Add the experimental nfs subtree to the kernel, that includes

	support for NFSv4 as well as NFSv2 and 3.
	It lives in 3 subdirs under sys/fs:
	nfs - functions that are common to the client and server
	nfsclient - a mutation of sys/nfsclient that call generic functions
	to do RPCs and handle state. As such, it retains the
	buffer cache handling characteristics and vnode semantics that
	are found in sys/nfsclient, for the most part.
	nfsserver - the server. It includes a DRC designed specifically for
	NFSv4, that is used instead of the generic DRC in sys/rpc.
	The build glue will be checked in later, so at this point, it
	consists of 3 new subdirs that should not affect kernel building.

Approved by:	kib (mentor)

1 files changed, 1257 insertions, 0 deletions

diff --git a/sys/fs/nfsclient/nfs_clvfsops.c b/sys/fs/nfsclient/nfs_clvfsops.c
new file mode 100644
index 0000000..1ceba85
--- /dev/null
+++ b/sys/fs/nfsclient/nfs_clvfsops.c
@@ -0,0 +1,1257 @@
+/*-
+ * Copyright (c) 1989, 1993, 1995
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Rick Macklem at The University of Guelph.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	from nfs_vfsops.c	8.12 (Berkeley) 5/20/95
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+
+#include "opt_bootp.h"
+#include "opt_nfsroot.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/bio.h>
+#include <sys/buf.h>
+#include <sys/clock.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/module.h>
+#include <sys/mount.h>
+#include <sys/proc.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/sockio.h>
+#include <sys/sysctl.h>
+#include <sys/vnode.h>
+#include <sys/signalvar.h>
+
+#include <vm/vm.h>
+#include <vm/vm_extern.h>
+#include <vm/uma.h>
+
+#include <net/if.h>
+#include <net/route.h>
+#include <netinet/in.h>
+
+#include <fs/nfs/nfsport.h>
+#include <fs/nfsclient/nfsnode.h>
+#include <fs/nfsclient/nfsmount.h>
+#include <fs/nfsclient/nfs.h>
+#include <fs/nfsclient/nfsdiskless.h>
+
+extern int nfscl_ticks;
+extern struct timeval nfsboottime;
+extern struct nfsstats	newnfsstats;
+
+MALLOC_DEFINE(M_NEWNFSREQ, "newnfsclient_req", "New NFS request header");
+MALLOC_DEFINE(M_NEWNFSMNT, "newnfsmnt", "New NFS mount struct");
+
+SYSCTL_DECL(_vfs_newnfs);
+SYSCTL_STRUCT(_vfs_newnfs, NFS_NFSSTATS, nfsstats, CTLFLAG_RW,
+	&newnfsstats, nfsstats, "S,nfsstats");
+static int nfs_ip_paranoia = 1;
+SYSCTL_INT(_vfs_newnfs, OID_AUTO, nfs_ip_paranoia, CTLFLAG_RW,
+    &nfs_ip_paranoia, 0, "");
+static int nfs_tprintf_initial_delay = NFS_TPRINTF_INITIAL_DELAY;
+SYSCTL_INT(_vfs_newnfs, NFS_TPRINTF_INITIAL_DELAY,
+        downdelayinitial, CTLFLAG_RW, &nfs_tprintf_initial_delay, 0, "");
+/* how long between console messages "nfs server foo not responding" */
+static int nfs_tprintf_delay = NFS_TPRINTF_DELAY;
+SYSCTL_INT(_vfs_newnfs, NFS_TPRINTF_DELAY,
+        downdelayinterval, CTLFLAG_RW, &nfs_tprintf_delay, 0, "");
+
+static void	nfs_decode_args(struct mount *mp, struct nfsmount *nmp,
+		    struct nfs_args *argp, struct ucred *, struct thread *);
+static int	mountnfs(struct nfs_args *, struct mount *,
+		    struct sockaddr *, char *, u_char *, u_char *, u_char *,
+		    struct vnode **, struct ucred *, struct thread *);
+static vfs_mount_t nfs_mount;
+static vfs_cmount_t nfs_cmount;
+static vfs_unmount_t nfs_unmount;
+static vfs_root_t nfs_root;
+static vfs_statfs_t nfs_statfs;
+static vfs_sync_t nfs_sync;
+static vfs_sysctl_t nfs_sysctl;
+
+/*
+ * nfs vfs operations.
+ */
+static struct vfsops nfs_vfsops = {
+	.vfs_init =		ncl_init,
+	.vfs_mount =		nfs_mount,
+	.vfs_cmount =		nfs_cmount,
+	.vfs_root =		nfs_root,
+	.vfs_statfs =		nfs_statfs,
+	.vfs_sync =		nfs_sync,
+	.vfs_uninit =		ncl_uninit,
+	.vfs_unmount =		nfs_unmount,
+	.vfs_sysctl =		nfs_sysctl,
+};
+VFS_SET(nfs_vfsops, newnfs, VFCF_NETWORK);
+
+/* So that loader and kldload(2) can find us, wherever we are.. */
+MODULE_VERSION(newnfs, 1);
+
+/*
+ * This structure must be filled in by a primary bootstrap or bootstrap
+ * server for a diskless/dataless machine. It is initialized below just
+ * to ensure that it is allocated to initialized data (.data not .bss).
