diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c
index 7a28e51e21fc..6b40e0f64141 100644
--- a/sys/fs/nfsserver/nfs_nfsdstate.c
+++ b/sys/fs/nfsserver/nfs_nfsdstate.c
@@ -1,8927 +1,9006 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 Rick Macklem, University of Guelph
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  */
 
 #include <sys/cdefs.h>
 #include "opt_inet.h"
 #include "opt_inet6.h"
 #include <sys/extattr.h>
 #include <fs/nfs/nfsport.h>
 
 int nfsrv_issuedelegs = 0;
 int nfsrv_dolocallocks = 0;
 struct nfsv4lock nfsv4rootfs_lock;
 time_t nfsdev_time = 0;
 int nfsrv_layouthashsize;
 volatile int nfsrv_layoutcnt = 0;
 
 NFSD_VNET_DEFINE(struct nfsrv_stablefirst, nfsrv_stablefirst);
 
 NFSD_VNET_DECLARE(int, nfsrv_numnfsd);
 NFSD_VNET_DECLARE(struct nfsstatsv1 *, nfsstatsv1_p);
 
 extern uint32_t nfs_srvmaxio;
 extern int nfsrv_lease;
 extern struct timeval nfsboottime;
 extern u_int32_t newnfs_true, newnfs_false;
 extern struct mtx nfsrv_dslock_mtx;
 extern struct mtx nfsrv_recalllock_mtx;
 extern struct mtx nfsrv_dontlistlock_mtx;
 extern int nfsd_debuglevel;
 extern u_int nfsrv_dsdirsize;
 extern struct nfsdevicehead nfsrv_devidhead;
 extern int nfsrv_doflexfile;
 extern int nfsrv_maxpnfsmirror;
 NFSV4ROOTLOCKMUTEX;
 NFSSTATESPINLOCK;
 extern struct nfsdontlisthead nfsrv_dontlisthead;
 extern volatile int nfsrv_devidcnt;
 extern struct nfslayouthead nfsrv_recalllisthead;
 extern char *nfsrv_zeropnfsdat;
 
 SYSCTL_DECL(_vfs_nfsd);
 int	nfsrv_statehashsize = NFSSTATEHASHSIZE;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, statehashsize, CTLFLAG_RDTUN,
     &nfsrv_statehashsize, 0,
     "Size of state hash table set via loader.conf");
 
 int	nfsrv_clienthashsize = NFSCLIENTHASHSIZE;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, clienthashsize, CTLFLAG_RDTUN,
     &nfsrv_clienthashsize, 0,
     "Size of client hash table set via loader.conf");
 
 int	nfsrv_lockhashsize = NFSLOCKHASHSIZE;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, fhhashsize, CTLFLAG_RDTUN,
     &nfsrv_lockhashsize, 0,
     "Size of file handle hash table set via loader.conf");
 
 int	nfsrv_sessionhashsize = NFSSESSIONHASHSIZE;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, sessionhashsize, CTLFLAG_RDTUN,
     &nfsrv_sessionhashsize, 0,
     "Size of session hash table set via loader.conf");
 
 int	nfsrv_layouthighwater = NFSLAYOUTHIGHWATER;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, layouthighwater, CTLFLAG_RDTUN,
     &nfsrv_layouthighwater, 0,
     "High water mark for number of layouts set via loader.conf");
 
 static int	nfsrv_v4statelimit = NFSRV_V4STATELIMIT;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, v4statelimit, CTLFLAG_RWTUN,
     &nfsrv_v4statelimit, 0,
     "High water limit for NFSv4 opens+locks+delegations");
 
 static int	nfsrv_writedelegifpos = 0;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, writedelegifpos, CTLFLAG_RW,
     &nfsrv_writedelegifpos, 0,
     "Issue a write delegation for read opens if possible");
 
 static int	nfsrv_allowreadforwriteopen = 1;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, allowreadforwriteopen, CTLFLAG_RW,
     &nfsrv_allowreadforwriteopen, 0,
     "Allow Reads to be done with Write Access StateIDs");
 
 int	nfsrv_pnfsatime = 0;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, pnfsstrictatime, CTLFLAG_RW,
     &nfsrv_pnfsatime, 0,
     "For pNFS service, do Getattr ops to keep atime up-to-date");
 
 int	nfsrv_flexlinuxhack = 0;
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, flexlinuxhack, CTLFLAG_RW,
     &nfsrv_flexlinuxhack, 0,
     "For Linux clients, hack around Flex File Layout bug");
 
 /*
  * Hash lists for nfs V4.
  */
 NFSD_VNET_DEFINE(struct nfsclienthashhead *, nfsclienthash);
 NFSD_VNET_DEFINE(struct nfslockhashhead *, nfslockhash);
 NFSD_VNET_DEFINE(struct nfssessionhash *, nfssessionhash);
 
 struct nfslayouthash		*nfslayouthash;
 volatile int nfsrv_dontlistlen = 0;
 
 static u_int32_t nfsrv_openpluslock = 0, nfsrv_delegatecnt = 0;
 static int nfsrv_returnoldstateid = 0, nfsrv_clients = 0;
 static int nfsrv_clienthighwater = NFSRV_CLIENTHIGHWATER;
 static int nfsrv_nogsscallback = 0;
 static volatile int nfsrv_writedelegcnt = 0;
 static int nfsrv_faildscnt;
 
 NFSD_VNET_DEFINE_STATIC(time_t, nfsrvboottime);
 
 /* local functions */
 static void nfsrv_dumpaclient(struct nfsclient *clp,
     struct nfsd_dumpclients *dumpp);
 static void nfsrv_freeopenowner(struct nfsstate *stp, int cansleep,
     NFSPROC_T *p);
 static int nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep,
     NFSPROC_T *p);
 static void nfsrv_freelockowner(struct nfsstate *stp, vnode_t vp, int cansleep,
     NFSPROC_T *p);
 static void nfsrv_freeallnfslocks(struct nfsstate *stp, vnode_t vp,
     int cansleep, NFSPROC_T *p);
 static void nfsrv_freenfslock(struct nfslock *lop);
 static void nfsrv_freenfslockfile(struct nfslockfile *lfp);
 static void nfsrv_freedeleg(struct nfsstate *);
 static int nfsrv_getstate(struct nfsclient *clp, nfsv4stateid_t *stateidp, 
     u_int32_t flags, struct nfsstate **stpp);
 static void nfsrv_getowner(struct nfsstatehead *hp, struct nfsstate *new_stp,
     struct nfsstate **stpp);
 static int nfsrv_getlockfh(vnode_t vp, u_short flags,
     struct nfslockfile *new_lfp, fhandle_t *nfhp, NFSPROC_T *p);
 static int nfsrv_getlockfile(u_short flags, struct nfslockfile **new_lfpp,
     struct nfslockfile **lfpp, fhandle_t *nfhp, int lockit);
 static void nfsrv_insertlock(struct nfslock *new_lop,
     struct nfslock *insert_lop, struct nfsstate *stp, struct nfslockfile *lfp);
 static void nfsrv_updatelock(struct nfsstate *stp, struct nfslock **new_lopp,
     struct nfslock **other_lopp, struct nfslockfile *lfp);
 static int nfsrv_getipnumber(u_char *cp);
 static int nfsrv_checkrestart(nfsquad_t clientid, u_int32_t flags,
     nfsv4stateid_t *stateidp, int specialid);
 static int nfsrv_checkgrace(struct nfsrv_descript *nd, struct nfsclient *clp,
     u_int32_t flags);
 static int nfsrv_docallback(struct nfsclient *clp, int procnum,
     nfsv4stateid_t *stateidp, int trunc, fhandle_t *fhp,
     struct nfsvattr *nap, nfsattrbit_t *attrbitp, int laytype, NFSPROC_T *p);
 static int nfsrv_cbcallargs(struct nfsrv_descript *nd, struct nfsclient *clp,
     uint32_t callback, int op, const char *optag, struct nfsdsession **sepp,
     int *slotposp);
 static u_int32_t nfsrv_nextclientindex(void);
 static u_int32_t nfsrv_nextstateindex(struct nfsclient *clp);
 static void nfsrv_markstable(struct nfsclient *clp);
 static void nfsrv_markreclaim(struct nfsclient *clp);
 static int nfsrv_checkstable(struct nfsclient *clp);
 static int nfsrv_clientconflict(struct nfsclient *clp, int *haslockp, struct 
     vnode *vp, NFSPROC_T *p);
 static int nfsrv_delegconflict(struct nfsstate *stp, int *haslockp,
     NFSPROC_T *p, vnode_t vp);
 static int nfsrv_cleandeleg(vnode_t vp, struct nfslockfile *lfp,
     struct nfsclient *clp, int *haslockp, NFSPROC_T *p);
 static int nfsrv_notsamecredname(int op, struct nfsrv_descript *nd,
     struct nfsclient *clp);
 static time_t nfsrv_leaseexpiry(void);
 static void nfsrv_delaydelegtimeout(struct nfsstate *stp);
 static int nfsrv_checkseqid(struct nfsrv_descript *nd, u_int32_t seqid,
     struct nfsstate *stp, struct nfsrvcache *op);
 static int nfsrv_nootherstate(struct nfsstate *stp);
 static int nfsrv_locallock(vnode_t vp, struct nfslockfile *lfp, int flags,
     uint64_t first, uint64_t end, struct nfslockconflict *cfp, NFSPROC_T *p);
 static void nfsrv_localunlock(vnode_t vp, struct nfslockfile *lfp,
     uint64_t init_first, uint64_t init_end, NFSPROC_T *p);
 static int nfsrv_dolocal(vnode_t vp, struct nfslockfile *lfp, int flags,
     int oldflags, uint64_t first, uint64_t end, struct nfslockconflict *cfp,
     NFSPROC_T *p);
 static void nfsrv_locallock_rollback(vnode_t vp, struct nfslockfile *lfp,
     NFSPROC_T *p);
 static void nfsrv_locallock_commit(struct nfslockfile *lfp, int flags,
     uint64_t first, uint64_t end);
 static void nfsrv_locklf(struct nfslockfile *lfp);
 static void nfsrv_unlocklf(struct nfslockfile *lfp);
 static struct nfsdsession *nfsrv_findsession(uint8_t *sessionid);
 static int nfsrv_freesession(struct nfsrv_descript *nd, struct nfsdsession *sep,
     uint8_t *sessionid, bool locked, SVCXPRT **old_xprtp);
 static int nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp,
     int dont_replycache, struct nfsdsession **sepp, int *slotposp);
 static int nfsv4_getcbsession(struct nfsclient *clp, struct nfsdsession **sepp);
 static int nfsrv_addlayout(struct nfsrv_descript *nd, struct nfslayout **lypp,
     nfsv4stateid_t *stateidp, char *layp, int *layoutlenp, NFSPROC_T *p);
 static void nfsrv_freelayout(struct nfslayouthead *lhp, struct nfslayout *lyp);
 static void nfsrv_freelayoutlist(nfsquad_t clientid);
 static void nfsrv_freelayouts(nfsquad_t *clid, fsid_t *fs, int laytype,
     int iomode);
 static void nfsrv_freealllayouts(void);
 static void nfsrv_freedevid(struct nfsdevice *ds);
 static int nfsrv_setdsserver(char *dspathp, char *mdspathp, NFSPROC_T *p,
     struct nfsdevice **dsp);
 static void nfsrv_deleteds(struct nfsdevice *fndds);
 static void nfsrv_allocdevid(struct nfsdevice *ds, char *addr, char *dnshost);
 static void nfsrv_freealldevids(void);
 static void nfsrv_flexlayouterr(struct nfsrv_descript *nd, uint32_t *layp,
     int maxcnt, NFSPROC_T *p);
 static int nfsrv_recalllayout(nfsquad_t clid, nfsv4stateid_t *stateidp,
     fhandle_t *fhp, struct nfslayout *lyp, int changed, int laytype,
     NFSPROC_T *p);
 static int nfsrv_findlayout(nfsquad_t *clientidp, fhandle_t *fhp, int laytype,
     NFSPROC_T *, struct nfslayout **lypp);
 static int nfsrv_fndclid(nfsquad_t *clidvec, nfsquad_t clid, int clidcnt);
 static struct nfslayout *nfsrv_filelayout(struct nfsrv_descript *nd, int iomode,
     fhandle_t *fhp, fhandle_t *dsfhp, char *devid, fsid_t fs);
 static struct nfslayout *nfsrv_flexlayout(struct nfsrv_descript *nd, int iomode,
     int mirrorcnt, fhandle_t *fhp, fhandle_t *dsfhp, char *devid, fsid_t fs);
 static int nfsrv_dontlayout(fhandle_t *fhp);
 static int nfsrv_createdsfile(vnode_t vp, fhandle_t *fhp, struct pnfsdsfile *pf,
     vnode_t dvp, struct nfsdevice *ds, struct ucred *cred, NFSPROC_T *p,
     vnode_t *tvpp);
 static struct nfsdevice *nfsrv_findmirroredds(struct nfsmount *nmp);
 static int nfsrv_checkmachcred(int op, struct nfsrv_descript *nd,
     struct nfsclient *clp);
 static void nfsrv_issuedelegation(struct vnode *vp, struct nfsclient *clp,
     struct nfsrv_descript *nd, int delegate, int writedeleg, int readonly,
     u_quad_t filerev, uint64_t rdonly, struct nfsstate **new_delegp,
     struct nfsstate *new_stp, struct nfslockfile *lfp, uint32_t *rflagsp,
     nfsv4stateid_t *delegstateidp);
+static void nfsrv_clientlock(bool mlocked);
+static void nfsrv_clientunlock(bool mlocked);
+
+/*
+ * Lock the client structure, either with the mutex or the exclusive nfsd lock.
+ */
+static void
+nfsrv_clientlock(bool mlocked)
+{
+	int igotlock;
+
+	if (mlocked) {
+		NFSLOCKSTATE();
+	} else {
+		NFSLOCKV4ROOTMUTEX();
+		nfsv4_relref(&nfsv4rootfs_lock);
+		do {
+			igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
+			    NFSV4ROOTLOCKMUTEXPTR, NULL);
+		} while (!igotlock);
+		NFSUNLOCKV4ROOTMUTEX();
+	}
+}
+
+/*
+ * Unlock the client structure.
+ */
+static void
+nfsrv_clientunlock(bool mlocked)
+{
+
+	if (mlocked) {
+		NFSUNLOCKSTATE();
+	} else {
+		NFSLOCKV4ROOTMUTEX();
+		nfsv4_unlock(&nfsv4rootfs_lock, 1);
+		NFSUNLOCKV4ROOTMUTEX();
+	}
+}
 
 /*
  * Scan the client list for a match and either return the current one,
  * create a new entry or return an error.
  * If returning a non-error, the clp structure must either be linked into
  * the client list or free'd.
  */
 int
 nfsrv_setclient(struct nfsrv_descript *nd, struct nfsclient **new_clpp,
     nfsquad_t *clientidp, nfsquad_t *confirmp, NFSPROC_T *p)
 {
 	struct nfsclient *clp = NULL, *new_clp = *new_clpp;
 	int i, error = 0, ret;
 	struct nfsstate *stp, *tstp;
 #ifdef INET
 	struct sockaddr_in *sin, *rin;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *sin6, *rin6;
 #endif
 	struct nfsdsession *sep, *nsep;
-	int zapit = 0, gotit, hasstate = 0, igotlock;
+	SVCXPRT *old_xprt;
+	struct nfssessionhead old_sess;
+	int zapit = 0, gotit, hasstate = 0;
+	bool mlocked;
 	static u_int64_t confirm_index = 0;
 
 	/*
 	 * Check for state resource limit exceeded.
 	 */
 	if (nfsrv_openpluslock > nfsrv_v4statelimit) {
 		error = NFSERR_RESOURCE;
 		goto out;
 	}
 
 	if (nfsrv_issuedelegs == 0 ||
 	    ((nd->nd_flag & ND_GSS) != 0 && nfsrv_nogsscallback != 0))
 		/*
 		 * Don't do callbacks when delegations are disabled or
 		 * for AUTH_GSS unless enabled via nfsrv_nogsscallback.
 		 * If establishing a callback connection is attempted
 		 * when a firewall is blocking the callback path, the
 		 * server may wait too long for the connect attempt to
 		 * succeed during the Open. Some clients, such as Linux,
 		 * may timeout and give up on the Open before the server
 		 * replies. Also, since AUTH_GSS callbacks are not
 		 * yet interoperability tested, they might cause the
 		 * server to crap out, if they get past the Init call to
 		 * the client.
 		 */
 		new_clp->lc_program = 0;
 
+	mlocked = true;
+	if (nfsrv_dolocallocks != 0)
+		mlocked = false;
 	/* Lock out other nfsd threads */
-	NFSLOCKV4ROOTMUTEX();
-	nfsv4_relref(&nfsv4rootfs_lock);
-	do {
-		igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
-		    NFSV4ROOTLOCKMUTEXPTR, NULL);
-	} while (!igotlock);
-	NFSUNLOCKV4ROOTMUTEX();
+	nfsrv_clientlock(mlocked);
 
 	/*
 	 * Search for a match in the client list.
 	 */
 	gotit = i = 0;
 	while (i < nfsrv_clienthashsize && !gotit) {
 	    LIST_FOREACH(clp, &NFSD_VNET(nfsclienthash)[i], lc_hash) {
 		if (new_clp->lc_idlen == clp->lc_idlen &&
 		    !NFSBCMP(new_clp->lc_id, clp->lc_id, clp->lc_idlen)) {
 			gotit = 1;
 			break;
 		}
 	    }
 	    if (gotit == 0)
 		i++;
 	}
+	old_xprt = NULL;
 	if (!gotit ||
 	    (clp->lc_flags & (LCL_NEEDSCONFIRM | LCL_ADMINREVOKED))) {
 		if ((nd->nd_flag & ND_NFSV41) != 0 && confirmp->lval[1] != 0) {
 			/*
 			 * For NFSv4.1, if confirmp->lval[1] is non-zero, the
 			 * client is trying to update a confirmed clientid.
 			 */
-			NFSLOCKV4ROOTMUTEX();
-			nfsv4_unlock(&nfsv4rootfs_lock, 1);
-			NFSUNLOCKV4ROOTMUTEX();
+			nfsrv_clientunlock(mlocked);
 			confirmp->lval[1] = 0;
 			error = NFSERR_NOENT;
 			goto out;
 		}
 		/*
 		 * Get rid of the old one.
 		 */
 		if (i != nfsrv_clienthashsize) {
 			LIST_REMOVE(clp, lc_hash);
-			nfsrv_cleanclient(clp, p, false, NULL);
+			if (mlocked)
+				nfsrv_cleanclient(clp, p, true, &old_xprt);
+			else
+				nfsrv_cleanclient(clp, p, false, NULL);
 			nfsrv_freedeleglist(&clp->lc_deleg);
 			nfsrv_freedeleglist(&clp->lc_olddeleg);
 			zapit = 1;
 		}
 		/*
 		 * Add it after assigning a client id to it.
 		 */
 		new_clp->lc_flags |= LCL_NEEDSCONFIRM;
 		if ((nd->nd_flag & ND_NFSV41) != 0) {
 			confirmp->lval[0] = ++confirm_index;
 			new_clp->lc_confirm.lval[0] = confirmp->lval[0] - 1;
 		} else
 			confirmp->qval = new_clp->lc_confirm.qval =
 			    ++confirm_index;
 		clientidp->lval[0] = new_clp->lc_clientid.lval[0] =
 		    NFSD_VNET(nfsrvboottime);
 		clientidp->lval[1] = new_clp->lc_clientid.lval[1] =
 		    nfsrv_nextclientindex();
 		new_clp->lc_stateindex = 0;
 		new_clp->lc_statemaxindex = 0;
 		new_clp->lc_prevsess = 0;
 		new_clp->lc_cbref = 0;
 		new_clp->lc_expiry = nfsrv_leaseexpiry();
 		LIST_INIT(&new_clp->lc_open);
 		LIST_INIT(&new_clp->lc_deleg);
 		LIST_INIT(&new_clp->lc_olddeleg);
 		LIST_INIT(&new_clp->lc_session);
 		for (i = 0; i < nfsrv_statehashsize; i++)
 			LIST_INIT(&new_clp->lc_stateid[i]);
 		LIST_INSERT_HEAD(NFSCLIENTHASH(new_clp->lc_clientid), new_clp,
 		    lc_hash);
 		NFSD_VNET(nfsstatsv1_p)->srvclients++;
 		nfsrv_openpluslock++;
 		nfsrv_clients++;
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
-		if (zapit)
+		nfsrv_clientunlock(mlocked);
+		if (zapit != 0) {
+			if (old_xprt != NULL)
+				SVC_RELEASE(old_xprt);
 			nfsrv_zapclient(clp, p);
+		}
 		*new_clpp = NULL;
 		goto out;
 	}
 
 	/*
 	 * Now, handle the cases where the id is already issued.
 	 */
 	if (nfsrv_notsamecredname(NFSV4OP_EXCHANGEID, nd, clp)) {
 	    /*
 	     * Check to see if there is expired state that should go away.
 	     */
 	    if (clp->lc_expiry < NFSD_MONOSEC &&
 	        (!LIST_EMPTY(&clp->lc_open) || !LIST_EMPTY(&clp->lc_deleg))) {
-		nfsrv_cleanclient(clp, p, false, NULL);
+		if (mlocked)
+		    nfsrv_cleanclient(clp, p, true, &old_xprt);
+		else
+		    nfsrv_cleanclient(clp, p, false, NULL);
 		nfsrv_freedeleglist(&clp->lc_deleg);
 	    }
 
 	    /*
 	     * If there is outstanding state, then reply NFSERR_CLIDINUSE per
 	     * RFC3530 Sec. 8.1.2 last para.
 	     */
 	    if (!LIST_EMPTY(&clp->lc_deleg)) {
 		hasstate = 1;
 	    } else if (LIST_EMPTY(&clp->lc_open)) {
 		hasstate = 0;
 	    } else {
 		hasstate = 0;
 		/* Look for an Open on the OpenOwner */
 		LIST_FOREACH(stp, &clp->lc_open, ls_list) {
 		    if (!LIST_EMPTY(&stp->ls_open)) {
 			hasstate = 1;
 			break;
 		    }
 		}
 	    }
 	    if (hasstate) {
 		/*
 		 * If the uid doesn't match, return NFSERR_CLIDINUSE after
 		 * filling out the correct ipaddr and portnum.
 		 */
 		switch (clp->lc_req.nr_nam->sa_family) {
 #ifdef INET
 		case AF_INET:
 			sin = (struct sockaddr_in *)new_clp->lc_req.nr_nam;
 			rin = (struct sockaddr_in *)clp->lc_req.nr_nam;
 			sin->sin_addr.s_addr = rin->sin_addr.s_addr;
 			sin->sin_port = rin->sin_port;
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			sin6 = (struct sockaddr_in6 *)new_clp->lc_req.nr_nam;
 			rin6 = (struct sockaddr_in6 *)clp->lc_req.nr_nam;
 			sin6->sin6_addr = rin6->sin6_addr;
 			sin6->sin6_port = rin6->sin6_port;
 			break;
 #endif
 		}
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		nfsrv_clientunlock(mlocked);
+		if (old_xprt != NULL)
+			SVC_RELEASE(old_xprt);
 		error = NFSERR_CLIDINUSE;
 		goto out;
 	    }
 	}
 
 	if (NFSBCMP(new_clp->lc_verf, clp->lc_verf, NFSX_VERF)) {
 		/*
 		 * If the verifier has changed, the client has rebooted
 		 * and a new client id is issued. The old state info
 		 * can be thrown away once the SetClientID_Confirm or
 		 * Create_Session that confirms the clientid occurs.
 		 */
 		LIST_REMOVE(clp, lc_hash);
 
-		/* Get rid of all sessions on this clientid. */
-		LIST_FOREACH_SAFE(sep, &clp->lc_session, sess_list, nsep) {
-			ret = nfsrv_freesession(NULL, sep, NULL, false, NULL);
-			if (ret != 0)
-				printf("nfsrv_setclient: verifier changed free"
-				    " session failed=%d\n", ret);
-		}
+		LIST_NEWHEAD(&old_sess, &clp->lc_session, sess_list);
 
 		new_clp->lc_flags |= LCL_NEEDSCONFIRM;
 		if ((nd->nd_flag & ND_NFSV41) != 0) {
 			confirmp->lval[0] = ++confirm_index;
 			new_clp->lc_confirm.lval[0] = confirmp->lval[0] - 1;
 		} else
 			confirmp->qval = new_clp->lc_confirm.qval =
 			    ++confirm_index;
 		clientidp->lval[0] = new_clp->lc_clientid.lval[0] =
 		    NFSD_VNET(nfsrvboottime);
 		clientidp->lval[1] = new_clp->lc_clientid.lval[1] =
 		    nfsrv_nextclientindex();
 		new_clp->lc_stateindex = 0;
 		new_clp->lc_statemaxindex = 0;
 		new_clp->lc_prevsess = 0;
 		new_clp->lc_cbref = 0;
 		new_clp->lc_expiry = nfsrv_leaseexpiry();
 
 		/*
 		 * Save the state until confirmed.
 		 */
 		LIST_NEWHEAD(&new_clp->lc_open, &clp->lc_open, ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_open, ls_list)
 			tstp->ls_clp = new_clp;
 		LIST_NEWHEAD(&new_clp->lc_deleg, &clp->lc_deleg, ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_deleg, ls_list)
 			tstp->ls_clp = new_clp;
 		LIST_NEWHEAD(&new_clp->lc_olddeleg, &clp->lc_olddeleg,
 		    ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_olddeleg, ls_list)
 			tstp->ls_clp = new_clp;
 		for (i = 0; i < nfsrv_statehashsize; i++) {
 			LIST_NEWHEAD(&new_clp->lc_stateid[i],
 			    &clp->lc_stateid[i], ls_hash);
 			LIST_FOREACH(tstp, &new_clp->lc_stateid[i], ls_hash)
 				tstp->ls_clp = new_clp;
 		}
 		LIST_INIT(&new_clp->lc_session);
 		LIST_INSERT_HEAD(NFSCLIENTHASH(new_clp->lc_clientid), new_clp,
 		    lc_hash);
 		NFSD_VNET(nfsstatsv1_p)->srvclients++;
 		nfsrv_openpluslock++;
 		nfsrv_clients++;
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		if (!mlocked) {
+			nfsrv_clientunlock(mlocked);
+			NFSLOCKSTATE();
+		}
 
 		/*
 		 * Must wait until any outstanding callback on the old clp
 		 * completes.
 		 */
-		NFSLOCKSTATE();
 		while (clp->lc_cbref) {
 			clp->lc_flags |= LCL_WAKEUPWANTED;
 			(void)mtx_sleep(clp, NFSSTATEMUTEXPTR, PZERO - 1,
 			    "nfsd clp", 10 * hz);
 		}
 		NFSUNLOCKSTATE();
+		if (old_xprt != NULL)
+			SVC_RELEASE(old_xprt);
+		/* Get rid of all sessions on this clientid. */
+		LIST_FOREACH_SAFE(sep, &old_sess, sess_list, nsep) {
+			ret = nfsrv_freesession(NULL, sep, NULL, false, NULL);
+			if (ret != 0)
+				printf("nfsrv_setclient: verifier changed free"
+				    " session failed=%d\n", ret);
+		}
+
 		nfsrv_zapclient(clp, p);
 		*new_clpp = NULL;
 		goto out;
 	}
 
 	/* For NFSv4.1, mark that we found a confirmed clientid. */
 	if ((nd->nd_flag & ND_NFSV41) != 0) {
 		clientidp->lval[0] = clp->lc_clientid.lval[0];
 		clientidp->lval[1] = clp->lc_clientid.lval[1];
 		confirmp->lval[0] = 0;	/* Ignored by client */
 		confirmp->lval[1] = 1;
 	} else {
 		/*
 		 * id and verifier match, so update the net address info
 		 * and get rid of any existing callback authentication
 		 * handle, so a new one will be acquired.
 		 */
 		LIST_REMOVE(clp, lc_hash);
 		new_clp->lc_flags |= (LCL_NEEDSCONFIRM | LCL_DONTCLEAN);
 		new_clp->lc_expiry = nfsrv_leaseexpiry();
 		confirmp->qval = new_clp->lc_confirm.qval = ++confirm_index;
 		clientidp->lval[0] = new_clp->lc_clientid.lval[0] =
 		    clp->lc_clientid.lval[0];
 		clientidp->lval[1] = new_clp->lc_clientid.lval[1] =
 		    clp->lc_clientid.lval[1];
 		new_clp->lc_delegtime = clp->lc_delegtime;
 		new_clp->lc_stateindex = clp->lc_stateindex;
 		new_clp->lc_statemaxindex = clp->lc_statemaxindex;
 		new_clp->lc_cbref = 0;
 		LIST_NEWHEAD(&new_clp->lc_open, &clp->lc_open, ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_open, ls_list)
 			tstp->ls_clp = new_clp;
 		LIST_NEWHEAD(&new_clp->lc_deleg, &clp->lc_deleg, ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_deleg, ls_list)
 			tstp->ls_clp = new_clp;
 		LIST_NEWHEAD(&new_clp->lc_olddeleg, &clp->lc_olddeleg, ls_list);
 		LIST_FOREACH(tstp, &new_clp->lc_olddeleg, ls_list)
 			tstp->ls_clp = new_clp;
 		for (i = 0; i < nfsrv_statehashsize; i++) {
 			LIST_NEWHEAD(&new_clp->lc_stateid[i],
 			    &clp->lc_stateid[i], ls_hash);
 			LIST_FOREACH(tstp, &new_clp->lc_stateid[i], ls_hash)
 				tstp->ls_clp = new_clp;
 		}
 		LIST_INIT(&new_clp->lc_session);
 		LIST_INSERT_HEAD(NFSCLIENTHASH(new_clp->lc_clientid), new_clp,
 		    lc_hash);
 		NFSD_VNET(nfsstatsv1_p)->srvclients++;
 		nfsrv_openpluslock++;
 		nfsrv_clients++;
 	}
-	NFSLOCKV4ROOTMUTEX();
-	nfsv4_unlock(&nfsv4rootfs_lock, 1);
-	NFSUNLOCKV4ROOTMUTEX();
+	if (!mlocked)
+		nfsrv_clientunlock(mlocked);
 
 	if ((nd->nd_flag & ND_NFSV41) == 0) {
 		/*
 		 * Must wait until any outstanding callback on the old clp
 		 * completes.
 		 */
-		NFSLOCKSTATE();
+		if (!mlocked)
+			NFSLOCKSTATE();
 		while (clp->lc_cbref) {
 			clp->lc_flags |= LCL_WAKEUPWANTED;
 			(void)mtx_sleep(clp, NFSSTATEMUTEXPTR, PZERO - 1,
 			    "nfsdclp", 10 * hz);
 		}
 		NFSUNLOCKSTATE();
+		if (old_xprt != NULL)
+			SVC_RELEASE(old_xprt);
 		nfsrv_zapclient(clp, p);
 		*new_clpp = NULL;
+	} else {
+		if (mlocked)
+			NFSUNLOCKSTATE();
+		if (old_xprt != NULL)
+			SVC_RELEASE(old_xprt);
 	}
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Check to see if the client id exists and optionally confirm it.
  */
 int
 nfsrv_getclient(nfsquad_t clientid, int opflags, struct nfsclient **clpp,
     struct nfsdsession *nsep, nfsquad_t confirm, uint32_t cbprogram,
     struct nfsrv_descript *nd, NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfsstate *stp;
 	int i;
 	struct nfsclienthashhead *hp;
-	int error = 0, igotlock, doneok;
+	int error = 0, doneok, igotlock;
 	struct nfssessionhash *shp;
 	struct nfsdsession *sep;
 	uint64_t sessid[2];
-	bool sess_replay;
+	CLIENT *client;
+	SVCXPRT *old_xprt;
+	bool mlocked, sess_replay;
 	static uint64_t next_sess = 0;
 
 	if (clpp)
 		*clpp = NULL;
 	if ((nd == NULL || (nd->nd_flag & ND_NFSV41) == 0 ||
 	    opflags != CLOPS_RENEW) && NFSD_VNET(nfsrvboottime) !=
 	    clientid.lval[0]) {
 		error = NFSERR_STALECLIENTID;
 		goto out;
 	}
 
 	/*
 	 * If called with opflags == CLOPS_RENEW, the State Lock is
 	 * already held. Otherwise, we need to get either that or,
 	 * for the case of Confirm, lock out the nfsd threads.
 	 */
+	client = NULL;
+	old_xprt = NULL;
+	mlocked = true;
+	if (nfsrv_dolocallocks != 0)
+		mlocked = false;
 	if (opflags & CLOPS_CONFIRM) {
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_relref(&nfsv4rootfs_lock);
-		do {
-			igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
-			    NFSV4ROOTLOCKMUTEXPTR, NULL);
-		} while (!igotlock);
+		if (nsep != NULL &&
+		    (nsep->sess_crflags & NFSV4CRSESS_CONNBACKCHAN) != 0)
+			client = (struct __rpc_client *)
+			    clnt_bck_create(nd->nd_xprt->xp_socket,
+			    cbprogram, NFSV4_CBVERS);
+		if (mlocked) {
+			nfsrv_clientlock(mlocked);
+		} else {
+			NFSLOCKV4ROOTMUTEX();
+			nfsv4_relref(&nfsv4rootfs_lock);
+			do {
+				igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1,
+				    NULL, NFSV4ROOTLOCKMUTEXPTR, NULL);
+			} while (!igotlock);
+		}
 		/*
 		 * Create a new sessionid here, since we need to do it where
 		 * there is a mutex held to serialize update of next_sess.
 		 */
 		if ((nd->nd_flag & ND_NFSV41) != 0) {
 			sessid[0] = ++next_sess;
 			sessid[1] = clientid.qval;
 		}
-		NFSUNLOCKV4ROOTMUTEX();
+		if (!mlocked)
+			NFSUNLOCKV4ROOTMUTEX();
 	} else if (opflags != CLOPS_RENEW) {
 		NFSLOCKSTATE();
 	}
 
 	/* For NFSv4.1, the clp is acquired from the associated session. */
 	if (nd != NULL && (nd->nd_flag & ND_NFSV41) != 0 &&
 	    opflags == CLOPS_RENEW) {
 		clp = NULL;
 		if ((nd->nd_flag & ND_HASSEQUENCE) != 0) {
 			shp = NFSSESSIONHASH(nd->nd_sessionid);
 			NFSLOCKSESSION(shp);
 			sep = nfsrv_findsession(nd->nd_sessionid);
 			if (sep != NULL)
 				clp = sep->sess_clp;
 			NFSUNLOCKSESSION(shp);
 		}
 	} else {
 		hp = NFSCLIENTHASH(clientid);
 		LIST_FOREACH(clp, hp, lc_hash) {
 			if (clp->lc_clientid.lval[1] == clientid.lval[1])
 				break;
 		}
 	}
 	if (clp == NULL) {
 		if (opflags & CLOPS_CONFIRM)
 			error = NFSERR_STALECLIENTID;
 		else
 			error = NFSERR_EXPIRED;
 	} else if (clp->lc_flags & LCL_ADMINREVOKED) {
 		/*
 		 * If marked admin revoked, just return the error.
 		 */
 		error = NFSERR_ADMINREVOKED;
 	}
 	if (error) {
 		if (opflags & CLOPS_CONFIRM) {
-			NFSLOCKV4ROOTMUTEX();
-			nfsv4_unlock(&nfsv4rootfs_lock, 1);
-			NFSUNLOCKV4ROOTMUTEX();
+			nfsrv_clientunlock(mlocked);
+			if (client != NULL)
+				CLNT_RELEASE(client);
 		} else if (opflags != CLOPS_RENEW) {
 			NFSUNLOCKSTATE();
 		}
 		goto out;
 	}
 
 	/*
 	 * Perform any operations specified by the opflags.
 	 */
 	if (opflags & CLOPS_CONFIRM) {
 		sess_replay = false;
 		if ((nd->nd_flag & ND_NFSV41) != 0) {
 		    /*
 		     * For the case where lc_confirm.lval[0] == confirm.lval[0],
 		     * use the new session, but with the previous sessionid.
 		     * This is not exactly what the RFC describes, but should
 		     * result in the same reply as the previous CreateSession.
 		     */
 		    if (clp->lc_confirm.lval[0] + 1 == confirm.lval[0]) {
 			clp->lc_confirm.lval[0] = confirm.lval[0];
 			clp->lc_prevsess = sessid[0];
 		    } else if (clp->lc_confirm.lval[0] == confirm.lval[0]) {
 			if (clp->lc_prevsess == 0)
 			    error = NFSERR_SEQMISORDERED;
 			else
 			    sessid[0] = clp->lc_prevsess;
 			sess_replay = true;
 		    } else
 			error = NFSERR_SEQMISORDERED;
 		} else if ((nd->nd_flag & ND_NFSV41) == 0 &&
 		     clp->lc_confirm.qval != confirm.qval)
 			error = NFSERR_STALECLIENTID;
 		if (error == 0 && nfsrv_notsamecredname(NFSV4OP_CREATESESSION,
 		    nd, clp))
 			error = NFSERR_CLIDINUSE;
 
 		if (!error) {
 		    if ((clp->lc_flags & (LCL_NEEDSCONFIRM | LCL_DONTCLEAN)) ==
 			LCL_NEEDSCONFIRM) {
 			/*
 			 * Hang onto the delegations (as old delegations)
 			 * for an Open with CLAIM_DELEGATE_PREV unless in
 			 * grace, but get rid of the rest of the state.
 			 */
-			nfsrv_cleanclient(clp, p, false, NULL);
+			if (mlocked)
+				nfsrv_cleanclient(clp, p, true, &old_xprt);
+			else
+				nfsrv_cleanclient(clp, p, false, NULL);
 			nfsrv_freedeleglist(&clp->lc_olddeleg);
 			if (nfsrv_checkgrace(nd, clp, 0)) {
 			    /* In grace, so just delete delegations */
 			    nfsrv_freedeleglist(&clp->lc_deleg);
 			} else {
 			    LIST_FOREACH(stp, &clp->lc_deleg, ls_list)
 				stp->ls_flags |= NFSLCK_OLDDELEG;
 			    clp->lc_delegtime = NFSD_MONOSEC +
 				nfsrv_lease + NFSRV_LEASEDELTA;
 			    LIST_NEWHEAD(&clp->lc_olddeleg, &clp->lc_deleg,
 				ls_list);
 			}
 			if ((nd->nd_flag & ND_NFSV41) != 0)
 			    clp->lc_program = cbprogram;
 		    }
 		    clp->lc_flags &= ~(LCL_NEEDSCONFIRM | LCL_DONTCLEAN);
 		    if (clp->lc_program)
 			clp->lc_flags |= LCL_NEEDSCBNULL;
 		    /* For NFSv4.1, link the session onto the client. */
 		    if (nsep != NULL) {
 			/* Hold a reference on the xprt for a backchannel. */
 			if ((nsep->sess_crflags & NFSV4CRSESS_CONNBACKCHAN)
 			    != 0 && !sess_replay) {
-			    if (clp->lc_req.nr_client == NULL)
-				clp->lc_req.nr_client = (struct __rpc_client *)
-				    clnt_bck_create(nd->nd_xprt->xp_socket,
-				    cbprogram, NFSV4_CBVERS);
+			    if (clp->lc_req.nr_client == NULL) {
+				clp->lc_req.nr_client = client;
+				client = NULL;
+			    }
 			    if (clp->lc_req.nr_client != NULL) {
 				SVC_ACQUIRE(nd->nd_xprt);
 				CLNT_ACQUIRE(clp->lc_req.nr_client);
 				nd->nd_xprt->xp_p2 = clp->lc_req.nr_client;
 				/* Disable idle timeout. */
 				nd->nd_xprt->xp_idletimeout = 0;
 				nsep->sess_cbsess.nfsess_xprt = nd->nd_xprt;
 			    } else
 				nsep->sess_crflags &= ~NFSV4CRSESS_CONNBACKCHAN;
 			}
 			NFSBCOPY(sessid, nsep->sess_sessionid,
 			    NFSX_V4SESSIONID);
 			NFSBCOPY(sessid, nsep->sess_cbsess.nfsess_sessionid,
 			    NFSX_V4SESSIONID);
 			if (!sess_replay) {
 			    shp = NFSSESSIONHASH(nsep->sess_sessionid);
-			    NFSLOCKSTATE();
+			    if (!mlocked)
+				NFSLOCKSTATE();
 			    NFSLOCKSESSION(shp);
 			    LIST_INSERT_HEAD(&shp->list, nsep, sess_hash);
 			    LIST_INSERT_HEAD(&clp->lc_session, nsep, sess_list);
 			    nsep->sess_clp = clp;
 			    NFSUNLOCKSESSION(shp);
-			    NFSUNLOCKSTATE();
+			    if (!mlocked)
+				NFSUNLOCKSTATE();
 			}
 		    }
 		}
 	} else if (clp->lc_flags & LCL_NEEDSCONFIRM) {
 		error = NFSERR_EXPIRED;
 	}
 
 	/*
 	 * If called by the Renew Op, we must check the principal.
 	 */
 	if (!error && (opflags & CLOPS_RENEWOP)) {
 	    if (nfsrv_notsamecredname(0, nd, clp)) {
 		doneok = 0;
 		for (i = 0; i < nfsrv_statehashsize && doneok == 0; i++) {
 		    LIST_FOREACH(stp, &clp->lc_stateid[i], ls_hash) {
 			if ((stp->ls_flags & NFSLCK_OPEN) &&
 			    stp->ls_uid == nd->nd_cred->cr_uid) {
 				doneok = 1;
 				break;
 			}
 		    }
 		}
 		if (!doneok)
 			error = NFSERR_ACCES;
 	    }
 	    if (!error && (clp->lc_flags & LCL_CBDOWN))
 		error = NFSERR_CBPATHDOWN;
 	}
 	if ((!error || error == NFSERR_CBPATHDOWN) &&
 	     (opflags & CLOPS_RENEW)) {
 		clp->lc_expiry = nfsrv_leaseexpiry();
 	}
 	if (opflags & CLOPS_CONFIRM) {
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		nfsrv_clientunlock(mlocked);
+		if (client != NULL)
+			CLNT_RELEASE(client);
+		if (old_xprt != NULL)
+			SVC_RELEASE(old_xprt);
 	} else if (opflags != CLOPS_RENEW) {
 		NFSUNLOCKSTATE();
 	}
 	if (clpp)
 		*clpp = clp;
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Perform the NFSv4.1 destroy clientid.
  */
 int
 nfsrv_destroyclient(struct nfsrv_descript *nd, nfsquad_t clientid, NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfsclienthashhead *hp;
-	int error = 0, i, igotlock;
+	SVCXPRT *old_xprt;
+	int error = 0, i;
+	bool mlocked;
 
 	if (NFSD_VNET(nfsrvboottime) != clientid.lval[0]) {
 		error = NFSERR_STALECLIENTID;
 		goto out;
 	}
 
+	mlocked = true;
+	if (nfsrv_dolocallocks != 0)
+		mlocked = false;
 	/* Lock out other nfsd threads */
-	NFSLOCKV4ROOTMUTEX();
-	nfsv4_relref(&nfsv4rootfs_lock);
-	do {
-		igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
-		    NFSV4ROOTLOCKMUTEXPTR, NULL);
-	} while (igotlock == 0);
-	NFSUNLOCKV4ROOTMUTEX();
+	nfsrv_clientlock(mlocked);
 
 	hp = NFSCLIENTHASH(clientid);
 	LIST_FOREACH(clp, hp, lc_hash) {
 		if (clp->lc_clientid.lval[1] == clientid.lval[1])
 			break;
 	}
 	if (clp == NULL) {
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		nfsrv_clientunlock(mlocked);
 		/* Just return ok, since it is gone. */
 		goto out;
 	}
 
 	/* Check for the SP4_MACH_CRED case. */
 	error = nfsrv_checkmachcred(NFSV4OP_DESTROYCLIENTID, nd, clp);
 	if (error != 0) {
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		nfsrv_clientunlock(mlocked);
 		goto out;
 	}
 
 	/*
 	 * Free up all layouts on the clientid.  Should the client return the
 	 * layouts?
 	 */
 	nfsrv_freelayoutlist(clientid);
 
 	/* Scan for state on the clientid. */
 	for (i = 0; i < nfsrv_statehashsize; i++)
 		if (!LIST_EMPTY(&clp->lc_stateid[i])) {
-			NFSLOCKV4ROOTMUTEX();
-			nfsv4_unlock(&nfsv4rootfs_lock, 1);
-			NFSUNLOCKV4ROOTMUTEX();
+			nfsrv_clientunlock(mlocked);
 			error = NFSERR_CLIENTIDBUSY;
 			goto out;
 		}
 	if (!LIST_EMPTY(&clp->lc_session) || !LIST_EMPTY(&clp->lc_deleg)) {
-		NFSLOCKV4ROOTMUTEX();
-		nfsv4_unlock(&nfsv4rootfs_lock, 1);
-		NFSUNLOCKV4ROOTMUTEX();
+		nfsrv_clientunlock(mlocked);
 		error = NFSERR_CLIENTIDBUSY;
 		goto out;
 	}
 
