1 /* $OpenBSD: tape.c,v 1.47 2021/01/21 00:16:36 mortimer Exp $ */ 2 /* $NetBSD: tape.c,v 1.11 1997/06/05 11:13:26 lukem Exp $ */ 3 4 /*- 5 * Copyright (c) 1980, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/param.h> /* MAXBSIZE DEV_BSIZE */ 34 #include <sys/socket.h> 35 #include <sys/time.h> 36 #include <sys/wait.h> 37 #include <sys/stat.h> 38 #include <ufs/ffs/fs.h> 39 #include <ufs/ufs/dinode.h> 40 41 #include <protocols/dumprestore.h> 42 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <signal.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <time.h> 50 #include <unistd.h> 51 #include <limits.h> 52 53 #include "dump.h" 54 #include "pathnames.h" 55 56 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 57 58 ino_t curino; /* current inumber; used globally */ 59 int newtape; /* new tape flag */ 60 union u_spcl u_spcl; /* mapping of variables in a control block */ 61 62 static int tapefd; /* tape file descriptor */ 63 static int64_t asize; /* number of 0.1" units written on cur tape */ 64 static int writesize; /* size of malloc()ed buffer for tape */ 65 static int64_t lastspclrec = -1; /* tape block number of last written header */ 66 static int trecno = 0; /* next record to write in current block */ 67 static int64_t blocksthisvol; /* number of blocks on current output file */ 68 static char *nexttape; 69 70 static ssize_t atomic(ssize_t (*)(int, void *, size_t), int, char *, int); 71 static void doslave(int, int); 72 static void enslave(void); 73 static void flushtape(void); 74 static void killall(void); 75 static void rollforward(void); 76 77 void tperror(int signo); 78 void sigpipe(int signo); 79 void proceed(int signo); 80 81 /* 82 * Concurrent dump mods (Caltech) - disk block reading and tape writing 83 * are exported to several slave processes. While one slave writes the 84 * tape, the others read disk blocks; they pass control of the tape in 85 * a ring via signals. The parent process traverses the filesystem and 86 * sends writeheader()'s and lists of daddr's to the slaves via pipes. 87 * The following structure defines the instruction packets sent to slaves. 88 */ 89 struct req { 90 daddr_t dblk; 91 int count; 92 }; 93 static int reqsiz; 94 95 #define SLAVES 3 /* 1 slave writing, 1 reading, 1 for slack */ 96 static struct slave { 97 int64_t tapea; /* header number at start of this chunk */ 98 int64_t firstrec; /* record number of this block */ 99 int count; /* count to next header (used for TS_TAPE */ 100 /* after EOT) */ 101 int inode; /* inode that we are currently dealing with */ 102 int fd; /* FD for this slave */ 103 pid_t pid; /* PID for this slave */ 104 int sent; /* 1 == we've sent this slave requests */ 105 char (*tblock)[TP_BSIZE]; /* buffer for data blocks */ 106 struct req *req; /* buffer for requests */ 107 } slaves[SLAVES+1]; 108 static struct slave *slp; 109 110 static char (*nextblock)[TP_BSIZE]; 111 112 static time_t tstart_volume; /* time of volume start */ 113 static int64_t tapea_volume; /* value of spcl.c_tapea at volume start */ 114 115 static pid_t master; /* pid of master, for sending error signals */ 116 static int tenths; /* length of tape used per block written */ 117 static volatile sig_atomic_t caught; /* have we caught the signal to proceed? */ 118 119 int 120 alloctape(void) 121 { 122 int pgoff = getpagesize() - 1; 123 char *buf; 124 int i; 125 126 writesize = ntrec * TP_BSIZE; 127 reqsiz = (ntrec + 1) * sizeof(struct req); 128 /* 129 * CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode 130 * (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require 131 * repositioning after stopping, i.e, streaming mode, where the gap is 132 * variable, 0.30" to 0.45". The gap is maximal when the tape stops. 