xref: /netbsd-src/sys/fs/adosfs/advnops.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: advnops.c,v 1.29 2008/05/16 09:21:59 hannken Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Christian E. Hopps
5  * Copyright (c) 1996 Matthias Scheler
6  * All rights reserved.
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 Christian E. Hopps.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: advnops.c,v 1.29 2008/05/16 09:21:59 hannken Exp $");
36 
37 #if defined(_KERNEL_OPT)
38 #include "opt_quota.h"
39 #endif
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/vnode.h>
44 #include <sys/mount.h>
45 #include <sys/time.h>
46 #include <sys/queue.h>
47 #include <sys/namei.h>
48 #include <sys/buf.h>
49 #include <sys/dirent.h>
50 #include <sys/inttypes.h>
51 #include <sys/malloc.h>
52 #include <sys/pool.h>
53 #include <sys/stat.h>
54 #include <sys/unistd.h>
55 #include <sys/proc.h>
56 #include <sys/kauth.h>
57 
58 #include <miscfs/genfs/genfs.h>
59 #include <miscfs/specfs/specdev.h>
60 #include <fs/adosfs/adosfs.h>
61 
62 extern struct vnodeops adosfs_vnodeops;
63 
64 #define	adosfs_open	genfs_nullop
65 int	adosfs_getattr	__P((void *));
66 int	adosfs_read	__P((void *));
67 int	adosfs_write	__P((void *));
68 #define	adosfs_fcntl	genfs_fcntl
69 #define	adosfs_ioctl	genfs_enoioctl
70 #define	adosfs_poll	genfs_poll
71 int	adosfs_strategy	__P((void *));
72 int	adosfs_link	__P((void *));
73 int	adosfs_symlink	__P((void *));
74 #define	adosfs_abortop	genfs_abortop
75 int	adosfs_bmap	__P((void *));
76 int	adosfs_print	__P((void *));
77 int	adosfs_readdir	__P((void *));
78 int	adosfs_access	__P((void *));
79 int	adosfs_readlink	__P((void *));
80 int	adosfs_inactive	__P((void *));
81 int	adosfs_reclaim	__P((void *));
82 int	adosfs_pathconf	__P((void *));
83 
84 #define adosfs_close 	genfs_nullop
85 #define adosfs_fsync 	genfs_nullop
86 #define adosfs_seek 	genfs_seek
87 
88 #define adosfs_advlock 	genfs_einval
89 #define adosfs_bwrite 	genfs_eopnotsupp
90 #define adosfs_create 	genfs_eopnotsupp
91 #define adosfs_mkdir 	genfs_eopnotsupp
92 #define adosfs_mknod 	genfs_eopnotsupp
93 #define adosfs_revoke	genfs_revoke
94 #define adosfs_mmap 	genfs_mmap
95 #define adosfs_remove 	genfs_eopnotsupp
96 #define adosfs_rename 	genfs_eopnotsupp
97 #define adosfs_rmdir 	genfs_eopnotsupp
98 #define adosfs_setattr 	genfs_eopnotsupp
99 
100 const struct vnodeopv_entry_desc adosfs_vnodeop_entries[] = {
101 	{ &vop_default_desc, vn_default_error },
102 	{ &vop_lookup_desc, adosfs_lookup },		/* lookup */
103 	{ &vop_create_desc, adosfs_create },		/* create */
104 	{ &vop_mknod_desc, adosfs_mknod },		/* mknod */
105 	{ &vop_open_desc, adosfs_open },		/* open */
106 	{ &vop_close_desc, adosfs_close },		/* close */
107 	{ &vop_access_desc, adosfs_access },		/* access */
108 	{ &vop_getattr_desc, adosfs_getattr },		/* getattr */
109 	{ &vop_setattr_desc, adosfs_setattr },		/* setattr */
110 	{ &vop_read_desc, adosfs_read },		/* read */
111 	{ &vop_write_desc, adosfs_write },		/* write */
112 	{ &vop_fcntl_desc, adosfs_fcntl },		/* fcntl */
