BSD 4.4 Lite Kernel Sources

1 files changed, 1228 insertions, 0 deletions

diff --git a/sys/nfs/nfs_nqlease.c b/sys/nfs/nfs_nqlease.c
new file mode 100644
index 0000000..965f461
--- /dev/null
+++ b/sys/nfs/nfs_nqlease.c
@@ -0,0 +1,1228 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Rick Macklem at The University of Guelph.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)nfs_nqlease.c	8.3 (Berkeley) 1/4/94
+ */
+
+/*
+ * References:
+ *	Cary G. Gray and David R. Cheriton, "Leases: An Efficient Fault-Tolerant
+ *		Mechanism for Distributed File Cache Consistency",
+ *		In Proc. of the Twelfth ACM Symposium on Operating Systems
+ *		Principals, pg. 202-210, Litchfield Park, AZ, Dec. 1989.
+ *	Michael N. Nelson, Brent B. Welch and John K. Ousterhout, "Caching
+ *		in the Sprite Network File System", ACM TOCS 6(1),
+ *		pages 134-154, February 1988.
+ *	V. Srinivasan and Jeffrey C. Mogul, "Spritely NFS: Implementation and
+ *		Performance of Cache-Consistency Protocols", Digital
+ *		Equipment Corporation WRL Research Report 89/5, May 1989.
+ */
+#include <sys/param.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/file.h>
+#include <sys/buf.h>
+#include <sys/stat.h>
+#include <sys/protosw.h>
+
+#include <netinet/in.h>
+#include <nfs/rpcv2.h>
+#include <nfs/nfsv2.h>
+#include <nfs/nfs.h>
+#include <nfs/nfsm_subs.h>
+#include <nfs/xdr_subs.h>
+#include <nfs/nqnfs.h>
+#include <nfs/nfsnode.h>
+#include <nfs/nfsmount.h>
+
+/*
+ * List head for the lease queue and other global data.
+ * At any time a lease is linked into a list ordered by increasing expiry time.
+ */
+#define	NQFHHASH(f)	((*((u_long *)(f)))&nqfheadhash)
+
+union nqsrvthead nqthead;
+struct nqlease **nqfhead;
+u_long nqfheadhash;
+time_t nqnfsstarttime = (time_t)0;
+u_long nqnfs_prog, nqnfs_vers;
+int nqsrv_clockskew = NQ_CLOCKSKEW;
+int nqsrv_writeslack = NQ_WRITESLACK;
+int nqsrv_maxlease = NQ_MAXLEASE;
+int nqsrv_maxnumlease = NQ_MAXNUMLEASE;
+void nqsrv_instimeq(), nqsrv_send_eviction(), nfs_sndunlock();
+void nqsrv_unlocklease(), nqsrv_waitfor_expiry(), nfsrv_slpderef();
+void nqsrv_addhost(), nqsrv_locklease(), nqnfs_serverd();
+void nqnfs_clientlease();
+struct mbuf *nfsm_rpchead();
+
+/*
+ * Signifies which rpcs can have piggybacked lease requests
+ */
+int nqnfs_piggy[NFS_NPROCS] = {
+	0,
+	NQL_READ,
+	NQL_WRITE,
+	0,
+	NQL_READ,
+	NQL_READ,
+	NQL_READ,
+	0,
+	NQL_WRITE,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	NQL_READ,
+	0,
+	NQL_READ,
+	0,
+	0,
+	0,
+	0,
+};
+
+int nnnnnn = sizeof (struct nqlease);
+int oooooo = sizeof (struct nfsnode);
+extern nfstype nfs_type[9];
+extern struct nfssvc_sock *nfs_udpsock, *nfs_cltpsock;
+extern struct nfsd nfsd_head;
+extern int nfsd_waiting;
+extern struct nfsreq nfsreqh;
+
+#define TRUE	1
+#define	FALSE	0
+
+/*
+ * Get or check for a lease for "vp", based on NQL_CHECK flag.
+ * The rules are as follows:
+ * - if a current non-caching lease, reply non-caching
+ * - if a current lease for same host only, extend lease
+ * - if a read cachable lease and a read lease request
+ *	add host to list any reply cachable
+ * - else { set non-cachable for read-write sharing }
+ *	send eviction notice messages to all other hosts that have lease
+ *	wait for lease termination { either by receiving vacated messages
+ *					from all the other hosts or expiry
+ *					via. timeout }
+ *	modify lease to non-cachable
+ * - else if no current lease, issue new one
+ * - reply
+ * - return boolean TRUE iff nam should be m_freem()'d
+ * NB: Since nqnfs_serverd() is called from a timer, any potential tsleep()
+ *     in here must be framed by nqsrv_locklease() and nqsrv_unlocklease().
+ *     nqsrv_locklease() is coded such that at least one of LC_LOCKED and
+ *     LC_WANTED is set whenever a process is tsleeping in it. The exception
+ *     is when a new lease is being allocated, since it is not in the timer
+ *     queue yet. (Ditto for the splsoftclock() and splx(s) calls)
+ */
+nqsrv_getlease(vp, duration, flags, nd, nam, cachablep, frev, cred)
+	struct vnode *vp;
+	u_long *duration;
+	int flags;
+	struct nfsd *nd;
+	struct mbuf *nam;
+	int *cachablep;
+	u_quad_t *frev;
+	struct ucred *cred;
+{
+	register struct nqlease *lp, *lq, **lpp;
+	register struct nqhost *lph;
+	struct nqlease *tlp;
+	struct nqm **lphp;
+	struct vattr vattr;
+	fhandle_t fh;
+	int i, ok, error, s;
+
+	if (vp->v_type != VREG && vp->v_type != VDIR && vp->v_type != VLNK)
+		return (0);
+	if (*duration > nqsrv_maxlease)
+		*duration = nqsrv_maxlease;
+	if (error = VOP_GETATTR(vp, &vattr, cred, nd->nd_procp))
+		return (error);
+	*frev = vattr.va_filerev;
+	s = splsoftclock();
+	tlp = vp->v_lease;
+	if ((flags & NQL_CHECK) == 0)
+		nfsstats.srvnqnfs_getleases++;
+	if (tlp == (struct nqlease *)0) {
+
+		/*
+		 * Find the lease by searching the hash list.
