summaryrefslogtreecommitdiff
path: root/sys/adosfs/advfsops.c
blob: bfaea0c383772b6a872f6a5eae3ca6e2eec15c11 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
/*	$OpenBSD: advfsops.c,v 1.17 2000/04/25 06:10:15 niklas Exp $	*/
/*	$NetBSD: advfsops.c,v 1.24 1996/12/22 10:10:12 cgd Exp $	*/

/*
 * Copyright (c) 1994 Christian E. Hopps
 * Copyright (c) 1996 Matthias Scheler
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christian E. Hopps.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <sys/disklabel.h>
#include <sys/fcntl.h>
#include <sys/namei.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#include <sys/buf.h>

#include <machine/endian.h>

#include <miscfs/specfs/specdev.h> /* XXX */
#include <adosfs/adosfs.h>

int	 adosfs_init __P((struct vfsconf *));
int	 adosfs_mount __P((struct mount *, const char *, caddr_t, struct nameidata *,
    struct proc *));
int	 adosfs_start __P((struct mount *, int, struct proc *));
int	 adosfs_unmount __P((struct mount *, int, struct proc *));
int	 adosfs_root __P((struct mount *, struct vnode **));
int	 adosfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
    struct proc *));
int	 adosfs_statfs __P((struct mount *, struct statfs *, struct proc *));
int	 adosfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
int	 adosfs_vget __P((struct mount *, ino_t, struct vnode **));
int	 adosfs_fhtovp __P((struct mount *, struct fid *, struct vnode **));

int	 adosfs_vptofh __P((struct vnode *, struct fid *));

int	 adosfs_mountfs __P((struct vnode *, struct mount *, struct proc *));
int	 adosfs_loadbitmap __P((struct adosfsmount *));

int
adosfs_mount(mp, path, data, ndp, p)
	struct mount *mp;
	const char *path;
	caddr_t data;
	struct nameidata *ndp;
	struct proc *p;
{
	struct vnode *devvp;
	struct adosfs_args args;
	struct adosfsmount *amp;
	size_t size;
	int error;
	mode_t accessmode;

	error = copyin(data, (caddr_t)&args, sizeof(struct adosfs_args));
	if (error)
		return(error);
	
#if 0
	if (mp->mnt_flag & MNT_UPDATE)
		return (EOPNOTSUPP);
#endif
	if ((mp->mnt_flag & MNT_RDONLY) == 0)
		return (EROFS);
	/*
	 * If updating, check whether changing from read-only to
	 * read/write; if there is no device name, that's all we do.
	 */
	if (mp->mnt_flag & MNT_UPDATE) {
		amp = VFSTOADOSFS(mp);
		if (args.fspec == 0)
			return (vfs_export(mp, &amp->export, &args.export));
	}
	/*
	 * Not an update, or updating the name: look up the name
	 * and verify that it refers to a sensible block device.
	 */
	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
	if ((error = namei(ndp)) != 0)
		return (error);
	devvp = ndp->ni_vp;

	if (devvp->v_type != VBLK) {
		vrele(devvp);
		return (ENOTBLK);
	}
	if (major(devvp->v_rdev) >= nblkdev) {
		vrele(devvp);
		return (ENXIO);
	}
	/*
	 * If mount by non-root, then verify that user has necessary
	 * permissions on the device.
	 */
	if (p->p_ucred->cr_uid != 0) {
		accessmode = VREAD;
		if ((mp->mnt_flag & MNT_RDONLY) == 0)
			accessmode |= VWRITE;
		vn_lock(devvp, LK_EXCLUSIVE  | LK_RETRY, p);
		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
		if (error) {
			vput(devvp);
			return (error);
		}
		VOP_UNLOCK(devvp, 0, p);
	}
/* MNT_UPDATE? */
	if ((error = adosfs_mountfs(devvp, mp, p)) != 0) {
		vrele(devvp);
		return (error);
	}
	amp = VFSTOADOSFS(mp);
	amp->uid = args.uid;
	amp->gid = args.gid;
	amp->mask = args.mask;
	(void)copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
	(void)copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
	    &size);
	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
	bcopy(&args, &mp->mnt_stat.mount_info.adosfs_args, sizeof(args));
	return (0);
}

int
adosfs_mountfs(devvp, mp, p)
	struct vnode *devvp;
	struct mount *mp;
	struct proc *p;
{
	struct disklabel dl;
	struct partition *parp;
	struct adosfsmount *amp;
	struct buf *bp;
	struct vnode *rvp;
	int error, part, i;

	part = DISKPART(devvp->v_rdev);
	amp = NULL;

