libdm-iface.c

Linux Device Mapper Source Code

	do {
		names = (void *) names + next;
		if (names->dev == dev) {
			strncpy(buf, names->name, len);
			r = 1;
			break;
		}
		next = names->next;
	} while (next);

      out:
	dm_task_destroy(dmt);
	return r;
}

static struct dm_ioctl *_flatten(struct dm_task *dmt, unsigned repeat_count)
{
	const size_t min_size = 16 * 1024;
	const int (*version)[3];

	struct dm_ioctl *dmi;
	struct target *t;
	struct dm_target_msg *tmsg;
	size_t len = sizeof(struct dm_ioctl);
	void *b, *e;
	int count = 0;

	for (t = dmt->head; t; t = t->next) {
		len += sizeof(struct dm_target_spec);
		len += strlen(t->params) + 1 + ALIGNMENT;
		count++;
	}

	if (count && (dmt->sector || dmt->message)) {
		log_error("targets and message are incompatible");
		return NULL;
	}

	if (count && dmt->newname) {
		log_error("targets and newname are incompatible");
		return NULL;
	}

	if (count && dmt->geometry) {
		log_error("targets and geometry are incompatible");
		return NULL;
	}

	if (dmt->newname && (dmt->sector || dmt->message)) {
		log_error("message and newname are incompatible");
		return NULL;
	}

	if (dmt->newname && dmt->geometry) {
		log_error("geometry and newname are incompatible");
		return NULL;
	}

	if (dmt->geometry && (dmt->sector || dmt->message)) {
		log_error("geometry and message are incompatible");
		return NULL;
	}

	if (dmt->sector && !dmt->message) {
		log_error("message is required with sector");
		return NULL;
	}

	if (dmt->newname)
		len += strlen(dmt->newname) + 1;

	if (dmt->message)
		len += sizeof(struct dm_target_msg) + strlen(dmt->message) + 1;

	if (dmt->geometry)
		len += strlen(dmt->geometry) + 1;

	/*
	 * Give len a minimum size so that we have space to store
	 * dependencies or status information.
	 */
	if (len < min_size)
		len = min_size;

	/* Increase buffer size if repeating because buffer was too small */
	while (repeat_count--)
		len *= 2;

	if (!(dmi = dm_malloc(len)))
		return NULL;

	memset(dmi, 0, len);

	version = &_cmd_data_v4[dmt->type].version;

	dmi->version[0] = (*version)[0];
	dmi->version[1] = (*version)[1];
	dmi->version[2] = (*version)[2];

	dmi->data_size = len;
	dmi->data_start = sizeof(struct dm_ioctl);

	if (dmt->minor >= 0) {
		if (dmt->major <= 0) {
			log_error("Missing major number for persistent device.");
			goto bad;
		}
		dmi->flags |= DM_PERSISTENT_DEV_FLAG;
		dmi->dev = MKDEV(dmt->major, dmt->minor);
	}

	/* Does driver support device number referencing? */
	if (_dm_version_minor < 3 && !dmt->dev_name && !dmt->uuid && dmi->dev) {
		if (!_lookup_dev_name(dmi->dev, dmi->name, sizeof(dmi->name))) {
			log_error("Unable to find name for device (%" PRIu32
				  ":%" PRIu32 ")", dmt->major, dmt->minor);
			goto bad;
		}
		log_verbose("device (%" PRIu32 ":%" PRIu32 ") is %s "
			    "for compatibility with old kernel",
			    dmt->major, dmt->minor, dmi->name);
	}

	if (dmt->dev_name)
		strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));

	if (dmt->uuid)
		strncpy(dmi->uuid, dmt->uuid, sizeof(dmi->uuid));

	if (dmt->type == DM_DEVICE_SUSPEND)
		dmi->flags |= DM_SUSPEND_FLAG;
	if (dmt->no_flush)
		dmi->flags |= DM_NOFLUSH_FLAG;
	if (dmt->read_only)
		dmi->flags |= DM_READONLY_FLAG;
	if (dmt->skip_lockfs)
		dmi->flags |= DM_SKIP_LOCKFS_FLAG;