113 	{ &vop_ioctl_desc, adosfs_ioctl },		/* ioctl */
114 	{ &vop_poll_desc, adosfs_poll },		/* poll */
115 	{ &vop_kqfilter_desc, genfs_kqfilter },		/* kqfilter */
116 	{ &vop_revoke_desc, adosfs_revoke },		/* revoke */
117 	{ &vop_mmap_desc, adosfs_mmap },		/* mmap */
118 	{ &vop_fsync_desc, adosfs_fsync },		/* fsync */
119 	{ &vop_seek_desc, adosfs_seek },		/* seek */
120 	{ &vop_remove_desc, adosfs_remove },		/* remove */
121 	{ &vop_link_desc, adosfs_link },		/* link */
122 	{ &vop_rename_desc, adosfs_rename },		/* rename */
123 	{ &vop_mkdir_desc, adosfs_mkdir },		/* mkdir */
124 	{ &vop_rmdir_desc, adosfs_rmdir },		/* rmdir */
125 	{ &vop_symlink_desc, adosfs_symlink },		/* symlink */
126 	{ &vop_readdir_desc, adosfs_readdir },		/* readdir */
127 	{ &vop_readlink_desc, adosfs_readlink },	/* readlink */
128 	{ &vop_abortop_desc, adosfs_abortop },		/* abortop */
129 	{ &vop_inactive_desc, adosfs_inactive },	/* inactive */
130 	{ &vop_reclaim_desc, adosfs_reclaim },		/* reclaim */
131 	{ &vop_lock_desc, genfs_lock },			/* lock */
132 	{ &vop_unlock_desc, genfs_unlock },		/* unlock */
133 	{ &vop_bmap_desc, adosfs_bmap },		/* bmap */
134 	{ &vop_strategy_desc, adosfs_strategy },	/* strategy */
135 	{ &vop_print_desc, adosfs_print },		/* print */
136 	{ &vop_islocked_desc, genfs_islocked },		/* islocked */
137 	{ &vop_pathconf_desc, adosfs_pathconf },	/* pathconf */
138 	{ &vop_advlock_desc, adosfs_advlock },		/* advlock */
139 	{ &vop_bwrite_desc, adosfs_bwrite },		/* bwrite */
140 	{ &vop_getpages_desc, genfs_getpages },		/* getpages */
141 	{ &vop_putpages_desc, genfs_putpages },		/* putpages */
142 	{ NULL, NULL }
143 };
144 
145 const struct vnodeopv_desc adosfs_vnodeop_opv_desc =
146 	{ &adosfs_vnodeop_p, adosfs_vnodeop_entries };
147 
148 int
149 adosfs_getattr(v)
150 	void *v;
151 {
152 	struct vop_getattr_args /* {
153 		struct vnode *a_vp;
154 		struct vattr *a_vap;
155 		kauth_cred_t a_cred;
156 	} */ *sp = v;
157 	struct vattr *vap;
158 	struct adosfsmount *amp;
159 	struct anode *ap;
160 	u_long fblks;
161 
162 #ifdef ADOSFS_DIAGNOSTIC
163 	advopprint(sp);
164 #endif
165 	vap = sp->a_vap;
166 	ap = VTOA(sp->a_vp);
167 	amp = ap->amp;
168 	vattr_null(vap);
169 	vap->va_uid = ap->uid;
170 	vap->va_gid = ap->gid;
171 	vap->va_fsid = sp->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
172 	vap->va_atime.tv_sec = vap->va_mtime.tv_sec = vap->va_ctime.tv_sec =
173 		ap->mtime.days * 24 * 60 * 60 + ap->mtime.mins * 60 +
174 		ap->mtime.ticks / 50 + (8 * 365 + 2) * 24 * 60 * 60;
175 	vap->va_atime.tv_nsec = vap->va_mtime.tv_nsec = vap->va_ctime.tv_nsec = 0;
176 	vap->va_gen = 0;
177 	vap->va_flags = 0;
178 	vap->va_rdev = NODEV;
179 	vap->va_fileid = ap->block;
180 	vap->va_type = sp->a_vp->v_type;
181 	vap->va_mode = adunixprot(ap->adprot) & amp->mask;
182 	if (sp->a_vp->v_type == VDIR) {
183 		vap->va_nlink = 1;	/* XXX bogus, oh well */
184 		vap->va_bytes = amp->bsize;
185 		vap->va_size = amp->bsize;
186 	} else {
187 		/*
188 		 * XXX actually we can track this if we were to walk the list
189 		 * of links if it exists.