+		 */
+		fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
+		if (error = VFS_VPTOFH(vp, &fh.fh_fid)) {
+			splx(s);
+			return (error);
+		}
+		lpp = &nqfhead[NQFHHASH(fh.fh_fid.fid_data)];
+		for (lp = *lpp; lp; lp = lp->lc_fhnext)
+			if (fh.fh_fsid.val[0] == lp->lc_fsid.val[0] &&
+			    fh.fh_fsid.val[1] == lp->lc_fsid.val[1] &&
+			    !bcmp(fh.fh_fid.fid_data, lp->lc_fiddata,
+				  fh.fh_fid.fid_len - sizeof (long))) {
+				/* Found it */
+				lp->lc_vp = vp;
+				vp->v_lease = lp;
+				tlp = lp;
+				break;
+			}
+	}
+	lp = tlp;
+	if (lp) {
+		if ((lp->lc_flag & LC_NONCACHABLE) ||
+		    (lp->lc_morehosts == (struct nqm *)0 &&
+		     nqsrv_cmpnam(nd->nd_slp, nam, &lp->lc_host)))
+			goto doreply;
+		if ((flags & NQL_READ) && (lp->lc_flag & LC_WRITE)==0) {
+			if (flags & NQL_CHECK)
+				goto doreply;
+			if (nqsrv_cmpnam(nd->nd_slp, nam, &lp->lc_host))
+				goto doreply;
+			i = 0;
+			if (lp->lc_morehosts) {
+				lph = lp->lc_morehosts->lpm_hosts;
+				lphp = &lp->lc_morehosts->lpm_next;
+				ok = 1;
+			} else {
+				lphp = &lp->lc_morehosts;
+				ok = 0;
+			}
+			while (ok && (lph->lph_flag & LC_VALID)) {
+				if (nqsrv_cmpnam(nd->nd_slp, nam, lph))
+					goto doreply;
+				if (++i == LC_MOREHOSTSIZ) {
+					i = 0;
+					if (*lphp) {
+						lph = (*lphp)->lpm_hosts;
+						lphp = &((*lphp)->lpm_next);
+					} else
+						ok = 0;
+				} else
+					lph++;
+			}
+			nqsrv_locklease(lp);
+			if (!ok) {
+				*lphp = (struct nqm *)
+					malloc(sizeof (struct nqm),
+						M_NQMHOST, M_WAITOK);
+				bzero((caddr_t)*lphp, sizeof (struct nqm));
+				lph = (*lphp)->lpm_hosts;
+			}
+			nqsrv_addhost(lph, nd->nd_slp, nam);
+			nqsrv_unlocklease(lp);
+		} else {
+			lp->lc_flag |= LC_NONCACHABLE;
+			nqsrv_locklease(lp);
+			nqsrv_send_eviction(vp, lp, nd->nd_slp, nam, cred);
+			nqsrv_waitfor_expiry(lp);
+			nqsrv_unlocklease(lp);
+		}
+doreply:
+		/*
+		 * Update the lease and return
+		 */
+		if ((flags & NQL_CHECK) == 0)
+			nqsrv_instimeq(lp, *duration);
+		if (lp->lc_flag & LC_NONCACHABLE)
+			*cachablep = 0;
+		else {
+			*cachablep = 1;
+			if (flags & NQL_WRITE)
+				lp->lc_flag |= LC_WRITTEN;
+		}
+		splx(s);
+		return (0);
+	}
+	splx(s);
+	if (flags & NQL_CHECK)
+		return (0);
+
+	/*
+	 * Allocate new lease
+	 * The value of nqsrv_maxnumlease should be set generously, so that
+	 * the following "printf" happens infrequently.
+	 */
+	if (nfsstats.srvnqnfs_leases > nqsrv_maxnumlease) {
+		printf("Nqnfs server, too many leases\n");
+		do {
+			(void) tsleep((caddr_t)&lbolt, PSOCK,
+					"nqsrvnuml", 0);
+		} while (nfsstats.srvnqnfs_leases > nqsrv_maxnumlease);
+	}
+	MALLOC(lp, struct nqlease *, sizeof (struct nqlease), M_NQLEASE, M_WAITOK);
+	bzero((caddr_t)lp, sizeof (struct nqlease));
+	if (flags & NQL_WRITE)
+		lp->lc_flag |= (LC_WRITE | LC_WRITTEN);
+	nqsrv_addhost(&lp->lc_host, nd->nd_slp, nam);
+	lp->lc_vp = vp;
+	lp->lc_fsid = fh.fh_fsid;
+	bcopy(fh.fh_fid.fid_data, lp->lc_fiddata, fh.fh_fid.fid_len - sizeof (long));
+	if (lq = *lpp)
+		lq->lc_fhprev = &lp->lc_fhnext;
+	lp->lc_fhnext = lq;
+	lp->lc_fhprev = lpp;
+	*lpp = lp;
+	vp->v_lease = lp;
+	s = splsoftclock();
+	nqsrv_instimeq(lp, *duration);
+	splx(s);
+	*cachablep = 1;
+	if (++nfsstats.srvnqnfs_leases > nfsstats.srvnqnfs_maxleases)
+		nfsstats.srvnqnfs_maxleases = nfsstats.srvnqnfs_leases;
+	return (0);
+}
+
+/*
+ * Local lease check for server syscalls.
