Re: Anyone recall the dreaded tstile issue?

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>> I have found enough time to have a quick look at the code, and I've
>> found a code path that looks like what I was looking for: something
>> that blocks until a git subprocess finishes without handling
>> filesystem requests in the meantime.  I'll need to reorganize the
>> code a little to fix that.

> Doesn't thie problem need a deeper fix?  It is annoying that a poorly
> programmed userland process can kill the system.

No more so than a puffs backing process that mounts the filesystem and
then goes into an infinite loop.  This sort of failure mode is one of
the risks of userland-backed filesystems.  It just took me a while to
track it down, largely for complete lack of prior experience with
anything of the sort.

Or consider while (1) { fork(); }.

Also, and not directly related to your remark, I now suspect that if
I'd told ddb to kill the gitfs process(es), the system would have come
unstuck.

I don't see this as fundamentally different (though admittedly less
severe than) dd if=/dev/urandom of=/dev/mem: if root does something
sloppy, Bad Things can happen.  I think you will have trouble
completely preventing userland from wedging or crashing the system
while still preserving a useful system.

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