190 		 * XXX for now, just set nlink to 2 if this is a hard link
191 		 * to a file, or a file with a hard link.
192 		 */
193 		vap->va_nlink = 1 + (ap->linkto != 0);
194 		/*
195 		 * round up to nearest blocks add number of file list
196 		 * blocks needed and mutiply by number of bytes per block.
197 		 */
198 		fblks = howmany(ap->fsize, amp->dbsize);
199 		fblks += howmany(fblks, ANODENDATBLKENT(ap));
200 		vap->va_bytes = fblks * amp->dbsize;
201 		vap->va_size = ap->fsize;
202 
203 		vap->va_blocksize = amp->dbsize;
204 	}
205 #ifdef ADOSFS_DIAGNOSTIC
206 	printf(" 0)");
207 #endif
208 	return(0);
209 }
210 /*
211  * are things locked??? they need to be to avoid this being
212  * deleted or changed (data block pointer blocks moving about.)
213  */
214 int
215 adosfs_read(v)
216 	void *v;
217 {
218 	struct vop_read_args /* {
219 		struct vnode *a_vp;
220 		struct uio *a_uio;
221 		int a_ioflag;
222 		kauth_cred_t a_cred;
223 	} */ *sp = v;
224 	struct vnode *vp = sp->a_vp;
225 	struct adosfsmount *amp;
226 	struct anode *ap;
227 	struct uio *uio;
228 	struct buf *bp;
229 	daddr_t lbn;
230 	int size, diff, error;
231 	long n, on;
232 
233 #ifdef ADOSFS_DIAGNOSTIC
234 	advopprint(sp);
235 #endif
236 	error = 0;
237 	uio = sp->a_uio;
238 	ap = VTOA(sp->a_vp);
239 	amp = ap->amp;
240 	/*
241 	 * Return EOF for character devices, EIO for others
242 	 */
243 	if (sp->a_vp->v_type != VREG) {
244 		error = EIO;
245 		goto reterr;
246 	}
247 	if (uio->uio_resid == 0)
248 		goto reterr;
249 	if (uio->uio_offset < 0) {
250 		error = EINVAL;
251 		goto reterr;
252 	}
253 
254 	/*
255 	 * to expensive to let general algorithm figure out that
256 	 * we are beyond the file.  Do it now.
257 	 */
258 	if (uio->uio_offset >= ap->fsize)
259 		goto reterr;
260 
261 	/*
262 	 * taken from ufs_read()
263 	 */
264 
265 	if (vp->v_type == VREG && IS_FFS(amp)) {
266 		const int advice = IO_ADV_DECODE(sp->a_ioflag);
267 		error = 0;
268 
269 		while (uio->uio_resid > 0) {
270 			void *win;
271 			int flags;
272 			vsize_t bytelen = MIN(ap->fsize - uio->uio_offset,
273 					      uio->uio_resid);
274 
275 			if (bytelen == 0) {
276 				break;
277 			}
278 			win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
279 					&bytelen, advice, UBC_READ);
280 			error = uiomove(win, bytelen, uio);
281 			flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0;
282 			ubc_release(win, flags);
283 			if (error) {
284 				break;
285 			}
286 		}
287 		goto out;
288 	}
289 
290 	do {
291 		size = amp->dbsize;
292 		lbn = uio->uio_offset / size;
293 		on = uio->uio_offset % size;
294 		n = MIN(size - on, uio->uio_resid);
295 		diff = ap->fsize - uio->uio_offset;
296 		/*
297 		 * check for EOF
298 		 */
299 		if (diff <= 0)
300 			return(0);
301 		if (diff < n)
302 			n = diff;
303 		/*
304 		 * read ahead could possibly be worth something
305 		 * but not much as ados makes little attempt to
306 		 * make things contigous
307 		 */
308 		error = bread(sp->a_vp, lbn, amp->bsize, NOCRED, 0, &bp);
309 		if (error) {
310 			brelse(bp, 0);
311 			goto reterr;
312 		}
313 		if (!IS_FFS(amp)) {
