getfh() fails if one or more of the following are true:
[ENOTDIR]
A component of the path prefix of path is not a directory.
[ENAMETOOLONG]
The length of a component of path exceeds {NAME_MAX} characters, or the length of path exceeds {PATH_MAX} characters.
[ENOENT]
The file referred to by path does not exist.
[EACCES]
Search permission is denied for a component of the path prefix of path.
[ELOOP]
Too many symbolic links were encountered in translating path.
[EFAULT]
fhp points to an invalid address.
[EIO]
An I/O error occurred while reading from or writing to the file system.
[E2BIG]
The memory allocated for the file handle is too small. The size needed has been written to the variable pointed to by fh_size.
[ENOMEM]
The kernel failed to allocate temporary memory to create a filehandle of the requested size.