dirs.c

早期freebsd实现

					   "reclen name too big (%d > %d) ",
					   dp->d_namlen, NAME_MAX);
				vprintf(stdout, "\n");
				loc += i;
				continue;
			}
			loc += dp->d_reclen;
			if (dp->d_ino != 0) {
				putent(dp);
			}
		}
	}
}

/*
 * These variables are "local" to the following two functions.
 */
char dirbuf[DIRBLKSIZ];
long dirloc = 0;
long prev = 0;

/*
 * add a new directory entry to a file.
 */
static void
putent(dp)
	struct direct *dp;
{
	dp->d_reclen = DIRSIZ(0, dp);
	if (dirloc + dp->d_reclen > DIRBLKSIZ) {
		((struct direct *)(dirbuf + prev))->d_reclen =
		    DIRBLKSIZ - prev;
		(void) fwrite(dirbuf, 1, DIRBLKSIZ, df);
		dirloc = 0;
	}
	bcopy((char *)dp, dirbuf + dirloc, (long)dp->d_reclen);
	prev = dirloc;
	dirloc += dp->d_reclen;
}

/*
 * flush out a directory that is finished.
 */
static void
flushent()
{
	((struct direct *)(dirbuf + prev))->d_reclen = DIRBLKSIZ - prev;
	(void) fwrite(dirbuf, (int)dirloc, 1, df);
	seekpt = ftell(df);
	dirloc = 0;
}

static void
dcvt(odp, ndp)
	register struct odirect *odp;
	register struct direct *ndp;
{

	bzero((char *)ndp, (long)(sizeof *ndp));
	ndp->d_ino =  odp->d_ino;
	ndp->d_type = DT_UNKNOWN;
	(void) strncpy(ndp->d_name, odp->d_name, ODIRSIZ);
	ndp->d_namlen = strlen(ndp->d_name);
	ndp->d_reclen = DIRSIZ(0, ndp);
}

/*
 * Seek to an entry in a directory.
 * Only values returned by rst_telldir should be passed to rst_seekdir.
 * This routine handles many directories in a single file.
 * It takes the base of the directory in the file, plus
 * the desired seek offset into it.
 */
static void
rst_seekdir(dirp, loc, base)
	register RST_DIR *dirp;
	long loc, base;
{

	if (loc == rst_telldir(dirp))
		return;
	loc -= base;
	if (loc < 0)
		fprintf(stderr, "bad seek pointer to rst_seekdir %d\n", loc);
	(void) lseek(dirp->dd_fd, base + (loc & ~(DIRBLKSIZ - 1)), SEEK_SET);
	dirp->dd_loc = loc & (DIRBLKSIZ - 1);
	if (dirp->dd_loc != 0)
		dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf, DIRBLKSIZ);
}

/*
 * get next entry in a directory.
 */
struct direct *
rst_readdir(dirp)
	register RST_DIR *dirp;
{
	register struct direct *dp;

	for (;;) {
		if (dirp->dd_loc == 0) {
			dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf, 
			    DIRBLKSIZ);
			if (dirp->dd_size <= 0) {
				dprintf(stderr, "error reading directory\n");
				return (NULL);
			}
		}
		if (dirp->dd_loc >= dirp->dd_size) {
			dirp->dd_loc = 0;
			continue;
		}
		dp = (struct direct *)(dirp->dd_buf + dirp->dd_loc);
		if (dp->d_reclen == 0 ||
		    dp->d_reclen > DIRBLKSIZ + 1 - dirp->dd_loc) {
			dprintf(stderr, "corrupted directory: bad reclen %d\n",
				dp->d_reclen);
			return (NULL);
		}
		dirp->dd_loc += dp->d_reclen;
		if (dp->d_ino == 0 && strcmp(dp->d_name, "/") != 0)
			continue;
		if (dp->d_ino >= maxino) {
			dprintf(stderr, "corrupted directory: bad inum %d\n",
				dp->d_ino);
			continue;
		}
		return (dp);
	}
}

/*
 * Simulate the opening of a directory
 */
RST_DIR *
rst_opendir(name)
	const char *name;
{
	struct inotab *itp;
	RST_DIR *dirp;
	ino_t ino;

	if ((ino = dirlookup(name)) > 0 &&
	    (itp = inotablookup(ino)) != NULL) {
		dirp = opendirfile(dirfile);
		rst_seekdir(dirp, itp->t_seekpt, itp->t_seekpt);
		return (dirp);
	}
	return (NULL);
}

/*
 * In our case, there is nothing to do when closing a directory.
 */
void
rst_closedir(dirp)
	RST_DIR *dirp;
{

	(void)close(dirp->dd_fd);
	free(dirp);
	return;
}

/*
 * Simulate finding the current offset in the directory.
 */
static long
rst_telldir(dirp)
	RST_DIR *dirp;
{
	return ((long)lseek(dirp->dd_fd,
	    (off_t)0, SEEK_CUR) - dirp->dd_size + dirp->dd_loc);
}

/*
 * Open a directory file.
 */
static RST_DIR *
opendirfile(name)
	const char *name;
{
	register RST_DIR *dirp;
	register int fd;

	if ((fd = open(name, O_RDONLY)) == -1)
		return (NULL);
	if ((dirp = malloc(sizeof(RST_DIR))) == NULL) {
		(void)close(fd);
		return (NULL);
	}
	dirp->dd_fd = fd;
	dirp->dd_loc = 0;
	return (dirp);
}

