HFS kernel module for FreeBSD

Status

The HFS kernel module is based on the Darwin 6.6 (MacOS 10.2.6) source.

The HFS kernel driver from Darwin has been adapted to the framework of FreeBSD 5.

A particular effort has been made to ensure that this port adhere to the FreeBSD kernel interfaces and lock semantics.

Known Problems and Limitations

Only devices with the block size of 512 bytes are supported.

While the journaled variant of HFS Plus should be recognized, journaling itself isn't supported. If such a volume has been mounted read-write in FreeBSD, using it in Darwin or MacOS X may cause problems. That is to say: For now, avoid mounting journaled volumes read-write in FreeBSD.

Disk quotas are unsupported on HFS volumes.

Copying a large batch of files to an md(4) disk formatted as HFS with a small block size may lock up the system. This problem seems to happen because of a deadlock on disk buffer space between HFS and md(4). This was observed on a system with 64 RAM and a plain HFS volume image with the 512-byte allocation block (default for the disk size used.) Increasing RAM or allocation block size hid the problem.


$Id: kernel.html,v 1.3 2003/06/23 15:30:57 yar Exp $