xref: /dflybsd-src/sys/vfs/nfs/nfs_vfsops.c (revision 3412cacb5a88ff95d06808eeed783b8499b5256e)
1 /*
2  * Copyright (c) 1989, 1993, 1995
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  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)nfs_vfsops.c	8.12 (Berkeley) 5/20/95
37  * $FreeBSD: src/sys/nfs/nfs_vfsops.c,v 1.91.2.7 2003/01/27 20:04:08 dillon Exp $
38  * $DragonFly: src/sys/vfs/nfs/nfs_vfsops.c,v 1.10 2003/11/15 21:05:44 dillon Exp $
39  */
40 
41 #include "opt_bootp.h"
42 
43 #include <sys/param.h>
44 #include <sys/sockio.h>
45 #include <sys/proc.h>
46 #include <sys/vnode.h>
47 #include <sys/kernel.h>
48 #include <sys/sysctl.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/mbuf.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/systm.h>
55 
56 #include <vm/vm.h>
57 #include <vm/vm_extern.h>
58 #include <vm/vm_zone.h>
59 
60 #include <net/if.h>
61 #include <net/route.h>
62 #include <netinet/in.h>
63 
64 #include "rpcv2.h"
65 #include "nfsproto.h"
66 #include "nfs.h"
67 #include "nfsmount.h"
68 #include "nfsnode.h"
69 #include "xdr_subs.h"
70 #include "nfsm_subs.h"
71 #include "nfsdiskless.h"
72 #include "nqnfs.h"
73 
74 extern int	nfs_mountroot (struct mount *mp);
75 
76 extern int	nfs_ticks;
77 
78 MALLOC_DEFINE(M_NFSREQ, "NFS req", "NFS request header");
79 MALLOC_DEFINE(M_NFSBIGFH, "NFSV3 bigfh", "NFS version 3 file handle");
80 MALLOC_DEFINE(M_NFSD, "NFS daemon", "Nfs server daemon structure");
81 MALLOC_DEFINE(M_NFSDIROFF, "NFSV3 diroff", "NFS directory offset data");
82 MALLOC_DEFINE(M_NFSRVDESC, "NFSV3 srvdesc", "NFS server socket descriptor");
83 MALLOC_DEFINE(M_NFSUID, "NFS uid", "Nfs uid mapping structure");
84 MALLOC_DEFINE(M_NQLEASE, "NQNFS Lease", "Nqnfs lease");
85 MALLOC_DEFINE(M_NFSHASH, "NFS hash", "NFS hash tables");
86 
87 vm_zone_t nfsmount_zone;
88 
89 struct nfsstats	nfsstats;
90 SYSCTL_NODE(_vfs, OID_AUTO, nfs, CTLFLAG_RW, 0, "NFS filesystem");
91 SYSCTL_STRUCT(_vfs_nfs, NFS_NFSSTATS, nfsstats, CTLFLAG_RD,
92 	&nfsstats, nfsstats, "");
93 static int nfs_ip_paranoia = 1;
94 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_ip_paranoia, CTLFLAG_RW,
95 	&nfs_ip_paranoia, 0, "");
96 #ifdef NFS_DEBUG
97 int nfs_debug;
98 SYSCTL_INT(_vfs_nfs, OID_AUTO, debug, CTLFLAG_RW, &nfs_debug, 0, "");
99 #endif
100 
101 static int	nfs_iosize (struct nfsmount *nmp);
102 static void	nfs_decode_args (struct nfsmount *nmp,
103 			struct nfs_args *argp);
104 static int	mountnfs (struct nfs_args *,struct mount *,
105 			struct sockaddr *,char *,char *,struct vnode **);
106 static int	nfs_mount ( struct mount *mp, char *path, caddr_t data,
107 			struct nameidata *ndp, struct thread *td);
108 static int	nfs_unmount ( struct mount *mp, int mntflags,
109 			struct thread *td);
110 static int	nfs_root ( struct mount *mp, struct vnode **vpp);
111 static int	nfs_statfs ( struct mount *mp, struct statfs *sbp,
112 			struct thread *td);
113 static int	nfs_sync ( struct mount *mp, int waitfor,
114 			struct thread *td);
115 
116 /*
117  * nfs vfs operations.
118  */
119 static struct vfsops nfs_vfsops = {
120 	nfs_mount,
121 	vfs_stdstart,
122 	nfs_unmount,
123 	nfs_root,
124 	vfs_stdquotactl,
125 	nfs_statfs,
126 	nfs_sync,
127 	vfs_stdvget,
128 	vfs_stdfhtovp,		/* shouldn't happen */
129 	vfs_stdcheckexp,
130 	vfs_stdvptofh,		/* shouldn't happen */
131 	nfs_init,
132 	nfs_uninit,
133 	vfs_stdextattrctl,
134 };
135 VFS_SET(nfs_vfsops, nfs, VFCF_NETWORK);
136 
137 /*
138  * This structure must be filled in by a primary bootstrap or bootstrap
139  * server for a diskless/dataless machine. It is initialized below just
140  * to ensure that it is allocated to initialized data (.data not .bss).
