2 * Ported to Linux's Second Extended File System as part of the
3 * dump and restore backup suit
4 * Remy Card <card@Linux.EU.Org>, 1994-1997
5 * Stelian Pop <pop@noos.fr>, 1999-2000
6 * Stelian Pop <pop@noos.fr> - AlcĂ´ve <www.alcove.fr>, 2000
10 * Copyright (c) 1980, 1991, 1993
11 * The Regents of the University of California. All rights reserved.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the University of
24 * California, Berkeley and its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 static const char rcsid[] =
44 "$Id: tape.c,v 1.30 2001/02/16 13:38:47 stelian Exp $";
49 #include <sys/types.h>
50 #include <linux/types.h>
52 #include <sys/param.h>
53 #include <sys/socket.h>
57 #include <linux/ext2_fs.h>
58 #include <bsdcompat.h>
61 #include <sys/vnode.h>
64 #include <ufs/inode.h>
66 #include <ufs/ufs/dinode.h>
67 #include <ufs/ffs/fs.h>
69 #endif /* __linux__ */
71 #include <protocols/dumprestore.h>
78 #include <compaterr.h>
88 #include <ext2fs/ext2fs.h>
93 int writesize; /* size of malloc()ed buffer for tape */
94 long lastspclrec = -1; /* tape block number of last written header */
95 int trecno = 0; /* next record to write in current block */
96 extern long blocksperfile; /* number of blocks per output file */
97 long blocksthisvol; /* number of blocks on current output file */
98 extern int ntrec; /* blocking factor on tape */
105 static ssize_t atomic_read __P((int, void *, size_t));
106 static ssize_t atomic_write __P((int, const void *, size_t));
107 static void doslave __P((int, int));
108 static void enslave __P((void));
109 static void flushtape __P((void));
110 static void killall __P((void));
111 static void rollforward __P((void));
112 static int system_command __P((const char *, const char *, int));
115 * Concurrent dump mods (Caltech) - disk block reading and tape writing
116 * are exported to several slave processes. While one slave writes the
117 * tape, the others read disk blocks; they pass control of the tape in
118 * a ring via signals. The parent process traverses the filesystem and
119 * sends writeheader()'s and lists of daddr's to the slaves via pipes.
120 * The following structure defines the instruction packets sent to slaves.
128 #define SLAVES 3 /* 1 slave writing, 1 reading, 1 for slack */
130 int tapea; /* header number at start of this chunk */
131 int count; /* count to next header (used for TS_TAPE */
133 int inode; /* inode that we are currently dealing with */
134 int fd; /* FD for this slave */
135 int pid; /* PID for this slave */
136 int sent; /* 1 == we've sent this slave requests */
137 int firstrec; /* record number of this block */
138 char (*tblock)[TP_BSIZE]; /* buffer for data blocks */
139 struct req *req; /* buffer for requests */
143 char (*nextblock)[TP_BSIZE];
145 static time_t tstart_volume; /* time of volume start */
146 static int tapea_volume; /* value of spcl.c_tapea at volume start */
148 int master; /* pid of master, for sending error signals */
149 int tenths; /* length of tape used per block written */
150 static int caught; /* have we caught the signal to proceed? */
151 static int ready; /* have we reached the lock point without having */
152 /* received the SIGUSR2 signal from the prev slave? */
153 static sigjmp_buf jmpbuf; /* where to jump to if we are ready when the */
154 /* SIGUSR2 arrives from the previous slave */
159 int pgoff = getpagesize() - 1;
163 writesize = ntrec * TP_BSIZE;
164 reqsiz = (ntrec + 1) * sizeof(struct req);
166 * CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode
167 * (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require
168 * repositioning after stopping, i.e, streaming mode, where the gap is
169 * variable, 0.30" to 0.45". The gap is maximal when the tape stops.
171 if (blocksperfile == 0 && !unlimited)
172 tenths = writesize / density +
173 (cartridge ? 16 : density == 625 ? 5 : 8);
175 * Allocate tape buffer contiguous with the array of instruction
176 * packets, so flushtape() can write them together with one write().
177 * Align tape buffer on page boundary to speed up tape write().
