svn commit: r239983 - stable/8/sys/netinet

[Bjoern A. Zeeb]

On Sat, 1 Sep 2012, Mikolaj Golub wrote:

> Author: trociny
> Date: Sat Sep  1 10:33:53 2012
> New Revision: 239983
> URL: http://svn.freebsd.org/changeset/base/239983
>
> Log:
>  MFC r239075:
>
>  In tcp timers, check INP_DROPPED flag a little later, after
>  callout_deactivate(), so if INP_DROPPED is set we return with the
>  timer active flag cleared.
>
>  For me this fixes negative keep timer values reported by `netstat -x'
>  for connections in CLOSE state.


panic: Lock tcp not read locked @ /w/src/sys/netinet/tcp_timer.c:497

reproducable on the cluster.  Probably wrong all the way up to HEAD?


> Modified:
>  stable/8/sys/netinet/tcp_timer.c
> Directory Properties:
>  stable/8/sys/   (props changed)
>
> Modified: stable/8/sys/netinet/tcp_timer.c
> ==============================================================================
> --- stable/8/sys/netinet/tcp_timer.c	Sat Sep  1 10:32:40 2012	(r239982)
> +++ stable/8/sys/netinet/tcp_timer.c	Sat Sep  1 10:33:53 2012	(r239983)
> @@ -176,13 +176,18 @@ tcp_timer_delack(void *xtp)
> 		return;
> 	}
> 	INP_WLOCK(inp);
> -	if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_delack)
> -	    || !callout_active(&tp->t_timers->tt_delack)) {
> +	if (callout_pending(&tp->t_timers->tt_delack) ||
> +	    !callout_active(&tp->t_timers->tt_delack)) {
> 		INP_WUNLOCK(inp);
> 		CURVNET_RESTORE();
> 		return;
> 	}
> 	callout_deactivate(&tp->t_timers->tt_delack);
> +	if ((inp->inp_flags & INP_DROPPED) != 0) {
> +		INP_WUNLOCK(inp);
> +		CURVNET_RESTORE();
> +		return;
> +	}
>
> 	tp->t_flags |= TF_ACKNOW;
> 	TCPSTAT_INC(tcps_delack);
> @@ -222,7 +227,7 @@ tcp_timer_2msl(void *xtp)
> 	}
> 	INP_WLOCK(inp);
> 	tcp_free_sackholes(tp);
> -	if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_2msl) ||
> +	if (callout_pending(&tp->t_timers->tt_2msl) ||
> 	    !callout_active(&tp->t_timers->tt_2msl)) {
> 		INP_WUNLOCK(tp->t_inpcb);
> 		INP_INFO_WUNLOCK(&V_tcbinfo);
> @@ -230,6 +235,12 @@ tcp_timer_2msl(void *xtp)
> 		return;
> 	}
> 	callout_deactivate(&tp->t_timers->tt_2msl);
> +	if ((inp->inp_flags & INP_DROPPED) != 0) {
> +		INP_WUNLOCK(inp);
> +		INP_INFO_WUNLOCK(&V_tcbinfo);
> +		CURVNET_RESTORE();
> +		return;
> +	}
> 	/*
> 	 * 2 MSL timeout in shutdown went off.  If we're closed but
> 	 * still waiting for peer to close and connection has been idle
> @@ -293,14 +304,20 @@ tcp_timer_keep(void *xtp)
> 		return;
> 	}
> 	INP_WLOCK(inp);
> -	if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_keep)
> -	    || !callout_active(&tp->t_timers->tt_keep)) {
> +	if (callout_pending(&tp->t_timers->tt_keep) ||
> +	    !callout_active(&tp->t_timers->tt_keep)) {
> 		INP_WUNLOCK(inp);
> 		INP_INFO_WUNLOCK(&V_tcbinfo);
> 		CURVNET_RESTORE();
> 		return;
> 	}
> 	callout_deactivate(&tp->t_timers->tt_keep);
> +	if ((inp->inp_flags & INP_DROPPED) != 0) {
> +		INP_WUNLOCK(inp);
> +		INP_INFO_WUNLOCK(&V_tcbinfo);
> +		CURVNET_RESTORE();
> +		return;
> +	}
> 	/*
> 	 * Keep-alive timer went off; send something
> 	 * or drop connection if idle for too long.
> @@ -388,14 +405,20 @@ tcp_timer_persist(void *xtp)
> 		return;
> 	}
> 	INP_WLOCK(inp);
> -	if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_persist)
> -	    || !callout_active(&tp->t_timers->tt_persist)) {
> +	if (callout_pending(&tp->t_timers->tt_persist) ||
> +	    !callout_active(&tp->t_timers->tt_persist)) {
> 		INP_WUNLOCK(inp);
> 		INP_INFO_WUNLOCK(&V_tcbinfo);
> 		CURVNET_RESTORE();
> 		return;
> 	}
> 	callout_deactivate(&tp->t_timers->tt_persist);
> +	if ((inp->inp_flags & INP_DROPPED) != 0) {
> +		INP_WUNLOCK(inp);
> +		INP_INFO_WUNLOCK(&V_tcbinfo);
> +		CURVNET_RESTORE();
> +		return;
> +	}
> 	/*
> 	 * Persistance timer into zero window.
> 	 * Force a byte to be output, if possible.
> @@ -461,14 +484,20 @@ tcp_timer_rexmt(void * xtp)
> 		return;
> 	}
> 	INP_WLOCK(inp);
> -	if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_rexmt)
> -	    || !callout_active(&tp->t_timers->tt_rexmt)) {
> +	if (callout_pending(&tp->t_timers->tt_rexmt) ||
> +	    !callout_active(&tp->t_timers->tt_rexmt)) {
> 		INP_WUNLOCK(inp);
> 		INP_INFO_WUNLOCK(&V_tcbinfo);
> 		CURVNET_RESTORE();
> 		return;
> 	}
> 	callout_deactivate(&tp->t_timers->tt_rexmt);
> +	if ((inp->inp_flags & INP_DROPPED) != 0) {
> +		INP_WUNLOCK(inp);
> +		INP_INFO_RUNLOCK(&V_tcbinfo);
> +		CURVNET_RESTORE();
> +		return;
> +	}
> 	tcp_free_sackholes(tp);
> 	/*
> 	 * Retransmission timer went off.  Message has not
>

-- 
Bjoern A. Zeeb                                 You have to have visions!
          Stop bit received. Insert coin for new address family.