Author: rrs
Date: Tue Aug 16 12:40:56 2016
New Revision: 304218
URL: https://svnweb.freebsd.org/changeset/base/304218
Log:
This cleans up the timer code in TCP and also makes it so we do not
take the INFO lock *unless* we are really going to delete the TCB.
Differential Revision: D7136
Modified:
head/sys/netinet/tcp_timer.c
head/sys/netinet/tcp_timer.h
Modified: head/sys/netinet/tcp_timer.c
==============================================================================
--- head/sys/netinet/tcp_timer.c Tue Aug 16 12:13:12 2016
(r304217)
+++ head/sys/netinet/tcp_timer.c Tue Aug 16 12:40:56 2016
(r304218)
@@ -294,11 +294,6 @@ tcp_timer_delack(void *xtp)
CURVNET_RESTORE();
return;
}
- KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
- ("%s: tp %p tcpcb can't be stopped here", __func__, tp));
- KASSERT((tp->t_timers->tt_flags & TT_DELACK) != 0,
- ("%s: tp %p delack callout should be running", __func__, tp));
-
tp->t_flags |= TF_ACKNOW;
TCPSTAT_INC(tcps_delack);
(void) tp->t_fb->tfb_tcp_output(tp);
@@ -306,6 +301,39 @@ tcp_timer_delack(void *xtp)
CURVNET_RESTORE();
}
+int
+tcp_inpinfo_lock_add(struct inpcb *inp)
+{
+ in_pcbref(inp);
+ INP_WUNLOCK(inp);
+ INP_INFO_RLOCK(&V_tcbinfo);
+ INP_WLOCK(inp);
+ if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
+ return(1);
+ }
+ return(0);
+
+}
+
+void
+tcp_inpinfo_lock_del(struct inpcb *inp, struct tcpcb *tp)
+{
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ if (inp && (tp == NULL)) {
+ /*
+ * If tcp_close/drop() gets called and tp
+ * returns NULL, then the function dropped
+ * the inp lock, we hold a reference keeping
+ * this around, so we must re-aquire the
+ * INP_WLOCK() in order to proceed with
+ * our dropping the inp reference.
+ */
+ INP_WLOCK(inp);
+ }
+ if (inp && in_pcbrele_wlocked(inp) == 0)
+ INP_WUNLOCK(inp);
+}
+
void
tcp_timer_2msl(void *xtp)
{
@@ -317,7 +345,6 @@ tcp_timer_2msl(void *xtp)
ostate = tp->t_state;
#endif
- INP_INFO_RLOCK(&V_tcbinfo);
inp = tp->t_inpcb;
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
INP_WLOCK(inp);
@@ -325,21 +352,17 @@ tcp_timer_2msl(void *xtp)
if (callout_pending(&tp->t_timers->tt_2msl) ||
!callout_active(&tp->t_timers->tt_2msl)) {
INP_WUNLOCK(tp->t_inpcb);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
callout_deactivate(&tp->t_timers->tt_2msl);
if ((inp->inp_flags & INP_DROPPED) != 0) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
- KASSERT((tp->t_timers->tt_flags & TT_2MSL) != 0,
- ("%s: tp %p 2msl callout should be running", __func__, tp));
/*
* 2 MSL timeout in shutdown went off. If we're closed but
* still waiting for peer to close and connection has been idle
@@ -355,7 +378,6 @@ tcp_timer_2msl(void *xtp)
*/
if ((inp->inp_flags & INP_TIMEWAIT) != 0) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
@@ -363,15 +385,26 @@ tcp_timer_2msl(void *xtp)
tp->t_inpcb && tp->t_inpcb->inp_socket &&
(tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE)) {
TCPSTAT_INC(tcps_finwait2_drops);
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
tp = tcp_close(tp);
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
} else {
if (ticks - tp->t_rcvtime <= TP_MAXIDLE(tp)) {
