Xv Fat Discussion

General Introduction
This is a memorandum page for the discussion about the xvFAT File System which enables the stable operation of the removable mass media on USB. Because of the interoperability with the PC, FAT will be an useful file system. However the Linux implementation of the file system is not taking account of the stable operation of the system when it is used for the removable media. In the worst case, Linux system would be panicked when it is removed inadequately.

On 25th May 2005, Sony have called for the private technical discussion on this technology. Sony showed their improvement of the FAT file system to make it "Panic Free" in most case of the user operation of removing media.

Notice to non Japanese speakers :  We sincerely apologize to whom may not to be convenient in making conversation in Japanese. This session may include many discussion in Japanese.

Here, you may find the introduction of the XvFat.
 * English : [[Media:20050325-xvfat-intro-en.pdf]]
 * Thanks to Mr. Asai's (IBM) cooperation in translating it into English.
 * Japanese : [[Media:20050325-xvfat-intro-jpn.pdf]]

Mailing List

 * A mailing list is prepared for this discussion.
 * Note: Messages in Japanese is allowed however for the convenience of non Japanese speakers, please add slight summary of the message in English.
 * Please register sig_xvfat@tree.celinuxforum.org ;)
 * Registration Site http://tree.celinuxforum.org/mailman/listinfo/sig_xvfat
 * Non CE Linux Forum Members are also welcomed

Why FAT?

 * FAT can be used for both CE products and PC commonly, which may prevent the user confusion.

Problem of the FAT for Removable Media

 * We knew that in such condition that when the user plug off the device while OS is writing the data to the media, in the worst case the OS fall to "Panic". It will never be allowed by the users.
 * Our users may allow the data is not saved when the media is removed while data writing.
 * But we have to be careful that those requirements may be vary to the products.

Presentation Material

 * By Machida san of Sony is here.
 * The material is here :
 * [[Media:20050520-xvfat-discussion-1.pdf]] (Japanese)
 * [[Media:20050520-xvfat-discussion-en.pdf]] (English)
 * At the International Technical Jamboree on 14th June, 2005
 * [[Media:20050614-celf-xvfs.pdf]]

To do items

 * Sony is going to isolate the improvement and split it into the elements for the acceptation to the master kernel.

Please pay attention to

 * http://www.linuxdevices.com/news/NS9955450995.html
 * http://hardware.slashdot.org/article.pl?sid=05/06/07/0314221&from=rss
 * Slash Dot...

Patch for 2.4.20 for your reference
[[Media:20050715-xvfat-2.4.20.patch]]