 	/* Destroy the clientid and return ok. */
-	nfsrv_cleanclient(clp, p, false, NULL);
+	old_xprt = NULL;
+	if (mlocked)
+		nfsrv_cleanclient(clp, p, true, &old_xprt);
+	else
+		nfsrv_cleanclient(clp, p, false, NULL);
 	nfsrv_freedeleglist(&clp->lc_deleg);
 	nfsrv_freedeleglist(&clp->lc_olddeleg);
 	LIST_REMOVE(clp, lc_hash);
-	NFSLOCKV4ROOTMUTEX();
-	nfsv4_unlock(&nfsv4rootfs_lock, 1);
-	NFSUNLOCKV4ROOTMUTEX();
+	nfsrv_clientunlock(mlocked);
+	if (old_xprt != NULL)
+		SVC_RELEASE(old_xprt);
 	nfsrv_zapclient(clp, p);
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Called from the new nfssvc syscall to admin revoke a clientid.
  * Returns 0 for success, error otherwise.
  */
 int
 nfsrv_adminrevoke(struct nfsd_clid *revokep, NFSPROC_T *p)
 {
 	struct nfsclient *clp = NULL;
 	int i, error = 0;
 	int gotit, igotlock;
 
 	/*
 	 * First, lock out the nfsd so that state won't change while the
 	 * revocation record is being written to the stable storage restart
 	 * file.
 	 */
 	NFSLOCKV4ROOTMUTEX();
 	do {
 		igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
 		    NFSV4ROOTLOCKMUTEXPTR, NULL);
 	} while (!igotlock);
 	NFSUNLOCKV4ROOTMUTEX();
 
 	/*
 	 * Search for a match in the client list.
 	 */
 	gotit = i = 0;
 	while (i < nfsrv_clienthashsize && !gotit) {
 	    LIST_FOREACH(clp, &NFSD_VNET(nfsclienthash)[i], lc_hash) {
 		if (revokep->nclid_idlen == clp->lc_idlen &&
 		    !NFSBCMP(revokep->nclid_id, clp->lc_id, clp->lc_idlen)) {
 			gotit = 1;
 			break;
 		}
 	    }
 	    i++;
 	}
 	if (!gotit) {
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_unlock(&nfsv4rootfs_lock, 0);
 		NFSUNLOCKV4ROOTMUTEX();
 		error = EPERM;
 		goto out;
 	}
 
 	/*
 	 * Now, write out the revocation record
 	 */
 	nfsrv_writestable(clp->lc_id, clp->lc_idlen, NFSNST_REVOKE, p);
 	nfsrv_backupstable();
 
 	/*
 	 * and clear out the state, marking the clientid revoked.
 	 */
 	clp->lc_flags &= ~LCL_CALLBACKSON;
 	clp->lc_flags |= LCL_ADMINREVOKED;
 	nfsrv_cleanclient(clp, p, false, NULL);
 	nfsrv_freedeleglist(&clp->lc_deleg);
 	nfsrv_freedeleglist(&clp->lc_olddeleg);
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_unlock(&nfsv4rootfs_lock, 0);
 	NFSUNLOCKV4ROOTMUTEX();
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Dump out stats for all clients. Called from nfssvc(2), that is used
  * nfsstatsv1.
  */
 void
 nfsrv_dumpclients(struct nfsd_dumpclients *dumpp, int maxcnt)
 {
 	struct nfsclient *clp;
 	int i = 0, cnt = 0;
 
 	/*
 	 * First, get a reference on the nfsv4rootfs_lock so that an
 	 * exclusive lock cannot be acquired while dumping the clients.
 	 */
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_getref(&nfsv4rootfs_lock, NULL, NFSV4ROOTLOCKMUTEXPTR, NULL);
 	NFSUNLOCKV4ROOTMUTEX();
 	NFSLOCKSTATE();
 	/*
 	 * Rattle through the client lists until done.
 	 */
 	while (i < nfsrv_clienthashsize && cnt < maxcnt) {
 	    clp = LIST_FIRST(&NFSD_VNET(nfsclienthash)[i]);
 	    while (clp != LIST_END(&NFSD_VNET(nfsclienthash)[i]) && cnt <
 		maxcnt) {
 		nfsrv_dumpaclient(clp, &dumpp[cnt]);
 		cnt++;
 		clp = LIST_NEXT(clp, lc_hash);
 	    }
 	    i++;
 	}
 	if (cnt < maxcnt)
 	    dumpp[cnt].ndcl_clid.nclid_idlen = 0;
 	NFSUNLOCKSTATE();
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_relref(&nfsv4rootfs_lock);
 	NFSUNLOCKV4ROOTMUTEX();
 }
 
 /*
  * Dump stats for a client. Must be called with the NFSSTATELOCK and spl'd.
  */
 static void
 nfsrv_dumpaclient(struct nfsclient *clp, struct nfsd_dumpclients *dumpp)
 {
 	struct nfsstate *stp, *openstp, *lckownstp;
 	struct nfslock *lop;
 	sa_family_t af;
 #ifdef INET
 	struct sockaddr_in *rin;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *rin6;
 #endif
 
 	dumpp->ndcl_nopenowners = dumpp->ndcl_nlockowners = 0;
 	dumpp->ndcl_nopens = dumpp->ndcl_nlocks = 0;
 	dumpp->ndcl_ndelegs = dumpp->ndcl_nolddelegs = 0;
 	dumpp->ndcl_flags = clp->lc_flags;
 	dumpp->ndcl_clid.nclid_idlen = clp->lc_idlen;
 	NFSBCOPY(clp->lc_id, dumpp->ndcl_clid.nclid_id, clp->lc_idlen);
 	af = clp->lc_req.nr_nam->sa_family;
 	dumpp->ndcl_addrfam = af;
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		rin = (struct sockaddr_in *)clp->lc_req.nr_nam;
 		dumpp->ndcl_cbaddr.sin_addr = rin->sin_addr;
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		rin6 = (struct sockaddr_in6 *)clp->lc_req.nr_nam;
 		dumpp->ndcl_cbaddr.sin6_addr = rin6->sin6_addr;
 		break;
 #endif
 	}
 
 	/*
 	 * Now, scan the state lists and total up the opens and locks.
 	 */
 	LIST_FOREACH(stp, &clp->lc_open, ls_list) {
 	    dumpp->ndcl_nopenowners++;
 	    LIST_FOREACH(openstp, &stp->ls_open, ls_list) {
 		dumpp->ndcl_nopens++;
 		LIST_FOREACH(lckownstp, &openstp->ls_open, ls_list) {
 		    dumpp->ndcl_nlockowners++;
 		    LIST_FOREACH(lop, &lckownstp->ls_lock, lo_lckowner) {
 			dumpp->ndcl_nlocks++;
 		    }
 		}
 	    }
 	}
 
 	/*
 	 * and the delegation lists.
 	 */
 	LIST_FOREACH(stp, &clp->lc_deleg, ls_list) {
 	    dumpp->ndcl_ndelegs++;
 	}
 	LIST_FOREACH(stp, &clp->lc_olddeleg, ls_list) {
 	    dumpp->ndcl_nolddelegs++;
 	}
 }
 
 /*
  * Dump out lock stats for a file.
  */
 void
 nfsrv_dumplocks(vnode_t vp, struct nfsd_dumplocks *ldumpp, int maxcnt,
     NFSPROC_T *p)
 {
 	struct nfsstate *stp;
 	struct nfslock *lop;
 	int cnt = 0;
 	struct nfslockfile *lfp;
 	sa_family_t af;
 #ifdef INET
 	struct sockaddr_in *rin;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *rin6;
 #endif
 	int ret;
 	fhandle_t nfh;
 
 	ret = nfsrv_getlockfh(vp, 0, NULL, &nfh, p);
 	/*
 	 * First, get a reference on the nfsv4rootfs_lock so that an
 	 * exclusive lock on it cannot be acquired while dumping the locks.
 	 */
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_getref(&nfsv4rootfs_lock, NULL, NFSV4ROOTLOCKMUTEXPTR, NULL);
 	NFSUNLOCKV4ROOTMUTEX();
 	NFSLOCKSTATE();
 	if (!ret)
 		ret = nfsrv_getlockfile(0, NULL, &lfp, &nfh, 0);
 	if (ret) {
 		ldumpp[0].ndlck_clid.nclid_idlen = 0;
 		NFSUNLOCKSTATE();
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_relref(&nfsv4rootfs_lock);
 		NFSUNLOCKV4ROOTMUTEX();
 		return;
 	}
 
 	/*
 	 * For each open share on file, dump it out.
 	 */
 	stp = LIST_FIRST(&lfp->lf_open);
 	while (stp != LIST_END(&lfp->lf_open) && cnt < maxcnt) {
 		ldumpp[cnt].ndlck_flags = stp->ls_flags;
 		ldumpp[cnt].ndlck_stateid.seqid = stp->ls_stateid.seqid;
 		ldumpp[cnt].ndlck_stateid.other[0] = stp->ls_stateid.other[0];
 		ldumpp[cnt].ndlck_stateid.other[1] = stp->ls_stateid.other[1];
 		ldumpp[cnt].ndlck_stateid.other[2] = stp->ls_stateid.other[2];
 		ldumpp[cnt].ndlck_owner.nclid_idlen =
 		    stp->ls_openowner->ls_ownerlen;
 		NFSBCOPY(stp->ls_openowner->ls_owner,
 		    ldumpp[cnt].ndlck_owner.nclid_id,
 		    stp->ls_openowner->ls_ownerlen);
 		ldumpp[cnt].ndlck_clid.nclid_idlen = stp->ls_clp->lc_idlen;
 		NFSBCOPY(stp->ls_clp->lc_id, ldumpp[cnt].ndlck_clid.nclid_id,
 		    stp->ls_clp->lc_idlen);
 		af = stp->ls_clp->lc_req.nr_nam->sa_family;
 		ldumpp[cnt].ndlck_addrfam = af;
 		switch (af) {
 #ifdef INET
 		case AF_INET:
 			rin = (struct sockaddr_in *)stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin_addr = rin->sin_addr;
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			rin6 = (struct sockaddr_in6 *)
 			    stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin6_addr = rin6->sin6_addr;
 			break;
 #endif
 		}
 		stp = LIST_NEXT(stp, ls_file);
 		cnt++;
 	}
 
 	/*
 	 * and all locks.
 	 */
 	lop = LIST_FIRST(&lfp->lf_lock);
 	while (lop != LIST_END(&lfp->lf_lock) && cnt < maxcnt) {
 		stp = lop->lo_stp;
 		ldumpp[cnt].ndlck_flags = lop->lo_flags;
 		ldumpp[cnt].ndlck_first = lop->lo_first;
 		ldumpp[cnt].ndlck_end = lop->lo_end;
 		ldumpp[cnt].ndlck_stateid.seqid = stp->ls_stateid.seqid;
 		ldumpp[cnt].ndlck_stateid.other[0] = stp->ls_stateid.other[0];
 		ldumpp[cnt].ndlck_stateid.other[1] = stp->ls_stateid.other[1];
 		ldumpp[cnt].ndlck_stateid.other[2] = stp->ls_stateid.other[2];
 		ldumpp[cnt].ndlck_owner.nclid_idlen = stp->ls_ownerlen;
 		NFSBCOPY(stp->ls_owner, ldumpp[cnt].ndlck_owner.nclid_id,
 		    stp->ls_ownerlen);
 		ldumpp[cnt].ndlck_clid.nclid_idlen = stp->ls_clp->lc_idlen;
 		NFSBCOPY(stp->ls_clp->lc_id, ldumpp[cnt].ndlck_clid.nclid_id,
 		    stp->ls_clp->lc_idlen);
 		af = stp->ls_clp->lc_req.nr_nam->sa_family;
 		ldumpp[cnt].ndlck_addrfam = af;
 		switch (af) {
 #ifdef INET
 		case AF_INET:
 			rin = (struct sockaddr_in *)stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin_addr = rin->sin_addr;
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			rin6 = (struct sockaddr_in6 *)
 			    stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin6_addr = rin6->sin6_addr;
 			break;
 #endif
 		}
 		lop = LIST_NEXT(lop, lo_lckfile);
 		cnt++;
 	}
 
 	/*
 	 * and the delegations.
 	 */
 	stp = LIST_FIRST(&lfp->lf_deleg);
 	while (stp != LIST_END(&lfp->lf_deleg) && cnt < maxcnt) {
 		ldumpp[cnt].ndlck_flags = stp->ls_flags;
 		ldumpp[cnt].ndlck_stateid.seqid = stp->ls_stateid.seqid;
 		ldumpp[cnt].ndlck_stateid.other[0] = stp->ls_stateid.other[0];
 		ldumpp[cnt].ndlck_stateid.other[1] = stp->ls_stateid.other[1];
 		ldumpp[cnt].ndlck_stateid.other[2] = stp->ls_stateid.other[2];
 		ldumpp[cnt].ndlck_owner.nclid_idlen = 0;
 		ldumpp[cnt].ndlck_clid.nclid_idlen = stp->ls_clp->lc_idlen;
 		NFSBCOPY(stp->ls_clp->lc_id, ldumpp[cnt].ndlck_clid.nclid_id,
 		    stp->ls_clp->lc_idlen);
 		af = stp->ls_clp->lc_req.nr_nam->sa_family;
 		ldumpp[cnt].ndlck_addrfam = af;
 		switch (af) {
 #ifdef INET
 		case AF_INET:
 			rin = (struct sockaddr_in *)stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin_addr = rin->sin_addr;
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			rin6 = (struct sockaddr_in6 *)
 			    stp->ls_clp->lc_req.nr_nam;
 			ldumpp[cnt].ndlck_cbaddr.sin6_addr = rin6->sin6_addr;
 			break;
 #endif
 		}
 		stp = LIST_NEXT(stp, ls_file);
 		cnt++;
 	}
 
 	/*
 	 * If list isn't full, mark end of list by setting the client name
 	 * to zero length.
 	 */
 	if (cnt < maxcnt)
 		ldumpp[cnt].ndlck_clid.nclid_idlen = 0;
 	NFSUNLOCKSTATE();
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_relref(&nfsv4rootfs_lock);
 	NFSUNLOCKV4ROOTMUTEX();
 }
 
 /*
  * Server timer routine. It can scan any linked list, so long
  * as it holds the spin/mutex lock and there is no exclusive lock on
  * nfsv4rootfs_lock.
  * (For OpenBSD, a kthread is ok. For FreeBSD, I think it is ok
  *  to do this from a callout, since the spin locks work. For
  *  Darwin, I'm not sure what will work correctly yet.)
  * Should be called once per second.
  */
 void
 nfsrv_servertimer(void *arg __unused)
 {
 	struct nfsclient *clp, *nclp;
 	struct nfsstate *stp, *nstp;
 	int got_ref, i;
 
 	/*
 	 * Make sure nfsboottime is set. This is used by V3 as well
 	 * as V4. Note that nfsboottime is not nfsrvboottime, which is
 	 * only used by the V4 server for leases.
 	 */
 	if (nfsboottime.tv_sec == 0)
 		NFSSETBOOTTIME(nfsboottime);
 
 	/*
 	 * If server hasn't started yet, just return.
 	 */
 	NFSLOCKSTATE();
 	if (NFSD_VNET(nfsrv_stablefirst).nsf_eograce == 0) {
 		NFSUNLOCKSTATE();
 		return;
 	}
 	if (!(NFSD_VNET(nfsrv_stablefirst).nsf_flags & NFSNSF_UPDATEDONE)) {
 		if (!(NFSD_VNET(nfsrv_stablefirst).nsf_flags &
 		      NFSNSF_GRACEOVER) &&
 		    NFSD_MONOSEC > NFSD_VNET(nfsrv_stablefirst).nsf_eograce)
 			NFSD_VNET(nfsrv_stablefirst).nsf_flags |=
 			    (NFSNSF_GRACEOVER | NFSNSF_NEEDLOCK);
 		NFSUNLOCKSTATE();
 		return;
 	}
 
 	/*
 	 * Try and get a reference count on the nfsv4rootfs_lock so that
 	 * no nfsd thread can acquire an exclusive lock on it before this
 	 * call is done. If it is already exclusively locked, just return.
 	 */
 	NFSLOCKV4ROOTMUTEX();
 	got_ref = nfsv4_getref_nonblock(&nfsv4rootfs_lock);
 	NFSUNLOCKV4ROOTMUTEX();
 	if (got_ref == 0) {
 		NFSUNLOCKSTATE();
 		return;
 	}
 
 	/*
 	 * For each client...
 	 */
 	for (i = 0; i < nfsrv_clienthashsize; i++) {
 	    clp = LIST_FIRST(&NFSD_VNET(nfsclienthash)[i]);
 	    while (clp != LIST_END(&NFSD_VNET(nfsclienthash)[i])) {
 		nclp = LIST_NEXT(clp, lc_hash);
 		if (!(clp->lc_flags & LCL_EXPIREIT)) {
 		    if (((clp->lc_expiry + NFSRV_STALELEASE) < NFSD_MONOSEC
 			 && ((LIST_EMPTY(&clp->lc_deleg)
 			      && LIST_EMPTY(&clp->lc_open)) ||
 			     nfsrv_clients > nfsrv_clienthighwater)) ||
 			(clp->lc_expiry + NFSRV_MOULDYLEASE) < NFSD_MONOSEC ||
 			(clp->lc_expiry < NFSD_MONOSEC &&
 			 (nfsrv_openpluslock * 10 / 9) > nfsrv_v4statelimit)) {
 			/*
 			 * Lease has expired several nfsrv_lease times ago:
 			 * PLUS
 			 *    - no state is associated with it
 			 *    OR
 			 *    - above high water mark for number of clients
 			 *      (nfsrv_clienthighwater should be large enough
 			 *       that this only occurs when clients fail to
 			 *       use the same nfs_client_id4.id. Maybe somewhat
 			 *       higher that the maximum number of clients that
 			 *       will mount this server?)
 			 * OR
 			 * Lease has expired a very long time ago
 			 * OR
 			 * Lease has expired PLUS the number of opens + locks
 			 * has exceeded 90% of capacity
 			 *
 			 * --> Mark for expiry. The actual expiry will be done
 			 *     by an nfsd sometime soon.
 			 */
 			clp->lc_flags |= LCL_EXPIREIT;
 			NFSD_VNET(nfsrv_stablefirst).nsf_flags |=
 			    (NFSNSF_NEEDLOCK | NFSNSF_EXPIREDCLIENT);
 		    } else {
 			/*
 			 * If there are no opens, increment no open tick cnt
 			 * If time exceeds NFSNOOPEN, mark it to be thrown away
 			 * otherwise, if there is an open, reset no open time
 			 * Hopefully, this will avoid excessive re-creation
 			 * of open owners and subsequent open confirms.
 			 */
 			stp = LIST_FIRST(&clp->lc_open);
 			while (stp != LIST_END(&clp->lc_open)) {
 				nstp = LIST_NEXT(stp, ls_list);
 				if (LIST_EMPTY(&stp->ls_open)) {
 					stp->ls_noopens++;
 					if (stp->ls_noopens > NFSNOOPEN ||
 					    (nfsrv_openpluslock * 2) >
 					    nfsrv_v4statelimit)
 						NFSD_VNET(nfsrv_stablefirst).nsf_flags |=
 							NFSNSF_NOOPENS;
 				} else {
 					stp->ls_noopens = 0;
 				}
 				stp = nstp;
 			}
 		    }
 		}
 		clp = nclp;
 	    }
 	}
 	NFSUNLOCKSTATE();
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_relref(&nfsv4rootfs_lock);
 	NFSUNLOCKV4ROOTMUTEX();
 }
 
 /*
  * The following set of functions free up the various data structures.
  */
 /*
  * Clear out all open/lock state related to this nfsclient.
  * Caller must hold an exclusive lock on nfsv4rootfs_lock, so that
  * there are no other active nfsd threads.
  */
 void
 nfsrv_cleanclient(struct nfsclient *clp, NFSPROC_T *p, bool locked,
     SVCXPRT **old_xprtp)
 {
 	struct nfsstate *stp, *nstp;
 	struct nfsdsession *sep, *nsep;
 
-	LIST_FOREACH_SAFE(stp, &clp->lc_open, ls_list, nstp)
-		nfsrv_freeopenowner(stp, 1, p);
+	LIST_FOREACH_SAFE(stp, &clp->lc_open, ls_list, nstp) {
+		if (locked)
+			nfsrv_freeopenowner(stp, 0, p);
+		else
+			nfsrv_freeopenowner(stp, 1, p);
+	}
 	if ((clp->lc_flags & LCL_ADMINREVOKED) == 0)
 		LIST_FOREACH_SAFE(sep, &clp->lc_session, sess_list, nsep)
 			(void)nfsrv_freesession(NULL, sep, NULL, locked,
 			    old_xprtp);
 }
 
 /*
  * Free a client that has been cleaned. It should also already have been
  * removed from the lists.
  * (Just to be safe w.r.t. newnfs_disconnect(), call this function when
  *  softclock interrupts are enabled.)
  */
 void
 nfsrv_zapclient(struct nfsclient *clp, NFSPROC_T *p)
 {
 
 #ifdef notyet
 	if ((clp->lc_flags & (LCL_GSS | LCL_CALLBACKSON)) ==
 	     (LCL_GSS | LCL_CALLBACKSON) &&
 	    (clp->lc_hand.nfsh_flag & NFSG_COMPLETE) &&
 	    clp->lc_handlelen > 0) {
 		clp->lc_hand.nfsh_flag &= ~NFSG_COMPLETE;
 		clp->lc_hand.nfsh_flag |= NFSG_DESTROYED;
 		(void) nfsrv_docallback(clp, NFSV4PROC_CBNULL,
 			NULL, 0, NULL, NULL, NULL, 0, p);
 	}
 #endif
 	newnfs_disconnect(NULL, &clp->lc_req);
 	free(clp->lc_req.nr_nam, M_SONAME);
 	NFSFREEMUTEX(&clp->lc_req.nr_mtx);
 	free(clp->lc_stateid, M_NFSDCLIENT);
 	free(clp, M_NFSDCLIENT);
 	NFSLOCKSTATE();
 	NFSD_VNET(nfsstatsv1_p)->srvclients--;
 	nfsrv_openpluslock--;
 	nfsrv_clients--;
 	NFSUNLOCKSTATE();
 }
 
 /*
  * Free a list of delegation state structures.
  * (This function will also free all nfslockfile structures that no
  *  longer have associated state.)
  */
 void
 nfsrv_freedeleglist(struct nfsstatehead *sthp)
 {
 	struct nfsstate *stp, *nstp;
 
 	LIST_FOREACH_SAFE(stp, sthp, ls_list, nstp) {
 		nfsrv_freedeleg(stp);
 	}
 	LIST_INIT(sthp);
 }
 
 /*
  * Free up a delegation.
  */
 static void
 nfsrv_freedeleg(struct nfsstate *stp)
 {
 	struct nfslockfile *lfp;
 
 	LIST_REMOVE(stp, ls_hash);
 	LIST_REMOVE(stp, ls_list);
 	LIST_REMOVE(stp, ls_file);
 	if ((stp->ls_flags & NFSLCK_DELEGWRITE) != 0)
 		nfsrv_writedelegcnt--;
 	lfp = stp->ls_lfp;
 	if (LIST_EMPTY(&lfp->lf_open) &&
 	    LIST_EMPTY(&lfp->lf_lock) && LIST_EMPTY(&lfp->lf_deleg) &&
 	    LIST_EMPTY(&lfp->lf_locallock) && LIST_EMPTY(&lfp->lf_rollback) &&
 	    lfp->lf_usecount == 0 &&
 	    nfsv4_testlock(&lfp->lf_locallock_lck) == 0)
 		nfsrv_freenfslockfile(lfp);
 	free(stp, M_NFSDSTATE);
 	NFSD_VNET(nfsstatsv1_p)->srvdelegates--;
 	nfsrv_openpluslock--;
 	nfsrv_delegatecnt--;
 }
 
 /*
  * This function frees an open owner and all associated opens.
  */
 static void
 nfsrv_freeopenowner(struct nfsstate *stp, int cansleep, NFSPROC_T *p)
 {
 	struct nfsstate *nstp, *tstp;
 
 	LIST_REMOVE(stp, ls_list);
 	/*
 	 * Now, free all associated opens.
 	 */
 	nstp = LIST_FIRST(&stp->ls_open);
 	while (nstp != LIST_END(&stp->ls_open)) {
 		tstp = nstp;
 		nstp = LIST_NEXT(nstp, ls_list);
 		(void) nfsrv_freeopen(tstp, NULL, cansleep, p);
 	}
 	if (stp->ls_op)
 		nfsrvd_derefcache(stp->ls_op);
 	free(stp, M_NFSDSTATE);
 	NFSD_VNET(nfsstatsv1_p)->srvopenowners--;
 	nfsrv_openpluslock--;
 }
 
 /*
  * This function frees an open (nfsstate open structure) with all associated
  * lock_owners and locks. It also frees the nfslockfile structure iff there
  * are no other opens on the file.
  * Returns 1 if it free'd the nfslockfile, 0 otherwise.
  */
 static int
 nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep, NFSPROC_T *p)
 {
 	struct nfsstate *nstp, *tstp;
 	struct nfslockfile *lfp;
 	int ret;
 
 	LIST_REMOVE(stp, ls_hash);
 	LIST_REMOVE(stp, ls_list);
 	LIST_REMOVE(stp, ls_file);
 
 	lfp = stp->ls_lfp;
 	/*
 	 * Now, free all lockowners associated with this open.
 	 */
 	LIST_FOREACH_SAFE(tstp, &stp->ls_open, ls_list, nstp)
 		nfsrv_freelockowner(tstp, vp, cansleep, p);
 
 	/*
 	 * The nfslockfile is freed here if there are no locks
 	 * associated with the open.
 	 * If there are locks associated with the open, the
 	 * nfslockfile structure can be freed via nfsrv_freelockowner().
 	 * Acquire the state mutex to avoid races with calls to
 	 * nfsrv_getlockfile().
 	 */
 	if (cansleep != 0)
 		NFSLOCKSTATE();
 	if (lfp != NULL && LIST_EMPTY(&lfp->lf_open) &&
 	    LIST_EMPTY(&lfp->lf_deleg) && LIST_EMPTY(&lfp->lf_lock) &&
 	    LIST_EMPTY(&lfp->lf_locallock) && LIST_EMPTY(&lfp->lf_rollback) &&
 	    lfp->lf_usecount == 0 &&
 	    (cansleep != 0 || nfsv4_testlock(&lfp->lf_locallock_lck) == 0)) {
 		nfsrv_freenfslockfile(lfp);
 		ret = 1;
 	} else
 		ret = 0;
 	if (cansleep != 0)
 		NFSUNLOCKSTATE();
 	free(stp, M_NFSDSTATE);
 	NFSD_VNET(nfsstatsv1_p)->srvopens--;
 	nfsrv_openpluslock--;
 	return (ret);
 }
 
 /*
  * Frees a lockowner and all associated locks.
  */
 static void
 nfsrv_freelockowner(struct nfsstate *stp, vnode_t vp, int cansleep,
     NFSPROC_T *p)
 {
 
 	LIST_REMOVE(stp, ls_hash);
 	LIST_REMOVE(stp, ls_list);
 	nfsrv_freeallnfslocks(stp, vp, cansleep, p);
 	if (stp->ls_op)
 		nfsrvd_derefcache(stp->ls_op);
 	free(stp, M_NFSDSTATE);
 	NFSD_VNET(nfsstatsv1_p)->srvlockowners--;
 	nfsrv_openpluslock--;
 }
 
 /*
  * Free all the nfs locks on a lockowner.
  */
 static void
 nfsrv_freeallnfslocks(struct nfsstate *stp, vnode_t vp, int cansleep,
     NFSPROC_T *p)
 {
 	struct nfslock *lop, *nlop;
 	struct nfsrollback *rlp, *nrlp;
 	struct nfslockfile *lfp = NULL;
 	int gottvp = 0;
 	vnode_t tvp = NULL;
 	uint64_t first, end;
 
 	if (vp != NULL)
 		ASSERT_VOP_UNLOCKED(vp, "nfsrv_freeallnfslocks: vnode locked");
 	lop = LIST_FIRST(&stp->ls_lock);
 	while (lop != LIST_END(&stp->ls_lock)) {
 		nlop = LIST_NEXT(lop, lo_lckowner);
 		/*
 		 * Since all locks should be for the same file, lfp should
 		 * not change.
 		 */
 		if (lfp == NULL)
 			lfp = lop->lo_lfp;
 		else if (lfp != lop->lo_lfp)
 			panic("allnfslocks");
 		/*
 		 * If vp is NULL and cansleep != 0, a vnode must be acquired
 		 * from the file handle. This only occurs when called from
 		 * nfsrv_cleanclient().
 		 */
 		if (gottvp == 0) {
 			if (nfsrv_dolocallocks == 0)
 				tvp = NULL;
 			else if (vp == NULL && cansleep != 0) {
 				tvp = nfsvno_getvp(&lfp->lf_fh);
 				if (tvp != NULL)
 					NFSVOPUNLOCK(tvp);
 			} else
 				tvp = vp;
 			gottvp = 1;
 		}
 
 		if (tvp != NULL) {
 			if (cansleep == 0)
 				panic("allnfs2");
 			first = lop->lo_first;
 			end = lop->lo_end;
 			nfsrv_freenfslock(lop);
 			nfsrv_localunlock(tvp, lfp, first, end, p);
 			LIST_FOREACH_SAFE(rlp, &lfp->lf_rollback, rlck_list,
 			    nrlp)
 				free(rlp, M_NFSDROLLBACK);
 			LIST_INIT(&lfp->lf_rollback);
 		} else
 			nfsrv_freenfslock(lop);
 		lop = nlop;
 	}
 	if (vp == NULL && tvp != NULL)
 		vrele(tvp);
 }
 
 /*
  * Free an nfslock structure.
  */
 static void
 nfsrv_freenfslock(struct nfslock *lop)
 {
 
 	if (lop->lo_lckfile.le_prev != NULL) {
 		LIST_REMOVE(lop, lo_lckfile);
 		NFSD_VNET(nfsstatsv1_p)->srvlocks--;
 		nfsrv_openpluslock--;
 	}
 	LIST_REMOVE(lop, lo_lckowner);
 	free(lop, M_NFSDLOCK);
 }
 
 /*
  * This function frees an nfslockfile structure.
  */
 static void
 nfsrv_freenfslockfile(struct nfslockfile *lfp)
 {
 
 	LIST_REMOVE(lfp, lf_hash);
 	free(lfp, M_NFSDLOCKFILE);
 }
 
 /*
  * This function looks up an nfsstate structure via stateid.
  */
 static int
 nfsrv_getstate(struct nfsclient *clp, nfsv4stateid_t *stateidp, __unused u_int32_t flags,
     struct nfsstate **stpp)
 {
 	struct nfsstate *stp;
 	struct nfsstatehead *hp;
 	int error = 0;
 
 	*stpp = NULL;
 	hp = NFSSTATEHASH(clp, *stateidp);
 	LIST_FOREACH(stp, hp, ls_hash) {
 		if (!NFSBCMP(stp->ls_stateid.other, stateidp->other,
 			NFSX_STATEIDOTHER))
 			break;
 	}
 
 	/*
 	 * If no state id in list, return NFSERR_BADSTATEID.
 	 */
 	if (stp == LIST_END(hp)) {
 		error = NFSERR_BADSTATEID;
 		goto out;
 	}
 	*stpp = stp;
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * This function gets an nfsstate structure via owner string.
  */
 static void
 nfsrv_getowner(struct nfsstatehead *hp, struct nfsstate *new_stp,
     struct nfsstate **stpp)
 {
 	struct nfsstate *stp;
 
 	*stpp = NULL;
 	LIST_FOREACH(stp, hp, ls_list) {
 		if (new_stp->ls_ownerlen == stp->ls_ownerlen &&
 		  !NFSBCMP(new_stp->ls_owner,stp->ls_owner,stp->ls_ownerlen)) {
 			*stpp = stp;
 			return;
 		}
 	}
 }
 
 /*
  * Lock control function called to update lock status.
  * Returns 0 upon success, -1 if there is no lock and the flags indicate
  * that one isn't to be created and an NFSERR_xxx for other errors.
  * The structures new_stp and new_lop are passed in as pointers that should
  * be set to NULL if the structure is used and shouldn't be free'd.
  * For the NFSLCK_TEST and NFSLCK_CHECK cases, the structures are
  * never used and can safely be allocated on the stack. For all other
  * cases, *new_stpp and *new_lopp should be malloc'd before the call,
  * in case they are used.
  */
 int
 nfsrv_lockctrl(vnode_t vp, struct nfsstate **new_stpp,
     struct nfslock **new_lopp, struct nfslockconflict *cfp,
     nfsquad_t clientid, nfsv4stateid_t *stateidp,
     __unused struct nfsexstuff *exp,
     struct nfsrv_descript *nd, NFSPROC_T *p)
 {
 	struct nfslock *lop;
 	struct nfsstate *new_stp = *new_stpp;
 	struct nfslock *new_lop = *new_lopp;
 	struct nfsstate *tstp, *mystp, *nstp;
 	int specialid = 0;
 	struct nfslockfile *lfp;
 	struct nfslock *other_lop = NULL;
 	struct nfsstate *stp, *lckstp = NULL;
 	struct nfsclient *clp = NULL;
 	u_int32_t bits;
 	int error = 0, haslock = 0, ret, reterr;
 	int getlckret, delegation = 0, filestruct_locked, vnode_unlocked = 0;
 	fhandle_t nfh;
 	uint64_t first, end;
 	uint32_t lock_flags;
 
 	if (new_stp->ls_flags & (NFSLCK_CHECK | NFSLCK_SETATTR)) {
 		/*
 		 * Note the special cases of "all 1s" or "all 0s" stateids and
 		 * let reads with all 1s go ahead.
 		 */
 		if (new_stp->ls_stateid.seqid == 0x0 &&
 		    new_stp->ls_stateid.other[0] == 0x0 &&
 		    new_stp->ls_stateid.other[1] == 0x0 &&
 		    new_stp->ls_stateid.other[2] == 0x0)
 			specialid = 1;
 		else if (new_stp->ls_stateid.seqid == 0xffffffff &&
 		    new_stp->ls_stateid.other[0] == 0xffffffff &&
 		    new_stp->ls_stateid.other[1] == 0xffffffff &&
 		    new_stp->ls_stateid.other[2] == 0xffffffff)
 			specialid = 2;
 	}
 
 	/*
 	 * Check for restart conditions (client and server).
 	 */
 	error = nfsrv_checkrestart(clientid, new_stp->ls_flags,
 	    &new_stp->ls_stateid, specialid);
 	if (error)
 		goto out;
 
 	/*
 	 * Check for state resource limit exceeded.
 	 */
 	if ((new_stp->ls_flags & NFSLCK_LOCK) &&
 	    nfsrv_openpluslock > nfsrv_v4statelimit) {
 		error = NFSERR_RESOURCE;
 		goto out;
 	}
 
 	/*
 	 * For the lock case, get another nfslock structure,
 	 * just in case we need it.
 	 * Malloc now, before we start sifting through the linked lists,
 	 * in case we have to wait for memory.
 	 */
 tryagain:
 	if (new_stp->ls_flags & NFSLCK_LOCK)
 		other_lop = malloc(sizeof (struct nfslock),
 		    M_NFSDLOCK, M_WAITOK);
 	filestruct_locked = 0;
 	reterr = 0;
 	lfp = NULL;
 
 	/*
 	 * Get the lockfile structure for CFH now, so we can do a sanity
 	 * check against the stateid, before incrementing the seqid#, since
 	 * we want to return NFSERR_BADSTATEID on failure and the seqid#
 	 * shouldn't be incremented for this case.
 	 * If nfsrv_getlockfile() returns -1, it means "not found", which
 	 * will be handled later.
 	 * If we are doing Lock/LockU and local locking is enabled, sleep
 	 * lock the nfslockfile structure.
 	 */
 	getlckret = nfsrv_getlockfh(vp, new_stp->ls_flags, NULL, &nfh, p);
 	NFSLOCKSTATE();
 	if (getlckret == 0) {
 		if ((new_stp->ls_flags & (NFSLCK_LOCK | NFSLCK_UNLOCK)) != 0 &&
 		    nfsrv_dolocallocks != 0 && nd->nd_repstat == 0) {
 			getlckret = nfsrv_getlockfile(new_stp->ls_flags, NULL,
 			    &lfp, &nfh, 1);
 			if (getlckret == 0)
 				filestruct_locked = 1;
 		} else
 			getlckret = nfsrv_getlockfile(new_stp->ls_flags, NULL,
 			    &lfp, &nfh, 0);
 	}
 	if (getlckret != 0 && getlckret != -1)
 		reterr = getlckret;
 
 	if (filestruct_locked != 0) {
 		LIST_INIT(&lfp->lf_rollback);
 		if ((new_stp->ls_flags & NFSLCK_LOCK)) {
 			/*
 			 * For local locking, do the advisory locking now, so
 			 * that any conflict can be detected. A failure later
 			 * can be rolled back locally. If an error is returned,
 			 * struct nfslockfile has been unlocked and any local
 			 * locking rolled back.
 			 */
 			NFSUNLOCKSTATE();
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl1");
 				vnode_unlocked = 1;
 				NFSVOPUNLOCK(vp);
 			}
 			reterr = nfsrv_locallock(vp, lfp,
 			    (new_lop->lo_flags & (NFSLCK_READ | NFSLCK_WRITE)),
 			    new_lop->lo_first, new_lop->lo_end, cfp, p);
 			NFSLOCKSTATE();
 		}
 	}
 
 	if (specialid == 0) {
 	    if (new_stp->ls_flags & NFSLCK_TEST) {
 		/*
 		 * RFC 3530 does not list LockT as an op that renews a
 		 * lease, but the consensus seems to be that it is ok
 		 * for a server to do so.
 		 */
 		error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 		    (nfsquad_t)((u_quad_t)0), 0, nd, p);
 
 		/*
 		 * Since NFSERR_EXPIRED, NFSERR_ADMINREVOKED are not valid
 		 * error returns for LockT, just go ahead and test for a lock,
 		 * since there are no locks for this client, but other locks
 		 * can conflict. (ie. same client will always be false)
 		 */
 		if (error == NFSERR_EXPIRED || error == NFSERR_ADMINREVOKED)
 		    error = 0;
 		lckstp = new_stp;
 	    } else {
 	      error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 		(nfsquad_t)((u_quad_t)0), 0, nd, p);
 	      if (error == 0)
 		/*
 		 * Look up the stateid
 		 */
 		error = nfsrv_getstate(clp, &new_stp->ls_stateid,
 		  new_stp->ls_flags, &stp);
 	      /*
 	       * do some sanity checks for an unconfirmed open or a
 	       * stateid that refers to the wrong file, for an open stateid
 	       */
 	      if (error == 0 && (stp->ls_flags & NFSLCK_OPEN) &&
 		  ((stp->ls_openowner->ls_flags & NFSLCK_NEEDSCONFIRM) ||
 		   (getlckret == 0 && stp->ls_lfp != lfp))){
 		      /*
 		       * NFSLCK_SETATTR should return OK rather than NFSERR_BADSTATEID
 		       * The only exception is using SETATTR with SIZE.
 		       * */
                     if ((new_stp->ls_flags &
                          (NFSLCK_SETATTR | NFSLCK_CHECK)) != NFSLCK_SETATTR)
 			     error = NFSERR_BADSTATEID;
 	      }
 	      
 		if (error == 0 &&
 		  (stp->ls_flags & (NFSLCK_DELEGREAD | NFSLCK_DELEGWRITE)) &&
 		  getlckret == 0 && stp->ls_lfp != lfp)
 			error = NFSERR_BADSTATEID;
 
 	      /*
 	       * If the lockowner stateid doesn't refer to the same file,
 	       * I believe that is considered ok, since some clients will
 	       * only create a single lockowner and use that for all locks
 	       * on all files.
 	       * For now, log it as a diagnostic, instead of considering it
 	       * a BadStateid.
 	       */
 	      if (error == 0 && (stp->ls_flags &
 		  (NFSLCK_OPEN | NFSLCK_DELEGREAD | NFSLCK_DELEGWRITE)) == 0 &&
 		  getlckret == 0 && stp->ls_lfp != lfp) {
 #ifdef DIAGNOSTIC
 		  printf("Got a lock statid for different file open\n");
 #endif
 		  /*
 		  error = NFSERR_BADSTATEID;
 		  */
 	      }
 
 	      if (error == 0) {
 		    if (new_stp->ls_flags & NFSLCK_OPENTOLOCK) {
 			/*
 			 * If haslock set, we've already checked the seqid.
 			 */
 			if (!haslock) {
 			    if (stp->ls_flags & NFSLCK_OPEN)
 				error = nfsrv_checkseqid(nd, new_stp->ls_seq,
 				    stp->ls_openowner, new_stp->ls_op);
 			    else
 				error = NFSERR_BADSTATEID;
 			}
 			if (!error)
 			    nfsrv_getowner(&stp->ls_open, new_stp, &lckstp);
 			if (lckstp) {
 			    /*
 			     * For NFSv4.1 and NFSv4.2 allow an
 			     * open_to_lock_owner when the lock_owner already
 			     * exists.  Just clear NFSLCK_OPENTOLOCK so that
 			     * a new lock_owner will not be created.
 			     * RFC7530 states that the error for NFSv4.0
 			     * is NFS4ERR_BAD_SEQID.
 			     */
 			    if ((nd->nd_flag & ND_NFSV41) != 0)
 				new_stp->ls_flags &= ~NFSLCK_OPENTOLOCK;
 			    else
 				error = NFSERR_BADSEQID;
 			} else
 			    lckstp = new_stp;
 		    } else if (new_stp->ls_flags&(NFSLCK_LOCK|NFSLCK_UNLOCK)) {
 			/*
 			 * If haslock set, ditto above.
 			 */
 			if (!haslock) {
 			    if (stp->ls_flags & NFSLCK_OPEN)
 				error = NFSERR_BADSTATEID;
 			    else
 				error = nfsrv_checkseqid(nd, new_stp->ls_seq,
 				    stp, new_stp->ls_op);
 			}
 			lckstp = stp;
 		    } else {
 			lckstp = stp;
 		    }
 	      }
 	      /*
 	       * If the seqid part of the stateid isn't the same, return
 	       * NFSERR_OLDSTATEID for cases other than I/O Ops.
 	       * For I/O Ops, only return NFSERR_OLDSTATEID if
 	       * nfsrv_returnoldstateid is set. (The consensus on the email
 	       * list was that most clients would prefer to not receive
 	       * NFSERR_OLDSTATEID for I/O Ops, but the RFC suggests that that
 	       * is what will happen, so I use the nfsrv_returnoldstateid to
 	       * allow for either server configuration.)
 	       */
 	      if (!error && stp->ls_stateid.seqid!=new_stp->ls_stateid.seqid &&
 		  (((nd->nd_flag & ND_NFSV41) == 0 &&
 		   (!(new_stp->ls_flags & NFSLCK_CHECK) ||
 		    nfsrv_returnoldstateid)) ||
 		   ((nd->nd_flag & ND_NFSV41) != 0 &&
 		    new_stp->ls_stateid.seqid != 0)))
 		    error = NFSERR_OLDSTATEID;
 	    }
 	}
 
 	/*
 	 * Now we can check for grace.
 	 */
 	if (!error)
 		error = nfsrv_checkgrace(nd, clp, new_stp->ls_flags);
 	if ((new_stp->ls_flags & NFSLCK_RECLAIM) && !error &&
 		nfsrv_checkstable(clp))
 		error = NFSERR_NOGRACE;
 	/*
 	 * If we successfully Reclaimed state, note that.
 	 */
 	if ((new_stp->ls_flags & NFSLCK_RECLAIM) && !error)
 		nfsrv_markstable(clp);
 
