On Tue, 17 Jul 2018, Arnd Bergmann wrote:

That would definitely help. See below for the stat implementation
I did in my musl libc prototype based on statx(). It passes the
LTP syscall tests, but that doesn't mean all the corner cases
are correct.

Well, you definitely need explicit timestamp conversions on the result of 
statx to be usable in struct stat when userspace "long" is 64-bit, for BE 
because otherwise the integer nanoseconds will be in the wrong place for 
struct timespec, and for LE if the "__reserved is held in case we need a 
yet finer resolution." might start being returned as nonzero (for integer 
attoseconds, I suppose) in future.

-- 
Joseph S. Myers
joseph@codesourcery.com