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-rw-r--r--Documentation/networking/ip-sysctl.txt3
-rw-r--r--include/linux/tcp.h1
-rw-r--r--include/net/tcp.h14
-rw-r--r--include/uapi/linux/snmp.h1
-rw-r--r--net/ipv4/proc.c1
-rw-r--r--net/ipv4/tcp.c2
-rw-r--r--net/ipv4/tcp_input.c53
-rw-r--r--net/ipv4/tcp_metrics.c4
-rw-r--r--net/ipv4/tcp_minisocks.c5
-rw-r--r--net/ipv4/tcp_output.c5
10 files changed, 12 insertions, 77 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index d8676dda7fa6..46c7e1085efc 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -289,8 +289,7 @@ tcp_ecn_fallback - BOOLEAN
Default: 1 (fallback enabled)
tcp_fack - BOOLEAN
- Enable FACK congestion avoidance and fast retransmission.
- The value is not used, if tcp_sack is not enabled.
+ This is a legacy option, it has no effect anymore.
tcp_fin_timeout - INTEGER
The length of time an orphaned (no longer referenced by any
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 22f40c96a15b..9574936fe041 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -85,7 +85,6 @@ struct tcp_sack_block {
/*These are used to set the sack_ok field in struct tcp_options_received */
#define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */
-#define TCP_FACK_ENABLED (1 << 1) /*1 = FACK is enabled locally*/
#define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/
struct tcp_options_received {
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 2f2c69ad31b2..ed71511e67a6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -384,7 +384,6 @@ void tcp_update_metrics(struct sock *sk);
void tcp_init_metrics(struct sock *sk);
void tcp_metrics_init(void);
bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst);
-void tcp_disable_fack(struct tcp_sock *tp);
void tcp_close(struct sock *sk, long timeout);
void tcp_init_sock(struct sock *sk);
void tcp_init_transfer(struct sock *sk, int bpf_op);
@@ -776,7 +775,7 @@ struct tcp_skb_cb {
};
__u8 tcp_flags; /* TCP header flags. (tcp[13]) */
- __u8 sacked; /* State flags for SACK/FACK. */
+ __u8 sacked; /* State flags for SACK. */
#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
#define TCPCB_LOST 0x04 /* SKB is lost */
@@ -1066,7 +1065,6 @@ void tcp_rate_check_app_limited(struct sock *sk);
*
* tcp_is_sack - SACK enabled
* tcp_is_reno - No SACK
- * tcp_is_fack - FACK enabled, implies SACK enabled
*/
static inline int tcp_is_sack(const struct tcp_sock *tp)
{
@@ -1078,16 +1076,6 @@ static inline bool tcp_is_reno(const struct tcp_sock *tp)
return !tcp_is_sack(tp);
}
-static inline bool tcp_is_fack(const struct tcp_sock *tp)
-{
- return tp->rx_opt.sack_ok & TCP_FACK_ENABLED;
-}
-
-static inline void tcp_enable_fack(struct tcp_sock *tp)
-{
- tp->rx_opt.sack_ok |= TCP_FACK_ENABLED;
-}
-
static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
{
return tp->sacked_out + tp->lost_out;
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 0d941cdd8e8c..33a70ece462f 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -191,7 +191,6 @@ enum
LINUX_MIB_TCPRENORECOVERY, /* TCPRenoRecovery */
LINUX_MIB_TCPSACKRECOVERY, /* TCPSackRecovery */
LINUX_MIB_TCPSACKRENEGING, /* TCPSACKReneging */
- LINUX_MIB_TCPFACKREORDER, /* TCPFACKReorder */
LINUX_MIB_TCPSACKREORDER, /* TCPSACKReorder */
LINUX_MIB_TCPRENOREORDER, /* TCPRenoReorder */
LINUX_MIB_TCPTSREORDER, /* TCPTSReorder */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 127153f1ed8a..9f37c4727861 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -212,7 +212,6 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY),
SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY),
SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING),
- SNMP_MIB_ITEM("TCPFACKReorder", LINUX_MIB_TCPFACKREORDER),
SNMP_MIB_ITEM("TCPSACKReorder", LINUX_MIB_TCPSACKREORDER),
SNMP_MIB_ITEM("TCPRenoReorder", LINUX_MIB_TCPRENOREORDER),