133 */ 134 if (blocksperfile == 0 && !unlimited) 135 tenths = writesize / density + 136 (cartridge ? 16 : density == 625 ? 5 : 8); 137 /* 138 * Allocate tape buffer contiguous with the array of instruction 139 * packets, so flushtape() can write them together with one write(). 140 * Align tape buffer on page boundary to speed up tape write(). 141 */ 142 for (i = 0; i <= SLAVES; i++) { 143 buf = malloc((unsigned)(reqsiz + writesize + pgoff + TP_BSIZE)); 144 if (buf == NULL) 145 return(0); 146 slaves[i].tblock = (char (*)[TP_BSIZE]) 147 (((long)&buf[ntrec + 1] + pgoff) &~ pgoff); 148 slaves[i].req = (struct req *)slaves[i].tblock - ntrec - 1; 149 } 150 slp = &slaves[0]; 151 slp->count = 1; 152 slp->tapea = 0; 153 slp->firstrec = 0; 154 nextblock = slp->tblock; 155 return(1); 156 } 157 158 void 159 writerec(char *dp, int isspcl) 160 { 161 162 slp->req[trecno].dblk = 0; 163 slp->req[trecno].count = 1; 164 *(union u_spcl *)(*(nextblock)++) = *(union u_spcl *)dp; 165 if (isspcl) 166 lastspclrec = spcl.c_tapea; 167 trecno++; 168 spcl.c_tapea++; 169 if (trecno >= ntrec) 170 flushtape(); 171 } 172 173 void 174 dumpblock(daddr_t blkno, int size) 175 { 176 int avail, tpblks; 177 daddr_t dblkno; 178 179 dblkno = fsbtodb(sblock, blkno); 180 tpblks = size >> tp_bshift; 181 while ((avail = MINIMUM(tpblks, ntrec - trecno)) > 0) { 182 slp->req[trecno].dblk = dblkno; 183 slp->req[trecno].count = avail; 184 trecno += avail; 185 spcl.c_tapea += avail; 186 if (trecno >= ntrec) 187 flushtape(); 188 dblkno += avail << (tp_bshift - (ffs(DEV_BSIZE) - 1)); 189 tpblks -= avail; 190 } 191 } 192 193 int nogripe = 0; 194 195 /* ARGSUSED */ 196 void 197 tperror(int signo) 198 { 199 /* XXX - signal races */ 200 201 if (pipeout) { 202 msg("write error on %s\n", tape); 203 quit("Cannot recover\n"); 204 /* NOTREACHED */ 205 } 206 msg("write error %lld blocks into volume %d\n", 207 (long long)blocksthisvol, tapeno); 208 broadcast("DUMP WRITE ERROR!\n"); 209 if (!query("Do you want to restart?")) 210 dumpabort(0); 211 msg("Closing this volume. Prepare to restart with new media;\n"); 212 msg("this dump volume will be rewritten.\n"); 213 killall(); 214 nogripe = 1; 215 close_rewind(); 216 Exit(X_REWRITE); 217 } 218 219 /* ARGSUSED */ 220 void 221 sigpipe(int signo) 222 { 223 224 quit("Broken pipe\n"); 225 } 226 227 /* 228 * do_stats -- 229 * Update xferrate stats 230 */ 231 time_t 232 do_stats(void) 233 { 234 time_t tnow, ttaken; 235 int64_t blocks; 236 237 (void)time(&tnow); 238 ttaken = tnow - tstart_volume; 239 blocks = spcl.c_tapea - tapea_volume; 240 msg("Volume %d completed at: %s", tapeno, ctime(&tnow)); 241 if (ttaken > 0) { 242 msg("Volume %d took %lld:%02lld:%02lld\n", tapeno, 243 (long long)ttaken / 3600, ((long long)ttaken % 3600) / 60, 244 (long long)ttaken % 60); 245 blocks /= ttaken; 246 msg("Volume %d transfer rate: %lld KB/s\n", tapeno, blocks); 247 xferrate += blocks; 248 } 249 return(tnow); 250 } 251 252 /* 253 * statussig -- 254 * information message upon receipt of SIGINFO 255 * (derived from optr.c::timeest()) 256 * XXX not safe 257 */ 258 /* ARGSUSED */ 259 void 260 statussig(int signo) 261 { 262 time_t tnow, deltat; 263 int save_errno = errno; 264 265 if (blockswritten < 500) 266 return; 267 (void) time(&tnow); 268 deltat = tstart_writing - tnow + (1.0 * (tnow - tstart_writing)) 269 / blockswritten * tapesize; 270 /* XXX not safe due to floating point printf */ 271 dprintf(STDERR_FILENO, 272 "dump: %s %3.2f%% done at %lld KB/s, finished in %d:%02d\n", 273 tape, (blockswritten * 100.0) / tapesize, 274 (spcl.c_tapea - tapea_volume) / (tnow - tstart_volume), 275 (int)(deltat / 3600), (int)((deltat % 3600) / 60)); 276 errno = save_errno; 277 } 278 279 static void 280 flushtape(void) 281 { 282 int i, blks, got; 283 int64_t lastfirstrec; 284 285 int siz = (char *)nextblock - (char *)slp->req; 286 287 slp->req[trecno].count = 0; /* Sentinel */ 288 289 if (atomic((ssize_t (*)(int, void *, size_t))write, slp->fd, 290 (char *)slp->req, siz) != siz) 291 quit("error writing command pipe: %s\n", strerror(errno)); 292 slp->sent = 1; /* we sent a request, read the response later */ 293 294 lastfirstrec = slp->firstrec; 295 296 if (++slp >= &slaves[SLAVES]) 297 slp = &slaves[0]; 298 299 /* Read results back from next slave */ 300 if (slp->sent) { 301 if (atomic(read, slp->fd, (char *)&got, sizeof(got)) 302 != sizeof(got)) { 303 perror(" DUMP: error reading command pipe in master"); 304 dumpabort(0); 305 } 306 slp->sent = 0; 307 308 /* Check for end of tape */ 309 if (got < writesize) { 310 msg("End of tape detected\n"); 311 312 /* 313 * Drain the results, don't care what the values were. 314 * If we read them here then trewind won't... 315 */ 316 for (i = 0; i < SLAVES; i++) { 317 if (slaves[i].sent) { 318 if (atomic(read, slaves[i].fd, 319 (char *)&got, sizeof(got)) 320 != sizeof(got)) { 321 perror(" DUMP: error reading command pipe in master"); 322 dumpabort(0); 323 } 324 slaves[i].sent = 0; 325 } 326 } 327 328 close_rewind(); 329 rollforward(); 330 return; 331 } 332 } 333 334 blks = 0; 335 if (spcl.c_type != TS_END && spcl.c_type != TS_CLRI && 336 spcl.c_type != TS_BITS) { 337 if (spcl.c_count > TP_NINDIR) 338 quit("c_count too large\n"); 339 for (i = 0; i < spcl.c_count; i++) 340 if (spcl.c_addr[i] != 0) 341 blks++; 342 } 343 slp->count = lastspclrec + blks + 1 - spcl.c_tapea; 344 slp->tapea = spcl.c_tapea; 345 slp->firstrec = lastfirstrec + ntrec; 346 slp->inode = curino; 347 nextblock = slp->tblock; 348 trecno = 0; 349 asize += tenths; 350 blockswritten += ntrec; 351 blocksthisvol += ntrec; 352 if (!pipeout && !unlimited && (blocksperfile ? 353 (blocksthisvol >= blocksperfile) : (asize > tsize))) { 354 close_rewind(); 355 startnewtape(0); 356 } 357 timeest(); 358 } 359 360 void 361 trewind(void) 362 { 363 struct stat sb; 364 int f, got; 365 366 for (f = 0; f < SLAVES; f++) { 367 /* 368 * Drain the results, but unlike EOT we DO (or should) care 369 * what the return values were, since if we detect EOT after 370 * we think we've written the last blocks to the tape anyway, 371 * we have to replay those blocks with rollforward. 372 * 373 * fixme: punt for now. 374 */ 375 if (slaves[f].sent) { 376 if (atomic(read, slaves[f].fd, (char *)&got, sizeof(got)) 377 != sizeof(got)) { 378 perror(" DUMP: error reading command pipe in master"); 379 dumpabort(0); 380 } 381 slaves[f].sent = 0; 382 if (got != writesize) { 383 msg("EOT detected in last 2 tape records!\n"); 384 msg("Use a longer tape, decrease the size estimate\n"); 385 quit("or use no size estimate at all.