Module fiemap 

Physical extent layout of files via FS_IOC_FIEMAP

FS_IOC_FIEMAP is a standard VFS ioctl (not btrfs-specific) that reports the physical extents backing a file. It is the mechanism btrfs filesystem du uses to determine how much disk space each file occupies and which extents are shared with other files.

Structs

FileExtentInfo

Summary of the physical extent usage of a single file.

Functions

file_extents

Query FS_IOC_FIEMAP for every extent of the file referred to by fd.