xref: /dragonfly/sys/vfs/nfs/nfs_vfsops.c (revision 6b5c5d0d)
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 1.51 2007/09/04 00:48:18 dillon Exp $
39  */
40 
41 #include "opt_bootp.h"
42 #include "opt_nfsroot.h"
43 
44 #include <sys/param.h>
45 #include <sys/sockio.h>
46 #include <sys/proc.h>
47 #include <sys/vnode.h>
48 #include <sys/fcntl.h>
49 #include <sys/kernel.h>
50 #include <sys/sysctl.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/mbuf.h>
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <sys/systm.h>
57 
58 #include <vm/vm.h>
59 #include <vm/vm_extern.h>
60 #include <vm/vm_zone.h>
61 
62 #include <net/if.h>
63 #include <net/route.h>
64 #include <netinet/in.h>
65 
66 #include <sys/thread2.h>
67 
68 #include "rpcv2.h"
69 #include "nfsproto.h"
70 #include "nfs.h"
71 #include "nfsmount.h"
72 #include "nfsnode.h"
73 #include "xdr_subs.h"
74 #include "nfsm_subs.h"
75 #include "nfsdiskless.h"
76 #include "nfsmountrpc.h"
77 
78 extern int	nfs_mountroot(struct mount *mp);
79 extern void	bootpc_init(void);
80 
81 extern int	nfs_ticks;
82 extern struct vop_ops nfsv2_vnode_vops;
83 extern struct vop_ops nfsv2_fifo_vops;
84 extern struct vop_ops nfsv2_spec_vops;
85 
86 MALLOC_DEFINE(M_NFSREQ, "NFS req", "NFS request header");
87 MALLOC_DEFINE(M_NFSBIGFH, "NFSV3 bigfh", "NFS version 3 file handle");
88 MALLOC_DEFINE(M_NFSD, "NFS daemon", "Nfs server daemon structure");
89 MALLOC_DEFINE(M_NFSDIROFF, "NFSV3 diroff", "NFS directory offset data");
90 MALLOC_DEFINE(M_NFSRVDESC, "NFSV3 srvdesc", "NFS server socket descriptor");
91 MALLOC_DEFINE(M_NFSUID, "NFS uid", "Nfs uid mapping structure");
92 MALLOC_DEFINE(M_NFSHASH, "NFS hash", "NFS hash tables");
93 
94 vm_zone_t nfsmount_zone;
95 
96 struct nfsstats	nfsstats;
97 SYSCTL_NODE(_vfs, OID_AUTO, nfs, CTLFLAG_RW, 0, "NFS filesystem");
98 SYSCTL_STRUCT(_vfs_nfs, NFS_NFSSTATS, nfsstats, CTLFLAG_RD,
99 	&nfsstats, nfsstats, "");
100 static int nfs_ip_paranoia = 1;
101 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_ip_paranoia, CTLFLAG_RW,
102 	&nfs_ip_paranoia, 0, "");
103 #ifdef NFS_DEBUG
104 int nfs_debug;
105 SYSCTL_INT(_vfs_nfs, OID_AUTO, debug, CTLFLAG_RW, &nfs_debug, 0, "");
106 #endif
107 
108 /*
109  * Tunable to determine the Read/Write unit size.  Maximum value
110  * is NFS_MAXDATA.  We also default to NFS_MAXDATA.
111  */
112 static int nfs_io_size = NFS_MAXDATA;
113 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_io_size, CTLFLAG_RW,
114 	&nfs_io_size, 0, "NFS optimal I/O unit size");
115 
116 static void	nfs_decode_args (struct nfsmount *nmp,
117 			struct nfs_args *argp);
118 static int	mountnfs (struct nfs_args *,struct mount *,
119 			struct sockaddr *,char *,char *,struct vnode **);
120 static int	nfs_mount ( struct mount *mp, char *path, caddr_t data,
121 			struct ucred *cred);
122 static int	nfs_unmount ( struct mount *mp, int mntflags);
123 static int	nfs_root ( struct mount *mp, struct vnode **vpp);
124 static int	nfs_statfs ( struct mount *mp, struct statfs *sbp,
125 			struct ucred *cred);
126 static int	nfs_sync ( struct mount *mp, int waitfor);
127 
128 /*
129  * nfs vfs operations.
130  */
131 static struct vfsops nfs_vfsops = {
132 	.vfs_mount =    	nfs_mount,
133 	.vfs_unmount =  	nfs_unmount,
134 	.vfs_root =     	nfs_root,
135 	.vfs_statfs =    	nfs_statfs,
136 	.vfs_sync =     	nfs_sync,
137 	.vfs_init =     	nfs_init,
138 	.vfs_uninit =    	nfs_uninit
139 };
140 VFS_SET(nfs_vfsops, nfs, VFCF_NETWORK);
141 
142 /*
143  * This structure must be filled in by a primary bootstrap or bootstrap
144  * server for a diskless/dataless machine. It is initialized below just
145  * to ensure that it is allocated to initialized data (.data not .bss).
146  */
147 struct nfs_diskless nfs_diskless = { { { 0 } } };
148 struct nfsv3_diskless nfsv3_diskless = { { { 0 } } };
149 int nfs_diskless_valid = 0;
150 
151 SYSCTL_INT(_vfs_nfs, OID_AUTO, diskless_valid, CTLFLAG_RD,
152 	&nfs_diskless_valid, 0, "");
153 
154 SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_rootpath, CTLFLAG_RD,
155 	nfsv3_diskless.root_hostnam, 0, "");
156 
157 SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_rootaddr, CTLFLAG_RD,
158 	&nfsv3_diskless.root_saddr, sizeof nfsv3_diskless.root_saddr,
159 	"%Ssockaddr_in", "");
160 
161 SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_swappath, CTLFLAG_RD,
162 	nfsv3_diskless.swap_hostnam, 0, "");
163 
164 SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_swapaddr, CTLFLAG_RD,
165 	&nfsv3_diskless.swap_saddr, sizeof nfsv3_diskless.swap_saddr,
166 	"%Ssockaddr_in","");
167 
168 
169 void nfsargs_ntoh (struct nfs_args *);
170 static int nfs_mountdiskless (char *, char *, int,
171 				  struct sockaddr_in *, struct nfs_args *,
172 				  struct thread *, struct vnode **,
173 				  struct mount **);
174 static void nfs_convert_diskless (void);
175 static void nfs_convert_oargs (struct nfs_args *args,
176 				   struct onfs_args *oargs);
177 
178 /*
179  * Calculate the buffer I/O block size to use.  The maximum V2 block size
180  * is typically 8K, the maximum datagram size is typically 16K, and the
181  * maximum V3 block size is typically 32K.  The buffer cache tends to work
182  * best with 16K blocks but we allow 32K for TCP connections.