+ */
+struct nfs_diskless newnfs_diskless = { { { 0 } } };
+struct nfsv3_diskless newnfsv3_diskless = { { { 0 } } };
+int newnfs_diskless_valid = 0;
+
+SYSCTL_INT(_vfs_newnfs, OID_AUTO, diskless_valid, CTLFLAG_RD,
+	&newnfs_diskless_valid, 0, "");
+
+SYSCTL_STRING(_vfs_newnfs, OID_AUTO, diskless_rootpath, CTLFLAG_RD,
+	newnfsv3_diskless.root_hostnam, 0, "");
+
+SYSCTL_OPAQUE(_vfs_newnfs, OID_AUTO, diskless_rootaddr, CTLFLAG_RD,
+	&newnfsv3_diskless.root_saddr, sizeof newnfsv3_diskless.root_saddr,
+	"%Ssockaddr_in", "");
+
+
+void		newnfsargs_ntoh(struct nfs_args *);
+static int	nfs_mountdiskless(char *,
+		    struct sockaddr_in *, struct nfs_args *,
+		    struct thread *, struct vnode **, struct mount *);
+static void	nfs_convert_diskless(void);
+static void	nfs_convert_oargs(struct nfs_args *args,
+		    struct onfs_args *oargs);
+
+int
+newnfs_iosize(struct nfsmount *nmp)
+{
+	int iosize, maxio;
+
+	/* First, set the upper limit for iosize */
+	if (nmp->nm_flag & NFSMNT_NFSV4) {
+		maxio = NFS_MAXBSIZE;
+	} else if (nmp->nm_flag & NFSMNT_NFSV3) {
+		if (nmp->nm_sotype == SOCK_DGRAM)
+			maxio = NFS_MAXDGRAMDATA;
+		else
+			maxio = NFS_MAXBSIZE;
+	} else {
+		maxio = NFS_V2MAXDATA;
+	}
+	if (nmp->nm_rsize > maxio || nmp->nm_rsize == 0)
+		nmp->nm_rsize = maxio;
+	if (nmp->nm_rsize > MAXBSIZE)
+		nmp->nm_rsize = MAXBSIZE;
+	if (nmp->nm_readdirsize > maxio || nmp->nm_readdirsize == 0)
+		nmp->nm_readdirsize = maxio;
+	if (nmp->nm_readdirsize > nmp->nm_rsize)
+		nmp->nm_readdirsize = nmp->nm_rsize;
+	if (nmp->nm_wsize > maxio || nmp->nm_wsize == 0)
+		nmp->nm_wsize = maxio;
+	if (nmp->nm_wsize > MAXBSIZE)
+		nmp->nm_wsize = MAXBSIZE;
+
+	/*
+	 * Calculate the size used for io buffers.  Use the larger
+	 * of the two sizes to minimise nfs requests but make sure
+	 * that it is at least one VM page to avoid wasting buffer
+	 * space.
+	 */
+	iosize = imax(nmp->nm_rsize, nmp->nm_wsize);
+	iosize = imax(iosize, PAGE_SIZE);
+	nmp->nm_mountp->mnt_stat.f_iosize = iosize;
+	return (iosize);
+}
+
+static void
+nfs_convert_oargs(struct nfs_args *args, struct onfs_args *oargs)
+{
+
+	args->version = NFS_ARGSVERSION;
+	args->addr = oargs->addr;
+	args->addrlen = oargs->addrlen;
+	args->sotype = oargs->sotype;
+	args->proto = oargs->proto;
+	args->fh = oargs->fh;
+	args->fhsize = oargs->fhsize;
+	args->flags = oargs->flags;
+	args->wsize = oargs->wsize;
+	args->rsize = oargs->rsize;
+	args->readdirsize = oargs->readdirsize;
+	args->timeo = oargs->timeo;
+	args->retrans = oargs->retrans;
+	args->readahead = oargs->readahead;
+	args->hostname = oargs->hostname;
+}
+
+static void
+nfs_convert_diskless(void)
+{
+
+	bcopy(&newnfs_diskless.myif, &newnfsv3_diskless.myif,
+		sizeof(struct ifaliasreq));
+	bcopy(&newnfs_diskless.mygateway, &newnfsv3_diskless.mygateway,
+		sizeof(struct sockaddr_in));
+	nfs_convert_oargs(&newnfsv3_diskless.root_args,&newnfs_diskless.root_args);
+	if (newnfsv3_diskless.root_args.flags & NFSMNT_NFSV3) {
+		newnfsv3_diskless.root_fhsize = NFSX_MYFH;
+		bcopy(newnfs_diskless.root_fh, newnfsv3_diskless.root_fh, NFSX_MYFH);
+	} else {
+		newnfsv3_diskless.root_fhsize = NFSX_V2FH;
+		bcopy(newnfs_diskless.root_fh, newnfsv3_diskless.root_fh, NFSX_V2FH);
+	}
+	bcopy(&newnfs_diskless.root_saddr,&newnfsv3_diskless.root_saddr,
+		sizeof(struct sockaddr_in));
+	bcopy(newnfs_diskless.root_hostnam, newnfsv3_diskless.root_hostnam, MNAMELEN);
+	newnfsv3_diskless.root_time = newnfs_diskless.root_time;
+	bcopy(newnfs_diskless.my_hostnam, newnfsv3_diskless.my_hostnam,
+		MAXHOSTNAMELEN);
+	newnfs_diskless_valid = 3;
+}
+
+/*
+ * nfs statfs call
+ */
+static int
+nfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
+{
+	struct vnode *vp;
+	struct nfsmount *nmp = VFSTONFS(mp);
+	struct nfsvattr nfsva;
+	struct nfsfsinfo fs;
+	struct nfsstatfs sb;
+	int error = 0, attrflag, gotfsinfo = 0, ret;
+	struct nfsnode *np;
+
+	error = vfs_busy(mp, MBF_NOWAIT);
+	if (error)
+		return (error);
+	error = ncl_nget(mp, nmp->nm_fh, nmp->nm_fhsize, &np);
+	if (error) {
+		vfs_unbusy(mp);
+		return (error);
+	}
+	vp = NFSTOV(np);
+	mtx_lock(&nmp->nm_mtx);
+	if (NFSHASNFSV3(nmp) && !NFSHASGOTFSINFO(nmp)) {
+		mtx_unlock(&nmp->nm_mtx);
+		error = nfsrpc_fsinfo(vp, &fs, td->td_ucred, td, &nfsva,
+		    &attrflag, NULL);
+		if (!error)
+			gotfsinfo = 1;
+	} else
+		mtx_unlock(&nmp->nm_mtx);
+	if (!error)
+		error = nfsrpc_statfs(vp, &sb, &fs, td->td_ucred, td, &nfsva,
+		    &attrflag, NULL);
+	if (attrflag == 0) {
+		ret = nfsrpc_getattrnovp(nmp, nmp->nm_fh, nmp->nm_fhsize, 1,
+		    td->td_ucred, td, &nfsva, NULL);
+		if (ret) {
+			/*
+			 * Just set default values to get things going.