SNMP_MIB_ITEM("TCPTSReorder", LINUX_MIB_TCPTSREORDER),
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index bc71a27d5ad9..337555076043 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2509,8 +2509,6 @@ static int tcp_repair_options_est(struct sock *sk,
return -EINVAL;
tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
- if (sock_net(sk)->ipv4.sysctl_tcp_fack)
- tcp_enable_fack(tp);
break;
case TCPOPT_TIMESTAMP:
if (opt.opt_val != 0)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9ceaa1fdc3ab..487e181cff86 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -842,18 +842,6 @@ __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst)
return min_t(__u32, cwnd, tp->snd_cwnd_clamp);
}
-/*
- * Packet counting of FACK is based on in-order assumptions, therefore TCP
- * disables it when reordering is detected
- */
-void tcp_disable_fack(struct tcp_sock *tp)
-{
- /* RFC3517 uses different metric in lost marker => reset on change */
- if (tcp_is_fack(tp))
- tp->lost_skb_hint = NULL;
- tp->rx_opt.sack_ok &= ~TCP_FACK_ENABLED;
-}
-
/* Take a notice that peer is sending D-SACKs */
static void tcp_dsack_seen(struct tcp_sock *tp)
{
@@ -881,7 +869,6 @@ static void tcp_update_reordering(struct sock *sk, const int metric,
tp->sacked_out,
tp->undo_marker ? tp->undo_retrans : 0);
#endif
- tcp_disable_fack(tp);
}
tp->rack.reord = 1;
@@ -891,8 +878,6 @@ static void tcp_update_reordering(struct sock *sk, const int metric,
mib_idx = LINUX_MIB_TCPTSREORDER;
else if (tcp_is_reno(tp))
mib_idx = LINUX_MIB_TCPRENOREORDER;
- else if (tcp_is_fack(tp))
- mib_idx = LINUX_MIB_TCPFACKREORDER;
else
mib_idx = LINUX_MIB_TCPSACKREORDER;
@@ -970,7 +955,6 @@ void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb)
* 3. Loss detection event of two flavors:
* A. Scoreboard estimator decided the packet is lost.
* A'. Reno "three dupacks" marks head of queue lost.
- * A''. Its FACK modification, head until snd.fack is lost.
* B. SACK arrives sacking SND.NXT at the moment, when the
* segment was retransmitted.
* 4. D-SACK added new rule: D-SACK changes any tag to S.
@@ -1248,7 +1232,7 @@ static u8 tcp_sacktag_one(struct sock *sk,
fack_count += pcount;
/* Lost marker hint past SACKed? Tweak RFC3517 cnt */
- if (!tcp_is_fack(tp) && tp->lost_skb_hint &&
+ if (tp->lost_skb_hint &&
before(start_seq, TCP_SKB_CB(tp->lost_skb_hint)->seq))
tp->lost_cnt_hint += pcount;
@@ -2051,10 +2035,6 @@ static inline int tcp_fackets_out(const struct tcp_sock *tp)
* counter when SACK is enabled (without SACK, sacked_out is used for
* that purpose).
*
- * Instead, with FACK TCP uses fackets_out that includes both SACKed
- * segments up to the highest received SACK block so far and holes in
- * between them.
- *
* With reordering, holes may still be in flight, so RFC3517 recovery
* uses pure sacked_out (total number of SACKed segments) even though
* it violates the RFC that uses duplicate ACKs, often these are equal
@@ -2064,10 +2044,10 @@ static inline int tcp_fackets_out(const struct tcp_sock *tp)
*/
static inline int tcp_dupack_heuristics(const struct tcp_sock *tp)
{
- return tcp_is_fack(tp) ? tp->fackets_out : tp->sacked_out + 1;
+ return tp->sacked_out + 1;
}
-/* Linux NewReno/SACK/FACK/ECN state machine.
+/* Linux NewReno/SACK/ECN state machine.
* --------------------------------------
*
* "Open" Normal state, no dubious events, fast path.
@@ -2132,16 +2112,6 @@ static inline int tcp_dupack_heuristics(const struct tcp_sock *tp)
* dynamically measured and adjusted. This is implemented in
* tcp_rack_mark_lost.
*
- * FACK (Disabled by default. Subsumbed by RACK):
- * It is the simplest heuristics. As soon as we decided
- * that something is lost, we decide that _all_ not SACKed
- * packets until the most forward SACK are lost. I.e.
- * lost_out = fackets_out - sacked_out and left_out = fackets_out.
