xref: /freebsd/sys/fs/udf/udf_vnops.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*-
2  * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /* udf_vnops.c */
30 /* Take care of the vnode side of things */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/namei.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/stat.h>
38 #include <sys/bio.h>
39 #include <sys/conf.h>
40 #include <sys/buf.h>
41 #include <sys/iconv.h>
42 #include <sys/mount.h>
43 #include <sys/vnode.h>
44 #include <sys/dirent.h>
45 #include <sys/queue.h>
46 #include <sys/unistd.h>
47 #include <sys/endian.h>
48 
49 #include <vm/uma.h>
50 
51 #include <fs/udf/ecma167-udf.h>
52 #include <fs/udf/osta.h>
53 #include <fs/udf/udf.h>
54 #include <fs/udf/udf_mount.h>
55 
56 extern struct iconv_functions *udf_iconv;
57 
58 static vop_access_t	udf_access;
59 static vop_getattr_t	udf_getattr;
60 static vop_open_t	udf_open;
61 static vop_ioctl_t	udf_ioctl;
62 static vop_pathconf_t	udf_pathconf;
63 static vop_print_t	udf_print;
64 static vop_read_t	udf_read;
65 static vop_readdir_t	udf_readdir;
66 static vop_readlink_t	udf_readlink;
67 static vop_setattr_t	udf_setattr;
68 static vop_strategy_t	udf_strategy;
69 static vop_bmap_t	udf_bmap;
70 static vop_cachedlookup_t	udf_lookup;
71 static vop_reclaim_t	udf_reclaim;
72 static vop_vptofh_t	udf_vptofh;
73 static int udf_readatoffset(struct udf_node *node, int *size, off_t offset,
74     struct buf **bp, uint8_t **data);
75 static int udf_bmap_internal(struct udf_node *node, off_t offset,
76     daddr_t *sector, uint32_t *max_size);
77 
78 static struct vop_vector udf_vnodeops = {
79 	.vop_default =		&default_vnodeops,
80 
81 	.vop_access =		udf_access,
82 	.vop_bmap =		udf_bmap,
83 	.vop_cachedlookup =	udf_lookup,
84 	.vop_getattr =		udf_getattr,
85 	.vop_ioctl =		udf_ioctl,
86 	.vop_lookup =		vfs_cache_lookup,
87 	.vop_open =		udf_open,
88 	.vop_pathconf =		udf_pathconf,
89 	.vop_print =		udf_print,
90 	.vop_read =		udf_read,
91 	.vop_readdir =		udf_readdir,
92 	.vop_readlink =		udf_readlink,
93 	.vop_reclaim =		udf_reclaim,
94 	.vop_setattr =		udf_setattr,
95 	.vop_strategy =		udf_strategy,
96 	.vop_vptofh =		udf_vptofh,
97 };
98 
99 struct vop_vector udf_fifoops = {
100 	.vop_default =		&fifo_specops,
101 	.vop_access =		udf_access,
102 	.vop_getattr =		udf_getattr,
103 	.vop_print =		udf_print,
104 	.vop_reclaim =		udf_reclaim,
105 	.vop_setattr =		udf_setattr,
106 	.vop_vptofh =		udf_vptofh,
107 };
108 
109 static MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
110 static MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");
111 
112 #define UDF_INVALID_BMAP	-1
113 
114 int
115 udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
116 {
117 	int error;
118 	struct vnode *vp;
119 
120 	error = getnewvnode("udf", mp, &udf_vnodeops, &vp);
121 	if (error) {
122 		printf("udf_allocv: failed to allocate new vnode\n");
123 		return (error);
124 	}
125 
126 	*vpp = vp;
127 	return (0);
128 }
129 
130 /* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
131 static mode_t
132 udf_permtomode(struct udf_node *node)
133 {
134 	uint32_t perm;
135 	uint16_t flags;
136 	mode_t mode;
137 
138 	perm = le32toh(node->fentry->perm);
139 	flags = le16toh(node->fentry->icbtag.flags);
140 
141 	mode = perm & UDF_FENTRY_PERM_USER_MASK;
