Net2/usr/src/sbin/dump/dumptape.c
/*-
* Copyright (c) 1980, 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)dumptape.c 5.18 (Berkeley) 4/24/91";
#endif /* not lint */
#include <sys/param.h>
#include <sys/wait.h>
#include <ufs/dir.h>
#include <ufs/dinode.h>
#include <ufs/fs.h>
#include <signal.h>
#include <fcntl.h>
#include <protocols/dumprestore.h>
#include <errno.h>
#ifdef __STDC__
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#endif
#include "dump.h"
#include "pathnames.h"
char (*tblock)[TP_BSIZE]; /* pointer to malloc()ed buffer for tape */
int writesize; /* size of malloc()ed buffer for tape */
long lastspclrec = -1; /* tape block number of last written header */
int trecno = 0; /* next record to write in current block */
extern long blocksperfile; /* number of blocks per output file */
long blocksthisvol; /* number of blocks on current output file */
extern int ntrec; /* blocking factor on tape */
extern int cartridge;
char *nexttape;
#ifdef RDUMP
extern char *host;
int rmtopen(), rmtwrite();
void rmtclose();
#endif RDUMP
int atomic();
void doslave(), enslave(), flushtape(), killall();
/*
* Concurrent dump mods (Caltech) - disk block reading and tape writing
* are exported to several slave processes. While one slave writes the
* tape, the others read disk blocks; they pass control of the tape in
* a ring via flock(). The parent process traverses the filesystem and
* sends writeheader()'s and lists of daddr's to the slaves via pipes.
*/
struct req { /* instruction packets sent to slaves */
daddr_t dblk;
int count;
} *req;
int reqsiz;
#define SLAVES 3 /* 1 slave writing, 1 reading, 1 for slack */
int slavefd[SLAVES]; /* pipes from master to each slave */
int slavepid[SLAVES]; /* used by killall() */
int rotor; /* next slave to be instructed */
int master; /* pid of master, for sending error signals */
int tenths; /* length of tape used per block written */
int
alloctape()
{
int pgoff = getpagesize() - 1;
writesize = ntrec * TP_BSIZE;
reqsiz = ntrec * sizeof(struct req);
/*
* CDC 92181's and 92185's make 0.8" gaps in 1600-bpi start/stop mode
* (see DEC TU80 User's Guide). The shorter gaps of 6250-bpi require
* repositioning after stopping, i.e, streaming mode, where the gap is
* variable, 0.30" to 0.45". The gap is maximal when the tape stops.
*/
if (blocksperfile == 0)
tenths = writesize / density +
(cartridge ? 16 : density == 625 ? 5 : 8);
/*
* Allocate tape buffer contiguous with the array of instruction
* packets, so flushtape() can write them together with one write().
* Align tape buffer on page boundary to speed up tape write().
*/
req = (struct req *)malloc(reqsiz + writesize + pgoff);
if (req == NULL)
return(0);
tblock = (char (*)[TP_BSIZE]) (((long)&req[ntrec] + pgoff) &~ pgoff);
req = (struct req *)tblock - ntrec;
return(1);
}
void
writerec(dp)
char *dp;
{
req[trecno].dblk = (daddr_t)0;
req[trecno].count = 1;
*(union u_spcl *)(*tblock++) = *(union u_spcl *)dp; /* movc3 */
lastspclrec = spcl.c_tapea;
trecno++;
spcl.c_tapea++;
if (trecno >= ntrec)
flushtape();
}
void
dumpblock(blkno, size)
daddr_t blkno;
int size;
{
int avail, tpblks, dblkno;
dblkno = fsbtodb(sblock, blkno);
tpblks = size >> tp_bshift;
while ((avail = MIN(tpblks, ntrec - trecno)) > 0) {
req[trecno].dblk = dblkno;
req[trecno].count = avail;
trecno += avail;
spcl.c_tapea += avail;
if (trecno >= ntrec)
flushtape();
dblkno += avail << (tp_bshift - dev_bshift);
tpblks -= avail;
}
}
int nogripe = 0;
void
tperror()
{
if (pipeout) {
msg("write error on %s\n", tape);
quit("Cannot recover\n");
/* NOTREACHED */
}
msg("write error %d blocks into volume %d\n", blocksthisvol, tapeno);
broadcast("DUMP WRITE ERROR!\n");
if (!query("Do you want to restart?"))
dumpabort();
msg("Closing this volume. Prepare to restart with new media;\n");
msg("this dump volume will be rewritten.\n");
killall();
nogripe = 1;
close_rewind();
Exit(X_REWRITE);
}
void
sigpipe()
{
quit("Broken pipe\n");
}
void
flushtape()
{
#ifndef __STDC__
int write();
#endif
int siz = (char *)tblock - (char *)req;
if (atomic(write, slavefd[rotor], req, siz) != siz)
quit("error writing command pipe: %s\n", strerror(errno));
if (++rotor >= SLAVES)
rotor = 0;
tblock = (char (*)[TP_BSIZE]) &req[ntrec];
trecno = 0;
asize += tenths;
blockswritten += ntrec;
blocksthisvol += ntrec;
if (!pipeout && (blocksperfile ?