314 			if (bp->b_resid > 0)
315 				error = EIO; /* OFS needs the complete block */
316 			else if (adoswordn(bp, 0) != BPT_DATA) {
317 #ifdef DIAGNOSTIC
318 				printf("adosfs: bad primary type blk %" PRId64 "\n",
319 				    bp->b_blkno / (amp->bsize / DEV_BSIZE));
320 #endif
321 				error = EINVAL;
322 			} else if (adoscksum(bp, ap->nwords)) {
323 #ifdef DIAGNOSTIC
324 				printf("adosfs: blk %" PRId64 " failed cksum.\n",
325 				    bp->b_blkno / (amp->bsize / DEV_BSIZE));
326 #endif
327 				error = EINVAL;
328 			}
329 		}
330 
331 		if (error) {
332 			brelse(bp, 0);
333 			goto reterr;
334 		}
335 #ifdef ADOSFS_DIAGNOSTIC
336 		printf(" %" PRId64 "+%ld-%" PRId64 "+%ld", lbn, on, lbn, n);
337 #endif
338 		n = MIN(n, size - bp->b_resid);
339 		error = uiomove((char *)bp->b_data + on +
340 				amp->bsize - amp->dbsize, (int)n, uio);
341 		brelse(bp, 0);
342 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
343 
344 out:
345 reterr:
346 #ifdef ADOSFS_DIAGNOSTIC
347 	printf(" %d)", error);
348 #endif
349 	return(error);
350 }
351 
352 int
353 adosfs_write(v)
354 	void *v;
355 {
356 #ifdef ADOSFS_DIAGNOSTIC
357 	struct vop_write_args /* {
358 		struct vnode *a_vp;
359 		struct uio *a_uio;
360 		int a_ioflag;
361 		kauth_cred_t a_cred;
362 	} */ *sp = v;
363 	advopprint(sp);
364 	printf(" EOPNOTSUPP)");
365 #endif
366 	return(EOPNOTSUPP);
367 }
368 
369 /*
370  * Just call the device strategy routine
371  */
372 int
373 adosfs_strategy(v)
374 	void *v;
375 {
376 	struct vop_strategy_args /* {
377 		struct vnode *a_vp;
378 		struct buf *a_bp;
379 	} */ *sp = v;
380 	struct buf *bp;
381 	struct anode *ap;
382 	struct vnode *vp;
383 	int error;
384 
385 #ifdef ADOSFS_DIAGNOSTIC
386 	advopprint(sp);
387 #endif
388 	bp = sp->a_bp;
389 	if (bp->b_vp == NULL) {
390 		bp->b_error = EIO;
391 		biodone(bp);
392 		error = EIO;
393 		goto reterr;
394 	}
395 	vp = sp->a_vp;
396 	ap = VTOA(vp);
397 	if (bp->b_blkno == bp->b_lblkno) {
398 		error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL);
399 		if (error) {
400 			bp->b_flags = error;
401 			biodone(bp);
402 			goto reterr;
403 		}
404 	}
405 	if ((long)bp->b_blkno == -1) {
406 		biodone(bp);
407 		error = 0;
408 		goto reterr;
409 	}
410 	vp = ap->amp->devvp;
411 	error = VOP_STRATEGY(vp, bp);
412 reterr:
413 #ifdef ADOSFS_DIAGNOSTIC
414 	printf(" %d)", error);
415 #endif
416 	return(error);
417 }
418 
419 int
420 adosfs_link(v)
421 	void *v;
422 {
423 	struct vop_link_args /* {
424 		struct vnode *a_dvp;
425 		struct vnode *a_vp;
426 		struct componentname *a_cnp;
427 	} */ *ap = v;
428 
429 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
430 	vput(ap->a_dvp);
431 	return (EROFS);
432 }
433 
434 int
435 adosfs_symlink(v)
436 	void *v;
437 {
438 	struct vop_symlink_args /* {
439 		struct vnode *a_dvp;
440 		struct vnode **a_vpp;
441 		struct componentname *a_cnp;
442 		struct vattr *a_vap;
443 		char *a_target;
444 	} */ *ap = v;
445 
446 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
447 	vput(ap->a_dvp);
448 	return (EROFS);
449 }
450 
451 /*
452  * Wait until the vnode has finished changing state.
