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33 * @(#)tape.c 8.4 (Berkeley) 5/1/95
34 * $FreeBSD: src/sbin/dump/tape.c,v 1.12.2.3 2002/02/23 22:32:51 iedowse Exp $
35 * $DragonFly: src/sbin/dump/tape.c,v 1.8 2004/12/27 22:36:37 liamfoy Exp $
38 #include <sys/param.h>
39 #include <sys/socket.h>
44 #include <sys/vnode.h>
47 #include <ufs/inode.h>
49 #include <vfs/ufs/dinode.h>
50 #include <vfs/ufs/fs.h>
53 #include <protocols/dumprestore.h>
70 int writesize; /* size of malloc()ed buffer for tape */
71 long lastspclrec = -1; /* tape block number of last written header */
72 int trecno = 0; /* next record to write in current block */
73 extern long blocksperfile; /* number of blocks per output file */
74 long blocksthisvol; /* number of blocks on current output file */
75 extern int ntrec; /* blocking factor on tape */
80 static int atomic(ssize_t (*)(), int, char *, int);
81 static void doslave(int, int);
82 static void enslave(void);
83 static void flushtape(void);
84 static void killall(void);
85 static void rollforward(void);
88 * Concurrent dump mods (Caltech) - disk block reading and tape writing
89 * are exported to several slave processes. While one slave writes the
90 * tape, the others read disk blocks; they pass control of the tape in
91 * a ring via signals. The parent process traverses the filesystem and
92 * sends writeheader()'s and lists of daddr's to the slaves via pipes.
93 * The following structure defines the instruction packets sent to slaves.
101 #define SLAVES 3 /* 1 slave writing, 1 reading, 1 for slack */
103 int tapea; /* header number at start of this chunk */
104 int count; /* count to next header (used for TS_TAPE */
106 int inode; /* inode that we are currently dealing with */
107 int fd; /* FD for this slave */
108 int pid; /* PID for this slave */
109 int sent; /* 1 == we've sent this slave requests */
110 int firstrec; /* record number of this block */
111 char (*tblock)[TP_BSIZE]; /* buffer for data blocks */
112 struct req *req; /* buffer for requests */
116 char (*nextblock)[TP_BSIZE];
118 int master; /* pid of master, for sending error signals */
119 int tenths; /* length of tape used per block written */
120 static int caught; /* have we caught the signal to proceed? */
121 static int ready; /* have we reached the lock point without having */
122 /* received the SIGUSR2 signal from the prev slave? */
123 static jmp_buf jmpbuf; /* where to jump to if we are ready when the */
124 /* SIGUSR2 arrives from the previous slave */
129 int pgoff = getpagesize() - 1;
133 writesize = ntrec * TP_BSIZE;
134 reqsiz = (ntrec + 1) * sizeof(struct req);
136 * CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode
137 * (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require
138 * repositioning after stopping, i.e, streaming mode, where the gap is
139 * variable, 0.30" to 0.45". The gap is maximal when the tape stops.
141 if (blocksperfile == 0 && !unlimited)
142 tenths = writesize / density +
143 (cartridge ? 16 : density == 625 ? 5 : 8);
145 * Allocate tape buffer contiguous with the array of instruction
146 * packets, so flushtape() can write them together with one write().
147 * Align tape buffer on page boundary to speed up tape write().
149 for (i = 0; i <= SLAVES; i++) {
151 malloc((unsigned)(reqsiz + writesize + pgoff + TP_BSIZE));
154 slaves[i].tblock = (char (*)[TP_BSIZE])
155 (((long)&buf[ntrec + 1] + pgoff) &~ pgoff);
156 slaves[i].req = (struct req *)slaves[i].tblock - ntrec - 1;
162 nextblock = slp->tblock;
167 writerec(char *dp, int isspcl)
170 slp->req[trecno].dblk = (daddr_t)0;
171 slp->req[trecno].count = 1;
173 *(union u_spcl *)(*(nextblock)++) = *(union u_spcl *)dp;
175 bcopy(dp, *(nextblock)++, sizeof (union u_spcl));
178 lastspclrec = spcl.c_tapea;
186 dumpblock(daddr_t blkno, int size)
188 int avail, tpblks, dblkno;
190 dblkno = fsbtodb(sblock, 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;
196 spcl.c_tapea += avail;
199 dblkno += avail << (tp_bshift - dev_bshift);
211 msg("write error on %s\n", tape);
212 quit("Cannot recover\n");
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?"))