183  *
184  * We force the block size to be at least a page for buffer cache efficiency.
185  */
186 static int
187 nfs_iosize(int v3, int sotype)
188 {
189 	int iosize;
190 	int iomax;
191 
192 	if (v3) {
193 		if (sotype == SOCK_STREAM)
194 			iomax = NFS_MAXDATA;
195 		else
196 			iomax = NFS_MAXDGRAMDATA;
197 	} else {
198 		iomax = NFS_V2MAXDATA;
199 	}
200 	if ((iosize = nfs_io_size) > iomax)
201 		iosize = iomax;
202 	if (iosize < PAGE_SIZE)
203 		iosize = PAGE_SIZE;
204 
205 	/*
206 	 * This is an aweful hack but until the buffer cache is rewritten
207 	 * we need it.  The problem is that when you combine write() with
208 	 * mmap() the vm_page->valid bits can become weird looking
209 	 * (e.g. 0xfc).  This occurs because NFS uses piecemeal buffers
210 	 * at the file EOF.  To solve the problem the BIO system needs to
211 	 * be guarenteed that the NFS iosize for regular files will be a
212 	 * multiple of PAGE_SIZE so it can invalidate the whole page
213 	 * rather then just the piece of it owned by the buffer when
214 	 * NFS does vinvalbuf() calls.
215 	 */
216 	if (iosize & PAGE_MASK)
217 		iosize = (iosize & ~PAGE_MASK) + PAGE_SIZE;
218 	return iosize;
219 }
220 
221 static void
222 nfs_convert_oargs(struct nfs_args *args, struct onfs_args *oargs)
223 {
224 	args->version = NFS_ARGSVERSION;
225 	args->addr = oargs->addr;
226 	args->addrlen = oargs->addrlen;
227 	args->sotype = oargs->sotype;
228 	args->proto = oargs->proto;
229 	args->fh = oargs->fh;
230 	args->fhsize = oargs->fhsize;
231 	args->flags = oargs->flags;
232 	args->wsize = oargs->wsize;
233 	args->rsize = oargs->rsize;
234 	args->readdirsize = oargs->readdirsize;
235 	args->timeo = oargs->timeo;
236 	args->retrans = oargs->retrans;
237 	args->maxgrouplist = oargs->maxgrouplist;
238 	args->readahead = oargs->readahead;
239 	args->deadthresh = oargs->deadthresh;
240 	args->hostname = oargs->hostname;
241 }
242 
243 static void
244 nfs_convert_diskless(void)
245 {
246 	int i;
247 
248 	bcopy(&nfs_diskless.myif, &nfsv3_diskless.myif,
249 		sizeof(struct ifaliasreq));
250 	bcopy(&nfs_diskless.mygateway, &nfsv3_diskless.mygateway,
251 		sizeof(struct sockaddr_in));
252 	nfs_convert_oargs(&nfsv3_diskless.swap_args,&nfs_diskless.swap_args);
253 
254 	bcopy(nfs_diskless.swap_fh,nfsv3_diskless.swap_fh,NFSX_V2FH);
255 	nfsv3_diskless.swap_fhsize = NFSX_V2FH;
256 	for (i = NFSX_V2FH - 1; i >= 0; --i) {
257 		if (nfs_diskless.swap_fh[i])
258 			break;
259 	}
260 	if (i < 0)
261 		nfsv3_diskless.swap_fhsize = 0;
262 
263 	bcopy(&nfs_diskless.swap_saddr,&nfsv3_diskless.swap_saddr,
264 		sizeof(struct sockaddr_in));
265 	bcopy(nfs_diskless.swap_hostnam,nfsv3_diskless.swap_hostnam, MNAMELEN);
266 	nfsv3_diskless.swap_nblks = nfs_diskless.swap_nblks;
267 	bcopy(&nfs_diskless.swap_ucred, &nfsv3_diskless.swap_ucred,
268 		sizeof(struct ucred));
269 	nfs_convert_oargs(&nfsv3_diskless.root_args,&nfs_diskless.root_args);
270 
271 	bcopy(nfs_diskless.root_fh,nfsv3_diskless.root_fh,NFSX_V2FH);
272 	nfsv3_diskless.root_fhsize = NFSX_V2FH;
273 	for (i = NFSX_V2FH - 1; i >= 0; --i) {
274 		if (nfs_diskless.root_fh[i])
275 			break;
276 	}
277 	if (i < 0)
278 		nfsv3_diskless.root_fhsize = 0;
279 
280 	bcopy(&nfs_diskless.root_saddr,&nfsv3_diskless.root_saddr,
281 		sizeof(struct sockaddr_in));
282 	bcopy(nfs_diskless.root_hostnam,nfsv3_diskless.root_hostnam, MNAMELEN);
283 	nfsv3_diskless.root_time = nfs_diskless.root_time;
284 	bcopy(nfs_diskless.my_hostnam,nfsv3_diskless.my_hostnam,
285 		MAXHOSTNAMELEN);
286 	nfs_diskless_valid = 3;
287 }
288 
289 /*
290  * nfs statfs call
291  */
292 int
293 nfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
294 {
295 	struct vnode *vp;
296 	struct nfs_statfs *sfp;
297 	caddr_t cp;
298 	u_int32_t *tl;
299 	int32_t t1, t2;
300 	caddr_t bpos, dpos, cp2;
301 	struct nfsmount *nmp = VFSTONFS(mp);
302 	thread_t td = curthread;
303 	int error = 0, v3 = (nmp->nm_flag & NFSMNT_NFSV3), retattr;
304 	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
305 	struct nfsnode *np;
306 	u_quad_t tquad;
307 
308 #ifndef nolint
309 	sfp = (struct nfs_statfs *)0;
310 #endif
311 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
312 	if (error)
313 		return (error);
