static int _md_sysfs_attribute_snprintf(char *path, size_t size,
const char *sysfs_dir,
struct device *blkdev,
const char *attribute)
{
struct stat info;
dev_t dev = blkdev->dev;
int ret = -1;
if (!sysfs_dir || !*sysfs_dir)
return ret;
if (MAJOR(dev) == blkext_major()) {
/* lookup parent MD device from blkext partition */
if (!get_primary_dev(sysfs_dir, blkdev, &dev))
return ret;
}
if (MAJOR(dev) != md_major())
return ret;
ret = dm_snprintf(path, size, "%s/dev/block/%d:%d/md/%s", sysfs_dir,
(int)MAJOR(dev), (int)MINOR(dev), attribute);
if (ret < 0) {
log_error("dm_snprintf md %s failed", attribute);
return ret;
}
if (stat(path, &info) == -1) {
if (errno != ENOENT) {
log_sys_error("stat", path);
return ret;
}
/* old sysfs structure */
ret = dm_snprintf(path, size, "%s/block/md%d/md/%s",
sysfs_dir, (int)MINOR(dev), attribute);
if (ret < 0) {
log_error("dm_snprintf old md %s failed", attribute);
return ret;
}
}
return ret;
}
int dev_subsystem_part_major(const struct device *dev)
{
dev_t primary_dev;
if (MAJOR(dev->dev) == _md_major)
return 1;
if (MAJOR(dev->dev) == _drbd_major)
return 1;
if (MAJOR(dev->dev) == _emcpower_major)
return 1;
if ((MAJOR(dev->dev) == _blkext_major) &&
(get_primary_dev(sysfs_dir_path(), dev, &primary_dev)) &&
(MAJOR(primary_dev) == _md_major))
return 1;
return 0;
}
static unsigned long _dev_topology_attribute(const char *attribute,
const char *sysfs_dir,
struct device *dev)
{
const char *sysfs_fmt_str = "%s/dev/block/%d:%d/%s";
char path[PATH_MAX+1], buffer[64];
FILE *fp;
struct stat info;
dev_t uninitialized_var(primary);
unsigned long result = 0UL;
if (!attribute || !*attribute)
return_0;
if (!sysfs_dir || !*sysfs_dir)
return_0;
if (dm_snprintf(path, PATH_MAX, sysfs_fmt_str, sysfs_dir,
(int)MAJOR(dev->dev), (int)MINOR(dev->dev),
attribute) < 0) {
log_error("dm_snprintf %s failed", attribute);
return 0;
}
/*
* check if the desired sysfs attribute exists
* - if not: either the kernel doesn't have topology support
* or the device could be a partition
*/
if (stat(path, &info) == -1) {
if (errno != ENOENT) {
log_sys_error("stat", path);
return 0;
}
if (!get_primary_dev(sysfs_dir, dev, &primary))
return 0;
/* get attribute from partition's primary device */
if (dm_snprintf(path, PATH_MAX, sysfs_fmt_str, sysfs_dir,
(int)MAJOR(primary), (int)MINOR(primary),
attribute) < 0) {
log_error("primary dm_snprintf %s failed", attribute);
return 0;
}
if (stat(path, &info) == -1) {
if (errno != ENOENT)
log_sys_error("stat", path);
return 0;
}
}
if (!(fp = fopen(path, "r"))) {
log_sys_error("fopen", path);
return 0;
}
if (!fgets(buffer, sizeof(buffer), fp)) {
log_sys_error("fgets", path);
goto out;
}
if (sscanf(buffer, "%lu", &result) != 1) {
log_error("sysfs file %s not in expected format: %s", path,
buffer);
goto out;
}
log_very_verbose("Device %s %s is %lu bytes.",
dev_name(dev), attribute, result);
out:
if (fclose(fp))
log_sys_error("fclose", path);
return result >> SECTOR_SHIFT;
}