Re: [PATCH] Revert "mountd: handle allocation failures in auth_unix_ip upcall"

[Steve Dickson <SteveD@redhat.com>]

Hello,

On 26/11/12 17:51, J. Bruce Fields wrote:
>> What exactly is the problem with the current code?
>> > 
>> > client_resolve() can return a NULL in some cases.  Why is it OK to
>> > pass a NULL "ai" to client_compose() ?  Looks like that can result in
>> > a mountd segfault.
> Bah, I thought I'd checked this and found it was prepared to handle
> that, but no:
> 
> 	client_check->check_wildcard()
> 
> looks like it can oops.
Yeah... added client_check->check_netgroup() to this list...

> 
> OK, I'll take another look.
A simply check that ai is not null when calling client_compose() should work..

> 
>> > The kernel won't get any downcall reply in that
>> > case!  Is that what you are trying to fix?
>> > 
>> > WRT my original objection: In general I don't see how to make it
>> > impossible for mountd to fail.
> Sure, but mountd is required for the server to function, so it's just a
> question of how we fail.
> 
>> > Thus the kernel needs to be better about recovering when mountd
>> > suddenly disappears.
> Currently it drops and lets the client retry.  I suspect that's the
> correct thing to do, but alternatives are welcomed.
This one things I didn't see happen... the client retrying... expected it would...

steved.