+ * Just set up args and let nqsrv_getlease() do the rest.
+ */
+void
+lease_check(vp, p, cred, flag)
+	struct vnode *vp;
+	struct proc *p;
+	struct ucred *cred;
+	int flag;
+{
+	int duration = 0, cache;
+	struct nfsd nfsd;
+	u_quad_t frev;
+
+	nfsd.nd_slp = NQLOCALSLP;
+	nfsd.nd_procp = p;
+	(void) nqsrv_getlease(vp, &duration, NQL_CHECK | flag, &nfsd,
+		(struct mbuf *)0, &cache, &frev, cred);
+}
+
+/*
+ * Add a host to an nqhost structure for a lease.
+ */
+void
+nqsrv_addhost(lph, slp, nam)
+	register struct nqhost *lph;
+	struct nfssvc_sock *slp;
+	struct mbuf *nam;
+{
+	register struct sockaddr_in *saddr;
+
+	if (slp == NQLOCALSLP)
+		lph->lph_flag |= (LC_VALID | LC_LOCAL);
+	else if (slp == nfs_udpsock) {
+		saddr = mtod(nam, struct sockaddr_in *);
+		lph->lph_flag |= (LC_VALID | LC_UDP);
+		lph->lph_inetaddr = saddr->sin_addr.s_addr;
+		lph->lph_port = saddr->sin_port;
+	} else if (slp == nfs_cltpsock) {
+		lph->lph_nam = m_copym(nam, 0, M_COPYALL, M_WAIT);
+		lph->lph_flag |= (LC_VALID | LC_CLTP);
+	} else {
+		lph->lph_flag |= (LC_VALID | LC_SREF);
+		lph->lph_slp = slp;
+		slp->ns_sref++;
+	}
+}
+
+/*
+ * Update the lease expiry time and position it in the timer queue correctly.
+ */
+void
+nqsrv_instimeq(lp, duration)
+	register struct nqlease *lp;
+	u_long duration;
+{
+	register struct nqlease *tlp;
+	time_t newexpiry;
+
+	newexpiry = time.tv_sec + duration + nqsrv_clockskew;
+	if (lp->lc_expiry == newexpiry)
+		return;
+	if (lp->lc_chain1[0])
+		remque(lp);
+	lp->lc_expiry = newexpiry;
+
+	/*
+	 * Find where in the queue it should be.
+	 */
+	tlp = nqthead.th_chain[1];
+	while (tlp->lc_expiry > newexpiry && tlp != (struct nqlease *)&nqthead)
+		tlp = tlp->lc_chain1[1];
+	if (tlp == nqthead.th_chain[1])
+		NQSTORENOVRAM(newexpiry);
+	insque(lp, tlp);
+}
+
+/*
+ * Compare the requesting host address with the lph entry in the lease.
+ * Return true iff it is the same.
+ * This is somewhat messy due to the union in the nqhost structure.
+ * The local host is indicated by the special value of NQLOCALSLP for slp.
+ */
+nqsrv_cmpnam(slp, nam, lph)
+	register struct nfssvc_sock *slp;
+	struct mbuf *nam;
+	register struct nqhost *lph;
+{
+	register struct sockaddr_in *saddr;
+	struct mbuf *addr;
+	union nethostaddr lhaddr;
+	int ret;
+
+	if (slp == NQLOCALSLP) {
+		if (lph->lph_flag & LC_LOCAL)
+			return (1);
+		else
+			return (0);
+	}
+	if (slp == nfs_udpsock || slp == nfs_cltpsock)
+		addr = nam;
+	else
+		addr = slp->ns_nam;
+	if (lph->lph_flag & LC_UDP)
+		ret = netaddr_match(AF_INET, &lph->lph_haddr, addr);
+	else if (lph->lph_flag & LC_CLTP)
+		ret = netaddr_match(AF_ISO, &lph->lph_claddr, addr);
+	else {
+		if ((lph->lph_slp->ns_flag & SLP_VALID) == 0)
+			return (0);
+		saddr = mtod(lph->lph_slp->ns_nam, struct sockaddr_in *);
+		if (saddr->sin_family == AF_INET)
+			lhaddr.had_inetaddr = saddr->sin_addr.s_addr;
+		else
+			lhaddr.had_nam = lph->lph_slp->ns_nam;
+		ret = netaddr_match(saddr->sin_family, &lhaddr, addr);
+	}
+	return (ret);
+}
+
+/*
+ * Send out eviction notice messages to all other hosts for the lease.
