Re: FAT32 superiority over ext2 :-)

Juri Haberland (juri@koschikode.com)
25 Jun 2001 15:04:47 -0000


In article <0106250203070J.00430@starship> you wrote:
> On Monday 25 June 2001 01:49, Albert D. Cahalan wrote:
>> Daniel Phillips writes:
>> > On Monday 25 June 2001 00:54, Albert D. Cahalan wrote:
>> >> By dumb luck (?), FAT32 is compatible with the phase-tree algorithm
>> >> as seen in Tux2. This means it offers full data integrity.
>> >> Yep, it whips your typical journalling filesystem. Look at what
>> >> we have in the superblock (boot sector):
>> >>
>> >> __u32 fat32_length; /* sectors/FAT */
>> >> __u16 flags; /* bit 8: fat mirroring, low 4: active fat */
>> >> __u8 version[2]; /* major, minor filesystem version */
>> >> __u32 root_cluster; /* first cluster in root directory */
>> >> __u16 info_sector; /* filesystem info sector */
>> >>
>> >> All in one atomic write, one can...
>> >>
>> >> 1. change the active FAT
>> >> 2. change the root directory
>> >> 3. change the free space count
>> >>
>> >> That's enough to atomically move from one phase to the next.
>> >> You create new directories in the free space, and make FAT
>> >> changes to an inactive FAT copy. Then you write the superblock
>> >> to atomically transition to the next phase.

[--snip--]

> When can we expect the patch?

Don't! Blasphemy!!!

Juri ;-)

-- 
Juri Haberland  <juri@koschikode.com> 

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