multi.c

创建一个符合iso-9660标准的iso文件系统

		pnt[i]->next = this_dir->contents;
		pnt[i]->filedir = this_dir;
		this_dir->contents = pnt[i];
		pnt[i] = NULL;
	}


	/*
	 * If we don't have an entry for the translation table, then don't
	 * bother trying to copy the starting extent over. Note that it is
	 * possible that if we are copying the entire directory, the entry for
	 * the translation table will have already been inserted into the
	 * linked list and removed from the old entries list, in which case we
	 * want to leave the extent number as it was before.
	 */
	if (ttbl_extent == 0) {
		return;
	}
	/*
	 * Finally, check the directory we are creating to see whether there
	 * are any new entries in it.  If there are not, we can reuse the same
	 * translation table.
	 */
	for (s_entry = this_dir->contents; s_entry; s_entry = s_entry->next) {
		/*
		 * Don't care about '.' or '..'.  They are never in the table
		 * anyways.
		 */
		if (s_entry->name != NULL && strcmp(s_entry->name, ".") == 0) {
			continue;
		}
		if (s_entry->name != NULL && strcmp(s_entry->name, "..") == 0) {
			continue;
		}
/*		if( strcmp(s_entry->name, "<translation table>") == 0)*/
		if (strcmp(s_entry->name, trans_tbl) == 0) {
			continue;
		}
		if ((s_entry->de_flags & SAFE_TO_REUSE_TABLE_ENTRY) == 0) {
			return;
		}
	}

	/*
	 * Locate the translation table, and re-use the same extent. It isn't
	 * clear that there should ever be one in there already so for now we
	 * try and muddle through the best we can.
	 */
	for (s_entry = this_dir->contents; s_entry; s_entry = s_entry->next) {
/*      	if( strcmp(s_entry->name, "<translation table>") == 0)*/
		if (strcmp(s_entry->name, trans_tbl) == 0) {
			fprintf(stderr, "Should never get here\n");
			set_733(s_entry->isorec.extent, ttbl_extent);
			return;
		}
	}

	pnt[ttbl_index]->next = this_dir->contents;
	pnt[ttbl_index]->filedir = this_dir;
	this_dir->contents = pnt[ttbl_index];
	pnt[ttbl_index] = NULL;
}


/*
 * Here we have a case of a directory that has completely disappeared from
 * the face of the earth on the tree we are mastering from.  Go through and
 * merge it into the tree, as well as everything beneath it.
 *
 * Note that if a directory has been moved for some reason, this will
 * incorrectly pick it up and attempt to merge it back into the old
 * location.  FIXME(eric).
 */
static int
merge_old_directory_into_tree(dpnt, parent)
	struct directory_entry	*dpnt;
	struct directory *parent;
{
	struct directory_entry **contents = NULL;
	int		i;
	int		n_orig;
	struct directory *this_dir,
			*next_brother;
	char		whole_path[1024];

	this_dir = (struct directory *) e_malloc(sizeof(struct directory));
	memset(this_dir, 0, sizeof(struct directory));
	this_dir->next = NULL;
	this_dir->subdir = NULL;
	this_dir->self = dpnt;
	this_dir->contents = NULL;
	this_dir->size = 0;
	this_dir->extent = 0;
	this_dir->depth = parent->depth + 1;
	this_dir->parent = parent;
	if (!parent->subdir)
		parent->subdir = this_dir;
	else {
		next_brother = parent->subdir;
		while (next_brother->next)
			next_brother = next_brother->next;
		next_brother->next = this_dir;
	}

	/* Set the name for this directory. */
	strcpy(whole_path, parent->de_name);
	strcat(whole_path, SPATH_SEPARATOR);
	strcat(whole_path, dpnt->name);
	this_dir->de_name = strdup(whole_path);
	this_dir->whole_name = strdup(whole_path);

