xref: /dragonfly/sys/vfs/nfs/nfs_vfsops.c (revision 99dd49c5)
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 1.54 2008/07/31 20:23:40 swildner 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 = NULL;
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 		mp->mnt_vfc->vfc_refcount--;
535 		crit_exit();
536 		return (error);
537 	}
538 
539 	swap_mp = NULL;
540 	if (nd->swap_nblks) {
541 
542 		/* Convert to DEV_BSIZE instead of Kilobyte */
543 		nd->swap_nblks *= 2;
544 
545 		/*
546 		 * Create a fake mount point just for the swap vnode so that the
547 		 * swap file can be on a different server from the rootfs.
548 		 */
549 		nd->swap_args.fh = nd->swap_fh;
550 		nd->swap_args.fhsize = nd->swap_fhsize;
551 		l = ntohl(nd->swap_saddr.sin_addr.s_addr);
552 		ksnprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
553 			(l >> 24) & 0xff, (l >> 16) & 0xff,
554 			(l >>  8) & 0xff, (l >>  0) & 0xff,nd->swap_hostnam);
555 		kprintf("NFS SWAP: %s\n",buf);
556 		if ((error = nfs_mountdiskless(buf, "/swap", 0,
557 		    &nd->swap_saddr, &nd->swap_args, td, &vp, &swap_mp)) != 0) {
558 			crit_exit();
559 			return (error);
560 		}
561 		vfs_unbusy(swap_mp);
562 
563 		VTONFS(vp)->n_size = VTONFS(vp)->n_vattr.va_size =
564 				nd->swap_nblks * DEV_BSIZE ;
565 
566 		/*
567 		 * Since the swap file is not the root dir of a file system,
568 		 * hack it to a regular file.
569 		 */
570 		vp->v_flag = 0;
571 		vref(vp);
572 		nfs_setvtype(vp, VREG);
573 		swaponvp(td, vp, nd->swap_nblks);
574 	}
575 
576 	mp->mnt_flag |= MNT_ROOTFS;
577 	vfs_unbusy(mp);
578 
579 	/*
580 	 * This is not really an nfs issue, but it is much easier to
581 	 * set hostname here and then let the "/etc/rc.xxx" files
582 	 * mount the right /var based upon its preset value.
583 	 */
584 	bcopy(nd->my_hostnam, hostname, MAXHOSTNAMELEN);
585 	hostname[MAXHOSTNAMELEN - 1] = '\0';
586 	for (i = 0; i < MAXHOSTNAMELEN; i++)
587 		if (hostname[i] == '\0')
588 			break;
589 	inittodr(ntohl(nd->root_time));
590 	crit_exit();
591 	return (0);
592 }
593 
594 /*
595  * Internal version of mount system call for diskless setup.
596  */
597 static int
598 nfs_mountdiskless(char *path, char *which, int mountflag,
599 	struct sockaddr_in *sin, struct nfs_args *args, struct thread *td,
600 	struct vnode **vpp, struct mount **mpp)
601 {
602 	struct mount *mp;
603 	struct sockaddr *nam;
604 	int didalloc = 0;
605 	int error;
606 
607 	mp = *mpp;
608 
609 	if (mp == NULL) {
610 		if ((error = vfs_rootmountalloc("nfs", path, &mp)) != 0) {
611 			kprintf("nfs_mountroot: NFS not configured");
612 			return (error);
613 		}
614 		didalloc = 1;
615 	}
616 	mp->mnt_kern_flag = 0;
617 	mp->mnt_flag = mountflag;
618 	nam = dup_sockaddr((struct sockaddr *)sin);
619 
620 #if defined(BOOTP) || defined(NFS_ROOT)
621 	if (args->fhsize == 0) {
622 		char *xpath = path;
623 
624 		kprintf("NFS_ROOT: No FH passed from loader, attempting mount rpc...");
625 		while (*xpath && *xpath != ':')
626 			++xpath;
627 		if (*xpath)
628 			++xpath;
629 		args->fhsize = 0;
630 		error = md_mount(sin, xpath, args->fh, &args->fhsize, args, td);
631 		if (error) {
632 			kprintf("failed error %d.\n", error);
633 			goto haderror;
634 		}
635 		kprintf("success!\n");
636 	}
637 #endif
638 
639 	if ((error = mountnfs(args, mp, nam, which, path, vpp)) != 0) {
640 #if defined(BOOTP) || defined(NFS_ROOT)
641 haderror:
642 #endif
643 		kprintf("nfs_mountroot: mount %s on %s: %d", path, which, error);
644 		mp->mnt_vfc->vfc_refcount--;
645 		vfs_unbusy(mp);
646 		if (didalloc)
647 			kfree(mp, M_MOUNT);
648 		FREE(nam, M_SONAME);
649 		return (error);
650 	}
651 	*mpp = mp;
652 	return (0);
653 }
654 
655 static void
656 nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp)
657 {
658 	int adjsock;
659 	int maxio;
660 
661 	crit_enter();
662 	/*
663 	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
664 	 * no sense in that context.