 	/*
 	 * At this point, either error == NFSERR_BADSTATEID or the
 	 * seqid# has been updated, so we can return any error.
 	 * If error == 0, there may be an error in:
 	 *    nd_repstat - Set by the calling function.
 	 *    reterr - Set above, if getting the nfslockfile structure
 	 *       or acquiring the local lock failed.
 	 *    (If both of these are set, nd_repstat should probably be
 	 *     returned, since that error was detected before this
 	 *     function call.)
 	 */
 	if (error != 0 || nd->nd_repstat != 0 || reterr != 0) {
 		if (error == 0) {
 			if (nd->nd_repstat != 0)
 				error = nd->nd_repstat;
 			else
 				error = reterr;
 		}
 		if (filestruct_locked != 0) {
 			/* Roll back local locks. */
 			NFSUNLOCKSTATE();
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl2");
 				vnode_unlocked = 1;
 				NFSVOPUNLOCK(vp);
 			}
 			nfsrv_locallock_rollback(vp, lfp, p);
 			NFSLOCKSTATE();
 			nfsrv_unlocklf(lfp);
 		}
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * Check the nfsrv_getlockfile return.
 	 * Returned -1 if no structure found.
 	 */
 	if (getlckret == -1) {
 		error = NFSERR_EXPIRED;
 		/*
 		 * Called from lockt, so no lock is OK.
 		 */
 		if (new_stp->ls_flags & NFSLCK_TEST) {
 			error = 0;
 		} else if (new_stp->ls_flags &
 		    (NFSLCK_CHECK | NFSLCK_SETATTR)) {
 			/*
 			 * Called to check for a lock, OK if the stateid is all
 			 * 1s or all 0s, but there should be an nfsstate
 			 * otherwise.
 			 * (ie. If there is no open, I'll assume no share
 			 *  deny bits.)
 			 */
 			if (specialid)
 				error = 0;
 			else
 				error = NFSERR_BADSTATEID;
 		}
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * For NFSLCK_CHECK and NFSLCK_LOCK, test for a share conflict.
 	 * For NFSLCK_CHECK, allow a read if write access is granted,
 	 * but check for a deny. For NFSLCK_LOCK, require correct access,
 	 * which implies a conflicting deny can't exist.
 	 */
 	if (new_stp->ls_flags & (NFSLCK_CHECK | NFSLCK_LOCK)) {
 	    /*
 	     * Four kinds of state id:
 	     * - specialid (all 0s or all 1s), only for NFSLCK_CHECK
 	     * - stateid for an open
 	     * - stateid for a delegation
 	     * - stateid for a lock owner
 	     */
 	    if (!specialid) {
 		if (stp->ls_flags & (NFSLCK_DELEGREAD | NFSLCK_DELEGWRITE)) {
 		    delegation = 1;
 		    mystp = stp;
 		    nfsrv_delaydelegtimeout(stp);
 	        } else if (stp->ls_flags & NFSLCK_OPEN) {
 		    mystp = stp;
 		} else {
 		    mystp = stp->ls_openstp;
 		}
 		/*
 		 * If locking or checking, require correct access
 		 * bit set.
 		 */
 		if (((new_stp->ls_flags & NFSLCK_LOCK) &&
 		     !((new_lop->lo_flags >> NFSLCK_LOCKSHIFT) &
 		       mystp->ls_flags & NFSLCK_ACCESSBITS)) ||
 		    ((new_stp->ls_flags & (NFSLCK_CHECK|NFSLCK_READACCESS)) ==
 		      (NFSLCK_CHECK | NFSLCK_READACCESS) &&
 		     !(mystp->ls_flags & NFSLCK_READACCESS) &&
 		     nfsrv_allowreadforwriteopen == 0) ||
 		    ((new_stp->ls_flags & (NFSLCK_CHECK|NFSLCK_WRITEACCESS)) ==
 		      (NFSLCK_CHECK | NFSLCK_WRITEACCESS) &&
 		     !(mystp->ls_flags & NFSLCK_WRITEACCESS))) {
 			if (filestruct_locked != 0) {
 				/* Roll back local locks. */
 				NFSUNLOCKSTATE();
 				if (vnode_unlocked == 0) {
 					ASSERT_VOP_ELOCKED(vp,
 					    "nfsrv_lockctrl3");
 					vnode_unlocked = 1;
 					NFSVOPUNLOCK(vp);
 				}
 				nfsrv_locallock_rollback(vp, lfp, p);
 				NFSLOCKSTATE();
 				nfsrv_unlocklf(lfp);
 			}
 			NFSUNLOCKSTATE();
 			error = NFSERR_OPENMODE;
 			goto out;
 		}
 	    } else
 		mystp = NULL;
 	    if ((new_stp->ls_flags & NFSLCK_CHECK) && !delegation) {
 		/*
 		 * Check for a conflicting deny bit.
 		 */
 		LIST_FOREACH(tstp, &lfp->lf_open, ls_file) {
 		    if (tstp != mystp) {
 			bits = tstp->ls_flags;
 			bits >>= NFSLCK_SHIFT;
 			if (new_stp->ls_flags & bits & NFSLCK_ACCESSBITS) {
 			    KASSERT(vnode_unlocked == 0,
 				("nfsrv_lockctrl: vnode unlocked1"));
 			    ret = nfsrv_clientconflict(tstp->ls_clp, &haslock,
 				vp, p);
 			    if (ret == 1) {
 				/*
 				* nfsrv_clientconflict unlocks state
 				 * when it returns non-zero.
 				 */
 				lckstp = NULL;
 				goto tryagain;
 			    }
 			    if (ret == 0)
 				NFSUNLOCKSTATE();
 			    if (ret == 2)
 				error = NFSERR_PERM;
 			    else
 				error = NFSERR_OPENMODE;
 			    goto out;
 			}
 		    }
 		}
 
 		/* We're outta here */
 		NFSUNLOCKSTATE();
 		goto out;
 	    }
 	}
 
 	/*
 	 * For setattr, just get rid of all the Delegations for other clients.
 	 */
 	if (new_stp->ls_flags & NFSLCK_SETATTR) {
 		KASSERT(vnode_unlocked == 0,
 		    ("nfsrv_lockctrl: vnode unlocked2"));
 		ret = nfsrv_cleandeleg(vp, lfp, clp, &haslock, p);
 		if (ret) {
 			/*
 			 * nfsrv_cleandeleg() unlocks state when it
 			 * returns non-zero.
 			 */
 			if (ret == -1) {
 				lckstp = NULL;
 				goto tryagain;
 			}
 			error = ret;
 			goto out;
 		}
 		if (!(new_stp->ls_flags & NFSLCK_CHECK) ||
 		    (LIST_EMPTY(&lfp->lf_open) && LIST_EMPTY(&lfp->lf_lock) &&
 		     LIST_EMPTY(&lfp->lf_deleg))) {
 			NFSUNLOCKSTATE();
 			goto out;
 		}
 	}
 
 	/*
 	 * Check for a conflicting delegation. If one is found, call
 	 * nfsrv_delegconflict() to handle it. If the v4root lock hasn't
 	 * been set yet, it will get the lock. Otherwise, it will recall
 	 * the delegation. Then, we try try again...
 	 * I currently believe the conflict algorithm to be:
 	 * For Lock Ops (Lock/LockT/LockU)
 	 * - there is a conflict iff a different client has a write delegation
 	 * For Reading (Read Op)
 	 * - there is a conflict iff a different client has a write delegation
 	 *   (the specialids are always a different client)
 	 * For Writing (Write/Setattr of size)
 	 * - there is a conflict if a different client has any delegation
 	 * - there is a conflict if the same client has a read delegation
 	 *   (I don't understand why this isn't allowed, but that seems to be
 	 *    the current consensus?)
 	 */
 	tstp = LIST_FIRST(&lfp->lf_deleg);
 	while (tstp != LIST_END(&lfp->lf_deleg)) {
 	    nstp = LIST_NEXT(tstp, ls_file);
 	    if ((((new_stp->ls_flags&(NFSLCK_LOCK|NFSLCK_UNLOCK|NFSLCK_TEST))||
 		 ((new_stp->ls_flags & NFSLCK_CHECK) &&
 		  (new_lop->lo_flags & NFSLCK_READ))) &&
 		  clp != tstp->ls_clp &&
 		 (tstp->ls_flags & NFSLCK_DELEGWRITE)) ||
 		 ((new_stp->ls_flags & NFSLCK_CHECK) &&
 		   (new_lop->lo_flags & NFSLCK_WRITE) &&
 		  (clp != tstp->ls_clp ||
 		   (tstp->ls_flags & NFSLCK_DELEGREAD)))) {
 		ret = 0;
 		if (filestruct_locked != 0) {
 			/* Roll back local locks. */
 			NFSUNLOCKSTATE();
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl4");
 				NFSVOPUNLOCK(vp);
 			}
 			nfsrv_locallock_rollback(vp, lfp, p);
 			NFSLOCKSTATE();
 			nfsrv_unlocklf(lfp);
 			NFSUNLOCKSTATE();
 			NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 			vnode_unlocked = 0;
 			if (VN_IS_DOOMED(vp))
 				ret = NFSERR_SERVERFAULT;
 			NFSLOCKSTATE();
 		}
 		if (ret == 0)
 			ret = nfsrv_delegconflict(tstp, &haslock, p, vp);
 		if (ret) {
 		    /*
 		     * nfsrv_delegconflict unlocks state when it
 		     * returns non-zero, which it always does.
 		     */
 		    if (other_lop) {
 			free(other_lop, M_NFSDLOCK);
 			other_lop = NULL;
 		    }
 		    if (ret == -1) {
 			lckstp = NULL;
 			goto tryagain;
 		    }
 		    error = ret;
 		    goto out;
 		}
 		/* Never gets here. */
 	    }
 	    tstp = nstp;
 	}
 
 	/*
 	 * Handle the unlock case by calling nfsrv_updatelock().
 	 * (Should I have done some access checking above for unlock? For now,
 	 *  just let it happen.)
 	 */
 	if (new_stp->ls_flags & NFSLCK_UNLOCK) {
 		first = new_lop->lo_first;
 		end = new_lop->lo_end;
 		nfsrv_updatelock(stp, new_lopp, &other_lop, lfp);
 		stateidp->seqid = ++(stp->ls_stateid.seqid);
 		if ((nd->nd_flag & ND_NFSV41) != 0 && stateidp->seqid == 0)
 			stateidp->seqid = stp->ls_stateid.seqid = 1;
 		stateidp->other[0] = stp->ls_stateid.other[0];
 		stateidp->other[1] = stp->ls_stateid.other[1];
 		stateidp->other[2] = stp->ls_stateid.other[2];
 		if (filestruct_locked != 0) {
 			NFSUNLOCKSTATE();
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl5");
 				vnode_unlocked = 1;
 				NFSVOPUNLOCK(vp);
 			}
 			/* Update the local locks. */
 			nfsrv_localunlock(vp, lfp, first, end, p);
 			NFSLOCKSTATE();
 			nfsrv_unlocklf(lfp);
 		}
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * Search for a conflicting lock. A lock conflicts if:
 	 * - the lock range overlaps and
 	 * - at least one lock is a write lock and
 	 * - it is not owned by the same lock owner
 	 */
 	if (!delegation) {
 	  LIST_FOREACH(lop, &lfp->lf_lock, lo_lckfile) {
 	    if (new_lop->lo_end > lop->lo_first &&
 		new_lop->lo_first < lop->lo_end &&
 		(new_lop->lo_flags == NFSLCK_WRITE ||
 		 lop->lo_flags == NFSLCK_WRITE) &&
 		lckstp != lop->lo_stp &&
 		(clp != lop->lo_stp->ls_clp ||
 		 lckstp->ls_ownerlen != lop->lo_stp->ls_ownerlen ||
 		 NFSBCMP(lckstp->ls_owner, lop->lo_stp->ls_owner,
 		    lckstp->ls_ownerlen))) {
 		if (other_lop) {
 		    free(other_lop, M_NFSDLOCK);
 		    other_lop = NULL;
 		}
 		if (vnode_unlocked != 0)
 		    ret = nfsrv_clientconflict(lop->lo_stp->ls_clp, &haslock,
 			NULL, p);
 		else
 		    ret = nfsrv_clientconflict(lop->lo_stp->ls_clp, &haslock,
 			vp, p);
 		if (ret == 1) {
 		    if (filestruct_locked != 0) {
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl6");
 				NFSVOPUNLOCK(vp);
 			}
 			/* Roll back local locks. */
 			nfsrv_locallock_rollback(vp, lfp, p);
 			NFSLOCKSTATE();
 			nfsrv_unlocklf(lfp);
 			NFSUNLOCKSTATE();
 			NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 			vnode_unlocked = 0;
 			if (VN_IS_DOOMED(vp)) {
 				error = NFSERR_SERVERFAULT;
 				goto out;
 			}
 		    }
 		    /*
 		     * nfsrv_clientconflict() unlocks state when it
 		     * returns non-zero.
 		     */
 		    lckstp = NULL;
 		    goto tryagain;
 		}
 		/*
 		 * Found a conflicting lock, so record the conflict and
 		 * return the error.
 		 */
 		if (cfp != NULL && ret == 0) {
 		    cfp->cl_clientid.lval[0]=lop->lo_stp->ls_stateid.other[0];
 		    cfp->cl_clientid.lval[1]=lop->lo_stp->ls_stateid.other[1];
 		    cfp->cl_first = lop->lo_first;
 		    cfp->cl_end = lop->lo_end;
 		    cfp->cl_flags = lop->lo_flags;
 		    cfp->cl_ownerlen = lop->lo_stp->ls_ownerlen;
 		    NFSBCOPY(lop->lo_stp->ls_owner, cfp->cl_owner,
 			cfp->cl_ownerlen);
 		}
 		if (ret == 2)
 		    error = NFSERR_PERM;
 		else if (new_stp->ls_flags & NFSLCK_RECLAIM)
 		    error = NFSERR_RECLAIMCONFLICT;
 		else if (new_stp->ls_flags & NFSLCK_CHECK)
 		    error = NFSERR_LOCKED;
 		else
 		    error = NFSERR_DENIED;
 		if (filestruct_locked != 0 && ret == 0) {
 			/* Roll back local locks. */
 			NFSUNLOCKSTATE();
 			if (vnode_unlocked == 0) {
 				ASSERT_VOP_ELOCKED(vp, "nfsrv_lockctrl7");
 				vnode_unlocked = 1;
 				NFSVOPUNLOCK(vp);
 			}
 			nfsrv_locallock_rollback(vp, lfp, p);
 			NFSLOCKSTATE();
 			nfsrv_unlocklf(lfp);
 		}
 		if (ret == 0)
 			NFSUNLOCKSTATE();
 		goto out;
 	    }
 	  }
 	}
 
 	/*
 	 * We only get here if there was no lock that conflicted.
 	 */
 	if (new_stp->ls_flags & (NFSLCK_TEST | NFSLCK_CHECK)) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * We only get here when we are creating or modifying a lock.
 	 * There are two variants:
 	 * - exist_lock_owner where lock_owner exists
 	 * - open_to_lock_owner with new lock_owner
 	 */
 	first = new_lop->lo_first;
 	end = new_lop->lo_end;
 	lock_flags = new_lop->lo_flags;
 	if (!(new_stp->ls_flags & NFSLCK_OPENTOLOCK)) {
 		nfsrv_updatelock(lckstp, new_lopp, &other_lop, lfp);
 		stateidp->seqid = ++(lckstp->ls_stateid.seqid);
 		if ((nd->nd_flag & ND_NFSV41) != 0 && stateidp->seqid == 0)
 			stateidp->seqid = lckstp->ls_stateid.seqid = 1;
 		stateidp->other[0] = lckstp->ls_stateid.other[0];
 		stateidp->other[1] = lckstp->ls_stateid.other[1];
 		stateidp->other[2] = lckstp->ls_stateid.other[2];
 	} else {
 		/*
 		 * The new open_to_lock_owner case.
 		 * Link the new nfsstate into the lists.
 		 */
 		new_stp->ls_seq = new_stp->ls_opentolockseq;
 		nfsrvd_refcache(new_stp->ls_op);
 		stateidp->seqid = new_stp->ls_stateid.seqid = 1;
 		stateidp->other[0] = new_stp->ls_stateid.other[0] =
 		    clp->lc_clientid.lval[0];
 		stateidp->other[1] = new_stp->ls_stateid.other[1] =
 		    clp->lc_clientid.lval[1];
 		stateidp->other[2] = new_stp->ls_stateid.other[2] =
 		    nfsrv_nextstateindex(clp);
 		new_stp->ls_clp = clp;
 		LIST_INIT(&new_stp->ls_lock);
 		new_stp->ls_openstp = stp;
 		new_stp->ls_lfp = lfp;
 		nfsrv_insertlock(new_lop, (struct nfslock *)new_stp, new_stp,
 		    lfp);
 		LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_stp->ls_stateid),
 		    new_stp, ls_hash);
 		LIST_INSERT_HEAD(&stp->ls_open, new_stp, ls_list);
 		*new_lopp = NULL;
 		*new_stpp = NULL;
 		NFSD_VNET(nfsstatsv1_p)->srvlockowners++;
 		nfsrv_openpluslock++;
 	}
 	if (filestruct_locked != 0) {
 		NFSUNLOCKSTATE();
 		nfsrv_locallock_commit(lfp, lock_flags, first, end);
 		NFSLOCKSTATE();
 		nfsrv_unlocklf(lfp);
 	}
 	NFSUNLOCKSTATE();
 
 out:
 	if (haslock) {
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_unlock(&nfsv4rootfs_lock, 1);
 		NFSUNLOCKV4ROOTMUTEX();
 	}
 	if (vnode_unlocked != 0) {
 		NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 		if (error == 0 && VN_IS_DOOMED(vp))
 			error = NFSERR_SERVERFAULT;
 	}
 	if (other_lop)
 		free(other_lop, M_NFSDLOCK);
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Check for state errors for Open.
  * repstat is passed back out as an error if more critical errors
  * are not detected.
  */
 int
 nfsrv_opencheck(nfsquad_t clientid, nfsv4stateid_t *stateidp,
     struct nfsstate *new_stp, vnode_t vp, struct nfsrv_descript *nd,
     NFSPROC_T *p, int repstat)
 {
 	struct nfsstate *stp, *nstp;
 	struct nfsclient *clp;
 	struct nfsstate *ownerstp;
 	struct nfslockfile *lfp, *new_lfp;
 	int error = 0, haslock = 0, ret, readonly = 0, getfhret = 0;
 
 	if ((new_stp->ls_flags & NFSLCK_SHAREBITS) == NFSLCK_READACCESS)
 		readonly = 1;
 	/*
 	 * Check for restart conditions (client and server).
 	 */
 	error = nfsrv_checkrestart(clientid, new_stp->ls_flags,
 		&new_stp->ls_stateid, 0);
 	if (error)
 		goto out;
 
 	/*
 	 * Check for state resource limit exceeded.
 	 * Technically this should be SMP protected, but the worst
 	 * case error is "out by one or two" on the count when it
 	 * returns NFSERR_RESOURCE and the limit is just a rather
 	 * arbitrary high water mark, so no harm is done.
 	 */
 	if (nfsrv_openpluslock > nfsrv_v4statelimit) {
 		error = NFSERR_RESOURCE;
 		goto out;
 	}
 
 tryagain:
 	new_lfp = malloc(sizeof (struct nfslockfile),
 	    M_NFSDLOCKFILE, M_WAITOK);
 	if (vp)
 		getfhret = nfsrv_getlockfh(vp, new_stp->ls_flags, new_lfp,
 		    NULL, p);
 	NFSLOCKSTATE();
 	/*
 	 * Get the nfsclient structure.
 	 */
 	error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 	    (nfsquad_t)((u_quad_t)0), 0, nd, p);
 
 	/*
 	 * Look up the open owner. See if it needs confirmation and
 	 * check the seq#, as required.
 	 */
 	if (!error)
 		nfsrv_getowner(&clp->lc_open, new_stp, &ownerstp);
 
 	if (!error && ownerstp) {
 		error = nfsrv_checkseqid(nd, new_stp->ls_seq, ownerstp,
 		    new_stp->ls_op);
 		/*
 		 * If the OpenOwner hasn't been confirmed, assume the
 		 * old one was a replay and this one is ok.
 		 * See: RFC3530 Sec. 14.2.18.
 		 */
 		if (error == NFSERR_BADSEQID &&
 		    (ownerstp->ls_flags & NFSLCK_NEEDSCONFIRM))
 			error = 0;
 	}
 
 	/*
 	 * Check for grace.
 	 */
 	if (!error)
 		error = nfsrv_checkgrace(nd, clp, new_stp->ls_flags);
 	if ((new_stp->ls_flags & NFSLCK_RECLAIM) && !error &&
 		nfsrv_checkstable(clp))
 		error = NFSERR_NOGRACE;
 
 	/*
 	 * If none of the above errors occurred, let repstat be
 	 * returned.
 	 */
 	if (repstat && !error)
 		error = repstat;
 	if (error) {
 		NFSUNLOCKSTATE();
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		free(new_lfp, M_NFSDLOCKFILE);
 		goto out;
 	}
 
 	/*
 	 * If vp == NULL, the file doesn't exist yet, so return ok.
 	 * (This always happens on the first pass, so haslock must be 0.)
 	 */
 	if (vp == NULL) {
 		NFSUNLOCKSTATE();
 		free(new_lfp, M_NFSDLOCKFILE);
 		goto out;
 	}
 
 	/*
 	 * Get the structure for the underlying file.
 	 */
 	if (getfhret)
 		error = getfhret;
 	else
 		error = nfsrv_getlockfile(new_stp->ls_flags, &new_lfp, &lfp,
 		    NULL, 0);
 	if (new_lfp)
 		free(new_lfp, M_NFSDLOCKFILE);
 	if (error) {
 		NFSUNLOCKSTATE();
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		goto out;
 	}
 
 	/*
 	 * Search for a conflicting open/share.
 	 */
 	if (new_stp->ls_flags & NFSLCK_DELEGCUR) {
 	    /*
 	     * For Delegate_Cur, search for the matching Delegation,
 	     * which indicates no conflict.
 	     * An old delegation should have been recovered by the
 	     * client doing a Claim_DELEGATE_Prev, so I won't let
 	     * it match and return NFSERR_EXPIRED. Should I let it
 	     * match?
 	     */
 	    LIST_FOREACH(stp, &lfp->lf_deleg, ls_file) {
 		if (!(stp->ls_flags & NFSLCK_OLDDELEG) &&
 		    (((nd->nd_flag & ND_NFSV41) != 0 &&
 		    stateidp->seqid == 0) ||
 		    stateidp->seqid == stp->ls_stateid.seqid) &&
 		    !NFSBCMP(stateidp->other, stp->ls_stateid.other,
 			  NFSX_STATEIDOTHER))
 			break;
 	    }
 	    if (stp == LIST_END(&lfp->lf_deleg) ||
 		((new_stp->ls_flags & NFSLCK_WRITEACCESS) &&
 		 (stp->ls_flags & NFSLCK_DELEGREAD))) {
 		NFSUNLOCKSTATE();
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		error = NFSERR_EXPIRED;
 		goto out;
 	    }
 	}
 
 	/*
 	 * Check for access/deny bit conflicts. I check for the same
 	 * owner as well, in case the client didn't bother.
 	 */
 	LIST_FOREACH(stp, &lfp->lf_open, ls_file) {
 		if (!(new_stp->ls_flags & NFSLCK_DELEGCUR) &&
 		    (((new_stp->ls_flags & NFSLCK_ACCESSBITS) &
 		      ((stp->ls_flags>>NFSLCK_SHIFT) & NFSLCK_ACCESSBITS))||
 		     ((stp->ls_flags & NFSLCK_ACCESSBITS) &
 		      ((new_stp->ls_flags>>NFSLCK_SHIFT)&NFSLCK_ACCESSBITS)))){
 			ret = nfsrv_clientconflict(stp->ls_clp,&haslock,vp,p);
 			if (ret == 1) {
 				/*
 				 * nfsrv_clientconflict() unlocks
 				 * state when it returns non-zero.
 				 */
 				goto tryagain;
 			}
 			if (ret == 2)
 				error = NFSERR_PERM;
 			else if (new_stp->ls_flags & NFSLCK_RECLAIM)
 				error = NFSERR_RECLAIMCONFLICT;
 			else
 				error = NFSERR_SHAREDENIED;
 			if (ret == 0)
 				NFSUNLOCKSTATE();
 			if (haslock) {
 				NFSLOCKV4ROOTMUTEX();
 				nfsv4_unlock(&nfsv4rootfs_lock, 1);
 				NFSUNLOCKV4ROOTMUTEX();
 			}
 			goto out;
 		}
 	}
 
 	/*
 	 * Check for a conflicting delegation. If one is found, call
 	 * nfsrv_delegconflict() to handle it. If the v4root lock hasn't
 	 * been set yet, it will get the lock. Otherwise, it will recall
 	 * the delegation. Then, we try try again...
 	 * (If NFSLCK_DELEGCUR is set, it has a delegation, so there
 	 *  isn't a conflict.)
 	 * I currently believe the conflict algorithm to be:
 	 * For Open with Read Access and Deny None
 	 * - there is a conflict iff a different client has a write delegation
 	 * For Open with other Write Access or any Deny except None
 	 * - there is a conflict if a different client has any delegation
 	 * - there is a conflict if the same client has a read delegation
 	 *   (The current consensus is that this last case should be
 	 *    considered a conflict since the client with a read delegation
 	 *    could have done an Open with ReadAccess and WriteDeny
 	 *    locally and then not have checked for the WriteDeny.)
 	 *    The exception is a NFSv4.1/4.2 client that has requested
 	 *    an atomic upgrade to a write delegation.
 	 * Don't check for a Reclaim, since that will be dealt with
 	 * by nfsrv_openctrl().
 	 */
 	if (!(new_stp->ls_flags &
 		(NFSLCK_DELEGPREV | NFSLCK_DELEGCUR | NFSLCK_RECLAIM))) {
 	    stp = LIST_FIRST(&lfp->lf_deleg);
 	    while (stp != LIST_END(&lfp->lf_deleg)) {
 		nstp = LIST_NEXT(stp, ls_file);
 		if ((readonly && stp->ls_clp != clp &&
 		     (stp->ls_flags & NFSLCK_DELEGWRITE) != 0) ||
 		    (!readonly && (stp->ls_clp != clp ||
 		     ((stp->ls_flags & NFSLCK_DELEGREAD) != 0 &&
 		      (new_stp->ls_flags & NFSLCK_WANTWDELEG) == 0)))) {
 			ret = nfsrv_delegconflict(stp, &haslock, p, vp);
 			if (ret) {
 			    /*
 			     * nfsrv_delegconflict() unlocks state
 			     * when it returns non-zero.
 			     */
 			    if (ret == -1)
 				goto tryagain;
 			    error = ret;
 			    goto out;
 			}
 		}
 		stp = nstp;
 	    }
 	}
 	NFSUNLOCKSTATE();
 	if (haslock) {
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_unlock(&nfsv4rootfs_lock, 1);
 		NFSUNLOCKV4ROOTMUTEX();
 	}
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Open control function to create/update open state for an open.
  */
 int
 nfsrv_openctrl(struct nfsrv_descript *nd, vnode_t vp,
     struct nfsstate **new_stpp, nfsquad_t clientid, nfsv4stateid_t *stateidp,
     nfsv4stateid_t *delegstateidp, u_int32_t *rflagsp, struct nfsexstuff *exp,
     NFSPROC_T *p, u_quad_t filerev)
 {
 	struct nfsstate *new_stp = *new_stpp;
 	struct nfsstate *stp, *nstp;
 	struct nfsstate *openstp = NULL, *new_open, *ownerstp, *new_deleg;
 	struct nfslockfile *lfp, *new_lfp;
 	struct nfsclient *clp;
 	int error = 0, haslock = 0, ret, delegate = 1, writedeleg = 1;
 	int readonly = 0, cbret = 1, getfhret = 0;
 	int gotstate = 0, len = 0;
 	u_char *clidp = NULL;
 
 	if ((new_stp->ls_flags & NFSLCK_SHAREBITS) == NFSLCK_READACCESS)
 		readonly = 1;
 	/*
 	 * Check for restart conditions (client and server).
 	 * (Paranoia, should have been detected by nfsrv_opencheck().)
 	 * If an error does show up, return NFSERR_EXPIRED, since the
 	 * the seqid# has already been incremented.
 	 */
 	error = nfsrv_checkrestart(clientid, new_stp->ls_flags,
 	    &new_stp->ls_stateid, 0);
 	if (error) {
 		printf("Nfsd: openctrl unexpected restart err=%d\n",
 		    error);
 		error = NFSERR_EXPIRED;
 		goto out;
 	}
 
 	clidp = malloc(NFSV4_OPAQUELIMIT, M_TEMP, M_WAITOK);
 tryagain:
 	new_lfp = malloc(sizeof (struct nfslockfile),
 	    M_NFSDLOCKFILE, M_WAITOK);
 	new_open = malloc(sizeof (struct nfsstate),
 	    M_NFSDSTATE, M_WAITOK);
 	new_deleg = malloc(sizeof (struct nfsstate),
 	    M_NFSDSTATE, M_WAITOK);
 	getfhret = nfsrv_getlockfh(vp, new_stp->ls_flags, new_lfp,
 	    NULL, p);
 	NFSLOCKSTATE();
 	/*
 	 * Get the client structure. Since the linked lists could be changed
 	 * by other nfsd processes if this process does a tsleep(), one of
 	 * two things must be done.
 	 * 1 - don't tsleep()
 	 * or
 	 * 2 - get the nfsv4_lock() { indicated by haslock == 1 }
 	 *     before using the lists, since this lock stops the other
 	 *     nfsd. This should only be used for rare cases, since it
 	 *     essentially single threads the nfsd.
 	 *     At this time, it is only done for cases where the stable
 	 *     storage file must be written prior to completion of state
 	 *     expiration.
 	 */
 	error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 	    (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (!error && (clp->lc_flags & LCL_NEEDSCBNULL) &&
 	    clp->lc_program) {
 		/*
 		 * This happens on the first open for a client
 		 * that supports callbacks.
 		 */
 		NFSUNLOCKSTATE();
 		/*
 		 * Although nfsrv_docallback() will sleep, clp won't
 		 * go away, since they are only removed when the
 		 * nfsv4_lock() has blocked the nfsd threads. The
 		 * fields in clp can change, but having multiple
 		 * threads do this Null callback RPC should be
 		 * harmless.
 		 */
 		cbret = nfsrv_docallback(clp, NFSV4PROC_CBNULL,
 		    NULL, 0, NULL, NULL, NULL, 0, p);
 		NFSLOCKSTATE();
 		clp->lc_flags &= ~LCL_NEEDSCBNULL;
 		if (!cbret)
 			clp->lc_flags |= LCL_CALLBACKSON;
 	}
 
 	/*
 	 * Look up the open owner. See if it needs confirmation and
 	 * check the seq#, as required.
 	 */
 	if (!error)
 		nfsrv_getowner(&clp->lc_open, new_stp, &ownerstp);
 
 	if (error) {
 		NFSUNLOCKSTATE();
 		printf("Nfsd: openctrl unexpected state err=%d\n",
 			error);
 		free(new_lfp, M_NFSDLOCKFILE);
 		free(new_open, M_NFSDSTATE);
 		free(new_deleg, M_NFSDSTATE);
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		error = NFSERR_EXPIRED;
 		goto out;
 	}
 
 	if (new_stp->ls_flags & NFSLCK_RECLAIM)
 		nfsrv_markstable(clp);
 
 	/*
 	 * Get the structure for the underlying file.
 	 */
 	if (getfhret)
 		error = getfhret;
 	else
 		error = nfsrv_getlockfile(new_stp->ls_flags, &new_lfp, &lfp,
 		    NULL, 0);
 	if (new_lfp)
 		free(new_lfp, M_NFSDLOCKFILE);
 	if (error) {
 		NFSUNLOCKSTATE();
 		printf("Nfsd openctrl unexpected getlockfile err=%d\n",
 		    error);
 		free(new_open, M_NFSDSTATE);
 		free(new_deleg, M_NFSDSTATE);
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		goto out;
 	}
 
 	/*
 	 * Search for a conflicting open/share.
 	 */
 	if (new_stp->ls_flags & NFSLCK_DELEGCUR) {
 	    /*
 	     * For Delegate_Cur, search for the matching Delegation,
 	     * which indicates no conflict.
 	     * An old delegation should have been recovered by the
 	     * client doing a Claim_DELEGATE_Prev, so I won't let
 	     * it match and return NFSERR_EXPIRED. Should I let it
 	     * match?
 	     */
 	    LIST_FOREACH(stp, &lfp->lf_deleg, ls_file) {
 		if (!(stp->ls_flags & NFSLCK_OLDDELEG) &&
 		    (((nd->nd_flag & ND_NFSV41) != 0 &&
 		    stateidp->seqid == 0) ||
 		    stateidp->seqid == stp->ls_stateid.seqid) &&
 		    !NFSBCMP(stateidp->other, stp->ls_stateid.other,
 			NFSX_STATEIDOTHER))
 			break;
 	    }
 	    if (stp == LIST_END(&lfp->lf_deleg) ||
 		((new_stp->ls_flags & NFSLCK_WRITEACCESS) &&
 		 (stp->ls_flags & NFSLCK_DELEGREAD))) {
 		NFSUNLOCKSTATE();
 		printf("Nfsd openctrl unexpected expiry\n");
 		free(new_open, M_NFSDSTATE);
 		free(new_deleg, M_NFSDSTATE);
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		error = NFSERR_EXPIRED;
 		goto out;
 	    }
 
 	    /*
 	     * Don't issue a Delegation, since one already exists and
 	     * delay delegation timeout, as required.
 	     */
 	    delegate = 0;
 	    nfsrv_delaydelegtimeout(stp);
 	}
 
 	/*
 	 * Check for access/deny bit conflicts. I also check for the
 	 * same owner, since the client might not have bothered to check.
 	 * Also, note an open for the same file and owner, if found,
 	 * which is all we do here for Delegate_Cur, since conflict
 	 * checking is already done.
 	 */
 	LIST_FOREACH(stp, &lfp->lf_open, ls_file) {
 		if (ownerstp && stp->ls_openowner == ownerstp)
 			openstp = stp;
 		if (!(new_stp->ls_flags & NFSLCK_DELEGCUR)) {
 		    /*
 		     * If another client has the file open, the only
 		     * delegation that can be issued is a Read delegation
 		     * and only if it is a Read open with Deny none.
 		     */
 		    if (clp != stp->ls_clp) {
 			if ((stp->ls_flags & NFSLCK_SHAREBITS) ==
 			    NFSLCK_READACCESS)
 			    writedeleg = 0;
 			else
 			    delegate = 0;
 		    }
 		    if(((new_stp->ls_flags & NFSLCK_ACCESSBITS) &
 		        ((stp->ls_flags>>NFSLCK_SHIFT) & NFSLCK_ACCESSBITS))||
 		       ((stp->ls_flags & NFSLCK_ACCESSBITS) &
 		        ((new_stp->ls_flags>>NFSLCK_SHIFT)&NFSLCK_ACCESSBITS))){
 			ret = nfsrv_clientconflict(stp->ls_clp,&haslock,vp,p);
 			if (ret == 1) {
 				/*
 				 * nfsrv_clientconflict() unlocks state
 				 * when it returns non-zero.
 				 */
 				free(new_open, M_NFSDSTATE);
 				free(new_deleg, M_NFSDSTATE);
 				openstp = NULL;
 				goto tryagain;
 			}
 			if (ret == 2)
 				error = NFSERR_PERM;
 			else if (new_stp->ls_flags & NFSLCK_RECLAIM)
 				error = NFSERR_RECLAIMCONFLICT;
 			else
 				error = NFSERR_SHAREDENIED;
 			if (ret == 0)
 				NFSUNLOCKSTATE();
 			if (haslock) {
 				NFSLOCKV4ROOTMUTEX();
 				nfsv4_unlock(&nfsv4rootfs_lock, 1);
 				NFSUNLOCKV4ROOTMUTEX();
 			}
 			free(new_open, M_NFSDSTATE);
 			free(new_deleg, M_NFSDSTATE);
 			printf("nfsd openctrl unexpected client cnfl\n");
 			goto out;
 		    }
 		}
 	}
 
 	/*
 	 * Check for a conflicting delegation. If one is found, call
 	 * nfsrv_delegconflict() to handle it. If the v4root lock hasn't
 	 * been set yet, it will get the lock. Otherwise, it will recall
 	 * the delegation. Then, we try try again...
 	 * (If NFSLCK_DELEGCUR is set, it has a delegation, so there
 	 *  isn't a conflict.)
 	 * I currently believe the conflict algorithm to be:
 	 * For Open with Read Access and Deny None
 	 * - there is a conflict iff a different client has a write delegation
 	 * For Open with other Write Access or any Deny except None
 	 * - there is a conflict if a different client has any delegation
 	 * - there is a conflict if the same client has a read delegation
 	 *   (The current consensus is that this last case should be
 	 *    considered a conflict since the client with a read delegation
 	 *    could have done an Open with ReadAccess and WriteDeny
 	 *    locally and then not have checked for the WriteDeny.)
 	 *    The exception is a NFSv4.1/4.2 client that has requested
 	 *    an atomic upgrade to a write delegation.
 	 */
 	if (!(new_stp->ls_flags & (NFSLCK_DELEGPREV | NFSLCK_DELEGCUR))) {
 	    stp = LIST_FIRST(&lfp->lf_deleg);
 	    while (stp != LIST_END(&lfp->lf_deleg)) {
 		nstp = LIST_NEXT(stp, ls_file);
 		if (stp->ls_clp != clp && (stp->ls_flags & NFSLCK_DELEGREAD))
 			writedeleg = 0;
 		else if (stp->ls_clp != clp ||
 		    (stp->ls_flags & NFSLCK_DELEGWRITE) != 0 ||
 		    (new_stp->ls_flags & NFSLCK_WANTWDELEG) == 0)
 			delegate = 0;
 		if ((readonly && stp->ls_clp != clp &&
 		     (stp->ls_flags & NFSLCK_DELEGWRITE) != 0) ||
 		    (!readonly && (stp->ls_clp != clp ||
 		     ((stp->ls_flags & NFSLCK_DELEGREAD) != 0 &&
 		      (new_stp->ls_flags & NFSLCK_WANTWDELEG) == 0)))) {
 		    if (new_stp->ls_flags & NFSLCK_RECLAIM) {
 			delegate = 2;
 		    } else {
 			ret = nfsrv_delegconflict(stp, &haslock, p, vp);
 			if (ret) {
 			    /*
 			     * nfsrv_delegconflict() unlocks state
 			     * when it returns non-zero.
 			     */
 			    printf("Nfsd openctrl unexpected deleg cnfl\n");
 			    free(new_open, M_NFSDSTATE);
 			    free(new_deleg, M_NFSDSTATE);
 			    if (ret == -1) {
 				openstp = NULL;
 				goto tryagain;
 			    }
 			    error = ret;
 			    goto out;
 			}
 		    }
 		}
 		stp = nstp;
 	    }
 	}
 
 	/*
 	 * We only get here if there was no open that conflicted.
 	 * If an open for the owner exists, or in the access/deny bits.
 	 * Otherwise it is a new open. If the open_owner hasn't been
 	 * confirmed, replace the open with the new one needing confirmation,
 	 * otherwise add the open.
 	 */
 	if (new_stp->ls_flags & NFSLCK_DELEGPREV) {
 	    /*
 	     * Handle NFSLCK_DELEGPREV by searching the old delegations for
 	     * a match. If found, just move the old delegation to the current
 	     * delegation list and issue open. If not found, return
 	     * NFSERR_EXPIRED.
 	     */
 	    LIST_FOREACH(stp, &clp->lc_olddeleg, ls_list) {
 		if (stp->ls_lfp == lfp) {
 		    /* Found it */
 		    if (stp->ls_clp != clp)
 			panic("olddeleg clp");
 		    LIST_REMOVE(stp, ls_list);
 		    LIST_REMOVE(stp, ls_hash);
 		    stp->ls_flags &= ~NFSLCK_OLDDELEG;
 		    stp->ls_stateid.seqid = delegstateidp->seqid = 1;
 		    stp->ls_stateid.other[0] = delegstateidp->other[0] =
 			clp->lc_clientid.lval[0];
 		    stp->ls_stateid.other[1] = delegstateidp->other[1] =
 			clp->lc_clientid.lval[1];
 		    stp->ls_stateid.other[2] = delegstateidp->other[2] =
 			nfsrv_nextstateindex(clp);
 		    stp->ls_compref = nd->nd_compref;
 		    LIST_INSERT_HEAD(&clp->lc_deleg, stp, ls_list);
 		    LIST_INSERT_HEAD(NFSSTATEHASH(clp,
 			stp->ls_stateid), stp, ls_hash);
 		    if (stp->ls_flags & NFSLCK_DELEGWRITE)
 			*rflagsp |= NFSV4OPEN_WRITEDELEGATE;
 		    else
 			*rflagsp |= NFSV4OPEN_READDELEGATE;
 		    clp->lc_delegtime = NFSD_MONOSEC +
 			nfsrv_lease + NFSRV_LEASEDELTA;
 
 		    /*
 		     * Now, do the associated open.
 		     */
 		    new_open->ls_stateid.seqid = 1;
 		    new_open->ls_stateid.other[0] = clp->lc_clientid.lval[0];
 		    new_open->ls_stateid.other[1] = clp->lc_clientid.lval[1];
 		    new_open->ls_stateid.other[2] = nfsrv_nextstateindex(clp);
 		    new_open->ls_flags = (new_stp->ls_flags&NFSLCK_DENYBITS)|
 			NFSLCK_OPEN;
 		    if (stp->ls_flags & NFSLCK_DELEGWRITE)
 			new_open->ls_flags |= (NFSLCK_READACCESS |
 			    NFSLCK_WRITEACCESS);
 		    else
 			new_open->ls_flags |= NFSLCK_READACCESS;
 		    new_open->ls_uid = new_stp->ls_uid;
 		    new_open->ls_lfp = lfp;
 		    new_open->ls_clp = clp;
 		    LIST_INIT(&new_open->ls_open);
 		    LIST_INSERT_HEAD(&lfp->lf_open, new_open, ls_file);
 		    LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_open->ls_stateid),
 			new_open, ls_hash);
 		    /*
 		     * and handle the open owner
 		     */
 		    if (ownerstp) {
 			new_open->ls_openowner = ownerstp;
 			LIST_INSERT_HEAD(&ownerstp->ls_open,new_open,ls_list);
 		    } else {
 			new_open->ls_openowner = new_stp;
 			new_stp->ls_flags = 0;
 			nfsrvd_refcache(new_stp->ls_op);
 			new_stp->ls_noopens = 0;
 			LIST_INIT(&new_stp->ls_open);
 			LIST_INSERT_HEAD(&new_stp->ls_open, new_open, ls_list);
 			LIST_INSERT_HEAD(&clp->lc_open, new_stp, ls_list);
 			*new_stpp = NULL;
 			NFSD_VNET(nfsstatsv1_p)->srvopenowners++;
 			nfsrv_openpluslock++;
 		    }
 		    openstp = new_open;
 		    new_open = NULL;
 		    NFSD_VNET(nfsstatsv1_p)->srvopens++;
 		    nfsrv_openpluslock++;
 		    break;
 		}
 	    }
 	    if (stp == LIST_END(&clp->lc_olddeleg))
 		error = NFSERR_EXPIRED;
 	} else if (new_stp->ls_flags & (NFSLCK_DELEGREAD | NFSLCK_DELEGWRITE)) {
 	    /*
 	     * Scan to see that no delegation for this client and file
 	     * doesn't already exist.
 	     * There also shouldn't yet be an Open for this file and
 	     * openowner.
 	     */
 	    LIST_FOREACH(stp, &lfp->lf_deleg, ls_file) {
 		if (stp->ls_clp == clp)
 		    break;
 	    }
 	    if (stp == LIST_END(&lfp->lf_deleg) && openstp == NULL) {
 		/*
 		 * This is the Claim_Previous case with a delegation
 		 * type != Delegate_None.
 		 */
 		/*
 		 * First, add the delegation. (Although we must issue the
 		 * delegation, we can also ask for an immediate return.)
 		 */
 		new_deleg->ls_stateid.seqid = delegstateidp->seqid = 1;
 		new_deleg->ls_stateid.other[0] = delegstateidp->other[0] =
 		    clp->lc_clientid.lval[0];
 		new_deleg->ls_stateid.other[1] = delegstateidp->other[1] =
 		    clp->lc_clientid.lval[1];
 		new_deleg->ls_stateid.other[2] = delegstateidp->other[2] =
 		    nfsrv_nextstateindex(clp);
 		if (new_stp->ls_flags & NFSLCK_DELEGWRITE) {
 		    new_deleg->ls_flags = (NFSLCK_DELEGWRITE |
 			NFSLCK_READACCESS | NFSLCK_WRITEACCESS);
 		    *rflagsp |= NFSV4OPEN_WRITEDELEGATE;
 		    nfsrv_writedelegcnt++;
 		} else {
 		    new_deleg->ls_flags = (NFSLCK_DELEGREAD |
 			NFSLCK_READACCESS);
 		    *rflagsp |= NFSV4OPEN_READDELEGATE;
 		}
 		new_deleg->ls_uid = new_stp->ls_uid;
 		new_deleg->ls_lfp = lfp;
 		new_deleg->ls_clp = clp;
 		new_deleg->ls_filerev = filerev;
 		new_deleg->ls_compref = nd->nd_compref;
 		new_deleg->ls_lastrecall = 0;
 		LIST_INSERT_HEAD(&lfp->lf_deleg, new_deleg, ls_file);
 		LIST_INSERT_HEAD(NFSSTATEHASH(clp,
 		    new_deleg->ls_stateid), new_deleg, ls_hash);
 		LIST_INSERT_HEAD(&clp->lc_deleg, new_deleg, ls_list);
 		new_deleg = NULL;
 		if (delegate == 2 || nfsrv_issuedelegs == 0 ||
 		    (clp->lc_flags & (LCL_CALLBACKSON | LCL_CBDOWN)) !=
 		     LCL_CALLBACKSON ||
 		    NFSRV_V4DELEGLIMIT(nfsrv_delegatecnt) ||
 		    !NFSVNO_DELEGOK(vp))
 		    *rflagsp |= NFSV4OPEN_RECALL;
 		NFSD_VNET(nfsstatsv1_p)->srvdelegates++;
 		nfsrv_openpluslock++;
 		nfsrv_delegatecnt++;
 