314 	vp = NFSTOV(np);
315 	/* ignore the passed cred */
316 	cred = crget();
317 	cred->cr_ngroups = 1;
318 	if (v3 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
319 		(void)nfs_fsinfo(nmp, vp, td);
320 	nfsstats.rpccnt[NFSPROC_FSSTAT]++;
321 	nfsm_reqhead(vp, NFSPROC_FSSTAT, NFSX_FH(v3));
322 	nfsm_fhtom(vp, v3);
323 	nfsm_request(vp, NFSPROC_FSSTAT, td, cred);
324 	if (v3)
325 		nfsm_postop_attr(vp, retattr, NFS_LATTR_NOSHRINK);
326 	if (error) {
327 		if (mrep != NULL)
328 			m_freem(mrep);
329 		goto nfsmout;
330 	}
331 	nfsm_dissect(sfp, struct nfs_statfs *, NFSX_STATFS(v3));
332 	sbp->f_flags = nmp->nm_flag;
333 	sbp->f_iosize = nfs_iosize(v3, nmp->nm_sotype);
334 
335 	if (v3) {
336 		sbp->f_bsize = NFS_FABLKSIZE;
337 		tquad = fxdr_hyper(&sfp->sf_tbytes);
338 		sbp->f_blocks = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
339 		tquad = fxdr_hyper(&sfp->sf_fbytes);
340 		sbp->f_bfree = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
341 		tquad = fxdr_hyper(&sfp->sf_abytes);
342 		sbp->f_bavail = (long)(tquad / ((u_quad_t)NFS_FABLKSIZE));
343 		sbp->f_files = (fxdr_unsigned(int32_t,
344 		    sfp->sf_tfiles.nfsuquad[1]) & 0x7fffffff);
345 		sbp->f_ffree = (fxdr_unsigned(int32_t,
346 		    sfp->sf_ffiles.nfsuquad[1]) & 0x7fffffff);
347 	} else {
348 		sbp->f_bsize = fxdr_unsigned(int32_t, sfp->sf_bsize);
349 		sbp->f_blocks = fxdr_unsigned(int32_t, sfp->sf_blocks);
350 		sbp->f_bfree = fxdr_unsigned(int32_t, sfp->sf_bfree);
351 		sbp->f_bavail = fxdr_unsigned(int32_t, sfp->sf_bavail);
352 		sbp->f_files = 0;
353 		sbp->f_ffree = 0;
354 	}
355 	if (sbp != &mp->mnt_stat) {
356 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
357 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
358 	}
359 	m_freem(mrep);
360 nfsmout:
361 	vput(vp);
362 	crfree(cred);
363 	return (error);
364 }
365 
366 /*
367  * nfs version 3 fsinfo rpc call
368  */
369 int
370 nfs_fsinfo(struct nfsmount *nmp, struct vnode *vp, struct thread *td)
371 {
372 	struct nfsv3_fsinfo *fsp;
373 	caddr_t cp;
374 	int32_t t1, t2;
375 	u_int32_t *tl, pref, max;
376 	caddr_t bpos, dpos, cp2;
377 	int error = 0, retattr;
378 	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
379 	u_int64_t maxfsize;
380 
381 	nfsstats.rpccnt[NFSPROC_FSINFO]++;
382 	nfsm_reqhead(vp, NFSPROC_FSINFO, NFSX_FH(1));
383 	nfsm_fhtom(vp, 1);
384 	nfsm_request(vp, NFSPROC_FSINFO, td, nfs_vpcred(vp, ND_READ));
385 	nfsm_postop_attr(vp, retattr, NFS_LATTR_NOSHRINK);
386 	if (!error) {
387 		nfsm_dissect(fsp, struct nfsv3_fsinfo *, NFSX_V3FSINFO);
388 		pref = fxdr_unsigned(u_int32_t, fsp->fs_wtpref);
389 		if (pref < nmp->nm_wsize && pref >= NFS_FABLKSIZE)
390 			nmp->nm_wsize = (pref + NFS_FABLKSIZE - 1) &
391 				~(NFS_FABLKSIZE - 1);
392 		max = fxdr_unsigned(u_int32_t, fsp->fs_wtmax);
393 		if (max < nmp->nm_wsize && max > 0) {
394 			nmp->nm_wsize = max & ~(NFS_FABLKSIZE - 1);
395 			if (nmp->nm_wsize == 0)
396 				nmp->nm_wsize = max;
397 		}
398 		pref = fxdr_unsigned(u_int32_t, fsp->fs_rtpref);
399 		if (pref < nmp->nm_rsize && pref >= NFS_FABLKSIZE)
400 			nmp->nm_rsize = (pref + NFS_FABLKSIZE - 1) &
401 				~(NFS_FABLKSIZE - 1);
402 		max = fxdr_unsigned(u_int32_t, fsp->fs_rtmax);
403 		if (max < nmp->nm_rsize && max > 0) {
404 			nmp->nm_rsize = max & ~(NFS_FABLKSIZE - 1);
405 			if (nmp->nm_rsize == 0)
406 				nmp->nm_rsize = max;
407 		}
408 		pref = fxdr_unsigned(u_int32_t, fsp->fs_dtpref);
409 		if (pref < nmp->nm_readdirsize && pref >= NFS_DIRBLKSIZ)
410 			nmp->nm_readdirsize = (pref + NFS_DIRBLKSIZ - 1) &
411 				~(NFS_DIRBLKSIZ - 1);
412 		if (max < nmp->nm_readdirsize && max > 0) {
413 			nmp->nm_readdirsize = max & ~(NFS_DIRBLKSIZ - 1);
414 			if (nmp->nm_readdirsize == 0)
415 				nmp->nm_readdirsize = max;
416 		}
417 		maxfsize = fxdr_hyper(&fsp->fs_maxfilesize);
418 		if (maxfsize > 0 && maxfsize < nmp->nm_maxfilesize)
419 			nmp->nm_maxfilesize = maxfsize;
420 		nmp->nm_state |= NFSSTA_GOTFSINFO;
421 	}
422 	m_freem(mrep);
423 nfsmout:
424 	return (error);
425 }
426 
427 /*
428  * Mount a remote root fs via. nfs. This depends on the info in the
429  * nfs_diskless structure that has been filled in properly by some primary
430  * bootstrap.
