NetBSD/sbin/dump/traverse.c
hannken 8c21bc6224 Add ffs internal snapshots. Written by Marshall Kirk McKusick for FreeBSD.
- Not enabled by default. Needs kernel option FFS_SNAPSHOT.
- Change parameters of ffs_blkfree.
- Let the copy-on-write functions return an error so spec_strategy
    may fail if the copy-on-write fails.
- Change genfs_*lock*() to use vp->v_vnlock instead of &vp->v_lock.
- Add flag B_METAONLY to VOP_BALLOC to return indirect block buffer.
- Add a function ffs_checkfreefile needed for snapshot creation.
- Add special handling of snapshot files:
    Snapshots may not be opened for writing and the attributes are read-only.
    Use the mtime as the time this snapshot was taken.
    Deny mtime updates for snapshot files.
- Add function transferlockers to transfer any waiting processes from
  one lock to another.
- Add vfsop VFS_SNAPSHOT to take a snapshot and make it accessible through
  a vnode.
- Add snapshot support to ls, fsck_ffs and dump.

Welcome to 2.0F.

Approved by: Jason R. Thorpe <thorpej@netbsd.org>
2004-05-25 14:54:55 +00:00

746 lines
19 KiB
C

/* $NetBSD: traverse.c,v 1.44 2004/05/25 14:54:56 hannken Exp $ */
/*-
* Copyright (c) 1980, 1988, 1991, 1993
* 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. 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)traverse.c 8.7 (Berkeley) 6/15/95";
#else
__RCSID("$NetBSD: traverse.c,v 1.44 2004/05/25 14:54:56 hannken Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <ufs/ufs/dir.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <protocols/dumprestore.h>
#include <ctype.h>
#include <errno.h>
#include <fts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dump.h"
#define HASDUMPEDFILE 0x1
#define HASSUBDIRS 0x2
static int dirindir(ino_t, daddr_t, int, off_t *, u_int64_t *, int);
static void dmpindir(ino_t, daddr_t, int, off_t *);
static int searchdir(ino_t, daddr_t, long, off_t, u_int64_t *, int);
/*
* This is an estimation of the number of TP_BSIZE blocks in the file.
* It estimates the number of blocks in files with holes by assuming
* that all of the blocks accounted for by di_blocks are data blocks
* (when some of the blocks are usually used for indirect pointers);
* hence the estimate may be high.
*/
int64_t
blockest(union dinode *dp)
{
int64_t blkest, sizeest;
/*
* dp->di_size is the size of the file in bytes.
* dp->di_blocks stores the number of sectors actually in the file.
* If there are more sectors than the size would indicate, this just
* means that there are indirect blocks in the file or unused
* sectors in the last file block; we can safely ignore these
* (blkest = sizeest below).
* If the file is bigger than the number of sectors would indicate,
* then the file has holes in it. In this case we must use the
* block count to estimate the number of data blocks used, but
* we use the actual size for estimating the number of indirect
* dump blocks (sizeest vs. blkest in the indirect block
* calculation).
