static int _create_control(const char *control, uint32_t major, uint32_t minor)
{
int ret;
mode_t old_umask;
if (!major)
return 0;
old_umask = umask(DM_DEV_DIR_UMASK);
ret = dm_create_dir(dm_dir());
umask(old_umask);
if (!ret)
return 0;
log_verbose("Creating device %s (%u, %u)", control, major, minor);
if (mknod(control, S_IFCHR | S_IRUSR | S_IWUSR,
MKDEV(major, minor)) < 0) {
log_sys_error("mknod", control);
return 0;
}
#ifdef HAVE_SELINUX
if (!dm_set_selinux_context(control, S_IFCHR)) {
stack;
return 0;
}
#endif
return 1;
}
static int _create_control(const char *control, uint32_t major, uint32_t minor)
{
int ret;
mode_t old_umask;
if (!major)
return 0;
old_umask = umask(0022);
ret = dm_create_dir(dm_dir());
umask(old_umask);
if (!ret)
return 0;
log_verbose("Creating device %s (%u, %u)", control, major, minor);
if (mknod(control, S_IFCHR | S_IRUSR | S_IWUSR,
MKDEV(major, minor)) < 0) {
log_sys_error("mknod", control);
return 0;
}
return 1;
}
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;
}
/* Open control device if doesn't exist create it. */
static int _open_control(void)
{
char control[PATH_MAX];
uint32_t major = 0, minor = 0;
if (_control_fd != -1)
return 1;
#ifdef RUMP_ACTION
rump_init();
#endif
snprintf(control, sizeof(control), "%s/control", dm_dir());
if (!_control_device_number(&major, &minor))
log_error("Is device-mapper driver missing from kernel?");
if (!_control_exists(control, major, minor) &&
!_create_control(control, major, minor))
goto error;
if ((_control_fd = open(control, O_RDWR)) < 0) {
log_sys_error("open", control);
goto error;
}
return 1;
error:
log_error("Failure to communicate with kernel device-mapper driver.");
return 0;
}
static int _create_control(const char *control, uint32_t major, uint32_t minor)
{
int ret;
mode_t old_umask;
if (!major)
return 0;
old_umask = umask(DM_DEV_DIR_UMASK);
ret = dm_create_dir(dm_dir());
umask(old_umask);
if (!ret)
return 0;
log_verbose("Creating device %s (%u, %u)", control, major, minor);
old_umask = umask(0);
if (mknod(control, S_IFCHR | DM_CONTROL_DEVICE_MODE,
MKDEV(major, minor)) < 0) {
umask(old_umask);
log_sys_error("mknod", control);
return 0;
}
umask(old_umask);
if (chown(control, DM_DEVICE_UID, DM_DEVICE_GID) == -1) {
log_sys_error("chown", control);
return 0;
}
return 1;
}
static char *lookup_dev(const char *dev_id)
{
uint32_t major, minor;
dev_t dev;
char *result = NULL, buf[PATH_MAX + 1];
if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
return NULL;
dev = makedev(major, minor);
strncpy(buf, DEVICE_DIR, PATH_MAX);
buf[PATH_MAX] = '\0';
/* First try low level device */
if ((result = __lookup_dev(buf, dev, 0, 0)))
return result;
/* If it is dm, try DM dir */
if (dm_is_dm_major(major)) {
strncpy(buf, dm_dir(), PATH_MAX);
if ((result = __lookup_dev(buf, dev, 0, 0)))
return result;
}
strncpy(buf, DEVICE_DIR, PATH_MAX);
result = __lookup_dev(buf, dev, 0, 4);
/* If not found, return NULL */
return result;
}
/* Make up a dm path. */
char *
mkdm_path(struct lib_context *lc, const char *name)
{
char *ret;
const char *dir = dm_dir();
if ((ret = dbg_malloc(strlen(dir) + strlen(name) + 2)))
sprintf(ret, "%s/%s", dir, name);
else
log_alloc_err(lc, __func__);
return ret;
}
static int _open_control(void)
{
#ifdef DM_IOCTLS
char control[PATH_MAX];
uint32_t major = 0, minor;
if (_control_fd != -1)
return 1;
snprintf(control, sizeof(control), "%s/control", dm_dir());
if (!_control_device_number(&major, &minor))
log_error("Is device-mapper driver missing from kernel?");
if (!_control_exists(control, major, minor) &&
!_create_control(control, major, minor))
goto error;
if ((_control_fd = open(control, O_RDWR)) < 0) {
log_sys_error("open", control);
goto error;
}
if (!_create_dm_bitset()) {
log_error("Failed to set up list of device-mapper major numbers");
return 0;
}
return 1;
error:
log_error("Failure to communicate with kernel device-mapper driver.");
return 0;
#else
return 1;
#endif
}
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 _open_control(void)
{
#ifdef DM_IOCTLS
char control[PATH_MAX];
uint32_t major = 0, minor;
int dm_mod_autoload_support, needs_open;
if (_control_fd != -1)
return 1;
if (!_uname())
return 0;
snprintf(control, sizeof(control), "%s/%s", dm_dir(), DM_CONTROL_NODE);
/*
* dm-mod autoloading is supported since kernel 2.6.36.
* Udev daemon will try to read modules.devname file extracted
* by depmod and create any static nodes needed.
* The /dev/mapper/control node can be created and prepared this way.
* First access to such node should load dm-mod module automatically.
*/
dm_mod_autoload_support = KERNEL_VERSION(_kernel_major, _kernel_minor,
_kernel_release) >= KERNEL_VERSION(2, 6, 36);
/*
* If dm-mod autoloading is supported and the control node exists
* already try to open it now. This should autoload dm-mod module.
*/
if (dm_mod_autoload_support) {
if (!_get_proc_number(PROC_DEVICES, MISC_NAME, &major))
/* If major not found, just fallback to hardcoded value. */
major = MISC_MAJOR;
/* Recreate the node with correct major and minor if needed. */
if (!_control_exists(control, major, MAPPER_CTRL_MINOR) &&
!_create_control(control, major, MAPPER_CTRL_MINOR))
goto error;
_open_and_assign_control_fd(control, 1);
}
/*
* Get major and minor number assigned for the control node.
* In case we make use of the module autoload support, this
* information should be accessible now as well.
*/
if (!_control_device_number(&major, &minor))
log_error("Is device-mapper driver missing from kernel?");
/*
* Check the control node and its major and minor number.
* If there's anything wrong, remove the old node and create
* a correct one.
*/
if ((needs_open = !_control_exists(control, major, minor)) &&
!_create_control(control, major, minor)) {
_close_control_fd();
goto error;
}
/*
* For older kernels without dm-mod autoloading support, we always
* need to open the control node here - we still haven't done that!
* For newer kernels with dm-mod autoloading, we open it only if the
* node was recreated and corrected in previous step.
*/
if ((!dm_mod_autoload_support || needs_open) &&
!_open_and_assign_control_fd(control, 0))
goto error;
if (!_create_dm_bitset()) {
log_error("Failed to set up list of device-mapper major numbers");
return 0;
}
return 1;
error:
log_error("Failure to communicate with kernel device-mapper driver.");
return 0;
#else
return 1;
#endif
}
const char *dm_get_dir(void)
{
return dm_dir();
}
