xref: /macosx-10.10.1/xnu-2782.1.97/bsd/nfs/nfs4_vnops.c

/*
 * Copyright (c) 2006-2011 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@
 */

/*
 * vnode op calls for NFS version 4
 */
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/mount_internal.h>
#include <sys/malloc.h>
#include <sys/kpi_mbuf.h>
#include <sys/conf.h>
#include <sys/vnode_internal.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/ubc_internal.h>
#include <sys/attr.h>
#include <sys/signalvar.h>
#include <sys/uio_internal.h>
#include <sys/xattr.h>
#include <sys/paths.h>

#include <vfs/vfs_support.h>

#include <sys/vm.h>

#include <sys/time.h>
#include <kern/clock.h>
#include <libkern/OSAtomic.h>

#include <miscfs/fifofs/fifo.h>
#include <miscfs/specfs/specdev.h>

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

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <vm/vm_kern.h>

#include <kern/task.h>
#include <kern/sched_prim.h>

int
nfs4_access_rpc(nfsnode_t np, u_int32_t *access, int rpcflags, vfs_context_t ctx)
{
	int error = 0, lockerror = ENOENT, status, numops, slot;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	struct timeval now;
	uint32_t access_result = 0, supported = 0, missing;
	struct nfsmount *nmp = NFSTONMP(np);
	int nfsvers = nmp->nm_vers;
	uid_t uid;
	struct nfsreq_secinfo_args si;

	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (0);

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

	// PUTFH, ACCESS, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 17 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "access", 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_ACCESS);
	nfsm_chain_add_32(error, &nmreq, *access);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_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),
		&si, rpcflags, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	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_ACCESS);
	nfsm_chain_get_32(error, &nmrep, supported);
	nfsm_chain_get_32(error, &nmrep, access_result);
	nfsmout_if(error);
	if ((missing = (*access & ~supported))) {
		/* missing support for something(s) we wanted */
		if (missing & NFS_ACCESS_DELETE) {
			/*
			 * If the server doesn't report DELETE (possible
			 * on UNIX systems), we'll assume that it is OK
			 * and just let any subsequent delete action fail
			 * if it really isn't deletable.
			 */
			access_result |= NFS_ACCESS_DELETE;
		}
	}
	/* ".zfs" subdirectories may erroneously give a denied answer for modify/delete */
	if (nfs_access_dotzfs) {
		vnode_t dvp = NULLVP;
		if (np->n_flag & NISDOTZFSCHILD) /* may be able to create/delete snapshot dirs */
			access_result |= (NFS_ACCESS_MODIFY|NFS_ACCESS_EXTEND|NFS_ACCESS_DELETE);
		else if (((dvp = vnode_getparent(NFSTOV(np))) != NULLVP) && (VTONFS(dvp)->n_flag & NISDOTZFSCHILD))
			access_result |= NFS_ACCESS_DELETE; /* may be able to delete snapshot dirs */
		if (dvp != NULLVP)
			vnode_put(dvp);
	}
	/* Some servers report DELETE support but erroneously give a denied answer. */
	if (nfs_access_delete && (*access & NFS_ACCESS_DELETE) && !(access_result & NFS_ACCESS_DELETE))
		access_result |= NFS_ACCESS_DELETE;
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
	nfsmout_if(error);

	uid = kauth_cred_getuid(vfs_context_ucred(ctx));
	slot = nfs_node_access_slot(np, uid, 1);
	np->n_accessuid[slot] = uid;
	microuptime(&now);
	np->n_accessstamp[slot] = now.tv_sec;
	np->n_access[slot] = access_result;

	/* pass back the access returned with this request */
	*access = np->n_access[slot];
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_getattr_rpc(
	nfsnode_t np,
	mount_t mp,
	u_char *fhp,
	size_t fhsize,
	int flags,
	vfs_context_t ctx,
	struct nfs_vattr *nvap,
	u_int64_t *xidp)
{
	struct nfsmount *nmp = mp ? VFSTONFS(mp) : NFSTONMP(np);
	int error = 0, status, nfsvers, numops, rpcflags = 0, acls;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	acls = (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_ACL);

	if (np && (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)) {
		nfs4_default_attrs_for_referral_trigger(VTONFS(np->n_parent), NULL, 0, nvap, NULL);
		return (0);
	}

	if (flags & NGA_MONITOR) /* vnode monitor requests should be soft */
		rpcflags = R_RECOVER;

	if (flags & NGA_SOFT) /* Return ETIMEDOUT if server not responding */
		rpcflags |= R_SOFT;

	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, "getattr", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, fhp, fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	if ((flags & NGA_ACL) && acls)
		NFS_BITMAP_SET(bitmap, NFS_FATTR_ACL);
	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, mp, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx),
			NULL, rpcflags, &nmrep, xidp, &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);
	error = nfs4_parsefattr(&nmrep, NULL, nvap, NULL, NULL, NULL);
	nfsmout_if(error);
	if ((flags & NGA_ACL) && acls && !NFS_BITMAP_ISSET(nvap->nva_bitmap, NFS_FATTR_ACL)) {
		/* we asked for the ACL but didn't get one... assume there isn't one */
		NFS_BITMAP_SET(nvap->nva_bitmap, NFS_FATTR_ACL);
		nvap->nva_acl = NULL;
	}
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_readlink_rpc(nfsnode_t np, char *buf, uint32_t *buflenp, vfs_context_t ctx)
{
	struct nfsmount *nmp;
	int error = 0, lockerror = ENOENT, status, numops;
	uint32_t len = 0;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	NFSREQ_SECINFO_SET(&si, np, NULL, 0, NULL, 0);
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	// PUTFH, GETATTR, READLINK
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 16 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "readlink", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	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(np, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	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_chain_loadattr(error, &nmrep, np, NFS_VER4, &xid);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_READLINK);
	nfsm_chain_get_32(error, &nmrep, len);
	nfsmout_if(error);
	if (len >= *buflenp) {
		if (np->n_size && (np->n_size < *buflenp))
			len = np->n_size;
		else
			len = *buflenp - 1;
	}
	nfsm_chain_get_opaque(error, &nmrep, len, buf);
	if (!error)
		*buflenp = len;
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_read_rpc_async(
	nfsnode_t np,
	off_t offset,
	size_t len,
	thread_t thd,
	kauth_cred_t cred,
	struct nfsreq_cbinfo *cb,
	struct nfsreq **reqp)
{
	struct nfsmount *nmp;
	int error = 0, nfsvers, numops;
	nfs_stateid stateid;
	struct nfsm_chain nmreq;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

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

	// PUTFH, READ, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 22 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "read", 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_READ);
	nfs_get_stateid(np, thd, cred, &stateid);
	nfsm_chain_add_stateid(error, &nmreq, &stateid);
	nfsm_chain_add_64(error, &nmreq, offset);
	nfsm_chain_add_32(error, &nmreq, len);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request_async(np, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, 0, cb, reqp);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	return (error);
}

int
nfs4_read_rpc_async_finish(
	nfsnode_t np,
	struct nfsreq *req,
	uio_t uio,
	size_t *lenp,
	int *eofp)
{
	struct nfsmount *nmp;
	int error = 0, lockerror, nfsvers, numops, status, eof = 0;
	size_t retlen = 0;
	u_int64_t xid;
	struct nfsm_chain nmrep;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp)) {
		nfs_request_async_cancel(req);
		return (ENXIO);
	}
	nfsvers = nmp->nm_vers;

	nfsm_chain_null(&nmrep);

	error = nfs_request_async_finish(req, &nmrep, &xid, &status);
	if (error == EINPROGRESS) /* async request restarted */
		return (error);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	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_READ);
	nfsm_chain_get_32(error, &nmrep, eof);
	nfsm_chain_get_32(error, &nmrep, retlen);
	if (!error) {
		*lenp = MIN(retlen, *lenp);
		error = nfsm_chain_get_uio(&nmrep, *lenp, uio);
	}
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
	if (!lockerror)
		nfs_node_unlock(np);
	if (eofp) {
		if (!eof && !retlen)
			eof = 1;
		*eofp = eof;
	}
	nfsm_chain_cleanup(&nmrep);
	if (np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR)
		microuptime(&np->n_lastio);
	return (error);
}

int
nfs4_write_rpc_async(
	nfsnode_t np,
	uio_t uio,
	size_t len,
	thread_t thd,
	kauth_cred_t cred,
	int iomode,
	struct nfsreq_cbinfo *cb,
	struct nfsreq **reqp)
{
	struct nfsmount *nmp;
	mount_t mp;
	int error = 0, nfsvers, numops;
	nfs_stateid stateid;
	struct nfsm_chain nmreq;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	/* for async mounts, don't bother sending sync write requests */
	if ((iomode != NFS_WRITE_UNSTABLE) && nfs_allow_async &&
	    ((mp = NFSTOMP(np))) && (vfs_flags(mp) & MNT_ASYNC))
		iomode = NFS_WRITE_UNSTABLE;

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

	// PUTFH, WRITE, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 25 * NFSX_UNSIGNED + len);
	nfsm_chain_add_compound_header(error, &nmreq, "write", 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_WRITE);
	nfs_get_stateid(np, thd, cred, &stateid);
	nfsm_chain_add_stateid(error, &nmreq, &stateid);
	nfsm_chain_add_64(error, &nmreq, uio_offset(uio));
	nfsm_chain_add_32(error, &nmreq, iomode);
	nfsm_chain_add_32(error, &nmreq, len);
	if (!error)
		error = nfsm_chain_add_uio(&nmreq, uio, len);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request_async(np, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, 0, cb, reqp);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	return (error);
}

int
nfs4_write_rpc_async_finish(
	nfsnode_t np,
	struct nfsreq *req,
	int *iomodep,
	size_t *rlenp,
	uint64_t *wverfp)
{
	struct nfsmount *nmp;
	int error = 0, lockerror = ENOENT, nfsvers, numops, status;
	int committed = NFS_WRITE_FILESYNC;
	size_t rlen = 0;
	u_int64_t xid, wverf;
	mount_t mp;
	struct nfsm_chain nmrep;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp)) {
		nfs_request_async_cancel(req);
		return (ENXIO);
	}
	nfsvers = nmp->nm_vers;

	nfsm_chain_null(&nmrep);

	error = nfs_request_async_finish(req, &nmrep, &xid, &status);
	if (error == EINPROGRESS) /* async request restarted */
		return (error);
	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		error = ENXIO;
	if (!error && (lockerror = nfs_node_lock(np)))
		error = lockerror;
	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_WRITE);
	nfsm_chain_get_32(error, &nmrep, rlen);
	nfsmout_if(error);
	*rlenp = rlen;
	if (rlen <= 0)
		error = NFSERR_IO;
	nfsm_chain_get_32(error, &nmrep, committed);
	nfsm_chain_get_64(error, &nmrep, wverf);
	nfsmout_if(error);
	if (wverfp)
		*wverfp = wverf;
	lck_mtx_lock(&nmp->nm_lock);
	if (!(nmp->nm_state & NFSSTA_HASWRITEVERF)) {
		nmp->nm_verf = wverf;
		nmp->nm_state |= NFSSTA_HASWRITEVERF;
	} else if (nmp->nm_verf != wverf) {
		nmp->nm_verf = wverf;
	}
	lck_mtx_unlock(&nmp->nm_lock);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_chain_cleanup(&nmrep);
	if ((committed != NFS_WRITE_FILESYNC) && nfs_allow_async &&
	    ((mp = NFSTOMP(np))) && (vfs_flags(mp) & MNT_ASYNC))
		committed = NFS_WRITE_FILESYNC;
	*iomodep = committed;
	if (np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR)
		microuptime(&np->n_lastio);
	return (error);
}

int
nfs4_remove_rpc(
	nfsnode_t dnp,
	char *name,
	int namelen,
	thread_t thd,
	kauth_cred_t cred)
{
	int error = 0, lockerror = ENOENT, remove_error = 0, status;
	struct nfsmount *nmp;
	int nfsvers, numops;
	u_int64_t xid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(dnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (dnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	NFSREQ_SECINFO_SET(&si, dnp, NULL, 0, NULL, 0);
restart:
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	// PUTFH, REMOVE, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 17 * NFSX_UNSIGNED + namelen);
	nfsm_chain_add_compound_header(error, &nmreq, "remove", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, dnp->n_fhp, dnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_REMOVE);
	nfsm_chain_add_name(error, &nmreq, name, namelen, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request2(dnp, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, 0, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(dnp)))
		error = lockerror;
	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_REMOVE);
	remove_error = error;
	nfsm_chain_check_change_info(error, &nmrep, dnp);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, dnp, nfsvers, &xid);
	if (error && !lockerror)
		NATTRINVALIDATE(dnp);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);

	if (!lockerror) {
		dnp->n_flag |= NMODIFIED;
		nfs_node_unlock(dnp);
	}
	if (error == NFSERR_GRACE) {
		tsleep(&nmp->nm_state, (PZERO-1), "nfsgrace", 2*hz);
		goto restart;
	}

	return (remove_error);
}

int
nfs4_rename_rpc(
	nfsnode_t fdnp,
	char *fnameptr,
	int fnamelen,
	nfsnode_t tdnp,
	char *tnameptr,
	int tnamelen,
	vfs_context_t ctx)
{
	int error = 0, lockerror = ENOENT, status, nfsvers, numops;
	struct nfsmount *nmp;
	u_int64_t xid, savedxid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(fdnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (fdnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	if (tdnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

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

	// PUTFH(FROM), SAVEFH, PUTFH(TO), RENAME, GETATTR(TO), RESTOREFH, GETATTR(FROM)
	numops = 7;
	nfsm_chain_build_alloc_init(error, &nmreq, 30 * NFSX_UNSIGNED + fnamelen + tnamelen);
	nfsm_chain_add_compound_header(error, &nmreq, "rename", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, fdnp->n_fhp, fdnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_SAVEFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, tdnp->n_fhp, tdnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_RENAME);
	nfsm_chain_add_name(error, &nmreq, fnameptr, fnamelen, nmp);
	nfsm_chain_add_name(error, &nmreq, tnameptr, tnamelen, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, tdnp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_RESTOREFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, fdnp);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request(fdnp, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock2(fdnp, tdnp)))
		error = lockerror;
	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_SAVEFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_RENAME);
	nfsm_chain_check_change_info(error, &nmrep, fdnp);
	nfsm_chain_check_change_info(error, &nmrep, tdnp);
	/* directory attributes: if we don't get them, make sure to invalidate */
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	savedxid = xid;
	nfsm_chain_loadattr(error, &nmrep, tdnp, nfsvers, &xid);
	if (error && !lockerror)
		NATTRINVALIDATE(tdnp);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_RESTOREFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	xid = savedxid;
	nfsm_chain_loadattr(error, &nmrep, fdnp, nfsvers, &xid);
	if (error && !lockerror)
		NATTRINVALIDATE(fdnp);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	if (!lockerror) {
		fdnp->n_flag |= NMODIFIED;
		tdnp->n_flag |= NMODIFIED;
		nfs_node_unlock2(fdnp, tdnp);
	}
	return (error);
}

/*
 * NFS V4 readdir RPC.
 */
int
nfs4_readdir_rpc(nfsnode_t dnp, struct nfsbuf *bp, vfs_context_t ctx)
{
	struct nfsmount *nmp;
	int error = 0, lockerror, nfsvers, namedattr, rdirplus, bigcookies, numops;
	int i, status, more_entries = 1, eof, bp_dropped = 0;
	uint32_t nmreaddirsize, nmrsize;
	uint32_t namlen, skiplen, fhlen, xlen, attrlen, reclen, space_free, space_needed;
	uint64_t cookie, lastcookie, xid, savedxid;
	struct nfsm_chain nmreq, nmrep, nmrepsave;
	fhandle_t fh;
	struct nfs_vattr nvattr, *nvattrp;
	struct nfs_dir_buf_header *ndbhp;
	struct direntry *dp;
	char *padstart, padlen;
	const char *tag;
	uint32_t entry_attrs[NFS_ATTR_BITMAP_LEN];
	struct timeval now;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(dnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	nmreaddirsize = nmp->nm_readdirsize;
	nmrsize = nmp->nm_rsize;
	bigcookies = nmp->nm_state & NFSSTA_BIGCOOKIES;
	namedattr = (dnp->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR) ? 1 : 0;
	rdirplus = (NMFLAG(nmp, RDIRPLUS) || namedattr) ? 1 : 0;
	if (dnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	NFSREQ_SECINFO_SET(&si, dnp, NULL, 0, NULL, 0);

	/*
	 * Set up attribute request for entries.
	 * For READDIRPLUS functionality, get everything.
	 * Otherwise, just get what we need for struct direntry.
	 */
	if (rdirplus) {
		tag = "readdirplus";
		NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, entry_attrs);
		NFS_BITMAP_SET(entry_attrs, NFS_FATTR_FILEHANDLE);
	} else {
		tag = "readdir";
		NFS_CLEAR_ATTRIBUTES(entry_attrs);
		NFS_BITMAP_SET(entry_attrs, NFS_FATTR_TYPE);
		NFS_BITMAP_SET(entry_attrs, NFS_FATTR_FILEID);
		NFS_BITMAP_SET(entry_attrs, NFS_FATTR_MOUNTED_ON_FILEID);
	}
	NFS_BITMAP_SET(entry_attrs, NFS_FATTR_RDATTR_ERROR);

	/* lock to protect access to cookie verifier */
	if ((lockerror = nfs_node_lock(dnp)))
		return (lockerror);

	/* determine cookie to use, and move dp to the right offset */
	ndbhp = (struct nfs_dir_buf_header*)bp->nb_data;
	dp = NFS_DIR_BUF_FIRST_DIRENTRY(bp);
	if (ndbhp->ndbh_count) {
		for (i=0; i < ndbhp->ndbh_count-1; i++)
			dp = NFS_DIRENTRY_NEXT(dp);
		cookie = dp->d_seekoff;
		dp = NFS_DIRENTRY_NEXT(dp);
	} else {
		cookie = bp->nb_lblkno;
		/* increment with every buffer read */
		OSAddAtomic64(1, &nfsstats.readdir_bios);
	}
	lastcookie = cookie;

	/*
	 * The NFS client is responsible for the "." and ".." entries in the
	 * directory.  So, we put them at the start of the first buffer.
	 * Don't bother for attribute directories.
	 */
	if (((bp->nb_lblkno == 0) && (ndbhp->ndbh_count == 0)) &&
	    !(dnp->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR)) {
		fh.fh_len = 0;
		fhlen = rdirplus ? fh.fh_len + 1 : 0;
		xlen = rdirplus ? (fhlen + sizeof(time_t)) : 0;
		/* "." */
		namlen = 1;
		reclen = NFS_DIRENTRY_LEN(namlen + xlen);
		if (xlen)
			bzero(&dp->d_name[namlen+1], xlen);
		dp->d_namlen = namlen;
		strlcpy(dp->d_name, ".", namlen+1);
		dp->d_fileno = dnp->n_vattr.nva_fileid;
		dp->d_type = DT_DIR;
		dp->d_reclen = reclen;
		dp->d_seekoff = 1;
		padstart = dp->d_name + dp->d_namlen + 1 + xlen;
		dp = NFS_DIRENTRY_NEXT(dp);
		padlen = (char*)dp - padstart;
		if (padlen > 0)
			bzero(padstart, padlen);
		if (rdirplus) /* zero out attributes */
			bzero(NFS_DIR_BUF_NVATTR(bp, 0), sizeof(struct nfs_vattr));

		/* ".." */
		namlen = 2;
		reclen = NFS_DIRENTRY_LEN(namlen + xlen);
		if (xlen)
			bzero(&dp->d_name[namlen+1], xlen);
		dp->d_namlen = namlen;
		strlcpy(dp->d_name, "..", namlen+1);
		if (dnp->n_parent)
			dp->d_fileno = VTONFS(dnp->n_parent)->n_vattr.nva_fileid;
		else
			dp->d_fileno = dnp->n_vattr.nva_fileid;
		dp->d_type = DT_DIR;
		dp->d_reclen = reclen;
		dp->d_seekoff = 2;
		padstart = dp->d_name + dp->d_namlen + 1 + xlen;
		dp = NFS_DIRENTRY_NEXT(dp);
		padlen = (char*)dp - padstart;
		if (padlen > 0)
			bzero(padstart, padlen);
		if (rdirplus) /* zero out attributes */
			bzero(NFS_DIR_BUF_NVATTR(bp, 1), sizeof(struct nfs_vattr));

		ndbhp->ndbh_entry_end = (char*)dp - bp->nb_data;
		ndbhp->ndbh_count = 2;
	}

	/*
	 * Loop around doing readdir(plus) RPCs of size nm_readdirsize until
	 * the buffer is full (or we hit EOF).  Then put the remainder of the
	 * results in the next buffer(s).
	 */
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);
	while (nfs_dir_buf_freespace(bp, rdirplus) && !(ndbhp->ndbh_flags & NDB_FULL)) {

		// PUTFH, GETATTR, READDIR
		numops = 3;
		nfsm_chain_build_alloc_init(error, &nmreq, 26 * NFSX_UNSIGNED);
		nfsm_chain_add_compound_header(error, &nmreq, tag, numops);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
		nfsm_chain_add_fh(error, &nmreq, nfsvers, dnp->n_fhp, dnp->n_fhsize);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
		nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_READDIR);
		nfsm_chain_add_64(error, &nmreq, (cookie <= 2) ? 0 : cookie);
		nfsm_chain_add_64(error, &nmreq, dnp->n_cookieverf);
		nfsm_chain_add_32(error, &nmreq, nmreaddirsize);
		nfsm_chain_add_32(error, &nmreq, nmrsize);
		nfsm_chain_add_bitmap_supported(error, &nmreq, entry_attrs, nmp, dnp);
		nfsm_chain_build_done(error, &nmreq);
		nfsm_assert(error, (numops == 0), EPROTO);
		nfs_node_unlock(dnp);
		nfsmout_if(error);
		error = nfs_request(dnp, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

		if ((lockerror = nfs_node_lock(dnp)))
			error = lockerror;

		savedxid = xid;
		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_chain_loadattr(error, &nmrep, dnp, nfsvers, &xid);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_READDIR);
		nfsm_chain_get_64(error, &nmrep, dnp->n_cookieverf);
		nfsm_chain_get_32(error, &nmrep, more_entries);

		if (!lockerror) {
			nfs_node_unlock(dnp);
			lockerror = ENOENT;
		}
		nfsmout_if(error);

		if (rdirplus)
			microuptime(&now);

		/* loop through the entries packing them into the buffer */
		while (more_entries) {
			/* Entry: COOKIE, NAME, FATTR */
			nfsm_chain_get_64(error, &nmrep, cookie);
			nfsm_chain_get_32(error, &nmrep, namlen);
			nfsmout_if(error);
			if (!bigcookies && (cookie >> 32) && (nmp == NFSTONMP(dnp))) {
				/* we've got a big cookie, make sure flag is set */
				lck_mtx_lock(&nmp->nm_lock);
				nmp->nm_state |= NFSSTA_BIGCOOKIES;
				lck_mtx_unlock(&nmp->nm_lock);
				bigcookies = 1;
			}
			/* just truncate names that don't fit in direntry.d_name */
			if (namlen <= 0) {
				error = EBADRPC;
				goto nfsmout;
			}
			if (namlen > (sizeof(dp->d_name)-1)) {
				skiplen = namlen - sizeof(dp->d_name) + 1;
				namlen = sizeof(dp->d_name) - 1;
			} else {
				skiplen = 0;
			}
			/* guess that fh size will be same as parent */
			fhlen = rdirplus ? (1 + dnp->n_fhsize) : 0;
			xlen = rdirplus ? (fhlen + sizeof(time_t)) : 0;
			attrlen = rdirplus ? sizeof(struct nfs_vattr) : 0;
			reclen = NFS_DIRENTRY_LEN(namlen + xlen);
			space_needed = reclen + attrlen;
			space_free = nfs_dir_buf_freespace(bp, rdirplus);
			if (space_needed > space_free) {
				/*
				 * We still have entries to pack, but we've
				 * run out of room in the current buffer.
				 * So we need to move to the next buffer.
				 * The block# for the next buffer is the
				 * last cookie in the current buffer.
				 */
nextbuffer:
				ndbhp->ndbh_flags |= NDB_FULL;
				nfs_buf_release(bp, 0);
				bp_dropped = 1;
				bp = NULL;
				error = nfs_buf_get(dnp, lastcookie, NFS_DIRBLKSIZ, vfs_context_thread(ctx), NBLK_READ, &bp);
				nfsmout_if(error);
				/* initialize buffer */
				ndbhp = (struct nfs_dir_buf_header*)bp->nb_data;
				ndbhp->ndbh_flags = 0;
				ndbhp->ndbh_count = 0;
				ndbhp->ndbh_entry_end = sizeof(*ndbhp);
				ndbhp->ndbh_ncgen = dnp->n_ncgen;
				space_free = nfs_dir_buf_freespace(bp, rdirplus);
				dp = NFS_DIR_BUF_FIRST_DIRENTRY(bp);
				/* increment with every buffer read */
				OSAddAtomic64(1, &nfsstats.readdir_bios);
			}
			nmrepsave = nmrep;
			dp->d_fileno = cookie; /* placeholder */
			dp->d_seekoff = cookie;
			dp->d_namlen = namlen;
			dp->d_reclen = reclen;
			dp->d_type = DT_UNKNOWN;
			nfsm_chain_get_opaque(error, &nmrep, namlen, dp->d_name);
			nfsmout_if(error);
			dp->d_name[namlen] = '\0';
			if (skiplen)
				nfsm_chain_adv(error, &nmrep,
					nfsm_rndup(namlen + skiplen) - nfsm_rndup(namlen));
			nfsmout_if(error);
			nvattrp = rdirplus ? NFS_DIR_BUF_NVATTR(bp, ndbhp->ndbh_count) : &nvattr;
			error = nfs4_parsefattr(&nmrep, NULL, nvattrp, &fh, NULL, NULL);
			if (!error && NFS_BITMAP_ISSET(nvattrp->nva_bitmap, NFS_FATTR_ACL)) {
				/* we do NOT want ACLs returned to us here */
				NFS_BITMAP_CLR(nvattrp->nva_bitmap, NFS_FATTR_ACL);
				if (nvattrp->nva_acl) {
					kauth_acl_free(nvattrp->nva_acl);
					nvattrp->nva_acl = NULL;
				}
			}
			if (error && NFS_BITMAP_ISSET(nvattrp->nva_bitmap, NFS_FATTR_RDATTR_ERROR)) {
				/* OK, we may not have gotten all of the attributes but we will use what we can. */
				if ((error == NFSERR_MOVED) || (error == NFSERR_INVAL)) {
					/* set this up to look like a referral trigger */
					nfs4_default_attrs_for_referral_trigger(dnp, dp->d_name, namlen, nvattrp, &fh);
				}
				error = 0;
			}
			/* check for more entries after this one */
			nfsm_chain_get_32(error, &nmrep, more_entries);
			nfsmout_if(error);

			/* Skip any "." and ".." entries returned from server. */
			/* Also skip any bothersome named attribute entries. */
			if (((dp->d_name[0] == '.') && ((namlen == 1) || ((namlen == 2) && (dp->d_name[1] == '.')))) ||
			    (namedattr && (namlen == 11) && (!strcmp(dp->d_name, "SUNWattr_ro") || !strcmp(dp->d_name, "SUNWattr_rw")))) {
				lastcookie = cookie;
				continue;
			}

			if (NFS_BITMAP_ISSET(nvattrp->nva_bitmap, NFS_FATTR_TYPE))
				dp->d_type = IFTODT(VTTOIF(nvattrp->nva_type));
			if (NFS_BITMAP_ISSET(nvattrp->nva_bitmap, NFS_FATTR_FILEID))
				dp->d_fileno = nvattrp->nva_fileid;
			if (rdirplus) {
				/* fileid is already in d_fileno, so stash xid in attrs */
				nvattrp->nva_fileid = savedxid;
				if (NFS_BITMAP_ISSET(nvattrp->nva_bitmap, NFS_FATTR_FILEHANDLE)) {
					fhlen = fh.fh_len + 1;
					xlen = fhlen + sizeof(time_t);
					reclen = NFS_DIRENTRY_LEN(namlen + xlen);
					space_needed = reclen + attrlen;
					if (space_needed > space_free) {
						/* didn't actually have the room... move on to next buffer */
						nmrep = nmrepsave;
						goto nextbuffer;
					}
					/* pack the file handle into the record */
					dp->d_name[dp->d_namlen+1] = fh.fh_len;
					bcopy(fh.fh_data, &dp->d_name[dp->d_namlen+2], fh.fh_len);
				} else {
					/* mark the file handle invalid */
					fh.fh_len = 0;
					fhlen = fh.fh_len + 1;
					xlen = fhlen + sizeof(time_t);
					reclen = NFS_DIRENTRY_LEN(namlen + xlen);
					bzero(&dp->d_name[dp->d_namlen+1], fhlen);
				}
				*(time_t*)(&dp->d_name[dp->d_namlen+1+fhlen]) = now.tv_sec;
				dp->d_reclen = reclen;
			}
			padstart = dp->d_name + dp->d_namlen + 1 + xlen;
			ndbhp->ndbh_count++;
			lastcookie = cookie;

			/* advance to next direntry in buffer */
			dp = NFS_DIRENTRY_NEXT(dp);
			ndbhp->ndbh_entry_end = (char*)dp - bp->nb_data;
			/* zero out the pad bytes */
			padlen = (char*)dp - padstart;
			if (padlen > 0)
				bzero(padstart, padlen);
		}
		/* Finally, get the eof boolean */
		nfsm_chain_get_32(error, &nmrep, eof);
		nfsmout_if(error);
		if (eof) {
			ndbhp->ndbh_flags |= (NDB_FULL|NDB_EOF);
			nfs_node_lock_force(dnp);
			dnp->n_eofcookie = lastcookie;
			nfs_node_unlock(dnp);
		} else {
			more_entries = 1;
		}
		if (bp_dropped) {
			nfs_buf_release(bp, 0);
			bp = NULL;
			break;
		}
		if ((lockerror = nfs_node_lock(dnp)))
			error = lockerror;
		nfsmout_if(error);
		nfsm_chain_cleanup(&nmrep);
		nfsm_chain_null(&nmreq);
	}
nfsmout:
	if (bp_dropped && bp)
		nfs_buf_release(bp, 0);
	if (!lockerror)
		nfs_node_unlock(dnp);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (bp_dropped ? NFSERR_DIRBUFDROPPED : error);
}

int
nfs4_lookup_rpc_async(
	nfsnode_t dnp,
	char *name,
	int namelen,
	vfs_context_t ctx,
	struct nfsreq **reqp)
{
	int error = 0, isdotdot = 0, nfsvers, numops;
	struct nfsm_chain nmreq;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	struct nfsmount *nmp;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(dnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (dnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	if ((name[0] == '.') && (name[1] == '.') && (namelen == 2)) {
		isdotdot = 1;
		NFSREQ_SECINFO_SET(&si, dnp, NULL, 0, NULL, 0);
	} else {
		NFSREQ_SECINFO_SET(&si, dnp, dnp->n_fhp, dnp->n_fhsize, name, namelen);
	}

	nfsm_chain_null(&nmreq);

	// PUTFH, GETATTR, LOOKUP(P), GETFH, GETATTR (FH)
	numops = 5;
	nfsm_chain_build_alloc_init(error, &nmreq, 20 * NFSX_UNSIGNED + namelen);
	nfsm_chain_add_compound_header(error, &nmreq, "lookup", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, dnp->n_fhp, dnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
	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, name, namelen, nmp);
	}
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	/* some ".zfs" directories can't handle being asked for some attributes */
	if ((dnp->n_flag & NISDOTZFS) && !isdotdot)
		NFS_BITMAP_CLR(bitmap, NFS_FATTR_NAMED_ATTR);
	if ((dnp->n_flag & NISDOTZFSCHILD) && isdotdot)
		NFS_BITMAP_CLR(bitmap, NFS_FATTR_NAMED_ATTR);
	if (((namelen == 4) && (name[0] == '.') && (name[1] == 'z') && (name[2] == 'f') && (name[3] == 's')))
		NFS_BITMAP_CLR(bitmap, NFS_FATTR_NAMED_ATTR);
	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_request_async(dnp, NULL, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, reqp);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	return (error);
}


int
nfs4_lookup_rpc_async_finish(
	nfsnode_t dnp,
	char *name,
	int namelen,
	vfs_context_t ctx,
	struct nfsreq *req,
	u_int64_t *xidp,
	fhandle_t *fhp,
	struct nfs_vattr *nvap)
{
	int error = 0, lockerror = ENOENT, status, nfsvers, numops, isdotdot = 0;
	uint32_t op = NFS_OP_LOOKUP;
	u_int64_t xid;
	struct nfsmount *nmp;
	struct nfsm_chain nmrep;

	nmp = NFSTONMP(dnp);
	nfsvers = nmp->nm_vers;
	if ((name[0] == '.') && (name[1] == '.') && (namelen == 2))
		isdotdot = 1;

	nfsm_chain_null(&nmrep);

	error = nfs_request_async_finish(req, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(dnp)))
		error = lockerror;
	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);
	if (xidp)
		*xidp = xid;
	nfsm_chain_loadattr(error, &nmrep, dnp, nfsvers, &xid);

	nfsm_chain_op_check(error, &nmrep, (isdotdot ? NFS_OP_LOOKUPP : NFS_OP_LOOKUP));
	nfsmout_if(error || !fhp || !nvap);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETFH);
	nfsm_chain_get_32(error, &nmrep, fhp->fh_len);
	nfsm_chain_get_opaque(error, &nmrep, fhp->fh_len, fhp->fh_data);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	if ((error == NFSERR_MOVED) || (error == NFSERR_INVAL)) {
		/* set this up to look like a referral trigger */
		nfs4_default_attrs_for_referral_trigger(dnp, name, namelen, nvap, fhp);
		error = 0;
	} else {
		nfsmout_if(error);
		error = nfs4_parsefattr(&nmrep, NULL, nvap, NULL, NULL, NULL);
	}
nfsmout:
	if (!lockerror)
		nfs_node_unlock(dnp);
	nfsm_chain_cleanup(&nmrep);
	if (!error && (op == NFS_OP_LOOKUP) && (nmp->nm_state & NFSSTA_NEEDSECINFO)) {
		/* We still need to get SECINFO to set default for mount. */
		/* Do so for the first LOOKUP that returns successfully. */
		struct nfs_sec sec;

		sec.count = NX_MAX_SEC_FLAVORS;
		error = nfs4_secinfo_rpc(nmp, &req->r_secinfo, vfs_context_ucred(ctx), sec.flavors, &sec.count);
		/* [sigh] some implementations return "illegal" error for unsupported ops */
		if (error == NFSERR_OP_ILLEGAL)
			error = 0;
		if (!error) {
			/* set our default security flavor to the first in the list */
			lck_mtx_lock(&nmp->nm_lock);
			if (sec.count)
				nmp->nm_auth = sec.flavors[0];
			nmp->nm_state &= ~NFSSTA_NEEDSECINFO;
			lck_mtx_unlock(&nmp->nm_lock);
		}
	}
	return (error);
}

int
nfs4_commit_rpc(
	nfsnode_t np,
	uint64_t offset,
	uint64_t count,
	kauth_cred_t cred,
	uint64_t wverf)
{
	struct nfsmount *nmp;
	int error = 0, lockerror, status, nfsvers, numops;
	u_int64_t xid, newwverf;
	uint32_t count32;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	FSDBG(521, np, offset, count, nmp ? nmp->nm_state : 0);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	if (!(nmp->nm_state & NFSSTA_HASWRITEVERF))
		return (0);
	nfsvers = nmp->nm_vers;

	if (count > UINT32_MAX)
		count32 = 0;
	else
		count32 = count;

