libdm-iface.c

Linux Device Mapper Source Code

      bad:
	dm_free(dmi);
	return NULL;
}

static int _dm_names_v1(struct dm_ioctl_v1 *dmi)
{
	const char *dev_dir = dm_dir();
	int r = 1, len;
	const char *name;
	struct dirent *dirent;
	DIR *d;
	struct dm_names *names, *old_names = NULL;
	void *end = (void *) dmi + dmi->data_size;
	struct stat buf;
	char path[PATH_MAX];

	log_warn("WARNING: Device list may be incomplete with interface "
		  "version 1.");
	log_warn("Please upgrade your kernel device-mapper driver.");

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

	names = (struct dm_names *) ((void *) dmi + dmi->data_start);

	names->dev = 0;		/* Flags no data */

	while ((dirent = readdir(d))) {
		name = dirent->d_name;

		if (name[0] == '.' || !strcmp(name, "control"))
			continue;

		if (old_names)
			old_names->next = (uint32_t) ((void *) names -
						      (void *) old_names);
		snprintf(path, sizeof(path), "%s/%s", dev_dir, name);
		if (stat(path, &buf)) {
			log_sys_error("stat", path);
			continue;
		}
		if (!S_ISBLK(buf.st_mode))
			continue;
		names->dev = (uint64_t) buf.st_rdev;
		names->next = 0;
		len = strlen(name);
		if (((void *) (names + 1) + len + 1) >= end) {
			log_error("Insufficient buffer space for device list");
			r = 0;
			break;
		}

		strcpy(names->name, name);

		old_names = names;
		names = _align((void *) ++names + len + 1, ALIGNMENT);
	}

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

	return r;
}

static int _dm_task_run_v1(struct dm_task *dmt)
{
	struct dm_ioctl_v1 *dmi;
	unsigned int command;

	dmi = _flatten_v1(dmt);
	if (!dmi) {
		log_error("Couldn't create ioctl argument.");
		return 0;
	}

	if (!_open_control())
		return 0;

	if ((unsigned) dmt->type >=
	    (sizeof(_cmd_data_v1) / sizeof(*_cmd_data_v1))) {
		log_error("Internal error: unknown device-mapper task %d",
			  dmt->type);
		goto bad;
	}

	command = _cmd_data_v1[dmt->type].cmd;

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

	log_debug("dm %s %s %s%s%s [%u]", _cmd_data_v1[dmt->type].name,
		  dmi->name, dmi->uuid, dmt->newname ? " " : "",
		  dmt->newname ? dmt->newname : "",
		  dmi->data_size);
	if (dmt->type == DM_DEVICE_LIST) {
		if (!_dm_names_v1(dmi))
			goto bad;
	} 
#ifdef DM_IOCTLS
	else if (ioctl(_control_fd, command, dmi) < 0) {
		if (_log_suppress)
			log_verbose("device-mapper: %s ioctl failed: %s", 
				    _cmd_data_v1[dmt->type].name,
				    strerror(errno));
		else
			log_error("device-mapper: %s ioctl failed: %s",
				  _cmd_data_v1[dmt->type].name,
				  strerror(errno));
		goto bad;
	}
#else /* Userspace alternative for testing */
#endif

	if (dmi->flags & DM_BUFFER_FULL_FLAG)
		/* FIXME Increase buffer size and retry operation (if query) */
		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:
		rm_dev_node(dmt->dev_name);
		break;

	case DM_DEVICE_RENAME:
		rename_dev_node(dmt->dev_name, dmt->newname);
		break;

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

	case DM_DEVICE_STATUS:
	case DM_DEVICE_TABLE:
		if (!_unmarshal_status_v1(dmt, dmi))
			goto bad;
		break;

	case DM_DEVICE_SUSPEND:
	case DM_DEVICE_RESUME:
		dmt->type = DM_DEVICE_INFO;
		if (!dm_task_run(dmt))
			goto bad;
		dm_free(dmi);	/* We'll use what info returned */
		return 1;
	}

	dmt->dmi.v1 = dmi;
	return 1;

      bad:
	dm_free(dmi);
	return 0;
}

#endif

/*
 * Protocol Version 4 functions.
 */

int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size)
{
	unsigned *v;