	/*
	 * Now fill this directory using information from the previous session.
	 */
	contents = read_merging_directory(&dpnt->isorec, &n_orig);
	/*
	 * Start by simply copying the '.', '..' and non-directory entries to
	 * this directory.  Technically we could let merge_remaining_entries
	 * handle this, but it gets rather confused by the '.' and '..' entries
	 */
	for (i = 0; i < n_orig; i++) {
		/*
		 * We can always reuse the TRANS.TBL in this particular case.
		 */
		contents[i]->de_flags |= SAFE_TO_REUSE_TABLE_ENTRY;

		if (((contents[i]->isorec.flags[0] & ISO_DIRECTORY) != 0)
			&& (i >= 2)) {
			continue;
		}
		/* If we have a directory, don't reuse the extent number. */
		if ((contents[i]->isorec.flags[0] & ISO_DIRECTORY) != 0) {
			memset(contents[i]->isorec.extent, 0, 8);

			if (strcmp(contents[i]->name, ".") == 0)
				this_dir->dir_flags |= DIR_HAS_DOT;

			if (strcmp(contents[i]->name, "..") == 0)
				this_dir->dir_flags |= DIR_HAS_DOTDOT;
		}
		/*
		 * for regilar files, we do it here.
		 * If it has CL or RE attributes, remember its extent
		 */
		check_rr_relocation(contents[i]); 

		/*
		 * Set the whole name for this file.
		 */
		strcpy(whole_path, this_dir->whole_name);
		strcat(whole_path, SPATH_SEPARATOR);
		strcat(whole_path, contents[i]->name);

		contents[i]->whole_name = strdup(whole_path);

		contents[i]->next = this_dir->contents;
		contents[i]->filedir = this_dir;
		this_dir->contents = contents[i];
		contents[i] = NULL;
	}

	/*
	 * and for directories, we do it here.
	 * If it has CL or RE attributes, remember its extent
	 */
	check_rr_relocation(dpnt);

	/*
	 * Zero the extent number for ourselves.
	 */
	memset(dpnt->isorec.extent, 0, 8);

	/*
	 * Anything that is left are other subdirectories that need to be
	 * merged.
	 */
	merge_remaining_entries(this_dir, contents, n_orig);
	free_mdinfo(contents, n_orig);
#if 0
	/*
	 * This is no longer required.  The post-scan sort will handle all of
	 * this for us.
	 */
	sort_n_finish(this_dir);
#endif

	return 0;
}


char           *cdrecord_data = NULL;

int
get_session_start(file_addr)
	int		*file_addr;
{
	char		*pnt;

#ifdef CDRECORD_DETERMINES_FIRST_WRITABLE_ADDRESS
	/*
	 * FIXME(eric).  We need to coordinate with cdrecord to obtain the
	 * parameters.  For now, we assume we are writing the 2nd session, so
	 * we start from the session that starts at 0.
	 */
	*file_addr = (16 << 11);

	/*
	 * We need to coordinate with cdrecord to get the next writable address
	 * from the device.  Here is where we use it.
	 */
	session_start = last_extent = last_extent_written = cdrecord_result();
#else

	if (cdrecord_data == NULL) {
#ifdef	USE_LIBSCHILY
		comerrno(EX_BAD,
		    "Special parameters for cdrecord not specified with -C\n");
#else
		fprintf(stderr,
		    "Special parameters for cdrecord not specified with -C\n");
		exit(1);
#endif
	}
	/*
	 * Next try and find the ',' in there which delimits the two numbers.
	 */
	pnt = strchr(cdrecord_data, ',');
	if (pnt == NULL) {
#ifdef	USE_LIBSCHILY
		comerrno(EX_BAD, "Malformed cdrecord parameters\n");
#else
		fprintf(stderr, "Malformed cdrecord parameters\n");
		exit(1);
#endif
	}
	*pnt = '\0';
	if (file_addr != NULL) {
		*file_addr = atol(cdrecord_data) * SECTOR_SIZE;
	}
	pnt++;

	session_start = last_extent = last_extent_written = atol(pnt);

	pnt--;
	*pnt = ',';

#endif
	return 0;
}

/*
 * This function scans the directory tree, looking for files, and it makes
 * note of everything that is found.  We also begin to construct the ISO9660
 * directory entries, so that we can determine how large each directory is.
 */
int
merge_previous_session(this_dir, mrootp)
	struct directory *this_dir;
	struct iso_directory_record *mrootp;
{
	struct directory_entry **orig_contents = NULL;
	struct directory_entry *odpnt = NULL;
	int		n_orig;
	struct directory_entry *s_entry;
	int		status;
	int		lstatus;
	struct stat     statbuf,
			lstatbuf;
	int		retcode;