	dmi->target_count = count;
	dmi->event_nr = dmt->event_nr;

	b = (void *) (dmi + 1);
	e = (void *) ((char *) dmi + len);

	for (t = dmt->head; t; t = t->next)
		if (!(b = _add_target(t, b, e)))
			goto bad;

	if (dmt->newname)
		strcpy(b, dmt->newname);

	if (dmt->message) {
		tmsg = (struct dm_target_msg *) b;
		tmsg->sector = dmt->sector;
		strcpy(tmsg->message, dmt->message);
	}

	if (dmt->geometry)
		strcpy(b, dmt->geometry);

	return dmi;

      bad:
	dm_free(dmi);
	return NULL;
}

static int _process_mapper_dir(struct dm_task *dmt)
{
	struct dirent *dirent;
	DIR *d;
	const char *dir;
	int r = 1;

	dir = dm_dir();
	if (!(d = opendir(dir))) {
		log_sys_error("opendir", dir);
		return 0;
	}

	while ((dirent = readdir(d))) {
		if (!strcmp(dirent->d_name, ".") ||
		    !strcmp(dirent->d_name, "..") ||
		    !strcmp(dirent->d_name, "control"))
			continue;
		dm_task_set_name(dmt, dirent->d_name);
		dm_task_run(dmt);
	}

	if (closedir(d))
		log_sys_error("closedir", dir);

	return r;
}

static int _process_all_v4(struct dm_task *dmt)
{
	struct dm_task *task;
	struct dm_names *names;
	unsigned next = 0;
	int r = 1;

	if (!(task = dm_task_create(DM_DEVICE_LIST)))
		return 0;

	if (!dm_task_run(task)) {
		r = 0;
		goto out;
	}

	if (!(names = dm_task_get_names(task))) {
		r = 0;
		goto out;
	}

	if (!names->dev)
		goto out;

	do {
		names = (void *) names + next;
		if (!dm_task_set_name(dmt, names->name)) {
			r = 0;
			goto out;
		}
		if (!dm_task_run(dmt))
			r = 0;
		next = names->next;
	} while (next);

      out:
	dm_task_destroy(task);
	return r;
}

static int _mknodes_v4(struct dm_task *dmt)
{
	(void) _process_mapper_dir(dmt);

	return _process_all_v4(dmt);
}

static int _create_and_load_v4(struct dm_task *dmt)
{
	struct dm_task *task;
	int r;

	/* Use new task struct to create the device */
	if (!(task = dm_task_create(DM_DEVICE_CREATE))) {
		log_error("Failed to create device-mapper task struct");
		return 0;
	}

	/* Copy across relevant fields */
	if (dmt->dev_name && !dm_task_set_name(task, dmt->dev_name)) {
		dm_task_destroy(task);
		return 0;
	}

	if (dmt->uuid && !dm_task_set_uuid(task, dmt->uuid)) {
		dm_task_destroy(task);
		return 0;
	}

	task->major = dmt->major;
	task->minor = dmt->minor;
	task->uid = dmt->uid;
	task->gid = dmt->gid;
	task->mode = dmt->mode;

	r = dm_task_run(task);
	dm_task_destroy(task);
	if (!r)
		return r;

	/* Next load the table */
	if (!(task = dm_task_create(DM_DEVICE_RELOAD))) {
		log_error("Failed to create device-mapper task struct");
		return 0;
	}

	/* Copy across relevant fields */
	if (dmt->dev_name && !dm_task_set_name(task, dmt->dev_name)) {
		dm_task_destroy(task);
		return 0;
	}

	task->read_only = dmt->read_only;
	task->head = dmt->head;
	task->tail = dmt->tail;

	r = dm_task_run(task);

	task->head = NULL;
	task->tail = NULL;
	dm_task_destroy(task);
	if (!r)
		goto revert;