219 msg("Closing this volume. Prepare to restart with new media;\n");
220 msg("this dump volume will be rewritten.\n");
231 quit("Broken pipe\n");
240 int siz = (char *)nextblock - (char *)slp->req;
242 slp->req[trecno].count = 0; /* Sentinel */
244 if (atomic(write, slp->fd, (char *)slp->req, siz) != siz)
245 quit("error writing command pipe: %s\n", strerror(errno));
246 slp->sent = 1; /* we sent a request, read the response later */
248 lastfirstrec = slp->firstrec;
250 if (++slp >= &slaves[SLAVES])
253 /* Read results back from next slave */
255 if (atomic(read, slp->fd, (char *)&got, sizeof got)
257 perror(" DUMP: error reading command pipe in master");
262 /* Check for end of tape */
263 if (got < writesize) {
264 msg("End of tape detected\n");
267 * Drain the results, don't care what the values were.
268 * If we read them here then trewind won't...
270 for (i = 0; i < SLAVES; i++) {
271 if (slaves[i].sent) {
272 if (atomic(read, slaves[i].fd,
273 (char *)&got, sizeof got)
275 perror(" DUMP: error reading command pipe in master");
289 if (spcl.c_type != TS_END) {
290 for (i = 0; i < spcl.c_count; i++)
291 if (spcl.c_addr[i] != 0)
294 slp->count = lastspclrec + blks + 1 - spcl.c_tapea;
295 slp->tapea = spcl.c_tapea;
296 slp->firstrec = lastfirstrec + ntrec;
298 nextblock = slp->tblock;
301 blockswritten += ntrec;
302 blocksthisvol += ntrec;
303 if (!pipeout && !unlimited && (blocksperfile ?
304 (blocksthisvol >= blocksperfile) : (asize > tsize))) {
318 for (f = 0; f < SLAVES; f++) {
320 * Drain the results, but unlike EOT we DO (or should) care
321 * what the return values were, since if we detect EOT after
322 * we think we've written the last blocks to the tape anyway,
323 * we have to replay those blocks with rollforward.
325 * fixme: punt for now.
327 if (slaves[f].sent) {
328 if (atomic(read, slaves[f].fd, (char *)&got, sizeof got)
330 perror(" DUMP: error reading command pipe in master");
334 if (got != writesize) {
335 msg("EOT detected in last 2 tape records!\n");
336 msg("Use a longer tape, decrease the size estimate\n");
337 quit("or use no size estimate at all.\n");
342 while (wait((int *)NULL) >= 0) /* wait for any signals from slaves */
348 msg("Closing %s\n", tape);
353 while (rmtopen(tape, 0) < 0)
359 if (fstat(tapefd, &sb) == 0 && S_ISFIFO(sb.st_mode)) {
364 while ((f = open(tape, 0)) < 0)
372 time_t tstart_changevol, tend_changevol;
377 time((time_t *)&(tstart_changevol));
379 msg("Change Volumes: Mount volume #%d\n", tapeno+1);
380 broadcast("CHANGE DUMP VOLUMES!\a\a\n");
382 while (!query("Is the new volume mounted and ready to go?"))
383 if (query("Do you want to abort?")) {
387 time((time_t *)&(tend_changevol));
388 if ((tstart_changevol != (time_t)-1) && (tend_changevol != (time_t)-1))
389 tstart_writing += (tend_changevol - tstart_changevol);
395 struct req *p, *q, *prev;
397 int i, size, savedtapea, got;
398 union u_spcl *ntb, *otb;
399 tslp = &slaves[SLAVES];
400 ntb = (union u_spcl *)tslp->tblock[1];
403 * Each of the N slaves should have requests that need to
404 * be replayed on the next tape. Use the extra slave buffers
405 * (slaves[SLAVES]) to construct request lists to be sent to
406 * each slave in turn.
408 for (i = 0; i < SLAVES; i++) {
410 otb = (union u_spcl *)slp->tblock;
413 * For each request in the current slave, copy it to tslp.