+			 */
+			NFSBZERO((caddr_t)&nfsva, sizeof (struct nfsvattr));
+			nfsva.na_vattr.va_type = VDIR;
+			nfsva.na_vattr.va_mode = 0777;
+			nfsva.na_vattr.va_nlink = 100;
+			nfsva.na_vattr.va_uid = (uid_t)0;
+			nfsva.na_vattr.va_gid = (gid_t)0;
+			nfsva.na_vattr.va_fileid = 2;
+			nfsva.na_vattr.va_gen = 1;
+			nfsva.na_vattr.va_blocksize = NFS_FABLKSIZE;
+			nfsva.na_vattr.va_size = 512 * 1024;
+		}
+	}
+	(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
+	if (!error) {
+	    mtx_lock(&nmp->nm_mtx);
+	    if (gotfsinfo || (nmp->nm_flag & NFSMNT_NFSV4))
+		nfscl_loadfsinfo(nmp, &fs);
+	    nfscl_loadsbinfo(nmp, &sb, sbp);
+	    sbp->f_flags = nmp->nm_flag;
+	    sbp->f_iosize = newnfs_iosize(nmp);
+	    mtx_unlock(&nmp->nm_mtx);
+	    if (sbp != &mp->mnt_stat) {
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	    }
+	    strncpy(&sbp->f_fstypename[0], mp->mnt_vfc->vfc_name, MFSNAMELEN);
+	} else if (NFS_ISV4(vp)) {
+		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
+	}
+	vput(vp);
+	vfs_unbusy(mp);
+	return (error);
+}
+
+/*
+ * nfs version 3 fsinfo rpc call
+ */
+int
+ncl_fsinfo(struct nfsmount *nmp, struct vnode *vp, struct ucred *cred,
+    struct thread *td)
+{
+	struct nfsfsinfo fs;
+	struct nfsvattr nfsva;
+	int error, attrflag;
+	
+	error = nfsrpc_fsinfo(vp, &fs, cred, td, &nfsva, &attrflag, NULL);
+	if (!error) {
+		if (attrflag)
+			(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0,
+			    1);
+		mtx_lock(&nmp->nm_mtx);
+		nfscl_loadfsinfo(nmp, &fs);
+		mtx_unlock(&nmp->nm_mtx);
+	}
+	return (error);
+}
+
+/*
+ * Mount a remote root fs via. nfs. This depends on the info in the
+ * newnfs_diskless structure that has been filled in properly by some primary
+ * bootstrap.
+ * It goes something like this:
+ * - do enough of "ifconfig" by calling ifioctl() so that the system
+ *   can talk to the server
+ * - If newnfs_diskless.mygateway is filled in, use that address as
+ *   a default gateway.
+ * - build the rootfs mount point and call mountnfs() to do the rest.
+ *
+ * It is assumed to be safe to read, modify, and write the nfsv3_diskless
+ * structure, as well as other global NFS client variables here, as
+ * ncl_mountroot() will be called once in the boot before any other NFS
+ * client activity occurs.
+ */
+int
+ncl_mountroot(struct mount *mp, struct thread *td)
+{
+	struct nfsv3_diskless *nd = &newnfsv3_diskless;
+	struct socket *so;
+	struct vnode *vp;
+	struct ifreq ir;
+	int error, i;
+	u_long l;
+	char buf[128];
+	char *cp;
+
+#if defined(BOOTP_NFSROOT) && defined(BOOTP)
+	bootpc_init();		/* use bootp to get newnfs_diskless filled in */
+#elif defined(NFS_ROOT)
+	nfs_setup_diskless();
+#endif
+
+	nfscl_init();
+
+	if (newnfs_diskless_valid == 0)
+		return (-1);
+	if (newnfs_diskless_valid == 1)
+		nfs_convert_diskless();
+
+	/*
+	 * XXX splnet, so networks will receive...
+	 */
+	splnet();
+
+	/*
+	 * Do enough of ifconfig(8) so that the critical net interface can
+	 * talk to the server.
+	 */
+	error = socreate(nd->myif.ifra_addr.sa_family, &so, nd->root_args.sotype, 0,
+	    td->td_ucred, td);
+	if (error)
+		panic("ncl_mountroot: socreate(%04x): %d",
+			nd->myif.ifra_addr.sa_family, error);
+
+#if 0 /* XXX Bad idea */
+	/*
+	 * We might not have been told the right interface, so we pass
+	 * over the first ten interfaces of the same kind, until we get
+	 * one of them configured.
+	 */
+
+	for (i = strlen(nd->myif.ifra_name) - 1;
+		nd->myif.ifra_name[i] >= '0' &&
+		nd->myif.ifra_name[i] <= '9';
+		nd->myif.ifra_name[i] ++) {
+		error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
+		if(!error)
+			break;
+	}
+#endif
+	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
+	if (error)
+		panic("ncl_mountroot: SIOCAIFADDR: %d", error);
+	if ((cp = getenv("boot.netif.mtu")) != NULL) {
+		ir.ifr_mtu = strtol(cp, NULL, 10);
+		bcopy(nd->myif.ifra_name, ir.ifr_name, IFNAMSIZ);
+		freeenv(cp);
+		error = ifioctl(so, SIOCSIFMTU, (caddr_t)&ir, td);
+		if (error)
+			printf("ncl_mountroot: SIOCSIFMTU: %d", error);
+	}
+	soclose(so);
+
+	/*
+	 * If the gateway field is filled in, set it as the default route.
+	 * Note that pxeboot will set a default route of 0 if the route
+	 * is not set by the DHCP server.  Check also for a value of 0
+	 * to avoid panicking inappropriately in that situation.
+	 */
+	if (nd->mygateway.sin_len != 0 &&
+	    nd->mygateway.sin_addr.s_addr != 0) {
+		struct sockaddr_in mask, sin;
+
+		bzero((caddr_t)&mask, sizeof(mask));
+		sin = mask;
+		sin.sin_family = AF_INET;
+		sin.sin_len = sizeof(sin);
+		error = rtrequest(RTM_ADD, (struct sockaddr *)&sin,
+		    (struct sockaddr *)&nd->mygateway,
+		    (struct sockaddr *)&mask,
+		    RTF_UP | RTF_GATEWAY, NULL);
+		if (error)
+			panic("ncl_mountroot: RTM_ADD: %d", error);
+	}
+
+	/*
+	 * Create the rootfs mount point.