665 	 */
666 	if (argp->sotype == SOCK_STREAM)
667 		nmp->nm_flag &= ~NFSMNT_NOCONN;
668 
669 	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
670 	if ((argp->flags & NFSMNT_NFSV3) == 0)
671 		nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
672 
673 	/* Re-bind if rsrvd port requested and wasn't on one */
674 	adjsock = !(nmp->nm_flag & NFSMNT_RESVPORT)
675 		  && (argp->flags & NFSMNT_RESVPORT);
676 	/* Also re-bind if we're switching to/from a connected UDP socket */
677 	adjsock |= ((nmp->nm_flag & NFSMNT_NOCONN) !=
678 		    (argp->flags & NFSMNT_NOCONN));
679 
680 	/* Update flags atomically.  Don't change the lock bits. */
681 	nmp->nm_flag = argp->flags | nmp->nm_flag;
682 	crit_exit();
683 
684 	if ((argp->flags & NFSMNT_TIMEO) && argp->timeo > 0) {
685 		nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;
686 		if (nmp->nm_timeo < NFS_MINTIMEO)
687 			nmp->nm_timeo = NFS_MINTIMEO;
688 		else if (nmp->nm_timeo > NFS_MAXTIMEO)
689 			nmp->nm_timeo = NFS_MAXTIMEO;
690 	}
691 
692 	if ((argp->flags & NFSMNT_RETRANS) && argp->retrans > 1) {
693 		nmp->nm_retry = argp->retrans;
694 		if (nmp->nm_retry > NFS_MAXREXMIT)
695 			nmp->nm_retry = NFS_MAXREXMIT;
696 	}
697 
698 	maxio = nfs_iosize(argp->flags & NFSMNT_NFSV3, argp->sotype);
699 
700 	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
701 		nmp->nm_wsize = argp->wsize;
702 		/* Round down to multiple of blocksize */
703 		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
704 		if (nmp->nm_wsize <= 0)
705 			nmp->nm_wsize = NFS_FABLKSIZE;
706 	}
707 	if (nmp->nm_wsize > maxio)
708 		nmp->nm_wsize = maxio;
709 	if (nmp->nm_wsize > MAXBSIZE)
710 		nmp->nm_wsize = MAXBSIZE;
711 
712 	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
713 		nmp->nm_rsize = argp->rsize;
714 		/* Round down to multiple of blocksize */
715 		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
716 		if (nmp->nm_rsize <= 0)
717 			nmp->nm_rsize = NFS_FABLKSIZE;
718 	}
719 	if (nmp->nm_rsize > maxio)
720 		nmp->nm_rsize = maxio;
721 	if (nmp->nm_rsize > MAXBSIZE)
722 		nmp->nm_rsize = MAXBSIZE;
723 
724 	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
725 		nmp->nm_readdirsize = argp->readdirsize;
726 	}
727 	if (nmp->nm_readdirsize > maxio)
728 		nmp->nm_readdirsize = maxio;
729 	if (nmp->nm_readdirsize > nmp->nm_rsize)
730 		nmp->nm_readdirsize = nmp->nm_rsize;
731 
732 	if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
733 		nmp->nm_acregmin = argp->acregmin;
734 	else
735 		nmp->nm_acregmin = NFS_MINATTRTIMO;
736 	if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
737 		nmp->nm_acregmax = argp->acregmax;
738 	else
739 		nmp->nm_acregmax = NFS_MAXATTRTIMO;
740 	if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
741 		nmp->nm_acdirmin = argp->acdirmin;
742 	else
743 		nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
744 	if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
745 		nmp->nm_acdirmax = argp->acdirmax;
746 	else
747 		nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;
748 	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
749 		nmp->nm_acdirmin = nmp->nm_acdirmax;
750 	if (nmp->nm_acregmin > nmp->nm_acregmax)
751 		nmp->nm_acregmin = nmp->nm_acregmax;
752 
753 	if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0) {