141  */
142 struct nfs_diskless nfs_diskless = { { { 0 } } };
143 struct nfsv3_diskless nfsv3_diskless = { { { 0 } } };
144 int nfs_diskless_valid = 0;
145 
146 SYSCTL_INT(_vfs_nfs, OID_AUTO, diskless_valid, CTLFLAG_RD,
147 	&nfs_diskless_valid, 0, "");
148 
149 SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_rootpath, CTLFLAG_RD,
150 	nfsv3_diskless.root_hostnam, 0, "");
151 
152 SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_rootaddr, CTLFLAG_RD,
153 	&nfsv3_diskless.root_saddr, sizeof nfsv3_diskless.root_saddr,
154 	"%Ssockaddr_in", "");
155 
156 SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_swappath, CTLFLAG_RD,
157 	nfsv3_diskless.swap_hostnam, 0, "");
158 
159 SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_swapaddr, CTLFLAG_RD,
160 	&nfsv3_diskless.swap_saddr, sizeof nfsv3_diskless.swap_saddr,
161 	"%Ssockaddr_in","");
162 
163 
164 void nfsargs_ntoh (struct nfs_args *);
165 static int nfs_mountdiskless (char *, char *, int,
166 				  struct sockaddr_in *, struct nfs_args *,
167 				  struct thread *, struct vnode **,
168 				  struct mount **);
169 static void nfs_convert_diskless (void);
170 static void nfs_convert_oargs (struct nfs_args *args,
171 				   struct onfs_args *oargs);
172 
173 static int
174 nfs_iosize(nmp)
175 	struct nfsmount* nmp;
176 {
177 	int iosize;
178 
179 	/*
180 	 * Calculate the size used for io buffers.  Use the larger
181 	 * of the two sizes to minimise nfs requests but make sure
182 	 * that it is at least one VM page to avoid wasting buffer
183 	 * space.
184 	 */
185 	iosize = max(nmp->nm_rsize, nmp->nm_wsize);
186 	if (iosize < PAGE_SIZE) iosize = PAGE_SIZE;
187 	return iosize;
188 }
189 
190 static void
191 nfs_convert_oargs(args, oargs)
192 	struct nfs_args *args;
193 	struct onfs_args *oargs;
194 {
195 	args->version = NFS_ARGSVERSION;
196 	args->addr = oargs->addr;
197 	args->addrlen = oargs->addrlen;
198 	args->sotype = oargs->sotype;
199 	args->proto = oargs->proto;
200 	args->fh = oargs->fh;
201 	args->fhsize = oargs->fhsize;
202 	args->flags = oargs->flags;
203 	args->wsize = oargs->wsize;
204 	args->rsize = oargs->rsize;
205 	args->readdirsize = oargs->readdirsize;
206 	args->timeo = oargs->timeo;
207 	args->retrans = oargs->retrans;
208 	args->maxgrouplist = oargs->maxgrouplist;
209 	args->readahead = oargs->readahead;
210 	args->leaseterm = oargs->leaseterm;
211 	args->deadthresh = oargs->deadthresh;
212 	args->hostname = oargs->hostname;
213 }
214 
215 static void
216 nfs_convert_diskless()
217 {
218 	bcopy(&nfs_diskless.myif, &nfsv3_diskless.myif,
219 		sizeof(struct ifaliasreq));
220 	bcopy(&nfs_diskless.mygateway, &nfsv3_diskless.mygateway,
221 		sizeof(struct sockaddr_in));
222 	nfs_convert_oargs(&nfsv3_diskless.swap_args,&nfs_diskless.swap_args);
223 	nfsv3_diskless.swap_fhsize = NFSX_V2FH;
224 	bcopy(nfs_diskless.swap_fh,nfsv3_diskless.swap_fh,NFSX_V2FH);
225 	bcopy(&nfs_diskless.swap_saddr,&nfsv3_diskless.swap_saddr,
226 		sizeof(struct sockaddr_in));
227 	bcopy(nfs_diskless.swap_hostnam,nfsv3_diskless.swap_hostnam, MNAMELEN);
228 	nfsv3_diskless.swap_nblks = nfs_diskless.swap_nblks;
229 	bcopy(&nfs_diskless.swap_ucred, &nfsv3_diskless.swap_ucred,
230 		sizeof(struct ucred));
231 	nfs_convert_oargs(&nfsv3_diskless.root_args,&nfs_diskless.root_args);
232 	nfsv3_diskless.root_fhsize = NFSX_V2FH;
233 	bcopy(nfs_diskless.root_fh,nfsv3_diskless.root_fh,NFSX_V2FH);
234 	bcopy(&nfs_diskless.root_saddr,&nfsv3_diskless.root_saddr,
235 		sizeof(struct sockaddr_in));
236 	bcopy(nfs_diskless.root_hostnam,nfsv3_diskless.root_hostnam, MNAMELEN);
237 	nfsv3_diskless.root_time = nfs_diskless.root_time;
238 	bcopy(nfs_diskless.my_hostnam,nfsv3_diskless.my_hostnam,
239 		MAXHOSTNAMELEN);
240 	nfs_diskless_valid = 3;
241 }
242 
243 /*
244  * nfs statfs call
245  */
246 int
247 nfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
248 {
249 	struct vnode *vp;
250 	struct nfs_statfs *sfp;
251 	caddr_t cp;
252 	u_int32_t *tl;
253 	int32_t t1, t2;
254 	caddr_t bpos, dpos, cp2;
255 	struct nfsmount *nmp = VFSTONFS(mp);
256 	int error = 0, v3 = (nmp->nm_flag & NFSMNT_NFSV3), retattr;
257 	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
258 	struct ucred *cred;
259 	struct nfsnode *np;
260 	u_quad_t tquad;
261 
262 #ifndef nolint
263 	sfp = (struct nfs_statfs *)0;
