xref: /original-bsd/sys/nfs/nfs_nqlease.c (revision 333da485)
1 /*
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * %sccs.include.redist.c%
9  *
10  *	@(#)nfs_nqlease.c	8.3 (Berkeley) 01/04/94
11  */
12 
13 /*
14  * References:
15  *	Cary G. Gray and David R. Cheriton, "Leases: An Efficient Fault-Tolerant
16  *		Mechanism for Distributed File Cache Consistency",
17  *		In Proc. of the Twelfth ACM Symposium on Operating Systems
18  *		Principals, pg. 202-210, Litchfield Park, AZ, Dec. 1989.
19  *	Michael N. Nelson, Brent B. Welch and John K. Ousterhout, "Caching
20  *		in the Sprite Network File System", ACM TOCS 6(1),
21  *		pages 134-154, February 1988.
22  *	V. Srinivasan and Jeffrey C. Mogul, "Spritely NFS: Implementation and
23  *		Performance of Cache-Consistency Protocols", Digital
24  *		Equipment Corporation WRL Research Report 89/5, May 1989.
25  */
26 #include <sys/param.h>
27 #include <sys/vnode.h>
28 #include <sys/mount.h>
29 #include <sys/kernel.h>
30 #include <sys/proc.h>
31 #include <sys/systm.h>
32 #include <sys/mbuf.h>
33 #include <sys/socket.h>
34 #include <sys/socketvar.h>
35 #include <sys/file.h>
36 #include <sys/buf.h>
37 #include <sys/stat.h>
38 #include <sys/protosw.h>
39 
40 #include <netinet/in.h>
41 #include <nfs/rpcv2.h>
42 #include <nfs/nfsv2.h>
43 #include <nfs/nfs.h>
44 #include <nfs/nfsm_subs.h>
45 #include <nfs/xdr_subs.h>
46 #include <nfs/nqnfs.h>
47 #include <nfs/nfsnode.h>
48 #include <nfs/nfsmount.h>
49 
50 /*
51  * List head for the lease queue and other global data.
52  * At any time a lease is linked into a list ordered by increasing expiry time.
53  */
54 #define	NQFHHASH(f)	((*((u_long *)(f)))&nqfheadhash)
55 
56 union nqsrvthead nqthead;
57 struct nqlease **nqfhead;
58 u_long nqfheadhash;
59 time_t nqnfsstarttime = (time_t)0;
60 u_long nqnfs_prog, nqnfs_vers;
61 int nqsrv_clockskew = NQ_CLOCKSKEW;
62 int nqsrv_writeslack = NQ_WRITESLACK;
63 int nqsrv_maxlease = NQ_MAXLEASE;
64 int nqsrv_maxnumlease = NQ_MAXNUMLEASE;
65 void nqsrv_instimeq(), nqsrv_send_eviction(), nfs_sndunlock();
66 void nqsrv_unlocklease(), nqsrv_waitfor_expiry(), nfsrv_slpderef();
67 void nqsrv_addhost(), nqsrv_locklease(), nqnfs_serverd();
68 void nqnfs_clientlease();
69 struct mbuf *nfsm_rpchead();
70 
71 /*
72  * Signifies which rpcs can have piggybacked lease requests
73  */
74 int nqnfs_piggy[NFS_NPROCS] = {
75 	0,
76 	NQL_READ,
77 	NQL_WRITE,
78 	0,
79 	NQL_READ,
80 	NQL_READ,
81 	NQL_READ,
82 	0,
83 	NQL_WRITE,
84 	0,
85 	0,
86 	0,
87 	0,
88 	0,
89 	0,
90 	0,
91 	NQL_READ,
92 	0,
93 	NQL_READ,
94 	0,
95 	0,
96 	0,
97 	0,
98 };
99 
100 int nnnnnn = sizeof (struct nqlease);
101 int oooooo = sizeof (struct nfsnode);
102 extern nfstype nfs_type[9];
103 extern struct nfssvc_sock *nfs_udpsock, *nfs_cltpsock;
104 extern struct nfsd nfsd_head;
105 extern int nfsd_waiting;
106 extern struct nfsreq nfsreqh;
107 
108 #define TRUE	1
109 #define	FALSE	0
110 
111 /*
112  * Get or check for a lease for "vp", based on NQL_CHECK flag.
113  * The rules are as follows:
114  * - if a current non-caching lease, reply non-caching
115  * - if a current lease for same host only, extend lease
116  * - if a read cachable lease and a read lease request
117  *	add host to list any reply cachable
118  * - else { set non-cachable for read-write sharing }
119  *	send eviction notice messages to all other hosts that have lease
120  *	wait for lease termination { either by receiving vacated messages
121  *					from all the other hosts or expiry
122  *					via. timeout }
123  *	modify lease to non-cachable
124  * - else if no current lease, issue new one
125  * - reply
126  * - return boolean TRUE iff nam should be m_freem()'d
127  * NB: Since nqnfs_serverd() is called from a timer, any potential tsleep()
128  *     in here must be framed by nqsrv_locklease() and nqsrv_unlocklease().
129  *     nqsrv_locklease() is coded such that at least one of LC_LOCKED and
130  *     LC_WANTED is set whenever a process is tsleeping in it. The exception
131  *     is when a new lease is being allocated, since it is not in the timer
132  *     queue yet. (Ditto for the splsoftclock() and splx(s) calls)
133  */
134 nqsrv_getlease(vp, duration, flags, nd, nam, cachablep, frev, cred)
135 	struct vnode *vp;
136 	u_long *duration;
137 	int flags;
138 	struct nfsd *nd;
139 	struct mbuf *nam;
140 	int *cachablep;
141 	u_quad_t *frev;
142 	struct ucred *cred;
143 {
144 	register struct nqlease *lp, *lq, **lpp;
145 	register struct nqhost *lph;
146 	struct nqlease *tlp;
147 	struct nqm **lphp;
148 	struct vattr vattr;
149 	fhandle_t fh;
150 	int i, ok, error, s;
151 
152 	if (vp->v_type != VREG && vp->v_type != VDIR && vp->v_type != VLNK)
153 		return (0);
154 	if (*duration > nqsrv_maxlease)
155 		*duration = nqsrv_maxlease;
156 	if (error = VOP_GETATTR(vp, &vattr, cred, nd->nd_procp))
157 		return (error);
158 	*frev = vattr.va_filerev;
159 	s = splsoftclock();
160 	tlp = vp->v_lease;
161 	if ((flags & NQL_CHECK) == 0)
162 		nfsstats.srvnqnfs_getleases++;
163 	if (tlp == (struct nqlease *)0) {
164 
165 		/*
166 		 * Find the lease by searching the hash list.