142 	mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
143 	mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
144 	mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
145 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
146 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);
147 
148 	return (mode);
149 }
150 
151 static int
152 udf_access(struct vop_access_args *a)
153 {
154 	struct vnode *vp;
155 	struct udf_node *node;
156 	accmode_t accmode;
157 	mode_t mode;
158 
159 	vp = a->a_vp;
160 	node = VTON(vp);
161 	accmode = a->a_accmode;
162 
163 	if (accmode & VWRITE) {
164 		switch (vp->v_type) {
165 		case VDIR:
166 		case VLNK:
167 		case VREG:
168 			return (EROFS);
169 			/* NOT REACHED */
170 		default:
171 			break;
172 		}
173 	}
174 
175 	mode = udf_permtomode(node);
176 
177 	return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
178 	    accmode, a->a_cred, NULL));
179 }
180 
181 static int
182 udf_open(struct vop_open_args *ap) {
183 	struct udf_node *np = VTON(ap->a_vp);
184 	off_t fsize;
185 
186 	fsize = le64toh(np->fentry->inf_len);
187 	vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
188 	return 0;
189 }
190 
191 static const int mon_lens[2][12] = {
192 	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
193 	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
194 };
195 
196 static int
197 udf_isaleapyear(int year)
198 {
199 	int i;
200 
201 	i = (year % 4) ? 0 : 1;
202 	i &= (year % 100) ? 1 : 0;
203 	i |= (year % 400) ? 0 : 1;
204 
205 	return i;
206 }
207 
208 /*
209  * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
210  */
211 static void
212 udf_timetotimespec(struct timestamp *time, struct timespec *t)
213 {
214 	int i, lpyear, daysinyear, year, startyear;
215 	union {
216 		uint16_t	u_tz_offset;
217 		int16_t		s_tz_offset;
218 	} tz;
219 
220 	/*
221 	 * DirectCD seems to like using bogus year values.
222 	 * Don't trust time->month as it will be used for an array index.
223 	 */
224 	year = le16toh(time->year);
225 	if (year < 1970 || time->month < 1 || time->month > 12) {
226 		t->tv_sec = 0;
227 		t->tv_nsec = 0;
228 		return;
229 	}
230 
231 	/* Calculate the time and day */
232 	t->tv_sec = time->second;
233 	t->tv_sec += time->minute * 60;
234 	t->tv_sec += time->hour * 3600;
235 	t->tv_sec += (time->day - 1) * 3600 * 24;
236 
237 	/* Calculate the month */
238 	lpyear = udf_isaleapyear(year);
239 	t->tv_sec += mon_lens[lpyear][time->month - 1] * 3600 * 24;
240 
241 	/* Speed up the calculation */
242 	startyear = 1970;
243 	if (year > 2009) {
244 		t->tv_sec += 1262304000;
245 		startyear += 40;
246 	} else if (year > 1999) {
247 		t->tv_sec += 946684800;
248 		startyear += 30;
249 	} else if (year > 1989) {
250 		t->tv_sec += 631152000;
251 		startyear += 20;
252 	} else if (year > 1979) {
253 		t->tv_sec += 315532800;
254 		startyear += 10;
255 	}
256 
257 	daysinyear = (year - startyear) * 365;
258 	for (i = startyear; i < year; i++)
259 		daysinyear += udf_isaleapyear(i);
260 	t->tv_sec += daysinyear * 3600 * 24;
261 
262 	/* Calculate microseconds */
263 	t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
264 	    time->usec;
265 
266 	/*
267 	 * Calculate the time zone.  The timezone is 12 bit signed 2's
268 	 * complement, so we gotta do some extra magic to handle it right.
