xref: /original-bsd/sys/ufs/lfs/lfs_vfsops.c (revision 93ab02a6)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)lfs_vfsops.c	7.54 (Berkeley) 04/19/91
8  */
9 
10 #include "param.h"
11 #include "systm.h"
12 #include "namei.h"
13 #include "proc.h"
14 #include "kernel.h"
15 #include "vnode.h"
16 #include "specdev.h"
17 #include "mount.h"
18 #include "buf.h"
19 #include "file.h"
20 #include "disklabel.h"
21 #include "ioctl.h"
22 #include "errno.h"
23 #include "malloc.h"
24 
25 #include "quota.h"
26 #include "fs.h"
27 #include "ufsmount.h"
28 #include "inode.h"
29 
30 struct vfsops ufs_vfsops = {
31 	ufs_mount,
32 	ufs_start,
33 	ufs_unmount,
34 	ufs_root,
35 	ufs_quotactl,
36 	ufs_statfs,
37 	ufs_sync,
38 	ufs_fhtovp,
39 	ufs_vptofh,
40 	ufs_init
41 };
42 
43 /*
44  * Flag to allow forcible unmounting.
45  */
46 int doforce = 1;
47 
48 /*
49  * Called by vfs_mountroot when ufs is going to be mounted as root.
50  *
51  * Name is updated by mount(8) after booting.
52  */
53 #define ROOTNAME	"root_device"
54 
55 ufs_mountroot()
56 {
57 	register struct mount *mp;
58 	extern struct vnode *rootvp;
59 	struct proc *p = curproc;	/* XXX */
60 	struct ufsmount *ump;
61 	register struct fs *fs;
62 	u_int size;
63 	int error;
64 
65 	mp = (struct mount *)malloc((u_long)sizeof(struct mount),
66 		M_MOUNT, M_WAITOK);
67 	mp->mnt_op = &ufs_vfsops;
68 	mp->mnt_flag = MNT_RDONLY;
69 	mp->mnt_exroot = 0;
70 	mp->mnt_mounth = NULLVP;
71 	error = mountfs(rootvp, mp, p);
72 	if (error) {
73 		free((caddr_t)mp, M_MOUNT);
74 		return (error);
75 	}
76 	if (error = vfs_lock(mp)) {
77 		(void)ufs_unmount(mp, 0, p);
78 		free((caddr_t)mp, M_MOUNT);
79 		return (error);
80 	}
81 	rootfs = mp;
82 	mp->mnt_next = mp;
83 	mp->mnt_prev = mp;
84 	mp->mnt_vnodecovered = NULLVP;
85 	ump = VFSTOUFS(mp);
86 	fs = ump->um_fs;
87 	bzero(fs->fs_fsmnt, sizeof(fs->fs_fsmnt));
88 	fs->fs_fsmnt[0] = '/';
89 	bcopy((caddr_t)fs->fs_fsmnt, (caddr_t)mp->mnt_stat.f_mntonname,
90 	    MNAMELEN);
91 	(void) copystr(ROOTNAME, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
92 	    &size);
93 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
94 	(void) ufs_statfs(mp, &mp->mnt_stat, p);
95 	vfs_unlock(mp);
96 	inittodr(fs->fs_time);
97 	return (0);
98 }
99 
100 /*
101  * VFS Operations.
102  *
103  * mount system call
104  */
105 ufs_mount(mp, path, data, ndp, p)
106 	register struct mount *mp;
107 	char *path;
108 	caddr_t data;
109 	struct nameidata *ndp;
110 	struct proc *p;
111 {
112 	struct vnode *devvp;
113 	struct ufs_args args;
114 	struct ufsmount *ump;
115 	register struct fs *fs;
116 	u_int size;
117 	int error;
118 
119 	if (error = copyin(data, (caddr_t)&args, sizeof (struct ufs_args)))
120 		return (error);
121 	/*
122 	 * Process export requests.