417 for (p = slp->req; p->count > 0; p += p->count) {
420 *ntb++ = *otb++; /* copy the datablock also */
425 quit("rollforward: protocol botch");
437 nextblock = tslp->tblock;
438 savedtapea = spcl.c_tapea;
439 spcl.c_tapea = slp->tapea;
441 spcl.c_tapea = savedtapea;
442 lastspclrec = savedtapea - 1;
444 size = (char *)ntb - (char *)q;
445 if (atomic(write, slp->fd, (char *)q, size) != size) {
446 perror(" DUMP: error writing command pipe");
450 if (++slp >= &slaves[SLAVES])
455 if (prev->dblk != 0) {
457 * If the last one was a disk block, make the
458 * first of this one be the last bit of that disk
461 q->dblk = prev->dblk +
462 prev->count * (TP_BSIZE / DEV_BSIZE);
463 ntb = (union u_spcl *)tslp->tblock;
466 * It wasn't a disk block. Copy the data to its
467 * new location in the buffer.
470 *((union u_spcl *)tslp->tblock) = *ntb;
471 ntb = (union u_spcl *)tslp->tblock[1];
475 nextblock = slp->tblock;
481 * Clear the first slaves' response. One hopes that it
482 * worked ok, otherwise the tape is much too short!
485 if (atomic(read, slp->fd, (char *)&got, sizeof got)
487 perror(" DUMP: error reading command pipe in master");
492 if (got != writesize) {
493 quit("EOT detected at start of the tape!\n");
499 * We implement taking and restoring checkpoints on the tape level.
500 * When each tape is opened, a new process is created by forking; this
501 * saves all of the necessary context in the parent. The child
502 * continues the dump; the parent waits around, saving the context.
503 * If the child returns X_REWRITE, then it had problems writing that tape;
504 * this causes the parent to fork again, duplicating the context, and
505 * everything continues as if nothing had happened.
508 startnewtape(int top)
516 void (*interrupt_save)();
518 sig_t interrupt_save;
521 interrupt_save = signal(SIGINT, SIG_IGN);
522 parentpid = getpid();
525 signal(SIGINT, interrupt_save);
527 * All signals are inherited...
529 setproctitle(NULL); /* Restore the proctitle. */
532 msg("Context save fork fails in parent %d\n", parentpid);
538 * save the context by waiting
539 * until the child doing all of the work returns.
540 * don't catch the interrupt
542 signal(SIGINT, SIG_IGN);
544 msg("Tape: %d; parent process: %d child process %d\n",
545 tapeno+1, parentpid, childpid);
547 while ((waitpid = wait(&status)) != childpid)
548 msg("Parent %d waiting for child %d has another child %d return\n",
549 parentpid, childpid, waitpid);
551 msg("Child %d returns LOB status %o\n",
552 childpid, status&0xFF);
554 status = (status >> 8) & 0xFF;
558 msg("Child %d finishes X_FINOK\n", childpid);
561 msg("Child %d finishes X_ABORT\n", childpid);
564 msg("Child %d finishes X_REWRITE\n", childpid);
567 msg("Child %d finishes unknown %d\n",
578 goto restore_check_point;
580 msg("Bad return code from dump: %d\n", status);
584 } else { /* we are the child; just continue */
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());
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.
595 tapeno++; /* current tape sequence */
596 if (nexttape || strchr(tape, ',')) {
597 if (nexttape && *nexttape)
599 if ((p = strchr(tape, ',')) != NULL) {
604 msg("Dumping volume %d on %s\n", tapeno, tape);
607 while ((tapefd = (host ? rmtopen(tape, 2) :
608 pipeout ? 1 : open(tape, O_WRONLY|O_CREAT, 0666))) < 0)
610 while ((tapefd = (pipeout ? 1 :
611 open(tape, O_WRONLY|O_CREAT, 0666))) < 0)
614 msg("Cannot open output \"%s\".\n", tape);
615 if (!query("Do you want to retry the open?"))
619 enslave(); /* Share open tape file descriptor with slaves */
620 signal(SIGINFO, infosch);
625 newtape++; /* new tape signal */
626 spcl.c_count = slp->count;
628 * measure firstrec in TP_BSIZE units since restore doesn't
629 * know the correct ntrec value...