179 for (i = 0; i <= SLAVES; i++) {
181 malloc((unsigned)(reqsiz + writesize + pgoff + TP_BSIZE));
184 slaves[i].tblock = (char (*)[TP_BSIZE])
186 (((long)&buf[reqsiz] + pgoff) &~ pgoff);
188 (((long)&buf[ntrec + 1] + pgoff) &~ pgoff);
190 slaves[i].req = (struct req *)slaves[i].tblock - ntrec - 1;
196 nextblock = slp->tblock;
201 writerec(const void *dp, int isspcl)
204 slp->req[trecno].dblk = (daddr_t)0;
205 slp->req[trecno].count = 1;
206 /* XXX post increment triggers an egcs-1.1.2-12 bug on alpha/sparc */
207 *(union u_spcl *)(*(nextblock)) = *(union u_spcl *)dp;
210 lastspclrec = spcl.c_tapea;
218 dumpblock(daddr_t blkno, int size)
220 int avail, tpblks, dblkno;
222 dblkno = fsbtodb(sblock, blkno);
223 tpblks = size >> tp_bshift;
224 while ((avail = MIN(tpblks, ntrec - trecno)) > 0) {
225 slp->req[trecno].dblk = dblkno;
226 slp->req[trecno].count = avail;
228 spcl.c_tapea += avail;
231 dblkno += avail << (tp_bshift - dev_bshift);
243 msg("write error on %s: %s\n", tape, strerror(errnum));
244 quit("Cannot recover\n");
247 msg("write error %d blocks into volume %d: %s\n", blocksthisvol, tapeno, strerror(errnum));
248 broadcast("DUMP WRITE ERROR!\n");
249 if (query("Do you want to rewrite this volume?")) {
250 msg("Closing this volume. Prepare to restart with new media;\n");
251 msg("this dump volume will be rewritten.\n");
257 if (query("Do you want to start the next tape?"))
266 quit("Broken pipe\n");
271 * Update xferrate stats
284 ttaken = tnow - tstart_volume;
285 blocks = spcl.c_tapea - tapea_volume;
286 msg("Volume %d completed at: %s", tapeno,
292 msg("Volume %d: %ld tape blocks (%.2fMB)\n", tapeno,
293 blocks, ((double)blocks * TP_BSIZE / 1048576));
295 msg("Volume %d took %d:%02d:%02d\n", tapeno,
296 ttaken / 3600, (ttaken % 3600) / 60, ttaken % 60);
297 msg("Volume %d transfer rate: %ld KB/s\n", tapeno,
299 xferrate += blocks / ttaken;
305 mktimeest(time_t tnow)
307 static char msgbuf[128];
312 if (blockswritten < 500)
314 if (blockswritten > tapesize)
315 tapesize = blockswritten;
316 deltat = tstart_writing - tnow + (1.0 * (tnow - tstart_writing))
317 / blockswritten * tapesize;
318 if (tnow > tstart_volume)
319 (void)snprintf(msgbuf, sizeof(msgbuf),
320 "%3.2f%% done at %ld KB/s, finished in %d:%02d\n",
321 (blockswritten * 100.0) / tapesize,
322 (spcl.c_tapea - tapea_volume) / (tnow - tstart_volume),
323 (int)(deltat / 3600), (int)((deltat % 3600) / 60));
325 (void)snprintf(msgbuf, sizeof(msgbuf),
326 "%3.2f%% done, finished in %d:%02d\n",
327 (blockswritten * 100.0) / tapesize,
328 (int)(deltat / 3600), (int)((deltat % 3600) / 60));
336 * information message upon receipt of SIGINFO
339 statussig(int notused)
342 int save_errno = errno;
348 (void) time((time_t *) &tnow);
350 buf = mktimeest(tnow);
352 write(STDERR_FILENO, buf, strlen(buf));
363 int siz = (char *)nextblock - (char *)slp->req;
365 slp->req[trecno].count = 0; /* Sentinel */
367 if (atomic_write( slp->fd, (char *)slp->req, siz) != siz)
368 quit("error writing command pipe: %s\n", strerror(errno));
369 slp->sent = 1; /* we sent a request, read the response later */
371 lastfirstrec = slp->firstrec;
373 if (++slp >= &slaves[SLAVES])
376 /* Read results back from next slave */
378 if (atomic_read( slp->fd, (char *)&got, sizeof got)
380 perror(" DUMP: error reading command pipe in master");
385 /* Check for errors */
389 /* Check for end of tape */
390 if (got < writesize) {
391 msg("End of tape detected\n");
394 * Drain the results, don't care what the values were.
