Author: glebius
Date: Thu Nov 7 21:23:07 2019
New Revision: 354483
URL: https://svnweb.freebsd.org/changeset/base/354483
Log:
Now that all of the tcp_input() and all its branches are executed
in the network epoch, we can greatly simplify synchronization.
Remove all unneccesary epoch enters hidden under INP_INFO_RLOCK macro.
Remove some unneccesary assertions and convert necessary ones into the
NET_EPOCH_ASSERT macro.
Modified:
head/sys/netinet/tcp_input.c
head/sys/netinet/tcp_stacks/bbr.c
head/sys/netinet/tcp_stacks/rack.c
head/sys/netinet/tcp_stacks/rack_bbr_common.c
Modified: head/sys/netinet/tcp_input.c
==============================================================================
--- head/sys/netinet/tcp_input.c Thu Nov 7 21:14:59 2019
(r354482)
+++ head/sys/netinet/tcp_input.c Thu Nov 7 21:23:07 2019
(r354483)
@@ -561,7 +561,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
int rstreason = 0; /* For badport_bandlim accounting purposes */
uint8_t iptos;
struct m_tag *fwd_tag = NULL;
- struct epoch_tracker et;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
int isipv6;
@@ -570,7 +569,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
#endif /* INET6 */
struct tcpopt to; /* options in this segment */
char *s = NULL; /* address and port logging */
- int ti_locked;
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
@@ -581,6 +579,8 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
short ostate = 0;
#endif
+ NET_EPOCH_ASSERT();
+
#ifdef INET6
isipv6 = (mtod(m, struct ip *)->ip_v == 6) ? 1 : 0;
#endif
@@ -747,19 +747,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
drop_hdrlen = off0 + off;
/*
- * Locate pcb for segment; if we're likely to add or remove a
- * connection then first acquire pcbinfo lock. There are three cases
- * where we might discover later we need a write lock despite the
- * flags: ACKs moving a connection out of the syncache, ACKs for a
- * connection in TIMEWAIT and SYNs not targeting a listening socket.
- */
- if ((thflags & (TH_FIN | TH_RST)) != 0) {
- INP_INFO_RLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_RLOCKED;
- } else
- ti_locked = TI_UNLOCKED;
-
- /*
* Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
*/
if (
@@ -776,13 +763,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
findpcb:
-#ifdef INVARIANTS
- if (ti_locked == TI_RLOCKED) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
- } else {
- INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
- }
-#endif
#ifdef INET6
if (isipv6 && fwd_tag != NULL) {
struct sockaddr_in6 *next_hop6;
@@ -942,12 +922,6 @@ findpcb:
* XXXRW: It may be time to rethink timewait locking.
*/
if (inp->inp_flags & INP_TIMEWAIT) {
- if (ti_locked == TI_UNLOCKED) {
- INP_INFO_RLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_RLOCKED;
- }
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
if (thflags & TH_SYN)
tcp_dooptions(&to, optp, optlen, TO_SYN);
/*
@@ -955,7 +929,6 @@ findpcb:
*/
if (tcp_twcheck(inp, &to, th, m, tlen))
goto findpcb;
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return (IPPROTO_DONE);
}
/*
@@ -977,27 +950,6 @@ findpcb:
}
#endif
- /*
- * We've identified a valid inpcb, but it could be that we need an
- * inpcbinfo write lock but don't hold it. In this case, attempt to
- * acquire using the same strategy as the TIMEWAIT case above. If we
- * relock, we have to jump back to 'relocked' as the connection might
- * now be in TIMEWAIT.
- */
-#ifdef INVARIANTS
- if ((thflags & (TH_FIN | TH_RST)) != 0)
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-#endif
- if (!((tp->t_state == TCPS_ESTABLISHED && (thflags & TH_SYN) == 0) ||
- (tp->t_state == TCPS_LISTEN && (thflags & TH_SYN) &&
- !IS_FASTOPEN(tp->t_flags)))) {
- if (ti_locked == TI_UNLOCKED) {
- INP_INFO_RLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_RLOCKED;
- }
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
- }
-
#ifdef MAC
INP_WLOCK_ASSERT(inp);
if (mac_inpcb_check_deliver(inp, m))
@@ -1052,7 +1004,6 @@ findpcb:
*/
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
/*
* Parse the TCP options here because
* syncookies need access to the reflected
@@ -1130,8 +1081,6 @@ tfo_socket_result:
TCP_PROBE5(receive, NULL, tp, m, tp, th);
tp->t_fb->tfb_tcp_do_segment(m, th, so, tp,
drop_hdrlen, tlen,
iptos);
- if (ti_locked == TI_RLOCKED)
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return (IPPROTO_DONE);
}
/*
@@ -1334,10 +1283,6 @@ tfo_socket_result:
* Entry added to syncache and mbuf consumed.