+ */
+void
+nqsrv_send_eviction(vp, lp, slp, nam, cred)
+	struct vnode *vp;
+	register struct nqlease *lp;
+	struct nfssvc_sock *slp;
+	struct mbuf *nam;
+	struct ucred *cred;
+{
+	register struct nqhost *lph = &lp->lc_host;
+	register struct mbuf *m;
+	register int siz;
+	struct nqm *lphnext = lp->lc_morehosts;
+	struct mbuf *mreq, *mb, *mb2, *nam2, *mheadend;
+	struct socket *so;
+	struct sockaddr_in *saddr;
+	fhandle_t *fhp;
+	caddr_t bpos, cp;
+	u_long xid;
+	int len = 1, ok = 1, i = 0;
+	int sotype, *solockp;
+
+	while (ok && (lph->lph_flag & LC_VALID)) {
+		if (nqsrv_cmpnam(slp, nam, lph))
+			lph->lph_flag |= LC_VACATED;
+		else if ((lph->lph_flag & (LC_LOCAL | LC_VACATED)) == 0) {
+			if (lph->lph_flag & LC_UDP) {
+				MGET(nam2, M_WAIT, MT_SONAME);
+				saddr = mtod(nam2, struct sockaddr_in *);
+				nam2->m_len = saddr->sin_len =
+					sizeof (struct sockaddr_in);
+				saddr->sin_family = AF_INET;
+				saddr->sin_addr.s_addr = lph->lph_inetaddr;
+				saddr->sin_port = lph->lph_port;
+				so = nfs_udpsock->ns_so;
+			} else if (lph->lph_flag & LC_CLTP) {
+				nam2 = lph->lph_nam;
+				so = nfs_cltpsock->ns_so;
+			} else if (lph->lph_slp->ns_flag & SLP_VALID) {
+				nam2 = (struct mbuf *)0;
+				so = lph->lph_slp->ns_so;
+			} else
+				goto nextone;
+			sotype = so->so_type;
+			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
+				solockp = &lph->lph_slp->ns_solock;
+			else
+				solockp = (int *)0;
+			nfsm_reqhead((struct vnode *)0, NQNFSPROC_EVICTED,
+				NFSX_FH);
+			nfsm_build(cp, caddr_t, NFSX_FH);
+			bzero(cp, NFSX_FH);
+			fhp = (fhandle_t *)cp;
+			fhp->fh_fsid = vp->v_mount->mnt_stat.f_fsid;
+			VFS_VPTOFH(vp, &fhp->fh_fid);
+			m = mreq;
+			siz = 0;
+			while (m) {
+				siz += m->m_len;
+				m = m->m_next;
+			}
+			if (siz <= 0 || siz > NFS_MAXPACKET) {
+				printf("mbuf siz=%d\n",siz);
+				panic("Bad nfs svc reply");
+			}
+			m = nfsm_rpchead(cred, TRUE, NQNFSPROC_EVICTED,
+				RPCAUTH_UNIX, 5*NFSX_UNSIGNED, (char *)0,
+				mreq, siz, &mheadend, &xid);
+			/*
+			 * For stream protocols, prepend a Sun RPC
+			 * Record Mark.
+			 */
+			if (sotype == SOCK_STREAM) {
+				M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
+				*mtod(m, u_long *) = htonl(0x80000000 |
+					(m->m_pkthdr.len - NFSX_UNSIGNED));
+			}
+			if (((lph->lph_flag & (LC_UDP | LC_CLTP)) == 0 &&
+			    (lph->lph_slp->ns_flag & SLP_VALID) == 0) ||
+			    (solockp && (*solockp & NFSMNT_SNDLOCK)))
+				m_freem(m);
+			else {
+				if (solockp)
+					*solockp |= NFSMNT_SNDLOCK;
+				(void) nfs_send(so, nam2, m,
+						(struct nfsreq *)0);
+				if (solockp)
+					nfs_sndunlock(solockp);
+			}
+			if (lph->lph_flag & LC_UDP)
+				MFREE(nam2, m);
+		}
+nextone:
+		if (++i == len) {
+			if (lphnext) {
+				i = 0;
+				len = LC_MOREHOSTSIZ;
+				lph = lphnext->lpm_hosts;
+				lphnext = lphnext->lpm_next;
+			} else
+				ok = 0;
+		} else
+			lph++;
+	}
+}
+
+/*
+ * Wait for the lease to expire.
+ * This will occur when all clients have sent "vacated" messages to
+ * this server OR when it expires do to timeout.
+ */
+void
+nqsrv_waitfor_expiry(lp)
+	register struct nqlease *lp;
+{
+	register struct nqhost *lph;
+	register int i;
+	struct nqm *lphnext;
+	int len, ok;
+
+tryagain:
+	if (time.tv_sec > lp->lc_expiry)
+		return;
+	lph = &lp->lc_host;
+	lphnext = lp->lc_morehosts;
+	len = 1;
+	i = 0;
+	ok = 1;
+	while (ok && (lph->lph_flag & LC_VALID)) {
+		if ((lph->lph_flag & (LC_LOCAL | LC_VACATED)) == 0) {
+			lp->lc_flag |= LC_EXPIREDWANTED;
+			(void) tsleep((caddr_t)&lp->lc_flag, PSOCK,
+					"nqexp", 0);
+			goto tryagain;
+		}
+		if (++i == len) {
+			if (lphnext) {
+				i = 0;
+				len = LC_MOREHOSTSIZ;
+				lph = lphnext->lpm_hosts;
+				lphnext = lphnext->lpm_next;
+			} else
+				ok = 0;
+		} else
+			lph++;
+	}
+}
+
+/*
+ * Nqnfs server timer that maintains the server lease queue.
+ * Scan the lease queue for expired entries:
+ * - when one is found, wakeup anyone waiting for it
+ *   else dequeue and free
+ */
+void
+nqnfs_serverd()
+{
+	register struct nqlease *lp, *lq;
+	register struct nqhost *lph;
+	struct nqlease *nextlp;
+	struct nqm *lphnext, *olphnext;
+	struct mbuf *n;
+	int i, len, ok;
+
+	lp = nqthead.th_chain[0];
+	while (lp != (struct nqlease *)&nqthead) {
+		if (lp->lc_expiry >= time.tv_sec)
+			break;
+		nextlp = lp->lc_chain1[0];
+		if (lp->lc_flag & LC_EXPIREDWANTED) {
+			lp->lc_flag &= ~LC_EXPIREDWANTED;
+			wakeup((caddr_t)&lp->lc_flag);
+		} else if ((lp->lc_flag & (LC_LOCKED | LC_WANTED)) == 0) {
+		    /*
+		     * Make a best effort at keeping a write caching lease long
+		     * enough by not deleting it until it has been explicitly
+		     * vacated or there have been no writes in the previous
+		     * write_slack seconds since expiry and the nfsds are not
+		     * all busy. The assumption is that if the nfsds are not
+		     * all busy now (no queue of nfs requests), then the client
+		     * would have been able to do at least one write to the
+		     * file during the last write_slack seconds if it was still
+		     * trying to push writes to the server.
