xref: /csrg-svn/sys/nfs/nfs_syscalls.c (revision 52903)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * 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_syscalls.c	7.29 (Berkeley) 03/09/92
11  */
12 
13 #include "param.h"
14 #include "systm.h"
15 #include "kernel.h"
16 #include "file.h"
17 #include "stat.h"
18 #include "vnode.h"
19 #include "mount.h"
20 #include "proc.h"
21 #include "uio.h"
22 #include "malloc.h"
23 #include "buf.h"
24 #include "mbuf.h"
25 #include "socket.h"
26 #include "socketvar.h"
27 #include "domain.h"
28 #include "protosw.h"
29 #include "namei.h"
30 #include "netinet/in.h"
31 #include "netinet/tcp.h"
32 #ifdef ISO
33 #include "netiso/iso.h"
34 #endif
35 #include "machine/endian.h"
36 #include "rpcv2.h"
37 #include "nfsv2.h"
38 #include "nfs.h"
39 #include "nfsrvcache.h"
40 #include "nfsmount.h"
41 #include "nqnfs.h"
42 
43 /* Global defs. */
44 extern u_long nfs_prog, nfs_vers;
45 extern int (*nfsrv_procs[NFS_NPROCS])();
46 extern struct buf nfs_bqueue;
47 extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
48 extern int nfs_numasync;
49 extern time_t nqnfsstarttime;
50 extern struct nfsrv_req nsrvq_head;
51 extern struct nfsd nfsd_head;
52 extern int nqsrv_writeslack;
53 struct nfssvc_sock *nfs_udpsock, *nfs_cltpsock;
54 int nuidhash_max = NFS_MAXUIDHASH;
55 static int nfs_numnfsd = 0;
56 int nfsd_waiting = 0;
57 static int notstarted = 1;
58 static int modify_flag = 0;
59 void nfsrv_cleancache(), nfsrv_rcv(), nfsrv_wakenfsd(), nfs_sndunlock();
60 void nfsrv_slpderef();
61 
62 #define	TRUE	1
63 #define	FALSE	0
64 
65 static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON];
66 /*
67  * NFS server system calls
68  * getfh() lives here too, but maybe should move to kern/vfs_syscalls.c
69  */
70 
71 /*
72  * Get file handle system call
73  */
74 getfh(p, uap, retval)
75 	struct proc *p;
76 	register struct args {
77 		char	*fname;
78 		fhandle_t *fhp;
79 	} *uap;
80 	int *retval;
81 {
82 	register struct vnode *vp;
83 	fhandle_t fh;
84 	int error;
85 	struct nameidata nd;
86 
87 	/*
88 	 * Must be super user
89 	 */
90 	if (error = suser(p->p_ucred, &p->p_acflag))
91 		return (error);
92 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->fname, p);
93 	if (error = namei(&nd))
94 		return (error);
95 	vp = nd.ni_vp;
96 	bzero((caddr_t)&fh, sizeof(fh));
97 	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
98 	error = VFS_VPTOFH(vp, &fh.fh_fid);
99 	vput(vp);
100 	if (error)
101 		return (error);
102 	error = copyout((caddr_t)&fh, (caddr_t)uap->fhp, sizeof (fh));
103 	return (error);
104 }
105 
106 static struct nfssvc_sock nfssvc_sockhead;
107 
108 /*
109  * Nfs server psuedo system call for the nfsd's