- if (!callout_reset(&tp->t_timers->tt_2msl,
- TP_KEEPINTVL(tp), tcp_timer_2msl, tp)) {
- tp->t_timers->tt_flags &= ~TT_2MSL_RST;
+ callout_reset(&tp->t_timers->tt_2msl,
+ TP_KEEPINTVL(tp), tcp_timer_2msl, tp);
+ } else {
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
}
- } else
- tp = tcp_close(tp);
+ tp = tcp_close(tp);
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
}
#ifdef TCPDEBUG
@@ -383,7 +416,7 @@ tcp_timer_2msl(void *xtp)
if (tp != NULL)
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
+out:
CURVNET_RESTORE();
}
@@ -399,28 +432,23 @@ tcp_timer_keep(void *xtp)
ostate = tp->t_state;
#endif
- INP_INFO_RLOCK(&V_tcbinfo);
inp = tp->t_inpcb;
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
INP_WLOCK(inp);
if (callout_pending(&tp->t_timers->tt_keep) ||
!callout_active(&tp->t_timers->tt_keep)) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
callout_deactivate(&tp->t_timers->tt_keep);
if ((inp->inp_flags & INP_DROPPED) != 0) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
- KASSERT((tp->t_timers->tt_flags & TT_KEEP) != 0,
- ("%s: tp %p keep callout should be running", __func__, tp));
/*
* Keep-alive timer went off; send something
* or drop connection if idle for too long.
@@ -452,14 +480,11 @@ tcp_timer_keep(void *xtp)
tp->rcv_nxt, tp->snd_una - 1, 0);
free(t_template, M_TEMP);
}
- if (!callout_reset(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
- tcp_timer_keep, tp)) {
- tp->t_timers->tt_flags &= ~TT_KEEP_RST;
- }
- } else if (!callout_reset(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
- tcp_timer_keep, tp)) {
- tp->t_timers->tt_flags &= ~TT_KEEP_RST;
- }
+ callout_reset(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
+ tcp_timer_keep, tp);
+ } else
+ callout_reset(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
+ tcp_timer_keep, tp);
#ifdef TCPDEBUG
if (inp->inp_socket->so_options & SO_DEBUG)
@@ -468,12 +493,16 @@ tcp_timer_keep(void *xtp)
#endif
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
dropit:
TCPSTAT_INC(tcps_keepdrops);
+
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
tp = tcp_drop(tp, ETIMEDOUT);
#ifdef TCPDEBUG
@@ -482,9 +511,8 @@ dropit:
PRU_SLOWTIMO);
#endif
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
- if (tp != NULL)
- INP_WUNLOCK(tp->t_inpcb);
- INP_INFO_RUNLOCK(&V_tcbinfo);
+ tcp_inpinfo_lock_del(inp, tp);
+out:
CURVNET_RESTORE();
}
@@ -499,28 +527,23 @@ tcp_timer_persist(void *xtp)
ostate = tp->t_state;
#endif
- INP_INFO_RLOCK(&V_tcbinfo);
inp = tp->t_inpcb;
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
INP_WLOCK(inp);
if (callout_pending(&tp->t_timers->tt_persist) ||
!callout_active(&tp->t_timers->tt_persist)) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
callout_deactivate(&tp->t_timers->tt_persist);
if ((inp->inp_flags & INP_DROPPED) != 0) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
CURVNET_RESTORE();
return;
}
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
- KASSERT((tp->t_timers->tt_flags & TT_PERSIST) != 0,
- ("%s: tp %p persist callout should be running", __func__, tp));
/*
* Persistence timer into zero window.
* Force a byte to be output, if possible.