+		     */
+		    if ((lp->lc_flag & (LC_WRITE | LC_VACATED)) == LC_WRITE &&
+			((lp->lc_flag & LC_WRITTEN) || nfsd_waiting == 0)) {
+			lp->lc_flag &= ~LC_WRITTEN;
+			nqsrv_instimeq(lp, nqsrv_writeslack);
+		    } else {
+			remque(lp);
+			if (lq = lp->lc_fhnext)
+				lq->lc_fhprev = lp->lc_fhprev;
+			*lp->lc_fhprev = lq;
+			/*
+			 * This soft reference may no longer be valid, but
+			 * no harm done. The worst case is if the vnode was
+			 * recycled and has another valid lease reference,
+			 * which is dereferenced prematurely.
+			 */
+			lp->lc_vp->v_lease = (struct nqlease *)0;
+			lph = &lp->lc_host;
+			lphnext = lp->lc_morehosts;
+			olphnext = (struct nqm *)0;
+			len = 1;
+			i = 0;
+			ok = 1;
+			while (ok && (lph->lph_flag & LC_VALID)) {
+				if (lph->lph_flag & LC_CLTP)
+					MFREE(lph->lph_nam, n);
+				if (lph->lph_flag & LC_SREF)
+					nfsrv_slpderef(lph->lph_slp);
+				if (++i == len) {
+					if (olphnext) {
+						free((caddr_t)olphnext, M_NQMHOST);
+						olphnext = (struct nqm *)0;
+					}
+					if (lphnext) {
+						olphnext = lphnext;
+						i = 0;
+						len = LC_MOREHOSTSIZ;
+						lph = lphnext->lpm_hosts;
+						lphnext = lphnext->lpm_next;
+					} else
+						ok = 0;
+				} else
+					lph++;
+			}
+			FREE((caddr_t)lp, M_NQLEASE);
+			if (olphnext)
+				free((caddr_t)olphnext, M_NQMHOST);
+			nfsstats.srvnqnfs_leases--;
+		    }
+		}
+		lp = nextlp;
+	}
+}
+
+/*
+ * Called from nfssvc_nfsd() for a getlease rpc request.
+ * Do the from/to xdr translation and call nqsrv_getlease() to
+ * do the real work.
+ */
+nqnfsrv_getlease(nfsd, mrep, md, dpos, cred, nam, mrq)
+	struct nfsd *nfsd;
+	struct mbuf *mrep, *md;
+	caddr_t dpos;
+	struct ucred *cred;
+	struct mbuf *nam, **mrq;
+{
+	register struct nfsv2_fattr *fp;
+	struct vattr va;
+	register struct vattr *vap = &va;
+	struct vnode *vp;
+	nfsv2fh_t nfh;
+	fhandle_t *fhp;
+	register u_long *tl;
+	register long t1;
+	u_quad_t frev;
+	caddr_t bpos;
+	int error = 0;
+	char *cp2;
+	struct mbuf *mb, *mb2, *mreq;
+	int flags, rdonly, cache;
+
+	fhp = &nfh.fh_generic;
+	nfsm_srvmtofh(fhp);
+	nfsm_dissect(tl, u_long *, 2*NFSX_UNSIGNED);
+	flags = fxdr_unsigned(int, *tl++);
+	nfsd->nd_duration = fxdr_unsigned(int, *tl);
+	if (error = nfsrv_fhtovp(fhp,
+	    TRUE, &vp, cred, nfsd->nd_slp, nam, &rdonly))
+		nfsm_reply(0);
+	if (rdonly && flags == NQL_WRITE) {
+		error = EROFS;
+		nfsm_reply(0);
+	}
+	(void) nqsrv_getlease(vp, &nfsd->nd_duration, flags, nfsd,
+		nam, &cache, &frev, cred);
+	error = VOP_GETATTR(vp, vap, cred, nfsd->nd_procp);
+	vput(vp);
+	nfsm_reply(NFSX_NQFATTR + 4*NFSX_UNSIGNED);
+	nfsm_build(tl, u_long *, 4*NFSX_UNSIGNED);
+	*tl++ = txdr_unsigned(cache);
+	*tl++ = txdr_unsigned(nfsd->nd_duration);
+	txdr_hyper(&frev, tl);
+	nfsm_build(fp, struct nfsv2_fattr *, NFSX_NQFATTR);
+	nfsm_srvfillattr;
+	nfsm_srvdone;
+}
+
+/*
+ * Called from nfssvc_nfsd() when a "vacated" message is received from a
+ * client. Find the entry and expire it.
+ */
+nqnfsrv_vacated(nfsd, mrep, md, dpos, cred, nam, mrq)
+	struct nfsd *nfsd;
+	struct mbuf *mrep, *md;
+	caddr_t dpos;
+	struct ucred *cred;
+	struct mbuf *nam, **mrq;
+{
+	register struct nqlease *lp;
+	register struct nqhost *lph;
+	struct nqlease *tlp = (struct nqlease *)0;
+	nfsv2fh_t nfh;
+	fhandle_t *fhp;
+	register u_long *tl;
+	register long t1;
+	struct nqm *lphnext;
+	int error = 0, i, len, ok, gotit = 0;
+	char *cp2;
+
+	fhp = &nfh.fh_generic;
+	nfsm_srvmtofh(fhp);
+	m_freem(mrep);
+	/*
+	 * Find the lease by searching the hash list.