+	 */
+	nd->root_args.fh = nd->root_fh;
+	nd->root_args.fhsize = nd->root_fhsize;
+	l = ntohl(nd->root_saddr.sin_addr.s_addr);
+	snprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
+		(l >> 24) & 0xff, (l >> 16) & 0xff,
+		(l >>  8) & 0xff, (l >>  0) & 0xff, nd->root_hostnam);
+	printf("NFS ROOT: %s\n", buf);
+	if ((error = nfs_mountdiskless(buf,
+	    &nd->root_saddr, &nd->root_args, td, &vp, mp)) != 0) {
+		return (error);
+	}
+
+	/*
+	 * This is not really an nfs issue, but it is much easier to
+	 * set hostname here and then let the "/etc/rc.xxx" files
+	 * mount the right /var based upon its preset value.
+	 */
+	bcopy(nd->my_hostnam, hostname, MAXHOSTNAMELEN);
+	hostname[MAXHOSTNAMELEN - 1] = '\0';
+	for (i = 0; i < MAXHOSTNAMELEN; i++)
+		if (hostname[i] == '\0')
+			break;
+	inittodr(ntohl(nd->root_time));
+	return (0);
+}
+
+/*
+ * Internal version of mount system call for diskless setup.
+ */
+static int
+nfs_mountdiskless(char *path,
+    struct sockaddr_in *sin, struct nfs_args *args, struct thread *td,
+    struct vnode **vpp, struct mount *mp)
+{
+	struct sockaddr *nam;
+	int error;
+
+	nam = sodupsockaddr((struct sockaddr *)sin, M_WAITOK);
+	if ((error = mountnfs(args, mp, nam, path, NULL, NULL, NULL, vpp,
+	    td->td_ucred, td)) != 0) {
+		printf("ncl_mountroot: mount %s on /: %d\n", path, error);
+		return (error);
+	}
+	return (0);
+}
+
+static void
+nfs_decode_args(struct mount *mp, struct nfsmount *nmp, struct nfs_args *argp,
+    struct ucred *cred, struct thread *td)
+{
+	int s;
+	int adjsock;
+
+	s = splnet();
+
+	/*
+	 * Set read-only flag if requested; otherwise, clear it if this is
+	 * an update.  If this is not an update, then either the read-only
+	 * flag is already clear, or this is a root mount and it was set
+	 * intentionally at some previous point.
+	 */
+	if (vfs_getopt(mp->mnt_optnew, "ro", NULL, NULL) == 0) {
+		MNT_ILOCK(mp);
+		mp->mnt_flag |= MNT_RDONLY;
+		MNT_IUNLOCK(mp);
+	} else if (mp->mnt_flag & MNT_UPDATE) {
+		MNT_ILOCK(mp);
+		mp->mnt_flag &= ~MNT_RDONLY;
+		MNT_IUNLOCK(mp);
+	}
+
+	/*
+	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
+	 * no sense in that context.  Also, set up appropriate retransmit
+	 * and soft timeout behavior.
+	 */
+	if (argp->sotype == SOCK_STREAM) {
+		nmp->nm_flag &= ~NFSMNT_NOCONN;
+		nmp->nm_timeo = NFS_MAXTIMEO;
+	}
+
+	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
+	if ((argp->flags & NFSMNT_NFSV3) == 0)
+		nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
+
+	/* Also re-bind if we're switching to/from a connected UDP socket */
+	adjsock = ((nmp->nm_flag & NFSMNT_NOCONN) !=
+		    (argp->flags & NFSMNT_NOCONN));
+
+	/* Update flags atomically.  Don't change the lock bits. */
+	nmp->nm_flag = argp->flags | nmp->nm_flag;
+	splx(s);
+
+	if ((argp->flags & NFSMNT_TIMEO) && argp->timeo > 0) {
+		nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;
+		if (nmp->nm_timeo < NFS_MINTIMEO)
+			nmp->nm_timeo = NFS_MINTIMEO;
+		else if (nmp->nm_timeo > NFS_MAXTIMEO)
+			nmp->nm_timeo = NFS_MAXTIMEO;
+	}
+
+	if ((argp->flags & NFSMNT_RETRANS) && argp->retrans > 1) {
+		nmp->nm_retry = argp->retrans;
+		if (nmp->nm_retry > NFS_MAXREXMIT)
+			nmp->nm_retry = NFS_MAXREXMIT;
+	}
+
+	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
+		nmp->nm_wsize = argp->wsize;
+		/* Round down to multiple of blocksize */
+		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
+		if (nmp->nm_wsize <= 0)
+			nmp->nm_wsize = NFS_FABLKSIZE;
+	}
+
+	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
+		nmp->nm_rsize = argp->rsize;
+		/* Round down to multiple of blocksize */
+		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
+		if (nmp->nm_rsize <= 0)
+			nmp->nm_rsize = NFS_FABLKSIZE;
+	}
+
+	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
+		nmp->nm_readdirsize = argp->readdirsize;
+	}
+
+	if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
+		nmp->nm_acregmin = argp->acregmin;
+	else
+		nmp->nm_acregmin = NFS_MINATTRTIMO;
+	if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
+		nmp->nm_acregmax = argp->acregmax;
+	else
+		nmp->nm_acregmax = NFS_MAXATTRTIMO;
+	if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
+		nmp->nm_acdirmin = argp->acdirmin;
+	else
+		nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
+	if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
+		nmp->nm_acdirmax = argp->acdirmax;
+	else
+		nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;
+	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
+		nmp->nm_acdirmin = nmp->nm_acdirmax;
+	if (nmp->nm_acregmin > nmp->nm_acregmax)
+		nmp->nm_acregmin = nmp->nm_acregmax;
+
+	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0) {
+		if (argp->readahead <= NFS_MAXRAHEAD)
+			nmp->nm_readahead = argp->readahead;
+		else
+			nmp->nm_readahead = NFS_MAXRAHEAD;
+	}
+	if ((argp->flags & NFSMNT_WCOMMITSIZE) && argp->wcommitsize >= 0) {
+		if (argp->wcommitsize < nmp->nm_wsize)
+			nmp->nm_wcommitsize = nmp->nm_wsize;
+		else
+			nmp->nm_wcommitsize = argp->wcommitsize;
+	}
+
+	adjsock |= ((nmp->nm_sotype != argp->sotype) ||
+		    (nmp->nm_soproto != argp->proto));
+
+	if (nmp->nm_client != NULL && adjsock) {
+		int haslock = 0, error = 0;
+
+		if (nmp->nm_sotype == SOCK_STREAM) {
+			error = newnfs_sndlock(&nmp->nm_sockreq.nr_lock);
+			if (!error)
+				haslock = 1;
+		}
+		if (!error) {
+		    newnfs_disconnect(&nmp->nm_sockreq);
+		    if (haslock)
+			newnfs_sndunlock(&nmp->nm_sockreq.nr_lock);
+		    nmp->nm_sotype = argp->sotype;
+		    nmp->nm_soproto = argp->proto;
+		    if (nmp->nm_sotype == SOCK_DGRAM)
+			while (newnfs_connect(nmp, &nmp->nm_sockreq,
+			    cred, td, 0)) {
+				printf("newnfs_args: retrying connect\n");
+				(void) nfs_catnap(PSOCK, "newnfscon");
+			}
+		}
+	} else {
+		nmp->nm_sotype = argp->sotype;
+		nmp->nm_soproto = argp->proto;
+	}
+}
+
+static const char *nfs_opts[] = { "from", "nfs_args",
+    "noatime", "noexec", "suiddir", "nosuid", "nosymfollow", "union",
+    "noclusterr", "noclusterw", "multilabel", "acls", "force", "update",
+    "async", "dumbtimer", "noconn", "nolockd", "intr", "rdirplus", "resvport",
+    "readdirsize", "soft", "hard", "mntudp", "tcp", "wsize", "rsize",
+    "retrans", "acregmin", "acregmax", "acdirmin", "acdirmax", 
+    NULL };
+
+/*
+ * VFS Operations.