631 spcl.c_firstrec = slp->firstrec;
633 spcl.c_type = TS_TAPE;
634 spcl.c_flags |= DR_NEWHEADER;
635 writeheader((ino_t)slp->inode);
636 spcl.c_flags &=~ DR_NEWHEADER;
638 msg("Volume %d begins with blocks from inode %d\n",
647 if (master != 0 && master != getpid())
648 /* Signals master to call dumpabort */
649 kill(master, SIGTERM);
652 msg("The ENTIRE dump is aborted.\n");
665 msg("pid = %d exits with status %d\n", getpid(), status);
671 * proceed - handler for SIGUSR2, used to synchronize IO between the slaves.
690 signal(SIGTERM, dumpabort); /* Slave sends SIGTERM on dumpabort() */
691 signal(SIGPIPE, sigpipe);
692 signal(SIGUSR1, tperror); /* Slave sends SIGUSR1 on tape errors */
693 signal(SIGUSR2, proceed); /* Slave sends SIGUSR2 to next slave */
695 for (i = 0; i < SLAVES; i++) {
696 if (i == slp - &slaves[0]) {
702 if (socketpair(AF_UNIX, SOCK_STREAM, 0, cmd) < 0 ||
703 (slaves[i].pid = fork()) < 0)
704 quit("too many slaves, %d (recompile smaller): %s\n",
707 slaves[i].fd = cmd[1];
709 if (slaves[i].pid == 0) { /* Slave starts up here */
710 for (j = 0; j <= i; j++)
712 signal(SIGINT, SIG_IGN); /* Master handles this */
718 for (i = 0; i < SLAVES; i++)
719 atomic(write, slaves[i].fd,
720 (char *) &slaves[(i + 1) % SLAVES].pid,
721 sizeof slaves[0].pid);
731 for (i = 0; i < SLAVES; i++)
732 if (slaves[i].pid > 0) {
733 kill(slaves[i].pid, SIGKILL);
739 * Synchronization - each process has a lockfile, and shares file
740 * descriptors to the following process's lockfile. When our write
741 * completes, we release our lock on the following process's lock-
742 * file, allowing the following process to lock it and proceed. We
743 * get the lock back for the next cycle by swapping descriptors.
746 doslave(int cmd, int slave_number)
749 int nextslave, size, wrote = 0, eot_count;
752 * Need our own seek pointer.
755 if ((diskfd = open(disk, O_RDONLY)) < 0)
756 quit("slave couldn't reopen disk: %s\n", strerror(errno));
759 * Need the pid of the next slave in the loop...
761 if ((nread = atomic(read, cmd, (char *)&nextslave, sizeof nextslave))
762 != sizeof nextslave) {
763 quit("master/slave protocol botched - didn't get pid of next slave.\n");
767 * Get list of blocks to dump, read the blocks into tape buffer
769 while ((nread = atomic(read, cmd, (char *)slp->req, reqsiz)) == reqsiz) {
770 struct req *p = slp->req;
772 for (trecno = 0; trecno < ntrec;
773 trecno += p->count, p += p->count) {
775 bread(p->dblk, slp->tblock[trecno],
776 p->count * TP_BSIZE);
778 if (p->count != 1 || atomic(read, cmd,
779 (char *)slp->tblock[trecno],
780 TP_BSIZE) != TP_BSIZE)
781 quit("master/slave protocol botched.\n");
784 if (setjmp(jmpbuf) == 0) {
792 /* Try to write the data... */
796 while (eot_count < 10 && size < writesize) {
799 wrote = rmtwrite(slp->tblock[0]+size,
803 wrote = write(tapefd, slp->tblock[0]+size,
806 printf("slave %d wrote %d\n", slave_number, wrote);
816 if (size != writesize)
817 printf("slave %d only wrote %d out of %d bytes and gave up.\n",
818 slave_number, size, writesize);
822 * Handle ENOSPC as an EOT condition.
824 if (wrote < 0 && errno == ENOSPC) {
833 kill(master, SIGUSR1);
838 * pass size of write back to master
841 atomic(write, cmd, (char *)&size, sizeof size);
845 * If partial write, don't want next slave to go.
846 * Also jolts him awake.
848 kill(nextslave, SIGUSR2);
851 quit("error reading command pipe: %s\n", strerror(errno));
855 * Since a read from a pipe may not return all we asked for,
856 * or a write may not write all we ask if we get a signal,
857 * loop until the count is satisfied (or error).
860 atomic(ssize_t (*func)(), int fd, char *buf, int count)
862 int got, need = count;
864 while ((got = (*func)(fd, buf, need)) > 0 && (need -= got) > 0)
866 return (got < 0 ? got : count - need);