431  * It goes something like this:
432  * - do enough of "ifconfig" by calling ifioctl() so that the system
433  *   can talk to the server
434  * - If nfs_diskless.mygateway is filled in, use that address as
435  *   a default gateway.
436  * - build the rootfs mount point and call mountnfs() to do the rest.
437  */
438 int
439 nfs_mountroot(struct mount *mp)
440 {
441 	struct mount  *swap_mp;
442 	struct nfsv3_diskless *nd = &nfsv3_diskless;
443 	struct socket *so;
444 	struct vnode *vp;
445 	struct thread *td = curthread;		/* XXX */
446 	int error, i;
447 	u_long l;
448 	char buf[128];
449 
450 #if defined(BOOTP_NFSROOT) && defined(BOOTP)
451 	bootpc_init();		/* use bootp to get nfs_diskless filled in */
452 #endif
453 
454 	/*
455 	 * XXX time must be non-zero when we init the interface or else
456 	 * the arp code will wedge...
457 	 */
458 	while (mycpu->gd_time_seconds == 0)
459 		tsleep(mycpu, 0, "arpkludge", 10);
460 
461 	/*
462 	 * The boot code may have passed us a diskless structure.
463 	 */
464 	if (nfs_diskless_valid == 1)
465 		nfs_convert_diskless();
466 
467 #define SINP(sockaddr)	((struct sockaddr_in *)(sockaddr))
468 	kprintf("nfs_mountroot: interface %s ip %s",
469 		nd->myif.ifra_name,
470 		inet_ntoa(SINP(&nd->myif.ifra_addr)->sin_addr));
471 	kprintf(" bcast %s",
472 		inet_ntoa(SINP(&nd->myif.ifra_broadaddr)->sin_addr));
473 	kprintf(" mask %s\n",
474 		inet_ntoa(SINP(&nd->myif.ifra_mask)->sin_addr));
475 #undef SINP
476 
477 	/*
478 	 * XXX splnet, so networks will receive...
479 	 */
480 	crit_enter();
481 
482 	/*
483 	 * BOOTP does not necessarily have to be compiled into the kernel
484 	 * for an NFS root to work.  If we inherited the network
485 	 * configuration for PXEBOOT then pxe_setup_nfsdiskless() has figured
486 	 * out our interface for us and all we need to do is ifconfig the
487 	 * interface.  We only do this if the interface has not already been
488 	 * ifconfig'd by e.g. BOOTP.
489 	 */
490 	error = socreate(nd->myif.ifra_addr.sa_family, &so, SOCK_DGRAM, 0, td);
491 	if (error) {
492 		panic("nfs_mountroot: socreate(%04x): %d",
493 			nd->myif.ifra_addr.sa_family, error);
494 	}
495 
496 	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, proc0.p_ucred);
497 	if (error)
498 		panic("nfs_mountroot: SIOCAIFADDR: %d", error);
499 
500 	soclose(so, FNONBLOCK);
501 
502 	/*
503 	 * If the gateway field is filled in, set it as the default route.
504 	 */
505 	if (nd->mygateway.sin_len != 0) {
506 		struct sockaddr_in mask, sin;
507 
508 		bzero((caddr_t)&mask, sizeof(mask));
509 		sin = mask;
510 		sin.sin_family = AF_INET;
511 		sin.sin_len = sizeof(sin);
512 		kprintf("nfs_mountroot: gateway %s\n",
513 			inet_ntoa(nd->mygateway.sin_addr));
514 		error = rtrequest_global(RTM_ADD, (struct sockaddr *)&sin,
515 					(struct sockaddr *)&nd->mygateway,
516 					(struct sockaddr *)&mask,
517 					RTF_UP | RTF_GATEWAY);
518 		if (error)
519 			kprintf("nfs_mountroot: unable to set gateway, error %d, continuing anyway\n", error);
520 	}
521 
522 	/*
523 	 * Create the rootfs mount point.
524 	 */
525 	nd->root_args.fh = nd->root_fh;
526 	nd->root_args.fhsize = nd->root_fhsize;
527 	l = ntohl(nd->root_saddr.sin_addr.s_addr);
528 	ksnprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
529 		(l >> 24) & 0xff, (l >> 16) & 0xff,
530 		(l >>  8) & 0xff, (l >>  0) & 0xff,nd->root_hostnam);
531 	kprintf("NFS ROOT: %s\n",buf);
532 	if ((error = nfs_mountdiskless(buf, "/", MNT_RDONLY,
533 	    &nd->root_saddr, &nd->root_args, td, &vp, &mp)) != 0) {
534 		if (swap_mp) {
535 			mp->mnt_vfc->vfc_refcount--;
536 			kfree(swap_mp, M_MOUNT);
537 		}
538 		crit_exit();
539 		return (error);
540 	}
541 
542 	swap_mp = NULL;
543 	if (nd->swap_nblks) {
544 
545 		/* Convert to DEV_BSIZE instead of Kilobyte */
546 		nd->swap_nblks *= 2;
547 
548 		/*
549 		 * Create a fake mount point just for the swap vnode so that the
550 		 * swap file can be on a different server from the rootfs.