 		/*
 		 * Now, do the associated open.
 		 */
 		new_open->ls_stateid.seqid = 1;
 		new_open->ls_stateid.other[0] = clp->lc_clientid.lval[0];
 		new_open->ls_stateid.other[1] = clp->lc_clientid.lval[1];
 		new_open->ls_stateid.other[2] = nfsrv_nextstateindex(clp);
 		new_open->ls_flags = (new_stp->ls_flags & NFSLCK_DENYBITS) |
 		    NFSLCK_OPEN;
 		if (new_stp->ls_flags & NFSLCK_DELEGWRITE)
 			new_open->ls_flags |= (NFSLCK_READACCESS |
 			    NFSLCK_WRITEACCESS);
 		else
 			new_open->ls_flags |= NFSLCK_READACCESS;
 		new_open->ls_uid = new_stp->ls_uid;
 		new_open->ls_lfp = lfp;
 		new_open->ls_clp = clp;
 		LIST_INIT(&new_open->ls_open);
 		LIST_INSERT_HEAD(&lfp->lf_open, new_open, ls_file);
 		LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_open->ls_stateid),
 		   new_open, ls_hash);
 		/*
 		 * and handle the open owner
 		 */
 		if (ownerstp) {
 		    new_open->ls_openowner = ownerstp;
 		    LIST_INSERT_HEAD(&ownerstp->ls_open, new_open, ls_list);
 		} else {
 		    new_open->ls_openowner = new_stp;
 		    new_stp->ls_flags = 0;
 		    nfsrvd_refcache(new_stp->ls_op);
 		    new_stp->ls_noopens = 0;
 		    LIST_INIT(&new_stp->ls_open);
 		    LIST_INSERT_HEAD(&new_stp->ls_open, new_open, ls_list);
 		    LIST_INSERT_HEAD(&clp->lc_open, new_stp, ls_list);
 		    *new_stpp = NULL;
 		    NFSD_VNET(nfsstatsv1_p)->srvopenowners++;
 		    nfsrv_openpluslock++;
 		}
 		openstp = new_open;
 		new_open = NULL;
 		NFSD_VNET(nfsstatsv1_p)->srvopens++;
 		nfsrv_openpluslock++;
 	    } else {
 		error = NFSERR_RECLAIMCONFLICT;
 	    }
 	} else if (ownerstp) {
 		if (ownerstp->ls_flags & NFSLCK_NEEDSCONFIRM) {
 		    /* Replace the open */
 		    if (ownerstp->ls_op)
 			nfsrvd_derefcache(ownerstp->ls_op);
 		    ownerstp->ls_op = new_stp->ls_op;
 		    nfsrvd_refcache(ownerstp->ls_op);
 		    ownerstp->ls_seq = new_stp->ls_seq;
 		    *rflagsp |= NFSV4OPEN_RESULTCONFIRM;
 		    stp = LIST_FIRST(&ownerstp->ls_open);
 		    stp->ls_flags = (new_stp->ls_flags & NFSLCK_SHAREBITS) |
 			NFSLCK_OPEN;
 		    stp->ls_stateid.seqid = 1;
 		    stp->ls_uid = new_stp->ls_uid;
 		    if (lfp != stp->ls_lfp) {
 			LIST_REMOVE(stp, ls_file);
 			LIST_INSERT_HEAD(&lfp->lf_open, stp, ls_file);
 			stp->ls_lfp = lfp;
 		    }
 		    openstp = stp;
 		} else if (openstp) {
 		    openstp->ls_flags |= (new_stp->ls_flags & NFSLCK_SHAREBITS);
 		    openstp->ls_stateid.seqid++;
 		    if ((nd->nd_flag & ND_NFSV41) != 0 &&
 			openstp->ls_stateid.seqid == 0)
 			openstp->ls_stateid.seqid = 1;
 
 		    /*
 		     * This is where we can choose to issue a delegation.
 		     */
 		    nfsrv_issuedelegation(vp, clp, nd, delegate, writedeleg,
 			readonly, filerev, NFSVNO_EXRDONLY(exp), &new_deleg,
 			new_stp, lfp, rflagsp, delegstateidp);
 		} else {
 		    new_open->ls_stateid.seqid = 1;
 		    new_open->ls_stateid.other[0] = clp->lc_clientid.lval[0];
 		    new_open->ls_stateid.other[1] = clp->lc_clientid.lval[1];
 		    new_open->ls_stateid.other[2] = nfsrv_nextstateindex(clp);
 		    new_open->ls_flags = (new_stp->ls_flags & NFSLCK_SHAREBITS)|
 			NFSLCK_OPEN;
 		    new_open->ls_uid = new_stp->ls_uid;
 		    new_open->ls_openowner = ownerstp;
 		    new_open->ls_lfp = lfp;
 		    new_open->ls_clp = clp;
 		    LIST_INIT(&new_open->ls_open);
 		    LIST_INSERT_HEAD(&lfp->lf_open, new_open, ls_file);
 		    LIST_INSERT_HEAD(&ownerstp->ls_open, new_open, ls_list);
 		    LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_open->ls_stateid),
 			new_open, ls_hash);
 		    openstp = new_open;
 		    new_open = NULL;
 		    NFSD_VNET(nfsstatsv1_p)->srvopens++;
 		    nfsrv_openpluslock++;
 
 		    /*
 		     * This is where we can choose to issue a delegation.
 		     */
 		    nfsrv_issuedelegation(vp, clp, nd, delegate, writedeleg,
 			readonly, filerev, NFSVNO_EXRDONLY(exp), &new_deleg,
 			new_stp, lfp, rflagsp, delegstateidp);
 		}
 	} else {
 		/*
 		 * New owner case. Start the open_owner sequence with a
 		 * Needs confirmation (unless a reclaim) and hang the
 		 * new open off it.
 		 */
 		new_open->ls_stateid.seqid = 1;
 		new_open->ls_stateid.other[0] = clp->lc_clientid.lval[0];
 		new_open->ls_stateid.other[1] = clp->lc_clientid.lval[1];
 		new_open->ls_stateid.other[2] = nfsrv_nextstateindex(clp);
 		new_open->ls_flags = (new_stp->ls_flags & NFSLCK_SHAREBITS) |
 		    NFSLCK_OPEN;
 		new_open->ls_uid = new_stp->ls_uid;
 		LIST_INIT(&new_open->ls_open);
 		new_open->ls_openowner = new_stp;
 		new_open->ls_lfp = lfp;
 		new_open->ls_clp = clp;
 		LIST_INSERT_HEAD(&lfp->lf_open, new_open, ls_file);
 		if (new_stp->ls_flags & NFSLCK_RECLAIM) {
 			new_stp->ls_flags = 0;
 		} else if ((nd->nd_flag & ND_NFSV41) != 0) {
 		    /*
 		     * This is where we can choose to issue a delegation.
 		     */
 		    nfsrv_issuedelegation(vp, clp, nd, delegate, writedeleg,
 			readonly, filerev, NFSVNO_EXRDONLY(exp), &new_deleg,
 			new_stp, lfp, rflagsp, delegstateidp);
 		    /* NFSv4.1 never needs confirmation. */
 		    new_stp->ls_flags = 0;
 
 		    /*
 		     * Since NFSv4.1 never does an OpenConfirm, the first
 		     * open state will be acquired here.
 		     */
 		    if (!(clp->lc_flags & LCL_STAMPEDSTABLE)) {
 			clp->lc_flags |= LCL_STAMPEDSTABLE;
 			len = clp->lc_idlen;
 			NFSBCOPY(clp->lc_id, clidp, len);
 			gotstate = 1;
 		    }
 		} else {
 		    *rflagsp |= NFSV4OPEN_RESULTCONFIRM;
 		    new_stp->ls_flags = NFSLCK_NEEDSCONFIRM;
 		}
 		nfsrvd_refcache(new_stp->ls_op);
 		new_stp->ls_noopens = 0;
 		LIST_INIT(&new_stp->ls_open);
 		LIST_INSERT_HEAD(&new_stp->ls_open, new_open, ls_list);
 		LIST_INSERT_HEAD(&clp->lc_open, new_stp, ls_list);
 		LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_open->ls_stateid),
 		    new_open, ls_hash);
 		openstp = new_open;
 		new_open = NULL;
 		*new_stpp = NULL;
 		NFSD_VNET(nfsstatsv1_p)->srvopens++;
 		nfsrv_openpluslock++;
 		NFSD_VNET(nfsstatsv1_p)->srvopenowners++;
 		nfsrv_openpluslock++;
 	}
 	if (!error) {
 		stateidp->seqid = openstp->ls_stateid.seqid;
 		stateidp->other[0] = openstp->ls_stateid.other[0];
 		stateidp->other[1] = openstp->ls_stateid.other[1];
 		stateidp->other[2] = openstp->ls_stateid.other[2];
 	}
 	NFSUNLOCKSTATE();
 	if (haslock) {
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_unlock(&nfsv4rootfs_lock, 1);
 		NFSUNLOCKV4ROOTMUTEX();
 	}
 	if (new_open)
 		free(new_open, M_NFSDSTATE);
 	if (new_deleg)
 		free(new_deleg, M_NFSDSTATE);
 
 	/*
 	 * If the NFSv4.1 client just acquired its first open, write a timestamp
 	 * to the stable storage file.
 	 */
 	if (gotstate != 0) {
 		nfsrv_writestable(clidp, len, NFSNST_NEWSTATE, p);
 		nfsrv_backupstable();
 	}
 
 out:
 	free(clidp, M_TEMP);
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Open update. Does the confirm, downgrade and close.
  */
 int
 nfsrv_openupdate(vnode_t vp, struct nfsstate *new_stp, nfsquad_t clientid,
     nfsv4stateid_t *stateidp, struct nfsrv_descript *nd, NFSPROC_T *p,
     int *retwriteaccessp)
 {
 	struct nfsstate *stp;
 	struct nfsclient *clp;
 	struct nfslockfile *lfp;
 	u_int32_t bits;
 	int error = 0, gotstate = 0, len = 0;
 	u_char *clidp = NULL;
 
 	/*
 	 * Check for restart conditions (client and server).
 	 */
 	error = nfsrv_checkrestart(clientid, new_stp->ls_flags,
 	    &new_stp->ls_stateid, 0);
 	if (error)
 		goto out;
 
 	clidp = malloc(NFSV4_OPAQUELIMIT, M_TEMP, M_WAITOK);
 	NFSLOCKSTATE();
 	/*
 	 * Get the open structure via clientid and stateid.
 	 */
 	error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 	    (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (!error)
 		error = nfsrv_getstate(clp, &new_stp->ls_stateid,
 		    new_stp->ls_flags, &stp);
 
 	/*
 	 * Sanity check the open.
 	 */
 	if (!error && (!(stp->ls_flags & NFSLCK_OPEN) ||
 		(!(new_stp->ls_flags & NFSLCK_CONFIRM) &&
 		 (stp->ls_openowner->ls_flags & NFSLCK_NEEDSCONFIRM)) ||
 		((new_stp->ls_flags & NFSLCK_CONFIRM) &&
 		 (!(stp->ls_openowner->ls_flags & NFSLCK_NEEDSCONFIRM)))))
 		error = NFSERR_BADSTATEID;
 
 	if (!error)
 		error = nfsrv_checkseqid(nd, new_stp->ls_seq,
 		    stp->ls_openowner, new_stp->ls_op);
 	if (!error && stp->ls_stateid.seqid != new_stp->ls_stateid.seqid &&
 	    (((nd->nd_flag & ND_NFSV41) == 0 &&
 	      !(new_stp->ls_flags & NFSLCK_CONFIRM)) ||
 	     ((nd->nd_flag & ND_NFSV41) != 0 &&
 	      new_stp->ls_stateid.seqid != 0)))
 		error = NFSERR_OLDSTATEID;
 	if (!error && vp->v_type != VREG) {
 		if (vp->v_type == VDIR)
 			error = NFSERR_ISDIR;
 		else
 			error = NFSERR_INVAL;
 	}
 
 	if (error) {
 		/*
 		 * If a client tries to confirm an Open with a bad
 		 * seqid# and there are no byte range locks or other Opens
 		 * on the openowner, just throw it away, so the next use of the
 		 * openowner will start a fresh seq#.
 		 */
 		if (error == NFSERR_BADSEQID &&
 		    (new_stp->ls_flags & NFSLCK_CONFIRM) &&
 		    nfsrv_nootherstate(stp))
 			nfsrv_freeopenowner(stp->ls_openowner, 0, p);
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * Set the return stateid.
 	 */
 	stateidp->seqid = stp->ls_stateid.seqid + 1;
 	if ((nd->nd_flag & ND_NFSV41) != 0 && stateidp->seqid == 0)
 		stateidp->seqid = 1;
 	stateidp->other[0] = stp->ls_stateid.other[0];
 	stateidp->other[1] = stp->ls_stateid.other[1];
 	stateidp->other[2] = stp->ls_stateid.other[2];
 	/*
 	 * Now, handle the three cases.
 	 */
 	if (new_stp->ls_flags & NFSLCK_CONFIRM) {
 		/*
 		 * If the open doesn't need confirmation, it seems to me that
 		 * there is a client error, but I'll just log it and keep going?
 		 */
 		if (!(stp->ls_openowner->ls_flags & NFSLCK_NEEDSCONFIRM))
 			printf("Nfsv4d: stray open confirm\n");
 		stp->ls_openowner->ls_flags = 0;
 		stp->ls_stateid.seqid++;
 		if ((nd->nd_flag & ND_NFSV41) != 0 &&
 		    stp->ls_stateid.seqid == 0)
 			stp->ls_stateid.seqid = 1;
 		if (!(clp->lc_flags & LCL_STAMPEDSTABLE)) {
 			clp->lc_flags |= LCL_STAMPEDSTABLE;
 			len = clp->lc_idlen;
 			NFSBCOPY(clp->lc_id, clidp, len);
 			gotstate = 1;
 		}
 		NFSUNLOCKSTATE();
 	} else if (new_stp->ls_flags & NFSLCK_CLOSE) {
 		lfp = stp->ls_lfp;
 		if (retwriteaccessp != NULL) {
 			if ((stp->ls_flags & NFSLCK_WRITEACCESS) != 0)
 				*retwriteaccessp = 1;
 			else
 				*retwriteaccessp = 0;
 		}
 		if (nfsrv_dolocallocks != 0 && !LIST_EMPTY(&stp->ls_open)) {
 			/* Get the lf lock */
 			nfsrv_locklf(lfp);
 			NFSUNLOCKSTATE();
 			ASSERT_VOP_ELOCKED(vp, "nfsrv_openupdate");
 			NFSVOPUNLOCK(vp);
 			if (nfsrv_freeopen(stp, vp, 1, p) == 0) {
 				NFSLOCKSTATE();
 				nfsrv_unlocklf(lfp);
 				NFSUNLOCKSTATE();
 			}
 			NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 		} else {
 			(void) nfsrv_freeopen(stp, NULL, 0, p);
 			NFSUNLOCKSTATE();
 		}
 	} else {
 		/*
 		 * Update the share bits, making sure that the new set are a
 		 * subset of the old ones.
 		 */
 		bits = (new_stp->ls_flags & NFSLCK_SHAREBITS);
 		if (~(stp->ls_flags) & bits) {
 			NFSUNLOCKSTATE();
 			error = NFSERR_INVAL;
 			goto out;
 		}
 		stp->ls_flags = (bits | NFSLCK_OPEN);
 		stp->ls_stateid.seqid++;
 		if ((nd->nd_flag & ND_NFSV41) != 0 &&
 		    stp->ls_stateid.seqid == 0)
 			stp->ls_stateid.seqid = 1;
 		NFSUNLOCKSTATE();
 	}
 
 	/*
 	 * If the client just confirmed its first open, write a timestamp
 	 * to the stable storage file.
 	 */
 	if (gotstate != 0) {
 		nfsrv_writestable(clidp, len, NFSNST_NEWSTATE, p);
 		nfsrv_backupstable();
 	}
 
 out:
 	free(clidp, M_TEMP);
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Delegation update. Does the purge and return.
  */
 int
 nfsrv_delegupdate(struct nfsrv_descript *nd, nfsquad_t clientid,
     nfsv4stateid_t *stateidp, vnode_t vp, int op, struct ucred *cred,
     NFSPROC_T *p, int *retwriteaccessp)
 {
 	struct nfsstate *stp;
 	struct nfsclient *clp;
 	int error = 0;
 	fhandle_t fh;
 
 	/*
 	 * Do a sanity check against the file handle for DelegReturn.
 	 */
 	if (vp) {
 		error = nfsvno_getfh(vp, &fh, p);
 		if (error)
 			goto out;
 	}
 	/*
 	 * Check for restart conditions (client and server).
 	 */
 	if (op == NFSV4OP_DELEGRETURN)
 		error = nfsrv_checkrestart(clientid, NFSLCK_DELEGRETURN,
 			stateidp, 0);
 	else
 		error = nfsrv_checkrestart(clientid, NFSLCK_DELEGPURGE,
 			stateidp, 0);
 
 	NFSLOCKSTATE();
 	/*
 	 * Get the open structure via clientid and stateid.
 	 */
 	if (!error)
 	    error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 		(nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (error) {
 		if (error == NFSERR_CBPATHDOWN)
 			error = 0;
 		if (error == NFSERR_STALECLIENTID && op == NFSV4OP_DELEGRETURN)
 			error = NFSERR_STALESTATEID;
 	}
 	if (!error && op == NFSV4OP_DELEGRETURN) {
 	    error = nfsrv_getstate(clp, stateidp, NFSLCK_DELEGRETURN, &stp);
 	    if (!error && stp->ls_stateid.seqid != stateidp->seqid &&
 		((nd->nd_flag & ND_NFSV41) == 0 || stateidp->seqid != 0))
 		error = NFSERR_OLDSTATEID;
 	}
 	/*
 	 * NFSERR_EXPIRED means that the state has gone away,
 	 * so Delegations have been purged. Just return ok.
 	 */
 	if (error == NFSERR_EXPIRED && op == NFSV4OP_DELEGPURGE) {
 		NFSUNLOCKSTATE();
 		error = 0;
 		goto out;
 	}
 	if (error) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	if (op == NFSV4OP_DELEGRETURN) {
 		if (NFSBCMP((caddr_t)&fh, (caddr_t)&stp->ls_lfp->lf_fh,
 		    sizeof (fhandle_t))) {
 			NFSUNLOCKSTATE();
 			error = NFSERR_BADSTATEID;
 			goto out;
 		}
 		if (retwriteaccessp != NULL) {
 			if ((stp->ls_flags & NFSLCK_DELEGWRITE) != 0)
 				*retwriteaccessp = 1;
 			else
 				*retwriteaccessp = 0;
 		}
 		nfsrv_freedeleg(stp);
 	} else {
 		nfsrv_freedeleglist(&clp->lc_olddeleg);
 	}
 	NFSUNLOCKSTATE();
 	error = 0;
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Release lock owner.
  */
 int
 nfsrv_releaselckown(struct nfsstate *new_stp, nfsquad_t clientid,
     NFSPROC_T *p)
 {
 	struct nfsstate *stp, *nstp, *openstp, *ownstp;
 	struct nfsclient *clp;
 	int error = 0;
 
 	/*
 	 * Check for restart conditions (client and server).
 	 */
 	error = nfsrv_checkrestart(clientid, new_stp->ls_flags,
 	    &new_stp->ls_stateid, 0);
 	if (error)
 		goto out;
 
 	NFSLOCKSTATE();
 	/*
 	 * Get the lock owner by name.
 	 */
 	error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 	    (nfsquad_t)((u_quad_t)0), 0, NULL, p);
 	if (error) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 	LIST_FOREACH(ownstp, &clp->lc_open, ls_list) {
 	    LIST_FOREACH(openstp, &ownstp->ls_open, ls_list) {
 		stp = LIST_FIRST(&openstp->ls_open);
 		while (stp != LIST_END(&openstp->ls_open)) {
 		    nstp = LIST_NEXT(stp, ls_list);
 		    /*
 		     * If the owner matches, check for locks and
 		     * then free or return an error.
 		     */
 		    if (stp->ls_ownerlen == new_stp->ls_ownerlen &&
 			!NFSBCMP(stp->ls_owner, new_stp->ls_owner,
 			 stp->ls_ownerlen)){
 			if (LIST_EMPTY(&stp->ls_lock)) {
 			    nfsrv_freelockowner(stp, NULL, 0, p);
 			} else {
 			    NFSUNLOCKSTATE();
 			    error = NFSERR_LOCKSHELD;
 			    goto out;
 			}
 		    }
 		    stp = nstp;
 		}
 	    }
 	}
 	NFSUNLOCKSTATE();
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Get the file handle for a lock structure.
  */
 static int
 nfsrv_getlockfh(vnode_t vp, u_short flags, struct nfslockfile *new_lfp,
     fhandle_t *nfhp, NFSPROC_T *p)
 {
 	fhandle_t *fhp = NULL;
 	int error;
 
 	/*
 	 * For lock, use the new nfslock structure, otherwise just
 	 * a fhandle_t on the stack.
 	 */
 	if (flags & NFSLCK_OPEN) {
 		KASSERT(new_lfp != NULL, ("nfsrv_getlockfh: new_lfp NULL"));
 		fhp = &new_lfp->lf_fh;
 	} else if (nfhp) {
 		fhp = nfhp;
 	} else {
 		panic("nfsrv_getlockfh");
 	}
 	error = nfsvno_getfh(vp, fhp, p);
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Get an nfs lock structure. Allocate one, as required, and return a
  * pointer to it.
  * Returns an NFSERR_xxx upon failure or -1 to indicate no current lock.
  */
 static int
 nfsrv_getlockfile(u_short flags, struct nfslockfile **new_lfpp,
     struct nfslockfile **lfpp, fhandle_t *nfhp, int lockit)
 {
 	struct nfslockfile *lfp;
 	fhandle_t *fhp = NULL, *tfhp;
 	struct nfslockhashhead *hp;
 	struct nfslockfile *new_lfp = NULL;
 
 	/*
 	 * For lock, use the new nfslock structure, otherwise just
 	 * a fhandle_t on the stack.
 	 */
 	if (flags & NFSLCK_OPEN) {
 		new_lfp = *new_lfpp;
 		fhp = &new_lfp->lf_fh;
 	} else if (nfhp) {
 		fhp = nfhp;
 	} else {
 		panic("nfsrv_getlockfile");
 	}
 
 	hp = NFSLOCKHASH(fhp);
 	LIST_FOREACH(lfp, hp, lf_hash) {
 		tfhp = &lfp->lf_fh;
 		if (NFSVNO_CMPFH(fhp, tfhp)) {
 			if (lockit)
 				nfsrv_locklf(lfp);
 			*lfpp = lfp;
 			return (0);
 		}
 	}
 	if (!(flags & NFSLCK_OPEN))
 		return (-1);
 
 	/*
 	 * No match, so chain the new one into the list.
 	 */
 	LIST_INIT(&new_lfp->lf_open);
 	LIST_INIT(&new_lfp->lf_lock);
 	LIST_INIT(&new_lfp->lf_deleg);
 	LIST_INIT(&new_lfp->lf_locallock);
 	LIST_INIT(&new_lfp->lf_rollback);
 	new_lfp->lf_locallock_lck.nfslock_usecnt = 0;
 	new_lfp->lf_locallock_lck.nfslock_lock = 0;
 	new_lfp->lf_usecount = 0;
 	LIST_INSERT_HEAD(hp, new_lfp, lf_hash);
 	*lfpp = new_lfp;
 	*new_lfpp = NULL;
 	return (0);
 }
 
 /*
  * This function adds a nfslock lock structure to the list for the associated
  * nfsstate and nfslockfile structures. It will be inserted after the
  * entry pointed at by insert_lop.
  */
 static void
 nfsrv_insertlock(struct nfslock *new_lop, struct nfslock *insert_lop,
     struct nfsstate *stp, struct nfslockfile *lfp)
 {
 	struct nfslock *lop, *nlop;
 
 	new_lop->lo_stp = stp;
 	new_lop->lo_lfp = lfp;
 
 	if (stp != NULL) {
 		/* Insert in increasing lo_first order */
 		lop = LIST_FIRST(&lfp->lf_lock);
 		if (lop == LIST_END(&lfp->lf_lock) ||
 		    new_lop->lo_first <= lop->lo_first) {
 			LIST_INSERT_HEAD(&lfp->lf_lock, new_lop, lo_lckfile);
 		} else {
 			nlop = LIST_NEXT(lop, lo_lckfile);
 			while (nlop != LIST_END(&lfp->lf_lock) &&
 			       nlop->lo_first < new_lop->lo_first) {
 				lop = nlop;
 				nlop = LIST_NEXT(lop, lo_lckfile);
 			}
 			LIST_INSERT_AFTER(lop, new_lop, lo_lckfile);
 		}
 	} else {
 		new_lop->lo_lckfile.le_prev = NULL;	/* list not used */
 	}
 
 	/*
 	 * Insert after insert_lop, which is overloaded as stp or lfp for
 	 * an empty list.
 	 */
 	if (stp == NULL && (struct nfslockfile *)insert_lop == lfp)
 		LIST_INSERT_HEAD(&lfp->lf_locallock, new_lop, lo_lckowner);
 	else if ((struct nfsstate *)insert_lop == stp)
 		LIST_INSERT_HEAD(&stp->ls_lock, new_lop, lo_lckowner);
 	else
 		LIST_INSERT_AFTER(insert_lop, new_lop, lo_lckowner);
 	if (stp != NULL) {
 		NFSD_VNET(nfsstatsv1_p)->srvlocks++;
 		nfsrv_openpluslock++;
 	}
 }
 
 /*
  * This function updates the locking for a lock owner and given file. It
  * maintains a list of lock ranges ordered on increasing file offset that
  * are NFSLCK_READ or NFSLCK_WRITE and non-overlapping (aka POSIX style).
  * It always adds new_lop to the list and sometimes uses the one pointed
  * at by other_lopp.
  */
 static void
 nfsrv_updatelock(struct nfsstate *stp, struct nfslock **new_lopp,
     struct nfslock **other_lopp, struct nfslockfile *lfp)
 {
 	struct nfslock *new_lop = *new_lopp;
 	struct nfslock *lop, *tlop, *ilop;
 	struct nfslock *other_lop = *other_lopp;
 	int unlock = 0, myfile = 0;
 	u_int64_t tmp;
 
 	/*
 	 * Work down the list until the lock is merged.
 	 */
 	if (new_lop->lo_flags & NFSLCK_UNLOCK)
 		unlock = 1;
 	if (stp != NULL) {
 		ilop = (struct nfslock *)stp;
 		lop = LIST_FIRST(&stp->ls_lock);
 	} else {
 		ilop = (struct nfslock *)lfp;
 		lop = LIST_FIRST(&lfp->lf_locallock);
 	}
 	while (lop != NULL) {
 	    /*
 	     * Only check locks for this file that aren't before the start of
 	     * new lock's range.
 	     */
 	    if (lop->lo_lfp == lfp) {
 	      myfile = 1;
 	      if (lop->lo_end >= new_lop->lo_first) {
 		if (new_lop->lo_end < lop->lo_first) {
 			/*
 			 * If the new lock ends before the start of the
 			 * current lock's range, no merge, just insert
 			 * the new lock.
 			 */
 			break;
 		}
 		if (new_lop->lo_flags == lop->lo_flags ||
 		    (new_lop->lo_first <= lop->lo_first &&
 		     new_lop->lo_end >= lop->lo_end)) {
 			/*
 			 * This lock can be absorbed by the new lock/unlock.
 			 * This happens when it covers the entire range
 			 * of the old lock or is contiguous
 			 * with the old lock and is of the same type or an
 			 * unlock.
 			 */
 			if (lop->lo_first < new_lop->lo_first)
 				new_lop->lo_first = lop->lo_first;
 			if (lop->lo_end > new_lop->lo_end)
 				new_lop->lo_end = lop->lo_end;
 			tlop = lop;
 			lop = LIST_NEXT(lop, lo_lckowner);
 			nfsrv_freenfslock(tlop);
 			continue;
 		}
 
 		/*
 		 * All these cases are for contiguous locks that are not the
 		 * same type, so they can't be merged.
 		 */
 		if (new_lop->lo_first <= lop->lo_first) {
 			/*
 			 * This case is where the new lock overlaps with the
 			 * first part of the old lock. Move the start of the
 			 * old lock to just past the end of the new lock. The
 			 * new lock will be inserted in front of the old, since
 			 * ilop hasn't been updated. (We are done now.)
 			 */
 			lop->lo_first = new_lop->lo_end;
 			break;
 		}
 		if (new_lop->lo_end >= lop->lo_end) {
 			/*
 			 * This case is where the new lock overlaps with the
 			 * end of the old lock's range. Move the old lock's
 			 * end to just before the new lock's first and insert
 			 * the new lock after the old lock.
 			 * Might not be done yet, since the new lock could
 			 * overlap further locks with higher ranges.
 			 */
 			lop->lo_end = new_lop->lo_first;
 			ilop = lop;
 			lop = LIST_NEXT(lop, lo_lckowner);
 			continue;
 		}
 		/*
 		 * The final case is where the new lock's range is in the
 		 * middle of the current lock's and splits the current lock
 		 * up. Use *other_lopp to handle the second part of the
 		 * split old lock range. (We are done now.)
 		 * For unlock, we use new_lop as other_lop and tmp, since
 		 * other_lop and new_lop are the same for this case.
 		 * We noted the unlock case above, so we don't need
 		 * new_lop->lo_flags any longer.
 		 */
 		tmp = new_lop->lo_first;
 		if (other_lop == NULL) {
 			if (!unlock)
 				panic("nfsd srv update unlock");
 			other_lop = new_lop;
 			*new_lopp = NULL;
 		}
 		other_lop->lo_first = new_lop->lo_end;
 		other_lop->lo_end = lop->lo_end;
 		other_lop->lo_flags = lop->lo_flags;
 		other_lop->lo_stp = stp;
 		other_lop->lo_lfp = lfp;
 		lop->lo_end = tmp;
 		nfsrv_insertlock(other_lop, lop, stp, lfp);
 		*other_lopp = NULL;
 		ilop = lop;
 		break;
 	      }
 	    }
 	    ilop = lop;
 	    lop = LIST_NEXT(lop, lo_lckowner);
 	    if (myfile && (lop == NULL || lop->lo_lfp != lfp))
 		break;
 	}
 
 	/*
 	 * Insert the new lock in the list at the appropriate place.
 	 */
 	if (!unlock) {
 		nfsrv_insertlock(new_lop, ilop, stp, lfp);
 		*new_lopp = NULL;
 	}
 }
 
 /*
  * This function handles sequencing of locks, etc.
  * It returns an error that indicates what the caller should do.
  */
 static int
 nfsrv_checkseqid(struct nfsrv_descript *nd, u_int32_t seqid,
     struct nfsstate *stp, struct nfsrvcache *op)
 {
 	int error = 0;
 
 	if ((nd->nd_flag & ND_NFSV41) != 0)
 		/* NFSv4.1 ignores the open_seqid and lock_seqid. */
 		goto out;
 	if (op != nd->nd_rp)
 		panic("nfsrvstate checkseqid");
 	if (!(op->rc_flag & RC_INPROG))
 		panic("nfsrvstate not inprog");
 	if (stp->ls_op && stp->ls_op->rc_refcnt <= 0) {
 		printf("refcnt=%d\n", stp->ls_op->rc_refcnt);
 		panic("nfsrvstate op refcnt");
 	}
 
 	/* If ND_ERELOOKUP is set, the seqid has already been handled. */
 	if ((nd->nd_flag & ND_ERELOOKUP) != 0)
 		goto out;
 
 	if ((stp->ls_seq + 1) == seqid) {
 		if (stp->ls_op)
 			nfsrvd_derefcache(stp->ls_op);
 		stp->ls_op = op;
 		nfsrvd_refcache(op);
 		stp->ls_seq = seqid;
 		goto out;
 	} else if (stp->ls_seq == seqid && stp->ls_op &&
 		op->rc_xid == stp->ls_op->rc_xid &&
 		op->rc_refcnt == 0 &&
 		op->rc_reqlen == stp->ls_op->rc_reqlen &&
 		op->rc_cksum == stp->ls_op->rc_cksum) {
 		if (stp->ls_op->rc_flag & RC_INPROG) {
 			error = NFSERR_DONTREPLY;
 			goto out;
 		}
 		nd->nd_rp = stp->ls_op;
 		nd->nd_rp->rc_flag |= RC_INPROG;
 		nfsrvd_delcache(op);
 		error = NFSERR_REPLYFROMCACHE;
 		goto out;
 	}
 	error = NFSERR_BADSEQID;
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Get the client ip address for callbacks. If the strings can't be parsed,
  * just set lc_program to 0 to indicate no callbacks are possible.
  * (For cases where the address can't be parsed or is 0.0.0.0.0.0, set
  *  the address to the client's transport address. This won't be used
  *  for callbacks, but can be printed out by nfsstats for info.)
  * Return error if the xdr can't be parsed, 0 otherwise.
  */
 int
 nfsrv_getclientipaddr(struct nfsrv_descript *nd, struct nfsclient *clp)
 {
 	u_int32_t *tl;
 	u_char *cp, *cp2;
 	int i, j, maxalen = 0, minalen = 0;
 	sa_family_t af;
 #ifdef INET
 	struct sockaddr_in *rin = NULL, *sin;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *rin6 = NULL, *sin6;
 #endif
 	u_char *addr;
 	int error = 0, cantparse = 0;
 	union {
 		in_addr_t ival;
 		u_char cval[4];
 	} ip;
 	union {
 		in_port_t sval;
 		u_char cval[2];
 	} port;
 
 	/* 8 is the maximum length of the port# string. */
 	addr = malloc(INET6_ADDRSTRLEN + 8, M_TEMP, M_WAITOK);
 	clp->lc_req.nr_client = NULL;
 	clp->lc_req.nr_lock = 0;
 	af = AF_UNSPEC;
 	NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
 	i = fxdr_unsigned(int, *tl);
 	if (i >= 3 && i <= 4) {
 		error = nfsrv_mtostr(nd, addr, i);
 		if (error)
 			goto nfsmout;
 #ifdef INET
 		if (!strcmp(addr, "tcp")) {
 			clp->lc_flags |= LCL_TCPCALLBACK;
 			clp->lc_req.nr_sotype = SOCK_STREAM;
 			clp->lc_req.nr_soproto = IPPROTO_TCP;
 			af = AF_INET;
 		} else if (!strcmp(addr, "udp")) {
 			clp->lc_req.nr_sotype = SOCK_DGRAM;
 			clp->lc_req.nr_soproto = IPPROTO_UDP;
 			af = AF_INET;
 		}
 #endif
 #ifdef INET6
 		if (af == AF_UNSPEC) {
 			if (!strcmp(addr, "tcp6")) {
 				clp->lc_flags |= LCL_TCPCALLBACK;
 				clp->lc_req.nr_sotype = SOCK_STREAM;
 				clp->lc_req.nr_soproto = IPPROTO_TCP;
 				af = AF_INET6;
 			} else if (!strcmp(addr, "udp6")) {
 				clp->lc_req.nr_sotype = SOCK_DGRAM;
 				clp->lc_req.nr_soproto = IPPROTO_UDP;
 				af = AF_INET6;
 			}
 		}
 #endif
 		if (af == AF_UNSPEC) {
 			cantparse = 1;
 		}
 	} else {
 		cantparse = 1;
 		if (i > 0) {
 			error = nfsm_advance(nd, NFSM_RNDUP(i), -1);
 			if (error)
 				goto nfsmout;
 		}
 	}
 	/*
 	 * The caller has allocated clp->lc_req.nr_nam to be large enough
 	 * for either AF_INET or AF_INET6 and zeroed out the contents.
 	 * maxalen is set to the maximum length of the host IP address string
 	 * plus 8 for the maximum length of the port#.
 	 * minalen is set to the minimum length of the host IP address string
 	 * plus 4 for the minimum length of the port#.
 	 * These lengths do not include NULL termination,
 	 * so INET[6]_ADDRSTRLEN - 1 is used in the calculations.
 	 */
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		rin = (struct sockaddr_in *)clp->lc_req.nr_nam;
 		rin->sin_family = AF_INET;
 		rin->sin_len = sizeof(struct sockaddr_in);
 		maxalen = INET_ADDRSTRLEN - 1 + 8;
 		minalen = 7 + 4;
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		rin6 = (struct sockaddr_in6 *)clp->lc_req.nr_nam;
 		rin6->sin6_family = AF_INET6;
 		rin6->sin6_len = sizeof(struct sockaddr_in6);
 		maxalen = INET6_ADDRSTRLEN - 1 + 8;
 		minalen = 3 + 4;
 		break;
 #endif
 	}
 	NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
 	i = fxdr_unsigned(int, *tl);
 	if (i < 0) {
 		error = NFSERR_BADXDR;
 		goto nfsmout;
 	} else if (i == 0) {
 		cantparse = 1;
 	} else if (!cantparse && i <= maxalen && i >= minalen) {
 		error = nfsrv_mtostr(nd, addr, i);
 		if (error)
 			goto nfsmout;
 
 		/*
 		 * Parse out the address fields. We expect 6 decimal numbers
 		 * separated by '.'s for AF_INET and two decimal numbers
 		 * preceeded by '.'s for AF_INET6.
 		 */
 		cp = NULL;
 		switch (af) {
 #ifdef INET6
 		/*
 		 * For AF_INET6, first parse the host address.
 		 */
 		case AF_INET6:
 			cp = strchr(addr, '.');
 			if (cp != NULL) {
 				*cp++ = '\0';
 				if (inet_pton(af, addr, &rin6->sin6_addr) == 1)
 					i = 4;
 				else {
 					cp = NULL;
 					cantparse = 1;
 				}
 			}
 			break;
 #endif
 #ifdef INET
 		case AF_INET:
 			cp = addr;
 			i = 0;
 			break;
 #endif
 		}
 		while (cp != NULL && *cp && i < 6) {
 			cp2 = cp;
 			while (*cp2 && *cp2 != '.')
 				cp2++;
 			if (*cp2)
 				*cp2++ = '\0';
 			else if (i != 5) {
 				cantparse = 1;
 				break;
 			}
 			j = nfsrv_getipnumber(cp);
 			if (j >= 0) {
 				if (i < 4)
 					ip.cval[3 - i] = j;
 				else
 					port.cval[5 - i] = j;
 			} else {
 				cantparse = 1;
 				break;
 			}
 			cp = cp2;
 			i++;
 		}
 		if (!cantparse) {
 			/*
 			 * The host address INADDR_ANY is (mis)used to indicate
 			 * "there is no valid callback address".
 			 */
 			switch (af) {
 #ifdef INET6
 			case AF_INET6:
 				if (!IN6_ARE_ADDR_EQUAL(&rin6->sin6_addr,
 				    &in6addr_any))
 					rin6->sin6_port = htons(port.sval);
 				else
 					cantparse = 1;
 				break;
 #endif
 #ifdef INET
 			case AF_INET:
 				if (ip.ival != INADDR_ANY) {
 					rin->sin_addr.s_addr = htonl(ip.ival);
 					rin->sin_port = htons(port.sval);
 				} else {
 					cantparse = 1;
 				}
 				break;
 #endif
 			}
 		}
 	} else {
 		cantparse = 1;
 		if (i > 0) {
 			error = nfsm_advance(nd, NFSM_RNDUP(i), -1);
 			if (error)
 				goto nfsmout;
 		}
 	}
 	if (cantparse) {
 		switch (nd->nd_nam->sa_family) {
 #ifdef INET
 		case AF_INET:
 			sin = (struct sockaddr_in *)nd->nd_nam;
 			rin = (struct sockaddr_in *)clp->lc_req.nr_nam;
 			rin->sin_family = AF_INET;
 			rin->sin_len = sizeof(struct sockaddr_in);
 			rin->sin_addr.s_addr = sin->sin_addr.s_addr;
 			rin->sin_port = 0x0;
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			sin6 = (struct sockaddr_in6 *)nd->nd_nam;
 			rin6 = (struct sockaddr_in6 *)clp->lc_req.nr_nam;
 			rin6->sin6_family = AF_INET6;
 			rin6->sin6_len = sizeof(struct sockaddr_in6);
 			rin6->sin6_addr = sin6->sin6_addr;
 			rin6->sin6_port = 0x0;
 			break;
 #endif
 		}
 		clp->lc_program = 0;
 	}
 nfsmout:
 	free(addr, M_TEMP);
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Turn a string of up to three decimal digits into a number. Return -1 upon
  * error.
  */
 static int
 nfsrv_getipnumber(u_char *cp)
 {
 	int i = 0, j = 0;
 
 	while (*cp) {
 		if (j > 2 || *cp < '0' || *cp > '9')
 			return (-1);
 		i *= 10;
 		i += (*cp - '0');
 		cp++;
 		j++;
 	}
 	if (i < 256)
 		return (i);
 	return (-1);
 }
 
 /*
  * This function checks for restart conditions.
  */
 static int
 nfsrv_checkrestart(nfsquad_t clientid, u_int32_t flags,
     nfsv4stateid_t *stateidp, int specialid)
 {
 	int ret = 0;
 
 	/*
 	 * First check for a server restart. Open, LockT, ReleaseLockOwner
 	 * and DelegPurge have a clientid, the rest a stateid.
 	 */
 	if (flags &
 	    (NFSLCK_OPEN | NFSLCK_TEST | NFSLCK_RELEASE | NFSLCK_DELEGPURGE)) {
 		if (clientid.lval[0] != NFSD_VNET(nfsrvboottime)) {
 			ret = NFSERR_STALECLIENTID;
 			goto out;
 		}
 	} else if (stateidp->other[0] != NFSD_VNET(nfsrvboottime) &&
 		specialid == 0) {
 		ret = NFSERR_STALESTATEID;
 		goto out;
 	}
 
 	/*
 	 * Read, Write, Setattr and LockT can return NFSERR_GRACE and do
 	 * not use a lock/open owner seqid#, so the check can be done now.
 	 * (The others will be checked, as required, later.)
 	 */
 	if (!(flags & (NFSLCK_CHECK | NFSLCK_TEST)))
 		goto out;
 
 	NFSLOCKSTATE();
 	ret = nfsrv_checkgrace(NULL, NULL, flags);
 	NFSUNLOCKSTATE();
 
 out:
 	NFSEXITCODE(ret);
 	return (ret);
 }
 
 /*
  * Check for grace.
  */
 static int
 nfsrv_checkgrace(struct nfsrv_descript *nd, struct nfsclient *clp,
     u_int32_t flags)
 {
 	int error = 0, notreclaimed;
 	struct nfsrv_stable *sp;
 
 	if ((NFSD_VNET(nfsrv_stablefirst).nsf_flags & (NFSNSF_UPDATEDONE |
 	     NFSNSF_GRACEOVER)) == 0) {
 		/*
 		 * First, check to see if all of the clients have done a
 		 * ReclaimComplete.  If so, grace can end now.
 		 */
 		notreclaimed = 0;
 		LIST_FOREACH(sp, &NFSD_VNET(nfsrv_stablefirst).nsf_head,
 		    nst_list) {
 			if ((sp->nst_flag & NFSNST_RECLAIMED) == 0) {
 				notreclaimed = 1;
 				break;
 			}
 		}
 		if (notreclaimed == 0)
 			NFSD_VNET(nfsrv_stablefirst).nsf_flags |=
 			    (NFSNSF_GRACEOVER | NFSNSF_NEEDLOCK);
 	}
 
 	if ((NFSD_VNET(nfsrv_stablefirst).nsf_flags & NFSNSF_GRACEOVER) != 0) {
 		if (flags & NFSLCK_RECLAIM) {
 			error = NFSERR_NOGRACE;
 			goto out;
 		}
 	} else {
 		if (!(flags & NFSLCK_RECLAIM)) {
 			error = NFSERR_GRACE;
 			goto out;
 		}
 		if (nd != NULL && clp != NULL &&
 		    (nd->nd_flag & ND_NFSV41) != 0 &&
 		    (clp->lc_flags & LCL_RECLAIMCOMPLETE) != 0) {
 			error = NFSERR_NOGRACE;
 			goto out;
 		}
 
 		/*
 		 * If grace is almost over and we are still getting Reclaims,
 		 * extend grace a bit.
 		 */
 		if ((NFSD_MONOSEC + NFSRV_LEASEDELTA) >
 		    NFSD_VNET(nfsrv_stablefirst).nsf_eograce)
 			NFSD_VNET(nfsrv_stablefirst).nsf_eograce =
 				NFSD_MONOSEC + NFSRV_LEASEDELTA;
 	}
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Do a server callback.
  * The "trunc" argument is slightly overloaded and refers to different
  * boolean arguments for CBRECALL and CBLAYOUTRECALL.
  */
 static int
 nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp,
     int trunc, fhandle_t *fhp, struct nfsvattr *nap, nfsattrbit_t *attrbitp,
     int laytype, NFSPROC_T *p)
 {
 	struct mbuf *m;
 	u_int32_t *tl;
 	struct nfsrv_descript *nd;
 	struct ucred *cred;
 	int error = 0, slotpos;
 	u_int32_t callback;
 	struct nfsdsession *sep = NULL;
 	uint64_t tval;
 	bool dotls;
 
 	nd = malloc(sizeof(*nd), M_TEMP, M_WAITOK | M_ZERO);
 	cred = newnfs_getcred();
 	NFSLOCKSTATE();	/* mostly for lc_cbref++ */
 	if (clp->lc_flags & LCL_NEEDSCONFIRM) {
 		NFSUNLOCKSTATE();
 		panic("docallb");
 	}
 	clp->lc_cbref++;
 
 	/*
 	 * Fill the callback program# and version into the request
 	 * structure for newnfs_connect() to use.
 	 */
 	clp->lc_req.nr_prog = clp->lc_program;
 #ifdef notnow
 	if ((clp->lc_flags & LCL_NFSV41) != 0)
 		clp->lc_req.nr_vers = NFSV41_CBVERS;
 	else
 #endif
 		clp->lc_req.nr_vers = NFSV4_CBVERS;
 
 	/*
 	 * First, fill in some of the fields of nd and cr.
 	 */
 	nd->nd_flag = ND_NFSV4;
 	if (clp->lc_flags & LCL_GSS)
 		nd->nd_flag |= ND_KERBV;
 	if ((clp->lc_flags & LCL_NFSV41) != 0)
 		nd->nd_flag |= ND_NFSV41;
 	if ((clp->lc_flags & LCL_NFSV42) != 0)
 		nd->nd_flag |= ND_NFSV42;
 	nd->nd_repstat = 0;
 	cred->cr_uid = clp->lc_uid;
 	cred->cr_gid = clp->lc_gid;
 	callback = clp->lc_callback;
 	NFSUNLOCKSTATE();
 	cred->cr_ngroups = 1;
 
 	/*
 	 * Get the first mbuf for the request.
 	 */
 	MGET(m, M_WAITOK, MT_DATA);
 	m->m_len = 0;
 	nd->nd_mreq = nd->nd_mb = m;
 	nd->nd_bpos = mtod(m, caddr_t);
 