269 	 */
270 	tz.u_tz_offset = le16toh(time->type_tz);
271 	tz.u_tz_offset &= 0x0fff;
272 	if (tz.u_tz_offset & 0x0800)
273 		tz.u_tz_offset |= 0xf000;	/* extend the sign to 16 bits */
274 	if ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
275 		t->tv_sec -= tz.s_tz_offset * 60;
276 
277 	return;
278 }
279 
280 static int
281 udf_getattr(struct vop_getattr_args *a)
282 {
283 	struct vnode *vp;
284 	struct udf_node *node;
285 	struct vattr *vap;
286 	struct file_entry *fentry;
287 	struct timespec ts;
288 
289 	ts.tv_sec = 0;
290 
291 	vp = a->a_vp;
292 	vap = a->a_vap;
293 	node = VTON(vp);
294 	fentry = node->fentry;
295 
296 	vap->va_fsid = dev2udev(node->udfmp->im_dev);
297 	vap->va_fileid = node->hash_id;
298 	vap->va_mode = udf_permtomode(node);
299 	vap->va_nlink = le16toh(fentry->link_cnt);
300 	/*
301 	 * XXX The spec says that -1 is valid for uid/gid and indicates an
302 	 * invalid uid/gid.  How should this be represented?
303 	 */
304 	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
305 	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
306 	udf_timetotimespec(&fentry->atime, &vap->va_atime);
307 	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
308 	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
309 	vap->va_rdev = NODEV;
310 	if (vp->v_type & VDIR) {
311 		/*
312 		 * Directories that are recorded within their ICB will show
313 		 * as having 0 blocks recorded.  Since tradition dictates
314 		 * that directories consume at least one logical block,
315 		 * make it appear so.
316 		 */
317 		if (fentry->logblks_rec != 0) {
318 			vap->va_size =
319 			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
320 		} else {
321 			vap->va_size = node->udfmp->bsize;
322 		}
323 	} else {
324 		vap->va_size = le64toh(fentry->inf_len);
325 	}
326 	vap->va_flags = 0;
327 	vap->va_gen = 1;
328 	vap->va_blocksize = node->udfmp->bsize;
329 	vap->va_bytes = le64toh(fentry->inf_len);
330 	vap->va_type = vp->v_type;
331 	vap->va_filerev = 0; /* XXX */
332 	return (0);
333 }
334 
335 static int
336 udf_setattr(struct vop_setattr_args *a)
337 {
338 	struct vnode *vp;
339 	struct vattr *vap;
340 
341 	vp = a->a_vp;
342 	vap = a->a_vap;
343 	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
344 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
345 	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
346 		return (EROFS);
347 	if (vap->va_size != (u_quad_t)VNOVAL) {
348 		switch (vp->v_type) {
349 		case VDIR:
350 			return (EISDIR);
351 		case VLNK:
352 		case VREG:
353 			return (EROFS);
354 		case VCHR:
355 		case VBLK:
356 		case VSOCK:
357 		case VFIFO:
358 		case VNON:
359 		case VBAD:
360 		case VMARKER:
361 			return (0);
362 		}
363 	}
364 	return (0);
365 }
366 
367 /*
368  * File specific ioctls.
369  */
370 static int
371 udf_ioctl(struct vop_ioctl_args *a)
372 {
373 	printf("%s called\n", __func__);
374 	return (ENOTTY);
375 }
376 
377 /*
378  * I'm not sure that this has much value in a read-only filesystem, but
379  * cd9660 has it too.
