Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 16 Jan 2024 18:31:36 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: 507f87a799cf - main - sockets: retire sorflush()
Message-ID:  <202401161831.40GIVaUO055999@gitrepo.freebsd.org>

next in thread | raw e-mail | index | archive | help
The branch main has been updated by glebius:

URL: https://cgit.FreeBSD.org/src/commit/?id=507f87a799cf0811ce30f0ae7f10ba19b2fd3db3

commit 507f87a799cf0811ce30f0ae7f10ba19b2fd3db3
Author:     Gleb Smirnoff <glebius@FreeBSD.org>
AuthorDate: 2024-01-16 18:26:10 +0000
Commit:     Gleb Smirnoff <glebius@FreeBSD.org>
CommitDate: 2024-01-16 18:30:49 +0000

    sockets: retire sorflush()
    
    With removal of dom_dispose method the function boils down to two
    meaningful function calls: socantrcvmore() and sbrelease().  The latter is
    only relevant for protocols that use generic socket buffers.
    
    The socket I/O sx(9) lock acquisition in sorflush() is not relevant for
    shutdown(2) operation as it doesn't do any I/O that may interleave with
    read(2) or write(2).  The socket buffer mutex acquisition inside
    sbrelease() is what guarantees thread safety.  This sx(9) acquisition in
    soshutdown() can be tracked down to 4.4BSD times, where it used to be
    sblock(), and it was carried over through the years evolving together with
    sockets with no reconsideration of why do we carry it over.  I can't tell
    if that sblock() made sense back then, but it doesn't make any today.
    
    Reviewed by:            tuexen
    Differential Revision:  https://reviews.freebsd.org/D43415
---
 sys/kern/uipc_socket.c    | 36 +++---------------------------------
 sys/net/rtsock.c          |  6 ++++--
 sys/netinet/raw_ip.c      |  6 ++++--
 sys/netinet/sctp_usrreq.c |  6 +-----
 sys/netinet/tcp_usrreq.c  |  6 ++++--
 sys/netinet/udp_usrreq.c  |  6 ++++--
 sys/netinet6/raw_ip6.c    |  6 ++++--
 sys/sys/socketvar.h       |  1 -
 8 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 1626c6a7442d..65230e39e4ae 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -95,9 +95,9 @@
  *
  * NOTE: With regard to VNETs the general rule is that callers do not set
  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
- * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
- * and sorflush(), which are usually called from a pre-set VNET context.
- * sopoll() currently does not need a VNET context to be set.
+ * sofree() (and with that sorele(), sotryfree()), as well as sonewconn(),
+ * which are usually called from a pre-set VNET context. sopoll() currently
+ * does not need a VNET context to be set.
  */
 
 #include <sys/cdefs.h>
@@ -2971,36 +2971,6 @@ soshutdown(struct socket *so, enum shutdown_how how)
 	return (error);
 }
 
-/*
- * Used by several pr_shutdown implementations that use generic socket buffers.
- */
-void
-sorflush(struct socket *so)
-{
-	int error;
-
-	VNET_SO_ASSERT(so);
-
-	/*
-	 * Dislodge threads currently blocked in receive and wait to acquire
-	 * a lock against other simultaneous readers before clearing the
-	 * socket buffer.  Don't let our acquire be interrupted by a signal
-	 * despite any existing socket disposition on interruptable waiting.
-	 */
-	socantrcvmore(so);
-
-	error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
-	if (error != 0) {
-		KASSERT(SOLISTENING(so),
-		    ("%s: soiolock(%p) failed", __func__, so));
-		return;
-	}
-
-	sbrelease(so, SO_RCV);
-	SOCK_IO_RECV_UNLOCK(so);
-
-}
-
 /*
  * Wrapper for Socket established helper hook.
  * Parameters: socket, context of the hook point, hook id.
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 94d5e9e4bccc..cb149f176b6d 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -457,10 +457,12 @@ rts_shutdown(struct socket *so, enum shutdown_how how)
 	 */
 	switch (how) {
 	case SHUT_RD:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		break;
 	case SHUT_RDWR:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		/* FALLTHROUGH */
 	case SHUT_WR:
 		socantsendmore(so);
diff --git a/sys/netinet/raw_ip.c b/sys/netinet/raw_ip.c
index a6bef1c7e275..004aaea01bfa 100644
--- a/sys/netinet/raw_ip.c
+++ b/sys/netinet/raw_ip.c
@@ -994,10 +994,12 @@ rip_shutdown(struct socket *so, enum shutdown_how how)
 
 	switch (how) {
 	case SHUT_RD:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		break;
 	case SHUT_RDWR:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		/* FALLTHROUGH */
 	case SHUT_WR:
 		socantsendmore(so);
diff --git a/sys/netinet/sctp_usrreq.c b/sys/netinet/sctp_usrreq.c
index ec9f211b519b..51c056e052a5 100644
--- a/sys/netinet/sctp_usrreq.c
+++ b/sys/netinet/sctp_usrreq.c
@@ -868,11 +868,7 @@ sctp_shutdown(struct socket *so, enum shutdown_how how)
 			SCTP_TCB_UNLOCK(stcb);
 		}
 		SCTP_INP_WUNLOCK(inp);
-		/*
-		 * XXXGL: does SCTP need sorflush()? This is what old
-		 * soshutdown() used to do for all kinds of sockets.
-		 */
-		sorflush(so);
+		socantrcvmore(so);
 		if (how == SHUT_RD)
 			break;
 		/* FALLTHROUGH */
diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index ccd6a6149dae..7c8e3d7e72db 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -824,10 +824,12 @@ tcp_usr_shutdown(struct socket *so, enum shutdown_how how)
 
 	switch (how) {
 	case SHUT_RD:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		break;
 	case SHUT_RDWR:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		/* FALLTHROUGH */
 	case SHUT_WR:
 		/*
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index f91a96edeb68..b68ec95a923a 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -1696,10 +1696,12 @@ udp_shutdown(struct socket *so, enum shutdown_how how)
 
 	switch (how) {
 	case SHUT_RD:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		break;
 	case SHUT_RDWR:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		/* FALLTHROUGH */
 	case SHUT_WR:
 		socantsendmore(so);
diff --git a/sys/netinet6/raw_ip6.c b/sys/netinet6/raw_ip6.c
index 3264de331817..5b31a84f31eb 100644
--- a/sys/netinet6/raw_ip6.c
+++ b/sys/netinet6/raw_ip6.c
@@ -839,10 +839,12 @@ rip6_shutdown(struct socket *so, enum shutdown_how how)
 
 	switch (how) {
 	case SHUT_RD:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		break;
 	case SHUT_RDWR:
-		sorflush(so);
+		socantrcvmore(so);
+		sbrelease(so, SO_RCV);
 		/* FALLTHROUGH */
 	case SHUT_WR:
 		socantsendmore(so);
diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
index 19ca52177d17..5d651b36b1e7 100644
--- a/sys/sys/socketvar.h
+++ b/sys/sys/socketvar.h
@@ -501,7 +501,6 @@ int	soreceive_generic(struct socket *so, struct sockaddr **paddr,
 void	sorele_locked(struct socket *so);
 void	sodealloc(struct socket *);
 int	soreserve(struct socket *so, u_long sndcc, u_long rcvcc);
-void	sorflush(struct socket *so);
 int	sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 	    struct mbuf *top, struct mbuf *control, int flags,
 	    struct thread *td);



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202401161831.40GIVaUO055999>