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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2008-10-07 17:43:06 -0400
committerDavid S. Miller <davem@davemloft.net>2008-10-07 17:43:06 -0400
commit33f5f57eeb0c6386fdd85f9c690dc8d700ba7928 (patch)
tree4bd3421bfa3088018f8e355e6f47e43599748802 /net
parent654bed16cf86a9ef94495d9e6131b7ff7840a3dd (diff)
tcp: kill pointless urg_mode
It all started from me noticing that this urgent check in tcp_clean_rtx_queue is unnecessarily inside the loop. Then I took a longer look to it and found out that the users of urg_mode can trivially do without, well almost, there was one gotcha. Bonus: those funny people who use urg with >= 2^31 write_seq - snd_una could now rejoice too (that's the only purpose for the between being there, otherwise a simple compare would have done the thing). Not that I assume that the rest of the tcp code happily lives with such mind-boggling numbers :-). Alas, it turned out to be impossible to set wmem to such numbers anyway, yes I really tried a big sendfile after setting some wmem but nothing happened :-). ...Tcp_wmem is int and so is sk_sndbuf... So I hacked a bit variable to long and found out that it seems to work... :-) Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_input.c11
-rw-r--r--net/ipv4/tcp_minisocks.c1
-rw-r--r--net/ipv4/tcp_output.c18
4 files changed, 20 insertions, 14 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 7d3fe571d15f..eccb7165a80c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -497,10 +497,8 @@ static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
497static inline void tcp_mark_urg(struct tcp_sock *tp, int flags, 497static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
498 struct sk_buff *skb) 498 struct sk_buff *skb)
499{ 499{
500 if (flags & MSG_OOB) { 500 if (flags & MSG_OOB)
501 tp->urg_mode = 1;
502 tp->snd_up = tp->write_seq; 501 tp->snd_up = tp->write_seq;
503 }
504} 502}
505 503
506static inline void tcp_push(struct sock *sk, int flags, int mss_now, 504static inline void tcp_push(struct sock *sk, int flags, int mss_now,
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3b76bce769dd..c19f429dc443 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2836,7 +2836,8 @@ static u32 tcp_tso_acked(struct sock *sk, struct sk_buff *skb)
2836 * is before the ack sequence we can discard it as it's confirmed to have 2836 * is before the ack sequence we can discard it as it's confirmed to have
2837 * arrived at the other end. 2837 * arrived at the other end.
2838 */ 2838 */
2839static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets) 2839static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
2840 u32 prior_snd_una)
2840{ 2841{
2841 struct tcp_sock *tp = tcp_sk(sk); 2842 struct tcp_sock *tp = tcp_sk(sk);
2842 const struct inet_connection_sock *icsk = inet_csk(sk); 2843 const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -2903,9 +2904,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
2903 if (sacked & TCPCB_LOST) 2904 if (sacked & TCPCB_LOST)
2904 tp->lost_out -= acked_pcount; 2905 tp->lost_out -= acked_pcount;
2905 2906
2906 if (unlikely(tp->urg_mode && !before(end_seq, tp->snd_up)))
2907 tp->urg_mode = 0;
2908
2909 tp->packets_out -= acked_pcount; 2907 tp->packets_out -= acked_pcount;
2910 pkts_acked += acked_pcount; 2908 pkts_acked += acked_pcount;
2911 2909
@@ -2935,6 +2933,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
2935 tp->lost_skb_hint = NULL; 2933 tp->lost_skb_hint = NULL;
2936 } 2934 }
2937 2935
2936 if (likely(between(tp->snd_up, prior_snd_una, tp->snd_una)))
2937 tp->snd_up = tp->snd_una;
2938
2938 if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) 2939 if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
2939 flag |= FLAG_SACK_RENEGING; 2940 flag |= FLAG_SACK_RENEGING;
2940 2941
@@ -3311,7 +3312,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
3311 goto no_queue; 3312 goto no_queue;
3312 3313
3313 /* See if we can take anything off of the retransmit queue. */ 3314 /* See if we can take anything off of the retransmit queue. */
3314 flag |= tcp_clean_rtx_queue(sk, prior_fackets); 3315 flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una);
3315 3316
3316 if (tp->frto_counter) 3317 if (tp->frto_counter)
3317 frto_cwnd = tcp_process_frto(sk, flag); 3318 frto_cwnd = tcp_process_frto(sk, flag);