	/* Use the original structure last so the info will be correct */
	dmt->type = DM_DEVICE_RESUME;
	dm_free(dmt->uuid);
	dmt->uuid = NULL;

	r = dm_task_run(dmt);

	if (r)
		return r;

      revert:
 	dmt->type = DM_DEVICE_REMOVE;
	dm_free(dmt->uuid);
	dmt->uuid = NULL;

	if (!dm_task_run(dmt))
		log_error("Failed to revert device creation.");

	return r;
}

static int _reload_with_suppression_v4(struct dm_task *dmt)
{
	struct dm_task *task;
	struct target *t1, *t2;
	int r;

	/* New task to get existing table information */
	if (!(task = dm_task_create(DM_DEVICE_TABLE))) {
		log_error("Failed to create device-mapper task struct");
		return 0;
	}

	/* Copy across relevant fields */
	if (dmt->dev_name && !dm_task_set_name(task, dmt->dev_name)) {
		dm_task_destroy(task);
		return 0;
	}

	if (dmt->uuid && !dm_task_set_uuid(task, dmt->uuid)) {
		dm_task_destroy(task);
		return 0;
	}

	task->major = dmt->major;
	task->minor = dmt->minor;

	r = dm_task_run(task);

	if (!r) {
		dm_task_destroy(task);
		return r;
	}

	if ((task->dmi.v4->flags & DM_READONLY_FLAG) ? 1 : 0 != dmt->read_only)
		goto no_match;

	t1 = dmt->head;
	t2 = task->head;

	while (t1 && t2) {
		while (t2->params[strlen(t2->params) - 1] == ' ')
			t2->params[strlen(t2->params) - 1] = '\0';
		if ((t1->start != t2->start) ||
		    (t1->length != t2->length) ||
		    (strcmp(t1->type, t2->type)) ||
		    (strcmp(t1->params, t2->params)))
			goto no_match;
		t1 = t1->next;
		t2 = t2->next;
	}
	
	if (!t1 && !t2) {
		dmt->dmi.v4 = task->dmi.v4;
		task->dmi.v4 = NULL;
		dm_task_destroy(task);
		return 1;
	}

no_match:
	dm_task_destroy(task);

	/* Now do the original reload */
	dmt->suppress_identical_reload = 0;
	r = dm_task_run(dmt);

	return r;
}

static struct dm_ioctl *_do_dm_ioctl(struct dm_task *dmt, unsigned command,
				     unsigned repeat_count)
{
	struct dm_ioctl *dmi;

	dmi = _flatten(dmt, repeat_count);
	if (!dmi) {
		log_error("Couldn't create ioctl argument.");
		return NULL;
	}

	if (dmt->type == DM_DEVICE_TABLE)
		dmi->flags |= DM_STATUS_TABLE_FLAG;

	dmi->flags |= DM_EXISTS_FLAG;	/* FIXME */

	if (dmt->no_open_count)
		dmi->flags |= DM_SKIP_BDGET_FLAG;

	log_debug("dm %s %s %s%s%s %s%.0d%s%.0d%s"
		  "%s%c%c%s %.0" PRIu64 " %s [%u]",
		  _cmd_data_v4[dmt->type].name,
		  dmi->name, dmi->uuid, dmt->newname ? " " : "",
		  dmt->newname ? dmt->newname : "",
		  dmt->major > 0 ? "(" : "",
		  dmt->major > 0 ? dmt->major : 0,
		  dmt->major > 0 ? ":" : "",
		  dmt->minor > 0 ? dmt->minor : 0,
		  dmt->major > 0 && dmt->minor == 0 ? "0" : "",
		  dmt->major > 0 ? ") " : "",
		  dmt->no_open_count ? 'N' : 'O',
		  dmt->no_flush ? 'N' : 'F',
		  dmt->skip_lockfs ? "S " : "",
		  dmt->sector, dmt->message ? dmt->message : "",
		  dmi->data_size);
#ifdef DM_IOCTLS
	if (ioctl(_control_fd, command, dmi) < 0) {
		if (errno == ENXIO && ((dmt->type == DM_DEVICE_INFO) ||
				       (dmt->type == DM_DEVICE_MKNODES) ||
				       (dmt->type == DM_DEVICE_STATUS)))
			dmi->flags &= ~DM_EXISTS_FLAG;	/* FIXME */
		else {
			if (_log_suppress)
				log_verbose("device-mapper: %s ioctl "
					    "failed: %s",
				    	    _cmd_data_v4[dmt->type].name,
					    strerror(errno));
			else
				log_error("device-mapper: %s ioctl "
					  "failed: %s",
				    	   _cmd_data_v4[dmt->type].name,
					  strerror(errno));
			dm_free(dmi);
			return NULL;
		}
	}
#else /* Userspace alternative for testing */
#endif
	return dmi;
}

void dm_task_update_nodes(void)
{
	update_devs();
}

int dm_task_run(struct dm_task *dmt)
{
	struct dm_ioctl *dmi;
	unsigned command;