+	 */
+	for (lp = nqfhead[NQFHHASH(fhp->fh_fid.fid_data)]; lp;
+	     lp = lp->lc_fhnext)
+		if (fhp->fh_fsid.val[0] == lp->lc_fsid.val[0] &&
+		    fhp->fh_fsid.val[1] == lp->lc_fsid.val[1] &&
+		    !bcmp(fhp->fh_fid.fid_data, lp->lc_fiddata,
+			  MAXFIDSZ)) {
+			/* Found it */
+			tlp = lp;
+			break;
+		}
+	if (tlp) {
+		lp = tlp;
+		len = 1;
+		i = 0;
+		lph = &lp->lc_host;
+		lphnext = lp->lc_morehosts;
+		ok = 1;
+		while (ok && (lph->lph_flag & LC_VALID)) {
+			if (nqsrv_cmpnam(nfsd->nd_slp, nam, lph)) {
+				lph->lph_flag |= LC_VACATED;
+				gotit++;
+				break;
+			}
+			if (++i == len) {
+				if (lphnext) {
+					len = LC_MOREHOSTSIZ;
+					i = 0;
+					lph = lphnext->lpm_hosts;
+					lphnext = lphnext->lpm_next;
+				} else
+					ok = 0;
+			} else
+				lph++;
+		}
+		if ((lp->lc_flag & LC_EXPIREDWANTED) && gotit) {
+			lp->lc_flag &= ~LC_EXPIREDWANTED;
+			wakeup((caddr_t)&lp->lc_flag);
+		}
+nfsmout:
+		return (EPERM);
+	}
+	return (EPERM);
+}
+
+/*
+ * Client get lease rpc function.
+ */
+nqnfs_getlease(vp, rwflag, cred, p)
+	register struct vnode *vp;
+	int rwflag;
+	struct ucred *cred;
+	struct proc *p;
+{
+	register u_long *tl;
+	register caddr_t cp;
+	register long t1;
+	register struct nfsnode *np;
+	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
+	caddr_t bpos, dpos, cp2;
+	time_t reqtime;
+	int error = 0;
+	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
+	int cachable;
+	u_quad_t frev;
+	
+	nfsstats.rpccnt[NQNFSPROC_GETLEASE]++;
+	mb = mreq = nfsm_reqh(vp, NQNFSPROC_GETLEASE, NFSX_FH+2*NFSX_UNSIGNED,
+		 &bpos);
+	nfsm_fhtom(vp);
+	nfsm_build(tl, u_long *, 2*NFSX_UNSIGNED);
+	*tl++ = txdr_unsigned(rwflag);
+	*tl = txdr_unsigned(nmp->nm_leaseterm);
+	reqtime = time.tv_sec;
+	nfsm_request(vp, NQNFSPROC_GETLEASE, p, cred);
+	np = VTONFS(vp);
+	nfsm_dissect(tl, u_long *, 4*NFSX_UNSIGNED);
+	cachable = fxdr_unsigned(int, *tl++);
+	reqtime += fxdr_unsigned(int, *tl++);
+	if (reqtime > time.tv_sec) {
+		fxdr_hyper(tl, &frev);
+		nqnfs_clientlease(nmp, np, rwflag, cachable, reqtime, frev);
+		nfsm_loadattr(vp, (struct vattr *)0);
+	} else
+		error = NQNFS_EXPIRED;
+	nfsm_reqdone;
+	return (error);
+}
+
+/*
+ * Client vacated message function.
+ */
+nqnfs_vacated(vp, cred)
+	register struct vnode *vp;
+	struct ucred *cred;
+{
+	register caddr_t cp;
+	register struct mbuf *m;
+	register int i;
+	caddr_t bpos;
+	u_long xid;
+	int error = 0;
+	struct mbuf *mreq, *mb, *mb2, *mheadend;
+	struct nfsmount *nmp;
+	struct nfsreq myrep;
+	
+	nmp = VFSTONFS(vp->v_mount);
+	nfsstats.rpccnt[NQNFSPROC_VACATED]++;
+	nfsm_reqhead(vp, NQNFSPROC_VACATED, NFSX_FH);
+	nfsm_fhtom(vp);
+	m = mreq;
+	i = 0;
+	while (m) {
+		i += m->m_len;
+		m = m->m_next;
+	}
+	m = nfsm_rpchead(cred, TRUE, NQNFSPROC_VACATED,
+		RPCAUTH_UNIX, 5*NFSX_UNSIGNED, (char *)0,
+		mreq, i, &mheadend, &xid);
+	if (nmp->nm_sotype == SOCK_STREAM) {
+		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
+		*mtod(m, u_long *) = htonl(0x80000000 | (m->m_pkthdr.len -
+			NFSX_UNSIGNED));
+	}
+	myrep.r_flags = 0;
+	myrep.r_nmp = nmp;
+	if (nmp->nm_soflags & PR_CONNREQUIRED)
+		(void) nfs_sndlock(&nmp->nm_flag, (struct nfsreq *)0);
+	(void) nfs_send(nmp->nm_so, nmp->nm_nam, m, &myrep);
+	if (nmp->nm_soflags & PR_CONNREQUIRED)
+		nfs_sndunlock(&nmp->nm_flag);
+	return (error);
+}
+
+/*
+ * Called for client side callbacks
+ */
+nqnfs_callback(nmp, mrep, md, dpos)
+	struct nfsmount *nmp;
+	struct mbuf *mrep, *md;
+	caddr_t dpos;
+{
+	register struct vnode *vp;
+	register u_long *tl;
+	register long t1;
+	nfsv2fh_t nfh;
+	fhandle_t *fhp;
+	struct nfsnode *np;
+	struct nfsd nd;
+	int error;
+	char *cp2;
+
+	nd.nd_mrep = mrep;
+	nd.nd_md = md;
+	nd.nd_dpos = dpos;
+	if (error = nfs_getreq(&nd, FALSE))
+		return (error);
+	md = nd.nd_md;
+	dpos = nd.nd_dpos;
+	if (nd.nd_procnum != NQNFSPROC_EVICTED) {
+		m_freem(mrep);
+		return (EPERM);
+	}
+	fhp = &nfh.fh_generic;
+	nfsm_srvmtofh(fhp);
+	m_freem(mrep);
+	if (error = nfs_nget(nmp->nm_mountp, fhp, &np))
+		return (error);
+	vp = NFSTOV(np);
+	if (np->n_tnext) {
+		np->n_expiry = 0;
+		np->n_flag |= NQNFSEVICTED;
+		if (np->n_tprev != (struct nfsnode *)nmp) {
+			if (np->n_tnext == (struct nfsnode *)nmp)
+				nmp->nm_tprev = np->n_tprev;
+			else
+				np->n_tnext->n_tprev = np->n_tprev;
+			np->n_tprev->n_tnext = np->n_tnext;
+			np->n_tnext = nmp->nm_tnext;
+			nmp->nm_tnext = np;
+			np->n_tprev = (struct nfsnode *)nmp;
+			if (np->n_tnext == (struct nfsnode *)nmp)
+				nmp->nm_tprev = np;
+			else
+				np->n_tnext->n_tprev = np;
+		}
+	}
+	vrele(vp);
+	nfsm_srvdone;
+}
+
+/*
+ * Nqnfs client helper daemon. Runs once a second to expire leases.