380  */
381 static int
382 udf_pathconf(struct vop_pathconf_args *a)
383 {
384 
385 	switch (a->a_name) {
386 	case _PC_LINK_MAX:
387 		*a->a_retval = 65535;
388 		return (0);
389 	case _PC_NAME_MAX:
390 		*a->a_retval = NAME_MAX;
391 		return (0);
392 	case _PC_PATH_MAX:
393 		*a->a_retval = PATH_MAX;
394 		return (0);
395 	case _PC_NO_TRUNC:
396 		*a->a_retval = 1;
397 		return (0);
398 	default:
399 		return (EINVAL);
400 	}
401 }
402 
403 static int
404 udf_print(struct vop_print_args *ap)
405 {
406 	struct vnode *vp = ap->a_vp;
407 	struct udf_node *node = VTON(vp);
408 
409 	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
410 	    devtoname(node->udfmp->im_dev));
411 	if (vp->v_type == VFIFO)
412 		fifo_printinfo(vp);
413 	printf("\n");
414 	return (0);
415 }
416 
417 #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
418 #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
419 #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
420 
421 static inline int
422 is_data_in_fentry(const struct udf_node *node)
423 {
424 	const struct file_entry *fentry = node->fentry;
425 
426 	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
427 }
428 
429 static int
430 udf_read(struct vop_read_args *ap)
431 {
432 	struct vnode *vp = ap->a_vp;
433 	struct uio *uio = ap->a_uio;
434 	struct udf_node *node = VTON(vp);
435 	struct udf_mnt *udfmp;
436 	struct file_entry *fentry;
437 	struct buf *bp;
438 	uint8_t *data;
439 	daddr_t lbn, rablock;
440 	off_t diff, fsize;
441 	ssize_t n;
442 	int error = 0;
443 	long size, on;
444 
445 	if (uio->uio_resid == 0)
446 		return (0);
447 	if (uio->uio_offset < 0)
448 		return (EINVAL);
449 
450 	if (is_data_in_fentry(node)) {
451 		fentry = node->fentry;
452 		data = &fentry->data[le32toh(fentry->l_ea)];
453 		fsize = le32toh(fentry->l_ad);
454 
455 		n = uio->uio_resid;
456 		diff = fsize - uio->uio_offset;
457 		if (diff <= 0)
458 			return (0);
459 		if (diff < n)
460 			n = diff;
461 		error = uiomove(data + uio->uio_offset, (int)n, uio);
462 		return (error);
463 	}
464 
465 	fsize = le64toh(node->fentry->inf_len);
466 	udfmp = node->udfmp;
467 	do {
468 		lbn = lblkno(udfmp, uio->uio_offset);
469 		on = blkoff(udfmp, uio->uio_offset);
470 		n = min((u_int)(udfmp->bsize - on),
471 			uio->uio_resid);
472 		diff = fsize - uio->uio_offset;
473 		if (diff <= 0)
474 			return (0);
475 		if (diff < n)
476 			n = diff;
477 		size = udfmp->bsize;
478 		rablock = lbn + 1;
479 		if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
480 			if (lblktosize(udfmp, rablock) < fsize) {
481 				error = cluster_read(vp, fsize, lbn, size,
482 				    NOCRED, uio->uio_resid,
483 				    (ap->a_ioflag >> 16), 0, &bp);
484 			} else {
485 				error = bread(vp, lbn, size, NOCRED, &bp);
486 			}
487 		} else {
488 			error = bread(vp, lbn, size, NOCRED, &bp);
489 		}
490 		n = min(n, size - bp->b_resid);
491 		if (error) {
492 			brelse(bp);
493 			return (error);
494 		}
495 
496 		error = uiomove(bp->b_data + on, (int)n, uio);
497 		brelse(bp);
498 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
499 	return (error);
500 }
501 
502 /*
503  * Call the OSTA routines to translate the name from a CS0 dstring to a
504  * 16-bit Unicode String.  Hooks need to be placed in here to translate from
505  * Unicode to the encoding that the kernel/user expects.  Return the length
506  * of the translated string.
507  */
508 static int
509 udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
510 {
511 	unicode_t *transname;
512 	char *unibuf, *unip;
513 	int i, destlen;
514 	ssize_t unilen = 0;
515 	size_t destleft = MAXNAMLEN;
516 
517 	/* Convert 16-bit Unicode to destname */
518 	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
519 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
520 		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
521 		unip = unibuf;
522 		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
523 			printf("udf: Unicode translation failed\n");
524 			uma_zfree(udf_zone_trans, unibuf);
525 			return 0;
526 		}
527 
528 		while (unilen > 0 && destleft > 0) {
529 			udf_iconv->conv(udfmp->im_d2l, __DECONST(const char **,
530 			    &unibuf), (size_t *)&unilen, (char **)&destname,
531 			    &destleft);
532 			/* Unconverted character found */
533 			if (unilen > 0 && destleft > 0) {
534 				*destname++ = '?';
535 				destleft--;
536 				unibuf += 2;
537 				unilen -= 2;
538 			}
539 		}
540 		uma_zfree(udf_zone_trans, unip);
541 		*destname = '\0';
542 		destlen = MAXNAMLEN - (int)destleft;
543 	} else {
544 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
545 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
546 
547 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
548 			printf("udf: Unicode translation failed\n");
549 			uma_zfree(udf_zone_trans, transname);
550 			return 0;
551 		}
552 
553 		for (i = 0; i < unilen ; i++) {
554 			if (transname[i] & 0xff00) {
555 				destname[i] = '.';	/* Fudge the 16bit chars */
556 			} else {
557 				destname[i] = transname[i] & 0xff;
558 			}
559 		}
560 		uma_zfree(udf_zone_trans, transname);
561 		destname[unilen] = 0;
562 		destlen = (int)unilen;
563 	}
564 
565 	return (destlen);
566 }
567 
568 /*
569  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
570  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
571  * here also.
