Constant SECTOR_SIZE 

const SECTOR_SIZE: u64 = 512;

Copied from psutil:

“man iostat” states that sectors are equivalent with blocks and have a size of 512 bytes. Despite this value can be queried at runtime via /sys/block/{DISK}/queue/hw_sector_size and results may vary between 1k, 2k, or 4k… 512 appears to be a magic constant used throughout Linux source code:

• https://stackoverflow.com/a/38136179/376587
• https://lists.gt.net/linux/kernel/2241060
• https://github.com/giampaolo/psutil/issues/1305
• https://github.com/torvalds/linux/blob/4f671fe2f9523a1ea206f63fe60a7c7b3a56d5c7/include/linux/bio.h#L99
• https://lkml.org/lkml/2015/8/17/234