Date: Thu, 8 Sep 2022 16:16:46 GMT From: Gleb Smirnoff <glebius@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: e80062a2d433 - main - tcp: avoid call to soisconnected() on transition to ESTABLISHED Message-ID: <202209081616.288GGkE7074939@gitrepo.freebsd.org>
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The branch main has been updated by glebius: URL: https://cgit.FreeBSD.org/src/commit/?id=e80062a2d43376a3b89ca68ab6c6f63b8e032e1d commit e80062a2d43376a3b89ca68ab6c6f63b8e032e1d Author: Gleb Smirnoff <glebius@FreeBSD.org> AuthorDate: 2022-09-08 16:16:04 +0000 Commit: Gleb Smirnoff <glebius@FreeBSD.org> CommitDate: 2022-09-08 16:16:04 +0000 tcp: avoid call to soisconnected() on transition to ESTABLISHED This call existed since pre-FreeBSD times, and it is hard to understand why it was there in the first place. After 6f3caa6d815 it definitely became necessary always and commit message from f1ee30ccd60 confirms that. Now that 6f3caa6d815 is effectively backed out by 07285bb4c22, the call appears to be useful only for sockets that landed on the incomplete queue, e.g. sockets that have accept_filter(9) enabled on them. Provide a new TCP flag to mark connections that are known to be on the incomplete queue, and call soisconnected() only for those connections. Reviewed by: rrs, tuexen Differential revision: https://reviews.freebsd.org/D36488 --- sys/kern/uipc_socket.c | 8 ++++++-- sys/netinet/tcp_input.c | 5 ++++- sys/netinet/tcp_syncache.c | 3 ++- sys/netinet/tcp_usrreq.c | 4 ++-- sys/netinet/tcp_var.h | 2 +- sys/sys/socketvar.h | 2 +- 6 files changed, 16 insertions(+), 8 deletions(-) diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c index 360b7b56cee5..7f5e70d14e91 100644 --- a/sys/kern/uipc_socket.c +++ b/sys/kern/uipc_socket.c @@ -800,7 +800,7 @@ sonewconn(struct socket *head, int connstatus) return (NULL); } - solisten_enqueue(so, connstatus); + (void)solisten_enqueue(so, connstatus); return (so); } @@ -808,8 +808,10 @@ sonewconn(struct socket *head, int connstatus) /* * Enqueue socket cloned by solisten_clone() to the listen queue of the * listener it has been cloned from. + * + * Return 'true' if socket landed on complete queue, otherwise 'false'. */ -void +bool solisten_enqueue(struct socket *so, int connstatus) { struct socket *head = so->so_listen; @@ -827,6 +829,7 @@ solisten_enqueue(struct socket *so, int connstatus) so->so_qstate = SQ_COMP; head->sol_qlen++; solisten_wakeup(head); /* unlocks */ + return (true); } else { /* * Keep removing sockets from the head until there's room for @@ -853,6 +856,7 @@ solisten_enqueue(struct socket *so, int connstatus) so->so_qstate = SQ_INCOMP; head->sol_incqlen++; SOLISTEN_UNLOCK(head); + return (false); } } diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index e8f2676f2aa8..86071141b174 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -2433,7 +2433,10 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, case TCPS_SYN_RECEIVED: TCPSTAT_INC(tcps_connects); - soisconnected(so); + if (tp->t_flags & TF_INCQUEUE) { + tp->t_flags &= ~TF_INCQUEUE; + soisconnected(so); + } /* Do window scaling? */ if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == (TF_RCVD_SCALE|TF_REQ_SCALE)) { diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c index 76272179dac6..f0ee539fa1ec 100644 --- a/sys/netinet/tcp_syncache.c +++ b/sys/netinet/tcp_syncache.c @@ -1039,7 +1039,8 @@ syncache_socket(struct syncache *sc, struct socket *lso, struct mbuf *m) TCPSTAT_INC(tcps_accepts); TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, TCPS_LISTEN); - solisten_enqueue(so, SS_ISCONNECTED); + if (!solisten_enqueue(so, SS_ISCONNECTED)) + tp->t_flags |= TF_INCQUEUE; return (so); diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c index d1b7ce5daa67..474cdb4d7787 100644 --- a/sys/netinet/tcp_usrreq.c +++ b/sys/netinet/tcp_usrreq.c @@ -2978,8 +2978,8 @@ db_print_tflags(u_int t_flags) db_printf("%sTF_MORETOCOME", comma ? ", " : ""); comma = 1; } - if (t_flags & TF_LQ_OVERFLOW) { - db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : ""); + if (t_flags & TF_INCQUEUE) { + db_printf("%sTF_INCQUEUE", comma ? ", " : ""); comma = 1; } if (t_flags & TF_LASTIDLE) { diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h index 20bf72dcd9d0..6019f162090e 100644 --- a/sys/netinet/tcp_var.h +++ b/sys/netinet/tcp_var.h @@ -515,7 +515,7 @@ tcp_unlock_or_drop(struct tcpcb *tp, int tcp_output_retval) #define TF_WAKESOR 0x00004000 /* wake up receive socket */ #define TF_GPUTINPROG 0x00008000 /* Goodput measurement in progress */ #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */ -#define TF_LQ_OVERFLOW 0x00020000 /* listen queue overflow */ +#define TF_INCQUEUE 0x00020000 /* on incomplete queue of listener */ #define TF_LASTIDLE 0x00040000 /* connection was previously idle */ #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */ #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */ diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h index 678642eeff6d..0c60b9e13cf2 100644 --- a/sys/sys/socketvar.h +++ b/sys/sys/socketvar.h @@ -474,7 +474,7 @@ int solisten(struct socket *so, int backlog, struct thread *td); void solisten_proto(struct socket *so, int backlog); void solisten_proto_abort(struct socket *so); int solisten_proto_check(struct socket *so); -void solisten_enqueue(struct socket *, int); +bool solisten_enqueue(struct socket *, int); int solisten_dequeue(struct socket *, struct socket **, int); struct socket * solisten_clone(struct socket *);
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