[apple/xnu.git] / bsd / nfs / nfs_vfsops.c

/*
 * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 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.
 *
 *      @(#)nfs_vfsops.c        8.12 (Berkeley) 5/20/95
 * FreeBSD-Id: nfs_vfsops.c,v 1.52 1997/11/12 05:42:21 julian Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/signal.h>
#include <sys/proc_internal.h> /* for fs rooting to update rootdir in fdp */
#include <sys/kauth.h>
#include <sys/vnode_internal.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/mount_internal.h>
#include <sys/kpi_mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/fcntl.h>
#include <libkern/OSAtomic.h>

#include <sys/vm.h>
#include <sys/vmparam.h>

#if !defined(NO_MOUNT_PRIVATE)
#include <sys/filedesc.h>
#endif /* NO_MOUNT_PRIVATE */

#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfsmount.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfsm_subs.h>
#include <nfs/nfsdiskless.h>
#include <nfs/nfs_lock.h>

extern int      nfs_mountroot(void);

extern int      nfs_ticks;
extern int      nfs_mount_type;
extern int      nfs_resv_mounts;

struct nfsstats nfsstats;
static int nfs_sysctl(int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, vfs_context_t);
/* XXX CSM 11/25/97 Upgrade sysctl.h someday */
#ifdef notyet
SYSCTL_NODE(_vfs, MOUNT_NFS, nfs, CTLFLAG_RW, 0, "NFS filesystem");
SYSCTL_STRUCT(_vfs_nfs, NFS_NFSSTATS, nfsstats, CTLFLAG_RD,
        &nfsstats, nfsstats, "");
#endif

SYSCTL_DECL(_vfs_generic_nfs);
SYSCTL_NODE(_vfs_generic_nfs, OID_AUTO, client, CTLFLAG_RW, 0,
    "nfs client hinge");
/* how long NFS will wait before signalling vfs that it's down. */
static int nfs_tprintf_initial_delay = NFS_TPRINTF_INITIAL_DELAY;
SYSCTL_INT(_vfs_generic_nfs_client, NFS_TPRINTF_INITIAL_DELAY,
    initialdowndelay, 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_generic_nfs_client, NFS_TPRINTF_DELAY,
    nextdowndelay, CTLFLAG_RW, &nfs_tprintf_delay, 0, "");

static int      nfs_iosize(struct nfsmount *nmp);
static int      mountnfs(struct user_nfs_args *,mount_t,mbuf_t,proc_t,vnode_t *);
static int      nfs_mount(mount_t mp, vnode_t vp, user_addr_t data, vfs_context_t context);
static int      nfs_start(mount_t mp, int flags, vfs_context_t context);
static int      nfs_unmount(mount_t mp, int mntflags, vfs_context_t context);
static int      nfs_root(mount_t mp, vnode_t *vpp, vfs_context_t context);
static int      nfs_statfs(mount_t mp, struct vfsstatfs *sbp, vfs_context_t context);
static int      nfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context);
static int      nfs_sync( mount_t mp, int waitfor, vfs_context_t context);
static int      nfs_vptofh(vnode_t vp, int *fhlenp, unsigned char *fhp, vfs_context_t context);
static int      nfs_fhtovp(mount_t mp, int fhlen, unsigned char *fhp, vnode_t *vpp, vfs_context_t context);
static int      nfs_vget(mount_t , ino64_t, vnode_t *, vfs_context_t context);


/*
 * nfs vfs operations.
 */
struct vfsops nfs_vfsops = {
        nfs_mount,
        nfs_start,
        nfs_unmount,
        nfs_root,
        NULL,           /* quotactl */
        nfs_vfs_getattr,
        nfs_sync,
        nfs_vget,
        nfs_fhtovp,
        nfs_vptofh,
        nfs_init,
        nfs_sysctl,
        NULL            /* setattr */
};


static int
nfs_mount_diskless(struct nfs_dlmount *, const char *, int, vnode_t *, mount_t *);
#if !defined(NO_MOUNT_PRIVATE)
static int
nfs_mount_diskless_private(struct nfs_dlmount *, const char *, int, vnode_t *, mount_t *);
#endif /* NO_MOUNT_PRIVATE */

static int nfs_iosize(nmp)
        struct nfsmount* nmp;
{
        int iosize;

        /*
         * 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 and to allow easy mmapping of I/O buffers.
         * The read/write rpc calls handle the splitting up of
         * buffers into multiple requests if the buffer size is
         * larger than the I/O size.
         */
        iosize = max(nmp->nm_rsize, nmp->nm_wsize);
        if (iosize < PAGE_SIZE)
                iosize = PAGE_SIZE;
        return (trunc_page_32(iosize));
}

/*
 * nfs statfs call
 */
int
nfs_statfs(mount_t mp, struct vfsstatfs *sbp, vfs_context_t context)
{
        proc_t p = vfs_context_proc(context);
        vnode_t vp;
        struct nfs_statfs *sfp;
        caddr_t cp;
        u_long *tl;
        long t1, t2;
        caddr_t bpos, dpos, cp2;
        struct nfsmount *nmp = VFSTONFS(mp);
        int error = 0, v3 = (nmp->nm_flag & NFSMNT_NFSV3), retattr;
        mbuf_t mreq, mrep, md, mb, mb2;
        u_int64_t xid;
        kauth_cred_t cred;
        struct ucred temp_cred;

#ifndef nolint
        sfp = (struct nfs_statfs *)0;
#endif
        vp = nmp->nm_dvp;
        if ((error = vnode_get(vp)))
                return(error);

        bzero(&temp_cred, sizeof(temp_cred));
        temp_cred.cr_ngroups = 1;
        cred = kauth_cred_create(&temp_cred);

        if (v3 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
                nfs_fsinfo(nmp, vp, cred, p);
        nfsm_reqhead(NFSX_FH(v3));
        if (error) {
                kauth_cred_rele(cred);
                vnode_put(vp);
                return (error);
        }
        OSAddAtomic(1, (SInt32*)&nfsstats.rpccnt[NFSPROC_FSSTAT]);
        nfsm_fhtom(vp, v3);
        nfsm_request(vp, NFSPROC_FSSTAT, p, cred, &xid);
        if (v3 && mrep)
                nfsm_postop_attr_update(vp, v3, retattr, &xid);
        nfsm_dissect(sfp, struct nfs_statfs *, NFSX_STATFS(v3));

        sbp->f_flags = nmp->nm_flag;
        sbp->f_iosize = nfs_iosize(nmp);
        if (v3) {
                /*
                 * Adjust block size to get total block count to fit in a long.
                 * If we can't increase block size enough, clamp to max long.
                 */
                u_quad_t tquad, tquad2, bsize;
                bsize = NFS_FABLKSIZE;

                fxdr_hyper(&sfp->sf_tbytes, &tquad);
                tquad /= bsize;
                while ((tquad & ~0x7fffffff) && (bsize < 0x40000000)) {
                        bsize <<= 1;
                        tquad >>= 1;
                }
                sbp->f_blocks = (tquad & ~0x7fffffff) ? 0x7fffffff : (long)tquad;

                fxdr_hyper(&sfp->sf_fbytes, &tquad);
                tquad /= bsize;
                sbp->f_bfree = (tquad & ~0x7fffffff) ? 0x7fffffff : (long)tquad;

                fxdr_hyper(&sfp->sf_abytes, &tquad);
                tquad /= bsize;
                sbp->f_bavail = (tquad & ~0x7fffffff) ? 0x7fffffff : (long)tquad;

                sbp->f_bsize = (long)bsize;