395 * If we read them here then trewind won't...
397 for (i = 0; i < SLAVES; i++) {
398 if (slaves[i].sent) {
399 if (atomic_read( slaves[i].fd,
400 (char *)&got, sizeof got)
402 perror(" DUMP: error reading command pipe in master");
416 if (spcl.c_type != TS_END) {
417 for (i = 0; i < spcl.c_count; i++)
418 if (spcl.c_addr[i] != 0)
421 slp->count = lastspclrec + blks + 1 - spcl.c_tapea;
422 slp->tapea = spcl.c_tapea;
423 slp->firstrec = lastfirstrec + ntrec;
425 nextblock = slp->tblock;
428 blockswritten += ntrec;
429 blocksthisvol += ntrec;
430 if (!pipeout && !unlimited && (blocksperfile ?
431 (blocksthisvol >= blocksperfile) : (asize > tsize))) {
439 * Executes the command in a shell.
440 * Returns -1 if an error occured, the exit status of
441 * the command on success.
443 int system_command(const char *command, const char *device, int volnum) {
445 char commandstr[4096];
449 perror(" DUMP: unable to fork");
455 #if OLD_STYLE_FSCRIPT
456 snprintf(commandstr, sizeof(commandstr), "%s", command);
458 snprintf(commandstr, sizeof(commandstr), "%s %s %d", command, device, volnum);
460 commandstr[sizeof(commandstr) - 1] = '\0';
461 execl("/bin/sh", "sh", "-c", commandstr, NULL);
462 perror(" DUMP: unable to execute shell");
466 if (waitpid(pid, &status, 0) == -1) {
467 if (errno != EINTR) {
468 perror(" DUMP: waitpid error");
472 if (WIFEXITED(status))
473 return WEXITSTATUS(status);
486 for (f = 0; f < SLAVES; f++) {
488 * Drain the results, but unlike EOT we DO (or should) care
489 * what the return values were, since if we detect EOT after
490 * we think we've written the last blocks to the tape anyway,
491 * we have to replay those blocks with rollforward.
493 * fixme: punt for now.
495 if (slaves[f].sent) {
496 if (atomic_read( slaves[f].fd, (char *)&got, sizeof got)
498 perror(" DUMP: error reading command pipe in master");
506 if (got != writesize) {
507 msg("EOT detected in last 2 tape records!\n");
508 msg("Use a longer tape, decrease the size estimate\n");
509 quit("or use no size estimate at all.\n");
512 (void) close(slaves[f].fd);
514 while (wait((int *)NULL) >= 0) /* wait for any signals from slaves */
519 msg("Closing %s\n", tape);
524 while (rmtopen(tape, 0) < 0)
531 (void) close(tapefd);
532 while ((f = open(tape, 0)) < 0)
537 if (eot_script && spcl.c_type != TS_END) {
538 msg("Launching %s\n", eot_script);
539 eot_code = system_command(eot_script, tape, tapeno);
541 if (eot_code != 0 && eot_code != 1) {
542 msg("Dump aborted by the end of tape script\n");
554 if (nexttape || Mflag || (eot_code == 0) )
557 msg("Change Volumes: Mount volume #%d\n", tapeno+1);
558 broadcast("CHANGE DUMP VOLUMES!\7\7\n");
560 while (!query("Is the new volume mounted and ready to go?"))
561 if (query("Do you want to abort?")) {
570 register struct req *p, *q, *prev;
571 register struct slave *tslp;
572 int i, size, savedtapea, got;
573 union u_spcl *ntb, *otb;
578 tslp = &slaves[SLAVES];
579 ntb = (union u_spcl *)tslp->tblock[1];
582 * Each of the N slaves should have requests that need to
583 * be replayed on the next tape. Use the extra slave buffers
584 * (slaves[SLAVES]) to construct request lists to be sent to
585 * each slave in turn.
587 for (i = 0; i < SLAVES; i++) {
589 otb = (union u_spcl *)slp->tblock;
592 * For each request in the current slave, copy it to tslp.