167 		 */
168 		fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
169 		if (error = VFS_VPTOFH(vp, &fh.fh_fid)) {
170 			splx(s);
171 			return (error);
172 		}
173 		lpp = &nqfhead[NQFHHASH(fh.fh_fid.fid_data)];
174 		for (lp = *lpp; lp; lp = lp->lc_fhnext)
175 			if (fh.fh_fsid.val[0] == lp->lc_fsid.val[0] &&
176 			    fh.fh_fsid.val[1] == lp->lc_fsid.val[1] &&
177 			    !bcmp(fh.fh_fid.fid_data, lp->lc_fiddata,
178 				  fh.fh_fid.fid_len - sizeof (long))) {
179 				/* Found it */
180 				lp->lc_vp = vp;
181 				vp->v_lease = lp;
182 				tlp = lp;
183 				break;
184 			}
185 	}
186 	lp = tlp;
187 	if (lp) {
188 		if ((lp->lc_flag & LC_NONCACHABLE) ||
189 		    (lp->lc_morehosts == (struct nqm *)0 &&
190 		     nqsrv_cmpnam(nd->nd_slp, nam, &lp->lc_host)))
191 			goto doreply;
192 		if ((flags & NQL_READ) && (lp->lc_flag & LC_WRITE)==0) {
193 			if (flags & NQL_CHECK)
194 				goto doreply;
195 			if (nqsrv_cmpnam(nd->nd_slp, nam, &lp->lc_host))
196 				goto doreply;
197 			i = 0;
198 			if (lp->lc_morehosts) {
199 				lph = lp->lc_morehosts->lpm_hosts;
200 				lphp = &lp->lc_morehosts->lpm_next;
201 				ok = 1;
202 			} else {
203 				lphp = &lp->lc_morehosts;
204 				ok = 0;
205 			}
206 			while (ok && (lph->lph_flag & LC_VALID)) {
207 				if (nqsrv_cmpnam(nd->nd_slp, nam, lph))
208 					goto doreply;
209 				if (++i == LC_MOREHOSTSIZ) {
210 					i = 0;
211 					if (*lphp) {
212 						lph = (*lphp)->lpm_hosts;
213 						lphp = &((*lphp)->lpm_next);
214 					} else
215 						ok = 0;
216 				} else
217 					lph++;
218 			}
219 			nqsrv_locklease(lp);
220 			if (!ok) {
221 				*lphp = (struct nqm *)
222 					malloc(sizeof (struct nqm),
223 						M_NQMHOST, M_WAITOK);
224 				bzero((caddr_t)*lphp, sizeof (struct nqm));
225 				lph = (*lphp)->lpm_hosts;
226 			}
227 			nqsrv_addhost(lph, nd->nd_slp, nam);
228 			nqsrv_unlocklease(lp);
229 		} else {
230 			lp->lc_flag |= LC_NONCACHABLE;
231 			nqsrv_locklease(lp);
232 			nqsrv_send_eviction(vp, lp, nd->nd_slp, nam, cred);
233 			nqsrv_waitfor_expiry(lp);
234 			nqsrv_unlocklease(lp);
235 		}
236 doreply:
237 		/*
238 		 * Update the lease and return
239 		 */
240 		if ((flags & NQL_CHECK) == 0)
241 			nqsrv_instimeq(lp, *duration);
242 		if (lp->lc_flag & LC_NONCACHABLE)
243 			*cachablep = 0;
244 		else {
245 			*cachablep = 1;
246 			if (flags & NQL_WRITE)
247 				lp->lc_flag |= LC_WRITTEN;
248 		}
249 		splx(s);
250 		return (0);
251 	}
252 	splx(s);
253 	if (flags & NQL_CHECK)
254 		return (0);
255 
256 	/*
257 	 * Allocate new lease
258 	 * The value of nqsrv_maxnumlease should be set generously, so that
259 	 * the following "printf" happens infrequently.
260 	 */
261 	if (nfsstats.srvnqnfs_leases > nqsrv_maxnumlease) {
262 		printf("Nqnfs server, too many leases\n");
263 		do {
264 			(void) tsleep((caddr_t)&lbolt, PSOCK,
265 					"nqsrvnuml", 0);
266 		} while (nfsstats.srvnqnfs_leases > nqsrv_maxnumlease);
267 	}
268 	MALLOC(lp, struct nqlease *, sizeof (struct nqlease), M_NQLEASE, M_WAITOK);
269 	bzero((caddr_t)lp, sizeof (struct nqlease));
270 	if (flags & NQL_WRITE)
271 		lp->lc_flag |= (LC_WRITE | LC_WRITTEN);
272 	nqsrv_addhost(&lp->lc_host, nd->nd_slp, nam);
273 	lp->lc_vp = vp;
274 	lp->lc_fsid = fh.fh_fsid;
275 	bcopy(fh.fh_fid.fid_data, lp->lc_fiddata, fh.fh_fid.fid_len - sizeof (long));
276 	if (lq = *lpp)
277 		lq->lc_fhprev = &lp->lc_fhnext;
278 	lp->lc_fhnext = lq;
279 	lp->lc_fhprev = lpp;
280 	*lpp = lp;
281 	vp->v_lease = lp;
282 	s = splsoftclock();
283 	nqsrv_instimeq(lp, *duration);
284 	splx(s);
285 	*cachablep = 1;
286 	if (++nfsstats.srvnqnfs_leases > nfsstats.srvnqnfs_maxleases)
287 		nfsstats.srvnqnfs_maxleases = nfsstats.srvnqnfs_leases;
288 	return (0);
289 }
290 
291 /*
292  * Local lease check for server syscalls.
293  * Just set up args and let nqsrv_getlease() do the rest.