                /* adjust file slots too... */
                fxdr_hyper(&sfp->sf_tfiles, &tquad);
                fxdr_hyper(&sfp->sf_ffiles, &tquad2);
                while (tquad & ~0x7fffffff) {
                        tquad >>= 1;
                        tquad2 >>= 1;
                }
                sbp->f_files = tquad;
                sbp->f_ffree = tquad2;
        } else {
                sbp->f_bsize = fxdr_unsigned(long, sfp->sf_bsize);
                sbp->f_blocks = fxdr_unsigned(long, sfp->sf_blocks);
                sbp->f_bfree = fxdr_unsigned(long, sfp->sf_bfree);
                sbp->f_bavail = fxdr_unsigned(long, sfp->sf_bavail);
                sbp->f_files = 0;
                sbp->f_ffree = 0;
        }
        nfsm_reqdone;
        kauth_cred_rele(cred);
        vnode_put(vp);
        return (error);
}

/*
 * The nfs_statfs code is complicated, and used by mountnfs(), so leave it as-is
 * and handle VFS_GETATTR by calling nfs_statfs and copying fields.
 */
static int
nfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
{
        int error = 0;
        
        if (VFSATTR_IS_ACTIVE(fsap, f_bsize)  ||
            VFSATTR_IS_ACTIVE(fsap, f_iosize) ||
            VFSATTR_IS_ACTIVE(fsap, f_blocks) ||
            VFSATTR_IS_ACTIVE(fsap, f_bfree)  ||
            VFSATTR_IS_ACTIVE(fsap, f_bavail) ||
            VFSATTR_IS_ACTIVE(fsap, f_bused)  ||
            VFSATTR_IS_ACTIVE(fsap, f_files)  ||
            VFSATTR_IS_ACTIVE(fsap, f_ffree)) {
                struct vfsstatfs sb;

                error = nfs_statfs(mp, &sb, context);
                if (!error) {
                        VFSATTR_RETURN(fsap, f_bsize, sb.f_bsize);
                        VFSATTR_RETURN(fsap, f_iosize, sb.f_iosize);
                        VFSATTR_RETURN(fsap, f_blocks, sb.f_blocks);
                        VFSATTR_RETURN(fsap, f_bfree, sb.f_bfree);
                        VFSATTR_RETURN(fsap, f_bavail, sb.f_bavail);
                        VFSATTR_RETURN(fsap, f_bused, sb.f_blocks - sb.f_bfree);
                        VFSATTR_RETURN(fsap, f_files, sb.f_files);
                        VFSATTR_RETURN(fsap, f_ffree, sb.f_ffree);
                }
        }

        if (VFSATTR_IS_ACTIVE(fsap, f_capabilities)) {
                struct nfsmount *nmp;
                struct nfsv3_pathconf pc;
                u_int32_t caps, valid;
                vnode_t vp;
                int v3;

                if (!(nmp = VFSTONFS(mp)))
                        return (ENXIO);
                vp = nmp->nm_dvp;
                v3 = (nmp->nm_flag & NFSMNT_NFSV3);

                /*
                 * The capabilities[] array defines what this volume supports.
                 *
                 * The valid[] array defines which bits this code understands
                 * the meaning of (whether the volume has that capability or not).
                 * Any zero bits here means "I don't know what you're asking about"
                 * and the caller cannot tell whether that capability is
                 * present or not.
                 */
                caps = valid = 0;
                if (v3) {
                        /* try to get fsinfo if we haven't already */
                        if (!(nmp->nm_state & NFSSTA_GOTFSINFO)) {
                                nfs_fsinfo(nmp, vp, vfs_context_ucred(context),
                                        vfs_context_proc(context));
                                if (!(nmp = VFSTONFS(vnode_mount(vp))))
                                        return (ENXIO);
                        }
                        if (nmp->nm_state & NFSSTA_GOTFSINFO) {
                                /* fsinfo indicates (non)support of links and symlinks */
                                valid |= VOL_CAP_FMT_SYMBOLICLINKS |
                                         VOL_CAP_FMT_HARDLINKS;
                                if (nmp->nm_fsinfo.fsproperties & NFSV3FSINFO_SYMLINK)
                                        caps |= VOL_CAP_FMT_SYMBOLICLINKS;
                                if (nmp->nm_fsinfo.fsproperties & NFSV3FSINFO_LINK)
                                        caps |= VOL_CAP_FMT_HARDLINKS;
                                /* if fsinfo indicates all pathconf info is the same, */
                                /* we can use it to report case attributes */
                                if ((nmp->nm_fsinfo.fsproperties & NFSV3FSINFO_HOMOGENEOUS) &&
                                    !(nmp->nm_state & NFSSTA_GOTPATHCONF)) {
                                        /* no cached pathconf info, try to get now */
                                        error = nfs_pathconfrpc(vp, &pc,
                                                        vfs_context_ucred(context),
                                                        vfs_context_proc(context));
                                        if (!(nmp = VFSTONFS(vnode_mount(vp))))
                                                return (ENXIO);
                                        if (!error) {
                                                /* all files have the same pathconf info, */
                                                /* so cache a copy of the results */
                                                nfs_pathconf_cache(nmp, &pc);
                                        }
                                }
                                if (nmp->nm_state & NFSSTA_GOTPATHCONF) {
                                        valid |= VOL_CAP_FMT_CASE_SENSITIVE |
                                                 VOL_CAP_FMT_CASE_PRESERVING;
                                        if (!(nmp->nm_fsinfo.pcflags &
                                                NFSPCINFO_CASE_INSENSITIVE))
                                                caps |= VOL_CAP_FMT_CASE_SENSITIVE;
                                        if (nmp->nm_fsinfo.pcflags &
                                                NFSPCINFO_CASE_PRESERVING)
                                                caps |= VOL_CAP_FMT_CASE_PRESERVING;
                                }
                                /* Is server's max file size at least 2TB? */
                                if (nmp->nm_fsinfo.maxfilesize >= 0x20000000000ULL)
                                        caps |= VOL_CAP_FMT_2TB_FILESIZE;
                        } else {
                                /*
                                 * NFSv3 supports 64 bits of file size.
                                 * Without FSINFO from the server, we'll
                                 * just assume maxfilesize >= 2TB
                                 */
                                caps |= VOL_CAP_FMT_2TB_FILESIZE;
                        }
                }
                fsap->f_capabilities.capabilities[VOL_CAPABILITIES_FORMAT] =
                        // VOL_CAP_FMT_PERSISTENTOBJECTIDS |
                        // VOL_CAP_FMT_SYMBOLICLINKS |
                        // VOL_CAP_FMT_HARDLINKS |
                        // VOL_CAP_FMT_JOURNAL |
                        // VOL_CAP_FMT_JOURNAL_ACTIVE |
                        // VOL_CAP_FMT_NO_ROOT_TIMES |
                        // VOL_CAP_FMT_SPARSE_FILES |
                        // VOL_CAP_FMT_ZERO_RUNS |
                        // VOL_CAP_FMT_CASE_SENSITIVE |
                        // VOL_CAP_FMT_CASE_PRESERVING |
                        // VOL_CAP_FMT_FAST_STATFS |
                        // VOL_CAP_FMT_2TB_FILESIZE |
                        caps;
                fsap->f_capabilities.valid[VOL_CAPABILITIES_FORMAT] =
                        VOL_CAP_FMT_PERSISTENTOBJECTIDS |
                        // VOL_CAP_FMT_SYMBOLICLINKS |
                        // VOL_CAP_FMT_HARDLINKS |
                        // VOL_CAP_FMT_JOURNAL |
                        // VOL_CAP_FMT_JOURNAL_ACTIVE |
                        // VOL_CAP_FMT_NO_ROOT_TIMES |
                        // VOL_CAP_FMT_SPARSE_FILES |
                        // VOL_CAP_FMT_ZERO_RUNS |
                        // VOL_CAP_FMT_CASE_SENSITIVE |
                        // VOL_CAP_FMT_CASE_PRESERVING |
                        VOL_CAP_FMT_FAST_STATFS |
                        VOL_CAP_FMT_2TB_FILESIZE |
                        valid;