	/*
	 * Parse the same directory in the image that we are merging for
	 * multisession stuff.
	 */
	orig_contents = read_merging_directory(mrootp, &n_orig);
	if (orig_contents == NULL) {
		return (0);
	}

	/*
	 * Now we scan the directory itself, and look at what is inside of it.
	 */
	for (s_entry = this_dir->contents; s_entry; s_entry = s_entry->next) {
		status = stat_filter(s_entry->whole_name, &statbuf);
		lstatus = lstat_filter(s_entry->whole_name, &lstatbuf);

		/*
		 * We always should create an entirely new directory tree
		 * whenever we generate a new session, unless there were
		 * *no* changes whatsoever to any of the directories, in which
		 * case it would be kind of pointless to generate a new
		 * session.
		 * I believe it is possible to rigorously prove that any change
		 * anywhere in the filesystem will force the entire tree to be
		 * regenerated because the modified directory will get a new
		 * extent number.  Since each subdirectory of the changed
		 * directory has a '..' entry, all of them will need to be
		 * rewritten too, and since the parent directory of the
		 * modified directory will have an extent pointer to the
	   	 * directory it too will need to be rewritten.  Thus we will
		 * never be able to reuse any directory information when
		 * writing new sessions.
		 *
		 * We still check the previous session so we can mark off the
		 * equivalent entry in the list we got from the original disc,
		 * however.
		 */

		/*
		 * The check_prev_session function looks for an identical
		 * entry in the previous session.  If we see it, then we copy
		 * the extent number to s_entry, and cross it off the list.
		 * It returns 2 if it's a directory
		 */
		retcode = check_prev_session(orig_contents, n_orig, s_entry,
			&statbuf, &lstatbuf, &odpnt);
		if (retcode == -1)
			return (-1);

		if (retcode == 2 && odpnt != NULL) {
			int             dflag;

			if (strcmp(s_entry->name, ".") != 0 &&
					strcmp(s_entry->name, "..") != 0) {
				struct directory *child;

				/*
				 * XXX It seems that the tree that has been
				 * XXX read from the previous session does not
				 * XXX carry whole_name entries. We provide a
				 * XXX hack in
				 * XXX multi.c:find_or_create_directory()
				 * XXX that should be removed when a
				 * XXX reasonable method could be found.
				 */
				child = find_or_create_directory(this_dir,
					s_entry->whole_name,
					s_entry, 1);
				dflag = merge_previous_session(child,
					&odpnt->isorec);
				if (dflag == -1) {
					return (-1);
				}
				free(odpnt);
				odpnt = NULL;
			}
		}
	}

	/*
	 * Whatever is left over, are things which are no longer in the tree on
	 * disk. We need to also merge these into the tree.
	 */
	merge_remaining_entries(this_dir, orig_contents, n_orig);
	free_mdinfo(orig_contents, n_orig);
	return (1);
}

/*
 * This code deals with relocated directories which may exist 
 * in the previous session. 
 */
struct dir_extent_link  {
	unsigned int		extent;
	struct directory_entry	*de;
	struct dir_extent_link	*next;
};

static struct dir_extent_link	*cl_dirs = NULL;
static struct dir_extent_link	*re_dirs = NULL;

static void
check_rr_relocation(de)
	struct directory_entry *de;
{
	unsigned char   sector[SECTOR_SIZE];
	unsigned char  *pnt = de->rr_attributes;
		 int    len = de->rr_attr_size;
	int             cont_extent = 0,
	                cont_offset = 0,
	                cont_size = 0;

	pnt = parse_xa(pnt, &len, /*dpnt*/ 0);
	while (len >= 4) {
		if (pnt[3] != 1 && pnt[3] != 2) {
#ifdef USE_LIBSCHILY
			errmsgno(EX_BAD, "**BAD RRVERSION (%d) for %c%c\n", pnt[3], pnt[0], pnt[1]);
#else
			fprintf(stderr, "**BAD RRVERSION (%d) for %c%c\n", pnt[3], pnt[0], pnt[1]);
#endif
		}
		if (strncmp((char *) pnt, "CL", 2) == 0) {
			struct dir_extent_link *dlink = e_malloc(sizeof(*dlink));

			dlink->extent = isonum_733(pnt + 4);
			dlink->de = de;
			dlink->next = cl_dirs;
			cl_dirs = dlink;