572  */
573 static int
574 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
575 {
576 	char *transname;
577 	int error = 0;
578 
579 	/* This is overkill, but not worth creating a new zone */
580 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
581 
582 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
583 
584 	/* Easy check.  If they aren't the same length, they aren't equal */
585 	if ((cs0len == 0) || (cs0len != cmplen))
586 		error = -1;
587 	else
588 		error = bcmp(transname, cmpname, cmplen);
589 
590 	uma_zfree(udf_zone_trans, transname);
591 	return (error);
592 }
593 
594 struct udf_uiodir {
595 	struct dirent *dirent;
596 	u_long *cookies;
597 	int ncookies;
598 	int acookies;
599 	int eofflag;
600 };
601 
602 static int
603 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
604 {
605 	if (uiodir->cookies != NULL) {
606 		if (++uiodir->acookies > uiodir->ncookies) {
607 			uiodir->eofflag = 0;
608 			return (-1);
609 		}
610 		*uiodir->cookies++ = cookie;
611 	}
612 
613 	if (uio->uio_resid < de_size) {
614 		uiodir->eofflag = 0;
615 		return (-1);
616 	}
617 
618 	return (uiomove(uiodir->dirent, de_size, uio));
619 }
620 
621 static struct udf_dirstream *
622 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
623 {
624 	struct udf_dirstream *ds;
625 
626 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
627 
628 	ds->node = node;
629 	ds->offset = offset;
630 	ds->udfmp = udfmp;
631 	ds->fsize = fsize;
632 
633 	return (ds);
634 }
635 
636 static struct fileid_desc *
637 udf_getfid(struct udf_dirstream *ds)
638 {
639 	struct fileid_desc *fid;
640 	int error, frag_size = 0, total_fid_size;
641 
642 	/* End of directory? */
643 	if (ds->offset + ds->off >= ds->fsize) {
644 		ds->error = 0;
645 		return (NULL);
646 	}
647 
648 	/* Grab the first extent of the directory */
649 	if (ds->off == 0) {
650 		ds->size = 0;
651 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
652 		    &ds->bp, &ds->data);
653 		if (error) {
654 			ds->error = error;
655 			if (ds->bp != NULL)
656 				brelse(ds->bp);
657 			return (NULL);
658 		}
659 	}
660 
661 	/*
662 	 * Clean up from a previous fragmented FID.
663 	 * XXX Is this the right place for this?
664 	 */
665 	if (ds->fid_fragment && ds->buf != NULL) {
666 		ds->fid_fragment = 0;
667 		free(ds->buf, M_UDFFID);
668 	}
669 
670 	fid = (struct fileid_desc*)&ds->data[ds->off];
671 
672 	/*
673 	 * Check to see if the fid is fragmented. The first test
674 	 * ensures that we don't wander off the end of the buffer
675 	 * looking for the l_iu and l_fi fields.
676 	 */
677 	if (ds->off + UDF_FID_SIZE > ds->size ||
678 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
679 
680 		/* Copy what we have of the fid into a buffer */
681 		frag_size = ds->size - ds->off;
682 		if (frag_size >= ds->udfmp->bsize) {
683 			printf("udf: invalid FID fragment\n");
684 			ds->error = EINVAL;
685 			return (NULL);
686 		}
687 
688 		/*
689 		 * File ID descriptors can only be at most one
690 		 * logical sector in size.