	/*
	 * Disallow multiple mounts of the same device.
	 * Disallow mounting of a device that is currently in use
	 * (except for root, which might share swap device for miniroot).
	 * Flush out any old buffers remaining from a previous use.
	 */
	if ((error = vfs_mountedon(devvp)) != 0)
		return (error);
	if (vcount(devvp) > 1 && devvp != rootvp)
		return (EBUSY);
	if ((error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0)) != 0)
		return (error);

	/* 
	 * open blkdev and read root block
	 */
	if ((error = VOP_OPEN(devvp, FREAD, NOCRED, p)) != 0)
		return (error);
	error = VOP_IOCTL(devvp, DIOCGDINFO,(caddr_t)&dl, FREAD, NOCRED, p);
	if (error)
		goto fail;

	parp = &dl.d_partitions[part];
	amp = malloc(sizeof(struct adosfsmount), M_ADOSFSMNT, M_WAITOK);
	bzero((char *)amp, sizeof(struct adosfsmount));
	amp->mp = mp;
	if (dl.d_type == DTYPE_FLOPPY) {
		amp->bsize = dl.d_secsize;
		amp->secsperblk = 1;
	}
	else {
		amp->bsize = parp->p_fsize * parp->p_frag;
		amp->secsperblk = parp->p_frag;
	}
	amp->rootb = (parp->p_size / amp->secsperblk - 1 + parp->p_cpg) >> 1;
	amp->numblks = parp->p_size / amp->secsperblk - parp->p_cpg;

	bp = NULL;
	if ((error = bread(devvp, (daddr_t)BBOFF,
			   amp->bsize, NOCRED, &bp)) != 0)
		goto fail;

	amp->dostype = adoswordn(bp, 0);
	brelse(bp);

	if (amp->dostype < 0x444f5300 || amp->dostype > 0x444f5305) {
		error = EINVAL;
		goto fail;
	}

	amp->nwords = amp->bsize >> 2;
	amp->dbsize = amp->bsize - (IS_FFS(amp) ? 0 : OFS_DATA_OFFSET);
	amp->devvp = devvp;
	
	mp->mnt_data = (qaddr_t)amp;
        mp->mnt_stat.f_fsid.val[0] = (int32_t)devvp->v_rdev;
        mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_ADOSFS);
	mp->mnt_flag |= MNT_LOCAL;
	devvp->v_specmountpoint = mp;

	/*
	 * init anode table.
	 */
	for (i = 0; i < ANODEHASHSZ; i++) 
		LIST_INIT(&amp->anodetab[i]);

	/*
	 * get the root anode, if not a valid fs this will fail.
	 */
	if ((error = VFS_ROOT(mp, &rvp)) != 0)
		goto fail;
	/* allocate and load bitmap, set free space */
	amp->bitmap = malloc(((amp->numblks + 31) / 32) * sizeof(*amp->bitmap),
	    M_ADOSFSBITMAP, M_WAITOK);
	if (amp->bitmap)
		adosfs_loadbitmap(amp);
	if (mp->mnt_flag & MNT_RDONLY && amp->bitmap) {
		/*
		 * Don't need the bitmap any more if it's read-only.
		 */
		free(amp->bitmap, M_ADOSFSBITMAP);
		amp->bitmap = NULL;
	}
	vput(rvp);

	return(0);

fail:
	(void) VOP_CLOSE(devvp, FREAD, NOCRED, p);
	if (amp && amp->bitmap)
		free(amp->bitmap, M_ADOSFSBITMAP);
	if (amp)
		free(amp, M_ADOSFSMNT);
	return (error);
}

int
adosfs_start(mp, flags, p)
	struct mount *mp;
	int flags;
	struct proc *p;
{

	return (0);
}

int
adosfs_unmount(mp, mntflags, p)
	struct mount *mp;
	int mntflags;
	struct proc *p;
{
	struct adosfsmount *amp;
	int error, flags;

	flags = 0;
	if (mntflags & MNT_FORCE)
		flags |= FORCECLOSE;
	if ((error = vflush(mp, NULLVP, flags)) != 0)
		return (error);
	amp = VFSTOADOSFS(mp);
	amp->devvp->v_specmountpoint = NULL;
	error = VOP_CLOSE(amp->devvp, FREAD, NOCRED, p);
	vrele(amp->devvp);
	if (amp->bitmap)
		free(amp->bitmap, M_ADOSFSBITMAP);
	free(amp, M_ADOSFSMNT);
	mp->mnt_data = (qaddr_t)0;
	mp->mnt_flag &= ~MNT_LOCAL;
	return (error);
}