110  * Based on the flag value it either:
111  * - adds a socket to the selection list
112  * - remains in the kernel as an nfsd
113  * - remains in the kernel as an nfsiod
114  */
115 nfssvc(p, uap, retval)
116 	struct proc *p;
117 	register struct args {
118 		int flag;
119 		caddr_t argp;
120 	} *uap;
121 	int *retval;
122 {
123 	struct nameidata nd;
124 	struct file *fp;
125 	struct mbuf *nam;
126 	struct nfsd_args nfsdarg;
127 	struct nfsd_srvargs nfsd_srvargs, *nsd = &nfsd_srvargs;
128 	struct nfsd_cargs ncd;
129 	struct nfsd *nfsd;
130 	struct nfssvc_sock *slp;
131 	struct nfsuid *nuidp, **nuh;
132 	struct nfsmount *nmp;
133 	int error;
134 
135 	/*
136 	 * Must be super user
137 	 */
138 	if (error = suser(p->p_ucred, &p->p_acflag))
139 		return (error);
140 	if (nfssvc_sockhead.ns_next == NULL) {
141 		nfs_udpsock = (struct nfssvc_sock *)
142 		    malloc(sizeof (struct nfssvc_sock), M_NFSSVC, M_WAITOK);
143 		bzero((caddr_t)nfs_udpsock, sizeof (struct nfssvc_sock));
144 		nfs_cltpsock = (struct nfssvc_sock *)
145 		    malloc(sizeof (struct nfssvc_sock), M_NFSSVC, M_WAITOK);
146 		bzero((caddr_t)nfs_cltpsock, sizeof (struct nfssvc_sock));
147 		nfssvc_sockhead.ns_next = nfs_udpsock;
148 		nfs_udpsock->ns_next = nfs_cltpsock;
149 		nfs_cltpsock->ns_next = &nfssvc_sockhead;
150 		nfssvc_sockhead.ns_prev = nfs_cltpsock;
151 		nfs_cltpsock->ns_prev = nfs_udpsock;
152 		nfs_udpsock->ns_prev = &nfssvc_sockhead;
153 		nfs_udpsock->ns_lrunext = nfs_udpsock->ns_lruprev =
154 			(struct nfsuid *)nfs_udpsock;
155 		nfs_cltpsock->ns_lrunext = nfs_cltpsock->ns_lruprev =
156 			(struct nfsuid *)nfs_cltpsock;
157 		nfsd_head.nd_next = nfsd_head.nd_prev = &nfsd_head;
158 		nfsd_head.nd_flag = 0;
159 	}
160 	if (uap->flag & NFSSVC_BIOD)
161 		error = nfssvc_iod(p);
162 	else if (uap->flag & NFSSVC_MNTD) {
163 		if (error = copyin(uap->argp, (caddr_t)&ncd, sizeof (ncd)))
164 			return (error);
165 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
166 			ncd.ncd_dirp, p);
167 		if (error = namei(&nd))
168 			return (error);
169 		if ((nd.ni_vp->v_flag & VROOT) == 0)
170 			error = EINVAL;
171 		nmp = VFSTONFS(nd.ni_vp->v_mount);
172 		vput(nd.ni_vp);
173 		if (error)
174 			return (error);
175 		else if (nmp->nm_flag & NFSMNT_MNTD)
176 			return (0);
177 		nmp->nm_flag |= NFSMNT_MNTD;
178 		error = nqnfs_clientd(nmp, p->p_ucred, &ncd, uap->flag,
179 			uap->argp, p);
180 	} else if (uap->flag & NFSSVC_ADDSOCK) {
181 		if (error = copyin(uap->argp, (caddr_t)&nfsdarg,
182 		    sizeof(nfsdarg)))
183 			return (error);
184 		if (error = getsock(p->p_fd, nfsdarg.sock, &fp))
185 			return (error);
186 		/*
187 		 * Get the client address for connected sockets.