453  */
454 int
455 adosfs_bmap(v)
456 	void *v;
457 {
458 	struct vop_bmap_args /* {
459 		struct vnode *a_vp;
460 		daddr_t  a_bn;
461 		struct vnode **a_vpp;
462 		daddr_t *a_bnp;
463 		int *a_runp;
464 	} */ *sp = v;
465 	struct anode *ap;
466 	struct buf *flbp;
467 	long nb, flblk, flblkoff, fcnt;
468 	daddr_t *bnp;
469 	daddr_t bn;
470 	int error;
471 
472 #ifdef ADOSFS_DIAGNOSTIC
473 	advopprint(sp);
474 #endif
475 	ap = VTOA(sp->a_vp);
476 	bn = sp->a_bn;
477 	bnp = sp->a_bnp;
478 	if (sp->a_runp) {
479 		*sp->a_runp = 0;
480 	}
481 	error = 0;
482 
483 	if (sp->a_vpp != NULL)
484 		*sp->a_vpp = ap->amp->devvp;
485 	if (bnp == NULL)
486 		goto reterr;
487 	if (bn < 0) {
488 		error = EFBIG;
489 		goto reterr;
490 	}
491 	if (sp->a_vp->v_type != VREG) {
492 		error = EINVAL;
493 		goto reterr;
494 	}
495 
496 	/*
497 	 * walk the chain of file list blocks until we find
498 	 * the one that will yield the block pointer we need.
499 	 */
500 	if (ap->type == AFILE)
501 		nb = ap->block;			/* pointer to ourself */
502 	else if (ap->type == ALFILE)
503 		nb = ap->linkto;		/* pointer to real file */
504 	else {
505 		error = EINVAL;
506 		goto reterr;
507 	}
508 
509 	flblk = bn / ANODENDATBLKENT(ap);
510 	flbp = NULL;
511 
512 	/*
513 	 * check last indirect block cache
514 	 */
515 	if (flblk < ap->lastlindblk)
516 		fcnt = 0;
517 	else {
518 		flblk -= ap->lastlindblk;
519 		fcnt = ap->lastlindblk;
520 		nb = ap->lastindblk;
521 	}
522 	while (flblk >= 0) {
523 		if (flbp)
524 			brelse(flbp, 0);
525 		if (nb == 0) {
526 #ifdef DIAGNOSTIC
527 			printf("adosfs: bad file list chain.\n");
528 #endif
529 			error = EINVAL;
530 			goto reterr;
531 		}
532 		error = bread(ap->amp->devvp, nb * ap->amp->bsize / DEV_BSIZE,
533 			      ap->amp->bsize, NOCRED, 0, &flbp);
534 		if (error) {
535 			brelse(flbp, 0);
536 			goto reterr;
537 		}
538 		if (adoscksum(flbp, ap->nwords)) {
539 #ifdef DIAGNOSTIC
540 			printf("adosfs: blk %ld failed cksum.\n", nb);
541 #endif
542 			brelse(flbp, 0);
543 			error = EINVAL;
544 			goto reterr;
545 		}
546 		/*
547 		 * update last indirect block cache
548 		 */
549 		ap->lastlindblk = fcnt++;
550 		ap->lastindblk = nb;
551 
552 		nb = adoswordn(flbp, ap->nwords - 2);
553 		flblk--;
554 	}
555 	/*
556 	 * calculate offset of block number in table.  The table starts
557 	 * at nwords - 51 and goes to offset 6 or less if indicated by the
558 	 * valid table entries stored at offset ADBI_NBLKTABENT.