123 	 */
124 	if ((args.exflags & MNT_EXPORTED) || (mp->mnt_flag & MNT_EXPORTED)) {
125 		if (args.exflags & MNT_EXPORTED)
126 			mp->mnt_flag |= MNT_EXPORTED;
127 		else
128 			mp->mnt_flag &= ~MNT_EXPORTED;
129 		if (args.exflags & MNT_EXRDONLY)
130 			mp->mnt_flag |= MNT_EXRDONLY;
131 		else
132 			mp->mnt_flag &= ~MNT_EXRDONLY;
133 		mp->mnt_exroot = args.exroot;
134 	}
135 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
136 		if ((error = getmdev(&devvp, args.fspec, ndp, p)) != 0)
137 			return (error);
138 		error = mountfs(devvp, mp, p);
139 	} else {
140 		ump = VFSTOUFS(mp);
141 		fs = ump->um_fs;
142 		if (fs->fs_ronly && (mp->mnt_flag & MNT_RDONLY) == 0)
143 			fs->fs_ronly = 0;
144 		/*
145 		 * Verify that the specified device is the one that
146 		 * is really being used for the root file system.
147 		 */
148 		if (args.fspec == 0)
149 			return (0);
150 		if ((error = getmdev(&devvp, args.fspec, ndp, p)) != 0)
151 			return (error);
152 		if (devvp != ump->um_devvp)
153 			error = EINVAL;	/* needs translation */
154 		else
155 			vrele(devvp);
156 	}
157 	if (error) {
158 		vrele(devvp);
159 		return (error);
160 	}
161 	ump = VFSTOUFS(mp);
162 	fs = ump->um_fs;
163 	(void) copyinstr(path, fs->fs_fsmnt, sizeof(fs->fs_fsmnt) - 1, &size);
164 	bzero(fs->fs_fsmnt + size, sizeof(fs->fs_fsmnt) - size);
165 	bcopy((caddr_t)fs->fs_fsmnt, (caddr_t)mp->mnt_stat.f_mntonname,
166 	    MNAMELEN);
167 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
168 	    &size);
169 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
170 	(void) ufs_statfs(mp, &mp->mnt_stat, p);
171 	return (0);
172 }
173 
174 /*
175  * Common code for mount and mountroot
176  */
177 mountfs(devvp, mp, p)
178 	register struct vnode *devvp;
179 	struct mount *mp;
180 	struct proc *p;
181 {
182 	register struct ufsmount *ump = (struct ufsmount *)0;
183 	struct buf *bp = NULL;
184 	register struct fs *fs;
185 	dev_t dev = devvp->v_rdev;
186 	struct partinfo dpart;
187 	caddr_t base, space;
188 	int havepart = 0, blks;
189 	int error, i, size;
190 	int needclose = 0;
191 	int ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
192 	extern struct vnode *rootvp;
193 
194 	/*
195 	 * Disallow multiple mounts of the same device.
196 	 * Disallow mounting of a device that is currently in use
197 	 * (except for root, which might share swap device for miniroot).
198 	 * Flush out any old buffers remaining from a previous use.