188 		 */
189 		if (nfsdarg.name == NULL || nfsdarg.namelen == 0)
190 			nam = (struct mbuf *)0;
191 		else if (error = sockargs(&nam, nfsdarg.name, nfsdarg.namelen,
192 			MT_SONAME))
193 			return (error);
194 		error = nfssvc_addsock(fp, nam);
195 	} else {
196 		if (error = copyin(uap->argp, (caddr_t)nsd, sizeof (*nsd)))
197 			return (error);
198 		if ((uap->flag & NFSSVC_AUTHIN) && (nfsd = nsd->nsd_nfsd) &&
199 			(nfsd->nd_slp->ns_flag & SLP_VALID)) {
200 			slp = nfsd->nd_slp;
201 			if (slp->ns_numuids < nuidhash_max) {
202 				slp->ns_numuids++;
203 				nuidp = (struct nfsuid *)
204 				   malloc(sizeof (struct nfsuid), M_NFSUID, M_WAITOK);
205 			} else
206 				nuidp = (struct nfsuid *)0;
207 			if ((slp->ns_flag & SLP_VALID) == 0) {
208 			    if (nuidp)
209 				free((caddr_t)nuidp, M_NFSUID);
210 			} else {
211 			    if (nuidp == (struct nfsuid *)0) {
212 				nuidp = slp->ns_lruprev;
213 				remque(nuidp);
214 				if (nuidp->nu_hprev)
215 					nuidp->nu_hprev->nu_hnext = nuidp->nu_hnext;
216 				if (nuidp->nu_hnext)
217 					nuidp->nu_hnext->nu_hprev = nuidp->nu_hprev;
218 			    }
219 			    nuidp->nu_cr = nsd->nsd_cr;
220 			    nuidp->nu_cr.cr_ref = 1;
221 			    nuidp->nu_uid = nsd->nsd_uid;
222 			    insque(nuidp, (struct nfsuid *)slp);
223 			    nuh = &slp->ns_uidh[NUIDHASH(nsd->nsd_uid)];
224 			    if (nuidp->nu_hnext = *nuh)
225 				nuidp->nu_hnext->nu_hprev = nuidp;
226 			    nuidp->nu_hprev = (struct nfsuid *)0;
227 			    *nuh = nuidp;
228 			}
229 		}
230 		if ((uap->flag & NFSSVC_AUTHINFAIL) && (nfsd = nsd->nsd_nfsd))
231 			nfsd->nd_flag |= NFSD_AUTHFAIL;
232 		error = nfssvc_nfsd(nsd, uap->argp, p);
233 	}
234 	if (error == EINTR || error == ERESTART)
235 		error = 0;
236 	return (error);
237 }
238 
239 /*
240  * Adds a socket to the list for servicing by nfsds.
241  */
242 nfssvc_addsock(fp, mynam)
243 	struct file *fp;
244 	struct mbuf *mynam;
245 {
246 	register struct mbuf *m;
247 	register int siz;
248 	register struct nfssvc_sock *slp;
249 	register struct socket *so;
250 	struct nfssvc_sock *tslp;
251 	int error, s;
252 
253 	so = (struct socket *)fp->f_data;
254 	tslp = (struct nfssvc_sock *)0;
255 	/*
256 	 * Add it to the list, as required.
257 	 */
258 	if (so->so_proto->pr_protocol == IPPROTO_UDP) {
259 		tslp = nfs_udpsock;
260 		if (tslp->ns_flag & SLP_VALID) {
261 			m_freem(mynam);
262 			return (EPERM);
263 		}
264 #ifdef ISO
265 	} else if (so->so_proto->pr_protocol == ISOPROTO_CLTP) {
266 		tslp = nfs_cltpsock;
267 		if (tslp->ns_flag & SLP_VALID) {
268 			m_freem(mynam);
269 			return (EPERM);
270 		}
271 #endif /* ISO */
272 	}
273 	if (so->so_type == SOCK_STREAM)
274 		siz = NFS_MAXPACKET + sizeof (u_long);
275 	else
276 		siz = NFS_MAXPACKET;
277 	if (error = soreserve(so, siz, siz)) {
278 		m_freem(mynam);
279 		return (error);
280 	}
281 
282 	/*
283 	 * Set protocol specific options { for now TCP only } and
284 	 * reserve some space. For datagram sockets, this can get called
285 	 * repeatedly for the same socket, but that isn't harmful.
