xnu-3248.60.10.tar.gz

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

/*
 * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_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. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * 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_OSREFERENCE_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 $
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#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 <sys/quota.h>
#include <sys/priv.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/krpc.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs_gss.h>
#include <nfs/nfsmount.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfsm_subs.h>
#include <nfs/nfsdiskless.h>
#include <nfs/nfs_lock.h>
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif

#include <pexpert/pexpert.h>

#define NFS_VFS_DBG(...) NFS_DBG(NFS_FAC_VFS, 7, ## __VA_ARGS__)

/*
 * NFS client globals
 */

int nfs_ticks;
static lck_grp_t *nfs_global_grp, *nfs_mount_grp;
lck_mtx_t *nfs_global_mutex;
uint32_t nfs_fs_attr_bitmap[NFS_ATTR_BITMAP_LEN];
uint32_t nfs_object_attr_bitmap[NFS_ATTR_BITMAP_LEN];
uint32_t nfs_getattr_bitmap[NFS_ATTR_BITMAP_LEN];
struct nfsclientidlist nfsclientids;

/* NFS requests */
struct nfs_reqqhead nfs_reqq;
lck_grp_t *nfs_request_grp;
lck_mtx_t *nfs_request_mutex;
thread_call_t nfs_request_timer_call;
int nfs_request_timer_on;
u_int32_t nfs_xid = 0;
u_int32_t nfs_xidwrap = 0;		/* to build a (non-wrapping) 64 bit xid */

thread_call_t nfs_buf_timer_call;

/* NFSv4 */
lck_grp_t *nfs_open_grp;
uint32_t nfs_open_owner_seqnum = 0;
uint32_t nfs_lock_owner_seqnum = 0;
thread_call_t nfs4_callback_timer_call;
int nfs4_callback_timer_on = 0;

/* nfsiod */
lck_grp_t *nfsiod_lck_grp;
lck_mtx_t *nfsiod_mutex;
struct nfsiodlist nfsiodfree, nfsiodwork;
struct nfsiodmountlist nfsiodmounts;
int nfsiod_thread_count = 0;
int nfsiod_thread_max = NFS_DEFASYNCTHREAD;
int nfs_max_async_writes = NFS_DEFMAXASYNCWRITES;

int nfs_iosize = NFS_IOSIZE;
int nfs_access_cache_timeout = NFS_MAXATTRTIMO;
int nfs_access_delete = 1; /* too many servers get this wrong - workaround on by default */
int nfs_access_dotzfs = 1;
int nfs_access_for_getattr = 0;
int nfs_allow_async = 0;
int nfs_statfs_rate_limit = NFS_DEFSTATFSRATELIMIT;
int nfs_lockd_mounts = 0;
int nfs_lockd_request_sent = 0;
int nfs_idmap_ctrl = NFS_IDMAP_CTRL_USE_IDMAP_SERVICE;
int nfs_callback_port = 0;

int nfs_tprintf_initial_delay = NFS_TPRINTF_INITIAL_DELAY;
int nfs_tprintf_delay = NFS_TPRINTF_DELAY;


int		mountnfs(char *, mount_t, vfs_context_t, vnode_t *);
static int	nfs_mount_diskless(struct nfs_dlmount *, const char *, int, vnode_t *, mount_t *, vfs_context_t);
#if !defined(NO_MOUNT_PRIVATE)
static int	nfs_mount_diskless_private(struct nfs_dlmount *, const char *, int, vnode_t *, mount_t *, vfs_context_t);
#endif /* NO_MOUNT_PRIVATE */
int		nfs_mount_connect(struct nfsmount *);
void		nfs_mount_drain_and_cleanup(struct nfsmount *);
void		nfs_mount_cleanup(struct nfsmount *);
int		nfs_mountinfo_assemble(struct nfsmount *, struct xdrbuf *);
int		nfs4_mount_update_path_with_symlink(struct nfsmount *, struct nfs_fs_path *, uint32_t, fhandle_t *, int *, fhandle_t *, vfs_context_t);

/*
 * NFS VFS operations.
 */
int	nfs_vfs_mount(mount_t, vnode_t, user_addr_t, vfs_context_t);
int	nfs_vfs_start(mount_t, int, vfs_context_t);
int	nfs_vfs_unmount(mount_t, int, vfs_context_t);
int	nfs_vfs_root(mount_t, vnode_t *, vfs_context_t);
int	nfs_vfs_quotactl(mount_t, int, uid_t, caddr_t, vfs_context_t);
int	nfs_vfs_getattr(mount_t, struct vfs_attr *, vfs_context_t);
int	nfs_vfs_sync(mount_t, int, vfs_context_t);
int	nfs_vfs_vget(mount_t, ino64_t, vnode_t *, vfs_context_t);
int	nfs_vfs_vptofh(vnode_t, int *, unsigned char *, vfs_context_t);
int	nfs_vfs_fhtovp(mount_t, int, unsigned char *, vnode_t *, vfs_context_t);
int	nfs_vfs_init(struct vfsconf *);
int	nfs_vfs_sysctl(int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, vfs_context_t);

struct vfsops nfs_vfsops = {
	nfs_vfs_mount,
	nfs_vfs_start,
	nfs_vfs_unmount,
	nfs_vfs_root,
	nfs_vfs_quotactl,
	nfs_vfs_getattr,
	nfs_vfs_sync,
	nfs_vfs_vget,
	nfs_vfs_fhtovp,
	nfs_vfs_vptofh,
	nfs_vfs_init,
	nfs_vfs_sysctl,
	NULL,		/* setattr */
	{ NULL,		/* reserved */
	  NULL,		/* reserved */
	  NULL,		/* reserved */
	  NULL,		/* reserved */
	  NULL,		/* reserved */
	  NULL,		/* reserved */
	  NULL }	/* reserved */
};


/*
 * version-specific NFS functions
 */
int nfs3_mount(struct nfsmount *, vfs_context_t, nfsnode_t *);
int nfs4_mount(struct nfsmount *, vfs_context_t, nfsnode_t *);
int nfs3_fsinfo(struct nfsmount *, nfsnode_t, vfs_context_t);
int nfs3_update_statfs(struct nfsmount *, vfs_context_t);
int nfs4_update_statfs(struct nfsmount *, vfs_context_t);
#if !QUOTA
#define nfs3_getquota	NULL
#define nfs4_getquota	NULL
#else
int nfs3_getquota(struct nfsmount *, vfs_context_t, uid_t, int, struct dqblk *);
int nfs4_getquota(struct nfsmount *, vfs_context_t, uid_t, int, struct dqblk *);
#endif

struct nfs_funcs nfs3_funcs = {
	nfs3_mount,
	nfs3_update_statfs,
	nfs3_getquota,
	nfs3_access_rpc,
	nfs3_getattr_rpc,
	nfs3_setattr_rpc,
	nfs3_read_rpc_async,
	nfs3_read_rpc_async_finish,
	nfs3_readlink_rpc,
	nfs3_write_rpc_async,
	nfs3_write_rpc_async_finish,
	nfs3_commit_rpc,
	nfs3_lookup_rpc_async,
	nfs3_lookup_rpc_async_finish,
	nfs3_remove_rpc,
	nfs3_rename_rpc,
	nfs3_setlock_rpc,
	nfs3_unlock_rpc,
	nfs3_getlock_rpc
	};
struct nfs_funcs nfs4_funcs = {
	nfs4_mount,
	nfs4_update_statfs,
	nfs4_getquota,
	nfs4_access_rpc,
	nfs4_getattr_rpc,
	nfs4_setattr_rpc,
	nfs4_read_rpc_async,
	nfs4_read_rpc_async_finish,
	nfs4_readlink_rpc,
	nfs4_write_rpc_async,
	nfs4_write_rpc_async_finish,
	nfs4_commit_rpc,
	nfs4_lookup_rpc_async,
	nfs4_lookup_rpc_async_finish,
	nfs4_remove_rpc,
	nfs4_rename_rpc,
	nfs4_setlock_rpc,
	nfs4_unlock_rpc,
	nfs4_getlock_rpc
	};

/*
 * Called once to initialize data structures...
 */
int
nfs_vfs_init(__unused struct vfsconf *vfsp)
{
	int i;

	/*
	 * Check to see if major data structures haven't bloated.
	 */
	if (sizeof (struct nfsnode) > NFS_NODEALLOC) {
		printf("struct nfsnode bloated (> %dbytes)\n", NFS_NODEALLOC);
		printf("Try reducing NFS_SMALLFH\n");
	}
	if (sizeof (struct nfsmount) > NFS_MNTALLOC)
		printf("struct nfsmount bloated (> %dbytes)\n", NFS_MNTALLOC);

	nfs_ticks = (hz * NFS_TICKINTVL + 500) / 1000;
	if (nfs_ticks < 1)
		nfs_ticks = 1;

	/* init async I/O thread pool state */
	TAILQ_INIT(&nfsiodfree);
	TAILQ_INIT(&nfsiodwork);
	TAILQ_INIT(&nfsiodmounts);
	nfsiod_lck_grp = lck_grp_alloc_init("nfsiod", LCK_GRP_ATTR_NULL);
	nfsiod_mutex = lck_mtx_alloc_init(nfsiod_lck_grp, LCK_ATTR_NULL);

	/* init lock groups, etc. */
	nfs_mount_grp = lck_grp_alloc_init("nfs_mount", LCK_GRP_ATTR_NULL);
	nfs_open_grp = lck_grp_alloc_init("nfs_open", LCK_GRP_ATTR_NULL);
	nfs_global_grp = lck_grp_alloc_init("nfs_global", LCK_GRP_ATTR_NULL);

	nfs_global_mutex = lck_mtx_alloc_init(nfs_global_grp, LCK_ATTR_NULL);

	/* init request list mutex */
	nfs_request_grp = lck_grp_alloc_init("nfs_request", LCK_GRP_ATTR_NULL);
	nfs_request_mutex = lck_mtx_alloc_init(nfs_request_grp, LCK_ATTR_NULL);

	/* initialize NFS request list */
	TAILQ_INIT(&nfs_reqq);

	nfs_nbinit();			/* Init the nfsbuf table */
	nfs_nhinit();			/* Init the nfsnode table */
	nfs_lockinit();			/* Init the nfs lock state */
	nfs_gss_init();			/* Init RPCSEC_GSS security */

	/* NFSv4 stuff */
	NFS4_PER_FS_ATTRIBUTES(nfs_fs_attr_bitmap);
	NFS4_PER_OBJECT_ATTRIBUTES(nfs_object_attr_bitmap);
	NFS4_DEFAULT_ATTRIBUTES(nfs_getattr_bitmap);
	for (i=0; i < NFS_ATTR_BITMAP_LEN; i++)
		nfs_getattr_bitmap[i] &= nfs_object_attr_bitmap[i];
	TAILQ_INIT(&nfsclientids);

	/* initialize NFS timer callouts */
	nfs_request_timer_call = thread_call_allocate(nfs_request_timer, NULL);
	nfs_buf_timer_call = thread_call_allocate(nfs_buf_timer, NULL);
	nfs4_callback_timer_call = thread_call_allocate(nfs4_callback_timer, NULL);

	return (0);
}

/*
 * nfs statfs call
 */
int
nfs3_update_statfs(struct nfsmount *nmp, vfs_context_t ctx)
{
	nfsnode_t np;
	int error = 0, lockerror, status, nfsvers;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	uint32_t val = 0;

	nfsvers = nmp->nm_vers;
	np = nmp->nm_dnp;
	if (!np)
		return (ENXIO);
	if ((error = vnode_get(NFSTOV(np))))
		return (error);

	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	nfsm_chain_build_alloc_init(error, &nmreq, NFSX_FH(nfsvers));
	nfsm_chain_add_fh(error, &nmreq, nfsvers, np->n_fhp, np->n_fhsize);
	nfsm_chain_build_done(error, &nmreq);
	nfsmout_if(error);
	error = nfs_request2(np, NULL, &nmreq, NFSPROC_FSSTAT, vfs_context_thread(ctx),
		vfs_context_ucred(ctx), NULL, R_SOFT, &nmrep, &xid, &status);
	if (error == ETIMEDOUT)
		goto nfsmout;
	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	if (nfsvers == NFS_VER3)
		nfsm_chain_postop_attr_update(error, &nmrep, np, &xid);
	if (!lockerror)
		nfs_node_unlock(np);
	if (!error)
		error = status;
	nfsm_assert(error, NFSTONMP(np), ENXIO);
	nfsmout_if(error);
	lck_mtx_lock(&nmp->nm_lock);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_TOTAL);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_FREE);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_AVAIL);
	if (nfsvers == NFS_VER3) {
		NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_FILES_AVAIL);
		NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_FILES_TOTAL);
		NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_FILES_FREE);
		nmp->nm_fsattr.nfsa_bsize = NFS_FABLKSIZE;
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_space_total);
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_space_free);
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_space_avail);
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_files_total);
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_files_free);
		nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_files_avail);
		// skip invarsec
	} else {
		nfsm_chain_adv(error, &nmrep, NFSX_UNSIGNED); // skip tsize?
		nfsm_chain_get_32(error, &nmrep, nmp->nm_fsattr.nfsa_bsize);
		nfsm_chain_get_32(error, &nmrep, val);
		nfsmout_if(error);
		if (nmp->nm_fsattr.nfsa_bsize <= 0)
			nmp->nm_fsattr.nfsa_bsize = NFS_FABLKSIZE;
		nmp->nm_fsattr.nfsa_space_total = (uint64_t)val * nmp->nm_fsattr.nfsa_bsize;
		nfsm_chain_get_32(error, &nmrep, val);
		nfsmout_if(error);
		nmp->nm_fsattr.nfsa_space_free = (uint64_t)val * nmp->nm_fsattr.nfsa_bsize;
		nfsm_chain_get_32(error, &nmrep, val);
		nfsmout_if(error);
		nmp->nm_fsattr.nfsa_space_avail = (uint64_t)val * nmp->nm_fsattr.nfsa_bsize;
	}
	lck_mtx_unlock(&nmp->nm_lock);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	vnode_put(NFSTOV(np));
	return (error);
}

int
nfs4_update_statfs(struct nfsmount *nmp, vfs_context_t ctx)
{
	nfsnode_t np;
	int error = 0, lockerror, status, nfsvers, numops;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	struct nfs_vattr nvattr;
	struct nfsreq_secinfo_args si;

	nfsvers = nmp->nm_vers;
	np = nmp->nm_dnp;
	if (!np)
		return (ENXIO);
	if ((error = vnode_get(NFSTOV(np))))
		return (error);

	NFSREQ_SECINFO_SET(&si, np, NULL, 0, NULL, 0);
	NVATTR_INIT(&nvattr);
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	// PUTFH + GETATTR
	numops = 2;
	nfsm_chain_build_alloc_init(error, &nmreq, 15 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "statfs", nmp->nm_minor_vers, numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS4_STATFS_ATTRIBUTES(bitmap);
	nfsm_chain_add_bitmap_supported(error, &nmreq, bitmap, nmp, np);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request2(np, NULL, &nmreq, NFSPROC4_COMPOUND,
		vfs_context_thread(ctx), vfs_context_ucred(ctx),
		NULL, R_SOFT, &nmrep, &xid, &status);
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_assert(error, NFSTONMP(np), ENXIO);
	nfsmout_if(error);
	lck_mtx_lock(&nmp->nm_lock);
	error = nfs4_parsefattr(&nmrep, &nmp->nm_fsattr, &nvattr, NULL, NULL, NULL);
	lck_mtx_unlock(&nmp->nm_lock);
	nfsmout_if(error);
	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	if (!error)
		nfs_loadattrcache(np, &nvattr, &xid, 0);
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_assert(error, NFSTONMP(np), ENXIO);
	nfsmout_if(error);
	nmp->nm_fsattr.nfsa_bsize = NFS_FABLKSIZE;
nfsmout:
	NVATTR_CLEANUP(&nvattr);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	vnode_put(NFSTOV(np));
	return (error);
}


/*
 * The NFS VFS_GETATTR function: "statfs"-type information is retrieved
 * using the nf_update_statfs() function, and other attributes are cobbled
 * together from whatever sources we can (getattr, fsinfo, pathconf).
 */
int
nfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t ctx)
{
	struct nfsmount *nmp;
	uint32_t bsize;
	int error = 0, nfsvers;

	nmp = VFSTONFS(mp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	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)) {
		int statfsrate = nfs_statfs_rate_limit;
		int refresh = 1;

		/*
		 * Are we rate-limiting statfs RPCs?
		 * (Treat values less than 1 or greater than 1,000,000 as no limit.)
		 */
		if ((statfsrate > 0) && (statfsrate < 1000000)) {
			struct timeval now;
			uint32_t stamp;

			microuptime(&now);
			lck_mtx_lock(&nmp->nm_lock);
			stamp = (now.tv_sec * statfsrate) + (now.tv_usec / (1000000/statfsrate));
			if (stamp != nmp->nm_fsattrstamp) {
				refresh = 1;
				nmp->nm_fsattrstamp = stamp;
			} else {
				refresh = 0;
			}
			lck_mtx_unlock(&nmp->nm_lock);
		}

		if (refresh && !nfs_use_cache(nmp))
			error = nmp->nm_funcs->nf_update_statfs(nmp, ctx);
		if ((error == ESTALE) || (error == ETIMEDOUT))
			error = 0;
		if (error)
			return (error);

		lck_mtx_lock(&nmp->nm_lock);
		VFSATTR_RETURN(fsap, f_iosize, nfs_iosize);
		VFSATTR_RETURN(fsap, f_bsize, nmp->nm_fsattr.nfsa_bsize);
		bsize = nmp->nm_fsattr.nfsa_bsize;
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_TOTAL))
			VFSATTR_RETURN(fsap, f_blocks, nmp->nm_fsattr.nfsa_space_total / bsize);
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_FREE))
			VFSATTR_RETURN(fsap, f_bfree, nmp->nm_fsattr.nfsa_space_free / bsize);
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_AVAIL))
			VFSATTR_RETURN(fsap, f_bavail, nmp->nm_fsattr.nfsa_space_avail / bsize);
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_TOTAL) &&
		    NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SPACE_FREE))
			VFSATTR_RETURN(fsap, f_bused,
				(nmp->nm_fsattr.nfsa_space_total / bsize) -
				(nmp->nm_fsattr.nfsa_space_free / bsize));
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_FILES_TOTAL))
			VFSATTR_RETURN(fsap, f_files, nmp->nm_fsattr.nfsa_files_total);
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_FILES_FREE))
			VFSATTR_RETURN(fsap, f_ffree, nmp->nm_fsattr.nfsa_files_free);
		lck_mtx_unlock(&nmp->nm_lock);
	}

	if (VFSATTR_IS_ACTIVE(fsap, f_capabilities)) {
		u_int32_t caps, valid;
		nfsnode_t np = nmp->nm_dnp;

		nfsm_assert(error, VFSTONFS(mp) && np, ENXIO);
		if (error)
			return (error);
		lck_mtx_lock(&nmp->nm_lock);

		/*
		 * 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 (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SYMLINK_SUPPORT)) {
			valid |= VOL_CAP_FMT_SYMBOLICLINKS;
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_SYMLINK)
				caps |= VOL_CAP_FMT_SYMBOLICLINKS;
		}
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_LINK_SUPPORT)) {
			valid |= VOL_CAP_FMT_HARDLINKS;
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_LINK)
				caps |= VOL_CAP_FMT_HARDLINKS;
		}
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_CASE_INSENSITIVE)) {
			valid |= VOL_CAP_FMT_CASE_SENSITIVE;
			if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_CASE_INSENSITIVE))
				caps |= VOL_CAP_FMT_CASE_SENSITIVE;
		}
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_CASE_PRESERVING)) {
			valid |= VOL_CAP_FMT_CASE_PRESERVING;
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_CASE_PRESERVING)
				caps |= VOL_CAP_FMT_CASE_PRESERVING;
		}
		/* Note: VOL_CAP_FMT_2TB_FILESIZE is actually used to test for "large file support" */
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXFILESIZE)) {
			/* Is server's max file size at least 4GB? */
			if (nmp->nm_fsattr.nfsa_maxfilesize >= 0x100000000ULL)
				caps |= VOL_CAP_FMT_2TB_FILESIZE;
		} else if (nfsvers >= NFS_VER3) {
			/*
			 * NFSv3 and up supports 64 bits of file size.
			 * So, we'll just assume maxfilesize >= 4GB
			 */
			caps |= VOL_CAP_FMT_2TB_FILESIZE;
		}
		if (nfsvers >= NFS_VER4) {
			caps |= VOL_CAP_FMT_HIDDEN_FILES;
			valid |= VOL_CAP_FMT_HIDDEN_FILES;
			// VOL_CAP_FMT_OPENDENYMODES
//			caps |= VOL_CAP_FMT_OPENDENYMODES;
//			valid |= VOL_CAP_FMT_OPENDENYMODES;
		}
		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 |
			// VOL_CAP_FMT_OPENDENYMODES |
			// VOL_CAP_FMT_HIDDEN_FILES |
			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 |
			// VOL_CAP_FMT_OPENDENYMODES |
			// VOL_CAP_FMT_HIDDEN_FILES |
			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 (nfsvers >= NFS_VER4) {
			caps = VOL_CAP_INT_ADVLOCK | VOL_CAP_INT_FLOCK;
			valid = VOL_CAP_INT_ADVLOCK | VOL_CAP_INT_FLOCK;
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_ACL)
				caps |= VOL_CAP_INT_EXTENDED_SECURITY;
			valid |= VOL_CAP_INT_EXTENDED_SECURITY;
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR)
				caps |= VOL_CAP_INT_EXTENDED_ATTR;
			valid |= VOL_CAP_INT_EXTENDED_ATTR;
#if NAMEDSTREAMS
			if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR)
				caps |= VOL_CAP_INT_NAMEDSTREAMS;
			valid |= VOL_CAP_INT_NAMEDSTREAMS;
#endif
		} else if (nmp->nm_lockmode == NFS_LOCK_MODE_DISABLED) {
			/* 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 |
			// VOL_CAP_INT_MANLOCK |
			// VOL_CAP_INT_NAMEDSTREAMS |
			// VOL_CAP_INT_EXTENDED_ATTR |
			VOL_CAP_INT_REMOTE_EVENT |
			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 |
			// VOL_CAP_INT_MANLOCK |
			// VOL_CAP_INT_NAMEDSTREAMS |
			// VOL_CAP_INT_EXTENDED_ATTR |
			VOL_CAP_INT_REMOTE_EVENT |
			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);
		lck_mtx_unlock(&nmp->nm_lock);
	}

	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
nfs3_fsinfo(struct nfsmount *nmp, nfsnode_t np, vfs_context_t ctx)
{
	int error = 0, lockerror, status, nmlocked = 0;
	u_int64_t xid;
	uint32_t val, prefsize, maxsize;
	struct nfsm_chain nmreq, nmrep;

	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	nfsm_chain_build_alloc_init(error, &nmreq, NFSX_FH(nmp->nm_vers));
	nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, np->n_fhp, np->n_fhsize);
	nfsm_chain_build_done(error, &nmreq);
	nfsmout_if(error);
	error = nfs_request(np, NULL, &nmreq, NFSPROC_FSINFO, ctx, NULL, &nmrep, &xid, &status);
	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_postop_attr_update(error, &nmrep, np, &xid);
	if (!lockerror)
		nfs_node_unlock(np);
	if (!error)
		error = status;
	nfsmout_if(error);

	lck_mtx_lock(&nmp->nm_lock);
	nmlocked = 1;

	nfsm_chain_get_32(error, &nmrep, maxsize);
	nfsm_chain_get_32(error, &nmrep, prefsize);
	nfsmout_if(error);
	nmp->nm_fsattr.nfsa_maxread = maxsize;
	if (prefsize < nmp->nm_rsize)
		nmp->nm_rsize = (prefsize + NFS_FABLKSIZE - 1) &
			~(NFS_FABLKSIZE - 1);
	if ((maxsize > 0) && (maxsize < nmp->nm_rsize)) {
		nmp->nm_rsize = maxsize & ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_rsize == 0)
			nmp->nm_rsize = maxsize;
	}
	nfsm_chain_adv(error, &nmrep, NFSX_UNSIGNED); // skip rtmult

	nfsm_chain_get_32(error, &nmrep, maxsize);
	nfsm_chain_get_32(error, &nmrep, prefsize);
	nfsmout_if(error);
	nmp->nm_fsattr.nfsa_maxwrite = maxsize;
	if (prefsize < nmp->nm_wsize)
		nmp->nm_wsize = (prefsize + NFS_FABLKSIZE - 1) &
			~(NFS_FABLKSIZE - 1);
	if ((maxsize > 0) && (maxsize < nmp->nm_wsize)) {
		nmp->nm_wsize = maxsize & ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_wsize == 0)
			nmp->nm_wsize = maxsize;
	}
	nfsm_chain_adv(error, &nmrep, NFSX_UNSIGNED); // skip wtmult

	nfsm_chain_get_32(error, &nmrep, prefsize);
	nfsmout_if(error);
	if ((prefsize > 0) && (prefsize < nmp->nm_readdirsize))
		nmp->nm_readdirsize = prefsize;
	if ((nmp->nm_fsattr.nfsa_maxread > 0) &&
	    (nmp->nm_fsattr.nfsa_maxread < nmp->nm_readdirsize))
		nmp->nm_readdirsize = nmp->nm_fsattr.nfsa_maxread;

	nfsm_chain_get_64(error, &nmrep, nmp->nm_fsattr.nfsa_maxfilesize);

	nfsm_chain_adv(error, &nmrep, 2 * NFSX_UNSIGNED); // skip time_delta

	/* convert FS properties to our own flags */
	nfsm_chain_get_32(error, &nmrep, val);
	nfsmout_if(error);
	if (val & NFSV3FSINFO_LINK)
		nmp->nm_fsattr.nfsa_flags |= NFS_FSFLAG_LINK;
	if (val & NFSV3FSINFO_SYMLINK)
		nmp->nm_fsattr.nfsa_flags |= NFS_FSFLAG_SYMLINK;
	if (val & NFSV3FSINFO_HOMOGENEOUS)
		nmp->nm_fsattr.nfsa_flags |= NFS_FSFLAG_HOMOGENEOUS;
	if (val & NFSV3FSINFO_CANSETTIME)
		nmp->nm_fsattr.nfsa_flags |= NFS_FSFLAG_SET_TIME;
	nmp->nm_state |= NFSSTA_GOTFSINFO;
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXREAD);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXWRITE);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXFILESIZE);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_LINK_SUPPORT);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_SYMLINK_SUPPORT);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_HOMOGENEOUS);
	NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_CANSETTIME);
nfsmout:
	if (nmlocked)
		lck_mtx_unlock(&nmp->nm_lock);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	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(void)
{
	struct nfs_diskless nd;
	mount_t mp = NULL;
	vnode_t vp = NULL;
	vfs_context_t ctx;
	int error;
#if !defined(NO_MOUNT_PRIVATE)
	mount_t mppriv = NULL;
	vnode_t vppriv = NULL;
#endif /* NO_MOUNT_PRIVATE */
	int v3, sotype;

