If you try to use quotactl on Linux...
Always remember to do this:
#define _LINUX_QUOTA_VERSION 2
Or else, your code will break in misterious ways.
That's because sys/quota.h has this:
/*
* Select between different incompatible quota versions.
* Default to the version used by Linux kernel version 2.4.21
* or earlier (in RHEL version 1 is AS2.1, version 2 is RHEL3 and later). */
#ifndef _LINUX_QUOTA_VERSION
# define _LINUX_QUOTA_VERSION 1
#endif
Why? I have no idea. But this is true at least on Centos4, I have no clue of this is also true for your distro, but it is sooooo wrong :-(