                /*
                 * We don't support most of the interfaces.
                 *
                 * We MAY support locking, but we don't have any easy way of probing.
                 * We can tell if there's no lockd running or if locks have been
                 * disabled for a mount, so we can definitely answer NO in that case.
                 * Any attempt to send a request to lockd to test for locking support
                 * may cause the lazily-launched locking daemons to be started
                 * unnecessarily.  So we avoid that.  However, we do record if we ever
                 * successfully perform a lock operation on a mount point, so if it
                 * looks like lock ops have worked, we do report that we support them.
                 */
                caps = valid = 0;
                if ((!nfslockdvnode && !nfslockdwaiting) ||
                    (nmp->nm_flag & NFSMNT_NOLOCKS)) {
                        /* locks disabled on this mount, so they definitely won't work */
                        valid = VOL_CAP_INT_ADVLOCK | VOL_CAP_INT_FLOCK;
                } else if (nmp->nm_state & NFSSTA_LOCKSWORK) {
                        caps = VOL_CAP_INT_ADVLOCK | VOL_CAP_INT_FLOCK;
                        valid = VOL_CAP_INT_ADVLOCK | VOL_CAP_INT_FLOCK;
                }
                fsap->f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] =
                        // VOL_CAP_INT_SEARCHFS |
                        // VOL_CAP_INT_ATTRLIST |
                        // VOL_CAP_INT_NFSEXPORT |
                        // VOL_CAP_INT_READDIRATTR |
                        // VOL_CAP_INT_EXCHANGEDATA |
                        // VOL_CAP_INT_COPYFILE |
                        // VOL_CAP_INT_ALLOCATE |
                        // VOL_CAP_INT_VOL_RENAME |
                        // VOL_CAP_INT_ADVLOCK |
                        // VOL_CAP_INT_FLOCK |
                        // VOL_CAP_INT_EXTENDED_SECURITY |
                        // VOL_CAP_INT_USERACCESS |
                        caps;
                fsap->f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] =
                        VOL_CAP_INT_SEARCHFS |
                        VOL_CAP_INT_ATTRLIST |
                        VOL_CAP_INT_NFSEXPORT |
                        VOL_CAP_INT_READDIRATTR |
                        VOL_CAP_INT_EXCHANGEDATA |
                        VOL_CAP_INT_COPYFILE |
                        VOL_CAP_INT_ALLOCATE |
                        VOL_CAP_INT_VOL_RENAME |
                        // VOL_CAP_INT_ADVLOCK |
                        // VOL_CAP_INT_FLOCK |
                        // VOL_CAP_INT_EXTENDED_SECURITY |
                        // VOL_CAP_INT_USERACCESS |
                        valid;

                fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED1] = 0;
                fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED1] = 0;

                fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED2] = 0;
                fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED2] = 0;

                VFSATTR_SET_SUPPORTED(fsap, f_capabilities);
        }

        if (VFSATTR_IS_ACTIVE(fsap, f_attributes)) {
                fsap->f_attributes.validattr.commonattr = 0;
                fsap->f_attributes.validattr.volattr =
                        ATTR_VOL_CAPABILITIES | ATTR_VOL_ATTRIBUTES;
                fsap->f_attributes.validattr.dirattr = 0;
                fsap->f_attributes.validattr.fileattr = 0;
                fsap->f_attributes.validattr.forkattr = 0;

                fsap->f_attributes.nativeattr.commonattr = 0;
                fsap->f_attributes.nativeattr.volattr =
                        ATTR_VOL_CAPABILITIES | ATTR_VOL_ATTRIBUTES;
                fsap->f_attributes.nativeattr.dirattr = 0;
                fsap->f_attributes.nativeattr.fileattr = 0;
                fsap->f_attributes.nativeattr.forkattr = 0;

                VFSATTR_SET_SUPPORTED(fsap, f_attributes);
        }

        return (error);
}

/*
 * nfs version 3 fsinfo rpc call
 */
int
nfs_fsinfo(nmp, vp, cred, p)
        struct nfsmount *nmp;
        vnode_t vp;
        kauth_cred_t cred;
        proc_t p;
{
        struct nfsv3_fsinfo *fsp;
        caddr_t cp;
        long t1, t2;
        u_long *tl;
        int prefsize, maxsize;
        caddr_t bpos, dpos, cp2;
        int error = 0, retattr;
        mbuf_t mreq, mrep, md, mb, mb2;
        u_int64_t xid;