- * It is absolutely correct estimate, if network does not reorder
- * packets. And it loses any connection to reality when reordering
- * takes place. We use FACK by default until reordering
- * is suspected on the path to this destination.
- *
* If the receiver does not support SACK:
*
* NewReno (RFC6582): in Recovery we assume that one segment
@@ -2190,7 +2160,7 @@ static bool tcp_time_to_recover(struct sock *sk, int flag)
}
/* Detect loss in event "A" above by marking head of queue up as lost.
- * For FACK or non-SACK(Reno) senders, the first "packets" number of segments
+ * For non-SACK(Reno) senders, the first "packets" number of segments
* are considered lost. For RFC3517 SACK, a segment is considered lost if it
* has at least tp->reordering SACKed seqments above it; "packets" refers to
* the maximum SACKed segments to pass before reaching this limit.
@@ -2226,12 +2196,12 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
break;
oldcnt = cnt;
- if (tcp_is_fack(tp) || tcp_is_reno(tp) ||
+ if (tcp_is_reno(tp) ||
(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
cnt += tcp_skb_pcount(skb);
if (cnt > packets) {
- if ((tcp_is_sack(tp) && !tcp_is_fack(tp)) ||
+ if (tcp_is_sack(tp) ||
(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) ||
(oldcnt >= packets))
break;
@@ -2262,11 +2232,6 @@ static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit)
if (tcp_is_reno(tp)) {
tcp_mark_head_lost(sk, 1, 1);
- } else if (tcp_is_fack(tp)) {
- int lost = tp->fackets_out - tp->reordering;
- if (lost <= 0)
- lost = 1;
- tcp_mark_head_lost(sk, lost, 0);
} else {
int sacked_upto = tp->sacked_out - tp->reordering;
if (sacked_upto >= 0)
@@ -3199,8 +3164,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
if (reord < prior_fackets && reord <= tp->fackets_out)
tcp_update_reordering(sk, tp->fackets_out - reord, 0);
- delta = tcp_is_fack(tp) ? pkts_acked :
- prior_sacked - tp->sacked_out;
+ delta = prior_sacked - tp->sacked_out;
tp->lost_cnt_hint -= min(tp->lost_cnt_hint, delta);
}
@@ -5708,9 +5672,6 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
tp->tcp_header_len = sizeof(struct tcphdr);
}
- if (tcp_is_sack(tp) && sock_net(sk)->ipv4.sysctl_tcp_fack)
- tcp_enable_fack(tp);
-
tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
tcp_initialize_rcv_mss(sk);
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 9d5ddebfd831..7097f92d16e5 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -470,10 +470,8 @@ void tcp_init_metrics(struct sock *sk)
tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
}
val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
- if (val && tp->reordering != val) {
- tcp_disable_fack(tp);
+ if (val && tp->reordering != val)
tp->reordering = val;
- }
crtt = tcp_metric_get(tm, TCP_METRIC_RTT);
rcu_read_unlock();
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 4bb86580decd..326c9282bf94 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -509,10 +509,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
keepalive_time_when(newtp));
newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;
- if ((newtp->rx_opt.sack_ok = ireq->sack_ok) != 0) {
- if (sock_net(sk)->ipv4.sysctl_tcp_fack)
- tcp_enable_fack(newtp);
- }
+ newtp->rx_opt.sack_ok = ireq->sack_ok;
newtp->window_clamp = req->rsk_window_clamp;
newtp->rcv_ssthresh = req->rsk_rcv_wnd;
newtp->rcv_wnd = req->rsk_rcv_wnd;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9b98d35aa0d8..094c429b4401 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1257,7 +1257,7 @@ static void tcp_adjust_pcount(struct sock *sk, const struct sk_buff *skb, int de
if (tp->lost_skb_hint &&
before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->lost_skb_hint)->seq) &&
- (tcp_is_fack(tp) || (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)))
+ (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
tp->lost_cnt_hint -= decr;
tcp_verify_left_out(tp);
@@ -2961,9 +2961,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
* retransmitted data is acknowledged. It tries to continue
* resending the rest of the retransmit queue, until either
* we've sent it all or the congestion window limit is reached.
- * If doing SACK, the first ACK which comes back for a timeout
- * based retransmit packet might feed us FACK information again.
- * If so, we use it to avoid unnecessarily retransmissions.
*/
void tcp_xmit_retransmit_queue(struct sock *sk)
{
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 17:56:09 +0000