*/
if (DIP(dp, flags) & SF_SNAPSHOT)
return (1);
blkest = howmany(ufs_fragroundup(ufsib,
dbtob((u_int64_t)DIP(dp, blocks))), TP_BSIZE);
sizeest = howmany(ufs_fragroundup(ufsib, DIP(dp, size)), TP_BSIZE);
if (blkest > sizeest)
blkest = sizeest;
if (DIP(dp, size) > ufsib->ufs_bsize * NDADDR) {
/* calculate the number of indirect blocks on the dump tape */
blkest +=
howmany(sizeest - NDADDR * ufsib->ufs_bsize / TP_BSIZE,
TP_NINDIR);
}
return (blkest + 1);
}
/* Auxiliary macro to pick up files changed since previous dump. */
#define CHANGEDSINCE(dp, t) \
(DIP((dp), mtime) >= (t) || DIP((dp), ctime) >= (t))
/* The WANTTODUMP macro decides whether a file should be dumped. */
#ifdef UF_NODUMP
#define WANTTODUMP(dp) \
(CHANGEDSINCE(dp, iswap64(spcl.c_ddate)) && \
(nonodump || (DIP((dp), flags) & UF_NODUMP) != UF_NODUMP))
#else
#define WANTTODUMP(dp) CHANGEDSINCE(dp, iswap64(spcl.c_ddate))
#endif
/*
* Determine if given inode should be dumped
*/
void
mapfileino(ino_t ino, u_int64_t *tape_size, int *dirskipped)
{
int mode;
union dinode *dp;
/*
* Skip inode if we've already marked it for dumping
*/
if (TSTINO(ino, usedinomap))
return;
dp = getino(ino);
if ((mode = (DIP(dp, mode) & IFMT)) == 0)
return;
/*
* Put all dirs in dumpdirmap, inodes that are to be dumped in the
* used map. All inode but dirs who have the nodump attribute go
* to the usedinomap.
*/
SETINO(ino, usedinomap);
if (mode == IFDIR)
SETINO(ino, dumpdirmap);
if (WANTTODUMP(dp)) {
SETINO(ino, dumpinomap);
if (mode != IFREG && mode != IFDIR && mode != IFLNK)
*tape_size += 1;
else
*tape_size += blockest(dp);
return;
}
if (mode == IFDIR) {
#ifdef UF_NODUMP
if (!nonodump && (DIP(dp, flags) & UF_NODUMP))
CLRINO(ino, usedinomap);
#endif
*dirskipped = 1;
}
}
/*
* Dump pass 1.
*
* Walk the inode list for a file system to find all allocated inodes
* that have been modified since the previous dump time. Also, find all
* the directories in the file system.
* disk may be NULL if dirv is NULL.
*/
int
mapfiles(ino_t maxino, u_int64_t *tape_size, char *diskname, char * const *dirv)
{
int anydirskipped = 0;
if (dirv != NULL) {
char curdir[MAXPATHLEN];
FTS *dirh;
FTSENT *entry;
int d;
if (getcwd(curdir, sizeof(curdir)) == NULL) {
msg("Can't determine cwd: %s\n", strerror(errno));
dumpabort(0);
}
if ((dirh = fts_open(dirv, FTS_PHYSICAL|FTS_SEEDOT|FTS_XDEV,
NULL)) == NULL) {
msg("fts_open failed: %s\n", strerror(errno));
dumpabort(0);
}
while ((entry = fts_read(dirh)) != NULL) {
switch (entry->fts_info) {
case FTS_DNR: /* an error */
case FTS_ERR:
case FTS_NS:
msg("Can't fts_read %s: %s\n", entry->fts_path,
strerror(errno));
case FTS_DP: /* already seen dir */
continue;
}
mapfileino(entry->fts_statp->st_ino, tape_size,
&anydirskipped);
}
(void)fts_close(dirh);
/*
* Add any parent directories
*/
for (d = 0 ; dirv[d] != NULL ; d++) {
char path[MAXPATHLEN];
if (dirv[d][0] != '/')
(void)snprintf(path, sizeof(path), "%s/%s",
curdir, dirv[d]);
else
(void)snprintf(path, sizeof(path), "%s",
dirv[d]);
while (strcmp(path, diskname) != 0) {
char *p;
struct stat sb;
if (*path == '\0')
break;
if ((p = strrchr(path, '/')) == NULL)
break;
if (p == path)
break;
*p = '\0';
if (stat(path, &sb) == -1) {
msg("Can't stat %s: %s\n", path,
strerror(errno));
break;
}
mapfileino(sb.st_ino, tape_size, &anydirskipped);
}
}
/*
* Ensure that the root inode actually appears in the
* file list for a subdir
*/
mapfileino(ROOTINO, tape_size, &anydirskipped);
} else {
fs_mapinodes(maxino, tape_size, &anydirskipped);
}
/*
* Restore gets very upset if the root is not dumped,
* so ensure that it always is dumped.