        nfsm_reqhead(NFSX_FH(1));
        if (error)
                return (error);
        OSAddAtomic(1, (SInt32*)&nfsstats.rpccnt[NFSPROC_FSINFO]);
        nfsm_fhtom(vp, 1);
        nfsm_request(vp, NFSPROC_FSINFO, p, cred, &xid);
        if (mrep) {
                nfsm_postop_attr_update(vp, 1, retattr, &xid);
        }
        if (!error) {
                nfsm_dissect(fsp, struct nfsv3_fsinfo *, NFSX_V3FSINFO);
                prefsize = fxdr_unsigned(u_long, fsp->fs_wtpref);
                if (prefsize < nmp->nm_wsize)
                        nmp->nm_wsize = (prefsize + NFS_FABLKSIZE - 1) &
                                ~(NFS_FABLKSIZE - 1);
                maxsize = fxdr_unsigned(u_long, fsp->fs_wtmax);
                if (maxsize < nmp->nm_wsize) {
                        nmp->nm_wsize = maxsize & ~(NFS_FABLKSIZE - 1);
                        if (nmp->nm_wsize == 0)
                                nmp->nm_wsize = maxsize;
                }
                prefsize = fxdr_unsigned(u_long, fsp->fs_rtpref);
                if (prefsize < nmp->nm_rsize)
                        nmp->nm_rsize = (prefsize + NFS_FABLKSIZE - 1) &
                                ~(NFS_FABLKSIZE - 1);
                maxsize = fxdr_unsigned(u_long, fsp->fs_rtmax);
                if (maxsize < nmp->nm_rsize) {
                        nmp->nm_rsize = maxsize & ~(NFS_FABLKSIZE - 1);
                        if (nmp->nm_rsize == 0)
                                nmp->nm_rsize = maxsize;
                }
                prefsize = fxdr_unsigned(u_long, fsp->fs_dtpref);
                if (prefsize < nmp->nm_readdirsize)
                        nmp->nm_readdirsize = prefsize;
                if (maxsize < nmp->nm_readdirsize) {
                        nmp->nm_readdirsize = maxsize;
                }
                fxdr_hyper(&fsp->fs_maxfilesize, &nmp->nm_fsinfo.maxfilesize);
                nmp->nm_fsinfo.fsproperties = fxdr_unsigned(u_long, fsp->fs_properties);
                nmp->nm_state |= NFSSTA_GOTFSINFO;
        }
        nfsm_reqdone;
        return (error);
}

/*
 * Mount a remote root fs via. nfs. This depends on the info in the
 * nfs_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 nfs_diskless.mygateway is filled in, use that address as
 *   a default gateway.
 * - hand craft the swap nfs vnode hanging off a fake mount point
 *      if swdevt[0].sw_dev == NODEV
 * - build the rootfs mount point and call mountnfs() to do the rest.
 */
int
nfs_mountroot()
{
        struct nfs_diskless nd;
        struct nfs_vattr nvattr;
        mount_t mp;
        vnode_t vp;
        proc_t procp;
        int error;
#if !defined(NO_MOUNT_PRIVATE)
        mount_t mppriv;
        vnode_t vppriv;
#endif /* NO_MOUNT_PRIVATE */
        int v3, sotype;

        procp = current_proc(); /* XXX */

        /*
         * Call nfs_boot_init() to fill in the nfs_diskless struct.
         * Note: networking must already have been configured before
         * we're called.
         */
        bzero((caddr_t) &nd, sizeof(nd));
        error = nfs_boot_init(&nd, procp);
        if (error) {
                panic("nfs_boot_init failed with %d\n", error);
        }

        /*
         * Try NFSv3 first, then fallback to NFSv2.
         * Likewise, try TCP first, then fall back to UDP.
         */
        v3 = 1;
        sotype = SOCK_STREAM;

tryagain:
        error = nfs_boot_getfh(&nd, procp, v3, sotype);
        if (error) {
                if (error == EHOSTDOWN || error == EHOSTUNREACH) {
                        if (nd.nd_root.ndm_path)
                                FREE_ZONE(nd.nd_root.ndm_path, 
                                          MAXPATHLEN, M_NAMEI);
                        if (nd.nd_private.ndm_path)
                                FREE_ZONE(nd.nd_private.ndm_path, 
                                          MAXPATHLEN, M_NAMEI);
                        return (error);
                }
                if (v3) {
                        if (sotype == SOCK_STREAM) {
                                printf("nfs_boot_getfh(v3,TCP) failed with %d, trying UDP...\n", error);
                                sotype = SOCK_DGRAM;
                                goto tryagain;
                        }
                        printf("nfs_boot_getfh(v3,UDP) failed with %d, trying v2...\n", error);
                        v3 = 0;
                        sotype = SOCK_STREAM;
                        goto tryagain;
                } else if (sotype == SOCK_STREAM) {
                        printf("nfs_boot_getfh(v2,TCP) failed with %d, trying UDP...\n", error);
                        sotype = SOCK_DGRAM;
                        goto tryagain;
                }
                panic("nfs_boot_getfh(v2,UDP) failed with %d\n", error);
        }

        /*
         * Create the root mount point.
         */
#if !defined(NO_MOUNT_PRIVATE)
        if ((error = nfs_mount_diskless(&nd.nd_root, "/", MNT_RDONLY|MNT_ROOTFS, &vp, &mp)))
#else
        if ((error = nfs_mount_diskless(&nd.nd_root, "/", MNT_ROOTFS, &vp, &mp)))
#endif /* NO_MOUNT_PRIVATE */
        {
                if (v3) {
                        if (sotype == SOCK_STREAM) {
                                printf("nfs_mount_diskless(v3,TCP) failed with %d, trying UDP...\n", error);
                                sotype = SOCK_DGRAM;
                                goto tryagain;
                        }
                        printf("nfs_mount_diskless(v3,UDP) failed with %d, trying v2...\n", error);
                        v3 = 0;
                        sotype = SOCK_STREAM;
                        goto tryagain;
                } else if (sotype == SOCK_STREAM) {
                        printf("nfs_mount_diskless(v2,TCP) failed with %d, trying UDP...\n", error);
                        sotype = SOCK_DGRAM;
                        goto tryagain;
                }
                panic("nfs_mount_diskless(v2,UDP) root failed with %d\n", error);
        }
        printf("root on %s\n", (char *)&nd.nd_root.ndm_host);

        vfs_unbusy(mp);
        mount_list_add(mp);
        rootvp = vp;
        
#if !defined(NO_MOUNT_PRIVATE)
        if (nd.nd_private.ndm_saddr.sin_addr.s_addr) {
            error = nfs_mount_diskless_private(&nd.nd_private, "/private",
                                               0, &vppriv, &mppriv);
            if (error) {
                panic("nfs_mount_diskless private failed with %d\n", error);
            }
            printf("private on %s\n", (char *)&nd.nd_private.ndm_host);
            
            vfs_unbusy(mppriv);
            mount_list_add(mppriv);
        }

#endif /* NO_MOUNT_PRIVATE */

        if (nd.nd_root.ndm_path)
                FREE_ZONE(nd.nd_root.ndm_path, MAXPATHLEN, M_NAMEI);
        if (nd.nd_private.ndm_path)
                FREE_ZONE(nd.nd_private.ndm_path, MAXPATHLEN, M_NAMEI);

        /* Get root attributes (for the time). */
        error = nfs_getattr(vp, &nvattr, kauth_cred_get(), procp);
        if (error) panic("nfs_mountroot: getattr for root");
        return (0);
}

