Function robust_unlink

util1.c:496–541

* Robust unlink: some OS'es (HPUX) refuse to unlink busy files, so * rename to /.rsyncNNN instead. * * Note that successive rsync runs will shuffle the filenames around a * bit as long as the file is still busy; this is because this function * does not know if the unlink call is due to a new file coming in, or * --delete trying to remove old .rsyncNNN files, hence it renames it * each

 * each time.
 **/
int robust_unlink(const char *fname)
{
#ifndef ETXTBSY
	return do_unlink_at(fname);
#else
	static int counter = 1;
	int rc, pos, start;
	char path[MAXPATHLEN];

	rc = do_unlink_at(fname);
	if (rc == 0 || errno != ETXTBSY)
		return rc;

	if ((pos = strlcpy(path, fname, MAXPATHLEN)) >= MAXPATHLEN)
		pos = MAXPATHLEN - 1;

	while (pos > 0 && path[pos-1] != '/')
		pos--;
	pos += strlcpy(path+pos, ".rsync", MAXPATHLEN-pos);

	if (pos > (MAXPATHLEN-MAX_RENAMES_DIGITS-1)) {
		errno = ETXTBSY;
		return -1;
	}

	/* start where the last one left off to reduce chance of clashes */
	start = counter;
	do {
		snprintf(&path[pos], MAX_RENAMES_DIGITS+1, "%03d", counter);
		if (++counter >= MAX_RENAMES)
			counter = 1;
	} while ((rc = access(path, 0)) == 0 && counter != start);

	if (INFO_GTE(MISC, 1)) {
		rprintf(FWARNING, "renaming %s to %s because of text busy\n",
			fname, path);
	}

	/* maybe we should return rename()'s exit status? Nah. */
	if (do_rename_at(fname, path) != 0) {
		errno = ETXTBSY;
		return -1;
	}
	return 0;
#endif
}

/* Returns 0 on successful rename, 1 if we successfully copied the file
 * across filesystems, -2 if copy_file() failed, and -1 on other errors.