Overview

#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <fcntl.h>

int fallocate(int fd, int mode, off_t offset, off_t len);

Allocating disk space

• FALLOC_FL_KEEP_SIZE
• FALLOC_FL_UNSHARE

Deallocatiing file space

• FALLOC_FL_PUNCH_HOLE

Collapsing file space

• FALLOC_FL_COLLAPSE_RANGE

Zeroing file space

• FALLOC_FL_ZERO_RANGE

Increasing file space

• FALLOC_FL_INSERT_RANGE