286 	 */
287 	if (so->so_type == SOCK_STREAM) {
288 		MGET(m, M_WAIT, MT_SOOPTS);
289 		*mtod(m, int *) = 1;
290 		m->m_len = sizeof(int);
291 		sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
292 	}
293 	if (so->so_proto->pr_domain->dom_family == AF_INET &&
294 	    so->so_proto->pr_protocol == IPPROTO_TCP) {
295 		MGET(m, M_WAIT, MT_SOOPTS);
296 		*mtod(m, int *) = 1;
297 		m->m_len = sizeof(int);
298 		sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
299 	}
300 	so->so_rcv.sb_flags &= ~SB_NOINTR;
301 	so->so_rcv.sb_timeo = 0;
302 	so->so_snd.sb_flags &= ~SB_NOINTR;
303 	so->so_snd.sb_timeo = 0;
304 	if (tslp)
305 		slp = tslp;
306 	else {
307 		slp = (struct nfssvc_sock *)
308 			malloc(sizeof (struct nfssvc_sock), M_NFSSVC, M_WAITOK);
309 		bzero((caddr_t)slp, sizeof (struct nfssvc_sock));
310 		slp->ns_prev = nfssvc_sockhead.ns_prev;
311 		slp->ns_prev->ns_next = slp;
312 		slp->ns_next = &nfssvc_sockhead;
313 		nfssvc_sockhead.ns_prev = slp;
314 		slp->ns_lrunext = slp->ns_lruprev = (struct nfsuid *)slp;
315 	}
316 	slp->ns_so = so;
317 	slp->ns_nam = mynam;
318 	fp->f_count++;
319 	slp->ns_fp = fp;
320 	s = splnet();
321 	so->so_upcallarg = (caddr_t)slp;
322 	so->so_upcall = nfsrv_rcv;
323 	slp->ns_flag = (SLP_VALID | SLP_NEEDQ);
324 	nfsrv_wakenfsd(slp);
325 	splx(s);
326 	return (0);
327 }
328 
329 /*
330  * Called by nfssvc() for nfsds. Just loops around servicing rpc requests
331  * until it is killed by a signal.
332  */
333 nfssvc_nfsd(nsd, argp, p)
334 	struct nfsd_srvargs *nsd;
335 	caddr_t argp;
336 	struct proc *p;
337 {
338 	register struct mbuf *m, *nam2;
339 	register int siz;
340 	register struct nfssvc_sock *slp;
341 	register struct socket *so;
342 	register int *solockp;
343 	struct nfssvc_sock *oslp;
344 	struct nfsd *nd = nsd->nsd_nfsd;
345 	struct mbuf *mreq, *nam;
346 	int error, cacherep, s;
347 	int sotype;
348 
349 	s = splnet();
350 	if (nd == (struct nfsd *)0) {
351 		nsd->nsd_nfsd = nd = (struct nfsd *)
352 			malloc(sizeof (struct nfsd), M_NFSD, M_WAITOK);
353 		bzero((caddr_t)nd, sizeof (struct nfsd));
354 		nd->nd_procp = p;
355 		nd->nd_cr.cr_ref = 1;
356 		insque(nd, &nfsd_head);
357 		nfs_numnfsd++;
358 	}
359 	/*
360 	 * Loop getting rpc requests until SIGKILL.