int
adosfs_root(mp, vpp)
	struct mount *mp;
	struct vnode **vpp;
{
	struct vnode *nvp;
	int error;

	if ((error = VFS_VGET(mp, ABLKTOINO(VFSTOADOSFS(mp)->rootb), &nvp)) !=
	    0)
		return (error);
	/* XXX verify it's a root block? */
	*vpp = nvp;
	return (0);
}

int
adosfs_statfs(mp, sbp, p)
	struct mount *mp;
	struct statfs *sbp;
	struct proc *p;
{
	struct adosfsmount *amp;

	amp = VFSTOADOSFS(mp);
	sbp->f_bsize = amp->bsize;
	sbp->f_iosize = amp->dbsize;
	sbp->f_blocks = amp->numblks;
	sbp->f_bfree = amp->freeblks;
	sbp->f_bavail = amp->freeblks;
	sbp->f_files = 0;		/* who knows */
	sbp->f_ffree = 0;		/* " " */
	if (sbp != &mp->mnt_stat) {
		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
		bcopy(&mp->mnt_stat.mount_info.adosfs_args,
		    &sbp->mount_info.adosfs_args, sizeof(struct adosfs_args));
	}
	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
	return (0);
}

/* 
 * lookup an anode, check mount's hash table if not found, create
 * return locked and referenced al la vget(vp, 1);
 */
int
adosfs_vget(mp, an, vpp)
	struct mount *mp;
	ino_t an;
	struct vnode **vpp;
{
	struct adosfsmount *amp;
	struct vnode *vp;
	struct anode *ap;
	struct buf *bp;
	char *nam, *tmp;
	int namlen, error;

	error = 0;
	amp = VFSTOADOSFS(mp);
	bp = NULL;

	/* 
	 * check hash table. we are done if found
	 */
 retry:
	if ((*vpp = adosfs_ahashget(mp, an)) != NULL)
		return (0);

	error = getnewvnode(VT_ADOSFS, mp, adosfs_vnodeop_p, &vp);
	if (error)
		return (error);

	/*
	 * setup, insert in hash, and lock before io.
	 */
	vp->v_data = ap = malloc(sizeof(struct anode), M_ANODE, M_WAITOK);
	bzero(ap, sizeof(struct anode));
	lockinit(&ap->a_lock, PINOD, "anode", 0, 0);
	ap->vp = vp;
	ap->amp = amp;
	ap->block = AINOTOBLK(an);
	ap->nwords = amp->nwords;
	error = adosfs_ainshash(amp, ap);

	if (error) {
		vrele (vp);

		if (error == EEXIST)
			goto retry;

		return (error);
	}

	if ((error = bread(amp->devvp, an * amp->secsperblk, amp->bsize,
	    NOCRED, &bp)) != 0) {
		vput(vp);
		return (error);
	}

	/*
	 * get type and fill rest in based on that.
	 */
	switch (ap->type = adosfs_getblktype(amp, bp)) {
	case AROOT:
		vp->v_type = VDIR;
		vp->v_flag |= VROOT;
		ap->mtimev.days = adoswordn(bp, ap->nwords - 10);
		ap->mtimev.mins = adoswordn(bp, ap->nwords - 9);
		ap->mtimev.ticks = adoswordn(bp, ap->nwords - 8);
		ap->created.days = adoswordn(bp, ap->nwords - 7);
		ap->created.mins = adoswordn(bp, ap->nwords - 6);
		ap->created.ticks = adoswordn(bp, ap->nwords - 5);
		break;
	case ALDIR:
	case ADIR:
		vp->v_type = VDIR;
		break;
	case ALFILE:
	case AFILE:
		vp->v_type = VREG;
		ap->fsize = adoswordn(bp, ap->nwords - 47);
		break;
	case ASLINK:		/* XXX soft link */
		vp->v_type = VLNK;
		/*
		 * convert from BCPL string and
		 * from: "part:dir/file" to: "/part/dir/file"
		 */
		nam = bp->b_data + (6 * sizeof(u_int32_t));
		namlen = strlen(nam);
		tmp = nam;
		while (*tmp && *tmp != ':')
			tmp++;
		if (*tmp == 0) {
			ap->slinkto = malloc(namlen + 1, M_ANODE, M_WAITOK);
			bcopy(nam, ap->slinkto, namlen);
		} else if (*nam == ':') {
			ap->slinkto = malloc(namlen + 1, M_ANODE, M_WAITOK);
			bcopy(nam, ap->slinkto, namlen);
			ap->slinkto[0] = '/';
		} else {
			ap->slinkto = malloc(namlen + 2, M_ANODE, M_WAITOK);
			ap->slinkto[0] = '/';
			bcopy(nam, &ap->slinkto[1], namlen);
			ap->slinkto[tmp - nam + 1] = '/';
			namlen++;
		}
		ap->slinkto[namlen] = 0;
		ap->fsize = namlen;
		break;
	default:
		brelse(bp);
		vput(vp);
		return (EINVAL);
	}

