From: Alexander Bluhm <bluhm@openbsd.org>
Subject: nfs shared socket lock
To: tech@openbsd.org
Date: Fri, 14 Feb 2025 20:02:19 +0100

Hi,

The socket functions that are called by NFS code are MP safe.
Shared net lock together with socket lock is sufficient.

ok?

bluhm

Index: nfs/krpc_subr.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/nfs/krpc_subr.c,v
diff -u -p -r1.39 krpc_subr.c
--- nfs/krpc_subr.c	1 May 2024 13:15:59 -0000	1.39
+++ nfs/krpc_subr.c	13 Feb 2025 12:54:08 -0000
@@ -276,9 +276,9 @@ krpc_call(struct sockaddr_in *sa, u_int 
 	sin->sin_family = AF_INET;
 	sin->sin_addr.s_addr = INADDR_ANY;
 	sin->sin_port = htons(0);
-	solock(so);
+	solock_shared(so);
 	error = sobind(so, m, &proc0);
-	sounlock(so);
+	sounlock_shared(so);
 	m_freem(m);
 	if (error) {
 		printf("bind failed\n");
Index: nfs/nfs_socket.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/nfs/nfs_socket.c,v
diff -u -p -r1.155 nfs_socket.c
--- nfs/nfs_socket.c	30 Jan 2025 14:40:50 -0000	1.155
+++ nfs/nfs_socket.c	13 Feb 2025 12:48:34 -0000
@@ -281,9 +281,9 @@ nfs_connect(struct nfsmount *nmp, struct
 		sin->sin_family = AF_INET;
 		sin->sin_addr.s_addr = INADDR_ANY;
 		sin->sin_port = htons(0);
-		solock(so);
+		solock_shared(so);
 		error = sobind(so, nam, &proc0);
-		sounlock(so);
+		sounlock_shared(so);
 		if (error)
 			goto bad;
 
@@ -305,7 +305,7 @@ nfs_connect(struct nfsmount *nmp, struct
 			goto bad;
 		}
 	} else {
-		solock(so);
+		solock_shared(so);
 		error = soconnect(so, nmp->nm_nam);
 		if (error)
 			goto bad_locked;
@@ -330,7 +330,7 @@ nfs_connect(struct nfsmount *nmp, struct
 			so->so_error = 0;
 			goto bad_locked;
 		}
-		sounlock(so);
+		sounlock_shared(so);
 	}
 	/*
 	 * Always set receive timeout to detect server crash and reconnect.
@@ -367,7 +367,7 @@ nfs_connect(struct nfsmount *nmp, struct
 	} else {
 		panic("%s: nm_sotype %d", __func__, nmp->nm_sotype);
 	}
-	solock(so);
+	solock_shared(so);
 	error = soreserve(so, sndreserve, rcvreserve);
 	if (error)
 		goto bad_locked;
@@ -377,7 +377,7 @@ nfs_connect(struct nfsmount *nmp, struct
 	mtx_enter(&so->so_snd.sb_mtx);
 	so->so_snd.sb_flags |= SB_NOINTR;
 	mtx_leave(&so->so_snd.sb_mtx);
-	sounlock(so);
+	sounlock_shared(so);
 
 	m_freem(mopt);
 	m_freem(nam);
@@ -390,7 +390,7 @@ nfs_connect(struct nfsmount *nmp, struct
 	return (0);
 
 bad_locked:
-	sounlock(so);
+	sounlock_shared(so);
 bad:
 
 	m_freem(mopt);
Index: nfs/nfs_syscalls.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/nfs/nfs_syscalls.c,v
diff -u -p -r1.128 nfs_syscalls.c
--- nfs/nfs_syscalls.c	18 Sep 2024 05:21:19 -0000	1.128
+++ nfs/nfs_syscalls.c	13 Feb 2025 12:55:27 -0000
@@ -247,9 +247,9 @@ nfssvc_addsock(struct file *fp, struct m
 		siz = NFS_MAXPACKET + sizeof (u_long);
 	else
 		siz = NFS_MAXPACKET;
-	solock(so);
+	solock_shared(so);
 	error = soreserve(so, siz, siz); 
-	sounlock(so);
+	sounlock_shared(so);
 	if (error) {
 		m_freem(mynam);
 		return (error);
@@ -275,7 +275,7 @@ nfssvc_addsock(struct file *fp, struct m
 		sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
 		m_freem(m);
 	}
-	solock(so);
+	solock_shared(so);
 	mtx_enter(&so->so_rcv.sb_mtx);
 	so->so_rcv.sb_flags &= ~SB_NOINTR;
 	so->so_rcv.sb_timeo_nsecs = INFSLP;
@@ -284,7 +284,7 @@ nfssvc_addsock(struct file *fp, struct m
 	so->so_snd.sb_flags &= ~SB_NOINTR;
 	so->so_snd.sb_timeo_nsecs = INFSLP;
 	mtx_leave(&so->so_snd.sb_mtx);
-	sounlock(so);
+	sounlock_shared(so);
 	if (tslp)
 		slp = tslp;
 	else {