#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_driver_version_v1(dmt, version, size);
#endif

	if (!dmt->dmi.v4) {
		version[0] = '\0';
		return 0;
	}

	v = dmt->dmi.v4->version;
	snprintf(version, size, "%u.%u.%u", v[0], v[1], v[2]);
	_dm_version_minor = v[1];
	_dm_version_patchlevel = v[2];

	return 1;
}

static int _check_version(char *version, size_t size, int log_suppress)
{
	struct dm_task *task;
	int r;

	if (!(task = dm_task_create(DM_DEVICE_VERSION))) {
		log_error("Failed to get device-mapper version");
		version[0] = '\0';
		return 0;
	}

	if (log_suppress)
		_log_suppress = 1;

	r = dm_task_run(task);
	dm_task_get_driver_version(task, version, size);
	dm_task_destroy(task);
	_log_suppress = 0;

	return r;
}

/*
 * Find out device-mapper's major version number the first time 
 * this is called and whether or not we support it.
 */
int dm_check_version(void)
{
	char libversion[64], dmversion[64];
	const char *compat = "";

	if (_version_checked)
		return _version_ok;

	_version_checked = 1;

	if (_check_version(dmversion, sizeof(dmversion), _dm_compat))
		return 1;

	if (!_dm_compat)
		goto bad;

	log_verbose("device-mapper ioctl protocol version %u failed. "
		    "Trying protocol version 1.", _dm_version);
	_dm_version = 1;
	if (_check_version(dmversion, sizeof(dmversion), 0)) {
		log_verbose("Using device-mapper ioctl protocol version 1");
		return 1;
	}

	compat = "(compat)";

	dm_get_library_version(libversion, sizeof(libversion));

	log_error("Incompatible libdevmapper %s%s and kernel driver %s",
		  libversion, compat, dmversion);

      bad:
	_version_ok = 0;
	return 0;
}

void *dm_get_next_target(struct dm_task *dmt, void *next,
			 uint64_t *start, uint64_t *length,
			 char **target_type, char **params)
{
	struct target *t = (struct target *) next;

	if (!t)
		t = dmt->head;

	if (!t)
		return NULL;

	*start = t->start;
	*length = t->length;
	*target_type = t->type;
	*params = t->params;

	return t->next;
}

/* Unmarshall the target info returned from a status call */
static int _unmarshal_status(struct dm_task *dmt, struct dm_ioctl *dmi)
{
	char *outbuf = (char *) dmi + dmi->data_start;
	char *outptr = outbuf;
	uint32_t i;
	struct dm_target_spec *spec;

	for (i = 0; i < dmi->target_count; i++) {
		spec = (struct dm_target_spec *) outptr;
		if (!dm_task_add_target(dmt, spec->sector_start,
					spec->length,
					spec->target_type,
					outptr + sizeof(*spec))) {
			return 0;
		}

		outptr = outbuf + spec->next;
	}

	return 1;
}

int dm_format_dev(char *buf, int bufsize, uint32_t dev_major,
		  uint32_t dev_minor)
{
	int r;

#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_format_dev_v1(buf, bufsize, dev_major, dev_minor);
#endif

	if (bufsize < 8)
		return 0;

	r = snprintf(buf, (size_t) bufsize, "%u:%u", dev_major, dev_minor);
	if (r < 0 || r > bufsize - 1)
		return 0;

	return 1;
}

int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
{
#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_info_v1(dmt, info);
#endif

	if (!dmt->dmi.v4)
		return 0;

	memset(info, 0, sizeof(*info));

	info->exists = dmt->dmi.v4->flags & DM_EXISTS_FLAG ? 1 : 0;
	if (!info->exists)
		return 1;

	info->suspended = dmt->dmi.v4->flags & DM_SUSPEND_FLAG ? 1 : 0;
	info->read_only = dmt->dmi.v4->flags & DM_READONLY_FLAG ? 1 : 0;
	info->live_table = dmt->dmi.v4->flags & DM_ACTIVE_PRESENT_FLAG ? 1 : 0;
	info->inactive_table = dmt->dmi.v4->flags & DM_INACTIVE_PRESENT_FLAG ?
	    1 : 0;
	info->target_count = dmt->dmi.v4->target_count;
	info->open_count = dmt->dmi.v4->open_count;
	info->event_nr = dmt->dmi.v4->event_nr;
	info->major = MAJOR(dmt->dmi.v4->dev);
	info->minor = MINOR(dmt->dmi.v4->dev);

	return 1;
}

const char *dm_task_get_name(const struct dm_task *dmt)
{
#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_name_v1(dmt);
#endif

	return (dmt->dmi.v4->name);
}

const char *dm_task_get_uuid(const struct dm_task *dmt)
{
#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_uuid_v1(dmt);
#endif

	return (dmt->dmi.v4->uuid);
}

struct dm_deps *dm_task_get_deps(struct dm_task *dmt)
{
#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_deps_v1(dmt);
#endif

	return (struct dm_deps *) (((void *) dmt->dmi.v4) +
				   dmt->dmi.v4->data_start);
}