	/*
	 * Get appropriate data from this block;  hard link needs
	 * to get other data from the "real" block.
	 */

	/*
	 * copy in name (from original block)
	 */
	nam = bp->b_data + (ap->nwords - 20) * sizeof(u_int32_t);
	namlen = *(u_char *)nam++;
	if (namlen > 30) {
#ifdef DIAGNOSTIC
		printf("adosfs: aget: name length too long blk %d\n", an);
#endif
		brelse(bp);
		vput(vp);
		return (EINVAL);
	}
	bcopy(nam, ap->name, namlen);
	ap->name[namlen] = 0;

	/* 
	 * if dir alloc hash table and copy it in 
	 */
	if (vp->v_type == VDIR) {
		int i;

		ap->ntabent = ANODETABENT(ap);
		ap->tab = malloc(ap->ntabent * (sizeof(daddr_t) + sizeof(int)),
		    M_ANODE, M_WAITOK);
		ap->tabi = (int *)&ap->tab[ap->ntabent];
		bzero(ap->tabi, ANODETABENT(ap) * sizeof(int));
		for (i = 0; i < ap->ntabent; i++)
			ap->tab[i] = (daddr_t)adoswordn(bp, i + 6);
	}

	/*
	 * misc.
	 */
	ap->pblock = (daddr_t)adoswordn(bp, ap->nwords - 3);
	ap->hashf = (daddr_t)adoswordn(bp, ap->nwords - 4);
	ap->linknext = (daddr_t)adoswordn(bp, ap->nwords - 10);
	ap->linkto = (daddr_t)adoswordn(bp, ap->nwords - 11);

	/*
	 * setup last indirect block cache.
	 */
	ap->lastlindblk = 0;
	if (ap->type == AFILE)  {
		ap->lastindblk = ap->block;
		if (adoswordn(bp, ap->nwords - 10))
			ap->linkto = ap->block;
	} else if (ap->type == ALFILE) {
		ap->lastindblk = ap->linkto;
		brelse(bp);
		bp = NULL;
		error = bread(amp->devvp, ap->linkto * amp->secsperblk,
		    amp->bsize, NOCRED, &bp);
		ap->fsize = adoswordn(bp, ap->nwords - 47);
		/*
		 * Should ap->block be set to the real file header block?
		 */
		ap->block = ap->linkto;
	}

	if (ap->type == AROOT) {
		ap->adprot = 15;
		ap->uid = amp->uid;
		ap->gid = amp->gid;
	} else {
		ap->adprot = adoswordn(bp, ap->nwords - 48) ^ 15;
		/*
		 * Get uid/gid from extensions in file header
		 * (really need to know if this is a muFS partition)
		 */
		ap->uid = (adoswordn(bp, ap->nwords - 49) >> 16) & 0xffff;
		ap->gid = adoswordn(bp, ap->nwords - 49) & 0xffff;
		if (ap->uid || ap->gid) {
			if (ap->uid == 0xffff)
				ap->uid = 0;
			if (ap->gid == 0xffff)
				ap->gid = 0;
			ap->adprot |= 0x40000000;	/* Kludge */
		}
		else {
			/*
			 * uid & gid extension don't exist,
			 * so use the mount-point uid/gid
			 */
			ap->uid = amp->uid;
			ap->gid = amp->gid;
		}
	}
	ap->mtime.days = adoswordn(bp, ap->nwords - 23);
	ap->mtime.mins = adoswordn(bp, ap->nwords - 22);
	ap->mtime.ticks = adoswordn(bp, ap->nwords - 21);

	*vpp = vp;		/* return vp */
	brelse(bp);		/* release buffer */
	return (0);
}

/*
 * Load the bitmap into memory, and count the number of available
 * blocks.
 * The bitmap will be released if the filesystem is read-only;  it's
 * only needed to find the free space.
 */
int
adosfs_loadbitmap(amp)
	struct adosfsmount *amp;
{
	struct buf *bp, *mapbp;
	u_int32_t bits;
	daddr_t bn;
	int blkix, endix, mapix, bmsize, n;
	int error;