\n"); 386 } 387 } 388 (void) close(slaves[f].fd); 389 } 390 while (wait((int *)NULL) >= 0) /* wait for any signals from slaves */ 391 /* void */; 392 393 if (pipeout) 394 return; 395 396 msg("Closing %s\n", tape); 397 398 #ifdef RDUMP 399 if (host) { 400 rmtclose(); 401 while (rmtopen(tape, O_RDONLY) < 0) 402 sleep(10); 403 rmtclose(); 404 return; 405 } 406 #endif 407 /* 408 * st(4) says: "Bit 1 of the minor number specifies whether an eject is 409 * attempted when the device is closed. When it is set, the device 410 * will attempt to eject its media on close ...". 411 * 412 * If the tape has been ejected, looping on open() will generate 'Media 413 * not present' errors until a tape is loaded. Once loaded the tape 414 * will be immediately ejected as a result of the second close(). 415 * 416 * So if the tape will be ejected, just close and return. 417 */ 418 if ((fstat(tapefd, &sb) == 0) && (minor(sb.st_rdev) & 0x02)) { 419 (void) close(tapefd); 420 return; 421 } 422 423 (void) close(tapefd); 424 while ((f = open(tape, O_RDONLY)) == -1) 425 sleep (10); 426 (void) close(f); 427 } 428 429 void 430 close_rewind(void) 431 { 432 trewind(); 433 (void)do_stats(); 434 if (nexttape) 435 return; 436 if (!nogripe) { 437 msg("Change Volumes: Mount volume #%d\n", tapeno+1); 438 broadcast("CHANGE DUMP VOLUMES!\7\7\n"); 439 } 440 while (!query("Is the new volume mounted and ready to go?")) 441 if (query("Do you want to abort?")) { 442 dumpabort(0); 443 /*NOTREACHED*/ 444 } 445 } 446 447 void 448 rollforward(void) 449 { 450 struct req *p, *q, *prev; 451 struct slave *tslp; 452 int i, size, got; 453 int64_t savedtapea; 454 union u_spcl *ntb, *otb; 455 tslp = &slaves[SLAVES]; 456 ntb = (union u_spcl *)tslp->tblock[1]; 457 458 /* 459 * Each of the N slaves should have requests that need to 460 * be replayed on the next tape. Use the extra slave buffers 461 * (slaves[SLAVES]) to construct request lists to be sent to 462 * each slave in turn. 463 */ 464 for (i = 0; i < SLAVES; i++) { 465 q = &tslp->req[1]; 466 otb = (union u_spcl *)slp->tblock; 467 468 /* 469 * For each request in the current slave, copy it to tslp. 470 */ 471 472 prev = NULL; 473 for (p = slp->req; p->count > 0; p += p->count) { 474 *q = *p; 475 if (p->dblk == 0) 476 *ntb++ = *otb++; /* copy the datablock also */ 477 prev = q; 478 q += q->count; 479 } 480 if (prev == NULL) 481 quit("rollforward: protocol botch\n"); 482 if (prev->dblk != 0) 483 prev->count -= 1; 484 else 485 ntb--; 486 q -= 1; 487 q->count = 0; 488 q = &tslp->req[0]; 489 if (i == 0) { 490 q->dblk = 0; 491 q->count = 1; 492 trecno = 0; 493 nextblock = tslp->tblock; 494 savedtapea = spcl.c_tapea; 495 spcl.c_tapea = slp->tapea; 496 startnewtape(0); 497 spcl.c_tapea = savedtapea; 498 lastspclrec = savedtapea - 1; 499 } 500 size = (char *)ntb - (char *)q; 501 if (atomic((ssize_t (*)(int, void *, size_t))write, 502 slp->fd, (char *)q, size) != size) { 503 perror(" DUMP: error writing command pipe"); 504 dumpabort(0); 505 } 506 slp->sent = 1; 507 if (++slp >= &slaves[SLAVES]) 508 slp = &slaves[0]; 509 510 q->count = 1; 511 512 if (prev->dblk != 0) { 513 /* 514 * If the last one was a disk block, make the 515 * first of this one be the last bit of that disk 516 * block... 517 */ 518 q->dblk = prev->dblk + 519 prev->count * (TP_BSIZE / DEV_BSIZE); 520 ntb = (union u_spcl *)tslp->tblock; 521 } else { 522 /* 523 * It wasn't a disk block. Copy the data to its 524 * new location in the buffer. 