691 		 */
692 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
693 		     M_WAITOK | M_ZERO);
694 		bcopy(fid, ds->buf, frag_size);
695 
696 		/* Reduce all of the casting magic */
697 		fid = (struct fileid_desc*)ds->buf;
698 
699 		if (ds->bp != NULL)
700 			brelse(ds->bp);
701 
702 		/* Fetch the next allocation */
703 		ds->offset += ds->size;
704 		ds->size = 0;
705 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
706 		    &ds->bp, &ds->data);
707 		if (error) {
708 			ds->error = error;
709 			return (NULL);
710 		}
711 
712 		/*
713 		 * If the fragment was so small that we didn't get
714 		 * the l_iu and l_fi fields, copy those in.
715 		 */
716 		if (frag_size < UDF_FID_SIZE)
717 			bcopy(ds->data, &ds->buf[frag_size],
718 			    UDF_FID_SIZE - frag_size);
719 
720 		/*
721 		 * Now that we have enough of the fid to work with,
722 		 * copy in the rest of the fid from the new
723 		 * allocation.
724 		 */
725 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
726 		if (total_fid_size > ds->udfmp->bsize) {
727 			printf("udf: invalid FID\n");
728 			ds->error = EIO;
729 			return (NULL);
730 		}
731 		bcopy(ds->data, &ds->buf[frag_size],
732 		    total_fid_size - frag_size);
733 
734 		ds->fid_fragment = 1;
735 	} else {
736 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
737 	}
738 
739 	/*
740 	 * Update the offset. Align on a 4 byte boundary because the
741 	 * UDF spec says so.
742 	 */
743 	ds->this_off = ds->offset + ds->off;
744 	if (!ds->fid_fragment) {
745 		ds->off += (total_fid_size + 3) & ~0x03;
746 	} else {
747 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
748 	}
749 
750 	return (fid);
751 }
752 
753 static void
754 udf_closedir(struct udf_dirstream *ds)
755 {
756 
757 	if (ds->bp != NULL)
758 		brelse(ds->bp);
759 
760 	if (ds->fid_fragment && ds->buf != NULL)
761 		free(ds->buf, M_UDFFID);
762 
763 	uma_zfree(udf_zone_ds, ds);
764 }
765 
766 static int
767 udf_readdir(struct vop_readdir_args *a)
768 {
769 	struct vnode *vp;
770 	struct uio *uio;
771 	struct dirent dir;
772 	struct udf_node *node;
773 	struct udf_mnt *udfmp;
774 	struct fileid_desc *fid;
775 	struct udf_uiodir uiodir;
776 	struct udf_dirstream *ds;
777 	u_long *cookies = NULL;
778 	int ncookies;
779 	int error = 0;
780 
781 	vp = a->a_vp;
782 	uio = a->a_uio;
783 	node = VTON(vp);
784 	udfmp = node->udfmp;
785 	uiodir.eofflag = 1;
786 
787 	if (a->a_ncookies != NULL) {
788 		/*
789 		 * Guess how many entries are needed.  If we run out, this
790 		 * function will be called again and thing will pick up were
791 		 * it left off.
792 		 */
793 		ncookies = uio->uio_resid / 8;
794 		cookies = malloc(sizeof(u_long) * ncookies,
795 		    M_TEMP, M_WAITOK);
796 		if (cookies == NULL)
797 			return (ENOMEM);
798 		uiodir.ncookies = ncookies;
799 		uiodir.cookies = cookies;
800 		uiodir.acookies = 0;
801 	} else {
802 		uiodir.cookies = NULL;
803 	}
804 
805 	/*
806 	 * Iterate through the file id descriptors.  Give the parent dir
807 	 * entry special attention.