(blocksthisvol >= blocksperfile) : (asize > tsize))) {
close_rewind();
startnewtape();
}
timeest();
}
void
trewind()
{
int f;
if (pipeout)
return;
for (f = 0; f < SLAVES; f++)
close(slavefd[f]);
while (wait((int *)NULL) >= 0) /* wait for any signals from slaves */
/* void */;
msg("Closing %s\n", tape);
#ifdef RDUMP
if (host) {
rmtclose();
while (rmtopen(tape, 0) < 0)
sleep(10);
rmtclose();
return;
}
#endif RDUMP
close(tapefd);
while ((f = open(tape, 0)) < 0)
sleep (10);
close(f);
}
void
close_rewind()
{
trewind();
if (nexttape)
return;
if (!nogripe) {
msg("Change Volumes: Mount volume #%d\n", tapeno+1);
broadcast("CHANGE DUMP VOLUMES!\7\7\n");
}
while (!query("Is the new volume mounted and ready to go?"))
if (query("Do you want to abort?")) {
dumpabort();
/*NOTREACHED*/
}
}
/*
* We implement taking and restoring checkpoints on the tape level.
* When each tape is opened, a new process is created by forking; this
* saves all of the necessary context in the parent. The child
* continues the dump; the parent waits around, saving the context.
* If the child returns X_REWRITE, then it had problems writing that tape;
* this causes the parent to fork again, duplicating the context, and
* everything continues as if nothing had happened.
*/
void
startnewtape()
{
int parentpid;
int childpid;
int status;
int waitpid;
sig_t interrupt;
int blks, i;
char *p;
interrupt = signal(SIGINT, SIG_IGN);
parentpid = getpid();
restore_check_point:
(void)signal(SIGINT, interrupt);
/*
* All signals are inherited...
*/
childpid = fork();
if (childpid < 0) {
msg("Context save fork fails in parent %d\n", parentpid);
Exit(X_ABORT);
}
if (childpid != 0) {
/*
* PARENT:
* save the context by waiting
* until the child doing all of the work returns.
* don't catch the interrupt
*/
signal(SIGINT, SIG_IGN);
#ifdef TDEBUG
msg("Tape: %d; parent process: %d child process %d\n",
tapeno+1, parentpid, childpid);
#endif TDEBUG
while ((waitpid = wait(&status)) != childpid)
msg("Parent %d waiting for child %d has another child %d return\n",
parentpid, childpid, waitpid);
if (status & 0xFF) {
msg("Child %d returns LOB status %o\n",
childpid, status&0xFF);
}
status = (status >> 8) & 0xFF;
#ifdef TDEBUG
switch(status) {
case X_FINOK:
msg("Child %d finishes X_FINOK\n", childpid);
break;
case X_ABORT:
msg("Child %d finishes X_ABORT\n", childpid);
break;
case X_REWRITE:
msg("Child %d finishes X_REWRITE\n", childpid);
break;
default:
msg("Child %d finishes unknown %d\n",
childpid, status);
break;
}
#endif TDEBUG
switch(status) {
case X_FINOK:
Exit(X_FINOK);
case X_ABORT:
Exit(X_ABORT);
case X_REWRITE:
goto restore_check_point;
default:
msg("Bad return code from dump: %d\n", status);
Exit(X_ABORT);
}
/*NOTREACHED*/
} else { /* we are the child; just continue */
#ifdef TDEBUG
sleep(4); /* allow time for parent's message to get out */
msg("Child on Tape %d has parent %d, my pid = %d\n",
tapeno+1, parentpid, getpid());
#endif TDEBUG
/*
* If we have a name like "/dev/rmt0,/dev/rmt1",
* use the name before the comma first, and save
* the remaining names for subsequent volumes.
*/
tapeno++; /* current tape sequence */
if (nexttape || index(tape, ',')) {
if (nexttape && *nexttape)
tape = nexttape;
if (p = index(tape, ',')) {
*p = '\0';
nexttape = p + 1;
} else
nexttape = NULL;
msg("Dumping volume %d on %s\n", tapeno, tape);
}
#ifdef RDUMP
while ((tapefd = (host ? rmtopen(tape, 2) :
pipeout ? 1 : open(tape, O_WRONLY|O_CREAT, 0666))) < 0)
#else RDUMP
while ((tapefd =
pipeout ? 1 : open(tape, O_WRONLY|O_CREAT, 0666)) < 0)
#endif RDUMP
{
msg("Cannot open output \"%s\".\n", tape);
if (!query("Do you want to retry the open?"))
