From 598856407d4e20ebb4de01a91a93d89325924d43 Mon Sep 17 00:00:00 2001 From: Damian Lukowski Date: Wed, 10 Feb 2010 18:04:08 -0800 Subject: tcp: fix ICMP-RTO war Make sure, that TCP has a nonzero RTT estimation after three-way handshake. Currently, a listening TCP has a value of 0 for srtt, rttvar and rto right after the three-way handshake is completed with TCP timestamps disabled. This will lead to corrupt RTO recalculation and retransmission flood when RTO is recalculated on backoff reversion as introduced in "Revert RTO on ICMP destination unreachable" (f1ecd5d9e7366609d640ff4040304ea197fbc618). This behaviour can be provoked by connecting to a server which "responds first" (like SMTP) and rejecting every packet after the handshake with dest-unreachable, which will lead to softirq load on the server (up to 30% per socket in some tests). Thanks to Ilpo Jarvinen for providing debug patches and to Denys Fedoryshchenko for reporting and testing. Changes since v3: Removed bad characters in patchfile. Reported-by: Denys Fedoryshchenko Signed-off-by: Damian Lukowski Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 28e029632493..3fddc69ccccc 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5783,11 +5783,9 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, /* tcp_ack considers this ACK as duplicate * and does not calculate rtt. - * Fix it at least with timestamps. + * Force it here. */ - if (tp->rx_opt.saw_tstamp && - tp->rx_opt.rcv_tsecr && !tp->srtt) - tcp_ack_saw_tstamp(sk, 0); + tcp_ack_update_rtt(sk, 0, 0); if (tp->rx_opt.tstamp_ok) tp->advmss -= TCPOLEN_TSTAMP_ALIGNED; -- cgit v1.2.2 From 7e38017557bc0b87434d184f8804cadb102bb903 Mon Sep 17 00:00:00 2001 From: Andreas Petlund Date: Thu, 18 Feb 2010 04:48:19 +0000 Subject: net: TCP thin dupack This patch enables fast retransmissions after one dupACK for TCP if the stream is identified as thin. This will reduce latencies for thin streams that are not able to trigger fast retransmissions due to high packet interarrival time. This mechanism is only active if enabled by iocontrol or syscontrol and the stream is identified as thin. Signed-off-by: Andreas Petlund Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3fddc69ccccc..788851ca8c5d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -89,6 +89,8 @@ int sysctl_tcp_frto __read_mostly = 2; int sysctl_tcp_frto_response __read_mostly; int sysctl_tcp_nometrics_save __read_mostly; +int sysctl_tcp_thin_dupack __read_mostly; + int sysctl_tcp_moderate_rcvbuf __read_mostly = 1; int sysctl_tcp_abc __read_mostly; @@ -2447,6 +2449,16 @@ static int tcp_time_to_recover(struct sock *sk) return 1; } + /* If a thin stream is detected, retransmit after first + * received dupack. Employ only if SACK is supported in order + * to avoid possible corner-case series of spurious retransmissions + * Use only if there are no unsent data. + */ + if ((tp->thin_dupack || sysctl_tcp_thin_dupack) && + tcp_stream_is_thin(tp) && tcp_dupack_heuristics(tp) > 1 && + tcp_is_sack(tp) && !tcp_send_head(sk)) + return 1; + return 0; } -- cgit v1.2.2 From 6830c25b7d08fbbd922959425193791bc42079f2 Mon Sep 17 00:00:00 2001 From: Lennart Schulte Date: Wed, 17 Mar 2010 02:16:29 +0000 Subject: tcp: Fix tcp_mark_head_lost() with packets == 0 A packet is marked as lost in case packets == 0, although nothing should be done. This results in a too early retransmitted packet during recovery in some cases. This small patch fixes this issue by returning immediately. Signed-off-by: Lennart Schulte Signed-off-by: Arnd Hannemann Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 788851ca8c5d..c096a4218b8f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2511,6 +2511,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets) int err; unsigned int mss; + if (packets == 0) + return; + WARN_ON(packets > tp->packets_out); if (tp->lost_skb_hint) { skb = tp->lost_skb_hint; -- cgit v1.2.2 From b138338056fc423c61a583d45f8aa64cfad87131 Mon Sep 17 00:00:00 2001 From: Frans Pop Date: Wed, 24 Mar 2010 07:57:28 +0000 Subject: net: remove trailing space in messages Signed-off-by: Frans Pop Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c096a4218b8f..7b31476a4063 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4318,7 +4318,7 @@ static void tcp_ofo_queue(struct sock *sk) } if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) { - SOCK_DEBUG(sk, "ofo packet was already received \n"); + SOCK_DEBUG(sk, "ofo packet was already received\n"); __skb_unlink(skb, &tp->out_of_order_queue); __kfree_skb(skb); continue; -- cgit v1.2.2 From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- net/ipv4/tcp_input.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c096a4218b8f..f240f57b2199 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -62,6 +62,7 @@ */ #include +#include #include #include #include -- cgit v1.2.2 From b6c6712a42ca3f9fa7f4a3d7c40e3a9dd1fd9e03 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Apr 2010 23:03:29 +0000 Subject: net: sk_dst_cache RCUification With latest CONFIG_PROVE_RCU stuff, I felt more comfortable to make this work. sk->sk_dst_cache is currently protected by a rwlock (sk_dst_lock) This rwlock is readlocked for a very small amount of time, and dst entries are already freed after RCU grace period. This calls for RCU again :) This patch converts sk_dst_lock to a spinlock, and use RCU for readers. __sk_dst_get() is supposed to be called with rcu_read_lock() or if socket locked by user, so use appropriate rcu_dereference_check() condition (rcu_read_lock_held() || sock_owned_by_user(sk)) This patch avoids two atomic ops per tx packet on UDP connected sockets, for example, and permits sk_dst_lock to be much less dirtied. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 4000b10610b7..ae3ec15fb630 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3710,7 +3710,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag) } if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) - dst_confirm(sk->sk_dst_cache); + dst_confirm(__sk_dst_get(sk)); return 1; @@ -5833,7 +5833,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, if (tp->snd_una == tp->write_seq) { tcp_set_state(sk, TCP_FIN_WAIT2); sk->sk_shutdown |= SEND_SHUTDOWN; - dst_confirm(sk->sk_dst_cache); + dst_confirm(__sk_dst_get(sk)); if (!sock_flag(sk, SOCK_DEAD)) /* Wake up lingering close() */ -- cgit v1.2.2 From f84af32cbca70a3c6d30463dc08c7984af11c277 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 28 Apr 2010 15:31:51 -0700 Subject: net: ip_queue_rcv_skb() helper When queueing a skb to socket, we can immediately release its dst if target socket do not use IP_CMSG_PKTINFO. tcp_data_queue() can drop dst too. This to benefit from a hot cache line and avoid the receiver, possibly on another cpu, to dirty this cache line himself. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ae3ec15fb630..e82162c211bf 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4367,6 +4367,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) goto drop; + skb_dst_drop(skb); __skb_pull(skb, th->doff * 4); TCP_ECN_accept_cwr(tp, skb); -- cgit v1.2.2 From ccbd6a5a4f76e821ed36f69fdaf59817c3a7f18e Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Fri, 14 May 2010 10:58:26 +0000 Subject: net: Remove unnecessary semicolons after switch statements Also added an explicit break; to avoid a fallthrough in net/ipv4/tcp_input.c Signed-off-by: Joe Perches Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e82162c211bf..3e6dafcb1071 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3845,12 +3845,13 