	/*
	 * 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);
	if (error)
		panic("nfs_boot_init: unable to initialize NFS root system information, "
		      "error %d, check configuration: %s\n", error, PE_boot_args());

	/*
	 * 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, v3, sotype);
	if (error) {
		if (error == EHOSTDOWN || error == EHOSTUNREACH) {
			if (nd.nd_root.ndm_mntfrom)
				FREE_ZONE(nd.nd_root.ndm_mntfrom,
					  MAXPATHLEN, M_NAMEI);
			if (nd.nd_root.ndm_path)
				FREE_ZONE(nd.nd_root.ndm_path,
					  MAXPATHLEN, M_NAMEI);
			if (nd.nd_private.ndm_mntfrom)
				FREE_ZONE(nd.nd_private.ndm_mntfrom,
					  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 mount (v3,TCP) failed with error %d, trying UDP...\n", error);
				sotype = SOCK_DGRAM;
				goto tryagain;
			}
			printf("NFS mount (v3,UDP) failed with error %d, trying v2...\n", error);
			v3 = 0;
			sotype = SOCK_STREAM;
			goto tryagain;
		} else if (sotype == SOCK_STREAM) {
			printf("NFS mount (v2,TCP) failed with error %d, trying UDP...\n", error);
			sotype = SOCK_DGRAM;
			goto tryagain;
		} else {
			printf("NFS mount (v2,UDP) failed with error %d, giving up...\n", error);
		}
		switch(error) {
		case EPROGUNAVAIL:
			panic("NFS mount failed: NFS server mountd not responding, check server configuration: %s", PE_boot_args());
		case EACCES:
		case EPERM:
			panic("NFS mount failed: NFS server refused mount, check server configuration: %s", PE_boot_args());
		default:
			panic("NFS mount failed with error %d, check configuration: %s", error, PE_boot_args());
		}
	}

	ctx = vfs_context_kernel();

	/*
	 * Create the root mount point.
	 */
#if !defined(NO_MOUNT_PRIVATE)
	{
		//PWC hack until we have a real "mount" tool to remount root rw
		int rw_root=0;
		int flags = MNT_ROOTFS|MNT_RDONLY;
		PE_parse_boot_argn("-rwroot_hack", &rw_root, sizeof (rw_root));
		if(rw_root)
		{
			flags = MNT_ROOTFS;
			kprintf("-rwroot_hack in effect: mounting root fs read/write\n");
		}
				
	if ((error = nfs_mount_diskless(&nd.nd_root, "/", flags, &vp, &mp, ctx)))
#else
	if ((error = nfs_mount_diskless(&nd.nd_root, "/", MNT_ROOTFS, &vp, &mp, ctx)))
#endif /* NO_MOUNT_PRIVATE */
	{
		if (v3) {
			if (sotype == SOCK_STREAM) {
				printf("NFS root mount (v3,TCP) failed with %d, trying UDP...\n", error);
				sotype = SOCK_DGRAM;
				goto tryagain;
			}
			printf("NFS root mount (v3,UDP) failed with %d, trying v2...\n", error);
			v3 = 0;
			sotype = SOCK_STREAM;
			goto tryagain;
		} else if (sotype == SOCK_STREAM) {
			printf("NFS root mount (v2,TCP) failed with %d, trying UDP...\n", error);
			sotype = SOCK_DGRAM;
			goto tryagain;
		} else {
			printf("NFS root mount (v2,UDP) failed with error %d, giving up...\n", error);
		}
		panic("NFS root mount failed with error %d, check configuration: %s\n", error, PE_boot_args());
	}
	}
	printf("root on %s\n", nd.nd_root.ndm_mntfrom);

	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, ctx);
	    if (error)
		panic("NFS /private mount failed with error %d, check configuration: %s\n", error, PE_boot_args());
	    printf("private on %s\n", nd.nd_private.ndm_mntfrom);

	    vfs_unbusy(mppriv);
	    mount_list_add(mppriv);
	}

#endif /* NO_MOUNT_PRIVATE */

	if (nd.nd_root.ndm_mntfrom)
		FREE_ZONE(nd.nd_root.ndm_mntfrom, MAXPATHLEN, M_NAMEI);
	if (nd.nd_root.ndm_path)
		FREE_ZONE(nd.nd_root.ndm_path, MAXPATHLEN, M_NAMEI);
	if (nd.nd_private.ndm_mntfrom)
		FREE_ZONE(nd.nd_private.ndm_mntfrom, 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(VTONFS(vp), NULL, ctx, NGA_UNCACHED);
	if (error)
		panic("NFS mount: failed to get attributes for root directory, error %d, check server", error);
	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,
	vfs_context_t ctx)
{
	mount_t mp;
	int error, numcomps;
	char *xdrbuf, *p, *cp, *frompath, *endserverp;
	char uaddr[MAX_IPv4_STR_LEN];
	struct xdrbuf xb;
	uint32_t mattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t mflags_mask[NFS_MFLAG_BITMAP_LEN];
	uint32_t mflags[NFS_MFLAG_BITMAP_LEN];
	uint32_t argslength_offset, attrslength_offset, end_offset;

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

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

	/* find the server-side path being mounted */
	frompath = ndmntp->ndm_mntfrom;
	if (*frompath == '[') {  /* skip IPv6 literal address */
		while (*frompath && (*frompath != ']'))
			frompath++;
		if (*frompath == ']')
			frompath++;
	}
	while (*frompath && (*frompath != ':'))
		frompath++;
	endserverp = frompath;
	while (*frompath && (*frompath == ':'))
		frompath++;
	/* count fs location path components */
	p = frompath;
	while (*p && (*p == '/'))
		p++;
	numcomps = 0;
	while (*p) {
		numcomps++;
		while (*p && (*p != '/'))
			p++;
		while (*p && (*p == '/'))
			p++;
	}

	/* convert address to universal address string */
	if (inet_ntop(AF_INET, &ndmntp->ndm_saddr.sin_addr, uaddr, sizeof(uaddr)) != uaddr) {
		printf("nfs_mount_diskless: bad address\n");
		return (EINVAL);
	}

	/* prepare mount attributes */
	NFS_BITMAP_ZERO(mattrs, NFS_MATTR_BITMAP_LEN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_VERSION);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_SOCKET_TYPE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_PORT);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FH);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FS_LOCATIONS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFLAGS);

	/* prepare mount flags */
	NFS_BITMAP_ZERO(mflags_mask, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_ZERO(mflags, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RESVPORT);
	NFS_BITMAP_SET(mflags, NFS_MFLAG_RESVPORT);

	/* build xdr buffer */
	xb_init_buffer(&xb, NULL, 0);
	xb_add_32(error, &xb, NFS_ARGSVERSION_XDR);
	argslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // args length
	xb_add_32(error, &xb, NFS_XDRARGS_VERSION_0);
	xb_add_bitmap(error, &xb, mattrs, NFS_MATTR_BITMAP_LEN);
	attrslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // attrs length
	xb_add_32(error, &xb, ndmntp->ndm_nfsv3 ? 3 : 2); // NFS version
	xb_add_string(error, &xb, ((ndmntp->ndm_sotype == SOCK_DGRAM) ? "udp" : "tcp"), 3);
	xb_add_32(error, &xb, ntohs(ndmntp->ndm_saddr.sin_port)); // NFS port
	xb_add_fh(error, &xb, &ndmntp->ndm_fh[0], ndmntp->ndm_fhlen);
	/* fs location */
	xb_add_32(error, &xb, 1); /* fs location count */
	xb_add_32(error, &xb, 1); /* server count */
	xb_add_string(error, &xb, ndmntp->ndm_mntfrom, (endserverp - ndmntp->ndm_mntfrom)); /* server name */
	xb_add_32(error, &xb, 1); /* address count */
	xb_add_string(error, &xb, uaddr, strlen(uaddr)); /* address */
	xb_add_32(error, &xb, 0); /* empty server info */
	xb_add_32(error, &xb, numcomps); /* pathname component count */
	p = frompath;
	while (*p && (*p == '/'))
		p++;
	while (*p) {
		cp = p;
		while (*p && (*p != '/'))
			p++;
		xb_add_string(error, &xb, cp, (p - cp)); /* component */
		if (error)
			break;
		while (*p && (*p == '/'))
			p++;
	}
	xb_add_32(error, &xb, 0); /* empty fsl info */
	xb_add_32(error, &xb, mntflag); /* MNT flags */
	xb_build_done(error, &xb);

	/* update opaque counts */
	end_offset = xb_offset(&xb);
	if (!error) {
		error = xb_seek(&xb, argslength_offset);
		xb_add_32(error, &xb, end_offset - argslength_offset + XDRWORD/*version*/);
	}
	if (!error) {
		error = xb_seek(&xb, attrslength_offset);
		xb_add_32(error, &xb, end_offset - attrslength_offset - XDRWORD/*don't include length field*/);
	}
	if (error) {
		printf("nfs_mount_diskless: error %d assembling mount args\n", error);
		xb_cleanup(&xb);
		return (error);
	}
	/* grab the assembled buffer */
	xdrbuf = xb_buffer_base(&xb);
	xb.xb_flags &= ~XB_CLEANUP;

	/* do the mount */
	if ((error = mountnfs(xdrbuf, mp, ctx, 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);
#if CONFIG_MACF
		mac_mount_label_destroy(mp);
#endif
		FREE_ZONE(mp, sizeof(struct mount), M_MOUNT);
	} else {
		*mpp = mp;
	}
	xb_cleanup(&xb);
	return (error);
}

#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,
	vfs_context_t ctx)
{
	mount_t mp;
	int error, numcomps;
	proc_t procp;
	struct vfstable *vfsp;
	struct nameidata nd;
	vnode_t vp;
	char *xdrbuf = NULL, *p, *cp, *frompath, *endserverp;
	char uaddr[MAX_IPv4_STR_LEN];
	struct xdrbuf xb;
	uint32_t mattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t mflags_mask[NFS_MFLAG_BITMAP_LEN], mflags[NFS_MFLAG_BITMAP_LEN];
	uint32_t argslength_offset, attrslength_offset, end_offset;

	procp = current_proc(); /* XXX */
	xb_init(&xb, 0);

	{
	/*
	 * 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");
			goto out;
		}
		fdp->fd_cdir = rootvnode;
		fdp->fd_rdir = NULL;
	}

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

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

	/*
	 * Allocate and initialize the filesystem.
	 */
	mp = _MALLOC_ZONE((u_int32_t)sizeof(struct mount), M_MOUNT, M_WAITOK);
	if (!mp) {
		printf("nfs_mountroot: unable to allocate mount structure\n");
		vnode_put(vp);
		error = ENOMEM;
		goto out;
	}
	bzero((char *)mp, sizeof(struct mount));

	/* Initialize the default IO constraints */
	mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
	mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
	mp->mnt_ioflags = 0;
	mp->mnt_realrootvp = NULLVP;
	mp->mnt_authcache_ttl = CACHED_LOOKUP_RIGHT_TTL;

	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;
	vp = NULLVP;
	mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
	(void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
	(void) copystr(ndmntp->ndm_mntfrom, mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN - 1, 0);
#if CONFIG_MACF
	mac_mount_label_init(mp);
	mac_mount_label_associate(ctx, mp);
#endif

	/* find the server-side path being mounted */
	frompath = ndmntp->ndm_mntfrom;
	if (*frompath == '[') {  /* skip IPv6 literal address */
		while (*frompath && (*frompath != ']'))
			frompath++;
		if (*frompath == ']')
			frompath++;
	}
	while (*frompath && (*frompath != ':'))
		frompath++;
	endserverp = frompath;
	while (*frompath && (*frompath == ':'))
		frompath++;
	/* count fs location path components */
	p = frompath;
	while (*p && (*p == '/'))
		p++;
	numcomps = 0;
	while (*p) {
		numcomps++;
		while (*p && (*p != '/'))
			p++;
		while (*p && (*p == '/'))
			p++;
	}

	/* convert address to universal address string */
	if (inet_ntop(AF_INET, &ndmntp->ndm_saddr.sin_addr, uaddr, sizeof(uaddr)) != uaddr) {
		printf("nfs_mountroot: bad address\n");
		error = EINVAL;
		goto out;
	}

	/* prepare mount attributes */
	NFS_BITMAP_ZERO(mattrs, NFS_MATTR_BITMAP_LEN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_VERSION);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_SOCKET_TYPE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_PORT);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FH);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FS_LOCATIONS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFLAGS);

	/* prepare mount flags */
	NFS_BITMAP_ZERO(mflags_mask, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_ZERO(mflags, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RESVPORT);
	NFS_BITMAP_SET(mflags, NFS_MFLAG_RESVPORT);

	/* build xdr buffer */
	xb_init_buffer(&xb, NULL, 0);
	xb_add_32(error, &xb, NFS_ARGSVERSION_XDR);
	argslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // args length
	xb_add_32(error, &xb, NFS_XDRARGS_VERSION_0);
	xb_add_bitmap(error, &xb, mattrs, NFS_MATTR_BITMAP_LEN);
	attrslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // attrs length
	xb_add_32(error, &xb, ndmntp->ndm_nfsv3 ? 3 : 2); // NFS version
	xb_add_string(error, &xb, ((ndmntp->ndm_sotype == SOCK_DGRAM) ? "udp" : "tcp"), 3);
	xb_add_32(error, &xb, ntohs(ndmntp->ndm_saddr.sin_port)); // NFS port
	xb_add_fh(error, &xb, &ndmntp->ndm_fh[0], ndmntp->ndm_fhlen);
	/* fs location */
	xb_add_32(error, &xb, 1); /* fs location count */
	xb_add_32(error, &xb, 1); /* server count */
	xb_add_string(error, &xb, ndmntp->ndm_mntfrom, (endserverp - ndmntp->ndm_mntfrom)); /* server name */
	xb_add_32(error, &xb, 1); /* address count */
	xb_add_string(error, &xb, uaddr, strlen(uaddr)); /* address */
	xb_add_32(error, &xb, 0); /* empty server info */
	xb_add_32(error, &xb, numcomps); /* pathname component count */
	p = frompath;
	while (*p && (*p == '/'))
		p++;
	while (*p) {
		cp = p;
		while (*p && (*p != '/'))
			p++;
		xb_add_string(error, &xb, cp, (p - cp)); /* component */
		if (error)
			break;
		while (*p && (*p == '/'))
			p++;
	}
	xb_add_32(error, &xb, 0); /* empty fsl info */
	xb_add_32(error, &xb, mntflag); /* MNT flags */
	xb_build_done(error, &xb);

	/* update opaque counts */
	end_offset = xb_offset(&xb);
	if (!error) {
		error = xb_seek(&xb, argslength_offset);
		xb_add_32(error, &xb, end_offset - argslength_offset + XDRWORD/*version*/);
	}
	if (!error) {
		error = xb_seek(&xb, attrslength_offset);
		xb_add_32(error, &xb, end_offset - attrslength_offset - XDRWORD/*don't include length field*/);
	}
	if (error) {
		printf("nfs_mountroot: error %d assembling mount args\n", error);
		goto out;
	}
	/* grab the assembled buffer */
	xdrbuf = xb_buffer_base(&xb);
	xb.xb_flags &= ~XB_CLEANUP;

	/* do the mount */
	if ((error = mountnfs(xdrbuf, mp, ctx, &vp))) {
		printf("nfs_mountroot: mount %s failed: %d\n", mntname, error);
		vnode_put(mp->mnt_vnodecovered);
		mount_list_lock();
		vfsp->vfc_refcount--;
		mount_list_unlock();
		vfs_unbusy(mp);
		mount_lock_destroy(mp);
#if CONFIG_MACF
		mac_mount_label_destroy(mp);
#endif
		FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
		goto out;
	}

	*mpp = mp;
	*vpp = vp;
out:
	xb_cleanup(&xb);
	return (error);
}
#endif /* NO_MOUNT_PRIVATE */

/*
 * Convert old style NFS mount args to XDR.
 */
static int
nfs_convert_old_nfs_args(mount_t mp, user_addr_t data, vfs_context_t ctx, int argsversion, int inkernel, char **xdrbufp)
{
	int error = 0, args64bit, argsize, numcomps;
	struct user_nfs_args args;
	struct nfs_args tempargs;
	caddr_t argsp;
	size_t len;
	u_char nfh[NFS4_FHSIZE];
	char *mntfrom, *endserverp, *frompath, *p, *cp;
	struct sockaddr_storage ss;
	void *sinaddr;
	char uaddr[MAX_IPv6_STR_LEN];
	uint32_t mattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t mflags_mask[NFS_MFLAG_BITMAP_LEN], mflags[NFS_MFLAG_BITMAP_LEN];
	uint32_t nfsvers, nfslockmode = 0, argslength_offset, attrslength_offset, end_offset;
	struct xdrbuf xb;

	*xdrbufp = NULL;

	/* allocate a temporary buffer for mntfrom */
	MALLOC_ZONE(mntfrom, char*, MAXPATHLEN, M_NAMEI, M_WAITOK);
	if (!mntfrom)
		return (ENOMEM);

	args64bit = (inkernel || vfs_context_is64bit(ctx));
	argsp = args64bit ? (void*)&args : (void*)&tempargs;

	argsize = args64bit ? sizeof(args) : sizeof(tempargs);
	switch (argsversion) {
	case 3:
		argsize -= NFS_ARGSVERSION4_INCSIZE;
	case 4:
		argsize -= NFS_ARGSVERSION5_INCSIZE;
	case 5:
		argsize -= NFS_ARGSVERSION6_INCSIZE;
	case 6:
		break;
	default:
		error = EPROGMISMATCH;
		goto nfsmout;
	}

	/* read in the structure */
	if (inkernel)
		bcopy(CAST_DOWN(void *, data), argsp, argsize);
	else
		error = copyin(data, argsp, argsize);
	nfsmout_if(error);

	if (!args64bit) {
		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 (args.version >= 4) {
			args.acregmin = tempargs.acregmin;
			args.acregmax = tempargs.acregmax;
			args.acdirmin = tempargs.acdirmin;
			args.acdirmax = tempargs.acdirmax;
		}
		if (args.version >= 5)
			args.auth = tempargs.auth;
		if (args.version >= 6)
			args.deadtimeout = tempargs.deadtimeout;
	}

	if ((args.fhsize < 0) || (args.fhsize > NFS4_FHSIZE)) {
		error = EINVAL;
		goto nfsmout;
	}
	if (args.fhsize > 0) {
		if (inkernel)
			bcopy(CAST_DOWN(void *, args.fh), (caddr_t)nfh, args.fhsize);
		else
			error = copyin(args.fh, (caddr_t)nfh, args.fhsize);
		nfsmout_if(error);
	}

	if (inkernel)
		error = copystr(CAST_DOWN(void *, args.hostname), mntfrom, MAXPATHLEN-1, &len);
	else
		error = copyinstr(args.hostname, mntfrom, MAXPATHLEN-1, &len);
	nfsmout_if(error);
	bzero(&mntfrom[len], MAXPATHLEN - len);

	/* find the server-side path being mounted */
	frompath = mntfrom;
	if (*frompath == '[') {  /* skip IPv6 literal address */
		while (*frompath && (*frompath != ']'))
			frompath++;
		if (*frompath == ']')
			frompath++;
	}
	while (*frompath && (*frompath != ':'))
		frompath++;
	endserverp = frompath;
	while (*frompath && (*frompath == ':'))
		frompath++;
	/* count fs location path components */
	p = frompath;
	while (*p && (*p == '/'))
		p++;
	numcomps = 0;
	while (*p) {
		numcomps++;
		while (*p && (*p != '/'))
			p++;
		while (*p && (*p == '/'))
			p++;
	}

	/* copy socket address */
	if (inkernel)
		bcopy(CAST_DOWN(void *, args.addr), &ss, args.addrlen);
	else {
		if ((size_t)args.addrlen > sizeof (struct sockaddr_storage))
			error = EINVAL;
		else
			error = copyin(args.addr, &ss, args.addrlen);
	}
	nfsmout_if(error);
	ss.ss_len = args.addrlen;

	/* convert address to universal address string */
	if (ss.ss_family == AF_INET)
		sinaddr = &((struct sockaddr_in*)&ss)->sin_addr;
	else if (ss.ss_family == AF_INET6)
		sinaddr = &((struct sockaddr_in6*)&ss)->sin6_addr;
	else
		sinaddr = NULL;
	if (!sinaddr || (inet_ntop(ss.ss_family, sinaddr, uaddr, sizeof(uaddr)) != uaddr)) {
		error = EINVAL;
		goto nfsmout;
	}

	/* prepare mount flags */
	NFS_BITMAP_ZERO(mflags_mask, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_ZERO(mflags, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_SOFT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_INTR);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RESVPORT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOCONNECT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_DUMBTIMER);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_CALLUMNT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RDIRPLUS);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NONEGNAMECACHE);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_MUTEJUKEBOX);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOQUOTA);
	if (args.flags & NFSMNT_SOFT)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_SOFT);
	if (args.flags & NFSMNT_INT)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_INTR);
	if (args.flags & NFSMNT_RESVPORT)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_RESVPORT);
	if (args.flags & NFSMNT_NOCONN)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NOCONNECT);
	if (args.flags & NFSMNT_DUMBTIMR)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_DUMBTIMER);
	if (args.flags & NFSMNT_CALLUMNT)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_CALLUMNT);
	if (args.flags & NFSMNT_RDIRPLUS)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_RDIRPLUS);
	if (args.flags & NFSMNT_NONEGNAMECACHE)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NONEGNAMECACHE);
	if (args.flags & NFSMNT_MUTEJUKEBOX)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_MUTEJUKEBOX);
	if (args.flags & NFSMNT_NOQUOTA)
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NOQUOTA);

	/* prepare mount attributes */
	NFS_BITMAP_ZERO(mattrs, NFS_MATTR_BITMAP_LEN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FLAGS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_VERSION);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_SOCKET_TYPE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_PORT);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FH);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FS_LOCATIONS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFLAGS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFROM);
	if (args.flags & NFSMNT_NFSV4)
		nfsvers = 4;
	else if (args.flags & NFSMNT_NFSV3)
		nfsvers = 3;
	else
		nfsvers = 2;
	if ((args.flags & NFSMNT_RSIZE) && (args.rsize > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_READ_SIZE);
	if ((args.flags & NFSMNT_WSIZE) && (args.wsize > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_WRITE_SIZE);
	if ((args.flags & NFSMNT_TIMEO) && (args.timeo > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_REQUEST_TIMEOUT);
	if ((args.flags & NFSMNT_RETRANS) && (args.retrans > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_SOFT_RETRY_COUNT);
	if ((args.flags & NFSMNT_MAXGRPS) && (args.maxgrouplist > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_MAX_GROUP_LIST);
	if ((args.flags & NFSMNT_READAHEAD) && (args.readahead > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_READAHEAD);
	if ((args.flags & NFSMNT_READDIRSIZE) && (args.readdirsize > 0))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_READDIR_SIZE);
	if ((args.flags & NFSMNT_NOLOCKS) ||
	    (args.flags & NFSMNT_LOCALLOCKS)) {
		NFS_BITMAP_SET(mattrs, NFS_MATTR_LOCK_MODE);
		if (args.flags & NFSMNT_NOLOCKS)
			nfslockmode = NFS_LOCK_MODE_DISABLED;
		else if (args.flags & NFSMNT_LOCALLOCKS)
			nfslockmode = NFS_LOCK_MODE_LOCAL;
		else
			nfslockmode = NFS_LOCK_MODE_ENABLED;
	}
	if (args.version >= 4) {
		if ((args.flags & NFSMNT_ACREGMIN) && (args.acregmin > 0))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_REG_MIN);
		if ((args.flags & NFSMNT_ACREGMAX) && (args.acregmax > 0))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_REG_MAX);
		if ((args.flags & NFSMNT_ACDIRMIN) && (args.acdirmin > 0))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MIN);
		if ((args.flags & NFSMNT_ACDIRMAX) && (args.acdirmax > 0))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MAX);
	}
	if (args.version >= 5) {
		if ((args.flags & NFSMNT_SECFLAVOR) || (args.flags & NFSMNT_SECSYSOK))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_SECURITY);
	}
	if (args.version >= 6) {
		if ((args.flags & NFSMNT_DEADTIMEOUT) && (args.deadtimeout > 0))
			NFS_BITMAP_SET(mattrs, NFS_MATTR_DEAD_TIMEOUT);
	}