 	/*
 	 * and build the callback request.
 	 */
 	if (procnum == NFSV4OP_CBGETATTR) {
 		nd->nd_procnum = NFSV4PROC_CBCOMPOUND;
 		error = nfsrv_cbcallargs(nd, clp, callback, NFSV4OP_CBGETATTR,
 		    "CB Getattr", &sep, &slotpos);
 		if (error != 0) {
 			m_freem(nd->nd_mreq);
 			goto errout;
 		}
 		(void)nfsm_fhtom(NULL, nd, (u_int8_t *)fhp, NFSX_MYFH, 0);
 		(void)nfsrv_putattrbit(nd, attrbitp);
 	} else if (procnum == NFSV4OP_CBRECALL) {
 		nd->nd_procnum = NFSV4PROC_CBCOMPOUND;
 		error = nfsrv_cbcallargs(nd, clp, callback, NFSV4OP_CBRECALL,
 		    "CB Recall", &sep, &slotpos);
 		if (error != 0) {
 			m_freem(nd->nd_mreq);
 			goto errout;
 		}
 		NFSM_BUILD(tl, u_int32_t *, NFSX_UNSIGNED + NFSX_STATEID);
 		*tl++ = txdr_unsigned(stateidp->seqid);
 		NFSBCOPY((caddr_t)stateidp->other, (caddr_t)tl,
 		    NFSX_STATEIDOTHER);
 		tl += (NFSX_STATEIDOTHER / NFSX_UNSIGNED);
 		if (trunc)
 			*tl = newnfs_true;
 		else
 			*tl = newnfs_false;
 		(void)nfsm_fhtom(NULL, nd, (u_int8_t *)fhp, NFSX_MYFH, 0);
 	} else if (procnum == NFSV4OP_CBLAYOUTRECALL) {
 		NFSD_DEBUG(4, "docallback layout recall\n");
 		nd->nd_procnum = NFSV4PROC_CBCOMPOUND;
 		error = nfsrv_cbcallargs(nd, clp, callback,
 		    NFSV4OP_CBLAYOUTRECALL, "CB Reclayout", &sep, &slotpos);
 		NFSD_DEBUG(4, "aft cbcallargs=%d\n", error);
 		if (error != 0) {
 			m_freem(nd->nd_mreq);
 			goto errout;
 		}
 		NFSM_BUILD(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
 		*tl++ = txdr_unsigned(laytype);
 		*tl++ = txdr_unsigned(NFSLAYOUTIOMODE_ANY);
 		if (trunc)
 			*tl++ = newnfs_true;
 		else
 			*tl++ = newnfs_false;
 		*tl = txdr_unsigned(NFSV4LAYOUTRET_FILE);
 		(void)nfsm_fhtom(NULL, nd, (uint8_t *)fhp, NFSX_MYFH, 0);
 		NFSM_BUILD(tl, u_int32_t *, 2 * NFSX_HYPER + NFSX_STATEID);
 		tval = 0;
 		txdr_hyper(tval, tl); tl += 2;
 		tval = UINT64_MAX;
 		txdr_hyper(tval, tl); tl += 2;
 		*tl++ = txdr_unsigned(stateidp->seqid);
 		NFSBCOPY(stateidp->other, tl, NFSX_STATEIDOTHER);
 		tl += (NFSX_STATEIDOTHER / NFSX_UNSIGNED);
 		NFSD_DEBUG(4, "aft args\n");
 	} else if (procnum == NFSV4PROC_CBNULL) {
 		nd->nd_procnum = NFSV4PROC_CBNULL;
 		if ((clp->lc_flags & LCL_NFSV41) != 0) {
 			error = nfsv4_getcbsession(clp, &sep);
 			if (error != 0) {
 				m_freem(nd->nd_mreq);
 				goto errout;
 			}
 		}
 	} else {
 		error = NFSERR_SERVERFAULT;
 		m_freem(nd->nd_mreq);
 		goto errout;
 	}
 
 	/*
 	 * Call newnfs_connect(), as required, and then newnfs_request().
 	 */
 	dotls = false;
 	if ((clp->lc_flags & LCL_TLSCB) != 0)
 		dotls = true;
 	(void) newnfs_sndlock(&clp->lc_req.nr_lock);
 	if (clp->lc_req.nr_client == NULL) {
 		if ((clp->lc_flags & LCL_NFSV41) != 0) {
 			error = ECONNREFUSED;
 			if (procnum != NFSV4PROC_CBNULL)
 				nfsv4_freeslot(&sep->sess_cbsess, slotpos,
 				    true);
 			nfsrv_freesession(NULL, sep, NULL, false, NULL);
 		} else if (nd->nd_procnum == NFSV4PROC_CBNULL)
 			error = newnfs_connect(NULL, &clp->lc_req, cred,
 			    NULL, 1, dotls, &clp->lc_req.nr_client);
 		else
 			error = newnfs_connect(NULL, &clp->lc_req, cred,
 			    NULL, 3, dotls, &clp->lc_req.nr_client);
 	}
 	newnfs_sndunlock(&clp->lc_req.nr_lock);
 	NFSD_DEBUG(4, "aft sndunlock=%d\n", error);
 	if (!error) {
 		if ((nd->nd_flag & ND_NFSV41) != 0) {
 			KASSERT(sep != NULL, ("sep NULL"));
 			if (sep->sess_cbsess.nfsess_xprt != NULL)
 				error = newnfs_request(nd, NULL, clp,
 				    &clp->lc_req, NULL, NULL, cred,
 				    clp->lc_program, clp->lc_req.nr_vers, NULL,
 				    1, NULL, &sep->sess_cbsess);
 			else {
 				/*
 				 * This should probably never occur, but if a
 				 * client somehow does an RPC without a
 				 * SequenceID Op that causes a callback just
 				 * after the nfsd threads have been terminated
 				 * and restarted we could conceivably get here
 				 * without a backchannel xprt.
 				 */
 				printf("nfsrv_docallback: no xprt\n");
 				error = ECONNREFUSED;
 			}
 			NFSD_DEBUG(4, "aft newnfs_request=%d\n", error);
 			if (error != 0 && procnum != NFSV4PROC_CBNULL) {
 				/*
 				 * It is likely that the callback was never
 				 * processed by the client and, as such,
 				 * the sequence# for the session slot needs
 				 * to be backed up by one to avoid a
 				 * NFSERR_SEQMISORDERED error reply.
 				 * For the unlikely case where the callback
 				 * was processed by the client, this will
 				 * make the next callback on the slot
 				 * appear to be a retry.
 				 * Since callbacks never specify that the
 				 * reply be cached, this "apparent retry"
 				 * should not be a problem.
 				 */
 				nfsv4_freeslot(&sep->sess_cbsess, slotpos,
 				    true);
 			}
 			nfsrv_freesession(NULL, sep, NULL, false, NULL);
 		} else
 			error = newnfs_request(nd, NULL, clp, &clp->lc_req,
 			    NULL, NULL, cred, clp->lc_program,
 			    clp->lc_req.nr_vers, NULL, 1, NULL, NULL);
 	}
 errout:
 	NFSFREECRED(cred);
 
 	/*
 	 * If error is set here, the Callback path isn't working
 	 * properly, so twiddle the appropriate LCL_ flags.
 	 * (nd_repstat != 0 indicates the Callback path is working,
 	 *  but the callback failed on the client.)
 	 */
 	if (error) {
 		/*
 		 * Mark the callback pathway down, which disabled issuing
 		 * of delegations and gets Renew to return NFSERR_CBPATHDOWN.
 		 */
 		NFSLOCKSTATE();
 		clp->lc_flags |= LCL_CBDOWN;
 		NFSUNLOCKSTATE();
 	} else {
 		/*
 		 * Callback worked. If the callback path was down, disable
 		 * callbacks, so no more delegations will be issued. (This
 		 * is done on the assumption that the callback pathway is
 		 * flakey.)
 		 */
 		NFSLOCKSTATE();
 		if (clp->lc_flags & LCL_CBDOWN)
 			clp->lc_flags &= ~(LCL_CBDOWN | LCL_CALLBACKSON);
 		NFSUNLOCKSTATE();
 		if (nd->nd_repstat) {
 			error = nd->nd_repstat;
 			NFSD_DEBUG(1, "nfsrv_docallback op=%d err=%d\n",
 			    procnum, error);
 		} else if (error == 0 && procnum == NFSV4OP_CBGETATTR)
 			error = nfsv4_loadattr(nd, NULL, nap, NULL, NULL, 0,
 			    NULL, NULL, NULL, NULL, NULL, 0, NULL, NULL, NULL,
 			    p, NULL);
 		m_freem(nd->nd_mrep);
 	}
 	NFSLOCKSTATE();
 	clp->lc_cbref--;
 	if ((clp->lc_flags & LCL_WAKEUPWANTED) && clp->lc_cbref == 0) {
 		clp->lc_flags &= ~LCL_WAKEUPWANTED;
 		wakeup(clp);
 	}
 	NFSUNLOCKSTATE();
 
 	free(nd, M_TEMP);
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Set up the compound RPC for the callback.
  */
 static int
 nfsrv_cbcallargs(struct nfsrv_descript *nd, struct nfsclient *clp,
     uint32_t callback, int op, const char *optag, struct nfsdsession **sepp,
     int *slotposp)
 {
 	uint32_t *tl;
 	int error, len;
 
 	len = strlen(optag);
 	(void)nfsm_strtom(nd, optag, len);
 	NFSM_BUILD(tl, uint32_t *, 4 * NFSX_UNSIGNED);
 	if ((nd->nd_flag & ND_NFSV41) != 0) {
 		if ((nd->nd_flag & ND_NFSV42) != 0)
 			*tl++ = txdr_unsigned(NFSV42_MINORVERSION);
 		else
 			*tl++ = txdr_unsigned(NFSV41_MINORVERSION);
 		*tl++ = txdr_unsigned(callback);
 		*tl++ = txdr_unsigned(2);
 		*tl = txdr_unsigned(NFSV4OP_CBSEQUENCE);
 		error = nfsv4_setcbsequence(nd, clp, 1, sepp, slotposp);
 		if (error != 0)
 			return (error);
 		NFSM_BUILD(tl, u_int32_t *, NFSX_UNSIGNED);
 		*tl = txdr_unsigned(op);
 	} else {
 		*tl++ = txdr_unsigned(NFSV4_MINORVERSION);
 		*tl++ = txdr_unsigned(callback);
 		*tl++ = txdr_unsigned(1);
 		*tl = txdr_unsigned(op);
 	}
 	return (0);
 }
 
 /*
  * Return the next index# for a clientid. Mostly just increment and return
  * the next one, but... if the 32bit unsigned does actually wrap around,
  * it should be rebooted.
  * At an average rate of one new client per second, it will wrap around in
  * approximately 136 years. (I think the server will have been shut
  * down or rebooted before then.)
  */
 static u_int32_t
 nfsrv_nextclientindex(void)
 {
 	static u_int32_t client_index = 0;
 
 	client_index++;
 	if (client_index != 0)
 		return (client_index);
 
 	printf("%s: out of clientids\n", __func__);
 	return (client_index);
 }
 
 /*
  * Return the next index# for a stateid. Mostly just increment and return
  * the next one, but... if the 32bit unsigned does actually wrap around
  * (will a BSD server stay up that long?), find
  * new start and end values.
  */
 static u_int32_t
 nfsrv_nextstateindex(struct nfsclient *clp)
 {
 	struct nfsstate *stp;
 	int i;
 	u_int32_t canuse, min_index, max_index;
 
 	if (!(clp->lc_flags & LCL_INDEXNOTOK)) {
 		clp->lc_stateindex++;
 		if (clp->lc_stateindex != clp->lc_statemaxindex)
 			return (clp->lc_stateindex);
 	}
 
 	/*
 	 * Yuck, we've hit the end.
 	 * Look for a new min and max.
 	 */
 	min_index = 0;
 	max_index = 0xffffffff;
 	for (i = 0; i < nfsrv_statehashsize; i++) {
 	    LIST_FOREACH(stp, &clp->lc_stateid[i], ls_hash) {
 		if (stp->ls_stateid.other[2] > 0x80000000) {
 		    if (stp->ls_stateid.other[2] < max_index)
 			max_index = stp->ls_stateid.other[2];
 		} else {
 		    if (stp->ls_stateid.other[2] > min_index)
 			min_index = stp->ls_stateid.other[2];
 		}
 	    }
 	}
 
 	/*
 	 * Yikes, highly unlikely, but I'll handle it anyhow.
 	 */
 	if (min_index == 0x80000000 && max_index == 0x80000001) {
 	    canuse = 0;
 	    /*
 	     * Loop around until we find an unused entry. Return that
 	     * and set LCL_INDEXNOTOK, so the search will continue next time.
 	     * (This is one of those rare cases where a goto is the
 	     *  cleanest way to code the loop.)
 	     */
 tryagain:
 	    for (i = 0; i < nfsrv_statehashsize; i++) {
 		LIST_FOREACH(stp, &clp->lc_stateid[i], ls_hash) {
 		    if (stp->ls_stateid.other[2] == canuse) {
 			canuse++;
 			goto tryagain;
 		    }
 		}
 	    }
 	    clp->lc_flags |= LCL_INDEXNOTOK;
 	    return (canuse);
 	}
 
 	/*
 	 * Ok to start again from min + 1.
 	 */
 	clp->lc_stateindex = min_index + 1;
 	clp->lc_statemaxindex = max_index;
 	clp->lc_flags &= ~LCL_INDEXNOTOK;
 	return (clp->lc_stateindex);
 }
 
 /*
  * The following functions handle the stable storage file that deals with
  * the edge conditions described in RFC3530 Sec. 8.6.3.
  * The file is as follows:
  * - a single record at the beginning that has the lease time of the
  *   previous server instance (before the last reboot) and the nfsrvboottime
  *   values for the previous server boots.
  *   These previous boot times are used to ensure that the current
  *   nfsrvboottime does not, somehow, get set to a previous one.
  *   (This is important so that Stale ClientIDs and StateIDs can
  *    be recognized.)
  *   The number of previous nfsvrboottime values precedes the list.
  * - followed by some number of appended records with:
  *   - client id string
  *   - flag that indicates it is a record revoking state via lease
  *     expiration or similar
  *     OR has successfully acquired state.
  * These structures vary in length, with the client string at the end, up
  * to NFSV4_OPAQUELIMIT in size.
  *
  * At the end of the grace period, the file is truncated, the first
  * record is rewritten with updated information and any acquired state
  * records for successful reclaims of state are written.
  *
  * Subsequent records are appended when the first state is issued to
  * a client and when state is revoked for a client.
  *
  * When reading the file in, state issued records that come later in
  * the file override older ones, since the append log is in cronological order.
  * If, for some reason, the file can't be read, the grace period is
  * immediately terminated and all reclaims get NFSERR_NOGRACE.
  */
 
 /*
  * Read in the stable storage file. Called by nfssvc() before the nfsd
  * processes start servicing requests.
  */
 void
 nfsrv_setupstable(NFSPROC_T *p)
 {
 	struct nfsrv_stablefirst *sf = &NFSD_VNET(nfsrv_stablefirst);
 	struct nfsrv_stable *sp, *nsp;
 	struct nfst_rec *tsp;
 	int error, i, tryagain;
 	off_t off = 0;
 	ssize_t aresid, len;
 
 	/*
 	 * If NFSNSF_UPDATEDONE is set, this is a restart of the nfsds without
 	 * a reboot, so state has not been lost.
 	 */
 	if (sf->nsf_flags & NFSNSF_UPDATEDONE)
 		return;
 	/*
 	 * Set Grace over just until the file reads successfully.
 	 */
 	NFSD_VNET(nfsrvboottime) = time_second;
 	LIST_INIT(&sf->nsf_head);
 	sf->nsf_flags = (NFSNSF_GRACEOVER | NFSNSF_NEEDLOCK);
 	sf->nsf_eograce = NFSD_MONOSEC + NFSRV_LEASEDELTA;
 	if (sf->nsf_fp == NULL)
 		return;
 	error = NFSD_RDWR(UIO_READ, NFSFPVNODE(sf->nsf_fp),
 	    (caddr_t)&sf->nsf_rec, sizeof (struct nfsf_rec), off, UIO_SYSSPACE,
 	    0, NFSFPCRED(sf->nsf_fp), &aresid, p);
 	if (error || aresid || sf->nsf_numboots == 0 ||
 		sf->nsf_numboots > NFSNSF_MAXNUMBOOTS)
 		return;
 
 	/*
 	 * Now, read in the boottimes.
 	 */
 	sf->nsf_bootvals = (time_t *)malloc((sf->nsf_numboots + 1) *
 		sizeof(time_t), M_TEMP, M_WAITOK);
 	off = sizeof (struct nfsf_rec);
 	error = NFSD_RDWR(UIO_READ, NFSFPVNODE(sf->nsf_fp),
 	    (caddr_t)sf->nsf_bootvals, sf->nsf_numboots * sizeof (time_t), off,
 	    UIO_SYSSPACE, 0, NFSFPCRED(sf->nsf_fp), &aresid, p);
 	if (error || aresid) {
 		free(sf->nsf_bootvals, M_TEMP);
 		sf->nsf_bootvals = NULL;
 		return;
 	}
 
 	/*
 	 * Make sure this nfsrvboottime is different from all recorded
 	 * previous ones.
 	 */
 	do {
 		tryagain = 0;
 		for (i = 0; i < sf->nsf_numboots; i++) {
 			if (NFSD_VNET(nfsrvboottime) == sf->nsf_bootvals[i]) {
 				NFSD_VNET(nfsrvboottime)++;
 				tryagain = 1;
 				break;
 			}
 		}
 	} while (tryagain);
 
 	sf->nsf_flags |= NFSNSF_OK;
 	off += (sf->nsf_numboots * sizeof (time_t));
 
 	/*
 	 * Read through the file, building a list of records for grace
 	 * checking.
 	 * Each record is between sizeof (struct nfst_rec) and
 	 * sizeof (struct nfst_rec) + NFSV4_OPAQUELIMIT - 1
 	 * and is actually sizeof (struct nfst_rec) + nst_len - 1.
 	 */
 	tsp = (struct nfst_rec *)malloc(sizeof (struct nfst_rec) +
 		NFSV4_OPAQUELIMIT - 1, M_TEMP, M_WAITOK);
 	do {
 	    error = NFSD_RDWR(UIO_READ, NFSFPVNODE(sf->nsf_fp),
 	        (caddr_t)tsp, sizeof (struct nfst_rec) + NFSV4_OPAQUELIMIT - 1,
 	        off, UIO_SYSSPACE, 0, NFSFPCRED(sf->nsf_fp), &aresid, p);
 	    len = (sizeof (struct nfst_rec) + NFSV4_OPAQUELIMIT - 1) - aresid;
 	    if (error || (len > 0 && (len < sizeof (struct nfst_rec) ||
 		len < (sizeof (struct nfst_rec) + tsp->len - 1)))) {
 		/*
 		 * Yuck, the file has been corrupted, so just return
 		 * after clearing out any restart state, so the grace period
 		 * is over.
 		 */
 		LIST_FOREACH_SAFE(sp, &sf->nsf_head, nst_list, nsp) {
 			LIST_REMOVE(sp, nst_list);
 			free(sp, M_TEMP);
 		}
 		free(tsp, M_TEMP);
 		sf->nsf_flags &= ~NFSNSF_OK;
 		free(sf->nsf_bootvals, M_TEMP);
 		sf->nsf_bootvals = NULL;
 		return;
 	    }
 	    if (len > 0) {
 		off += sizeof (struct nfst_rec) + tsp->len - 1;
 		/*
 		 * Search the list for a matching client.
 		 */
 		LIST_FOREACH(sp, &sf->nsf_head, nst_list) {
 			if (tsp->len == sp->nst_len &&
 			    !NFSBCMP(tsp->client, sp->nst_client, tsp->len))
 				break;
 		}
 		if (sp == LIST_END(&sf->nsf_head)) {
 			sp = (struct nfsrv_stable *)malloc(tsp->len +
 				sizeof (struct nfsrv_stable) - 1, M_TEMP,
 				M_WAITOK);
 			NFSBCOPY((caddr_t)tsp, (caddr_t)&sp->nst_rec,
 				sizeof (struct nfst_rec) + tsp->len - 1);
 			LIST_INSERT_HEAD(&sf->nsf_head, sp, nst_list);
 		} else {
 			if (tsp->flag == NFSNST_REVOKE)
 				sp->nst_flag |= NFSNST_REVOKE;
 			else
 				/*
 				 * A subsequent timestamp indicates the client
 				 * did a setclientid/confirm and any previous
 				 * revoke is no longer relevant.
 				 */
 				sp->nst_flag &= ~NFSNST_REVOKE;
 		}
 	    }
 	} while (len > 0);
 	free(tsp, M_TEMP);
 	sf->nsf_flags = NFSNSF_OK;
 	sf->nsf_eograce = NFSD_MONOSEC + sf->nsf_lease +
 		NFSRV_LEASEDELTA;
 }
 
 /*
  * Update the stable storage file, now that the grace period is over.
  */
 void
 nfsrv_updatestable(NFSPROC_T *p)
 {
 	struct nfsrv_stablefirst *sf = &NFSD_VNET(nfsrv_stablefirst);
 	struct nfsrv_stable *sp, *nsp;
 	int i;
 	struct nfsvattr nva;
 	vnode_t vp;
 #if defined(__FreeBSD_version) && (__FreeBSD_version >= 500000)
 	mount_t mp = NULL;
 #endif
 	int error;
 
 	if (sf->nsf_fp == NULL || (sf->nsf_flags & NFSNSF_UPDATEDONE))
 		return;
 	sf->nsf_flags |= NFSNSF_UPDATEDONE;
 	/*
 	 * Ok, we need to rewrite the stable storage file.
 	 * - truncate to 0 length
 	 * - write the new first structure
 	 * - loop through the data structures, writing out any that
 	 *   have timestamps older than the old boot
 	 */
 	if (sf->nsf_bootvals) {
 		sf->nsf_numboots++;
 		for (i = sf->nsf_numboots - 2; i >= 0; i--)
 			sf->nsf_bootvals[i + 1] = sf->nsf_bootvals[i];
 	} else {
 		sf->nsf_numboots = 1;
 		sf->nsf_bootvals = (time_t *)malloc(sizeof(time_t),
 			M_TEMP, M_WAITOK);
 	}
 	sf->nsf_bootvals[0] = NFSD_VNET(nfsrvboottime);
 	sf->nsf_lease = nfsrv_lease;
 	NFSVNO_ATTRINIT(&nva);
 	NFSVNO_SETATTRVAL(&nva, size, 0);
 	vp = NFSFPVNODE(sf->nsf_fp);
 	vn_start_write(vp, &mp, V_WAIT);
 	if (NFSVOPLOCK(vp, LK_EXCLUSIVE) == 0) {
 		error = nfsvno_setattr(vp, &nva, NFSFPCRED(sf->nsf_fp), p,
 		    NULL);
 		NFSVOPUNLOCK(vp);
 	} else
 		error = EPERM;
 	vn_finished_write(mp);
 	if (!error)
 	    error = NFSD_RDWR(UIO_WRITE, vp,
 		(caddr_t)&sf->nsf_rec, sizeof (struct nfsf_rec), (off_t)0,
 		UIO_SYSSPACE, IO_SYNC, NFSFPCRED(sf->nsf_fp), NULL, p);
 	if (!error)
 	    error = NFSD_RDWR(UIO_WRITE, vp,
 		(caddr_t)sf->nsf_bootvals,
 		sf->nsf_numboots * sizeof (time_t),
 		(off_t)(sizeof (struct nfsf_rec)),
 		UIO_SYSSPACE, IO_SYNC, NFSFPCRED(sf->nsf_fp), NULL, p);
 	free(sf->nsf_bootvals, M_TEMP);
 	sf->nsf_bootvals = NULL;
 	if (error) {
 		sf->nsf_flags &= ~NFSNSF_OK;
 		printf("EEK! Can't write NfsV4 stable storage file\n");
 		return;
 	}
 	sf->nsf_flags |= NFSNSF_OK;
 
 	/*
 	 * Loop through the list and write out timestamp records for
 	 * any clients that successfully reclaimed state.
 	 */
 	LIST_FOREACH_SAFE(sp, &sf->nsf_head, nst_list, nsp) {
 		if (sp->nst_flag & NFSNST_GOTSTATE) {
 			nfsrv_writestable(sp->nst_client, sp->nst_len,
 				NFSNST_NEWSTATE, p);
 			sp->nst_clp->lc_flags |= LCL_STAMPEDSTABLE;
 		}
 		LIST_REMOVE(sp, nst_list);
 		free(sp, M_TEMP);
 	}
 	nfsrv_backupstable();
 }
 
 /*
  * Append a record to the stable storage file.
  */
 void
 nfsrv_writestable(u_char *client, int len, int flag, NFSPROC_T *p)
 {
 	struct nfsrv_stablefirst *sf = &NFSD_VNET(nfsrv_stablefirst);
 	struct nfst_rec *sp;
 	int error;
 
 	if (!(sf->nsf_flags & NFSNSF_OK) || sf->nsf_fp == NULL)
 		return;
 	sp = (struct nfst_rec *)malloc(sizeof (struct nfst_rec) +
 		len - 1, M_TEMP, M_WAITOK);
 	sp->len = len;
 	NFSBCOPY(client, sp->client, len);
 	sp->flag = flag;
 	error = NFSD_RDWR(UIO_WRITE, NFSFPVNODE(sf->nsf_fp),
 	    (caddr_t)sp, sizeof (struct nfst_rec) + len - 1, (off_t)0,
 	    UIO_SYSSPACE, (IO_SYNC | IO_APPEND), NFSFPCRED(sf->nsf_fp), NULL, p);
 	free(sp, M_TEMP);
 	if (error) {
 		sf->nsf_flags &= ~NFSNSF_OK;
 		printf("EEK! Can't write NfsV4 stable storage file\n");
 	}
 }
 
 /*
  * This function is called during the grace period to mark a client
  * that successfully reclaimed state.
  */
 static void
 nfsrv_markstable(struct nfsclient *clp)
 {
 	struct nfsrv_stable *sp;
 
 	/*
 	 * First find the client structure.
 	 */
 	LIST_FOREACH(sp, &NFSD_VNET(nfsrv_stablefirst).nsf_head, nst_list) {
 		if (sp->nst_len == clp->lc_idlen &&
 		    !NFSBCMP(sp->nst_client, clp->lc_id, sp->nst_len))
 			break;
 	}
 	if (sp == LIST_END(&NFSD_VNET(nfsrv_stablefirst).nsf_head))
 		return;
 
 	/*
 	 * Now, just mark it and set the nfsclient back pointer.
 	 */
 	sp->nst_flag |= NFSNST_GOTSTATE;
 	sp->nst_clp = clp;
 }
 
 /*
  * This function is called when a NFSv4.1 client does a ReclaimComplete.
  * Very similar to nfsrv_markstable(), except for the flag being set.
  */
 static void
 nfsrv_markreclaim(struct nfsclient *clp)
 {
 	struct nfsrv_stable *sp;
 
 	/*
 	 * First find the client structure.
 	 */
 	LIST_FOREACH(sp, &NFSD_VNET(nfsrv_stablefirst).nsf_head, nst_list) {
 		if (sp->nst_len == clp->lc_idlen &&
 		    !NFSBCMP(sp->nst_client, clp->lc_id, sp->nst_len))
 			break;
 	}
 	if (sp == LIST_END(&NFSD_VNET(nfsrv_stablefirst).nsf_head))
 		return;
 
 	/*
 	 * Now, just set the flag.
 	 */
 	sp->nst_flag |= NFSNST_RECLAIMED;
 
 	/*
 	 * Free up any old delegations.
 	 */
 	nfsrv_freedeleglist(&clp->lc_olddeleg);
 }
 
 /*
  * This function is called for a reclaim, to see if it gets grace.
  * It returns 0 if a reclaim is allowed, 1 otherwise.
  */
 static int
 nfsrv_checkstable(struct nfsclient *clp)
 {
 	struct nfsrv_stable *sp;
 
 	/*
 	 * First, find the entry for the client.
 	 */
 	LIST_FOREACH(sp, &NFSD_VNET(nfsrv_stablefirst).nsf_head, nst_list) {
 		if (sp->nst_len == clp->lc_idlen &&
 		    !NFSBCMP(sp->nst_client, clp->lc_id, sp->nst_len))
 			break;
 	}
 
 	/*
 	 * If not in the list, state was revoked or no state was issued
 	 * since the previous reboot, a reclaim is denied.
 	 */
 	if (sp == LIST_END(&NFSD_VNET(nfsrv_stablefirst).nsf_head) ||
 	    (sp->nst_flag & NFSNST_REVOKE) ||
 	    !(NFSD_VNET(nfsrv_stablefirst).nsf_flags & NFSNSF_OK))
 		return (1);
 	return (0);
 }
 
 /*
  * Test for and try to clear out a conflicting client. This is called by
  * nfsrv_lockctrl() and nfsrv_openctrl() when conflicts with other clients
  * a found.
  * The trick here is that it can't revoke a conflicting client with an
  * expired lease unless it holds the v4root lock, so...
  * If no v4root lock, get the lock and return 1 to indicate "try again".
  * Return 0 to indicate the conflict can't be revoked and 1 to indicate
  * the revocation worked and the conflicting client is "bye, bye", so it
  * can be tried again.
  * Return 2 to indicate that the vnode is VIRF_DOOMED after NFSVOPLOCK().
  * Unlocks State before a non-zero value is returned.
  */
 static int
 nfsrv_clientconflict(struct nfsclient *clp, int *haslockp, vnode_t vp,
     NFSPROC_T *p)
 {
 	int gotlock, lktype = 0;
 
 	/*
 	 * If lease hasn't expired, we can't fix it.
 	 */
 	if (clp->lc_expiry >= NFSD_MONOSEC ||
 	    !(NFSD_VNET(nfsrv_stablefirst).nsf_flags & NFSNSF_UPDATEDONE))
 		return (0);
 	if (*haslockp == 0) {
 		NFSUNLOCKSTATE();
 		if (vp != NULL) {
 			lktype = NFSVOPISLOCKED(vp);
 			NFSVOPUNLOCK(vp);
 		}
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_relref(&nfsv4rootfs_lock);
 		do {
 			gotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
 			    NFSV4ROOTLOCKMUTEXPTR, NULL);
 		} while (!gotlock);
 		NFSUNLOCKV4ROOTMUTEX();
 		*haslockp = 1;
 		if (vp != NULL) {
 			NFSVOPLOCK(vp, lktype | LK_RETRY);
 			if (VN_IS_DOOMED(vp))
 				return (2);
 		}
 		return (1);
 	}
 	NFSUNLOCKSTATE();
 
 	/*
 	 * Ok, we can expire the conflicting client.
 	 */
 	nfsrv_writestable(clp->lc_id, clp->lc_idlen, NFSNST_REVOKE, p);
 	nfsrv_backupstable();
 	nfsrv_cleanclient(clp, p, false, NULL);
 	nfsrv_freedeleglist(&clp->lc_deleg);
 	nfsrv_freedeleglist(&clp->lc_olddeleg);
 	LIST_REMOVE(clp, lc_hash);
 	nfsrv_zapclient(clp, p);
 	return (1);
 }
 
 /*
  * Resolve a delegation conflict.
  * Returns 0 to indicate the conflict was resolved without sleeping.
  * Return -1 to indicate that the caller should check for conflicts again.
  * Return > 0 for an error that should be returned, normally NFSERR_DELAY.
  *
  * Also, manipulate the nfsv4root_lock, as required. It isn't changed
  * for a return of 0, since there was no sleep and it could be required
  * later. It is released for a return of NFSERR_DELAY, since the caller
  * will return that error. It is released when a sleep was done waiting
  * for the delegation to be returned or expire (so that other nfsds can
  * handle ops). Then, it must be acquired for the write to stable storage.
  * (This function is somewhat similar to nfsrv_clientconflict(), but
  *  the semantics differ in a couple of subtle ways. The return of 0
  *  indicates the conflict was resolved without sleeping here, not
  *  that the conflict can't be resolved and the handling of nfsv4root_lock
  *  differs, as noted above.)
  * Unlocks State before returning a non-zero value.
  */
 static int
 nfsrv_delegconflict(struct nfsstate *stp, int *haslockp, NFSPROC_T *p,
     vnode_t vp)
 {
 	struct nfsclient *clp = stp->ls_clp;
 	int gotlock, error, lktype = 0, retrycnt, zapped_clp;
 	nfsv4stateid_t tstateid;
 	fhandle_t tfh;
 
 	/*
 	 * If the conflict is with an old delegation...
 	 */
 	if (stp->ls_flags & NFSLCK_OLDDELEG) {
 		/*
 		 * You can delete it, if it has expired.
 		 */
 		if (clp->lc_delegtime < NFSD_MONOSEC) {
 			nfsrv_freedeleg(stp);
 			NFSUNLOCKSTATE();
 			error = -1;
 			goto out;
 		}
 		NFSUNLOCKSTATE();
 		/*
 		 * During this delay, the old delegation could expire or it
 		 * could be recovered by the client via an Open with
 		 * CLAIM_DELEGATE_PREV.
 		 * Release the nfsv4root_lock, if held.
 		 */
 		if (*haslockp) {
 			*haslockp = 0;
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		error = NFSERR_DELAY;
 		goto out;
 	}
 
 	/*
 	 * It's a current delegation, so:
 	 * - check to see if the delegation has expired
 	 *   - if so, get the v4root lock and then expire it
 	 */
 	if ((stp->ls_flags & NFSLCK_DELEGRECALL) == 0 || (stp->ls_lastrecall <
 	    NFSD_MONOSEC && clp->lc_expiry >= NFSD_MONOSEC &&
 	    stp->ls_delegtime >= NFSD_MONOSEC)) {
 		/*
 		 * - do a recall callback, since not yet done
 		 * For now, never allow truncate to be set. To use
 		 * truncate safely, it must be guaranteed that the
 		 * Remove, Rename or Setattr with size of 0 will
 		 * succeed and that would require major changes to
 		 * the VFS/Vnode OPs.
 		 * Set the expiry time large enough so that it won't expire
 		 * until after the callback, then set it correctly, once
 		 * the callback is done. (The delegation will now time
 		 * out whether or not the Recall worked ok. The timeout
 		 * will be extended when ops are done on the delegation
 		 * stateid, up to the timelimit.)
 		 */
 		if ((stp->ls_flags & NFSLCK_DELEGRECALL) == 0) {
 			stp->ls_delegtime = NFSD_MONOSEC + (2 * nfsrv_lease) +
 			    NFSRV_LEASEDELTA;
 			stp->ls_delegtimelimit = NFSD_MONOSEC + (6 *
 			    nfsrv_lease) + NFSRV_LEASEDELTA;
 			stp->ls_flags |= NFSLCK_DELEGRECALL;
 		}
 		stp->ls_lastrecall = time_uptime + 1;
 
 		/*
 		 * Loop NFSRV_CBRETRYCNT times while the CBRecall replies
 		 * NFSERR_BADSTATEID or NFSERR_BADHANDLE. This is done
 		 * in order to try and avoid a race that could happen
 		 * when a CBRecall request passed the Open reply with
 		 * the delegation in it when transitting the network.
 		 * Since nfsrv_docallback will sleep, don't use stp after
 		 * the call.
 		 */
 		NFSBCOPY((caddr_t)&stp->ls_stateid, (caddr_t)&tstateid,
 		    sizeof (tstateid));
 		NFSBCOPY((caddr_t)&stp->ls_lfp->lf_fh, (caddr_t)&tfh,
 		    sizeof (tfh));
 		NFSUNLOCKSTATE();
 		if (*haslockp) {
 			*haslockp = 0;
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		retrycnt = 0;
 		do {
 		    error = nfsrv_docallback(clp, NFSV4OP_CBRECALL,
 			&tstateid, 0, &tfh, NULL, NULL, 0, p);
 		    retrycnt++;
 		} while ((error == NFSERR_BADSTATEID ||
 		    error == NFSERR_BADHANDLE) && retrycnt < NFSV4_CBRETRYCNT);
 		error = NFSERR_DELAY;
 		goto out;
 	}
 
 	if (clp->lc_expiry >= NFSD_MONOSEC &&
 	    stp->ls_delegtime >= NFSD_MONOSEC) {
 		NFSUNLOCKSTATE();
 		/*
 		 * A recall has been done, but it has not yet expired.
 		 * So, RETURN_DELAY.
 		 */
 		if (*haslockp) {
 			*haslockp = 0;
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		error = NFSERR_DELAY;
 		goto out;
 	}
 
 	/*
 	 * If we don't yet have the lock, just get it and then return,
 	 * since we need that before deleting expired state, such as
 	 * this delegation.
 	 * When getting the lock, unlock the vnode, so other nfsds that
 	 * are in progress, won't get stuck waiting for the vnode lock.
 	 */
 	if (*haslockp == 0) {
 		NFSUNLOCKSTATE();
 		if (vp != NULL) {
 			lktype = NFSVOPISLOCKED(vp);
 			NFSVOPUNLOCK(vp);
 		}
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_relref(&nfsv4rootfs_lock);
 		do {
 			gotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
 			    NFSV4ROOTLOCKMUTEXPTR, NULL);
 		} while (!gotlock);
 		NFSUNLOCKV4ROOTMUTEX();
 		*haslockp = 1;
 		if (vp != NULL) {
 			NFSVOPLOCK(vp, lktype | LK_RETRY);
 			if (VN_IS_DOOMED(vp)) {
 				*haslockp = 0;
 				NFSLOCKV4ROOTMUTEX();
 				nfsv4_unlock(&nfsv4rootfs_lock, 1);
 				NFSUNLOCKV4ROOTMUTEX();
 				error = NFSERR_PERM;
 				goto out;
 			}
 		}
 		error = -1;
 		goto out;
 	}
 
 	NFSUNLOCKSTATE();
 	/*
 	 * Ok, we can delete the expired delegation.
 	 * First, write the Revoke record to stable storage and then
 	 * clear out the conflict.
 	 * Since all other nfsd threads are now blocked, we can safely
 	 * sleep without the state changing.
 	 */
 	nfsrv_writestable(clp->lc_id, clp->lc_idlen, NFSNST_REVOKE, p);
 	nfsrv_backupstable();
 	if (clp->lc_expiry < NFSD_MONOSEC) {
 		nfsrv_cleanclient(clp, p, false, NULL);
 		nfsrv_freedeleglist(&clp->lc_deleg);
 		nfsrv_freedeleglist(&clp->lc_olddeleg);
 		LIST_REMOVE(clp, lc_hash);
 		zapped_clp = 1;
 	} else {
 		nfsrv_freedeleg(stp);
 		zapped_clp = 0;
 	}
 	if (zapped_clp)
 		nfsrv_zapclient(clp, p);
 	error = -1;
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Check for a remove allowed, if remove is set to 1 and get rid of
  * delegations.
  */
 int
 nfsrv_checkremove(vnode_t vp, int remove, struct nfsrv_descript *nd,
     nfsquad_t clientid, NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfsstate *stp;
 	struct nfslockfile *lfp;
 	int error, haslock = 0;
 	fhandle_t nfh;
 
 	clp = NULL;
 	/*
 	 * First, get the lock file structure.
 	 * (A return of -1 means no associated state, so remove ok.)
 	 */
 	error = nfsrv_getlockfh(vp, NFSLCK_CHECK, NULL, &nfh, p);
 tryagain:
 	NFSLOCKSTATE();
 	if (error == 0 && clientid.qval != 0)
 		error = nfsrv_getclient(clientid, CLOPS_RENEW, &clp, NULL,
 		    (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (!error)
 		error = nfsrv_getlockfile(NFSLCK_CHECK, NULL, &lfp, &nfh, 0);
 	if (error) {
 		NFSUNLOCKSTATE();
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		if (error == -1)
 			error = 0;
 		goto out;
 	}
 
 	/*
 	 * Now, we must Recall any delegations.
 	 */
 	error = nfsrv_cleandeleg(vp, lfp, clp, &haslock, p);
 	if (error) {
 		/*
 		 * nfsrv_cleandeleg() unlocks state for non-zero
 		 * return.
 		 */
 		if (error == -1)
 			goto tryagain;
 		if (haslock) {
 			NFSLOCKV4ROOTMUTEX();
 			nfsv4_unlock(&nfsv4rootfs_lock, 1);
 			NFSUNLOCKV4ROOTMUTEX();
 		}
 		goto out;
 	}
 
 	/*
 	 * Now, look for a conflicting open share.
 	 */
 	if (remove) {
 		/*
 		 * If the entry in the directory was the last reference to the
 		 * corresponding filesystem object, the object can be destroyed
 		 * */
 		if(lfp->lf_usecount>1)
 			LIST_FOREACH(stp, &lfp->lf_open, ls_file) {
 				if (stp->ls_flags & NFSLCK_WRITEDENY) {
 					error = NFSERR_FILEOPEN;
 					break;
 				}
 			}
 	}
 
 	NFSUNLOCKSTATE();
 	if (haslock) {
 		NFSLOCKV4ROOTMUTEX();
 		nfsv4_unlock(&nfsv4rootfs_lock, 1);
 		NFSUNLOCKV4ROOTMUTEX();
 	}
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Clear out all delegations for the file referred to by lfp.
  * May return NFSERR_DELAY, if there will be a delay waiting for
  * delegations to expire.
  * Returns -1 to indicate it slept while recalling a delegation.
  * This function has the side effect of deleting the nfslockfile structure,
  * if it no longer has associated state and didn't have to sleep.
  * Unlocks State before a non-zero value is returned.
  */
 static int
 nfsrv_cleandeleg(vnode_t vp, struct nfslockfile *lfp,
     struct nfsclient *clp, int *haslockp, NFSPROC_T *p)
 {
 	struct nfsstate *stp, *nstp;
 	int ret = 0;
 
 	stp = LIST_FIRST(&lfp->lf_deleg);
 	while (stp != LIST_END(&lfp->lf_deleg)) {
 		nstp = LIST_NEXT(stp, ls_file);
 		if (stp->ls_clp != clp) {
 			ret = nfsrv_delegconflict(stp, haslockp, p, vp);
 			if (ret) {
 				/*
 				 * nfsrv_delegconflict() unlocks state
 				 * when it returns non-zero.
 				 */
 				goto out;
 			}
 		}
 		stp = nstp;
 	}
 out:
 	NFSEXITCODE(ret);
 	return (ret);
 }
 
 /*
  * There are certain operations that, when being done outside of NFSv4,
  * require that any NFSv4 delegation for the file be recalled.
  * This function is to be called for those cases:
  * VOP_RENAME() - When a delegation is being recalled for any reason,
  *	the client may have to do Opens against the server, using the file's
  *	final component name. If the file has been renamed on the server,
  *	that component name will be incorrect and the Open will fail.
  * VOP_REMOVE() - Theoretically, a client could Open a file after it has
  *	been removed on the server, if there is a delegation issued to
  *	that client for the file. I say "theoretically" since clients
  *	normally do an Access Op before the Open and that Access Op will
  *	fail with ESTALE. Note that NFSv2 and 3 don't even do Opens, so
  *	they will detect the file's removal in the same manner. (There is
  *	one case where RFC3530 allows a client to do an Open without first
  *	doing an Access Op, which is passage of a check against the ACE
  *	returned with a Write delegation, but current practice is to ignore
  *	the ACE and always do an Access Op.)
  *	Since the functions can only be called with an unlocked vnode, this
  *	can't be done at this time.
  * VOP_ADVLOCK() - When a client holds a delegation, it can issue byte range
  *	locks locally in the client, which are not visible to the server. To
  *	deal with this, issuing of delegations for a vnode must be disabled
  *	and all delegations for the vnode recalled. This is done via the
  *	second function, using the VV_DISABLEDELEG vflag on the vnode.
  */
 void
 nfsd_recalldelegation(vnode_t vp, NFSPROC_T *p)
 {
 	time_t starttime;
 	int error;
 
 	/*
 	 * First, check to see if the server is currently running and it has
 	 * been called for a regular file when issuing delegations.
 	 */
 	if (NFSD_VNET(nfsrv_numnfsd) == 0 || vp->v_type != VREG ||
 	    nfsrv_issuedelegs == 0)
 		return;
 
 	KASSERT((NFSVOPISLOCKED(vp) != LK_EXCLUSIVE), ("vp %p is locked", vp));
 	/*
 	 * First, get a reference on the nfsv4rootfs_lock so that an
 	 * exclusive lock cannot be acquired by another thread.
 	 */
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_getref(&nfsv4rootfs_lock, NULL, NFSV4ROOTLOCKMUTEXPTR, NULL);
 	NFSUNLOCKV4ROOTMUTEX();
 
 	/*
 	 * Now, call nfsrv_checkremove() in a loop while it returns
 	 * NFSERR_DELAY. Return upon any other error or when timed out.
 	 */
 	starttime = NFSD_MONOSEC;
 	do {
 		if (NFSVOPLOCK(vp, LK_EXCLUSIVE) == 0) {
 			error = nfsrv_checkremove(vp, 0, NULL,
 			    (nfsquad_t)((u_quad_t)0), p);
 			NFSVOPUNLOCK(vp);
 		} else
 			error = EPERM;
 		if (error == NFSERR_DELAY) {
 			if (NFSD_MONOSEC - starttime > NFS_REMOVETIMEO)
 				break;
 			/* Sleep for a short period of time */
 			(void) nfs_catnap(PZERO, 0, "nfsremove");
 		}
 	} while (error == NFSERR_DELAY);
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_relref(&nfsv4rootfs_lock);
 	NFSUNLOCKV4ROOTMUTEX();
 }
 
 void
 nfsd_disabledelegation(vnode_t vp, NFSPROC_T *p)
 {
 
 #ifdef VV_DISABLEDELEG
 	/*
 	 * First, flag issuance of delegations disabled.
 	 */
 	atomic_set_long(&vp->v_vflag, VV_DISABLEDELEG);
 #endif
 
 	/*
 	 * Then call nfsd_recalldelegation() to get rid of all extant
 	 * delegations.
 	 */
 	nfsd_recalldelegation(vp, p);
 }
 