		} else if (strncmp((char *) pnt, "RE", 2) == 0) {
			struct dir_extent_link *dlink = e_malloc(sizeof(*dlink));

			dlink->extent = de->starting_block;
			dlink->de = de;
			dlink->next = re_dirs;
			re_dirs = dlink;

		} else if (strncmp((char *) pnt, "CE", 2) == 0) {
			cont_extent = isonum_733(pnt + 4);
			cont_offset = isonum_733(pnt + 12);
			cont_size = isonum_733(pnt + 20);

		} else if (strncmp((char *) pnt, "ST", 2) == 0) {
			len = pnt[2];
		}
		len -= pnt[2];
		pnt += pnt[2];
		if (len <= 3 && cont_extent) {
			/* ??? What if cont_offset+cont_size > SECTOR_SIZE */
			readsecs(cont_extent, sector, 1);
			pnt = sector + cont_offset;
			len = cont_size;
			cont_extent = cont_offset = cont_size = 0;
		}
	}

}

void
match_cl_re_entries()
{
	struct dir_extent_link *re = re_dirs;

	/* for each relocated directory */
	for (; re; re = re->next) {
		struct dir_extent_link *cl = cl_dirs;

		for (; cl; cl = cl->next) {
			/* find a place where it was relocated from */
			if (cl->extent == re->extent) {
				/* set link to that place */
				re->de->parent_rec = cl->de;
				re->de->filedir = cl->de->filedir;

				/*
				 * see if it is in rr_moved
				 */
				if (reloc_dir != NULL) {
					struct directory_entry *rr_moved_e = reloc_dir->contents;

					for (; rr_moved_e; rr_moved_e = rr_moved_e->next) {
						/* yes it is */
						if (re->de == rr_moved_e) {
							/* forget it */
							re->de = NULL;
						}
					}
				}
				break;
			}
		}
	}
}

void
finish_cl_pl_for_prev_session()
{
	struct dir_extent_link *re = re_dirs;

	/* for those that were relocated, but NOT to rr_moved */
	re = re_dirs;
	for (; re; re = re->next) {
		if (re->de != NULL) {
			/*
			 * here we have hypothetical case when previous session
			 * was not created by mkisofs and contains relocations
			 */
			struct directory_entry *s_entry = re->de;
			struct directory_entry *s_entry1;
			struct directory *d_entry = reloc_dir->subdir;

			/* do the same as finish_cl_pl_entries */
			if (s_entry->de_flags & INHIBIT_ISO9660_ENTRY) {
				continue;
			}
			while (d_entry) {
				if (d_entry->self == s_entry)
					break;
				d_entry = d_entry->next;
			};
			if (!d_entry) {
#ifdef USE_LIBSCHILY
				comerrno(EX_BAD, "Unable to locate directory parent\n");
#else
				fprintf(stderr, "Unable to locate directory parent\n");
				exit(1);
#endif
			};

			if (s_entry->filedir != NULL && s_entry->parent_rec != NULL) {
				char           *rr_attr;

				/*
				 * First fix the PL pointer in the directory in the
				 * rr_reloc dir
				 */
				s_entry1 = d_entry->contents->next;
				rr_attr = find_rr_attribute(s_entry1->rr_attributes,
					s_entry1->total_rr_attr_size, "PL");
				if (rr_attr != NULL)
					set_733(rr_attr + 4, s_entry->filedir->extent);

				/* Now fix the CL pointer */
				s_entry1 = s_entry->parent_rec;

				rr_attr = find_rr_attribute(s_entry1->rr_attributes,
					s_entry1->total_rr_attr_size, "CL");
				if (rr_attr != NULL)
					set_733(rr_attr + 4, d_entry->extent);
			}
		}
	}
	/* free memory */
	re = re_dirs;
	while (re) {
		struct dir_extent_link *next = re->next;

		free(re);
		re = next;
	}
	re = cl_dirs;
	while (re) {
		struct dir_extent_link *next = re->next;

		free(re);
		re = next;
	}
}