*/
SETINO(ROOTINO, dumpinomap);
return (anydirskipped);
}
/*
* Dump pass 2.
*
* Scan each directory on the file system to see if it has any modified
* files in it. If it does, and has not already been added to the dump
* list (because it was itself modified), then add it. If a directory
* has not been modified itself, contains no modified files and has no
* subdirectories, then it can be deleted from the dump list and from
* the list of directories. By deleting it from the list of directories,
* its parent may now qualify for the same treatment on this or a later
* pass using this algorithm.
*/
int
mapdirs(ino_t maxino, u_int64_t *tape_size)
{
union dinode *dp, di;
int i, isdir, nodump;
char *map;
ino_t ino;
off_t filesize;
int ret, change = 0;
daddr_t blk;
isdir = 0; /* XXX just to get gcc to shut up */
for (map = dumpdirmap, ino = 1; ino < maxino; ino++) {
if (((ino - 1) % NBBY) == 0) /* map is offset by 1 */
isdir = *map++;
else
isdir >>= 1;
/*
* If dir has been removed from the used map, it's either
* because it had the nodump flag, or it inherited it from
* its parent. A directory can't be in dumpinomap if
* not in usedinomap, but we have to go throuh it anyway
* to propagate the nodump attribute.
*/
nodump = (TSTINO(ino, usedinomap) == 0);
if ((isdir & 1) == 0 ||
(TSTINO(ino, dumpinomap) && nodump == 0))
continue;
dp = getino(ino);
/*
* inode buf may be changed in searchdir().
*/
if (is_ufs2)
di.dp2 = dp->dp2;
else
di.dp1 = dp->dp1;
filesize = DIP(&di, size);
for (ret = 0, i = 0; filesize > 0 && i < NDADDR; i++) {
if (is_ufs2)
blk = iswap64(di.dp2.di_db[i]);
else
blk = iswap32(di.dp1.di_db[i]);
if (blk != 0)
ret |= searchdir(ino, blk,
(long)ufs_dblksize(ufsib, &di, i),
filesize, tape_size, nodump);
if (ret & HASDUMPEDFILE)
filesize = 0;
else
filesize -= ufsib->ufs_bsize;
}
for (i = 0; filesize > 0 && i < NIADDR; i++) {
if (is_ufs2)
blk = iswap64(di.dp2.di_ib[i]);
else
blk = iswap32(di.dp1.di_ib[i]);
if (blk == 0)
continue;
ret |= dirindir(ino, blk, i, &filesize,
tape_size, nodump);
}
if (ret & HASDUMPEDFILE) {
SETINO(ino, dumpinomap);
*tape_size += blockest(&di);
change = 1;
continue;
}
if (nodump) {
if (ret & HASSUBDIRS)
change = 1; /* subdirs have inherited nodump */
CLRINO(ino, dumpdirmap);
} else if ((ret & HASSUBDIRS) == 0) {
if (!TSTINO(ino, dumpinomap)) {
CLRINO(ino, dumpdirmap);
change = 1;
}
}
}
return (change);
}
/*
* Read indirect blocks, and pass the data blocks to be searched
* as directories. Quit as soon as any entry is found that will
* require the directory to be dumped.