294  */
295 void
296 lease_check(vp, p, cred, flag)
297 	struct vnode *vp;
298 	struct proc *p;
299 	struct ucred *cred;
300 	int flag;
301 {
302 	int duration = 0, cache;
303 	struct nfsd nfsd;
304 	u_quad_t frev;
305 
306 	nfsd.nd_slp = NQLOCALSLP;
307 	nfsd.nd_procp = p;
308 	(void) nqsrv_getlease(vp, &duration, NQL_CHECK | flag, &nfsd,
309 		(struct mbuf *)0, &cache, &frev, cred);
310 }
311 
312 /*
313  * Add a host to an nqhost structure for a lease.
314  */
315 void
316 nqsrv_addhost(lph, slp, nam)
317 	register struct nqhost *lph;
318 	struct nfssvc_sock *slp;
319 	struct mbuf *nam;
320 {
321 	register struct sockaddr_in *saddr;
322 
323 	if (slp == NQLOCALSLP)
324 		lph->lph_flag |= (LC_VALID | LC_LOCAL);
325 	else if (slp == nfs_udpsock) {
326 		saddr = mtod(nam, struct sockaddr_in *);
327 		lph->lph_flag |= (LC_VALID | LC_UDP);
328 		lph->lph_inetaddr = saddr->sin_addr.s_addr;
329 		lph->lph_port = saddr->sin_port;
330 	} else if (slp == nfs_cltpsock) {
331 		lph->lph_nam = m_copym(nam, 0, M_COPYALL, M_WAIT);
332 		lph->lph_flag |= (LC_VALID | LC_CLTP);
333 	} else {
334 		lph->lph_flag |= (LC_VALID | LC_SREF);
335 		lph->lph_slp = slp;
336 		slp->ns_sref++;
337 	}
338 }
339 
340 /*
341  * Update the lease expiry time and position it in the timer queue correctly.
342  */
343 void
344 nqsrv_instimeq(lp, duration)
345 	register struct nqlease *lp;
346 	u_long duration;
347 {
348 	register struct nqlease *tlp;
349 	time_t newexpiry;
350 
351 	newexpiry = time.tv_sec + duration + nqsrv_clockskew;
352 	if (lp->lc_expiry == newexpiry)
353 		return;
354 	if (lp->lc_chain1[0])
355 		remque(lp);
356 	lp->lc_expiry = newexpiry;
357 
358 	/*
359 	 * Find where in the queue it should be.
360 	 */
361 	tlp = nqthead.th_chain[1];
362 	while (tlp->lc_expiry > newexpiry && tlp != (struct nqlease *)&nqthead)
363 		tlp = tlp->lc_chain1[1];
364 	if (tlp == nqthead.th_chain[1])
365 		NQSTORENOVRAM(newexpiry);
366 	insque(lp, tlp);
367 }
368 
369 /*
370  * Compare the requesting host address with the lph entry in the lease.
371  * Return true iff it is the same.
372  * This is somewhat messy due to the union in the nqhost structure.
373  * The local host is indicated by the special value of NQLOCALSLP for slp.
374  */
375 nqsrv_cmpnam(slp, nam, lph)
376 	register struct nfssvc_sock *slp;
377 	struct mbuf *nam;
378 	register struct nqhost *lph;
379 {
380 	register struct sockaddr_in *saddr;
381 	struct mbuf *addr;
382 	union nethostaddr lhaddr;
383 	int ret;
384 
385 	if (slp == NQLOCALSLP) {
386 		if (lph->lph_flag & LC_LOCAL)
387 			return (1);
388 		else
389 			return (0);
390 	}
391 	if (slp == nfs_udpsock || slp == nfs_cltpsock)
392 		addr = nam;
393 	else
394 		addr = slp->ns_nam;
395 	if (lph->lph_flag & LC_UDP)
396 		ret = netaddr_match(AF_INET, &lph->lph_haddr, addr);
397 	else if (lph->lph_flag & LC_CLTP)
398 		ret = netaddr_match(AF_ISO, &lph->lph_claddr, addr);
399 	else {
400 		if ((lph->lph_slp->ns_flag & SLP_VALID) == 0)
401 			return (0);
402 		saddr = mtod(lph->lph_slp->ns_nam, struct sockaddr_in *);
403 		if (saddr->sin_family == AF_INET)
404 			lhaddr.had_inetaddr = saddr->sin_addr.s_addr;
405 		else
406 			lhaddr.had_nam = lph->lph_slp->ns_nam;
407 		ret = netaddr_match(saddr->sin_family, &lhaddr, addr);
408 	}
409 	return (ret);
410 }
411 
412 /*
413  * Send out eviction notice messages to all other hosts for the lease.
414  */
415 void
416 nqsrv_send_eviction(vp, lp, slp, nam, cred)
417 	struct vnode *vp;
418 	register struct nqlease *lp;
419 	struct nfssvc_sock *slp;
420 	struct mbuf *nam;
421 	struct ucred *cred;
422 {
423 	register struct nqhost *lph = &lp->lc_host;
424 	register struct mbuf *m;
425 	register int siz;
426 	struct nqm *lphnext = lp->lc_morehosts;
427 	struct mbuf *mreq, *mb, *mb2, *nam2, *mheadend;
428 	struct socket *so;
429 	struct sockaddr_in *saddr;
430 	fhandle_t *fhp;
431 	caddr_t bpos, cp;
432 	u_long xid;
433 	int len = 1, ok = 1, i = 0;
434 	int sotype, *solockp;
435 
436 	while (ok && (lph->lph_flag & LC_VALID)) {
437 		if (nqsrv_cmpnam(slp, nam, lph))
438 			lph->lph_flag |= LC_VACATED;
439 		else if ((lph->lph_flag & (LC_LOCAL | LC_VACATED)) == 0) {
440 			if (lph->lph_flag & LC_UDP) {
441 				MGET(nam2, M_WAIT, MT_SONAME);
442 				saddr = mtod(nam2, struct sockaddr_in *);
443 				nam2->m_len = saddr->sin_len =
444 					sizeof (struct sockaddr_in);
445 				saddr->sin_family = AF_INET;
446 				saddr->sin_addr.s_addr = lph->lph_inetaddr;
447 				saddr->sin_port = lph->lph_port;
448 				so = nfs_udpsock->ns_so;
449 			} else if (lph->lph_flag & LC_CLTP) {
450 				nam2 = lph->lph_nam;
451 				so = nfs_cltpsock->ns_so;
452 			} else if (lph->lph_slp->ns_flag & SLP_VALID) {
453 				nam2 = (struct mbuf *)0;
454 				so = lph->lph_slp->ns_so;
455 			} else
456 				goto nextone;
457 			sotype = so->so_type;
458 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
459 				solockp = &lph->lph_slp->ns_solock;
460 			else
461 				solockp = (int *)0;
462 			nfsm_reqhead((struct vnode *)0, NQNFSPROC_EVICTED,
463 				NFSX_FH);
464 			nfsm_build(cp, caddr_t, NFSX_FH);
465 			bzero(cp, NFSX_FH);
466 			fhp = (fhandle_t *)cp;
467 			fhp->fh_fsid = vp->v_mount->mnt_stat.f_fsid;
468 			VFS_VPTOFH(vp, &fhp->fh_fid);
469 			m = mreq;
470 			siz = 0;
471 			while (m) {
472 				siz += m->m_len;
473 				m = m->m_next;
474 			}
475 			if (siz <= 0 || siz > NFS_MAXPACKET) {
476 				printf("mbuf siz=%d\n",siz);
477 				panic("Bad nfs svc reply");
478 			}
479 			m = nfsm_rpchead(cred, TRUE, NQNFSPROC_EVICTED,
480 				RPCAUTH_UNIX, 5*NFSX_UNSIGNED, (char *)0,
481 				mreq, siz, &mheadend, &xid);
482 			/*
483 			 * For stream protocols, prepend a Sun RPC
484 			 * Record Mark.