199 	 */
200 	if (error = mountedon(devvp))
201 		return (error);
202 	if (vcount(devvp) > 1 && devvp != rootvp)
203 		return (EBUSY);
204 	vinvalbuf(devvp, 1);
205 	if (error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED, p))
206 		return (error);
207 	needclose = 1;
208 	if (VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, NOCRED, p) != 0)
209 		size = DEV_BSIZE;
210 	else {
211 		havepart = 1;
212 		size = dpart.disklab->d_secsize;
213 	}
214 	if (error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp))
215 		goto out;
216 	fs = bp->b_un.b_fs;
217 	if (fs->fs_magic != FS_MAGIC || fs->fs_bsize > MAXBSIZE ||
218 	    fs->fs_bsize < sizeof(struct fs)) {
219 		error = EINVAL;		/* XXX needs translation */
220 		goto out;
221 	}
222 	ump = (struct ufsmount *)malloc(sizeof *ump, M_UFSMNT, M_WAITOK);
223 	ump->um_fs = (struct fs *)malloc((u_long)fs->fs_sbsize, M_SUPERBLK,
224 	    M_WAITOK);
225 	bcopy((caddr_t)bp->b_un.b_addr, (caddr_t)ump->um_fs,
226 	   (u_int)fs->fs_sbsize);
227 	if (fs->fs_sbsize < SBSIZE)
228 		bp->b_flags |= B_INVAL;
229 	brelse(bp);
230 	bp = NULL;
231 	fs = ump->um_fs;
232 	fs->fs_ronly = ronly;
233 	if (ronly == 0)
234 		fs->fs_fmod = 1;
235 	if (havepart) {
236 		dpart.part->p_fstype = FS_BSDFFS;
237 		dpart.part->p_fsize = fs->fs_fsize;
238 		dpart.part->p_frag = fs->fs_frag;
239 		dpart.part->p_cpg = fs->fs_cpg;
240 	}
241 	blks = howmany(fs->fs_cssize, fs->fs_fsize);
242 	base = space = (caddr_t)malloc((u_long)fs->fs_cssize, M_SUPERBLK,
243 	    M_WAITOK);
244 	for (i = 0; i < blks; i += fs->fs_frag) {
245 		size = fs->fs_bsize;
246 		if (i + fs->fs_frag > blks)
247 			size = (blks - i) * fs->fs_fsize;
248 		error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
249 			NOCRED, &bp);
250 		if (error) {
251 			free((caddr_t)base, M_SUPERBLK);
252 			goto out;
253 		}
254 		bcopy((caddr_t)bp->b_un.b_addr, space, (u_int)size);
255 		fs->fs_csp[fragstoblks(fs, i)] = (struct csum *)space;
256 		space += size;
257 		brelse(bp);
258 		bp = NULL;
259 	}
260 	mp->mnt_data = (qaddr_t)ump;
261 	mp->mnt_stat.f_fsid.val[0] = (long)dev;
262 	mp->mnt_stat.f_fsid.val[1] = MOUNT_UFS;
263 	mp->mnt_flag |= MNT_LOCAL;
264 	ump->um_mountp = mp;
265 	ump->um_dev = dev;
266 	ump->um_devvp = devvp;
267 	for (i = 0; i < MAXQUOTAS; i++)
268 		ump->um_quotas[i] = NULLVP;
269 	devvp->v_specflags |= SI_MOUNTEDON;
270 
271 	/* Sanity checks for old file systems.			   XXX */
272 	fs->fs_npsect = MAX(fs->fs_npsect, fs->fs_nsect);	/* XXX */
273 	fs->fs_interleave = MAX(fs->fs_interleave, 1);		/* XXX */
274 	if (fs->fs_postblformat == FS_42POSTBLFMT)		/* XXX */
275 		fs->fs_nrpos = 8;				/* XXX */
276 	return (0);
277 out:
278 	if (bp)
279 		brelse(bp);
280 	if (needclose)
281 		(void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED, p);
282 	if (ump) {
283 		free((caddr_t)ump->um_fs, M_SUPERBLK);
284 		free((caddr_t)ump, M_UFSMNT);
285 		mp->mnt_data = (qaddr_t)0;
286 	}
287 	return (error);
288 }
289 
290 /*
291  * Make a filesystem operational.
292  * Nothing to do at the moment.