754 		if (argp->maxgrouplist <= NFS_MAXGRPS)
755 			nmp->nm_numgrps = argp->maxgrouplist;
756 		else
757 			nmp->nm_numgrps = NFS_MAXGRPS;
758 	}
759 	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0) {
760 		if (argp->readahead <= NFS_MAXRAHEAD)
761 			nmp->nm_readahead = argp->readahead;
762 		else
763 			nmp->nm_readahead = NFS_MAXRAHEAD;
764 	}
765 	if ((argp->flags & NFSMNT_DEADTHRESH) && argp->deadthresh >= 1) {
766 		if (argp->deadthresh <= NFS_NEVERDEAD)
767 			nmp->nm_deadthresh = argp->deadthresh;
768 		else
769 			nmp->nm_deadthresh = NFS_NEVERDEAD;
770 	}
771 
772 	adjsock |= ((nmp->nm_sotype != argp->sotype) ||
773 		    (nmp->nm_soproto != argp->proto));
774 	nmp->nm_sotype = argp->sotype;
775 	nmp->nm_soproto = argp->proto;
776 
777 	if (nmp->nm_so && adjsock) {
778 		nfs_safedisconnect(nmp);
779 		if (nmp->nm_sotype == SOCK_DGRAM)
780 			while (nfs_connect(nmp, NULL)) {
781 				kprintf("nfs_args: retrying connect\n");
782 				(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
783 			}
784 	}
785 }
786 
787 /*
788  * VFS Operations.
789  *
790  * mount system call
791  * It seems a bit dumb to copyinstr() the host and path here and then
792  * bcopy() them in mountnfs(), but I wanted to detect errors before
793  * doing the sockargs() call because sockargs() allocates an mbuf and
794  * an error after that means that I have to release the mbuf.
795  */
796 /* ARGSUSED */
797 static int
798 nfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
799 {
800 	int error;
801 	struct nfs_args args;
802 	struct sockaddr *nam;
803 	struct vnode *vp;
804 	char pth[MNAMELEN], hst[MNAMELEN];
805 	size_t len;
806 	u_char nfh[NFSX_V3FHMAX];
807 
808 	if (path == NULL) {
809 		nfs_mountroot(mp);
810 		return (0);
811 	}
812 	error = copyin(data, (caddr_t)&args, sizeof (struct nfs_args));
813 	if (error)
814 		return (error);
815 	if (args.version != NFS_ARGSVERSION) {
816 #ifdef COMPAT_PRELITE2
817 		/*
818 		 * If the argument version is unknown, then assume the
819 		 * caller is a pre-lite2 4.4BSD client and convert its
820 		 * arguments.
821 		 */
822 		struct onfs_args oargs;
823 		error = copyin(data, (caddr_t)&oargs, sizeof (struct onfs_args));
824 		if (error)
825 			return (error);
826 		nfs_convert_oargs(&args,&oargs);
827 #else /* !COMPAT_PRELITE2 */
828 		return (EPROGMISMATCH);
829 #endif /* COMPAT_PRELITE2 */
830 	}
831 	if (mp->mnt_flag & MNT_UPDATE) {
832 		struct nfsmount *nmp = VFSTONFS(mp);
833 
834 		if (nmp == NULL)
835 			return (EIO);
836 		/*
837 		 * When doing an update, we can't change from or to
838 		 * v3, or change cookie translation
839 		 */
840 		args.flags = (args.flags &
841 		    ~(NFSMNT_NFSV3/*|NFSMNT_XLATECOOKIE*/)) |
842 		    (nmp->nm_flag &
843 			(NFSMNT_NFSV3/*|NFSMNT_XLATECOOKIE*/));
844 		nfs_decode_args(nmp, &args);
845 		return (0);
846 	}
847 
848 	/*
849 	 * Make the nfs_ip_paranoia sysctl serve as the default connection
850 	 * or no-connection mode for those protocols that support
851 	 * no-connection mode (the flag will be cleared later for protocols
852 	 * that do not support no-connection mode).  This will allow a client
853 	 * to receive replies from a different IP then the request was
854 	 * sent to.  Note: default value for nfs_ip_paranoia is 1 (paranoid),
855 	 * not 0.