485 			 */
486 			if (sotype == SOCK_STREAM) {
487 				M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
488 				*mtod(m, u_long *) = htonl(0x80000000 |
489 					(m->m_pkthdr.len - NFSX_UNSIGNED));
490 			}
491 			if (((lph->lph_flag & (LC_UDP | LC_CLTP)) == 0 &&
492 			    (lph->lph_slp->ns_flag & SLP_VALID) == 0) ||
493 			    (solockp && (*solockp & NFSMNT_SNDLOCK)))
494 				m_freem(m);
495 			else {
496 				if (solockp)
497 					*solockp |= NFSMNT_SNDLOCK;
498 				(void) nfs_send(so, nam2, m,
499 						(struct nfsreq *)0);
500 				if (solockp)
501 					nfs_sndunlock(solockp);
502 			}
503 			if (lph->lph_flag & LC_UDP)
504 				MFREE(nam2, m);
505 		}
506 nextone:
507 		if (++i == len) {
508 			if (lphnext) {
509 				i = 0;
510 				len = LC_MOREHOSTSIZ;
511 				lph = lphnext->lpm_hosts;
512 				lphnext = lphnext->lpm_next;
513 			} else
514 				ok = 0;
515 		} else
516 			lph++;
517 	}
518 }
519 
520 /*
521  * Wait for the lease to expire.
522  * This will occur when all clients have sent "vacated" messages to
523  * this server OR when it expires do to timeout.
524  */
525 void
526 nqsrv_waitfor_expiry(lp)
527 	register struct nqlease *lp;
528 {
529 	register struct nqhost *lph;
530 	register int i;
531 	struct nqm *lphnext;
532 	int len, ok;
533 
534 tryagain:
535 	if (time.tv_sec > lp->lc_expiry)
536 		return;
537 	lph = &lp->lc_host;
538 	lphnext = lp->lc_morehosts;
539 	len = 1;
540 	i = 0;
541 	ok = 1;
542 	while (ok && (lph->lph_flag & LC_VALID)) {
543 		if ((lph->lph_flag & (LC_LOCAL | LC_VACATED)) == 0) {
544 			lp->lc_flag |= LC_EXPIREDWANTED;
545 			(void) tsleep((caddr_t)&lp->lc_flag, PSOCK,
546 					"nqexp", 0);
547 			goto tryagain;
548 		}
549 		if (++i == len) {
550 			if (lphnext) {
551 				i = 0;
552 				len = LC_MOREHOSTSIZ;
553 				lph = lphnext->lpm_hosts;
554 				lphnext = lphnext->lpm_next;
555 			} else
556 				ok = 0;
557 		} else
558 			lph++;
559 	}
560 }
561 
562 /*
563  * Nqnfs server timer that maintains the server lease queue.
564  * Scan the lease queue for expired entries:
565  * - when one is found, wakeup anyone waiting for it
566  *   else dequeue and free
567  */
568 void
569 nqnfs_serverd()
570 {
571 	register struct nqlease *lp, *lq;
572 	register struct nqhost *lph;
573 	struct nqlease *nextlp;
574 	struct nqm *lphnext, *olphnext;
575 	struct mbuf *n;
576 	int i, len, ok;
577 
578 	lp = nqthead.th_chain[0];
579 	while (lp != (struct nqlease *)&nqthead) {
580 		if (lp->lc_expiry >= time.tv_sec)
581 			break;
582 		nextlp = lp->lc_chain1[0];
583 		if (lp->lc_flag & LC_EXPIREDWANTED) {
584 			lp->lc_flag &= ~LC_EXPIREDWANTED;
585 			wakeup((caddr_t)&lp->lc_flag);
586 		} else if ((lp->lc_flag & (LC_LOCKED | LC_WANTED)) == 0) {
587 		    /*
588 		     * Make a best effort at keeping a write caching lease long
589 		     * enough by not deleting it until it has been explicitly
590 		     * vacated or there have been no writes in the previous
591 		     * write_slack seconds since expiry and the nfsds are not
592 		     * all busy. The assumption is that if the nfsds are not
593 		     * all busy now (no queue of nfs requests), then the client
594 		     * would have been able to do at least one write to the
595 		     * file during the last write_slack seconds if it was still
596 		     * trying to push writes to the server.