	/* build xdr buffer */
	xb_init_buffer(&xb, NULL, 0);
	xb_add_32(error, &xb, args.version);
	argslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // args length
	xb_add_32(error, &xb, NFS_XDRARGS_VERSION_0);
	xb_add_bitmap(error, &xb, mattrs, NFS_MATTR_BITMAP_LEN);
	attrslength_offset = xb_offset(&xb);
	xb_add_32(error, &xb, 0); // attrs length
	xb_add_bitmap(error, &xb, mflags_mask, NFS_MFLAG_BITMAP_LEN); /* mask */
	xb_add_bitmap(error, &xb, mflags, NFS_MFLAG_BITMAP_LEN); /* value */
	xb_add_32(error, &xb, nfsvers);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READ_SIZE))
		xb_add_32(error, &xb, args.rsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_WRITE_SIZE))
		xb_add_32(error, &xb, args.wsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READDIR_SIZE))
		xb_add_32(error, &xb, args.readdirsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READAHEAD))
		xb_add_32(error, &xb, args.readahead);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MIN)) {
		xb_add_32(error, &xb, args.acregmin);
		xb_add_32(error, &xb, 0);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MAX)) {
		xb_add_32(error, &xb, args.acregmax);
		xb_add_32(error, &xb, 0);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MIN)) {
		xb_add_32(error, &xb, args.acdirmin);
		xb_add_32(error, &xb, 0);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MAX)) {
		xb_add_32(error, &xb, args.acdirmax);
		xb_add_32(error, &xb, 0);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_LOCK_MODE))
		xb_add_32(error, &xb, nfslockmode);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SECURITY)) {
		uint32_t flavors[2], i=0;
		if (args.flags & NFSMNT_SECFLAVOR)
			flavors[i++] = args.auth;
		if ((args.flags & NFSMNT_SECSYSOK) && ((i == 0) || (flavors[0] != RPCAUTH_SYS)))
			flavors[i++] = RPCAUTH_SYS;
		xb_add_word_array(error, &xb, flavors, i);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MAX_GROUP_LIST))
		xb_add_32(error, &xb, args.maxgrouplist);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOCKET_TYPE))
		xb_add_string(error, &xb, ((args.sotype == SOCK_DGRAM) ? "udp" : "tcp"), 3);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_PORT))
		xb_add_32(error, &xb, ((ss.ss_family == AF_INET) ? 
			ntohs(((struct sockaddr_in*)&ss)->sin_port) :
			ntohs(((struct sockaddr_in6*)&ss)->sin6_port)));
	/* NFS_MATTR_MOUNT_PORT (not available in old args) */
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_REQUEST_TIMEOUT)) {
		/* convert from .1s increments to time */
		xb_add_32(error, &xb, args.timeo/10);
		xb_add_32(error, &xb, (args.timeo%10)*100000000);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOFT_RETRY_COUNT))
		xb_add_32(error, &xb, args.retrans);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_DEAD_TIMEOUT)) {
		xb_add_32(error, &xb, args.deadtimeout);
		xb_add_32(error, &xb, 0);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FH))
		xb_add_fh(error, &xb, &nfh[0], args.fhsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FS_LOCATIONS)) {
		xb_add_32(error, &xb, 1); /* fs location count */
		xb_add_32(error, &xb, 1); /* server count */
		xb_add_string(error, &xb, mntfrom, (endserverp - mntfrom)); /* server name */
		xb_add_32(error, &xb, 1); /* address count */
		xb_add_string(error, &xb, uaddr, strlen(uaddr)); /* address */
		xb_add_32(error, &xb, 0); /* empty server info */
		xb_add_32(error, &xb, numcomps); /* pathname component count */
		nfsmout_if(error);
		p = frompath;
		while (*p && (*p == '/'))
			p++;
		while (*p) {
			cp = p;
			while (*p && (*p != '/'))
				p++;
			xb_add_string(error, &xb, cp, (p - cp)); /* component */
			nfsmout_if(error);
			while (*p && (*p == '/'))
				p++;
		}
		xb_add_32(error, &xb, 0); /* empty fsl info */
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFLAGS))
		xb_add_32(error, &xb, (vfs_flags(mp) & MNT_VISFLAGMASK)); /* VFS MNT_* flags */
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFROM))
		xb_add_string(error, &xb, mntfrom, strlen(mntfrom)); /* fixed f_mntfromname */
	xb_build_done(error, &xb);

	/* update opaque counts */
	end_offset = xb_offset(&xb);
	error = xb_seek(&xb, argslength_offset);
	xb_add_32(error, &xb, end_offset - argslength_offset + XDRWORD/*version*/);
	nfsmout_if(error);
	error = xb_seek(&xb, attrslength_offset);
	xb_add_32(error, &xb, end_offset - attrslength_offset - XDRWORD/*don't include length field*/);

	if (!error) {
		/* grab the assembled buffer */
		*xdrbufp = xb_buffer_base(&xb);
		xb.xb_flags &= ~XB_CLEANUP;
	}
nfsmout:
	xb_cleanup(&xb);
	FREE_ZONE(mntfrom, MAXPATHLEN, M_NAMEI);
	return (error);
}

/*
 * VFS Operations.
 *
 * mount system call
 */
int
nfs_vfs_mount(mount_t mp, vnode_t vp, user_addr_t data, vfs_context_t ctx)
{
	int error = 0, inkernel = vfs_iskernelmount(mp);
	uint32_t argsversion, argslength;
	char *xdrbuf = NULL;

	/* read in version */
	if (inkernel)
		bcopy(CAST_DOWN(void *, data), &argsversion, sizeof(argsversion));
	else if ((error = copyin(data, &argsversion, sizeof(argsversion))))
		return (error);

	/* If we have XDR args, then all values in the buffer are in network order */
	if (argsversion == htonl(NFS_ARGSVERSION_XDR))
		argsversion = NFS_ARGSVERSION_XDR;

	switch (argsversion) {
	case 3:
	case 4:
	case 5:
	case 6:
		/* convert old-style args to xdr */
		error = nfs_convert_old_nfs_args(mp, data, ctx, argsversion, inkernel, &xdrbuf);
		break;
	case NFS_ARGSVERSION_XDR:
		/* copy in xdr buffer */
		if (inkernel)
			bcopy(CAST_DOWN(void *, (data + XDRWORD)), &argslength, XDRWORD);
		else
			error = copyin((data + XDRWORD), &argslength, XDRWORD);
		if (error)
			break;
		argslength = ntohl(argslength);
		/* put a reasonable limit on the size of the XDR args */
		if (argslength > 16*1024) {
			error = E2BIG;
			break;
		}
		/* allocate xdr buffer */
		xdrbuf = xb_malloc(xdr_rndup(argslength));
		if (!xdrbuf) {
			error = ENOMEM;
			break;
		}
		if (inkernel)
			bcopy(CAST_DOWN(void *, data), xdrbuf, argslength);
		else
			error = copyin(data, xdrbuf, argslength);
		break;
	default:
		error = EPROGMISMATCH;
	}

	if (error) {
		if (xdrbuf)
			xb_free(xdrbuf);
		return (error);
	}
	error = mountnfs(xdrbuf, mp, ctx, &vp);
	return (error);
}

/*
 * Common code for mount and mountroot
 */

/* Set up an NFSv2/v3 mount */
int
nfs3_mount(
	struct nfsmount *nmp,
	vfs_context_t ctx,
	nfsnode_t *npp)
{
	int error = 0;
	struct nfs_vattr nvattr;
	u_int64_t xid;

	*npp = NULL;

	if (!nmp->nm_fh)
		return (EINVAL);

	/*
	 * Get file attributes for the mountpoint.  These are needed
	 * in order to properly create the root vnode.
	 */
	error = nfs3_getattr_rpc(NULL, nmp->nm_mountp, nmp->nm_fh->fh_data, nmp->nm_fh->fh_len, 0,
			ctx, &nvattr, &xid);
	if (error)
		goto out;

	error = nfs_nget(nmp->nm_mountp, NULL, NULL, nmp->nm_fh->fh_data, nmp->nm_fh->fh_len,
			&nvattr, &xid, RPCAUTH_UNKNOWN, NG_MARKROOT, npp);
	if (*npp)
		nfs_node_unlock(*npp);
	if (error)
		goto out;

	/*
	 * Try to make sure we have all the general info from the server.
	 */
	if (nmp->nm_vers == NFS_VER2) {
		NFS_BITMAP_SET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXNAME);
		nmp->nm_fsattr.nfsa_maxname = NFS_MAXNAMLEN;
	} else if (nmp->nm_vers == NFS_VER3) {
		/* get the NFSv3 FSINFO */
		error = nfs3_fsinfo(nmp, *npp, ctx);
		if (error)
			goto out;
		/* If the server indicates all pathconf info is */
		/* the same, grab a copy of that info now */
		if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_HOMOGENEOUS) &&
		    (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_HOMOGENEOUS)) {
			struct nfs_fsattr nfsa;
			if (!nfs3_pathconf_rpc(*npp, &nfsa, ctx)) {
				/* cache a copy of the results */
				lck_mtx_lock(&nmp->nm_lock);
				nfs3_pathconf_cache(nmp, &nfsa);
				lck_mtx_unlock(&nmp->nm_lock);
			}
		}
	}
out:
	if (*npp && error) {
		vnode_put(NFSTOV(*npp));
		vnode_recycle(NFSTOV(*npp));
		*npp = NULL;
	}
	return (error);
}

/*
 * Update an NFSv4 mount path with the contents of the symlink.
 *
 * Read the link for the given file handle.
 * Insert the link's components into the path.
 */
int
nfs4_mount_update_path_with_symlink(struct nfsmount *nmp, struct nfs_fs_path *nfsp, uint32_t curcomp, fhandle_t *dirfhp, int *depthp, fhandle_t *fhp, vfs_context_t ctx)
{
	int error = 0, status, numops;
	uint32_t len = 0, comp, newcomp, linkcompcount;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq rq, *req = &rq;
	struct nfsreq_secinfo_args si;
	char *link = NULL, *p, *q, ch;
	struct nfs_fs_path nfsp2;

	bzero(&nfsp2, sizeof(nfsp2));
	if (dirfhp->fh_len)
		NFSREQ_SECINFO_SET(&si, NULL, dirfhp->fh_data, dirfhp->fh_len, nfsp->np_components[curcomp], 0);
	else
		NFSREQ_SECINFO_SET(&si, NULL, NULL, 0, nfsp->np_components[curcomp], 0);
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	MALLOC_ZONE(link, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); 
	if (!link)
		error = ENOMEM;

	// PUTFH, READLINK
	numops = 2;
	nfsm_chain_build_alloc_init(error, &nmreq, 12 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "readlink", nmp->nm_minor_vers, numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, fhp->fh_data, fhp->fh_len);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_READLINK);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request_async(NULL, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, &req);
	if (!error)
		error = nfs_request_async_finish(req, &nmrep, &xid, &status);

	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_READLINK);
	nfsm_chain_get_32(error, &nmrep, len);
	nfsmout_if(error);
	if (len == 0)
		error = ENOENT;
	else if (len >= MAXPATHLEN)
		len = MAXPATHLEN - 1;
	nfsm_chain_get_opaque(error, &nmrep, len, link);
	nfsmout_if(error);
	/* make sure link string is terminated properly */
	link[len] = '\0';

	/* count the number of components in link */
	p = link;
	while (*p && (*p == '/'))
		p++;
	linkcompcount = 0;
	while (*p) {
		linkcompcount++;
		while (*p && (*p != '/'))
			p++;
		while (*p && (*p == '/'))
			p++;
	}

	/* free up used components */
	for (comp=0; comp <= curcomp; comp++) {
		if (nfsp->np_components[comp]) {
			FREE(nfsp->np_components[comp], M_TEMP);
			nfsp->np_components[comp] = NULL;
		}
	}

	/* set up new path */
	nfsp2.np_compcount = nfsp->np_compcount - curcomp - 1 + linkcompcount;
	MALLOC(nfsp2.np_components, char **, nfsp2.np_compcount*sizeof(char*), M_TEMP, M_WAITOK|M_ZERO);
	if (!nfsp2.np_components) {
		error = ENOMEM;
		goto nfsmout;
	}

	/* add link components */
	p = link;
	while (*p && (*p == '/'))
		p++;
	for (newcomp=0; newcomp < linkcompcount; newcomp++) {
		/* find end of component */
		q = p;
		while (*q && (*q != '/'))
			q++;
		MALLOC(nfsp2.np_components[newcomp], char *, q-p+1, M_TEMP, M_WAITOK|M_ZERO);
		if (!nfsp2.np_components[newcomp]) {
			error = ENOMEM;
			break;
		}
		ch = *q;
		*q = '\0';
		strlcpy(nfsp2.np_components[newcomp], p, q-p+1);
		*q = ch;
		p = q;
		while (*p && (*p == '/'))
			p++;
	}
	nfsmout_if(error);

	/* add remaining components */
	for(comp = curcomp + 1; comp < nfsp->np_compcount; comp++,newcomp++) {
		nfsp2.np_components[newcomp] = nfsp->np_components[comp];
		nfsp->np_components[comp] = NULL;
	}

	/* move new path into place */
	FREE(nfsp->np_components, M_TEMP);
	nfsp->np_components = nfsp2.np_components;
	nfsp->np_compcount = nfsp2.np_compcount;
	nfsp2.np_components = NULL;

	/* for absolute link, let the caller now that the next dirfh is root */
	if (link[0] == '/') {
		dirfhp->fh_len = 0;
		*depthp = 0;
	}
nfsmout:
	if (link)
		FREE_ZONE(link, MAXPATHLEN, M_NAMEI);
	if (nfsp2.np_components) {
		for (comp=0; comp < nfsp2.np_compcount; comp++)
			if (nfsp2.np_components[comp])
				FREE(nfsp2.np_components[comp], M_TEMP);
		FREE(nfsp2.np_components, M_TEMP);
	}
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/* Set up an NFSv4 mount */
int
nfs4_mount(
	struct nfsmount *nmp,
	vfs_context_t ctx,
	nfsnode_t *npp)
{
	struct nfsm_chain nmreq, nmrep;
	int error = 0, numops, status, interval, isdotdot, loopcnt = 0, depth = 0;
	struct nfs_fs_path fspath, *nfsp, fspath2;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], comp, comp2;
	fhandle_t fh, dirfh;
	struct nfs_vattr nvattr;
	u_int64_t xid;
	struct nfsreq rq, *req = &rq;
	struct nfsreq_secinfo_args si;
	struct nfs_sec sec;
	struct nfs_fs_locations nfsls;

	*npp = NULL;
	fh.fh_len = dirfh.fh_len = 0;
	TAILQ_INIT(&nmp->nm_open_owners);
	TAILQ_INIT(&nmp->nm_delegations);
	TAILQ_INIT(&nmp->nm_dreturnq);
	nmp->nm_stategenid = 1;
	NVATTR_INIT(&nvattr);
	bzero(&nfsls, sizeof(nfsls));
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	/*
	 * If no security flavors were specified we'll want to default to the server's
	 * preferred flavor.  For NFSv4.0 we need a file handle and name to get that via
	 * SECINFO, so we'll do that on the last component of the server path we are
	 * mounting.  If we are mounting the server's root, we'll need to defer the
	 * SECINFO call to the first successful LOOKUP request.
	 */
	if (!nmp->nm_sec.count)
		nmp->nm_state |= NFSSTA_NEEDSECINFO;

	/* make a copy of the current location's path */
	nfsp = &nmp->nm_locations.nl_locations[nmp->nm_locations.nl_current.nli_loc]->nl_path;
	bzero(&fspath, sizeof(fspath));
	fspath.np_compcount = nfsp->np_compcount;
	if (fspath.np_compcount > 0) {
		MALLOC(fspath.np_components, char **, fspath.np_compcount*sizeof(char*), M_TEMP, M_WAITOK|M_ZERO);
		if (!fspath.np_components) {
			error = ENOMEM;
			goto nfsmout;
		}
		for (comp=0; comp < nfsp->np_compcount; comp++) {
			int slen = strlen(nfsp->np_components[comp]);
			MALLOC(fspath.np_components[comp], char *, slen+1, M_TEMP, M_WAITOK|M_ZERO);
			if (!fspath.np_components[comp]) {
				error = ENOMEM;
				break;
			}
			strlcpy(fspath.np_components[comp], nfsp->np_components[comp], slen+1);
		}
		if (error)
			goto nfsmout;
	}

	/* for mirror mounts, we can just use the file handle passed in */
	if (nmp->nm_fh) {
		dirfh.fh_len = nmp->nm_fh->fh_len;
		bcopy(nmp->nm_fh->fh_data, dirfh.fh_data, dirfh.fh_len);
		NFSREQ_SECINFO_SET(&si, NULL, dirfh.fh_data, dirfh.fh_len, NULL, 0);
		goto gotfh;
	}

	/* otherwise, we need to get the fh for the directory we are mounting */

	/* if no components, just get root */
	if (fspath.np_compcount == 0) {
nocomponents:
		// PUTROOTFH + GETATTR(FH)
		NFSREQ_SECINFO_SET(&si, NULL, NULL, 0, NULL, 0);
		numops = 2;
		nfsm_chain_build_alloc_init(error, &nmreq, 9 * NFSX_UNSIGNED);
		nfsm_chain_add_compound_header(error, &nmreq, "mount", nmp->nm_minor_vers, numops);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTROOTFH);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
		NFS_CLEAR_ATTRIBUTES(bitmap);
		NFS4_DEFAULT_ATTRIBUTES(bitmap);
		NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
		nfsm_chain_add_bitmap(error, &nmreq, bitmap, NFS_ATTR_BITMAP_LEN);
		nfsm_chain_build_done(error, &nmreq);
		nfsm_assert(error, (numops == 0), EPROTO);
		nfsmout_if(error);
		error = nfs_request_async(NULL, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND,
				vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, &req);
		if (!error)
			error = nfs_request_async_finish(req, &nmrep, &xid, &status);
		nfsm_chain_skip_tag(error, &nmrep);
		nfsm_chain_get_32(error, &nmrep, numops);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTROOTFH);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
		nfsmout_if(error);
		NFS_CLEAR_ATTRIBUTES(nmp->nm_fsattr.nfsa_bitmap);
		error = nfs4_parsefattr(&nmrep, &nmp->nm_fsattr, &nvattr, &dirfh, NULL, NULL);
		if (!error && !NFS_BITMAP_ISSET(&nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE)) {
			printf("nfs: mount didn't return filehandle?\n");
			error = EBADRPC;
		}
		nfsmout_if(error);
		nfsm_chain_cleanup(&nmrep);
		nfsm_chain_null(&nmreq);
		NVATTR_CLEANUP(&nvattr);
		goto gotfh;
	}

	/* look up each path component */
	for (comp=0; comp < fspath.np_compcount; ) {
		isdotdot = 0;
		if (fspath.np_components[comp][0] == '.') {
			if (fspath.np_components[comp][1] == '\0') {
				/* skip "." */
				comp++;
				continue;
			}
			/* treat ".." specially */
			if ((fspath.np_components[comp][1] == '.') &&
			    (fspath.np_components[comp][2] == '\0'))
			    	isdotdot = 1;
			if (isdotdot && (dirfh.fh_len == 0)) {
				/* ".." in root directory is same as "." */
				comp++;
				continue;
			}
		}
		// PUT(ROOT)FH + LOOKUP(P) + GETFH + GETATTR
		if (dirfh.fh_len == 0)
			NFSREQ_SECINFO_SET(&si, NULL, NULL, 0, isdotdot ? NULL : fspath.np_components[comp], 0);
		else
			NFSREQ_SECINFO_SET(&si, NULL, dirfh.fh_data, dirfh.fh_len, isdotdot ? NULL : fspath.np_components[comp], 0);
		numops = 4;
		nfsm_chain_build_alloc_init(error, &nmreq, 18 * NFSX_UNSIGNED);
		nfsm_chain_add_compound_header(error, &nmreq, "mount", nmp->nm_minor_vers, numops);
		numops--;
		if (dirfh.fh_len) {
			nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
			nfsm_chain_add_fh(error, &nmreq, NFS_VER4, dirfh.fh_data, dirfh.fh_len);
		} else {
			nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTROOTFH);
		}
		numops--;
		if (isdotdot) {
			nfsm_chain_add_32(error, &nmreq, NFS_OP_LOOKUPP);
		} else {
			nfsm_chain_add_32(error, &nmreq, NFS_OP_LOOKUP);
			nfsm_chain_add_name(error, &nmreq,
				fspath.np_components[comp], strlen(fspath.np_components[comp]), nmp);
		}
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_GETFH);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
		NFS_CLEAR_ATTRIBUTES(bitmap);
		NFS4_DEFAULT_ATTRIBUTES(bitmap);
		/* if no namedattr support or component is ".zfs", clear NFS_FATTR_NAMED_ATTR */
		if (NMFLAG(nmp, NONAMEDATTR) || !strcmp(fspath.np_components[comp], ".zfs"))
			NFS_BITMAP_CLR(bitmap, NFS_FATTR_NAMED_ATTR);
		nfsm_chain_add_bitmap(error, &nmreq, bitmap, NFS_ATTR_BITMAP_LEN);
		nfsm_chain_build_done(error, &nmreq);
		nfsm_assert(error, (numops == 0), EPROTO);
		nfsmout_if(error);
		error = nfs_request_async(NULL, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND,
				vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, &req);
		if (!error)
			error = nfs_request_async_finish(req, &nmrep, &xid, &status);
		nfsm_chain_skip_tag(error, &nmrep);
		nfsm_chain_get_32(error, &nmrep, numops);
		nfsm_chain_op_check(error, &nmrep, dirfh.fh_len ? NFS_OP_PUTFH : NFS_OP_PUTROOTFH);
		nfsm_chain_op_check(error, &nmrep, isdotdot ? NFS_OP_LOOKUPP : NFS_OP_LOOKUP);
		nfsmout_if(error);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_GETFH);
		nfsm_chain_get_32(error, &nmrep, fh.fh_len);
		nfsm_chain_get_opaque(error, &nmrep, fh.fh_len, fh.fh_data);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
		if (!error) {
			NFS_CLEAR_ATTRIBUTES(nmp->nm_fsattr.nfsa_bitmap);
			error = nfs4_parsefattr(&nmrep, &nmp->nm_fsattr, &nvattr, NULL, NULL, &nfsls);
		}
		nfsm_chain_cleanup(&nmrep);
		nfsm_chain_null(&nmreq);
		if (error) {
			/* LOOKUP succeeded but GETATTR failed?  This could be a referral. */
			/* Try the lookup again with a getattr for fs_locations. */
			nfs_fs_locations_cleanup(&nfsls);
			error = nfs4_get_fs_locations(nmp, NULL, dirfh.fh_data, dirfh.fh_len, fspath.np_components[comp], ctx, &nfsls);
			if (!error && (nfsls.nl_numlocs < 1))
				error = ENOENT;
			nfsmout_if(error);
			if (++loopcnt > MAXSYMLINKS) {
				/* too many symlink/referral redirections */
				error = ELOOP;
				goto nfsmout;
			}
			/* tear down the current connection */
			nfs_disconnect(nmp);
			/* replace fs locations */
			nfs_fs_locations_cleanup(&nmp->nm_locations);
			nmp->nm_locations = nfsls;
			bzero(&nfsls, sizeof(nfsls));
			/* initiate a connection using the new fs locations */
			error = nfs_mount_connect(nmp);
			if (!error && !(nmp->nm_locations.nl_current.nli_flags & NLI_VALID))
				error = EIO;
			nfsmout_if(error);
			/* add new server's remote path to beginning of our path and continue */
			nfsp = &nmp->nm_locations.nl_locations[nmp->nm_locations.nl_current.nli_loc]->nl_path;
			bzero(&fspath2, sizeof(fspath2));
			fspath2.np_compcount = (fspath.np_compcount - comp - 1) + nfsp->np_compcount;
			if (fspath2.np_compcount > 0) {
				MALLOC(fspath2.np_components, char **, fspath2.np_compcount*sizeof(char*), M_TEMP, M_WAITOK|M_ZERO);
				if (!fspath2.np_components) {
					error = ENOMEM;
					goto nfsmout;
				}
				for (comp2=0; comp2 < nfsp->np_compcount; comp2++) {
					int slen = strlen(nfsp->np_components[comp2]);
					MALLOC(fspath2.np_components[comp2], char *, slen+1, M_TEMP, M_WAITOK|M_ZERO);
					if (!fspath2.np_components[comp2]) {
						/* clean up fspath2, then error out */
						while (comp2 > 0) {
							comp2--;
							FREE(fspath2.np_components[comp2], M_TEMP);
						}
						FREE(fspath2.np_components, M_TEMP);
						error = ENOMEM;
						goto nfsmout;
					}
					strlcpy(fspath2.np_components[comp2], nfsp->np_components[comp2], slen+1);
				}
				if ((fspath.np_compcount - comp - 1) > 0)
					bcopy(&fspath.np_components[comp+1], &fspath2.np_components[nfsp->np_compcount], (fspath.np_compcount - comp - 1)*sizeof(char*));
				/* free up unused parts of old path (prior components and component array) */
				do {
					FREE(fspath.np_components[comp], M_TEMP);
				} while (comp-- > 0);
				FREE(fspath.np_components, M_TEMP);
				/* put new path in place */
				fspath = fspath2;
			}
			/* reset dirfh and component index */
			dirfh.fh_len = 0;
			comp = 0;
			NVATTR_CLEANUP(&nvattr);
			if (fspath.np_compcount == 0)
				goto nocomponents;
			continue;
		}
		nfsmout_if(error);
		/* if file handle is for a symlink, then update the path with the symlink contents */
		if (NFS_BITMAP_ISSET(&nvattr.nva_bitmap, NFS_FATTR_TYPE) && (nvattr.nva_type == VLNK)) {
			if (++loopcnt > MAXSYMLINKS)
				error = ELOOP;
			else
				error = nfs4_mount_update_path_with_symlink(nmp, &fspath, comp, &dirfh, &depth, &fh, ctx);
			nfsmout_if(error);
			/* directory file handle is either left the same or reset to root (if link was absolute) */
			/* path traversal starts at beginning of the path again */
			comp = 0;
			NVATTR_CLEANUP(&nvattr);
			nfs_fs_locations_cleanup(&nfsls);
			continue;
		}
		NVATTR_CLEANUP(&nvattr);
		nfs_fs_locations_cleanup(&nfsls);
		/* not a symlink... */
		if ((nmp->nm_state & NFSSTA_NEEDSECINFO) && (comp == (fspath.np_compcount-1)) && !isdotdot) {
			/* need to get SECINFO for the directory being mounted */
			if (dirfh.fh_len == 0)
				NFSREQ_SECINFO_SET(&si, NULL, NULL, 0, isdotdot ? NULL : fspath.np_components[comp], 0);
			else
				NFSREQ_SECINFO_SET(&si, NULL, dirfh.fh_data, dirfh.fh_len, isdotdot ? NULL : fspath.np_components[comp], 0);
			sec.count = NX_MAX_SEC_FLAVORS;
			error = nfs4_secinfo_rpc(nmp, &si, vfs_context_ucred(ctx), sec.flavors, &sec.count);
			/* [sigh] some implementations return "illegal" error for unsupported ops */
			if (error == NFSERR_OP_ILLEGAL)
				error = 0;
			nfsmout_if(error);
			/* set our default security flavor to the first in the list */
			if (sec.count)
				nmp->nm_auth = sec.flavors[0];
			nmp->nm_state &= ~NFSSTA_NEEDSECINFO;
		}
		/* advance directory file handle, component index, & update depth */
		dirfh = fh;
		comp++;
		if (!isdotdot) /* going down the hierarchy */
			depth++;
		else if (--depth <= 0)  /* going up the hierarchy */
			dirfh.fh_len = 0; /* clear dirfh when we hit root */
	}

gotfh:
	/* get attrs for mount point root */
	numops = NMFLAG(nmp, NONAMEDATTR) ? 2 : 3; // PUTFH + GETATTR + OPENATTR
	nfsm_chain_build_alloc_init(error, &nmreq, 25 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "mount", nmp->nm_minor_vers, numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, dirfh.fh_data, dirfh.fh_len);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_CLEAR_ATTRIBUTES(bitmap);
	NFS4_DEFAULT_ATTRIBUTES(bitmap);
	/* if no namedattr support or last component is ".zfs", clear NFS_FATTR_NAMED_ATTR */
	if (NMFLAG(nmp, NONAMEDATTR) || ((fspath.np_compcount > 0) && !strcmp(fspath.np_components[fspath.np_compcount-1], ".zfs")))
		NFS_BITMAP_CLR(bitmap, NFS_FATTR_NAMED_ATTR);
	nfsm_chain_add_bitmap(error, &nmreq, bitmap, NFS_ATTR_BITMAP_LEN);
	if (!NMFLAG(nmp, NONAMEDATTR)) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_OPENATTR);
		nfsm_chain_add_32(error, &nmreq, 0);
	}
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request_async(NULL, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, &req);
	if (!error)
		error = nfs_request_async_finish(req, &nmrep, &xid, &status);
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	NFS_CLEAR_ATTRIBUTES(nmp->nm_fsattr.nfsa_bitmap);
	error = nfs4_parsefattr(&nmrep, &nmp->nm_fsattr, &nvattr, NULL, NULL, NULL);
	nfsmout_if(error);
	if (!NMFLAG(nmp, NONAMEDATTR)) {
		nfsm_chain_op_check(error, &nmrep, NFS_OP_OPENATTR);
		if (error == ENOENT)
			error = 0;
		/* [sigh] some implementations return "illegal" error for unsupported ops */
		if (error || !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_NAMED_ATTR)) {
			nmp->nm_fsattr.nfsa_flags &= ~NFS_FSFLAG_NAMED_ATTR;
		} else {
			nmp->nm_fsattr.nfsa_flags |= NFS_FSFLAG_NAMED_ATTR;
		}
	} else {
		nmp->nm_fsattr.nfsa_flags &= ~NFS_FSFLAG_NAMED_ATTR;
	}
	if (NMFLAG(nmp, NOACL)) /* make sure ACL support is turned off */
		nmp->nm_fsattr.nfsa_flags &= ~NFS_FSFLAG_ACL;
	if (NMFLAG(nmp, ACLONLY) && !(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_ACL))
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_ACLONLY);
	if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_FH_EXPIRE_TYPE)) {
		uint32_t fhtype = ((nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_FHTYPE_MASK) >> NFS_FSFLAG_FHTYPE_SHIFT);
		if (fhtype != NFS_FH_PERSISTENT)
			printf("nfs: warning: non-persistent file handles! for %s\n", vfs_statfs(nmp->nm_mountp)->f_mntfromname);
	}