/*
 * Internal version of mount system call for diskless setup.
 */
static int
nfs_mount_diskless(
        struct nfs_dlmount *ndmntp,
        const char *mntname,
        int mntflag,
        vnode_t *vpp,
        mount_t *mpp)
{
        struct user_nfs_args args;
        mount_t mp;
        mbuf_t m;
        int error;
        proc_t procp;

        procp = current_proc(); /* XXX */

        if ((error = vfs_rootmountalloc("nfs", ndmntp->ndm_host, &mp))) {
                printf("nfs_mount_diskless: NFS not configured");
                return (error);
        }

        mp->mnt_flag |= mntflag;
        if (!(mntflag & MNT_RDONLY))
                mp->mnt_flag &= ~MNT_RDONLY;

        /* Initialize mount args. */
        bzero((caddr_t) &args, sizeof(args));
        args.addr     = CAST_USER_ADDR_T(&ndmntp->ndm_saddr);
        args.addrlen  = ndmntp->ndm_saddr.sin_len;
        args.sotype   = ndmntp->ndm_sotype;
        args.fh       = CAST_USER_ADDR_T(&ndmntp->ndm_fh[0]);
        args.fhsize   = ndmntp->ndm_fhlen;
        args.hostname = CAST_USER_ADDR_T(ndmntp->ndm_host);
        args.flags    = NFSMNT_RESVPORT;
        if (ndmntp->ndm_nfsv3)
                args.flags |= NFSMNT_NFSV3;

        error = mbuf_get(MBUF_WAITOK, MBUF_TYPE_SONAME, &m);
        if (error) {
                printf("nfs_mount_diskless: mbuf_get(soname) failed");
                return (error);
        }
        mbuf_setlen(m, ndmntp->ndm_saddr.sin_len);
        bcopy((caddr_t)args.addr, mbuf_data(m), ndmntp->ndm_saddr.sin_len);
        if ((error = mountnfs(&args, mp, m, procp, vpp))) {
                printf("nfs_mountroot: mount %s failed: %d\n", mntname, error);
                // XXX vfs_rootmountfailed(mp);
                mount_list_lock();
                mp->mnt_vtable->vfc_refcount--;
                mount_list_unlock();
                vfs_unbusy(mp);
                mount_lock_destroy(mp);
                FREE_ZONE(mp, sizeof(struct mount), M_MOUNT);
                return (error);
        }
        *mpp = mp;
        return (0);
}

#if !defined(NO_MOUNT_PRIVATE)
/*
 * Internal version of mount system call to mount "/private"
 * separately in diskless setup
 */
static int
nfs_mount_diskless_private(
        struct nfs_dlmount *ndmntp,
        const char *mntname,
        int mntflag,
        vnode_t *vpp,
        mount_t *mpp)
{
        struct user_nfs_args args;
        mount_t mp;
        mbuf_t m;
        int error;
        proc_t procp;
        struct vfstable *vfsp;
        struct nameidata nd;
        vnode_t vp;
        struct vfs_context context;

        procp = current_proc(); /* XXX */
        context.vc_proc = procp;
        context.vc_ucred = kauth_cred_get();

        {
        /*
         * mimic main()!. Temporarily set up rootvnode and other stuff so
         * that namei works. Need to undo this because main() does it, too
         */
                struct filedesc *fdp;   /* pointer to file descriptor state */
                fdp = procp->p_fd;
                mountlist.tqh_first->mnt_flag |= MNT_ROOTFS;

                /* Get the vnode for '/'. Set fdp->fd_cdir to reference it. */
                if (VFS_ROOT(mountlist.tqh_first, &rootvnode, NULL))
                        panic("cannot find root vnode");
                error = vnode_ref(rootvnode);
                if (error) {
                        printf("nfs_mountroot: vnode_ref() failed on root vnode!\n");
                        return (error);
                }
                fdp->fd_cdir = rootvnode;
                fdp->fd_rdir = NULL;
        }

        /*
         * Get vnode to be covered
         */
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
            mntname, &context);
        if ((error = namei(&nd))) {
                printf("nfs_mountroot: private namei failed!\n");
                return (error);
        }
        {
                /* undo vnode_ref() in mimic main()! */
                vnode_rele(rootvnode);
        }
        nameidone(&nd);
        vp = nd.ni_vp;

        if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context)) ||
            (error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
                vnode_put(vp);
                return (error);
        }
        if (vnode_vtype(vp) != VDIR) {
                vnode_put(vp);
                return (ENOTDIR);
        }
        for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
                if (!strcmp(vfsp->vfc_name, "nfs"))
                        break;
        if (vfsp == NULL) {
                printf("nfs_mountroot: private NFS not configured\n");
                vnode_put(vp);
                return (ENODEV);
        }
        if (vnode_mountedhere(vp) != NULL) {
                vnode_put(vp);
                return (EBUSY);
        }

        /*
         * Allocate and initialize the filesystem.
         */
        mp = _MALLOC_ZONE((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
        if (!mp) {
                printf("nfs_mountroot: unable to allocate mount structure\n");
                vnode_put(vp);
                return (ENOMEM);
        }
        bzero((char *)mp, (u_long)sizeof(struct mount));

        /* Initialize the default IO constraints */
        mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
        mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;

        mount_lock_init(mp);
        TAILQ_INIT(&mp->mnt_vnodelist);
        TAILQ_INIT(&mp->mnt_workerqueue);
        TAILQ_INIT(&mp->mnt_newvnodes);
        (void)vfs_busy(mp, LK_NOWAIT);
        TAILQ_INIT(&mp->mnt_vnodelist);
        mount_list_lock();
        vfsp->vfc_refcount++;
        mount_list_unlock();
        mp->mnt_vtable = vfsp;
        mp->mnt_op = vfsp->vfc_vfsops;
        // mp->mnt_stat.f_type = vfsp->vfc_typenum;
        mp->mnt_flag = mntflag;
        mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
        strncpy(mp->mnt_vfsstat.f_fstypename, vfsp->vfc_name, MFSNAMELEN-1);
        vp->v_mountedhere = mp;
        mp->mnt_vnodecovered = vp;
        mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
        (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MNAMELEN - 1, 0);
        (void) copystr(ndmntp->ndm_host, mp->mnt_vfsstat.f_mntfromname, MNAMELEN - 1, 0);

