Re: [PATCH net 1/3] net/smc: Resolve the race between link group access and termination

[Wen Gu]

On 2022/1/10 8:25 pm, Karsten Graul wrote:
> On 10/01/2022 10:26, Wen Gu wrote:
> > We encountered some crashes caused by the race between the access
> > and the termination of link groups.

> > @@ -1120,8 +1122,22 @@ void smc_conn_free(struct smc_connection *conn)
> >   {
> >   	struct smc_link_group *lgr = conn->lgr;
> >   
> > -	if (!lgr)
> > +	if (!lgr || conn->freed)
> > +		/* The connection has never been registered in a
> > +		 * link group, or has already been freed.
> > +		 *
> > +		 * Check to ensure that the refcnt of link group
> > +		 * won't be put incorrectly.
>
> I would delete the second sentence here, its obvious enough.
>
> > +		 */
> >   		return;
> > +
> > +	conn->freed = 1;
> > +	if (!conn->alert_token_local)
> > +		/* The connection was registered in a link group
> > +		 * defore, but now it is unregistered from it.
>
> 'before' ... But would maybe the following be more exact:
>
> 'Connection already unregistered from link group.'
>
>
> We still review the patches...

Thanks for your detailed and patient review. The comments will
be improved as you suggested.

Thanks,
Wen Gu