posix_fallocate
===============

POSIX specification:
 https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fallocate.html

Gnulib module: ---

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  * This function is missing on some platforms: macOS 11.1, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.

  * POSIX specifies that EINVAL should be returned when the file system doesn't support the allocation operation directly.  glibc however emulates the file system allocation with writes where unsupported, and apps have depended on that long term implementation.  This is both inefficient, and as of glibc 2.21 at least, buggy on certain NFS setups.

  * On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.