597 		     */
598 		    if ((lp->lc_flag & (LC_WRITE | LC_VACATED)) == LC_WRITE &&
599 			((lp->lc_flag & LC_WRITTEN) || nfsd_waiting == 0)) {
600 			lp->lc_flag &= ~LC_WRITTEN;
601 			nqsrv_instimeq(lp, nqsrv_writeslack);
602 		    } else {
603 			remque(lp);
604 			if (lq = lp->lc_fhnext)
605 				lq->lc_fhprev = lp->lc_fhprev;
606 			*lp->lc_fhprev = lq;
607 			/*
608 			 * This soft reference may no longer be valid, but
609 			 * no harm done. The worst case is if the vnode was
610 			 * recycled and has another valid lease reference,
611 			 * which is dereferenced prematurely.
612 			 */
613 			lp->lc_vp->v_lease = (struct nqlease *)0;
614 			lph = &lp->lc_host;
615 			lphnext = lp->lc_morehosts;
616 			olphnext = (struct nqm *)0;
617 			len = 1;
618 			i = 0;
619 			ok = 1;
620 			while (ok && (lph->lph_flag & LC_VALID)) {
621 				if (lph->lph_flag & LC_CLTP)
622 					MFREE(lph->lph_nam, n);
623 				if (lph->lph_flag & LC_SREF)
624 					nfsrv_slpderef(lph->lph_slp);
625 				if (++i == len) {
626 					if (olphnext) {
627 						free((caddr_t)olphnext, M_NQMHOST);
628 						olphnext = (struct nqm *)0;
629 					}
630 					if (lphnext) {
631 						olphnext = lphnext;
632 						i = 0;
633 						len = LC_MOREHOSTSIZ;
634 						lph = lphnext->lpm_hosts;
635 						lphnext = lphnext->lpm_next;
636 					} else
637 						ok = 0;
638 				} else
639 					lph++;
640 			}
641 			FREE((caddr_t)lp, M_NQLEASE);
642 			if (olphnext)
643 				free((caddr_t)olphnext, M_NQMHOST);
644 			nfsstats.srvnqnfs_leases--;
645 		    }
646 		}
647 		lp = nextlp;
648 	}
649 }
650 
651 /*
652  * Called from nfssvc_nfsd() for a getlease rpc request.
653  * Do the from/to xdr translation and call nqsrv_getlease() to
654  * do the real work.
655  */
656 nqnfsrv_getlease(nfsd, mrep, md, dpos, cred, nam, mrq)
657 	struct nfsd *nfsd;
658 	struct mbuf *mrep, *md;
659 	caddr_t dpos;
660 	struct ucred *cred;
661 	struct mbuf *nam, **mrq;
662 {
663 	register struct nfsv2_fattr *fp;
664 	struct vattr va;
665 	register struct vattr *vap = &va;
666 	struct vnode *vp;
667 	nfsv2fh_t nfh;
668 	fhandle_t *fhp;
669 	register u_long *tl;
670 	register long t1;
671 	u_quad_t frev;
672 	caddr_t bpos;
673 	int error = 0;
674 	char *cp2;
675 	struct mbuf *mb, *mb2, *mreq;
676 	int flags, rdonly, cache;
677 
678 	fhp = &nfh.fh_generic;
679 	nfsm_srvmtofh(fhp);
680 	nfsm_dissect(tl, u_long *, 2*NFSX_UNSIGNED);
681 	flags = fxdr_unsigned(int, *tl++);
682 	nfsd->nd_duration = fxdr_unsigned(int, *tl);
683 	if (error = nfsrv_fhtovp(fhp,
684 	    TRUE, &vp, cred, nfsd->nd_slp, nam, &rdonly))
685 		nfsm_reply(0);
686 	if (rdonly && flags == NQL_WRITE) {
687 		error = EROFS;
688 		nfsm_reply(0);
689 	}
690 	(void) nqsrv_getlease(vp, &nfsd->nd_duration, flags, nfsd,
691 		nam, &cache, &frev, cred);
692 	error = VOP_GETATTR(vp, vap, cred, nfsd->nd_procp);
693 	vput(vp);
694 	nfsm_reply(NFSX_NQFATTR + 4*NFSX_UNSIGNED);
695 	nfsm_build(tl, u_long *, 4*NFSX_UNSIGNED);
696 	*tl++ = txdr_unsigned(cache);
697 	*tl++ = txdr_unsigned(nfsd->nd_duration);
698 	txdr_hyper(&frev, tl);
699 	nfsm_build(fp, struct nfsv2_fattr *, NFSX_NQFATTR);
700 	nfsm_srvfillattr;
701 	nfsm_srvdone;
702 }
703 
704 /*
705  * Called from nfssvc_nfsd() when a "vacated" message is received from a
706  * client. Find the entry and expire it.
707  */
708 nqnfsrv_vacated(nfsd, mrep, md, dpos, cred, nam, mrq)
709 	struct nfsd *nfsd;
710 	struct mbuf *mrep, *md;
711 	caddr_t dpos;
712 	struct ucred *cred;
713 	struct mbuf *nam, **mrq;
714 {
715 	register struct nqlease *lp;
716 	register struct nqhost *lph;
717 	struct nqlease *tlp = (struct nqlease *)0;
718 	nfsv2fh_t nfh;
719 	fhandle_t *fhp;
720 	register u_long *tl;
721 	register long t1;
722 	struct nqm *lphnext;
723 	int error = 0, i, len, ok, gotit = 0;
724 	char *cp2;
725 
726 	fhp = &nfh.fh_generic;
727 	nfsm_srvmtofh(fhp);
728 	m_freem(mrep);
729 	/*
730 	 * Find the lease by searching the hash list.
731 	 */
732 	for (lp = nqfhead[NQFHHASH(fhp->fh_fid.fid_data)]; lp;
733 	     lp = lp->lc_fhnext)
734 		if (fhp->fh_fsid.val[0] == lp->lc_fsid.val[0] &&
735 		    fhp->fh_fsid.val[1] == lp->lc_fsid.val[1] &&
736 		    !bcmp(fhp->fh_fid.fid_data, lp->lc_fiddata,
737 			  MAXFIDSZ)) {
738 			/* Found it */
739 			tlp = lp;
740 			break;
741 		}
742 	if (tlp) {
743 		lp = tlp;
744 		len = 1;
745 		i = 0;
746 		lph = &lp->lc_host;
747 		lphnext = lp->lc_morehosts;
748 		ok = 1;
749 		while (ok && (lph->lph_flag & LC_VALID)) {
750 			if (nqsrv_cmpnam(nfsd->nd_slp, nam, lph)) {
751 				lph->lph_flag |= LC_VACATED;
752 				gotit++;
753 				break;
754 			}
755 			if (++i == len) {
756 				if (lphnext) {
757 					len = LC_MOREHOSTSIZ;
758 					i = 0;
759 					lph = lphnext->lpm_hosts;
760 					lphnext = lphnext->lpm_next;
761 				} else
762 					ok = 0;
763 			} else
764 				lph++;
765 		}
766 		if ((lp->lc_flag & LC_EXPIREDWANTED) && gotit) {
767 			lp->lc_flag &= ~LC_EXPIREDWANTED;
768 			wakeup((caddr_t)&lp->lc_flag);
769 		}
770 nfsmout:
771 		return (EPERM);
772 	}
773 	return (EPERM);
774 }
775 
776 /*
777  * Client get lease rpc function.