+ *
+ * mount system call
+ * It seems a bit dumb to copyinstr() the host and path here and then
+ * bcopy() them in mountnfs(), but I wanted to detect errors before
+ * doing the sockargs() call because sockargs() allocates an mbuf and
+ * an error after that means that I have to release the mbuf.
+ */
+/* ARGSUSED */
+static int
+nfs_mount(struct mount *mp, struct thread *td)
+{
+	struct nfs_args args = {
+	    .version = NFS_ARGSVERSION,
+	    .addr = NULL,
+	    .addrlen = sizeof (struct sockaddr_in),
+	    .sotype = SOCK_STREAM,
+	    .proto = 0,
+	    .fh = NULL,
+	    .fhsize = 0,
+	    .flags = 0,
+	    .wsize = NFS_WSIZE,
+	    .rsize = NFS_RSIZE,
+	    .readdirsize = NFS_READDIRSIZE,
+	    .timeo = 10,
+	    .retrans = NFS_RETRANS,
+	    .readahead = NFS_DEFRAHEAD,
+	    .wcommitsize = 0,			/* was: NQ_DEFLEASE */
+	    .hostname = NULL,
+	    /* args version 4 */
+	    .acregmin = NFS_MINATTRTIMO,
+	    .acregmax = NFS_MAXATTRTIMO,
+	    .acdirmin = NFS_MINDIRATTRTIMO,
+	    .acdirmax = NFS_MAXDIRATTRTIMO,
+	    .dirlen = 0,
+	    .krbnamelen = 0,
+	};
+	int error;
+	struct sockaddr *nam;
+	struct vnode *vp;
+	char hst[MNAMELEN];
+	size_t len;
+	u_char nfh[NFSX_FHMAX], krbname[100], dirpath[100], srvkrbname[100];
+
+	if (vfs_filteropt(mp->mnt_optnew, nfs_opts)) {
+		error = EINVAL;
+		goto out;
+	}
+
+	if ((mp->mnt_flag & (MNT_ROOTFS | MNT_UPDATE)) == MNT_ROOTFS) {
+		error = ncl_mountroot(mp, td);
+		goto out;
+	}
+
+	error = vfs_copyopt(mp->mnt_optnew, "nfs_args", &args, sizeof args);
+	if (error)
+		goto out;
+
+	if (args.version != NFS_ARGSVERSION) {
+		error = EPROGMISMATCH;
+		goto out;
+	}
+
+	nfscl_init();
+
+	if (mp->mnt_flag & MNT_UPDATE) {
+		struct nfsmount *nmp = VFSTONFS(mp);
+
+		if (nmp == NULL) {
+			error = EIO;
+			goto out;
+		}
+		/*
+		 * When doing an update, we can't change version,
+		 * security, switch lockd strategies or change cookie
+		 * translation
+		 */
+		args.flags = (args.flags &
+		    ~(NFSMNT_NFSV3 |
+		      NFSMNT_NFSV4 |
+		      NFSMNT_KERB |
+		      NFSMNT_INTEGRITY |
+		      NFSMNT_PRIVACY |
+		      NFSMNT_NOLOCKD /*|NFSMNT_XLATECOOKIE*/)) |
+		    (nmp->nm_flag &
+			(NFSMNT_NFSV3 |
+			 NFSMNT_NFSV4 |
+			 NFSMNT_KERB |
+			 NFSMNT_INTEGRITY |
+			 NFSMNT_PRIVACY |
+			 NFSMNT_NOLOCKD /*|NFSMNT_XLATECOOKIE*/));
+		nfs_decode_args(mp, nmp, &args, td->td_ucred, td);
+		goto out;
+	}
+
+	/*
+	 * Make the nfs_ip_paranoia sysctl serve as the default connection
+	 * or no-connection mode for those protocols that support 
+	 * no-connection mode (the flag will be cleared later for protocols
+	 * that do not support no-connection mode).  This will allow a client
+	 * to receive replies from a different IP then the request was
+	 * sent to.  Note: default value for nfs_ip_paranoia is 1 (paranoid),
+	 * not 0.