361 	 */
362 	for (;;) {
363 		if ((nd->nd_flag & NFSD_REQINPROG) == 0) {
364 			while (nd->nd_slp == (struct nfssvc_sock *)0 &&
365 				 (nfsd_head.nd_flag & NFSD_CHECKSLP) == 0) {
366 				nd->nd_flag |= NFSD_WAITING;
367 				nfsd_waiting++;
368 				error = tsleep((caddr_t)nd, PSOCK | PCATCH, "nfsd", 0);
369 				nfsd_waiting--;
370 				if (error)
371 					goto done;
372 			}
373 			if (nd->nd_slp == (struct nfssvc_sock *)0 &&
374 				(nfsd_head.nd_flag & NFSD_CHECKSLP)) {
375 				slp = nfssvc_sockhead.ns_next;
376 				while (slp != &nfssvc_sockhead) {
377 				    if ((slp->ns_flag & (SLP_VALID | SLP_DOREC))
378 					== (SLP_VALID | SLP_DOREC)) {
379 					    slp->ns_flag &= ~SLP_DOREC;
380 					    nd->nd_slp = slp;
381 					    break;
382 				    }
383 				    slp = slp->ns_next;
384 				}
385 				if (slp == &nfssvc_sockhead)
386 					nfsd_head.nd_flag &= ~NFSD_CHECKSLP;
387 			}
388 			if ((slp = nd->nd_slp) == (struct nfssvc_sock *)0 ||
389 			    (slp->ns_flag & SLP_VALID) == 0) {
390 				nd->nd_slp = (struct nfssvc_sock *)0;
391 				continue;
392 			}
393 			slp->ns_sref++;
394 			if (slp->ns_flag & SLP_DISCONN)
395 				nfsrv_zapsock(slp);
396 			else if (slp->ns_flag & SLP_NEEDQ) {
397 				slp->ns_flag &= ~SLP_NEEDQ;
398 				(void) nfs_sndlock(&slp->ns_solock,
399 					(struct nfsreq *)0);
400 				nfsrv_rcv(slp->ns_so, (caddr_t)slp, M_WAIT);
401 				nfs_sndunlock(&slp->ns_solock);
402 			}
403 			error = nfsrv_dorec(slp, nd);
404 			nd->nd_flag |= NFSD_REQINPROG;
405 		} else {
406 			error = 0;
407 			slp = nd->nd_slp;
408 		}
409 		if (error || (slp->ns_flag & SLP_VALID) == 0) {
410 			nd->nd_slp = (struct nfssvc_sock *)0;
411 			nd->nd_flag &= ~NFSD_REQINPROG;
412 			nfsrv_slpderef(slp);
413 			continue;
414 		}
415 		splx(s);
416 		so = slp->ns_so;
417 		sotype = so->so_type;
418 
419 		/*
420 		 * Check to see if authorization is needed.
421 		 */
422 		if (nd->nd_flag & NFSD_NEEDAUTH) {
423 			nd->nd_flag &= ~NFSD_NEEDAUTH;
424 			nsd->nsd_uid = nd->nd_cr.cr_uid;
425 			nsd->nsd_haddr =
426 			    mtod(slp->ns_nam, struct sockaddr_in *)->sin_addr.s_addr;
427 			nsd->nsd_authlen = nd->nd_authlen;
428 			(void) copyout(nd->nd_authstr, nsd->nsd_authstr,
429 				 nd->nd_authlen);
430 			(void) copyout((caddr_t)nsd, argp, sizeof (*nsd));
431 			return (ENEEDAUTH);
432 		}
433 		if (so->so_proto->pr_flags & PR_CONNREQUIRED)
434 			solockp = &slp->ns_solock;
435 		else
436 			solockp = (int *)0;
437 		nd->nd_repstat = 0;
438 		/*
439 		 * nam == nam2 for connectionless protocols such as UDP
440 		 * nam2 == NULL for connection based protocols to disable
441 		 *    recent request caching.
442 		 */
443 		nam2 = nd->nd_nam;
444 
445 		if (nam2) {
446 			nam = nam2;
447 			cacherep = nfsrv_getcache(nam2, nd, &mreq);
448 		} else {
449 			nam = slp->ns_nam;
450 			cacherep = RC_DOIT;
451 		}
452 
453 		/*
454 		 * Check for just starting up for NQNFS and send
455 		 * fake "try again later" replies to the NQNFS clients.