@@ -537,7 +560,12 @@ tcp_timer_persist(void *xtp)
(ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
TCPSTAT_INC(tcps_persistdrop);
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
tp = tcp_drop(tp, ETIMEDOUT);
+ tcp_inpinfo_lock_del(inp, tp);
goto out;
}
/*
@@ -547,7 +575,12 @@ tcp_timer_persist(void *xtp)
if (tp->t_state > TCPS_CLOSE_WAIT &&
(ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
TCPSTAT_INC(tcps_persistdrop);
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
tp = tcp_drop(tp, ETIMEDOUT);
+ tcp_inpinfo_lock_del(inp, tp);
goto out;
}
tcp_setpersist(tp);
@@ -555,15 +588,13 @@ tcp_timer_persist(void *xtp)
(void) tp->t_fb->tfb_tcp_output(tp);
tp->t_flags &= ~TF_FORCEDATA;
-out:
#ifdef TCPDEBUG
if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
#endif
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
- if (tp != NULL)
- INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&V_tcbinfo);
+ INP_WUNLOCK(inp);
+out:
CURVNET_RESTORE();
}
@@ -573,36 +604,29 @@ tcp_timer_rexmt(void * xtp)
struct tcpcb *tp = xtp;
CURVNET_SET(tp->t_vnet);
int rexmt;
- int headlocked;
struct inpcb *inp;
#ifdef TCPDEBUG
int ostate;
ostate = tp->t_state;
#endif
-
- INP_INFO_RLOCK(&V_tcbinfo);
inp = tp->t_inpcb;
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
INP_WLOCK(inp);
if (callout_pending(&tp->t_timers->tt_rexmt) ||
!callout_active(&tp->t_timers->tt_rexmt)) {
INP_WUNLOCK(inp);
- INP_INFO_RUNLOCK(&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;
}
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
- KASSERT((tp->t_timers->tt_flags & TT_REXMT) != 0,
- ("%s: tp %p rexmt callout should be running", __func__, tp));
tcp_free_sackholes(tp);
if (tp->t_fb->tfb_tcp_rexmit_tmr) {
/* The stack has a timer action too. */
@@ -616,14 +640,15 @@ tcp_timer_rexmt(void * xtp)
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
TCPSTAT_INC(tcps_timeoutdrop);
-
+ if (tcp_inpinfo_lock_add(inp)) {
+ tcp_inpinfo_lock_del(inp, tp);
+ goto out;
+ }
tp = tcp_drop(tp, tp->t_softerror ?
tp->t_softerror : ETIMEDOUT);
- headlocked = 1;
+ tcp_inpinfo_lock_del(inp, tp);
goto out;
}
- INP_INFO_RUNLOCK(&V_tcbinfo);
- headlocked = 0;
if (tp->t_state == TCPS_SYN_SENT) {
/*
* If the SYN was retransmitted, indicate CWND to be
@@ -811,17 +836,14 @@ tcp_timer_rexmt(void * xtp)
(void) tp->t_fb->tfb_tcp_output(tp);
-out:
#ifdef TCPDEBUG
if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
PRU_SLOWTIMO);
#endif
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
- if (tp != NULL)
- INP_WUNLOCK(inp);
- if (headlocked)
- INP_INFO_RUNLOCK(&V_tcbinfo);
+ INP_WUNLOCK(inp);
+out:
CURVNET_RESTORE();
}
@@ -832,7 +854,6 @@ tcp_timer_activate(struct tcpcb *tp, uin
timeout_t *f_callout;
struct inpcb *inp = tp->t_inpcb;
int cpu = inp_to_cpuid(inp);
- uint32_t f_reset;
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
@@ -846,27 +867,22 @@ tcp_timer_activate(struct tcpcb *tp, uin
case TT_DELACK:
t_callout = &tp->t_timers->tt_delack;
f_callout = tcp_timer_delack;
- f_reset = TT_DELACK_RST;
break;
case TT_REXMT:
t_callout = &tp->t_timers->tt_rexmt;
f_callout = tcp_timer_rexmt;
- f_reset = TT_REXMT_RST;
break;
case TT_PERSIST:
t_callout = &tp->t_timers->tt_persist;
f_callout = tcp_timer_persist;
- f_reset = TT_PERSIST_RST;
break;
case TT_KEEP:
t_callout = &tp->t_timers->tt_keep;
f_callout = tcp_timer_keep;
- f_reset = TT_KEEP_RST;
break;
case TT_2MSL:
t_callout = &tp->t_timers->tt_2msl;
f_callout = tcp_timer_2msl;
- f_reset = TT_2MSL_RST;
break;
default:
if (tp->t_fb->tfb_tcp_timer_activate) {
@@ -876,24 +892,9 @@ tcp_timer_activate(struct tcpcb *tp, uin
panic("tp %p bad timer_type %#x", tp, timer_type);
}
if (delta == 0) {
- if ((tp->t_timers->tt_flags & timer_type) &&
- (callout_stop(t_callout) > 0) &&
- (tp->t_timers->tt_flags & f_reset)) {
- tp->t_timers->tt_flags &= ~(timer_type | f_reset);
- }
+ callout_stop(t_callout);
} else {
- if ((tp->t_timers->tt_flags & timer_type) == 0) {
- tp->t_timers->tt_flags |= (timer_type | f_reset);
- callout_reset_on(t_callout, delta, f_callout, tp, cpu);
- } else {
- /* Reset already running callout on the same CPU. */
- if (!callout_reset(t_callout, delta, f_callout, tp)) {
- /*
- * Callout not cancelled, consider it as not
- * properly restarted. */
- tp->t_timers->tt_flags &= ~f_reset;
- }
- }
+ callout_reset_on(t_callout, delta, f_callout, tp, cpu);
}
}
@@ -931,30 +932,23 @@ void
tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
{
struct callout *t_callout;
- uint32_t f_reset;
tp->t_timers->tt_flags |= TT_STOPPED;
-
switch (timer_type) {
case TT_DELACK:
t_callout = &tp->t_timers->tt_delack;
- f_reset = TT_DELACK_RST;
break;
case TT_REXMT:
t_callout = &tp->t_timers->tt_rexmt;
- f_reset = TT_REXMT_RST;
break;
case TT_PERSIST:
t_callout = &tp->t_timers->tt_persist;
- f_reset = TT_PERSIST_RST;
break;
case TT_KEEP:
t_callout = &tp->t_timers->tt_keep;
- f_reset = TT_KEEP_RST;
break;
case TT_2MSL:
t_callout = &tp->t_timers->tt_2msl;
- f_reset = TT_2MSL_RST;
break;
default:
if (tp->t_fb->tfb_tcp_timer_stop) {
@@ -968,15 +962,13 @@ tcp_timer_stop(struct tcpcb *tp, uint32_
panic("tp %p bad timer_type %#x", tp, timer_type);
}
- if (tp->t_timers->tt_flags & timer_type) {
- if (callout_async_drain(t_callout, tcp_timer_discard) == 0) {
- /*
- * Can't stop the callout, defer tcpcb actual deletion
- * to the last one. We do this using the async drain
- * function and incrementing the count in
- */
- tp->t_timers->tt_draincnt++;
- }
+ if (callout_async_drain(t_callout, tcp_timer_discard) == 0) {
+ /*
+ * Can't stop the callout, defer tcpcb actual deletion
+ * to the last one. We do this using the async drain
+ * function and incrementing the count in
+ */
+ tp->t_timers->tt_draincnt++;
}
}
Modified: head/sys/netinet/tcp_timer.h
==============================================================================
--- head/sys/netinet/tcp_timer.h Tue Aug 16 12:13:12 2016
(r304217)
+++ head/sys/netinet/tcp_timer.h Tue Aug 16 12:40:56 2016
(r304218)
@@ -191,6 +191,9 @@ extern int tcp_syn_backoff[];
extern int tcp_finwait2_timeout;
extern int tcp_fast_finwait2_recycle;
+int tcp_inpinfo_lock_add(struct inpcb *inp);
+void tcp_inpinfo_lock_del(struct inpcb *inp, struct tcpcb *tp);
+
void tcp_timer_init(void);
void tcp_timer_2msl(void *xtp);
void tcp_timer_discard(void *);
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