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index f976fc57892c..779f2e9d0689 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -395,6 +395,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
395 newtp->pred_flags = 0; 395 newtp->pred_flags = 0;
396 newtp->rcv_wup = newtp->copied_seq = newtp->rcv_nxt = treq->rcv_isn + 1; 396 newtp->rcv_wup = newtp->copied_seq = newtp->rcv_nxt = treq->rcv_isn + 1;
397 newtp->snd_sml = newtp->snd_una = newtp->snd_nxt = treq->snt_isn + 1; 397 newtp->snd_sml = newtp->snd_una = newtp->snd_nxt = treq->snt_isn + 1;
398 newtp->snd_up = treq->snt_isn + 1;
398 399
399 tcp_prequeue_init(newtp); 400 tcp_prequeue_init(newtp);
400 401
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 493553c71d32..990a58493235 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -345,6 +345,11 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
345 TCP_SKB_CB(skb)->end_seq = seq; 345 TCP_SKB_CB(skb)->end_seq = seq;
346} 346}
347 347
348static inline int tcp_urg_mode(const struct tcp_sock *tp)
349{
350 return tp->snd_una != tp->snd_up;
351}
352
348#define OPTION_SACK_ADVERTISE (1 << 0) 353#define OPTION_SACK_ADVERTISE (1 << 0)
349#define OPTION_TS (1 << 1) 354#define OPTION_TS (1 << 1)
350#define OPTION_MD5 (1 << 2) 355#define OPTION_MD5 (1 << 2)
@@ -646,7 +651,8 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
646 th->check = 0; 651 th->check = 0;
647 th->urg_ptr = 0; 652 th->urg_ptr = 0;
648 653
649 if (unlikely(tp->urg_mode && 654 /* The urg_mode check is necessary during a below snd_una win probe */
655 if (unlikely(tcp_urg_mode(tp) &&
650 between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) { 656 between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
651 th->urg_ptr = htons(tp->snd_up - tcb->seq); 657 th->urg_ptr = htons(tp->snd_up - tcb->seq);
652 th->urg = 1; 658 th->urg = 1;
@@ -1012,7 +1018,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
1012/* Compute the current effective MSS, taking SACKs and IP options, 1018/* Compute the current effective MSS, taking SACKs and IP options,
1013 * and even PMTU discovery events into account. 1019 * and even PMTU discovery events into account.
1014 * 1020 *
1015 * LARGESEND note: !urg_mode is overkill, only frames up to snd_up 1021 * LARGESEND note: !tcp_urg_mode is overkill, only frames up to snd_up
1016 * cannot be large. However, taking into account rare use of URG, this 1022 * cannot be large. However, taking into account rare use of URG, this
1017 * is not a big flaw. 1023 * is not a big flaw.
1018 */ 1024 */
@@ -1029,7 +1035,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
1029 1035
1030 mss_now = tp->mss_cache; 1036 mss_now = tp->mss_cache;
1031 1037
1032 if (large_allowed && sk_can_gso(sk) && !tp->urg_mode) 1038 if (large_allowed && sk_can_gso(sk) && !tcp_urg_mode(tp))
1033 doing_tso = 1; 1039 doing_tso = 1;
1034 1040
1035 if (dst) { 1041 if (dst) {
@@ -1193,7 +1199,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
1193 /* Don't use the nagle rule for urgent data (or for the final FIN). 1199 /* Don't use the nagle rule for urgent data (or for the final FIN).
1194 * Nagle can be ignored during F-RTO too (see RFC4138). 1200 * Nagle can be ignored during F-RTO too (see RFC4138).
1195 */ 1201 */
1196 if (tp->urg_mode || (tp->frto_counter == 2) || 1202 if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
1197 (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) 1203 (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
1198 return 1; 1204 return 1;
1199 1205
@@ -2358,6 +2364,7 @@ static void tcp_connect_init(struct sock *sk)
2358 tcp_init_wl(tp, tp->write_seq, 0); 2364 tcp_init_wl(tp, tp->write_seq, 0);
2359 tp->snd_una = tp->write_seq; 2365 tp->snd_una = tp->write_seq;
2360 tp->snd_sml = tp->write_seq; 2366 tp->snd_sml = tp->write_seq;
2367 tp->snd_up = tp->write_seq;
2361 tp->rcv_nxt = 0; 2368 tp->rcv_nxt = 0;
2362 tp->rcv_wup = 0; 2369 tp->rcv_wup = 0;
2363 tp->copied_seq = 0; 2370 tp->copied_seq = 0;
@@ -2567,8 +2574,7 @@ int tcp_write_wakeup(struct sock *sk)
2567 tcp_event_new_data_sent(sk, skb); 2574 tcp_event_new_data_sent(sk, skb);
2568 return err; 2575 return err;
2569 } else { 2576 } else {
2570 if (tp->urg_mode && 2577 if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
2571 between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
2572 tcp_xmit_probe_skb(sk, 1); 2578 tcp_xmit_probe_skb(sk, 1);
2573 return tcp_xmit_probe_skb(sk, 0); 2579 return tcp_xmit_probe_skb(sk, 0);
2574 } 2580 }