+	 */
+	if (nfs_ip_paranoia == 0)
+		args.flags |= NFSMNT_NOCONN;
+	if (args.fhsize < 0 || args.fhsize > NFSX_FHMAX) {
+		error = EINVAL;
+		goto out;
+	}
+	if (args.fhsize > 0) {
+		error = copyin((caddr_t)args.fh, (caddr_t)nfh, args.fhsize);
+		if (error)
+			goto out;
+	}
+	error = copyinstr(args.hostname, hst, MNAMELEN-1, &len);
+	if (error)
+		goto out;
+	bzero(&hst[len], MNAMELEN - len);
+	if (args.krbnamelen > 0) {
+		if (args.krbnamelen >= 100) {
+			error = EINVAL;
+			goto out;
+		}
+		error = copyin(args.krbname, krbname, args.krbnamelen);
+		if (error)
+			goto out;
+		krbname[args.krbnamelen] = '\0';
+	} else {
+		krbname[0] = '\0';
+		args.krbnamelen = 0;
+	}
+	if (args.dirlen > 0) {
+		if (args.dirlen >= 100) {
+			error = EINVAL;
+			goto out;
+		}
+		error = copyin(args.dirpath, dirpath, args.dirlen);
+		if (error)
+			goto out;
+		dirpath[args.dirlen] = '\0';
+	} else {
+		dirpath[0] = '\0';
+		args.dirlen = 0;
+	}
+	if (args.srvkrbnamelen > 0) {
+		if (args.srvkrbnamelen >= 100) {
+			error = EINVAL;
+			goto out;
+		}
+		error = copyin(args.srvkrbname, srvkrbname, args.srvkrbnamelen);
+		if (error)
+			goto out;
+		srvkrbname[args.srvkrbnamelen] = '\0';
+	} else {
+		srvkrbname[0] = '\0';
+		args.srvkrbnamelen = 0;
+	}
+	/* sockargs() call must be after above copyin() calls */
+	error = getsockaddr(&nam, (caddr_t)args.addr, args.addrlen);
+	if (error)
+		goto out;
+	args.fh = nfh;
+	error = mountnfs(&args, mp, nam, hst, krbname, dirpath, srvkrbname,
+	    &vp, td->td_ucred, td);
+out:
+	if (!error) {
+		MNT_ILOCK(mp);
+		mp->mnt_kern_flag |= (MNTK_MPSAFE|MNTK_LOOKUP_SHARED);
+		MNT_IUNLOCK(mp);
+	}
+	return (error);
+}
+
+
+/*
+ * VFS Operations.
+ *
+ * mount system call
+ * It seems a bit dumb to copyinstr() the host and path here and then
+ * bcopy() them in mountnfs(), but I wanted to detect errors before
+ * doing the sockargs() call because sockargs() allocates an mbuf and
+ * an error after that means that I have to release the mbuf.
+ */
+/* ARGSUSED */
+static int
+nfs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
+{
+	int error;
+	struct nfs_args args;
+
+	error = copyin(data, &args, sizeof (struct nfs_args));
+	if (error)
+		return error;
+
+	ma = mount_arg(ma, "nfs_args", &args, sizeof args);
+
+	error = kernel_mount(ma, flags);
+	return (error);
+}
+
+/*
+ * Common code for mount and mountroot
+ */
+static int
+mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
+    char *hst, u_char *krbname, u_char *dirpath, u_char *srvkrbname,
+    struct vnode **vpp, struct ucred *cred, struct thread *td)
+{
+	struct nfsmount *nmp;
+	struct nfsnode *np;
+	int error, trycnt, ret, clearintr;
+	struct nfsvattr nfsva;
+	static u_int64_t clval = 0;
+
+	if (mp->mnt_flag & MNT_UPDATE) {
+		nmp = VFSTONFS(mp);
+		printf("%s: MNT_UPDATE is no longer handled here\n", __func__);
+		FREE(nam, M_SONAME);
+		return (0);
+	} else {
+		MALLOC(nmp, struct nfsmount *, sizeof (struct nfsmount) +
+		    argp->krbnamelen + argp->dirlen + argp->srvkrbnamelen + 2,
+		    M_NEWNFSMNT, M_WAITOK);
+		bzero((caddr_t)nmp, sizeof (struct nfsmount) +
+		    argp->krbnamelen + argp->dirlen + argp->srvkrbnamelen + 2);
+		TAILQ_INIT(&nmp->nm_bufq);
+		if (clval == 0)
+			clval = (u_int64_t)nfsboottime.tv_sec;
+		nmp->nm_clval = clval++;
+		nmp->nm_krbnamelen = argp->krbnamelen;
+		nmp->nm_dirpathlen = argp->dirlen;
+		nmp->nm_srvkrbnamelen = argp->srvkrbnamelen;
+		if (nmp->nm_dirpathlen > 0) {
+			/*
+			 * Since we will be doing dirpath as root,
+			 * set nm_uid to the real uid doing the mount,
+			 * since that is normally the user with a valid TGT.
+			 */
+			nmp->nm_uid = td->td_ucred->cr_ruid;
+		} else {
+			/*
+			 * Just set to -1, so the first Op
+			 * will set it later, to the uid of
+			 * the process doing that (usually
+			 * from a first open in the mount
+			 * point).
+			 */
+			nmp->nm_uid = (uid_t)-1;
+		}
+
+		/* Copy and null terminate all the names */
+		if (nmp->nm_krbnamelen > 0) {
+			bcopy(krbname, nmp->nm_krbname, nmp->nm_krbnamelen);
+			nmp->nm_name[nmp->nm_krbnamelen] = '\0';
+		}
+		if (nmp->nm_dirpathlen > 0) {
+			bcopy(dirpath, NFSMNT_DIRPATH(nmp),
+			    nmp->nm_dirpathlen);
+			nmp->nm_name[nmp->nm_krbnamelen + nmp->nm_dirpathlen
+			    + 1] = '\0';
+		}
+		if (nmp->nm_srvkrbnamelen > 0) {
+			bcopy(srvkrbname, NFSMNT_SRVKRBNAME(nmp),
+			    nmp->nm_srvkrbnamelen);
+			nmp->nm_name[nmp->nm_krbnamelen + nmp->nm_dirpathlen
+			    + nmp->nm_srvkrbnamelen + 2] = '\0';
+		}
+		nmp->nm_sockreq.nr_cred = crhold(cred);
+		mtx_init(&nmp->nm_sockreq.nr_mtx, "nfssock", NULL, MTX_DEF);
+		mp->mnt_data = nmp;
+	}
+	vfs_getnewfsid(mp);
+	nmp->nm_mountp = mp;
+	mtx_init(&nmp->nm_mtx, "NFSmount lock", NULL, MTX_DEF | MTX_DUPOK);			
+
+	/*
+	 * V2 can only handle 32 bit filesizes.  A 4GB-1 limit may be too
+	 * high, depending on whether we end up with negative offsets in
+	 * the client or server somewhere.  2GB-1 may be safer.
+	 *
+	 * For V3, ncl_fsinfo will adjust this as necessary.  Assume maximum
+	 * that we can handle until we find out otherwise.
+	 * XXX Our "safe" limit on the client is what we can store in our
+	 * buffer cache using signed(!) block numbers.