264 #endif
265 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
266 	if (error)
267 		return (error);
268 	vp = NFSTOV(np);
269 	cred = crget();
270 	cred->cr_ngroups = 1;
271 	if (v3 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
272 		(void)nfs_fsinfo(nmp, vp, td);
273 	nfsstats.rpccnt[NFSPROC_FSSTAT]++;
274 	nfsm_reqhead(vp, NFSPROC_FSSTAT, NFSX_FH(v3));
275 	nfsm_fhtom(vp, v3);
276 	nfsm_request(vp, NFSPROC_FSSTAT, td, cred);
277 	if (v3)
278 		nfsm_postop_attr(vp, retattr);
279 	if (error) {
280 		if (mrep != NULL)
281 			m_freem(mrep);
282 		goto nfsmout;
283 	}
284 	nfsm_dissect(sfp, struct nfs_statfs *, NFSX_STATFS(v3));
285 	sbp->f_flags = nmp->nm_flag;
286 	sbp->f_iosize = nfs_iosize(nmp);
287 	if (v3) {
288 		sbp->f_bsize = NFS_FABLKSIZE;
289 		tquad = fxdr_hyper(&sfp->sf_tbytes);
290 		sbp->f_blocks = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
291 		tquad = fxdr_hyper(&sfp->sf_fbytes);
292 		sbp->f_bfree = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
293 		tquad = fxdr_hyper(&sfp->sf_abytes);
294 		sbp->f_bavail = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
295 		sbp->f_files = (fxdr_unsigned(int32_t,
296 		    sfp->sf_tfiles.nfsuquad[1]) & 0x7fffffff);
297 		sbp->f_ffree = (fxdr_unsigned(int32_t,
298 		    sfp->sf_ffiles.nfsuquad[1]) & 0x7fffffff);
299 	} else {
300 		sbp->f_bsize = fxdr_unsigned(int32_t, sfp->sf_bsize);
301 		sbp->f_blocks = fxdr_unsigned(int32_t, sfp->sf_blocks);
302 		sbp->f_bfree = fxdr_unsigned(int32_t, sfp->sf_bfree);
303 		sbp->f_bavail = fxdr_unsigned(int32_t, sfp->sf_bavail);
304 		sbp->f_files = 0;
305 		sbp->f_ffree = 0;
306 	}
307 	if (sbp != &mp->mnt_stat) {
308 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
309 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
310 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
311 	}
312 	m_freem(mrep);
313 nfsmout:
314 	vput(vp);
315 	crfree(cred);
316 	return (error);
317 }
318 
319 /*
320  * nfs version 3 fsinfo rpc call
321  */
322 int
323 nfs_fsinfo(struct nfsmount *nmp, struct vnode *vp, struct thread *td)
324 {
325 	struct nfsv3_fsinfo *fsp;
326 	caddr_t cp;
327 	int32_t t1, t2;
328 	u_int32_t *tl, pref, max;
329 	caddr_t bpos, dpos, cp2;
330 	int error = 0, retattr;
331 	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
332 	u_int64_t maxfsize;
333 
334 	nfsstats.rpccnt[NFSPROC_FSINFO]++;
335 	nfsm_reqhead(vp, NFSPROC_FSINFO, NFSX_FH(1));
336 	nfsm_fhtom(vp, 1);
337 	nfsm_request(vp, NFSPROC_FSINFO, td, nfs_vpcred(vp, ND_READ));
338 	nfsm_postop_attr(vp, retattr);
339 	if (!error) {
340 		nfsm_dissect(fsp, struct nfsv3_fsinfo *, NFSX_V3FSINFO);
341 		pref = fxdr_unsigned(u_int32_t, fsp->fs_wtpref);
342 		if (pref < nmp->nm_wsize && pref >= NFS_FABLKSIZE)
343 			nmp->nm_wsize = (pref + NFS_FABLKSIZE - 1) &
344 				~(NFS_FABLKSIZE - 1);
345 		max = fxdr_unsigned(u_int32_t, fsp->fs_wtmax);
346 		if (max < nmp->nm_wsize && max > 0) {
347 			nmp->nm_wsize = max & ~(NFS_FABLKSIZE - 1);
348 			if (nmp->nm_wsize == 0)
349 				nmp->nm_wsize = max;
350 		}
351 		pref = fxdr_unsigned(u_int32_t, fsp->fs_rtpref);
352 		if (pref < nmp->nm_rsize && pref >= NFS_FABLKSIZE)
353 			nmp->nm_rsize = (pref + NFS_FABLKSIZE - 1) &
354 				~(NFS_FABLKSIZE - 1);
355 		max = fxdr_unsigned(u_int32_t, fsp->fs_rtmax);
356 		if (max < nmp->nm_rsize && max > 0) {
357 			nmp->nm_rsize = max & ~(NFS_FABLKSIZE - 1);
358 			if (nmp->nm_rsize == 0)
359 				nmp->nm_rsize = max;
360 		}
361 		pref = fxdr_unsigned(u_int32_t, fsp->fs_dtpref);
362 		if (pref < nmp->nm_readdirsize && pref >= NFS_DIRBLKSIZ)
363 			nmp->nm_readdirsize = (pref + NFS_DIRBLKSIZ - 1) &
364 				~(NFS_DIRBLKSIZ - 1);
365 		if (max < nmp->nm_readdirsize && max > 0) {
366 			nmp->nm_readdirsize = max & ~(NFS_DIRBLKSIZ - 1);
367 			if (nmp->nm_readdirsize == 0)
368 				nmp->nm_readdirsize = max;
369 		}
370 		maxfsize = fxdr_hyper(&fsp->fs_maxfilesize);
371 		if (maxfsize > 0 && maxfsize < nmp->nm_maxfilesize)
372 			nmp->nm_maxfilesize = maxfsize;
373 		nmp->nm_state |= NFSSTA_GOTFSINFO;
374 	}
375 	m_freem(mrep);
376 nfsmout:
377 	return (error);
378 }
379 
380 /*
381  * Mount a remote root fs via. nfs. This depends on the info in the
382  * nfs_diskless structure that has been filled in properly by some primary
383  * bootstrap.