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

	// PUTFH, COMMIT, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 19 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "commit", 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_COMMIT);
	nfsm_chain_add_64(error, &nmreq, offset);
	nfsm_chain_add_32(error, &nmreq, count32);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_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,
			current_thread(), cred, &si, 0, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	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_COMMIT);
	nfsm_chain_get_64(error, &nmrep, newwverf);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
	if (!lockerror)
		nfs_node_unlock(np);
	nfsmout_if(error);
	lck_mtx_lock(&nmp->nm_lock);
	if (nmp->nm_verf != newwverf)
		nmp->nm_verf = newwverf;
	if (wverf != newwverf)
		error = NFSERR_STALEWRITEVERF;
	lck_mtx_unlock(&nmp->nm_lock);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_pathconf_rpc(
	nfsnode_t np,
	struct nfs_fsattr *nfsap,
	vfs_context_t ctx)
{
	u_int64_t xid;
	int error = 0, lockerror, status, nfsvers, numops;
	struct nfsm_chain nmreq, nmrep;
	struct nfsmount *nmp = NFSTONMP(np);
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	struct nfs_vattr nvattr;
	struct nfsreq_secinfo_args si;

	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

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

	/* NFSv4: fetch "pathconf" info for this node */
	// PUTFH, GETATTR
	numops = 2;
	nfsm_chain_build_alloc_init(error, &nmreq, 16 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "pathconf", 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);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_MAXLINK);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_MAXNAME);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_NO_TRUNC);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_CHOWN_RESTRICTED);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_CASE_INSENSITIVE);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_CASE_PRESERVING);
	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_request(np, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &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);
	error = nfs4_parsefattr(&nmrep, nfsap, &nvattr, NULL, NULL, NULL);
	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);
nfsmout:
	NVATTR_CLEANUP(&nvattr);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_vnop_getattr(
	struct vnop_getattr_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		struct vnode_attr *a_vap;
		vfs_context_t a_context;
	} */ *ap)
{
	struct vnode_attr *vap = ap->a_vap;
	struct nfsmount *nmp;
	struct nfs_vattr nva;
	int error, acls, ngaflags;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	acls = (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_ACL);

	ngaflags = NGA_CACHED;
	if (VATTR_IS_ACTIVE(vap, va_acl) && acls)
		ngaflags |= NGA_ACL;
	error = nfs_getattr(VTONFS(ap->a_vp), &nva, ap->a_context, ngaflags);
	if (error)
		return (error);

	/* copy what we have in nva to *a_vap */
	if (VATTR_IS_ACTIVE(vap, va_rdev) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_RAWDEV)) {
		dev_t rdev = makedev(nva.nva_rawdev.specdata1, nva.nva_rawdev.specdata2);
		VATTR_RETURN(vap, va_rdev, rdev);
	}
	if (VATTR_IS_ACTIVE(vap, va_nlink) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_NUMLINKS))
		VATTR_RETURN(vap, va_nlink, nva.nva_nlink);
	if (VATTR_IS_ACTIVE(vap, va_data_size) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_SIZE))
		VATTR_RETURN(vap, va_data_size, nva.nva_size);
	// VATTR_RETURN(vap, va_data_alloc, ???);
	// VATTR_RETURN(vap, va_total_size, ???);
	if (VATTR_IS_ACTIVE(vap, va_total_alloc) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_SPACE_USED))
		VATTR_RETURN(vap, va_total_alloc, nva.nva_bytes);
	if (VATTR_IS_ACTIVE(vap, va_uid) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_OWNER))
		VATTR_RETURN(vap, va_uid, nva.nva_uid);
	if (VATTR_IS_ACTIVE(vap, va_uuuid) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_OWNER))
		VATTR_RETURN(vap, va_uuuid, nva.nva_uuuid);
	if (VATTR_IS_ACTIVE(vap, va_gid) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_OWNER_GROUP))
		VATTR_RETURN(vap, va_gid, nva.nva_gid);
	if (VATTR_IS_ACTIVE(vap, va_guuid) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_OWNER_GROUP))
		VATTR_RETURN(vap, va_guuid, nva.nva_guuid);
	if (VATTR_IS_ACTIVE(vap, va_mode)) {
		if (NMFLAG(nmp, ACLONLY) || !NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_MODE))
			VATTR_RETURN(vap, va_mode, 0777);
		else
			VATTR_RETURN(vap, va_mode, nva.nva_mode);
	}
	if (VATTR_IS_ACTIVE(vap, va_flags) &&
	    (NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_ARCHIVE) ||
	     NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_HIDDEN) ||
	     (nva.nva_flags & NFS_FFLAG_TRIGGER))) {
		uint32_t flags = 0;
		if (NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_ARCHIVE) &&
		    (nva.nva_flags & NFS_FFLAG_ARCHIVED))
			flags |= SF_ARCHIVED;
		if (NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_HIDDEN) &&
		    (nva.nva_flags & NFS_FFLAG_HIDDEN))
			flags |= UF_HIDDEN;
		VATTR_RETURN(vap, va_flags, flags);
	}
	if (VATTR_IS_ACTIVE(vap, va_create_time) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TIME_CREATE)) {
		vap->va_create_time.tv_sec = nva.nva_timesec[NFSTIME_CREATE];
		vap->va_create_time.tv_nsec = nva.nva_timensec[NFSTIME_CREATE];
		VATTR_SET_SUPPORTED(vap, va_create_time);
	}
	if (VATTR_IS_ACTIVE(vap, va_access_time) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TIME_ACCESS)) {
		vap->va_access_time.tv_sec = nva.nva_timesec[NFSTIME_ACCESS];
		vap->va_access_time.tv_nsec = nva.nva_timensec[NFSTIME_ACCESS];
		VATTR_SET_SUPPORTED(vap, va_access_time);
	}
	if (VATTR_IS_ACTIVE(vap, va_modify_time) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TIME_MODIFY)) {
		vap->va_modify_time.tv_sec = nva.nva_timesec[NFSTIME_MODIFY];
		vap->va_modify_time.tv_nsec = nva.nva_timensec[NFSTIME_MODIFY];
		VATTR_SET_SUPPORTED(vap, va_modify_time);
	}
	if (VATTR_IS_ACTIVE(vap, va_change_time) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TIME_METADATA)) {
		vap->va_change_time.tv_sec = nva.nva_timesec[NFSTIME_CHANGE];
		vap->va_change_time.tv_nsec = nva.nva_timensec[NFSTIME_CHANGE];
		VATTR_SET_SUPPORTED(vap, va_change_time);
	}
	if (VATTR_IS_ACTIVE(vap, va_backup_time) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TIME_BACKUP)) {
		vap->va_backup_time.tv_sec = nva.nva_timesec[NFSTIME_BACKUP];
		vap->va_backup_time.tv_nsec = nva.nva_timensec[NFSTIME_BACKUP];
		VATTR_SET_SUPPORTED(vap, va_backup_time);
	}
	if (VATTR_IS_ACTIVE(vap, va_fileid) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_FILEID))
		VATTR_RETURN(vap, va_fileid, nva.nva_fileid);
	if (VATTR_IS_ACTIVE(vap, va_type) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_TYPE))
		VATTR_RETURN(vap, va_type, nva.nva_type);
	if (VATTR_IS_ACTIVE(vap, va_filerev) && NFS_BITMAP_ISSET(nva.nva_bitmap, NFS_FATTR_CHANGE))
		VATTR_RETURN(vap, va_filerev, nva.nva_change);

	if (VATTR_IS_ACTIVE(vap, va_acl) && acls) {
		VATTR_RETURN(vap, va_acl, nva.nva_acl);
		nva.nva_acl = NULL;
	}

	// other attrs we might support someday:
	// VATTR_RETURN(vap, va_encoding, ??? /* potentially unnormalized UTF-8? */);

	NVATTR_CLEANUP(&nva);
	return (error);
}

int
nfs4_setattr_rpc(
	nfsnode_t np,
	struct vnode_attr *vap,
	vfs_context_t ctx)
{
	struct nfsmount *nmp = NFSTONMP(np);
	int error = 0, setattr_error = 0, lockerror = ENOENT, status, nfsvers, numops;
	u_int64_t xid, nextxid;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	uint32_t getbitmap[NFS_ATTR_BITMAP_LEN];
	uint32_t setbitmap[NFS_ATTR_BITMAP_LEN];
	nfs_stateid stateid;
	struct nfsreq_secinfo_args si;

	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	if (VATTR_IS_ACTIVE(vap, va_flags) && (vap->va_flags & ~(SF_ARCHIVED|UF_HIDDEN))) {
		/* we don't support setting unsupported flags (duh!) */
		if (vap->va_active & ~VNODE_ATTR_va_flags)
			return (EINVAL);	/* return EINVAL if other attributes also set */
		else
			return (ENOTSUP);	/* return ENOTSUP for chflags(2) */
	}

	/* don't bother requesting some changes if they don't look like they are changing */
	if (VATTR_IS_ACTIVE(vap, va_uid) && (vap->va_uid == np->n_vattr.nva_uid))
		VATTR_CLEAR_ACTIVE(vap, va_uid);
	if (VATTR_IS_ACTIVE(vap, va_gid) && (vap->va_gid == np->n_vattr.nva_gid))
		VATTR_CLEAR_ACTIVE(vap, va_gid);
	if (VATTR_IS_ACTIVE(vap, va_uuuid) && kauth_guid_equal(&vap->va_uuuid, &np->n_vattr.nva_uuuid))
		VATTR_CLEAR_ACTIVE(vap, va_uuuid);
	if (VATTR_IS_ACTIVE(vap, va_guuid) && kauth_guid_equal(&vap->va_guuid, &np->n_vattr.nva_guuid))
		VATTR_CLEAR_ACTIVE(vap, va_guuid);

tryagain:
	/* do nothing if no attributes will be sent */
	nfs_vattr_set_bitmap(nmp, bitmap, vap);
	if (!bitmap[0] && !bitmap[1])
		return (0);

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

	/*
	 * Prepare GETATTR bitmap: if we are setting the ACL or mode, we
	 * need to invalidate any cached ACL.  And if we had an ACL cached,
	 * we might as well also fetch the new value.
	 */
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, getbitmap);
	if (NFS_BITMAP_ISSET(bitmap, NFS_FATTR_ACL) ||
	    NFS_BITMAP_ISSET(bitmap, NFS_FATTR_MODE)) {
		if (NACLVALID(np))
			NFS_BITMAP_SET(getbitmap, NFS_FATTR_ACL);
		NACLINVALIDATE(np);
	}

	// PUTFH, SETATTR, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 40 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "setattr", 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_SETATTR);
	if (VATTR_IS_ACTIVE(vap, va_data_size))
		nfs_get_stateid(np, vfs_context_thread(ctx), vfs_context_ucred(ctx), &stateid);
	else
		stateid.seqid = stateid.other[0] = stateid.other[1] = stateid.other[2] = 0;
	nfsm_chain_add_stateid(error, &nmreq, &stateid);
	nfsm_chain_add_fattr4(error, &nmreq, vap, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, getbitmap, nmp, np);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request(np, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_SETATTR);
	nfsmout_if(error == EBADRPC);
	setattr_error = error;
	error = 0;
	bmlen = NFS_ATTR_BITMAP_LEN;
	nfsm_chain_get_bitmap(error, &nmrep, setbitmap, bmlen);
	if (!error) {
		if (VATTR_IS_ACTIVE(vap, va_data_size) && (np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			microuptime(&np->n_lastio);
		nfs_vattr_set_supported(setbitmap, vap);
		error = setattr_error;
	}
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
	if (error)
		NATTRINVALIDATE(np);
	/*
	 * We just changed the attributes and we want to make sure that we
	 * see the latest attributes.  Get the next XID.  If it's not the
	 * next XID after the SETATTR XID, then it's possible that another
	 * RPC was in flight at the same time and it might put stale attributes
	 * in the cache.  In that case, we invalidate the attributes and set
	 * the attribute cache XID to guarantee that newer attributes will
	 * get loaded next.
	 */
	nextxid = 0;
	nfs_get_xid(&nextxid);
	if (nextxid != (xid + 1)) {
		np->n_xid = nextxid;
		NATTRINVALIDATE(np);
	}
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	if ((setattr_error == EINVAL) && VATTR_IS_ACTIVE(vap, va_acl) && VATTR_IS_ACTIVE(vap, va_mode) && !NMFLAG(nmp, ACLONLY)) {
		/*
		 * Some server's may not like ACL/mode combos that get sent.
		 * If it looks like that's what the server choked on, try setting
		 * just the ACL and not the mode (unless it looks like everything
		 * but mode was already successfully set).
		 */
		if (((bitmap[0] & setbitmap[0]) != bitmap[0]) ||
		    ((bitmap[1] & (setbitmap[1]|NFS_FATTR_MODE)) != bitmap[1])) {
			VATTR_CLEAR_ACTIVE(vap, va_mode);
			error = 0;
			goto tryagain;
		}
	}
	return (error);
}

/*
 * Wait for any pending recovery to complete.
 */
int
nfs_mount_state_wait_for_recovery(struct nfsmount *nmp)
{
	struct timespec ts = { 1, 0 };
	int error = 0, slpflag = NMFLAG(nmp, INTR) ? PCATCH : 0;

	lck_mtx_lock(&nmp->nm_lock);
	while (nmp->nm_state & NFSSTA_RECOVER) {
		if ((error = nfs_sigintr(nmp, NULL, current_thread(), 1)))
			break;
		nfs_mount_sock_thread_wake(nmp);
		msleep(&nmp->nm_state, &nmp->nm_lock, slpflag|(PZERO-1), "nfsrecoverwait", &ts);
		slpflag = 0;
	}
	lck_mtx_unlock(&nmp->nm_lock);

	return (error);
}

/*
 * We're about to use/manipulate NFS mount's open/lock state.
 * Wait for any pending state recovery to complete, then
 * mark the state as being in use (which will hold off
 * the recovery thread until we're done).
 */
int
nfs_mount_state_in_use_start(struct nfsmount *nmp, thread_t thd)
{
	struct timespec ts = { 1, 0 };
	int error = 0, slpflag = (NMFLAG(nmp, INTR) && thd) ? PCATCH : 0;

	if (nfs_mount_gone(nmp))
		return (ENXIO);
	lck_mtx_lock(&nmp->nm_lock);
	if (nmp->nm_state & (NFSSTA_FORCE|NFSSTA_DEAD)) {
		lck_mtx_unlock(&nmp->nm_lock);
		return (ENXIO);
	}
	while (nmp->nm_state & NFSSTA_RECOVER) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 1)))
			break;
		nfs_mount_sock_thread_wake(nmp);
		msleep(&nmp->nm_state, &nmp->nm_lock, slpflag|(PZERO-1), "nfsrecoverwait", &ts);
		slpflag = 0;
	}
	if (!error)
		nmp->nm_stateinuse++;
	lck_mtx_unlock(&nmp->nm_lock);

	return (error);
}

/*
 * We're done using/manipulating the NFS mount's open/lock
 * state.  If the given error indicates that recovery should
 * be performed, we'll initiate recovery.
 */
int
nfs_mount_state_in_use_end(struct nfsmount *nmp, int error)
{
	int restart = nfs_mount_state_error_should_restart(error);

	if (nfs_mount_gone(nmp))
		return (restart);
	lck_mtx_lock(&nmp->nm_lock);
	if (restart && (error != NFSERR_OLD_STATEID) && (error != NFSERR_GRACE)) {
		printf("nfs_mount_state_in_use_end: error %d, initiating recovery for %s, 0x%x\n",
			error, vfs_statfs(nmp->nm_mountp)->f_mntfromname, nmp->nm_stategenid);
		nfs_need_recover(nmp, error);
	}
	if (nmp->nm_stateinuse > 0)
		nmp->nm_stateinuse--;
	else
		panic("NFS mount state in use count underrun");
	if (!nmp->nm_stateinuse && (nmp->nm_state & NFSSTA_RECOVER))
		wakeup(&nmp->nm_stateinuse);
	lck_mtx_unlock(&nmp->nm_lock);
	if (error == NFSERR_GRACE)
		tsleep(&nmp->nm_state, (PZERO-1), "nfsgrace", 2*hz);

	return (restart);
}

/*
 * Does the error mean we should restart/redo a state-related operation?
 */
int
nfs_mount_state_error_should_restart(int error)
{
	switch (error) {
	case NFSERR_STALE_STATEID:
	case NFSERR_STALE_CLIENTID:
	case NFSERR_ADMIN_REVOKED:
	case NFSERR_EXPIRED:
	case NFSERR_OLD_STATEID:
	case NFSERR_BAD_STATEID:
	case NFSERR_GRACE:
		return (1);
	}
	return (0);
}

/*
 * In some cases we may want to limit how many times we restart a
 * state-related operation - e.g. we're repeatedly getting NFSERR_GRACE.
 * Base the limit on the lease (as long as it's not too short).
 */
uint
nfs_mount_state_max_restarts(struct nfsmount *nmp)
{
	return (MAX(nmp->nm_fsattr.nfsa_lease, 60));
}

/*
 * Does the error mean we probably lost a delegation?
 */
int
nfs_mount_state_error_delegation_lost(int error)
{
	switch (error) {
	case NFSERR_STALE_STATEID:
	case NFSERR_ADMIN_REVOKED:
	case NFSERR_EXPIRED:
	case NFSERR_OLD_STATEID:
	case NFSERR_BAD_STATEID:
	case NFSERR_GRACE: /* ugh! (stupid) RFC 3530 specifically disallows CLAIM_DELEGATE_CUR during grace period? */
		return (1);
	}
	return (0);
}


/*
 * Mark an NFS node's open state as busy.
 */
int
nfs_open_state_set_busy(nfsnode_t np, thread_t thd)
{
	struct nfsmount *nmp;
	struct timespec ts = {2, 0};
	int error = 0, slpflag;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	slpflag = (NMFLAG(nmp, INTR) && thd) ? PCATCH : 0;

	lck_mtx_lock(&np->n_openlock);
	while (np->n_openflags & N_OPENBUSY) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 0)))
			break;
		np->n_openflags |= N_OPENWANT;
		msleep(&np->n_openflags, &np->n_openlock, slpflag, "nfs_open_state_set_busy", &ts);
		slpflag = 0;
	}
	if (!error)
		np->n_openflags |= N_OPENBUSY;
	lck_mtx_unlock(&np->n_openlock);

	return (error);
}

/*
 * Clear an NFS node's open state busy flag and wake up
 * anyone wanting it.
 */
void
nfs_open_state_clear_busy(nfsnode_t np)
{
	int wanted;

	lck_mtx_lock(&np->n_openlock);
	if (!(np->n_openflags & N_OPENBUSY))
		panic("nfs_open_state_clear_busy");
	wanted = (np->n_openflags & N_OPENWANT);
	np->n_openflags &= ~(N_OPENBUSY|N_OPENWANT);
	lck_mtx_unlock(&np->n_openlock);
	if (wanted)
		wakeup(&np->n_openflags);
}

/*
 * Search a mount's open owner list for the owner for this credential.
 * If not found and "alloc" is set, then allocate a new one.
 */
struct nfs_open_owner *
nfs_open_owner_find(struct nfsmount *nmp, kauth_cred_t cred, int alloc)
{
	uid_t uid = kauth_cred_getuid(cred);
	struct nfs_open_owner *noop, *newnoop = NULL;

tryagain:
	lck_mtx_lock(&nmp->nm_lock);
	TAILQ_FOREACH(noop, &nmp->nm_open_owners, noo_link) {
		if (kauth_cred_getuid(noop->noo_cred) == uid)
			break;
	}

	if (!noop && !newnoop && alloc) {
		lck_mtx_unlock(&nmp->nm_lock);
		MALLOC(newnoop, struct nfs_open_owner *, sizeof(struct nfs_open_owner), M_TEMP, M_WAITOK);
		if (!newnoop)
			return (NULL);
		bzero(newnoop, sizeof(*newnoop));
		lck_mtx_init(&newnoop->noo_lock, nfs_open_grp, LCK_ATTR_NULL);
		newnoop->noo_mount = nmp;
		kauth_cred_ref(cred);
		newnoop->noo_cred = cred;
		newnoop->noo_name = OSAddAtomic(1, &nfs_open_owner_seqnum);
		TAILQ_INIT(&newnoop->noo_opens);
		goto tryagain;
	}
	if (!noop && newnoop) {
		newnoop->noo_flags |= NFS_OPEN_OWNER_LINK;
		TAILQ_INSERT_HEAD(&nmp->nm_open_owners, newnoop, noo_link);
		noop = newnoop;
	}
	lck_mtx_unlock(&nmp->nm_lock);

	if (newnoop && (noop != newnoop))
		nfs_open_owner_destroy(newnoop);

	if (noop)
		nfs_open_owner_ref(noop);

	return (noop);
}

/*
 * destroy an open owner that's no longer needed
 */
void
nfs_open_owner_destroy(struct nfs_open_owner *noop)
{
	if (noop->noo_cred)
		kauth_cred_unref(&noop->noo_cred);
	lck_mtx_destroy(&noop->noo_lock, nfs_open_grp);
	FREE(noop, M_TEMP);
}

/*
 * acquire a reference count on an open owner
 */
void
nfs_open_owner_ref(struct nfs_open_owner *noop)
{
	lck_mtx_lock(&noop->noo_lock);
	noop->noo_refcnt++;
	lck_mtx_unlock(&noop->noo_lock);
}

/*
 * drop a reference count on an open owner and destroy it if
 * it is no longer referenced and no longer on the mount's list.
 */
void
nfs_open_owner_rele(struct nfs_open_owner *noop)
{
	lck_mtx_lock(&noop->noo_lock);
	if (noop->noo_refcnt < 1)
		panic("nfs_open_owner_rele: no refcnt");
	noop->noo_refcnt--;
	if (!noop->noo_refcnt && (noop->noo_flags & NFS_OPEN_OWNER_BUSY))
		panic("nfs_open_owner_rele: busy");
	/* XXX we may potentially want to clean up idle/unused open owner structures */
	if (noop->noo_refcnt || (noop->noo_flags & NFS_OPEN_OWNER_LINK)) {
		lck_mtx_unlock(&noop->noo_lock);
		return;
	}
	/* owner is no longer referenced or linked to mount, so destroy it */
	lck_mtx_unlock(&noop->noo_lock);
	nfs_open_owner_destroy(noop);
}

/*
 * Mark an open owner as busy because we are about to
 * start an operation that uses and updates open owner state.
 */
int
nfs_open_owner_set_busy(struct nfs_open_owner *noop, thread_t thd)
{
	struct nfsmount *nmp;
	struct timespec ts = {2, 0};
	int error = 0, slpflag;

	nmp = noop->noo_mount;
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	slpflag = (NMFLAG(nmp, INTR) && thd) ? PCATCH : 0;

	lck_mtx_lock(&noop->noo_lock);
	while (noop->noo_flags & NFS_OPEN_OWNER_BUSY) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 0)))
			break;
		noop->noo_flags |= NFS_OPEN_OWNER_WANT;
		msleep(noop, &noop->noo_lock, slpflag, "nfs_open_owner_set_busy", &ts);
		slpflag = 0;
	}
	if (!error)
		noop->noo_flags |= NFS_OPEN_OWNER_BUSY;
	lck_mtx_unlock(&noop->noo_lock);

	return (error);
}

/*
 * Clear the busy flag on an open owner and wake up anyone waiting
 * to mark it busy.
 */
void
nfs_open_owner_clear_busy(struct nfs_open_owner *noop)
{
	int wanted;

	lck_mtx_lock(&noop->noo_lock);
	if (!(noop->noo_flags & NFS_OPEN_OWNER_BUSY))
		panic("nfs_open_owner_clear_busy");
	wanted = (noop->noo_flags & NFS_OPEN_OWNER_WANT);
	noop->noo_flags &= ~(NFS_OPEN_OWNER_BUSY|NFS_OPEN_OWNER_WANT);
	lck_mtx_unlock(&noop->noo_lock);
	if (wanted)
		wakeup(noop);
}

/*
 * Given an open/lock owner and an error code, increment the
 * sequence ID if appropriate.
 */
void
nfs_owner_seqid_increment(struct nfs_open_owner *noop, struct nfs_lock_owner *nlop, int error)
{
	switch (error) {
	case NFSERR_STALE_CLIENTID:
	case NFSERR_STALE_STATEID:
	case NFSERR_OLD_STATEID:
	case NFSERR_BAD_STATEID:
	case NFSERR_BAD_SEQID:
	case NFSERR_BADXDR:
	case NFSERR_RESOURCE:
	case NFSERR_NOFILEHANDLE:
		/* do not increment the open seqid on these errors */
		return;
	}
	if (noop)
		noop->noo_seqid++;
	if (nlop)
		nlop->nlo_seqid++;
}

/*
 * Search a node's open file list for any conflicts with this request.
 * Also find this open owner's open file structure.
 * If not found and "alloc" is set, then allocate one.
 */
int
nfs_open_file_find(
	nfsnode_t np,
	struct nfs_open_owner *noop,
	struct nfs_open_file **nofpp,
	uint32_t accessMode,
	uint32_t denyMode,
	int alloc)
{
	*nofpp = NULL;
	return nfs_open_file_find_internal(np, noop, nofpp, accessMode, denyMode, alloc);
}

/*
 * Internally, allow using a provisional nodeless nofp (passed in via *nofpp)
 * if an existing one is not found.  This is used in "create" scenarios to
 * officially add the provisional nofp to the node once the node is created.
 */
int
nfs_open_file_find_internal(
	nfsnode_t np,
	struct nfs_open_owner *noop,
	struct nfs_open_file **nofpp,
	uint32_t accessMode,
	uint32_t denyMode,
	int alloc)
{
	struct nfs_open_file *nofp = NULL, *nofp2, *newnofp = NULL;

	if (!np)
		goto alloc;
tryagain:
	lck_mtx_lock(&np->n_openlock);
	TAILQ_FOREACH(nofp2, &np->n_opens, nof_link) {
		if (nofp2->nof_owner == noop) {
			nofp = nofp2;
			if (!accessMode)
				break;
		}
		if ((accessMode & nofp2->nof_deny) || (denyMode & nofp2->nof_access)) {
			/* This request conflicts with an existing open on this client. */
			lck_mtx_unlock(&np->n_openlock);
			return (EACCES);
		}
	}

	/*
	 * If this open owner doesn't have an open
	 * file structure yet, we create one for it.
	 */
	if (!nofp && !*nofpp && !newnofp && alloc) {
		lck_mtx_unlock(&np->n_openlock);
alloc:
		MALLOC(newnofp, struct nfs_open_file *, sizeof(struct nfs_open_file), M_TEMP, M_WAITOK);
		if (!newnofp)
			return (ENOMEM);
		bzero(newnofp, sizeof(*newnofp));
		lck_mtx_init(&newnofp->nof_lock, nfs_open_grp, LCK_ATTR_NULL);
		newnofp->nof_owner = noop;
		nfs_open_owner_ref(noop);
		newnofp->nof_np = np;
		lck_mtx_lock(&noop->noo_lock);
		TAILQ_INSERT_HEAD(&noop->noo_opens, newnofp, nof_oolink);
		lck_mtx_unlock(&noop->noo_lock);
		if (np)
			goto tryagain;
	}
	if (!nofp) {
		if (*nofpp) {
			(*nofpp)->nof_np = np;
			nofp = *nofpp;
		} else {
			nofp = newnofp;
		}
		if (nofp && np)
			TAILQ_INSERT_HEAD(&np->n_opens, nofp, nof_link);
	}
	if (np)
		lck_mtx_unlock(&np->n_openlock);

	if (alloc && newnofp && (nofp != newnofp))
		nfs_open_file_destroy(newnofp);

	*nofpp = nofp;
	return (nofp ? 0 : ESRCH);
}

/*
 * Destroy an open file structure.
 */
void
nfs_open_file_destroy(struct nfs_open_file *nofp)
{
	lck_mtx_lock(&nofp->nof_owner->noo_lock);
	TAILQ_REMOVE(&nofp->nof_owner->noo_opens, nofp, nof_oolink);
	lck_mtx_unlock(&nofp->nof_owner->noo_lock);
	nfs_open_owner_rele(nofp->nof_owner);
	lck_mtx_destroy(&nofp->nof_lock, nfs_open_grp);
	FREE(nofp, M_TEMP);
}

/*
 * Mark an open file as busy because we are about to
 * start an operation that uses and updates open file state.
 */
int
nfs_open_file_set_busy(struct nfs_open_file *nofp, thread_t thd)
{
	struct nfsmount *nmp;
	struct timespec ts = {2, 0};
	int error = 0, slpflag;

	nmp = nofp->nof_owner->noo_mount;
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	slpflag = (NMFLAG(nmp, INTR) && thd) ? PCATCH : 0;

	lck_mtx_lock(&nofp->nof_lock);
	while (nofp->nof_flags & NFS_OPEN_FILE_BUSY) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 0)))
			break;
		nofp->nof_flags |= NFS_OPEN_FILE_WANT;
		msleep(nofp, &nofp->nof_lock, slpflag, "nfs_open_file_set_busy", &ts);
		slpflag = 0;
	}
	if (!error)
		nofp->nof_flags |= NFS_OPEN_FILE_BUSY;
	lck_mtx_unlock(&nofp->nof_lock);

	return (error);
}

/*
 * Clear the busy flag on an open file and wake up anyone waiting
 * to mark it busy.
 */
void
nfs_open_file_clear_busy(struct nfs_open_file *nofp)
{
	int wanted;

	lck_mtx_lock(&nofp->nof_lock);
	if (!(nofp->nof_flags & NFS_OPEN_FILE_BUSY))
		panic("nfs_open_file_clear_busy");
	wanted = (nofp->nof_flags & NFS_OPEN_FILE_WANT);
	nofp->nof_flags &= ~(NFS_OPEN_FILE_BUSY|NFS_OPEN_FILE_WANT);
	lck_mtx_unlock(&nofp->nof_lock);
	if (wanted)
		wakeup(nofp);
}

/*
 * Add the open state for the given access/deny modes to this open file.
 */
void
nfs_open_file_add_open(struct nfs_open_file *nofp, uint32_t accessMode, uint32_t denyMode, int delegated)
{
	lck_mtx_lock(&nofp->nof_lock);
	nofp->nof_access |= accessMode;
	nofp->nof_deny |= denyMode;

	if (delegated) {
		if (denyMode == NFS_OPEN_SHARE_DENY_NONE) {
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_d_r++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_d_w++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_d_rw++;
		} else if (denyMode == NFS_OPEN_SHARE_DENY_WRITE) {
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_d_r_dw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_d_w_dw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_d_rw_dw++;
		} else { /* NFS_OPEN_SHARE_DENY_BOTH */
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_d_r_drw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_d_w_drw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_d_rw_drw++;
		}
	} else {
		if (denyMode == NFS_OPEN_SHARE_DENY_NONE) {
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_r++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_w++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_rw++;
		} else if (denyMode == NFS_OPEN_SHARE_DENY_WRITE) {
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_r_dw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_w_dw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_rw_dw++;
		} else { /* NFS_OPEN_SHARE_DENY_BOTH */
			if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
				nofp->nof_r_drw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
				nofp->nof_w_drw++;
			else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
				nofp->nof_rw_drw++;
		}
	}

	nofp->nof_opencnt++;
	lck_mtx_unlock(&nofp->nof_lock);
}

/*
 * Find which particular open combo will be closed and report what
 * the new modes will be and whether the open was delegated.
 */
void
nfs_open_file_remove_open_find(
	struct nfs_open_file *nofp,
	uint32_t accessMode,
	uint32_t denyMode,
	uint32_t *newAccessMode,
	uint32_t *newDenyMode,
	int *delegated)
{
	/*
	 * Calculate new modes: a mode bit gets removed when there's only
	 * one count in all the corresponding counts
	 */
	*newAccessMode = nofp->nof_access;
	*newDenyMode = nofp->nof_deny;

	if ((accessMode & NFS_OPEN_SHARE_ACCESS_READ) &&
	    (nofp->nof_access & NFS_OPEN_SHARE_ACCESS_READ) &&
	    ((nofp->nof_r + nofp->nof_d_r +
	      nofp->nof_rw + nofp->nof_d_rw +
	      nofp->nof_r_dw + nofp->nof_d_r_dw +
	      nofp->nof_rw_dw + nofp->nof_d_rw_dw +
	      nofp->nof_r_drw + nofp->nof_d_r_drw +
	      nofp->nof_rw_dw + nofp->nof_d_rw_dw) == 1))
		*newAccessMode &= ~NFS_OPEN_SHARE_ACCESS_READ;
	if ((accessMode & NFS_OPEN_SHARE_ACCESS_WRITE) &&
	    (nofp->nof_access & NFS_OPEN_SHARE_ACCESS_WRITE) &&
	    ((nofp->nof_w + nofp->nof_d_w +
	      nofp->nof_rw + nofp->nof_d_rw +
	      nofp->nof_w_dw + nofp->nof_d_w_dw +
	      nofp->nof_rw_dw + nofp->nof_d_rw_dw +
	      nofp->nof_w_drw + nofp->nof_d_w_drw +
	      nofp->nof_rw_dw + nofp->nof_d_rw_dw) == 1))
		*newAccessMode &= ~NFS_OPEN_SHARE_ACCESS_WRITE;
	if ((denyMode & NFS_OPEN_SHARE_DENY_READ) &&
	    (nofp->nof_deny & NFS_OPEN_SHARE_DENY_READ) &&
	    ((nofp->nof_r_drw + nofp->nof_d_r_drw +
	      nofp->nof_w_drw + nofp->nof_d_w_drw +
	      nofp->nof_rw_drw + nofp->nof_d_rw_drw) == 1))
		*newDenyMode &= ~NFS_OPEN_SHARE_DENY_READ;
	if ((denyMode & NFS_OPEN_SHARE_DENY_WRITE) &&
	    (nofp->nof_deny & NFS_OPEN_SHARE_DENY_WRITE) &&
	    ((nofp->nof_r_drw + nofp->nof_d_r_drw +
	      nofp->nof_w_drw + nofp->nof_d_w_drw +
	      nofp->nof_rw_drw + nofp->nof_d_rw_drw +
	      nofp->nof_r_dw + nofp->nof_d_r_dw +
	      nofp->nof_w_dw + nofp->nof_d_w_dw +
	      nofp->nof_rw_dw + nofp->nof_d_rw_dw) == 1))
		*newDenyMode &= ~NFS_OPEN_SHARE_DENY_WRITE;

