LockedOpenFile - initializes a new lock and protects the file from concurrent access across mount points.

Open - Call os.OpenFile.

RLockedOpenFile - returns a wrapped read locked file, if the file doesn't exist at path returns an error.

TryLockedOpenFile - tries a new write lock, functionality it is similar to LockedOpenFile with with syscall.LOCK_EX mode but along with syscall.LOCK_NB such that the function doesn't wait forever but instead returns if it cannot acquire a write lock.

ErrAlreadyLocked is returned if the underlying fd is already locked.

LockedFile represents a locked file.

RLockedFile represents a read locked file, implements a special closer which only closes the associated *os.File when the ref count.