dumpabort();
}
enslave(); /* Share open tape file descriptor with slaves */
asize = 0;
blocksthisvol = 0;
newtape++; /* new tape signal */
blks = 0;
if (spcl.c_type != TS_END)
for (i = 0; i < spcl.c_count; i++)
if (spcl.c_addr[i] != 0)
blks++;
spcl.c_count = blks + 1 - spcl.c_tapea + lastspclrec;
spcl.c_volume++;
spcl.c_type = TS_TAPE;
spcl.c_flags |= DR_NEWHEADER;
writeheader(curino);
spcl.c_flags &=~ DR_NEWHEADER;
if (tapeno > 1)
msg("Volume %d begins with blocks from inode %d\n",
tapeno, curino);
}
}
void
dumpabort()
{
if (master != 0 && master != getpid())
kill(master, SIGTERM); /* Signals master to call dumpabort */
else {
killall();
msg("The ENTIRE dump is aborted.\n");
}
Exit(X_ABORT);
}
void
Exit(status)
int status;
{
#ifdef TDEBUG
msg("pid = %d exits with status %d\n", getpid(), status);
#endif TDEBUG
exit(status);
}
/*
* could use pipe() for this if flock() worked on pipes
*/
void
lockfile(fd)
int fd[2];
{
char tmpname[20];
strcpy(tmpname, _PATH_LOCK);
mktemp(tmpname);
if ((fd[1] = creat(tmpname, 0400)) < 0)
quit("cannot create lockfile %s: %s\n",
tmpname, strerror(errno));
if ((fd[0] = open(tmpname, 0)) < 0)
quit("cannot reopen lockfile %s: %s\n",
tmpname, strerror(errno));
(void) unlink(tmpname);
}
void
enslave()
{
int first[2], prev[2], next[2], cmd[2]; /* file descriptors */
register int i, j;
master = getpid();
signal(SIGTERM, dumpabort); /* Slave sends SIGTERM on dumpabort() */
signal(SIGPIPE, sigpipe);
signal(SIGUSR1, tperror); /* Slave sends SIGUSR1 on tape errors */
lockfile(first);
for (i = 0; i < SLAVES; i++) {
if (i == 0) {
prev[0] = first[1];
prev[1] = first[0];
} else {
prev[0] = next[0];
prev[1] = next[1];
flock(prev[1], LOCK_EX);
}
if (i < SLAVES - 1) {
lockfile(next);
} else {
next[0] = first[0];
next[1] = first[1]; /* Last slave loops back */
}
if (pipe(cmd) < 0 || (slavepid[i] = fork()) < 0)
quit("too many slaves, %d (recompile smaller): %s\n",
i, strerror(errno));
slavefd[i] = cmd[1];
if (slavepid[i] == 0) { /* Slave starts up here */
for (j = 0; j <= i; j++)
close(slavefd[j]);
signal(SIGINT, SIG_IGN); /* Master handles this */
doslave(cmd[0], prev, next);
Exit(X_FINOK);
}
close(cmd[0]);
if (i > 0) {
close(prev[0]);
close(prev[1]);
}
}
close(first[0]);
close(first[1]);
master = 0; rotor = 0;
}
void
killall()
{
register int i;
for (i = 0; i < SLAVES; i++)
if (slavepid[i] > 0)
kill(slavepid[i], SIGKILL);
}
/*
* Synchronization - each process has a lockfile, and shares file
* descriptors to the following process's lockfile. When our write
* completes, we release our lock on the following process's lock-
* file, allowing the following process to lock it and proceed. We
* get the lock back for the next cycle by swapping descriptors.
*/
void
doslave(cmd, prev, next)
register int cmd, prev[2], next[2];
{
register int nread, toggle = 0;
int nwrite;
#ifndef __STDC__
int read();
#endif
/*
* Need our own seek pointer.
*/
close(diskfd);
if ((diskfd = open(disk, O_RDONLY)) < 0)
quit("slave couldn't reopen disk: %s\n", strerror(errno));
/*
* Get list of blocks to dump, read the blocks into tape buffer
*/
while ((nread = atomic(read, cmd, req, reqsiz)) == reqsiz) {
register struct req *p = req;
for (trecno = 0; trecno < ntrec; trecno += p->count, p += p->count) {
if (p->dblk) {
bread(p->dblk, tblock[trecno],
p->count * TP_BSIZE);
} else {
if (p->count != 1 || atomic(read, cmd,
tblock[trecno], TP_BSIZE) != TP_BSIZE)
quit("master/slave protocol botched.\n");
}
}
flock(prev[toggle], LOCK_EX); /* Wait our turn */
#ifdef RDUMP
if ((nwrite = (host ? rmtwrite(tblock[0], writesize)
: write(tapefd, tblock[0], writesize))) != writesize) {
#else RDUMP
if ((nwrite = write(tapefd, tblock[0], writesize))
!= writesize) {
#endif RDUMP
if (nwrite == -1)
perror("write");
else
msg("short write: got %d instead of %d\n",
nwrite, writesize);
kill(master, SIGUSR1);
for (;;)
sigpause(0);
}
toggle ^= 1;
flock(next[toggle], LOCK_UN); /* Next slave's turn */
} /* Also jolts him awake */
if (nread != 0)
quit("error reading command pipe: %s\n", strerror(errno));
}
/*
* Since a read from a pipe may not return all we asked for,
* or a write may not write all we ask if we get a signal,
* loop until the count is satisfied (or error).
*/
int
atomic(func, fd, buf, count)
int (*func)(), fd, count;
char *buf;
{
int got, need = count;
while ((got = (*func)(fd, buf, need)) > 0 && (need -= got) > 0)
buf += got;
return (got < 0 ? got : count - need);
}