	/* Find the corresponding open access/deny mode counter. */
	if (denyMode == NFS_OPEN_SHARE_DENY_NONE) {
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
			*delegated = (nofp->nof_d_r != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
			*delegated = (nofp->nof_d_w != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
			*delegated = (nofp->nof_d_rw != 0);
		else
			*delegated = 0;
	} else if (denyMode == NFS_OPEN_SHARE_DENY_WRITE) {
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
			*delegated = (nofp->nof_d_r_dw != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
			*delegated = (nofp->nof_d_w_dw != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
			*delegated = (nofp->nof_d_rw_dw != 0);
		else
			*delegated = 0;
	} else { /* NFS_OPEN_SHARE_DENY_BOTH */
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ)
			*delegated = (nofp->nof_d_r_drw != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE)
			*delegated = (nofp->nof_d_w_drw != 0);
		else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH)
			*delegated = (nofp->nof_d_rw_drw != 0);
		else
			*delegated = 0;
	}
}

/*
 * Remove the open state for the given access/deny modes to this open file.
 */
void
nfs_open_file_remove_open(struct nfs_open_file *nofp, uint32_t accessMode, uint32_t denyMode)
{
	uint32_t newAccessMode, newDenyMode;
	int delegated = 0;

	lck_mtx_lock(&nofp->nof_lock);
	nfs_open_file_remove_open_find(nofp, accessMode, denyMode, &newAccessMode, &newDenyMode, &delegated);

	/* Decrement the corresponding open access/deny mode counter. */
	if (denyMode == NFS_OPEN_SHARE_DENY_NONE) {
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ) {
			if (delegated) {
				if (nofp->nof_d_r == 0)
					NP(nofp->nof_np, "nfs: open(R) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_r--;
			} else {
				if (nofp->nof_r == 0)
					NP(nofp->nof_np, "nfs: open(R) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_r--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE) {
			if (delegated) {
				if (nofp->nof_d_w == 0)
					NP(nofp->nof_np, "nfs: open(W) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_w--;
			} else {
				if (nofp->nof_w == 0)
					NP(nofp->nof_np, "nfs: open(W) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_w--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH) {
			if (delegated) {
				if (nofp->nof_d_rw == 0)
					NP(nofp->nof_np, "nfs: open(RW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_rw--;
			} else {
				if (nofp->nof_rw == 0)
					NP(nofp->nof_np, "nfs: open(RW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_rw--;
			}
		}
	} else if (denyMode == NFS_OPEN_SHARE_DENY_WRITE) {
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ) {
			if (delegated) {
				if (nofp->nof_d_r_dw == 0)
					NP(nofp->nof_np, "nfs: open(R,DW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_r_dw--;
			} else {
				if (nofp->nof_r_dw == 0)
					NP(nofp->nof_np, "nfs: open(R,DW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_r_dw--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE) {
			if (delegated) {
				if (nofp->nof_d_w_dw == 0)
					NP(nofp->nof_np, "nfs: open(W,DW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_w_dw--;
			} else {
				if (nofp->nof_w_dw == 0)
					NP(nofp->nof_np, "nfs: open(W,DW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_w_dw--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH) {
			if (delegated) {
				if (nofp->nof_d_rw_dw == 0)
					NP(nofp->nof_np, "nfs: open(RW,DW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_rw_dw--;
			} else {
				if (nofp->nof_rw_dw == 0)
					NP(nofp->nof_np, "nfs: open(RW,DW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_rw_dw--;
			}
		}
	} else { /* NFS_OPEN_SHARE_DENY_BOTH */
		if (accessMode == NFS_OPEN_SHARE_ACCESS_READ) {
			if (delegated) {
				if (nofp->nof_d_r_drw == 0)
					NP(nofp->nof_np, "nfs: open(R,DRW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_r_drw--;
			} else {
				if (nofp->nof_r_drw == 0)
					NP(nofp->nof_np, "nfs: open(R,DRW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_r_drw--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_WRITE) {
			if (delegated) {
				if (nofp->nof_d_w_drw == 0)
					NP(nofp->nof_np, "nfs: open(W,DRW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_w_drw--;
			} else {
				if (nofp->nof_w_drw == 0)
					NP(nofp->nof_np, "nfs: open(W,DRW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_w_drw--;
			}
		} else if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH) {
			if (delegated) {
				if (nofp->nof_d_rw_drw == 0)
					NP(nofp->nof_np, "nfs: open(RW,DRW) delegated count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_d_rw_drw--;
			} else {
				if (nofp->nof_rw_drw == 0)
					NP(nofp->nof_np, "nfs: open(RW,DRW) count underrun, %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
				else
					nofp->nof_rw_drw--;
			}
		}
	}

	/* update the modes */
	nofp->nof_access = newAccessMode;
	nofp->nof_deny = newDenyMode;
	nofp->nof_opencnt--;
	lck_mtx_unlock(&nofp->nof_lock);
}


/*
 * Get the current (delegation, lock, open, default) stateid for this node.
 * If node has a delegation, use that stateid.
 * If pid has a lock, use the lockowner's stateid.
 * Or use the open file's stateid.
 * If no open file, use a default stateid of all ones.
 */
void
nfs_get_stateid(nfsnode_t np, thread_t thd, kauth_cred_t cred, nfs_stateid *sid)
{
	struct nfsmount *nmp = NFSTONMP(np);
	proc_t p = thd ? get_bsdthreadtask_info(thd) : current_proc();  // XXX async I/O requests don't have a thread
	struct nfs_open_owner *noop = NULL;
	struct nfs_open_file *nofp = NULL;
	struct nfs_lock_owner *nlop = NULL;
	nfs_stateid *s = NULL;

	if (np->n_openflags & N_DELEG_MASK) {
		s = &np->n_dstateid;
	} else {
		if (p)
			nlop = nfs_lock_owner_find(np, p, 0);
		if (nlop && !TAILQ_EMPTY(&nlop->nlo_locks)) {
			/* we hold locks, use lock stateid */
			s = &nlop->nlo_stateid;
		} else if (((noop = nfs_open_owner_find(nmp, cred, 0))) &&
			 (nfs_open_file_find(np, noop, &nofp, 0, 0, 0) == 0) &&
			 !(nofp->nof_flags & NFS_OPEN_FILE_LOST) &&
			 nofp->nof_access) {
			/* we (should) have the file open, use open stateid */
			if (nofp->nof_flags & NFS_OPEN_FILE_REOPEN)
				nfs4_reopen(nofp, thd);
			if (!(nofp->nof_flags & NFS_OPEN_FILE_LOST))
				s = &nofp->nof_stateid;
		}
	}

	if (s) {
		sid->seqid = s->seqid;
		sid->other[0] = s->other[0];
		sid->other[1] = s->other[1];
		sid->other[2] = s->other[2];
	} else {
		/* named attributes may not have a stateid for reads, so don't complain for them */
		if (!(np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			NP(np, "nfs_get_stateid: no stateid");
		sid->seqid = sid->other[0] = sid->other[1] = sid->other[2] = 0xffffffff;
	}
	if (nlop)
		nfs_lock_owner_rele(nlop);
	if (noop)
		nfs_open_owner_rele(noop);
}


/*
 * When we have a delegation, we may be able to perform the OPEN locally.
 * Perform the OPEN by checking the delegation ACE and/or checking via ACCESS.
 */
int
nfs4_open_delegated(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	uint32_t accessMode,
	uint32_t denyMode,
	vfs_context_t ctx)
{
	int error = 0, ismember, readtoo = 0, authorized = 0;
	uint32_t action;
	struct kauth_acl_eval eval;
	kauth_cred_t cred = vfs_context_ucred(ctx);

	if (!(accessMode & NFS_OPEN_SHARE_ACCESS_READ)) {
		/*
		 * Try to open it for read access too,
		 * so the buffer cache can read data.
		 */
		readtoo = 1;
		accessMode |= NFS_OPEN_SHARE_ACCESS_READ;
	}

tryagain:
	action = 0;
	if (accessMode & NFS_OPEN_SHARE_ACCESS_READ)
		action |= KAUTH_VNODE_READ_DATA;
	if (accessMode & NFS_OPEN_SHARE_ACCESS_WRITE)
		action |= KAUTH_VNODE_WRITE_DATA;

	/* evaluate ACE (if we have one) */
	if (np->n_dace.ace_flags) {
		eval.ae_requested = action;
		eval.ae_acl = &np->n_dace;
		eval.ae_count = 1;
		eval.ae_options = 0;
		if (np->n_vattr.nva_uid == kauth_cred_getuid(cred))
			eval.ae_options |= KAUTH_AEVAL_IS_OWNER;
		error = kauth_cred_ismember_gid(cred, np->n_vattr.nva_gid, &ismember);
		if (!error && ismember)
			eval.ae_options |= KAUTH_AEVAL_IN_GROUP;

		eval.ae_exp_gall = KAUTH_VNODE_GENERIC_ALL_BITS;
		eval.ae_exp_gread = KAUTH_VNODE_GENERIC_READ_BITS;
		eval.ae_exp_gwrite = KAUTH_VNODE_GENERIC_WRITE_BITS;
		eval.ae_exp_gexec = KAUTH_VNODE_GENERIC_EXECUTE_BITS;

		error = kauth_acl_evaluate(cred, &eval);

		if (!error && (eval.ae_result == KAUTH_RESULT_ALLOW))
			authorized = 1;
	}

	if (!authorized) {
		/* need to ask the server via ACCESS */
		struct vnop_access_args naa;
		naa.a_desc = &vnop_access_desc;
		naa.a_vp = NFSTOV(np);
		naa.a_action = action;
		naa.a_context = ctx;
		if (!(error = nfs_vnop_access(&naa)))
			authorized = 1;
	}

	if (!authorized) {
		if (readtoo) {
			/* try again without the extra read access */
			accessMode &= ~NFS_OPEN_SHARE_ACCESS_READ;
			readtoo = 0;
			goto tryagain;
		}
		return (error ? error : EACCES);
	}

	nfs_open_file_add_open(nofp, accessMode, denyMode, 1);

	return (0);
}


/*
 * Open a file with the given access/deny modes.
 *
 * If we have a delegation, we may be able to handle the open locally.
 * Otherwise, we will always send the open RPC even if this open's mode is
 * a subset of all the existing opens.  This makes sure that we will always
 * be able to do a downgrade to any of the open modes.
 *
 * Note: local conflicts should have already been checked in nfs_open_file_find().
 */
int
nfs4_open(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	uint32_t accessMode,
	uint32_t denyMode,
	vfs_context_t ctx)
{
	vnode_t vp = NFSTOV(np);
	vnode_t dvp = NULL;
	struct componentname cn;
	const char *vname = NULL;
	size_t namelen;
	char smallname[128];
	char *filename = NULL;
	int error = 0, readtoo = 0;

	/*
	 * We can handle the OPEN ourselves if we have a delegation,
	 * unless it's a read delegation and the open is asking for
	 * either write access or deny read.  We also don't bother to
	 * use the delegation if it's being returned.
	 */
	if (np->n_openflags & N_DELEG_MASK) {
		if ((error = nfs_open_state_set_busy(np, vfs_context_thread(ctx))))
			return (error);
		if ((np->n_openflags & N_DELEG_MASK) && !(np->n_openflags & N_DELEG_RETURN) &&
		    (((np->n_openflags & N_DELEG_MASK) == N_DELEG_WRITE) ||
		     (!(accessMode & NFS_OPEN_SHARE_ACCESS_WRITE) && !(denyMode & NFS_OPEN_SHARE_DENY_READ)))) {
			error = nfs4_open_delegated(np, nofp, accessMode, denyMode, ctx);
			nfs_open_state_clear_busy(np);
			return (error);
		}
		nfs_open_state_clear_busy(np);
	}

	/*
	 * [sigh] We can't trust VFS to get the parent right for named
	 * attribute nodes.  (It likes to reparent the nodes after we've
	 * created them.)  Luckily we can probably get the right parent
	 * from the n_parent we have stashed away.
	 */
	if ((np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR) &&
	    (((dvp = np->n_parent)) && (error = vnode_get(dvp))))
		dvp = NULL;
	if (!dvp)
		dvp = vnode_getparent(vp);
	vname = vnode_getname(vp);
	if (!dvp || !vname) {
		if (!error)
			error = EIO;
		goto out;
	}
	filename = &smallname[0];
	namelen = snprintf(filename, sizeof(smallname), "%s", vname);
	if (namelen >= sizeof(smallname)) {
		MALLOC(filename, char *, namelen+1, M_TEMP, M_WAITOK);
		if (!filename) {
			error = ENOMEM;
			goto out;
		}
		snprintf(filename, namelen+1, "%s", vname);
	}
	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = filename;
	cn.cn_namelen = namelen;

	if (!(accessMode & NFS_OPEN_SHARE_ACCESS_READ)) {
		/*
		 * Try to open it for read access too,
		 * so the buffer cache can read data.
		 */
		readtoo = 1;
		accessMode |= NFS_OPEN_SHARE_ACCESS_READ;
	}
tryagain:
	error = nfs4_open_rpc(nofp, ctx, &cn, NULL, dvp, &vp, NFS_OPEN_NOCREATE, accessMode, denyMode);
	if (error) {
		if (!nfs_mount_state_error_should_restart(error) &&
		    (error != EINTR) && (error != ERESTART) && readtoo) {
			/* try again without the extra read access */
			accessMode &= ~NFS_OPEN_SHARE_ACCESS_READ;
			readtoo = 0;
			goto tryagain;
		}
		goto out;
	}
	nfs_open_file_add_open(nofp, accessMode, denyMode, 0);
out:
	if (filename && (filename != &smallname[0]))
		FREE(filename, M_TEMP);
	if (vname)
		vnode_putname(vname);
	if (dvp != NULLVP)
		vnode_put(dvp);
	return (error);
}

int
nfs_vnop_mmap(
	struct vnop_mmap_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		int a_fflags;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	vnode_t vp = ap->a_vp;
	nfsnode_t np = VTONFS(vp);
	int error = 0, accessMode, denyMode, delegated;
	struct nfsmount *nmp;
	struct nfs_open_owner *noop = NULL;
	struct nfs_open_file *nofp = NULL;

	nmp = VTONMP(vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!vnode_isreg(vp) || !(ap->a_fflags & (PROT_READ|PROT_WRITE)))
		return (EINVAL);
	if (np->n_flag & NREVOKE)
		return (EIO);

	/*
	 * fflags contains some combination of: PROT_READ, PROT_WRITE
	 * Since it's not possible to mmap() without having the file open for reading,
	 * read access is always there (regardless if PROT_READ is not set).
	 */
	accessMode = NFS_OPEN_SHARE_ACCESS_READ;
	if (ap->a_fflags & PROT_WRITE)
		accessMode |= NFS_OPEN_SHARE_ACCESS_WRITE;
	denyMode = NFS_OPEN_SHARE_DENY_NONE;

	noop = nfs_open_owner_find(nmp, vfs_context_ucred(ctx), 1);
	if (!noop)
		return (ENOMEM);

restart:
	error = nfs_mount_state_in_use_start(nmp, NULL);
	if (error) {
		nfs_open_owner_rele(noop);
		return (error);
	}
	if (np->n_flag & NREVOKE) {
		error = EIO;
		nfs_mount_state_in_use_end(nmp, 0);
		nfs_open_owner_rele(noop);
		return (error);
	}

	error = nfs_open_file_find(np, noop, &nofp, 0, 0, 1);
	if (error || (!error && (nofp->nof_flags & NFS_OPEN_FILE_LOST))) {
		NP(np, "nfs_vnop_mmap: no open file for owner, error %d, %d", error, kauth_cred_getuid(noop->noo_cred));
		error = EPERM;
	}
	if (!error && (nofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
		nfs_mount_state_in_use_end(nmp, 0);
		error = nfs4_reopen(nofp, NULL);
		nofp = NULL;
		if (!error)
			goto restart;
	}
	if (!error)
		error = nfs_open_file_set_busy(nofp, NULL);
	if (error) {
		nofp = NULL;
		goto out;
	}

	/*
	 * The open reference for mmap must mirror an existing open because
	 * we may need to reclaim it after the file is closed.
	 * So grab another open count matching the accessMode passed in.
	 * If we already had an mmap open, prefer read/write without deny mode.
	 * This means we may have to drop the current mmap open first.
	 */

	if (!nofp->nof_access) {
		if (accessMode != NFS_OPEN_SHARE_ACCESS_READ) {
			/* not asking for just read access -> fail */
			error = EPERM;
			goto out;
		}
		/* we don't have the file open, so open it for read access */
		if (nmp->nm_vers < NFS_VER4) {
			/* NFS v2/v3 opens are always allowed - so just add it. */
			nfs_open_file_add_open(nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE, 0);
			error = 0;
		} else {
			error = nfs4_open(np, nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE, ctx);
		}
		if (!error)
			nofp->nof_flags |= NFS_OPEN_FILE_NEEDCLOSE;
		if (error)
			goto out;
	}

	/* determine deny mode for open */
	if (accessMode == NFS_OPEN_SHARE_ACCESS_BOTH) {
		if (nofp->nof_d_rw || nofp->nof_d_rw_dw || nofp->nof_d_rw_drw) {
			delegated = 1;
			if (nofp->nof_d_rw)
				denyMode = NFS_OPEN_SHARE_DENY_NONE;
			else if (nofp->nof_d_rw_dw)
				denyMode = NFS_OPEN_SHARE_DENY_WRITE;
			else if (nofp->nof_d_rw_drw)
				denyMode = NFS_OPEN_SHARE_DENY_BOTH;
		} else if (nofp->nof_rw || nofp->nof_rw_dw || nofp->nof_rw_drw) {
			delegated = 0;
			if (nofp->nof_rw)
				denyMode = NFS_OPEN_SHARE_DENY_NONE;
			else if (nofp->nof_rw_dw)
				denyMode = NFS_OPEN_SHARE_DENY_WRITE;
			else if (nofp->nof_rw_drw)
				denyMode = NFS_OPEN_SHARE_DENY_BOTH;
		} else {
			error = EPERM;
		}
	} else { /* NFS_OPEN_SHARE_ACCESS_READ */
		if (nofp->nof_d_r || nofp->nof_d_r_dw || nofp->nof_d_r_drw) {
			delegated = 1;
			if (nofp->nof_d_r)
				denyMode = NFS_OPEN_SHARE_DENY_NONE;
			else if (nofp->nof_d_r_dw)
				denyMode = NFS_OPEN_SHARE_DENY_WRITE;
			else if (nofp->nof_d_r_drw)
				denyMode = NFS_OPEN_SHARE_DENY_BOTH;
		} else if (nofp->nof_r || nofp->nof_r_dw || nofp->nof_r_drw) {
			delegated = 0;
			if (nofp->nof_r)
				denyMode = NFS_OPEN_SHARE_DENY_NONE;
			else if (nofp->nof_r_dw)
				denyMode = NFS_OPEN_SHARE_DENY_WRITE;
			else if (nofp->nof_r_drw)
				denyMode = NFS_OPEN_SHARE_DENY_BOTH;
		} else {
			error = EPERM;
		}
	}
	if (error) /* mmap mode without proper open mode */
		goto out;

	/*
	 * If the existing mmap access is more than the new access OR the
	 * existing access is the same and the existing deny mode is less,
	 * then we'll stick with the existing mmap open mode.
	 */
	if ((nofp->nof_mmap_access > accessMode) ||
	    ((nofp->nof_mmap_access == accessMode) && (nofp->nof_mmap_deny <= denyMode)))
		goto out;

	/* update mmap open mode */
	if (nofp->nof_mmap_access) {
		error = nfs_close(np, nofp, nofp->nof_mmap_access, nofp->nof_mmap_deny, ctx);
		if (error) {
			if (!nfs_mount_state_error_should_restart(error))
				NP(np, "nfs_vnop_mmap: close of previous mmap mode failed: %d, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
			NP(np, "nfs_vnop_mmap: update, close error %d, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
			goto out;
		}
		nofp->nof_mmap_access = nofp->nof_mmap_deny = 0;
	}

	nfs_open_file_add_open(nofp, accessMode, denyMode, delegated);
	nofp->nof_mmap_access = accessMode;
	nofp->nof_mmap_deny = denyMode;

out:
	if (nofp)
		nfs_open_file_clear_busy(nofp);
	if (nfs_mount_state_in_use_end(nmp, error)) {
		nofp = NULL;
		goto restart;
	}
	if (noop)
		nfs_open_owner_rele(noop);

	if (!error) {
		int ismapped = 0;
		nfs_node_lock_force(np);
		if ((np->n_flag & NISMAPPED) == 0) {
			np->n_flag |= NISMAPPED;
			ismapped = 1;
		}
		nfs_node_unlock(np);
		if (ismapped) {
			lck_mtx_lock(&nmp->nm_lock);
			nmp->nm_state &= ~NFSSTA_SQUISHY;
			nmp->nm_curdeadtimeout = nmp->nm_deadtimeout;
			if (nmp->nm_curdeadtimeout <= 0)
				nmp->nm_deadto_start = 0;
			nmp->nm_mappers++;
			lck_mtx_unlock(&nmp->nm_lock);
		}
	}

	return (error);
}


int
nfs_vnop_mnomap(
	struct vnop_mnomap_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	vnode_t vp = ap->a_vp;
	nfsnode_t np = VTONFS(vp);
	struct nfsmount *nmp;
	struct nfs_open_file *nofp = NULL;
	off_t size;
	int error;
	int is_mapped_flag = 0;

	nmp = VTONMP(vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	nfs_node_lock_force(np);
	if (np->n_flag & NISMAPPED) {
		is_mapped_flag = 1;
		np->n_flag &= ~NISMAPPED;
	}
	nfs_node_unlock(np);
	if (is_mapped_flag) {
		lck_mtx_lock(&nmp->nm_lock);
		if (nmp->nm_mappers)
			nmp->nm_mappers--;
		else
			NP(np, "nfs_vnop_mnomap: removing mmap reference from mount, but mount has no files mmapped");
		lck_mtx_unlock(&nmp->nm_lock);
	}

	/* flush buffers/ubc before we drop the open (in case it's our last open) */
	nfs_flush(np, MNT_WAIT, vfs_context_thread(ctx), V_IGNORE_WRITEERR);
	if (UBCINFOEXISTS(vp) && (size = ubc_getsize(vp)))
		ubc_msync(vp, 0, size, NULL, UBC_PUSHALL | UBC_SYNC);

	/* walk all open files and close all mmap opens */
loop:
	error = nfs_mount_state_in_use_start(nmp, NULL);
	if (error)
		return (error);
	lck_mtx_lock(&np->n_openlock);
	TAILQ_FOREACH(nofp, &np->n_opens, nof_link) {
		if (!nofp->nof_mmap_access)
			continue;
		lck_mtx_unlock(&np->n_openlock);
		if (nofp->nof_flags & NFS_OPEN_FILE_REOPEN) {
			nfs_mount_state_in_use_end(nmp, 0);
			error = nfs4_reopen(nofp, NULL);
			if (!error)
				goto loop;
		}
		if (!error)
			error = nfs_open_file_set_busy(nofp, NULL);
		if (error) {
			lck_mtx_lock(&np->n_openlock);
			break;
		}
		if (nofp->nof_mmap_access) {
			error = nfs_close(np, nofp, nofp->nof_mmap_access, nofp->nof_mmap_deny, ctx);
			if (!nfs_mount_state_error_should_restart(error)) {
				if (error) /* not a state-operation-restarting error, so just clear the access */
					NP(np, "nfs_vnop_mnomap: close of mmap mode failed: %d, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
				nofp->nof_mmap_access = nofp->nof_mmap_deny = 0;
			}
			if (error)
				NP(np, "nfs_vnop_mnomap: error %d, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
		}
		nfs_open_file_clear_busy(nofp);
		nfs_mount_state_in_use_end(nmp, error);
		goto loop;
	}
	lck_mtx_unlock(&np->n_openlock);
	nfs_mount_state_in_use_end(nmp, error);
	return (error);
}

/*
 * Search a node's lock owner list for the owner for this process.
 * If not found and "alloc" is set, then allocate a new one.
 */
struct nfs_lock_owner *
nfs_lock_owner_find(nfsnode_t np, proc_t p, int alloc)
{
	pid_t pid = proc_pid(p);
	struct nfs_lock_owner *nlop, *newnlop = NULL;

tryagain:
	lck_mtx_lock(&np->n_openlock);
	TAILQ_FOREACH(nlop, &np->n_lock_owners, nlo_link) {
		if (nlop->nlo_pid != pid)
			continue;
		if (timevalcmp(&nlop->nlo_pid_start, &p->p_start, ==))
			break;
		/* stale lock owner... reuse it if we can */
		if (nlop->nlo_refcnt) {
			TAILQ_REMOVE(&np->n_lock_owners, nlop, nlo_link);
			nlop->nlo_flags &= ~NFS_LOCK_OWNER_LINK;
			lck_mtx_unlock(&np->n_openlock);
			goto tryagain;
		}
		nlop->nlo_pid_start = p->p_start;
		nlop->nlo_seqid = 0;
		nlop->nlo_stategenid = 0;
		break;
	}

	if (!nlop && !newnlop && alloc) {
		lck_mtx_unlock(&np->n_openlock);
		MALLOC(newnlop, struct nfs_lock_owner *, sizeof(struct nfs_lock_owner), M_TEMP, M_WAITOK);
		if (!newnlop)
			return (NULL);
		bzero(newnlop, sizeof(*newnlop));
		lck_mtx_init(&newnlop->nlo_lock, nfs_open_grp, LCK_ATTR_NULL);
		newnlop->nlo_pid = pid;
		newnlop->nlo_pid_start = p->p_start;
		newnlop->nlo_name = OSAddAtomic(1, &nfs_lock_owner_seqnum);
		TAILQ_INIT(&newnlop->nlo_locks);
		goto tryagain;
	}
	if (!nlop && newnlop) {
		newnlop->nlo_flags |= NFS_LOCK_OWNER_LINK;
		TAILQ_INSERT_HEAD(&np->n_lock_owners, newnlop, nlo_link);
		nlop = newnlop;
	}
	lck_mtx_unlock(&np->n_openlock);

	if (newnlop && (nlop != newnlop))
		nfs_lock_owner_destroy(newnlop);

	if (nlop)
		nfs_lock_owner_ref(nlop);

	return (nlop);
}

/*
 * destroy a lock owner that's no longer needed
 */
void
nfs_lock_owner_destroy(struct nfs_lock_owner *nlop)
{
	if (nlop->nlo_open_owner) {
		nfs_open_owner_rele(nlop->nlo_open_owner);
		nlop->nlo_open_owner = NULL;
	}
	lck_mtx_destroy(&nlop->nlo_lock, nfs_open_grp);
	FREE(nlop, M_TEMP);
}

/*
 * acquire a reference count on a lock owner
 */
void
nfs_lock_owner_ref(struct nfs_lock_owner *nlop)
{
	lck_mtx_lock(&nlop->nlo_lock);
	nlop->nlo_refcnt++;
	lck_mtx_unlock(&nlop->nlo_lock);
}

/*
 * drop a reference count on a lock owner and destroy it if
 * it is no longer referenced and no longer on the mount's list.
 */
void
nfs_lock_owner_rele(struct nfs_lock_owner *nlop)
{
	lck_mtx_lock(&nlop->nlo_lock);
	if (nlop->nlo_refcnt < 1)
		panic("nfs_lock_owner_rele: no refcnt");
	nlop->nlo_refcnt--;
	if (!nlop->nlo_refcnt && (nlop->nlo_flags & NFS_LOCK_OWNER_BUSY))
		panic("nfs_lock_owner_rele: busy");
	/* XXX we may potentially want to clean up idle/unused lock owner structures */
	if (nlop->nlo_refcnt || (nlop->nlo_flags & NFS_LOCK_OWNER_LINK)) {
		lck_mtx_unlock(&nlop->nlo_lock);
		return;
	}
	/* owner is no longer referenced or linked to mount, so destroy it */
	lck_mtx_unlock(&nlop->nlo_lock);
	nfs_lock_owner_destroy(nlop);
}

/*
 * Mark a lock owner as busy because we are about to
 * start an operation that uses and updates lock owner state.
 */
int
nfs_lock_owner_set_busy(struct nfs_lock_owner *nlop, thread_t thd)
{
	struct nfsmount *nmp;
	struct timespec ts = {2, 0};
	int error = 0, slpflag;

	nmp = nlop->nlo_open_owner->noo_mount;
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	slpflag = (NMFLAG(nmp, INTR) && thd) ? PCATCH : 0;

	lck_mtx_lock(&nlop->nlo_lock);
	while (nlop->nlo_flags & NFS_LOCK_OWNER_BUSY) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 0)))
			break;
		nlop->nlo_flags |= NFS_LOCK_OWNER_WANT;
		msleep(nlop, &nlop->nlo_lock, slpflag, "nfs_lock_owner_set_busy", &ts);
		slpflag = 0;
	}
	if (!error)
		nlop->nlo_flags |= NFS_LOCK_OWNER_BUSY;
	lck_mtx_unlock(&nlop->nlo_lock);

	return (error);
}

/*
 * Clear the busy flag on a lock owner and wake up anyone waiting
 * to mark it busy.
 */
void
nfs_lock_owner_clear_busy(struct nfs_lock_owner *nlop)
{
	int wanted;

	lck_mtx_lock(&nlop->nlo_lock);
	if (!(nlop->nlo_flags & NFS_LOCK_OWNER_BUSY))
		panic("nfs_lock_owner_clear_busy");
	wanted = (nlop->nlo_flags & NFS_LOCK_OWNER_WANT);
	nlop->nlo_flags &= ~(NFS_LOCK_OWNER_BUSY|NFS_LOCK_OWNER_WANT);
	lck_mtx_unlock(&nlop->nlo_lock);
	if (wanted)
		wakeup(nlop);
}

/*
 * Insert a held lock into a lock owner's sorted list.
 * (flock locks are always inserted at the head the list)
 */
void
nfs_lock_owner_insert_held_lock(struct nfs_lock_owner *nlop, struct nfs_file_lock *newnflp)
{
	struct nfs_file_lock *nflp;

	/* insert new lock in lock owner's held lock list */
	lck_mtx_lock(&nlop->nlo_lock);
	if ((newnflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_FLOCK) {
		TAILQ_INSERT_HEAD(&nlop->nlo_locks, newnflp, nfl_lolink);
	} else {
		TAILQ_FOREACH(nflp, &nlop->nlo_locks, nfl_lolink) {
			if (newnflp->nfl_start < nflp->nfl_start)
				break;
		}
		if (nflp)
			TAILQ_INSERT_BEFORE(nflp, newnflp, nfl_lolink);
		else
			TAILQ_INSERT_TAIL(&nlop->nlo_locks, newnflp, nfl_lolink);
	}
	lck_mtx_unlock(&nlop->nlo_lock);
}

/*
 * Get a file lock structure for this lock owner.
 */
struct nfs_file_lock *
nfs_file_lock_alloc(struct nfs_lock_owner *nlop)
{
	struct nfs_file_lock *nflp = NULL;

	lck_mtx_lock(&nlop->nlo_lock);
	if (!nlop->nlo_alock.nfl_owner) {
		nflp = &nlop->nlo_alock;
		nflp->nfl_owner = nlop;
	}
	lck_mtx_unlock(&nlop->nlo_lock);
	if (!nflp) {
		MALLOC(nflp, struct nfs_file_lock *, sizeof(struct nfs_file_lock), M_TEMP, M_WAITOK);
		if (!nflp)
			return (NULL);
		bzero(nflp, sizeof(*nflp));
		nflp->nfl_flags |= NFS_FILE_LOCK_ALLOC;
		nflp->nfl_owner = nlop;
	}
	nfs_lock_owner_ref(nlop);
	return (nflp);
}

/*
 * destroy the given NFS file lock structure
 */
void
nfs_file_lock_destroy(struct nfs_file_lock *nflp)
{
	struct nfs_lock_owner *nlop = nflp->nfl_owner;

	if (nflp->nfl_flags & NFS_FILE_LOCK_ALLOC) {
		nflp->nfl_owner = NULL;
		FREE(nflp, M_TEMP);
	} else {
		lck_mtx_lock(&nlop->nlo_lock);
		bzero(nflp, sizeof(nflp));
		lck_mtx_unlock(&nlop->nlo_lock);
	}
	nfs_lock_owner_rele(nlop);
}

/*
 * Check if one file lock conflicts with another.
 * (nflp1 is the new lock.  nflp2 is the existing lock.)
 */
int
nfs_file_lock_conflict(struct nfs_file_lock *nflp1, struct nfs_file_lock *nflp2, int *willsplit)
{
	/* no conflict if lock is dead */
	if ((nflp1->nfl_flags & NFS_FILE_LOCK_DEAD) || (nflp2->nfl_flags & NFS_FILE_LOCK_DEAD))
		return (0);
	/* no conflict if it's ours - unless the lock style doesn't match */
	if ((nflp1->nfl_owner == nflp2->nfl_owner) &&
	    ((nflp1->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == (nflp2->nfl_flags & NFS_FILE_LOCK_STYLE_MASK))) {
		if (willsplit && (nflp1->nfl_type != nflp2->nfl_type) &&
		    (nflp1->nfl_start > nflp2->nfl_start) &&
		    (nflp1->nfl_end < nflp2->nfl_end))
			*willsplit = 1;
		return (0);
	}
	/* no conflict if ranges don't overlap */
	if ((nflp1->nfl_start > nflp2->nfl_end) || (nflp1->nfl_end < nflp2->nfl_start))
		return (0);
	/* no conflict if neither lock is exclusive */
	if ((nflp1->nfl_type != F_WRLCK) && (nflp2->nfl_type != F_WRLCK))
		return (0);
	/* conflict */
	return (1);
}