596 for (p = slp->req; p->count > 0; p += p->count) {
599 *ntb++ = *otb++; /* copy the datablock also */
604 quit("rollforward: protocol botch");
616 nextblock = tslp->tblock;
617 savedtapea = spcl.c_tapea;
618 spcl.c_tapea = slp->tapea;
620 spcl.c_tapea = savedtapea;
621 lastspclrec = savedtapea - 1;
623 size = (char *)ntb - (char *)q;
624 if (atomic_write( slp->fd, (char *)q, size) != size) {
625 perror(" DUMP: error writing command pipe");
630 lastfirstrec = slp->firstrec;
632 if (++slp >= &slaves[SLAVES])
637 if (prev->dblk != 0) {
639 * If the last one was a disk block, make the
640 * first of this one be the last bit of that disk
643 q->dblk = prev->dblk +
644 prev->count * (TP_BSIZE / DEV_BSIZE);
645 ntb = (union u_spcl *)tslp->tblock;
648 * It wasn't a disk block. Copy the data to its
649 * new location in the buffer.
652 *((union u_spcl *)tslp->tblock) = *ntb;
653 ntb = (union u_spcl *)tslp->tblock[1];
657 nextblock = slp->tblock;
660 /* XXX post increment triggers an egcs-1.1.2-12 bug on alpha/sparc */
661 *(union u_spcl *)(*nextblock) = *(union u_spcl *)tslp->tblock;
668 * Clear the first slaves' response. One hopes that it
669 * worked ok, otherwise the tape is much too short!
672 if (atomic_read( slp->fd, (char *)&got, sizeof got)
674 perror(" DUMP: error reading command pipe in master");
682 if (got != writesize) {
683 quit("EOT detected at start of the tape!\n");
689 if (spcl.c_type != TS_END) {
690 for (i = 0; i < spcl.c_count; i++)
691 if (spcl.c_addr[i] != 0)
695 slp->firstrec = lastfirstrec + ntrec;
696 slp->count = lastspclrec + blks + 1 - spcl.c_tapea;
699 blockswritten += ntrec;
700 blocksthisvol += ntrec;
705 * We implement taking and restoring checkpoints on the tape level.
706 * When each tape is opened, a new process is created by forking; this
707 * saves all of the necessary context in the parent. The child
708 * continues the dump; the parent waits around, saving the context.
709 * If the child returns X_REWRITE, then it had problems writing that tape;
710 * this causes the parent to fork again, duplicating the context, and
711 * everything continues as if nothing had happened.
714 startnewtape(int top)
725 sigaddset(&sigs, SIGINT);
726 sigprocmask(SIG_BLOCK, &sigs, NULL);
727 #else /* __linux__ */
729 void (*interrupt_save)();
731 sig_t interrupt_save;
733 interrupt_save = signal(SIGINT, SIG_IGN);
734 #endif /* __linux__ */
736 parentpid = getpid();
737 tapea_volume = spcl.c_tapea;
739 (void)time4(&tstart_volume);
741 (void)time((&tstart_volume);
746 sigprocmask(SIG_UNBLOCK, &sigs, NULL);
748 (void)signal(SIGINT, interrupt_save);
751 * All signals are inherited...
755 msg("Context save fork fails in parent %d\n", parentpid);
761 * save the context by waiting
762 * until the child doing all of the work returns.
763 * don't catch the interrupt
766 sigprocmask(SIG_BLOCK, &sigs, NULL);
768 signal(SIGINT, SIG_IGN);
771 msg("Tape: %d; parent process: %d child process %d\n",
772 tapeno+1, parentpid, childpid);
774 while ((waitpid = wait(&status)) != childpid)
775 if (waitpid != rshpid)
776 msg("Parent %d waiting for child %d has another child %d return\n",
777 parentpid, childpid, waitpid);
779 msg("Child %d returns LOB status %o\n",
780 childpid, status&0xFF);
782 status = (status >> 8) & 0xFF;
786 msg("Child %d finishes X_FINOK\n", childpid);
789 msg("Child %d finishes X_ABORT\n", childpid);
792 msg("Child %d finishes X_REWRITE\n", childpid);
795 msg("Child %d finishes unknown %d\n",
806 goto restore_check_point;
808 msg("Bad return code from dump: %d\n", status);
812 } else { /* we are the child; just continue */
814 sleep(4); /* allow time for parent's message to get out */
815 msg("Child on Tape %d has parent %d, my pid = %d\n",
816 tapeno+1, parentpid, getpid());
819 * If we have a name like "/dev/rmt0,/dev/rmt1",
820 * use the name before the comma first, and save
821 * the remaining names for subsequent volumes.