551 		 */
552 		nd->swap_args.fh = nd->swap_fh;
553 		nd->swap_args.fhsize = nd->swap_fhsize;
554 		l = ntohl(nd->swap_saddr.sin_addr.s_addr);
555 		ksnprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
556 			(l >> 24) & 0xff, (l >> 16) & 0xff,
557 			(l >>  8) & 0xff, (l >>  0) & 0xff,nd->swap_hostnam);
558 		kprintf("NFS SWAP: %s\n",buf);
559 		if ((error = nfs_mountdiskless(buf, "/swap", 0,
560 		    &nd->swap_saddr, &nd->swap_args, td, &vp, &swap_mp)) != 0) {
561 			crit_exit();
562 			return (error);
563 		}
564 		vfs_unbusy(swap_mp);
565 
566 		VTONFS(vp)->n_size = VTONFS(vp)->n_vattr.va_size =
567 				nd->swap_nblks * DEV_BSIZE ;
568 
569 		/*
570 		 * Since the swap file is not the root dir of a file system,
571 		 * hack it to a regular file.
572 		 */
573 		vp->v_flag = 0;
574 		vref(vp);
575 		nfs_setvtype(vp, VREG);
576 		swaponvp(td, vp, nd->swap_nblks);
577 	}
578 
579 	mp->mnt_flag |= MNT_ROOTFS;
580 	vfs_unbusy(mp);
581 
582 	/*
583 	 * This is not really an nfs issue, but it is much easier to
584 	 * set hostname here and then let the "/etc/rc.xxx" files
585 	 * mount the right /var based upon its preset value.
586 	 */
587 	bcopy(nd->my_hostnam, hostname, MAXHOSTNAMELEN);
588 	hostname[MAXHOSTNAMELEN - 1] = '\0';
589 	for (i = 0; i < MAXHOSTNAMELEN; i++)
590 		if (hostname[i] == '\0')
591 			break;
592 	inittodr(ntohl(nd->root_time));
593 	crit_exit();
594 	return (0);
595 }
596 
597 /*
598  * Internal version of mount system call for diskless setup.
599  */
600 static int
601 nfs_mountdiskless(char *path, char *which, int mountflag,
602 	struct sockaddr_in *sin, struct nfs_args *args, struct thread *td,
603 	struct vnode **vpp, struct mount **mpp)
604 {
605 	struct mount *mp;
606 	struct sockaddr *nam;
607 	int didalloc = 0;
608 	int error;
609 
610 	mp = *mpp;
611 
612 	if (mp == NULL) {
613 		if ((error = vfs_rootmountalloc("nfs", path, &mp)) != 0) {
614 			kprintf("nfs_mountroot: NFS not configured");
615 			return (error);
616 		}
617 		didalloc = 1;
618 	}
619 	mp->mnt_kern_flag = 0;
620 	mp->mnt_flag = mountflag;
621 	nam = dup_sockaddr((struct sockaddr *)sin);
622 
623 #if defined(BOOTP) || defined(NFS_ROOT)
624 	if (args->fhsize == 0) {
625 		kprintf("NFS_ROOT: No FH passed from loader, attempting mount rpc...");
626 		args->fhsize = 0;
627 		error = md_mount(sin, which, args->fh, &args->fhsize, args, td);
628 		if (error) {
629 			kprintf("failed.\n");
630 			goto haderror;
631 		}
632 		kprintf("success!\n");
633 	}
634 #endif
635 
636 	if ((error = mountnfs(args, mp, nam, which, path, vpp)) != 0) {
637 #if defined(BOOTP) || defined(NFS_ROOT)
638 haderror:
639 #endif
640 		kprintf("nfs_mountroot: mount %s on %s: %d", path, which, error);
641 		mp->mnt_vfc->vfc_refcount--;
642 		vfs_unbusy(mp);
643 		if (didalloc)
644 			kfree(mp, M_MOUNT);
645 		FREE(nam, M_SONAME);
646 		return (error);
647 	}
648 	*mpp = mp;
649 	return (0);
650 }
651 
652 static void
653 nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp)
654 {
655 	int adjsock;
656 	int maxio;
657 
658 	crit_enter();
659 	/*
660 	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
661 	 * no sense in that context.
662 	 */
663 	if (argp->sotype == SOCK_STREAM)
664 		nmp->nm_flag &= ~NFSMNT_NOCONN;
665 
666 	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
667 	if ((argp->flags & NFSMNT_NFSV3) == 0)
668 		nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
669 
670 	/* Re-bind if rsrvd port requested and wasn't on one */
671 	adjsock = !(nmp->nm_flag & NFSMNT_RESVPORT)
672 		  && (argp->flags & NFSMNT_RESVPORT);
673 	/* Also re-bind if we're switching to/from a connected UDP socket */
674 	adjsock |= ((nmp->nm_flag & NFSMNT_NOCONN) !=
675 		    (argp->flags & NFSMNT_NOCONN));
676 
677 	/* Update flags atomically.  Don't change the lock bits. */
678 	nmp->nm_flag = argp->flags | nmp->nm_flag;
679 	crit_exit();
680 
681 	if ((argp->flags & NFSMNT_TIMEO) && argp->timeo > 0) {
682 		nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;
683 		if (nmp->nm_timeo < NFS_MINTIMEO)
684 			nmp->nm_timeo = NFS_MINTIMEO;
685 		else if (nmp->nm_timeo > NFS_MAXTIMEO)
686 			nmp->nm_timeo = NFS_MAXTIMEO;
687 	}
688 
689 	if ((argp->flags & NFSMNT_RETRANS) && argp->retrans > 1) {
690 		nmp->nm_retry = argp->retrans;
691 		if (nmp->nm_retry > NFS_MAXREXMIT)
692 			nmp->nm_retry = NFS_MAXREXMIT;
693 	}
694 
695 	maxio = nfs_iosize(argp->flags & NFSMNT_NFSV3, argp->sotype);
696 
697 	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
698 		nmp->nm_wsize = argp->wsize;
699 		/* Round down to multiple of blocksize */
700 		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
701 		if (nmp->nm_wsize <= 0)
702 			nmp->nm_wsize = NFS_FABLKSIZE;
703 	}
704 	if (nmp->nm_wsize > maxio)
705 		nmp->nm_wsize = maxio;
706 	if (nmp->nm_wsize > MAXBSIZE)
707 		nmp->nm_wsize = MAXBSIZE;
708 
709 	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