struct dm_names *dm_task_get_names(struct dm_task *dmt)
{
#ifdef DM_COMPAT
	if (_dm_version == 1)
		return _dm_task_get_names_v1(dmt);
#endif

	return (struct dm_names *) (((void *) dmt->dmi.v4) +
				    dmt->dmi.v4->data_start);
}

struct dm_versions *dm_task_get_versions(struct dm_task *dmt)
{
	return (struct dm_versions *) (((void *) dmt->dmi.v4) +
				       dmt->dmi.v4->data_start);
}

int dm_task_set_ro(struct dm_task *dmt)
{
	dmt->read_only = 1;
	return 1;
}

int dm_task_suppress_identical_reload(struct dm_task *dmt)
{
	dmt->suppress_identical_reload = 1;
	return 1;
}

int dm_task_set_newname(struct dm_task *dmt, const char *newname)
{
	if (!(dmt->newname = dm_strdup(newname))) {
		log_error("dm_task_set_newname: strdup(%s) failed", newname);
		return 0;
	}

	return 1;
}

int dm_task_set_message(struct dm_task *dmt, const char *message)
{
	if (!(dmt->message = dm_strdup(message))) {
		log_error("dm_task_set_message: strdup(%s) failed", message);
		return 0;
	}

	return 1;
}

int dm_task_set_sector(struct dm_task *dmt, uint64_t sector)
{
	dmt->sector = sector;

	return 1;
}

int dm_task_set_geometry(struct dm_task *dmt, const char *cylinders, const char *heads, const char *sectors, const char *start)
{
	size_t len = strlen(cylinders) + 1 + strlen(heads) + 1 + strlen(sectors) + 1 + strlen(start) + 1;

	if (!(dmt->geometry = dm_malloc(len))) {
		log_error("dm_task_set_geometry: dm_malloc failed");
		return 0;
	}

	if (sprintf(dmt->geometry, "%s %s %s %s", cylinders, heads, sectors, start) < 0) {
		log_error("dm_task_set_geometry: sprintf failed");
		return 0;
	}

	return 1;
}

int dm_task_no_flush(struct dm_task *dmt)
{
	dmt->no_flush = 1;

	return 1;
}

int dm_task_no_open_count(struct dm_task *dmt)
{
	dmt->no_open_count = 1;

	return 1;
}

int dm_task_skip_lockfs(struct dm_task *dmt)
{
	dmt->skip_lockfs = 1;

	return 1;
}

int dm_task_set_event_nr(struct dm_task *dmt, uint32_t event_nr)
{
	dmt->event_nr = event_nr;

	return 1;
}

struct target *create_target(uint64_t start, uint64_t len, const char *type,
			     const char *params)
{
	struct target *t = dm_malloc(sizeof(*t));

	if (!t) {
		log_error("create_target: malloc(%" PRIsize_t ") failed",
			  sizeof(*t));
		return NULL;
	}

	memset(t, 0, sizeof(*t));

	if (!(t->params = dm_strdup(params))) {
		log_error("create_target: strdup(params) failed");
		goto bad;
	}

	if (!(t->type = dm_strdup(type))) {
		log_error("create_target: strdup(type) failed");
		goto bad;
	}

	t->start = start;
	t->length = len;
	return t;

      bad:
	dm_free(t->params);
	dm_free(t->type);
	dm_free(t);
	return NULL;
}

static void *_add_target(struct target *t, void *out, void *end)
{
	void *out_sp = out;
	struct dm_target_spec sp;
	size_t sp_size = sizeof(struct dm_target_spec);
	int len;
	const char no_space[] = "Ran out of memory building ioctl parameter";

	out += sp_size;
	if (out >= end) {
		log_error(no_space);
		return NULL;
	}

	sp.status = 0;
	sp.sector_start = t->start;
	sp.length = t->length;
	strncpy(sp.target_type, t->type, sizeof(sp.target_type));

	len = strlen(t->params);

	if ((out + len + 1) >= end) {
		log_error(no_space);

		log_error("t->params= '%s'", t->params);
		return NULL;
	}
	strcpy((char *) out, t->params);
	out += len + 1;

	/* align next block */
	out = _align(out, ALIGNMENT);

	sp.next = out - out_sp;
	memcpy(out_sp, &sp, sp_size);

	return out;
}

static int _lookup_dev_name(uint64_t dev, char *buf, size_t len)
{
	struct dm_names *names;
	unsigned next = 0;
	struct dm_task *dmt;
	int r = 0;
 
	if (!(dmt = dm_task_create(DM_DEVICE_LIST)))
		return 0;
 
	if (!dm_task_run(dmt))
		goto out;

	if (!(names = dm_task_get_names(dmt)))
		goto out;
 
	if (!names->dev)
		goto out;