 /*
  * Check for conflicting locks, etc. and then get rid of delegations.
  * (At one point I thought that I should get rid of delegations for any
  *  Setattr, since it could potentially disallow the I/O op (read or write)
  *  allowed by the delegation. However, Setattr Ops that aren't changing
  *  the size get a stateid of all 0s, so you can't tell if it is a delegation
  *  for the same client or a different one, so I decided to only get rid
  *  of delegations for other clients when the size is being changed.)
  * In general, a Setattr can disable NFS I/O Ops that are outstanding, such
  * as Write backs, even if there is no delegation, so it really isn't any
  * different?)
  */
 int
 nfsrv_checksetattr(vnode_t vp, struct nfsrv_descript *nd,
     nfsv4stateid_t *stateidp, struct nfsvattr *nvap, nfsattrbit_t *attrbitp,
     struct nfsexstuff *exp, NFSPROC_T *p)
 {
 	struct nfsstate st, *stp = &st;
 	struct nfslock lo, *lop = &lo;
 	int error = 0;
 	nfsquad_t clientid;
 
 	if (NFSISSET_ATTRBIT(attrbitp, NFSATTRBIT_SIZE)) {
 		stp->ls_flags = (NFSLCK_CHECK | NFSLCK_WRITEACCESS);
 		lop->lo_first = nvap->na_size;
 	} else {
 		stp->ls_flags = 0;
 		lop->lo_first = 0;
 	}
 	if (NFSISSET_ATTRBIT(attrbitp, NFSATTRBIT_OWNER) ||
 	    NFSISSET_ATTRBIT(attrbitp, NFSATTRBIT_OWNERGROUP) ||
 	    NFSISSET_ATTRBIT(attrbitp, NFSATTRBIT_MODE) ||
 	    NFSISSET_ATTRBIT(attrbitp, NFSATTRBIT_ACL))
 		stp->ls_flags |= NFSLCK_SETATTR;
 	if (stp->ls_flags == 0)
 		goto out;
 	lop->lo_end = NFS64BITSSET;
 	lop->lo_flags = NFSLCK_WRITE;
 	stp->ls_ownerlen = 0;
 	stp->ls_op = NULL;
 	stp->ls_uid = nd->nd_cred->cr_uid;
 	stp->ls_stateid.seqid = stateidp->seqid;
 	clientid.lval[0] = stp->ls_stateid.other[0] = stateidp->other[0];
 	clientid.lval[1] = stp->ls_stateid.other[1] = stateidp->other[1];
 	stp->ls_stateid.other[2] = stateidp->other[2];
 	error = nfsrv_lockctrl(vp, &stp, &lop, NULL, clientid,
 	    stateidp, exp, nd, p);
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * Check for a write delegation and do a CBGETATTR if there is one, updating
  * the attributes, as required.
  * Should I return an error if I can't get the attributes? (For now, I'll
  * just return ok.
  */
 int
 nfsrv_checkgetattr(struct nfsrv_descript *nd, vnode_t vp,
     struct nfsvattr *nvap, nfsattrbit_t *attrbitp, NFSPROC_T *p)
 {
 	struct nfsstate *stp;
 	struct nfslockfile *lfp;
 	struct nfsclient *clp;
 	struct nfsvattr nva;
 	fhandle_t nfh;
 	int error = 0;
 	nfsattrbit_t cbbits;
 	u_quad_t delegfilerev;
 
 	NFSCBGETATTR_ATTRBIT(attrbitp, &cbbits);
 	if (!NFSNONZERO_ATTRBIT(&cbbits))
 		goto out;
 	if (nfsrv_writedelegcnt == 0)
 		goto out;
 
 	/*
 	 * Get the lock file structure.
 	 * (A return of -1 means no associated state, so return ok.)
 	 */
 	error = nfsrv_getlockfh(vp, NFSLCK_CHECK, NULL, &nfh, p);
 	NFSLOCKSTATE();
 	if (!error)
 		error = nfsrv_getlockfile(NFSLCK_CHECK, NULL, &lfp, &nfh, 0);
 	if (error) {
 		NFSUNLOCKSTATE();
 		if (error == -1)
 			error = 0;
 		goto out;
 	}
 
 	/*
 	 * Now, look for a write delegation.
 	 */
 	LIST_FOREACH(stp, &lfp->lf_deleg, ls_file) {
 		if (stp->ls_flags & NFSLCK_DELEGWRITE)
 			break;
 	}
 	if (stp == LIST_END(&lfp->lf_deleg)) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 	clp = stp->ls_clp;
 
 	/* If the clientid is not confirmed, ignore the delegation. */
 	if (clp->lc_flags & LCL_NEEDSCONFIRM) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	delegfilerev = stp->ls_filerev;
 	/*
 	 * If the Write delegation was issued as a part of this Compound RPC
 	 * or if we have an Implied Clientid (used in a previous Op in this
 	 * compound) and it is the client the delegation was issued to,
 	 * just return ok.
 	 * I also assume that it is from the same client iff the network
 	 * host IP address is the same as the callback address. (Not
 	 * exactly correct by the RFC, but avoids a lot of Getattr
 	 * callbacks.)
 	 */
 	if (nd->nd_compref == stp->ls_compref ||
 	    ((nd->nd_flag & ND_IMPLIEDCLID) &&
 	     clp->lc_clientid.qval == nd->nd_clientid.qval) ||
 	     nfsaddr2_match(clp->lc_req.nr_nam, nd->nd_nam)) {
 		NFSUNLOCKSTATE();
 		goto out;
 	}
 
 	/*
 	 * We are now done with the delegation state structure,
 	 * so the statelock can be released and we can now tsleep().
 	 */
 
 	/*
 	 * Now, we must do the CB Getattr callback, to see if Change or Size
 	 * has changed.
 	 */
 	if (clp->lc_expiry >= NFSD_MONOSEC) {
 		NFSUNLOCKSTATE();
 		NFSVNO_ATTRINIT(&nva);
 		nva.na_filerev = NFS64BITSSET;
 		error = nfsrv_docallback(clp, NFSV4OP_CBGETATTR, NULL,
 		    0, &nfh, &nva, &cbbits, 0, p);
 		if (!error) {
 			if ((nva.na_filerev != NFS64BITSSET &&
 			    nva.na_filerev > delegfilerev) ||
 			    (NFSVNO_ISSETSIZE(&nva) &&
 			     nva.na_size != nvap->na_size)) {
 				error = nfsvno_updfilerev(vp, nvap, nd, p);
 				if (NFSVNO_ISSETSIZE(&nva))
 					nvap->na_size = nva.na_size;
 			}
 		} else
 			error = 0;	/* Ignore callback errors for now. */
 	} else {
 		NFSUNLOCKSTATE();
 	}
 
 out:
 	NFSEXITCODE2(error, nd);
 	return (error);
 }
 
 /*
  * This function looks for openowners that haven't had any opens for
  * a while and throws them away. Called by an nfsd when NFSNSF_NOOPENS
  * is set.
  */
 void
 nfsrv_throwawayopens(NFSPROC_T *p)
 {
 	struct nfsclient *clp, *nclp;
 	struct nfsstate *stp, *nstp;
 	int i;
 
 	NFSLOCKSTATE();
 	NFSD_VNET(nfsrv_stablefirst).nsf_flags &= ~NFSNSF_NOOPENS;
 	/*
 	 * For each client...
 	 */
 	for (i = 0; i < nfsrv_clienthashsize; i++) {
 	    LIST_FOREACH_SAFE(clp, &NFSD_VNET(nfsclienthash)[i], lc_hash,
 		nclp) {
 		LIST_FOREACH_SAFE(stp, &clp->lc_open, ls_list, nstp) {
 			if (LIST_EMPTY(&stp->ls_open) &&
 			    (stp->ls_noopens > NFSNOOPEN ||
 			     (nfsrv_openpluslock * 2) >
 			     nfsrv_v4statelimit))
 				nfsrv_freeopenowner(stp, 0, p);
 		}
 	    }
 	}
 	NFSUNLOCKSTATE();
 }
 
 /*
  * This function checks to see if the credentials are the same.
  * The check for same credentials is needed for state management operations
  * for NFSv4.0 or NFSv4.1/4.2 when SP4_MACH_CRED is configured via
  * ExchangeID.
  * Returns 1 for not same, 0 otherwise.
  */
 static int
 nfsrv_notsamecredname(int op, struct nfsrv_descript *nd, struct nfsclient *clp)
 {
 
 	/* Check for the SP4_MACH_CRED case. */
 	if (op != 0 && nfsrv_checkmachcred(op, nd, clp) != 0)
 		return (1);
 
 	/* For NFSv4.1/4.2, SP4_NONE always allows this. */
 	if ((nd->nd_flag & ND_NFSV41) != 0)
 		return (0);
 
 	if (nd->nd_flag & ND_GSS) {
 		if (!(clp->lc_flags & LCL_GSS))
 			return (1);
 		if (clp->lc_flags & LCL_NAME) {
 			if (nd->nd_princlen != clp->lc_namelen ||
 			    NFSBCMP(nd->nd_principal, clp->lc_name,
 				clp->lc_namelen))
 				return (1);
 			else
 				return (0);
 		}
 		if (nd->nd_cred->cr_uid == clp->lc_uid)
 			return (0);
 		else
 			return (1);
 	} else if (clp->lc_flags & LCL_GSS)
 		return (1);
 	/*
 	 * For AUTH_SYS, allow the same uid or root. (This is underspecified
 	 * in RFC3530, which talks about principals, but doesn't say anything
 	 * about uids for AUTH_SYS.)
 	 */
 	if (nd->nd_cred->cr_uid == clp->lc_uid || nd->nd_cred->cr_uid == 0)
 		return (0);
 	else
 		return (1);
 }
 
 /*
  * Calculate the lease expiry time.
  */
 static time_t
 nfsrv_leaseexpiry(void)
 {
 
 	if (NFSD_VNET(nfsrv_stablefirst).nsf_eograce > NFSD_MONOSEC)
 		return (NFSD_MONOSEC + 2 * (nfsrv_lease + NFSRV_LEASEDELTA));
 	return (NFSD_MONOSEC + nfsrv_lease + NFSRV_LEASEDELTA);
 }
 
 /*
  * Delay the delegation timeout as far as ls_delegtimelimit, as required.
  */
 static void
 nfsrv_delaydelegtimeout(struct nfsstate *stp)
 {
 
 	if ((stp->ls_flags & NFSLCK_DELEGRECALL) == 0)
 		return;
 
 	if ((stp->ls_delegtime + 15) > NFSD_MONOSEC &&
 	    stp->ls_delegtime < stp->ls_delegtimelimit) {
 		stp->ls_delegtime += nfsrv_lease;
 		if (stp->ls_delegtime > stp->ls_delegtimelimit)
 			stp->ls_delegtime = stp->ls_delegtimelimit;
 	}
 }
 
 /*
  * This function checks to see if there is any other state associated
  * with the openowner for this Open.
  * It returns 1 if there is no other state, 0 otherwise.
  */
 static int
 nfsrv_nootherstate(struct nfsstate *stp)
 {
 	struct nfsstate *tstp;
 
 	LIST_FOREACH(tstp, &stp->ls_openowner->ls_open, ls_list) {
 		if (tstp != stp || !LIST_EMPTY(&tstp->ls_lock))
 			return (0);
 	}
 	return (1);
 }
 
 /*
  * Create a list of lock deltas (changes to local byte range locking
  * that can be rolled back using the list) and apply the changes via
  * nfsvno_advlock(). Optionally, lock the list. It is expected that either
  * the rollback or update function will be called after this.
  * It returns an error (and rolls back, as required), if any nfsvno_advlock()
  * call fails. If it returns an error, it will unlock the list.
  */
 static int
 nfsrv_locallock(vnode_t vp, struct nfslockfile *lfp, int flags,
     uint64_t first, uint64_t end, struct nfslockconflict *cfp, NFSPROC_T *p)
 {
 	struct nfslock *lop, *nlop;
 	int error = 0;
 
 	/* Loop through the list of locks. */
 	lop = LIST_FIRST(&lfp->lf_locallock);
 	while (first < end && lop != NULL) {
 		nlop = LIST_NEXT(lop, lo_lckowner);
 		if (first >= lop->lo_end) {
 			/* not there yet */
 			lop = nlop;
 		} else if (first < lop->lo_first) {
 			/* new one starts before entry in list */
 			if (end <= lop->lo_first) {
 				/* no overlap between old and new */
 				error = nfsrv_dolocal(vp, lfp, flags,
 				    NFSLCK_UNLOCK, first, end, cfp, p);
 				if (error != 0)
 					break;
 				first = end;
 			} else {
 				/* handle fragment overlapped with new one */
 				error = nfsrv_dolocal(vp, lfp, flags,
 				    NFSLCK_UNLOCK, first, lop->lo_first, cfp,
 				    p);
 				if (error != 0)
 					break;
 				first = lop->lo_first;
 			}
 		} else {
 			/* new one overlaps this entry in list */
 			if (end <= lop->lo_end) {
 				/* overlaps all of new one */
 				error = nfsrv_dolocal(vp, lfp, flags,
 				    lop->lo_flags, first, end, cfp, p);
 				if (error != 0)
 					break;
 				first = end;
 			} else {
 				/* handle fragment overlapped with new one */
 				error = nfsrv_dolocal(vp, lfp, flags,
 				    lop->lo_flags, first, lop->lo_end, cfp, p);
 				if (error != 0)
 					break;
 				first = lop->lo_end;
 				lop = nlop;
 			}
 		}
 	}
 	if (first < end && error == 0)
 		/* handle fragment past end of list */
 		error = nfsrv_dolocal(vp, lfp, flags, NFSLCK_UNLOCK, first,
 		    end, cfp, p);
 
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Local lock unlock. Unlock all byte ranges that are no longer locked
  * by NFSv4. To do this, unlock any subranges of first-->end that
  * do not overlap with the byte ranges of any lock in the lfp->lf_lock
  * list. This list has all locks for the file held by other
  * <clientid, lockowner> tuples. The list is ordered by increasing
  * lo_first value, but may have entries that overlap each other, for
  * the case of read locks.
  */
 static void
 nfsrv_localunlock(vnode_t vp, struct nfslockfile *lfp, uint64_t init_first,
     uint64_t init_end, NFSPROC_T *p)
 {
 	struct nfslock *lop;
 	uint64_t first, end, prevfirst __unused;
 
 	first = init_first;
 	end = init_end;
 	while (first < init_end) {
 		/* Loop through all nfs locks, adjusting first and end */
 		prevfirst = 0;
 		LIST_FOREACH(lop, &lfp->lf_lock, lo_lckfile) {
 			KASSERT(prevfirst <= lop->lo_first,
 			    ("nfsv4 locks out of order"));
 			KASSERT(lop->lo_first < lop->lo_end,
 			    ("nfsv4 bogus lock"));
 			prevfirst = lop->lo_first;
 			if (first >= lop->lo_first &&
 			    first < lop->lo_end)
 				/*
 				 * Overlaps with initial part, so trim
 				 * off that initial part by moving first past
 				 * it.
 				 */
 				first = lop->lo_end;
 			else if (end > lop->lo_first &&
 			    lop->lo_first > first) {
 				/*
 				 * This lock defines the end of the
 				 * segment to unlock, so set end to the
 				 * start of it and break out of the loop.
 				 */
 				end = lop->lo_first;
 				break;
 			}
 			if (first >= end)
 				/*
 				 * There is no segment left to do, so
 				 * break out of this loop and then exit
 				 * the outer while() since first will be set
 				 * to end, which must equal init_end here.
 				 */
 				break;
 		}
 		if (first < end) {
 			/* Unlock this segment */
 			(void) nfsrv_dolocal(vp, lfp, NFSLCK_UNLOCK,
 			    NFSLCK_READ, first, end, NULL, p);
 			nfsrv_locallock_commit(lfp, NFSLCK_UNLOCK,
 			    first, end);
 		}
 		/*
 		 * Now move past this segment and look for any further
 		 * segment in the range, if there is one.
 		 */
 		first = end;
 		end = init_end;
 	}
 }
 
 /*
  * Do the local lock operation and update the rollback list, as required.
  * Perform the rollback and return the error if nfsvno_advlock() fails.
  */
 static int
 nfsrv_dolocal(vnode_t vp, struct nfslockfile *lfp, int flags, int oldflags,
     uint64_t first, uint64_t end, struct nfslockconflict *cfp, NFSPROC_T *p)
 {
 	struct nfsrollback *rlp;
 	int error = 0, ltype, oldltype;
 
 	if (flags & NFSLCK_WRITE)
 		ltype = F_WRLCK;
 	else if (flags & NFSLCK_READ)
 		ltype = F_RDLCK;
 	else
 		ltype = F_UNLCK;
 	if (oldflags & NFSLCK_WRITE)
 		oldltype = F_WRLCK;
 	else if (oldflags & NFSLCK_READ)
 		oldltype = F_RDLCK;
 	else
 		oldltype = F_UNLCK;
 	if (ltype == oldltype || (oldltype == F_WRLCK && ltype == F_RDLCK))
 		/* nothing to do */
 		goto out;
 	error = nfsvno_advlock(vp, ltype, first, end, p);
 	if (error != 0) {
 		if (cfp != NULL) {
 			cfp->cl_clientid.lval[0] = 0;
 			cfp->cl_clientid.lval[1] = 0;
 			cfp->cl_first = 0;
 			cfp->cl_end = NFS64BITSSET;
 			cfp->cl_flags = NFSLCK_WRITE;
 			cfp->cl_ownerlen = 5;
 			NFSBCOPY("LOCAL", cfp->cl_owner, 5);
 		}
 		nfsrv_locallock_rollback(vp, lfp, p);
 	} else if (ltype != F_UNLCK) {
 		rlp = malloc(sizeof (struct nfsrollback), M_NFSDROLLBACK,
 		    M_WAITOK);
 		rlp->rlck_first = first;
 		rlp->rlck_end = end;
 		rlp->rlck_type = oldltype;
 		LIST_INSERT_HEAD(&lfp->lf_rollback, rlp, rlck_list);
 	}
 
 out:
 	NFSEXITCODE(error);
 	return (error);
 }
 
 /*
  * Roll back local lock changes and free up the rollback list.
  */
 static void
 nfsrv_locallock_rollback(vnode_t vp, struct nfslockfile *lfp, NFSPROC_T *p)
 {
 	struct nfsrollback *rlp, *nrlp;
 
 	LIST_FOREACH_SAFE(rlp, &lfp->lf_rollback, rlck_list, nrlp) {
 		(void) nfsvno_advlock(vp, rlp->rlck_type, rlp->rlck_first,
 		    rlp->rlck_end, p);
 		free(rlp, M_NFSDROLLBACK);
 	}
 	LIST_INIT(&lfp->lf_rollback);
 }
 
 /*
  * Update local lock list and delete rollback list (ie now committed to the
  * local locks). Most of the work is done by the internal function.
  */
 static void
 nfsrv_locallock_commit(struct nfslockfile *lfp, int flags, uint64_t first,
     uint64_t end)
 {
 	struct nfsrollback *rlp, *nrlp;
 	struct nfslock *new_lop, *other_lop;
 
 	new_lop = malloc(sizeof (struct nfslock), M_NFSDLOCK, M_WAITOK);
 	if (flags & (NFSLCK_READ | NFSLCK_WRITE))
 		other_lop = malloc(sizeof (struct nfslock), M_NFSDLOCK,
 		    M_WAITOK);
 	else
 		other_lop = NULL;
 	new_lop->lo_flags = flags;
 	new_lop->lo_first = first;
 	new_lop->lo_end = end;
 	nfsrv_updatelock(NULL, &new_lop, &other_lop, lfp);
 	if (new_lop != NULL)
 		free(new_lop, M_NFSDLOCK);
 	if (other_lop != NULL)
 		free(other_lop, M_NFSDLOCK);
 
 	/* and get rid of the rollback list */
 	LIST_FOREACH_SAFE(rlp, &lfp->lf_rollback, rlck_list, nrlp)
 		free(rlp, M_NFSDROLLBACK);
 	LIST_INIT(&lfp->lf_rollback);
 }
 
 /*
  * Lock the struct nfslockfile for local lock updating.
  */
 static void
 nfsrv_locklf(struct nfslockfile *lfp)
 {
 	int gotlock;
 
 	/* lf_usecount ensures *lfp won't be free'd */
 	lfp->lf_usecount++;
 	do {
 		gotlock = nfsv4_lock(&lfp->lf_locallock_lck, 1, NULL,
 		    NFSSTATEMUTEXPTR, NULL);
 	} while (gotlock == 0);
 	lfp->lf_usecount--;
 }
 
 /*
  * Unlock the struct nfslockfile after local lock updating.
  */
 static void
 nfsrv_unlocklf(struct nfslockfile *lfp)
 {
 
 	nfsv4_unlock(&lfp->lf_locallock_lck, 0);
 }
 
 /*
  * Clear out all state for the NFSv4 server.
  * Must be called by a thread that can sleep when no nfsds are running.
  */
 void
 nfsrv_throwawayallstate(NFSPROC_T *p)
 {
 	struct nfsclient *clp, *nclp;
 	struct nfslockfile *lfp, *nlfp;
 	int i;
 
 	/*
 	 * For each client, clean out the state and then free the structure.
 	 */
 	for (i = 0; i < nfsrv_clienthashsize; i++) {
 		LIST_FOREACH_SAFE(clp, &NFSD_VNET(nfsclienthash)[i], lc_hash,
 		    nclp) {
 			nfsrv_cleanclient(clp, p, false, NULL);
 			nfsrv_freedeleglist(&clp->lc_deleg);
 			nfsrv_freedeleglist(&clp->lc_olddeleg);
 			free(clp->lc_stateid, M_NFSDCLIENT);
 			free(clp, M_NFSDCLIENT);
 		}
 	}
 
 	/*
 	 * Also, free up any remaining lock file structures.
 	 */
 	for (i = 0; i < nfsrv_lockhashsize; i++) {
 		LIST_FOREACH_SAFE(lfp, &NFSD_VNET(nfslockhash)[i], lf_hash,
 		    nlfp) {
 			printf("nfsd unload: fnd a lock file struct\n");
 			nfsrv_freenfslockfile(lfp);
 		}
 	}
 
 	/* And get rid of the deviceid structures and layouts. */
 	nfsrv_freealllayoutsanddevids();
 }
 
 /*
  * Check the sequence# for the session and slot provided as an argument.
  * Also, renew the lease if the session will return NFS_OK.
  */
 int
 nfsrv_checksequence(struct nfsrv_descript *nd, uint32_t sequenceid,
     uint32_t *highest_slotidp, uint32_t *target_highest_slotidp, int cache_this,
     uint32_t *sflagsp, NFSPROC_T *p)
 {
 	struct nfsdsession *sep;
 	struct nfssessionhash *shp;
 	int error;
 
 	shp = NFSSESSIONHASH(nd->nd_sessionid);
 	NFSLOCKSESSION(shp);
 	sep = nfsrv_findsession(nd->nd_sessionid);
 	if (sep == NULL) {
 		NFSUNLOCKSESSION(shp);
 		return (NFSERR_BADSESSION);
 	}
 	error = nfsv4_seqsession(sequenceid, nd->nd_slotid, *highest_slotidp,
 	    sep->sess_slots, NULL, NFSV4_SLOTS - 1);
 	if (error != 0) {
 		NFSUNLOCKSESSION(shp);
 		return (error);
 	}
 	if (cache_this != 0)
 		nd->nd_flag |= ND_SAVEREPLY;
 	/* Renew the lease. */
 	sep->sess_clp->lc_expiry = nfsrv_leaseexpiry();
 	nd->nd_clientid.qval = sep->sess_clp->lc_clientid.qval;
 	nd->nd_flag |= ND_IMPLIEDCLID;
 
 	/* Handle the SP4_MECH_CRED case for NFSv4.1/4.2. */
 	if ((sep->sess_clp->lc_flags & LCL_MACHCRED) != 0 &&
 	    (nd->nd_flag & (ND_GSSINTEGRITY | ND_GSSPRIVACY)) != 0 &&
 	    nd->nd_princlen == sep->sess_clp->lc_namelen &&
 	    !NFSBCMP(sep->sess_clp->lc_name, nd->nd_principal,
 	    nd->nd_princlen)) {
 		nd->nd_flag |= ND_MACHCRED;
 		NFSSET_OPBIT(&nd->nd_allowops, &sep->sess_clp->lc_allowops);
 	}
 
 	/* Save maximum request and reply sizes. */
 	nd->nd_maxreq = sep->sess_maxreq;
 	nd->nd_maxresp = sep->sess_maxresp;
 
 	*sflagsp = 0;
 	if (sep->sess_clp->lc_req.nr_client == NULL ||
 	    (sep->sess_clp->lc_flags & LCL_CBDOWN) != 0)
 		*sflagsp |= NFSV4SEQ_CBPATHDOWN;
 	NFSUNLOCKSESSION(shp);
 	if (error == NFSERR_EXPIRED) {
 		*sflagsp |= NFSV4SEQ_EXPIREDALLSTATEREVOKED;
 		error = 0;
 	} else if (error == NFSERR_ADMINREVOKED) {
 		*sflagsp |= NFSV4SEQ_ADMINSTATEREVOKED;
 		error = 0;
 	}
 	*highest_slotidp = *target_highest_slotidp = NFSV4_SLOTS - 1;
 	return (0);
 }
 
 /*
  * Check/set reclaim complete for this session/clientid.
  */
 int
 nfsrv_checkreclaimcomplete(struct nfsrv_descript *nd, int onefs)
 {
 	struct nfsdsession *sep;
 	struct nfssessionhash *shp;
 	int error = 0;
 
 	shp = NFSSESSIONHASH(nd->nd_sessionid);
 	NFSLOCKSTATE();
 	NFSLOCKSESSION(shp);
 	sep = nfsrv_findsession(nd->nd_sessionid);
 	if (sep == NULL) {
 		NFSUNLOCKSESSION(shp);
 		NFSUNLOCKSTATE();
 		return (NFSERR_BADSESSION);
 	}
 
 	if (onefs != 0)
 		sep->sess_clp->lc_flags |= LCL_RECLAIMONEFS;
 		/* Check to see if reclaim complete has already happened. */
 	else if ((sep->sess_clp->lc_flags & LCL_RECLAIMCOMPLETE) != 0)
 		error = NFSERR_COMPLETEALREADY;
 	else {
 		sep->sess_clp->lc_flags |= LCL_RECLAIMCOMPLETE;
 		nfsrv_markreclaim(sep->sess_clp);
 	}
 	NFSUNLOCKSESSION(shp);
 	NFSUNLOCKSTATE();
 	return (error);
 }
 
 /*
  * Cache the reply in a session slot.
  */
 void
 nfsrv_cache_session(struct nfsrv_descript *nd, struct mbuf **m)
 {
 	struct nfsdsession *sep;
 	struct nfssessionhash *shp;
 	char *buf, *cp;
 #ifdef INET
 	struct sockaddr_in *sin;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *sin6;
 #endif
 
 	shp = NFSSESSIONHASH(nd->nd_sessionid);
 	NFSLOCKSESSION(shp);
 	sep = nfsrv_findsession(nd->nd_sessionid);
 	if (sep == NULL) {
 		NFSUNLOCKSESSION(shp);
 		if ((NFSD_VNET(nfsrv_stablefirst).nsf_flags &
 		     NFSNSF_GRACEOVER) != 0) {
 			buf = malloc(INET6_ADDRSTRLEN, M_TEMP, M_WAITOK);
 			switch (nd->nd_nam->sa_family) {
 #ifdef INET
 			case AF_INET:
 				sin = (struct sockaddr_in *)nd->nd_nam;
 				cp = inet_ntop(sin->sin_family,
 				    &sin->sin_addr.s_addr, buf,
 				    INET6_ADDRSTRLEN);
 				break;
 #endif
 #ifdef INET6
 			case AF_INET6:
 				sin6 = (struct sockaddr_in6 *)nd->nd_nam;
 				cp = inet_ntop(sin6->sin6_family,
 				    &sin6->sin6_addr, buf, INET6_ADDRSTRLEN);
 				break;
 #endif
 			default:
 				cp = NULL;
 			}
 			if (cp != NULL)
 				printf("nfsrv_cache_session: no session "
 				    "IPaddr=%s, check NFS clients for unique "
 				    "/etc/hostid's\n", cp);
 			else
 				printf("nfsrv_cache_session: no session, "
 				    "check NFS clients for unique "
 				    "/etc/hostid's\n");
 			free(buf, M_TEMP);
 		}
 		m_freem(*m);
 		return;
 	}
 	nfsv4_seqsess_cacherep(nd->nd_slotid, sep->sess_slots, nd->nd_repstat,
 	    m);
 	NFSUNLOCKSESSION(shp);
 }
 
 /*
  * Search for a session that matches the sessionid.
  */
 static struct nfsdsession *
 nfsrv_findsession(uint8_t *sessionid)
 {
 	struct nfsdsession *sep;
 	struct nfssessionhash *shp;
 
 	shp = NFSSESSIONHASH(sessionid);
 	LIST_FOREACH(sep, &shp->list, sess_hash) {
 		if (!NFSBCMP(sessionid, sep->sess_sessionid, NFSX_V4SESSIONID))
 			break;
 	}
 	return (sep);
 }
 
 /*
  * Destroy a session.
  */
 int
 nfsrv_destroysession(struct nfsrv_descript *nd, uint8_t *sessionid)
 {
 	int error, igotlock, samesess;
 
 	samesess = 0;
 	if (!NFSBCMP(sessionid, nd->nd_sessionid, NFSX_V4SESSIONID) &&
 	    (nd->nd_flag & ND_HASSEQUENCE) != 0) {
 		samesess = 1;
 		if ((nd->nd_flag & ND_LASTOP) == 0)
 			return (NFSERR_BADSESSION);
 	}
 
 	/* Lock out other nfsd threads */
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_relref(&nfsv4rootfs_lock);
 	do {
 		igotlock = nfsv4_lock(&nfsv4rootfs_lock, 1, NULL,
 		    NFSV4ROOTLOCKMUTEXPTR, NULL);
 	} while (igotlock == 0);
 	NFSUNLOCKV4ROOTMUTEX();
 
 	error = nfsrv_freesession(nd, NULL, sessionid, false, NULL);
 	if (error == 0 && samesess != 0)
 		nd->nd_flag &= ~ND_HASSEQUENCE;
 
 	NFSLOCKV4ROOTMUTEX();
 	nfsv4_unlock(&nfsv4rootfs_lock, 1);
 	NFSUNLOCKV4ROOTMUTEX();
 	return (error);
 }
 
 /*
  * Bind a connection to a session.
  * For now, only certain variants are supported, since the current session
  * structure can only handle a single backchannel entry, which will be
  * applied to all connections if it is set.
  */
 int
 nfsrv_bindconnsess(struct nfsrv_descript *nd, uint8_t *sessionid, int *foreaftp)
 {
 	struct nfssessionhash *shp;
 	struct nfsdsession *sep;
 	struct nfsclient *clp;
 	SVCXPRT *savxprt;
 	int error;
 
 	error = 0;
 	savxprt = NULL;
 	shp = NFSSESSIONHASH(sessionid);
 	NFSLOCKSTATE();
 	NFSLOCKSESSION(shp);
 	sep = nfsrv_findsession(sessionid);
 	if (sep != NULL) {
 		clp = sep->sess_clp;
 		error = nfsrv_checkmachcred(NFSV4OP_BINDCONNTOSESS, nd, clp);
 		if (error != 0)
 			goto out;
 		if (*foreaftp == NFSCDFC4_BACK ||
 		    *foreaftp == NFSCDFC4_BACK_OR_BOTH ||
 		    *foreaftp == NFSCDFC4_FORE_OR_BOTH) {
 			/* Try to set up a backchannel. */
 			if (clp->lc_req.nr_client == NULL) {
 				NFSD_DEBUG(2, "nfsrv_bindconnsess: acquire "
 				    "backchannel\n");
 				clp->lc_req.nr_client = (struct __rpc_client *)
 				    clnt_bck_create(nd->nd_xprt->xp_socket,
 				    sep->sess_cbprogram, NFSV4_CBVERS);
 			}
 			if (clp->lc_req.nr_client != NULL) {
 				NFSD_DEBUG(2, "nfsrv_bindconnsess: set up "
 				    "backchannel\n");
 				savxprt = sep->sess_cbsess.nfsess_xprt;
 				SVC_ACQUIRE(nd->nd_xprt);
 				CLNT_ACQUIRE(clp->lc_req.nr_client);
 				nd->nd_xprt->xp_p2 = clp->lc_req.nr_client;
 				/* Disable idle timeout. */
 				nd->nd_xprt->xp_idletimeout = 0;
 				sep->sess_cbsess.nfsess_xprt = nd->nd_xprt;
 				sep->sess_crflags |= NFSV4CRSESS_CONNBACKCHAN;
 				clp->lc_flags |= LCL_DONEBINDCONN |
 				    LCL_NEEDSCBNULL;
 				clp->lc_flags &= ~LCL_CBDOWN;
 				if (*foreaftp == NFSCDFS4_BACK)
 					*foreaftp = NFSCDFS4_BACK;
 				else
 					*foreaftp = NFSCDFS4_BOTH;
 			} else if (*foreaftp != NFSCDFC4_BACK) {
 				NFSD_DEBUG(2, "nfsrv_bindconnsess: can't set "
 				    "up backchannel\n");
 				sep->sess_crflags &= ~NFSV4CRSESS_CONNBACKCHAN;
 				clp->lc_flags |= LCL_DONEBINDCONN;
 				*foreaftp = NFSCDFS4_FORE;
 			} else {
 				error = NFSERR_NOTSUPP;
 				printf("nfsrv_bindconnsess: Can't add "
 				    "backchannel\n");
 			}
 		} else {
 			NFSD_DEBUG(2, "nfsrv_bindconnsess: Set forechannel\n");
 			clp->lc_flags |= LCL_DONEBINDCONN;
 			*foreaftp = NFSCDFS4_FORE;
 		}
 	} else
 		error = NFSERR_BADSESSION;
 out:
 	NFSUNLOCKSESSION(shp);
 	NFSUNLOCKSTATE();
 	if (savxprt != NULL)
 		SVC_RELEASE(savxprt);
 	return (error);
 }
 
 /*
  * Free up a session structure.
  */
 static int
 nfsrv_freesession(struct nfsrv_descript *nd, struct nfsdsession *sep,
     uint8_t *sessionid, bool locked, SVCXPRT **old_xprtp)
 {
 	struct nfssessionhash *shp;
 	int i;
 
 	if (!locked)
 		NFSLOCKSTATE();
 	if (sep == NULL) {
 		shp = NFSSESSIONHASH(sessionid);
 		NFSLOCKSESSION(shp);
 		sep = nfsrv_findsession(sessionid);
 	} else {
 		shp = NFSSESSIONHASH(sep->sess_sessionid);
 		NFSLOCKSESSION(shp);
 	}
 	if (sep != NULL) {
 		/* Check for the SP4_MACH_CRED case. */
 		if (nd != NULL && nfsrv_checkmachcred(NFSV4OP_DESTROYSESSION,
 		    nd, sep->sess_clp) != 0) {
 			NFSUNLOCKSESSION(shp);
 			if (!locked)
 				NFSUNLOCKSTATE();
 			return (NFSERR_AUTHERR | AUTH_TOOWEAK);
 		}
 
 		sep->sess_refcnt--;
 		if (sep->sess_refcnt > 0) {
 			NFSUNLOCKSESSION(shp);
 			if (!locked)
 				NFSUNLOCKSTATE();
 			return (NFSERR_BACKCHANBUSY);
 		}
 		LIST_REMOVE(sep, sess_hash);
 		LIST_REMOVE(sep, sess_list);
 	}
 	NFSUNLOCKSESSION(shp);
 	if (!locked)
 		NFSUNLOCKSTATE();
 	if (sep == NULL)
 		return (NFSERR_BADSESSION);
 	for (i = 0; i < NFSV4_SLOTS; i++)
 		if (sep->sess_slots[i].nfssl_reply != NULL)
 			m_freem(sep->sess_slots[i].nfssl_reply);
 	if (!locked) {
 		if (sep->sess_cbsess.nfsess_xprt != NULL)
 			SVC_RELEASE(sep->sess_cbsess.nfsess_xprt);
 		if (old_xprtp != NULL)
 			*old_xprtp = NULL;
 	} else if (old_xprtp != NULL)
 		*old_xprtp = sep->sess_cbsess.nfsess_xprt;
 	free(sep, M_NFSDSESSION);
 	return (0);
 }
 
 /*
  * Free a stateid.
  * RFC5661 says that it should fail when there are associated opens, locks
  * or delegations. Since stateids represent opens, I don't see how you can
  * free an open stateid (it will be free'd when closed), so this function
  * only works for lock stateids (freeing the lock_owner) or delegations.
  */
 int
 nfsrv_freestateid(struct nfsrv_descript *nd, nfsv4stateid_t *stateidp,
     NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfsstate *stp;
 	int error;
 
 	NFSLOCKSTATE();
 	/*
 	 * Look up the stateid
 	 */
 	error = nfsrv_getclient((nfsquad_t)((u_quad_t)0), CLOPS_RENEW, &clp,
 	    NULL, (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (error == 0) {
 		/* First, check for a delegation. */
 		LIST_FOREACH(stp, &clp->lc_deleg, ls_list) {
 			if (!NFSBCMP(stp->ls_stateid.other, stateidp->other,
 			    NFSX_STATEIDOTHER))
 				break;
 		}
 		if (stp != NULL) {
 			nfsrv_freedeleg(stp);
 			NFSUNLOCKSTATE();
 			return (error);
 		}
 	}
 	/* Not a delegation, try for a lock_owner. */
 	if (error == 0)
 		error = nfsrv_getstate(clp, stateidp, 0, &stp);
 	if (error == 0 && ((stp->ls_flags & (NFSLCK_OPEN | NFSLCK_DELEGREAD |
 	    NFSLCK_DELEGWRITE)) != 0 || (stp->ls_flags & NFSLCK_LOCK) == 0))
 		/* Not a lock_owner stateid. */
 		error = NFSERR_LOCKSHELD;
 	if (error == 0 && !LIST_EMPTY(&stp->ls_lock))
 		error = NFSERR_LOCKSHELD;
 	if (error == 0)
 		nfsrv_freelockowner(stp, NULL, 0, p);
 	NFSUNLOCKSTATE();
 	return (error);
 }
 
 /*
  * Test a stateid.
  */
 int
 nfsrv_teststateid(struct nfsrv_descript *nd, nfsv4stateid_t *stateidp,
     NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfsstate *stp;
 	int error;
 
 	NFSLOCKSTATE();
 	/*
 	 * Look up the stateid
 	 */
 	error = nfsrv_getclient((nfsquad_t)((u_quad_t)0), CLOPS_RENEW, &clp,
 	    NULL, (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (error == 0)
 		error = nfsrv_getstate(clp, stateidp, 0, &stp);
 	if (error == 0 && stateidp->seqid != 0 &&
 	    SEQ_LT(stateidp->seqid, stp->ls_stateid.seqid))
 		error = NFSERR_OLDSTATEID;
 	NFSUNLOCKSTATE();
 	return (error);
 }
 
 /*
  * Generate the xdr for an NFSv4.1 CBSequence Operation.
  */
 static int
 nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp,
     int dont_replycache, struct nfsdsession **sepp, int *slotposp)
 {
 	struct nfsdsession *sep;
 	uint32_t *tl, slotseq = 0;
 	int maxslot;
 	uint8_t sessionid[NFSX_V4SESSIONID];
 	int error;
 
 	error = nfsv4_getcbsession(clp, sepp);
 	if (error != 0)
 		return (error);
 	sep = *sepp;
 	nfsv4_sequencelookup(NULL, &sep->sess_cbsess, slotposp, &maxslot,
 	    &slotseq, sessionid, true);
 	KASSERT(maxslot >= 0, ("nfsv4_setcbsequence neg maxslot"));
 
 	/* Build the Sequence arguments. */
 	NFSM_BUILD(tl, uint32_t *, NFSX_V4SESSIONID + 5 * NFSX_UNSIGNED);
 	bcopy(sessionid, tl, NFSX_V4SESSIONID);
 	tl += NFSX_V4SESSIONID / NFSX_UNSIGNED;
 	nd->nd_slotseq = tl;
 	nd->nd_slotid = *slotposp;
 	nd->nd_flag |= ND_HASSLOTID;
 	*tl++ = txdr_unsigned(slotseq);
 	*tl++ = txdr_unsigned(*slotposp);
 	*tl++ = txdr_unsigned(maxslot);
 	if (dont_replycache == 0)
 		*tl++ = newnfs_true;
 	else
 		*tl++ = newnfs_false;
 	*tl = 0;			/* No referring call list, for now. */
 	nd->nd_flag |= ND_HASSEQUENCE;
 	return (0);
 }
 
 /*
  * Get a session for the callback.
  */
 static int
 nfsv4_getcbsession(struct nfsclient *clp, struct nfsdsession **sepp)
 {
 	struct nfsdsession *sep;
 
 	NFSLOCKSTATE();
 	LIST_FOREACH(sep, &clp->lc_session, sess_list) {
 		if ((sep->sess_crflags & NFSV4CRSESS_CONNBACKCHAN) != 0)
 			break;
 	}
 	if (sep == NULL) {
 		NFSUNLOCKSTATE();
 		return (NFSERR_BADSESSION);
 	}
 	sep->sess_refcnt++;
 	*sepp = sep;
 	NFSUNLOCKSTATE();
 	return (0);
 }
 
 /*
  * Free up all backchannel xprts.  This needs to be done when the nfsd threads
  * exit, since those transports will all be going away.
  * This is only called after all the nfsd threads are done performing RPCs,
  * so locking shouldn't be an issue.
  */
 void
 nfsrv_freeallbackchannel_xprts(void)
 {
 	struct nfsdsession *sep;
 	struct nfsclient *clp;
 	SVCXPRT *xprt;
 	int i;
 
 	for (i = 0; i < nfsrv_clienthashsize; i++) {
 		LIST_FOREACH(clp, &NFSD_VNET(nfsclienthash)[i], lc_hash) {
 			LIST_FOREACH(sep, &clp->lc_session, sess_list) {
 				xprt = sep->sess_cbsess.nfsess_xprt;
 				sep->sess_cbsess.nfsess_xprt = NULL;
 				if (xprt != NULL)
 					SVC_RELEASE(xprt);
 			}
 		}
 	}
 }
 
 /*
  * Do a layout commit.  Actually just call nfsrv_updatemdsattr().
  * I have no idea if the rest of these arguments will ever be useful?
  */
 int
 nfsrv_layoutcommit(struct nfsrv_descript *nd, vnode_t vp, int layouttype,
     int hasnewoff, uint64_t newoff, uint64_t offset, uint64_t len,
     int hasnewmtime, struct timespec *newmtimep, int reclaim,
     nfsv4stateid_t *stateidp, int maxcnt, char *layp, int *hasnewsizep,
     uint64_t *newsizep, struct ucred *cred, NFSPROC_T *p)
 {
 	struct nfsvattr na;
 	int error;
 
 	error = nfsrv_updatemdsattr(vp, &na, p);
 	if (error == 0) {
 		*hasnewsizep = 1;
 		*newsizep = na.na_size;
 	}
 	return (error);
 }
 
 /*
  * Try and get a layout.
  */
 int
 nfsrv_layoutget(struct nfsrv_descript *nd, vnode_t vp, struct nfsexstuff *exp,
     int layouttype, int *iomode, uint64_t *offset, uint64_t *len,
     uint64_t minlen, nfsv4stateid_t *stateidp, int maxcnt, int *retonclose,
     int *layoutlenp, char *layp, struct ucred *cred, NFSPROC_T *p)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp;
 	char *devid;
 	fhandle_t fh, *dsfhp;
 	int error, mirrorcnt;
 
 	if (nfsrv_devidcnt == 0)
 		return (NFSERR_UNKNLAYOUTTYPE);
 
 	if (*offset != 0)
 		printf("nfsrv_layoutget: off=%ju len=%ju\n", (uintmax_t)*offset,
 		    (uintmax_t)*len);
 	error = nfsvno_getfh(vp, &fh, p);
 	NFSD_DEBUG(4, "layoutget getfh=%d\n", error);
 	if (error != 0)
 		return (error);
 
 	/*
 	 * For now, all layouts are for entire files.
 	 * Only issue Read/Write layouts if requested for a non-readonly fs.
 	 */
 	if (NFSVNO_EXRDONLY(exp)) {
 		if (*iomode == NFSLAYOUTIOMODE_RW)
 			return (NFSERR_LAYOUTTRYLATER);
 		*iomode = NFSLAYOUTIOMODE_READ;
 	}
 	if (*iomode != NFSLAYOUTIOMODE_RW)
 		*iomode = NFSLAYOUTIOMODE_READ;
 
 	/*
 	 * Check to see if a write layout can be issued for this file.
 	 * This is used during mirror recovery to avoid RW layouts being
 	 * issued for a file while it is being copied to the recovered
 	 * mirror.
 	 */
 	if (*iomode == NFSLAYOUTIOMODE_RW && nfsrv_dontlayout(&fh) != 0)
 		return (NFSERR_LAYOUTTRYLATER);
 
 	*retonclose = 0;
 	*offset = 0;
 	*len = UINT64_MAX;
 