	/* make sure it's a directory */
	if (!NFS_BITMAP_ISSET(&nvattr.nva_bitmap, NFS_FATTR_TYPE) || (nvattr.nva_type != VDIR)) {
		error = ENOTDIR;
		goto nfsmout;
	}

	/* save the NFS fsid */
	nmp->nm_fsid = nvattr.nva_fsid;

	/* create the root node */
	error = nfs_nget(nmp->nm_mountp, NULL, NULL, dirfh.fh_data, dirfh.fh_len, &nvattr, &xid, rq.r_auth, NG_MARKROOT, npp);
	nfsmout_if(error);

	if (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_ACL)
		vfs_setextendedsecurity(nmp->nm_mountp);

	/* adjust I/O sizes to server limits */
	if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXREAD) && (nmp->nm_fsattr.nfsa_maxread > 0)) {
		if (nmp->nm_fsattr.nfsa_maxread < (uint64_t)nmp->nm_rsize) {
			nmp->nm_rsize = nmp->nm_fsattr.nfsa_maxread & ~(NFS_FABLKSIZE - 1);
			if (nmp->nm_rsize == 0)
				nmp->nm_rsize = nmp->nm_fsattr.nfsa_maxread;
		}
	}
	if (NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_bitmap, NFS_FATTR_MAXWRITE) && (nmp->nm_fsattr.nfsa_maxwrite > 0)) {
		if (nmp->nm_fsattr.nfsa_maxwrite < (uint64_t)nmp->nm_wsize) {
			nmp->nm_wsize = nmp->nm_fsattr.nfsa_maxwrite & ~(NFS_FABLKSIZE - 1);
			if (nmp->nm_wsize == 0)
				nmp->nm_wsize = nmp->nm_fsattr.nfsa_maxwrite;
		}
	}

	/* set up lease renew timer */
	nmp->nm_renew_timer = thread_call_allocate(nfs4_renew_timer, nmp);
	interval = nmp->nm_fsattr.nfsa_lease / 2;
	if (interval < 1)
		interval = 1;
	nfs_interval_timer_start(nmp->nm_renew_timer, interval * 1000);

nfsmout:
	if (fspath.np_components) {
		for (comp=0; comp < fspath.np_compcount; comp++)
			if (fspath.np_components[comp])
				FREE(fspath.np_components[comp], M_TEMP);
		FREE(fspath.np_components, M_TEMP);
	}
	NVATTR_CLEANUP(&nvattr);
	nfs_fs_locations_cleanup(&nfsls);
	if (*npp)
		nfs_node_unlock(*npp);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/*
 * Thread to handle initial NFS mount connection.
 */
void
nfs_mount_connect_thread(void *arg, __unused wait_result_t wr)
{
	struct nfsmount *nmp = arg;
	int error = 0, savederror = 0, slpflag = (NMFLAG(nmp, INTR) ? PCATCH : 0);
	int done = 0, timeo, tries, maxtries;

	if (NM_OMFLAG(nmp, MNTQUICK)) {
		timeo = 8;
		maxtries = 1;
	} else {
		timeo = 30;
		maxtries = 2;
	}

	for (tries = 0; tries < maxtries; tries++) {
		error = nfs_connect(nmp, 1, timeo);
		switch (error) {
		case ETIMEDOUT:
		case EAGAIN:
		case EPIPE:
		case EADDRNOTAVAIL:
		case ENETDOWN:
		case ENETUNREACH:
		case ENETRESET:
		case ECONNABORTED:
		case ECONNRESET:
		case EISCONN:
		case ENOTCONN:
		case ESHUTDOWN:
		case ECONNREFUSED:
		case EHOSTDOWN:
		case EHOSTUNREACH:
			/* just keep retrying on any of these errors */
			break;
		case 0:
		default:
			/* looks like we got an answer... */
			done = 1;
			break;
		}

		/* save the best error */
		if (nfs_connect_error_class(error) >= nfs_connect_error_class(savederror))
			savederror = error;
		if (done) {
			error = savederror;
			break;
		}

		/* pause before next attempt */
		if ((error = nfs_sigintr(nmp, NULL, current_thread(), 0)))
			break;
		error = tsleep(nmp, PSOCK|slpflag, "nfs_mount_connect_retry", 2*hz);
		if (error && (error != EWOULDBLOCK))
			break;
		error = savederror;
	}

	/* update status of mount connect */
	lck_mtx_lock(&nmp->nm_lock);
	if (!nmp->nm_mounterror)
		nmp->nm_mounterror = error;
	nmp->nm_state &= ~NFSSTA_MOUNT_THREAD;
	lck_mtx_unlock(&nmp->nm_lock);
	wakeup(&nmp->nm_nss);
}

int
nfs_mount_connect(struct nfsmount *nmp)
{
	int error = 0, slpflag;
	thread_t thd;
	struct timespec ts = { 2, 0 };

	/*
	 * Set up the socket.  Perform initial search for a location/server/address to
	 * connect to and negotiate any unspecified mount parameters.  This work is
	 * done on a kernel thread to satisfy reserved port usage needs.
	 */
	slpflag = NMFLAG(nmp, INTR) ? PCATCH : 0;
	lck_mtx_lock(&nmp->nm_lock);
	/* set flag that the thread is running */
	nmp->nm_state |= NFSSTA_MOUNT_THREAD;
	if (kernel_thread_start(nfs_mount_connect_thread, nmp, &thd) != KERN_SUCCESS) {
		nmp->nm_state &= ~NFSSTA_MOUNT_THREAD;
		nmp->nm_mounterror = EIO;
		printf("nfs mount %s start socket connect thread failed\n", vfs_statfs(nmp->nm_mountp)->f_mntfromname);
	} else {
		thread_deallocate(thd);
	}

	/* wait until mount connect thread is finished/gone */
	while (nmp->nm_state & NFSSTA_MOUNT_THREAD) {
		error = msleep(&nmp->nm_nss, &nmp->nm_lock, slpflag|PSOCK, "nfsconnectthread", &ts);
		if ((error && (error != EWOULDBLOCK)) || ((error = nfs_sigintr(nmp, NULL, current_thread(), 1)))) {
			/* record error */
			if (!nmp->nm_mounterror)
				nmp->nm_mounterror = error;
			/* signal the thread that we are aborting */
			nmp->nm_sockflags |= NMSOCK_UNMOUNT;
			if (nmp->nm_nss)
				wakeup(nmp->nm_nss);
			/* and continue waiting on it to finish */
			slpflag = 0;
		}
	}
	lck_mtx_unlock(&nmp->nm_lock);

	/* grab mount connect status */
	error = nmp->nm_mounterror;

	return (error);
}

/* Table of maximum minor version for a given version */
uint32_t maxminorverstab[] = {
	0, /* Version 0 (does not exist) */
	0, /* Version 1 (does not exist) */
	0, /* Version 2 */
	0, /* Version 3 */
	0, /* Version 4 */
};

#define NFS_MAX_SUPPORTED_VERSION  ((long)(sizeof (maxminorverstab) / sizeof (uint32_t) - 1))
#define NFS_MAX_SUPPORTED_MINOR_VERSION(v) ((long)(maxminorverstab[(v)]))

#define DEFAULT_NFS_MIN_VERS VER2PVER(2, 0)
#define DEFAULT_NFS_MAX_VERS VER2PVER(3, 0)

/*
 * Common code to mount an NFS file system.
 */
int
mountnfs(
	char *xdrbuf,
	mount_t mp,
	vfs_context_t ctx,
	vnode_t *vpp)
{
	struct nfsmount *nmp;
	nfsnode_t np;
	int error = 0;
	struct vfsstatfs *sbp;
	struct xdrbuf xb;
	uint32_t i, val, maxio, iosize, len;
	uint32_t *mattrs;
	uint32_t *mflags_mask;
	uint32_t *mflags;
	uint32_t argslength, attrslength;
	struct nfs_location_index firstloc = { NLI_VALID, 0, 0, 0 };

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

	if (vfs_flags(mp) & MNT_UPDATE) {
		nmp = VFSTONFS(mp);
		/* update paths, file handles, etc, here	XXX */
		xb_free(xdrbuf);
		return (0);
	} else {
		/* allocate an NFS mount structure for this mount */
		MALLOC_ZONE(nmp, struct nfsmount *,
				sizeof (struct nfsmount), M_NFSMNT, M_WAITOK);
		if (!nmp) {
			xb_free(xdrbuf);
			return (ENOMEM);
		}
		bzero((caddr_t)nmp, sizeof (struct nfsmount));
		lck_mtx_init(&nmp->nm_lock, nfs_mount_grp, LCK_ATTR_NULL);
		TAILQ_INIT(&nmp->nm_resendq);
		TAILQ_INIT(&nmp->nm_iodq);
		TAILQ_INIT(&nmp->nm_gsscl);
		LIST_INIT(&nmp->nm_monlist);
		vfs_setfsprivate(mp, nmp);
		vfs_getnewfsid(mp);
		nmp->nm_mountp = mp;
		vfs_setauthopaque(mp);

		nfs_nhinit_finish();

		nmp->nm_args = xdrbuf;

		/* set up defaults */
		nmp->nm_ref = 0;
		nmp->nm_vers = 0;
		nmp->nm_min_vers = DEFAULT_NFS_MIN_VERS;
		nmp->nm_max_vers = DEFAULT_NFS_MAX_VERS;
		nmp->nm_timeo = NFS_TIMEO;
		nmp->nm_retry = NFS_RETRANS;
		nmp->nm_sotype = 0;
		nmp->nm_sofamily = 0;
		nmp->nm_nfsport = 0;
		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;
		nmp->nm_auth = RPCAUTH_SYS;
		nmp->nm_iodlink.tqe_next = NFSNOLIST;
		nmp->nm_deadtimeout = 0;
		nmp->nm_curdeadtimeout = 0;
		NFS_BITMAP_SET(nmp->nm_flags, NFS_MFLAG_NOACL);
		nmp->nm_realm = NULL;
		nmp->nm_principal = NULL;
		nmp->nm_sprinc = NULL;
	}

	mattrs = nmp->nm_mattrs;
	mflags = nmp->nm_mflags;
	mflags_mask = nmp->nm_mflags_mask;

	/* set up NFS mount with args */
	xb_init_buffer(&xb, xdrbuf, 2*XDRWORD);
	xb_get_32(error, &xb, val); /* version */
	xb_get_32(error, &xb, argslength); /* args length */
	nfsmerr_if(error);
	xb_init_buffer(&xb, xdrbuf, argslength);	/* restart parsing with actual buffer length */
	xb_get_32(error, &xb, val); /* version */
	xb_get_32(error, &xb, argslength); /* args length */
	xb_get_32(error, &xb, val); /* XDR args version */
	if (val != NFS_XDRARGS_VERSION_0)
		error = EINVAL;
	len = NFS_MATTR_BITMAP_LEN;
	xb_get_bitmap(error, &xb, mattrs, len); /* mount attribute bitmap */
	attrslength = 0;
	xb_get_32(error, &xb, attrslength); /* attrs length */
	if (!error && (attrslength > (argslength - ((4+NFS_MATTR_BITMAP_LEN+1)*XDRWORD))))
		error = EINVAL;
	nfsmerr_if(error);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FLAGS)) {
		len = NFS_MFLAG_BITMAP_LEN;
		xb_get_bitmap(error, &xb, mflags_mask, len); /* mount flag mask */
		len = NFS_MFLAG_BITMAP_LEN;
		xb_get_bitmap(error, &xb, mflags, len); /* mount flag values */
		if (!error) {
			/* clear all mask bits and OR in all the ones that are set */
			nmp->nm_flags[0] &= ~mflags_mask[0];
			nmp->nm_flags[0] |= (mflags_mask[0] & mflags[0]);
		}
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION)) {
		/* Can't specify a single version and a range */
		if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION_RANGE))
			error = EINVAL;
		xb_get_32(error, &xb, nmp->nm_vers);
		if (nmp->nm_vers > NFS_MAX_SUPPORTED_VERSION ||
		    nmp->nm_vers < NFS_VER2)
			error = EINVAL;
		if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_MINOR_VERSION))
			xb_get_32(error, &xb, nmp->nm_minor_vers);
		else
			nmp->nm_minor_vers = maxminorverstab[nmp->nm_vers];
		if (nmp->nm_minor_vers > maxminorverstab[nmp->nm_vers])
			error = EINVAL;
		nmp->nm_max_vers = nmp->nm_min_vers = 
			VER2PVER(nmp->nm_vers, nmp->nm_minor_vers);
	} 
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_MINOR_VERSION)) {
		/* should have also gotten NFS version (and already gotten minor version) */
		if (!NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION))
			error = EINVAL;
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION_RANGE)) {
		xb_get_32(error, &xb, nmp->nm_min_vers);
		xb_get_32(error, &xb, nmp->nm_max_vers);
		if ((nmp->nm_min_vers > nmp->nm_max_vers) ||
		    (PVER2MAJOR(nmp->nm_max_vers) > NFS_MAX_SUPPORTED_VERSION) ||
		    (PVER2MINOR(nmp->nm_min_vers) > maxminorverstab[PVER2MAJOR(nmp->nm_min_vers)]) ||
		    (PVER2MINOR(nmp->nm_max_vers) > maxminorverstab[PVER2MAJOR(nmp->nm_max_vers)]))
			error = EINVAL;
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READ_SIZE))
		xb_get_32(error, &xb, nmp->nm_rsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_WRITE_SIZE))
		xb_get_32(error, &xb, nmp->nm_wsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READDIR_SIZE))
		xb_get_32(error, &xb, nmp->nm_readdirsize);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READAHEAD))
		xb_get_32(error, &xb, nmp->nm_readahead);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MIN)) {
		xb_get_32(error, &xb, nmp->nm_acregmin);
		xb_skip(error, &xb, XDRWORD);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MAX)) {
		xb_get_32(error, &xb, nmp->nm_acregmax);
		xb_skip(error, &xb, XDRWORD);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MIN)) {
		xb_get_32(error, &xb, nmp->nm_acdirmin);
		xb_skip(error, &xb, XDRWORD);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MAX)) {
		xb_get_32(error, &xb, nmp->nm_acdirmax);
		xb_skip(error, &xb, XDRWORD);
	}
	nfsmerr_if(error);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_LOCK_MODE)) {
		xb_get_32(error, &xb, val);
		switch (val) {
		case NFS_LOCK_MODE_DISABLED:
		case NFS_LOCK_MODE_LOCAL:
			if (nmp->nm_vers >= NFS_VER4) {
				/* disabled/local lock mode only allowed on v2/v3 */
				error = EINVAL;
				break;
			}
			/* FALLTHROUGH */
		case NFS_LOCK_MODE_ENABLED:
			nmp->nm_lockmode = val;
			break;
		default:
			error = EINVAL;
		}
	}
	nfsmerr_if(error);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SECURITY)) {
		uint32_t seccnt;
		xb_get_32(error, &xb, seccnt);
		if (!error && ((seccnt < 1) || (seccnt > NX_MAX_SEC_FLAVORS)))
			error = EINVAL;
		nfsmerr_if(error);
		nmp->nm_sec.count = seccnt;
		for (i=0; i < seccnt; i++) {
			xb_get_32(error, &xb, nmp->nm_sec.flavors[i]);
			/* Check for valid security flavor */
			switch (nmp->nm_sec.flavors[i]) {
			case RPCAUTH_NONE:
			case RPCAUTH_SYS:
			case RPCAUTH_KRB5:
			case RPCAUTH_KRB5I:
			case RPCAUTH_KRB5P:
				break;
			default:
				error = EINVAL;
			}
		}
		/* start with the first flavor */
		nmp->nm_auth = nmp->nm_sec.flavors[0];
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MAX_GROUP_LIST))
		xb_get_32(error, &xb, nmp->nm_numgrps);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOCKET_TYPE)) {
		char sotype[6];

		xb_get_32(error, &xb, val);
		if (!error && ((val < 3) || (val > 5)))
			error = EINVAL;
		nfsmerr_if(error);
		error = xb_get_bytes(&xb, sotype, val, 0);
		nfsmerr_if(error);
		sotype[val] = '\0';
		if (!strcmp(sotype, "tcp")) {
			nmp->nm_sotype = SOCK_STREAM;
		} else if (!strcmp(sotype, "udp")) {
			nmp->nm_sotype = SOCK_DGRAM;
		} else if (!strcmp(sotype, "tcp4")) {
			nmp->nm_sotype = SOCK_STREAM;
			nmp->nm_sofamily = AF_INET;
		} else if (!strcmp(sotype, "udp4")) {
			nmp->nm_sotype = SOCK_DGRAM;
			nmp->nm_sofamily = AF_INET;
		} else if (!strcmp(sotype, "tcp6")) {
			nmp->nm_sotype = SOCK_STREAM;
			nmp->nm_sofamily = AF_INET6;
		} else if (!strcmp(sotype, "udp6")) {
			nmp->nm_sotype = SOCK_DGRAM;
			nmp->nm_sofamily = AF_INET6;
		} else if (!strcmp(sotype, "inet4")) {
			nmp->nm_sofamily = AF_INET;
		} else if (!strcmp(sotype, "inet6")) {
			nmp->nm_sofamily = AF_INET6;
		} else if (!strcmp(sotype, "inet")) {
			nmp->nm_sofamily = 0; /* ok */
		} else {
			error = EINVAL;
		}
		if (!error && (nmp->nm_vers >= NFS_VER4) && nmp->nm_sotype &&
		    (nmp->nm_sotype != SOCK_STREAM))
			error = EINVAL;		/* NFSv4 is only allowed over TCP. */
		nfsmerr_if(error);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_PORT))
		xb_get_32(error, &xb, nmp->nm_nfsport);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MOUNT_PORT))
		xb_get_32(error, &xb, nmp->nm_mountport);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_REQUEST_TIMEOUT)) {
		/* convert from time to 0.1s units */
		xb_get_32(error, &xb, nmp->nm_timeo);
		xb_get_32(error, &xb, val);
		nfsmerr_if(error);
		if (val >= 1000000000)
			error = EINVAL;
		nfsmerr_if(error);
		nmp->nm_timeo *= 10;
		nmp->nm_timeo += (val+100000000-1)/100000000;
		/* now convert to ticks */
		nmp->nm_timeo = (nmp->nm_timeo * NFS_HZ + 5) / 10;
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOFT_RETRY_COUNT)) {
		xb_get_32(error, &xb, val);
		if (!error && (val > 1))
			nmp->nm_retry = val;
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_DEAD_TIMEOUT)) {
		xb_get_32(error, &xb, nmp->nm_deadtimeout);
		xb_skip(error, &xb, XDRWORD);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FH)) {
		nfsmerr_if(error);
		MALLOC(nmp->nm_fh, fhandle_t *, sizeof(fhandle_t), M_TEMP, M_WAITOK|M_ZERO);
		if (!nmp->nm_fh)
			error = ENOMEM;
		xb_get_32(error, &xb, nmp->nm_fh->fh_len);
		nfsmerr_if(error);
		if (nmp->nm_fh->fh_len < 0 ||
		    (size_t)nmp->nm_fh->fh_len > sizeof(nmp->nm_fh->fh_data))
			error = EINVAL;
		else
			error = xb_get_bytes(&xb, (char*)&nmp->nm_fh->fh_data[0], nmp->nm_fh->fh_len, 0);
	}
	nfsmerr_if(error);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FS_LOCATIONS)) {
		uint32_t loc, serv, addr, comp;
		struct nfs_fs_location *fsl;
		struct nfs_fs_server *fss;
		struct nfs_fs_path *fsp;

		xb_get_32(error, &xb, nmp->nm_locations.nl_numlocs); /* fs location count */
		/* sanity check location count */
		if (!error && ((nmp->nm_locations.nl_numlocs < 1) || (nmp->nm_locations.nl_numlocs > 256)))
			error = EINVAL;
		nfsmerr_if(error);
		MALLOC(nmp->nm_locations.nl_locations, struct nfs_fs_location **, nmp->nm_locations.nl_numlocs * sizeof(struct nfs_fs_location*), M_TEMP, M_WAITOK|M_ZERO);
		if (!nmp->nm_locations.nl_locations)
			error = ENOMEM;
		for (loc = 0; loc < nmp->nm_locations.nl_numlocs; loc++) {
			nfsmerr_if(error);
			MALLOC(fsl, struct nfs_fs_location *, sizeof(struct nfs_fs_location), M_TEMP, M_WAITOK|M_ZERO);
			if (!fsl)
				error = ENOMEM;
			nmp->nm_locations.nl_locations[loc] = fsl;
			xb_get_32(error, &xb, fsl->nl_servcount); /* server count */
			/* sanity check server count */
			if (!error && ((fsl->nl_servcount < 1) || (fsl->nl_servcount > 256)))
				error = EINVAL;
			nfsmerr_if(error);
			MALLOC(fsl->nl_servers, struct nfs_fs_server **, fsl->nl_servcount * sizeof(struct nfs_fs_server*), M_TEMP, M_WAITOK|M_ZERO);
			if (!fsl->nl_servers)
				error = ENOMEM;
			for (serv = 0; serv < fsl->nl_servcount; serv++) {
				nfsmerr_if(error);
				MALLOC(fss, struct nfs_fs_server *, sizeof(struct nfs_fs_server), M_TEMP, M_WAITOK|M_ZERO);
				if (!fss)
					error = ENOMEM;
				fsl->nl_servers[serv] = fss;
				xb_get_32(error, &xb, val); /* server name length */
				/* sanity check server name length */
				if (!error && ((val < 1) || (val > MAXPATHLEN)))
					error = EINVAL;
				nfsmerr_if(error);
				MALLOC(fss->ns_name, char *, val+1, M_TEMP, M_WAITOK|M_ZERO);
				if (!fss->ns_name)
					error = ENOMEM;
				nfsmerr_if(error);
				error = xb_get_bytes(&xb, fss->ns_name, val, 0); /* server name */
				xb_get_32(error, &xb, fss->ns_addrcount); /* address count */
				/* sanity check address count (OK to be zero) */
				if (!error && (fss->ns_addrcount > 256))
					error = EINVAL;
				nfsmerr_if(error);
				if (fss->ns_addrcount > 0) {
					MALLOC(fss->ns_addresses, char **, fss->ns_addrcount * sizeof(char *), M_TEMP, M_WAITOK|M_ZERO);
					if (!fss->ns_addresses)
						error = ENOMEM;
					for (addr = 0; addr < fss->ns_addrcount; addr++) {
						xb_get_32(error, &xb, val); /* address length */
						/* sanity check address length */
						if (!error && ((val < 1) || (val > 128)))
							error = EINVAL;
						nfsmerr_if(error);
						MALLOC(fss->ns_addresses[addr], char *, val+1, M_TEMP, M_WAITOK|M_ZERO);
						if (!fss->ns_addresses[addr])
							error = ENOMEM;
						nfsmerr_if(error);
						error = xb_get_bytes(&xb, fss->ns_addresses[addr], val, 0); /* address */
					}
				}
				xb_get_32(error, &xb, val); /* server info length */
				xb_skip(error, &xb, val); /* skip server info */
			}
			/* get pathname */
			fsp = &fsl->nl_path;
			xb_get_32(error, &xb, fsp->np_compcount); /* component count */
			/* sanity check component count */
			if (!error && (fsp->np_compcount > MAXPATHLEN))
				error = EINVAL;
			nfsmerr_if(error);
			if (fsp->np_compcount) {
				MALLOC(fsp->np_components, char **, fsp->np_compcount * sizeof(char*), M_TEMP, M_WAITOK|M_ZERO);
				if (!fsp->np_components)
					error = ENOMEM;
			}
			for (comp = 0; comp < fsp->np_compcount; comp++) {
				xb_get_32(error, &xb, val); /* component length */
				/* sanity check component length */
				if (!error && (val == 0)) {
					/*
					 * Apparently some people think a path with zero components should
					 * be encoded with one zero-length component.  So, just ignore any
					 * zero length components.
					 */
					comp--;
					fsp->np_compcount--;
					if (fsp->np_compcount == 0) {
						FREE(fsp->np_components, M_TEMP);
						fsp->np_components = NULL;
					}
					continue;
				}
				if (!error && ((val < 1) || (val > MAXPATHLEN)))
					error = EINVAL;
				nfsmerr_if(error);
				MALLOC(fsp->np_components[comp], char *, val+1, M_TEMP, M_WAITOK|M_ZERO);
				if (!fsp->np_components[comp])
					error = ENOMEM;
				nfsmerr_if(error);
				error = xb_get_bytes(&xb, fsp->np_components[comp], val, 0); /* component */
			}
			xb_get_32(error, &xb, val); /* fs location info length */
			xb_skip(error, &xb, val); /* skip fs location info */
		}
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFLAGS))
		xb_skip(error, &xb, XDRWORD);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFROM)) {
		xb_get_32(error, &xb, len);
		nfsmerr_if(error);
		val = len;
		if (val >= sizeof(vfs_statfs(mp)->f_mntfromname))
			val = sizeof(vfs_statfs(mp)->f_mntfromname) - 1;
		error = xb_get_bytes(&xb, vfs_statfs(mp)->f_mntfromname, val, 0);
		if ((len - val) > 0)
			xb_skip(error, &xb, len - val);
		nfsmerr_if(error);
		vfs_statfs(mp)->f_mntfromname[val] = '\0';
	}
	nfsmerr_if(error);