293  */
294 /* ARGSUSED */
295 ufs_start(mp, flags, p)
296 	struct mount *mp;
297 	int flags;
298 	struct proc *p;
299 {
300 
301 	return (0);
302 }
303 
304 /*
305  * unmount system call
306  */
307 ufs_unmount(mp, mntflags, p)
308 	struct mount *mp;
309 	int mntflags;
310 	struct proc *p;
311 {
312 	register struct ufsmount *ump;
313 	register struct fs *fs;
314 	int i, error, ronly, flags = 0;
315 
316 	if (mntflags & MNT_FORCE) {
317 		if (!doforce || mp == rootfs)
318 			return (EINVAL);
319 		flags |= FORCECLOSE;
320 	}
321 	mntflushbuf(mp, 0);
322 	if (mntinvalbuf(mp))
323 		return (EBUSY);
324 	ump = VFSTOUFS(mp);
325 #ifdef QUOTA
326 	if (mp->mnt_flag & MNT_QUOTA) {
327 		if (error = vflush(mp, NULLVP, SKIPSYSTEM|flags))
328 			return (error);
329 		for (i = 0; i < MAXQUOTAS; i++) {
330 			if (ump->um_quotas[i] == NULLVP)
331 				continue;
332 			quotaoff(mp, i);
333 		}
334 		/*
335 		 * Here we fall through to vflush again to ensure
336 		 * that we have gotten rid of all the system vnodes.
337 		 */
338 	}
339 #endif
340 	if (error = vflush(mp, NULLVP, flags))
341 		return (error);
342 	fs = ump->um_fs;
343 	ronly = !fs->fs_ronly;
344 	ump->um_devvp->v_specflags &= ~SI_MOUNTEDON;
345 	error = VOP_CLOSE(ump->um_devvp, ronly ? FREAD : FREAD|FWRITE,
346 		NOCRED, p);
347 	vrele(ump->um_devvp);
348 	free((caddr_t)fs->fs_csp[0], M_SUPERBLK);
349 	free((caddr_t)fs, M_SUPERBLK);
350 	free((caddr_t)ump, M_UFSMNT);
351 	mp->mnt_data = (qaddr_t)0;
352 	mp->mnt_flag &= ~MNT_LOCAL;
353 	return (error);
354 }
355 
356 /*
357  * Check to see if a filesystem is mounted on a block device.
358  */
359 mountedon(vp)
360 	register struct vnode *vp;
361 {
362 	register struct vnode *vq;
363 
364 	if (vp->v_specflags & SI_MOUNTEDON)
365 		return (EBUSY);
366 	if (vp->v_flag & VALIASED) {
367 		for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
368 			if (vq->v_rdev != vp->v_rdev ||
369 			    vq->v_type != vp->v_type)
370 				continue;
371 			if (vq->v_specflags & SI_MOUNTEDON)
372 				return (EBUSY);
373 		}
374 	}
375 	return (0);
376 }
377 
378 /*
379  * Return root of a filesystem
380  */
381 ufs_root(mp, vpp)
382 	struct mount *mp;
383 	struct vnode **vpp;
384 {
385 	register struct inode *ip;
386 	struct inode *nip;
387 	struct vnode tvp;
388 	int error;
389 
390 	tvp.v_mount = mp;
391 	ip = VTOI(&tvp);
392 	ip->i_vnode = &tvp;
393 	ip->i_dev = VFSTOUFS(mp)->um_dev;
394 	error = iget(ip, (ino_t)ROOTINO, &nip);
395 	if (error)
396 		return (error);
397 	*vpp = ITOV(nip);
398 	return (0);
399 }
400 
401 /*
402  * Do operations associated with quotas
403  */
404 ufs_quotactl(mp, cmds, uid, arg, p)
405 	struct mount *mp;
406 	int cmds;
407 	uid_t uid;
408 	caddr_t arg;
409 	struct proc *p;
410 {
411 	struct ufsmount *ump = VFSTOUFS(mp);
412 	int cmd, type, error;
413 
414 #ifndef QUOTA
415 	return (EOPNOTSUPP);
416 #else
417 	if (uid == -1)