384  * It goes something like this:
385  * - do enough of "ifconfig" by calling ifioctl() so that the system
386  *   can talk to the server
387  * - If nfs_diskless.mygateway is filled in, use that address as
388  *   a default gateway.
389  * - build the rootfs mount point and call mountnfs() to do the rest.
390  */
391 int
392 nfs_mountroot(mp)
393 	struct mount *mp;
394 {
395 	struct mount  *swap_mp;
396 	struct nfsv3_diskless *nd = &nfsv3_diskless;
397 	struct socket *so;
398 	struct vnode *vp;
399 	struct thread *td = curthread;		/* XXX */
400 	int error, i;
401 	u_long l;
402 	char buf[128];
403 
404 #if defined(BOOTP_NFSROOT) && defined(BOOTP)
405 	bootpc_init();		/* use bootp to get nfs_diskless filled in */
406 #endif
407 
408 	/*
409 	 * XXX time must be non-zero when we init the interface or else
410 	 * the arp code will wedge...
411 	 */
412 	while (time_second == 0)
413 		tsleep(&time_second, 0, "arpkludge", 10);
414 
415 	if (nfs_diskless_valid==1)
416 	  nfs_convert_diskless();
417 
418 	/*
419 	 * XXX splnet, so networks will receive...
420 	 */
421 	splnet();
422 
423 #ifdef notyet
424 	/* Set up swap credentials. */
425 	proc0.p_ucred->cr_uid = ntohl(nd->swap_ucred.cr_uid);
426 	proc0.p_ucred->cr_gid = ntohl(nd->swap_ucred.cr_gid);
427 	if ((proc0.p_ucred->cr_ngroups = ntohs(nd->swap_ucred.cr_ngroups)) >
428 		NGROUPS)
429 		proc0.p_ucred->cr_ngroups = NGROUPS;
430 	for (i = 0; i < proc0.p_ucred->cr_ngroups; i++)
431 	    proc0.p_ucred->cr_groups[i] = ntohl(nd->swap_ucred.cr_groups[i]);
432 #endif
433 
434 	/*
435 	 * Do enough of ifconfig(8) so that the critical net interface can
436 	 * talk to the server.
437 	 */
438 	error = socreate(nd->myif.ifra_addr.sa_family, &so, SOCK_DGRAM, 0, td);
439 	if (error)
440 		panic("nfs_mountroot: socreate(%04x): %d",
441 			nd->myif.ifra_addr.sa_family, error);
442 
443 #if 0 /* XXX Bad idea */
444 	/*
445 	 * We might not have been told the right interface, so we pass
446 	 * over the first ten interfaces of the same kind, until we get
447 	 * one of them configured.
448 	 */
449 
450 	for (i = strlen(nd->myif.ifra_name) - 1;
451 		nd->myif.ifra_name[i] >= '0' &&
452 		nd->myif.ifra_name[i] <= '9';
453 		nd->myif.ifra_name[i] ++) {
454 		error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
455 		if(!error)
456 			break;
457 	}
458 #endif
459 	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
460 	if (error)
461 		panic("nfs_mountroot: SIOCAIFADDR: %d", error);
462 	soclose(so);
463 
464 	/*
465 	 * If the gateway field is filled in, set it as the default route.
466 	 */
467 	if (nd->mygateway.sin_len != 0) {
468 		struct sockaddr_in mask, sin;
469 
470 		bzero((caddr_t)&mask, sizeof(mask));
471 		sin = mask;
472 		sin.sin_family = AF_INET;
473 		sin.sin_len = sizeof(sin);
474 		error = rtrequest(RTM_ADD, (struct sockaddr *)&sin,
475 		    (struct sockaddr *)&nd->mygateway,
476 		    (struct sockaddr *)&mask,
477 		    RTF_UP | RTF_GATEWAY, (struct rtentry **)0);
478 		if (error)
479 			panic("nfs_mountroot: RTM_ADD: %d", error);
480 	}
481 
482 	/*
483 	 * Create the rootfs mount point.
484 	 */
485 	nd->root_args.fh = nd->root_fh;
486 	nd->root_args.fhsize = nd->root_fhsize;
487 	l = ntohl(nd->root_saddr.sin_addr.s_addr);
488 	snprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
489 		(l >> 24) & 0xff, (l >> 16) & 0xff,
490 		(l >>  8) & 0xff, (l >>  0) & 0xff,nd->root_hostnam);
491 	printf("NFS ROOT: %s\n",buf);
492 	if ((error = nfs_mountdiskless(buf, "/", MNT_RDONLY,
493 	    &nd->root_saddr, &nd->root_args, td, &vp, &mp)) != 0) {
494 		if (swap_mp) {
495 			mp->mnt_vfc->vfc_refcount--;
496 			free(swap_mp, M_MOUNT);
497 		}
498 		return (error);
499 	}
500 
501 	swap_mp = NULL;
502 	if (nd->swap_nblks) {
503 
504 		/* Convert to DEV_BSIZE instead of Kilobyte */
505 		nd->swap_nblks *= 2;
506 
507 		/*
508 		 * Create a fake mount point just for the swap vnode so that the
509 		 * swap file can be on a different server from the rootfs.
510 		 */
511 		nd->swap_args.fh = nd->swap_fh;
512 		nd->swap_args.fhsize = nd->swap_fhsize;
513 		l = ntohl(nd->swap_saddr.sin_addr.s_addr);
514 		snprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
515 			(l >> 24) & 0xff, (l >> 16) & 0xff,
516 			(l >>  8) & 0xff, (l >>  0) & 0xff,nd->swap_hostnam);
517 		printf("NFS SWAP: %s\n",buf);
518 		if ((error = nfs_mountdiskless(buf, "/swap", 0,
519 		    &nd->swap_saddr, &nd->swap_args, td, &vp, &swap_mp)) != 0)
520 			return (error);
521 		vfs_unbusy(swap_mp, td);
522 
523 		VTONFS(vp)->n_size = VTONFS(vp)->n_vattr.va_size =
524 				nd->swap_nblks * DEV_BSIZE ;
525 
526 		/*
527 		 * Since the swap file is not the root dir of a file system,
528 		 * hack it to a regular file.