*/
static int
dirindir(ino_t ino, daddr_t blkno, int ind_level, off_t *filesize,
u_int64_t *tape_size, int nodump)
{
int ret = 0;
int i;
union {
int64_t i64[MAXBSIZE / sizeof (int64_t)];
int32_t i32[MAXBSIZE / sizeof (int32_t)];
} idblk;
bread(fsatoda(ufsib, blkno), (char *)&idblk, (int)ufsib->ufs_bsize);
if (ind_level <= 0) {
for (i = 0; *filesize > 0 && i < ufsib->ufs_nindir; i++) {
if (is_ufs2)
blkno = iswap64(idblk.i64[i]);
else
blkno = iswap32(idblk.i32[i]);
if (blkno != 0)
ret |= searchdir(ino, blkno,
ufsib->ufs_bsize, *filesize,
tape_size, nodump);
if (ret & HASDUMPEDFILE)
*filesize = 0;
else
*filesize -= ufsib->ufs_bsize;
}
return (ret);
}
ind_level--;
for (i = 0; *filesize > 0 && i < ufsib->ufs_nindir; i++) {
if (is_ufs2)
blkno = iswap64(idblk.i64[i]);
else
blkno = iswap32(idblk.i32[i]);
if (blkno != 0)
ret |= dirindir(ino, blkno, ind_level, filesize,
tape_size, nodump);
}
return (ret);
}
/*
* Scan a disk block containing directory information looking to see if
* any of the entries are on the dump list and to see if the directory
* contains any subdirectories.
*/
static int
searchdir(ino_t dino, daddr_t blkno, long size, off_t filesize,
u_int64_t *tape_size, int nodump)
{
struct direct *dp;
union dinode *ip;
long loc, ret = 0;
char *dblk;
ino_t ino;
dblk = malloc(size);
if (dblk == NULL)
quit("searchdir: cannot allocate directory memory.\n");
bread(fsatoda(ufsib, blkno), dblk, (int)size);
if (filesize < size)
size = filesize;
for (loc = 0; loc < size; ) {
dp = (struct direct *)(dblk + loc);
if (dp->d_reclen == 0) {
msg("corrupted directory, inumber %d\n", dino);
break;
}
loc += iswap16(dp->d_reclen);
if (dp->d_ino == 0)
continue;
if (dp->d_name[0] == '.') {
if (dp->d_name[1] == '\0')
continue;
if (dp->d_name[1] == '.' && dp->d_name[2] == '\0')
continue;
}
ino = iswap32(dp->d_ino);
if (nodump) {
ip = getino(ino);
if (TSTINO(ino, dumpinomap)) {
CLRINO(ino, dumpinomap);
*tape_size -= blockest(ip);
}
/*
* Add back to dumpdirmap and remove from usedinomap
* to propagate nodump.
*/
if ((DIP(ip, mode) & IFMT) == IFDIR) {
SETINO(ino, dumpdirmap);
CLRINO(ino, usedinomap);
ret |= HASSUBDIRS;
}
} else {
if (TSTINO(ino, dumpinomap)) {
ret |= HASDUMPEDFILE;
if (ret & HASSUBDIRS)
break;
}
if (TSTINO(ino, dumpdirmap)) {
ret |= HASSUBDIRS;
if (ret & HASDUMPEDFILE)
break;
}
}
}
free(dblk);
return (ret);
}
/*
* Dump passes 3 and 4.
*
* Dump the contents of an inode to tape.
*/
void
dumpino(union dinode *dp, ino_t ino)
{
int ind_level, cnt;
off_t size;
char buf[TP_BSIZE];
daddr_t blk;
void *shortlink;
if (newtape) {
newtape = 0;
dumpmap(dumpinomap, TS_BITS, ino);
}
CLRINO(ino, dumpinomap);
/*
* Zero out the size of a snapshot so that it will be dumped
* as a zero length file.
*/
if (DIP(dp, flags) & SF_SNAPSHOT) {
DIP(dp, size) = 0;
DIP(dp, flags) &= ~SF_SNAPSHOT;
}
if (!is_ufs2) {
if (needswap)
ffs_dinode1_swap(&dp->dp1, &spcl.c_dinode);
else
spcl.c_dinode = dp->dp1;
} else {
if (needswap)
ffs_dinode2_swap(&dp->dp2, &dp->dp2);
spcl.c_mode = dp->dp2.di_mode;
spcl.c_size = dp->dp2.di_size;
spcl.c_atime = dp->dp2.di_atime;
spcl.c_atimensec = dp->dp2.di_atimensec;
spcl.c_mtime = dp->dp2.di_mtime;
spcl.c_mtimensec = dp->dp2.di_mtimensec;
spcl.c_birthtime = dp->dp2.di_birthtime;
spcl.c_birthtimensec = dp->dp2.di_birthnsec;
spcl.c_rdev = dp->dp2.di_rdev;
spcl.c_file_flags = dp->dp2.di_flags;
spcl.c_uid = dp->dp2.di_uid;
spcl.c_gid = dp->dp2.di_gid;
}
spcl.c_type = iswap32(TS_INODE);
spcl.c_count = 0;
switch (DIP(dp, mode) & IFMT) {
case 0:
/*
* Freed inode.