710 		nmp->nm_rsize = argp->rsize;
711 		/* Round down to multiple of blocksize */
712 		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
713 		if (nmp->nm_rsize <= 0)
714 			nmp->nm_rsize = NFS_FABLKSIZE;
715 	}
716 	if (nmp->nm_rsize > maxio)
717 		nmp->nm_rsize = maxio;
718 	if (nmp->nm_rsize > MAXBSIZE)
719 		nmp->nm_rsize = MAXBSIZE;
720 
721 	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
722 		nmp->nm_readdirsize = argp->readdirsize;
723 	}
724 	if (nmp->nm_readdirsize > maxio)
725 		nmp->nm_readdirsize = maxio;
726 	if (nmp->nm_readdirsize > nmp->nm_rsize)
727 		nmp->nm_readdirsize = nmp->nm_rsize;
728 
729 	if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
730 		nmp->nm_acregmin = argp->acregmin;
731 	else
732 		nmp->nm_acregmin = NFS_MINATTRTIMO;
733 	if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
734 		nmp->nm_acregmax = argp->acregmax;
735 	else
736 		nmp->nm_acregmax = NFS_MAXATTRTIMO;
737 	if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
738 		nmp->nm_acdirmin = argp->acdirmin;
739 	else
740 		nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
741 	if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
742 		nmp->nm_acdirmax = argp->acdirmax;
743 	else
744 		nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;
745 	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
746 		nmp->nm_acdirmin = nmp->nm_acdirmax;
747 	if (nmp->nm_acregmin > nmp->nm_acregmax)
748 		nmp->nm_acregmin = nmp->nm_acregmax;
749 
750 	if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0) {
751 		if (argp->maxgrouplist <= NFS_MAXGRPS)
752 			nmp->nm_numgrps = argp->maxgrouplist;
753 		else
754 			nmp->nm_numgrps = NFS_MAXGRPS;
755 	}
756 	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0) {
757 		if (argp->readahead <= NFS_MAXRAHEAD)
758 			nmp->nm_readahead = argp->readahead;
759 		else
760 			nmp->nm_readahead = NFS_MAXRAHEAD;
761 	}
762 	if ((argp->flags & NFSMNT_DEADTHRESH) && argp->deadthresh >= 1) {
763 		if (argp->deadthresh <= NFS_NEVERDEAD)
764 			nmp->nm_deadthresh = argp->deadthresh;
765 		else
766 			nmp->nm_deadthresh = NFS_NEVERDEAD;
767 	}
768 
769 	adjsock |= ((nmp->nm_sotype != argp->sotype) ||
770 		    (nmp->nm_soproto != argp->proto));
771 	nmp->nm_sotype = argp->sotype;
772 	nmp->nm_soproto = argp->proto;
773 
774 	if (nmp->nm_so && adjsock) {
775 		nfs_safedisconnect(nmp);
776 		if (nmp->nm_sotype == SOCK_DGRAM)
777 			while (nfs_connect(nmp, (struct nfsreq *)0)) {
778 				kprintf("nfs_args: retrying connect\n");
779 				(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
780 			}
781 	}
782 }
783 
784 /*
785  * VFS Operations.
786  *
787  * mount system call
788  * It seems a bit dumb to copyinstr() the host and path here and then
789  * bcopy() them in mountnfs(), but I wanted to detect errors before
790  * doing the sockargs() call because sockargs() allocates an mbuf and
791  * an error after that means that I have to release the mbuf.
792  */
793 /* ARGSUSED */
794 static int
795 nfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
796 {
797 	int error;
798 	struct nfs_args args;
799 	struct sockaddr *nam;
800 	struct vnode *vp;
801 	char pth[MNAMELEN], hst[MNAMELEN];
802 	size_t len;
803 	u_char nfh[NFSX_V3FHMAX];
804 
805 	if (path == NULL) {
806 		nfs_mountroot(mp);
807 		return (0);
808 	}
809 	error = copyin(data, (caddr_t)&args, sizeof (struct nfs_args));
810 	if (error)
811 		return (error);
812 	if (args.version != NFS_ARGSVERSION) {
813 #ifdef COMPAT_PRELITE2
814 		/*
815 		 * If the argument version is unknown, then assume the
816 		 * caller is a pre-lite2 4.4BSD client and convert its
817 		 * arguments.
818 		 */
819 		struct onfs_args oargs;
820 		error = copyin(data, (caddr_t)&oargs, sizeof (struct onfs_args));
821 		if (error)
822 			return (error);
823 		nfs_convert_oargs(&args,&oargs);
824 #else /* !COMPAT_PRELITE2 */
825 		return (EPROGMISMATCH);
826 #endif /* COMPAT_PRELITE2 */
827 	}
828 	if (mp->mnt_flag & MNT_UPDATE) {
829 		struct nfsmount *nmp = VFSTONFS(mp);
830 
831 		if (nmp == NULL)
832 			return (EIO);
833 		/*
834 		 * When doing an update, we can't change from or to
835 		 * v3, or change cookie translation
836 		 */
837 		args.flags = (args.flags &
838 		    ~(NFSMNT_NFSV3/*|NFSMNT_XLATECOOKIE*/)) |
839 		    (nmp->nm_flag &
840 			(NFSMNT_NFSV3/*|NFSMNT_XLATECOOKIE*/));
841 		nfs_decode_args(nmp, &args);
842 		return (0);
843 	}
844 
845 	/*
846 	 * Make the nfs_ip_paranoia sysctl serve as the default connection
847 	 * or no-connection mode for those protocols that support
848 	 * no-connection mode (the flag will be cleared later for protocols
849 	 * that do not support no-connection mode).  This will allow a client
850 	 * to receive replies from a different IP then the request was
851 	 * sent to.  Note: default value for nfs_ip_paranoia is 1 (paranoid),
852 	 * not 0.