418 		uid = p->p_cred->p_ruid;
419 	cmd = cmds >> SUBCMDSHIFT;
420 
421 	switch (cmd) {
422 	case Q_GETQUOTA:
423 	case Q_SYNC:
424 		if (uid == p->p_cred->p_ruid)
425 			break;
426 		/* fall through */
427 	default:
428 		if (error = suser(p->p_ucred, &p->p_acflag))
429 			return (error);
430 	}
431 
432 	type = cmd & SUBCMDMASK;
433 	if ((u_int)type >= MAXQUOTAS)
434 		return (EINVAL);
435 
436 	switch (cmd) {
437 
438 	case Q_QUOTAON:
439 		return (quotaon(p, mp, type, arg));
440 
441 	case Q_QUOTAOFF:
442 		if (vfs_busy(mp))
443 			return (0);
444 		error = quotaoff(mp, type);
445 		vfs_unbusy(mp);
446 		return (error);
447 
448 	case Q_SETQUOTA:
449 		return (setquota(mp, uid, type, arg));
450 
451 	case Q_SETUSE:
452 		return (setuse(mp, uid, type, arg));
453 
454 	case Q_GETQUOTA:
455 		return (getquota(mp, uid, type, arg));
456 
457 	case Q_SYNC:
458 		if (vfs_busy(mp))
459 			return (0);
460 		error = qsync(mp);
461 		vfs_unbusy(mp);
462 		return (error);
463 
464 	default:
465 		return (EINVAL);
466 	}
467 	/* NOTREACHED */
468 #endif
469 }
470 
471 /*
472  * Get file system statistics.
473  */
474 ufs_statfs(mp, sbp, p)
475 	struct mount *mp;
476 	register struct statfs *sbp;
477 	struct proc *p;
478 {
479 	register struct ufsmount *ump;
480 	register struct fs *fs;
481 
482 	ump = VFSTOUFS(mp);
483 	fs = ump->um_fs;
484 	if (fs->fs_magic != FS_MAGIC)
485 		panic("ufs_statfs");
486 	sbp->f_type = MOUNT_UFS;
487 	sbp->f_fsize = fs->fs_fsize;
488 	sbp->f_bsize = fs->fs_bsize;
489 	sbp->f_blocks = fs->fs_dsize;
490 	sbp->f_bfree = fs->fs_cstotal.cs_nbfree * fs->fs_frag +
491 		fs->fs_cstotal.cs_nffree;
492 	sbp->f_bavail = (fs->fs_dsize * (100 - fs->fs_minfree) / 100) -
493 		(fs->fs_dsize - sbp->f_bfree);
494 	sbp->f_files =  fs->fs_ncg * fs->fs_ipg - ROOTINO;
495 	sbp->f_ffree = fs->fs_cstotal.cs_nifree;
496 	if (sbp != &mp->mnt_stat) {
497 		bcopy((caddr_t)mp->mnt_stat.f_mntonname,
498 			(caddr_t)&sbp->f_mntonname[0], MNAMELEN);
499 		bcopy((caddr_t)mp->mnt_stat.f_mntfromname,
500 			(caddr_t)&sbp->f_mntfromname[0], MNAMELEN);
501 	}
502 	return (0);
503 }
504 
505 int	syncprt = 0;
506 
507 /*
508  * Go through the disk queues to initiate sandbagged IO;
509  * go through the inodes to write those that have been modified;
510  * initiate the writing of the super block if it has been modified.
511  *
512  * Note: we are always called with the filesystem marked `MPBUSY'.
513  */
514 ufs_sync(mp, waitfor)
515 	struct mount *mp;
516 	int waitfor;
517 {
518 	register struct vnode *vp;
519 	register struct inode *ip;
520 	register struct ufsmount *ump = VFSTOUFS(mp);
521 	register struct fs *fs;
522 	int error, allerror = 0;
523 
524 	if (syncprt)
525 		bufstats();
526 	fs = ump->um_fs;
527 	/*
528 	 * Write back modified superblock.
529 	 * Consistency check that the superblock
530 	 * is still in the buffer cache.