+	 */
+	if ((argp->flags & (NFSMNT_NFSV3 | NFSMNT_NFSV4)) == 0)
+		nmp->nm_maxfilesize = 0xffffffffLL;
+	else
+		nmp->nm_maxfilesize = (u_int64_t)0x80000000 * DEV_BSIZE - 1;
+
+	nmp->nm_timeo = NFS_TIMEO;
+	nmp->nm_retry = NFS_RETRANS;
+	if ((argp->flags & (NFSMNT_NFSV3 | NFSMNT_NFSV4)) == 0) {
+		nmp->nm_wsize = NFS_WSIZE;
+		nmp->nm_rsize = NFS_RSIZE;
+		nmp->nm_readdirsize = NFS_READDIRSIZE;
+	}
+	nmp->nm_wcommitsize = hibufspace / (desiredvnodes / 1000);
+	nmp->nm_numgrps = NFS_MAXGRPS;
+	nmp->nm_readahead = NFS_DEFRAHEAD;
+	nmp->nm_tprintf_delay = nfs_tprintf_delay;
+	if (nmp->nm_tprintf_delay < 0)
+		nmp->nm_tprintf_delay = 0;
+	nmp->nm_tprintf_initial_delay = nfs_tprintf_initial_delay;
+	if (nmp->nm_tprintf_initial_delay < 0)
+		nmp->nm_tprintf_initial_delay = 0;
+	nmp->nm_fhsize = argp->fhsize;
+	if (nmp->nm_fhsize > 0)
+		bcopy((caddr_t)argp->fh, (caddr_t)nmp->nm_fh, argp->fhsize);
+	bcopy(hst, mp->mnt_stat.f_mntfromname, MNAMELEN);
+	nmp->nm_nam = nam;
+	/* Set up the sockets and per-host congestion */
+	nmp->nm_sotype = argp->sotype;
+	nmp->nm_soproto = argp->proto;
+	nmp->nm_sockreq.nr_prog = NFS_PROG;
+	if ((argp->flags & NFSMNT_NFSV4))
+		nmp->nm_sockreq.nr_vers = NFS_VER4;
+	else if ((argp->flags & NFSMNT_NFSV3))
+		nmp->nm_sockreq.nr_vers = NFS_VER3;
+	else
+		nmp->nm_sockreq.nr_vers = NFS_VER2;
+
+	nfs_decode_args(mp, nmp, argp, cred, td);
+
+	/*
+	 * For Connection based sockets (TCP,...) do the connect here,
+	 * but make it interruptible, even for non-interuptible mounts.
+	 */
+	if ((nmp->nm_flag & NFSMNT_INT) == 0) {
+		nmp->nm_flag |= NFSMNT_INT;
+		clearintr = 1;
+	} else {
+		clearintr = 0;
+	}
+	if ((error = newnfs_connect(nmp, &nmp->nm_sockreq, cred, td, 0)))
+		goto bad;
+	if (clearintr)
+		nmp->nm_flag &= ~NFSMNT_INT;
+
+	/*
+	 * A reference count is needed on the nfsnode representing the
+	 * remote root.  If this object is not persistent, then backward
+	 * traversals of the mount point (i.e. "..") will not work if
+	 * the nfsnode gets flushed out of the cache. Ufs does not have
+	 * this problem, because one can identify root inodes by their
+	 * number == ROOTINO (2).
+	 */
+	if (nmp->nm_fhsize == 0 && (nmp->nm_flag & NFSMNT_NFSV4) &&
+	    nmp->nm_dirpathlen > 0) {
+		/*
+		 * If the fhsize on the mount point == 0 for V4, the mount
+		 * path needs to be looked up.
+		 */
+		trycnt = 3;
+		do {
+			error = nfsrpc_getdirpath(nmp, NFSMNT_DIRPATH(nmp),
+			    cred, td);
+			if (error)
+				(void) nfs_catnap(PZERO, "nfsgetdirp");
+		} while (error && --trycnt > 0);
+		if (error) {
+			error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
+			goto bad;
+		}
+	}
+	if (nmp->nm_fhsize > 0) {
+		error = ncl_nget(mp, nmp->nm_fh, nmp->nm_fhsize, &np);
+		if (error)
+			goto bad;
+		*vpp = NFSTOV(np);
+	
+		/*
+		 * Get file attributes and transfer parameters for the
+		 * mountpoint.  This has the side effect of filling in
+		 * (*vpp)->v_type with the correct value.
+		 */
+		ret = nfsrpc_getattrnovp(nmp, nmp->nm_fh, nmp->nm_fhsize, 1,
+		    cred, td, &nfsva, NULL);
+		if (ret) {
+			/*
+			 * Just set default values to get things going.
+			 */
+			NFSBZERO((caddr_t)&nfsva, sizeof (struct nfsvattr));
+			nfsva.na_vattr.va_type = VDIR;
+			nfsva.na_vattr.va_mode = 0777;
+			nfsva.na_vattr.va_nlink = 100;
+			nfsva.na_vattr.va_uid = (uid_t)0;
+			nfsva.na_vattr.va_gid = (gid_t)0;
+			nfsva.na_vattr.va_fileid = 2;
+			nfsva.na_vattr.va_gen = 1;
+			nfsva.na_vattr.va_blocksize = NFS_FABLKSIZE;
+			nfsva.na_vattr.va_size = 512 * 1024;
+		}
+		(void) nfscl_loadattrcache(vpp, &nfsva, NULL, NULL, 0, 1);
+		if (argp->flags & NFSMNT_NFSV3)
+			ncl_fsinfo(nmp, *vpp, cred, td);
+	
+		/*
+		 * Lose the lock but keep the ref.
+		 */
+		VOP_UNLOCK(*vpp, 0);
+		return (0);
+	}
+	error = EIO;
+
+bad:
+	newnfs_disconnect(&nmp->nm_sockreq);
+	crfree(nmp->nm_sockreq.nr_cred);
+	mtx_destroy(&nmp->nm_sockreq.nr_mtx);
+	mtx_destroy(&nmp->nm_mtx);
+	FREE(nmp, M_NEWNFSMNT);
+	FREE(nam, M_SONAME);
+	return (error);
+}
+
+/*
+ * unmount system call
+ */
+static int
+nfs_unmount(struct mount *mp, int mntflags, struct thread *td)
+{
+	struct nfsmount *nmp;
+	int error, flags = 0, trycnt = 0;
+
+	if (mntflags & MNT_FORCE)
+		flags |= FORCECLOSE;
+	nmp = VFSTONFS(mp);
+	/*
+	 * Goes something like this..