	bp = mapbp = NULL;
	bn = amp->rootb;
	if ((error = bread(amp->devvp, bn * amp->secsperblk, amp->bsize,
	    NOCRED, &bp)) != 0)
		return (error);
	blkix = amp->nwords - 49;
	endix = amp->nwords - 24;
	mapix = 0;
	bmsize = (amp->numblks + 31) / 32;
	while (mapix < bmsize) {
		if (adoswordn(bp, blkix) == 0)
			break;
		if (mapbp != NULL)
			brelse(mapbp);
		if ((error = bread(amp->devvp,
		    adoswordn(bp, blkix) * amp->secsperblk, amp->bsize,
		     NOCRED, &mapbp)) != 0)
			break;
		if (adoscksum(mapbp, amp->nwords)) {
#ifdef DIAGNOSTIC
			printf("adosfs: loadbitmap - cksum of blk %d failed\n",
			    adoswordn(bp, blkix));
#endif
			/* XXX Force read-only?  Set free space 0? */
			break;
		}
		n = 1;
		while (n < amp->nwords && mapix < bmsize) {
			amp->bitmap[mapix++] = bits = adoswordn(mapbp, n);
			++n;
			if (mapix == bmsize && amp->numblks & 31)
				bits &= ~(0xffffffff << (amp->numblks & 31));
			while (bits) {
				if (bits & 1)
					++amp->freeblks;
				bits >>= 1;
			}
		}
		++blkix;
		if (mapix < bmsize && blkix == endix) {
			bn = (daddr_t)adoswordn(bp, blkix);
			brelse(bp);
			if ((error = bread(amp->devvp, bn * amp->secsperblk,
			    amp->bsize, NOCRED, &bp)) != 0)
				break;
			/*
			 * Why is there no checksum on these blocks?
			 */
			blkix = 0;
			endix = amp->nwords - 1;
		}
	}
	if (bp)
		brelse(bp);
	if (mapbp)
		brelse(mapbp);
	return (error);
}


/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is in range
 * - call iget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the generation number matches
 */

/*
 * This is using the same layout as struct fid from mount.h for the first two
 * fields.
 */
struct ifid {
	u_short	ifid_len;
	u_short	ifid_pad;
	ino_t	ifid_ino;
	daddr_t	ifid_start;
};

int
adosfs_fhtovp(mp, fhp, vpp)
	struct mount *mp;
	struct fid *fhp;
	struct vnode **vpp;
{
	struct ifid *ifhp = (struct ifid *)fhp;
#if 0
	struct anode *ap;
#endif
	struct vnode *nvp;
	int error;

#ifdef ADOSFS_DIAGNOSTIC
	printf("adfhtovp(%x, %x, %x)\n", mp, fhp, vpp);
#endif
	
	if ((error = VFS_VGET(mp, ifhp->ifid_ino, &nvp)) != 0) {
		*vpp = NULLVP;
		return (error);
	}
#if 0
	ap = VTOA(nvp);
	if (ap->inode.iso_mode == 0) {
		vput(nvp);
		*vpp = NULLVP;
		return (ESTALE);
	}
#endif
	*vpp = nvp;
	return(0);
}

int
adosfs_vptofh(vp, fhp)
	struct vnode *vp;
	struct fid *fhp;
{
	struct anode *ap = VTOA(vp);
	struct ifid *ifhp;

	ifhp = (struct ifid *)fhp;
	ifhp->ifid_len = sizeof(struct ifid);
	
	ifhp->ifid_ino = ABLKTOINO(ap->block);
	ifhp->ifid_start = ap->block;
	
#ifdef ADOSFS_DIAGNOSTIC
	printf("advptofh(%x, %x)\n", vp, fhp);
#endif
	return(0);
}

int
adosfs_quotactl(mp, cmds, uid, arg, p)
	struct mount *mp;
	int cmds;
	uid_t uid;
	caddr_t arg;
	struct proc *p;
{
	return(EOPNOTSUPP);
}

int
adosfs_sync(mp, waitfor, uc, p)
	struct mount *mp;
	int waitfor;
	struct ucred *uc;
	struct proc *p;
{
#ifdef ADOSFS_DIAGNOSTIC
	printf("ad_sync(%x, %x)\n", mp, waitfor);
#endif
	return(0);
}

int
adosfs_init(struct vfsconf *vfsp)
{
	return (0);
}

/*
 * vfs generic function call table
 */
struct vfsops adosfs_vfsops = {
	adosfs_mount,
	adosfs_start,
	adosfs_unmount,
	adosfs_root,
	adosfs_quotactl,                
	adosfs_statfs,                  
	adosfs_sync,                    
	adosfs_vget,
	adosfs_fhtovp,                  
	adosfs_vptofh,                  
	adosfs_init,                    
};