        /* Initialize mount args. */
        bzero((caddr_t) &args, sizeof(args));
        args.addr     = CAST_USER_ADDR_T(&ndmntp->ndm_saddr);
        args.addrlen  = ndmntp->ndm_saddr.sin_len;
        args.sotype   = ndmntp->ndm_sotype;
        args.fh       = CAST_USER_ADDR_T(ndmntp->ndm_fh);
        args.fhsize   = ndmntp->ndm_fhlen;
        args.hostname = CAST_USER_ADDR_T(ndmntp->ndm_host);
        args.flags    = NFSMNT_RESVPORT;
        if (ndmntp->ndm_nfsv3)
                args.flags |= NFSMNT_NFSV3;

        error = mbuf_get(MBUF_WAITOK, MBUF_TYPE_SONAME, &m);
        if (error) {
                printf("nfs_mount_diskless_private: mbuf_get(soname) failed");
                return (error);
        }
        mbuf_setlen(m, ndmntp->ndm_saddr.sin_len);
        bcopy((caddr_t)args.addr, mbuf_data(m), ndmntp->ndm_saddr.sin_len);
        if ((error = mountnfs(&args, mp, m, procp, &vp))) {
                printf("nfs_mountroot: mount %s failed: %d\n", mntname, error);
                mount_list_lock();
                vfsp->vfc_refcount--;
                mount_list_unlock();
                vfs_unbusy(mp);
                mount_lock_destroy(mp);
                FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
                return (error);
        }

        *mpp = mp;
        *vpp = vp;
        return (0);
}
#endif /* NO_MOUNT_PRIVATE */

/*
 * VFS Operations.
 *
 * mount system call
 */
static int
nfs_mount(mount_t mp, vnode_t vp, user_addr_t data, vfs_context_t context)
{
        proc_t p = vfs_context_proc(context);
        int error, argsvers;
        struct user_nfs_args args;
        struct nfs_args tempargs;
        mbuf_t nam;
        size_t len;
        u_char nfh[NFSX_V3FHMAX];
        char *mntfrom;

        error = copyin(data, (caddr_t)&argsvers, sizeof (argsvers));
        if (error)
                return (error);

        switch (argsvers) {
        case 3:
                if (vfs_context_is64bit(context))
                        error = copyin(data, (caddr_t)&args, sizeof (struct user_nfs_args3));
                else
                        error = copyin(data, (caddr_t)&tempargs, sizeof (struct nfs_args3));
                break;
        case 4:
                if (vfs_context_is64bit(context))
                        error = copyin(data, (caddr_t)&args, sizeof (args));
                else
                        error = copyin(data, (caddr_t)&tempargs, sizeof (tempargs));
                break;
        default:
                return (EPROGMISMATCH);
        }
        if (error)
                return (error);

        if (!vfs_context_is64bit(context)) {
                args.version = tempargs.version;
                args.addrlen = tempargs.addrlen;
                args.sotype = tempargs.sotype;
                args.proto = tempargs.proto;
                args.fhsize = tempargs.fhsize;
                args.flags = tempargs.flags;
                args.wsize = tempargs.wsize;
                args.rsize = tempargs.rsize;
                args.readdirsize = tempargs.readdirsize;
                args.timeo = tempargs.timeo;
                args.retrans = tempargs.retrans;
                args.maxgrouplist = tempargs.maxgrouplist;
                args.readahead = tempargs.readahead;
                args.leaseterm = tempargs.leaseterm;
                args.deadthresh = tempargs.deadthresh;
                args.addr = CAST_USER_ADDR_T(tempargs.addr);
                args.fh = CAST_USER_ADDR_T(tempargs.fh);
                args.hostname = CAST_USER_ADDR_T(tempargs.hostname);
                if (argsvers >= 4) {
                        args.acregmin = tempargs.acregmin;
                        args.acregmax = tempargs.acregmax;
                        args.acdirmin = tempargs.acdirmin;
                        args.acdirmax = tempargs.acdirmax;
                }
        }

        if (args.fhsize < 0 || args.fhsize > NFSX_V3FHMAX)
                return (EINVAL);
        error = copyin(args.fh, (caddr_t)nfh, args.fhsize);
        if (error)
                return (error);

        mntfrom = &vfs_statfs(mp)->f_mntfromname[0];
        error = copyinstr(args.hostname, mntfrom, MAXPATHLEN-1, &len);
        if (error)
                return (error);
        bzero(&mntfrom[len], MAXPATHLEN - len);

        /* sockargs() call must be after above copyin() calls */
        error = sockargs(&nam, args.addr, args.addrlen, MBUF_TYPE_SONAME);
        if (error)
                return (error);

        args.fh = CAST_USER_ADDR_T(&nfh[0]);
        error = mountnfs(&args, mp, nam, p, &vp);
        return (error);
}

/*
 * Common code for mount and mountroot
 */
static int
mountnfs(
        struct user_nfs_args *argp,
        mount_t mp,
        mbuf_t nam,
        proc_t p,
        vnode_t *vpp)
{
        struct nfsmount *nmp;
        struct nfsnode *np;
        int error, maxio;
        struct nfs_vattr nvattrs;
        struct vfs_context context; /* XXX get from caller? */
        u_int64_t xid;

        /*
         * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
         * no sense in that context.
         */
        if (argp->sotype == SOCK_STREAM)
                argp->flags &= ~NFSMNT_NOCONN;
        
        if (vfs_flags(mp) & MNT_UPDATE) {
                nmp = VFSTONFS(mp);
                /* update paths, file handles, etc, here        XXX */
                mbuf_freem(nam);
                return (0);
        } else {
                MALLOC_ZONE(nmp, struct nfsmount *,
                                sizeof (struct nfsmount), M_NFSMNT, M_WAITOK);
                if (!nmp) {
                        mbuf_freem(nam);
                        return (ENOMEM);
                }
                bzero((caddr_t)nmp, sizeof (struct nfsmount));
                TAILQ_INIT(&nmp->nm_uidlruhead);
                TAILQ_INIT(&nmp->nm_bufq);
                vfs_setfsprivate(mp, nmp);
        }

        /* setup defaults */
        nmp->nm_timeo = NFS_TIMEO;
        nmp->nm_retry = NFS_RETRANS;
        if (argp->sotype == SOCK_DGRAM) {
                nmp->nm_wsize = NFS_DGRAM_WSIZE;
                nmp->nm_rsize = NFS_DGRAM_RSIZE;
        } else {
                nmp->nm_wsize = NFS_WSIZE;
                nmp->nm_rsize = NFS_RSIZE;
        }
        nmp->nm_readdirsize = NFS_READDIRSIZE;
        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_acregmin = NFS_MINATTRTIMO;
        nmp->nm_acregmax = NFS_MAXATTRTIMO;
        nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
        nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;

        vfs_getnewfsid(mp);
        nmp->nm_mountp = mp;
        vfs_setauthopaque(mp);
        nmp->nm_flag = argp->flags;
        nmp->nm_nam = nam;

        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_NFSV3) {
                if (argp->sotype == SOCK_DGRAM)
                        maxio = NFS_MAXDGRAMDATA;
                else
                        maxio = NFS_MAXDATA;
        } else
                maxio = NFS_V2MAXDATA;

        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 (nmp->nm_wsize > maxio)
                nmp->nm_wsize = maxio;
        if (nmp->nm_wsize > MAXBSIZE)
                nmp->nm_wsize = MAXBSIZE;