823 tapeno++; /* current tape sequence */
825 snprintf(tape, MAXPATHLEN, "%s%03d", tapeprefix, tapeno);
826 tape[MAXPATHLEN - 1] = '\0';
827 msg("Dumping volume %d on %s\n", tapeno, tape);
829 else if (nexttape || strchr(tapeprefix, ',')) {
830 if (nexttape && *nexttape)
831 tapeprefix = nexttape;
832 if ((p = strchr(tapeprefix, ',')) != NULL) {
837 strncpy(tape, tapeprefix, MAXPATHLEN);
838 tape[MAXPATHLEN - 1] = '\0';
839 msg("Dumping volume %d on %s\n", tapeno, tape);
842 while ((tapefd = (host ? rmtopen(tape, 2) : pipeout ?
844 open(tape, O_WRONLY|O_CREAT, 0666))) < 0)
846 while ((tapefd = (pipeout ? fileno(stdout) :
847 open(tape, O_WRONLY|O_CREAT, 0666))) < 0)
850 msg("Cannot open output \"%s\".\n", tape);
851 if (!query("Do you want to retry the open?"))
855 enslave(); /* Share open tape file descriptor with slaves */
860 newtape++; /* new tape signal */
861 spcl.c_count = slp->count;
863 * measure firstrec in TP_BSIZE units since restore doesn't
864 * know the correct ntrec value...
866 spcl.c_firstrec = slp->firstrec;
868 spcl.c_type = TS_TAPE;
869 spcl.c_flags |= DR_NEWHEADER;
870 writeheader((ino_t)slp->inode);
871 spcl.c_flags &=~ DR_NEWHEADER;
872 msg("Volume %d started at: %s", tapeno,
874 ctime4(&tstart_volume));
876 ctime(&tstart_volume));
879 msg("Volume %d begins with blocks from inode %d\n",
888 if (master != 0 && master != getpid())
889 /* Signals master to call dumpabort */
890 (void) kill(master, SIGTERM);
893 msg("The ENTIRE dump is aborted.\n");
906 msg("pid = %d exits with status %d\n", getpid(), status);
912 * proceed - handler for SIGUSR2, used to synchronize IO between the slaves.
918 siglongjmp(jmpbuf, 1);
926 #ifdef LINUX_FORK_BUG
934 { struct sigaction sa;
935 memset(&sa, 0, sizeof sa);
936 sigemptyset(&sa.sa_mask);
937 sa.sa_handler = dumpabort;
938 sigaction(SIGTERM, &sa, NULL); /* Slave sends SIGTERM on dumpabort() */
939 sa.sa_handler = sigpipe;
940 sigaction(SIGPIPE, &sa, NULL);
941 sa.sa_handler = proceed;
942 sa.sa_flags = SA_RESTART;
943 sigaction(SIGUSR2, &sa, NULL); /* Slave sends SIGUSR2 to next slave */
946 for (i = 0; i < SLAVES; i++) {
947 if (i == slp - &slaves[0]) {
953 if (socketpair(AF_UNIX, SOCK_STREAM, 0, cmd) < 0 ||
954 (slaves[i].pid = fork()) < 0)
955 quit("too many slaves, %d (recompile smaller): %s\n",
958 slaves[i].fd = cmd[1];
960 if (slaves[i].pid == 0) { /* Slave starts up here */
962 for (j = 0; j <= i; j++)
963 (void) close(slaves[j].fd);
965 sigaddset(&sigs, SIGINT); /* Master handles this */
967 sigaddset(&sigs, SIGINFO);
969 sigprocmask(SIG_BLOCK, &sigs, NULL);
971 #ifdef LINUX_FORK_BUG
972 if (atomic_write( cmd[0], (char *) &i, sizeof i)
974 quit("master/slave protocol botched 3\n");
981 #ifdef LINUX_FORK_BUG
983 * Wait for all slaves to _actually_ start to circumvent a bug in
984 * Linux kernels >= 2.1.3 where a signal sent to a child that hasn't
985 * returned from fork() causes a SEGV in the child process
987 for (i = 0; i < SLAVES; i++)
988 if (atomic_read( slaves[i].fd, (char *) &j, sizeof j) != sizeof j)
989 quit("master/slave protocol botched 4\n");
992 for (i = 0; i < SLAVES; i++)
993 (void) atomic_write( slaves[i].fd,
994 (char *) &slaves[(i + 1) % SLAVES].pid,
995 sizeof slaves[0].pid);
1005 for (i = 0; i < SLAVES; i++)
1006 if (slaves[i].pid > 0) {
1007 (void) kill(slaves[i].pid, SIGKILL);
1013 * Synchronization - each process has a lockfile, and shares file
1014 * descriptors to the following process's lockfile. When our write
1015 * completes, we release our lock on the following process's lock-
1016 * file, allowing the following process to lock it and proceed. We
1017 * get the lock back for the next cycle by swapping descriptors.
