is stat(2) read-after-write consistent with write(2)?

man 2 write states: >POSIX requires that a read(2) that can be proved to occur after a write() has returned will return the new data. Note that not all filesystems are POSIX conforming. In Linux, is this also true for stat(2) and fstat(2), in particular, for the stat.st_size member?
Specifically, if you open a file with O_CREAT, successfully write 948427 bytes to it, then either stat or fstat it, are you guaranteed to see a st_size of 948427?
(If so, is this a guarantee for POSIX filesystems, or something that typical Linux filesystems provide in practice, or a property of certain filesystems and not others?)