        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 (nmp->nm_rsize > maxio)
                nmp->nm_rsize = maxio;
        if (nmp->nm_rsize > MAXBSIZE)
                nmp->nm_rsize = MAXBSIZE;

        if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
                nmp->nm_readdirsize = argp->readdirsize;
        }
        if (nmp->nm_readdirsize > maxio)
                nmp->nm_readdirsize = maxio;
        if (nmp->nm_readdirsize > nmp->nm_rsize)
                nmp->nm_readdirsize = nmp->nm_rsize;

        if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0 &&
                argp->maxgrouplist <= NFS_MAXGRPS)
                nmp->nm_numgrps = argp->maxgrouplist;
        if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0 &&
                argp->readahead <= NFS_MAXRAHEAD)
                nmp->nm_readahead = argp->readahead;

        if (argp->version >= 4) {
                if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
                        nmp->nm_acregmin = argp->acregmin;
                if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
                        nmp->nm_acregmax = argp->acregmax;
                if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
                        nmp->nm_acdirmin = argp->acdirmin;
                if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
                        nmp->nm_acdirmax = argp->acdirmax;
                if (nmp->nm_acregmin > nmp->nm_acregmax)
                        nmp->nm_acregmin = nmp->nm_acregmax;
                if (nmp->nm_acdirmin > nmp->nm_acdirmax)
                        nmp->nm_acdirmin = nmp->nm_acdirmax;
        }

        /* Set up the sockets and per-host congestion */
        nmp->nm_sotype = argp->sotype;
        nmp->nm_soproto = argp->proto;

        /* make sure mbuf constants are set up */
        if (!nfs_mbuf_mlen)
                nfs_mbuf_init();

        /*
         * For Connection based sockets (TCP,...) defer the connect until
         * the first request, in case the server is not responding.
         */
        if (nmp->nm_sotype == SOCK_DGRAM &&
                (error = nfs_connect(nmp, (struct nfsreq *)0)))
                goto bad;

        /*
         * Get file attributes for the mountpoint.  These are needed
         * in order to properly create the root vnode.
         */
        // LP64todo - fix CAST_DOWN of argp->fh
        error = nfs_getattr_no_vnode(mp, CAST_DOWN(caddr_t, argp->fh), argp->fhsize,
                        proc_ucred(p), p, &nvattrs, &xid);
        if (error) {
                /*
                 * we got problems... we couldn't get the attributes
                 * from the NFS server... so the mount fails.
                 */
                goto bad;
        }

        /*
         * 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).
         */
        error = nfs_nget(mp, NULL, NULL, CAST_DOWN(caddr_t, argp->fh), argp->fhsize,
                        &nvattrs, &xid, NG_MARKROOT, &np);
        if (error)
                goto bad;

        /*
         * save this vnode pointer. That way nfs_unmount()
         * does not need to call nfs_nget() just get it to drop
         * this vnode reference.
         */
        nmp->nm_dvp = *vpp = NFSTOV(np);
        /* get usecount and drop iocount */
        error = vnode_ref(*vpp);
        if (error) {
                vnode_put(*vpp);
                goto bad;
        }
        vnode_put(*vpp);

        /*
         * Set the mount point's block I/O size.
         * We really need to do this after we get info back from
         * the server about what its preferred I/O sizes are.
         */
        if (nmp->nm_flag & NFSMNT_NFSV3)
                nfs_fsinfo(nmp, *vpp, proc_ucred(p), p);
        vfs_statfs(mp)->f_iosize = nfs_iosize(nmp);

        /*
         * V3 mounts give us a (relatively) reliable remote access(2)
         * call, so advertise the fact.
         *
         * XXX this may not be the best way to go, as the granularity
         *     offered isn't a good match to our needs.
         */
        if (nmp->nm_flag & NFSMNT_NFSV3)
                vfs_setauthopaqueaccess(mp);

        /*
         * Do statfs to ensure static info gets set to reasonable values.
         */
        context.vc_proc = p;
        context.vc_ucred = proc_ucred(p);
        nfs_statfs(mp, vfs_statfs(mp), &context);

        if (nmp->nm_flag & NFSMNT_RESVPORT)
                nfs_resv_mounts++;
        nmp->nm_state |= NFSSTA_MOUNTED;
        return (0);
bad:
        nfs_disconnect(nmp);
        FREE_ZONE((caddr_t)nmp, sizeof (struct nfsmount), M_NFSMNT);
        mbuf_freem(nam);
        return (error);
}


/*
 * unmount system call
 */
static int
nfs_unmount(
        mount_t mp,
        int mntflags,
        __unused vfs_context_t context)
{
        register struct nfsmount *nmp;
        vnode_t vp;
        int error, flags = 0;

        nmp = VFSTONFS(mp);
        /*
         * During a force unmount we want to...
         *   Mark that we are doing a force unmount.
         *   Make the mountpoint soft.
         */
        if (mntflags & MNT_FORCE) {
                flags |= FORCECLOSE;
                nmp->nm_state |= NFSSTA_FORCE;
                nmp->nm_flag |= NFSMNT_SOFT;
        }
        /*
         * Goes something like this..
         * - Call vflush() to clear out vnodes for this file system,
         *   except for the swap files. Deal with them in 2nd pass.
         * - Decrement reference on the vnode representing remote root.
         * - Close the socket
         * - Free up the data structures
         */
        vp = nmp->nm_dvp;
        
        /*
         * vflush will check for busy vnodes on mountpoint. 
         * Will do the right thing for MNT_FORCE. That is, we should
         * not get EBUSY back.
         */
        error = vflush(mp, vp, SKIPSWAP | flags);
        if (mntflags & MNT_FORCE) {
                error = vflush(mp, NULLVP, flags); /* locks vp in the process */
        } else {
                if (vnode_isinuse(vp, 1))
                        return (EBUSY);
                error = vflush(mp, vp, flags);
        }
        if (error)
                return (error);

        nmp->nm_state &= ~NFSSTA_MOUNTED;
        if (nmp->nm_flag & NFSMNT_RESVPORT) {
                if (--nfs_resv_mounts == 0)
                        nfs_bind_resv_thread_wake();
        }

        /*
         * Release the root vnode reference held by mountnfs()
         */
        vnode_rele(vp);

        (void)vflush(mp, NULLVP, FORCECLOSE);
        vfs_setfsprivate(mp, 0); /* don't want to end up using stale vp */

        nfs_disconnect(nmp);
        mbuf_freem(nmp->nm_nam);

        if ((nmp->nm_flag & NFSMNT_KERB) == 0) {
                struct nfsreq *rp;
                /*
                 * Loop through outstanding request list and remove dangling
                 * references to defunct nfsmount struct
                 */
                for (rp = nfs_reqq.tqh_first; rp; rp = rp->r_chain.tqe_next)
                        if (rp->r_nmp == nmp)
                                rp->r_nmp = (struct nfsmount *)0;
                /* Need to wake up any rcvlock waiters so they notice the unmount. */
                if (nmp->nm_state & NFSSTA_WANTRCV) {
                        nmp->nm_state &= ~NFSSTA_WANTRCV;
                        wakeup(&nmp->nm_state);
                }
                FREE_ZONE((caddr_t)nmp, sizeof (struct nfsmount), M_NFSMNT);
        }
        return (0);
}