/*
 * Set the mode, owner, and times for all new or changed directories
 */
void
setdirmodes(flags)
	int flags;
{
	FILE *mf;
	struct modeinfo node;
	struct entry *ep;
	char *cp;
	
	vprintf(stdout, "Set directory mode, owner, and times.\n");
	(void) sprintf(modefile, "%s/rstmode%d", _PATH_TMP, dumpdate);
	mf = fopen(modefile, "r");
	if (mf == NULL) {
		fprintf(stderr, "fopen: %s\n", strerror(errno));
		fprintf(stderr, "cannot open mode file %s\n", modefile);
		fprintf(stderr, "directory mode, owner, and times not set\n");
		return;
	}
	clearerr(mf);
	for (;;) {
		(void) fread((char *)&node, 1, sizeof(struct modeinfo), mf);
		if (feof(mf))
			break;
		ep = lookupino(node.ino);
		if (command == 'i' || command == 'x') {
			if (ep == NULL)
				continue;
			if ((flags & FORCE) == 0 && ep->e_flags & EXISTED) {
				ep->e_flags &= ~NEW;
				continue;
			}
			if (node.ino == ROOTINO &&
		   	    reply("set owner/mode for '.'") == FAIL)
				continue;
		}
		if (ep == NULL) {
			panic("cannot find directory inode %d\n", node.ino);
		} else {
			cp = myname(ep);
			(void) chown(cp, node.uid, node.gid);
			(void) chmod(cp, node.mode);
			utimes(cp, node.timep);
			ep->e_flags &= ~NEW;
		}
	}
	if (ferror(mf))
		panic("error setting directory modes\n");
	(void) fclose(mf);
}

/*
 * Generate a literal copy of a directory.
 */
int
genliteraldir(name, ino)
	char *name;
	ino_t ino;
{
	register struct inotab *itp;
	int ofile, dp, i, size;
	char buf[BUFSIZ];

	itp = inotablookup(ino);
	if (itp == NULL)
		panic("Cannot find directory inode %d named %s\n", ino, name);
	if ((ofile = creat(name, 0666)) < 0) {
		fprintf(stderr, "%s: ", name);
		(void) fflush(stderr);
		fprintf(stderr, "cannot create file: %s\n", strerror(errno));
		return (FAIL);
	}
	rst_seekdir(dirp, itp->t_seekpt, itp->t_seekpt);
	dp = dup(dirp->dd_fd);
	for (i = itp->t_size; i > 0; i -= BUFSIZ) {
		size = i < BUFSIZ ? i : BUFSIZ;
		if (read(dp, buf, (int) size) == -1) {
			fprintf(stderr,
				"write error extracting inode %d, name %s\n",
				curfile.ino, curfile.name);
			fprintf(stderr, "read: %s\n", strerror(errno));
			done(1);
		}
		if (!Nflag && write(ofile, buf, (int) size) == -1) {
			fprintf(stderr,
				"write error extracting inode %d, name %s\n",
				curfile.ino, curfile.name);
			fprintf(stderr, "write: %s\n", strerror(errno));
			done(1);
		}
	}
	(void) close(dp);
	(void) close(ofile);
	return (GOOD);
}

/*
 * Determine the type of an inode
 */
int
inodetype(ino)
	ino_t ino;
{
	struct inotab *itp;

	itp = inotablookup(ino);
	if (itp == NULL)
		return (LEAF);
	return (NODE);
}

/*
 * Allocate and initialize a directory inode entry.
 * If requested, save its pertinent mode, owner, and time info.
 */
static struct inotab *
allocinotab(ino, dip, seekpt)
	ino_t ino;
	struct dinode *dip;
	long seekpt;
{
	register struct inotab	*itp;
	struct modeinfo node;

	itp = calloc(1, sizeof(struct inotab));
	if (itp == NULL)
		panic("no memory directory table\n");
	itp->t_next = inotab[INOHASH(ino)];
	inotab[INOHASH(ino)] = itp;
	itp->t_ino = ino;
	itp->t_seekpt = seekpt;
	if (mf == NULL)
		return (itp);
	node.ino = ino;
	node.timep[0].tv_sec = dip->di_atime.ts_sec;
	node.timep[0].tv_usec = dip->di_atime.ts_nsec / 1000;
	node.timep[1].tv_sec = dip->di_mtime.ts_sec;
	node.timep[1].tv_usec = dip->di_mtime.ts_nsec / 1000;
	node.mode = dip->di_mode;
	node.uid = dip->di_uid;
	node.gid = dip->di_gid;
	(void) fwrite((char *)&node, 1, sizeof(struct modeinfo), mf);
	return (itp);
}

/*
 * Look up an inode in the table of directories
 */
static struct inotab *
inotablookup(ino)
	ino_t	ino;
{
	register struct inotab *itp;

	for (itp = inotab[INOHASH(ino)]; itp != NULL; itp = itp->t_next)
		if (itp->t_ino == ino)
			return (itp);
	return (NULL);
}

/*
 * Clean up and exit
 */
__dead void
done(exitcode)
	int exitcode;
{

	closemt();
	if (modefile[0] != '#')
		(void) unlink(modefile);
	if (dirfile[0] != '#')
		(void) unlink(dirfile);
	exit(exitcode);
}