); 499 } 500 } 501 } 502 503 /* 504 * We implement taking and restoring checkpoints on the tape level. 505 * When each tape is opened, a new process is created by forking; this 506 * saves all of the necessary context in the parent. The child 507 * continues the dump; the parent waits around, saving the context. 508 * If the child returns X_REWRITE, then it had problems writing that tape; 509 * this causes the parent to fork again, duplicating the context, and 510 * everything continues as if nothing had happened. 511 */ 512 void 513 startnewtape(int top) 514 { 515 int parentpid; 516 int childpid; 517 int status; 518 char *p; 519 sig_t interrupt_save; 520 521 interrupt_save = signal(SIGINT, SIG_IGN); 522 parentpid = getpid(); 523 524 restore_check_point: 525 (void)signal(SIGINT, interrupt_save); 526 /* 527 * All signals are inherited... 528 */ 529 setproctitle(NULL); /* Restore the proctitle. */ 530 childpid = fork(); 531 if (childpid < 0) { 532 msg("Context save fork fails in parent %d\n", parentpid); 533 Exit(X_ABORT); 534 } 535 if (childpid != 0) { 536 /* 537 * PARENT: 538 * save the context by waiting 539 * until the child doing all of the work returns. 540 * don't catch the interrupt 541 */ 542 signal(SIGINT, SIG_IGN); 543 #ifdef TDEBUG 544 msg("Tape: %d; parent process: %d child process %d\n", 545 tapeno+1, parentpid, childpid); 546 #endif /* TDEBUG */ 547 if (waitpid(childpid, &status, 0) == -1) 548 msg("Waiting for child %d: %s\n", childpid, 549 strerror(errno)); 550 if (status & 0xFF) { 551 msg("Child %d returns LOB status %o\n", 552 childpid, status&0xFF); 553 } 554 status = (status >> 8) & 0xFF; 555 #ifdef TDEBUG 556 switch(status) { 557 case X_FINOK: 558 msg("Child %d finishes X_FINOK\n", childpid); 559 break; 560 case X_ABORT: 561 msg("Child %d finishes X_ABORT\n", childpid); 562 break; 563 case X_REWRITE: 564 msg("Child %d finishes X_REWRITE\n", childpid); 565 break; 566 default: 567 msg("Child %d finishes unknown %d\n", 568 childpid, status); 569 break; 570 } 571 #endif /* TDEBUG */ 572 switch(status) { 573 case X_FINOK: 574 Exit(X_FINOK); 575 case X_ABORT: 576 Exit(X_ABORT); 577 case X_REWRITE: 578 goto restore_check_point; 579 default: 580 msg("Bad return code from dump: %d\n", status); 581 Exit(X_ABORT); 582 } 583 /*NOTREACHED*/ 584 } else { /* we are the child; just continue */ 585 #ifdef TDEBUG 586 sleep(4); /* allow time for parent's message to get out */ 587 msg("Child on Tape %d has parent %d, my pid = %d\n", 588 tapeno+1, parentpid, getpid()); 589 #endif /* TDEBUG */ 590 /* 591 * If we have a name like "/dev/rmt0,/dev/rmt1", 592 * use the name before the comma first, and save 593 * the remaining names for subsequent volumes. 594 */ 595 tapeno++; /* current tape sequence */ 596 if (nexttape || strchr(tape, ',')) { 597 if (nexttape && *nexttape) 598 tape = nexttape; 599 if ((p = strchr(tape, ',')) != NULL) { 600 *p = '\0'; 601 nexttape = p + 1; 602 } else 603 nexttape = NULL; 604 msg("Dumping volume %d on %s\n", tapeno, tape); 605 } 606 if (pipeout) { 607 tapefd = STDOUT_FILENO; 608 } else if (popenout) { 609 char volno[sizeof("2147483647")]; 610 611 (void)sprintf(volno, "%d", spcl.c_volume + 1); 612 if (setenv("DUMP_VOLUME", volno, 1) == -1) { 613 msg("Cannot set $DUMP_VOLUME.\n"); 614 dumpabort(0); 615 } 616 popenfp = popen(popenout, "w"); 617 if (popenfp == NULL) { 618 msg("Cannot open output pipeline \"%s\".