/*
 * Send an NFSv4 LOCK RPC to the server.
 */
int
nfs4_setlock_rpc(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	struct nfs_file_lock *nflp,
	int reclaim,
	int flags,
	thread_t thd,
	kauth_cred_t cred)
{
	struct nfs_lock_owner *nlop = nflp->nfl_owner;
	struct nfsmount *nmp;
	struct nfsm_chain nmreq, nmrep;
	uint64_t xid;
	uint32_t locktype;
	int error = 0, lockerror = ENOENT, newlocker, numops, status;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	newlocker = (nlop->nlo_stategenid != nmp->nm_stategenid);
	locktype = (nflp->nfl_flags & NFS_FILE_LOCK_WAIT) ?
			((nflp->nfl_type == F_WRLCK) ?
				NFS_LOCK_TYPE_WRITEW :
				NFS_LOCK_TYPE_READW) :
			((nflp->nfl_type == F_WRLCK) ?
				NFS_LOCK_TYPE_WRITE :
				NFS_LOCK_TYPE_READ);
	if (newlocker) {
		error = nfs_open_file_set_busy(nofp, thd);
		if (error)
			return (error);
		error = nfs_open_owner_set_busy(nofp->nof_owner, thd);
		if (error) {
			nfs_open_file_clear_busy(nofp);
			return (error);
		}
		if (!nlop->nlo_open_owner) {
			nfs_open_owner_ref(nofp->nof_owner);
			nlop->nlo_open_owner = nofp->nof_owner;
		}
	}
	error = nfs_lock_owner_set_busy(nlop, thd);
	if (error) {
		if (newlocker) {
			nfs_open_owner_clear_busy(nofp->nof_owner);
			nfs_open_file_clear_busy(nofp);
		}
		return (error);
	}

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

	// PUTFH, GETATTR, LOCK
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 33 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "lock", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_LOCK);
	nfsm_chain_add_32(error, &nmreq, locktype);
	nfsm_chain_add_32(error, &nmreq, reclaim);
	nfsm_chain_add_64(error, &nmreq, nflp->nfl_start);
	nfsm_chain_add_64(error, &nmreq, NFS_LOCK_LENGTH(nflp->nfl_start, nflp->nfl_end));
	nfsm_chain_add_32(error, &nmreq, newlocker);
	if (newlocker) {
		nfsm_chain_add_32(error, &nmreq, nofp->nof_owner->noo_seqid);
		nfsm_chain_add_stateid(error, &nmreq, &nofp->nof_stateid);
		nfsm_chain_add_32(error, &nmreq, nlop->nlo_seqid);
		nfsm_chain_add_lock_owner4(error, &nmreq, nmp, nlop);
	} else {
		nfsm_chain_add_stateid(error, &nmreq, &nlop->nlo_stateid);
		nfsm_chain_add_32(error, &nmreq, nlop->nlo_seqid);
	}
	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, flags|R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, NFS_VER4, &xid);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_LOCK);
	nfs_owner_seqid_increment(newlocker ? nofp->nof_owner : NULL, nlop, error);
	nfsm_chain_get_stateid(error, &nmrep, &nlop->nlo_stateid);

	/* Update the lock owner's stategenid once it appears the server has state for it. */
	/* We determine this by noting the request was successful (we got a stateid). */
	if (newlocker && !error)
		nlop->nlo_stategenid = nmp->nm_stategenid;
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_lock_owner_clear_busy(nlop);
	if (newlocker) {
		nfs_open_owner_clear_busy(nofp->nof_owner);
		nfs_open_file_clear_busy(nofp);
	}
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/*
 * Send an NFSv4 LOCKU RPC to the server.
 */
int
nfs4_unlock_rpc(
	nfsnode_t np,
	struct nfs_lock_owner *nlop,
	int type,
	uint64_t start,
	uint64_t end,
	int flags,
	thread_t thd,
	kauth_cred_t cred)
{
	struct nfsmount *nmp;
	struct nfsm_chain nmreq, nmrep;
	uint64_t xid;
	int error = 0, lockerror = ENOENT, numops, status;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	error = nfs_lock_owner_set_busy(nlop, NULL);
	if (error)
		return (error);

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

	// PUTFH, GETATTR, LOCKU
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 26 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "unlock", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_LOCKU);
	nfsm_chain_add_32(error, &nmreq, (type == F_WRLCK) ? NFS_LOCK_TYPE_WRITE : NFS_LOCK_TYPE_READ);
	nfsm_chain_add_32(error, &nmreq, nlop->nlo_seqid);
	nfsm_chain_add_stateid(error, &nmreq, &nlop->nlo_stateid);
	nfsm_chain_add_64(error, &nmreq, start);
	nfsm_chain_add_64(error, &nmreq, NFS_LOCK_LENGTH(start, end));
	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, flags|R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, NFS_VER4, &xid);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_LOCKU);
	nfs_owner_seqid_increment(NULL, nlop, error);
	nfsm_chain_get_stateid(error, &nmrep, &nlop->nlo_stateid);
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_lock_owner_clear_busy(nlop);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/*
 * Send an NFSv4 LOCKT RPC to the server.
 */
int
nfs4_getlock_rpc(
	nfsnode_t np,
	struct nfs_lock_owner *nlop,
	struct flock *fl,
	uint64_t start,
	uint64_t end,
	vfs_context_t ctx)
{
	struct nfsmount *nmp;
	struct nfsm_chain nmreq, nmrep;
	uint64_t xid, val64 = 0;
	uint32_t val = 0;
	int error = 0, lockerror, numops, status;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

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

	// PUTFH, GETATTR, LOCKT
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 26 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "locktest", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, NFS_VER4, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_LOCKT);
	nfsm_chain_add_32(error, &nmreq, (fl->l_type == F_WRLCK) ? NFS_LOCK_TYPE_WRITE : NFS_LOCK_TYPE_READ);
	nfsm_chain_add_64(error, &nmreq, start);
	nfsm_chain_add_64(error, &nmreq, NFS_LOCK_LENGTH(start, end));
	nfsm_chain_add_lock_owner4(error, &nmreq, nmp, nlop);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request(np, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, NFS_VER4, &xid);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_LOCKT);
	if (error == NFSERR_DENIED) {
		error = 0;
		nfsm_chain_get_64(error, &nmrep, fl->l_start);
		nfsm_chain_get_64(error, &nmrep, val64);
		fl->l_len = (val64 == UINT64_MAX) ? 0 : val64;
		nfsm_chain_get_32(error, &nmrep, val);
		fl->l_type = (val == NFS_LOCK_TYPE_WRITE) ? F_WRLCK : F_RDLCK;
		fl->l_pid = 0;
		fl->l_whence = SEEK_SET;
	} else if (!error) {
		fl->l_type = F_UNLCK;
	}
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}


/*
 * Check for any conflicts with the given lock.
 *
 * Checking for a lock doesn't require the file to be opened.
 * So we skip all the open owner, open file, lock owner work
 * and just check for a conflicting lock.
 */
int
nfs_advlock_getlock(
	nfsnode_t np,
	struct nfs_lock_owner *nlop,
	struct flock *fl,
	uint64_t start,
	uint64_t end,
	vfs_context_t ctx)
{
	struct nfsmount *nmp;
	struct nfs_file_lock *nflp;
	int error = 0, answered = 0;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

restart:
	if ((error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx))))
		return (error);

	lck_mtx_lock(&np->n_openlock);
	/* scan currently held locks for conflict */
	TAILQ_FOREACH(nflp, &np->n_locks, nfl_link) {
		if (nflp->nfl_flags & (NFS_FILE_LOCK_BLOCKED|NFS_FILE_LOCK_DEAD))
			continue;
		if ((start <= nflp->nfl_end) && (end >= nflp->nfl_start) &&
		    ((fl->l_type == F_WRLCK) || (nflp->nfl_type == F_WRLCK)))
			break;
	}
	if (nflp) {
		/* found a conflicting lock */
		fl->l_type = nflp->nfl_type;
		fl->l_pid = (nflp->nfl_flags & NFS_FILE_LOCK_STYLE_FLOCK) ? -1 : nflp->nfl_owner->nlo_pid;
		fl->l_start = nflp->nfl_start;
		fl->l_len = NFS_FLOCK_LENGTH(nflp->nfl_start, nflp->nfl_end);
		fl->l_whence = SEEK_SET;
		answered = 1;
	} else if ((np->n_openflags & N_DELEG_WRITE) && !(np->n_openflags & N_DELEG_RETURN)) {
		/*
		 * If we have a write delegation, we know there can't be other
		 * locks on the server.  So the answer is no conflicting lock found.
		 */
		fl->l_type = F_UNLCK;
		answered = 1;
	}
	lck_mtx_unlock(&np->n_openlock);
	if (answered) {
		nfs_mount_state_in_use_end(nmp, 0);
		return (0);
	}

	/* no conflict found locally, so ask the server */
	error = nmp->nm_funcs->nf_getlock_rpc(np, nlop, fl, start, end, ctx);

	if (nfs_mount_state_in_use_end(nmp, error))
		goto restart;
	return (error);
}

/*
 * Acquire a file lock for the given range.
 *
 * Add the lock (request) to the lock queue.
 * Scan the lock queue for any conflicting locks.
 * If a conflict is found, block or return an error.
 * Once end of queue is reached, send request to the server.
 * If the server grants the lock, scan the lock queue and
 * update any existing locks.  Then (optionally) scan the
 * queue again to coalesce any locks adjacent to the new one.
 */
int
nfs_advlock_setlock(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	struct nfs_lock_owner *nlop,
	int op,
	uint64_t start,
	uint64_t end,
	int style,
	short type,
	vfs_context_t ctx)
{
	struct nfsmount *nmp;
	struct nfs_file_lock *newnflp, *nflp, *nflp2 = NULL, *nextnflp, *flocknflp = NULL;
	struct nfs_file_lock *coalnflp;
	int error = 0, error2, willsplit = 0, delay, slpflag, busy = 0, inuse = 0, restart, inqueue = 0;
	struct timespec ts = {1, 0};

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	slpflag = NMFLAG(nmp, INTR) ? PCATCH : 0;

	if ((type != F_RDLCK) && (type != F_WRLCK))
		return (EINVAL);

	/* allocate a new lock */
	newnflp = nfs_file_lock_alloc(nlop);
	if (!newnflp)
		return (ENOLCK);
	newnflp->nfl_start = start;
	newnflp->nfl_end = end;
	newnflp->nfl_type = type;
	if (op == F_SETLKW)
		newnflp->nfl_flags |= NFS_FILE_LOCK_WAIT;
	newnflp->nfl_flags |= style;
	newnflp->nfl_flags |= NFS_FILE_LOCK_BLOCKED;

	if ((style == NFS_FILE_LOCK_STYLE_FLOCK) && (type == F_WRLCK)) {
		/*
		 * For exclusive flock-style locks, if we block waiting for the
		 * lock, we need to first release any currently held shared
		 * flock-style lock.  So, the first thing we do is check if we
		 * have a shared flock-style lock.
		 */
		nflp = TAILQ_FIRST(&nlop->nlo_locks);
		if (nflp && ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) != NFS_FILE_LOCK_STYLE_FLOCK))
			nflp = NULL;
		if (nflp && (nflp->nfl_type != F_RDLCK))
			nflp = NULL;
		flocknflp = nflp;
	}

restart:
	restart = 0;
	error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
	if (error)
		goto error_out;
	inuse = 1;
	if (np->n_flag & NREVOKE) {
		error = EIO;
		nfs_mount_state_in_use_end(nmp, 0);
		inuse = 0;
		goto error_out;
	}
	if (nofp->nof_flags & NFS_OPEN_FILE_REOPEN) {
		nfs_mount_state_in_use_end(nmp, 0);
		inuse = 0;
		error = nfs4_reopen(nofp, vfs_context_thread(ctx));
		if (error)
			goto error_out;
		goto restart;
	}

	lck_mtx_lock(&np->n_openlock);
	if (!inqueue) {
		/* insert new lock at beginning of list */
		TAILQ_INSERT_HEAD(&np->n_locks, newnflp, nfl_link);
		inqueue = 1;
	}

	/* scan current list of locks (held and pending) for conflicts */
	for (nflp = TAILQ_NEXT(newnflp, nfl_link); nflp; nflp = nextnflp) {
		nextnflp = TAILQ_NEXT(nflp, nfl_link);
		if (!nfs_file_lock_conflict(newnflp, nflp, &willsplit))
			continue;
		/* Conflict */
		if (!(newnflp->nfl_flags & NFS_FILE_LOCK_WAIT)) {
			error = EAGAIN;
			break;
		}
		/* Block until this lock is no longer held. */
		if (nflp->nfl_blockcnt == UINT_MAX) {
			error = ENOLCK;
			break;
		}
		nflp->nfl_blockcnt++;
		do {
			if (flocknflp) {
				/* release any currently held shared lock before sleeping */
				lck_mtx_unlock(&np->n_openlock);
				nfs_mount_state_in_use_end(nmp, 0);
				inuse = 0;
				error = nfs_advlock_unlock(np, nofp, nlop, 0, UINT64_MAX, NFS_FILE_LOCK_STYLE_FLOCK, ctx);
				flocknflp = NULL;
				if (!error)
					error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
				if (error) {
					lck_mtx_lock(&np->n_openlock);
					break;
				}
				inuse = 1;
				lck_mtx_lock(&np->n_openlock);
				/* no need to block/sleep if the conflict is gone */
				if (!nfs_file_lock_conflict(newnflp, nflp, NULL))
					break;
			}
			msleep(nflp, &np->n_openlock, slpflag, "nfs_advlock_setlock_blocked", &ts);
			slpflag = 0;
			error = nfs_sigintr(NFSTONMP(np), NULL, vfs_context_thread(ctx), 0);
			if (!error && (nmp->nm_state & NFSSTA_RECOVER)) {
				/* looks like we have a recover pending... restart */
				restart = 1;
				lck_mtx_unlock(&np->n_openlock);
				nfs_mount_state_in_use_end(nmp, 0);
				inuse = 0;
				lck_mtx_lock(&np->n_openlock);
				break;
			}
			if (!error && (np->n_flag & NREVOKE))
				error = EIO;
		} while (!error && nfs_file_lock_conflict(newnflp, nflp, NULL));
		nflp->nfl_blockcnt--;
		if ((nflp->nfl_flags & NFS_FILE_LOCK_DEAD) && !nflp->nfl_blockcnt) {
			TAILQ_REMOVE(&np->n_locks, nflp, nfl_link);
			nfs_file_lock_destroy(nflp);
		}
		if (error || restart)
			break;
		/* We have released n_openlock and we can't trust that nextnflp is still valid. */
		/* So, start this lock-scanning loop over from where it started. */
		nextnflp = TAILQ_NEXT(newnflp, nfl_link);
	}
	lck_mtx_unlock(&np->n_openlock);
	if (restart)
		goto restart;
	if (error)
		goto error_out;

	if (willsplit) {
		/*
		 * It looks like this operation is splitting a lock.
		 * We allocate a new lock now so we don't have to worry
		 * about the allocation failing after we've updated some state.
		 */
		nflp2 = nfs_file_lock_alloc(nlop);
		if (!nflp2) {
			error = ENOLCK;
			goto error_out;
		}
	}

	/* once scan for local conflicts is clear, send request to server */
	if ((error = nfs_open_state_set_busy(np, vfs_context_thread(ctx))))
		goto error_out;
	busy = 1;
	delay = 0;
	do {
		/* do we have a delegation? (that we're not returning?) */
		if ((np->n_openflags & N_DELEG_MASK) && !(np->n_openflags & N_DELEG_RETURN)) {
			if (np->n_openflags & N_DELEG_WRITE) {
				/* with a write delegation, just take the lock delegated */
				newnflp->nfl_flags |= NFS_FILE_LOCK_DELEGATED;
				error = 0;
				/* make sure the lock owner knows its open owner */
				if (!nlop->nlo_open_owner) {
					nfs_open_owner_ref(nofp->nof_owner);
					nlop->nlo_open_owner = nofp->nof_owner;
				}
				break;
			} else {
				/*
				 * If we don't have any non-delegated opens but we do have
				 * delegated opens, then we need to first claim the delegated
				 * opens so that the lock request on the server can be associated
				 * with an open it knows about.
				 */
				if ((!nofp->nof_rw_drw && !nofp->nof_w_drw && !nofp->nof_r_drw &&
				     !nofp->nof_rw_dw && !nofp->nof_w_dw && !nofp->nof_r_dw &&
				     !nofp->nof_rw && !nofp->nof_w && !nofp->nof_r) &&
				    (nofp->nof_d_rw_drw || nofp->nof_d_w_drw || nofp->nof_d_r_drw ||
				     nofp->nof_d_rw_dw || nofp->nof_d_w_dw || nofp->nof_d_r_dw ||
				     nofp->nof_d_rw || nofp->nof_d_w || nofp->nof_d_r)) {
					error = nfs4_claim_delegated_state_for_open_file(nofp, 0);
					if (error)
						break;
				}
			}
		}
		if (np->n_flag & NREVOKE)
			error = EIO;
		if (!error)
			error = nmp->nm_funcs->nf_setlock_rpc(np, nofp, newnflp, 0, 0, vfs_context_thread(ctx), vfs_context_ucred(ctx));
		if (!error || ((error != NFSERR_DENIED) && (error != NFSERR_GRACE)))
			break;
		/* request was denied due to either conflict or grace period */
		if ((error == NFSERR_DENIED) && !(newnflp->nfl_flags & NFS_FILE_LOCK_WAIT)) {
			error = EAGAIN;
			break;
		}
		if (flocknflp) {
			/* release any currently held shared lock before sleeping */
			nfs_open_state_clear_busy(np);
			busy = 0;
			nfs_mount_state_in_use_end(nmp, 0);
			inuse = 0;
			error2 = nfs_advlock_unlock(np, nofp, nlop, 0, UINT64_MAX, NFS_FILE_LOCK_STYLE_FLOCK, ctx);
			flocknflp = NULL;
			if (!error2)
				error2 = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
			if (!error2) {
				inuse = 1;
				error2 = nfs_open_state_set_busy(np, vfs_context_thread(ctx));
			}
			if (error2) {
				error = error2;
				break;
			}
			busy = 1;
		}
		/*
		 * Wait a little bit and send the request again.
		 * Except for retries of blocked v2/v3 request where we've already waited a bit.
		 */
		if ((nmp->nm_vers >= NFS_VER4) || (error == NFSERR_GRACE)) {
			if (error == NFSERR_GRACE)
				delay = 4;
			if (delay < 4)
				delay++;
			tsleep(newnflp, slpflag, "nfs_advlock_setlock_delay", delay * (hz/2));
			slpflag = 0;
		}
		error = nfs_sigintr(NFSTONMP(np), NULL, vfs_context_thread(ctx), 0);
		if (!error && (nmp->nm_state & NFSSTA_RECOVER)) {
			/* looks like we have a recover pending... restart */
			nfs_open_state_clear_busy(np);
			busy = 0;
			nfs_mount_state_in_use_end(nmp, 0);
			inuse = 0;
			goto restart;
		}
		if (!error && (np->n_flag & NREVOKE))
			error = EIO;
	} while (!error);

error_out:
	if (nfs_mount_state_error_should_restart(error)) {
		/* looks like we need to restart this operation */
		if (busy) {
			nfs_open_state_clear_busy(np);
			busy = 0;
		}
		if (inuse) {
			nfs_mount_state_in_use_end(nmp, error);
			inuse = 0;
		}
		goto restart;
	}
	lck_mtx_lock(&np->n_openlock);
	newnflp->nfl_flags &= ~NFS_FILE_LOCK_BLOCKED;
	if (error) {
		newnflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
		if (newnflp->nfl_blockcnt) {
			/* wake up anyone blocked on this lock */
			wakeup(newnflp);
		} else {
			/* remove newnflp from lock list and destroy */
			if (inqueue)
				TAILQ_REMOVE(&np->n_locks, newnflp, nfl_link);
			nfs_file_lock_destroy(newnflp);
		}
		lck_mtx_unlock(&np->n_openlock);
		if (busy)
			nfs_open_state_clear_busy(np);
		if (inuse)
			nfs_mount_state_in_use_end(nmp, error);
		if (nflp2)
			nfs_file_lock_destroy(nflp2);
		return (error);
	}

	/* server granted the lock */

	/*
	 * Scan for locks to update.
	 *
	 * Locks completely covered are killed.
	 * At most two locks may need to be clipped.
	 * It's possible that a single lock may need to be split.
	 */
	TAILQ_FOREACH_SAFE(nflp, &np->n_locks, nfl_link, nextnflp) {
		if (nflp == newnflp)
			continue;
		if (nflp->nfl_flags & (NFS_FILE_LOCK_BLOCKED|NFS_FILE_LOCK_DEAD))
			continue;
		if (nflp->nfl_owner != nlop)
			continue;
		if ((newnflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) != (nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK))
			continue;
		if ((newnflp->nfl_start > nflp->nfl_end) || (newnflp->nfl_end < nflp->nfl_start))
			continue;
		/* here's one to update */
		if ((newnflp->nfl_start <= nflp->nfl_start) && (newnflp->nfl_end >= nflp->nfl_end)) {
			/* The entire lock is being replaced. */
			nflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
			lck_mtx_lock(&nlop->nlo_lock);
			TAILQ_REMOVE(&nlop->nlo_locks, nflp, nfl_lolink);
			lck_mtx_unlock(&nlop->nlo_lock);
			/* lock will be destroyed below, if no waiters */
		} else if ((newnflp->nfl_start > nflp->nfl_start) && (newnflp->nfl_end < nflp->nfl_end)) {
			/* We're replacing a range in the middle of a lock. */
			/* The current lock will be split into two locks. */
			/* Update locks and insert new lock after current lock. */
			nflp2->nfl_flags |= (nflp->nfl_flags & (NFS_FILE_LOCK_STYLE_MASK|NFS_FILE_LOCK_DELEGATED));
			nflp2->nfl_type = nflp->nfl_type;
			nflp2->nfl_start = newnflp->nfl_end + 1;
			nflp2->nfl_end = nflp->nfl_end;
			nflp->nfl_end = newnflp->nfl_start - 1;
			TAILQ_INSERT_AFTER(&np->n_locks, nflp, nflp2, nfl_link);
			nfs_lock_owner_insert_held_lock(nlop, nflp2);
			nextnflp = nflp2;
			nflp2 = NULL;
		} else if (newnflp->nfl_start > nflp->nfl_start) {
			/* We're replacing the end of a lock. */
			nflp->nfl_end = newnflp->nfl_start - 1;
		} else if (newnflp->nfl_end < nflp->nfl_end) {
			/* We're replacing the start of a lock. */
			nflp->nfl_start = newnflp->nfl_end + 1;
		}
		if (nflp->nfl_blockcnt) {
			/* wake up anyone blocked on this lock */
			wakeup(nflp);
		} else if (nflp->nfl_flags & NFS_FILE_LOCK_DEAD) {
			/* remove nflp from lock list and destroy */
			TAILQ_REMOVE(&np->n_locks, nflp, nfl_link);
			nfs_file_lock_destroy(nflp);
		}
	}

	nfs_lock_owner_insert_held_lock(nlop, newnflp);

	/*
	 * POSIX locks should be coalesced when possible.
	 */
	if ((style == NFS_FILE_LOCK_STYLE_POSIX) && (nofp->nof_flags & NFS_OPEN_FILE_POSIXLOCK)) {
		/*
		 * Walk through the lock queue and check each of our held locks with
		 * the previous and next locks in the lock owner's "held lock list".
		 * If the two locks can be coalesced, we merge the current lock into
		 * the other (previous or next) lock.  Merging this way makes sure that
		 * lock ranges are always merged forward in the lock queue.  This is
		 * important because anyone blocked on the lock being "merged away"
		 * will still need to block on that range and it will simply continue
		 * checking locks that are further down the list.
		 */
		TAILQ_FOREACH_SAFE(nflp, &np->n_locks, nfl_link, nextnflp) {
			if (nflp->nfl_flags & (NFS_FILE_LOCK_BLOCKED|NFS_FILE_LOCK_DEAD))
				continue;
			if (nflp->nfl_owner != nlop)
				continue;
			if ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) != NFS_FILE_LOCK_STYLE_POSIX)
				continue;
			if (((coalnflp = TAILQ_PREV(nflp, nfs_file_lock_queue, nfl_lolink))) &&
			    ((coalnflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_POSIX) &&
			    (coalnflp->nfl_type == nflp->nfl_type) &&
			    (coalnflp->nfl_end == (nflp->nfl_start - 1))) {
				coalnflp->nfl_end = nflp->nfl_end;
				nflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
				lck_mtx_lock(&nlop->nlo_lock);
				TAILQ_REMOVE(&nlop->nlo_locks, nflp, nfl_lolink);
				lck_mtx_unlock(&nlop->nlo_lock);
			} else if (((coalnflp = TAILQ_NEXT(nflp, nfl_lolink))) &&
			    ((coalnflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_POSIX) &&
			    (coalnflp->nfl_type == nflp->nfl_type) &&
			    (coalnflp->nfl_start == (nflp->nfl_end + 1))) {
				coalnflp->nfl_start = nflp->nfl_start;
				nflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
				lck_mtx_lock(&nlop->nlo_lock);
				TAILQ_REMOVE(&nlop->nlo_locks, nflp, nfl_lolink);
				lck_mtx_unlock(&nlop->nlo_lock);
			}
			if (!(nflp->nfl_flags & NFS_FILE_LOCK_DEAD))
				continue;
			if (nflp->nfl_blockcnt) {
				/* wake up anyone blocked on this lock */
				wakeup(nflp);
			} else {
				/* remove nflp from lock list and destroy */
				TAILQ_REMOVE(&np->n_locks, nflp, nfl_link);
				nfs_file_lock_destroy(nflp);
			}
		}
	}

	lck_mtx_unlock(&np->n_openlock);
	nfs_open_state_clear_busy(np);
	nfs_mount_state_in_use_end(nmp, error);

	if (nflp2)
		nfs_file_lock_destroy(nflp2);
	return (error);
}

/*
 * Release all (same style) locks within the given range.
 */
int
nfs_advlock_unlock(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	struct nfs_lock_owner *nlop,
	uint64_t start,
	uint64_t end,
	int style,
	vfs_context_t ctx)
{
	struct nfsmount *nmp;
	struct nfs_file_lock *nflp, *nextnflp, *newnflp = NULL;
	int error = 0, willsplit = 0, send_unlock_rpcs = 1;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

restart:
	if ((error = nfs_mount_state_in_use_start(nmp, NULL)))
		return (error);
	if (nofp->nof_flags & NFS_OPEN_FILE_REOPEN) {
		nfs_mount_state_in_use_end(nmp, 0);
		error = nfs4_reopen(nofp, NULL);
		if (error)
			return (error);
		goto restart;
	}
	if ((error = nfs_open_state_set_busy(np, NULL))) {
		nfs_mount_state_in_use_end(nmp, error);
		return (error);
	}

	lck_mtx_lock(&np->n_openlock);
	if ((start > 0) && (end < UINT64_MAX) && !willsplit) {
		/*
		 * We may need to allocate a new lock if an existing lock gets split.
		 * So, we first scan the list to check for a split, and if there's
		 * going to be one, we'll allocate one now.
		 */
		TAILQ_FOREACH_SAFE(nflp, &np->n_locks, nfl_link, nextnflp) {
			if (nflp->nfl_flags & (NFS_FILE_LOCK_BLOCKED|NFS_FILE_LOCK_DEAD))
				continue;
			if (nflp->nfl_owner != nlop)
				continue;
			if ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) != style)
				continue;
			if ((start > nflp->nfl_end) || (end < nflp->nfl_start))
				continue;
			if ((start > nflp->nfl_start) && (end < nflp->nfl_end)) {
				willsplit = 1;
				break;
			}
		}
		if (willsplit) {
			lck_mtx_unlock(&np->n_openlock);
			nfs_open_state_clear_busy(np);
			nfs_mount_state_in_use_end(nmp, 0);
			newnflp = nfs_file_lock_alloc(nlop);
			if (!newnflp)
				return (ENOMEM);
			goto restart;
		}
	}

	/*
	 * Free all of our locks in the given range.
	 *
	 * Note that this process requires sending requests to the server.
	 * Because of this, we will release the n_openlock while performing
	 * the unlock RPCs.  The N_OPENBUSY state keeps the state of *held*
	 * locks from changing underneath us.  However, other entries in the
	 * list may be removed.  So we need to be careful walking the list.
	 */

	/*
	 * Don't unlock ranges that are held by other-style locks.
	 * If style is posix, don't send any unlock rpcs if flock is held.
	 * If we unlock an flock, don't send unlock rpcs for any posix-style
	 * ranges held - instead send unlocks for the ranges not held.
	 */
	if ((style == NFS_FILE_LOCK_STYLE_POSIX) &&
	    ((nflp = TAILQ_FIRST(&nlop->nlo_locks))) &&
	    ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_FLOCK))
		send_unlock_rpcs = 0;
	if ((style == NFS_FILE_LOCK_STYLE_FLOCK) &&
	    ((nflp = TAILQ_FIRST(&nlop->nlo_locks))) &&
	    ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_FLOCK) &&
	    ((nflp = TAILQ_NEXT(nflp, nfl_lolink))) &&
	    ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_POSIX)) {
		uint64_t s = 0;
		int type = TAILQ_FIRST(&nlop->nlo_locks)->nfl_type;
		int delegated = (TAILQ_FIRST(&nlop->nlo_locks)->nfl_flags & NFS_FILE_LOCK_DELEGATED);
		while (!delegated && nflp) {
			if ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) == NFS_FILE_LOCK_STYLE_POSIX) {
				/* unlock the range preceding this lock */
				lck_mtx_unlock(&np->n_openlock);
				error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, type, s, nflp->nfl_start-1, 0,
						vfs_context_thread(ctx), vfs_context_ucred(ctx));
				if (nfs_mount_state_error_should_restart(error)) {
					nfs_open_state_clear_busy(np);
					nfs_mount_state_in_use_end(nmp, error);
					goto restart;
				}
				lck_mtx_lock(&np->n_openlock);
				if (error)
					goto out;
				s = nflp->nfl_end+1;
			}
			nflp = TAILQ_NEXT(nflp, nfl_lolink);
		}
		if (!delegated) {
			lck_mtx_unlock(&np->n_openlock);
			error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, type, s, end, 0,
					vfs_context_thread(ctx), vfs_context_ucred(ctx));
			if (nfs_mount_state_error_should_restart(error)) {
				nfs_open_state_clear_busy(np);
				nfs_mount_state_in_use_end(nmp, error);
				goto restart;
			}
			lck_mtx_lock(&np->n_openlock);
			if (error)
				goto out;
		}
		send_unlock_rpcs = 0;
	}

	TAILQ_FOREACH_SAFE(nflp, &np->n_locks, nfl_link, nextnflp) {
		if (nflp->nfl_flags & (NFS_FILE_LOCK_BLOCKED|NFS_FILE_LOCK_DEAD))
			continue;
		if (nflp->nfl_owner != nlop)
			continue;
		if ((nflp->nfl_flags & NFS_FILE_LOCK_STYLE_MASK) != style)
			continue;
		if ((start > nflp->nfl_end) || (end < nflp->nfl_start))
			continue;
		/* here's one to unlock */
		if ((start <= nflp->nfl_start) && (end >= nflp->nfl_end)) {
			/* The entire lock is being unlocked. */
			if (send_unlock_rpcs && !(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED)) {
				lck_mtx_unlock(&np->n_openlock);
				error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, nflp->nfl_type, nflp->nfl_start, nflp->nfl_end, 0,
						vfs_context_thread(ctx), vfs_context_ucred(ctx));
				if (nfs_mount_state_error_should_restart(error)) {
					nfs_open_state_clear_busy(np);
					nfs_mount_state_in_use_end(nmp, error);
					goto restart;
				}
				lck_mtx_lock(&np->n_openlock);
			}
			nextnflp = TAILQ_NEXT(nflp, nfl_link);
			if (error)
				break;
			nflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
			lck_mtx_lock(&nlop->nlo_lock);
			TAILQ_REMOVE(&nlop->nlo_locks, nflp, nfl_lolink);
			lck_mtx_unlock(&nlop->nlo_lock);
			/* lock will be destroyed below, if no waiters */
		} else if ((start > nflp->nfl_start) && (end < nflp->nfl_end)) {
			/* We're unlocking a range in the middle of a lock. */
			/* The current lock will be split into two locks. */
			if (send_unlock_rpcs && !(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED)) {
				lck_mtx_unlock(&np->n_openlock);
				error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, nflp->nfl_type, start, end, 0,
						vfs_context_thread(ctx), vfs_context_ucred(ctx));
				if (nfs_mount_state_error_should_restart(error)) {
					nfs_open_state_clear_busy(np);
					nfs_mount_state_in_use_end(nmp, error);
					goto restart;
				}
				lck_mtx_lock(&np->n_openlock);
			}
			if (error)
				break;
			/* update locks and insert new lock after current lock */
			newnflp->nfl_flags |= (nflp->nfl_flags & (NFS_FILE_LOCK_STYLE_MASK|NFS_FILE_LOCK_DELEGATED));
			newnflp->nfl_type = nflp->nfl_type;
			newnflp->nfl_start = end + 1;
			newnflp->nfl_end = nflp->nfl_end;
			nflp->nfl_end = start - 1;
			TAILQ_INSERT_AFTER(&np->n_locks, nflp, newnflp, nfl_link);
			nfs_lock_owner_insert_held_lock(nlop, newnflp);
			nextnflp = newnflp;
			newnflp = NULL;
		} else if (start > nflp->nfl_start) {
			/* We're unlocking the end of a lock. */
			if (send_unlock_rpcs && !(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED)) {
				lck_mtx_unlock(&np->n_openlock);
				error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, nflp->nfl_type, start, nflp->nfl_end, 0,
						vfs_context_thread(ctx), vfs_context_ucred(ctx));
				if (nfs_mount_state_error_should_restart(error)) {
					nfs_open_state_clear_busy(np);
					nfs_mount_state_in_use_end(nmp, error);
					goto restart;
				}
				lck_mtx_lock(&np->n_openlock);
			}
			nextnflp = TAILQ_NEXT(nflp, nfl_link);
			if (error)
				break;
			nflp->nfl_end = start - 1;
		} else if (end < nflp->nfl_end) {
			/* We're unlocking the start of a lock. */
			if (send_unlock_rpcs && !(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED)) {
				lck_mtx_unlock(&np->n_openlock);
				error = nmp->nm_funcs->nf_unlock_rpc(np, nlop, nflp->nfl_type, nflp->nfl_start, end, 0,
						vfs_context_thread(ctx), vfs_context_ucred(ctx));
				if (nfs_mount_state_error_should_restart(error)) {
					nfs_open_state_clear_busy(np);
					nfs_mount_state_in_use_end(nmp, error);
					goto restart;
				}
				lck_mtx_lock(&np->n_openlock);
			}
			nextnflp = TAILQ_NEXT(nflp, nfl_link);
			if (error)
				break;
			nflp->nfl_start = end + 1;
		}
		if (nflp->nfl_blockcnt) {
			/* wake up anyone blocked on this lock */
			wakeup(nflp);
		} else if (nflp->nfl_flags & NFS_FILE_LOCK_DEAD) {
			/* remove nflp from lock list and destroy */
			TAILQ_REMOVE(&np->n_locks, nflp, nfl_link);
			nfs_file_lock_destroy(nflp);
		}
	}
out:
	lck_mtx_unlock(&np->n_openlock);
	nfs_open_state_clear_busy(np);
	nfs_mount_state_in_use_end(nmp, 0);

	if (newnflp)
		nfs_file_lock_destroy(newnflp);
	return (error);
}

/*
 * NFSv4 advisory file locking
 */
int
nfs_vnop_advlock(
	struct vnop_advlock_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		caddr_t a_id;
		int a_op;
		struct flock *a_fl;
		int a_flags;
		vfs_context_t a_context;
	} */ *ap)
{
	vnode_t vp = ap->a_vp;
	nfsnode_t np = VTONFS(ap->a_vp);
	struct flock *fl = ap->a_fl;
	int op = ap->a_op;
	int flags = ap->a_flags;
	vfs_context_t ctx = ap->a_context;
	struct nfsmount *nmp;
	struct nfs_open_owner *noop = NULL;
	struct nfs_open_file *nofp = NULL;
	struct nfs_lock_owner *nlop = NULL;
	off_t lstart;
	uint64_t start, end;
	int error = 0, modified, style;
	enum vtype vtype;
#define OFF_MAX QUAD_MAX

