From c5a1ae9a4cc4aef1505fa0aba079f834c3ee1af1 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 10 Dec 2006 00:09:21 -0200 Subject: [DCCP] ccid3: Perform history operations only after packet has been sent This migrates all packet history operations into the routine ccid3_hc_tx_packet_sent, thereby removing synchronization problems that occur when, as before, the operations are spread over multiple routines. The following minor simplifications are also applied: * several simplifications now follow from this change - several tests are now no longer required * removal of one unnecessary variable (dp) Justification: Currently packet history operations span two different routines, one of which is likely to pass through several iterations of sleeping and awakening. The first routine, ccid3_hc_tx_send_packet, allocates an entry and sets a few fields. The remaining fields are filled in when the second routine (which is not within a sleeping context), ccid3_hc_tx_packet_sent, is called. This has several strong drawbacks: * it is not necessary to split history operations - all fields can be filled in by the second routine * the first routine is called multiple times, until a packet can be sent, and sleeps meanwhile - this causes a lot of difficulties with regard to keeping the list consistent * since both routines do not have a producer-consumer like synchronization, it is very difficult to maintain data across calls to these routines * the fact that the routines are called in different contexts (sleeping, not sleeping) adds further problems Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo --- net/dccp/ccids/ccid3.c | 38 +++++++++----------------------------- 1 file changed, 9 insertions(+), 29 deletions(-) (limited to 'net') diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 6bb3f8352dad..ef68c35183ed 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -296,7 +296,6 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct dccp_tx_hist_entry *new_packet; struct timeval now; suseconds_t delay; @@ -310,21 +309,6 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) if (unlikely(skb->len == 0)) return -EBADMSG; - /* See if last packet allocated was not sent */ - new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist); - if (new_packet == NULL || new_packet->dccphtx_sent) { - new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist, - GFP_ATOMIC); - - if (unlikely(new_packet == NULL)) { - DCCP_WARN("%s, sk=%p, not enough mem to add to history," - "send refused\n", dccp_role(sk), sk); - return -ENOBUFS; - } - - dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet); - } - dccp_timestamp(sk, &now); switch (hctx->ccid3hctx_state) { @@ -380,31 +364,27 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) { - const struct dccp_sock *dp = dccp_sk(sk); struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); struct timeval now; struct dccp_tx_hist_entry *packet; BUG_ON(hctx == NULL); - dccp_timestamp(sk, &now); - ccid3_hc_tx_update_s(hctx, len); - packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist); + packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC); if (unlikely(packet == NULL)) { - DCCP_WARN("packet doesn't exist in history!\n"); - return; - } - if (unlikely(packet->dccphtx_sent)) { - DCCP_WARN("no unsent packet in history!\n"); + DCCP_CRIT("packet history - out of memory!"); return; } + dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet); + + dccp_timestamp(sk, &now); packet->dccphtx_tstamp = now; - packet->dccphtx_seqno = dp->dccps_gss; - hctx->ccid3hctx_idle = 0; - packet->dccphtx_rtt = hctx->ccid3hctx_rtt; - packet->dccphtx_sent = 1; + packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss; + packet->dccphtx_rtt = hctx->ccid3hctx_rtt; + packet->dccphtx_sent = 1; + hctx->ccid3hctx_idle = 0; } static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) -- cgit v1.2.3