856 	 */
857 	if (nfs_ip_paranoia == 0)
858 		args.flags |= NFSMNT_NOCONN;
859 	if (args.fhsize < 0 || args.fhsize > NFSX_V3FHMAX)
860 		return (EINVAL);
861 	error = copyin((caddr_t)args.fh, (caddr_t)nfh, args.fhsize);
862 	if (error)
863 		return (error);
864 	error = copyinstr(path, pth, MNAMELEN-1, &len);
865 	if (error)
866 		return (error);
867 	bzero(&pth[len], MNAMELEN - len);
868 	error = copyinstr(args.hostname, hst, MNAMELEN-1, &len);
869 	if (error)
870 		return (error);
871 	bzero(&hst[len], MNAMELEN - len);
872 	/* sockargs() call must be after above copyin() calls */
873 	error = getsockaddr(&nam, (caddr_t)args.addr, args.addrlen);
874 	if (error)
875 		return (error);
876 	args.fh = nfh;
877 	error = mountnfs(&args, mp, nam, pth, hst, &vp);
878 	return (error);
879 }
880 
881 /*
882  * Common code for mount and mountroot
883  */
884 static int
885 mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
886 	char *pth, char *hst, struct vnode **vpp)
887 {
888 	struct nfsmount *nmp;
889 	struct nfsnode *np;
890 	int error;
891 
892 	if (mp->mnt_flag & MNT_UPDATE) {
893 		nmp = VFSTONFS(mp);
894 		/* update paths, file handles, etc, here	XXX */
895 		FREE(nam, M_SONAME);
896 		return (0);
897 	} else {
898 		nmp = zalloc(nfsmount_zone);
899 		bzero((caddr_t)nmp, sizeof (struct nfsmount));
900 		TAILQ_INIT(&nmp->nm_uidlruhead);
901 		TAILQ_INIT(&nmp->nm_bioq);
902 		mp->mnt_data = (qaddr_t)nmp;
903 	}
904 	vfs_getnewfsid(mp);
905 	nmp->nm_mountp = mp;
906 
907 	/*
908 	 * V2 can only handle 32 bit filesizes.  A 4GB-1 limit may be too
909 	 * high, depending on whether we end up with negative offsets in
910 	 * the client or server somewhere.  2GB-1 may be safer.
911 	 *
912 	 * For V3, nfs_fsinfo will adjust this as necessary.  Assume maximum
913 	 * that we can handle until we find out otherwise.
914 	 * XXX Our "safe" limit on the client is what we can store in our
915 	 * buffer cache using signed(!) block numbers.
916 	 */
917 	if ((argp->flags & NFSMNT_NFSV3) == 0)
918 		nmp->nm_maxfilesize = 0xffffffffLL;
919 	else
920 		nmp->nm_maxfilesize = (u_int64_t)0x80000000 * DEV_BSIZE - 1;
921 
922 	nmp->nm_timeo = NFS_TIMEO;
923 	nmp->nm_retry = NFS_RETRANS;
924 	nmp->nm_wsize = nfs_iosize(argp->flags & NFSMNT_NFSV3, argp->sotype);
925 	nmp->nm_rsize = nmp->nm_wsize;
926 	nmp->nm_readdirsize = NFS_READDIRSIZE;
927 	nmp->nm_numgrps = NFS_MAXGRPS;
928 	nmp->nm_readahead = NFS_DEFRAHEAD;
929 	nmp->nm_deadthresh = NFS_DEADTHRESH;
930 	nmp->nm_fhsize = argp->fhsize;
931 	bcopy((caddr_t)argp->fh, (caddr_t)nmp->nm_fh, argp->fhsize);
932 	bcopy(hst, mp->mnt_stat.f_mntfromname, MNAMELEN);
933 	nmp->nm_nam = nam;
934 	/* Set up the sockets and per-host congestion */
935 	nmp->nm_sotype = argp->sotype;
936 	nmp->nm_soproto = argp->proto;
937 	nmp->nm_cred = crhold(proc0.p_ucred);
938 
939 	nfs_decode_args(nmp, argp);
940 
941 	/*
942 	 * For Connection based sockets (TCP,...) defer the connect until
943 	 * the first request, in case the server is not responding.