529 		 */
530 		vp->v_type = VREG;
531 		vp->v_flag = 0;
532 		VREF(vp);
533 		swaponvp(td, vp, NODEV, nd->swap_nblks);
534 	}
535 
536 	mp->mnt_flag |= MNT_ROOTFS;
537 	mp->mnt_vnodecovered = NULLVP;
538 	rootvp = vp;
539 	vfs_unbusy(mp, td);
540 
541 	/*
542 	 * This is not really an nfs issue, but it is much easier to
543 	 * set hostname here and then let the "/etc/rc.xxx" files
544 	 * mount the right /var based upon its preset value.
545 	 */
546 	bcopy(nd->my_hostnam, hostname, MAXHOSTNAMELEN);
547 	hostname[MAXHOSTNAMELEN - 1] = '\0';
548 	for (i = 0; i < MAXHOSTNAMELEN; i++)
549 		if (hostname[i] == '\0')
550 			break;
551 	inittodr(ntohl(nd->root_time));
552 	return (0);
553 }
554 
555 /*
556  * Internal version of mount system call for diskless setup.
557  */
558 static int
559 nfs_mountdiskless(char *path, char *which, int mountflag,
560 	struct sockaddr_in *sin, struct nfs_args *args, struct thread *td,
561 	struct vnode **vpp, struct mount **mpp)
562 {
563 	struct mount *mp;
564 	struct sockaddr *nam;
565 	int error;
566 	int didalloc = 0;
567 
568 	mp = *mpp;
569 
570 	if (mp == NULL) {
571 		if ((error = vfs_rootmountalloc("nfs", path, &mp)) != 0) {
572 			printf("nfs_mountroot: NFS not configured");
573 			return (error);
574 		}
575 		didalloc = 1;
576 	}
577 
578 	mp->mnt_kern_flag = 0;
579 	mp->mnt_flag = mountflag;
580 	nam = dup_sockaddr((struct sockaddr *)sin, 1);
581 	if ((error = mountnfs(args, mp, nam, which, path, vpp)) != 0) {
582 		printf("nfs_mountroot: mount %s on %s: %d", path, which, error);
583 		mp->mnt_vfc->vfc_refcount--;
584 		vfs_unbusy(mp, td);
585 		if (didalloc)
586 			free(mp, M_MOUNT);
587 		FREE(nam, M_SONAME);
588 		return (error);
589 	}
590 	(void) copystr(which, mp->mnt_stat.f_mntonname, MNAMELEN - 1, 0);
591 	*mpp = mp;
592 	return (0);
593 }
594 
595 static void
596 nfs_decode_args(nmp, argp)
597 	struct nfsmount *nmp;
598 	struct nfs_args *argp;
599 {
600 	int s;
601 	int adjsock;
602 	int maxio;
603 
604 	s = splnet();
605 	/*
606 	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
607 	 * no sense in that context.
608 	 */
609 	if (argp->sotype == SOCK_STREAM)
610 		nmp->nm_flag &= ~NFSMNT_NOCONN;
611 
612 	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
613 	if ((argp->flags & NFSMNT_NFSV3) == 0)
614 		nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
615 
616 	/* Re-bind if rsrvd port requested and wasn't on one */
617 	adjsock = !(nmp->nm_flag & NFSMNT_RESVPORT)
618 		  && (argp->flags & NFSMNT_RESVPORT);
619 	/* Also re-bind if we're switching to/from a connected UDP socket */
620 	adjsock |= ((nmp->nm_flag & NFSMNT_NOCONN) !=
621 		    (argp->flags & NFSMNT_NOCONN));
622 
623 	/* Update flags atomically.  Don't change the lock bits. */
624 	nmp->nm_flag = argp->flags | nmp->nm_flag;
625 	splx(s);
626 
627 	if ((argp->flags & NFSMNT_TIMEO) && argp->timeo > 0) {
628 		nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;
629 		if (nmp->nm_timeo < NFS_MINTIMEO)
630 			nmp->nm_timeo = NFS_MINTIMEO;
631 		else if (nmp->nm_timeo > NFS_MAXTIMEO)
632 			nmp->nm_timeo = NFS_MAXTIMEO;
633 	}
634 
635 	if ((argp->flags & NFSMNT_RETRANS) && argp->retrans > 1) {
636 		nmp->nm_retry = argp->retrans;
637 		if (nmp->nm_retry > NFS_MAXREXMIT)
638 			nmp->nm_retry = NFS_MAXREXMIT;
639 	}
640 
641 	if (argp->flags & NFSMNT_NFSV3) {
642 		if (argp->sotype == SOCK_DGRAM)
643 			maxio = NFS_MAXDGRAMDATA;
644 		else
645 			maxio = NFS_MAXDATA;
646 	} else
647 		maxio = NFS_V2MAXDATA;
648 
649 	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
650 		nmp->nm_wsize = argp->wsize;
651 		/* Round down to multiple of blocksize */
652 		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
653 		if (nmp->nm_wsize <= 0)
654 			nmp->nm_wsize = NFS_FABLKSIZE;
655 	}
656 	if (nmp->nm_wsize > maxio)
657 		nmp->nm_wsize = maxio;
658 	if (nmp->nm_wsize > MAXBSIZE)
659 		nmp->nm_wsize = MAXBSIZE;
660 
661 	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
662 		nmp->nm_rsize = argp->rsize;
663 		/* Round down to multiple of blocksize */
664 		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
665 		if (nmp->nm_rsize <= 0)
666 			nmp->nm_rsize = NFS_FABLKSIZE;
667 	}
668 	if (nmp->nm_rsize > maxio)
669 		nmp->nm_rsize = maxio;
670 	if (nmp->nm_rsize > MAXBSIZE)
671 		nmp->nm_rsize = MAXBSIZE;
672 
673 	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
674 		nmp->nm_readdirsize = argp->readdirsize;
675 	}
676 	if (nmp->nm_readdirsize > maxio)
677 		nmp->nm_readdirsize = maxio;
678 	if (nmp->nm_readdirsize > nmp->nm_rsize)
