modules/mount_changer.c

/* ----------------------------------------------------------------------- *
 *   
 *  mount_changer.c - module for Linux automountd to mount filesystems
 *                    from cd changers
 *
 *   Copyright 1999 Toby Jaffey - All Rights Reserved
 *   CD swapping code from linux kernel in Documentation/cdrom/ide-cd
 * Based on code originally from Gerhard Zuber <zuber@berlin.snafu.de>.
 * Changer status information, and rewrite for the new Uniform CDROM driver
 * interface by Erik Andersen <andersee@debian.org>.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
 *   USA; either version 2 of the License, or (at your option) any later
 *   version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <linux/cdrom.h>

#define MODULE_MOUNT
#include "automount.h"

#define MODPREFIX "mount(changer): "

int mount_version = AUTOFS_MOUNT_VERSION;	/* Required by protocol */

int swapCD(const char *device, const char *slotName);

int mount_init(void **context)
{
	return 0;
}

int mount_reinit(void **context)
{
	return 0;
}

int mount_mount(struct autofs_point *ap, const char *root, const char *name, int name_len,
		const char *what, const char *fstype, const char *options, void *context)
{
	char fullpath[PATH_MAX];
	char buf[MAX_ERR_BUF];
	int err;
	int len, status, existed = 1;

	if (ap->flags & MOUNT_FLAG_REMOUNT)
		return 0;

	fstype = "iso9660";

	/* Root offset of multi-mount */
	len = strlen(root);
	if (root[len - 1] == '/') {
		len = snprintf(fullpath, len, "%s", root);
	} else if (*name == '/') {
		/*
		 * Direct or offset mount, name is absolute path so
		 * don't use root (but with move mount changes root
		 * is now the same as name).
		 */
		len = sprintf(fullpath, "%s", root);
	} else {
		len = sprintf(fullpath, "%s/%s", root, name);
	}
	fullpath[len] = '\0';

	debug(ap->logopt, MODPREFIX "calling umount %s", what);

	err = spawn_umount(ap->logopt, what, NULL);
	if (err) {
		error(ap->logopt,
		      MODPREFIX
		      "umount of %s failed (all may be unmounted)",
		      what);
	}

	debug(ap->logopt, MODPREFIX "calling mkdir_path %s", fullpath);

	status = mkdir_path(fullpath, mp_mode);
	if (status && errno != EEXIST) {
		char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
		error(ap->logopt,
		      MODPREFIX "mkdir_path %s failed: %s", fullpath, estr);
		return 1;
	}

	if (!status)
		existed = 0;

	debug(ap->logopt, MODPREFIX "Swapping CD to slot %s", name);

	err = swapCD(what, name);
	if (err) {
		error(ap->logopt,
		      MODPREFIX "failed to swap CD to slot %s", name);
		return 1;
	}

	if (options && options[0]) {
		debug(ap->logopt, MODPREFIX
		      "calling mount -t %s -o %s %s %s",
		      fstype, options, what, fullpath);

		err = spawn_mount(ap->logopt, "-t", fstype,
			          "-o", options, what, fullpath, NULL);
	} else {
		debug(ap->logopt,
		      MODPREFIX "calling mount -t %s %s %s",
		      fstype, what, fullpath);

		err = spawn_mount(ap->logopt, "-t", fstype, what, fullpath, NULL);
	}

	if (err) {
		info(ap->logopt, MODPREFIX "failed to mount %s (type %s) on %s",
		    what, fstype, fullpath);

		if (ap->type != LKP_INDIRECT)
			return 1;

		if ((!(ap->flags & MOUNT_FLAG_GHOST) && name_len) || !existed)
			rmdir_path(ap, fullpath, ap->dev);

		return 1;
	} else {
		debug(ap->logopt, MODPREFIX "mounted %s type %s on %s",
		    what, fstype, fullpath);
		return 0;
	}
}

int mount_done(void *context)
{
	return 0;
}

int swapCD(const char *device, const char *slotName)
{
	int fd;			/* file descriptor for CD-ROM device */
	int status;		/* return status for system calls */
	int slot = -1;
	int total_slots_available;

	slot = atoi(slotName) - 1;

	/* open device */
	fd = open_fd(device, O_RDONLY | O_NONBLOCK);
	if (fd < 0) {
		logerr(MODPREFIX "Opening device %s failed : %s",
		      device, strerror(errno));
		return 1;
	}

	/* Check CD player status */
	total_slots_available = ioctl(fd, CDROM_CHANGER_NSLOTS);
	if (total_slots_available <= 1) {
		logerr(MODPREFIX
		      "Device %s is not an ATAPI compliant CD changer.",
		      device);
		close(fd);
		return 1;
	}

	/* load */
	slot = ioctl(fd, CDROM_SELECT_DISC, slot);
	if (slot < 0) {
		logerr(MODPREFIX "CDROM_SELECT_DISC failed");
		close(fd);
		return 1;
	}

	/* close device */
	status = close(fd);
	if (status != 0) {
		logerr(MODPREFIX "close failed for `%s': %s",
		      device, strerror(errno));
		return 1;
	}
	return 0;
}