778  */
779 nqnfs_getlease(vp, rwflag, cred, p)
780 	register struct vnode *vp;
781 	int rwflag;
782 	struct ucred *cred;
783 	struct proc *p;
784 {
785 	register u_long *tl;
786 	register caddr_t cp;
787 	register long t1;
788 	register struct nfsnode *np;
789 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
790 	caddr_t bpos, dpos, cp2;
791 	time_t reqtime;
792 	int error = 0;
793 	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
794 	int cachable;
795 	u_quad_t frev;
796 
797 	nfsstats.rpccnt[NQNFSPROC_GETLEASE]++;
798 	mb = mreq = nfsm_reqh(vp, NQNFSPROC_GETLEASE, NFSX_FH+2*NFSX_UNSIGNED,
799 		 &bpos);
800 	nfsm_fhtom(vp);
801 	nfsm_build(tl, u_long *, 2*NFSX_UNSIGNED);
802 	*tl++ = txdr_unsigned(rwflag);
803 	*tl = txdr_unsigned(nmp->nm_leaseterm);
804 	reqtime = time.tv_sec;
805 	nfsm_request(vp, NQNFSPROC_GETLEASE, p, cred);
806 	np = VTONFS(vp);
807 	nfsm_dissect(tl, u_long *, 4*NFSX_UNSIGNED);
808 	cachable = fxdr_unsigned(int, *tl++);
809 	reqtime += fxdr_unsigned(int, *tl++);
810 	if (reqtime > time.tv_sec) {
811 		fxdr_hyper(tl, &frev);
812 		nqnfs_clientlease(nmp, np, rwflag, cachable, reqtime, frev);
813 		nfsm_loadattr(vp, (struct vattr *)0);
814 	} else
815 		error = NQNFS_EXPIRED;
816 	nfsm_reqdone;
817 	return (error);
818 }
819 
820 /*
821  * Client vacated message function.
822  */
823 nqnfs_vacated(vp, cred)
824 	register struct vnode *vp;
825 	struct ucred *cred;
826 {
827 	register caddr_t cp;
828 	register struct mbuf *m;
829 	register int i;
830 	caddr_t bpos;
831 	u_long xid;
832 	int error = 0;
833 	struct mbuf *mreq, *mb, *mb2, *mheadend;
834 	struct nfsmount *nmp;
835 	struct nfsreq myrep;
836 
837 	nmp = VFSTONFS(vp->v_mount);
838 	nfsstats.rpccnt[NQNFSPROC_VACATED]++;
839 	nfsm_reqhead(vp, NQNFSPROC_VACATED, NFSX_FH);
840 	nfsm_fhtom(vp);
841 	m = mreq;
842 	i = 0;
843 	while (m) {
844 		i += m->m_len;
845 		m = m->m_next;
846 	}
847 	m = nfsm_rpchead(cred, TRUE, NQNFSPROC_VACATED,
848 		RPCAUTH_UNIX, 5*NFSX_UNSIGNED, (char *)0,
849 		mreq, i, &mheadend, &xid);
850 	if (nmp->nm_sotype == SOCK_STREAM) {
851 		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
852 		*mtod(m, u_long *) = htonl(0x80000000 | (m->m_pkthdr.len -
853 			NFSX_UNSIGNED));
854 	}
855 	myrep.r_flags = 0;
856 	myrep.r_nmp = nmp;
857 	if (nmp->nm_soflags & PR_CONNREQUIRED)
858 		(void) nfs_sndlock(&nmp->nm_flag, (struct nfsreq *)0);
859 	(void) nfs_send(nmp->nm_so, nmp->nm_nam, m, &myrep);
860 	if (nmp->nm_soflags & PR_CONNREQUIRED)
861 		nfs_sndunlock(&nmp->nm_flag);
862 	return (error);
863 }
864 
865 /*
866  * Called for client side callbacks
867  */
868 nqnfs_callback(nmp, mrep, md, dpos)
869 	struct nfsmount *nmp;
870 	struct mbuf *mrep, *md;
871 	caddr_t dpos;
872 {
873 	register struct vnode *vp;
874 	register u_long *tl;
875 	register long t1;
876 	nfsv2fh_t nfh;
877 	fhandle_t *fhp;
878 	struct nfsnode *np;
879 	struct nfsd nd;
880 	int error;
881 	char *cp2;
882 
883 	nd.nd_mrep = mrep;
884 	nd.nd_md = md;
885 	nd.nd_dpos = dpos;
886 	if (error = nfs_getreq(&nd, FALSE))
887 		return (error);
888 	md = nd.nd_md;
889 	dpos = nd.nd_dpos;
890 	if (nd.nd_procnum != NQNFSPROC_EVICTED) {
891 		m_freem(mrep);
892 		return (EPERM);
893 	}
894 	fhp = &nfh.fh_generic;
895 	nfsm_srvmtofh(fhp);
896 	m_freem(mrep);
897 	if (error = nfs_nget(nmp->nm_mountp, fhp, &np))
898 		return (error);
899 	vp = NFSTOV(np);
900 	if (np->n_tnext) {
901 		np->n_expiry = 0;
902 		np->n_flag |= NQNFSEVICTED;
903 		if (np->n_tprev != (struct nfsnode *)nmp) {
904 			if (np->n_tnext == (struct nfsnode *)nmp)
905 				nmp->nm_tprev = np->n_tprev;
906 			else
907 				np->n_tnext->n_tprev = np->n_tprev;
908 			np->n_tprev->n_tnext = np->n_tnext;
909 			np->n_tnext = nmp->nm_tnext;
910 			nmp->nm_tnext = np;
911 			np->n_tprev = (struct nfsnode *)nmp;
912 			if (np->n_tnext == (struct nfsnode *)nmp)
913 				nmp->nm_tprev = np;
914 			else
915 				np->n_tnext->n_tprev = np;
916 		}
917 	}
918 	vrele(vp);
919 	nfsm_srvdone;
920 }
921 
922 /*
923  * Nqnfs client helper daemon. Runs once a second to expire leases.
