Re: [9fans] 9vx (is this the right list)? import issue

[erik quanstrom <quanstro@quanstro.net>]

> I mean that the code as written is assuming that if a read or write
> errors out, it can only happen for one of two reasons:
> 1) there was an interrupt note, in which case strcmp(error, Eintr) == 0
> 2) there has been an error on the 9P connection, in which case
>    strcmp(error, Eintr) != 0 and the connection will never work again.
>
> My suggestion is to enforce #2: if a non-interrupt error happens,
> mark the connection so that the kernel won't even try to use it
> again.
>
> Separately, you might investigate what error is happening that
> violates the assumption above.  In 9vx, it is easy: case #1 happened
> but the error was spelled wrong.

how sure are we that 1 holds?  couldn't there be other,
legitimate and transient errors?  could a user-delivered
note sneak in and confuse the issue?

the problem with my solution is that it could leak tags.
i don't see this as a significant problem, but i could be
wrong.  i think the connection would need to be pretty
broken for tags to be leaked.

marking connections dead also adds tracking, but in
a new place.  it could have trouble if ever a transient error
happens when strcmp(error, Eintr) == 0, which can
happen in 9vx or dt.

- erik