/*
 * Return root of a filesystem
 */
static int
nfs_root(mount_t mp, vnode_t *vpp, __unused vfs_context_t context)
{
        vnode_t vp;
        struct nfsmount *nmp;
        int error;
        u_long vpid;

        nmp = VFSTONFS(mp);
        vp = nmp->nm_dvp;
        vpid = vnode_vid(vp);
        while ((error = vnode_getwithvid(vp, vpid))) {
                /* vnode_get() may return ENOENT if the dir changes. */
                /* If that happens, just try it again, else return the error. */
                if ((error != ENOENT) || (vnode_vid(vp) == vpid))
                        return (error);
                vpid = vnode_vid(vp);
        }
        *vpp = vp;
        return (0);
}

/*
 * Flush out the buffer cache
 */

struct nfs_sync_cargs {
        vfs_context_t context;
        int    waitfor;
        int    error;
};

static int
nfs_sync_callout(vnode_t vp, void *arg)
{
        struct nfs_sync_cargs *cargs = (struct nfs_sync_cargs*)arg;
        int error;

        if (LIST_EMPTY(&VTONFS(vp)->n_dirtyblkhd))
                return (VNODE_RETURNED);
        if (VTONFS(vp)->n_flag & NWRBUSY)
                return (VNODE_RETURNED);

        error = nfs_flush(vp, cargs->waitfor,
                        vfs_context_ucred(cargs->context),
                        vfs_context_proc(cargs->context), 0);
        if (error)
                cargs->error = error;

        return (VNODE_RETURNED);
}

static int
nfs_sync(mount_t mp, int waitfor, vfs_context_t context)
{
        struct nfs_sync_cargs cargs;

        cargs.waitfor = waitfor;
        cargs.context = context;
        cargs.error = 0;

        vnode_iterate(mp, 0, nfs_sync_callout, &cargs);

        return (cargs.error);
}

/*
 * NFS flat namespace lookup.
 * Currently unsupported.
 */
/*ARGSUSED*/
static int
nfs_vget(
        __unused mount_t mp,
        __unused ino64_t ino,
        __unused vnode_t *vpp,
        __unused vfs_context_t context)
{

        return (ENOTSUP);
}

/*
 * At this point, this should never happen
 */
/*ARGSUSED*/
static int
nfs_fhtovp(
        __unused mount_t mp,
        __unused int fhlen,
        __unused unsigned char *fhp,
        __unused vnode_t *vpp,
        __unused vfs_context_t context)
{

        return (ENOTSUP);
}

/*
 * Vnode pointer to File handle, should never happen either
 */
/*ARGSUSED*/
static int
nfs_vptofh(
        __unused vnode_t vp,
        __unused int *fhlenp,
        __unused unsigned char *fhp,
        __unused vfs_context_t context)
{

        return (ENOTSUP);
}

/*
 * Vfs start routine, a no-op.
 */
/*ARGSUSED*/
static int
nfs_start(
        __unused mount_t mp,
        __unused int flags,
        __unused vfs_context_t context)
{

        return (0);
}

/*
 * Do that sysctl thang...
 */
static int
nfs_sysctl(int *name, u_int namelen, user_addr_t oldp, size_t *oldlenp, 
           user_addr_t newp, size_t newlen, vfs_context_t context)
{
        int error = 0, val;
        struct sysctl_req *req = NULL;
        struct vfsidctl vc;
        struct user_vfsidctl user_vc;
        mount_t mp;
        struct nfsmount *nmp = NULL;
        struct vfsquery vq;
        boolean_t is_64_bit;

        /*
         * All names at this level are terminal.
         */
        if(namelen > 1)
                return ENOTDIR; /* overloaded */

        is_64_bit = vfs_context_is64bit(context);

        /* common code for "new style" VFS_CTL sysctl, get the mount. */
        switch (name[0]) {
        case VFS_CTL_TIMEO:
        case VFS_CTL_QUERY:
        case VFS_CTL_NOLOCKS:
                req = CAST_DOWN(struct sysctl_req *, oldp);
                if (is_64_bit) {
                        error = SYSCTL_IN(req, &user_vc, sizeof(user_vc));
                        if (error)
                                 return (error);
                        mp = vfs_getvfs(&user_vc.vc_fsid);
                } 
                else {
                        error = SYSCTL_IN(req, &vc, sizeof(vc));
                        if (error)
                                return (error);
                        mp = vfs_getvfs(&vc.vc_fsid);
                }
                if (mp == NULL)
                        return (ENOENT);
                nmp = VFSTONFS(mp);
                if (nmp == NULL)
                        return (ENOENT);
                bzero(&vq, sizeof(vq));
                req->newidx = 0;
                if (is_64_bit) {
                        req->newptr = user_vc.vc_ptr;
                        req->newlen = (size_t)user_vc.vc_len;
                }
                else {
                        req->newptr = CAST_USER_ADDR_T(vc.vc_ptr);
                        req->newlen = vc.vc_len;
                }
        }

        switch(name[0]) {
        case NFS_NFSSTATS:
                if(!oldp) {
                        *oldlenp = sizeof nfsstats;
                        return 0;
                }

                if(*oldlenp < sizeof nfsstats) {
                        *oldlenp = sizeof nfsstats;
                        return ENOMEM;
                }

                error = copyout(&nfsstats, oldp, sizeof nfsstats);
                if (error)
                        return (error);

                if(newp && newlen != sizeof nfsstats)
                        return EINVAL;

                if(newp) {
                        return copyin(newp, &nfsstats, sizeof nfsstats);
                }
                return 0;
        case VFS_CTL_NOLOCKS:
                val = (nmp->nm_flag & NFSMNT_NOLOCKS) ? 1 : 0;
                if (req->oldptr != USER_ADDR_NULL) {
                        error = SYSCTL_OUT(req, &val, sizeof(val));
                        if (error)
                                return (error);
                }
                if (req->newptr != USER_ADDR_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;
        case VFS_CTL_QUERY:
                if (nmp->nm_state & NFSSTA_TIMEO)
                        vq.vq_flags |= VQ_NOTRESP;
                if (!(nmp->nm_flag & NFSMNT_NOLOCKS) &&
                    (nmp->nm_state & NFSSTA_LOCKTIMEO))
                        vq.vq_flags |= VQ_NOTRESPLOCK;
                error = SYSCTL_OUT(req, &vq, sizeof(vq));
                break;
        case VFS_CTL_TIMEO:
                if (req->oldptr != USER_ADDR_NULL) {
                        error = SYSCTL_OUT(req, &nmp->nm_tprintf_initial_delay,
                            sizeof(nmp->nm_tprintf_initial_delay));
                        if (error)
                                return (error);
                }
                if (req->newptr != USER_ADDR_NULL) {
                        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 (error);
}