525 */ 526 q->dblk = 0; 527 *((union u_spcl *)tslp->tblock) = *ntb; 528 ntb = (union u_spcl *)tslp->tblock[1]; 529 } 530 } 531 slp->req[0] = *q; 532 nextblock = slp->tblock; 533 if (q->dblk == 0) 534 nextblock++; 535 trecno = 1; 536 537 /* 538 * Clear the first slaves' response. One hopes that it 539 * worked ok, otherwise the tape is much too short! 540 */ 541 if (slp->sent) { 542 if (atomic(read, slp->fd, (char *)&got, sizeof(got)) 543 != sizeof(got)) { 544 perror(" DUMP: error reading command pipe in master"); 545 dumpabort(0); 546 } 547 slp->sent = 0; 548 549 if (got != writesize) { 550 quit("EOT detected at start of the tape!\n"); 551 } 552 } 553 } 554 555 /* 556 * We implement taking and restoring checkpoints on the tape level. 557 * When each tape is opened, a new process is created by forking; this 558 * saves all of the necessary context in the parent. The child 559 * continues the dump; the parent waits around, saving the context. 560 * If the child returns X_REWRITE, then it had problems writing that tape; 561 * this causes the parent to fork again, duplicating the context, and 562 * everything continues as if nothing had happened. 563 */ 564 void 565 startnewtape(int top) 566 { 567 pid_t parentpid; 568 pid_t childpid; 569 int status; 570 pid_t waitingpid; 571 char *p; 572 sig_t interrupt_save; 573 574 interrupt_save = signal(SIGINT, SIG_IGN); 575 parentpid = getpid(); 576 tapea_volume = spcl.c_tapea; 577 (void)time(&tstart_volume); 578 579 restore_check_point: 580 (void)signal(SIGINT, interrupt_save); 581 /* 582 * All signals are inherited... 583 */ 584 childpid = fork(); 585 if (childpid == -1) { 586 msg("Context save fork fails in parent %d\n", parentpid); 587 Exit(X_ABORT); 588 } 589 if (childpid != 0) { 590 /* 591 * PARENT: 592 * save the context by waiting 593 * until the child doing all of the work returns. 594 * don't catch the interrupt 595 */ 596 signal(SIGINT, SIG_IGN); 597 #ifdef TDEBUG 598 msg("Tape: %d; parent process: %d child process %d\n", 599 tapeno+1, parentpid, childpid); 600 #endif /* TDEBUG */ 601 while ((waitingpid = wait(&status)) != childpid) 602 msg("Parent %d waiting for child %d has another child %d return\n", 603 parentpid, childpid, waitingpid); 604 if (status & 0xFF) { 605 msg("Child %d returns LOB status %o\n", 606 childpid, status&0xFF); 607 } 608 status = (status >> 8) & 0xFF; 609 #ifdef TDEBUG 610 switch(status) { 611 case X_FINOK: 612 msg("Child %d finishes X_FINOK\n", childpid); 613 break; 614 case X_ABORT: 615 msg("Child %d finishes X_ABORT\n", childpid); 616 break; 617 case X_REWRITE: 618 msg("Child %d finishes X_REWRITE\n", childpid); 619 break; 620 default: 621 msg("Child %d finishes unknown %d\n", 622 childpid, status); 623 break; 624 } 625 #endif /* TDEBUG */ 626 switch(status) { 627 case X_FINOK: 628 Exit(X_FINOK); 629 break; 630 case X_ABORT: 631 Exit(X_ABORT); 632 break; 633 case X_REWRITE: 634 goto restore_check_point; 635 default: 636 msg("Bad return code from dump: %d\n", status); 637 Exit(X_ABORT); 638 } 639 /*NOTREACHED*/ 640 } else { /* we are the child; just continue */ 641 #ifdef TDEBUG 642 sleep(4); /* allow time for parent's message to get out */ 643 msg("Child on Tape %d has parent %d, my pid = %d\n", 644 tapeno+1, parentpid, getpid()); 645 #endif /* TDEBUG */ 646 /* 647 * If we have a name like "/dev/rst0,/dev/rst1", 648 * use the name before the comma first, and save 649 * the remaining names for subsequent volumes. 