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx, /* 16-bit multiple */ opt_rx->cookie_plus = opsize; *hvpp = ptr; + break; default: /* ignore option */ break; - }; + } break; - }; + } ptr += opsize-2; length -= opsize; -- cgit v1.2.2 From 288fcee8b7aa98796d96cd5b1b2e8005639328bf Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 31 May 2010 23:48:19 -0700 Subject: net/ipv4/tcp_input.c: fix compilation breakage when FASTRETRANS_DEBUG > 1 Commit: c720c7e8383aff1cb219bddf474ed89d850336e3 missed these. Signed-off-by: Joe Perches Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3e6dafcb1071..548d575e6cc6 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2639,7 +2639,7 @@ static void DBGUNDO(struct sock *sk, const char *msg) if (sk->sk_family == AF_INET) { printk(KERN_DEBUG "Undo %s %pI4/%u c%u l%u ss%u/%u p%u\n", msg, - &inet->daddr, ntohs(inet->dport), + &inet->inet_daddr, ntohs(inet->inet_dport), tp->snd_cwnd, tcp_left_out(tp), tp->snd_ssthresh, tp->prior_ssthresh, tp->packets_out); @@ -2649,7 +2649,7 @@ static void DBGUNDO(struct sock *sk, const char *msg) struct ipv6_pinfo *np = inet6_sk(sk); printk(KERN_DEBUG "Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n", msg, - &np->daddr, ntohs(inet->dport), + &np->daddr, ntohs(inet->inet_dport), tp->snd_cwnd, tcp_left_out(tp), tp->snd_ssthresh, tp->prior_ssthresh, tp->packets_out); -- cgit v1.2.2 From a3433f35a55f7604742cae620c6dc6edfc70db6a Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Sat, 12 Jun 2010 14:01:43 +0000 Subject: tcp: unify tcp flag macros unify tcp flag macros: TCPHDR_FIN, TCPHDR_SYN, TCPHDR_RST, TCPHDR_PSH, TCPHDR_ACK, TCPHDR_URG, TCPHDR_ECE and TCPHDR_CWR. TCBCB_FLAG_* are replaced with the corresponding TCPHDR_*. Signed-off-by: Changli Gao ---- include/net/tcp.h | 24 ++++++------- net/ipv4/tcp.c | 8 ++-- net/ipv4/tcp_input.c | 2 - net/ipv4/tcp_output.c | 59 ++++++++++++++++----------------- net/netfilter/nf_conntrack_proto_tcp.c | 32 ++++++----------- net/netfilter/xt_TCPMSS.c | 4 -- 6 files changed, 58 insertions(+), 71 deletions(-) Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 548d575e6cc6..04334661fa28 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3286,7 +3286,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, * connection startup slow start one packet too * quickly. This is severely frowned upon behavior. */ - if (!(scb->flags & TCPCB_FLAG_SYN)) { + if (!(scb->flags & TCPHDR_SYN)) { flag |= FLAG_DATA_ACKED; } else { flag |= FLAG_SYN_ACKED; -- cgit v1.2.2 From 4bc2f18ba4f22a90ab593c0a580fc9a19c4777b6 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 9 Jul 2010 21:22:10 +0000 Subject: net/ipv4: EXPORT_SYMBOL cleanups CodingStyle cleanups EXPORT_SYMBOL should immediately follow the symbol declaration. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 04334661fa28..3c426cb318e7 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -78,10 +78,13 @@ int sysctl_tcp_window_scaling __read_mostly = 1; int sysctl_tcp_sack __read_mostly = 1; int sysctl_tcp_fack __read_mostly = 1; int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH; +EXPORT_SYMBOL(sysctl_tcp_reordering); int sysctl_tcp_ecn __read_mostly = 2; +EXPORT_SYMBOL(sysctl_tcp_ecn); int sysctl_tcp_dsack __read_mostly = 1; int sysctl_tcp_app_win __read_mostly = 31; int sysctl_tcp_adv_win_scale __read_mostly = 2; +EXPORT_SYMBOL(sysctl_tcp_adv_win_scale); int sysctl_tcp_stdurg __read_mostly; int sysctl_tcp_rfc1337 __read_mostly; @@ -419,6 +422,7 @@ void tcp_initialize_rcv_mss(struct sock *sk) inet_csk(sk)->icsk_ack.rcv_mss = hint; } +EXPORT_SYMBOL(tcp_initialize_rcv_mss); /* Receiver "autotuning" code. * @@ -2938,6 +2942,7 @@ void tcp_simple_retransmit(struct sock *sk) } tcp_xmit_retransmit_queue(sk); } +EXPORT_SYMBOL(tcp_simple_retransmit); /* Process an event, which