On Thu, Dec 19, 2013 at 10:27:38AM +0800, Hu Tao wrote: > +static int raw_preallocate2(int fd, int64_t offset, int64_t length) > +{ > + int ret = -1; > + > + ret = fallocate(fd, 0, offset, length); > + > + /* fallback to posix_fallocate() if fallocate() is not supported */ > + if (ret < 0 && (errno == ENOSYS || errno == EOPNOTSUPP)) { > + ret = posix_fallocate(fd, offset, length); > + } > + > + return ret;
Return value semantics differ between the two functions: * fallocate - return 0 or -1 with errno set * posix_fallocate - return 0 or error number (without using errno!) Please make it consistent. Usually in QEMU we return 0 on success and -errno on failure.