+	 * - Call vflush() to clear out vnodes for this filesystem
+	 * - Close the socket
+	 * - Free up the data structures
+	 */
+	/* In the forced case, cancel any outstanding requests. */
+	if (mntflags & MNT_FORCE) {
+		error = newnfs_nmcancelreqs(nmp);
+		if (error)
+			goto out;
+		/* For a forced close, get rid of the renew thread now */
+		nfscl_umount(nmp, td);
+	}
+	/* We hold 1 extra ref on the root vnode; see comment in mountnfs(). */
+	do {
+		error = vflush(mp, 1, flags, td);
+		if ((mntflags & MNT_FORCE) && error != 0 && ++trycnt < 30)
+			(void) nfs_catnap(PSOCK, "newndm");
+	} while ((mntflags & MNT_FORCE) && error != 0 && trycnt < 30);
+	if (error)
+		goto out;
+
+	/*
+	 * We are now committed to the unmount.
+	 */
+	if ((mntflags & MNT_FORCE) == 0)
+		nfscl_umount(nmp, td);
+	newnfs_disconnect(&nmp->nm_sockreq);
+	crfree(nmp->nm_sockreq.nr_cred);
+	FREE(nmp->nm_nam, M_SONAME);
+
+	mtx_destroy(&nmp->nm_sockreq.nr_mtx);
+	mtx_destroy(&nmp->nm_mtx);
+	FREE(nmp, M_NEWNFSMNT);
+out:
+	return (error);
+}
+
+/*
+ * Return root of a filesystem
+ */
+static int
+nfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
+{
+	struct vnode *vp;
+	struct nfsmount *nmp;
+	struct nfsnode *np;
+	int error;
+
+	nmp = VFSTONFS(mp);
+	error = ncl_nget(mp, nmp->nm_fh, nmp->nm_fhsize, &np);
+	if (error)
+		return error;
+	vp = NFSTOV(np);
+	/*
+	 * Get transfer parameters and attributes for root vnode once.
+	 */
+	mtx_lock(&nmp->nm_mtx);
+	if (NFSHASNFSV3(nmp) && !NFSHASGOTFSINFO(nmp)) {
+		mtx_unlock(&nmp->nm_mtx);
+		ncl_fsinfo(nmp, vp, curthread->td_ucred, curthread);
+	} else 
+		mtx_unlock(&nmp->nm_mtx);
+	if (vp->v_type == VNON)
+	    vp->v_type = VDIR;
+	vp->v_vflag |= VV_ROOT;
+	*vpp = vp;
+	return (0);
+}
+
+/*
+ * Flush out the buffer cache
+ */
+/* ARGSUSED */
+static int
+nfs_sync(struct mount *mp, int waitfor, struct thread *td)
+{
+	struct vnode *vp, *mvp;
+	int error, allerror = 0;
+
+	/*
+	 * Force stale buffer cache information to be flushed.
+	 */
+	MNT_ILOCK(mp);
+loop:
+	MNT_VNODE_FOREACH(vp, mp, mvp) {
+		VI_LOCK(vp);
+		MNT_IUNLOCK(mp);
+		/* XXX Racy bv_cnt check. */
+		if (VOP_ISLOCKED(vp) || vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
+		    waitfor == MNT_LAZY) {
+			VI_UNLOCK(vp);
+			MNT_ILOCK(mp);
+			continue;
+		}
+		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
+			MNT_ILOCK(mp);
+			MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
+			goto loop;
+		}
+		error = VOP_FSYNC(vp, waitfor, td);
+		if (error)
+			allerror = error;
+		VOP_UNLOCK(vp, 0);
+		vrele(vp);
+
+		MNT_ILOCK(mp);
+	}
+	MNT_IUNLOCK(mp);
+	return (allerror);
+}
+
+static int
+nfs_sysctl(struct mount *mp, fsctlop_t op, struct sysctl_req *req)
+{
+	struct nfsmount *nmp = VFSTONFS(mp);
+	struct vfsquery vq;
+	int error;
+
+	bzero(&vq, sizeof(vq));
+	switch (op) {
+#if 0
+	case VFS_CTL_NOLOCKS:
+		val = (nmp->nm_flag & NFSMNT_NOLOCKS) ? 1 : 0;
+ 		if (req->oldptr != NULL) {
+ 			error = SYSCTL_OUT(req, &val, sizeof(val));
+ 			if (error)
+ 				return (error);
+ 		}
+ 		if (req->newptr != NULL) {
+ 			error = SYSCTL_IN(req, &val, sizeof(val));
+ 			if (error)
+ 				return (error);
+			if (val)
+				nmp->nm_flag |= NFSMNT_NOLOCKS;
+			else
+				nmp->nm_flag &= ~NFSMNT_NOLOCKS;
+ 		}
+		break;
+#endif
+	case VFS_CTL_QUERY:
+		mtx_lock(&nmp->nm_mtx);
+		if (nmp->nm_state & NFSSTA_TIMEO)
+			vq.vq_flags |= VQ_NOTRESP;
+		mtx_unlock(&nmp->nm_mtx);
+#if 0
+		if (!(nmp->nm_flag & NFSMNT_NOLOCKS) &&
+		    (nmp->nm_state & NFSSTA_LOCKTIMEO))
+			vq.vq_flags |= VQ_NOTRESPLOCK;
+#endif
+		error = SYSCTL_OUT(req, &vq, sizeof(vq));
+		break;
+ 	case VFS_CTL_TIMEO:
+ 		if (req->oldptr != NULL) {
+ 			error = SYSCTL_OUT(req, &nmp->nm_tprintf_initial_delay,
+ 			    sizeof(nmp->nm_tprintf_initial_delay));
+ 			if (error)
+ 				return (error);
+ 		}
+ 		if (req->newptr != NULL) {
+			error = vfs_suser(mp, req->td);
+			if (error)
+				return (error);
+ 			error = SYSCTL_IN(req, &nmp->nm_tprintf_initial_delay,
+ 			    sizeof(nmp->nm_tprintf_initial_delay));
+ 			if (error)
+ 				return (error);
+ 			if (nmp->nm_tprintf_initial_delay < 0)
+ 				nmp->nm_tprintf_initial_delay = 0;
+ 		}
+		break;
+	default:
+		return (ENOTSUP);
+	}
+	return (0);
+}
+