can update packets-in-flight not trivially. * Main goal of this function is to calculate new estimate for left_out, @@ -3858,6 +3863,7 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx, } } } +EXPORT_SYMBOL(tcp_parse_options); static int tcp_parse_aligned_timestamp(struct tcp_sock *tp, struct tcphdr *th) { @@ -3931,6 +3937,7 @@ u8 *tcp_parse_md5sig_option(struct tcphdr *th) } return NULL; } +EXPORT_SYMBOL(tcp_parse_md5sig_option); #endif static inline void tcp_store_ts_recent(struct tcp_sock *tp) @@ -5432,6 +5439,7 @@ discard: __kfree_skb(skb); return 0; } +EXPORT_SYMBOL(tcp_rcv_established); static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, struct tcphdr *th, unsigned len) @@ -5931,14 +5939,4 @@ discard: } return 0; } - -EXPORT_SYMBOL(sysctl_tcp_ecn); -EXPORT_SYMBOL(sysctl_tcp_reordering); -EXPORT_SYMBOL(sysctl_tcp_adv_win_scale); -EXPORT_SYMBOL(tcp_parse_options); -#ifdef CONFIG_TCP_MD5SIG -EXPORT_SYMBOL(tcp_parse_md5sig_option); -#endif -EXPORT_SYMBOL(tcp_rcv_established); EXPORT_SYMBOL(tcp_rcv_state_process); -EXPORT_SYMBOL(tcp_initialize_rcv_mss); -- cgit v1.2.2 From ba78e2ddca844598c0efcbf2c76d73519a61b902 Mon Sep 17 00:00:00 2001 From: Dmitry Popov Date: Sat, 7 Aug 2010 20:24:28 -0700 Subject: tcp: no md5sig option size check bug tcp_parse_md5sig_option doesn't check md5sig option (TCPOPT_MD5SIG) length, but tcp_v[46]_inbound_md5_hash assume that it's at least 16 bytes long. Signed-off-by: Dmitry Popov Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3c426cb318e7..e663b78a2ef6 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3930,7 +3930,7 @@ u8 *tcp_parse_md5sig_option(struct tcphdr *th) if (opsize < 2 || opsize > length) return NULL; if (opcode == TCPOPT_MD5SIG) - return ptr; + return opsize == TCPOLEN_MD5SIG ? ptr : NULL; } ptr += opsize - 2; length -= opsize; -- cgit v1.2.2 From a4d258036ed9b2a1811c3670c6099203a0f284a0 Mon Sep 17 00:00:00 2001 From: Tom Marshall Date: Mon, 20 Sep 2010 15:42:05 -0700 Subject: tcp: Fix race in tcp_poll If a RST comes in immediately after checking sk->sk_err, tcp_poll will return POLLIN but not POLLOUT. Fix this by checking sk->sk_err at the end of tcp_poll. Additionally, ensure the correct order of operations on SMP machines with memory barriers. Signed-off-by: Tom Marshall Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e663b78a2ef6..149e79ac2891 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4048,6 +4048,8 @@ static void tcp_reset(struct sock *sk) default: sk->sk_err = ECONNRESET; } + /* This barrier is coupled with smp_rmb() in tcp_poll() */ + smp_wmb(); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_error_report(sk); -- cgit v1.2.2 From b3de7559afbb7a8a35b4be975a6adf6c5e3cdca0 Mon Sep 17 00:00:00 2001 From: Yuchung Cheng Date: Fri, 24 Sep 2010 13:22:06 +0000 Subject: tcp: fix TSO FACK loss marking in tcp_mark_head_lost MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When TCP uses FACK algorithm to mark lost packets in tcp_mark_head_lost(), if the number of packets in the (TSO) skb is greater than the number of packets that should be marked lost, TCP incorrectly exits the loop and marks no packets lost in the skb. This underestimates tp->lost_out and affects the recovery/retransmission. This patch fargments the skb and marks the correct amount of packets lost. Signed-off-by: Yuchung Cheng Acked-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 149e79ac2891..b55f60f6fcbe 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2545,7 +2545,8 @@ static void tcp_mark_head_lost(struct sock *sk, int packets) cnt += tcp_skb_pcount(skb); if (cnt > packets) { - if (tcp_is_sack(tp) || (oldcnt >= packets)) + if ((tcp_is_sack(tp) && !tcp_is_fack(tp)) || + (oldcnt >= packets)) break; mss = skb_shinfo(skb)->gso_size; -- cgit v1.2.2