924  * It also get authorization strings for "kerb" mounts.
925  * It must start at the beginning of the list again after any potential
926  * "sleep" since nfs_reclaim() called from vclean() can pull a node off
927  * the list asynchronously.
928  */
929 nqnfs_clientd(nmp, cred, ncd, flag, argp, p)
930 	register struct nfsmount *nmp;
931 	struct ucred *cred;
932 	struct nfsd_cargs *ncd;
933 	int flag;
934 	caddr_t argp;
935 	struct proc *p;
936 {
937 	register struct nfsnode *np;
938 	struct vnode *vp;
939 	struct nfsreq myrep;
940 	int error, vpid;
941 
942 	/*
943 	 * First initialize some variables
944 	 */
945 	nqnfs_prog = txdr_unsigned(NQNFS_PROG);
946 	nqnfs_vers = txdr_unsigned(NQNFS_VER1);
947 
948 	/*
949 	 * If an authorization string is being passed in, get it.
950 	 */
951 	if ((flag & NFSSVC_GOTAUTH) &&
952 		(nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_DISMNT)) == 0) {
953 		if (nmp->nm_flag & NFSMNT_HASAUTH)
954 			panic("cld kerb");
955 		if ((flag & NFSSVC_AUTHINFAIL) == 0) {
956 			if (ncd->ncd_authlen <= RPCAUTH_MAXSIZ &&
957 				copyin(ncd->ncd_authstr, nmp->nm_authstr,
958 				ncd->ncd_authlen) == 0) {
959 				nmp->nm_authtype = ncd->ncd_authtype;
960 				nmp->nm_authlen = ncd->ncd_authlen;
961 			} else
962 				nmp->nm_flag |= NFSMNT_AUTHERR;
963 		} else
964 			nmp->nm_flag |= NFSMNT_AUTHERR;
965 		nmp->nm_flag |= NFSMNT_HASAUTH;
966 		wakeup((caddr_t)&nmp->nm_authlen);
967 	} else
968 		nmp->nm_flag |= NFSMNT_WAITAUTH;
969 
970 	/*
971 	 * Loop every second updating queue until there is a termination sig.
972 	 */
973 	while ((nmp->nm_flag & NFSMNT_DISMNT) == 0) {
974 	    if (nmp->nm_flag & NFSMNT_NQNFS) {
975 		/*
976 		 * If there are no outstanding requests (and therefore no
977 		 * processes in nfs_reply) and there is data in the receive
978 		 * queue, poke for callbacks.
979 		 */
980 		if (nfsreqh.r_next == &nfsreqh && nmp->nm_so &&
981 		    nmp->nm_so->so_rcv.sb_cc > 0) {
982 		    myrep.r_flags = R_GETONEREP;
983 		    myrep.r_nmp = nmp;
984 		    myrep.r_mrep = (struct mbuf *)0;
985 		    myrep.r_procp = (struct proc *)0;
986 		    (void) nfs_reply(&myrep);
987 		}
988 
989 		/*
990 		 * Loop through the leases, updating as required.
991 		 */
992 		np = nmp->nm_tnext;
993 		while (np != (struct nfsnode *)nmp &&
994 		       (nmp->nm_flag & NFSMNT_DISMINPROG) == 0) {
995 			vp = NFSTOV(np);
996 if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash2");
997 			vpid = vp->v_id;
998 			if (np->n_expiry < time.tv_sec) {
999 			   if (vget(vp, 1) == 0) {
1000 			     nmp->nm_inprog = vp;
1001 			     if (vpid == vp->v_id) {
1002 if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash3");
1003 				if (np->n_tnext == (struct nfsnode *)nmp)
1004 					nmp->nm_tprev = np->n_tprev;
1005 				else
1006 					np->n_tnext->n_tprev = np->n_tprev;
1007 				if (np->n_tprev == (struct nfsnode *)nmp)
1008 					nmp->nm_tnext = np->n_tnext;
1009 				else
1010 					np->n_tprev->n_tnext = np->n_tnext;
1011 				np->n_tnext = (struct nfsnode *)0;
1012 				if ((np->n_flag & (NMODIFIED | NQNFSEVICTED))
1013 				    && vp->v_type == VREG) {
1014 					if (np->n_flag & NQNFSEVICTED) {
1015 						(void) nfs_vinvalbuf(vp,
1016 						       V_SAVE, cred, p, 0);
1017 						np->n_flag &= ~NQNFSEVICTED;
1018 						(void) nqnfs_vacated(vp, cred);
1019 					} else {
1020 						(void) VOP_FSYNC(vp, cred,
1021 						    MNT_WAIT, p);
1022 						np->n_flag &= ~NMODIFIED;
1023 					}
1024 				}
1025 			      }
1026 			      vrele(vp);
1027 			      nmp->nm_inprog = NULLVP;
1028 			    }
1029 			    if (np != nmp->nm_tnext)
1030 				np = nmp->nm_tnext;
1031 			    else
1032 				break;
1033 			} else if ((np->n_expiry - NQ_RENEWAL) < time.tv_sec) {
1034 			    if ((np->n_flag & (NQNFSWRITE | NQNFSNONCACHE))
1035 				 == NQNFSWRITE && vp->v_dirtyblkhd.lh_first &&
1036 				 vget(vp, 1) == 0) {
1037 				 nmp->nm_inprog = vp;
1038 if (vp->v_mount->mnt_stat.f_fsid.val[1] != MOUNT_NFS) panic("trash4");
1039 				 if (vpid == vp->v_id &&
1040 				     nqnfs_getlease(vp, NQL_WRITE, cred, p)==0)
1041 					np->n_brev = np->n_lrev;
1042 				 vrele(vp);
1043 				 nmp->nm_inprog = NULLVP;
1044 			    }
1045 			    if (np != nmp->nm_tnext)
1046 				np = nmp->nm_tnext;
1047 			    else
1048 				break;
1049 			} else
1050 				break;
1051 		}
1052 	    }
1053 
1054 	    /*
1055 	     * Get an authorization string, if required.