#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_run_v1(dmt);
#endif

	if ((unsigned) dmt->type >=
	    (sizeof(_cmd_data_v4) / sizeof(*_cmd_data_v4))) {
		log_error("Internal error: unknown device-mapper task %d",
			  dmt->type);
		return 0;
	}

	command = _cmd_data_v4[dmt->type].cmd;

	/* Old-style creation had a table supplied */
	if (dmt->type == DM_DEVICE_CREATE && dmt->head)
		return _create_and_load_v4(dmt);

	if (dmt->type == DM_DEVICE_MKNODES && !dmt->dev_name &&
	    !dmt->uuid && dmt->major <= 0)
		return _mknodes_v4(dmt);

	if ((dmt->type == DM_DEVICE_RELOAD) && dmt->suppress_identical_reload)
		return _reload_with_suppression_v4(dmt);

	if (!_open_control())
		return 0;

repeat_ioctl:
	if (!(dmi = _do_dm_ioctl(dmt, command, _ioctl_buffer_double_factor)))
		return 0;

	if (dmi->flags & DM_BUFFER_FULL_FLAG) {
		switch (dmt->type) {
		case DM_DEVICE_LIST_VERSIONS:
		case DM_DEVICE_LIST:
		case DM_DEVICE_DEPS:
		case DM_DEVICE_STATUS:
		case DM_DEVICE_TABLE:
		case DM_DEVICE_WAITEVENT:
			_ioctl_buffer_double_factor++;
			dm_free(dmi);
			goto repeat_ioctl;
		default:
			log_error("WARNING: libdevmapper buffer too small for data");
		}
	}

	switch (dmt->type) {
	case DM_DEVICE_CREATE:
		add_dev_node(dmt->dev_name, MAJOR(dmi->dev), MINOR(dmi->dev),
			     dmt->uid, dmt->gid, dmt->mode);
		break;

	case DM_DEVICE_REMOVE:
		/* FIXME Kernel needs to fill in dmi->name */
		if (dmt->dev_name)
			rm_dev_node(dmt->dev_name);
		break;

	case DM_DEVICE_RENAME:
		/* FIXME Kernel needs to fill in dmi->name */
		if (dmt->dev_name)
			rename_dev_node(dmt->dev_name, dmt->newname);
		break;

	case DM_DEVICE_MKNODES:
		if (dmi->flags & DM_EXISTS_FLAG)
			add_dev_node(dmi->name, MAJOR(dmi->dev),
				     MINOR(dmi->dev),
				     dmt->uid, dmt->gid, dmt->mode);
		else if (dmt->dev_name)
			rm_dev_node(dmt->dev_name);
		break;

	case DM_DEVICE_STATUS:
	case DM_DEVICE_TABLE:
	case DM_DEVICE_WAITEVENT:
		if (!_unmarshal_status(dmt, dmi))
			goto bad;
		break;
	}

	/* Was structure reused? */
	if (dmt->dmi.v4)
		dm_free(dmt->dmi.v4);
	dmt->dmi.v4 = dmi;
	return 1;

      bad:
	dm_free(dmi);
	return 0;
}

void dm_lib_release(void)
{
	if (_control_fd != -1) {
		close(_control_fd);
		_control_fd = -1;
	}
	update_devs();
}

void dm_lib_exit(void)
{
	dm_lib_release();
	if (_dm_bitset)
		dm_bitset_destroy(_dm_bitset);
	_dm_bitset = NULL;
	dm_dump_memory();
	_version_ok = 1;
	_version_checked = 0;
}