* Only the listen socket is unlocked by syncache_add().
*/
- if (ti_locked == TI_RLOCKED) {
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_UNLOCKED;
- }
INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
return (IPPROTO_DONE);
} else if (tp->t_state == TCPS_LISTEN) {
@@ -1370,25 +1315,11 @@ tfo_socket_result:
* the inpcb, and unlocks pcbinfo.
*/
tp->t_fb->tfb_tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen, iptos);
- if (ti_locked == TI_RLOCKED)
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return (IPPROTO_DONE);
dropwithreset:
TCP_PROBE5(receive, NULL, tp, m, tp, th);
- if (ti_locked == TI_RLOCKED) {
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_UNLOCKED;
- }
-#ifdef INVARIANTS
- else {
- KASSERT(ti_locked == TI_UNLOCKED, ("%s: dropwithreset "
- "ti_locked: %d", __func__, ti_locked));
- INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
- }
-#endif
-
if (inp != NULL) {
tcp_dropwithreset(m, th, tp, tlen, rstreason);
INP_WUNLOCK(inp);
@@ -1401,18 +1332,6 @@ dropunlock:
if (m != NULL)
TCP_PROBE5(receive, NULL, tp, m, tp, th);
- if (ti_locked == TI_RLOCKED) {
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
- ti_locked = TI_UNLOCKED;
- }
-#ifdef INVARIANTS
- else {
- KASSERT(ti_locked == TI_UNLOCKED, ("%s: dropunlock "
- "ti_locked: %d", __func__, ti_locked));
- INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
- }
-#endif
-
if (inp != NULL)
INP_WUNLOCK(inp);
@@ -1501,7 +1420,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
struct mbuf *mfree;
struct tcpopt to;
int tfo_syn;
-
+
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
@@ -1516,16 +1435,8 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
tp->sackhint.last_sack_ack = 0;
sack_changed = 0;
nsegs = max(1, m->m_pkthdr.lro_nsegs);
- /*
- * If this is either a state-changing packet or current state isn't
- * established, we require a write lock on tcbinfo. Otherwise, we
- * allow the tcbinfo to be in either alocked or unlocked, as the
- * caller may have unnecessarily acquired a write lock due to a race.
- */
- if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
- tp->t_state != TCPS_ESTABLISHED) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
- }
+
+ NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(tp->t_inpcb);
KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
__func__));
@@ -2047,7 +1958,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
tcp_state_change(tp, TCPS_SYN_RECEIVED);
}
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
@@ -2120,7 +2030,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
(tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
KASSERT(tp->t_state != TCPS_SYN_SENT,
("%s: TH_RST for TCPS_SYN_SENT th %p tp %p",
__func__, th, tp));
@@ -2163,8 +2072,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
*/
if ((thflags & TH_SYN) && tp->t_state != TCPS_SYN_SENT &&
tp->t_state != TCPS_SYN_RECEIVED) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
TCPSTAT_INC(tcps_badsyn);
if (V_tcp_insecure_syn &&
SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
@@ -2288,8 +2195,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, stru
*/
if ((so->so_state & SS_NOFDREF) &&
tp->t_state > TCPS_CLOSE_WAIT && tlen) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: %s: Received %d bytes of data "
"after socket was closed, "
@@ -2875,7 +2780,6 @@ process_ACK:
*/
case TCPS_CLOSING:
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tcp_twstart(tp);
m_freem(m);
return;
@@ -2890,7 +2794,6 @@ process_ACK:
*/
case TCPS_LAST_ACK:
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tp = tcp_close(tp);
goto drop;
}
@@ -3139,8 +3042,6 @@ dodata:
/* XXX */
* standard timers.