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	lck_mtx_lock(&nmp->nm_lock);
	if ((nmp->nm_vers <= NFS_VER3) && (nmp->nm_lockmode == NFS_LOCK_MODE_DISABLED)) {
		lck_mtx_unlock(&nmp->nm_lock);
		return (ENOTSUP);
	}
	lck_mtx_unlock(&nmp->nm_lock);

	if (np->n_flag & NREVOKE)
		return (EIO);
	vtype = vnode_vtype(ap->a_vp);
	if (vtype == VDIR) /* ignore lock requests on directories */
		return (0);
	if (vtype != VREG) /* anything other than regular files is invalid */
		return (EINVAL);

	/* Convert the flock structure into a start and end. */
	switch (fl->l_whence) {
	case SEEK_SET:
	case SEEK_CUR:
		/*
		 * Caller is responsible for adding any necessary offset
		 * to fl->l_start when SEEK_CUR is used.
		 */
		lstart = fl->l_start;
		break;
	case SEEK_END:
		/* need to flush, and refetch attributes to make */
		/* sure we have the correct end of file offset   */
		if ((error = nfs_node_lock(np)))
			return (error);
		modified = (np->n_flag & NMODIFIED);
		nfs_node_unlock(np);
		if (modified && ((error = nfs_vinvalbuf(vp, V_SAVE, ctx, 1))))
			return (error);
		if ((error = nfs_getattr(np, NULL, ctx, NGA_UNCACHED)))
			return (error);
		nfs_data_lock(np, NFS_DATA_LOCK_SHARED);
		if ((np->n_size > OFF_MAX) ||
		    ((fl->l_start > 0) && (np->n_size > (u_quad_t)(OFF_MAX - fl->l_start))))
			error = EOVERFLOW;
		lstart = np->n_size + fl->l_start;
		nfs_data_unlock(np);
		if (error)
			return (error);
		break;
	default:
		return (EINVAL);
	}
	if (lstart < 0)
		return (EINVAL);
	start = lstart;
	if (fl->l_len == 0) {
		end = UINT64_MAX;
	} else if (fl->l_len > 0) {
		if ((fl->l_len - 1) > (OFF_MAX - lstart))
			return (EOVERFLOW);
		end = start - 1 + fl->l_len;
	} else { /* l_len is negative */
		if ((lstart + fl->l_len) < 0)
			return (EINVAL);
		end = start - 1;
		start += fl->l_len;
	}
	if ((nmp->nm_vers == NFS_VER2) && ((start > INT32_MAX) || (fl->l_len && (end > INT32_MAX))))
		return (EINVAL);

	style = (flags & F_FLOCK) ? NFS_FILE_LOCK_STYLE_FLOCK : NFS_FILE_LOCK_STYLE_POSIX;
	if ((style == NFS_FILE_LOCK_STYLE_FLOCK) && ((start != 0) || (end != UINT64_MAX)))
		return (EINVAL);

	/* find the lock owner, alloc if not unlock */
	nlop = nfs_lock_owner_find(np, vfs_context_proc(ctx), (op != F_UNLCK));
	if (!nlop) {
		error = (op == F_UNLCK) ? 0 : ENOMEM;
		if (error)
			NP(np, "nfs_vnop_advlock: no lock owner, error %d", error);
		goto out;
	}

	if (op == F_GETLK) {
		error = nfs_advlock_getlock(np, nlop, fl, start, end, ctx);
	} else {
		/* find the open owner */
		noop = nfs_open_owner_find(nmp, vfs_context_ucred(ctx), 0);
		if (!noop) {
			NP(np, "nfs_vnop_advlock: no open owner %d", kauth_cred_getuid(vfs_context_ucred(ctx)));
			error = EPERM;
			goto out;
		}
		/* find the open file */
restart:
		error = nfs_open_file_find(np, noop, &nofp, 0, 0, 0);
		if (error)
			error = EBADF;
		if (!error && (nofp->nof_flags & NFS_OPEN_FILE_LOST)) {
			NP(np, "nfs_vnop_advlock: LOST %d", kauth_cred_getuid(nofp->nof_owner->noo_cred));
			error = EIO;
		}
		if (!error && (nofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
			error = nfs4_reopen(nofp, ((op == F_UNLCK) ? NULL : vfs_context_thread(ctx)));
			nofp = NULL;
			if (!error)
				goto restart;
		}
		if (error) {
			NP(np, "nfs_vnop_advlock: no open file %d, %d", error, kauth_cred_getuid(noop->noo_cred));
			goto out;
		}
		if (op == F_UNLCK) {
			error = nfs_advlock_unlock(np, nofp, nlop, start, end, style, ctx);
		} else if ((op == F_SETLK) || (op == F_SETLKW)) {
			if ((op == F_SETLK) && (flags & F_WAIT))
				op = F_SETLKW;
			error = nfs_advlock_setlock(np, nofp, nlop, op, start, end, style, fl->l_type, ctx);
		} else {
			/* not getlk, unlock or lock? */
			error = EINVAL;
		}
	}

out:
	if (nlop)
		nfs_lock_owner_rele(nlop);
	if (noop)
		nfs_open_owner_rele(noop);
	return (error);
}

/*
 * Check if an open owner holds any locks on a file.
 */
int
nfs_check_for_locks(struct nfs_open_owner *noop, struct nfs_open_file *nofp)
{
	struct nfs_lock_owner *nlop;

	TAILQ_FOREACH(nlop, &nofp->nof_np->n_lock_owners, nlo_link) {
		if (nlop->nlo_open_owner != noop)
			continue;
		if (!TAILQ_EMPTY(&nlop->nlo_locks))
			break;
	}
	return (nlop ? 1 : 0);
}

/*
 * Reopen simple (no deny, no locks) open state that was lost.
 */
int
nfs4_reopen(struct nfs_open_file *nofp, thread_t thd)
{
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfsmount *nmp = NFSTONMP(nofp->nof_np);
	nfsnode_t np = nofp->nof_np;
	vnode_t vp = NFSTOV(np);
	vnode_t dvp = NULL;
	struct componentname cn;
	const char *vname = NULL;
	const char *name = NULL;
	size_t namelen;
	char smallname[128];
	char *filename = NULL;
	int error = 0, done = 0, slpflag = NMFLAG(nmp, INTR) ? PCATCH : 0;
	struct timespec ts = { 1, 0 };

	lck_mtx_lock(&nofp->nof_lock);
	while (nofp->nof_flags & NFS_OPEN_FILE_REOPENING) {
		if ((error = nfs_sigintr(nmp, NULL, thd, 0)))
			break;
		msleep(&nofp->nof_flags, &nofp->nof_lock, slpflag|(PZERO-1), "nfsreopenwait", &ts);
		slpflag = 0;
	}
	if (error || !(nofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
		lck_mtx_unlock(&nofp->nof_lock);
		return (error);
	}
	nofp->nof_flags |= NFS_OPEN_FILE_REOPENING;
	lck_mtx_unlock(&nofp->nof_lock);

	nfs_node_lock_force(np);
	if ((vnode_vtype(vp) != VDIR) && np->n_sillyrename) {
		/*
		 * The node's been sillyrenamed, so we need to use
		 * the sillyrename directory/name to do the open.
		 */
		struct nfs_sillyrename *nsp = np->n_sillyrename;
		dvp = NFSTOV(nsp->nsr_dnp);
		if ((error = vnode_get(dvp))) {
			nfs_node_unlock(np);
			goto out;
		}
		name = nsp->nsr_name;
	} else {
		/*
		 * [sigh] We can't trust VFS to get the parent right for named
		 * attribute nodes.  (It likes to reparent the nodes after we've
		 * created them.)  Luckily we can probably get the right parent
		 * from the n_parent we have stashed away.
		 */
		if ((np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR) &&
		    (((dvp = np->n_parent)) && (error = vnode_get(dvp))))
			dvp = NULL;
		if (!dvp)
			dvp = vnode_getparent(vp);
		vname = vnode_getname(vp);
		if (!dvp || !vname) {
			if (!error)
				error = EIO;
			nfs_node_unlock(np);
			goto out;
		}
		name = vname;
	}
	filename = &smallname[0];
	namelen = snprintf(filename, sizeof(smallname), "%s", name);
	if (namelen >= sizeof(smallname)) {
		MALLOC(filename, char *, namelen+1, M_TEMP, M_WAITOK);
		if (!filename) {
			error = ENOMEM;
			goto out;
		}
		snprintf(filename, namelen+1, "%s", name);
	}
	nfs_node_unlock(np);
	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = filename;
	cn.cn_namelen = namelen;

restart:
	done = 0;
	if ((error = nfs_mount_state_in_use_start(nmp, thd)))
		goto out;

	if (nofp->nof_rw)
		error = nfs4_open_reopen_rpc(nofp, thd, noop->noo_cred, &cn, dvp, &vp, NFS_OPEN_SHARE_ACCESS_BOTH, NFS_OPEN_SHARE_DENY_NONE);
	if (!error && nofp->nof_w)
		error = nfs4_open_reopen_rpc(nofp, thd, noop->noo_cred, &cn, dvp, &vp, NFS_OPEN_SHARE_ACCESS_WRITE, NFS_OPEN_SHARE_DENY_NONE);
	if (!error && nofp->nof_r)
		error = nfs4_open_reopen_rpc(nofp, thd, noop->noo_cred, &cn, dvp, &vp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE);

	if (nfs_mount_state_in_use_end(nmp, error)) {
		if (error == NFSERR_GRACE)
			goto restart;
		printf("nfs4_reopen: RPC failed, error %d, lost %d, %s\n", error,
			(nofp->nof_flags & NFS_OPEN_FILE_LOST) ? 1 : 0, name ? name : "???");
		error = 0;
		goto out;
	}
	done = 1;
out:
	if (error && (error != EINTR) && (error != ERESTART))
		nfs_revoke_open_state_for_node(np);
	lck_mtx_lock(&nofp->nof_lock);
	nofp->nof_flags &= ~NFS_OPEN_FILE_REOPENING;
	if (done)
		nofp->nof_flags &= ~NFS_OPEN_FILE_REOPEN;
	else if (error)
		printf("nfs4_reopen: failed, error %d, lost %d, %s\n", error,
			(nofp->nof_flags & NFS_OPEN_FILE_LOST) ? 1 : 0, name ? name : "???");
	lck_mtx_unlock(&nofp->nof_lock);
	if (filename && (filename != &smallname[0]))
		FREE(filename, M_TEMP);
	if (vname)
		vnode_putname(vname);
	if (dvp != NULLVP)
		vnode_put(dvp);
	return (error);
}

/*
 * Send a normal OPEN RPC to open/create a file.
 */
int
nfs4_open_rpc(
	struct nfs_open_file *nofp,
	vfs_context_t ctx,
	struct componentname *cnp,
	struct vnode_attr *vap,
	vnode_t dvp,
	vnode_t *vpp,
	int create,
	int share_access,
	int share_deny)
{
	return (nfs4_open_rpc_internal(nofp, ctx, vfs_context_thread(ctx), vfs_context_ucred(ctx),
					cnp, vap, dvp, vpp, create, share_access, share_deny));
}

/*
 * Send an OPEN RPC to reopen a file.
 */
int
nfs4_open_reopen_rpc(
	struct nfs_open_file *nofp,
	thread_t thd,
	kauth_cred_t cred,
	struct componentname *cnp,
	vnode_t dvp,
	vnode_t *vpp,
	int share_access,
	int share_deny)
{
	return (nfs4_open_rpc_internal(nofp, NULL, thd, cred, cnp, NULL, dvp, vpp, NFS_OPEN_NOCREATE, share_access, share_deny));
}

/*
 * Send an OPEN_CONFIRM RPC to confirm an OPEN.
 */
int
nfs4_open_confirm_rpc(
	struct nfsmount *nmp,
	nfsnode_t dnp,
	u_char *fhp,
	int fhlen,
	struct nfs_open_owner *noop,
	nfs_stateid *sid,
	thread_t thd,
	kauth_cred_t cred,
	struct nfs_vattr *nvap,
	uint64_t *xidp)
{
	struct nfsm_chain nmreq, nmrep;
	int error = 0, status, numops;
	struct nfsreq_secinfo_args si;

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

	// PUTFH, OPEN_CONFIRM, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 23 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "open_confirm", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, fhp, fhlen);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_OPEN_CONFIRM);
	nfsm_chain_add_stateid(error, &nmreq, sid);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request2(dnp, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, R_NOINTR, &nmrep, xidp, &status);

	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN_CONFIRM);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, sid);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, nvap, NULL, NULL, NULL);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/*
 * common OPEN RPC code
 *
 * If create is set, ctx must be passed in.
 * Returns a node on success if no node passed in.
 */
int
nfs4_open_rpc_internal(
	struct nfs_open_file *nofp,
	vfs_context_t ctx,
	thread_t thd,
	kauth_cred_t cred,
	struct componentname *cnp,
	struct vnode_attr *vap,
	vnode_t dvp,
	vnode_t *vpp,
	int create,
	int share_access,
	int share_deny)
{
	struct nfsmount *nmp;
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfs_vattr nvattr;
	int error = 0, open_error = EIO, lockerror = ENOENT, busyerror = ENOENT, status;
	int nfsvers, namedattrs, numops, exclusive = 0, gotuid, gotgid;
	u_int64_t xid, savedxid = 0;
	nfsnode_t dnp = VTONFS(dvp);
	nfsnode_t np, newnp = NULL;
	vnode_t newvp = NULL;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	uint32_t rflags, delegation, recall;
	struct nfs_stateid stateid, dstateid, *sid;
	fhandle_t fh;
	struct nfsreq rq, *req = &rq;
	struct nfs_dulookup dul;
	char sbuf[64], *s;
	uint32_t ace_type, ace_flags, ace_mask, len, slen;
	struct kauth_ace ace;
	struct nfsreq_secinfo_args si;

	if (create && !ctx)
		return (EINVAL);

	nmp = VTONMP(dvp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	namedattrs = (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR);
	if (dnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	np = *vpp ? VTONFS(*vpp) : NULL;
	if (create && vap) {
		exclusive = (vap->va_vaflags & VA_EXCLUSIVE);
		nfs_avoid_needless_id_setting_on_create(dnp, vap, ctx);
		gotuid = VATTR_IS_ACTIVE(vap, va_uid);
		gotgid = VATTR_IS_ACTIVE(vap, va_gid);
		if (exclusive && (!VATTR_IS_ACTIVE(vap, va_access_time) || !VATTR_IS_ACTIVE(vap, va_modify_time)))
			vap->va_vaflags |= VA_UTIMES_NULL;
	} else {
		exclusive = gotuid = gotgid = 0;
	}
	if (nofp) {
		sid = &nofp->nof_stateid;
	} else {
		stateid.seqid = stateid.other[0] = stateid.other[1] = stateid.other[2] = 0;
		sid = &stateid;
	}

	if ((error = nfs_open_owner_set_busy(noop, thd)))
		return (error);
again:
	rflags = delegation = recall = 0;
	ace.ace_flags = 0;
	s = sbuf;
	slen = sizeof(sbuf);
	NVATTR_INIT(&nvattr);
	NFSREQ_SECINFO_SET(&si, dnp, NULL, 0, cnp->cn_nameptr, cnp->cn_namelen);

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

	// PUTFH, SAVEFH, OPEN(CREATE?), GETATTR(FH), RESTOREFH, GETATTR
	numops = 6;
	nfsm_chain_build_alloc_init(error, &nmreq, 53 * NFSX_UNSIGNED + cnp->cn_namelen);
	nfsm_chain_add_compound_header(error, &nmreq, create ? "create" : "open", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, dnp->n_fhp, dnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_SAVEFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_OPEN);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	nfsm_chain_add_32(error, &nmreq, share_access);
	nfsm_chain_add_32(error, &nmreq, share_deny);
	nfsm_chain_add_64(error, &nmreq, nmp->nm_clientid);
	nfsm_chain_add_32(error, &nmreq, NFSX_UNSIGNED);
	nfsm_chain_add_32(error, &nmreq, kauth_cred_getuid(noop->noo_cred));
	nfsm_chain_add_32(error, &nmreq, create);
	if (create) {
		if (exclusive) {
			static uint32_t create_verf; // XXX need a better verifier
			create_verf++;
			nfsm_chain_add_32(error, &nmreq, NFS_CREATE_EXCLUSIVE);
			/* insert 64 bit verifier */
			nfsm_chain_add_32(error, &nmreq, create_verf);
			nfsm_chain_add_32(error, &nmreq, create_verf);
		} else {
			nfsm_chain_add_32(error, &nmreq, NFS_CREATE_UNCHECKED);
			nfsm_chain_add_fattr4(error, &nmreq, vap, nmp);
		}
	}
	nfsm_chain_add_32(error, &nmreq, NFS_CLAIM_NULL);
	nfsm_chain_add_name(error, &nmreq, cnp->cn_nameptr, cnp->cn_namelen, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	nfsm_chain_add_bitmap_supported(error, &nmreq, bitmap, nmp, np);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_RESTOREFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	if (!error)
		error = busyerror = nfs_node_set_busy(dnp, thd);
	nfsmout_if(error);

	if (create && !namedattrs)
		nfs_dulookup_init(&dul, dnp, cnp->cn_nameptr, cnp->cn_namelen, ctx);

	error = nfs_request_async(dnp, NULL, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, R_NOINTR, NULL, &req);
	if (!error) {
		if (create && !namedattrs)
			nfs_dulookup_start(&dul, dnp, ctx);
		error = nfs_request_async_finish(req, &nmrep, &xid, &status);
		savedxid = xid;
	}

	if (create && !namedattrs)
		nfs_dulookup_finish(&dul, dnp, ctx);

	if ((lockerror = nfs_node_lock(dnp)))
		error = lockerror;
	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_SAVEFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, sid);
	nfsm_chain_check_change_info(error, &nmrep, dnp);
	nfsm_chain_get_32(error, &nmrep, rflags);
	bmlen = NFS_ATTR_BITMAP_LEN;
	nfsm_chain_get_bitmap(error, &nmrep, bitmap, bmlen);
	nfsm_chain_get_32(error, &nmrep, delegation);
	if (!error)
		switch (delegation) {
		case NFS_OPEN_DELEGATE_NONE:
			break;
		case NFS_OPEN_DELEGATE_READ:
		case NFS_OPEN_DELEGATE_WRITE:
			nfsm_chain_get_stateid(error, &nmrep, &dstateid);
			nfsm_chain_get_32(error, &nmrep, recall);
			if (delegation == NFS_OPEN_DELEGATE_WRITE) // space (skip) XXX
				nfsm_chain_adv(error, &nmrep, 3 * NFSX_UNSIGNED);
			/* if we have any trouble accepting the ACE, just invalidate it */
			ace_type = ace_flags = ace_mask = len = 0;
			nfsm_chain_get_32(error, &nmrep, ace_type);
			nfsm_chain_get_32(error, &nmrep, ace_flags);
			nfsm_chain_get_32(error, &nmrep, ace_mask);
			nfsm_chain_get_32(error, &nmrep, len);
			ace.ace_flags = nfs4_ace_nfstype_to_vfstype(ace_type, &error);
			ace.ace_flags |= nfs4_ace_nfsflags_to_vfsflags(ace_flags);
			ace.ace_rights = nfs4_ace_nfsmask_to_vfsrights(ace_mask);
			if (!error && (len >= slen)) {
				MALLOC(s, char*, len+1, M_TEMP, M_WAITOK);
				if (s)
					slen = len+1;
				else
					ace.ace_flags = 0;
			}
			if (s)
				nfsm_chain_get_opaque(error, &nmrep, len, s);
			else
				nfsm_chain_adv(error, &nmrep, nfsm_rndup(len));
			if (!error && s) {
				s[len] = '\0';
				if (nfs4_id2guid(s, &ace.ace_applicable, (ace_flags & NFS_ACE_IDENTIFIER_GROUP)))
					ace.ace_flags = 0;
			}
			if (error || !s)
				ace.ace_flags = 0;
			if (s && (s != sbuf))
				FREE(s, M_TEMP);
			break;
		default:
			error = EBADRPC;
			break;
		}
	/* At this point if we have no error, the object was created/opened. */
	open_error = error;
	nfsmout_if(error);
	if (create && vap && !exclusive)
		nfs_vattr_set_supported(bitmap, vap);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE)) {
		printf("nfs: open/create didn't return filehandle? %s\n", cnp->cn_nameptr);
		error = EBADRPC;
		goto nfsmout;
	}
	if (!create && np && !NFS_CMPFH(np, fh.fh_data, fh.fh_len)) {
		// XXX for the open case, what if fh doesn't match the vnode we think we're opening?
		// Solaris Named Attributes may do this due to a bug.... so don't warn for named attributes.
		if (!(np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			NP(np, "nfs4_open_rpc: warning: file handle mismatch");
	}
	/* directory attributes: if we don't get them, make sure to invalidate */
	nfsm_chain_op_check(error, &nmrep, NFS_OP_RESTOREFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, dnp, nfsvers, &xid);
	if (error)
		NATTRINVALIDATE(dnp);
	nfsmout_if(error);

	if (rflags & NFS_OPEN_RESULT_LOCKTYPE_POSIX)
		nofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;

	if (rflags & NFS_OPEN_RESULT_CONFIRM) {
		nfs_node_unlock(dnp);
		lockerror = ENOENT;
		NVATTR_CLEANUP(&nvattr);
		error = nfs4_open_confirm_rpc(nmp, dnp, fh.fh_data, fh.fh_len, noop, sid, thd, cred, &nvattr, &xid);
		nfsmout_if(error);
		savedxid = xid;
		if ((lockerror = nfs_node_lock(dnp)))
			error = lockerror;
	}

nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);

	if (!lockerror && create) {
		if (!open_error && (dnp->n_flag & NNEGNCENTRIES)) {
			dnp->n_flag &= ~NNEGNCENTRIES;
			cache_purge_negatives(dvp);
		}
		dnp->n_flag |= NMODIFIED;
		nfs_node_unlock(dnp);
		lockerror = ENOENT;
		nfs_getattr(dnp, NULL, ctx, NGA_CACHED);
	}
	if (!lockerror)
		nfs_node_unlock(dnp);
	if (!error && !np && fh.fh_len) {
		/* create the vnode with the filehandle and attributes */
		xid = savedxid;
		error = nfs_nget(NFSTOMP(dnp), dnp, cnp, fh.fh_data, fh.fh_len, &nvattr, &xid, rq.r_auth, NG_MAKEENTRY, &newnp);
		if (!error)
			newvp = NFSTOV(newnp);
	}
	NVATTR_CLEANUP(&nvattr);
	if (!busyerror)
		nfs_node_clear_busy(dnp);
	if ((delegation == NFS_OPEN_DELEGATE_READ) || (delegation == NFS_OPEN_DELEGATE_WRITE)) {
		if (!np)
			np = newnp;
		if (!error && np && !recall) {
			/* stuff the delegation state in the node */
			lck_mtx_lock(&np->n_openlock);
			np->n_openflags &= ~N_DELEG_MASK;
			np->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
			np->n_dstateid = dstateid;
			np->n_dace = ace;
			if (np->n_dlink.tqe_next == NFSNOLIST) {
				lck_mtx_lock(&nmp->nm_lock);
				if (np->n_dlink.tqe_next == NFSNOLIST)
					TAILQ_INSERT_TAIL(&nmp->nm_delegations, np, n_dlink);
				lck_mtx_unlock(&nmp->nm_lock);
			}
			lck_mtx_unlock(&np->n_openlock);
		} else {
			/* give the delegation back */
			if (np) {
				if (NFS_CMPFH(np, fh.fh_data, fh.fh_len)) {
					/* update delegation state and return it */
					lck_mtx_lock(&np->n_openlock);
					np->n_openflags &= ~N_DELEG_MASK;
					np->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
					np->n_dstateid = dstateid;
					np->n_dace = ace;
					if (np->n_dlink.tqe_next == NFSNOLIST) {
						lck_mtx_lock(&nmp->nm_lock);
						if (np->n_dlink.tqe_next == NFSNOLIST)
							TAILQ_INSERT_TAIL(&nmp->nm_delegations, np, n_dlink);
						lck_mtx_unlock(&nmp->nm_lock);
					}
					lck_mtx_unlock(&np->n_openlock);
					/* don't need to send a separate delegreturn for fh */
					fh.fh_len = 0;
				}
				/* return np's current delegation */
				nfs4_delegation_return(np, 0, thd, cred);
			}
			if (fh.fh_len) /* return fh's delegation if it wasn't for np */
				nfs4_delegreturn_rpc(nmp, fh.fh_data, fh.fh_len, &dstateid, 0, thd, cred);
		}
	}
	if (error) {
		if (exclusive && (error == NFSERR_NOTSUPP)) {
			exclusive = 0;
			goto again;
		}
		if (newvp) {
			nfs_node_unlock(newnp);
			vnode_put(newvp);
		}
	} else if (create) {
		nfs_node_unlock(newnp);
		if (exclusive) {
			error = nfs4_setattr_rpc(newnp, vap, ctx);
			if (error && (gotuid || gotgid)) {
				/* it's possible the server didn't like our attempt to set IDs. */
				/* so, let's try it again without those */
				VATTR_CLEAR_ACTIVE(vap, va_uid);
				VATTR_CLEAR_ACTIVE(vap, va_gid);
				error = nfs4_setattr_rpc(newnp, vap, ctx);
			}
		}
		if (error)
			vnode_put(newvp);
		else
			*vpp = newvp;
	}
	nfs_open_owner_clear_busy(noop);
	return (error);
}


/*
 * Send an OPEN RPC to claim a delegated open for a file
 */
int
nfs4_claim_delegated_open_rpc(
	struct nfs_open_file *nofp,
	int share_access,
	int share_deny,
	int flags)
{
	struct nfsmount *nmp;
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfs_vattr nvattr;
	int error = 0, lockerror = ENOENT, status;
	int nfsvers, numops;
	u_int64_t xid;
	nfsnode_t np = nofp->nof_np;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	uint32_t rflags = 0, delegation, recall = 0;
	fhandle_t fh;
	struct nfs_stateid dstateid;
	char sbuf[64], *s = sbuf;
	uint32_t ace_type, ace_flags, ace_mask, len, slen = sizeof(sbuf);
	struct kauth_ace ace;
	vnode_t dvp = NULL;
	const char *vname = NULL;
	const char *name = NULL;
	size_t namelen;
	char smallname[128];
	char *filename = NULL;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	nfs_node_lock_force(np);
	if ((vnode_vtype(NFSTOV(np)) != VDIR) && np->n_sillyrename) {
		/*
		 * The node's been sillyrenamed, so we need to use
		 * the sillyrename directory/name to do the open.
		 */
		struct nfs_sillyrename *nsp = np->n_sillyrename;
		dvp = NFSTOV(nsp->nsr_dnp);
		if ((error = vnode_get(dvp))) {
			nfs_node_unlock(np);
			goto out;
		}
		name = nsp->nsr_name;
	} else {
		/*
		 * [sigh] We can't trust VFS to get the parent right for named
		 * attribute nodes.  (It likes to reparent the nodes after we've
		 * created them.)  Luckily we can probably get the right parent
		 * from the n_parent we have stashed away.
		 */
		if ((np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR) &&
		    (((dvp = np->n_parent)) && (error = vnode_get(dvp))))
			dvp = NULL;
		if (!dvp)
			dvp = vnode_getparent(NFSTOV(np));
		vname = vnode_getname(NFSTOV(np));
		if (!dvp || !vname) {
			if (!error)
				error = EIO;
			nfs_node_unlock(np);
			goto out;
		}
		name = vname;
	}
	filename = &smallname[0];
	namelen = snprintf(filename, sizeof(smallname), "%s", name);
	if (namelen >= sizeof(smallname)) {
		MALLOC(filename, char *, namelen+1, M_TEMP, M_WAITOK);
		if (!filename) {
			error = ENOMEM;
			goto out;
		}
		snprintf(filename, namelen+1, "%s", name);
	}
	nfs_node_unlock(np);

	if ((error = nfs_open_owner_set_busy(noop, NULL)))
		return (error);

	NVATTR_INIT(&nvattr);
	delegation = NFS_OPEN_DELEGATE_NONE;
	dstateid = np->n_dstateid;
	NFSREQ_SECINFO_SET(&si, VTONFS(dvp), NULL, 0, filename, namelen);

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

	// PUTFH, OPEN, GETATTR(FH)
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 48 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "open_claim_d", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, VTONFS(dvp)->n_fhp, VTONFS(dvp)->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_OPEN);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	nfsm_chain_add_32(error, &nmreq, share_access);
	nfsm_chain_add_32(error, &nmreq, share_deny);
	// open owner: clientid + uid
	nfsm_chain_add_64(error, &nmreq, nmp->nm_clientid); // open_owner4.clientid
	nfsm_chain_add_32(error, &nmreq, NFSX_UNSIGNED);
	nfsm_chain_add_32(error, &nmreq, kauth_cred_getuid(noop->noo_cred)); // open_owner4.owner
	// openflag4
	nfsm_chain_add_32(error, &nmreq, NFS_OPEN_NOCREATE);
	// open_claim4
	nfsm_chain_add_32(error, &nmreq, NFS_CLAIM_DELEGATE_CUR);
	nfsm_chain_add_stateid(error, &nmreq, &np->n_dstateid);
	nfsm_chain_add_name(error, &nmreq, filename, namelen, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	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, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND, current_thread(),
			noop->noo_cred, &si, flags|R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, &nofp->nof_stateid);
	nfsm_chain_check_change_info(error, &nmrep, np);
	nfsm_chain_get_32(error, &nmrep, rflags);
	bmlen = NFS_ATTR_BITMAP_LEN;
	nfsm_chain_get_bitmap(error, &nmrep, bitmap, bmlen);
	nfsm_chain_get_32(error, &nmrep, delegation);
	if (!error)
		switch (delegation) {
		case NFS_OPEN_DELEGATE_NONE:
			// if (!(np->n_openflags & N_DELEG_RETURN)) /* don't warn if delegation is being returned */
			// 	printf("nfs: open delegated claim didn't return a delegation %s\n", filename ? filename : "???");
			break;
		case NFS_OPEN_DELEGATE_READ:
		case NFS_OPEN_DELEGATE_WRITE:
			if ((((np->n_openflags & N_DELEG_MASK) == N_DELEG_READ) &&
			     (delegation == NFS_OPEN_DELEGATE_WRITE)) ||
			    (((np->n_openflags & N_DELEG_MASK) == N_DELEG_WRITE) &&
			     (delegation == NFS_OPEN_DELEGATE_READ)))
				printf("nfs: open delegated claim returned a different delegation type! have %s got %s %s\n",
				     ((np->n_openflags & N_DELEG_MASK) == N_DELEG_WRITE) ? "W" : "R",
				     (delegation == NFS_OPEN_DELEGATE_WRITE) ? "W" : "R", filename ? filename : "???");
			nfsm_chain_get_stateid(error, &nmrep, &dstateid);
			nfsm_chain_get_32(error, &nmrep, recall);
			if (delegation == NFS_OPEN_DELEGATE_WRITE) // space (skip) XXX
				nfsm_chain_adv(error, &nmrep, 3 * NFSX_UNSIGNED);
			/* if we have any trouble accepting the ACE, just invalidate it */
			ace_type = ace_flags = ace_mask = len = 0;
			nfsm_chain_get_32(error, &nmrep, ace_type);
			nfsm_chain_get_32(error, &nmrep, ace_flags);
			nfsm_chain_get_32(error, &nmrep, ace_mask);
			nfsm_chain_get_32(error, &nmrep, len);
			ace.ace_flags = nfs4_ace_nfstype_to_vfstype(ace_type, &error);
			ace.ace_flags |= nfs4_ace_nfsflags_to_vfsflags(ace_flags);
			ace.ace_rights = nfs4_ace_nfsmask_to_vfsrights(ace_mask);
			if (!error && (len >= slen)) {
				MALLOC(s, char*, len+1, M_TEMP, M_WAITOK);
				if (s)
					slen = len+1;
				else
					ace.ace_flags = 0;
			}
			if (s)
				nfsm_chain_get_opaque(error, &nmrep, len, s);
			else
				nfsm_chain_adv(error, &nmrep, nfsm_rndup(len));
			if (!error && s) {
				s[len] = '\0';
				if (nfs4_id2guid(s, &ace.ace_applicable, (ace_flags & NFS_ACE_IDENTIFIER_GROUP)))
					ace.ace_flags = 0;
			}
			if (error || !s)
				ace.ace_flags = 0;
			if (s && (s != sbuf))
				FREE(s, M_TEMP);
			if (!error) {
				/* stuff the latest delegation state in the node */
				lck_mtx_lock(&np->n_openlock);
				np->n_openflags &= ~N_DELEG_MASK;
				np->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
				np->n_dstateid = dstateid;
				np->n_dace = ace;
				if (np->n_dlink.tqe_next == NFSNOLIST) {
					lck_mtx_lock(&nmp->nm_lock);
					if (np->n_dlink.tqe_next == NFSNOLIST)
						TAILQ_INSERT_TAIL(&nmp->nm_delegations, np, n_dlink);
					lck_mtx_unlock(&nmp->nm_lock);
				}
				lck_mtx_unlock(&np->n_openlock);
			}
			break;
		default:
			error = EBADRPC;
			break;
		}
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE)) {
		printf("nfs: open reclaim didn't return filehandle? %s\n", filename ? filename : "???");
		error = EBADRPC;
		goto nfsmout;
	}
	if (!NFS_CMPFH(np, fh.fh_data, fh.fh_len)) {
		// XXX what if fh doesn't match the vnode we think we're re-opening?
		// Solaris Named Attributes may do this due to a bug.... so don't warn for named attributes.
		if (!(np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			printf("nfs4_claim_delegated_open_rpc: warning: file handle mismatch %s\n", filename ? filename : "???");
	}
	error = nfs_loadattrcache(np, &nvattr, &xid, 1);
	nfsmout_if(error);
	if (rflags & NFS_OPEN_RESULT_LOCKTYPE_POSIX)
		nofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;
nfsmout:
	NVATTR_CLEANUP(&nvattr);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_open_owner_clear_busy(noop);
	if ((delegation == NFS_OPEN_DELEGATE_READ) || (delegation == NFS_OPEN_DELEGATE_WRITE)) {
		if (recall) {
			/*
			 * We're making a delegated claim.
			 * Don't return the delegation here in case we have more to claim.
			 * Just make sure it's queued up to be returned.
			 */
			nfs4_delegation_return_enqueue(np);
		}
	}
out:
	// if (!error)
	// 	printf("nfs: open claim delegated (%d, %d) succeeded for %s\n", share_access, share_deny, filename ? filename : "???");
	if (filename && (filename != &smallname[0]))
		FREE(filename, M_TEMP);
	if (vname)
		vnode_putname(vname);
	if (dvp != NULLVP)
		vnode_put(dvp);
	return (error);
}

