CDfs 2.6.12 review

CDfs is a file system for Linux systems that `exports' all tracks and boot images on a CD as normal files

License: GPL (GNU General Public License) File size: 0K Developer: Michiel Ronsse

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CDfs is a file system for Linux systems that `exports' all tracks and boot images on a CD as normal files. These files can then be mounted (e.g. for ISO and boot images), copied, played (audio and VideoCD tracks)...

The primary goal for developing this file system was to `unlock' information in old ISO images. For instance, if you have a multisession CD with two ISO images that both contain the file 'a', you only see the file 'a' in the second session if you use the iso9660 file system:

[root@k6 /root]# mount -t iso9660 -o ro /dev/cdrom /mnt/cdrom

[root@k6 /root]# ls -l /mnt/cdrom
total 2
-r-xr-xr-x 1 root root 2 Aug 8 19:16 a
-r-xr-xr-x 1 root root 2 Aug 8 19:19 b

If you mount the CD with the cdfs file system, you get the two sessions as files:

[root@k6 /root]# mount -t cdfs -o ro /dev/cdrom /mnt/cdfs

[root@k6 /root]# ls -l /mnt/cdfs
total 33389
-r--r--r-- 1 ronsse ronsse 33503232 Aug 8 19:36 sessions_1-1.iso
-r--r--r-- 1 ronsse ronsse 34121728 Aug 8 1999 sessions_1-2.iso

These files can then be mounted loop back:

[root@k6 /root]# mount -t iso9660 -o loop /cdfs/sessions_1-1.iso /mnt/loop1

[root@k6 /root]# mount -t iso9660 -o loop /cdfs/sessions_1-2.iso /mnt/loop2

and the file a can be accessed in both sessions

[root@k6 /root]# ls -l /mnt/loop1
total 9889
-r-xr-xr-x 1 root root 10104236 Aug 8 17:34 a

[root@k6 /root]# ls -l /mnt/loop2
total 2
-r-xr-xr-x 1 root root 2 Aug 8 19:16 a
-r-xr-xr-x 1 root root 2 Aug 8 19:19 b

The file system also allows you to access data on faulty multi session disks, e.g. disk with multiple single sessions instead of a multi session (for instance created with mkisofs without the proper -C parameters).

Limitations:
Red Book (audio), Yellow Book Mode 1 (data) , Green/White Book Mode 2 / XA Form 1 and Green/White Book Mode 2 / XA Form 2 (data) tracks are exported. Other types will be added in the future. Data tracks are checked for ISO, HFS and boot images. If none of these are found, the data track is exported as `unknown`. This version only exports the first HFS and boot image (anybody seen a CD with more than 1 HFS or boot image?).