853 	 */
854 	if (nfs_ip_paranoia == 0)
855 		args.flags |= NFSMNT_NOCONN;
856 	if (args.fhsize < 0 || args.fhsize > NFSX_V3FHMAX)
857 		return (EINVAL);
858 	error = copyin((caddr_t)args.fh, (caddr_t)nfh, args.fhsize);
859 	if (error)
860 		return (error);
861 	error = copyinstr(path, pth, MNAMELEN-1, &len);
862 	if (error)
863 		return (error);
864 	bzero(&pth[len], MNAMELEN - len);
865 	error = copyinstr(args.hostname, hst, MNAMELEN-1, &len);
866 	if (error)
867 		return (error);
868 	bzero(&hst[len], MNAMELEN - len);
869 	/* sockargs() call must be after above copyin() calls */
870 	error = getsockaddr(&nam, (caddr_t)args.addr, args.addrlen);
871 	if (error)
872 		return (error);
873 	args.fh = nfh;
874 	error = mountnfs(&args, mp, nam, pth, hst, &vp);
875 	return (error);
876 }
877 
878 /*
879  * Common code for mount and mountroot
880  */
881 static int
882 mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
883 	char *pth, char *hst, struct vnode **vpp)
884 {
885 	struct nfsmount *nmp;
886 	struct nfsnode *np;
887 	int error;
888 
889 	if (mp->mnt_flag & MNT_UPDATE) {
890 		nmp = VFSTONFS(mp);
891 		/* update paths, file handles, etc, here	XXX */
892 		FREE(nam, M_SONAME);
893 		return (0);
894 	} else {
895 		nmp = zalloc(nfsmount_zone);
896 		bzero((caddr_t)nmp, sizeof (struct nfsmount));
897 		TAILQ_INIT(&nmp->nm_uidlruhead);
898 		TAILQ_INIT(&nmp->nm_bioq);
899 		mp->mnt_data = (qaddr_t)nmp;
900 	}
901 	vfs_getnewfsid(mp);
902 	nmp->nm_mountp = mp;
903 
904 	/*
905 	 * V2 can only handle 32 bit filesizes.  A 4GB-1 limit may be too
906 	 * high, depending on whether we end up with negative offsets in
907 	 * the client or server somewhere.  2GB-1 may be safer.
908 	 *
909 	 * For V3, nfs_fsinfo will adjust this as necessary.  Assume maximum
910 	 * that we can handle until we find out otherwise.
911 	 * XXX Our "safe" limit on the client is what we can store in our
912 	 * buffer cache using signed(!) block numbers.
913 	 */
914 	if ((argp->flags & NFSMNT_NFSV3) == 0)
915 		nmp->nm_maxfilesize = 0xffffffffLL;
916 	else
917 		nmp->nm_maxfilesize = (u_int64_t)0x80000000 * DEV_BSIZE - 1;
918 
919 	nmp->nm_timeo = NFS_TIMEO;
920 	nmp->nm_retry = NFS_RETRANS;
921 	nmp->nm_wsize = nfs_iosize(argp->flags & NFSMNT_NFSV3, argp->sotype);
922 	nmp->nm_rsize = nmp->nm_wsize;
923 	nmp->nm_readdirsize = NFS_READDIRSIZE;
924 	nmp->nm_numgrps = NFS_MAXGRPS;
925 	nmp->nm_readahead = NFS_DEFRAHEAD;
926 	nmp->nm_deadthresh = NFS_DEADTHRESH;
927 	nmp->nm_fhsize = argp->fhsize;
928 	bcopy((caddr_t)argp->fh, (caddr_t)nmp->nm_fh, argp->fhsize);
929 	bcopy(hst, mp->mnt_stat.f_mntfromname, MNAMELEN);
930 	nmp->nm_nam = nam;
931 	/* Set up the sockets and per-host congestion */
932 	nmp->nm_sotype = argp->sotype;
933 	nmp->nm_soproto = argp->proto;
934 	nmp->nm_cred = crhold(proc0.p_ucred);
935 
936 	nfs_decode_args(nmp, argp);
937 
938 	/*
939 	 * For Connection based sockets (TCP,...) defer the connect until
940 	 * the first request, in case the server is not responding.
941 	 */
942 	if (nmp->nm_sotype == SOCK_DGRAM &&
943 		(error = nfs_connect(nmp, (struct nfsreq *)0)))
944 		goto bad;
945 
946 	/*
947 	 * This is silly, but it has to be set so that vinifod() works.
948 	 * We do not want to do an nfs_statfs() here since we can get
949 	 * stuck on a dead server and we are holding a lock on the mount
950 	 * point.
951 	 */
952 	mp->mnt_stat.f_iosize =
953 		nfs_iosize(nmp->nm_flag & NFSMNT_NFSV3, nmp->nm_sotype);
954 
955 	/*
956 	 * Install vop_ops for our vnops
957 	 */
958 	vfs_add_vnodeops(mp, &nfsv2_vnode_vops, &mp->mnt_vn_norm_ops);
959 	vfs_add_vnodeops(mp, &nfsv2_spec_vops, &mp->mnt_vn_spec_ops);
960 	vfs_add_vnodeops(mp, &nfsv2_fifo_vops, &mp->mnt_vn_fifo_ops);
961 
962 	/*
963 	 * A reference count is needed on the nfsnode representing the
964 	 * remote root.  If this object is not persistent, then backward
965 	 * traversals of the mount point (i.e. "..") will not work if
966 	 * the nfsnode gets flushed out of the cache. Ufs does not have
967 	 * this problem, because one can identify root inodes by their
968 	 * number == ROOTINO (2).
969 	 */
970 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
971 	if (error)
972 		goto bad;
973 	*vpp = NFSTOV(np);
974 
975 	/*
976 	 * Retrieval of mountpoint attributes is delayed until nfs_rot
977 	 * or nfs_statfs are first called.  This will happen either when
978 	 * we first traverse the mount point or if somebody does a df(1).
979 	 *
980 	 * NFSSTA_GOTFSINFO is used to flag if we have successfully
981 	 * retrieved mountpoint attributes.  In the case of NFSv3 we
982 	 * also flag static fsinfo.
983 	 */
984 	if (*vpp != NULL)
985 		(*vpp)->v_type = VNON;
986 
987 	/*
988 	 * Lose the lock but keep the ref.