679 		nmp->nm_readdirsize = nmp->nm_rsize;
680 
681 	if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
682 		nmp->nm_acregmin = argp->acregmin;
683 	else
684 		nmp->nm_acregmin = NFS_MINATTRTIMO;
685 	if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
686 		nmp->nm_acregmax = argp->acregmax;
687 	else
688 		nmp->nm_acregmax = NFS_MAXATTRTIMO;
689 	if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
690 		nmp->nm_acdirmin = argp->acdirmin;
691 	else
692 		nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
693 	if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
694 		nmp->nm_acdirmax = argp->acdirmax;
695 	else
696 		nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;
697 	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
698 		nmp->nm_acdirmin = nmp->nm_acdirmax;
699 	if (nmp->nm_acregmin > nmp->nm_acregmax)
700 		nmp->nm_acregmin = nmp->nm_acregmax;
701 
702 	if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0) {
703 		if (argp->maxgrouplist <= NFS_MAXGRPS)
704 			nmp->nm_numgrps = argp->maxgrouplist;
705 		else
706 			nmp->nm_numgrps = NFS_MAXGRPS;
707 	}
708 	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0) {
709 		if (argp->readahead <= NFS_MAXRAHEAD)
710 			nmp->nm_readahead = argp->readahead;
711 		else
712 			nmp->nm_readahead = NFS_MAXRAHEAD;
713 	}
714 	if ((argp->flags & NFSMNT_LEASETERM) && argp->leaseterm >= 2) {
715 		if (argp->leaseterm <= NQ_MAXLEASE)
716 			nmp->nm_leaseterm = argp->leaseterm;
717 		else
718 			nmp->nm_leaseterm = NQ_MAXLEASE;
719 	}
720 	if ((argp->flags & NFSMNT_DEADTHRESH) && argp->deadthresh >= 1) {
721 		if (argp->deadthresh <= NQ_NEVERDEAD)
722 			nmp->nm_deadthresh = argp->deadthresh;
723 		else
724 			nmp->nm_deadthresh = NQ_NEVERDEAD;
725 	}
726 
727 	adjsock |= ((nmp->nm_sotype != argp->sotype) ||
728 		    (nmp->nm_soproto != argp->proto));
729 	nmp->nm_sotype = argp->sotype;
730 	nmp->nm_soproto = argp->proto;
731 
732 	if (nmp->nm_so && adjsock) {
733 		nfs_safedisconnect(nmp);
734 		if (nmp->nm_sotype == SOCK_DGRAM)
735 			while (nfs_connect(nmp, (struct nfsreq *)0)) {
736 				printf("nfs_args: retrying connect\n");
737 				(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
738 			}
739 	}
740 }
741 
742 /*
743  * VFS Operations.
744  *
745  * mount system call
746  * It seems a bit dumb to copyinstr() the host and path here and then
747  * bcopy() them in mountnfs(), but I wanted to detect errors before
748  * doing the sockargs() call because sockargs() allocates an mbuf and
749  * an error after that means that I have to release the mbuf.
750  */
751 /* ARGSUSED */
752 static int
753 nfs_mount(struct mount *mp, char *path, caddr_t data,
754 	struct nameidata *ndp, struct thread *td)
755 {
756 	int error;
757 	struct nfs_args args;
758 	struct sockaddr *nam;
759 	struct vnode *vp;
760 	char pth[MNAMELEN], hst[MNAMELEN];
761 	size_t len;
762 	u_char nfh[NFSX_V3FHMAX];
763 
764 	if (path == NULL) {
765 		nfs_mountroot(mp);
766 		return (0);
767 	}
768 	error = copyin(data, (caddr_t)&args, sizeof (struct nfs_args));
769 	if (error)
770 		return (error);
771 	if (args.version != NFS_ARGSVERSION) {
772 #ifdef COMPAT_PRELITE2
773 		/*
774 		 * If the argument version is unknown, then assume the
775 		 * caller is a pre-lite2 4.4BSD client and convert its
776 		 * arguments.
777 		 */
778 		struct onfs_args oargs;
779 		error = copyin(data, (caddr_t)&oargs, sizeof (struct onfs_args));
780 		if (error)
781 			return (error);
782 		nfs_convert_oargs(&args,&oargs);
783 #else /* !COMPAT_PRELITE2 */
784 		return (EPROGMISMATCH);
785 #endif /* COMPAT_PRELITE2 */
786 	}
787 	if (mp->mnt_flag & MNT_UPDATE) {
788 		struct nfsmount *nmp = VFSTONFS(mp);
789 
790 		if (nmp == NULL)
791 			return (EIO);
792 		/*
793 		 * When doing an update, we can't change from or to
794 		 * v3 and/or nqnfs, or change cookie translation
795 		 */
796 		args.flags = (args.flags &
797 		    ~(NFSMNT_NFSV3|NFSMNT_NQNFS /*|NFSMNT_XLATECOOKIE*/)) |
798 		    (nmp->nm_flag &
799 			(NFSMNT_NFSV3|NFSMNT_NQNFS /*|NFSMNT_XLATECOOKIE*/));
800 		nfs_decode_args(nmp, &args);
801 		return (0);
802 	}
803 
804 	/*
805 	 * Make the nfs_ip_paranoia sysctl serve as the default connection
806 	 * or no-connection mode for those protocols that support
807 	 * no-connection mode (the flag will be cleared later for protocols
808 	 * that do not support no-connection mode).  This will allow a client
809 	 * to receive replies from a different IP then the request was
810 	 * sent to.  Note: default value for nfs_ip_paranoia is 1 (paranoid),
811 	 * not 0.