+ * It also get authorization strings for "kerb" mounts.
+ * It must start at the beginning of the list again after any potential
+ * "sleep" since nfs_reclaim() called from vclean() can pull a node off
+ * the list asynchronously.
+ */
+nqnfs_clientd(nmp, cred, ncd, flag, argp, p)
+	register struct nfsmount *nmp;
+	struct ucred *cred;
+	struct nfsd_cargs *ncd;
+	int flag;
+	caddr_t argp;
+	struct proc *p;
+{
+	register struct nfsnode *np;
+	struct vnode *vp;
+	struct nfsreq myrep;
+	int error, vpid;
+
+	/*
+	 * First initialize some variables
+	 */
+	nqnfs_prog = txdr_unsigned(NQNFS_PROG);
+	nqnfs_vers = txdr_unsigned(NQNFS_VER1);
+
+	/*
+	 * If an authorization string is being passed in, get it.
+	 */
+	if ((flag & NFSSVC_GOTAUTH) &&
+		(nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_DISMNT)) == 0) {
+		if (nmp->nm_flag & NFSMNT_HASAUTH)
+			panic("cld kerb");
+		if ((flag & NFSSVC_AUTHINFAIL) == 0) {
+			if (ncd->ncd_authlen <= RPCAUTH_MAXSIZ &&
+				copyin(ncd->ncd_authstr, nmp->nm_authstr,
+				ncd->ncd_authlen) == 0) {
+				nmp->nm_authtype = ncd->ncd_authtype;
+				nmp->nm_authlen = ncd->ncd_authlen;
+			} else
+				nmp->nm_flag |= NFSMNT_AUTHERR;
+		} else
+			nmp->nm_flag |= NFSMNT_AUTHERR;
+		nmp->nm_flag |= NFSMNT_HASAUTH;
+		wakeup((caddr_t)&nmp->nm_authlen);
+	} else
+		nmp->nm_flag |= NFSMNT_WAITAUTH;
+
+	/*
+	 * Loop every second updating queue until there is a termination sig.
+	 */
+	while ((nmp->nm_flag & NFSMNT_DISMNT) == 0) {
+	    if (nmp->nm_flag & NFSMNT_NQNFS) {
+		/*
+		 * If there are no outstanding requests (and therefore no
+		 * processes in nfs_reply) and there is data in the receive
+		 * queue, poke for callbacks.
+		 */
+		if (nfsreqh.r_next == &nfsreqh && nmp->nm_so &&
+		    nmp->nm_so->so_rcv.sb_cc > 0) {
+		    myrep.r_flags = R_GETONEREP;
+		    myrep.r_nmp = nmp;
+		    myrep.r_mrep = (struct mbuf *)0;
+		    myrep.r_procp = (struct proc *)0;
+		    (void) nfs_reply(&myrep);
+		}
+
+		/*
+		 * Loop through the leases, updating as required.
+		 */
+		np = nmp->nm_tnext;
+		while (np != (struct nfsnode *)nmp &&
+		       (nmp->nm_flag & NFSMNT_DISMINPROG) == 0) {
+			vp = NFSTOV(np);
+if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash2");
+			vpid = vp->v_id;
+			if (np->n_expiry < time.tv_sec) {
+			   if (vget(vp, 1) == 0) {
+			     nmp->nm_inprog = vp;
+			     if (vpid == vp->v_id) {
+if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash3");
+				if (np->n_tnext == (struct nfsnode *)nmp)
+					nmp->nm_tprev = np->n_tprev;
+				else
+					np->n_tnext->n_tprev = np->n_tprev;
+				if (np->n_tprev == (struct nfsnode *)nmp)
+					nmp->nm_tnext = np->n_tnext;
+				else
+					np->n_tprev->n_tnext = np->n_tnext;
+				np->n_tnext = (struct nfsnode *)0;
+				if ((np->n_flag & (NMODIFIED | NQNFSEVICTED))
+				    && vp->v_type == VREG) {
+					if (np->n_flag & NQNFSEVICTED) {
+						(void) nfs_vinvalbuf(vp,
+						       V_SAVE, cred, p, 0);
+						np->n_flag &= ~NQNFSEVICTED;
+						(void) nqnfs_vacated(vp, cred);
+					} else {
+						(void) VOP_FSYNC(vp, cred,
+						    MNT_WAIT, p);
+						np->n_flag &= ~NMODIFIED;
+					}
+				}
+			      }
+			      vrele(vp);
+			      nmp->nm_inprog = NULLVP;
+			    }
+			    if (np != nmp->nm_tnext)
+				np = nmp->nm_tnext;
+			    else
+				break;
+			} else if ((np->n_expiry - NQ_RENEWAL) < time.tv_sec) {
+			    if ((np->n_flag & (NQNFSWRITE | NQNFSNONCACHE))
+				 == NQNFSWRITE && vp->v_dirtyblkhd.lh_first &&
+				 vget(vp, 1) == 0) {
+				 nmp->nm_inprog = vp;
+if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash4");
+				 if (vpid == vp->v_id &&
+				     nqnfs_getlease(vp, NQL_WRITE, cred, p)==0)
+					np->n_brev = np->n_lrev;
+				 vrele(vp);
+				 nmp->nm_inprog = NULLVP;
+			    }
+			    if (np != nmp->nm_tnext)
+				np = nmp->nm_tnext;
+			    else
+				break;
+			} else
+				break;
+		}
+	    }
+
+	    /*
+	     * Get an authorization string, if required.