944 	 */
945 	if (nmp->nm_sotype == SOCK_DGRAM &&
946 		(error = nfs_connect(nmp, NULL)))
947 		goto bad;
948 
949 	/*
950 	 * This is silly, but it has to be set so that vinifod() works.
951 	 * We do not want to do an nfs_statfs() here since we can get
952 	 * stuck on a dead server and we are holding a lock on the mount
953 	 * point.
954 	 */
955 	mp->mnt_stat.f_iosize =
956 		nfs_iosize(nmp->nm_flag & NFSMNT_NFSV3, nmp->nm_sotype);
957 
958 	/*
959 	 * Install vop_ops for our vnops
960 	 */
961 	vfs_add_vnodeops(mp, &nfsv2_vnode_vops, &mp->mnt_vn_norm_ops);
962 	vfs_add_vnodeops(mp, &nfsv2_spec_vops, &mp->mnt_vn_spec_ops);
963 	vfs_add_vnodeops(mp, &nfsv2_fifo_vops, &mp->mnt_vn_fifo_ops);
964 
965 	/*
966 	 * A reference count is needed on the nfsnode representing the
967 	 * remote root.  If this object is not persistent, then backward
968 	 * traversals of the mount point (i.e. "..") will not work if
969 	 * the nfsnode gets flushed out of the cache. Ufs does not have
970 	 * this problem, because one can identify root inodes by their
971 	 * number == ROOTINO (2).
972 	 */
973 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
974 	if (error)
975 		goto bad;
976 	*vpp = NFSTOV(np);
977 
978 	/*
979 	 * Retrieval of mountpoint attributes is delayed until nfs_rot
980 	 * or nfs_statfs are first called.  This will happen either when
981 	 * we first traverse the mount point or if somebody does a df(1).
982 	 *
983 	 * NFSSTA_GOTFSINFO is used to flag if we have successfully
984 	 * retrieved mountpoint attributes.  In the case of NFSv3 we
985 	 * also flag static fsinfo.
986 	 */
987 	if (*vpp != NULL)
988 		(*vpp)->v_type = VNON;
989 
990 	/*
991 	 * Lose the lock but keep the ref.
992 	 */
993 	vn_unlock(*vpp);
994 
995 	return (0);
996 bad:
997 	nfs_disconnect(nmp);
998 	nfs_free_mount(nmp);
999 	FREE(nam, M_SONAME);
1000 	return (error);
1001 }
1002 
1003 /*
1004  * unmount system call
1005  */
1006 static int
1007 nfs_unmount(struct mount *mp, int mntflags)
1008 {
1009 	struct nfsmount *nmp;
1010 	int error, flags = 0;
1011 
1012 	if (mntflags & MNT_FORCE)
1013 		flags |= FORCECLOSE;
1014 	nmp = VFSTONFS(mp);
1015 	/*
1016 	 * Goes something like this..
1017 	 * - Call vflush() to clear out vnodes for this file system
1018 	 * - Close the socket
1019 	 * - Free up the data structures
1020 	 */
1021 	/* In the forced case, cancel any outstanding requests. */
1022 	if (flags & FORCECLOSE) {
1023 		error = nfs_nmcancelreqs(nmp);
1024 		if (error)
1025 			return (error);
1026 	}
1027 	/*
1028 	 * Must handshake with nfs_clientd() if it is active. XXX
1029 	 */
1030 	nmp->nm_state |= NFSSTA_DISMINPROG;
1031 
1032 	/* We hold 1 extra ref on the root vnode; see comment in mountnfs(). */
1033 	error = vflush(mp, 1, flags);
1034 	if (error) {
1035 		nmp->nm_state &= ~NFSSTA_DISMINPROG;
1036 		return (error);
1037 	}
1038 
1039 	/*
1040 	 * We are now committed to the unmount.
1041 	 * For NQNFS, let the server daemon free the nfsmount structure.