531 	 */
532 	if (fs->fs_fmod != 0) {
533 		if (fs->fs_ronly != 0) {		/* XXX */
534 			printf("fs = %s\n", fs->fs_fsmnt);
535 			panic("update: rofs mod");
536 		}
537 		fs->fs_fmod = 0;
538 		fs->fs_time = time.tv_sec;
539 		allerror = sbupdate(ump, waitfor);
540 	}
541 	/*
542 	 * Write back each (modified) inode.
543 	 */
544 loop:
545 	for (vp = mp->mnt_mounth; vp; vp = vp->v_mountf) {
546 		/*
547 		 * If the vnode that we are about to sync is no longer
548 		 * associated with this mount point, start over.
549 		 */
550 		if (vp->v_mount != mp)
551 			goto loop;
552 		if (VOP_ISLOCKED(vp))
553 			continue;
554 		ip = VTOI(vp);
555 		if ((ip->i_flag & (IMOD|IACC|IUPD|ICHG)) == 0 &&
556 		    vp->v_dirtyblkhd == NULL)
557 			continue;
558 		if (vget(vp))
559 			goto loop;
560 		if (vp->v_dirtyblkhd)
561 			vflushbuf(vp, 0);
562 		if ((ip->i_flag & (IMOD|IACC|IUPD|ICHG)) &&
563 		    (error = iupdat(ip, &time, &time, 0)))
564 			allerror = error;
565 		vput(vp);
566 	}
567 	/*
568 	 * Force stale file system control information to be flushed.
569 	 */
570 	vflushbuf(ump->um_devvp, waitfor == MNT_WAIT ? B_SYNC : 0);
571 #ifdef QUOTA
572 	qsync(mp);
573 #endif
574 	return (allerror);
575 }
576 
577 /*
578  * Write a superblock and associated information back to disk.
579  */
580 sbupdate(mp, waitfor)
581 	struct ufsmount *mp;
582 	int waitfor;
583 {
584 	register struct fs *fs = mp->um_fs;
585 	register struct buf *bp;
586 	int blks;
587 	caddr_t space;
588 	int i, size, error = 0;
589 
590 	bp = getblk(mp->um_devvp, SBLOCK, (int)fs->fs_sbsize);
591 	bcopy((caddr_t)fs, bp->b_un.b_addr, (u_int)fs->fs_sbsize);
592 	/* Restore compatibility to old file systems.		   XXX */
593 	if (fs->fs_postblformat == FS_42POSTBLFMT)		/* XXX */
594 		bp->b_un.b_fs->fs_nrpos = -1;			/* XXX */
595 	if (waitfor == MNT_WAIT)
596 		error = bwrite(bp);
597 	else
598 		bawrite(bp);
599 	blks = howmany(fs->fs_cssize, fs->fs_fsize);
600 	space = (caddr_t)fs->fs_csp[0];
601 	for (i = 0; i < blks; i += fs->fs_frag) {
602 		size = fs->fs_bsize;
603 		if (i + fs->fs_frag > blks)
604 			size = (blks - i) * fs->fs_fsize;
605 		bp = getblk(mp->um_devvp, fsbtodb(fs, fs->fs_csaddr + i), size);
606 		bcopy(space, bp->b_un.b_addr, (u_int)size);
607 		space += size;
608 		if (waitfor == MNT_WAIT)
609 			error = bwrite(bp);
610 		else
611 			bawrite(bp);
612 	}
613 	return (error);
614 }
615 
616 /*
617  * Print out statistics on the current allocation of the buffer pool.
618  * Can be enabled to print out on every ``sync'' by setting "syncprt"
619  * above.