 	/* First, see if a layout already exists and return if found. */
 	lhyp = NFSLAYOUTHASH(&fh);
 	NFSLOCKLAYOUT(lhyp);
 	error = nfsrv_findlayout(&nd->nd_clientid, &fh, layouttype, p, &lyp);
 	NFSD_DEBUG(4, "layoutget findlay=%d\n", error);
 	/*
 	 * Not sure if the seqid must be the same, so I won't check it.
 	 */
 	if (error == 0 && (stateidp->other[0] != lyp->lay_stateid.other[0] ||
 	    stateidp->other[1] != lyp->lay_stateid.other[1] ||
 	    stateidp->other[2] != lyp->lay_stateid.other[2])) {
 		if ((lyp->lay_flags & NFSLAY_CALLB) == 0) {
 			NFSUNLOCKLAYOUT(lhyp);
 			NFSD_DEBUG(1, "ret bad stateid\n");
 			return (NFSERR_BADSTATEID);
 		}
 		/*
 		 * I believe we get here because there is a race between
 		 * the client processing the CBLAYOUTRECALL and the layout
 		 * being deleted here on the server.
 		 * The client has now done a LayoutGet with a non-layout
 		 * stateid, as it would when there is no layout.
 		 * As such, free this layout and set error == NFSERR_BADSTATEID
 		 * so the code below will create a new layout structure as
 		 * would happen if no layout was found.
 		 * "lyp" will be set before being used below, but set it NULL
 		 * as a safety belt.
 		 */
 		nfsrv_freelayout(&lhyp->list, lyp);
 		lyp = NULL;
 		error = NFSERR_BADSTATEID;
 	}
 	if (error == 0) {
 		if (lyp->lay_layoutlen > maxcnt) {
 			NFSUNLOCKLAYOUT(lhyp);
 			NFSD_DEBUG(1, "ret layout too small\n");
 			return (NFSERR_TOOSMALL);
 		}
 		if (*iomode == NFSLAYOUTIOMODE_RW) {
 			if ((lyp->lay_flags & NFSLAY_NOSPC) != 0) {
 				NFSUNLOCKLAYOUT(lhyp);
 				NFSD_DEBUG(1, "ret layout nospace\n");
 				return (NFSERR_NOSPC);
 			}
 			lyp->lay_flags |= NFSLAY_RW;
 		} else
 			lyp->lay_flags |= NFSLAY_READ;
 		NFSBCOPY(lyp->lay_xdr, layp, lyp->lay_layoutlen);
 		*layoutlenp = lyp->lay_layoutlen;
 		if (++lyp->lay_stateid.seqid == 0)
 			lyp->lay_stateid.seqid = 1;
 		stateidp->seqid = lyp->lay_stateid.seqid;
 		NFSUNLOCKLAYOUT(lhyp);
 		NFSD_DEBUG(4, "ret fnd layout\n");
 		return (0);
 	}
 	NFSUNLOCKLAYOUT(lhyp);
 
 	/* Find the device id and file handle. */
 	dsfhp = malloc(sizeof(fhandle_t) * NFSDEV_MAXMIRRORS, M_TEMP, M_WAITOK);
 	devid = malloc(NFSX_V4DEVICEID * NFSDEV_MAXMIRRORS, M_TEMP, M_WAITOK);
 	error = nfsrv_dsgetdevandfh(vp, p, &mirrorcnt, dsfhp, devid);
 	NFSD_DEBUG(4, "layoutget devandfh=%d\n", error);
 	if (error == 0) {
 		if (layouttype == NFSLAYOUT_NFSV4_1_FILES) {
 			if (NFSX_V4FILELAYOUT > maxcnt)
 				error = NFSERR_TOOSMALL;
 			else
 				lyp = nfsrv_filelayout(nd, *iomode, &fh, dsfhp,
 				    devid, vp->v_mount->mnt_stat.f_fsid);
 		} else {
 			if (NFSX_V4FLEXLAYOUT(mirrorcnt) > maxcnt)
 				error = NFSERR_TOOSMALL;
 			else
 				lyp = nfsrv_flexlayout(nd, *iomode, mirrorcnt,
 				    &fh, dsfhp, devid,
 				    vp->v_mount->mnt_stat.f_fsid);
 		}
 	}
 	free(dsfhp, M_TEMP);
 	free(devid, M_TEMP);
 	if (error != 0)
 		return (error);
 
 	/*
 	 * Now, add this layout to the list.
 	 */
 	error = nfsrv_addlayout(nd, &lyp, stateidp, layp, layoutlenp, p);
 	NFSD_DEBUG(4, "layoutget addl=%d\n", error);
 	/*
 	 * The lyp will be set to NULL by nfsrv_addlayout() if it
 	 * linked the new structure into the lists.
 	 */
 	free(lyp, M_NFSDSTATE);
 	return (error);
 }
 
 /*
  * Generate a File Layout.
  */
 static struct nfslayout *
 nfsrv_filelayout(struct nfsrv_descript *nd, int iomode, fhandle_t *fhp,
     fhandle_t *dsfhp, char *devid, fsid_t fs)
 {
 	uint32_t *tl;
 	struct nfslayout *lyp;
 	uint64_t pattern_offset;
 
 	lyp = malloc(sizeof(struct nfslayout) + NFSX_V4FILELAYOUT, M_NFSDSTATE,
 	    M_WAITOK | M_ZERO);
 	lyp->lay_type = NFSLAYOUT_NFSV4_1_FILES;
 	if (iomode == NFSLAYOUTIOMODE_RW)
 		lyp->lay_flags = NFSLAY_RW;
 	else
 		lyp->lay_flags = NFSLAY_READ;
 	NFSBCOPY(fhp, &lyp->lay_fh, sizeof(*fhp));
 	lyp->lay_clientid.qval = nd->nd_clientid.qval;
 	lyp->lay_fsid = fs;
 	NFSBCOPY(devid, lyp->lay_deviceid, NFSX_V4DEVICEID);
 
 	/* Fill in the xdr for the files layout. */
 	tl = (uint32_t *)lyp->lay_xdr;
 	NFSBCOPY(devid, tl, NFSX_V4DEVICEID);		/* Device ID. */
 	tl += (NFSX_V4DEVICEID / NFSX_UNSIGNED);
 
 	/* Set the stripe size to the maximum I/O size. */
 	*tl++ = txdr_unsigned(nfs_srvmaxio & NFSFLAYUTIL_STRIPE_MASK);
 	*tl++ = 0;					/* 1st stripe index. */
 	pattern_offset = 0;
 	txdr_hyper(pattern_offset, tl); tl += 2;	/* Pattern offset. */
 	*tl++ = txdr_unsigned(1);			/* 1 file handle. */
 	*tl++ = txdr_unsigned(NFSX_V4PNFSFH);
 	NFSBCOPY(dsfhp, tl, sizeof(*dsfhp));
 	lyp->lay_layoutlen = NFSX_V4FILELAYOUT;
 	return (lyp);
 }
 
 #define	FLEX_OWNERID	"999"
 #define	FLEX_UID0	"0"
 /*
  * Generate a Flex File Layout.
  * The FLEX_OWNERID can be any string of 3 decimal digits. Although this
  * string goes on the wire, it isn't supposed to be used by the client,
  * since this server uses tight coupling.
  * Although not recommended by the spec., if vfs.nfsd.flexlinuxhack=1 use
  * a string of "0". This works around the Linux Flex File Layout driver bug
  * which uses the synthetic uid/gid strings for the "tightly coupled" case.
  */
 static struct nfslayout *
 nfsrv_flexlayout(struct nfsrv_descript *nd, int iomode, int mirrorcnt,
     fhandle_t *fhp, fhandle_t *dsfhp, char *devid, fsid_t fs)
 {
 	uint32_t *tl;
 	struct nfslayout *lyp;
 	uint64_t lenval;
 	int i;
 
 	lyp = malloc(sizeof(struct nfslayout) + NFSX_V4FLEXLAYOUT(mirrorcnt),
 	    M_NFSDSTATE, M_WAITOK | M_ZERO);
 	lyp->lay_type = NFSLAYOUT_FLEXFILE;
 	if (iomode == NFSLAYOUTIOMODE_RW)
 		lyp->lay_flags = NFSLAY_RW;
 	else
 		lyp->lay_flags = NFSLAY_READ;
 	NFSBCOPY(fhp, &lyp->lay_fh, sizeof(*fhp));
 	lyp->lay_clientid.qval = nd->nd_clientid.qval;
 	lyp->lay_fsid = fs;
 	lyp->lay_mirrorcnt = mirrorcnt;
 	NFSBCOPY(devid, lyp->lay_deviceid, NFSX_V4DEVICEID);
 
 	/* Fill in the xdr for the files layout. */
 	tl = (uint32_t *)lyp->lay_xdr;
 	lenval = 0;
 	txdr_hyper(lenval, tl); tl += 2;		/* Stripe unit. */
 	*tl++ = txdr_unsigned(mirrorcnt);		/* # of mirrors. */
 	for (i = 0; i < mirrorcnt; i++) {
 		*tl++ = txdr_unsigned(1);		/* One stripe. */
 		NFSBCOPY(devid, tl, NFSX_V4DEVICEID);	/* Device ID. */
 		tl += (NFSX_V4DEVICEID / NFSX_UNSIGNED);
 		devid += NFSX_V4DEVICEID;
 		*tl++ = txdr_unsigned(1);		/* Efficiency. */
 		*tl++ = 0;				/* Proxy Stateid. */
 		*tl++ = 0x55555555;
 		*tl++ = 0x55555555;
 		*tl++ = 0x55555555;
 		*tl++ = txdr_unsigned(1);		/* 1 file handle. */
 		*tl++ = txdr_unsigned(NFSX_V4PNFSFH);
 		NFSBCOPY(dsfhp, tl, sizeof(*dsfhp));
 		tl += (NFSM_RNDUP(NFSX_V4PNFSFH) / NFSX_UNSIGNED);
 		dsfhp++;
 		if (nfsrv_flexlinuxhack != 0) {
 			*tl++ = txdr_unsigned(strlen(FLEX_UID0));
 			*tl = 0;		/* 0 pad string. */
 			NFSBCOPY(FLEX_UID0, tl++, strlen(FLEX_UID0));
 			*tl++ = txdr_unsigned(strlen(FLEX_UID0));
 			*tl = 0;		/* 0 pad string. */
 			NFSBCOPY(FLEX_UID0, tl++, strlen(FLEX_UID0));
 		} else {
 			*tl++ = txdr_unsigned(strlen(FLEX_OWNERID));
 			NFSBCOPY(FLEX_OWNERID, tl++, NFSX_UNSIGNED);
 			*tl++ = txdr_unsigned(strlen(FLEX_OWNERID));
 			NFSBCOPY(FLEX_OWNERID, tl++, NFSX_UNSIGNED);
 		}
 	}
 	*tl++ = txdr_unsigned(0);		/* ff_flags. */
 	*tl = txdr_unsigned(60);		/* Status interval hint. */
 	lyp->lay_layoutlen = NFSX_V4FLEXLAYOUT(mirrorcnt);
 	return (lyp);
 }
 
 /*
  * Parse and process Flex File errors returned via LayoutReturn.
  */
 static void
 nfsrv_flexlayouterr(struct nfsrv_descript *nd, uint32_t *layp, int maxcnt,
     NFSPROC_T *p)
 {
 	uint32_t *tl;
 	int cnt, errcnt, i, j, opnum, stat;
 	char devid[NFSX_V4DEVICEID];
 
 	tl = layp;
 	maxcnt -= NFSX_UNSIGNED;
 	if (maxcnt > 0)
 		cnt = fxdr_unsigned(int, *tl++);
 	else
 		cnt = 0;
 	NFSD_DEBUG(4, "flexlayouterr cnt=%d\n", cnt);
 	for (i = 0; i < cnt; i++) {
 		maxcnt -= NFSX_STATEID + 2 * NFSX_HYPER +
 		    NFSX_UNSIGNED;
 		if (maxcnt <= 0)
 			break;
 		/* Skip offset, length and stateid for now. */
 		tl += (4 + NFSX_STATEID / NFSX_UNSIGNED);
 		errcnt = fxdr_unsigned(int, *tl++);
 		NFSD_DEBUG(4, "flexlayouterr errcnt=%d\n", errcnt);
 		for (j = 0; j < errcnt; j++) {
 			maxcnt -= NFSX_V4DEVICEID + 2 * NFSX_UNSIGNED;
 			if (maxcnt < 0)
 				break;
 			NFSBCOPY(tl, devid, NFSX_V4DEVICEID);
 			tl += (NFSX_V4DEVICEID / NFSX_UNSIGNED);
 			stat = fxdr_unsigned(int, *tl++);
 			opnum = fxdr_unsigned(int, *tl++);
 			NFSD_DEBUG(4, "flexlayouterr op=%d stat=%d\n", opnum,
 			    stat);
 			/*
 			 * Except for NFSERR_ACCES, NFSERR_STALE and
 			 * NFSERR_NOSPC errors, disable the mirror.
 			 */
 			if (stat != NFSERR_ACCES && stat != NFSERR_STALE &&
 			    stat != NFSERR_NOSPC)
 				nfsrv_delds(devid, p);
 
 			/* For NFSERR_NOSPC, mark all devids and layouts. */
 			if (stat == NFSERR_NOSPC)
 				nfsrv_marknospc(devid, true);
 		}
 	}
 }
 
 /*
  * This function removes all flex file layouts which has a mirror with
  * a device id that matches the argument.
  * Called when the DS represented by the device id has failed.
  */
 void
 nfsrv_flexmirrordel(char *devid, NFSPROC_T *p)
 {
 	uint32_t *tl;
 	struct nfslayout *lyp, *nlyp;
 	struct nfslayouthash *lhyp;
 	struct nfslayouthead loclyp;
 	int i, j;
 
 	NFSD_DEBUG(4, "flexmirrordel\n");
 	/* Move all layouts found onto a local list. */
 	TAILQ_INIT(&loclyp);
 	for (i = 0; i < nfsrv_layouthashsize; i++) {
 		lhyp = &nfslayouthash[i];
 		NFSLOCKLAYOUT(lhyp);
 		TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp) {
 			if (lyp->lay_type == NFSLAYOUT_FLEXFILE &&
 			    lyp->lay_mirrorcnt > 1) {
 				NFSD_DEBUG(4, "possible match\n");
 				tl = lyp->lay_xdr;
 				tl += 3;
 				for (j = 0; j < lyp->lay_mirrorcnt; j++) {
 					tl++;
 					if (NFSBCMP(devid, tl, NFSX_V4DEVICEID)
 					    == 0) {
 						/* Found one. */
 						NFSD_DEBUG(4, "fnd one\n");
 						TAILQ_REMOVE(&lhyp->list, lyp,
 						    lay_list);
 						TAILQ_INSERT_HEAD(&loclyp, lyp,
 						    lay_list);
 						break;
 					}
 					tl += (NFSX_V4DEVICEID / NFSX_UNSIGNED +
 					    NFSM_RNDUP(NFSX_V4PNFSFH) /
 					    NFSX_UNSIGNED + 11 * NFSX_UNSIGNED);
 				}
 			}
 		}
 		NFSUNLOCKLAYOUT(lhyp);
 	}
 
 	/* Now, try to do a Layout recall for each one found. */
 	TAILQ_FOREACH_SAFE(lyp, &loclyp, lay_list, nlyp) {
 		NFSD_DEBUG(4, "do layout recall\n");
 		/*
 		 * The layout stateid.seqid needs to be incremented
 		 * before doing a LAYOUT_RECALL callback.
 		 */
 		if (++lyp->lay_stateid.seqid == 0)
 			lyp->lay_stateid.seqid = 1;
 		nfsrv_recalllayout(lyp->lay_clientid, &lyp->lay_stateid,
 		    &lyp->lay_fh, lyp, 1, lyp->lay_type, p);
 		nfsrv_freelayout(&loclyp, lyp);
 	}
 }
 
 /*
  * Do a recall callback to the client for this layout.
  */
 static int
 nfsrv_recalllayout(nfsquad_t clid, nfsv4stateid_t *stateidp, fhandle_t *fhp,
     struct nfslayout *lyp, int changed, int laytype, NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	int error;
 
 	NFSD_DEBUG(4, "nfsrv_recalllayout\n");
 	error = nfsrv_getclient(clid, 0, &clp, NULL, (nfsquad_t)((u_quad_t)0),
 	    0, NULL, p);
 	NFSD_DEBUG(4, "aft nfsrv_getclient=%d\n", error);
 	if (error != 0) {
 		printf("nfsrv_recalllayout: getclient err=%d\n", error);
 		return (error);
 	}
 	if ((clp->lc_flags & LCL_NFSV41) != 0) {
 		error = nfsrv_docallback(clp, NFSV4OP_CBLAYOUTRECALL,
 		    stateidp, changed, fhp, NULL, NULL, laytype, p);
 		/* If lyp != NULL, handle an error return here. */
 		if (error != 0 && lyp != NULL) {
 			NFSDRECALLLOCK();
 			/*
 			 * Mark it returned, since no layout recall
 			 * has been done.
 			 * All errors seem to be non-recoverable, although
 			 * NFSERR_NOMATCHLAYOUT is a normal event.
 			 */
 			if ((lyp->lay_flags & NFSLAY_RECALL) != 0) {
 				lyp->lay_flags |= NFSLAY_RETURNED;
 				wakeup(lyp);
 			}
 			NFSDRECALLUNLOCK();
 			if (error != NFSERR_NOMATCHLAYOUT)
 				printf("nfsrv_recalllayout: err=%d\n", error);
 		}
 	} else
 		printf("nfsrv_recalllayout: clp not NFSv4.1\n");
 	return (error);
 }
 
 /*
  * Find a layout to recall when we exceed our high water mark.
  */
 void
 nfsrv_recalloldlayout(NFSPROC_T *p)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp;
 	nfsquad_t clientid;
 	nfsv4stateid_t stateid;
 	fhandle_t fh;
 	int error, laytype = 0, ret;
 
 	lhyp = &nfslayouthash[arc4random() % nfsrv_layouthashsize];
 	NFSLOCKLAYOUT(lhyp);
 	TAILQ_FOREACH_REVERSE(lyp, &lhyp->list, nfslayouthead, lay_list) {
 		if ((lyp->lay_flags & NFSLAY_CALLB) == 0) {
 			lyp->lay_flags |= NFSLAY_CALLB;
 			/*
 			 * The layout stateid.seqid needs to be incremented
 			 * before doing a LAYOUT_RECALL callback.
 			 */
 			if (++lyp->lay_stateid.seqid == 0)
 				lyp->lay_stateid.seqid = 1;
 			clientid = lyp->lay_clientid;
 			stateid = lyp->lay_stateid;
 			NFSBCOPY(&lyp->lay_fh, &fh, sizeof(fh));
 			laytype = lyp->lay_type;
 			break;
 		}
 	}
 	NFSUNLOCKLAYOUT(lhyp);
 	if (lyp != NULL) {
 		error = nfsrv_recalllayout(clientid, &stateid, &fh, NULL, 0,
 		    laytype, p);
 		if (error != 0 && error != NFSERR_NOMATCHLAYOUT)
 			NFSD_DEBUG(4, "recallold=%d\n", error);
 		if (error != 0) {
 			NFSLOCKLAYOUT(lhyp);
 			/*
 			 * Since the hash list was unlocked, we need to
 			 * find it again.
 			 */
 			ret = nfsrv_findlayout(&clientid, &fh, laytype, p,
 			    &lyp);
 			if (ret == 0 &&
 			    (lyp->lay_flags & NFSLAY_CALLB) != 0 &&
 			    lyp->lay_stateid.other[0] == stateid.other[0] &&
 			    lyp->lay_stateid.other[1] == stateid.other[1] &&
 			    lyp->lay_stateid.other[2] == stateid.other[2]) {
 				/*
 				 * The client no longer knows this layout, so
 				 * it can be free'd now.
 				 */
 				if (error == NFSERR_NOMATCHLAYOUT)
 					nfsrv_freelayout(&lhyp->list, lyp);
 				else {
 					/*
 					 * Leave it to be tried later by
 					 * clearing NFSLAY_CALLB and moving
 					 * it to the head of the list, so it
 					 * won't be tried again for a while.
 					 */
 					lyp->lay_flags &= ~NFSLAY_CALLB;
 					TAILQ_REMOVE(&lhyp->list, lyp,
 					    lay_list);
 					TAILQ_INSERT_HEAD(&lhyp->list, lyp,
 					    lay_list);
 				}
 			}
 			NFSUNLOCKLAYOUT(lhyp);
 		}
 	}
 }
 
 /*
  * Try and return layout(s).
  */
 int
 nfsrv_layoutreturn(struct nfsrv_descript *nd, vnode_t vp,
     int layouttype, int iomode, uint64_t offset, uint64_t len, int reclaim,
     int kind, nfsv4stateid_t *stateidp, int maxcnt, uint32_t *layp, int *fndp,
     struct ucred *cred, NFSPROC_T *p)
 {
 	struct nfsvattr na;
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp;
 	fhandle_t fh;
 	int error = 0;
 
 	*fndp = 0;
 	if (kind == NFSV4LAYOUTRET_FILE) {
 		error = nfsvno_getfh(vp, &fh, p);
 		if (error == 0) {
 			error = nfsrv_updatemdsattr(vp, &na, p);
 			if (error != 0)
 				printf("nfsrv_layoutreturn: updatemdsattr"
 				    " failed=%d\n", error);
 		}
 		if (error == 0) {
 			if (reclaim == newnfs_true) {
 				error = nfsrv_checkgrace(NULL, NULL,
 				    NFSLCK_RECLAIM);
 				if (error != NFSERR_NOGRACE)
 					error = 0;
 				return (error);
 			}
 			lhyp = NFSLAYOUTHASH(&fh);
 			NFSDRECALLLOCK();
 			NFSLOCKLAYOUT(lhyp);
 			error = nfsrv_findlayout(&nd->nd_clientid, &fh,
 			    layouttype, p, &lyp);
 			NFSD_DEBUG(4, "layoutret findlay=%d\n", error);
 			if (error == 0 &&
 			    stateidp->other[0] == lyp->lay_stateid.other[0] &&
 			    stateidp->other[1] == lyp->lay_stateid.other[1] &&
 			    stateidp->other[2] == lyp->lay_stateid.other[2]) {
 				NFSD_DEBUG(4, "nfsrv_layoutreturn: stateid %d"
 				    " %x %x %x laystateid %d %x %x %x"
 				    " off=%ju len=%ju flgs=0x%x\n",
 				    stateidp->seqid, stateidp->other[0],
 				    stateidp->other[1], stateidp->other[2],
 				    lyp->lay_stateid.seqid,
 				    lyp->lay_stateid.other[0],
 				    lyp->lay_stateid.other[1],
 				    lyp->lay_stateid.other[2],
 				    (uintmax_t)offset, (uintmax_t)len,
 				    lyp->lay_flags);
 				if (++lyp->lay_stateid.seqid == 0)
 					lyp->lay_stateid.seqid = 1;
 				stateidp->seqid = lyp->lay_stateid.seqid;
 				if (offset == 0 && len == UINT64_MAX) {
 					if ((iomode & NFSLAYOUTIOMODE_READ) !=
 					    0)
 						lyp->lay_flags &= ~NFSLAY_READ;
 					if ((iomode & NFSLAYOUTIOMODE_RW) != 0)
 						lyp->lay_flags &= ~NFSLAY_RW;
 					if ((lyp->lay_flags & (NFSLAY_READ |
 					    NFSLAY_RW)) == 0)
 						nfsrv_freelayout(&lhyp->list,
 						    lyp);
 					else
 						*fndp = 1;
 				} else
 					*fndp = 1;
 			}
 			NFSUNLOCKLAYOUT(lhyp);
 			/* Search the nfsrv_recalllist for a match. */
 			TAILQ_FOREACH(lyp, &nfsrv_recalllisthead, lay_list) {
 				if (NFSBCMP(&lyp->lay_fh, &fh,
 				    sizeof(fh)) == 0 &&
 				    lyp->lay_clientid.qval ==
 				    nd->nd_clientid.qval &&
 				    stateidp->other[0] ==
 				    lyp->lay_stateid.other[0] &&
 				    stateidp->other[1] ==
 				    lyp->lay_stateid.other[1] &&
 				    stateidp->other[2] ==
 				    lyp->lay_stateid.other[2]) {
 					lyp->lay_flags |= NFSLAY_RETURNED;
 					wakeup(lyp);
 					error = 0;
 				}
 			}
 			NFSDRECALLUNLOCK();
 		}
 		if (layouttype == NFSLAYOUT_FLEXFILE && layp != NULL)
 			nfsrv_flexlayouterr(nd, layp, maxcnt, p);
 	} else if (kind == NFSV4LAYOUTRET_FSID)
 		nfsrv_freelayouts(&nd->nd_clientid,
 		    &vp->v_mount->mnt_stat.f_fsid, layouttype, iomode);
 	else if (kind == NFSV4LAYOUTRET_ALL)
 		nfsrv_freelayouts(&nd->nd_clientid, NULL, layouttype, iomode);
 	else
 		error = NFSERR_INVAL;
 	if (error == -1)
 		error = 0;
 	return (error);
 }
 
 /*
  * Look for an existing layout.
  */
 static int
 nfsrv_findlayout(nfsquad_t *clientidp, fhandle_t *fhp, int laytype,
     NFSPROC_T *p, struct nfslayout **lypp)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp;
 	int ret;
 
 	*lypp = NULL;
 	ret = 0;
 	lhyp = NFSLAYOUTHASH(fhp);
 	TAILQ_FOREACH(lyp, &lhyp->list, lay_list) {
 		if (NFSBCMP(&lyp->lay_fh, fhp, sizeof(*fhp)) == 0 &&
 		    lyp->lay_clientid.qval == clientidp->qval &&
 		    lyp->lay_type == laytype)
 			break;
 	}
 	if (lyp != NULL)
 		*lypp = lyp;
 	else
 		ret = -1;
 	return (ret);
 }
 
 /*
  * Add the new layout, as required.
  */
 static int
 nfsrv_addlayout(struct nfsrv_descript *nd, struct nfslayout **lypp,
     nfsv4stateid_t *stateidp, char *layp, int *layoutlenp, NFSPROC_T *p)
 {
 	struct nfsclient *clp;
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 	fhandle_t *fhp;
 	int error;
 
 	KASSERT((nd->nd_flag & ND_IMPLIEDCLID) != 0,
 	    ("nfsrv_layoutget: no nd_clientid\n"));
 	lyp = *lypp;
 	fhp = &lyp->lay_fh;
 	NFSLOCKSTATE();
 	error = nfsrv_getclient((nfsquad_t)((u_quad_t)0), CLOPS_RENEW, &clp,
 	    NULL, (nfsquad_t)((u_quad_t)0), 0, nd, p);
 	if (error != 0) {
 		NFSUNLOCKSTATE();
 		return (error);
 	}
 	lyp->lay_stateid.seqid = stateidp->seqid = 1;
 	lyp->lay_stateid.other[0] = stateidp->other[0] =
 	    clp->lc_clientid.lval[0];
 	lyp->lay_stateid.other[1] = stateidp->other[1] =
 	    clp->lc_clientid.lval[1];
 	lyp->lay_stateid.other[2] = stateidp->other[2] =
 	    nfsrv_nextstateindex(clp);
 	NFSUNLOCKSTATE();
 
 	lhyp = NFSLAYOUTHASH(fhp);
 	NFSLOCKLAYOUT(lhyp);
 	TAILQ_FOREACH(nlyp, &lhyp->list, lay_list) {
 		if (NFSBCMP(&nlyp->lay_fh, fhp, sizeof(*fhp)) == 0 &&
 		    nlyp->lay_clientid.qval == nd->nd_clientid.qval)
 			break;
 	}
 	if (nlyp != NULL) {
 		/* A layout already exists, so use it. */
 		nlyp->lay_flags |= (lyp->lay_flags & (NFSLAY_READ | NFSLAY_RW));
 		NFSBCOPY(nlyp->lay_xdr, layp, nlyp->lay_layoutlen);
 		*layoutlenp = nlyp->lay_layoutlen;
 		if (++nlyp->lay_stateid.seqid == 0)
 			nlyp->lay_stateid.seqid = 1;
 		stateidp->seqid = nlyp->lay_stateid.seqid;
 		stateidp->other[0] = nlyp->lay_stateid.other[0];
 		stateidp->other[1] = nlyp->lay_stateid.other[1];
 		stateidp->other[2] = nlyp->lay_stateid.other[2];
 		NFSUNLOCKLAYOUT(lhyp);
 		return (0);
 	}
 
 	/* Insert the new layout in the lists. */
 	*lypp = NULL;
 	atomic_add_int(&nfsrv_layoutcnt, 1);
 	NFSD_VNET(nfsstatsv1_p)->srvlayouts++;
 	NFSBCOPY(lyp->lay_xdr, layp, lyp->lay_layoutlen);
 	*layoutlenp = lyp->lay_layoutlen;
 	TAILQ_INSERT_HEAD(&lhyp->list, lyp, lay_list);
 	NFSUNLOCKLAYOUT(lhyp);
 	return (0);
 }
 
 /*
  * Get the devinfo for a deviceid.
  */
 int
 nfsrv_getdevinfo(char *devid, int layouttype, uint32_t *maxcnt,
     uint32_t *notify, int *devaddrlen, char **devaddr)
 {
 	struct nfsdevice *ds;
 
 	if ((layouttype != NFSLAYOUT_NFSV4_1_FILES && layouttype !=
 	     NFSLAYOUT_FLEXFILE) ||
 	    (nfsrv_maxpnfsmirror > 1 && layouttype == NFSLAYOUT_NFSV4_1_FILES))
 		return (NFSERR_UNKNLAYOUTTYPE);
 
 	/*
 	 * Now, search for the device id.  Note that the structures won't go
 	 * away, but the order changes in the list.  As such, the lock only
 	 * needs to be held during the search through the list.
 	 */
 	NFSDDSLOCK();
 	TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 		if (NFSBCMP(devid, ds->nfsdev_deviceid, NFSX_V4DEVICEID) == 0 &&
 		    ds->nfsdev_nmp != NULL)
 			break;
 	}
 	NFSDDSUNLOCK();
 	if (ds == NULL)
 		return (NFSERR_NOENT);
 
 	/* If the correct nfsdev_XXXXaddrlen is > 0, we have the device info. */
 	*devaddrlen = 0;
 	if (layouttype == NFSLAYOUT_NFSV4_1_FILES) {
 		*devaddrlen = ds->nfsdev_fileaddrlen;
 		*devaddr = ds->nfsdev_fileaddr;
 	} else if (layouttype == NFSLAYOUT_FLEXFILE) {
 		*devaddrlen = ds->nfsdev_flexaddrlen;
 		*devaddr = ds->nfsdev_flexaddr;
 	}
 	if (*devaddrlen == 0)
 		return (NFSERR_UNKNLAYOUTTYPE);
 
 	/*
 	 * The XDR overhead is 3 unsigned values: layout_type,
 	 * length_of_address and notify bitmap.
 	 * If the notify array is changed to not all zeros, the
 	 * count of unsigned values must be increased.
 	 */
 	if (*maxcnt > 0 && *maxcnt < NFSM_RNDUP(*devaddrlen) +
 	    3 * NFSX_UNSIGNED) {
 		*maxcnt = NFSM_RNDUP(*devaddrlen) + 3 * NFSX_UNSIGNED;
 		return (NFSERR_TOOSMALL);
 	}
 	return (0);
 }
 
 /*
  * Free a list of layout state structures.
  */
 static void
 nfsrv_freelayoutlist(nfsquad_t clientid)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 	int i;
 
 	for (i = 0; i < nfsrv_layouthashsize; i++) {
 		lhyp = &nfslayouthash[i];
 		NFSLOCKLAYOUT(lhyp);
 		TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp) {
 			if (lyp->lay_clientid.qval == clientid.qval)
 				nfsrv_freelayout(&lhyp->list, lyp);
 		}
 		NFSUNLOCKLAYOUT(lhyp);
 	}
 }
 
 /*
  * Free up a layout.
  */
 static void
 nfsrv_freelayout(struct nfslayouthead *lhp, struct nfslayout *lyp)
 {
 
 	NFSD_DEBUG(4, "Freelayout=%p\n", lyp);
 	atomic_add_int(&nfsrv_layoutcnt, -1);
 	NFSD_VNET(nfsstatsv1_p)->srvlayouts--;
 	TAILQ_REMOVE(lhp, lyp, lay_list);
 	free(lyp, M_NFSDSTATE);
 }
 
 /*
  * Free up a device id.
  */
 void
 nfsrv_freeonedevid(struct nfsdevice *ds)
 {
 	int i;
 
 	atomic_add_int(&nfsrv_devidcnt, -1);
 	vrele(ds->nfsdev_dvp);
 	for (i = 0; i < nfsrv_dsdirsize; i++)
 		if (ds->nfsdev_dsdir[i] != NULL)
 			vrele(ds->nfsdev_dsdir[i]);
 	free(ds->nfsdev_fileaddr, M_NFSDSTATE);
 	free(ds->nfsdev_flexaddr, M_NFSDSTATE);
 	free(ds->nfsdev_host, M_NFSDSTATE);
 	free(ds, M_NFSDSTATE);
 }
 
 /*
  * Free up a device id and its mirrors.
  */
 static void
 nfsrv_freedevid(struct nfsdevice *ds)
 {
 
 	TAILQ_REMOVE(&nfsrv_devidhead, ds, nfsdev_list);
 	nfsrv_freeonedevid(ds);
 }
 
 /*
  * Free all layouts and device ids.
  * Done when the nfsd threads are shut down since there may be a new
  * modified device id list created when the nfsd is restarted.
  */
 void
 nfsrv_freealllayoutsanddevids(void)
 {
 	struct nfsdontlist *mrp, *nmrp;
 	struct nfslayout *lyp, *nlyp;
 
 	/* Get rid of the deviceid structures. */
 	nfsrv_freealldevids();
 	TAILQ_INIT(&nfsrv_devidhead);
 	nfsrv_devidcnt = 0;
 
 	/* Get rid of all layouts. */
 	nfsrv_freealllayouts();
 
 	/* Get rid of any nfsdontlist entries. */
 	LIST_FOREACH_SAFE(mrp, &nfsrv_dontlisthead, nfsmr_list, nmrp)
 		free(mrp, M_NFSDSTATE);
 	LIST_INIT(&nfsrv_dontlisthead);
 	nfsrv_dontlistlen = 0;
 
 	/* Free layouts in the recall list. */
 	TAILQ_FOREACH_SAFE(lyp, &nfsrv_recalllisthead, lay_list, nlyp)
 		nfsrv_freelayout(&nfsrv_recalllisthead, lyp);
 	TAILQ_INIT(&nfsrv_recalllisthead);
 }
 
 /*
  * Free layouts that match the arguments.
  */
 static void
 nfsrv_freelayouts(nfsquad_t *clid, fsid_t *fs, int laytype, int iomode)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 	int i;
 
 	for (i = 0; i < nfsrv_layouthashsize; i++) {
 		lhyp = &nfslayouthash[i];
 		NFSLOCKLAYOUT(lhyp);
 		TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp) {
 			if (clid->qval != lyp->lay_clientid.qval)
 				continue;
 			if (fs != NULL && fsidcmp(fs, &lyp->lay_fsid) != 0)
 				continue;
 			if (laytype != lyp->lay_type)
 				continue;
 			if ((iomode & NFSLAYOUTIOMODE_READ) != 0)
 				lyp->lay_flags &= ~NFSLAY_READ;
 			if ((iomode & NFSLAYOUTIOMODE_RW) != 0)
 				lyp->lay_flags &= ~NFSLAY_RW;
 			if ((lyp->lay_flags & (NFSLAY_READ | NFSLAY_RW)) == 0)
 				nfsrv_freelayout(&lhyp->list, lyp);
 		}
 		NFSUNLOCKLAYOUT(lhyp);
 	}
 }
 
 /*
  * Free all layouts for the argument file.
  */
 void
 nfsrv_freefilelayouts(fhandle_t *fhp)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 
 	lhyp = NFSLAYOUTHASH(fhp);
 	NFSLOCKLAYOUT(lhyp);
 	TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp) {
 		if (NFSBCMP(&lyp->lay_fh, fhp, sizeof(*fhp)) == 0)
 			nfsrv_freelayout(&lhyp->list, lyp);
 	}
 	NFSUNLOCKLAYOUT(lhyp);
 }
 
 /*
  * Free all layouts.
  */
 static void
 nfsrv_freealllayouts(void)
 {
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 	int i;
 
 	for (i = 0; i < nfsrv_layouthashsize; i++) {
 		lhyp = &nfslayouthash[i];
 		NFSLOCKLAYOUT(lhyp);
 		TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp)
 			nfsrv_freelayout(&lhyp->list, lyp);
 		NFSUNLOCKLAYOUT(lhyp);
 	}
 }
 
 /*
  * Look up the mount path for the DS server.
  */
 static int
 nfsrv_setdsserver(char *dspathp, char *mdspathp, NFSPROC_T *p,
     struct nfsdevice **dsp)
 {
 	struct nameidata nd;
 	struct nfsdevice *ds;
 	struct mount *mp;
 	int error, i;
 	char *dsdirpath;
 	size_t dsdirsize;
 
 	NFSD_DEBUG(4, "setdssrv path=%s\n", dspathp);
 	*dsp = NULL;
 	if (jailed(p->td_ucred)) {
 		printf("A pNFS nfsd cannot run in a jail\n");
 		return (EPERM);
 	}
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, UIO_SYSSPACE,
 	    dspathp);
 	error = namei(&nd);
 	NFSD_DEBUG(4, "lookup=%d\n", error);
 	if (error != 0)
 		return (error);
 	if (nd.ni_vp->v_type != VDIR) {
 		vput(nd.ni_vp);
 		NFSD_DEBUG(4, "dspath not dir\n");
 		return (ENOTDIR);
 	}
 	if (strcmp(nd.ni_vp->v_mount->mnt_vfc->vfc_name, "nfs") != 0) {
 		vput(nd.ni_vp);
 		NFSD_DEBUG(4, "dspath not an NFS mount\n");
 		return (ENXIO);
 	}
 
 	/*
 	 * Allocate a DS server structure with the NFS mounted directory
 	 * vnode reference counted, so that a non-forced dismount will
 	 * fail with EBUSY.
 	 * This structure is always linked into the list, even if an error
 	 * is being returned.  The caller will free the entire list upon
 	 * an error return.
 	 */
 	*dsp = ds = malloc(sizeof(*ds) + nfsrv_dsdirsize * sizeof(vnode_t),
 	    M_NFSDSTATE, M_WAITOK | M_ZERO);
 	ds->nfsdev_dvp = nd.ni_vp;
 	ds->nfsdev_nmp = VFSTONFS(nd.ni_vp->v_mount);
 	NFSVOPUNLOCK(nd.ni_vp);
 
 	dsdirsize = strlen(dspathp) + 16;
 	dsdirpath = malloc(dsdirsize, M_TEMP, M_WAITOK);
 	/* Now, create the DS directory structures. */
 	for (i = 0; i < nfsrv_dsdirsize; i++) {
 		snprintf(dsdirpath, dsdirsize, "%s/ds%d", dspathp, i);
 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 		    UIO_SYSSPACE, dsdirpath);
 		error = namei(&nd);
 		NFSD_DEBUG(4, "dsdirpath=%s lookup=%d\n", dsdirpath, error);
 		if (error != 0)
 			break;
 		if (nd.ni_vp->v_type != VDIR) {
 			vput(nd.ni_vp);
 			error = ENOTDIR;
 			NFSD_DEBUG(4, "dsdirpath not a VDIR\n");
 			break;
 		}
 		if (strcmp(nd.ni_vp->v_mount->mnt_vfc->vfc_name, "nfs") != 0) {
 			vput(nd.ni_vp);
 			error = ENXIO;
 			NFSD_DEBUG(4, "dsdirpath not an NFS mount\n");
 			break;
 		}
 		ds->nfsdev_dsdir[i] = nd.ni_vp;
 		NFSVOPUNLOCK(nd.ni_vp);
 	}
 	free(dsdirpath, M_TEMP);
 
 	if (strlen(mdspathp) > 0) {
 		/*
 		 * This DS stores file for a specific MDS exported file
 		 * system.
 		 */
 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 		    UIO_SYSSPACE, mdspathp);
 		error = namei(&nd);
 		NFSD_DEBUG(4, "mds lookup=%d\n", error);
 		if (error != 0)
 			goto out;
 		if (nd.ni_vp->v_type != VDIR) {
 			vput(nd.ni_vp);
 			error = ENOTDIR;
 			NFSD_DEBUG(4, "mdspath not dir\n");
 			goto out;
 		}
 		mp = nd.ni_vp->v_mount;
 		if ((mp->mnt_flag & MNT_EXPORTED) == 0) {
 			vput(nd.ni_vp);
 			error = ENXIO;
 			NFSD_DEBUG(4, "mdspath not an exported fs\n");
 			goto out;
 		}
 		ds->nfsdev_mdsfsid = mp->mnt_stat.f_fsid;
 		ds->nfsdev_mdsisset = 1;
 		vput(nd.ni_vp);
 	}
 
 out:
 	TAILQ_INSERT_TAIL(&nfsrv_devidhead, ds, nfsdev_list);
 	atomic_add_int(&nfsrv_devidcnt, 1);
 	return (error);
 }
 
 /*
  * Look up the mount path for the DS server and delete it.
  */
 int
 nfsrv_deldsserver(int op, char *dspathp, NFSPROC_T *p)
 {
 	struct mount *mp;
 	struct nfsmount *nmp;
 	struct nfsdevice *ds;
 	int error;
 
 	NFSD_DEBUG(4, "deldssrv path=%s\n", dspathp);
 	/*
 	 * Search for the path in the mount list.  Avoid looking the path
 	 * up, since this mount point may be hung, with associated locked
 	 * vnodes, etc.
 	 * Set NFSMNTP_CANCELRPCS so that any forced dismount will be blocked
 	 * until this completes.
 	 * As noted in the man page, this should be done before any forced
 	 * dismount on the mount point, but at least the handshake on
 	 * NFSMNTP_CANCELRPCS should make it safe.
 	 */
 	error = 0;
 	ds = NULL;
 	nmp = NULL;
 	mtx_lock(&mountlist_mtx);
 	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
 		if (strcmp(mp->mnt_stat.f_mntonname, dspathp) == 0 &&
 		    strcmp(mp->mnt_stat.f_fstypename, "nfs") == 0 &&
 		    mp->mnt_data != NULL) {
 			nmp = VFSTONFS(mp);
 			NFSLOCKMNT(nmp);
 			if ((nmp->nm_privflag & (NFSMNTP_FORCEDISM |
 			     NFSMNTP_CANCELRPCS)) == 0) {
 				nmp->nm_privflag |= NFSMNTP_CANCELRPCS;
 				NFSUNLOCKMNT(nmp);
 			} else {
 				NFSUNLOCKMNT(nmp);
 				nmp = NULL;
 			}
 			break;
 		}
 	}
 	mtx_unlock(&mountlist_mtx);
 
 	if (nmp != NULL) {
 		ds = nfsrv_deldsnmp(op, nmp, p);
 		NFSD_DEBUG(4, "deldsnmp=%p\n", ds);
 		if (ds != NULL) {
 			nfsrv_killrpcs(nmp);
 			NFSD_DEBUG(4, "aft killrpcs\n");
 		} else
 			error = ENXIO;
 		NFSLOCKMNT(nmp);
 		nmp->nm_privflag &= ~NFSMNTP_CANCELRPCS;
 		wakeup(nmp);
 		NFSUNLOCKMNT(nmp);
 	} else
 		error = EINVAL;
 	return (error);
 }
 
 /*
  * Search for and remove a DS entry which matches the "nmp" argument.
  * The nfsdevice structure pointer is returned so that the caller can
  * free it via nfsrv_freeonedevid().
  * For the forced case, do not try to do LayoutRecalls, since the server
  * must be shut down now anyhow.
  */
 struct nfsdevice *
 nfsrv_deldsnmp(int op, struct nfsmount *nmp, NFSPROC_T *p)
 {
 	struct nfsdevice *fndds;
 
 	NFSD_DEBUG(4, "deldsdvp\n");
 	NFSDDSLOCK();
 	if (op == PNFSDOP_FORCEDELDS)
 		fndds = nfsv4_findmirror(nmp);
 	else
 		fndds = nfsrv_findmirroredds(nmp);
 	if (fndds != NULL)
 		nfsrv_deleteds(fndds);
 	NFSDDSUNLOCK();
 	if (fndds != NULL) {
 		if (op != PNFSDOP_FORCEDELDS)
 			nfsrv_flexmirrordel(fndds->nfsdev_deviceid, p);
 		printf("pNFS server: mirror %s failed\n", fndds->nfsdev_host);
 	}
 	return (fndds);
 }
 
 /*
  * Similar to nfsrv_deldsnmp(), except that the DS is indicated by deviceid.
  * This function also calls nfsrv_killrpcs() to unblock RPCs on the mount
  * point.
  * Also, returns an error instead of the nfsdevice found.
  */
 int
 nfsrv_delds(char *devid, NFSPROC_T *p)
 {
 	struct nfsdevice *ds, *fndds;
 	struct nfsmount *nmp;
 	int fndmirror;
 