/*
 * Send an OPEN RPC to reclaim an open file.
 */
int
nfs4_open_reclaim_rpc(
	struct nfs_open_file *nofp,
	int share_access,
	int share_deny)
{
	struct nfsmount *nmp;
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfs_vattr nvattr;
	int error = 0, lockerror = ENOENT, status;
	int nfsvers, numops;
	u_int64_t xid;
	nfsnode_t np = nofp->nof_np;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	uint32_t rflags = 0, delegation, recall = 0;
	fhandle_t fh;
	struct nfs_stateid dstateid;
	char sbuf[64], *s = sbuf;
	uint32_t ace_type, ace_flags, ace_mask, len, slen = sizeof(sbuf);
	struct kauth_ace ace;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	if ((error = nfs_open_owner_set_busy(noop, NULL)))
		return (error);

	NVATTR_INIT(&nvattr);
	delegation = NFS_OPEN_DELEGATE_NONE;
	dstateid = np->n_dstateid;
	NFSREQ_SECINFO_SET(&si, np, NULL, 0, NULL, 0);

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

	// PUTFH, OPEN, GETATTR(FH)
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 48 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "open_reclaim", 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_OPEN);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	nfsm_chain_add_32(error, &nmreq, share_access);
	nfsm_chain_add_32(error, &nmreq, share_deny);
	// open owner: clientid + uid
	nfsm_chain_add_64(error, &nmreq, nmp->nm_clientid); // open_owner4.clientid
	nfsm_chain_add_32(error, &nmreq, NFSX_UNSIGNED);
	nfsm_chain_add_32(error, &nmreq, kauth_cred_getuid(noop->noo_cred)); // open_owner4.owner
	// openflag4
	nfsm_chain_add_32(error, &nmreq, NFS_OPEN_NOCREATE);
	// open_claim4
	nfsm_chain_add_32(error, &nmreq, NFS_CLAIM_PREVIOUS);
	delegation = (np->n_openflags & N_DELEG_READ) ? NFS_OPEN_DELEGATE_READ :
			(np->n_openflags & N_DELEG_WRITE) ? NFS_OPEN_DELEGATE_WRITE :
			NFS_OPEN_DELEGATE_NONE;
	nfsm_chain_add_32(error, &nmreq, delegation);
	delegation = NFS_OPEN_DELEGATE_NONE;
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	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, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND, current_thread(),
			noop->noo_cred, &si, R_RECOVER|R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, &nofp->nof_stateid);
	nfsm_chain_check_change_info(error, &nmrep, np);
	nfsm_chain_get_32(error, &nmrep, rflags);
	bmlen = NFS_ATTR_BITMAP_LEN;
	nfsm_chain_get_bitmap(error, &nmrep, bitmap, bmlen);
	nfsm_chain_get_32(error, &nmrep, delegation);
	if (!error)
		switch (delegation) {
		case NFS_OPEN_DELEGATE_NONE:
			if (np->n_openflags & N_DELEG_MASK) {
				/*
				 * Hey!  We were supposed to get our delegation back even
				 * if it was getting immediately recalled.  Bad server!
				 *
				 * Just try to return the existing delegation.
				 */
				// NP(np, "nfs: open reclaim didn't return delegation?");
				delegation = (np->n_openflags & N_DELEG_WRITE) ? NFS_OPEN_DELEGATE_WRITE : NFS_OPEN_DELEGATE_READ;
				recall = 1;
			}
			break;
		case NFS_OPEN_DELEGATE_READ:
		case NFS_OPEN_DELEGATE_WRITE:
			nfsm_chain_get_stateid(error, &nmrep, &dstateid);
			nfsm_chain_get_32(error, &nmrep, recall);
			if (delegation == NFS_OPEN_DELEGATE_WRITE) // space (skip) XXX
				nfsm_chain_adv(error, &nmrep, 3 * NFSX_UNSIGNED);
			/* if we have any trouble accepting the ACE, just invalidate it */
			ace_type = ace_flags = ace_mask = len = 0;
			nfsm_chain_get_32(error, &nmrep, ace_type);
			nfsm_chain_get_32(error, &nmrep, ace_flags);
			nfsm_chain_get_32(error, &nmrep, ace_mask);
			nfsm_chain_get_32(error, &nmrep, len);
			ace.ace_flags = nfs4_ace_nfstype_to_vfstype(ace_type, &error);
			ace.ace_flags |= nfs4_ace_nfsflags_to_vfsflags(ace_flags);
			ace.ace_rights = nfs4_ace_nfsmask_to_vfsrights(ace_mask);
			if (!error && (len >= slen)) {
				MALLOC(s, char*, len+1, M_TEMP, M_WAITOK);
				if (s)
					slen = len+1;
				else
					ace.ace_flags = 0;
			}
			if (s)
				nfsm_chain_get_opaque(error, &nmrep, len, s);
			else
				nfsm_chain_adv(error, &nmrep, nfsm_rndup(len));
			if (!error && s) {
				s[len] = '\0';
				if (nfs4_id2guid(s, &ace.ace_applicable, (ace_flags & NFS_ACE_IDENTIFIER_GROUP)))
					ace.ace_flags = 0;
			}
			if (error || !s)
				ace.ace_flags = 0;
			if (s && (s != sbuf))
				FREE(s, M_TEMP);
			if (!error) {
				/* stuff the delegation state in the node */
				lck_mtx_lock(&np->n_openlock);
				np->n_openflags &= ~N_DELEG_MASK;
				np->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
				np->n_dstateid = dstateid;
				np->n_dace = ace;
				if (np->n_dlink.tqe_next == NFSNOLIST) {
					lck_mtx_lock(&nmp->nm_lock);
					if (np->n_dlink.tqe_next == NFSNOLIST)
						TAILQ_INSERT_TAIL(&nmp->nm_delegations, np, n_dlink);
					lck_mtx_unlock(&nmp->nm_lock);
				}
				lck_mtx_unlock(&np->n_openlock);
			}
			break;
		default:
			error = EBADRPC;
			break;
		}
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE)) {
		NP(np, "nfs: open reclaim didn't return filehandle?");
		error = EBADRPC;
		goto nfsmout;
	}
	if (!NFS_CMPFH(np, fh.fh_data, fh.fh_len)) {
		// XXX what if fh doesn't match the vnode we think we're re-opening?
		// That should be pretty hard in this case, given that we are doing
		// the open reclaim using the file handle (and not a dir/name pair).
		// Solaris Named Attributes may do this due to a bug.... so don't warn for named attributes.
		if (!(np->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			NP(np, "nfs4_open_reclaim_rpc: warning: file handle mismatch");
	}
	error = nfs_loadattrcache(np, &nvattr, &xid, 1);
	nfsmout_if(error);
	if (rflags & NFS_OPEN_RESULT_LOCKTYPE_POSIX)
		nofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;
nfsmout:
	// if (!error)
	// 	NP(np, "nfs: open reclaim (%d, %d) succeeded", share_access, share_deny);
	NVATTR_CLEANUP(&nvattr);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_open_owner_clear_busy(noop);
	if ((delegation == NFS_OPEN_DELEGATE_READ) || (delegation == NFS_OPEN_DELEGATE_WRITE)) {
		if (recall)
			nfs4_delegation_return_enqueue(np);
	}
	return (error);
}

int
nfs4_open_downgrade_rpc(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	vfs_context_t ctx)
{
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfsmount *nmp;
	int error, lockerror = ENOENT, status, nfsvers, numops;
	struct nfsm_chain nmreq, nmrep;
	u_int64_t xid;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	if ((error = nfs_open_owner_set_busy(noop, NULL)))
		return (error);

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

	// PUTFH, OPEN_DOWNGRADE, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 23 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "open_downgrd", 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_OPEN_DOWNGRADE);
	nfsm_chain_add_stateid(error, &nmreq, &nofp->nof_stateid);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	nfsm_chain_add_32(error, &nmreq, nofp->nof_access);
	nfsm_chain_add_32(error, &nmreq, nofp->nof_deny);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_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),
			&si, R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN_DOWNGRADE);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, &nofp->nof_stateid);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_open_owner_clear_busy(noop);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

int
nfs4_close_rpc(
	nfsnode_t np,
	struct nfs_open_file *nofp,
	thread_t thd,
	kauth_cred_t cred,
	int flags)
{
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfsmount *nmp;
	int error, lockerror = ENOENT, status, nfsvers, numops;
	struct nfsm_chain nmreq, nmrep;
	u_int64_t xid;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;

	if ((error = nfs_open_owner_set_busy(noop, NULL)))
		return (error);

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

	// PUTFH, CLOSE, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 23 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "close", 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_CLOSE);
	nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
	nfsm_chain_add_stateid(error, &nmreq, &nofp->nof_stateid);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_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, thd, cred, &si, flags|R_NOINTR, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock(np)))
		error = lockerror;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_CLOSE);
	nfs_owner_seqid_increment(noop, NULL, error);
	nfsm_chain_get_stateid(error, &nmrep, &nofp->nof_stateid);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
nfsmout:
	if (!lockerror)
		nfs_node_unlock(np);
	nfs_open_owner_clear_busy(noop);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}


/*
 * Claim the delegated open combinations this open file holds.
 */
int
nfs4_claim_delegated_state_for_open_file(struct nfs_open_file *nofp, int flags)
{
	struct nfs_open_owner *noop = nofp->nof_owner;
	struct nfs_lock_owner *nlop;
	struct nfs_file_lock *nflp, *nextnflp;
	struct nfsmount *nmp;
	int error = 0, reopen = 0;

	if (nofp->nof_d_rw_drw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_BOTH, NFS_OPEN_SHARE_DENY_BOTH, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_rw_drw += nofp->nof_d_rw_drw;
			nofp->nof_d_rw_drw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if (!error && nofp->nof_d_w_drw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_WRITE, NFS_OPEN_SHARE_DENY_BOTH, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_w_drw += nofp->nof_d_w_drw;
			nofp->nof_d_w_drw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if (!error && nofp->nof_d_r_drw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_BOTH, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_r_drw += nofp->nof_d_r_drw;
			nofp->nof_d_r_drw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if (!error && nofp->nof_d_rw_dw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_BOTH, NFS_OPEN_SHARE_DENY_WRITE, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_rw_dw += nofp->nof_d_rw_dw;
			nofp->nof_d_rw_dw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if (!error && nofp->nof_d_w_dw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_WRITE, NFS_OPEN_SHARE_DENY_WRITE, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_w_dw += nofp->nof_d_w_dw;
			nofp->nof_d_w_dw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if (!error && nofp->nof_d_r_dw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_WRITE, flags);
		if (!error) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_r_dw += nofp->nof_d_r_dw;
			nofp->nof_d_r_dw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	/* non-deny-mode opens may be reopened if no locks are held */
	if (!error && nofp->nof_d_rw) {
		error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_BOTH, NFS_OPEN_SHARE_DENY_NONE, flags);
		/* for some errors, we should just try reopening the file */
		if (nfs_mount_state_error_delegation_lost(error))
			reopen = error;
		if (!error || reopen) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_rw += nofp->nof_d_rw;
			nofp->nof_d_rw = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	/* if we've already set reopen, we should move these other two opens from delegated to not delegated */
	if ((!error || reopen) && nofp->nof_d_w) {
		if (!error) {
			error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_WRITE, NFS_OPEN_SHARE_DENY_NONE, flags);
			/* for some errors, we should just try reopening the file */
			if (nfs_mount_state_error_delegation_lost(error))
				reopen = error;
		}
		if (!error || reopen) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_w += nofp->nof_d_w;
			nofp->nof_d_w = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}
	if ((!error || reopen) && nofp->nof_d_r) {
		if (!error) {
			error = nfs4_claim_delegated_open_rpc(nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE, flags);
			/* for some errors, we should just try reopening the file */
			if (nfs_mount_state_error_delegation_lost(error))
				reopen = error;
		}
		if (!error || reopen) {
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_r += nofp->nof_d_r;
			nofp->nof_d_r = 0;
			lck_mtx_unlock(&nofp->nof_lock);
		}
	}

	if (reopen) {
		/*
		 * Any problems with the delegation probably indicates that we
		 * should review/return all of our current delegation state.
		 */
		if ((nmp = NFSTONMP(nofp->nof_np))) {
			nfs4_delegation_return_enqueue(nofp->nof_np);
			lck_mtx_lock(&nmp->nm_lock);
			nfs_need_recover(nmp, NFSERR_EXPIRED);
			lck_mtx_unlock(&nmp->nm_lock);
		}
		if (reopen && (nfs_check_for_locks(noop, nofp) == 0)) {
			/* just reopen the file on next access */
			NP(nofp->nof_np, "nfs4_claim_delegated_state_for_open_file: %d, need reopen, %d",
				reopen, kauth_cred_getuid(nofp->nof_owner->noo_cred));
			lck_mtx_lock(&nofp->nof_lock);
			nofp->nof_flags |= NFS_OPEN_FILE_REOPEN;
			lck_mtx_unlock(&nofp->nof_lock);
			return (0);
		}
		if (reopen)
			NP(nofp->nof_np, "nfs4_claim_delegated_state_for_open_file: %d, locks prevent reopen, %d",
				reopen, kauth_cred_getuid(nofp->nof_owner->noo_cred));
	}

	if (!error && ((nmp = NFSTONMP(nofp->nof_np)))) {
		/* claim delegated locks */
		TAILQ_FOREACH(nlop, &nofp->nof_np->n_lock_owners, nlo_link) {
			if (nlop->nlo_open_owner != noop)
				continue;
			TAILQ_FOREACH_SAFE(nflp, &nlop->nlo_locks, nfl_lolink, nextnflp) {
				/* skip dead & blocked lock requests (shouldn't be any in the held lock list) */
				if (nflp->nfl_flags & (NFS_FILE_LOCK_DEAD|NFS_FILE_LOCK_BLOCKED))
					continue;
				/* skip non-delegated locks */
				if (!(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED))
					continue;
				error = nmp->nm_funcs->nf_setlock_rpc(nofp->nof_np, nofp, nflp, 0, flags, current_thread(), noop->noo_cred);
				if (error) {
					NP(nofp->nof_np, "nfs: delegated lock claim (0x%llx, 0x%llx) failed %d, %d",
						nflp->nfl_start, nflp->nfl_end, error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
					break;
				}
				// else {
				// 	NP(nofp->nof_np, "nfs: delegated lock claim (0x%llx, 0x%llx) succeeded, %d",
				// 		nflp->nfl_start, nflp->nfl_end, kauth_cred_getuid(nofp->nof_owner->noo_cred));
				// }
			}
			if (error)
				break;
		}
	}

	if (!error)  /* all state claimed successfully! */
		return (0);

	/* restart if it looks like a problem more than just losing the delegation */
	if (!nfs_mount_state_error_delegation_lost(error) &&
	    ((error == ETIMEDOUT) || nfs_mount_state_error_should_restart(error))) {
		NP(nofp->nof_np, "nfs delegated lock claim error %d, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));
		if ((error == ETIMEDOUT) && ((nmp = NFSTONMP(nofp->nof_np))))
			nfs_need_reconnect(nmp);
		return (error);
	}

	/* delegated state lost (once held but now not claimable) */
	NP(nofp->nof_np, "nfs delegated state claim error %d, state lost, %d", error, kauth_cred_getuid(nofp->nof_owner->noo_cred));

	/*
	 * Any problems with the delegation probably indicates that we
	 * should review/return all of our current delegation state.
	 */
	if ((nmp = NFSTONMP(nofp->nof_np))) {
		nfs4_delegation_return_enqueue(nofp->nof_np);
		lck_mtx_lock(&nmp->nm_lock);
		nfs_need_recover(nmp, NFSERR_EXPIRED);
		lck_mtx_unlock(&nmp->nm_lock);
	}

	/* revoke all open file state */
	nfs_revoke_open_state_for_node(nofp->nof_np);

	return (error);
}

/*
 * Release all open state for the given node.
 */
void
nfs_release_open_state_for_node(nfsnode_t np, int force)
{
	struct nfsmount *nmp = NFSTONMP(np);
	struct nfs_open_file *nofp;
	struct nfs_file_lock *nflp, *nextnflp;

	/* drop held locks */
	TAILQ_FOREACH_SAFE(nflp, &np->n_locks, nfl_link, nextnflp) {
		/* skip dead & blocked lock requests */
		if (nflp->nfl_flags & (NFS_FILE_LOCK_DEAD|NFS_FILE_LOCK_BLOCKED))
			continue;
		/* send an unlock if not a delegated lock */
		if (!force && nmp && !(nflp->nfl_flags & NFS_FILE_LOCK_DELEGATED))
			nmp->nm_funcs->nf_unlock_rpc(np, nflp->nfl_owner, F_WRLCK, nflp->nfl_start, nflp->nfl_end, R_RECOVER,
				NULL, nflp->nfl_owner->nlo_open_owner->noo_cred);
		/* kill/remove the lock */
		lck_mtx_lock(&np->n_openlock);
		nflp->nfl_flags |= NFS_FILE_LOCK_DEAD;
		lck_mtx_lock(&nflp->nfl_owner->nlo_lock);
		TAILQ_REMOVE(&nflp->nfl_owner->nlo_locks, nflp, nfl_lolink);
		lck_mtx_unlock(&nflp->nfl_owner->nlo_lock);
		if (nflp->nfl_blockcnt) {
			/* wake up anyone blocked on this lock */
			wakeup(nflp);
		} else {
			/* remove nflp from lock list and destroy */
			TAILQ_REMOVE(&np->n_locks, nflp, nfl_link);
			nfs_file_lock_destroy(nflp);
		}
		lck_mtx_unlock(&np->n_openlock);
	}

	lck_mtx_lock(&np->n_openlock);

	/* drop all opens */
	TAILQ_FOREACH(nofp, &np->n_opens, nof_link) {
		if (nofp->nof_flags & NFS_OPEN_FILE_LOST)
			continue;
		/* mark open state as lost */
		lck_mtx_lock(&nofp->nof_lock);
		nofp->nof_flags &= ~NFS_OPEN_FILE_REOPEN;
		nofp->nof_flags |= NFS_OPEN_FILE_LOST;

		lck_mtx_unlock(&nofp->nof_lock);
		if (!force && nmp && (nmp->nm_vers >= NFS_VER4))
			nfs4_close_rpc(np, nofp, NULL, nofp->nof_owner->noo_cred, R_RECOVER);
	}

	lck_mtx_unlock(&np->n_openlock);
}

/*
 * State for a node has been lost, drop it, and revoke the node.
 * Attempt to return any state if possible in case the server
 * might somehow think we hold it.
 */
void
nfs_revoke_open_state_for_node(nfsnode_t np)
{
	struct nfsmount *nmp;

	/* mark node as needing to be revoked */
	nfs_node_lock_force(np);
	if (np->n_flag & NREVOKE)  /* already revoked? */
	{
		NP(np, "nfs_revoke_open_state_for_node(): already revoked");
		nfs_node_unlock(np);
		return;
	}
	np->n_flag |= NREVOKE;
	nfs_node_unlock(np);

	nfs_release_open_state_for_node(np, 0);
	NP(np, "nfs: state lost for %p 0x%x", np, np->n_flag);

	/* mark mount as needing a revoke scan and have the socket thread do it. */
	if ((nmp = NFSTONMP(np))) {
		lck_mtx_lock(&nmp->nm_lock);
		nmp->nm_state |= NFSSTA_REVOKE;
		nfs_mount_sock_thread_wake(nmp);
		lck_mtx_unlock(&nmp->nm_lock);
	}
}

/*
 * Claim the delegated open combinations that each of this node's open files hold.
 */
int
nfs4_claim_delegated_state_for_node(nfsnode_t np, int flags)
{
	struct nfs_open_file *nofp;
	int error = 0;

	lck_mtx_lock(&np->n_openlock);

	/* walk the open file list looking for opens with delegated state to claim */
restart:
	TAILQ_FOREACH(nofp, &np->n_opens, nof_link) {
		if (!nofp->nof_d_rw_drw && !nofp->nof_d_w_drw && !nofp->nof_d_r_drw &&
		    !nofp->nof_d_rw_dw && !nofp->nof_d_w_dw && !nofp->nof_d_r_dw &&
		    !nofp->nof_d_rw && !nofp->nof_d_w && !nofp->nof_d_r)
			continue;
		lck_mtx_unlock(&np->n_openlock);
		error = nfs4_claim_delegated_state_for_open_file(nofp, flags);
		lck_mtx_lock(&np->n_openlock);
		if (error)
			break;
		goto restart;
	}

	lck_mtx_unlock(&np->n_openlock);

	return (error);
}

/*
 * Mark a node as needed to have its delegation returned.
 * Queue it up on the delegation return queue.
 * Make sure the thread is running.
 */
void
nfs4_delegation_return_enqueue(nfsnode_t np)
{
	struct nfsmount *nmp;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return;

	lck_mtx_lock(&np->n_openlock);
	np->n_openflags |= N_DELEG_RETURN;
	lck_mtx_unlock(&np->n_openlock);

	lck_mtx_lock(&nmp->nm_lock);
	if (np->n_dreturn.tqe_next == NFSNOLIST)
		TAILQ_INSERT_TAIL(&nmp->nm_dreturnq, np, n_dreturn);
	nfs_mount_sock_thread_wake(nmp);
	lck_mtx_unlock(&nmp->nm_lock);
}

/*
 * return any delegation we may have for the given node
 */
int
nfs4_delegation_return(nfsnode_t np, int flags, thread_t thd, kauth_cred_t cred)
{
	struct nfsmount *nmp;
	fhandle_t fh;
	nfs_stateid dstateid;
	int error;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	/* first, make sure the node's marked for delegation return */
	lck_mtx_lock(&np->n_openlock);
	np->n_openflags |= (N_DELEG_RETURN|N_DELEG_RETURNING);
	lck_mtx_unlock(&np->n_openlock);

	/* make sure nobody else is using the delegation state */
	if ((error = nfs_open_state_set_busy(np, NULL)))
		goto out;

	/* claim any delegated state */
	if ((error = nfs4_claim_delegated_state_for_node(np, flags)))
		goto out;

	/* return the delegation */
	lck_mtx_lock(&np->n_openlock);
	dstateid = np->n_dstateid;
	fh.fh_len = np->n_fhsize;
	bcopy(np->n_fhp, &fh.fh_data, fh.fh_len);
	lck_mtx_unlock(&np->n_openlock);
	error = nfs4_delegreturn_rpc(NFSTONMP(np), fh.fh_data, fh.fh_len, &dstateid, flags, thd, cred);
	/* assume delegation is gone for all errors except ETIMEDOUT, NFSERR_*MOVED */
	if ((error != ETIMEDOUT) && (error != NFSERR_MOVED) && (error != NFSERR_LEASE_MOVED)) {
		lck_mtx_lock(&np->n_openlock);
		np->n_openflags &= ~N_DELEG_MASK;
		lck_mtx_lock(&nmp->nm_lock);
		if (np->n_dlink.tqe_next != NFSNOLIST) {
			TAILQ_REMOVE(&nmp->nm_delegations, np, n_dlink);
			np->n_dlink.tqe_next = NFSNOLIST;
		}
		lck_mtx_unlock(&nmp->nm_lock);
		lck_mtx_unlock(&np->n_openlock);
	}

out:
	/* make sure it's no longer on the return queue and clear the return flags */
	lck_mtx_lock(&nmp->nm_lock);
	if (np->n_dreturn.tqe_next != NFSNOLIST) {
		TAILQ_REMOVE(&nmp->nm_dreturnq, np, n_dreturn);
		np->n_dreturn.tqe_next = NFSNOLIST;
	}
	lck_mtx_unlock(&nmp->nm_lock);
	lck_mtx_lock(&np->n_openlock);
	np->n_openflags &= ~(N_DELEG_RETURN|N_DELEG_RETURNING);
	lck_mtx_unlock(&np->n_openlock);

	if (error) {
		NP(np, "nfs4_delegation_return, error %d", error);
		if (error == ETIMEDOUT)
			nfs_need_reconnect(nmp);
		if (nfs_mount_state_error_should_restart(error)) {
			/* make sure recovery happens */
			lck_mtx_lock(&nmp->nm_lock);
			nfs_need_recover(nmp, nfs_mount_state_error_delegation_lost(error) ? NFSERR_EXPIRED : 0);
			lck_mtx_unlock(&nmp->nm_lock);
		}
	}

	nfs_open_state_clear_busy(np);

	return (error);
}

/*
 * RPC to return a delegation for a file handle
 */
int
nfs4_delegreturn_rpc(struct nfsmount *nmp, u_char *fhp, int fhlen, struct nfs_stateid *sid, int flags, thread_t thd, kauth_cred_t cred)
{
	int error = 0, status, numops;
	uint64_t xid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

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

	// PUTFH, DELEGRETURN
	numops = 2;
	nfsm_chain_build_alloc_init(error, &nmreq, 16 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "delegreturn", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, fhp, fhlen);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_DELEGRETURN);
	nfsm_chain_add_stateid(error, &nmreq, sid);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request2(NULL, nmp->nm_mountp, &nmreq, NFSPROC4_COMPOUND, thd, cred, &si, flags, &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_DELEGRETURN);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}


/*
 * NFS read call.
 * Just call nfs_bioread() to do the work.
 *
 * Note: the exec code paths have a tendency to call VNOP_READ (and VNOP_MMAP)
 * without first calling VNOP_OPEN, so we make sure the file is open here.
 */
int
nfs_vnop_read(
	struct vnop_read_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		struct uio *a_uio;
		int a_ioflag;
		vfs_context_t a_context;
	} */ *ap)
{
	vnode_t vp = ap->a_vp;
	vfs_context_t ctx = ap->a_context;
	nfsnode_t np;
	struct nfsmount *nmp;
	struct nfs_open_owner *noop;
	struct nfs_open_file *nofp;
	int error;

	if (vnode_vtype(ap->a_vp) != VREG)
		return (vnode_vtype(vp) == VDIR) ? EISDIR : EPERM;

	np = VTONFS(vp);
	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (np->n_flag & NREVOKE)
		return (EIO);

	noop = nfs_open_owner_find(nmp, vfs_context_ucred(ctx), 1);
	if (!noop)
		return (ENOMEM);
restart:
	error = nfs_open_file_find(np, noop, &nofp, 0, 0, 1);
	if (!error && (nofp->nof_flags & NFS_OPEN_FILE_LOST)) {
		NP(np, "nfs_vnop_read: LOST %d", kauth_cred_getuid(noop->noo_cred));
		error = EIO;
	}
	if (!error && (nofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
		error = nfs4_reopen(nofp, vfs_context_thread(ctx));
		nofp = NULL;
		if (!error)
			goto restart;
	}
	if (error) {
		nfs_open_owner_rele(noop);
		return (error);
	}
	if (!nofp->nof_access) {
		/* we don't have the file open, so open it for read access */
		error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
		if (error) {
			nfs_open_owner_rele(noop);
			return (error);
		}
		if (np->n_flag & NREVOKE) {
			error = EIO;
			nfs_mount_state_in_use_end(nmp, 0);
			nfs_open_owner_rele(noop);
			return (error);
		}
		error = nfs_open_file_set_busy(nofp, vfs_context_thread(ctx));
		if (error)
			nofp = NULL;
		if (!error) {
			if (nmp->nm_vers < NFS_VER4) {
				/* NFS v2/v3 opens are always allowed - so just add it. */
				nfs_open_file_add_open(nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE, 0);
			} else {
				error = nfs4_open(np, nofp, NFS_OPEN_SHARE_ACCESS_READ, NFS_OPEN_SHARE_DENY_NONE, ctx);
			}
		}
		if (!error)
			nofp->nof_flags |= NFS_OPEN_FILE_NEEDCLOSE;
		if (nofp)
			nfs_open_file_clear_busy(nofp);
		if (nfs_mount_state_in_use_end(nmp, error)) {
			nofp = NULL;
			goto restart;
		}
	}
	nfs_open_owner_rele(noop);
	if (error)
		return (error);
	return (nfs_bioread(VTONFS(ap->a_vp), ap->a_uio, ap->a_ioflag, ap->a_context));
}

/*
 * Note: the NFSv4 CREATE RPC is for everything EXCEPT regular files.
 * Files are created using the NFSv4 OPEN RPC.  So we must open the
 * file to create it and then close it.
 */
int
nfs4_vnop_create(
	struct vnop_create_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_dvp;
		vnode_t *a_vpp;
		struct componentname *a_cnp;
		struct vnode_attr *a_vap;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	struct componentname *cnp = ap->a_cnp;
	struct vnode_attr *vap = ap->a_vap;
	vnode_t dvp = ap->a_dvp;
	vnode_t *vpp = ap->a_vpp;
	struct nfsmount *nmp;
	nfsnode_t np;
	int error = 0, busyerror = 0, accessMode, denyMode;
	struct nfs_open_owner *noop = NULL;
	struct nfs_open_file *newnofp = NULL, *nofp = NULL;

	nmp = VTONMP(dvp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (vap)
		nfs_avoid_needless_id_setting_on_create(VTONFS(dvp), vap, ctx);

	noop = nfs_open_owner_find(nmp, vfs_context_ucred(ctx), 1);
	if (!noop)
		return (ENOMEM);

restart:
	error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
	if (error) {
		nfs_open_owner_rele(noop);
		return (error);
	}

	/* grab a provisional, nodeless open file */
	error = nfs_open_file_find(NULL, noop, &newnofp, 0, 0, 1);
	if (!error && (newnofp->nof_flags & NFS_OPEN_FILE_LOST)) {
		printf("nfs_vnop_create: LOST\n");
		error = EIO;
	}
	if (!error && (newnofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
		/* This shouldn't happen given that this is a new, nodeless nofp */
		nfs_mount_state_in_use_end(nmp, 0);
		error = nfs4_reopen(newnofp, vfs_context_thread(ctx));
		nfs_open_file_destroy(newnofp);
		newnofp = NULL;
		if (!error)
			goto restart;
	}
	if (!error)
		error = nfs_open_file_set_busy(newnofp, vfs_context_thread(ctx));
	if (error) {
		if (newnofp)
			nfs_open_file_destroy(newnofp);
		newnofp = NULL;
		goto out;
	}

	/*
	 * We're just trying to create the file.
	 * We'll create/open it RW, and set NFS_OPEN_FILE_CREATE.
	 */
	accessMode = NFS_OPEN_SHARE_ACCESS_BOTH;
	denyMode = NFS_OPEN_SHARE_DENY_NONE;

	/* Do the open/create */
	error = nfs4_open_rpc(newnofp, ctx, cnp, vap, dvp, vpp, NFS_OPEN_CREATE, accessMode, denyMode);
	if ((error == EACCES) && vap && !(vap->va_vaflags & VA_EXCLUSIVE) &&
	    VATTR_IS_ACTIVE(vap, va_mode) && !(vap->va_mode & S_IWUSR)) {
		/*
		 * Hmm... it looks like we may have a situation where the request was
		 * retransmitted because we didn't get the first response which successfully
		 * created/opened the file and then the second time we were denied the open
		 * because the mode the file was created with doesn't allow write access.
		 *
		 * We'll try to work around this by temporarily updating the mode and
		 * retrying the open.
		 */
		struct vnode_attr vattr;