	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_REALM)) {
		xb_get_32(error, &xb, len);
		if (!error && ((len < 1) || (len > MAXPATHLEN)))
			error=EINVAL;
		nfsmerr_if(error);
		/* allocate an extra byte for a leading '@' if its not already prepended to the realm */
		MALLOC(nmp->nm_realm, char *, len+2, M_TEMP, M_WAITOK|M_ZERO);
		if (!nmp->nm_realm)
			error = ENOMEM;
		nfsmerr_if(error);
		error = xb_get_bytes(&xb, nmp->nm_realm, len, 0);
		if (error == 0 && *nmp->nm_realm != '@') {
			bcopy(nmp->nm_realm, &nmp->nm_realm[1], len);
			nmp->nm_realm[0] = '@';
		}
	}
	nfsmerr_if(error);

	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_PRINCIPAL)) {
		xb_get_32(error, &xb, len);
		if (!error && ((len < 1) || (len > MAXPATHLEN)))
			error=EINVAL;
		nfsmerr_if(error);
		MALLOC(nmp->nm_principal, char *, len+1, M_TEMP, M_WAITOK|M_ZERO);
		if (!nmp->nm_principal)
			error = ENOMEM;
		nfsmerr_if(error);
		error = xb_get_bytes(&xb, nmp->nm_principal, len, 0);
	}
	nfsmerr_if(error);

	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SVCPRINCIPAL)) {
		xb_get_32(error, &xb, len);
		if (!error && ((len < 1) || (len > MAXPATHLEN)))
			error=EINVAL;
		nfsmerr_if(error);
		MALLOC(nmp->nm_sprinc, char *, len+1, M_TEMP, M_WAITOK|M_ZERO);
		if (!nmp->nm_sprinc)
			error = ENOMEM;
		nfsmerr_if(error);
		error = xb_get_bytes(&xb, nmp->nm_sprinc, len, 0);
	}
	nfsmerr_if(error);

	/*
	 * Sanity check/finalize settings.
	 */

	if (nmp->nm_timeo < NFS_MINTIMEO)
		nmp->nm_timeo = NFS_MINTIMEO;
	else if (nmp->nm_timeo > NFS_MAXTIMEO)
		nmp->nm_timeo = NFS_MAXTIMEO;
	if (nmp->nm_retry > NFS_MAXREXMIT)
		nmp->nm_retry = NFS_MAXREXMIT;

	if (nmp->nm_numgrps > NFS_MAXGRPS)
		nmp->nm_numgrps = NFS_MAXGRPS;
	if (nmp->nm_readahead > NFS_MAXRAHEAD)
		nmp->nm_readahead = NFS_MAXRAHEAD;
	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;

	/* need at least one fs location */
	if (nmp->nm_locations.nl_numlocs < 1)
		error = EINVAL;
	nfsmerr_if(error);

	/* init mount's mntfromname to first location */
	if (!NM_OMATTR_GIVEN(nmp, MNTFROM))
		nfs_location_mntfromname(&nmp->nm_locations, firstloc,
			vfs_statfs(mp)->f_mntfromname, sizeof(vfs_statfs(mp)->f_mntfromname), 0);

	/* Need to save the mounting credential for v4. */
	nmp->nm_mcred = vfs_context_ucred(ctx);
	if (IS_VALID_CRED(nmp->nm_mcred))
		kauth_cred_ref(nmp->nm_mcred);

	/*
	 * If a reserved port is required, check for that privilege.
	 * (Note that mirror mounts are exempt because the privilege was
	 * already checked for the original mount.)
	 */
	if (NMFLAG(nmp, RESVPORT) && !vfs_iskernelmount(mp))
		error = priv_check_cred(nmp->nm_mcred, PRIV_NETINET_RESERVEDPORT, 0);
	nfsmerr_if(error);

	/* do mount's initial socket connection */
	error = nfs_mount_connect(nmp);
	nfsmerr_if(error);

	/* set up the version-specific function tables */
	if (nmp->nm_vers < NFS_VER4)
		nmp->nm_funcs = &nfs3_funcs;
	else
		nmp->nm_funcs = &nfs4_funcs;

	/* sanity check settings now that version/connection is set */
	if (nmp->nm_vers == NFS_VER2)		/* ignore RDIRPLUS on NFSv2 */
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_RDIRPLUS);
	if (nmp->nm_vers >= NFS_VER4) {
		if (NFS_BITMAP_ISSET(nmp->nm_flags, NFS_MFLAG_ACLONLY)) /* aclonly trumps noacl */
			NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_NOACL);
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_CALLUMNT);
		if (nmp->nm_lockmode != NFS_LOCK_MODE_ENABLED)
			error = EINVAL; /* disabled/local lock mode only allowed on v2/v3 */
	} else {
		/* ignore these if not v4 */
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_NOCALLBACK);
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_NONAMEDATTR);
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_NOACL);
		NFS_BITMAP_CLR(nmp->nm_flags, NFS_MFLAG_ACLONLY);
	}
	nfsmerr_if(error);

	if (nmp->nm_sotype == SOCK_DGRAM) {
		/* I/O size defaults for UDP are different */
		if (!NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READ_SIZE))
			nmp->nm_rsize = NFS_DGRAM_RSIZE;
		if (!NFS_BITMAP_ISSET(mattrs, NFS_MATTR_WRITE_SIZE))
			nmp->nm_wsize = NFS_DGRAM_WSIZE;
	}

	/* round down I/O sizes to multiple of NFS_FABLKSIZE */
	nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
	if (nmp->nm_rsize <= 0)
		nmp->nm_rsize = NFS_FABLKSIZE;
	nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
	if (nmp->nm_wsize <= 0)
		nmp->nm_wsize = NFS_FABLKSIZE;

	/* and limit I/O sizes to maximum allowed */
	maxio = (nmp->nm_vers == NFS_VER2) ? NFS_V2MAXDATA :
		(nmp->nm_sotype == SOCK_DGRAM) ? NFS_MAXDGRAMDATA : NFS_MAXDATA;
	if (maxio > NFS_MAXBSIZE)
		maxio = NFS_MAXBSIZE;
	if (nmp->nm_rsize > maxio)
		nmp->nm_rsize = maxio;
	if (nmp->nm_wsize > maxio)
		nmp->nm_wsize = maxio;

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

	/* Set up the sockets and related info */
	if (nmp->nm_sotype == SOCK_DGRAM)
		TAILQ_INIT(&nmp->nm_cwndq);

	/*
	 * Get the root node/attributes from the NFS server and
	 * do any basic, version-specific setup.
	 */
	error = nmp->nm_funcs->nf_mount(nmp, ctx, &np);
	nfsmerr_if(error);

	/*
	 * A reference count is needed on the node representing the
	 * remote root.  If this object is not persistent, then backward
	 * traversals of the mount point (i.e. "..") will not work if
	 * the node gets flushed out of the cache.
	 */
	nmp->nm_dnp = np;
	*vpp = NFSTOV(np);
	/* get usecount and drop iocount */
	error = vnode_ref(*vpp);
	vnode_put(*vpp);
	if (error) {
		vnode_recycle(*vpp);
		goto nfsmerr;
	}

	/*
	 * Do statfs to ensure static info gets set to reasonable values.
	 */
	if ((error = nmp->nm_funcs->nf_update_statfs(nmp, ctx))) {
		int error2 = vnode_getwithref(*vpp);
		vnode_rele(*vpp);
		if (!error2)
			vnode_put(*vpp);
		vnode_recycle(*vpp);
		goto nfsmerr;
	}
	sbp = vfs_statfs(mp);
	sbp->f_bsize = nmp->nm_fsattr.nfsa_bsize;
	sbp->f_blocks = nmp->nm_fsattr.nfsa_space_total / sbp->f_bsize;
	sbp->f_bfree = nmp->nm_fsattr.nfsa_space_free / sbp->f_bsize;
	sbp->f_bavail = nmp->nm_fsattr.nfsa_space_avail / sbp->f_bsize;
	sbp->f_bused = (nmp->nm_fsattr.nfsa_space_total / sbp->f_bsize) -
			(nmp->nm_fsattr.nfsa_space_free / sbp->f_bsize);
	sbp->f_files = nmp->nm_fsattr.nfsa_files_total;
	sbp->f_ffree = nmp->nm_fsattr.nfsa_files_free;
	sbp->f_iosize = nfs_iosize;

	/*
	 * Calculate the size used for I/O 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;
	nmp->nm_biosize = trunc_page_32(iosize);

	/* For NFSv3 and greater, there is a (relatively) reliable ACCESS call. */
	if (nmp->nm_vers > NFS_VER2)
		vfs_setauthopaqueaccess(mp);

	switch (nmp->nm_lockmode) {
	case NFS_LOCK_MODE_DISABLED:
		break;
	case NFS_LOCK_MODE_LOCAL:
		vfs_setlocklocal(nmp->nm_mountp);
		break;
	case NFS_LOCK_MODE_ENABLED:
	default:
		if (nmp->nm_vers <= NFS_VER3)
			nfs_lockd_mount_register(nmp);
		break;
	}

	/* success! */
	lck_mtx_lock(&nmp->nm_lock);
	nmp->nm_state |= NFSSTA_MOUNTED;
	lck_mtx_unlock(&nmp->nm_lock);
	return (0);
nfsmerr:
	nfs_mount_cleanup(nmp);
	return (error);
}

#if CONFIG_TRIGGERS

/*
 * We've detected a file system boundary on the server and
 * need to mount a new file system so that our file systems
 * MIRROR the file systems on the server.
 *
 * Build the mount arguments for the new mount and call kernel_mount().
 */
int
nfs_mirror_mount_domount(vnode_t dvp, vnode_t vp, vfs_context_t ctx)
{
	nfsnode_t np = VTONFS(vp);
	nfsnode_t dnp = VTONFS(dvp);
	struct nfsmount *nmp = NFSTONMP(np);
	char fstype[MFSTYPENAMELEN], *mntfromname = NULL, *path = NULL, *relpath, *p, *cp;
	int error = 0, pathbuflen = MAXPATHLEN, i, mntflags = 0, referral, skipcopy = 0;
	size_t nlen;
	struct xdrbuf xb, xbnew;
	uint32_t mattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t newmattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t newmflags[NFS_MFLAG_BITMAP_LEN];
	uint32_t newmflags_mask[NFS_MFLAG_BITMAP_LEN];
	uint32_t argslength = 0, val, count, mlen, mlen2, rlen, relpathcomps;
	uint32_t argslength_offset, attrslength_offset, end_offset;
	uint32_t numlocs, loc, numserv, serv, numaddr, addr, numcomp, comp;
	char buf[XDRWORD];
	struct nfs_fs_locations nfsls;

	referral = (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL);
	if (referral)
		bzero(&nfsls, sizeof(nfsls));

	xb_init(&xbnew, 0);

	if (!nmp || (nmp->nm_state & (NFSSTA_FORCE|NFSSTA_DEAD)))
		return (ENXIO);

	/* allocate a couple path buffers we need */
	MALLOC_ZONE(mntfromname, char *, pathbuflen, M_NAMEI, M_WAITOK); 
	if (!mntfromname) {
		error = ENOMEM;
		goto nfsmerr;
	}
	MALLOC_ZONE(path, char *, pathbuflen, M_NAMEI, M_WAITOK); 
	if (!path) {
		error = ENOMEM;
		goto nfsmerr;
	}

	/* get the path for the directory being mounted on */
	error = vn_getpath(vp, path, &pathbuflen);
	if (error) {
		error = ENOMEM;
		goto nfsmerr;
	}

	/*
	 * Set up the mntfromname for the new mount based on the
	 * current mount's mntfromname and the directory's path
	 * relative to the current mount's mntonname.
	 * Set up relpath to point at the relative path on the current mount.
	 * Also, count the number of components in relpath.
	 * We'll be adding those to each fs location path in the new args.
	 */
	nlen = strlcpy(mntfromname, vfs_statfs(nmp->nm_mountp)->f_mntfromname, MAXPATHLEN);
	if ((nlen > 0) && (mntfromname[nlen-1] == '/')) { /* avoid double '/' in new name */
		mntfromname[nlen-1] = '\0';
		nlen--;
	}
	relpath = mntfromname + nlen;
	nlen = strlcat(mntfromname, path + strlen(vfs_statfs(nmp->nm_mountp)->f_mntonname), MAXPATHLEN);
	if (nlen >= MAXPATHLEN) {
		error = ENAMETOOLONG;
		goto nfsmerr;
	}
	/* count the number of components in relpath */
	p = relpath;
	while (*p && (*p == '/'))
		p++;
	relpathcomps = 0;
	while (*p) {
		relpathcomps++;
		while (*p && (*p != '/'))
			p++;
		while (*p && (*p == '/'))
			p++;
	}

	/* grab a copy of the file system type */
	vfs_name(vnode_mount(vp), fstype);

	/* for referrals, fetch the fs locations */
	if (referral) {
		const char *vname = vnode_getname(NFSTOV(np));
		if (!vname) {
			error = ENOENT;
		} else {
			error = nfs4_get_fs_locations(nmp, dnp, NULL, 0, vname, ctx, &nfsls);
			vnode_putname(vname);
			if (!error && (nfsls.nl_numlocs < 1))
				error = ENOENT;
		}
		nfsmerr_if(error);
	}

	/* set up NFS mount args based on current mount args */

#define xb_copy_32(E, XBSRC, XBDST, V) \
	do { \
		if (E) break; \
		xb_get_32((E), (XBSRC), (V)); \
		if (skipcopy) break; \
		xb_add_32((E), (XBDST), (V)); \
	} while (0)
#define xb_copy_opaque(E, XBSRC, XBDST) \
	do { \
		uint32_t __count, __val; \
		xb_copy_32((E), (XBSRC), (XBDST), __count); \
		if (E) break; \
		__count = nfsm_rndup(__count); \
		__count /= XDRWORD; \
		while (__count-- > 0) \
			xb_copy_32((E), (XBSRC), (XBDST), __val); \
	} while (0)

	xb_init_buffer(&xb, nmp->nm_args, 2*XDRWORD);
	xb_get_32(error, &xb, val); /* version */
	xb_get_32(error, &xb, argslength); /* args length */
	xb_init_buffer(&xb, nmp->nm_args, argslength);

	xb_init_buffer(&xbnew, NULL, 0);
	xb_copy_32(error, &xb, &xbnew, val); /* version */
	argslength_offset = xb_offset(&xbnew);
	xb_copy_32(error, &xb, &xbnew, val); /* args length */
	xb_copy_32(error, &xb, &xbnew, val); /* XDR args version */
	count = NFS_MATTR_BITMAP_LEN;
	xb_get_bitmap(error, &xb, mattrs, count); /* mount attribute bitmap */
	nfsmerr_if(error);
	for (i = 0; i < NFS_MATTR_BITMAP_LEN; i++)
		newmattrs[i] = mattrs[i];
	if (referral)
		NFS_BITMAP_SET(newmattrs, NFS_MATTR_FS_LOCATIONS);
	else
		NFS_BITMAP_SET(newmattrs, NFS_MATTR_FH);
	NFS_BITMAP_SET(newmattrs, NFS_MATTR_FLAGS);
	NFS_BITMAP_SET(newmattrs, NFS_MATTR_MNTFLAGS);
	NFS_BITMAP_CLR(newmattrs, NFS_MATTR_MNTFROM);
	xb_add_bitmap(error, &xbnew, newmattrs, NFS_MATTR_BITMAP_LEN);
	attrslength_offset = xb_offset(&xbnew);
	xb_copy_32(error, &xb, &xbnew, val); /* attrs length */
	NFS_BITMAP_ZERO(newmflags_mask, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_ZERO(newmflags, NFS_MFLAG_BITMAP_LEN);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FLAGS)) {
		count = NFS_MFLAG_BITMAP_LEN;
		xb_get_bitmap(error, &xb, newmflags_mask, count); /* mount flag mask bitmap */
		count = NFS_MFLAG_BITMAP_LEN;
		xb_get_bitmap(error, &xb, newmflags, count); /* mount flag bitmap */
	}
	NFS_BITMAP_SET(newmflags_mask, NFS_MFLAG_EPHEMERAL);
	NFS_BITMAP_SET(newmflags, NFS_MFLAG_EPHEMERAL);
	xb_add_bitmap(error, &xbnew, newmflags_mask, NFS_MFLAG_BITMAP_LEN);
	xb_add_bitmap(error, &xbnew, newmflags, NFS_MFLAG_BITMAP_LEN);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_MINOR_VERSION))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_VERSION_RANGE)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READ_SIZE))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_WRITE_SIZE))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READDIR_SIZE))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_READAHEAD))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MIN)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_REG_MAX)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MIN)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MAX)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_LOCK_MODE))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SECURITY)) {
		xb_copy_32(error, &xb, &xbnew, count);
		while (!error && (count-- > 0))
			xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MAX_GROUP_LIST))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOCKET_TYPE))
		xb_copy_opaque(error, &xb, &xbnew);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_NFS_PORT))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MOUNT_PORT))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_REQUEST_TIMEOUT)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SOFT_RETRY_COUNT))
		xb_copy_32(error, &xb, &xbnew, val);
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_DEAD_TIMEOUT)) {
		xb_copy_32(error, &xb, &xbnew, val);
		xb_copy_32(error, &xb, &xbnew, val);
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FH)) {
		xb_get_32(error, &xb, count);
		xb_skip(error, &xb, count);
	}
	if (!referral) {
		/* set the initial file handle to the directory's file handle */
		xb_add_fh(error, &xbnew, np->n_fhp, np->n_fhsize);
	}
	/* copy/extend/skip fs locations */
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_FS_LOCATIONS)) {
		numlocs = numserv = numaddr = numcomp = 0;
		if (referral) /* don't copy the fs locations for a referral */
			skipcopy = 1;
		xb_copy_32(error, &xb, &xbnew, numlocs); /* location count */
		for (loc = 0; !error && (loc < numlocs); loc++) {
			xb_copy_32(error, &xb, &xbnew, numserv); /* server count */
			for (serv = 0; !error && (serv < numserv); serv++) {
				xb_copy_opaque(error, &xb, &xbnew); /* server name */
				xb_copy_32(error, &xb, &xbnew, numaddr); /* address count */
				for (addr = 0; !error && (addr < numaddr); addr++)
					xb_copy_opaque(error, &xb, &xbnew); /* address */
				xb_copy_opaque(error, &xb, &xbnew); /* server info */
			}
			/* pathname */
			xb_get_32(error, &xb, numcomp); /* component count */
			if (!skipcopy)
				xb_add_32(error, &xbnew, numcomp+relpathcomps); /* new component count */
			for (comp = 0; !error && (comp < numcomp); comp++)
				xb_copy_opaque(error, &xb, &xbnew); /* component */
			/* add additional components */
			for (comp = 0; !skipcopy && !error && (comp < relpathcomps); comp++) {
				p = relpath;
				while (*p && (*p == '/'))
					p++;
				while (*p && !error) {
					cp = p;
					while (*p && (*p != '/'))
						p++;
					xb_add_string(error, &xbnew, cp, (p - cp)); /* component */
					while (*p && (*p == '/'))
						p++;
				}
			}
			xb_copy_opaque(error, &xb, &xbnew); /* fs location info */
		}
		if (referral)
			skipcopy = 0;
	}
	if (referral) {
		/* add referral's fs locations */
		xb_add_32(error, &xbnew, nfsls.nl_numlocs);			/* FS_LOCATIONS */
		for (loc = 0; !error && (loc < nfsls.nl_numlocs); loc++) {
			xb_add_32(error, &xbnew, nfsls.nl_locations[loc]->nl_servcount);
			for (serv = 0; !error && (serv < nfsls.nl_locations[loc]->nl_servcount); serv++) {
				xb_add_string(error, &xbnew, nfsls.nl_locations[loc]->nl_servers[serv]->ns_name,
					strlen(nfsls.nl_locations[loc]->nl_servers[serv]->ns_name));
				xb_add_32(error, &xbnew, nfsls.nl_locations[loc]->nl_servers[serv]->ns_addrcount);
				for (addr = 0; !error && (addr < nfsls.nl_locations[loc]->nl_servers[serv]->ns_addrcount); addr++)
					xb_add_string(error, &xbnew, nfsls.nl_locations[loc]->nl_servers[serv]->ns_addresses[addr],
						strlen(nfsls.nl_locations[loc]->nl_servers[serv]->ns_addresses[addr]));
				xb_add_32(error, &xbnew, 0); /* empty server info */
			}
			xb_add_32(error, &xbnew, nfsls.nl_locations[loc]->nl_path.np_compcount);
			for (comp = 0; !error && (comp < nfsls.nl_locations[loc]->nl_path.np_compcount); comp++)
				xb_add_string(error, &xbnew, nfsls.nl_locations[loc]->nl_path.np_components[comp],
					strlen(nfsls.nl_locations[loc]->nl_path.np_components[comp]));
			xb_add_32(error, &xbnew, 0); /* empty fs location info */
		}
	}
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFLAGS))
		xb_get_32(error, &xb, mntflags);
	/*
	 * We add the following mount flags to the ones for the mounted-on mount:
	 * MNT_DONTBROWSE - to keep the mount from showing up as a separate volume
	 * MNT_AUTOMOUNTED - to keep DiskArb from retriggering the mount after
	 *                   an unmount (looking for /.autodiskmounted)
	 */
	mntflags |= (MNT_AUTOMOUNTED | MNT_DONTBROWSE);
	xb_add_32(error, &xbnew, mntflags);
	if (!referral && NFS_BITMAP_ISSET(mattrs, NFS_MATTR_MNTFROM)) {
		/* copy mntfrom string and add relpath */
		rlen = strlen(relpath);
		xb_get_32(error, &xb, mlen);
		nfsmerr_if(error);
		mlen2 = mlen + ((relpath[0] != '/') ? 1 : 0) + rlen;
		xb_add_32(error, &xbnew, mlen2);
		count = mlen/XDRWORD;
		/* copy the original string */
		while (count-- > 0)
			xb_copy_32(error, &xb, &xbnew, val);
		if (!error && (mlen % XDRWORD)) {
			error = xb_get_bytes(&xb, buf, mlen%XDRWORD, 0);
			if (!error)
				error = xb_add_bytes(&xbnew, buf, mlen%XDRWORD, 1);
		}
		/* insert a '/' if the relative path doesn't start with one */
		if (!error && (relpath[0] != '/')) {
			buf[0] = '/';
			error = xb_add_bytes(&xbnew, buf, 1, 1);
		}
		/* add the additional relative path */
		if (!error)
			error = xb_add_bytes(&xbnew, relpath, rlen, 1);
		/* make sure the resulting string has the right number of pad bytes */
		if (!error && (mlen2 != nfsm_rndup(mlen2))) {
			bzero(buf, sizeof(buf));
			count = nfsm_rndup(mlen2) - mlen2;
			error = xb_add_bytes(&xbnew, buf, count, 1);
		}
	}
	xb_build_done(error, &xbnew);

	/* update opaque counts */
	end_offset = xb_offset(&xbnew);
	if (!error) {
		error = xb_seek(&xbnew, argslength_offset);
		argslength = end_offset - argslength_offset + XDRWORD/*version*/;
		xb_add_32(error, &xbnew, argslength);
	}
	if (!error) {
		error = xb_seek(&xbnew, attrslength_offset);
		xb_add_32(error, &xbnew, end_offset - attrslength_offset - XDRWORD/*don't include length field*/);
	}
	nfsmerr_if(error);

	/*
	 * For kernel_mount() call, use the existing mount flags (instead of the
	 * original flags) because flags like MNT_NOSUID and MNT_NODEV may have
	 * been silently enforced.
	 */
	mntflags = vnode_vfsvisflags(vp);
	mntflags |= (MNT_AUTOMOUNTED | MNT_DONTBROWSE);

	/* do the mount */
	error = kernel_mount(fstype, dvp, vp, path, xb_buffer_base(&xbnew), argslength,
			mntflags, KERNEL_MOUNT_PERMIT_UNMOUNT | KERNEL_MOUNT_NOAUTH, ctx);

nfsmerr:
	if (error)
		printf("nfs: mirror mount of %s on %s failed (%d)\n",
			mntfromname, path, error);
	/* clean up */
	xb_cleanup(&xbnew);
	if (referral)
		nfs_fs_locations_cleanup(&nfsls);
	if (path)
		FREE_ZONE(path, MAXPATHLEN, M_NAMEI);
	if (mntfromname)
		FREE_ZONE(mntfromname, MAXPATHLEN, M_NAMEI);
	if (!error)
		nfs_ephemeral_mount_harvester_start();
	return (error);
}

/*
 * trigger vnode functions
 */

resolver_result_t
nfs_mirror_mount_trigger_resolve(
	vnode_t vp,
	const struct componentname *cnp,
	enum path_operation pop,
	__unused int flags,
	__unused void *data,
	vfs_context_t ctx)
{
	nfsnode_t np = VTONFS(vp);
	vnode_t pvp = NULLVP;
	int error = 0;
	resolver_result_t result;