456 		 */
457 		if (notstarted && nqnfsstarttime <= time.tv_sec) {
458 			if (modify_flag) {
459 				nqnfsstarttime = time.tv_sec + nqsrv_writeslack;
460 				modify_flag = 0;
461 			} else
462 				notstarted = 0;
463 		}
464 		if (notstarted) {
465 			if (nd->nd_nqlflag == NQL_NOVAL)
466 				cacherep = RC_DROPIT;
467 			else if (nd->nd_procnum != NFSPROC_WRITE) {
468 				nd->nd_procnum = NFSPROC_NOOP;
469 				nd->nd_repstat = NQNFS_TRYLATER;
470 				cacherep = RC_DOIT;
471 			} else
472 				modify_flag = 1;
473 		} else if (nd->nd_flag & NFSD_AUTHFAIL) {
474 			nd->nd_flag &= ~NFSD_AUTHFAIL;
475 			nd->nd_procnum = NFSPROC_NOOP;
476 			nd->nd_repstat = NQNFS_AUTHERR;
477 			cacherep = RC_DOIT;
478 		}
479 
480 		switch (cacherep) {
481 		case RC_DOIT:
482 			error = (*(nfsrv_procs[nd->nd_procnum]))(nd,
483 				nd->nd_mrep, nd->nd_md, nd->nd_dpos, &nd->nd_cr,
484 				nam, &mreq);
485 			if (nd->nd_cr.cr_ref != 1) {
486 				printf("nfssvc cref=%d\n", nd->nd_cr.cr_ref);
487 				panic("nfssvc cref");
488 			}
489 			if (error) {
490 				if (nd->nd_procnum != NQNFSPROC_VACATED)
491 					nfsstats.srv_errs++;
492 				if (nam2) {
493 					nfsrv_updatecache(nam2, nd, FALSE, mreq);
494 					m_freem(nam2);
495 				}
496 				break;
497 			}
498 			nfsstats.srvrpccnt[nd->nd_procnum]++;
499 			if (nam2)
500 				nfsrv_updatecache(nam2, nd, TRUE, mreq);
501 			nd->nd_mrep = (struct mbuf *)0;
502 		case RC_REPLY:
503 			m = mreq;
504 			siz = 0;
505 			while (m) {
506 				siz += m->m_len;
507 				m = m->m_next;
508 			}
509 			if (siz <= 0 || siz > NFS_MAXPACKET) {
510 				printf("mbuf siz=%d\n",siz);
511 				panic("Bad nfs svc reply");
512 			}
513 			m = mreq;
514 			m->m_pkthdr.len = siz;
515 			m->m_pkthdr.rcvif = (struct ifnet *)0;
516 			/*
517 			 * For stream protocols, prepend a Sun RPC
518 			 * Record Mark.
519 			 */
520 			if (sotype == SOCK_STREAM) {
521 				M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
522 				*mtod(m, u_long *) = htonl(0x80000000 | siz);
523 			}
524 			if (solockp)
525 				(void) nfs_sndlock(solockp, (struct nfsreq *)0);
526 			if (slp->ns_flag & SLP_VALID)
527 			    error = nfs_send(so, nam2, m, (struct nfsreq *)0);
528 			else {
529 			    error = EPIPE;
530 			    m_freem(m);
531 			}
532 			if (nam2)
533 				MFREE(nam2, m);
534 			if (nd->nd_mrep)
535 				m_freem(nd->nd_mrep);
536 			if (error == EPIPE)
537 				nfsrv_zapsock(slp);
538 			if (solockp)
539 				nfs_sndunlock(solockp);
540 			if (error == EINTR || error == ERESTART) {
541 				nfsrv_slpderef(slp);
542 				s = splnet();
543 				goto done;
544 			}
545 			break;
546 		case RC_DROPIT:
547 			m_freem(nd->nd_mrep);
548 			m_freem(nam2);
549 			break;
550 		};
551 		s = splnet();
552 		if (nfsrv_dorec(slp, nd)) {
553 			nd->nd_flag &= ~NFSD_REQINPROG;
554 			nd->nd_slp = (struct nfssvc_sock *)0;
555 			nfsrv_slpderef(slp);
556 		}
557 	}
558 done:
559 	remque(nd);
560 	splx(s);
561 	free((caddr_t)nd, M_NFSD);
562 	nsd->nsd_nfsd = (struct nfsd *)0;
563 	if (--nfs_numnfsd == 0) {
564 		slp = nfssvc_sockhead.ns_next;
565 		while (slp != &nfssvc_sockhead) {
566 			if (slp->ns_flag & SLP_VALID)
567 				nfsrv_zapsock(slp);
568 			oslp = slp;
569 			slp = slp->ns_next;
570 			free((caddr_t)oslp, M_NFSSVC);
571 		}
572 		nfssvc_sockhead.ns_next = (struct nfssvc_sock *)0;
573 		nfsrv_cleancache();	/* And clear out server cache */
574 	}
575 	return (error);
576 }
577 
578 /*
579  * Asynchronous I/O daemons for client nfs.