		/* first make sure it's there */
		int error2 = nfs_lookitup(VTONFS(dvp), cnp->cn_nameptr, cnp->cn_namelen, ctx, &np);
		if (!error2 && np) {
			nfs_node_unlock(np);
			*vpp = NFSTOV(np);
			if (vnode_vtype(NFSTOV(np)) == VREG) {
				VATTR_INIT(&vattr);
				VATTR_SET(&vattr, va_mode, (vap->va_mode | S_IWUSR));
				if (!nfs4_setattr_rpc(np, &vattr, ctx)) {
					error2 = nfs4_open_rpc(newnofp, ctx, cnp, NULL, dvp, vpp, NFS_OPEN_NOCREATE, accessMode, denyMode);
					VATTR_INIT(&vattr);
					VATTR_SET(&vattr, va_mode, vap->va_mode);
					nfs4_setattr_rpc(np, &vattr, ctx);
					if (!error2)
						error = 0;
				}
			}
			if (error) {
				vnode_put(*vpp);
				*vpp = NULL;
			}
		}
	}
	if (!error && !*vpp) {
		printf("nfs4_open_rpc returned without a node?\n");
		/* Hmmm... with no node, we have no filehandle and can't close it */
		error = EIO;
	}
	if (error) {
		/* need to cleanup our temporary nofp */
		nfs_open_file_clear_busy(newnofp);
		nfs_open_file_destroy(newnofp);
		newnofp = NULL;
		goto out;
	}
	/* After we have a node, add our open file struct to the node */
	np = VTONFS(*vpp);
	nfs_open_file_add_open(newnofp, accessMode, denyMode, 0);
	nofp = newnofp;
	error = nfs_open_file_find_internal(np, noop, &nofp, 0, 0, 0);
	if (error) {
		/* This shouldn't happen, because we passed in a new nofp to use. */
		printf("nfs_open_file_find_internal failed! %d\n", error);
		goto out;
	} else if (nofp != newnofp) {
		/*
		 * Hmm... an open file struct already exists.
		 * Mark the existing one busy and merge our open into it.
		 * Then destroy the one we created.
		 * Note: there's no chance of an open confict because the
		 * open has already been granted.
		 */
		busyerror = nfs_open_file_set_busy(nofp, NULL);
		nfs_open_file_add_open(nofp, accessMode, denyMode, 0);
		nofp->nof_stateid = newnofp->nof_stateid;
		if (newnofp->nof_flags & NFS_OPEN_FILE_POSIXLOCK)
			nofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;
		nfs_open_file_clear_busy(newnofp);
		nfs_open_file_destroy(newnofp);
	}
	newnofp = NULL;
	/* mark the node as holding a create-initiated open */
	nofp->nof_flags |= NFS_OPEN_FILE_CREATE;
	nofp->nof_creator = current_thread();
out:
	if (nofp && !busyerror)
		nfs_open_file_clear_busy(nofp);
	if (nfs_mount_state_in_use_end(nmp, error)) {
		nofp = newnofp = NULL;
		busyerror = 0;
		goto restart;
	}
	if (noop)
		nfs_open_owner_rele(noop);
	return (error);
}

/*
 * Note: the NFSv4 CREATE RPC is for everything EXCEPT regular files.
 */
int
nfs4_create_rpc(
	vfs_context_t ctx,
	nfsnode_t dnp,
	struct componentname *cnp,
	struct vnode_attr *vap,
	int type,
	char *link,
	nfsnode_t *npp)
{
	struct nfsmount *nmp;
	struct nfs_vattr nvattr;
	int error = 0, create_error = EIO, lockerror = ENOENT, busyerror = ENOENT, status;
	int nfsvers, namedattrs, numops;
	u_int64_t xid, savedxid = 0;
	nfsnode_t np = NULL;
	vnode_t newvp = NULL;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	const char *tag;
	nfs_specdata sd;
	fhandle_t fh;
	struct nfsreq rq, *req = &rq;
	struct nfs_dulookup dul;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(dnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	namedattrs = (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR);
	if (dnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	sd.specdata1 = sd.specdata2 = 0;

	switch (type) {
	case NFLNK:
		tag = "symlink";
		break;
	case NFBLK:
	case NFCHR:
		tag = "mknod";
		if (!VATTR_IS_ACTIVE(vap, va_rdev))
			return (EINVAL);
		sd.specdata1 = major(vap->va_rdev);
		sd.specdata2 = minor(vap->va_rdev);
		break;
	case NFSOCK:
	case NFFIFO:
		tag = "mknod";
		break;
	case NFDIR:
		tag = "mkdir";
		break;
	default:
		return (EINVAL);
	}

	nfs_avoid_needless_id_setting_on_create(dnp, vap, ctx);

	error = busyerror = nfs_node_set_busy(dnp, vfs_context_thread(ctx));
	if (!namedattrs)
		nfs_dulookup_init(&dul, dnp, cnp->cn_nameptr, cnp->cn_namelen, ctx);

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

	// PUTFH, SAVEFH, CREATE, GETATTR(FH), RESTOREFH, GETATTR
	numops = 6;
	nfsm_chain_build_alloc_init(error, &nmreq, 66 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, tag, numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, dnp->n_fhp, dnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_SAVEFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_CREATE);
	nfsm_chain_add_32(error, &nmreq, type);
	if (type == NFLNK) {
		nfsm_chain_add_name(error, &nmreq, link, strlen(link), nmp);
	} else if ((type == NFBLK) || (type == NFCHR)) {
		nfsm_chain_add_32(error, &nmreq, sd.specdata1);
		nfsm_chain_add_32(error, &nmreq, sd.specdata2);
	}
	nfsm_chain_add_name(error, &nmreq, cnp->cn_nameptr, cnp->cn_namelen, nmp);
	nfsm_chain_add_fattr4(error, &nmreq, vap, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	nfsm_chain_add_bitmap_supported(error, &nmreq, bitmap, nmp, NULL);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_RESTOREFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, dnp);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);

	error = nfs_request_async(dnp, NULL, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, 0, NULL, &req);
	if (!error) {
		if (!namedattrs)
			nfs_dulookup_start(&dul, dnp, ctx);
		error = nfs_request_async_finish(req, &nmrep, &xid, &status);
	}

	if ((lockerror = nfs_node_lock(dnp)))
		error = lockerror;
	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_SAVEFH);
	nfsmout_if(error);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_CREATE);
	nfsm_chain_check_change_info(error, &nmrep, dnp);
	bmlen = NFS_ATTR_BITMAP_LEN;
	nfsm_chain_get_bitmap(error, &nmrep, bitmap, bmlen);
	/* At this point if we have no error, the object was created. */
	/* if we don't get attributes, then we should lookitup. */
	create_error = error;
	nfsmout_if(error);
	nfs_vattr_set_supported(bitmap, vap);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE)) {
		printf("nfs: create/%s didn't return filehandle? %s\n", tag, cnp->cn_nameptr);
		error = EBADRPC;
		goto nfsmout;
	}
	/* directory attributes: if we don't get them, make sure to invalidate */
	nfsm_chain_op_check(error, &nmrep, NFS_OP_RESTOREFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	savedxid = xid;
	nfsm_chain_loadattr(error, &nmrep, dnp, nfsvers, &xid);
	if (error)
		NATTRINVALIDATE(dnp);

nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);

	if (!lockerror) {
		if (!create_error && (dnp->n_flag & NNEGNCENTRIES)) {
			dnp->n_flag &= ~NNEGNCENTRIES;
			cache_purge_negatives(NFSTOV(dnp));
		}
		dnp->n_flag |= NMODIFIED;
		nfs_node_unlock(dnp);
		/* nfs_getattr() will check changed and purge caches */
		nfs_getattr(dnp, NULL, ctx, NGA_CACHED);
	}

	if (!error && fh.fh_len) {
		/* create the vnode with the filehandle and attributes */
		xid = savedxid;
		error = nfs_nget(NFSTOMP(dnp), dnp, cnp, fh.fh_data, fh.fh_len, &nvattr, &xid, rq.r_auth, NG_MAKEENTRY, &np);
		if (!error)
			newvp = NFSTOV(np);
	}
	NVATTR_CLEANUP(&nvattr);

	if (!namedattrs)
		nfs_dulookup_finish(&dul, dnp, ctx);

	/*
	 * Kludge: Map EEXIST => 0 assuming that you have a reply to a retry
	 * if we can succeed in looking up the object.
	 */
	if ((create_error == EEXIST) || (!create_error && !newvp)) {
		error = nfs_lookitup(dnp, cnp->cn_nameptr, cnp->cn_namelen, ctx, &np);
		if (!error) {
			newvp = NFSTOV(np);
			if (vnode_vtype(newvp) != nfstov_type(type, nfsvers))
				error = EEXIST;
		}
	}
	if (!busyerror)
		nfs_node_clear_busy(dnp);
	if (error) {
		if (newvp) {
			nfs_node_unlock(np);
			vnode_put(newvp);
		}
	} else {
		nfs_node_unlock(np);
		*npp = np;
	}
	return (error);
}

int
nfs4_vnop_mknod(
	struct vnop_mknod_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_dvp;
		vnode_t *a_vpp;
		struct componentname *a_cnp;
		struct vnode_attr *a_vap;
		vfs_context_t a_context;
	} */ *ap)
{
	nfsnode_t np = NULL;
	struct nfsmount *nmp;
	int error;

	nmp = VTONMP(ap->a_dvp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!VATTR_IS_ACTIVE(ap->a_vap, va_type))
		return (EINVAL);
	switch (ap->a_vap->va_type) {
	case VBLK:
	case VCHR:
	case VFIFO:
	case VSOCK:
		break;
	default:
		return (ENOTSUP);
	}

	error = nfs4_create_rpc(ap->a_context, VTONFS(ap->a_dvp), ap->a_cnp, ap->a_vap,
			vtonfs_type(ap->a_vap->va_type, nmp->nm_vers), NULL, &np);
	if (!error)
		*ap->a_vpp = NFSTOV(np);
	return (error);
}

int
nfs4_vnop_mkdir(
	struct vnop_mkdir_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_dvp;
		vnode_t *a_vpp;
		struct componentname *a_cnp;
		struct vnode_attr *a_vap;
		vfs_context_t a_context;
	} */ *ap)
{
	nfsnode_t np = NULL;
	int error;

	error = nfs4_create_rpc(ap->a_context, VTONFS(ap->a_dvp), ap->a_cnp, ap->a_vap,
			NFDIR, NULL, &np);
	if (!error)
		*ap->a_vpp = NFSTOV(np);
	return (error);
}

int
nfs4_vnop_symlink(
	struct vnop_symlink_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_dvp;
		vnode_t *a_vpp;
		struct componentname *a_cnp;
		struct vnode_attr *a_vap;
		char *a_target;
		vfs_context_t a_context;
	} */ *ap)
{
	nfsnode_t np = NULL;
	int error;

	error = nfs4_create_rpc(ap->a_context, VTONFS(ap->a_dvp), ap->a_cnp, ap->a_vap,
			NFLNK, ap->a_target, &np);
	if (!error)
		*ap->a_vpp = NFSTOV(np);
	return (error);
}

int
nfs4_vnop_link(
	struct vnop_link_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		vnode_t a_tdvp;
		struct componentname *a_cnp;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	vnode_t vp = ap->a_vp;
	vnode_t tdvp = ap->a_tdvp;
	struct componentname *cnp = ap->a_cnp;
	int error = 0, lockerror = ENOENT, status;
	struct nfsmount *nmp;
	nfsnode_t np = VTONFS(vp);
	nfsnode_t tdnp = VTONFS(tdvp);
	int nfsvers, numops;
	u_int64_t xid, savedxid;
	struct nfsm_chain nmreq, nmrep;
	struct nfsreq_secinfo_args si;

	if (vnode_mount(vp) != vnode_mount(tdvp))
		return (EXDEV);

	nmp = VTONMP(vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	nfsvers = nmp->nm_vers;
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);
	if (tdnp->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (EINVAL);

	/*
	 * Push all writes to the server, so that the attribute cache
	 * doesn't get "out of sync" with the server.
	 * XXX There should be a better way!
	 */
	nfs_flush(np, MNT_WAIT, vfs_context_thread(ctx), V_IGNORE_WRITEERR);

	if ((error = nfs_node_set_busy2(tdnp, np, vfs_context_thread(ctx))))
		return (error);

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

	// PUTFH(SOURCE), SAVEFH, PUTFH(DIR), LINK, GETATTR(DIR), RESTOREFH, GETATTR
	numops = 7;
	nfsm_chain_build_alloc_init(error, &nmreq, 29 * NFSX_UNSIGNED + cnp->cn_namelen);
	nfsm_chain_add_compound_header(error, &nmreq, "link", 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_SAVEFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nfsvers, tdnp->n_fhp, tdnp->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_LINK);
	nfsm_chain_add_name(error, &nmreq, cnp->cn_nameptr, cnp->cn_namelen, nmp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, tdnp);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_RESTOREFH);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_supported(error, &nmreq, nfs_getattr_bitmap, nmp, np);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request(tdnp, NULL, &nmreq, NFSPROC4_COMPOUND, ctx, &si, &nmrep, &xid, &status);

	if ((lockerror = nfs_node_lock2(tdnp, np))) {
		error = lockerror;
		goto nfsmout;
	}
	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_SAVEFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_LINK);
	nfsm_chain_check_change_info(error, &nmrep, tdnp);
	/* directory attributes: if we don't get them, make sure to invalidate */
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	savedxid = xid;
	nfsm_chain_loadattr(error, &nmrep, tdnp, nfsvers, &xid);
	if (error)
		NATTRINVALIDATE(tdnp);
	/* link attributes: if we don't get them, make sure to invalidate */
	nfsm_chain_op_check(error, &nmrep, NFS_OP_RESTOREFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	xid = savedxid;
	nfsm_chain_loadattr(error, &nmrep, np, nfsvers, &xid);
	if (error)
		NATTRINVALIDATE(np);
nfsmout:
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	if (!lockerror)
		tdnp->n_flag |= NMODIFIED;
	/* Kludge: Map EEXIST => 0 assuming that it is a reply to a retry. */
	if (error == EEXIST)
		error = 0;
	if (!error && (tdnp->n_flag & NNEGNCENTRIES)) {
		tdnp->n_flag &= ~NNEGNCENTRIES;
		cache_purge_negatives(tdvp);
	}
	if (!lockerror)
		nfs_node_unlock2(tdnp, np);
	nfs_node_clear_busy2(tdnp, np);
	return (error);
}

int
nfs4_vnop_rmdir(
	struct vnop_rmdir_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_dvp;
		vnode_t a_vp;
		struct componentname *a_cnp;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	vnode_t vp = ap->a_vp;
	vnode_t dvp = ap->a_dvp;
	struct componentname *cnp = ap->a_cnp;
	struct nfsmount *nmp;
	int error = 0, namedattrs;
	nfsnode_t np = VTONFS(vp);
	nfsnode_t dnp = VTONFS(dvp);
	struct nfs_dulookup dul;

	if (vnode_vtype(vp) != VDIR)
		return (EINVAL);

	nmp = NFSTONMP(dnp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	namedattrs = (nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR);

	if ((error = nfs_node_set_busy2(dnp, np, vfs_context_thread(ctx))))
		return (error);

	if (!namedattrs) {
		nfs_dulookup_init(&dul, dnp, cnp->cn_nameptr, cnp->cn_namelen, ctx);
		nfs_dulookup_start(&dul, dnp, ctx);
	}

	error = nfs4_remove_rpc(dnp, cnp->cn_nameptr, cnp->cn_namelen,
			vfs_context_thread(ctx), vfs_context_ucred(ctx));

	nfs_name_cache_purge(dnp, np, cnp, ctx);
	/* nfs_getattr() will check changed and purge caches */
	nfs_getattr(dnp, NULL, ctx, NGA_CACHED);
	if (!namedattrs)
		nfs_dulookup_finish(&dul, dnp, ctx);
	nfs_node_clear_busy2(dnp, np);

	/*
	 * Kludge: Map ENOENT => 0 assuming that you have a reply to a retry.
	 */
	if (error == ENOENT)
		error = 0;
	if (!error) {
		/*
		 * remove nfsnode from hash now so we can't accidentally find it
		 * again if another object gets created with the same filehandle
		 * before this vnode gets reclaimed
		 */
		lck_mtx_lock(nfs_node_hash_mutex);
		if (np->n_hflag & NHHASHED) {
			LIST_REMOVE(np, n_hash);
			np->n_hflag &= ~NHHASHED;
			FSDBG(266, 0, np, np->n_flag, 0xb1eb1e);
		}
		lck_mtx_unlock(nfs_node_hash_mutex);
	}
	return (error);
}

/*
 * NFSv4 Named Attributes
 *
 * Both the extended attributes interface and the named streams interface
 * are backed by NFSv4 named attributes.  The implementations for both use
 * a common set of routines in an attempt to reduce code duplication, to
 * increase efficiency, to increase caching of both names and data, and to
 * confine the complexity.
 *
 * Each NFS node caches its named attribute directory's file handle.
 * The directory nodes for the named attribute directories are handled
 * exactly like regular directories (with a couple minor exceptions).
 * Named attribute nodes are also treated as much like regular files as
 * possible.
 *
 * Most of the heavy lifting is done by nfs4_named_attr_get().
 */

/*
 * Get the given node's attribute directory node.
 * If !fetch, then only return a cached node.
 * Otherwise, we will attempt to fetch the node from the server.
 * (Note: the node should be marked busy.)
 */
nfsnode_t
nfs4_named_attr_dir_get(nfsnode_t np, int fetch, vfs_context_t ctx)
{
	nfsnode_t adnp = NULL;
	struct nfsmount *nmp;
	int error = 0, status, numops;
	struct nfsm_chain nmreq, nmrep;
	u_int64_t xid;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN];
	fhandle_t fh;
	struct nfs_vattr nvattr;
	struct componentname cn;
	struct nfsreq rq, *req = &rq;
	struct nfsreq_secinfo_args si;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (NULL);
	if (np->n_vattr.nva_flags & NFS_FFLAG_TRIGGER_REFERRAL)
		return (NULL);

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

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(_PATH_FORKSPECIFIER, const, char *); /* "/..namedfork/" */
	cn.cn_namelen = strlen(_PATH_FORKSPECIFIER);
	cn.cn_nameiop = LOOKUP;

	if (np->n_attrdirfh) {
		// XXX can't set parent correctly (to np) yet
		error = nfs_nget(nmp->nm_mountp, NULL, &cn, np->n_attrdirfh+1, *np->n_attrdirfh,
				NULL, NULL, RPCAUTH_UNKNOWN, NG_NOCREATE, &adnp);
		if (adnp)
			goto nfsmout;
	}
	if (!fetch) {
		error = ENOENT;
		goto nfsmout;
	}

	// PUTFH, OPENATTR, GETATTR
	numops = 3;
	nfsm_chain_build_alloc_init(error, &nmreq, 22 * NFSX_UNSIGNED);
	nfsm_chain_add_compound_header(error, &nmreq, "openattr", numops);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
	nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, np->n_fhp, np->n_fhsize);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_OPENATTR);
	nfsm_chain_add_32(error, &nmreq, 0);
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	nfsm_chain_add_bitmap_masked(error, &nmreq, bitmap,
		NFS_ATTR_BITMAP_LEN, nmp->nm_fsattr.nfsa_supp_attr);
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request_async(np, NULL, &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_OPENATTR);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE) || !fh.fh_len) {
		error = ENOENT;
		goto nfsmout;
	}
	if (!np->n_attrdirfh || (*np->n_attrdirfh != fh.fh_len)) {
		/* (re)allocate attrdir fh buffer */
		if (np->n_attrdirfh)
			FREE(np->n_attrdirfh, M_TEMP);
		MALLOC(np->n_attrdirfh, u_char*, fh.fh_len+1, M_TEMP, M_WAITOK);
	}
	if (!np->n_attrdirfh) {
		error = ENOMEM;
		goto nfsmout;
	}
	/* cache the attrdir fh in the node */
	*np->n_attrdirfh = fh.fh_len;
	bcopy(fh.fh_data, np->n_attrdirfh+1, fh.fh_len);
	/* create node for attrdir */
	// XXX can't set parent correctly (to np) yet
	error = nfs_nget(NFSTOMP(np), NULL, &cn, fh.fh_data, fh.fh_len, &nvattr, &xid, rq.r_auth, 0, &adnp);
nfsmout:
	NVATTR_CLEANUP(&nvattr);
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);

	if (adnp) {
		/* sanity check that this node is an attribute directory */
		if (adnp->n_vattr.nva_type != VDIR)
			error = EINVAL;
		if (!(adnp->n_vattr.nva_flags & NFS_FFLAG_IS_ATTR))
			error = EINVAL;
		nfs_node_unlock(adnp);
		if (error)
			vnode_put(NFSTOV(adnp));
	}
	return (error ? NULL : adnp);
}

/*
 * Get the given node's named attribute node for the name given.
 *
 * In an effort to increase the performance of named attribute access, we try
 * to reduce server requests by doing the following:
 *
 * - cache the node's named attribute directory file handle in the node
 * - maintain a directory vnode for the attribute directory
 * - use name cache entries (positive and negative) to speed up lookups
 * - optionally open the named attribute (with the given accessMode) in the same RPC
 * - combine attribute directory retrieval with the lookup/open RPC
 * - optionally prefetch the named attribute's first block of data in the same RPC
 *
 * Also, in an attempt to reduce the number of copies/variations of this code,
 * parts of the RPC building/processing code are conditionalized on what is
 * needed for any particular request (openattr, lookup vs. open, read).
 *
 * Note that because we may not have the attribute directory node when we start
 * the lookup/open, we lock both the node and the attribute directory node.
 */

#define NFS_GET_NAMED_ATTR_CREATE		0x1
#define NFS_GET_NAMED_ATTR_CREATE_GUARDED	0x2
#define NFS_GET_NAMED_ATTR_TRUNCATE		0x4
#define NFS_GET_NAMED_ATTR_PREFETCH		0x8

int
nfs4_named_attr_get(
	nfsnode_t np,
	struct componentname *cnp,
	uint32_t accessMode,
	int flags,
	vfs_context_t ctx,
	nfsnode_t *anpp,
	struct nfs_open_file **nofpp)
{
	struct nfsmount *nmp;
	int error = 0, open_error = EIO;
	int inuse = 0, adlockerror = ENOENT, busyerror = ENOENT, adbusyerror = ENOENT, nofpbusyerror = ENOENT;
	int create, guarded, prefetch, truncate, noopbusy = 0;
	int open, status, numops, hadattrdir, negnamecache;
	struct nfs_vattr nvattr;
	struct vnode_attr vattr;
	nfsnode_t adnp = NULL, anp = NULL;
	vnode_t avp = NULL;
	u_int64_t xid, savedxid = 0;
	struct nfsm_chain nmreq, nmrep;
	uint32_t bitmap[NFS_ATTR_BITMAP_LEN], bmlen;
	uint32_t denyMode, rflags, delegation, recall, eof, rlen, retlen;
	nfs_stateid stateid, dstateid;
	fhandle_t fh;
	struct nfs_open_owner *noop = NULL;
	struct nfs_open_file *newnofp = NULL, *nofp = NULL;
	struct vnop_access_args naa;
	thread_t thd;
	kauth_cred_t cred;
	struct timeval now;
	char sbuf[64], *s;
	uint32_t ace_type, ace_flags, ace_mask, len, slen;
	struct kauth_ace ace;
	struct nfsreq rq, *req = &rq;
	struct nfsreq_secinfo_args si;

	*anpp = NULL;
	fh.fh_len = 0;
	rflags = delegation = recall = eof = rlen = retlen = 0;
	ace.ace_flags = 0;
	s = sbuf;
	slen = sizeof(sbuf);

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);
	NVATTR_INIT(&nvattr);
	negnamecache = !NMFLAG(nmp, NONEGNAMECACHE);
	thd = vfs_context_thread(ctx);
	cred = vfs_context_ucred(ctx);
	create = (flags & NFS_GET_NAMED_ATTR_CREATE) ? NFS_OPEN_CREATE : NFS_OPEN_NOCREATE;
	guarded = (flags & NFS_GET_NAMED_ATTR_CREATE_GUARDED) ? NFS_CREATE_GUARDED : NFS_CREATE_UNCHECKED;
	truncate = (flags & NFS_GET_NAMED_ATTR_TRUNCATE);
	prefetch = (flags & NFS_GET_NAMED_ATTR_PREFETCH);

	if (!create) {
		error = nfs_getattr(np, &nvattr, ctx, NGA_CACHED);
		if (error)
			return (error);
		if (NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_NAMED_ATTR) &&
		    !(nvattr.nva_flags & NFS_FFLAG_HAS_NAMED_ATTRS))
			return (ENOATTR);
	} else if (accessMode == NFS_OPEN_SHARE_ACCESS_NONE) {
		/* shouldn't happen... but just be safe */
		printf("nfs4_named_attr_get: create with no access %s\n", cnp->cn_nameptr);
		accessMode = NFS_OPEN_SHARE_ACCESS_READ;
	}
	open = (accessMode != NFS_OPEN_SHARE_ACCESS_NONE);
	if (open) {
		/*
		 * We're trying to open the file.
		 * We'll create/open it with the given access mode,
		 * and set NFS_OPEN_FILE_CREATE.
		 */
		denyMode = NFS_OPEN_SHARE_DENY_NONE;
		if (prefetch && guarded)
			prefetch = 0;  /* no sense prefetching data that can't be there */

		noop = nfs_open_owner_find(nmp, vfs_context_ucred(ctx), 1);
		if (!noop)
			return (ENOMEM);
	}

	if ((error = busyerror = nfs_node_set_busy(np, vfs_context_thread(ctx))))
		return (error);

	adnp = nfs4_named_attr_dir_get(np, 0, ctx);
	hadattrdir = (adnp != NULL);
	if (prefetch) {
		microuptime(&now);
		/* use the special state ID because we don't have a real one to send */
		stateid.seqid = stateid.other[0] = stateid.other[1] = stateid.other[2] = 0;
		rlen = MIN(nmp->nm_rsize, nmp->nm_biosize);
	}
	NFSREQ_SECINFO_SET(&si, np, NULL, 0, NULL, 0);
	nfsm_chain_null(&nmreq);
	nfsm_chain_null(&nmrep);

	if (hadattrdir) {
		if ((error = adbusyerror = nfs_node_set_busy(adnp, vfs_context_thread(ctx))))
			goto nfsmout;
		/* nfs_getattr() will check changed and purge caches */
		error = nfs_getattr(adnp, NULL, ctx, NGA_CACHED);
		nfsmout_if(error);
		error = cache_lookup(NFSTOV(adnp), &avp, cnp);
		switch (error) {
		case ENOENT:
			/* negative cache entry */
			goto nfsmout;
		case 0:
			/* cache miss */
			/* try dir buf cache lookup */
			error = nfs_dir_buf_cache_lookup(adnp, &anp, cnp, ctx, 0);
			if (!error && anp) {
				/* dir buf cache hit */
				*anpp = anp;
				error = -1;
			}
			if (error != -1) /* cache miss */
				break;
			/* FALLTHROUGH */
		case -1:
			/* cache hit, not really an error */
			OSAddAtomic64(1, &nfsstats.lookupcache_hits);
			if (!anp && avp)
				*anpp = anp = VTONFS(avp);

			nfs_node_clear_busy(adnp);
			adbusyerror = ENOENT;

			/* check for directory access */
			naa.a_desc = &vnop_access_desc;
			naa.a_vp = NFSTOV(adnp);
			naa.a_action = KAUTH_VNODE_SEARCH;
			naa.a_context = ctx;

			/* compute actual success/failure based on accessibility */
			error = nfs_vnop_access(&naa);
			/* FALLTHROUGH */
		default:
			/* we either found it, or hit an error */
			if (!error && guarded) {
				/* found cached entry but told not to use it */
				error = EEXIST;
				vnode_put(NFSTOV(anp));
				*anpp = anp = NULL;
			}
			/* we're done if error or we don't need to open */
			if (error || !open)
				goto nfsmout;
			/* no error and we need to open... */
		}
	}

	if (open) {
restart:
		error = nfs_mount_state_in_use_start(nmp, vfs_context_thread(ctx));
		if (error) {
			nfs_open_owner_rele(noop);
			noop = NULL;
			goto nfsmout;
		}
		inuse = 1;

		/* grab an open file - possibly provisional/nodeless if cache_lookup() failed */
		error = nfs_open_file_find(anp, noop, &newnofp, 0, 0, 1);
		if (!error && (newnofp->nof_flags & NFS_OPEN_FILE_LOST)) {
			printf("nfs4_named_attr_get: LOST %d %s\n", kauth_cred_getuid(noop->noo_cred), cnp->cn_nameptr);
			error = EIO;
		}
		if (!error && (newnofp->nof_flags & NFS_OPEN_FILE_REOPEN)) {
			nfs_mount_state_in_use_end(nmp, 0);
			error = nfs4_reopen(newnofp, vfs_context_thread(ctx));
			nfs_open_file_destroy(newnofp);
			newnofp = NULL;
			if (!error)
				goto restart;
		}
		if (!error)
			error = nfs_open_file_set_busy(newnofp, vfs_context_thread(ctx));
		if (error) {
			if (newnofp)
				nfs_open_file_destroy(newnofp);
			newnofp = NULL;
			goto nfsmout;
		}
		if (anp) {
			/*
			 * We already have the node.  So we just need to open
			 * it - which we may be able to do with a delegation.
			 */
			open_error = error = nfs4_open(anp, newnofp, accessMode, denyMode, ctx);
			if (!error) {
				/* open succeeded, so our open file is no longer temporary */
				nofp = newnofp;
				nofpbusyerror = 0;
				newnofp = NULL;
				if (nofpp)
					*nofpp = nofp;
			}
			goto nfsmout;
		}
	}

	/*
	 * We either don't have the attrdir or we didn't find the attribute
	 * in the name cache, so we need to talk to the server.
	 *
	 * If we don't have the attrdir, we'll need to ask the server for that too.
	 * If the caller is requesting that the attribute be created, we need to
	 * make sure the attrdir is created.
	 * The caller may also request that the first block of an existing attribute
	 * be retrieved at the same time.
	 */

	if (open) {
		/* need to mark the open owner busy during the RPC */
		if ((error = nfs_open_owner_set_busy(noop, thd)))
			goto nfsmout;
		noopbusy = 1;
	}

