Re: [9fans] Plan 9 server controls impaired and steps taken before

[Russ Cox <russcox@gmail.com>]

> > There is a window (I think ten seconds) between snap -a
> > and fossil deciding to start archiving.  If you access any
> > file in those ten seconds then enough of the root gets
> > copied-on-write that you shouldn't see the deadlock at all.
> >
> 
> What happens if some accesses come from Internet during that time ?
> Files in /sys/log/* are big enough.
> Sorry I couldn't understand "the root".

The root of the tree of files and blocks.  It's copy-on-write
after a snapshot but snap -a locks the blocks while it is
archiving.  If the block has already been copied, no big deal.
If it's still the one in the file tree (not been copied-on-write yet)
then you can't access it until the archiver finishes.  I should
fix this to be some sort of read lock but it's not completely
straightforward.

Russ