989 	 */
990 	vn_unlock(*vpp);
991 
992 	return (0);
993 bad:
994 	nfs_disconnect(nmp);
995 	nfs_free_mount(nmp);
996 	FREE(nam, M_SONAME);
997 	return (error);
998 }
999 
1000 /*
1001  * unmount system call
1002  */
1003 static int
1004 nfs_unmount(struct mount *mp, int mntflags)
1005 {
1006 	struct nfsmount *nmp;
1007 	int error, flags = 0;
1008 
1009 	if (mntflags & MNT_FORCE)
1010 		flags |= FORCECLOSE;
1011 	nmp = VFSTONFS(mp);
1012 	/*
1013 	 * Goes something like this..
1014 	 * - Call vflush() to clear out vnodes for this file system
1015 	 * - Close the socket
1016 	 * - Free up the data structures
1017 	 */
1018 	/* In the forced case, cancel any outstanding requests. */
1019 	if (flags & FORCECLOSE) {
1020 		error = nfs_nmcancelreqs(nmp);
1021 		if (error)
1022 			return (error);
1023 	}
1024 	/*
1025 	 * Must handshake with nfs_clientd() if it is active. XXX
1026 	 */
1027 	nmp->nm_state |= NFSSTA_DISMINPROG;
1028 
1029 	/* We hold 1 extra ref on the root vnode; see comment in mountnfs(). */
1030 	error = vflush(mp, 1, flags);
1031 	if (error) {
1032 		nmp->nm_state &= ~NFSSTA_DISMINPROG;
1033 		return (error);
1034 	}
1035 
1036 	/*
1037 	 * We are now committed to the unmount.
1038 	 * For NQNFS, let the server daemon free the nfsmount structure.
1039 	 */
1040 	if (nmp->nm_flag & NFSMNT_KERB)
1041 		nmp->nm_state |= NFSSTA_DISMNT;
1042 
1043 	nfs_disconnect(nmp);
1044 	FREE(nmp->nm_nam, M_SONAME);
1045 
1046 	if ((nmp->nm_flag & NFSMNT_KERB) == 0)
1047 		nfs_free_mount(nmp);
1048 	return (0);
1049 }
1050 
1051 void
1052 nfs_free_mount(struct nfsmount *nmp)
1053 {
1054 	if (nmp->nm_cred)  {
1055 		crfree(nmp->nm_cred);
1056 		nmp->nm_cred = NULL;
1057 	}
1058 	zfree(nfsmount_zone, nmp);
1059 }
1060 
1061 /*
1062  * Return root of a filesystem
1063  */
1064 static int
1065 nfs_root(struct mount *mp, struct vnode **vpp)
1066 {
1067 	struct vnode *vp;
1068 	struct nfsmount *nmp;
1069 	struct vattr attrs;
1070 	struct nfsnode *np;
1071 	int error;
1072 
1073 	nmp = VFSTONFS(mp);
1074 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
1075 	if (error)
1076 		return (error);
1077 	vp = NFSTOV(np);
1078 
1079 	/*
1080 	 * Get transfer parameters and root vnode attributes
1081 	 */
1082 	if ((nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
1083 	    if (nmp->nm_flag & NFSMNT_NFSV3) {
1084 		error = nfs_fsinfo(nmp, vp, curthread);
1085 		mp->mnt_stat.f_iosize = nfs_iosize(1, nmp->nm_sotype);
1086 	    } else {
1087 		if ((error = VOP_GETATTR(vp, &attrs)) == 0)
1088 			nmp->nm_state |= NFSSTA_GOTFSINFO;
1089 
1090 	    }
1091 	} else {
1092 	    /*
1093 	     * The root vnode is usually cached by the namecache so do not
1094 	     * try to avoid going over the wire even if we have previous
1095 	     * information cached.  A stale NFS mount can loop
1096 	     * forever resolving the root vnode if we return no-error when
1097 	     * there is in fact an error.
1098 	     */
1099 	    np->n_attrstamp = 0;
1100 	    error = VOP_GETATTR(vp, &attrs);
1101 	}
1102 	if (vp->v_type == VNON)
1103 	    nfs_setvtype(vp, VDIR);
1104 	vp->v_flag = VROOT;
1105 	if (error)
1106 		vput(vp);
1107 	else
1108 		*vpp = vp;
1109 	return (error);
1110 }
1111 
1112 extern int syncprt;
1113 
1114 struct scaninfo {
1115 	int rescan;
1116 	int waitfor;
1117 	int allerror;
1118 };
1119 
1120 static int nfs_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1121 static int nfs_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1122 
1123 /*
1124  * Flush out the buffer cache
1125  */
1126 /* ARGSUSED */
1127 static int
1128 nfs_sync(struct mount *mp, int waitfor)
1129 {
1130 	struct scaninfo scaninfo;
1131 	int error;
1132 
1133 	scaninfo.rescan = 0;
1134 	scaninfo.waitfor = waitfor;
1135 	scaninfo.allerror = 0;
1136 
1137 	/*
1138 	 * Force stale buffer cache information to be flushed.
1139 	 */
1140 	error = 0;
1141 	while (error == 0 && scaninfo.rescan) {
1142 		scaninfo.rescan = 0;
1143 		error = vmntvnodescan(mp, VMSC_GETVP, nfs_sync_scan1,
1144 					nfs_sync_scan2, &scaninfo);
1145 	}
1146 	return(error);
1147 }
1148 
1149 static int
1150 nfs_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1151 {
1152     struct scaninfo *info = data;
1153 
1154     if (vn_islocked(vp) || RB_EMPTY(&vp->v_rbdirty_tree))
1155 	return(-1);
1156     if (info->waitfor == MNT_LAZY)
1157 	return(-1);
1158     return(0);
1159 }
1160 
1161 static int
1162 nfs_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1163 {
1164     struct scaninfo *info = data;
1165     int error;
1166 
1167     error = VOP_FSYNC(vp, info->waitfor);
1168     if (error)
1169 	info->allerror = error;
1170     return(0);
1171 }
1172 
1173