650 */ 651 tapeno++; /* current tape sequence */ 652 if (nexttape || strchr(tape, ',')) { 653 if (nexttape && *nexttape) 654 tape = nexttape; 655 if ((p = strchr(tape, ',')) != NULL) { 656 *p = '\0'; 657 nexttape = p + 1; 658 } else 659 nexttape = NULL; 660 msg("Dumping volume %d on %s\n", tapeno, tape); 661 } 662 #ifdef RDUMP 663 while ((tapefd = (host ? rmtopen(tape, O_WRONLY|O_CREAT) : 664 pipeout ? 1 : open(tape, O_WRONLY|O_CREAT, 0666))) == -1) 665 #else 666 while ((tapefd = (pipeout ? 1 : 667 open(tape, O_WRONLY|O_CREAT, 0666))) == -1) 668 #endif 669 { 670 msg("Cannot open output \"%s\".\n", tape); 671 if (!query("Do you want to retry the open?")) 672 dumpabort(0); 673 } 674 675 enslave(); /* Share open tape file descriptor with slaves */ 676 677 asize = 0; 678 blocksthisvol = 0; 679 if (top) 680 newtape++; /* new tape signal */ 681 spcl.c_count = slp->count; 682 /* 683 * measure firstrec in TP_BSIZE units since restore doesn't 684 * know the correct ntrec value... 685 */ 686 spcl.c_firstrec = slp->firstrec; 687 spcl.c_volume++; 688 spcl.c_type = TS_TAPE; 689 if (sblock->fs_magic != FS_UFS2_MAGIC) 690 spcl.c_flags |= DR_NEWHEADER; 691 writeheader((ino_t)slp->inode); 692 if (sblock->fs_magic != FS_UFS2_MAGIC) 693 spcl.c_flags &=~ DR_NEWHEADER; 694 msg("Volume %d started at: %s", tapeno, ctime(&tstart_volume)); 695 if (tapeno > 1) 696 msg("Volume %d begins with blocks from inode %llu\n", 697 tapeno, (unsigned long long)slp->inode); 698 } 699 } 700 701 /* ARGSUSED */ 702 void 703 dumpabort(int signo) 704 { 705 706 if (master != 0 && master != getpid()) 707 /* Signals master to call dumpabort */ 708 (void) kill(master, SIGTERM); 709 else { 710 killall(); 711 msg("The ENTIRE dump is aborted.\n"); 712 } 713 #ifdef RDUMP 714 rmtclose(); 715 #endif 716 Exit(X_ABORT); 717 } 718 719 __dead void 720 Exit(int status) 721 { 722 723 #ifdef TDEBUG 724 msg("pid = %d exits with status %d\n", getpid(), status); 725 #endif /* TDEBUG */ 726 exit(status); 727 } 728 729 /* 730 * proceed - handler for SIGUSR2, used to synchronize IO between the slaves. 731 */ 732 /* ARGSUSED */ 733 void 734 proceed(int signo) 735 { 736 caught++; 737 } 738 739 void 740 enslave(void) 741 { 742 int cmd[2]; 743 int i, j; 744 745 master = getpid(); 746 747 signal(SIGTERM, dumpabort); /* Slave sends SIGTERM on dumpabort() */ 748 signal(SIGPIPE, sigpipe); 749 signal(SIGUSR1, tperror); /* Slave sends SIGUSR1 on tape errors */ 750 signal(SIGUSR2, proceed); /* Slave sends SIGUSR2 to next slave */ 751 752 for (i = 0; i < SLAVES; i++) { 753 if (i == slp - &slaves[0]) { 754 caught = 1; 755 } else { 756 caught = 0; 757 } 758 759 if (socketpair(AF_UNIX, SOCK_STREAM, 0, cmd) == -1 || 760 (slaves[i].pid = fork()) == -1) 761 quit("too many slaves, %d (recompile smaller): %s\n", 762 i, strerror(errno)); 763 764 slaves[i].fd = cmd[1]; 765 slaves[i].sent = 0; 766 if (slaves[i].pid == 0) { /* Slave starts up here */ 767 for (j = 0; j <= i; j++) 768 (void) close(slaves[j].fd); 769 signal(SIGINT, SIG_IGN); /* Master handles this */ 770 signal(SIGINFO, SIG_IGN); 771 doslave(cmd[0], i); 772 Exit(X_FINOK); 773 } 774 } 775 776 for (i = 0; i < SLAVES; i++) 777 (void) atomic((ssize_t (*)(int, void *, size_t))write, 778 slaves[i].fd, (char *) &slaves[(i + 1) % SLAVES].pid, 779 sizeof(slaves[0].pid)); 780 master = 0; 781 } 782 783 void 784 killall(void) 785 { 786 int i; 787 788 for (i = 0; i < SLAVES; i++) 789 if (slaves[i].pid > 0) { 790 (void) kill(slaves[i].pid, SIGKILL); 791 slaves[i].pid = 0; 792 } 793 } 794 795 /* 796 * Synchronization - each process has a lockfile, and shares file 797 * descriptors to the following process's lockfile. When our write 798 * completes, we release our lock on the following process's lock- 799 * file, allowing the following process to lock it and proceed. We 800 * get the lock back for the next cycle by swapping descriptors. 