559 	 */
560 	flblkoff = bn % ANODENDATBLKENT(ap);
561 	if (flblkoff < adoswordn(flbp, 2 /* ADBI_NBLKTABENT */)) {
562 		flblkoff = (ap->nwords - 51) - flblkoff;
563 		*bnp = adoswordn(flbp, flblkoff) * ap->amp->bsize / DEV_BSIZE;
564 	} else {
565 #ifdef DIAGNOSTIC
566 		printf("flblk offset %ld too large in lblk %ld blk %" PRId64 "\n",
567 		    flblkoff, (long)bn, flbp->b_blkno);
568 #endif
569 		error = EINVAL;
570 	}
571 	brelse(flbp, 0);
572 reterr:
573 #ifdef ADOSFS_DIAGNOSTIC
574 	if (error == 0 && bnp)
575 		printf(" %lld => %lld", (long long)bn, (long long)*bnp);
576 	printf(" %d)\n", error);
577 #endif
578 	return(error);
579 }
580 
581 /*
582  * Print out the contents of a adosfs vnode.
583  */
584 /* ARGSUSED */
585 int
586 adosfs_print(v)
587 	void *v;
588 {
589 #if 0
590 	struct vop_print_args /* {
591 		struct vnode *a_vp;
592 	} */ *sp = v;
593 #endif
594 	return(0);
595 }
596 
597 int
598 adosfs_readdir(v)
599 	void *v;
600 {
601 	struct vop_readdir_args /* {
602 		struct vnode *a_vp;
603 		struct uio *a_uio;
604 		kauth_cred_t a_cred;
605 		int *a_eofflag;
606 		off_t **a_cookies;
607 		int *a_ncookies;
608 	} */ *sp = v;
609 	int error, first, useri, chainc, hashi, scanned;
610 	u_long nextbn;
611 	struct dirent ad, *adp;
612 	struct anode *pap, *ap;
613 	struct vnode *vp;
614 	struct uio *uio = sp->a_uio;
615 	off_t uoff = uio->uio_offset;
616 	off_t *cookies = NULL;
617 	int ncookies = 0;
618 
619 #ifdef ADOSFS_DIAGNOSTIC
620 	advopprint(sp);
621 #endif
622 
623 	if (sp->a_vp->v_type != VDIR) {
624 		error = ENOTDIR;
625 		goto reterr;
626 	}
627 
628 	if (uoff < 0) {
629 		error = EINVAL;
630 		goto reterr;
631 	}
632 
633 	pap = VTOA(sp->a_vp);
634 	adp = &ad;
635 	error = nextbn = hashi = chainc = scanned = 0;
636 	first = useri = uoff / sizeof ad;
637 
638 	/*
639 	 * If offset requested is not on a slot boundary
640 	 */
641 	if (uoff % sizeof ad) {
642 		error = EINVAL;
643 		goto reterr;
644 	}
645 
646 	for (;;) {
647 		if (hashi == pap->ntabent) {
648 			*sp->a_eofflag = 1;
649 			break;
650 		}
651 		if (pap->tab[hashi] == 0) {
652 			hashi++;
653 			continue;
654 		}
655 		if (nextbn == 0)
656 			nextbn = pap->tab[hashi];
657 
658 		/*
659 		 * First determine if we can skip this chain
660 		 */
661 		if (chainc == 0) {
662 			int skip;
663 
664 			skip = useri - scanned;
665 			if (pap->tabi[hashi] > 0 && pap->tabi[hashi] <= skip) {
666 				scanned += pap->tabi[hashi];
667 				hashi++;
668 				nextbn = 0;
669 				continue;
670 			}
671 		}
672 
673 		/*
674 		 * Now [continue to] walk the chain
675 		 */
676 		ap = NULL;
677 		do {
678 			error = VFS_VGET(pap->amp->mp, (ino_t)nextbn, &vp);
679 			if (error)
680 				goto reterr;
681 			ap = VTOA(vp);
682 			scanned++;
683 			chainc++;
684 			nextbn = ap->hashf;
685 
686 			/*
687 			 * check for end of chain.