\n", 619 popenout); 620 dumpabort(0); 621 } 622 tapefd = fileno(popenfp); 623 } else { 624 #ifdef RDUMP 625 while ((tapefd = (host ? rmtopen(tape, 2) : 626 open(tape, O_WRONLY|O_CREAT, 0666))) < 0) 627 #else 628 while ((tapefd = 629 open(tape, O_WRONLY|O_CREAT, 0666)) < 0) 630 #endif 631 { 632 msg("Cannot open output \"%s\".\n", tape); 633 if (!query("Do you want to retry the open?")) 634 dumpabort(0); 635 } 636 } 637 638 create_workers(); /* Share open tape file descriptor with workers */ 639 if (popenout) 640 close(tapefd); /* Give up our copy of it. */ 641 signal(SIGINFO, infosch); 642 643 asize = 0; 644 blocksthisvol = 0; 645 if (top) 646 newtape++; /* new tape signal */ 647 spcl.c_count = wp->count; 648 /* 649 * measure firstrec in TP_BSIZE units since restore doesn't 650 * know the correct ntrec value... 651 */ 652 spcl.c_firstrec = wp->firstrec; 653 spcl.c_volume++; 654 spcl.c_type = TS_TAPE; 655 writeheader((ino_t)wp->inode); 656 if (tapeno > 1) 657 msg("Volume %d begins with blocks from inode %d\n", 658 tapeno, wp->inode); 659 } 660 } 661 662 void 663 dumpabort(int signo __unused) 664 { 665 666 if (master != 0 && master != getpid()) 667 /* Signals master to call dumpabort */ 668 (void) kill(master, SIGTERM); 669 else { 670 killall(); 671 msg("The ENTIRE dump is aborted.\n"); 672 } 673 #ifdef RDUMP 674 rmtclose(); 675 #endif 676 Exit(X_ABORT); 677 } 678 679 void 680 Exit(int status) 681 { 682 683 #ifdef TDEBUG 684 msg("pid = %d exits with status %d\n", getpid(), status); 685 #endif /* TDEBUG */ 686 exit(status); 687 } 688 689 /* 690 * proceed - handler for SIGUSR2, used to synchronize IO between the workers. 691 */ 692 void 693 proceed(int signo __unused) 694 { 695 696 if (ready) 697 longjmp(jmpbuf, 1); 698 caught++; 699 } 700 701 void 702 create_workers(void) 703 { 704 int cmd[2]; 705 int i, j; 706 707 master = getpid(); 708 709 signal(SIGTERM, dumpabort); /* Worker sends SIGTERM on dumpabort() */ 710 signal(SIGPIPE, sigpipe); 711 signal(SIGUSR1, tperror); /* Worker sends SIGUSR1 on tape errors */ 712 signal(SIGUSR2, proceed); /* Worker sends SIGUSR2 to next worker */ 713 714 for (i = 0; i < WORKERS; i++) { 715 if (i == wp - &workers[0]) { 716 caught = 1; 717 } else { 718 caught = 0; 719 } 720 721 if (socketpair(AF_UNIX, SOCK_STREAM, 0, cmd) < 0 || 722 (workers[i].pid = fork()) < 0) 723 quit("too many workers, %d (recompile smaller): %s\n", 724 i, strerror(errno)); 725 726 workers[i].fd = cmd[1]; 727 workers[i].sent = 0; 728 if (workers[i].pid == 0) { /* Worker starts up here */ 729 for (j = 0; j <= i; j++) 730 (void) close(workers[j].fd); 731 signal(SIGINT, SIG_IGN); /* Master handles this */ 732 worker(cmd[0], i); 733 Exit(X_FINOK); 734 } 735 } 736 737 for (i = 0; i < WORKERS; i++) 738 (void) atomic_write(workers[i].fd, 739 (const void *) &workers[(i + 1) % WORKERS].pid, 740 sizeof workers[0].pid); 741 742 master = 0; 743 } 744 745 void 746 killall(void) 747 { 748 int i; 749 750 for (i = 0; i < WORKERS; i++) 751 if (workers[i].pid > 0) { 752 (void) kill(workers[i].pid, SIGKILL); 753 workers[i].sent = 0; 754 } 755 } 756 757 /* 758 * Synchronization - each process has a lockfile, and shares file 759 * descriptors to the following process's lockfile. When our write 760 * completes, we release our lock on the following process's lock- 761 * file, allowing the following process to lock it and proceed. We 762 * get the lock back for the next cycle by swapping descriptors. 