+	     */
+	    if ((nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_DISMNT | NFSMNT_HASAUTH)) == 0) {
+		ncd->ncd_authuid = nmp->nm_authuid;
+		if (copyout((caddr_t)ncd, argp, sizeof (struct nfsd_cargs)))
+			nmp->nm_flag |= NFSMNT_WAITAUTH;
+		else
+			return (ENEEDAUTH);
+	    }
+
+	    /*
+	     * Wait a bit (no pun) and do it again.
+	     */
+	    if ((nmp->nm_flag & NFSMNT_DISMNT) == 0 &&
+		(nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_HASAUTH))) {
+		    error = tsleep((caddr_t)&nmp->nm_authstr, PSOCK | PCATCH,
+			"nqnfstimr", hz / 3);
+		    if (error == EINTR || error == ERESTART)
+			(void) dounmount(nmp->nm_mountp, 0, p);
+	    }
+	}
+	free((caddr_t)nmp, M_NFSMNT);
+	if (error == EWOULDBLOCK)
+		error = 0;
+	return (error);
+}
+
+/*
+ * Adjust all timer queue expiry times when the time of day clock is changed.
+ * Called from the settimeofday() syscall.
+ */
+void
+lease_updatetime(deltat)
+	register int deltat;
+{
+	register struct nqlease *lp;
+	register struct nfsnode *np;
+	struct mount *mp;
+	struct nfsmount *nmp;
+	int s;
+
+	if (nqnfsstarttime != 0)
+		nqnfsstarttime += deltat;
+	s = splsoftclock();
+	lp = nqthead.th_chain[0];
+	while (lp != (struct nqlease *)&nqthead) {
+		lp->lc_expiry += deltat;
+		lp = lp->lc_chain1[0];
+	}
+	splx(s);
+
+	/*
+	 * Search the mount list for all nqnfs mounts and do their timer
+	 * queues.
+	 */
+	for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next) {
+		if (mp->mnt_stat.f_fsid.val[1] == MOUNT_NFS) {
+			nmp = VFSTONFS(mp);
+			if (nmp->nm_flag & NFSMNT_NQNFS) {
+				np = nmp->nm_tnext;
+				while (np != (struct nfsnode *)nmp) {
+					np->n_expiry += deltat;
+					np = np->n_tnext;
+				}
+			}
+		}
+	}
+}
+
+/*
+ * Lock a server lease.
+ */
+void
+nqsrv_locklease(lp)
+	struct nqlease *lp;
+{
+
+	while (lp->lc_flag & LC_LOCKED) {
+		lp->lc_flag |= LC_WANTED;
+		(void) tsleep((caddr_t)lp, PSOCK, "nqlc", 0);
+	}
+	lp->lc_flag |= LC_LOCKED;
+	lp->lc_flag &= ~LC_WANTED;
+}
+
+/*
+ * Unlock a server lease.
+ */
+void
+nqsrv_unlocklease(lp)
+	struct nqlease *lp;
+{
+
+	lp->lc_flag &= ~LC_LOCKED;
+	if (lp->lc_flag & LC_WANTED)
+		wakeup((caddr_t)lp);
+}
+
+/*
+ * Update a client lease.
+ */
+void
+nqnfs_clientlease(nmp, np, rwflag, cachable, expiry, frev)
+	register struct nfsmount *nmp;
+	register struct nfsnode *np;
+	int rwflag, cachable;
+	time_t expiry;
+	u_quad_t frev;
+{
+	register struct nfsnode *tp;
+
+	if (np->n_tnext) {
+		if (np->n_tnext == (struct nfsnode *)nmp)
+			nmp->nm_tprev = np->n_tprev;
+		else
+			np->n_tnext->n_tprev = np->n_tprev;
+		if (np->n_tprev == (struct nfsnode *)nmp)
+			nmp->nm_tnext = np->n_tnext;
+		else
+			np->n_tprev->n_tnext = np->n_tnext;
+		if (rwflag == NQL_WRITE)
+			np->n_flag |= NQNFSWRITE;
+	} else if (rwflag == NQL_READ)
+		np->n_flag &= ~NQNFSWRITE;
+	else
+		np->n_flag |= NQNFSWRITE;
+	if (cachable)
+		np->n_flag &= ~NQNFSNONCACHE;
+	else
+		np->n_flag |= NQNFSNONCACHE;
+	np->n_expiry = expiry;
+	np->n_lrev = frev;
+	tp = nmp->nm_tprev;
+	while (tp != (struct nfsnode *)nmp && tp->n_expiry > np->n_expiry)
+		tp = tp->n_tprev;
+	if (tp == (struct nfsnode *)nmp) {
+		np->n_tnext = nmp->nm_tnext;
+		nmp->nm_tnext = np;
+	} else {
+		np->n_tnext = tp->n_tnext;
+		tp->n_tnext = np;
+	}
+	np->n_tprev = tp;
+	if (np->n_tnext == (struct nfsnode *)nmp)
+		nmp->nm_tprev = np;
+	else
+		np->n_tnext->n_tprev = np;
+}