688 			 */
689 			if (nextbn == 0) {
690 				pap->tabi[hashi] = chainc;
691 				hashi++;
692 				chainc = 0;
693 			} else if (pap->tabi[hashi] <= 0 &&
694 			    -chainc < pap->tabi[hashi])
695 				pap->tabi[hashi] = -chainc;
696 
697 			if (useri >= scanned) {
698 				vput(vp);
699 				ap = NULL;
700 			}
701 		} while (ap == NULL && nextbn != 0);
702 
703 		/*
704 		 * We left the loop but without a result so do main over.
705 		 */
706 		if (ap == NULL)
707 			continue;
708 		/*
709 		 * Fill in dirent record
710 		 */
711 		memset(adp, 0, sizeof *adp);
712 		adp->d_fileno = ap->block;
713 		/*
714 		 * This deserves a function in kern/vfs_subr.c
715 		 */
716 		switch (ATOV(ap)->v_type) {
717 		case VREG:
718 			adp->d_type = DT_REG;
719 			break;
720 		case VDIR:
721 			adp->d_type = DT_DIR;
722 			break;
723 		case VLNK:
724 			adp->d_type = DT_LNK;
725 			break;
726 		default:
727 			adp->d_type = DT_UNKNOWN;
728 			break;
729 		}
730 		adp->d_namlen = strlen(ap->name);
731 		memcpy(adp->d_name, ap->name, adp->d_namlen);
732 		adp->d_reclen = _DIRENT_SIZE(adp);
733 		vput(vp);
734 
735 		if (adp->d_reclen > uio->uio_resid) {
736 			if (useri == first)	/* no room for even one entry */
737 				error = EINVAL;
738 			break;
739 		}
740 		error = uiomove(adp, adp->d_reclen, uio);
741 		if (error)
742 			break;
743 		useri++;
744 	}
745 	ncookies = useri - first;
746 	uio->uio_offset = uoff + ncookies * sizeof ad;
747 reterr:
748 #ifdef ADOSFS_DIAGNOSTIC
749 	printf(" %d)", error);
750 #endif
751 	if (sp->a_ncookies != NULL) {
752 		*sp->a_ncookies = ncookies;
753 		if (!error) {
754 			*sp->a_cookies = cookies =
755 			   malloc(ncookies * sizeof *cookies, M_TEMP, M_WAITOK);
756 
757 			while (ncookies--) {
758 				uoff += sizeof ad;
759 				*cookies++ = uoff;
760 			}
761 		} else
762 			*sp->a_cookies = NULL;
763 	}
764 
765 	return(error);
766 }
767 
768 
769 int
770 adosfs_access(v)
771 	void *v;
772 {
773 	struct vop_access_args /* {
774 		struct vnode *a_vp;
775 		int  a_mode;
776 		kauth_cred_t a_cred;
777 	} */ *sp = v;
778 	struct anode *ap;
779 	struct vnode *vp = sp->a_vp;
780 	int error;
781 
782 #ifdef ADOSFS_DIAGNOSTIC
783 	advopprint(sp);
784 #endif
785 
786 	ap = VTOA(vp);
787 #ifdef DIAGNOSTIC
788 	if (!VOP_ISLOCKED(vp)) {
789 		vprint("adosfs_access: not locked", sp->a_vp);
790 		panic("adosfs_access: not locked");
791 	}
792 #endif
793 	/*
794 	 * Disallow write attempts unless the file is a socket,
795 	 * fifo, or a block or character device resident on the
796 	 * file system.