763 */ 764 static void 765 worker(int cmd, int worker_number) 766 { 767 int nread; 768 int nextworker, size, wrote, eot_count; 769 770 /* 771 * Need our own seek pointer. 772 */ 773 (void) close(diskfd); 774 if ((diskfd = open(disk, O_RDONLY)) < 0) 775 quit("worker couldn't reopen disk: %s\n", strerror(errno)); 776 777 /* 778 * Need the pid of the next worker in the loop... 779 */ 780 if ((nread = atomic_read(cmd, (void *)&nextworker, sizeof nextworker)) 781 != sizeof nextworker) { 782 quit("master/worker protocol botched - didn't get pid of next worker.\n"); 783 } 784 785 /* 786 * Get list of blocks to dump, read the blocks into tape buffer 787 */ 788 while ((nread = atomic_read(cmd, (void *)wp->req, reqsiz)) == reqsiz) { 789 struct req *p = wp->req; 790 791 for (trecno = 0; trecno < ntrec; 792 trecno += p->count, p += p->count) { 793 if (p->dblk) { 794 blkread(p->dblk, wp->tblock[trecno], 795 p->count * TP_BSIZE); 796 } else { 797 if (p->count != 1 || atomic_read(cmd, 798 (void *)wp->tblock[trecno], 799 TP_BSIZE) != TP_BSIZE) 800 quit("master/worker protocol botched.\n"); 801 } 802 } 803 if (setjmp(jmpbuf) == 0) { 804 ready = 1; 805 if (!caught) 806 (void) pause(); 807 } 808 ready = 0; 809 caught = 0; 810 811 /* Try to write the data... */ 812 eot_count = 0; 813 size = 0; 814 815 wrote = 0; 816 while (eot_count < 10 && size < writesize) { 817 #ifdef RDUMP 818 if (host) 819 wrote = rmtwrite(wp->tblock[0]+size, 820 writesize-size); 821 else 822 #endif 823 wrote = write(tapefd, wp->tblock[0]+size, 824 writesize-size); 825 #ifdef WRITEDEBUG 826 printf("worker %d wrote %d\n", worker_number, wrote); 827 #endif 828 if (wrote < 0) 829 break; 830 if (wrote == 0) 831 eot_count++; 832 size += wrote; 833 } 834 835 #ifdef WRITEDEBUG 836 if (size != writesize) 837 printf("worker %d only wrote %d out of %d bytes and gave up.\n", 838 worker_number, size, writesize); 839 #endif 840 841 /* 842 * Handle ENOSPC as an EOT condition. 843 */ 844 if (wrote < 0 && errno == ENOSPC) { 845 wrote = 0; 846 eot_count++; 847 } 848 849 if (eot_count > 0) 850 size = 0; 851 852 if (wrote < 0) { 853 (void) kill(master, SIGUSR1); 854 for (;;) 855 (void) sigpause(0); 856 } else { 857 /* 858 * pass size of write back to master 859 * (for EOT handling) 860 */ 861 (void)atomic_write(cmd, (const void *)&size, 862 sizeof size); 863 } 864 865 /* 866 * If partial write, don't want next worker to go. 867 * Also jolts him awake. 868 */ 869 (void) kill(nextworker, SIGUSR2); 870 } 871 if (nread != 0) 872 quit("error reading command pipe: %s\n", strerror(errno)); 873 } 874 875 /* 876 * Since a read from a pipe may not return all we asked for, 877 * loop until the count is satisfied (or error). 878 */ 879 static int 880 atomic_read(int fd, void *buf, int count) 881 { 882 int got, need = count; 883 884 while ((got = read(fd, buf, need)) > 0 && (need -= got) > 0) 885 buf += got; 886 return (got < 0 ? got : count - need); 887 } 888 889 /* 890 * Since a write to a pipe may not write all we ask if we get a signal, 891 * loop until the count is satisfied (or error). 892 */ 893 static int 894 atomic_write(int fd, const void *buf, int count) 895 { 896 int got, need = count; 897 898 while ((got = write(fd, buf, need)) > 0 && (need -= got) > 0) 899 buf += got; 900 return (got < 0 ? got : count - need); 901 } 902