	/*
	 * We have a trigger node that doesn't have anything mounted on it yet.
	 * We'll do the mount if either:
	 * (a) this isn't the last component of the path OR
	 * (b) this is an op that looks like it should trigger the mount.
	 */
	if (cnp->cn_flags & ISLASTCN) {
		switch (pop) {
		case OP_MOUNT:
		case OP_UNMOUNT:
		case OP_STATFS:
		case OP_LINK:
		case OP_UNLINK:
		case OP_RENAME:
		case OP_MKNOD:
		case OP_MKFIFO:
		case OP_SYMLINK:
		case OP_ACCESS:
		case OP_GETATTR:
		case OP_MKDIR:
		case OP_RMDIR:
		case OP_REVOKE:
		case OP_GETXATTR:
		case OP_LISTXATTR:
			/* don't perform the mount for these operations */
			result = vfs_resolver_result(np->n_trigseq, RESOLVER_NOCHANGE, 0);
#ifdef NFS_TRIGGER_DEBUG
			NP(np, "nfs trigger RESOLVE: no change, last %d nameiop %d, seq %d",
				(cnp->cn_flags & ISLASTCN) ? 1 : 0, cnp->cn_nameiop, np->n_trigseq);
#endif
			return (result);
		case OP_OPEN:
		case OP_CHDIR:
		case OP_CHROOT:
		case OP_TRUNCATE:
		case OP_COPYFILE:
		case OP_PATHCONF:
		case OP_READLINK:
		case OP_SETATTR:
		case OP_EXCHANGEDATA:
		case OP_SEARCHFS:
		case OP_FSCTL:
		case OP_SETXATTR:
		case OP_REMOVEXATTR:
		default:
			/* go ahead and do the mount */
			break;
		}
	}

	if (vnode_mountedhere(vp) != NULL) {
		/*
		 * Um... there's already something mounted.
		 * Been there.  Done that.  Let's just say it succeeded.
		 */
		error = 0;
		goto skipmount;
	}

	if ((error = nfs_node_set_busy(np, vfs_context_thread(ctx)))) {
		result = vfs_resolver_result(np->n_trigseq, RESOLVER_ERROR, error);
#ifdef NFS_TRIGGER_DEBUG
		NP(np, "nfs trigger RESOLVE: busy error %d, last %d nameiop %d, seq %d",
			error, (cnp->cn_flags & ISLASTCN) ? 1 : 0, cnp->cn_nameiop, np->n_trigseq);
#endif
		return (result);
	}

	pvp = vnode_getparent(vp);
	if (pvp == NULLVP)
		error = EINVAL;
	if (!error)
		error = nfs_mirror_mount_domount(pvp, vp, ctx);
skipmount:
	if (!error)
		np->n_trigseq++;
	result = vfs_resolver_result(np->n_trigseq, error ? RESOLVER_ERROR : RESOLVER_RESOLVED, error);
#ifdef NFS_TRIGGER_DEBUG
	NP(np, "nfs trigger RESOLVE: %s %d, last %d nameiop %d, seq %d",
		error ? "error" : "resolved", error,
		(cnp->cn_flags & ISLASTCN) ? 1 : 0, cnp->cn_nameiop, np->n_trigseq);
#endif

	if (pvp != NULLVP)
		vnode_put(pvp);
	nfs_node_clear_busy(np);
	return (result);
}

resolver_result_t
nfs_mirror_mount_trigger_unresolve(
	vnode_t vp,
	int flags,
	__unused void *data,
	vfs_context_t ctx)
{
	nfsnode_t np = VTONFS(vp);
	mount_t mp;
	int error;
	resolver_result_t result;

	if ((error = nfs_node_set_busy(np, vfs_context_thread(ctx)))) {
		result = vfs_resolver_result(np->n_trigseq, RESOLVER_ERROR, error);
#ifdef NFS_TRIGGER_DEBUG
		NP(np, "nfs trigger UNRESOLVE: busy error %d, seq %d", error, np->n_trigseq);
#endif
		return (result);
	}

	mp = vnode_mountedhere(vp);
	if (!mp)
		error = EINVAL;
	if (!error)
		error = vfs_unmountbyfsid(&(vfs_statfs(mp)->f_fsid), flags, ctx);
	if (!error)
		np->n_trigseq++;
	result = vfs_resolver_result(np->n_trigseq, error ? RESOLVER_ERROR : RESOLVER_UNRESOLVED, error);
#ifdef NFS_TRIGGER_DEBUG
	NP(np, "nfs trigger UNRESOLVE: %s %d, seq %d",
		error ? "error" : "unresolved", error, np->n_trigseq);
#endif
	nfs_node_clear_busy(np);
	return (result);
}

resolver_result_t
nfs_mirror_mount_trigger_rearm(
	vnode_t vp,
	__unused int flags,
	__unused void *data,
	vfs_context_t ctx)
{
	nfsnode_t np = VTONFS(vp);
	int error;
	resolver_result_t result;

	if ((error = nfs_node_set_busy(np, vfs_context_thread(ctx)))) {
		result = vfs_resolver_result(np->n_trigseq, RESOLVER_ERROR, error);
#ifdef NFS_TRIGGER_DEBUG
		NP(np, "nfs trigger REARM: busy error %d, seq %d", error, np->n_trigseq);
#endif
		return (result);
	}

	np->n_trigseq++;
	result = vfs_resolver_result(np->n_trigseq,
			vnode_mountedhere(vp) ? RESOLVER_RESOLVED : RESOLVER_UNRESOLVED, 0);
#ifdef NFS_TRIGGER_DEBUG
	NP(np, "nfs trigger REARM: %s, seq %d",
		vnode_mountedhere(vp) ? "resolved" : "unresolved", np->n_trigseq);
#endif
	nfs_node_clear_busy(np);
	return (result);
}

/*
 * Periodically attempt to unmount ephemeral (mirror) mounts in an attempt to limit
 * the number of unused mounts.
 */

#define NFS_EPHEMERAL_MOUNT_HARVEST_INTERVAL	120	/* how often the harvester runs */
struct nfs_ephemeral_mount_harvester_info {
	fsid_t		fsid;		/* FSID that we need to try to unmount */
	uint32_t	mountcount;	/* count of ephemeral mounts seen in scan */
 };
/* various globals for the harvester */
static thread_call_t nfs_ephemeral_mount_harvester_timer = NULL;
static int nfs_ephemeral_mount_harvester_on = 0;

kern_return_t thread_terminate(thread_t);

static int
nfs_ephemeral_mount_harvester_callback(mount_t mp, void *arg)
{
	struct nfs_ephemeral_mount_harvester_info *hinfo = arg;
	struct nfsmount *nmp;
	struct timeval now;

	if (strcmp(mp->mnt_vfsstat.f_fstypename, "nfs"))
		return (VFS_RETURNED);
	nmp = VFSTONFS(mp);
	if (!nmp || !NMFLAG(nmp, EPHEMERAL))
		return (VFS_RETURNED);
	hinfo->mountcount++;

	/* avoid unmounting mounts that have been triggered within the last harvest interval */
	microtime(&now);
	if ((nmp->nm_mounttime >> 32) > ((uint32_t)now.tv_sec - NFS_EPHEMERAL_MOUNT_HARVEST_INTERVAL))
		return (VFS_RETURNED);

	if (hinfo->fsid.val[0] || hinfo->fsid.val[1]) {
		/* attempt to unmount previously-found ephemeral mount */
		vfs_unmountbyfsid(&hinfo->fsid, 0, vfs_context_kernel());
		hinfo->fsid.val[0] = hinfo->fsid.val[1] = 0;
	}

	/*
	 * We can't call unmount here since we hold a mount iter ref
	 * on mp so save its fsid for the next call iteration to unmount.
	 */
	hinfo->fsid.val[0] = mp->mnt_vfsstat.f_fsid.val[0];
	hinfo->fsid.val[1] = mp->mnt_vfsstat.f_fsid.val[1];

	return (VFS_RETURNED);
}

/*
 * Spawn a thread to do the ephemeral mount harvesting.
 */
static void
nfs_ephemeral_mount_harvester_timer_func(void)
{
	thread_t thd;

	if (kernel_thread_start(nfs_ephemeral_mount_harvester, NULL, &thd) == KERN_SUCCESS)
		thread_deallocate(thd);
}

/*
 * Iterate all mounts looking for NFS ephemeral mounts to try to unmount.
 */
void
nfs_ephemeral_mount_harvester(__unused void *arg, __unused wait_result_t wr)
{
	struct nfs_ephemeral_mount_harvester_info hinfo;
	uint64_t deadline;

	hinfo.mountcount = 0;
	hinfo.fsid.val[0] = hinfo.fsid.val[1] = 0;
	vfs_iterate(VFS_ITERATE_TAIL_FIRST, nfs_ephemeral_mount_harvester_callback, &hinfo);
	if (hinfo.fsid.val[0] || hinfo.fsid.val[1]) {
		/* attempt to unmount last found ephemeral mount */
		vfs_unmountbyfsid(&hinfo.fsid, 0, vfs_context_kernel());
	}

	lck_mtx_lock(nfs_global_mutex);
	if (!hinfo.mountcount) {
		/* no more ephemeral mounts - don't need timer */
		nfs_ephemeral_mount_harvester_on = 0;
	} else {
		/* re-arm the timer */
		clock_interval_to_deadline(NFS_EPHEMERAL_MOUNT_HARVEST_INTERVAL, NSEC_PER_SEC, &deadline);
		thread_call_enter_delayed(nfs_ephemeral_mount_harvester_timer, deadline);
		nfs_ephemeral_mount_harvester_on = 1;
	}
	lck_mtx_unlock(nfs_global_mutex);

	/* thread done */
	thread_terminate(current_thread());
}

/*
 * Make sure the NFS ephemeral mount harvester timer is running.
 */
void
nfs_ephemeral_mount_harvester_start(void)
{
	uint64_t deadline;

	lck_mtx_lock(nfs_global_mutex);
	if (nfs_ephemeral_mount_harvester_on) {
		lck_mtx_unlock(nfs_global_mutex);
		return;
	}
	if (nfs_ephemeral_mount_harvester_timer == NULL)
		nfs_ephemeral_mount_harvester_timer = thread_call_allocate((thread_call_func_t)nfs_ephemeral_mount_harvester_timer_func, NULL);
	clock_interval_to_deadline(NFS_EPHEMERAL_MOUNT_HARVEST_INTERVAL, NSEC_PER_SEC, &deadline);
	thread_call_enter_delayed(nfs_ephemeral_mount_harvester_timer, deadline);
	nfs_ephemeral_mount_harvester_on = 1;
	lck_mtx_unlock(nfs_global_mutex);
}

#endif

/*
 * Send a MOUNT protocol MOUNT request to the server to get the initial file handle (and security).
 */
int
nfs3_mount_rpc(struct nfsmount *nmp, struct sockaddr *sa, int sotype, int nfsvers, char *path, vfs_context_t ctx, int timeo, fhandle_t *fh, struct nfs_sec *sec)
{
	int error = 0, slen, mntproto;
	thread_t thd = vfs_context_thread(ctx);
	kauth_cred_t cred = vfs_context_ucred(ctx);
	uint64_t xid = 0;
	struct nfsm_chain nmreq, nmrep;
	mbuf_t mreq;
	uint32_t mntvers, mntport, val;
	struct sockaddr_storage ss;
	struct sockaddr *saddr = (struct sockaddr*)&ss;

	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	mntvers = (nfsvers == NFS_VER2) ? RPCMNT_VER1 : RPCMNT_VER3;
	mntproto = (NM_OMFLAG(nmp, MNTUDP) || (sotype == SOCK_DGRAM)) ? IPPROTO_UDP : IPPROTO_TCP;
	sec->count = 0;

	bcopy(sa, saddr, min(sizeof(ss), sa->sa_len));
	if (saddr->sa_family == AF_INET) {
		if (nmp->nm_mountport)
			((struct sockaddr_in*)saddr)->sin_port = htons(nmp->nm_mountport);
		mntport = ntohs(((struct sockaddr_in*)saddr)->sin_port);
	} else {
		if (nmp->nm_mountport)
			((struct sockaddr_in6*)saddr)->sin6_port = htons(nmp->nm_mountport);
		mntport = ntohs(((struct sockaddr_in6*)saddr)->sin6_port);
	}

	while (!mntport) {
		error = nfs_portmap_lookup(nmp, ctx, saddr, NULL, RPCPROG_MNT, mntvers, mntproto, timeo);
		nfsmout_if(error);
		if (saddr->sa_family == AF_INET)
			mntport = ntohs(((struct sockaddr_in*)saddr)->sin_port);
		else
			mntport = ntohs(((struct sockaddr_in6*)saddr)->sin6_port);
		if (!mntport) {
			/* if not found and TCP, then retry with UDP */
			if (mntproto == IPPROTO_UDP) {
				error = EPROGUNAVAIL;
				break;
			}
			mntproto = IPPROTO_UDP;
			bcopy(sa, saddr, min(sizeof(ss), sa->sa_len));
		}
	}
	nfsmout_if(error || !mntport);

	/* MOUNT protocol MOUNT request */
	slen = strlen(path);
	nfsm_chain_build_alloc_init(error, &nmreq, NFSX_UNSIGNED + nfsm_rndup(slen));
	nfsm_chain_add_name(error, &nmreq, path, slen, nmp);
	nfsm_chain_build_done(error, &nmreq);
	nfsmout_if(error);
	error = nfsm_rpchead2(nmp, (mntproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM,
			RPCPROG_MNT, mntvers, RPCMNT_MOUNT,
			RPCAUTH_SYS, cred, NULL, nmreq.nmc_mhead, &xid, &mreq);
	nfsmout_if(error);
	nmreq.nmc_mhead = NULL;
	error = nfs_aux_request(nmp, thd, saddr, NULL,
			((mntproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM),
			mreq, R_XID32(xid), 1, timeo, &nmrep);
	nfsmout_if(error);
	nfsm_chain_get_32(error, &nmrep, val);
	if (!error && val)
		error = val;
	nfsm_chain_get_fh(error, &nmrep, nfsvers, fh);
	if (!error && (nfsvers > NFS_VER2)) {
		sec->count = NX_MAX_SEC_FLAVORS;
		error = nfsm_chain_get_secinfo(&nmrep, &sec->flavors[0], &sec->count);
	}
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}


/*
 * Send a MOUNT protocol UNMOUNT request to tell the server we've unmounted it.
 */
void
nfs3_umount_rpc(struct nfsmount *nmp, vfs_context_t ctx, int timeo)
{
	int error = 0, slen, mntproto;
	thread_t thd = vfs_context_thread(ctx);
	kauth_cred_t cred = vfs_context_ucred(ctx);
	char *path;
	uint64_t xid = 0;
	struct nfsm_chain nmreq, nmrep;
	mbuf_t mreq;
	uint32_t mntvers, mntport;
	struct sockaddr_storage ss;
	struct sockaddr *saddr = (struct sockaddr*)&ss;

	if (!nmp->nm_saddr)
		return;

	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	mntvers = (nmp->nm_vers == NFS_VER2) ? RPCMNT_VER1 : RPCMNT_VER3;
	mntproto = (NM_OMFLAG(nmp, MNTUDP) || (nmp->nm_sotype == SOCK_DGRAM)) ? IPPROTO_UDP : IPPROTO_TCP;
	mntport = nmp->nm_mountport;

	bcopy(nmp->nm_saddr, saddr, min(sizeof(ss), nmp->nm_saddr->sa_len));
	if (saddr->sa_family == AF_INET)
		((struct sockaddr_in*)saddr)->sin_port = htons(mntport);
	else
		((struct sockaddr_in6*)saddr)->sin6_port = htons(mntport);

	while (!mntport) {
		error = nfs_portmap_lookup(nmp, ctx, saddr, NULL, RPCPROG_MNT, mntvers, mntproto, timeo);
  		nfsmout_if(error);
		if (saddr->sa_family == AF_INET)
			mntport = ntohs(((struct sockaddr_in*)saddr)->sin_port);
		else
			mntport = ntohs(((struct sockaddr_in6*)saddr)->sin6_port);
		/* if not found and mntvers > VER1, then retry with VER1 */
		if (!mntport) {
			if (mntvers > RPCMNT_VER1) {
				mntvers = RPCMNT_VER1;
			} else if (mntproto == IPPROTO_TCP) {
				mntproto = IPPROTO_UDP;
				mntvers = (nmp->nm_vers == NFS_VER2) ? RPCMNT_VER1 : RPCMNT_VER3;
			} else {
				break;
			}
			bcopy(nmp->nm_saddr, saddr, min(sizeof(ss), nmp->nm_saddr->sa_len));
		}
	}
	nfsmout_if(!mntport);

	/* MOUNT protocol UNMOUNT request */
	path = &vfs_statfs(nmp->nm_mountp)->f_mntfromname[0];
	while (*path && (*path != '/'))
		path++;
	slen = strlen(path);
	nfsm_chain_build_alloc_init(error, &nmreq, NFSX_UNSIGNED + nfsm_rndup(slen));
	nfsm_chain_add_name(error, &nmreq, path, slen, nmp);
	nfsm_chain_build_done(error, &nmreq);
	nfsmout_if(error);
	error = nfsm_rpchead2(nmp, (mntproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM,
			RPCPROG_MNT, RPCMNT_VER1, RPCMNT_UMOUNT,
			RPCAUTH_SYS, cred, NULL, nmreq.nmc_mhead, &xid, &mreq);
	nfsmout_if(error);
	nmreq.nmc_mhead = NULL;
	error = nfs_aux_request(nmp, thd, saddr, NULL,
		((mntproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM),
		mreq, R_XID32(xid), 1, timeo, &nmrep);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
}

/*
 * unmount system call
 */
int
nfs_vfs_unmount(
	mount_t mp,
	int mntflags,
	__unused vfs_context_t ctx)
{
	struct nfsmount *nmp;
	vnode_t vp;
	int error, flags = 0;
	struct timespec ts = { 1, 0 };

	nmp = VFSTONFS(mp);
	lck_mtx_lock(&nmp->nm_lock);
	/*
	 * Set the flag indicating that an unmount attempt is in progress.
	 */
	nmp->nm_state |= NFSSTA_UNMOUNTING;
	/*
	 * 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;
		NFS_BITMAP_SET(nmp->nm_flags, NFS_MFLAG_SOFT);
	}
	/*
	 * Wait for any in-progress monitored node scan to complete.
	 */
	while (nmp->nm_state & NFSSTA_MONITOR_SCAN)
		msleep(&nmp->nm_state, &nmp->nm_lock, PZERO-1, "nfswaitmonscan", &ts);
	/*
	 * 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.
	 * - Clean up the NFS mount structure.
	 */
	vp = NFSTOV(nmp->nm_dnp);
	lck_mtx_unlock(&nmp->nm_lock);

	/*
	 * 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))
			error = EBUSY;
		else
			error = vflush(mp, vp, flags);
	}
	if (error) {
		lck_mtx_lock(&nmp->nm_lock);
		nmp->nm_state &= ~NFSSTA_UNMOUNTING;
		lck_mtx_unlock(&nmp->nm_lock);
		return (error);
	}

	lck_mtx_lock(&nmp->nm_lock);
	nmp->nm_dnp = NULL;
	lck_mtx_unlock(&nmp->nm_lock);

	/*
	 * Release the root vnode reference held by mountnfs()
	 */
	error = vnode_get(vp);
	vnode_rele(vp);
	if (!error)
		vnode_put(vp);

	vflush(mp, NULLVP, FORCECLOSE);

	/* Wait for all other references to be released and free the mount */
	nfs_mount_drain_and_cleanup(nmp);
	
	return (0);
}

/*
 * cleanup/destroy NFS fs locations structure
 */
void
nfs_fs_locations_cleanup(struct nfs_fs_locations *nfslsp)
{
	struct nfs_fs_location *fsl;
	struct nfs_fs_server *fss;
	struct nfs_fs_path *fsp;
	uint32_t loc, serv, addr, comp;

	/* free up fs locations */
	if (!nfslsp->nl_numlocs || !nfslsp->nl_locations)
		return;

	for (loc = 0; loc < nfslsp->nl_numlocs; loc++) {
		fsl = nfslsp->nl_locations[loc];
		if (!fsl)
			continue;
		if ((fsl->nl_servcount > 0) && fsl->nl_servers) {
			for (serv = 0; serv < fsl->nl_servcount; serv++) {
				fss = fsl->nl_servers[serv];
				if (!fss)
					continue;
				if ((fss->ns_addrcount > 0) && fss->ns_addresses) {
					for (addr = 0; addr < fss->ns_addrcount; addr++)
						FREE(fss->ns_addresses[addr], M_TEMP);
					FREE(fss->ns_addresses, M_TEMP);
				}
				FREE(fss->ns_name, M_TEMP);
				FREE(fss, M_TEMP);
			}
			FREE(fsl->nl_servers, M_TEMP);
		}
		fsp = &fsl->nl_path;
		if (fsp->np_compcount && fsp->np_components) {
			for (comp = 0; comp < fsp->np_compcount; comp++)
				if (fsp->np_components[comp])
					FREE(fsp->np_components[comp], M_TEMP);
			FREE(fsp->np_components, M_TEMP);
		}
		FREE(fsl, M_TEMP);
	}
	FREE(nfslsp->nl_locations, M_TEMP);
	nfslsp->nl_numlocs = 0;
	nfslsp->nl_locations = NULL;
}

void
nfs_mount_rele(struct nfsmount *nmp)
{
	int wup = 0;

	lck_mtx_lock(&nmp->nm_lock);
	if (nmp->nm_ref < 1)
		panic("nfs zombie mount underflow\n");
	nmp->nm_ref--;
	if (nmp->nm_ref == 0)
		wup = nmp->nm_state & NFSSTA_MOUNT_DRAIN;
	lck_mtx_unlock(&nmp->nm_lock);
	if (wup)
		wakeup(&nmp->nm_ref);
}

void
nfs_mount_drain_and_cleanup(struct nfsmount *nmp)
{
	lck_mtx_lock(&nmp->nm_lock);
	nmp->nm_state |= NFSSTA_MOUNT_DRAIN;
	while (nmp->nm_ref > 0) {
		msleep(&nmp->nm_ref, &nmp->nm_lock, PZERO-1, "nfs_mount_drain", NULL);
	}
	assert(nmp->nm_ref == 0);
	lck_mtx_unlock(&nmp->nm_lock);
	nfs_mount_cleanup(nmp);
}

/*
 * nfs_mount_zombie
 */
void
nfs_mount_zombie(struct nfsmount *nmp, int nm_state_flags)
{
	struct nfsreq *req, *treq;
	struct nfs_reqqhead iodq, resendq;
	struct timespec ts = { 1, 0 };
	struct nfs_open_owner *noop, *nextnoop;
	nfsnode_t np;
	int docallback;

	lck_mtx_lock(&nmp->nm_lock);
	nmp->nm_state |= nm_state_flags;
	nmp->nm_ref++;
	lck_mtx_unlock(&nmp->nm_lock);
	
	/* stop callbacks */
	if ((nmp->nm_vers >= NFS_VER4) && !NMFLAG(nmp, NOCALLBACK) && nmp->nm_cbid)
		nfs4_mount_callback_shutdown(nmp);

	/* Destroy any RPCSEC_GSS contexts */
	nfs_gss_clnt_ctx_unmount(nmp);

	/* mark the socket for termination */
	lck_mtx_lock(&nmp->nm_lock);
	nmp->nm_sockflags |= NMSOCK_UNMOUNT;

	/* Have the socket thread send the unmount RPC, if requested/appropriate. */
	if ((nmp->nm_vers < NFS_VER4) && (nmp->nm_state & NFSSTA_MOUNTED) &&
	    !(nmp->nm_state & (NFSSTA_FORCE|NFSSTA_DEAD)) && NMFLAG(nmp, CALLUMNT))
		nfs_mount_sock_thread_wake(nmp);

	/* wait for the socket thread to terminate */
	while (nmp->nm_sockthd && current_thread() != nmp->nm_sockthd) {
		wakeup(&nmp->nm_sockthd);
		msleep(&nmp->nm_sockthd, &nmp->nm_lock, PZERO-1, "nfswaitsockthd", &ts);
	}
	lck_mtx_unlock(&nmp->nm_lock);

	/* tear down the socket */
	nfs_disconnect(nmp);

	lck_mtx_lock(&nmp->nm_lock);

	if ((nmp->nm_vers >= NFS_VER4) && !NMFLAG(nmp, NOCALLBACK) && nmp->nm_cbid) {
		/* clear out any pending delegation return requests */
		while ((np = TAILQ_FIRST(&nmp->nm_dreturnq))) {
			TAILQ_REMOVE(&nmp->nm_dreturnq, np, n_dreturn);
			np->n_dreturn.tqe_next = NFSNOLIST;
		}
	}

	/* cancel any renew timer */
	if ((nmp->nm_vers >= NFS_VER4) && nmp->nm_renew_timer) {
		thread_call_cancel(nmp->nm_renew_timer);
		thread_call_free(nmp->nm_renew_timer);
	}

	lck_mtx_unlock(&nmp->nm_lock);

	if (nmp->nm_state & NFSSTA_MOUNTED)
		switch (nmp->nm_lockmode) {
		case NFS_LOCK_MODE_DISABLED:
		case NFS_LOCK_MODE_LOCAL:
			break;
		case NFS_LOCK_MODE_ENABLED:
		default:
			if (nmp->nm_vers <= NFS_VER3) {
				nfs_lockd_mount_unregister(nmp);
				nmp->nm_lockmode = NFS_LOCK_MODE_DISABLED;
			}
			break;
		}

	if ((nmp->nm_vers >= NFS_VER4) && nmp->nm_longid) {
		/* remove/deallocate the client ID data */
		lck_mtx_lock(nfs_global_mutex);
		TAILQ_REMOVE(&nfsclientids, nmp->nm_longid, nci_link);
		if (nmp->nm_longid->nci_id)
			FREE(nmp->nm_longid->nci_id, M_TEMP);
		FREE(nmp->nm_longid, M_TEMP);
		lck_mtx_unlock(nfs_global_mutex);
	}

	/*
	 * Be sure all requests for this mount are completed
	 * and removed from the resend queue.
	 */
	TAILQ_INIT(&resendq);
	lck_mtx_lock(nfs_request_mutex);
	TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
		if (req->r_nmp == nmp) {
			lck_mtx_lock(&req->r_mtx);
			if (!req->r_error && req->r_nmrep.nmc_mhead == NULL)
				req->r_error = EIO;
			if (req->r_flags & R_RESENDQ) {
				lck_mtx_lock(&nmp->nm_lock);
				req->r_flags &= ~R_RESENDQ;
				if (req->r_rchain.tqe_next != NFSREQNOLIST) {
					TAILQ_REMOVE(&nmp->nm_resendq, req, r_rchain);
					/*
					 * Queue up the request so that we can unreference them 
					 * with out holding nfs_request_mutex
					 */
					TAILQ_INSERT_TAIL(&resendq, req, r_rchain);
				}
				lck_mtx_unlock(&nmp->nm_lock);
			}
			wakeup(req);
			lck_mtx_unlock(&req->r_mtx);
		}
	}
	lck_mtx_unlock(nfs_request_mutex);