797 	 */
798 	if (sp->a_mode & VWRITE) {
799 		switch (vp->v_type) {
800 		case VDIR:
801 		case VLNK:
802 		case VREG:
803 			return (EROFS);
804 		default:
805 			break;
806 		}
807 	}
808 #ifdef QUOTA
809 #endif
810 	error = vaccess(sp->a_vp->v_type, adunixprot(ap->adprot) & ap->amp->mask,
811 	    ap->uid, ap->gid, sp->a_mode, sp->a_cred);
812 #ifdef ADOSFS_DIAGNOSTIC
813 	printf(" %d)", error);
814 #endif
815 	return(error);
816 }
817 
818 int
819 adosfs_readlink(v)
820 	void *v;
821 {
822 	struct vop_readlink_args /* {
823 		struct vnode *a_vp;
824 		struct uio *a_uio;
825 		kauth_cred_t a_cred;
826 	} */ *sp = v;
827 	struct anode *ap;
828 	int error;
829 
830 #ifdef ADOSFS_DIAGNOSTIC
831 	advopprint(sp);
832 #endif
833 	ap = VTOA(sp->a_vp);
834 	error = uiomove(ap->slinkto, strlen(ap->slinkto), sp->a_uio);
835 #ifdef ADOSFS_DIAGNOSTIC
836 	printf(" %d)", error);
837 #endif
838 	return (error);
839 }
840 
841 /*ARGSUSED*/
842 int
843 adosfs_inactive(v)
844 	void *v;
845 {
846 	struct vop_inactive_args /* {
847 		struct vnode *a_vp;
848 		bool *a_recycle;
849 	} */ *sp = v;
850 	struct vnode *vp = sp->a_vp;
851 #ifdef ADOSFS_DIAGNOSTIC
852 	advopprint(sp);
853 #endif
854 	VOP_UNLOCK(vp, 0);
855 	/* XXX this needs to check if file was deleted */
856 	*sp->a_recycle = true;
857 
858 #ifdef ADOSFS_DIAGNOSTIC
859 	printf(" 0)");
860 #endif
861 	return(0);
862 }
863 
864 /*
865  * the kernel wants its vnode back.
866  * no lock needed we are being called from vclean()
867  */
868 int
869 adosfs_reclaim(v)
870 	void *v;
871 {
872 	struct vop_reclaim_args /* {
873 		struct vnode *a_vp;
874 	} */ *sp = v;
875 	struct vnode *vp;
876 	struct anode *ap;
877 
878 #ifdef ADOSFS_DIAGNOSTIC
879 	printf("(reclaim 0)");
880 #endif
881 	vp = sp->a_vp;
882 	ap = VTOA(vp);
883 	LIST_REMOVE(ap, link);
884 	cache_purge(vp);
885 	if (vp->v_type == VDIR && ap->tab)
886 		free(ap->tab, M_ANODE);
887 	else if (vp->v_type == VLNK && ap->slinkto)
888 		free(ap->slinkto, M_ANODE);
889 	genfs_node_destroy(vp);
890 	pool_put(&adosfs_node_pool, ap);
891 	vp->v_data = NULL;
892 	return(0);
893 }
894 
895 /*
896  * POSIX pathconf info, grabbed from kern/u fs, probably need to
897  * investigate exactly what each return type means as they are probably
898  * not valid currently
899  */
900 int
901 adosfs_pathconf(v)
902 	void *v;
903 {
904 	struct vop_pathconf_args /* {
905 		struct vnode *a_vp;
906 		int a_name;
907 		register_t *a_retval;
908 	} */ *ap = v;
909 
910 	switch (ap->a_name) {
911 	case _PC_LINK_MAX:
912 		*ap->a_retval = LINK_MAX;
913 		return (0);
914 	case _PC_NAME_MAX:
915 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_namemax;
916 		return (0);
917 	case _PC_PATH_MAX:
918 		*ap->a_retval = PATH_MAX;
919 		return (0);
920 	case _PC_PIPE_BUF:
921 		*ap->a_retval = PIPE_BUF;
922 		return (0);
923 	case _PC_CHOWN_RESTRICTED:
924 		*ap->a_retval = 1;
925 		return (0);
926 	case _PC_VDISABLE:
927 		*ap->a_retval = _POSIX_VDISABLE;
928 		return (0);
929 	case _PC_SYNC_IO:
930 		*ap->a_retval = 1;
931 		return (0);
932 	case _PC_FILESIZEBITS:
933 		*ap->a_retval = 32;
934 		return (0);
935 	default:
936 		return (EINVAL);
937 	}
938 	/* NOTREACHED */
939 }
940