*/
case TCPS_FIN_WAIT_2:
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
tcp_twstart(tp);
return;
}
Modified: head/sys/netinet/tcp_stacks/bbr.c
==============================================================================
--- head/sys/netinet/tcp_stacks/bbr.c Thu Nov 7 21:14:59 2019
(r354482)
+++ head/sys/netinet/tcp_stacks/bbr.c Thu Nov 7 21:23:07 2019
(r354483)
@@ -8618,7 +8618,6 @@ dodata: /* XXX */
bbr->rc_timer_first = 1;
bbr_timer_cancel(bbr,
__LINE__, bbr->r_ctl.rc_rcvtime);
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(tp->t_inpcb);
tcp_twstart(tp);
return (1);
@@ -9619,7 +9618,6 @@ bbr_check_data_after_close(struct mbuf *m, struct tcp_
struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
{
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
if (bbr->rc_allow_data_af_clo == 0) {
close_now:
tp = tcp_close(tp);
@@ -9861,7 +9859,6 @@ bbr_do_closing(struct mbuf *m, struct tcphdr *th, stru
return (ret_val);
}
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tcp_twstart(tp);
m_freem(m);
return (1);
@@ -9974,7 +9971,6 @@ bbr_do_lastack(struct mbuf *m, struct tcphdr *th, stru
return (ret_val);
}
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tp = tcp_close(tp);
ctf_do_drop(m, tp);
return (1);
Modified: head/sys/netinet/tcp_stacks/rack.c
==============================================================================
--- head/sys/netinet/tcp_stacks/rack.c Thu Nov 7 21:14:59 2019
(r354482)
+++ head/sys/netinet/tcp_stacks/rack.c Thu Nov 7 21:23:07 2019
(r354483)
@@ -5875,7 +5875,6 @@ dodata: /* XXX */
case TCPS_FIN_WAIT_2:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tcp_twstart(tp);
return (1);
}
@@ -6353,7 +6352,6 @@ rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, st
tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
tcp_state_change(tp, TCPS_SYN_RECEIVED);
}
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* Advance th->th_seq to correspond to first data byte. If data,
@@ -6847,7 +6845,6 @@ rack_check_data_after_close(struct mbuf *m,
{
struct tcp_rack *rack;
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_allow_data_af_clo == 0) {
close_now:
@@ -7079,7 +7076,6 @@ rack_do_closing(struct mbuf *m, struct tcphdr *th, str
return (ret_val);
}
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tcp_twstart(tp);
m_freem(m);
return (1);
@@ -7187,7 +7183,6 @@ rack_do_lastack(struct mbuf *m, struct tcphdr *th, str
return (ret_val);
}
if (ourfinisacked) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tp = tcp_close(tp);
ctf_do_drop(m, tp);
return (1);
@@ -7650,16 +7645,8 @@ rack_do_segment_nounlock(struct mbuf *m, struct tcphdr
kern_prefetch(rack, &prev_state);
prev_state = 0;
thflags = th->th_flags;
- /*
- * If this is either a state-changing packet or current state isn't
- * established, we require a read lock on tcbinfo. Otherwise, we
- * allow the tcbinfo to be in either locked or unlocked, as the
- * caller may have unnecessarily acquired a lock due to a race.
- */
- if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
- tp->t_state != TCPS_ESTABLISHED) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
- }
+
+ NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(tp->t_inpcb);
KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
__func__));
Modified: head/sys/netinet/tcp_stacks/rack_bbr_common.c
==============================================================================
--- head/sys/netinet/tcp_stacks/rack_bbr_common.c Thu Nov 7 21:14:59
2019 (r354482)
+++ head/sys/netinet/tcp_stacks/rack_bbr_common.c Thu Nov 7 21:23:07
2019 (r354483)
@@ -253,7 +253,6 @@ ctf_process_inbound_raw(struct tcpcb *tp, struct socke
*/
struct mbuf *m_save;
struct ether_header *eh;
- struct epoch_tracker et;
struct tcphdr *th;
#ifdef INET6
struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */
@@ -268,14 +267,8 @@ ctf_process_inbound_raw(struct tcpcb *tp, struct socke
uint16_t drop_hdrlen;
uint8_t iptos, no_vn=0, bpf_req=0;
- /*
- * This is a bit deceptive, we get the
- * "info epoch" which is really the network
- * epoch. This covers us on both any INP
- * type change but also if the ifp goes
- * away it covers us as well.
- */
- INP_INFO_RLOCK_ET(&V_tcbinfo, et);
+ NET_EPOCH_ASSERT();
+
if (m && m->m_pkthdr.rcvif)
ifp = m->m_pkthdr.rcvif;
else
@@ -445,7 +438,6 @@ skip_vnet:
}
if (no_vn == 0)
CURVNET_RESTORE();
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return(retval);
}
skipped_pkt:
@@ -453,7 +445,6 @@ skipped_pkt:
}
if (no_vn == 0)
CURVNET_RESTORE();
- INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return(retval);
}
@@ -680,7 +671,6 @@ ctf_process_rst(struct mbuf *m, struct tcphdr *th, str
SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
(tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) {
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
KASSERT(tp->t_state != TCPS_SYN_SENT,
("%s: TH_RST for TCPS_SYN_SENT th %p tp %p",
__func__, th, tp));
@@ -732,7 +722,8 @@ ctf_process_rst(struct mbuf *m, struct tcphdr *th, str
void
ctf_challenge_ack(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t
* ret_val)
{
- INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+
+ NET_EPOCH_ASSERT();
TCPSTAT_INC(tcps_badsyn);
if (V_tcp_insecure_syn &&
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