*/
return;
case IFLNK:
/*
* Check for short symbolic link.
*/
if (DIP(dp, size) > 0 &&
#ifdef FS_44INODEFMT
(DIP(dp, size) < ufsib->ufs_maxsymlinklen ||
(ufsib->ufs_maxsymlinklen == 0 && DIP(dp, blocks) == 0))
#else
DIP(dp, blocks) == 0
#endif
) {
spcl.c_addr[0] = 1;
spcl.c_count = iswap32(1);
writeheader(ino);
if (is_ufs2)
shortlink = dp->dp2.di_db;
else
shortlink = dp->dp1.di_db;
memmove(buf, shortlink, DIP(dp, size));
buf[DIP(dp, size)] = '\0';
writerec(buf, 0);
return;
}
/* fall through */
case IFDIR:
case IFREG:
if (DIP(dp, size) > 0)
break;
/* fall through */
case IFIFO:
case IFSOCK:
case IFCHR:
case IFBLK:
writeheader(ino);
return;
default:
msg("Warning: undefined file type 0%o\n", DIP(dp, mode) & IFMT);
return;
}
if (DIP(dp, size) > NDADDR * ufsib->ufs_bsize)
cnt = NDADDR * ufsib->ufs_frag;
else
cnt = howmany(DIP(dp, size), ufsib->ufs_fsize);
if (is_ufs2)
blksout64(&dp->dp2.di_db[0], cnt, ino);
else
blksout32(&dp->dp1.di_db[0], cnt, ino);
if ((size = DIP(dp, size) - NDADDR * ufsib->ufs_bsize) <= 0)
return;
for (ind_level = 0; ind_level < NIADDR; ind_level++) {
if (is_ufs2)
blk = iswap64(dp->dp2.di_ib[ind_level]);
else
blk = iswap32(dp->dp1.di_ib[ind_level]);
dmpindir(ino, blk, ind_level, &size);
if (size <= 0)
return;
}
}
/*
* Read indirect blocks, and pass the data blocks to be dumped.
*/
static void
dmpindir(ino_t ino, daddr_t blk, int ind_level, off_t *size)
{
int i, cnt;
union {
int32_t i32[MAXBSIZE / sizeof (int32_t)];
int64_t i64[MAXBSIZE / sizeof (int64_t)];
} idblk;
daddr_t iblk;
if (blk != 0)
bread(fsatoda(ufsib, blk), (char *)&idblk,
(int) ufsib->ufs_bsize);
else
memset(&idblk, 0, (int)ufsib->ufs_bsize);
if (ind_level <= 0) {
if (*size < ufsib->ufs_nindir * ufsib->ufs_bsize)
cnt = howmany(*size, ufsib->ufs_fsize);
else
cnt = ufsib->ufs_nindir * ufsib->ufs_frag;
*size -= ufsib->ufs_nindir * ufsib->ufs_bsize;
if (is_ufs2)
blksout64(&idblk.i64[0], cnt, ino);
else
blksout32(&idblk.i32[0], cnt, ino);
return;
}
ind_level--;
for (i = 0; i < ufsib->ufs_nindir; i++) {
if (is_ufs2)
iblk = iswap64(idblk.i64[i]);
else
iblk = iswap32(idblk.i32[i]);
dmpindir(ino, iblk, ind_level, size);
if (*size <= 0)
return;
}
}
/*
* Collect up the data into tape record sized buffers and output them.