1056 	     */
1057 	    if ((nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_DISMNT | NFSMNT_HASAUTH)) == 0) {
1058 		ncd->ncd_authuid = nmp->nm_authuid;
1059 		if (copyout((caddr_t)ncd, argp, sizeof (struct nfsd_cargs)))
1060 			nmp->nm_flag |= NFSMNT_WAITAUTH;
1061 		else
1062 			return (ENEEDAUTH);
1063 	    }
1064 
1065 	    /*
1066 	     * Wait a bit (no pun) and do it again.
1067 	     */
1068 	    if ((nmp->nm_flag & NFSMNT_DISMNT) == 0 &&
1069 		(nmp->nm_flag & (NFSMNT_WAITAUTH | NFSMNT_HASAUTH))) {
1070 		    error = tsleep((caddr_t)&nmp->nm_authstr, PSOCK | PCATCH,
1071 			"nqnfstimr", hz / 3);
1072 		    if (error == EINTR || error == ERESTART)
1073 			(void) dounmount(nmp->nm_mountp, 0, p);
1074 	    }
1075 	}
1076 	free((caddr_t)nmp, M_NFSMNT);
1077 	if (error == EWOULDBLOCK)
1078 		error = 0;
1079 	return (error);
1080 }
1081 
1082 /*
1083  * Adjust all timer queue expiry times when the time of day clock is changed.
1084  * Called from the settimeofday() syscall.
1085  */
1086 void
1087 lease_updatetime(deltat)
1088 	register int deltat;
1089 {
1090 	register struct nqlease *lp;
1091 	register struct nfsnode *np;
1092 	struct mount *mp;
1093 	struct nfsmount *nmp;
1094 	int s;
1095 
1096 	if (nqnfsstarttime != 0)
1097 		nqnfsstarttime += deltat;
1098 	s = splsoftclock();
1099 	lp = nqthead.th_chain[0];
1100 	while (lp != (struct nqlease *)&nqthead) {
1101 		lp->lc_expiry += deltat;
1102 		lp = lp->lc_chain1[0];
1103 	}
1104 	splx(s);
1105 
1106 	/*
1107 	 * Search the mount list for all nqnfs mounts and do their timer
1108 	 * queues.
1109 	 */
1110 	for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next) {
1111 		if (mp->mnt_stat.f_fsid.val[1] == MOUNT_NFS) {
1112 			nmp = VFSTONFS(mp);
1113 			if (nmp->nm_flag & NFSMNT_NQNFS) {
1114 				np = nmp->nm_tnext;
1115 				while (np != (struct nfsnode *)nmp) {
1116 					np->n_expiry += deltat;
1117 					np = np->n_tnext;
1118 				}
1119 			}
1120 		}
1121 	}
1122 }
1123 
1124 /*
1125  * Lock a server lease.
1126  */
1127 void
1128 nqsrv_locklease(lp)
1129 	struct nqlease *lp;
1130 {
1131 
1132 	while (lp->lc_flag & LC_LOCKED) {
1133 		lp->lc_flag |= LC_WANTED;
1134 		(void) tsleep((caddr_t)lp, PSOCK, "nqlc", 0);
1135 	}
1136 	lp->lc_flag |= LC_LOCKED;
1137 	lp->lc_flag &= ~LC_WANTED;
1138 }
1139 
1140 /*
1141  * Unlock a server lease.
1142  */
1143 void
1144 nqsrv_unlocklease(lp)
1145 	struct nqlease *lp;
1146 {
1147 
1148 	lp->lc_flag &= ~LC_LOCKED;
1149 	if (lp->lc_flag & LC_WANTED)
1150 		wakeup((caddr_t)lp);
1151 }
1152 
1153 /*
1154  * Update a client lease.
1155  */
1156 void
1157 nqnfs_clientlease(nmp, np, rwflag, cachable, expiry, frev)
1158 	register struct nfsmount *nmp;
1159 	register struct nfsnode *np;
1160 	int rwflag, cachable;
1161 	time_t expiry;
1162 	u_quad_t frev;
1163 {
1164 	register struct nfsnode *tp;
1165 
1166 	if (np->n_tnext) {
1167 		if (np->n_tnext == (struct nfsnode *)nmp)
1168 			nmp->nm_tprev = np->n_tprev;
1169 		else
1170 			np->n_tnext->n_tprev = np->n_tprev;
1171 		if (np->n_tprev == (struct nfsnode *)nmp)
1172 			nmp->nm_tnext = np->n_tnext;
1173 		else
1174 			np->n_tprev->n_tnext = np->n_tnext;
1175 		if (rwflag == NQL_WRITE)
1176 			np->n_flag |= NQNFSWRITE;
1177 	} else if (rwflag == NQL_READ)
1178 		np->n_flag &= ~NQNFSWRITE;
1179 	else
1180 		np->n_flag |= NQNFSWRITE;
1181 	if (cachable)
1182 		np->n_flag &= ~NQNFSNONCACHE;
1183 	else
1184 		np->n_flag |= NQNFSNONCACHE;
1185 	np->n_expiry = expiry;
1186 	np->n_lrev = frev;
1187 	tp = nmp->nm_tprev;
1188 	while (tp != (struct nfsnode *)nmp && tp->n_expiry > np->n_expiry)
1189 		tp = tp->n_tprev;
1190 	if (tp == (struct nfsnode *)nmp) {
1191 		np->n_tnext = nmp->nm_tnext;
1192 		nmp->nm_tnext = np;
1193 	} else {
1194 		np->n_tnext = tp->n_tnext;
1195 		tp->n_tnext = np;
1196 	}
1197 	np->n_tprev = tp;
1198 	if (np->n_tnext == (struct nfsnode *)nmp)
1199 		nmp->nm_tprev = np;
1200 	else
1201 		np->n_tnext->n_tprev = np;
1202 }
1203