The
undelete() succeeds unless:
[EACCES]
Search permission is denied for a component of the path prefix, or write permission is denied on the directory containing the name to be undeleted.
[EEXIST]
The path does not reference a whiteout.
[EFAULT]
path points outside the process's allocated address space.
[EINVAL]
The pathname contains a character with the high-order bit set.
[EIO]
An I/O error occurred while updating the directory entry.
[ELOOP]
Too many symbolic links were encountered in translating the pathname.
[ENAMETOOLONG]
A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
[ENOENT]
The named whiteout does not exist.
[ENOTDIR]
A component of the path prefix is not a directory.
[EPERM]
The directory containing the name is marked sticky, and the containing directory is not owned by the effective user ID.
[EROFS]
The name resides on a read-only file system.