	/*
	 * We'd like to get updated post-open/lookup attributes for the
	 * directory and we may also want to prefetch some data via READ.
	 * We'd like the READ results to be last so that we can leave the
	 * data in the mbufs until the end.
	 *
	 * At a minimum we're sending: PUTFH, LOOKUP/OPEN, GETATTR, PUTFH, GETATTR
	 */
	numops = 5;
	if (!hadattrdir)
		numops += 3;	// also sending: OPENATTR, GETATTR, OPENATTR
	if (prefetch)
		numops += 4;	// also sending: SAVEFH, RESTOREFH, NVERIFY, READ
	nfsm_chain_build_alloc_init(error, &nmreq, 64 * NFSX_UNSIGNED + cnp->cn_namelen);
	nfsm_chain_add_compound_header(error, &nmreq, "getnamedattr", numops);
	if (hadattrdir) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
		nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, adnp->n_fhp, adnp->n_fhsize);
	} else {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
		nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, np->n_fhp, np->n_fhsize);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_OPENATTR);
		nfsm_chain_add_32(error, &nmreq, create ? 1 : 0);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
		NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
		NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
		nfsm_chain_add_bitmap_masked(error, &nmreq, bitmap,
			NFS_ATTR_BITMAP_LEN, nmp->nm_fsattr.nfsa_supp_attr);
	}
	if (open) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_OPEN);
		nfsm_chain_add_32(error, &nmreq, noop->noo_seqid);
		nfsm_chain_add_32(error, &nmreq, accessMode);
		nfsm_chain_add_32(error, &nmreq, denyMode);
		nfsm_chain_add_64(error, &nmreq, nmp->nm_clientid);
		nfsm_chain_add_32(error, &nmreq, NFSX_UNSIGNED);
		nfsm_chain_add_32(error, &nmreq, kauth_cred_getuid(noop->noo_cred));
		nfsm_chain_add_32(error, &nmreq, create);
		if (create) {
			nfsm_chain_add_32(error, &nmreq, guarded);
			VATTR_INIT(&vattr);
			if (truncate)
				VATTR_SET(&vattr, va_data_size, 0);
			nfsm_chain_add_fattr4(error, &nmreq, &vattr, nmp);
		}
		nfsm_chain_add_32(error, &nmreq, NFS_CLAIM_NULL);
		nfsm_chain_add_name(error, &nmreq, cnp->cn_nameptr, cnp->cn_namelen, nmp);
	} else {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_LOOKUP);
		nfsm_chain_add_name(error, &nmreq, cnp->cn_nameptr, cnp->cn_namelen, nmp);
	}
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	NFS_COPY_ATTRIBUTES(nfs_getattr_bitmap, bitmap);
	NFS_BITMAP_SET(bitmap, NFS_FATTR_FILEHANDLE);
	nfsm_chain_add_bitmap_masked(error, &nmreq, bitmap,
		NFS_ATTR_BITMAP_LEN, nmp->nm_fsattr.nfsa_supp_attr);
	if (prefetch) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_SAVEFH);
	}
	if (hadattrdir) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
		nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, adnp->n_fhp, adnp->n_fhsize);
	} else {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_PUTFH);
		nfsm_chain_add_fh(error, &nmreq, nmp->nm_vers, np->n_fhp, np->n_fhsize);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_OPENATTR);
		nfsm_chain_add_32(error, &nmreq, 0);
	}
	numops--;
	nfsm_chain_add_32(error, &nmreq, NFS_OP_GETATTR);
	nfsm_chain_add_bitmap_masked(error, &nmreq, nfs_getattr_bitmap,
		NFS_ATTR_BITMAP_LEN, nmp->nm_fsattr.nfsa_supp_attr);
	if (prefetch) {
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_RESTOREFH);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_NVERIFY);
		VATTR_INIT(&vattr);
		VATTR_SET(&vattr, va_data_size, 0);
		nfsm_chain_add_fattr4(error, &nmreq, &vattr, nmp);
		numops--;
		nfsm_chain_add_32(error, &nmreq, NFS_OP_READ);
		nfsm_chain_add_stateid(error, &nmreq, &stateid);
		nfsm_chain_add_64(error, &nmreq, 0);
		nfsm_chain_add_32(error, &nmreq, rlen);
	}
	nfsm_chain_build_done(error, &nmreq);
	nfsm_assert(error, (numops == 0), EPROTO);
	nfsmout_if(error);
	error = nfs_request_async(hadattrdir ? adnp : np, NULL, &nmreq, NFSPROC4_COMPOUND,
			vfs_context_thread(ctx), vfs_context_ucred(ctx), &si, open ? R_NOINTR: 0, NULL, &req);
	if (!error)
		error = nfs_request_async_finish(req, &nmrep, &xid, &status);

	if (hadattrdir && ((adlockerror = nfs_node_lock(adnp))))
		error = adlockerror;
	savedxid = xid;
	nfsm_chain_skip_tag(error, &nmrep);
	nfsm_chain_get_32(error, &nmrep, numops);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	if (!hadattrdir) {
		nfsm_chain_op_check(error, &nmrep, NFS_OP_OPENATTR);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
		nfsmout_if(error);
		error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
		nfsmout_if(error);
		if (NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE) && fh.fh_len) {
			if (!np->n_attrdirfh || (*np->n_attrdirfh != fh.fh_len)) {
				/* (re)allocate attrdir fh buffer */
				if (np->n_attrdirfh)
					FREE(np->n_attrdirfh, M_TEMP);
				MALLOC(np->n_attrdirfh, u_char*, fh.fh_len+1, M_TEMP, M_WAITOK);
			}
			if (np->n_attrdirfh) {
				/* remember the attrdir fh in the node */
				*np->n_attrdirfh = fh.fh_len;
				bcopy(fh.fh_data, np->n_attrdirfh+1, fh.fh_len);
				/* create busied node for attrdir */
				struct componentname cn;
				bzero(&cn, sizeof(cn));
				cn.cn_nameptr = __CAST_AWAY_QUALIFIER(_PATH_FORKSPECIFIER, const, char *); /* "/..namedfork/" */
				cn.cn_namelen = strlen(_PATH_FORKSPECIFIER);
				cn.cn_nameiop = LOOKUP;
				// XXX can't set parent correctly (to np) yet
				error = nfs_nget(NFSTOMP(np), NULL, &cn, fh.fh_data, fh.fh_len, &nvattr, &xid, rq.r_auth, 0, &adnp);
				if (!error) {
					adlockerror = 0;
					/* set the node busy */
					SET(adnp->n_flag, NBUSY);
					adbusyerror = 0;
				}
				/* if no adnp, oh well... */
				error = 0;
			}
		}
		NVATTR_CLEANUP(&nvattr);
		fh.fh_len = 0;
	}
	if (open) {
		nfsm_chain_op_check(error, &nmrep, NFS_OP_OPEN);
		nfs_owner_seqid_increment(noop, NULL, error);
		nfsm_chain_get_stateid(error, &nmrep, &newnofp->nof_stateid);
		nfsm_chain_check_change_info(error, &nmrep, adnp);
		nfsm_chain_get_32(error, &nmrep, rflags);
		bmlen = NFS_ATTR_BITMAP_LEN;
		nfsm_chain_get_bitmap(error, &nmrep, bitmap, bmlen);
		nfsm_chain_get_32(error, &nmrep, delegation);
		if (!error)
			switch (delegation) {
			case NFS_OPEN_DELEGATE_NONE:
				break;
			case NFS_OPEN_DELEGATE_READ:
			case NFS_OPEN_DELEGATE_WRITE:
				nfsm_chain_get_stateid(error, &nmrep, &dstateid);
				nfsm_chain_get_32(error, &nmrep, recall);
				if (delegation == NFS_OPEN_DELEGATE_WRITE) // space (skip) XXX
					nfsm_chain_adv(error, &nmrep, 3 * NFSX_UNSIGNED);
				/* if we have any trouble accepting the ACE, just invalidate it */
				ace_type = ace_flags = ace_mask = len = 0;
				nfsm_chain_get_32(error, &nmrep, ace_type);
				nfsm_chain_get_32(error, &nmrep, ace_flags);
				nfsm_chain_get_32(error, &nmrep, ace_mask);
				nfsm_chain_get_32(error, &nmrep, len);
				ace.ace_flags = nfs4_ace_nfstype_to_vfstype(ace_type, &error);
				ace.ace_flags |= nfs4_ace_nfsflags_to_vfsflags(ace_flags);
				ace.ace_rights = nfs4_ace_nfsmask_to_vfsrights(ace_mask);
				if (!error && (len >= slen)) {
					MALLOC(s, char*, len+1, M_TEMP, M_WAITOK);
					if (s)
						slen = len+1;
					else
						ace.ace_flags = 0;
				}
				if (s)
					nfsm_chain_get_opaque(error, &nmrep, len, s);
				else
					nfsm_chain_adv(error, &nmrep, nfsm_rndup(len));
				if (!error && s) {
					s[len] = '\0';
					if (nfs4_id2guid(s, &ace.ace_applicable, (ace_flags & NFS_ACE_IDENTIFIER_GROUP)))
						ace.ace_flags = 0;
				}
				if (error || !s)
					ace.ace_flags = 0;
				if (s && (s != sbuf))
					FREE(s, M_TEMP);
				break;
			default:
				error = EBADRPC;
				break;
			}
		/* At this point if we have no error, the object was created/opened. */
		open_error = error;
	} else {
		nfsm_chain_op_check(error, &nmrep, NFS_OP_LOOKUP);
	}
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	error = nfs4_parsefattr(&nmrep, NULL, &nvattr, &fh, NULL, NULL);
	nfsmout_if(error);
	if (!NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_FILEHANDLE) || !fh.fh_len) {
		error = EIO;
		goto nfsmout;
	}
	if (prefetch)
		nfsm_chain_op_check(error, &nmrep, NFS_OP_SAVEFH);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_PUTFH);
	if (!hadattrdir)
		nfsm_chain_op_check(error, &nmrep, NFS_OP_OPENATTR);
	nfsm_chain_op_check(error, &nmrep, NFS_OP_GETATTR);
	nfsmout_if(error);
	xid = savedxid;
	nfsm_chain_loadattr(error, &nmrep, adnp, nmp->nm_vers, &xid);
	nfsmout_if(error);

	if (open) {
		if (rflags & NFS_OPEN_RESULT_LOCKTYPE_POSIX)
			newnofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;
		if (rflags & NFS_OPEN_RESULT_CONFIRM) {
			if (adnp) {
				nfs_node_unlock(adnp);
				adlockerror = ENOENT;
			}
			NVATTR_CLEANUP(&nvattr);
			error = nfs4_open_confirm_rpc(nmp, adnp ? adnp : np, fh.fh_data, fh.fh_len, noop, &newnofp->nof_stateid, thd, cred, &nvattr, &xid);
			nfsmout_if(error);
			savedxid = xid;
			if ((adlockerror = nfs_node_lock(adnp)))
				error = adlockerror;
		}
	}

nfsmout:
	if (open && adnp && !adlockerror) {
		if (!open_error && (adnp->n_flag & NNEGNCENTRIES)) {
			adnp->n_flag &= ~NNEGNCENTRIES;
			cache_purge_negatives(NFSTOV(adnp));
		}
		adnp->n_flag |= NMODIFIED;
		nfs_node_unlock(adnp);
		adlockerror = ENOENT;
		nfs_getattr(adnp, NULL, ctx, NGA_CACHED);
	}
	if (adnp && !adlockerror && (error == ENOENT) &&
	    (cnp->cn_flags & MAKEENTRY) && (cnp->cn_nameiop != CREATE) && negnamecache) {
		/* add a negative entry in the name cache */
		cache_enter(NFSTOV(adnp), NULL, cnp);
		adnp->n_flag |= NNEGNCENTRIES;
	}
	if (adnp && !adlockerror) {
		nfs_node_unlock(adnp);
		adlockerror = ENOENT;
	}
	if (!error && !anp && fh.fh_len) {
		/* create the vnode with the filehandle and attributes */
		xid = savedxid;
		error = nfs_nget(NFSTOMP(np), adnp, cnp, fh.fh_data, fh.fh_len, &nvattr, &xid, rq.r_auth, NG_MAKEENTRY, &anp);
		if (!error) {
			*anpp = anp;
			nfs_node_unlock(anp);
		}
		if (!error && open) {
			nfs_open_file_add_open(newnofp, accessMode, denyMode, 0);
			/* After we have a node, add our open file struct to the node */
			nofp = newnofp;
			error = nfs_open_file_find_internal(anp, noop, &nofp, 0, 0, 0);
			if (error) {
				/* This shouldn't happen, because we passed in a new nofp to use. */
				printf("nfs_open_file_find_internal failed! %d\n", error);
				nofp = NULL;
			} else if (nofp != newnofp) {
				/*
				 * Hmm... an open file struct already exists.
				 * Mark the existing one busy and merge our open into it.
				 * Then destroy the one we created.
				 * Note: there's no chance of an open confict because the
				 * open has already been granted.
				 */
				nofpbusyerror = nfs_open_file_set_busy(nofp, NULL);
				nfs_open_file_add_open(nofp, accessMode, denyMode, 0);
				nofp->nof_stateid = newnofp->nof_stateid;
				if (newnofp->nof_flags & NFS_OPEN_FILE_POSIXLOCK)
					nofp->nof_flags |= NFS_OPEN_FILE_POSIXLOCK;
				nfs_open_file_clear_busy(newnofp);
				nfs_open_file_destroy(newnofp);
				newnofp = NULL;
			}
			if (!error) {
				newnofp = NULL;
				nofpbusyerror = 0;
				/* mark the node as holding a create-initiated open */
				nofp->nof_flags |= NFS_OPEN_FILE_CREATE;
				nofp->nof_creator = current_thread();
				if (nofpp)
					*nofpp = nofp;
			}
		}
	}
	NVATTR_CLEANUP(&nvattr);
	if (open && ((delegation == NFS_OPEN_DELEGATE_READ) || (delegation == NFS_OPEN_DELEGATE_WRITE))) {
		if (!error && anp && !recall) {
			/* stuff the delegation state in the node */
			lck_mtx_lock(&anp->n_openlock);
			anp->n_openflags &= ~N_DELEG_MASK;
			anp->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
			anp->n_dstateid = dstateid;
			anp->n_dace = ace;
			if (anp->n_dlink.tqe_next == NFSNOLIST) {
				lck_mtx_lock(&nmp->nm_lock);
				if (anp->n_dlink.tqe_next == NFSNOLIST)
					TAILQ_INSERT_TAIL(&nmp->nm_delegations, anp, n_dlink);
				lck_mtx_unlock(&nmp->nm_lock);
			}
			lck_mtx_unlock(&anp->n_openlock);
		} else {
			/* give the delegation back */
			if (anp) {
				if (NFS_CMPFH(anp, fh.fh_data, fh.fh_len)) {
					/* update delegation state and return it */
					lck_mtx_lock(&anp->n_openlock);
					anp->n_openflags &= ~N_DELEG_MASK;
					anp->n_openflags |= ((delegation == NFS_OPEN_DELEGATE_READ) ? N_DELEG_READ : N_DELEG_WRITE);
					anp->n_dstateid = dstateid;
					anp->n_dace = ace;
					if (anp->n_dlink.tqe_next == NFSNOLIST) {
						lck_mtx_lock(&nmp->nm_lock);
						if (anp->n_dlink.tqe_next == NFSNOLIST)
							TAILQ_INSERT_TAIL(&nmp->nm_delegations, anp, n_dlink);
						lck_mtx_unlock(&nmp->nm_lock);
					}
					lck_mtx_unlock(&anp->n_openlock);
					/* don't need to send a separate delegreturn for fh */
					fh.fh_len = 0;
				}
				/* return anp's current delegation */
				nfs4_delegation_return(anp, 0, thd, cred);
			}
			if (fh.fh_len) /* return fh's delegation if it wasn't for anp */
				nfs4_delegreturn_rpc(nmp, fh.fh_data, fh.fh_len, &dstateid, 0, thd, cred);
		}
	}
	if (open) {
		if (newnofp) {
			/* need to cleanup our temporary nofp */
			nfs_open_file_clear_busy(newnofp);
			nfs_open_file_destroy(newnofp);
			newnofp = NULL;
		} else if (nofp && !nofpbusyerror) {
			nfs_open_file_clear_busy(nofp);
			nofpbusyerror = ENOENT;
		}
		if (inuse && nfs_mount_state_in_use_end(nmp, error)) {
			inuse = 0;
			nofp = newnofp = NULL;
			rflags = delegation = recall = eof = rlen = retlen = 0;
			ace.ace_flags = 0;
			s = sbuf;
			slen = sizeof(sbuf);
			nfsm_chain_cleanup(&nmreq);
			nfsm_chain_cleanup(&nmrep);
			if (anp) {
				vnode_put(NFSTOV(anp));
				*anpp = anp = NULL;
			}
			hadattrdir = (adnp != NULL);
			if (noopbusy) {
				nfs_open_owner_clear_busy(noop);
				noopbusy = 0;
			}
			goto restart;
		}
		if (noop) {
			if (noopbusy) {
				nfs_open_owner_clear_busy(noop);
				noopbusy = 0;
			}
			nfs_open_owner_rele(noop);
		}
	}
	if (!error && prefetch && nmrep.nmc_mhead) {
		nfsm_chain_op_check(error, &nmrep, NFS_OP_RESTOREFH);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_NVERIFY);
		nfsm_chain_op_check(error, &nmrep, NFS_OP_READ);
		nfsm_chain_get_32(error, &nmrep, eof);
		nfsm_chain_get_32(error, &nmrep, retlen);
		if (!error && anp) {
			/*
			 * There can be one problem with doing the prefetch.
			 * Because we don't have the node before we start the RPC, we
			 * can't have the buffer busy while the READ is performed.
			 * So there is a chance that other I/O occured on the same
			 * range of data while we were performing this RPC.  If that
			 * happens, then it's possible the data we have in the READ
			 * response is no longer up to date.
			 * Once we have the node and the buffer, we need to make sure
			 * that there's no chance we could be putting stale data in
			 * the buffer.
			 * So, we check if the range read is dirty or if any I/O may
			 * have occured on it while we were performing our RPC.
			 */
			struct nfsbuf *bp = NULL;
			int lastpg;
			uint32_t pagemask;

			retlen = MIN(retlen, rlen);

			/* check if node needs size update or invalidation */
			if (ISSET(anp->n_flag, NUPDATESIZE))
				nfs_data_update_size(anp, 0);
			if (!(error = nfs_node_lock(anp))) {
				if (anp->n_flag & NNEEDINVALIDATE) {
					anp->n_flag &= ~NNEEDINVALIDATE;
					nfs_node_unlock(anp);
					error = nfs_vinvalbuf(NFSTOV(anp), V_SAVE|V_IGNORE_WRITEERR, ctx, 1);
					if (!error) /* lets play it safe and just drop the data */
						error = EIO;
				} else {
					nfs_node_unlock(anp);
				}
			}

			/* calculate page mask for the range of data read */
			lastpg = (trunc_page_32(retlen) - 1) / PAGE_SIZE;
			pagemask = ((1 << (lastpg + 1)) - 1);

			if (!error)
				error = nfs_buf_get(anp, 0, nmp->nm_biosize, thd, NBLK_READ|NBLK_NOWAIT, &bp);
			/* don't save the data if dirty or potential I/O conflict */
			if (!error && bp && !bp->nb_dirtyoff && !(bp->nb_dirty & pagemask) &&
			    timevalcmp(&anp->n_lastio, &now, <)) {
				OSAddAtomic64(1, &nfsstats.read_bios);
				CLR(bp->nb_flags, (NB_DONE|NB_ASYNC));
				SET(bp->nb_flags, NB_READ);
				NFS_BUF_MAP(bp);
				nfsm_chain_get_opaque(error, &nmrep, retlen, bp->nb_data);
				if (error) {
					bp->nb_error = error;
					SET(bp->nb_flags, NB_ERROR);
				} else {
					bp->nb_offio = 0;
					bp->nb_endio = rlen;
					if ((retlen > 0) && (bp->nb_endio < (int)retlen))
						bp->nb_endio = retlen;
					if (eof || (retlen == 0)) {
						/* zero out the remaining data (up to EOF) */
						off_t rpcrem, eofrem, rem;
						rpcrem = (rlen - retlen);
						eofrem = anp->n_size - (NBOFF(bp) + retlen);
						rem = (rpcrem < eofrem) ? rpcrem : eofrem;
						if (rem > 0)
							bzero(bp->nb_data + retlen, rem);
					} else if ((retlen < rlen) && !ISSET(bp->nb_flags, NB_ERROR)) {
						/* ugh... short read ... just invalidate for now... */
						SET(bp->nb_flags, NB_INVAL);
					}
				}
				nfs_buf_read_finish(bp);
				microuptime(&anp->n_lastio);
			}
			if (bp)
				nfs_buf_release(bp, 1);
		}
		error = 0; /* ignore any transient error in processing the prefetch */
	}
	if (adnp && !adbusyerror) {
		nfs_node_clear_busy(adnp);
		adbusyerror = ENOENT;
	}
	if (!busyerror) {
		nfs_node_clear_busy(np);
		busyerror = ENOENT;
	}
	if (adnp)
		vnode_put(NFSTOV(adnp));
	if (error && *anpp) {
		vnode_put(NFSTOV(*anpp));
		*anpp = NULL;
	}
	nfsm_chain_cleanup(&nmreq);
	nfsm_chain_cleanup(&nmrep);
	return (error);
}

/*
 * Remove a named attribute.
 */
int
nfs4_named_attr_remove(nfsnode_t np, nfsnode_t anp, const char *name, vfs_context_t ctx)
{
	nfsnode_t adnp = NULL;
	struct nfsmount *nmp;
	struct componentname cn;
	struct vnop_remove_args vra;
	int error, putanp = 0;

	nmp = NFSTONMP(np);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(name, const, char *);
	cn.cn_namelen = strlen(name);
	cn.cn_nameiop = DELETE;
	cn.cn_flags = 0;

	if (!anp) {
		error = nfs4_named_attr_get(np, &cn, NFS_OPEN_SHARE_ACCESS_NONE,
				0, ctx, &anp, NULL);
		if ((!error && !anp) || (error == ENOATTR))
			error = ENOENT;
		if (error) {
			if (anp) {
				vnode_put(NFSTOV(anp));
				anp = NULL;
			}
			goto out;
		}
		putanp = 1;
	}

	if ((error = nfs_node_set_busy(np, vfs_context_thread(ctx))))
		goto out;
	adnp = nfs4_named_attr_dir_get(np, 1, ctx);
	nfs_node_clear_busy(np);
	if (!adnp) {
		error = ENOENT;
		goto out;
	}

	vra.a_desc = &vnop_remove_desc;
	vra.a_dvp = NFSTOV(adnp);
	vra.a_vp = NFSTOV(anp);
	vra.a_cnp = &cn;
	vra.a_flags = 0;
	vra.a_context = ctx;
	error = nfs_vnop_remove(&vra);
out:
	if (adnp)
		vnode_put(NFSTOV(adnp));
	if (putanp)
		vnode_put(NFSTOV(anp));
	return (error);
}

int
nfs4_vnop_getxattr(
	struct vnop_getxattr_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		const char * a_name;
		uio_t a_uio;
		size_t *a_size;
		int a_options;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	struct nfsmount *nmp;
	struct nfs_vattr nvattr;
	struct componentname cn;
	nfsnode_t anp;
	int error = 0, isrsrcfork;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);
	error = nfs_getattr(VTONFS(ap->a_vp), &nvattr, ctx, NGA_CACHED);
	if (error)
		return (error);
	if (NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_NAMED_ATTR) &&
	    !(nvattr.nva_flags & NFS_FFLAG_HAS_NAMED_ATTRS))
		return (ENOATTR);

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(ap->a_name, const, char *);
	cn.cn_namelen = strlen(ap->a_name);
	cn.cn_nameiop = LOOKUP;
	cn.cn_flags = MAKEENTRY;

	/* we'll normally try to prefetch data for xattrs... the resource fork is really a stream */
	isrsrcfork = (bcmp(ap->a_name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) == 0);

	error = nfs4_named_attr_get(VTONFS(ap->a_vp), &cn, NFS_OPEN_SHARE_ACCESS_NONE,
			!isrsrcfork ? NFS_GET_NAMED_ATTR_PREFETCH : 0, ctx, &anp, NULL);
	if ((!error && !anp) || (error == ENOENT))
		error = ENOATTR;
	if (!error) {
		if (ap->a_uio)
			error = nfs_bioread(anp, ap->a_uio, 0, ctx);
		else
			*ap->a_size = anp->n_size;
	}
	if (anp)
		vnode_put(NFSTOV(anp));
	return (error);
}

int
nfs4_vnop_setxattr(
	struct vnop_setxattr_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		const char * a_name;
		uio_t a_uio;
		int a_options;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	int options = ap->a_options;
	uio_t uio = ap->a_uio;
	const char *name = ap->a_name;
	struct nfsmount *nmp;
	struct componentname cn;
	nfsnode_t anp = NULL;
	int error = 0, closeerror = 0, flags, isrsrcfork, isfinderinfo, empty = 0, i;
#define FINDERINFOSIZE 32
	uint8_t finfo[FINDERINFOSIZE];
	uint32_t *finfop;
	struct nfs_open_file *nofp = NULL;
	char uio_buf [ UIO_SIZEOF(1) ];
	uio_t auio;
	struct vnop_write_args vwa;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);

	if ((options & XATTR_CREATE) && (options & XATTR_REPLACE))
		return (EINVAL);

	/* XXX limitation based on need to back up uio on short write */
	if (uio_iovcnt(uio) > 1) {
		printf("nfs4_vnop_setxattr: iovcnt > 1\n");
		return (EINVAL);
	}

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(name, const, char *);
	cn.cn_namelen = strlen(name);
	cn.cn_nameiop = CREATE;
	cn.cn_flags = MAKEENTRY;

	isfinderinfo = (bcmp(name, XATTR_FINDERINFO_NAME, sizeof(XATTR_FINDERINFO_NAME)) == 0);
	isrsrcfork = isfinderinfo ? 0 : (bcmp(name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) == 0);
	if (!isrsrcfork)
		uio_setoffset(uio, 0);
	if (isfinderinfo) {
		if (uio_resid(uio) != sizeof(finfo))
			return (ERANGE);
		error = uiomove((char*)&finfo, sizeof(finfo), uio);
		if (error)
			return (error);
		/* setting a FinderInfo of all zeroes means remove the FinderInfo */
		empty = 1;
		for (i=0, finfop=(uint32_t*)&finfo; i < (int)(sizeof(finfo)/sizeof(uint32_t)); i++)
			if (finfop[i]) {
				empty = 0;
				break;
			}
		if (empty && !(options & (XATTR_CREATE|XATTR_REPLACE))) {
			error = nfs4_named_attr_remove(VTONFS(ap->a_vp), anp, name, ctx);
			if (error == ENOENT)
				error = 0;
			return (error);
		}
		/* first, let's see if we get a create/replace error */
	}

	/*
	 * create/open the xattr
	 *
	 * We need to make sure not to create it if XATTR_REPLACE.
	 * For all xattrs except the resource fork, we also want to
	 * truncate the xattr to remove any current data.  We'll do
	 * that by setting the size to 0 on create/open.
	 */
	flags = 0;
	if (!(options & XATTR_REPLACE))
		flags |= NFS_GET_NAMED_ATTR_CREATE;
	if (options & XATTR_CREATE)
		flags |= NFS_GET_NAMED_ATTR_CREATE_GUARDED;
	if (!isrsrcfork)
		flags |= NFS_GET_NAMED_ATTR_TRUNCATE;

	error = nfs4_named_attr_get(VTONFS(ap->a_vp), &cn, NFS_OPEN_SHARE_ACCESS_BOTH,
			flags, ctx, &anp, &nofp);
	if (!error && !anp)
		error = ENOATTR;
	if (error)
		goto out;
	/* grab the open state from the get/create/open */
	if (nofp && !(error = nfs_open_file_set_busy(nofp, NULL))) {
		nofp->nof_flags &= ~NFS_OPEN_FILE_CREATE;
		nofp->nof_creator = NULL;
		nfs_open_file_clear_busy(nofp);
	}

	/* Setting an empty FinderInfo really means remove it, skip to the close/remove */
	if (isfinderinfo && empty)
		goto doclose;

	/*
	 * Write the data out and flush.
	 *
	 * For FinderInfo, we've already copied the data to finfo, so do I/O from there.
	 */
	vwa.a_desc = &vnop_write_desc;
	vwa.a_vp = NFSTOV(anp);
	vwa.a_uio = NULL;
	vwa.a_ioflag = 0;
	vwa.a_context = ctx;
	if (isfinderinfo) {
		auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_WRITE, &uio_buf, sizeof(uio_buf));
		uio_addiov(auio, (uintptr_t)&finfo, sizeof(finfo));
		vwa.a_uio = auio;
	} else if (uio_resid(uio) > 0) {
		vwa.a_uio = uio;
	}
	if (vwa.a_uio) {
		error = nfs_vnop_write(&vwa);
		if (!error)
			error = nfs_flush(anp, MNT_WAIT, vfs_context_thread(ctx), 0);
	}
doclose:
	/* Close the xattr. */
	if (nofp) {
		int busyerror = nfs_open_file_set_busy(nofp, NULL);
		closeerror = nfs_close(anp, nofp, NFS_OPEN_SHARE_ACCESS_BOTH, NFS_OPEN_SHARE_DENY_NONE, ctx);
		if (!busyerror)
			nfs_open_file_clear_busy(nofp);
	}
	if (!error && isfinderinfo && empty) { /* Setting an empty FinderInfo really means remove it */
		error = nfs4_named_attr_remove(VTONFS(ap->a_vp), anp, name, ctx);
		if (error == ENOENT)
			error = 0;
	}
	if (!error)
		error = closeerror;
out:
	if (anp)
		vnode_put(NFSTOV(anp));
	if (error == ENOENT)
		error = ENOATTR;
	return (error);
}

int
nfs4_vnop_removexattr(
	struct vnop_removexattr_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		const char * a_name;
		int a_options;
		vfs_context_t a_context;
	} */ *ap)
{
	struct nfsmount *nmp = VTONMP(ap->a_vp);
	int error;

	if (nfs_mount_gone(nmp))
		return (ENXIO);
	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);

	error = nfs4_named_attr_remove(VTONFS(ap->a_vp), NULL, ap->a_name, ap->a_context);
	if (error == ENOENT)
		error = ENOATTR;
	return (error);
}

int
nfs4_vnop_listxattr(
	struct vnop_listxattr_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		uio_t a_uio;
		size_t *a_size;
		int a_options;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	nfsnode_t np = VTONFS(ap->a_vp);
	uio_t uio = ap->a_uio;
	nfsnode_t adnp = NULL;
	struct nfsmount *nmp;
	int error, done, i;
	struct nfs_vattr nvattr;
	uint64_t cookie, nextcookie, lbn = 0;
	struct nfsbuf *bp = NULL;
	struct nfs_dir_buf_header *ndbhp;
	struct direntry *dp;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);

	error = nfs_getattr(np, &nvattr, ctx, NGA_CACHED);
	if (error)
		return (error);
	if (NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_NAMED_ATTR) &&
	    !(nvattr.nva_flags & NFS_FFLAG_HAS_NAMED_ATTRS))
		return (0);

	if ((error = nfs_node_set_busy(np, vfs_context_thread(ctx))))
		return (error);
	adnp = nfs4_named_attr_dir_get(np, 1, ctx);
	nfs_node_clear_busy(np);
	if (!adnp)
		goto out;

	if ((error = nfs_node_lock(adnp)))
		goto out;

	if (adnp->n_flag & NNEEDINVALIDATE) {
		adnp->n_flag &= ~NNEEDINVALIDATE;
		nfs_invaldir(adnp);
		nfs_node_unlock(adnp);
		error = nfs_vinvalbuf(NFSTOV(adnp), 0, ctx, 1);
		if (!error)
			error = nfs_node_lock(adnp);
		if (error)
			goto out;
	}

	/*
	 * check for need to invalidate when (re)starting at beginning
	 */
	if (adnp->n_flag & NMODIFIED) {
		nfs_invaldir(adnp);
		nfs_node_unlock(adnp);
		if ((error = nfs_vinvalbuf(NFSTOV(adnp), 0, ctx, 1)))
			goto out;
	} else {
		nfs_node_unlock(adnp);
	}
	/* nfs_getattr() will check changed and purge caches */
	if ((error = nfs_getattr(adnp, &nvattr, ctx, NGA_UNCACHED)))
		goto out;

	if (uio && (uio_resid(uio) == 0))
		goto out;

	done = 0;
	nextcookie = lbn = 0;

	while (!error && !done) {
		OSAddAtomic64(1, &nfsstats.biocache_readdirs);
		cookie = nextcookie;
getbuffer:
		error = nfs_buf_get(adnp, lbn, NFS_DIRBLKSIZ, vfs_context_thread(ctx), NBLK_READ, &bp);
		if (error)
			goto out;
		ndbhp = (struct nfs_dir_buf_header*)bp->nb_data;
		if (!ISSET(bp->nb_flags, NB_CACHE) || !ISSET(ndbhp->ndbh_flags, NDB_FULL)) {
			if (!ISSET(bp->nb_flags, NB_CACHE)) { /* initialize the buffer */
				ndbhp->ndbh_flags = 0;
				ndbhp->ndbh_count = 0;
				ndbhp->ndbh_entry_end = sizeof(*ndbhp);
				ndbhp->ndbh_ncgen = adnp->n_ncgen;
			}
			error = nfs_buf_readdir(bp, ctx);
			if (error == NFSERR_DIRBUFDROPPED)
				goto getbuffer;
			if (error)
				nfs_buf_release(bp, 1);
			if (error && (error != ENXIO) && (error != ETIMEDOUT) && (error != EINTR) && (error != ERESTART)) {
				if (!nfs_node_lock(adnp)) {
					nfs_invaldir(adnp);
					nfs_node_unlock(adnp);
				}
				nfs_vinvalbuf(NFSTOV(adnp), 0, ctx, 1);
				if (error == NFSERR_BAD_COOKIE)
					error = ENOENT;
			}
			if (error)
				goto out;
		}

		/* go through all the entries copying/counting */
		dp = NFS_DIR_BUF_FIRST_DIRENTRY(bp);
		for (i=0; i < ndbhp->ndbh_count; i++) {
			if (!xattr_protected(dp->d_name)) {
				if (uio == NULL) {
					*ap->a_size += dp->d_namlen + 1;
				} else if (uio_resid(uio) < (dp->d_namlen + 1)) {
					error = ERANGE;
				} else {
					error = uiomove(dp->d_name, dp->d_namlen+1, uio);
					if (error && (error != EFAULT))
						error = ERANGE;
				}
			}
			nextcookie = dp->d_seekoff;
			dp = NFS_DIRENTRY_NEXT(dp);
		}

		if (i == ndbhp->ndbh_count) {
			/* hit end of buffer, move to next buffer */
			lbn = nextcookie;
			/* if we also hit EOF, we're done */
			if (ISSET(ndbhp->ndbh_flags, NDB_EOF))
				done = 1;
		}
		if (!error && !done && (nextcookie == cookie)) {
			printf("nfs readdir cookie didn't change 0x%llx, %d/%d\n", cookie, i, ndbhp->ndbh_count);
			error = EIO;
		}
		nfs_buf_release(bp, 1);
	}
out:
	if (adnp)
		vnode_put(NFSTOV(adnp));
	return (error);
}

#if NAMEDSTREAMS
int
nfs4_vnop_getnamedstream(
	struct vnop_getnamedstream_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		vnode_t *a_svpp;
		const char *a_name;
		enum nsoperation a_operation;
		int a_flags;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	struct nfsmount *nmp;
	struct nfs_vattr nvattr;
	struct componentname cn;
	nfsnode_t anp;
	int error = 0;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);
	error = nfs_getattr(VTONFS(ap->a_vp), &nvattr, ctx, NGA_CACHED);
	if (error)
		return (error);
	if (NFS_BITMAP_ISSET(nvattr.nva_bitmap, NFS_FATTR_NAMED_ATTR) &&
	    !(nvattr.nva_flags & NFS_FFLAG_HAS_NAMED_ATTRS))
		return (ENOATTR);

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(ap->a_name, const, char *);
	cn.cn_namelen = strlen(ap->a_name);
	cn.cn_nameiop = LOOKUP;
	cn.cn_flags = MAKEENTRY;

	error = nfs4_named_attr_get(VTONFS(ap->a_vp), &cn, NFS_OPEN_SHARE_ACCESS_NONE,
			0, ctx, &anp, NULL);
	if ((!error && !anp) || (error == ENOENT))
		error = ENOATTR;
	if (!error && anp)
		*ap->a_svpp = NFSTOV(anp);
	else if (anp)
		vnode_put(NFSTOV(anp));
	return (error);
}

int
nfs4_vnop_makenamedstream(
	struct vnop_makenamedstream_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t *a_svpp;
		vnode_t a_vp;
		const char *a_name;
		int a_flags;
		vfs_context_t a_context;
	} */ *ap)
{
	vfs_context_t ctx = ap->a_context;
	struct nfsmount *nmp;
	struct componentname cn;
	nfsnode_t anp;
	int error = 0;

	nmp = VTONMP(ap->a_vp);
	if (nfs_mount_gone(nmp))
		return (ENXIO);

	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);

	bzero(&cn, sizeof(cn));
	cn.cn_nameptr = __CAST_AWAY_QUALIFIER(ap->a_name, const, char *);
	cn.cn_namelen = strlen(ap->a_name);
	cn.cn_nameiop = CREATE;
	cn.cn_flags = MAKEENTRY;

	error = nfs4_named_attr_get(VTONFS(ap->a_vp), &cn, NFS_OPEN_SHARE_ACCESS_BOTH,
			NFS_GET_NAMED_ATTR_CREATE, ctx, &anp, NULL);
	if ((!error && !anp) || (error == ENOENT))
		error = ENOATTR;
	if (!error && anp)
		*ap->a_svpp = NFSTOV(anp);
	else if (anp)
		vnode_put(NFSTOV(anp));
	return (error);
}

int
nfs4_vnop_removenamedstream(
	struct vnop_removenamedstream_args /* {
		struct vnodeop_desc *a_desc;
		vnode_t a_vp;
		vnode_t a_svp;
		const char *a_name;
		int a_flags;
		vfs_context_t a_context;
	} */ *ap)
{
	struct nfsmount *nmp = VTONMP(ap->a_vp);
	nfsnode_t np = ap->a_vp ? VTONFS(ap->a_vp) : NULL;
	nfsnode_t anp = ap->a_svp ? VTONFS(ap->a_svp) : NULL;

	if (nfs_mount_gone(nmp))
		return (ENXIO);

	/*
	 * Given that a_svp is a named stream, checking for
	 * named attribute support is kinda pointless.
	 */
	if (!(nmp->nm_fsattr.nfsa_flags & NFS_FSFLAG_NAMED_ATTR))
		return (ENOTSUP);

	return (nfs4_named_attr_remove(np, anp, ap->a_name, ap->a_context));
}

#endif