 	NFSD_DEBUG(4, "delds\n");
 	/*
 	 * Search the DS server list for a match with devid.
 	 * Remove the DS entry if found and there is a mirror.
 	 */
 	fndds = NULL;
 	nmp = NULL;
 	fndmirror = 0;
 	NFSDDSLOCK();
 	TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 		if (NFSBCMP(ds->nfsdev_deviceid, devid, NFSX_V4DEVICEID) == 0 &&
 		    ds->nfsdev_nmp != NULL) {
 			NFSD_DEBUG(4, "fnd main ds\n");
 			fndds = ds;
 			break;
 		}
 	}
 	if (fndds == NULL) {
 		NFSDDSUNLOCK();
 		return (ENXIO);
 	}
 	if (fndds->nfsdev_mdsisset == 0 && nfsrv_faildscnt > 0)
 		fndmirror = 1;
 	else if (fndds->nfsdev_mdsisset != 0) {
 		/* For the fsid is set case, search for a mirror. */
 		TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 			if (ds != fndds && ds->nfsdev_nmp != NULL &&
 			    ds->nfsdev_mdsisset != 0 &&
 			    fsidcmp(&ds->nfsdev_mdsfsid,
 			    &fndds->nfsdev_mdsfsid) == 0) {
 				fndmirror = 1;
 				break;
 			}
 		}
 	}
 	if (fndmirror != 0) {
 		nmp = fndds->nfsdev_nmp;
 		NFSLOCKMNT(nmp);
 		if ((nmp->nm_privflag & (NFSMNTP_FORCEDISM |
 		     NFSMNTP_CANCELRPCS)) == 0) {
 			nmp->nm_privflag |= NFSMNTP_CANCELRPCS;
 			NFSUNLOCKMNT(nmp);
 			nfsrv_deleteds(fndds);
 		} else {
 			NFSUNLOCKMNT(nmp);
 			nmp = NULL;
 		}
 	}
 	NFSDDSUNLOCK();
 	if (nmp != NULL) {
 		nfsrv_flexmirrordel(fndds->nfsdev_deviceid, p);
 		printf("pNFS server: mirror %s failed\n", fndds->nfsdev_host);
 		nfsrv_killrpcs(nmp);
 		NFSLOCKMNT(nmp);
 		nmp->nm_privflag &= ~NFSMNTP_CANCELRPCS;
 		wakeup(nmp);
 		NFSUNLOCKMNT(nmp);
 		return (0);
 	}
 	return (ENXIO);
 }
 
 /*
  * Mark a DS as disabled by setting nfsdev_nmp = NULL.
  */
 static void
 nfsrv_deleteds(struct nfsdevice *fndds)
 {
 
 	NFSD_DEBUG(4, "deleteds: deleting a mirror\n");
 	fndds->nfsdev_nmp = NULL;
 	if (fndds->nfsdev_mdsisset == 0)
 		nfsrv_faildscnt--;
 }
 
 /*
  * Fill in the addr structures for the File and Flex File layouts.
  */
 static void
 nfsrv_allocdevid(struct nfsdevice *ds, char *addr, char *dnshost)
 {
 	uint32_t *tl;
 	char *netprot;
 	int addrlen;
 	static uint64_t new_devid = 0;
 
 	if (strchr(addr, ':') != NULL)
 		netprot = "tcp6";
 	else
 		netprot = "tcp";
 
 	/* Fill in the device id. */
 	NFSBCOPY(&nfsdev_time, ds->nfsdev_deviceid, sizeof(nfsdev_time));
 	new_devid++;
 	NFSBCOPY(&new_devid, &ds->nfsdev_deviceid[sizeof(nfsdev_time)],
 	    sizeof(new_devid));
 
 	/*
 	 * Fill in the file addr (actually the nfsv4_file_layout_ds_addr4
 	 * as defined in RFC5661) in XDR.
 	 */
 	addrlen = NFSM_RNDUP(strlen(addr)) + NFSM_RNDUP(strlen(netprot)) +
 	    6 * NFSX_UNSIGNED;
 	NFSD_DEBUG(4, "hn=%s addr=%s netprot=%s\n", dnshost, addr, netprot);
 	ds->nfsdev_fileaddrlen = addrlen;
 	tl = malloc(addrlen, M_NFSDSTATE, M_WAITOK | M_ZERO);
 	ds->nfsdev_fileaddr = (char *)tl;
 	*tl++ = txdr_unsigned(1);		/* One stripe with index 0. */
 	*tl++ = 0;
 	*tl++ = txdr_unsigned(1);		/* One multipath list */
 	*tl++ = txdr_unsigned(1);		/* with one entry in it. */
 	/* The netaddr for this one entry. */
 	*tl++ = txdr_unsigned(strlen(netprot));
 	NFSBCOPY(netprot, tl, strlen(netprot));
 	tl += (NFSM_RNDUP(strlen(netprot)) / NFSX_UNSIGNED);
 	*tl++ = txdr_unsigned(strlen(addr));
 	NFSBCOPY(addr, tl, strlen(addr));
 
 	/*
 	 * Fill in the flex file addr (actually the ff_device_addr4
 	 * as defined for Flexible File Layout) in XDR.
 	 */
 	addrlen = NFSM_RNDUP(strlen(addr)) + NFSM_RNDUP(strlen(netprot)) +
 	    14 * NFSX_UNSIGNED;
 	ds->nfsdev_flexaddrlen = addrlen;
 	tl = malloc(addrlen, M_NFSDSTATE, M_WAITOK | M_ZERO);
 	ds->nfsdev_flexaddr = (char *)tl;
 	*tl++ = txdr_unsigned(1);		/* One multipath entry. */
 	/* The netaddr for this one entry. */
 	*tl++ = txdr_unsigned(strlen(netprot));
 	NFSBCOPY(netprot, tl, strlen(netprot));
 	tl += (NFSM_RNDUP(strlen(netprot)) / NFSX_UNSIGNED);
 	*tl++ = txdr_unsigned(strlen(addr));
 	NFSBCOPY(addr, tl, strlen(addr));
 	tl += (NFSM_RNDUP(strlen(addr)) / NFSX_UNSIGNED);
 	*tl++ = txdr_unsigned(2);		/* Two NFS Versions. */
 	*tl++ = txdr_unsigned(NFS_VER4);	/* NFSv4. */
 	*tl++ = txdr_unsigned(NFSV42_MINORVERSION); /* Minor version 2. */
 	*tl++ = txdr_unsigned(nfs_srvmaxio);	/* DS max rsize. */
 	*tl++ = txdr_unsigned(nfs_srvmaxio);	/* DS max wsize. */
 	*tl++ = newnfs_true;			/* Tightly coupled. */
 	*tl++ = txdr_unsigned(NFS_VER4);	/* NFSv4. */
 	*tl++ = txdr_unsigned(NFSV41_MINORVERSION); /* Minor version 1. */
 	*tl++ = txdr_unsigned(nfs_srvmaxio);	/* DS max rsize. */
 	*tl++ = txdr_unsigned(nfs_srvmaxio);	/* DS max wsize. */
 	*tl = newnfs_true;			/* Tightly coupled. */
 
 	ds->nfsdev_hostnamelen = strlen(dnshost);
 	ds->nfsdev_host = malloc(ds->nfsdev_hostnamelen + 1, M_NFSDSTATE,
 	    M_WAITOK);
 	NFSBCOPY(dnshost, ds->nfsdev_host, ds->nfsdev_hostnamelen + 1);
 }
 
 /*
  * Create the device id list.
  * Return 0 if the nfsd threads are to run and ENXIO if the "-p" argument
  * is misconfigured.
  */
 int
 nfsrv_createdevids(struct nfsd_nfsd_args *args, NFSPROC_T *p)
 {
 	struct nfsdevice *ds;
 	char *addrp, *dnshostp, *dspathp, *mdspathp;
 	int error, i;
 
 	addrp = args->addr;
 	dnshostp = args->dnshost;
 	dspathp = args->dspath;
 	mdspathp = args->mdspath;
 	nfsrv_maxpnfsmirror = args->mirrorcnt;
 	if (addrp == NULL || dnshostp == NULL || dspathp == NULL ||
 	    mdspathp == NULL)
 		return (0);
 
 	/*
 	 * Loop around for each nul-terminated string in args->addr,
 	 * args->dnshost, args->dnspath and args->mdspath.
 	 */
 	while (addrp < (args->addr + args->addrlen) &&
 	    dnshostp < (args->dnshost + args->dnshostlen) &&
 	    dspathp < (args->dspath + args->dspathlen) &&
 	    mdspathp < (args->mdspath + args->mdspathlen)) {
 		error = nfsrv_setdsserver(dspathp, mdspathp, p, &ds);
 		if (error != 0) {
 			/* Free all DS servers. */
 			nfsrv_freealldevids();
 			nfsrv_devidcnt = 0;
 			return (ENXIO);
 		}
 		nfsrv_allocdevid(ds, addrp, dnshostp);
 		addrp += (strlen(addrp) + 1);
 		dnshostp += (strlen(dnshostp) + 1);
 		dspathp += (strlen(dspathp) + 1);
 		mdspathp += (strlen(mdspathp) + 1);
 	}
 	if (nfsrv_devidcnt < nfsrv_maxpnfsmirror) {
 		/* Free all DS servers. */
 		nfsrv_freealldevids();
 		nfsrv_devidcnt = 0;
 		nfsrv_maxpnfsmirror = 1;
 		return (ENXIO);
 	}
 	/* We can fail at most one less DS than the mirror level. */
 	nfsrv_faildscnt = nfsrv_maxpnfsmirror - 1;
 
 	/*
 	 * Allocate the nfslayout hash table now, since this is a pNFS server.
 	 * Make it 1% of the high water mark and at least 100.
 	 */
 	if (nfslayouthash == NULL) {
 		nfsrv_layouthashsize = nfsrv_layouthighwater / 100;
 		if (nfsrv_layouthashsize < 100)
 			nfsrv_layouthashsize = 100;
 		nfslayouthash = mallocarray(nfsrv_layouthashsize,
 		    sizeof(struct nfslayouthash), M_NFSDSESSION, M_WAITOK |
 		    M_ZERO);
 		for (i = 0; i < nfsrv_layouthashsize; i++) {
 			mtx_init(&nfslayouthash[i].mtx, "nfslm", NULL, MTX_DEF);
 			TAILQ_INIT(&nfslayouthash[i].list);
 		}
 	}
 	return (0);
 }
 
 /*
  * Free all device ids.
  */
 static void
 nfsrv_freealldevids(void)
 {
 	struct nfsdevice *ds, *nds;
 
 	TAILQ_FOREACH_SAFE(ds, &nfsrv_devidhead, nfsdev_list, nds)
 		nfsrv_freedevid(ds);
 }
 
 /*
  * Check to see if there is a Read/Write Layout plus either:
  * - A Write Delegation
  * or
  * - An Open with Write_access.
  * Return 1 if this is the case and 0 otherwise.
  * This function is used by nfsrv_proxyds() to decide if doing a Proxy
  * Getattr RPC to the Data Server (DS) is necessary.
  */
 #define	NFSCLIDVECSIZE	6
 int
 nfsrv_checkdsattr(vnode_t vp, NFSPROC_T *p)
 {
 	fhandle_t fh, *tfhp;
 	struct nfsstate *stp;
 	struct nfslayout *lyp;
 	struct nfslayouthash *lhyp;
 	struct nfslockhashhead *hp;
 	struct nfslockfile *lfp;
 	nfsquad_t clid[NFSCLIDVECSIZE];
 	int clidcnt, ret;
 
 	ret = nfsvno_getfh(vp, &fh, p);
 	if (ret != 0)
 		return (0);
 
 	/* First check for a Read/Write Layout. */
 	clidcnt = 0;
 	lhyp = NFSLAYOUTHASH(&fh);
 	NFSLOCKLAYOUT(lhyp);
 	TAILQ_FOREACH(lyp, &lhyp->list, lay_list) {
 		if (NFSBCMP(&lyp->lay_fh, &fh, sizeof(fh)) == 0 &&
 		    ((lyp->lay_flags & NFSLAY_RW) != 0 ||
 		     ((lyp->lay_flags & NFSLAY_READ) != 0 &&
 		      nfsrv_pnfsatime != 0))) {
 			if (clidcnt < NFSCLIDVECSIZE)
 				clid[clidcnt].qval = lyp->lay_clientid.qval;
 			clidcnt++;
 		}
 	}
 	NFSUNLOCKLAYOUT(lhyp);
 	if (clidcnt == 0) {
 		/* None found, so return 0. */
 		return (0);
 	}
 
 	/* Get the nfslockfile for this fh. */
 	NFSLOCKSTATE();
 	hp = NFSLOCKHASH(&fh);
 	LIST_FOREACH(lfp, hp, lf_hash) {
 		tfhp = &lfp->lf_fh;
 		if (NFSVNO_CMPFH(&fh, tfhp))
 			break;
 	}
 	if (lfp == NULL) {
 		/* None found, so return 0. */
 		NFSUNLOCKSTATE();
 		return (0);
 	}
 
 	/* Now, look for a Write delegation for this clientid. */
 	LIST_FOREACH(stp, &lfp->lf_deleg, ls_file) {
 		if ((stp->ls_flags & NFSLCK_DELEGWRITE) != 0 &&
 		    nfsrv_fndclid(clid, stp->ls_clp->lc_clientid, clidcnt) != 0)
 			break;
 	}
 	if (stp != NULL) {
 		/* Found one, so return 1. */
 		NFSUNLOCKSTATE();
 		return (1);
 	}
 
 	/* No Write delegation, so look for an Open with Write_access. */
 	LIST_FOREACH(stp, &lfp->lf_open, ls_file) {
 		KASSERT((stp->ls_flags & NFSLCK_OPEN) != 0,
 		    ("nfsrv_checkdsattr: Non-open in Open list\n"));
 		if ((stp->ls_flags & NFSLCK_WRITEACCESS) != 0 &&
 		    nfsrv_fndclid(clid, stp->ls_clp->lc_clientid, clidcnt) != 0)
 			break;
 	}
 	NFSUNLOCKSTATE();
 	if (stp != NULL)
 		return (1);
 	return (0);
 }
 
 /*
  * Look for a matching clientid in the vector. Return 1 if one might match.
  */
 static int
 nfsrv_fndclid(nfsquad_t *clidvec, nfsquad_t clid, int clidcnt)
 {
 	int i;
 
 	/* If too many for the vector, return 1 since there might be a match. */
 	if (clidcnt > NFSCLIDVECSIZE)
 		return (1);
 
 	for (i = 0; i < clidcnt; i++)
 		if (clidvec[i].qval == clid.qval)
 			return (1);
 	return (0);
 }
 
 /*
  * Check the don't list for "vp" and see if issuing an rw layout is allowed.
  * Return 1 if issuing an rw layout isn't allowed, 0 otherwise.
  */
 static int
 nfsrv_dontlayout(fhandle_t *fhp)
 {
 	struct nfsdontlist *mrp;
 	int ret;
 
 	if (nfsrv_dontlistlen == 0)
 		return (0);
 	ret = 0;
 	NFSDDONTLISTLOCK();
 	LIST_FOREACH(mrp, &nfsrv_dontlisthead, nfsmr_list) {
 		if (NFSBCMP(fhp, &mrp->nfsmr_fh, sizeof(*fhp)) == 0 &&
 		    (mrp->nfsmr_flags & NFSMR_DONTLAYOUT) != 0) {
 			ret = 1;
 			break;
 		}
 	}
 	NFSDDONTLISTUNLOCK();
 	return (ret);
 }
 
 #define	PNFSDS_COPYSIZ	65536
 /*
  * Create a new file on a DS and copy the contents of an extant DS file to it.
  * This can be used for recovery of a DS file onto a recovered DS.
  * The steps are:
  * - When called, the MDS file's vnode is locked, blocking LayoutGet operations.
  * - Disable issuing of read/write layouts for the file via the nfsdontlist,
  *   so that they will be disabled after the MDS file's vnode is unlocked.
  * - Set up the nfsrv_recalllist so that recall of read/write layouts can
  *   be done.
  * - Unlock the MDS file's vnode, so that the client(s) can perform proxied
  *   writes, LayoutCommits and LayoutReturns for the file when completing the
  *   LayoutReturn requested by the LayoutRecall callback.
  * - Issue a LayoutRecall callback for all read/write layouts and wait for
  *   them to be returned. (If the LayoutRecall callback replies
  *   NFSERR_NOMATCHLAYOUT, they are gone and no LayoutReturn is needed.)
  * - Exclusively lock the MDS file's vnode.  This ensures that no proxied
  *   writes are in progress or can occur during the DS file copy.
  *   It also blocks Setattr operations.
  * - Create the file on the recovered mirror.
  * - Copy the file from the operational DS.
  * - Copy any ACL from the MDS file to the new DS file.
  * - Set the modify time of the new DS file to that of the MDS file.
  * - Update the extended attribute for the MDS file.
  * - Enable issuing of rw layouts by deleting the nfsdontlist entry.
  * - The caller will unlock the MDS file's vnode allowing operations
  *   to continue normally, since it is now on the mirror again.
  */
 int
 nfsrv_copymr(vnode_t vp, vnode_t fvp, vnode_t dvp, struct nfsdevice *ds,
     struct pnfsdsfile *pf, struct pnfsdsfile *wpf, int mirrorcnt,
     struct ucred *cred, NFSPROC_T *p)
 {
 	struct nfsdontlist *mrp, *nmrp;
 	struct nfslayouthash *lhyp;
 	struct nfslayout *lyp, *nlyp;
 	struct nfslayouthead thl;
 	struct mount *mp, *tvmp;
 	struct acl *aclp;
 	struct vattr va;
 	struct timespec mtime;
 	fhandle_t fh;
 	vnode_t tvp;
 	off_t rdpos, wrpos;
 	ssize_t aresid;
 	char *dat;
 	int didprintf, ret, retacl, xfer;
 
 	ASSERT_VOP_LOCKED(fvp, "nfsrv_copymr fvp");
 	ASSERT_VOP_LOCKED(vp, "nfsrv_copymr vp");
 	/*
 	 * Allocate a nfsdontlist entry and set the NFSMR_DONTLAYOUT flag
 	 * so that no more RW layouts will get issued.
 	 */
 	ret = nfsvno_getfh(vp, &fh, p);
 	if (ret != 0) {
 		NFSD_DEBUG(4, "nfsrv_copymr: getfh=%d\n", ret);
 		return (ret);
 	}
 	nmrp = malloc(sizeof(*nmrp), M_NFSDSTATE, M_WAITOK);
 	nmrp->nfsmr_flags = NFSMR_DONTLAYOUT;
 	NFSBCOPY(&fh, &nmrp->nfsmr_fh, sizeof(fh));
 	NFSDDONTLISTLOCK();
 	LIST_FOREACH(mrp, &nfsrv_dontlisthead, nfsmr_list) {
 		if (NFSBCMP(&fh, &mrp->nfsmr_fh, sizeof(fh)) == 0)
 			break;
 	}
 	if (mrp == NULL) {
 		LIST_INSERT_HEAD(&nfsrv_dontlisthead, nmrp, nfsmr_list);
 		mrp = nmrp;
 		nmrp = NULL;
 		nfsrv_dontlistlen++;
 		NFSD_DEBUG(4, "nfsrv_copymr: in dontlist\n");
 	} else {
 		NFSDDONTLISTUNLOCK();
 		free(nmrp, M_NFSDSTATE);
 		NFSD_DEBUG(4, "nfsrv_copymr: dup dontlist\n");
 		return (ENXIO);
 	}
 	NFSDDONTLISTUNLOCK();
 
 	/*
 	 * Search for all RW layouts for this file.  Move them to the
 	 * recall list, so they can be recalled and their return noted.
 	 */
 	lhyp = NFSLAYOUTHASH(&fh);
 	NFSDRECALLLOCK();
 	NFSLOCKLAYOUT(lhyp);
 	TAILQ_FOREACH_SAFE(lyp, &lhyp->list, lay_list, nlyp) {
 		if (NFSBCMP(&lyp->lay_fh, &fh, sizeof(fh)) == 0 &&
 		    (lyp->lay_flags & NFSLAY_RW) != 0) {
 			TAILQ_REMOVE(&lhyp->list, lyp, lay_list);
 			TAILQ_INSERT_HEAD(&nfsrv_recalllisthead, lyp, lay_list);
 			lyp->lay_trycnt = 0;
 		}
 	}
 	NFSUNLOCKLAYOUT(lhyp);
 	NFSDRECALLUNLOCK();
 
 	ret = 0;
 	mp = tvmp = NULL;
 	didprintf = 0;
 	TAILQ_INIT(&thl);
 	/* Unlock the MDS vp, so that a LayoutReturn can be done on it. */
 	NFSVOPUNLOCK(vp);
 	/* Now, do a recall for all layouts not yet recalled. */
 tryagain:
 	NFSDRECALLLOCK();
 	TAILQ_FOREACH(lyp, &nfsrv_recalllisthead, lay_list) {
 		if (NFSBCMP(&lyp->lay_fh, &fh, sizeof(fh)) == 0 &&
 		    (lyp->lay_flags & NFSLAY_RECALL) == 0) {
 			lyp->lay_flags |= NFSLAY_RECALL;
 			/*
 			 * The layout stateid.seqid needs to be incremented
 			 * before doing a LAYOUT_RECALL callback.
 			 */
 			if (++lyp->lay_stateid.seqid == 0)
 				lyp->lay_stateid.seqid = 1;
 			NFSDRECALLUNLOCK();
 			nfsrv_recalllayout(lyp->lay_clientid, &lyp->lay_stateid,
 			    &lyp->lay_fh, lyp, 0, lyp->lay_type, p);
 			NFSD_DEBUG(4, "nfsrv_copymr: recalled layout\n");
 			goto tryagain;
 		}
 	}
 
 	/* Now wait for them to be returned. */
 tryagain2:
 	TAILQ_FOREACH(lyp, &nfsrv_recalllisthead, lay_list) {
 		if (NFSBCMP(&lyp->lay_fh, &fh, sizeof(fh)) == 0) {
 			if ((lyp->lay_flags & NFSLAY_RETURNED) != 0) {
 				TAILQ_REMOVE(&nfsrv_recalllisthead, lyp,
 				    lay_list);
 				TAILQ_INSERT_HEAD(&thl, lyp, lay_list);
 				NFSD_DEBUG(4,
 				    "nfsrv_copymr: layout returned\n");
 			} else {
 				lyp->lay_trycnt++;
 				ret = mtx_sleep(lyp, NFSDRECALLMUTEXPTR,
 				    PVFS | PCATCH, "nfsmrl", hz);
 				NFSD_DEBUG(4, "nfsrv_copymr: aft sleep=%d\n",
 				    ret);
 				if (ret == EINTR || ret == ERESTART)
 					break;
 				if ((lyp->lay_flags & NFSLAY_RETURNED) == 0) {
 					/*
 					 * Give up after 60sec and return
 					 * ENXIO, failing the copymr.
 					 * This layout will remain on the
 					 * recalllist.  It can only be cleared
 					 * by restarting the nfsd.
 					 * This seems the safe way to handle
 					 * it, since it cannot be safely copied
 					 * with an outstanding RW layout.
 					 */
 					if (lyp->lay_trycnt >= 60) {
 						ret = ENXIO;
 						break;
 					}
 					if (didprintf == 0) {
 						printf("nfsrv_copymr: layout "
 						    "not returned\n");
 						didprintf = 1;
 					}
 				}
 			}
 			goto tryagain2;
 		}
 	}
 	NFSDRECALLUNLOCK();
 	/* We can now get rid of the layouts that have been returned. */
 	TAILQ_FOREACH_SAFE(lyp, &thl, lay_list, nlyp)
 		nfsrv_freelayout(&thl, lyp);
 
 	/*
 	 * Do the vn_start_write() calls here, before the MDS vnode is
 	 * locked and the tvp is created (locked) in the NFS file system
 	 * that dvp is in.
 	 * For tvmp, this probably isn't necessary, since it will be an
 	 * NFS mount and they are not suspendable at this time.
 	 */
 	if (ret == 0)
 		ret = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
 	if (ret == 0) {
 		tvmp = dvp->v_mount;
 		ret = vn_start_write(NULL, &tvmp, V_WAIT | V_PCATCH);
 	}
 
 	/*
 	 * LK_EXCLUSIVE lock the MDS vnode, so that any
 	 * proxied writes through the MDS will be blocked until we have
 	 * completed the copy and update of the extended attributes.
 	 * This will also ensure that any attributes and ACL will not be
 	 * changed until the copy is complete.
 	 */
 	NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 	if (ret == 0 && VN_IS_DOOMED(vp)) {
 		NFSD_DEBUG(4, "nfsrv_copymr: lk_exclusive doomed\n");
 		ret = ESTALE;
 	}
 
 	/* Create the data file on the recovered DS. */
 	if (ret == 0)
 		ret = nfsrv_createdsfile(vp, &fh, pf, dvp, ds, cred, p, &tvp);
 
 	/* Copy the DS file, if created successfully. */
 	if (ret == 0) {
 		/*
 		 * Get any NFSv4 ACL on the MDS file, so that it can be set
 		 * on the new DS file.
 		 */
 		aclp = acl_alloc(M_WAITOK | M_ZERO);
 		retacl = VOP_GETACL(vp, ACL_TYPE_NFS4, aclp, cred, p);
 		if (retacl != 0 && retacl != ENOATTR)
 			NFSD_DEBUG(1, "nfsrv_copymr: vop_getacl=%d\n", retacl);
 		dat = malloc(PNFSDS_COPYSIZ, M_TEMP, M_WAITOK);
 		/* Malloc a block of 0s used to check for holes. */
 		if (nfsrv_zeropnfsdat == NULL)
 			nfsrv_zeropnfsdat = malloc(PNFSDS_COPYSIZ, M_TEMP,
 			    M_WAITOK | M_ZERO);
 		rdpos = wrpos = 0;
 		ret = VOP_GETATTR(fvp, &va, cred);
 		aresid = 0;
 		while (ret == 0 && aresid == 0) {
 			ret = vn_rdwr(UIO_READ, fvp, dat, PNFSDS_COPYSIZ,
 			    rdpos, UIO_SYSSPACE, IO_NODELOCKED, cred, NULL,
 			    &aresid, p);
 			xfer = PNFSDS_COPYSIZ - aresid;
 			if (ret == 0 && xfer > 0) {
 				rdpos += xfer;
 				/*
 				 * Skip the write for holes, except for the
 				 * last block.
 				 */
 				if (xfer < PNFSDS_COPYSIZ || rdpos ==
 				    va.va_size || NFSBCMP(dat,
 				    nfsrv_zeropnfsdat, PNFSDS_COPYSIZ) != 0)
 					ret = vn_rdwr(UIO_WRITE, tvp, dat, xfer,
 					    wrpos, UIO_SYSSPACE, IO_NODELOCKED,
 					    cred, NULL, NULL, p);
 				if (ret == 0)
 					wrpos += xfer;
 			}
 		}
 
 		/* If there is an ACL and the copy succeeded, set the ACL. */
 		if (ret == 0 && retacl == 0) {
 			ret = VOP_SETACL(tvp, ACL_TYPE_NFS4, aclp, cred, p);
 			/*
 			 * Don't consider these as errors, since VOP_GETACL()
 			 * can return an ACL when they are not actually
 			 * supported.  For example, for UFS, VOP_GETACL()
 			 * will return a trivial ACL based on the uid/gid/mode
 			 * when there is no ACL on the file.
 			 * This case should be recognized as a trivial ACL
 			 * by UFS's VOP_SETACL() and succeed, but...
 			 */
 			if (ret == ENOATTR || ret == EOPNOTSUPP || ret == EPERM)
 				ret = 0;
 		}
 
 		if (ret == 0)
 			ret = VOP_FSYNC(tvp, MNT_WAIT, p);
 
 		/* Set the DS data file's modify time that of the MDS file. */
 		if (ret == 0)
 			ret = VOP_GETATTR(vp, &va, cred);
 		if (ret == 0) {
 			mtime = va.va_mtime;
 			VATTR_NULL(&va);
 			va.va_mtime = mtime;
 			ret = VOP_SETATTR(tvp, &va, cred);
 		}
 
 		vput(tvp);
 		acl_free(aclp);
 		free(dat, M_TEMP);
 	}
 	if (tvmp != NULL)
 		vn_finished_write(tvmp);
 
 	/* Update the extended attributes for the newly created DS file. */
 	if (ret == 0)
 		ret = vn_extattr_set(vp, IO_NODELOCKED,
 		    EXTATTR_NAMESPACE_SYSTEM, "pnfsd.dsfile",
 		    sizeof(*wpf) * mirrorcnt, (char *)wpf, p);
 	if (mp != NULL)
 		vn_finished_write(mp);
 
 	/* Get rid of the dontlist entry, so that Layouts can be issued. */
 	NFSDDONTLISTLOCK();
 	LIST_REMOVE(mrp, nfsmr_list);
 	NFSDDONTLISTUNLOCK();
 	free(mrp, M_NFSDSTATE);
 	return (ret);
 }
 
 /*
  * Create a data storage file on the recovered DS.
  */
 static int
 nfsrv_createdsfile(vnode_t vp, fhandle_t *fhp, struct pnfsdsfile *pf,
     vnode_t dvp, struct nfsdevice *ds, struct ucred *cred, NFSPROC_T *p,
     vnode_t *tvpp)
 {
 	struct vattr va, nva;
 	int error;
 
 	/* Make data file name based on FH. */
 	error = VOP_GETATTR(vp, &va, cred);
 	if (error == 0) {
 		/* Set the attributes for "vp" to Setattr the DS vp. */
 		VATTR_NULL(&nva);
 		nva.va_uid = va.va_uid;
 		nva.va_gid = va.va_gid;
 		nva.va_mode = va.va_mode;
 		nva.va_size = 0;
 		VATTR_NULL(&va);
 		va.va_type = VREG;
 		va.va_mode = nva.va_mode;
 		NFSD_DEBUG(4, "nfsrv_dscreatefile: dvp=%p pf=%p\n", dvp, pf);
 		error = nfsrv_dscreate(dvp, &va, &nva, fhp, pf, NULL,
 		    pf->dsf_filename, cred, p, tvpp);
 	}
 	return (error);
 }
 
 /*
  * Look up the MDS file shared locked, and then get the extended attribute
  * to find the extant DS file to be copied to the new mirror.
  * If successful, *vpp is set to the MDS file's vp and *nvpp is
  * set to a DS data file for the MDS file, both exclusively locked.
  * The "buf" argument has the pnfsdsfile structure from the MDS file
  * in it and buflen is set to its length.
  */
 int
 nfsrv_mdscopymr(char *mdspathp, char *dspathp, char *curdspathp, char *buf,
     int *buflenp, char *fname, NFSPROC_T *p, struct vnode **vpp,
     struct vnode **nvpp, struct pnfsdsfile **pfp, struct nfsdevice **dsp,
     struct nfsdevice **fdsp)
 {
 	struct nameidata nd;
 	struct vnode *vp, *curvp;
 	struct pnfsdsfile *pf;
 	struct nfsmount *nmp, *curnmp;
 	int dsdir, error, mirrorcnt, ippos;
 
 	vp = NULL;
 	curvp = NULL;
 	curnmp = NULL;
 	*dsp = NULL;
 	*fdsp = NULL;
 	if (dspathp == NULL && curdspathp != NULL)
 		return (EPERM);
 
 	/*
 	 * Look up the MDS file shared locked.  The lock will be upgraded
 	 * to an exclusive lock after any rw layouts have been returned.
 	 */
 	NFSD_DEBUG(4, "mdsopen path=%s\n", mdspathp);
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, UIO_SYSSPACE,
 	    mdspathp);
 	error = namei(&nd);
 	NFSD_DEBUG(4, "lookup=%d\n", error);
 	if (error != 0)
 		return (error);
 	if (nd.ni_vp->v_type != VREG) {
 		vput(nd.ni_vp);
 		NFSD_DEBUG(4, "mdspath not reg\n");
 		return (EISDIR);
 	}
 	vp = nd.ni_vp;
 
 	if (curdspathp != NULL) {
 		/*
 		 * Look up the current DS path and find the nfsdev structure for
 		 * it.
 		 */
 		NFSD_DEBUG(4, "curmdsdev path=%s\n", curdspathp);
 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 		    UIO_SYSSPACE, curdspathp);
 		error = namei(&nd);
 		NFSD_DEBUG(4, "ds lookup=%d\n", error);
 		if (error != 0) {
 			vput(vp);
 			return (error);
 		}
 		if (nd.ni_vp->v_type != VDIR) {
 			vput(nd.ni_vp);
 			vput(vp);
 			NFSD_DEBUG(4, "curdspath not dir\n");
 			return (ENOTDIR);
 		}
 		if (strcmp(nd.ni_vp->v_mount->mnt_vfc->vfc_name, "nfs") != 0) {
 			vput(nd.ni_vp);
 			vput(vp);
 			NFSD_DEBUG(4, "curdspath not an NFS mount\n");
 			return (ENXIO);
 		}
 		curnmp = VFSTONFS(nd.ni_vp->v_mount);
 
 		/* Search the nfsdev list for a match. */
 		NFSDDSLOCK();
 		*fdsp = nfsv4_findmirror(curnmp);
 		NFSDDSUNLOCK();
 		if (*fdsp == NULL)
 			curnmp = NULL;
 		if (curnmp == NULL) {
 			vput(nd.ni_vp);
 			vput(vp);
 			NFSD_DEBUG(4, "mdscopymr: no current ds\n");
 			return (ENXIO);
 		}
 		curvp = nd.ni_vp;
 	}
 
 	if (dspathp != NULL) {
 		/* Look up the nfsdev path and find the nfsdev structure. */
 		NFSD_DEBUG(4, "mdsdev path=%s\n", dspathp);
 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 		    UIO_SYSSPACE, dspathp);
 		error = namei(&nd);
 		NFSD_DEBUG(4, "ds lookup=%d\n", error);
 		if (error != 0) {
 			vput(vp);
 			if (curvp != NULL)
 				vput(curvp);
 			return (error);
 		}
 		if (nd.ni_vp->v_type != VDIR || nd.ni_vp == curvp) {
 			vput(nd.ni_vp);
 			vput(vp);
 			if (curvp != NULL)
 				vput(curvp);
 			NFSD_DEBUG(4, "dspath not dir\n");
 			if (nd.ni_vp == curvp)
 				return (EPERM);
 			return (ENOTDIR);
 		}
 		if (strcmp(nd.ni_vp->v_mount->mnt_vfc->vfc_name, "nfs") != 0) {
 			vput(nd.ni_vp);
 			vput(vp);
 			if (curvp != NULL)
 				vput(curvp);
 			NFSD_DEBUG(4, "dspath not an NFS mount\n");
 			return (ENXIO);
 		}
 		nmp = VFSTONFS(nd.ni_vp->v_mount);
 
 		/*
 		 * Search the nfsdevice list for a match.  If curnmp == NULL,
 		 * this is a recovery and there must be a mirror.
 		 */
 		NFSDDSLOCK();
 		if (curnmp == NULL)
 			*dsp = nfsrv_findmirroredds(nmp);
 		else
 			*dsp = nfsv4_findmirror(nmp);
 		NFSDDSUNLOCK();
 		if (*dsp == NULL) {
 			vput(nd.ni_vp);
 			vput(vp);
 			if (curvp != NULL)
 				vput(curvp);
 			NFSD_DEBUG(4, "mdscopymr: no ds\n");
 			return (ENXIO);
 		}
 	} else {
 		nd.ni_vp = NULL;
 		nmp = NULL;
 	}
 
 	/*
 	 * Get a vp for an available DS data file using the extended
 	 * attribute on the MDS file.
 	 * If there is a valid entry for the new DS in the extended attribute
 	 * on the MDS file (as checked via the nmp argument),
 	 * nfsrv_dsgetsockmnt() returns EEXIST, so no copying will occur.
 	 */
 	error = nfsrv_dsgetsockmnt(vp, 0, buf, buflenp, &mirrorcnt, p,
 	    NULL, NULL, NULL, fname, nvpp, &nmp, curnmp, &ippos, &dsdir);
 	if (curvp != NULL)
 		vput(curvp);
 	if (nd.ni_vp == NULL) {
 		if (error == 0 && nmp != NULL) {
 			/* Search the nfsdev list for a match. */
 			NFSDDSLOCK();
 			*dsp = nfsrv_findmirroredds(nmp);
 			NFSDDSUNLOCK();
 		}
 		if (error == 0 && (nmp == NULL || *dsp == NULL)) {
 			if (nvpp != NULL && *nvpp != NULL) {
 				vput(*nvpp);
 				*nvpp = NULL;
 			}
 			error = ENXIO;
 		}
 	} else
 		vput(nd.ni_vp);
 
 	/*
 	 * When dspathp != NULL and curdspathp == NULL, this is a recovery
 	 * and is only allowed if there is a 0.0.0.0 IP address entry.
 	 * When curdspathp != NULL, the ippos will be set to that entry.
 	 */
 	if (error == 0 && dspathp != NULL && ippos == -1) {
 		if (nvpp != NULL && *nvpp != NULL) {
 			vput(*nvpp);
 			*nvpp = NULL;
 		}
 		error = ENXIO;
 	}
 	if (error == 0) {
 		*vpp = vp;
 
 		pf = (struct pnfsdsfile *)buf;
 		if (ippos == -1) {
 			/* If no zeroip pnfsdsfile, add one. */
 			ippos = *buflenp / sizeof(*pf);
 			*buflenp += sizeof(*pf);
 			pf += ippos;
 			pf->dsf_dir = dsdir;
 			strlcpy(pf->dsf_filename, fname,
 			    sizeof(pf->dsf_filename));
 		} else
 			pf += ippos;
 		*pfp = pf;
 	} else
 		vput(vp);
 	return (error);
 }
 
 /*
  * Search for a matching pnfsd mirror device structure, base on the nmp arg.
  * Return one if found, NULL otherwise.
  */
 static struct nfsdevice *
 nfsrv_findmirroredds(struct nfsmount *nmp)
 {
 	struct nfsdevice *ds, *fndds;
 	int fndmirror;
 
 	mtx_assert(NFSDDSMUTEXPTR, MA_OWNED);
 	/*
 	 * Search the DS server list for a match with nmp.
 	 * Remove the DS entry if found and there is a mirror.
 	 */
 	fndds = NULL;
 	fndmirror = 0;
 	if (nfsrv_devidcnt == 0)
 		return (fndds);
 	TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 		if (ds->nfsdev_nmp == nmp) {
 			NFSD_DEBUG(4, "nfsrv_findmirroredds: fnd main ds\n");
 			fndds = ds;
 			break;
 		}
 	}
 	if (fndds == NULL)
 		return (fndds);
 	if (fndds->nfsdev_mdsisset == 0 && nfsrv_faildscnt > 0)
 		fndmirror = 1;
 	else if (fndds->nfsdev_mdsisset != 0) {
 		/* For the fsid is set case, search for a mirror. */
 		TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 			if (ds != fndds && ds->nfsdev_nmp != NULL &&
 			    ds->nfsdev_mdsisset != 0 &&
 			    fsidcmp(&ds->nfsdev_mdsfsid,
 			    &fndds->nfsdev_mdsfsid) == 0) {
 				fndmirror = 1;
 				break;
 			}
 		}
 	}
 	if (fndmirror == 0) {
 		NFSD_DEBUG(4, "nfsrv_findmirroredds: no mirror for DS\n");
 		return (NULL);
 	}
 	return (fndds);
 }
 
 /*
  * Mark the appropriate devid and all associated layout as "out of space".
  */
 void
 nfsrv_marknospc(char *devid, bool setit)
 {
 	struct nfsdevice *ds;
 	struct nfslayout *lyp;
 	struct nfslayouthash *lhyp;
 	int i;
 
 	NFSDDSLOCK();
 	TAILQ_FOREACH(ds, &nfsrv_devidhead, nfsdev_list) {
 		if (NFSBCMP(ds->nfsdev_deviceid, devid, NFSX_V4DEVICEID) == 0) {
 			NFSD_DEBUG(1, "nfsrv_marknospc: devid %d\n", setit);
 			ds->nfsdev_nospc = setit;
 		}
 	}
 	NFSDDSUNLOCK();
 
 	for (i = 0; i < nfsrv_layouthashsize; i++) {
 		lhyp = &nfslayouthash[i];
 		NFSLOCKLAYOUT(lhyp);
 		TAILQ_FOREACH(lyp, &lhyp->list, lay_list) {
 			if (NFSBCMP(lyp->lay_deviceid, devid,
 			    NFSX_V4DEVICEID) == 0) {
 				NFSD_DEBUG(1, "nfsrv_marknospc: layout %d\n",
 				    setit);
 				if (setit)
 					lyp->lay_flags |= NFSLAY_NOSPC;
 				else
 					lyp->lay_flags &= ~NFSLAY_NOSPC;
 			}
 		}
 		NFSUNLOCKLAYOUT(lhyp);
 	}
 }
 
 /*
  * Check to see if SP4_MACH_CRED is in use and, if it is, check that the
  * correct machine credential is being used.
  */
 static int
 nfsrv_checkmachcred(int op, struct nfsrv_descript *nd, struct nfsclient *clp)
 {
 
 	if ((clp->lc_flags & LCL_MACHCRED) == 0 ||
 	    !NFSISSET_OPBIT(&clp->lc_mustops, op))
 		return (0);
 	KASSERT((nd->nd_flag & ND_NFSV41) != 0,
 	    ("nfsrv_checkmachcred: MachCred for NFSv4.0"));
 	if ((nd->nd_flag & (ND_GSSINTEGRITY | ND_GSSPRIVACY)) != 0 &&
 	    nd->nd_princlen == clp->lc_namelen &&
 	    !NFSBCMP(nd->nd_principal, clp->lc_name, nd->nd_princlen))
 		return (0);
 	return (NFSERR_AUTHERR | AUTH_TOOWEAK);
 }
 
 /*
  * Issue a delegation and, optionally set rflagsp for why not.
  */
 static void
 nfsrv_issuedelegation(struct vnode *vp, struct nfsclient *clp,
     struct nfsrv_descript *nd, int delegate, int writedeleg, int readonly,
     u_quad_t filerev, uint64_t rdonly, struct nfsstate **new_delegp,
     struct nfsstate *new_stp, struct nfslockfile *lfp, uint32_t *rflagsp,
     nfsv4stateid_t *delegstateidp)
 {
 	struct nfsstate *up_deleg, *new_deleg;
 
 	new_deleg = *new_delegp;
 	up_deleg = LIST_FIRST(&lfp->lf_deleg);
 	if ((new_stp->ls_flags & NFSLCK_WANTNODELEG) != 0)
 		*rflagsp |= NFSV4OPEN_WDNOTWANTED;
 	else if (nfsrv_issuedelegs == 0)
 		*rflagsp |= NFSV4OPEN_WDSUPPFTYPE;
 	else if (NFSRV_V4DELEGLIMIT(nfsrv_delegatecnt))
 		*rflagsp |= NFSV4OPEN_WDRESOURCE;
 	else if (delegate == 0 || !NFSVNO_DELEGOK(vp) ||
 	    (writedeleg == 0 && (readonly == 0 ||
 	    (new_stp->ls_flags & NFSLCK_WANTWDELEG) != 0)) ||
 	    (clp->lc_flags & (LCL_CALLBACKSON | LCL_CBDOWN)) !=
 	     LCL_CALLBACKSON) {
 		/* Is this a downgrade attempt? */
 		if (up_deleg != NULL && up_deleg->ls_clp == clp &&
 		    (up_deleg->ls_flags & NFSLCK_DELEGWRITE) != 0 &&
 		    (new_stp->ls_flags & NFSLCK_WANTRDELEG) != 0)
 			*rflagsp |= NFSV4OPEN_WDNOTSUPPDOWNGRADE;
 		else
 			*rflagsp |= NFSV4OPEN_WDCONTENTION;
 	} else if (up_deleg != NULL &&
 	    (up_deleg->ls_flags & NFSLCK_DELEGREAD) != 0 &&
 	    (new_stp->ls_flags & NFSLCK_WANTWDELEG) != 0) {
 		/* This is an atomic upgrade. */
 		up_deleg->ls_stateid.seqid++;
 		delegstateidp->seqid = up_deleg->ls_stateid.seqid;
 		delegstateidp->other[0] = up_deleg->ls_stateid.other[0];
 		delegstateidp->other[1] = up_deleg->ls_stateid.other[1];
 		delegstateidp->other[2] = up_deleg->ls_stateid.other[2];
 		up_deleg->ls_flags = (NFSLCK_DELEGWRITE |
 		    NFSLCK_READACCESS | NFSLCK_WRITEACCESS);
 		*rflagsp |= NFSV4OPEN_WRITEDELEGATE;
 		nfsrv_writedelegcnt++;
 	} else {
 		new_deleg->ls_stateid.seqid = delegstateidp->seqid = 1;
 		new_deleg->ls_stateid.other[0] = delegstateidp->other[0]
 		    = clp->lc_clientid.lval[0];
 		new_deleg->ls_stateid.other[1] = delegstateidp->other[1]
 		    = clp->lc_clientid.lval[1];
 		new_deleg->ls_stateid.other[2] = delegstateidp->other[2]
 		    = nfsrv_nextstateindex(clp);
 		if (writedeleg && !rdonly &&
 		    (nfsrv_writedelegifpos || !readonly) &&
 		    (new_stp->ls_flags & (NFSLCK_WANTRDELEG |
 		     NFSLCK_WANTWDELEG)) != NFSLCK_WANTRDELEG) {
 			new_deleg->ls_flags = (NFSLCK_DELEGWRITE |
 			    NFSLCK_READACCESS | NFSLCK_WRITEACCESS);
 			*rflagsp |= NFSV4OPEN_WRITEDELEGATE;
 			nfsrv_writedelegcnt++;
 		} else {
 			new_deleg->ls_flags = (NFSLCK_DELEGREAD |
 			    NFSLCK_READACCESS);
 			*rflagsp |= NFSV4OPEN_READDELEGATE;
 		}
 		new_deleg->ls_uid = new_stp->ls_uid;
 		new_deleg->ls_lfp = lfp;
 		new_deleg->ls_clp = clp;
 		new_deleg->ls_filerev = filerev;
 		new_deleg->ls_compref = nd->nd_compref;
 		new_deleg->ls_lastrecall = 0;
 		LIST_INSERT_HEAD(&lfp->lf_deleg, new_deleg, ls_file);
 		LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_deleg->ls_stateid),
 		    new_deleg, ls_hash);
 		LIST_INSERT_HEAD(&clp->lc_deleg, new_deleg, ls_list);
 		*new_delegp = NULL;
 		NFSD_VNET(nfsstatsv1_p)->srvdelegates++;
 		nfsrv_openpluslock++;
 		nfsrv_delegatecnt++;
 	}
 }