801 */ 802 static void 803 doslave(int cmd, int slave_number) 804 { 805 int nread, nextslave, size, wrote = 0, eot_count; 806 sigset_t nsigset, osigset; 807 808 /* 809 * Need our own seek pointer. 810 */ 811 (void) close(diskfd); 812 if ((diskfd = open(disk, O_RDONLY)) == -1) 813 quit("slave couldn't reopen disk: %s\n", strerror(errno)); 814 815 /* 816 * Need the pid of the next slave in the loop... 817 */ 818 if ((nread = atomic(read, cmd, (char *)&nextslave, sizeof(nextslave))) 819 != sizeof(nextslave)) { 820 quit("master/slave protocol botched - didn't get pid of next slave.\n"); 821 } 822 823 /* 824 * Get list of blocks to dump, read the blocks into tape buffer 825 */ 826 while ((nread = atomic(read, cmd, (char *)slp->req, reqsiz)) == reqsiz) { 827 struct req *p = slp->req; 828 829 for (trecno = 0; trecno < ntrec; 830 trecno += p->count, p += p->count) { 831 if (p->dblk) { 832 bread(p->dblk, slp->tblock[trecno], 833 p->count * TP_BSIZE); 834 } else { 835 if (p->count != 1 || atomic(read, cmd, 836 (char *)slp->tblock[trecno], 837 TP_BSIZE) != TP_BSIZE) 838 quit("master/slave protocol botched.\n"); 839 } 840 } 841 842 sigemptyset(&nsigset); 843 sigaddset(&nsigset, SIGUSR2); 844 sigprocmask(SIG_BLOCK, &nsigset, &osigset); 845 while (!caught) 846 sigsuspend(&osigset); 847 caught = 0; 848 sigprocmask(SIG_SETMASK, &osigset, NULL); 849 850 /* Try to write the data... */ 851 eot_count = 0; 852 size = 0; 853 854 while (eot_count < 10 && size < writesize) { 855 #ifdef RDUMP 856 if (host) 857 wrote = rmtwrite(slp->tblock[0]+size, 858 writesize-size); 859 else 860 #endif 861 wrote = write(tapefd, slp->tblock[0]+size, 862 writesize-size); 863 #ifdef WRITEDEBUG 864 printf("slave %d wrote %d\n", slave_number, wrote); 865 #endif 866 if (wrote < 0) 867 break; 868 if (wrote == 0) 869 eot_count++; 870 size += wrote; 871 } 872 873 #ifdef WRITEDEBUG 874 if (size != writesize) 875 printf("slave %d only wrote %d out of %d bytes and gave up.\n", 876 slave_number, size, writesize); 877 #endif 878 879 if (eot_count > 0) 880 size = 0; 881 882 /* 883 * Handle ENOSPC as an EOT condition 884 */ 885 if (wrote < 0 && errno == ENOSPC) { 886 wrote = 0; 887 eot_count++; 888 } 889 890 if (size < 0) { 891 (void) kill(master, SIGUSR1); 892 sigemptyset(&nsigset); 893 for (;;) 894 sigsuspend(&nsigset); 895 } else { 896 /* 897 * pass size of write back to master 898 * (for EOT handling) 899 */ 900 (void) atomic((ssize_t (*)(int, void *, size_t))write, 901 cmd, (char *)&size, sizeof(size)); 902 } 903 904 /* 905 * If partial write, don't want next slave to go. 906 * Also jolts him awake. 907 */ 908 (void) kill(nextslave, SIGUSR2); 909 } 910 if (nread != 0) 911 quit("error reading command pipe: %s\n", strerror(errno)); 912 } 913 914 /* 915 * Since a read from a pipe may not return all we asked for, 916 * or a write may not write all we ask if we get a signal, 917 * loop until the count is satisfied (or error). 918 */ 919 static ssize_t 920 atomic(ssize_t (*func)(int, void *, size_t), int fd, char *buf, int count) 921 { 922 ssize_t got, need = count; 923 924 while ((got = (*func)(fd, buf, need)) > 0 && (need -= got) > 0) 925 buf += got; 926 return (got < 0 ? got : count - need); 927 } 928