812 	 */
813 	if (nfs_ip_paranoia == 0)
814 		args.flags |= NFSMNT_NOCONN;
815 	if (args.fhsize < 0 || args.fhsize > NFSX_V3FHMAX)
816 		return (EINVAL);
817 	error = copyin((caddr_t)args.fh, (caddr_t)nfh, args.fhsize);
818 	if (error)
819 		return (error);
820 	error = copyinstr(path, pth, MNAMELEN-1, &len);
821 	if (error)
822 		return (error);
823 	bzero(&pth[len], MNAMELEN - len);
824 	error = copyinstr(args.hostname, hst, MNAMELEN-1, &len);
825 	if (error)
826 		return (error);
827 	bzero(&hst[len], MNAMELEN - len);
828 	/* sockargs() call must be after above copyin() calls */
829 	error = getsockaddr(&nam, (caddr_t)args.addr, args.addrlen);
830 	if (error)
831 		return (error);
832 	args.fh = nfh;
833 	error = mountnfs(&args, mp, nam, pth, hst, &vp);
834 	return (error);
835 }
836 
837 /*
838  * Common code for mount and mountroot
839  */
840 static int
841 mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
842 	char *pth, char *hst, struct vnode **vpp)
843 {
844 	struct nfsmount *nmp;
845 	struct nfsnode *np;
846 	int error;
847 	struct vattr attrs;
848 
849 	if (mp->mnt_flag & MNT_UPDATE) {
850 		nmp = VFSTONFS(mp);
851 		/* update paths, file handles, etc, here	XXX */
852 		FREE(nam, M_SONAME);
853 		return (0);
854 	} else {
855 		nmp = zalloc(nfsmount_zone);
856 		bzero((caddr_t)nmp, sizeof (struct nfsmount));
857 		TAILQ_INIT(&nmp->nm_uidlruhead);
858 		TAILQ_INIT(&nmp->nm_bufq);
859 		mp->mnt_data = (qaddr_t)nmp;
860 	}
861 	vfs_getnewfsid(mp);
862 	nmp->nm_mountp = mp;
863 	if (argp->flags & NFSMNT_NQNFS)
864 		/*
865 		 * We have to set mnt_maxsymlink to a non-zero value so
866 		 * that COMPAT_43 routines will know that we are setting
867 		 * the d_type field in directories (and can zero it for
868 		 * unsuspecting binaries).
869 		 */
870 		mp->mnt_maxsymlinklen = 1;
871 
872 	/*
873 	 * V2 can only handle 32 bit filesizes.  A 4GB-1 limit may be too
874 	 * high, depending on whether we end up with negative offsets in
875 	 * the client or server somewhere.  2GB-1 may be safer.
876 	 *
877 	 * For V3, nfs_fsinfo will adjust this as necessary.  Assume maximum
878 	 * that we can handle until we find out otherwise.
879 	 * XXX Our "safe" limit on the client is what we can store in our
880 	 * buffer cache using signed(!) block numbers.
881 	 */
882 	if ((argp->flags & NFSMNT_NFSV3) == 0)
883 		nmp->nm_maxfilesize = 0xffffffffLL;
884 	else
885 		nmp->nm_maxfilesize = (u_int64_t)0x80000000 * DEV_BSIZE - 1;
886 
887 	nmp->nm_timeo = NFS_TIMEO;
888 	nmp->nm_retry = NFS_RETRANS;
889 	nmp->nm_wsize = NFS_WSIZE;
890 	nmp->nm_rsize = NFS_RSIZE;
891 	nmp->nm_readdirsize = NFS_READDIRSIZE;
892 	nmp->nm_numgrps = NFS_MAXGRPS;
893 	nmp->nm_readahead = NFS_DEFRAHEAD;
894 	nmp->nm_leaseterm = NQ_DEFLEASE;
895 	nmp->nm_deadthresh = NQ_DEADTHRESH;
896 	CIRCLEQ_INIT(&nmp->nm_timerhead);
897 	nmp->nm_inprog = NULLVP;
898 	nmp->nm_fhsize = argp->fhsize;
899 	bcopy((caddr_t)argp->fh, (caddr_t)nmp->nm_fh, argp->fhsize);
900 	bcopy(hst, mp->mnt_stat.f_mntfromname, MNAMELEN);
901 	bcopy(pth, mp->mnt_stat.f_mntonname, MNAMELEN);
902 	nmp->nm_nam = nam;
903 	/* Set up the sockets and per-host congestion */
904 	nmp->nm_sotype = argp->sotype;
905 	nmp->nm_soproto = argp->proto;
906 	nmp->nm_cred = crhold(proc0.p_ucred);
907 
908 	nfs_decode_args(nmp, argp);
909 
910 	/*
911 	 * For Connection based sockets (TCP,...) defer the connect until
912 	 * the first request, in case the server is not responding.
913 	 */
914 	if (nmp->nm_sotype == SOCK_DGRAM &&
915 		(error = nfs_connect(nmp, (struct nfsreq *)0)))
916 		goto bad;
917 
918 	/*
919 	 * This is silly, but it has to be set so that vinifod() works.