*/
void
blksout32(int32_t *blkp, int frags, ino_t ino)
{
int32_t *bp;
int i, j, count, blks, tbperdb;
blks = howmany(frags * ufsib->ufs_fsize, TP_BSIZE);
tbperdb = ufsib->ufs_bsize >> tp_bshift;
for (i = 0; i < blks; i += TP_NINDIR) {
if (i + TP_NINDIR > blks)
count = blks;
else
count = i + TP_NINDIR;
for (j = i; j < count; j++)
if (blkp[j / tbperdb] != 0)
spcl.c_addr[j - i] = 1;
else
spcl.c_addr[j - i] = 0;
spcl.c_count = iswap32(count - i);
writeheader(ino);
bp = &blkp[i / tbperdb];
for (j = i; j < count; j += tbperdb, bp++)
if (*bp != 0) {
if (j + tbperdb <= count)
dumpblock(iswap32(*bp), (int)ufsib->ufs_bsize);
else
dumpblock(iswap32(*bp), (count - j) * TP_BSIZE);
}
spcl.c_type = iswap32(TS_ADDR);
}
}
void
blksout64(int64_t *blkp, int frags, ino_t ino)
{
int64_t *bp;
int i, j, count, blks, tbperdb;
blks = howmany(frags * ufsib->ufs_fsize, TP_BSIZE);
tbperdb = ufsib->ufs_bsize >> tp_bshift;
for (i = 0; i < blks; i += TP_NINDIR) {
if (i + TP_NINDIR > blks)
count = blks;
else
count = i + TP_NINDIR;
for (j = i; j < count; j++)
if (blkp[j / tbperdb] != 0)
spcl.c_addr[j - i] = 1;
else
spcl.c_addr[j - i] = 0;
spcl.c_count = iswap32(count - i);
writeheader(ino);
bp = &blkp[i / tbperdb];
for (j = i; j < count; j += tbperdb, bp++)
if (*bp != 0) {
if (j + tbperdb <= count)
dumpblock(iswap64(*bp), (int)ufsib->ufs_bsize);
else
dumpblock(iswap64(*bp), (count - j) * TP_BSIZE);
}
spcl.c_type = iswap32(TS_ADDR);
}
}
/*
* Dump a map to the tape.
*/
void
dumpmap(char *map, int type, ino_t ino)
{
int i;
char *cp;
spcl.c_type = iswap32(type);
spcl.c_count = iswap32(howmany(mapsize * sizeof(char), TP_BSIZE));
writeheader(ino);
for (i = 0, cp = map; i < iswap32(spcl.c_count); i++, cp += TP_BSIZE)
writerec(cp, 0);
}
/*
* Write a header record to the dump tape.
*/
void
writeheader(ino_t ino)
{
int32_t sum, cnt, *lp;
spcl.c_inumber = iswap32(ino);
if (is_ufs2)
spcl.c_magic = iswap32(FS_UFS2_MAGIC);
else {
spcl.c_magic = iswap32(NFS_MAGIC);
spcl.c_old_date = iswap32(iswap64(spcl.c_date));
spcl.c_old_ddate = iswap32(iswap64(spcl.c_ddate));
spcl.c_old_tapea = iswap32(iswap64(spcl.c_tapea));
spcl.c_old_firstrec = iswap32(iswap64(spcl.c_firstrec));
}
spcl.c_checksum = 0;
lp = (int32_t *)&spcl;
sum = 0;
cnt = sizeof(union u_spcl) / (4 * sizeof(int32_t));
while (--cnt >= 0) {
sum += iswap32(*lp++);
sum += iswap32(*lp++);
sum += iswap32(*lp++);
sum += iswap32(*lp++);
}
spcl.c_checksum = iswap32(CHECKSUM - sum);
writerec((char *)&spcl, 1);
}