580  * These babies just pretend to be disk interrupt service routines.
581  * They are mainly here for read ahead/write behind.
582  * Never returns unless it fails or gets killed.
583  */
584 nfssvc_iod(p)
585 	struct proc *p;
586 {
587 	register struct buf *bp, *dp;
588 	register int i, myiod;
589 	int error = 0;
590 
591 	/*
592 	 * Assign my position or return error if too many already running
593 	 */
594 	myiod = -1;
595 	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
596 		if (nfs_asyncdaemon[i] == 0) {
597 			nfs_asyncdaemon[i]++;
598 			myiod = i;
599 			break;
600 		}
601 	if (myiod == -1)
602 		return (EBUSY);
603 	nfs_numasync++;
604 	dp = &nfs_bqueue;
605 	/*
606 	 * Just loop around doin our stuff until SIGKILL
607 	 */
608 	for (;;) {
609 		while (dp->b_actf == NULL && error == 0) {
610 			nfs_iodwant[myiod] = p;
611 			error = tsleep((caddr_t)&nfs_iodwant[myiod],
612 				PWAIT | PCATCH, "nfsidl", 0);
613 			nfs_iodwant[myiod] = (struct proc *)0;
614 		}
615 		while (dp->b_actf != NULL) {
616 			/* Take one off the end of the list */
617 			bp = dp->b_actl;
618 			if (bp->b_actl == dp) {
619 				dp->b_actf = dp->b_actl = (struct buf *)0;
620 			} else {
621 				dp->b_actl = bp->b_actl;
622 				bp->b_actl->b_actf = dp;
623 			}
624 			(void) nfs_doio(bp, (struct proc *)0);
625 		}
626 		if (error) {
627 			nfs_asyncdaemon[myiod] = 0;
628 			nfs_numasync--;
629 			return (error);
630 		}
631 	}
632 }
633 
634 /*
635  * Shut down a socket associated with an nfssvc_sock structure.
636  * Should be called with the send lock set, if required.
637  * The trick here is to increment the sref at the start, so that the nfsds
638  * will stop using it and clear ns_flag at the end so that it will not be
639  * reassigned during cleanup.