	/* Since we've drop the request mutex we can now safely unreference the request */
	TAILQ_FOREACH_SAFE(req, &resendq, r_rchain, treq) {
		TAILQ_REMOVE(&resendq, req, r_rchain);
		nfs_request_rele(req);
	}

	/*
	 * Now handle and outstanding async requests. We need to walk the
	 * request queue again this time with the nfsiod_mutex held. No
	 * other iods can grab our requests until we've put them on our own
	 * local iod queue for processing.
	 */
	TAILQ_INIT(&iodq);
	lck_mtx_lock(nfs_request_mutex);
	lck_mtx_lock(nfsiod_mutex);
	TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
		if (req->r_nmp == nmp) {
			lck_mtx_lock(&req->r_mtx);
			if (req->r_callback.rcb_func
			    && !(req->r_flags & R_WAITSENT) && !(req->r_flags & R_IOD)) {
				/* 
				 * Since R_IOD is not set then we need to handle it. If
				 * we're not on a list add it to our iod queue. Otherwise
				 * we must already be on nm_iodq which is added to our
				 * local queue below.
				 * %%% We should really keep a back pointer to our iod queue
				 * that we're on.
				 */
				req->r_flags |= R_IOD;
				if (req->r_achain.tqe_next == NFSREQNOLIST) {
					TAILQ_INSERT_TAIL(&iodq, req, r_achain);
				}
			}
			lck_mtx_unlock(&req->r_mtx);
		}
	}

	/* finish any async I/O RPCs queued up */
	if (nmp->nm_iodlink.tqe_next != NFSNOLIST)
		TAILQ_REMOVE(&nfsiodmounts, nmp, nm_iodlink);
	TAILQ_CONCAT(&iodq, &nmp->nm_iodq, r_achain);
	lck_mtx_unlock(nfsiod_mutex);
	lck_mtx_unlock(nfs_request_mutex);

	TAILQ_FOREACH_SAFE(req, &iodq, r_achain, treq) {
		TAILQ_REMOVE(&iodq, req, r_achain);
		req->r_achain.tqe_next = NFSREQNOLIST;
		lck_mtx_lock(&req->r_mtx);
		docallback = !(req->r_flags & R_WAITSENT);
		lck_mtx_unlock(&req->r_mtx);
		if (docallback)
			req->r_callback.rcb_func(req);
	}

	/* clean up common state */
	lck_mtx_lock(&nmp->nm_lock);
 	while ((np = LIST_FIRST(&nmp->nm_monlist))) {
 		LIST_REMOVE(np, n_monlink);
 		np->n_monlink.le_next = NFSNOLIST;
 	}
	TAILQ_FOREACH_SAFE(noop, &nmp->nm_open_owners, noo_link, nextnoop) {
		TAILQ_REMOVE(&nmp->nm_open_owners, noop, noo_link);
		noop->noo_flags &= ~NFS_OPEN_OWNER_LINK;
		if (noop->noo_refcnt)
			continue;
		nfs_open_owner_destroy(noop);
	}
	lck_mtx_unlock(&nmp->nm_lock);

	/* clean up NFSv4 state */
	if (nmp->nm_vers >= NFS_VER4) {
		lck_mtx_lock(&nmp->nm_lock);
		while ((np = TAILQ_FIRST(&nmp->nm_delegations))) {
			TAILQ_REMOVE(&nmp->nm_delegations, np, n_dlink);
			np->n_dlink.tqe_next = NFSNOLIST;
		}
		lck_mtx_unlock(&nmp->nm_lock);
	}

	nfs_mount_rele(nmp);
}

/*
 * cleanup/destroy an nfsmount
 */
void
nfs_mount_cleanup(struct nfsmount *nmp)
{
	if (!nmp)
		return;

	nfs_mount_zombie(nmp, 0);

	NFS_VFS_DBG("Unmounting %s from %s\n",
		    vfs_statfs(nmp->nm_mountp)->f_mntfromname,
		    vfs_statfs(nmp->nm_mountp)->f_mntonname);
	NFS_VFS_DBG("nfs state = %x\n", nmp->nm_state);
	NFS_VFS_DBG("nfs socket flags = %x\n", nmp->nm_sockflags);
	NFS_VFS_DBG("nfs mount ref count is %d\n", nmp->nm_ref);
	NFS_VFS_DBG("mount ref count is %d\n", nmp->nm_mountp->mnt_count);
	
	if (nmp->nm_mountp)
		vfs_setfsprivate(nmp->nm_mountp, NULL);

	lck_mtx_lock(&nmp->nm_lock);
	if (nmp->nm_ref)
		panic("Some one has grabbed a ref %d\n", nmp->nm_ref);

	if (nmp->nm_saddr)
		FREE(nmp->nm_saddr, M_SONAME);
	if ((nmp->nm_vers < NFS_VER4) && nmp->nm_rqsaddr)
		FREE(nmp->nm_rqsaddr, M_SONAME);

	if (IS_VALID_CRED(nmp->nm_mcred))
		kauth_cred_unref(&nmp->nm_mcred);

	nfs_fs_locations_cleanup(&nmp->nm_locations);

	if (nmp->nm_realm)
		FREE(nmp->nm_realm, M_TEMP);
	if (nmp->nm_principal)
		FREE(nmp->nm_principal, M_TEMP);
	if (nmp->nm_sprinc)
		FREE(nmp->nm_sprinc, M_TEMP);
	
	if (nmp->nm_args)
		xb_free(nmp->nm_args);

	lck_mtx_unlock(&nmp->nm_lock);
	
	lck_mtx_destroy(&nmp->nm_lock, nfs_mount_grp);
	if (nmp->nm_fh)
		FREE(nmp->nm_fh, M_TEMP);
	FREE_ZONE((caddr_t)nmp, sizeof (struct nfsmount), M_NFSMNT);
}

/*
 * Return root of a filesystem
 */
int
nfs_vfs_root(mount_t mp, vnode_t *vpp, __unused vfs_context_t ctx)
{
	vnode_t vp;
	struct nfsmount *nmp;
	int error;
	u_int32_t vpid;

	nmp = VFSTONFS(mp);
	if (!nmp || !nmp->nm_dnp)
		return (ENXIO);
	vp = NFSTOV(nmp->nm_dnp);
	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);
}

/*
 * Do operations associated with quotas
 */
#if !QUOTA
int
nfs_vfs_quotactl(
	__unused mount_t mp,
	__unused int cmds,
	__unused uid_t uid,
	__unused caddr_t datap,
	__unused vfs_context_t context)
{
	return (ENOTSUP);
}
#else

int
nfs3_getquota(struct nfsmount *nmp, vfs_context_t ctx, uid_t id, int type, struct dqblk *dqb)
{
	int error = 0, slen, timeo;
	int rqport = 0, rqproto, rqvers = (type == GRPQUOTA) ? RPCRQUOTA_EXT_VER : RPCRQUOTA_VER;
	thread_t thd = vfs_context_thread(ctx);
	kauth_cred_t cred = vfs_context_ucred(ctx);
	char *path;
	uint64_t xid = 0;
	struct nfsm_chain nmreq, nmrep;
	mbuf_t mreq;
	uint32_t val = 0, bsize = 0;
	struct sockaddr *rqsaddr;
	struct timeval now;

	if (!nmp->nm_saddr)
		return (ENXIO);

	if (NMFLAG(nmp, NOQUOTA))
		return (ENOTSUP);

	if (!nmp->nm_rqsaddr)
		MALLOC(nmp->nm_rqsaddr, struct sockaddr *, sizeof(struct sockaddr_storage), M_SONAME, M_WAITOK|M_ZERO);
	if (!nmp->nm_rqsaddr)
		return (ENOMEM);
	rqsaddr = nmp->nm_rqsaddr;
	if (rqsaddr->sa_family == AF_INET6)
		rqport = ntohs(((struct sockaddr_in6*)rqsaddr)->sin6_port);
	else if (rqsaddr->sa_family == AF_INET)
		rqport = ntohs(((struct sockaddr_in*)rqsaddr)->sin_port);

	timeo = NMFLAG(nmp, SOFT) ? 10 : 60;
	rqproto = IPPROTO_UDP; /* XXX should prefer TCP if mount is TCP */

	/* check if we have a recently cached rquota port */
	microuptime(&now);
	if (!rqport || ((nmp->nm_rqsaddrstamp + 60) >= (uint32_t)now.tv_sec)) {
		/* send portmap request to get rquota port */
		bcopy(nmp->nm_saddr, rqsaddr, min(sizeof(struct sockaddr_storage), nmp->nm_saddr->sa_len));
		error = nfs_portmap_lookup(nmp, ctx, rqsaddr, NULL, RPCPROG_RQUOTA, rqvers, rqproto, timeo);
		if (error)
			return (error);
		if (rqsaddr->sa_family == AF_INET6)
			rqport = ntohs(((struct sockaddr_in6*)rqsaddr)->sin6_port);
		else if (rqsaddr->sa_family == AF_INET)
			rqport = ntohs(((struct sockaddr_in*)rqsaddr)->sin_port);
		else
			return (EIO);
		if (!rqport)
			return (ENOTSUP);
		microuptime(&now);
		nmp->nm_rqsaddrstamp = now.tv_sec;
	}

	/* rquota request */
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);
	path = &vfs_statfs(nmp->nm_mountp)->f_mntfromname[0];
	while (*path && (*path != '/'))
		path++;
	slen = strlen(path);
	nfsm_chain_build_alloc_init(error, &nmreq, 3 * NFSX_UNSIGNED + nfsm_rndup(slen));
	nfsm_chain_add_name(error, &nmreq, path, slen, nmp);
	if (type == GRPQUOTA)
		nfsm_chain_add_32(error, &nmreq, type);
	nfsm_chain_add_32(error, &nmreq, id);
	nfsm_chain_build_done(error, &nmreq);
	nfsmout_if(error);
	error = nfsm_rpchead2(nmp, (rqproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM,
			RPCPROG_RQUOTA, rqvers, RPCRQUOTA_GET,
			RPCAUTH_SYS, cred, NULL, nmreq.nmc_mhead, &xid, &mreq);
	nfsmout_if(error);
	nmreq.nmc_mhead = NULL;
	error = nfs_aux_request(nmp, thd, rqsaddr, NULL,
			(rqproto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM,
			mreq, R_XID32(xid), 0, timeo, &nmrep);
	nfsmout_if(error);

	/* parse rquota response */
	nfsm_chain_get_32(error, &nmrep, val);
	if (!error && (val != RQUOTA_STAT_OK)) {
		if (val == RQUOTA_STAT_NOQUOTA)
			error = ENOENT;
		else if (val == RQUOTA_STAT_EPERM)
			error = EPERM;
		else
			error = EIO;
	}
	nfsm_chain_get_32(error, &nmrep, bsize);
	nfsm_chain_adv(error, &nmrep, NFSX_UNSIGNED);
	nfsm_chain_get_32(error, &nmrep, val);
	nfsmout_if(error);
	dqb->dqb_bhardlimit = (uint64_t)val * bsize;
	nfsm_chain_get_32(error, &nmrep, val);
	nfsmout_if(error);
	dqb->dqb_bsoftlimit = (uint64_t)val * bsize;
	nfsm_chain_get_32(error, &nmrep, val);
	nfsmout_if(error);
	dqb->dqb_curbytes = (uint64_t)val * bsize;
	nfsm_chain_get_32(error, &nmrep, dqb->dqb_ihardlimit);
	nfsm_chain_get_32(error, &nmrep, dqb->dqb_isoftlimit);
	nfsm_chain_get_32(error, &nmrep, dqb->dqb_curinodes);
	nfsm_chain_get_32(error, &nmrep, dqb->dqb_btime);
	nfsm_chain_get_32(error, &nmrep, dqb->dqb_itime);
	nfsmout_if(error);
	dqb->dqb_id = id;
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_getquota(struct nfsmount *nmp, vfs_context_t ctx, uid_t id, int type, struct dqblk *dqb)
{
	nfsnode_t np;
	int error = 0, status, nfsvers, numops;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	thread_t thd = vfs_context_thread(ctx);
	kauth_cred_t cred = vfs_context_ucred(ctx);
	struct nfsreq_secinfo_args si;

	if (type != USRQUOTA)  /* NFSv4 only supports user quotas */
		return (ENOTSUP);

	/* first check that the server supports any of the quota attributes */
	if (!NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_AVAIL_HARD) &&
	    !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_AVAIL_SOFT) &&
	    !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_USED))
		return (ENOTSUP);

	/*
	 * The credential passed to the server needs to have
	 * an effective uid that matches the given uid.
	 */
	if (id != kauth_cred_getuid(cred)) {
		struct posix_cred temp_pcred;
		posix_cred_t pcred = posix_cred_get(cred);
		bzero(&temp_pcred, sizeof(temp_pcred));
		temp_pcred.cr_uid = id;
		temp_pcred.cr_ngroups = pcred->cr_ngroups;
		bcopy(pcred->cr_groups, temp_pcred.cr_groups, sizeof(temp_pcred.cr_groups));
		cred = posix_cred_create(&temp_pcred);
		if (!IS_VALID_CRED(cred))
			return (ENOMEM);
	} else {
		kauth_cred_ref(cred);
	}

	nfsvers = nmp->nm_vers;
	np = nmp->nm_dnp;
	if (!np)
		error = ENXIO;
	if (error || ((error = vnode_get(NFSTOV(np))))) {
		kauth_cred_unref(&cred);
		return(error);
	}

	NFSREQ_SECINFO_SET(&si, np, NULL, 0, NULL, 0);
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	// PUTFH + GETATTR
	numops = 2;
	nfsm_chain_build_alloc_init(error, &nmreq, 15 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "quota", nmp->nm_minor_vers, numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_CLEAR_ATTRIBUTES(bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_QUOTA_AVAIL_HARD);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_QUOTA_AVAIL_SOFT);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_QUOTA_USED);
	nfsm_chain_add_bitmap_supported(error, &nmreq, bitmap, nmp, NULL);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request2(np, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, 0, &nmrep, &xid, &status);
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_assert(error, NFSTONMP(np), ENXIO);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, NULL, NULL, dqb, NULL);
	nfsmout_if(error);
	nfsm_assert(error, NFSTONMP(np), ENXIO);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	vnode_put(NFSTOV(np));
	kauth_cred_unref(&cred);
	return (error);
}

int
nfs_vfs_quotactl(mount_t mp, int cmds, uid_t uid, caddr_t datap, vfs_context_t ctx)
{
	struct nfsmount *nmp;
	int cmd, type, error, nfsvers;
	uid_t euid = kauth_cred_getuid(vfs_context_ucred(ctx));
	struct dqblk *dqb = (struct dqblk*)datap;

	nmp = VFSTONFS(mp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	if (uid == ~0U)
		uid = euid;

	/* we can only support Q_GETQUOTA */
	cmd = cmds >> SUBCMDSHIFT;
	switch (cmd) {
	case Q_GETQUOTA:
		break;
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETQUOTA:
	case Q_SETUSE:
	case Q_SYNC:
	case Q_QUOTASTAT:
		return (ENOTSUP);
	default:
		return (EINVAL);
	}

	type = cmds & SUBCMDMASK;
	if ((u_int)type >= MAXQUOTAS)
		return (EINVAL);
	if ((uid != euid) && ((error = vfs_context_suser(ctx))))
		return (error);

	if (vfs_busy(mp, LK_NOWAIT))
		return (0);
	bzero(dqb, sizeof(*dqb));
	error = nmp->nm_funcs->nf_getquota(nmp, ctx, uid, type, dqb);
	vfs_unbusy(mp);
	return (error);
}
#endif

/*
 * Flush out the buffer cache
 */
int nfs_sync_callout(vnode_t, void *);

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

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

	if (np->n_flag & NREVOKE) {
		vn_revoke(vp, REVOKEALL, cargs->ctx);
		return (VNODE_RETURNED);
	}

	if (LIST_EMPTY(&np->n_dirtyblkhd))
		return (VNODE_RETURNED);
	if (np->n_wrbusy > 0)
		return (VNODE_RETURNED);
	if (np->n_bflag & (NBFLUSHINPROG|NBINVALINPROG))
		return (VNODE_RETURNED);

	error = nfs_flush(np, cargs->waitfor, vfs_context_thread(cargs->ctx), 0);
	if (error)
		cargs->error = error;

	return (VNODE_RETURNED);
}

int
nfs_vfs_sync(mount_t mp, int waitfor, vfs_context_t ctx)
{
	struct nfs_sync_cargs cargs;

	cargs.waitfor = waitfor;
	cargs.ctx = ctx;
	cargs.error = 0;

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

	return (cargs.error);
}

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

	return (ENOTSUP);
}

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

	return (ENOTSUP);
}

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

	return (ENOTSUP);
}

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

	return (0);
}

/*
 * Build the mount info buffer for NFS_MOUNTINFO.
 */
int
nfs_mountinfo_assemble(struct nfsmount *nmp, struct xdrbuf *xb)
{
	struct xdrbuf xbinfo, xborig;
	char sotype[6];
	uint32_t origargsvers, origargslength;
	uint32_t infolength_offset, curargsopaquelength_offset, curargslength_offset, attrslength_offset, curargs_end_offset, end_offset;
	uint32_t miattrs[NFS_MIATTR_BITMAP_LEN];
	uint32_t miflags_mask[NFS_MIFLAG_BITMAP_LEN];
	uint32_t miflags[NFS_MIFLAG_BITMAP_LEN];
	uint32_t mattrs[NFS_MATTR_BITMAP_LEN];
	uint32_t mflags_mask[NFS_MFLAG_BITMAP_LEN];
	uint32_t mflags[NFS_MFLAG_BITMAP_LEN];
	uint32_t loc, serv, addr, comp;
	int i, timeo, error = 0;

	/* set up mount info attr and flag bitmaps */
	NFS_BITMAP_ZERO(miattrs, NFS_MIATTR_BITMAP_LEN);
	NFS_BITMAP_SET(miattrs, NFS_MIATTR_FLAGS);
	NFS_BITMAP_SET(miattrs, NFS_MIATTR_ORIG_ARGS);
	NFS_BITMAP_SET(miattrs, NFS_MIATTR_CUR_ARGS);
	NFS_BITMAP_SET(miattrs, NFS_MIATTR_CUR_LOC_INDEX);
	NFS_BITMAP_ZERO(miflags_mask, NFS_MIFLAG_BITMAP_LEN);
	NFS_BITMAP_ZERO(miflags, NFS_MIFLAG_BITMAP_LEN);
	NFS_BITMAP_SET(miflags_mask, NFS_MIFLAG_DEAD);
	NFS_BITMAP_SET(miflags_mask, NFS_MIFLAG_NOTRESP);
	NFS_BITMAP_SET(miflags_mask, NFS_MIFLAG_RECOVERY);
	if (nmp->nm_state & NFSSTA_DEAD)
		NFS_BITMAP_SET(miflags, NFS_MIFLAG_DEAD);
	if ((nmp->nm_state & (NFSSTA_TIMEO|NFSSTA_JUKEBOXTIMEO)) ||
	    ((nmp->nm_state & NFSSTA_LOCKTIMEO) && (nmp->nm_lockmode == NFS_LOCK_MODE_ENABLED)))
		NFS_BITMAP_SET(miflags, NFS_MIFLAG_NOTRESP);
	if (nmp->nm_state & NFSSTA_RECOVER)
		NFS_BITMAP_SET(miflags, NFS_MIFLAG_RECOVERY);

	/* get original mount args length */
	xb_init_buffer(&xborig, nmp->nm_args, 2*XDRWORD);
	xb_get_32(error, &xborig, origargsvers); /* version */
	xb_get_32(error, &xborig, origargslength); /* args length */
	nfsmerr_if(error);

	/* set up current mount attributes bitmap */
	NFS_BITMAP_ZERO(mattrs, NFS_MATTR_BITMAP_LEN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FLAGS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_VERSION);
	if (nmp->nm_vers >= NFS_VER4)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_MINOR_VERSION);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_READ_SIZE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_WRITE_SIZE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_READDIR_SIZE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_READAHEAD);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_REG_MIN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_REG_MAX);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MIN);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_ATTRCACHE_DIR_MAX);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_LOCK_MODE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_SECURITY);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MAX_GROUP_LIST);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_SOCKET_TYPE);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_NFS_PORT);
	if ((nmp->nm_vers < NFS_VER4) && nmp->nm_mountport)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_MOUNT_PORT);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_REQUEST_TIMEOUT);
	if (NMFLAG(nmp, SOFT))
		NFS_BITMAP_SET(mattrs, NFS_MATTR_SOFT_RETRY_COUNT);
	if (nmp->nm_deadtimeout)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_DEAD_TIMEOUT);
	if (nmp->nm_fh)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_FH);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_FS_LOCATIONS);
	NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFLAGS);
	if (origargsvers < NFS_ARGSVERSION_XDR)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_MNTFROM);
	if (nmp->nm_realm)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_REALM);
	if (nmp->nm_principal)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_PRINCIPAL);
	if (nmp->nm_sprinc)
		NFS_BITMAP_SET(mattrs, NFS_MATTR_SVCPRINCIPAL);
	
	/* set up current mount flags bitmap */
	/* first set the flags that we will be setting - either on OR off */
	NFS_BITMAP_ZERO(mflags_mask, NFS_MFLAG_BITMAP_LEN);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_SOFT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_INTR);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RESVPORT);
	if (nmp->nm_sotype == SOCK_DGRAM)
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOCONNECT);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_DUMBTIMER);
	if (nmp->nm_vers < NFS_VER4)
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_CALLUMNT);
	if (nmp->nm_vers >= NFS_VER3)
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_RDIRPLUS);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NONEGNAMECACHE);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_MUTEJUKEBOX);
	if (nmp->nm_vers >= NFS_VER4) {
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_EPHEMERAL);
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOCALLBACK);
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NONAMEDATTR);
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOACL);
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_ACLONLY);
	}
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NFC);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_NOQUOTA);
	if (nmp->nm_vers < NFS_VER4)
		NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_MNTUDP);
	NFS_BITMAP_SET(mflags_mask, NFS_MFLAG_MNTQUICK);
	/* now set the flags that should be set */
	NFS_BITMAP_ZERO(mflags, NFS_MFLAG_BITMAP_LEN);
	if (NMFLAG(nmp, SOFT))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_SOFT);
	if (NMFLAG(nmp, INTR))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_INTR);
	if (NMFLAG(nmp, RESVPORT))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_RESVPORT);
	if ((nmp->nm_sotype == SOCK_DGRAM) && NMFLAG(nmp, NOCONNECT))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NOCONNECT);
	if (NMFLAG(nmp, DUMBTIMER))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_DUMBTIMER);
	if ((nmp->nm_vers < NFS_VER4) && NMFLAG(nmp, CALLUMNT))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_CALLUMNT);
	if ((nmp->nm_vers >= NFS_VER3) && NMFLAG(nmp, RDIRPLUS))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_RDIRPLUS);
	if (NMFLAG(nmp, NONEGNAMECACHE))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NONEGNAMECACHE);
	if (NMFLAG(nmp, MUTEJUKEBOX))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_MUTEJUKEBOX);
	if (nmp->nm_vers >= NFS_VER4) {
		if (NMFLAG(nmp, EPHEMERAL))
			NFS_BITMAP_SET(mflags, NFS_MFLAG_EPHEMERAL);
		if (NMFLAG(nmp, NOCALLBACK))
			NFS_BITMAP_SET(mflags, NFS_MFLAG_NOCALLBACK);
		if (NMFLAG(nmp, NONAMEDATTR))
			NFS_BITMAP_SET(mflags, NFS_MFLAG_NONAMEDATTR);
		if (NMFLAG(nmp, NOACL))
			NFS_BITMAP_SET(mflags, NFS_MFLAG_NOACL);
		if (NMFLAG(nmp, ACLONLY))
			NFS_BITMAP_SET(mflags, NFS_MFLAG_ACLONLY);
	}
	if (NMFLAG(nmp, NFC))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NFC);
	if (NMFLAG(nmp, NOQUOTA) || ((nmp->nm_vers >= NFS_VER4) &&
	    !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_AVAIL_HARD) &&
	    !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_AVAIL_SOFT) &&
	    !NFS_BITMAP_ISSET(nmp->nm_fsattr.nfsa_supp_attr, NFS_FATTR_QUOTA_USED)))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_NOQUOTA);
	if ((nmp->nm_vers < NFS_VER4) && NMFLAG(nmp, MNTUDP))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_MNTUDP);
	if (NMFLAG(nmp, MNTQUICK))
		NFS_BITMAP_SET(mflags, NFS_MFLAG_MNTQUICK);

	/* assemble info buffer: */
	xb_init_buffer(&xbinfo, NULL, 0);
	xb_add_32(error, &xbinfo, NFS_MOUNT_INFO_VERSION);
	infolength_offset = xb_offset(&xbinfo);
	xb_add_32(error, &xbinfo, 0);
	xb_add_bitmap(error, &xbinfo, miattrs, NFS_MIATTR_BITMAP_LEN);
	xb_add_bitmap(error, &xbinfo, miflags, NFS_MIFLAG_BITMAP_LEN);
	xb_add_32(error, &xbinfo, origargslength);
	if (!error)
		error = xb_add_bytes(&xbinfo, nmp->nm_args, origargslength, 0);

	/* the opaque byte count for the current mount args values: */
	curargsopaquelength_offset = xb_offset(&xbinfo);
	xb_add_32(error, &xbinfo, 0);

