soconnect2() & solock()

[Martin Pieuchot]

I'd like to push the lock *inside* soconnect2().  This is mostly a noop
as only AF_LOCAL support PRU_CONNECT2.  But having less solock/sounlock
dances in kern/uipc_syscalls.c helps mentally :)

ok?

Index: kern/uipc_socket.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_socket.c,v
retrieving revision 1.215
diff -u -p -r1.215 uipc_socket.c
--- kern/uipc_socket.c  10 Jan 2018 18:14:34 -0000      1.215
+++ kern/uipc_socket.c  7 Feb 2018 14:40:14 -0000
@@ -337,11 +337,12 @@ soconnect(struct socket *so, struct mbuf
 int
 soconnect2(struct socket *so1, struct socket *so2)
 {
-       int error;
+       int s, error;
 
-       soassertlocked(so1);
+       s = solock(so1);
        error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2, NULL,
            (struct mbuf *)so2, NULL, curproc);
+       sounlock(s);
        return (error);
 }
 
Index: kern/uipc_syscalls.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_syscalls.c,v
retrieving revision 1.162
diff -u -p -r1.162 uipc_syscalls.c
--- kern/uipc_syscalls.c        9 Jan 2018 15:14:23 -0000       1.162
+++ kern/uipc_syscalls.c        7 Feb 2018 14:39:23 -0000
@@ -447,7 +447,7 @@ sys_socketpair(struct proc *p, void *v, 
        struct filedesc *fdp = p->p_fd;
        struct file *fp1, *fp2;
        struct socket *so1, *so2;
-       int s, type, cloexec, nonblock, fflag, error, sv[2];
+       int type, cloexec, nonblock, fflag, error, sv[2];
 
        type  = SCARG(uap, type) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK);
        cloexec = (SCARG(uap, type) & SOCK_CLOEXEC) ? UF_EXCLOSE : 0;
@@ -461,9 +461,7 @@ sys_socketpair(struct proc *p, void *v, 
        if (error)
                goto free1;
 
-       s = solock(so1);
        error = soconnect2(so1, so2);
-       sounlock(s);
        if (error != 0)
                goto free2;
 
@@ -471,9 +469,7 @@ sys_socketpair(struct proc *p, void *v, 
                /*
                 * Datagram socket connection is asymmetric.
                 */
-               s = solock(so2);
                error = soconnect2(so2, so1);
-               sounlock(s);
                if (error != 0)
                        goto free2;
        }
Index: miscfs/fifofs/fifo_vnops.c
===================================================================
RCS file: /cvs/src/sys/miscfs/fifofs/fifo_vnops.c,v
retrieving revision 1.62
diff -u -p -r1.62 fifo_vnops.c
--- miscfs/fifofs/fifo_vnops.c  2 Jan 2018 06:38:45 -0000       1.62
+++ miscfs/fifofs/fifo_vnops.c  7 Feb 2018 14:38:38 -0000
@@ -143,14 +143,7 @@ fifo_open(void *v)
                        return (error);
                }
                fip->fi_writesock = wso;
-               /*
-                * XXXSMP
-                * We only lock `wso' because AF_LOCAL sockets are
-                * still relying on the KERNEL_LOCK().
-                */
-               s = solock(wso);
                if ((error = soconnect2(wso, rso)) != 0) {
-                       sounlock(s);
                        (void)soclose(wso);
                        (void)soclose(rso);
                        free(fip, M_VNODE, sizeof *fip);
@@ -158,6 +151,7 @@ fifo_open(void *v)
                        return (error);
                }
                fip->fi_readers = fip->fi_writers = 0;
+               s = solock(wso);
                wso->so_state |= SS_CANTSENDMORE;
                wso->so_snd.sb_lowat = PIPE_BUF;
        } else {