920 	 * We do not want to do an nfs_statfs() here since we can get
921 	 * stuck on a dead server and we are holding a lock on the mount
922 	 * point.
923 	 */
924 	mp->mnt_stat.f_iosize = nfs_iosize(nmp);
925 	/*
926 	 * A reference count is needed on the nfsnode representing the
927 	 * remote root.  If this object is not persistent, then backward
928 	 * traversals of the mount point (i.e. "..") will not work if
929 	 * the nfsnode gets flushed out of the cache. Ufs does not have
930 	 * this problem, because one can identify root inodes by their
931 	 * number == ROOTINO (2).
932 	 */
933 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
934 	if (error)
935 		goto bad;
936 	*vpp = NFSTOV(np);
937 
938 	/*
939 	 * Get file attributes for the mountpoint.  This has the side
940 	 * effect of filling in (*vpp)->v_type with the correct value.
941 	 */
942 	VOP_GETATTR(*vpp, &attrs, curthread);
943 
944 	/*
945 	 * Lose the lock but keep the ref.
946 	 */
947 	VOP_UNLOCK(*vpp, 0, curthread);
948 
949 	return (0);
950 bad:
951 	nfs_disconnect(nmp);
952 	nfs_free_mount(nmp);
953 	FREE(nam, M_SONAME);
954 	return (error);
955 }
956 
957 /*
958  * unmount system call
959  */
960 static int
961 nfs_unmount(struct mount *mp, int mntflags, struct thread *td)
962 {
963 	struct nfsmount *nmp;
964 	int error, flags = 0;
965 
966 	if (mntflags & MNT_FORCE)
967 		flags |= FORCECLOSE;
968 	nmp = VFSTONFS(mp);
969 	/*
970 	 * Goes something like this..
971 	 * - Call vflush() to clear out vnodes for this file system
972 	 * - Close the socket
973 	 * - Free up the data structures
974 	 */
975 	/* In the forced case, cancel any outstanding requests. */
976 	if (flags & FORCECLOSE) {
977 		error = nfs_nmcancelreqs(nmp);
978 		if (error)
979 			return (error);
980 	}
981 	/*
982 	 * Must handshake with nqnfs_clientd() if it is active.
983 	 */
984 	nmp->nm_state |= NFSSTA_DISMINPROG;
985 	while (nmp->nm_inprog != NULLVP)
986 		(void) tsleep((caddr_t)&lbolt, 0, "nfsdism", 0);
987 
988 	/* We hold 1 extra ref on the root vnode; see comment in mountnfs(). */
989 	error = vflush(mp, 1, flags);
990 	if (error) {
991 		nmp->nm_state &= ~NFSSTA_DISMINPROG;
992 		return (error);
993 	}
994 
995 	/*
996 	 * We are now committed to the unmount.
997 	 * For NQNFS, let the server daemon free the nfsmount structure.
998 	 */
999 	if (nmp->nm_flag & (NFSMNT_NQNFS | NFSMNT_KERB))
1000 		nmp->nm_state |= NFSSTA_DISMNT;
1001 
1002 	nfs_disconnect(nmp);
1003 	FREE(nmp->nm_nam, M_SONAME);
1004 
1005 	if ((nmp->nm_flag & (NFSMNT_NQNFS | NFSMNT_KERB)) == 0)
1006 		nfs_free_mount(nmp);
1007 	return (0);
1008 }
1009 
1010 void
1011 nfs_free_mount(struct nfsmount *nmp)
1012 {
1013 	if (nmp->nm_cred)  {
1014 		crfree(nmp->nm_cred);
1015 		nmp->nm_cred = NULL;
1016 	}
1017 	zfree(nfsmount_zone, nmp);
1018 }
1019 
1020 /*
1021  * Return root of a filesystem
1022  */
1023 static int
1024 nfs_root(mp, vpp)
1025 	struct mount *mp;
1026 	struct vnode **vpp;
1027 {
1028 	struct vnode *vp;
1029 	struct nfsmount *nmp;
1030 	struct nfsnode *np;
1031 	int error;
1032 
1033 	nmp = VFSTONFS(mp);
1034 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
1035 	if (error)
1036 		return (error);
1037 	vp = NFSTOV(np);
1038 	if (vp->v_type == VNON)
1039 	    vp->v_type = VDIR;
1040 	vp->v_flag = VROOT;
1041 	*vpp = vp;
1042 	return (0);
1043 }
1044 
1045 extern int syncprt;
1046 
1047 /*
1048  * Flush out the buffer cache
1049  */
1050 /* ARGSUSED */
1051 static int
1052 nfs_sync(struct mount *mp, int waitfor, struct thread *td)
1053 {
1054 	struct vnode *vp;
1055 	int error, allerror = 0;
1056 
1057 	/*
1058 	 * Force stale buffer cache information to be flushed.
1059 	 */
1060 loop:
1061 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
1062 	     vp != NULL;
1063 	     vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
1064 		/*
1065 		 * If the vnode that we are about to sync is no longer
1066 		 * associated with this mount point, start over.
1067 		 */
1068 		if (vp->v_mount != mp)
1069 			goto loop;
1070 		if (VOP_ISLOCKED(vp, NULL) || TAILQ_EMPTY(&vp->v_dirtyblkhd) ||
1071 		    waitfor == MNT_LAZY)
1072 			continue;
1073 		if (vget(vp, LK_EXCLUSIVE, td))
1074 			goto loop;
1075 		error = VOP_FSYNC(vp, waitfor, td);
1076 		if (error)
1077 			allerror = error;
1078 		vput(vp);
1079 	}
1080 	return (allerror);
1081 }
1082 
1083