Re: Starting a grad project that may change kernel VFS. Early research

[Pavel Machek <pavel@ucw.cz>]

> 2) Second Question. The two part idea.
>     I was thinking that a good way to handle this is that it starts with
> a file change in a directory. The directory entry contains a sum already
> for itself and all the subdirs and an adjustment is made immediately to
> that, it should be in the cache. Then we queue up the change to be sent
> to the parent(s?). These queued up events should be a low priority at a
> more human time like 1 second. If a large number of changes come to a
> directory, multiple adjustments hit the queue with the same (directory
> name, inode #?) and early ones are thrown out. So levels above would see
> at most a 1 per second low priority update.
> 
>     So when you issue a 'du -sh' or use anything that uses stat like
> filelight, it can get the size of all the subdirs without actually
> recursing through them, they have been built up over time.

I'd suggest you look at jack's recursive mtime idea, and then
implement your features on top of that, in userland.


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html