1042 	 */
1043 	if (nmp->nm_flag & NFSMNT_KERB)
1044 		nmp->nm_state |= NFSSTA_DISMNT;
1045 
1046 	nfs_disconnect(nmp);
1047 	FREE(nmp->nm_nam, M_SONAME);
1048 
1049 	if ((nmp->nm_flag & NFSMNT_KERB) == 0)
1050 		nfs_free_mount(nmp);
1051 	return (0);
1052 }
1053 
1054 void
1055 nfs_free_mount(struct nfsmount *nmp)
1056 {
1057 	if (nmp->nm_cred)  {
1058 		crfree(nmp->nm_cred);
1059 		nmp->nm_cred = NULL;
1060 	}
1061 	zfree(nfsmount_zone, nmp);
1062 }
1063 
1064 /*
1065  * Return root of a filesystem
1066  */
1067 static int
1068 nfs_root(struct mount *mp, struct vnode **vpp)
1069 {
1070 	struct vnode *vp;
1071 	struct nfsmount *nmp;
1072 	struct vattr attrs;
1073 	struct nfsnode *np;
1074 	int error;
1075 
1076 	nmp = VFSTONFS(mp);
1077 	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
1078 	if (error)
1079 		return (error);
1080 	vp = NFSTOV(np);
1081 
1082 	/*
1083 	 * Get transfer parameters and root vnode attributes
1084 	 */
1085 	if ((nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
1086 	    if (nmp->nm_flag & NFSMNT_NFSV3) {
1087 		error = nfs_fsinfo(nmp, vp, curthread);
1088 		mp->mnt_stat.f_iosize = nfs_iosize(1, nmp->nm_sotype);
1089 	    } else {
1090 		if ((error = VOP_GETATTR(vp, &attrs)) == 0)
1091 			nmp->nm_state |= NFSSTA_GOTFSINFO;
1092 
1093 	    }
1094 	} else {
1095 	    /*
1096 	     * The root vnode is usually cached by the namecache so do not
1097 	     * try to avoid going over the wire even if we have previous
1098 	     * information cached.  A stale NFS mount can loop
1099 	     * forever resolving the root vnode if we return no-error when
1100 	     * there is in fact an error.
1101 	     */
1102 	    np->n_attrstamp = 0;
1103 	    error = VOP_GETATTR(vp, &attrs);
1104 	}
1105 	if (vp->v_type == VNON)
1106 	    nfs_setvtype(vp, VDIR);
1107 	vp->v_flag = VROOT;
1108 	if (error)
1109 		vput(vp);
1110 	else
1111 		*vpp = vp;
1112 	return (error);
1113 }
1114 
1115 extern int syncprt;
1116 
1117 struct scaninfo {
1118 	int rescan;
1119 	int waitfor;
1120 	int allerror;
1121 };
1122 
1123 static int nfs_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1124 static int nfs_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1125 
1126 /*
1127  * Flush out the buffer cache
1128  */
1129 /* ARGSUSED */
1130 static int
1131 nfs_sync(struct mount *mp, int waitfor)
1132 {
1133 	struct scaninfo scaninfo;
1134 	int error;
1135 
1136 	scaninfo.rescan = 1;
1137 	scaninfo.waitfor = waitfor;
1138 	scaninfo.allerror = 0;
1139 
1140 	/*
1141 	 * Force stale buffer cache information to be flushed.
1142 	 */
1143 	error = 0;
1144 	while (error == 0 && scaninfo.rescan) {
1145 		scaninfo.rescan = 0;
1146 		error = vmntvnodescan(mp, VMSC_GETVP, nfs_sync_scan1,
1147 					nfs_sync_scan2, &scaninfo);
1148 	}
1149 	return(error);
1150 }
1151 
1152 static int
1153 nfs_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1154 {
1155     struct scaninfo *info = data;
1156 
1157     if (vn_islocked(vp) || RB_EMPTY(&vp->v_rbdirty_tree))
1158 	return(-1);
1159     if (info->waitfor == MNT_LAZY)
1160 	return(-1);
1161     return(0);
1162 }
1163 
1164 static int
1165 nfs_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1166 {
1167     struct scaninfo *info = data;
1168     int error;
1169 
1170     error = VOP_FSYNC(vp, info->waitfor);
1171     if (error)
1172 	info->allerror = error;
1173     return(0);
1174 }
1175 
1176