640  */
641 nfsrv_zapsock(slp)
642 	register struct nfssvc_sock *slp;
643 {
644 	register struct nfsuid *nuidp, *onuidp;
645 	register int i;
646 	struct socket *so;
647 	struct file *fp;
648 	struct mbuf *m;
649 
650 	slp->ns_flag = 0;
651 	if (fp = slp->ns_fp) {
652 		slp->ns_fp = (struct file *)0;
653 		so = slp->ns_so;
654 		so->so_upcall = NULL;
655 		soshutdown(so, 2);
656 		closef(fp, (struct proc *)0);
657 		if (slp->ns_nam)
658 			MFREE(slp->ns_nam, m);
659 		m_freem(slp->ns_raw);
660 		m_freem(slp->ns_rec);
661 		nuidp = slp->ns_lrunext;
662 		while (nuidp != (struct nfsuid *)slp) {
663 			onuidp = nuidp;
664 			nuidp = nuidp->nu_lrunext;
665 			free((caddr_t)onuidp, M_NFSUID);
666 		}
667 		slp->ns_lrunext = slp->ns_lruprev = (struct nfsuid *)slp;
668 		for (i = 0; i < NUIDHASHSIZ; i++)
669 			slp->ns_uidh[i] = (struct nfsuid *)0;
670 	}
671 }
672 
673 /*
674  * Get an authorization string for the uid by having the mount_nfs sitting
675  * on this mount point porpous out of the kernel and do it.
676  */
677 nfs_getauth(nmp, rep, cred, auth_type, auth_str, auth_len)
678 	register struct nfsmount *nmp;
679 	struct nfsreq *rep;
680 	struct ucred *cred;
681 	int *auth_type;
682 	char **auth_str;
683 	int *auth_len;
684 {
685 	int error = 0;
686 
687 	while ((nmp->nm_flag & NFSMNT_WAITAUTH) == 0) {
688 		nmp->nm_flag |= NFSMNT_WANTAUTH;
689 		(void) tsleep((caddr_t)&nmp->nm_authtype, PSOCK,
690 			"nfsauth1", 2 * hz);
691 		if (error = nfs_sigintr(nmp, rep, rep->r_procp)) {
692 			nmp->nm_flag &= ~NFSMNT_WANTAUTH;
693 			return (error);
694 		}
695 	}
696 	nmp->nm_flag &= ~(NFSMNT_WAITAUTH | NFSMNT_WANTAUTH);
697 	nmp->nm_authstr = *auth_str = (char *)malloc(RPCAUTH_MAXSIZ, M_TEMP, M_WAITOK);
698 	nmp->nm_authuid = cred->cr_uid;
699 	wakeup((caddr_t)&nmp->nm_authstr);
700 
701 	/*
702 	 * And wait for mount_nfs to do its stuff.
703 	 */
704 	while ((nmp->nm_flag & NFSMNT_HASAUTH) == 0 && error == 0) {
705 		(void) tsleep((caddr_t)&nmp->nm_authlen, PSOCK,
706 			"nfsauth2", 2 * hz);
707 		error = nfs_sigintr(nmp, rep, rep->r_procp);
708 	}
709 	if (nmp->nm_flag & NFSMNT_AUTHERR) {
710 		nmp->nm_flag &= ~NFSMNT_AUTHERR;
711 		error = EAUTH;
712 	}
713 	if (error)
714 		free((caddr_t)*auth_str, M_TEMP);
715 	else {
716 		*auth_type = nmp->nm_authtype;
717 		*auth_len = nmp->nm_authlen;
718 	}
719 	nmp->nm_flag &= ~NFSMNT_HASAUTH;
720 	nmp->nm_flag |= NFSMNT_WAITAUTH;
721 	if (nmp->nm_flag & NFSMNT_WANTAUTH) {
722 		nmp->nm_flag &= ~NFSMNT_WANTAUTH;
723 		wakeup((caddr_t)&nmp->nm_authtype);
724 	}
725 	return (error);
726 }
727 
728 /*
729  * Derefence a server socket structure. If it has no more references and
730  * is no longer valid, you can throw it away.
731  */
732 void
733 nfsrv_slpderef(slp)
734 	register struct nfssvc_sock *slp;
735 {
736 	if (--(slp->ns_sref) == 0 && (slp->ns_flag & SLP_VALID) == 0) {
737 		slp->ns_prev->ns_next = slp->ns_next;
738 		slp->ns_next->ns_prev = slp->ns_prev;
739 		free((caddr_t)slp, M_NFSSVC);
740 	}
741 }
742