diff options
Diffstat (limited to 'lib/device/dev-type.c')
| -rw-r--r-- | lib/device/dev-type.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/lib/device/dev-type.c b/lib/device/dev-type.c index deb5d6a0f..4ac3a4e76 100644 --- a/lib/device/dev-type.c +++ b/lib/device/dev-type.c @@ -380,6 +380,45 @@ static int _loop_is_with_partscan(struct device *dev) return partscan; } +int dev_get_partition_number(struct device *dev, int *num) +{ + char path[PATH_MAX]; + char buf[8] = { 0 }; + dev_t devt = dev->dev; + struct stat sb; + + if (dev->part != -1) { + *num = dev->part; + return 1; + } + + if (dm_snprintf(path, sizeof(path), "%sdev/block/%d:%d/partition", + dm_sysfs_dir(), (int)MAJOR(devt), (int)MINOR(devt)) < 0) { + log_error("Failed to create sysfs path for %s", dev_name(dev)); + return 0; + } + + if (stat(path, &sb)) { + dev->part = 0; + *num = 0; + return 1; + } + + if (!get_sysfs_value(path, buf, sizeof(buf), 0)) { + log_error("Failed to read sysfs path for %s", dev_name(dev)); + return 0; + } + + if (!buf[0]) { + log_error("Failed to read sysfs partition value for %s", dev_name(dev)); + return 0; + } + + dev->part = atoi(buf); + *num = dev->part; + return 1; +} + /* See linux/genhd.h and fs/partitions/msdos */ #define PART_MAGIC 0xAA55 #define PART_MAGIC_OFFSET UINT64_C(0x1FE) |