	/* Encode current mount args values */
	xb_add_32(error, &xbinfo, NFS_ARGSVERSION_XDR);
	curargslength_offset = xb_offset(&xbinfo);
	xb_add_32(error, &xbinfo, 0);
	xb_add_32(error, &xbinfo, NFS_XDRARGS_VERSION_0);
	xb_add_bitmap(error, &xbinfo, mattrs, NFS_MATTR_BITMAP_LEN);
	attrslength_offset = xb_offset(&xbinfo);
	xb_add_32(error, &xbinfo, 0);
	xb_add_bitmap(error, &xbinfo, mflags_mask, NFS_MFLAG_BITMAP_LEN);
	xb_add_bitmap(error, &xbinfo, mflags, NFS_MFLAG_BITMAP_LEN);
	xb_add_32(error, &xbinfo, nmp->nm_vers);		/* NFS_VERSION */
	if (nmp->nm_vers >= NFS_VER4)
		xb_add_32(error, &xbinfo, nmp->nm_minor_vers);	/* NFS_MINOR_VERSION */
	xb_add_32(error, &xbinfo, nmp->nm_rsize);		/* READ_SIZE */
	xb_add_32(error, &xbinfo, nmp->nm_wsize);		/* WRITE_SIZE */
	xb_add_32(error, &xbinfo, nmp->nm_readdirsize);		/* READDIR_SIZE */
	xb_add_32(error, &xbinfo, nmp->nm_readahead);		/* READAHEAD */
	xb_add_32(error, &xbinfo, nmp->nm_acregmin);		/* ATTRCACHE_REG_MIN */
	xb_add_32(error, &xbinfo, 0);				/* ATTRCACHE_REG_MIN */
	xb_add_32(error, &xbinfo, nmp->nm_acregmax);		/* ATTRCACHE_REG_MAX */
	xb_add_32(error, &xbinfo, 0);				/* ATTRCACHE_REG_MAX */
	xb_add_32(error, &xbinfo, nmp->nm_acdirmin);		/* ATTRCACHE_DIR_MIN */
	xb_add_32(error, &xbinfo, 0);				/* ATTRCACHE_DIR_MIN */
	xb_add_32(error, &xbinfo, nmp->nm_acdirmax);		/* ATTRCACHE_DIR_MAX */
	xb_add_32(error, &xbinfo, 0);				/* ATTRCACHE_DIR_MAX */
	xb_add_32(error, &xbinfo, nmp->nm_lockmode);		/* LOCK_MODE */
	if (nmp->nm_sec.count) {
		xb_add_32(error, &xbinfo, nmp->nm_sec.count);		/* SECURITY */
		nfsmerr_if(error);
		for (i=0; i < nmp->nm_sec.count; i++)
			xb_add_32(error, &xbinfo, nmp->nm_sec.flavors[i]);
	} else if (nmp->nm_servsec.count) {
		xb_add_32(error, &xbinfo, nmp->nm_servsec.count);	/* SECURITY */
		nfsmerr_if(error);
		for (i=0; i < nmp->nm_servsec.count; i++)
			xb_add_32(error, &xbinfo, nmp->nm_servsec.flavors[i]);
	} else {
		xb_add_32(error, &xbinfo, 1);				/* SECURITY */
		xb_add_32(error, &xbinfo, nmp->nm_auth);
	}
	xb_add_32(error, &xbinfo, nmp->nm_numgrps);		/* MAX_GROUP_LIST */
	nfsmerr_if(error);
	snprintf(sotype, sizeof(sotype), "%s%s", (nmp->nm_sotype == SOCK_DGRAM) ? "udp" : "tcp",
		nmp->nm_sofamily ? (nmp->nm_sofamily == AF_INET) ? "4" : "6" : "");
	xb_add_string(error, &xbinfo, sotype, strlen(sotype));	/* SOCKET_TYPE */
	xb_add_32(error, &xbinfo, ntohs(((struct sockaddr_in*)nmp->nm_saddr)->sin_port)); /* NFS_PORT */
	if ((nmp->nm_vers < NFS_VER4) && nmp->nm_mountport)
		xb_add_32(error, &xbinfo, nmp->nm_mountport);	/* MOUNT_PORT */
	timeo = (nmp->nm_timeo * 10) / NFS_HZ;
	xb_add_32(error, &xbinfo, timeo/10);			/* REQUEST_TIMEOUT */
	xb_add_32(error, &xbinfo, (timeo%10)*100000000);	/* REQUEST_TIMEOUT */
	if (NMFLAG(nmp, SOFT))
		xb_add_32(error, &xbinfo, nmp->nm_retry);	/* SOFT_RETRY_COUNT */
	if (nmp->nm_deadtimeout) {
		xb_add_32(error, &xbinfo, nmp->nm_deadtimeout);	/* DEAD_TIMEOUT */
		xb_add_32(error, &xbinfo, 0);			/* DEAD_TIMEOUT */
	}
	if (nmp->nm_fh)
		xb_add_fh(error, &xbinfo, &nmp->nm_fh->fh_data[0], nmp->nm_fh->fh_len); /* FH */
	xb_add_32(error, &xbinfo, nmp->nm_locations.nl_numlocs);			/* FS_LOCATIONS */
	for (loc = 0; !error && (loc < nmp->nm_locations.nl_numlocs); loc++) {
		xb_add_32(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_servcount);
		for (serv = 0; !error && (serv < nmp->nm_locations.nl_locations[loc]->nl_servcount); serv++) {
			xb_add_string(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_name,
				strlen(nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_name));
			xb_add_32(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_addrcount);
			for (addr = 0; !error && (addr < nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_addrcount); addr++)
				xb_add_string(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_addresses[addr],
					strlen(nmp->nm_locations.nl_locations[loc]->nl_servers[serv]->ns_addresses[addr]));
			xb_add_32(error, &xbinfo, 0); /* empty server info */
		}
		xb_add_32(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_path.np_compcount);
		for (comp = 0; !error && (comp < nmp->nm_locations.nl_locations[loc]->nl_path.np_compcount); comp++)
			xb_add_string(error, &xbinfo, nmp->nm_locations.nl_locations[loc]->nl_path.np_components[comp],
				strlen(nmp->nm_locations.nl_locations[loc]->nl_path.np_components[comp]));
		xb_add_32(error, &xbinfo, 0); /* empty fs location info */
	}
	xb_add_32(error, &xbinfo, vfs_flags(nmp->nm_mountp));		/* MNTFLAGS */
	if (origargsvers < NFS_ARGSVERSION_XDR)
		xb_add_string(error, &xbinfo, vfs_statfs(nmp->nm_mountp)->f_mntfromname,
			strlen(vfs_statfs(nmp->nm_mountp)->f_mntfromname));	/* MNTFROM */
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_REALM))
		xb_add_string(error, &xbinfo, nmp->nm_realm, strlen(nmp->nm_realm));
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_PRINCIPAL))
		xb_add_string(error, &xbinfo, nmp->nm_principal, strlen(nmp->nm_principal));
	if (NFS_BITMAP_ISSET(mattrs, NFS_MATTR_SVCPRINCIPAL))
		xb_add_string(error, &xbinfo, nmp->nm_sprinc, strlen(nmp->nm_sprinc));

	curargs_end_offset = xb_offset(&xbinfo);

	/* NFS_MIATTR_CUR_LOC_INDEX */
	xb_add_32(error, &xbinfo, nmp->nm_locations.nl_current.nli_flags);
	xb_add_32(error, &xbinfo, nmp->nm_locations.nl_current.nli_loc);
	xb_add_32(error, &xbinfo, nmp->nm_locations.nl_current.nli_serv);
	xb_add_32(error, &xbinfo, nmp->nm_locations.nl_current.nli_addr);

	xb_build_done(error, &xbinfo);

	/* update opaque counts */
	end_offset = xb_offset(&xbinfo);
	if (!error) {
		error = xb_seek(&xbinfo, attrslength_offset);
		xb_add_32(error, &xbinfo, curargs_end_offset - attrslength_offset - XDRWORD/*don't include length field*/);
	}
	if (!error) {
		error = xb_seek(&xbinfo, curargslength_offset);
		xb_add_32(error, &xbinfo, curargs_end_offset - curargslength_offset + XDRWORD/*version*/);
	}
	if (!error) {
		error = xb_seek(&xbinfo, curargsopaquelength_offset);
		xb_add_32(error, &xbinfo, curargs_end_offset - curargslength_offset + XDRWORD/*version*/);
	}
	if (!error) {
		error = xb_seek(&xbinfo, infolength_offset);
		xb_add_32(error, &xbinfo, end_offset - infolength_offset + XDRWORD/*version*/);
	}
	nfsmerr_if(error);

	/* copy result xdrbuf to caller */
	*xb = xbinfo;

	/* and mark the local copy as not needing cleanup */
	xbinfo.xb_flags &= ~XB_CLEANUP;
nfsmerr:
	xb_cleanup(&xbinfo);
	return (error);
}

/*
 * Do that sysctl thang...
 */
int
nfs_vfs_sysctl(int *name, u_int namelen, user_addr_t oldp, size_t *oldlenp,
           user_addr_t newp, size_t newlen, vfs_context_t ctx)
{
	int error = 0, val;
	int softnobrowse;
	struct sysctl_req *req = NULL;
	union union_vfsidctl vc;
	mount_t mp;
	struct nfsmount *nmp = NULL;
	struct vfsquery vq;
	struct nfsreq *rq;
	boolean_t is_64_bit;
	fsid_t fsid;
	struct xdrbuf xb;
	struct netfs_status *nsp = NULL;
	int timeoutmask;
	uint pos, totlen, count, numThreads;
#if NFSSERVER
	struct nfs_exportfs *nxfs;
	struct nfs_export *nx;
	struct nfs_active_user_list *ulist;
	struct nfs_export_stat_desc stat_desc;
	struct nfs_export_stat_rec statrec;
	struct nfs_user_stat_node *unode, *unode_next;
	struct nfs_user_stat_desc ustat_desc;
	struct nfs_user_stat_user_rec ustat_rec;
	struct nfs_user_stat_path_rec upath_rec;
	uint bytes_avail, bytes_total, recs_copied;
	uint numExports, numRecs;
#endif /* NFSSERVER */

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

	is_64_bit = vfs_context_is64bit(ctx);

	/* common code for "new style" VFS_CTL sysctl, get the mount. */
	switch (name[0]) {
	case VFS_CTL_TIMEO:
	case VFS_CTL_NOLOCKS:
	case VFS_CTL_NSTATUS:
	case VFS_CTL_QUERY:
		req = CAST_DOWN(struct sysctl_req *, oldp);
		if (req == NULL) {
			return EFAULT;
		}
		error = SYSCTL_IN(req, &vc, is_64_bit? sizeof(vc.vc64):sizeof(vc.vc32));
		if (error)
			return (error);
		mp = vfs_getvfs(&vc.vc32.vc_fsid); /* works for 32 and 64 */
		if (mp == NULL)
			return (ENOENT);
		nmp = VFSTONFS(mp);
		if (!nmp)
			return (ENOENT);
		bzero(&vq, sizeof(vq));
		req->newidx = 0;
		if (is_64_bit) {
			req->newptr = vc.vc64.vc_ptr;
			req->newlen = (size_t)vc.vc64.vc_len;
		} else {
			req->newptr = CAST_USER_ADDR_T(vc.vc32.vc_ptr);
			req->newlen = vc.vc32.vc_len;
		}
		break;
	}

	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 NFS_MOUNTINFO:
		/* read in the fsid */
		if (*oldlenp < sizeof(fsid))
			return (EINVAL);
		if ((error = copyin(oldp, &fsid, sizeof(fsid))))
			return (error);
		/* swizzle it back to host order */
		fsid.val[0] = ntohl(fsid.val[0]);
		fsid.val[1] = ntohl(fsid.val[1]);
		/* find mount and make sure it's NFS */
		if (((mp = vfs_getvfs(&fsid))) == NULL)
			return (ENOENT);
		if (strcmp(mp->mnt_vfsstat.f_fstypename, "nfs"))
			return (EINVAL);
		if (((nmp = VFSTONFS(mp))) == NULL)
			return (ENOENT);
		xb_init(&xb, 0);
		if ((error = nfs_mountinfo_assemble(nmp, &xb)))
			return (error);
		if (*oldlenp < xb.xb_u.xb_buffer.xbb_len)
			error = ENOMEM;
		else
			error = copyout(xb_buffer_base(&xb), oldp, xb.xb_u.xb_buffer.xbb_len);
		*oldlenp = xb.xb_u.xb_buffer.xbb_len;
		xb_cleanup(&xb);
		break;
#if NFSSERVER
	case NFS_EXPORTSTATS:
		/* setup export stat descriptor */
		stat_desc.rec_vers = NFS_EXPORT_STAT_REC_VERSION;

		if (!nfsrv_is_initialized()) {
			stat_desc.rec_count = 0;
			if (oldp && (*oldlenp >= sizeof(struct nfs_export_stat_desc)))
				error = copyout(&stat_desc, oldp, sizeof(struct nfs_export_stat_desc));
			*oldlenp = sizeof(struct nfs_export_stat_desc);
			return (error);
		}

		/* Count the number of exported directories */
		lck_rw_lock_shared(&nfsrv_export_rwlock);
		numExports = 0;
		LIST_FOREACH(nxfs, &nfsrv_exports, nxfs_next)
			LIST_FOREACH(nx, &nxfs->nxfs_exports, nx_next)
					numExports += 1;

		/* update stat descriptor's export record count */
		stat_desc.rec_count = numExports;

		/* calculate total size of required buffer */
		totlen = sizeof(struct nfs_export_stat_desc) + (numExports * sizeof(struct nfs_export_stat_rec));

		/* Check caller's buffer */
		if (oldp == 0) {
			lck_rw_done(&nfsrv_export_rwlock);
			/* indicate required buffer len */
			*oldlenp = totlen;
			return (0);
		}

		/* We require the caller's buffer to be at least large enough to hold the descriptor */
		if (*oldlenp < sizeof(struct nfs_export_stat_desc)) {
			lck_rw_done(&nfsrv_export_rwlock);
			/* indicate required buffer len */
			*oldlenp = totlen;
			return (ENOMEM);
		}

		/* indicate required buffer len */
		*oldlenp = totlen;

		/* check if export table is empty */
		if (!numExports) {
			lck_rw_done(&nfsrv_export_rwlock);
			error = copyout(&stat_desc, oldp, sizeof(struct nfs_export_stat_desc));
			return (error);
		}

		/* calculate how many actual export stat records fit into caller's buffer */
		numRecs = (*oldlenp - sizeof(struct nfs_export_stat_desc)) / sizeof(struct nfs_export_stat_rec);

		if (!numRecs) {
			/* caller's buffer can only accomodate descriptor */
			lck_rw_done(&nfsrv_export_rwlock);
			stat_desc.rec_count = 0;
			error = copyout(&stat_desc, oldp, sizeof(struct nfs_export_stat_desc));
			return (error);
		}

		/* adjust to actual number of records to copyout to caller's buffer */
		if (numRecs > numExports)
			numRecs = numExports;

		/* set actual number of records we are returning */
		stat_desc.rec_count = numRecs;

		/* first copy out the stat descriptor */
		pos = 0;
		error = copyout(&stat_desc, oldp + pos, sizeof(struct nfs_export_stat_desc));
		if (error) {
			lck_rw_done(&nfsrv_export_rwlock);
			return (error);
		}
		pos += sizeof(struct nfs_export_stat_desc);

		/* Loop through exported directories */
		count = 0;
		LIST_FOREACH(nxfs, &nfsrv_exports, nxfs_next) {
			LIST_FOREACH(nx, &nxfs->nxfs_exports, nx_next) {

				if (count >= numRecs)
					break;

				/* build exported filesystem path */
				snprintf(statrec.path, sizeof(statrec.path), "%s%s%s",
					nxfs->nxfs_path, ((nxfs->nxfs_path[1] && nx->nx_path[0]) ? "/" : ""),
					nx->nx_path);

				/* build the 64-bit export stat counters */
				statrec.ops = ((uint64_t)nx->nx_stats.ops.hi << 32) |
						nx->nx_stats.ops.lo;
				statrec.bytes_read = ((uint64_t)nx->nx_stats.bytes_read.hi << 32) |
						nx->nx_stats.bytes_read.lo;
				statrec.bytes_written = ((uint64_t)nx->nx_stats.bytes_written.hi << 32) |
						nx->nx_stats.bytes_written.lo;
				error = copyout(&statrec, oldp + pos, sizeof(statrec));
				if (error) {
					lck_rw_done(&nfsrv_export_rwlock);
					return (error);
				}
				/* advance buffer position */
				pos += sizeof(statrec);
			}
		}
		lck_rw_done(&nfsrv_export_rwlock);
		break;
	case NFS_USERSTATS:
		/* init structures used for copying out of kernel */
		ustat_desc.rec_vers = NFS_USER_STAT_REC_VERSION;
		ustat_rec.rec_type = NFS_USER_STAT_USER_REC;
		upath_rec.rec_type = NFS_USER_STAT_PATH_REC;

		/* initialize counters */
		bytes_total = sizeof(struct nfs_user_stat_desc);
		bytes_avail  = *oldlenp;
		recs_copied = 0;

		if (!nfsrv_is_initialized()) /* NFS server not initialized, so no stats */
			goto ustat_skip;

		/* reclaim old expired user nodes */
		nfsrv_active_user_list_reclaim();

		/* reserve space for the buffer descriptor */
		if (bytes_avail >= sizeof(struct nfs_user_stat_desc))
			bytes_avail -= sizeof(struct nfs_user_stat_desc);
		else
			bytes_avail = 0;

		/* put buffer position past the buffer descriptor */
		pos = sizeof(struct nfs_user_stat_desc);

		/* Loop through exported directories */
		lck_rw_lock_shared(&nfsrv_export_rwlock);
		LIST_FOREACH(nxfs, &nfsrv_exports, nxfs_next) {
			LIST_FOREACH(nx, &nxfs->nxfs_exports, nx_next) {
				/* copy out path */
				if (bytes_avail >= sizeof(struct nfs_user_stat_path_rec)) {
					snprintf(upath_rec.path, sizeof(upath_rec.path), "%s%s%s",
					    nxfs->nxfs_path, ((nxfs->nxfs_path[1] && nx->nx_path[0]) ? "/" : ""),
					    nx->nx_path);

					error = copyout(&upath_rec, oldp + pos, sizeof(struct nfs_user_stat_path_rec));
					if (error) {
						/* punt */
						goto ustat_done;
					}

					pos += sizeof(struct nfs_user_stat_path_rec);
					bytes_avail -= sizeof(struct nfs_user_stat_path_rec);
					recs_copied++;
				}
				else {
					/* Caller's buffer is exhausted */
					bytes_avail = 0;
				}

				bytes_total += sizeof(struct nfs_user_stat_path_rec);

				/* Scan through all user nodes of this export */
				ulist = &nx->nx_user_list;
				lck_mtx_lock(&ulist->user_mutex);
				for (unode = TAILQ_FIRST(&ulist->user_lru); unode; unode = unode_next) {
					unode_next = TAILQ_NEXT(unode, lru_link);

					/* copy out node if there is space */
					if (bytes_avail >= sizeof(struct nfs_user_stat_user_rec)) {
						/* prepare a user stat rec for copying out */
						ustat_rec.uid = unode->uid;
						bcopy(&unode->sock, &ustat_rec.sock, unode->sock.ss_len);
						ustat_rec.ops = unode->ops;
						ustat_rec.bytes_read = unode->bytes_read;
						ustat_rec.bytes_written = unode->bytes_written;
						ustat_rec.tm_start = unode->tm_start;
						ustat_rec.tm_last = unode->tm_last;

						error = copyout(&ustat_rec, oldp + pos, sizeof(struct nfs_user_stat_user_rec));

						if (error) {
							/* punt */
							lck_mtx_unlock(&ulist->user_mutex);
							goto ustat_done;
						}

						pos += sizeof(struct nfs_user_stat_user_rec);
						bytes_avail -= sizeof(struct nfs_user_stat_user_rec);
						recs_copied++;
					}
					else {
						/* Caller's buffer is exhausted */
						bytes_avail = 0;
					}
					bytes_total += sizeof(struct nfs_user_stat_user_rec);
				}
				/* can unlock this export's list now */
				lck_mtx_unlock(&ulist->user_mutex);
			}
		}

ustat_done:
		/* unlock the export table */
		lck_rw_done(&nfsrv_export_rwlock);

ustat_skip:
		/* indicate number of actual records copied */
		ustat_desc.rec_count = recs_copied;

		if (!error) {
			/* check if there was enough room for the buffer descriptor */
			if (*oldlenp >= sizeof(struct nfs_user_stat_desc))
				error = copyout(&ustat_desc, oldp, sizeof(struct nfs_user_stat_desc));
			else
				error = ENOMEM;

			/* always indicate required buffer size */
			*oldlenp = bytes_total;
		}
		break;
	case NFS_USERCOUNT:
		if (!oldp) {
			*oldlenp = sizeof(nfsrv_user_stat_node_count);
			return (0);
		}

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

		if (nfsrv_is_initialized()) {
			/* reclaim old expired user nodes */
			nfsrv_active_user_list_reclaim();
		}

		error = copyout(&nfsrv_user_stat_node_count, oldp, sizeof(nfsrv_user_stat_node_count));
		break;
#endif /* NFSSERVER */
	case VFS_CTL_NOLOCKS:
 		if (req->oldptr != USER_ADDR_NULL) {
			lck_mtx_lock(&nmp->nm_lock);
			val = (nmp->nm_lockmode == NFS_LOCK_MODE_DISABLED) ? 1 : 0;
			lck_mtx_unlock(&nmp->nm_lock);
 			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);
			lck_mtx_lock(&nmp->nm_lock);
			if (nmp->nm_lockmode == NFS_LOCK_MODE_LOCAL) {
				/* can't toggle locks when using local locks */
				error = EINVAL;
			} else if ((nmp->nm_vers >= NFS_VER4) && val) {
				/* can't disable locks for NFSv4 */
				error = EINVAL;
			} else if (val) {
				if ((nmp->nm_vers <= NFS_VER3) && (nmp->nm_lockmode == NFS_LOCK_MODE_ENABLED))
					nfs_lockd_mount_unregister(nmp);
				nmp->nm_lockmode = NFS_LOCK_MODE_DISABLED;
				nmp->nm_state &= ~NFSSTA_LOCKTIMEO;
			} else {
				if ((nmp->nm_vers <= NFS_VER3) && (nmp->nm_lockmode == NFS_LOCK_MODE_DISABLED))
					nfs_lockd_mount_register(nmp);
				nmp->nm_lockmode = NFS_LOCK_MODE_ENABLED;
			}
			lck_mtx_unlock(&nmp->nm_lock);
 		}
		break;
	case VFS_CTL_QUERY:
		lck_mtx_lock(&nmp->nm_lock);
		/* XXX don't allow users to know about/disconnect unresponsive, soft, nobrowse mounts */
		softnobrowse = (NMFLAG(nmp, SOFT) && (vfs_flags(nmp->nm_mountp) & MNT_DONTBROWSE));
		if (!softnobrowse && (nmp->nm_state & NFSSTA_TIMEO))
			vq.vq_flags |= VQ_NOTRESP;
		if (!softnobrowse && (nmp->nm_state & NFSSTA_JUKEBOXTIMEO) && !NMFLAG(nmp, MUTEJUKEBOX))
			vq.vq_flags |= VQ_NOTRESP;
		if (!softnobrowse && (nmp->nm_state & NFSSTA_LOCKTIMEO) &&
		    (nmp->nm_lockmode == NFS_LOCK_MODE_ENABLED))
			vq.vq_flags |= VQ_NOTRESP;
		if (nmp->nm_state & NFSSTA_DEAD)
			vq.vq_flags |= VQ_DEAD;
		lck_mtx_unlock(&nmp->nm_lock);
		error = SYSCTL_OUT(req, &vq, sizeof(vq));
		break;
 	case VFS_CTL_TIMEO:
 		if (req->oldptr != USER_ADDR_NULL) {
			lck_mtx_lock(&nmp->nm_lock);
			val = nmp->nm_tprintf_initial_delay;
			lck_mtx_unlock(&nmp->nm_lock);
 			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);
			lck_mtx_lock(&nmp->nm_lock);
 			if (val < 0)
 				nmp->nm_tprintf_initial_delay = 0;
			else
				nmp->nm_tprintf_initial_delay = val;
			lck_mtx_unlock(&nmp->nm_lock);
 		}
		break;
	case VFS_CTL_NSTATUS:
		/*
		 * Return the status of this mount.  This is much more
		 * information than VFS_CTL_QUERY.  In addition to the
		 * vq_flags return the significant mount options along
		 * with the list of threads blocked on the mount and
		 * how long the threads have been waiting.
		 */

		lck_mtx_lock(nfs_request_mutex);
		lck_mtx_lock(&nmp->nm_lock);

		/*
		 * Count the number of requests waiting for a reply.
		 * Note: there could be multiple requests from the same thread.
		 */
		numThreads = 0;
		TAILQ_FOREACH(rq, &nfs_reqq, r_chain) {
			if (rq->r_nmp == nmp)
				numThreads++;
		}

		/* Calculate total size of result buffer */
		totlen = sizeof(struct netfs_status) + (numThreads * sizeof(uint64_t));

		if (req->oldptr == USER_ADDR_NULL) {		// Caller is querying buffer size
			lck_mtx_unlock(&nmp->nm_lock);
			lck_mtx_unlock(nfs_request_mutex);
			return SYSCTL_OUT(req, NULL, totlen);
		}
		if (req->oldlen < totlen) {	// Check if caller's buffer is big enough
			lck_mtx_unlock(&nmp->nm_lock);
			lck_mtx_unlock(nfs_request_mutex);
			return (ERANGE);
		}

		MALLOC(nsp, struct netfs_status *, totlen, M_TEMP, M_WAITOK|M_ZERO);
		if (nsp == NULL) {
			lck_mtx_unlock(&nmp->nm_lock);
			lck_mtx_unlock(nfs_request_mutex);
			return (ENOMEM);
		}
		timeoutmask = NFSSTA_TIMEO | NFSSTA_LOCKTIMEO | NFSSTA_JUKEBOXTIMEO;
		if (nmp->nm_state & timeoutmask)
			nsp->ns_status |= VQ_NOTRESP;
		if (nmp->nm_state & NFSSTA_DEAD)
			nsp->ns_status |= VQ_DEAD;

		(void) nfs_mountopts(nmp, nsp->ns_mountopts, sizeof(nsp->ns_mountopts));
		nsp->ns_threadcount = numThreads;
		
		/*
		 * Get the thread ids of threads waiting for a reply
		 * and find the longest wait time.
		 */
		if (numThreads > 0) {
			struct timeval now;
			time_t sendtime;

			microuptime(&now);
			count = 0;
			sendtime = now.tv_sec;
			TAILQ_FOREACH(rq, &nfs_reqq, r_chain) {
				if (rq->r_nmp == nmp) {
					if (rq->r_start < sendtime)
						sendtime = rq->r_start;
		 			// A thread_id of zero is used to represent an async I/O request.
					nsp->ns_threadids[count] =
						rq->r_thread ? thread_tid(rq->r_thread) : 0;
					if (++count >= numThreads)
						break;
				}
			}
			nsp->ns_waittime = now.tv_sec - sendtime;
		}

		lck_mtx_unlock(&nmp->nm_lock);
		lck_mtx_unlock(nfs_request_mutex);

 		error = SYSCTL_OUT(req, nsp, totlen);
		FREE(nsp, M_TEMP);
		break;
	default:
		return (ENOTSUP);
	}
	return (error);
}