620  */
621 bufstats()
622 {
623 	int s, i, j, count;
624 	register struct buf *bp, *dp;
625 	int counts[MAXBSIZE/CLBYTES+1];
626 	static char *bname[BQUEUES] = { "LOCKED", "LRU", "AGE", "EMPTY" };
627 
628 	for (bp = bfreelist, i = 0; bp < &bfreelist[BQUEUES]; bp++, i++) {
629 		count = 0;
630 		for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
631 			counts[j] = 0;
632 		s = splbio();
633 		for (dp = bp->av_forw; dp != bp; dp = dp->av_forw) {
634 			counts[dp->b_bufsize/CLBYTES]++;
635 			count++;
636 		}
637 		splx(s);
638 		printf("%s: total-%d", bname[i], count);
639 		for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
640 			if (counts[j] != 0)
641 				printf(", %d-%d", j * CLBYTES, counts[j]);
642 		printf("\n");
643 	}
644 }
645 
646 /*
647  * File handle to vnode
648  *
649  * Have to be really careful about stale file handles:
650  * - check that the inode number is in range
651  * - call iget() to get the locked inode
652  * - check for an unallocated inode (i_mode == 0)
653  * - check that the generation number matches
654  */
655 ufs_fhtovp(mp, fhp, vpp)
656 	register struct mount *mp;
657 	struct fid *fhp;
658 	struct vnode **vpp;
659 {
660 	register struct ufid *ufhp;
661 	register struct fs *fs;
662 	register struct inode *ip;
663 	struct inode *nip;
664 	struct vnode tvp;
665 	int error;
666 
667 	ufhp = (struct ufid *)fhp;
668 	fs = VFSTOUFS(mp)->um_fs;
669 	if (ufhp->ufid_ino < ROOTINO ||
670 	    ufhp->ufid_ino >= fs->fs_ncg * fs->fs_ipg) {
671 		*vpp = NULLVP;
672 		return (EINVAL);
673 	}
674 	tvp.v_mount = mp;
675 	ip = VTOI(&tvp);
676 	ip->i_vnode = &tvp;
677 	ip->i_dev = VFSTOUFS(mp)->um_dev;
678 	if (error = iget(ip, ufhp->ufid_ino, &nip)) {
679 		*vpp = NULLVP;
680 		return (error);
681 	}
682 	ip = nip;
683 	if (ip->i_mode == 0) {
684 		iput(ip);
685 		*vpp = NULLVP;
686 		return (EINVAL);
687 	}
688 	if (ip->i_gen != ufhp->ufid_gen) {
689 		iput(ip);
690 		*vpp = NULLVP;
691 		return (EINVAL);
692 	}
693 	*vpp = ITOV(ip);
694 	return (0);
695 }
696 
697 /*
698  * Vnode pointer to File handle
699  */
700 /* ARGSUSED */
701 ufs_vptofh(vp, fhp)
702 	struct vnode *vp;
703 	struct fid *fhp;
704 {
705 	register struct inode *ip = VTOI(vp);
706 	register struct ufid *ufhp;
707 
708 	ufhp = (struct ufid *)fhp;
709 	ufhp->ufid_len = sizeof(struct ufid);
710 	ufhp->ufid_ino = ip->i_number;
711 	ufhp->ufid_gen = ip->i_gen;
712 	return (0);
713 }
714 
715 /*
716  * Check that the user's argument is a reasonable
717  * thing on which to mount, and return the device number if so.
718  */
719 getmdev(devvpp, fname, ndp, p)
720 	struct vnode **devvpp;
721 	caddr_t fname;
722 	register struct nameidata *ndp;
723 	struct proc *p;
724 {
725 	register struct vnode *vp;
726 	int error;
727 
728 	ndp->ni_nameiop = LOOKUP | FOLLOW;
729 	ndp->ni_segflg = UIO_USERSPACE;
730 	ndp->ni_dirp = fname;
731 	if (error = namei(ndp, p))
732 		return (error);
733 	vp = ndp->ni_vp;
734 	if (vp->v_type != VBLK) {
735 		vrele(vp);
736 		return (ENOTBLK);
737 	}
738 	if (major(vp->v_rdev) >= nblkdev) {
739 		vrele(vp);
740 		return (ENXIO);
741 	}
742 	*devvpp = vp;
743 	return (0);
744 }
745