> Stephen C. Tweedie:
> > Ordered writes have major problems. You want a list? OK: you get bad
> > cyclic dependencies (especially between inode blocks and bitmaps,
> > since multiple inodes get stored in a single block); if your data is
>
> I think (but could be wrong) that bitmaps can be recovered by e2fsck
> from the remaining information, so bitmaps could still be completely
> asynchronous as long as any other writes are ordered.
>
> > always being written, you NEVER get to update the inode; and Unixware
>
> Hmm, this looks like a real problem...
>
> > have got a broad-ranging patent for ordered filesystem writes anyway.
> > <sigh>.
Interesting, since IBM's VM/CMS has been using ordered filesystem writes
to do atomic metadata updates since, oh, 1967 or so? Not in a Unix style
filesystem, but close enough, I'd bet, to make Unixware's patent not as
broad as they think. (and for the bitmap type info as well).
Nick Simicich-njs@scifi.maid.com-(last choice) nick_simicich@bocaraton.ibm.com
http://scifi.maid.com/njs.html -- Stop by and Light Up The World!