1020 doslave(int cmd, int slave_number)
1023 int nextslave, size, eot_count;
1024 volatile int wrote = 0;
1030 * Need our own seek pointer.
1032 (void) close(diskfd);
1033 if ((diskfd = open(disk, O_RDONLY)) < 0)
1034 quit("slave couldn't reopen disk: %s\n", strerror(errno));
1037 retval = dump_fs_open(disk, &fs);
1039 quit("slave couldn't reopen disk: %s\n", error_message(retval));
1040 #endif /* __linux__ */
1043 * Need the pid of the next slave in the loop...
1045 if ((nread = atomic_read( cmd, (char *)&nextslave, sizeof nextslave))
1046 != sizeof nextslave) {
1047 quit("master/slave protocol botched - didn't get pid of next slave.\n");
1051 * Get list of blocks to dump, read the blocks into tape buffer
1053 while ((nread = atomic_read( cmd, (char *)slp->req, reqsiz)) == reqsiz) {
1054 register struct req *p = slp->req;
1056 for (trecno = 0; trecno < ntrec;
1057 trecno += p->count, p += p->count) {
1059 bread(p->dblk, slp->tblock[trecno],
1060 p->count * TP_BSIZE);
1062 if (p->count != 1 || atomic_read( cmd,
1063 (char *)slp->tblock[trecno],
1064 TP_BSIZE) != TP_BSIZE)
1065 quit("master/slave protocol botched.\n");
1068 if (sigsetjmp(jmpbuf, 1) == 0) {
1076 /* Try to write the data... */
1081 while (eot_count < 10 && size < writesize) {
1084 wrote = rmtwrite(slp->tblock[0]+size,
1088 wrote = write(tapefd, slp->tblock[0]+size,
1091 printf("slave %d wrote %d\n", slave_number, wrote);
1101 if (size != writesize)
1102 printf("slave %d only wrote %d out of %d bytes and gave up.\n",
1103 slave_number, size, writesize);
1107 * Handle ENOSPC as an EOT condition.
1109 if (wrote < 0 && errno == ENOSPC) {
1118 * pass errno back to master for special handling
1124 * pass size of write back to master
1125 * (for EOT handling)
1127 (void) atomic_write( cmd, (char *)&size, sizeof size);
1130 * If partial write, don't want next slave to go.
1131 * Also jolts him awake.
1133 (void) kill(nextslave, SIGUSR2);
1136 quit("error reading command pipe: %s\n", strerror(errno));
1140 * Since a read from a pipe may not return all we asked for,
1141 * or a write may not write all we ask if we get a signal,
1142 * loop until the count is satisfied (or error).
1145 atomic_read(int fd, void *buf, size_t count)
1147 int got, need = count;
1150 while ((got = read(fd, buf, need)) > 0 && (need -= got) > 0)
1152 } while (got == -1 && errno == EINTR);
1153 return (got < 0 ? got : count - need);
1157 * Since a read from a pipe may not return all we asked for,
1158 * or a write may not write all we ask if we get a signal,
1159 * loop until the count is satisfied (or error).
1162 atomic_write(int fd, const void *buf, size_t count)
1164 int got, need = count;
1167 while ((got = write(fd, buf, need)) > 0 && (need -= got) > 0)
1169 } while (got == -1 && errno == EINTR);
1170 return (got < 0 ? got : count - need);