808 	 */
809 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
810 	    node->udfmp);
811 
812 	while ((fid = udf_getfid(ds)) != NULL) {
813 
814 		/* XXX Should we return an error on a bad fid? */
815 		if (udf_checktag(&fid->tag, TAGID_FID)) {
816 			printf("Invalid FID tag\n");
817 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
818 			error = EIO;
819 			break;
820 		}
821 
822 		/* Is this a deleted file? */
823 		if (fid->file_char & UDF_FILE_CHAR_DEL)
824 			continue;
825 
826 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
827 			/* Do up the '.' and '..' entries.  Dummy values are
828 			 * used for the cookies since the offset here is
829 			 * usually zero, and NFS doesn't like that value
830 			 */
831 			dir.d_fileno = node->hash_id;
832 			dir.d_type = DT_DIR;
833 			dir.d_name[0] = '.';
834 			dir.d_name[1] = '\0';
835 			dir.d_namlen = 1;
836 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
837 			uiodir.dirent = &dir;
838 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
839 			if (error)
840 				break;
841 
842 			dir.d_fileno = udf_getid(&fid->icb);
843 			dir.d_type = DT_DIR;
844 			dir.d_name[0] = '.';
845 			dir.d_name[1] = '.';
846 			dir.d_name[2] = '\0';
847 			dir.d_namlen = 2;
848 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
849 			uiodir.dirent = &dir;
850 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
851 		} else {
852 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
853 			    &dir.d_name[0], fid->l_fi, udfmp);
854 			dir.d_fileno = udf_getid(&fid->icb);
855 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
856 			    DT_DIR : DT_UNKNOWN;
857 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
858 			uiodir.dirent = &dir;
859 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
860 			    ds->this_off);
861 		}
862 		if (error)
863 			break;
864 		uio->uio_offset = ds->offset + ds->off;
865 	}
866 
867 	/* tell the calling layer whether we need to be called again */
868 	*a->a_eofflag = uiodir.eofflag;
869 
870 	if (error < 0)
871 		error = 0;
872 	if (!error)
873 		error = ds->error;
874 
875 	udf_closedir(ds);
876 
877 	if (a->a_ncookies != NULL) {
878 		if (error)
879 			free(cookies, M_TEMP);
880 		else {
881 			*a->a_ncookies = uiodir.acookies;
882 			*a->a_cookies = cookies;
883 		}
884 	}
885 
886 	return (error);
887 }
888 
889 static int
890 udf_readlink(struct vop_readlink_args *ap)
891 {
892 	struct path_component *pc, *end;
893 	struct vnode *vp;
894 	struct uio uio;
895 	struct iovec iov[1];
896 	struct udf_node *node;
897 	void *buf;
898 	char *cp;
899 	int error, len, root;
900 
901 	/*
902 	 * A symbolic link in UDF is a list of variable-length path
903 	 * component structures.  We build a pathname in the caller's
904 	 * uio by traversing this list.
905 	 */
906 	vp = ap->a_vp;
907 	node = VTON(vp);
908 	len = le64toh(node->fentry->inf_len);
909 	buf = malloc(len, M_DEVBUF, M_WAITOK);
910 	iov[0].iov_len = len;
911 	iov[0].iov_base = buf;
912 	uio.uio_iov = iov;
913 	uio.uio_iovcnt = 1;
914 	uio.uio_offset = 0;
915 	uio.uio_resid = iov[0].iov_len;
916 	uio.uio_segflg = UIO_SYSSPACE;
917 	uio.uio_rw = UIO_READ;
918 	uio.uio_td = curthread;
919 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
920 	if (error)
921 		goto error;
922 
923 	pc = buf;
924 	end = (void *)((char *)buf + len);
925 	root = 0;
926 	while (pc < end) {
927 		switch (pc->type) {
928 		case UDF_PATH_ROOT:
929 			/* Only allow this at the beginning of a path. */
930 			if ((void *)pc != buf) {
931 				error = EINVAL;
932 				goto error;
933 			}
934 			cp = "/";
935 			len = 1;
936 			root = 1;
937 			break;
938 		case UDF_PATH_DOT:
939 			cp = ".";
940 			len = 1;
941 			break;
942 		case UDF_PATH_DOTDOT:
943 			cp = "..";
944 			len = 2;
945 			break;
946 		case UDF_PATH_PATH:
947 			if (pc->length == 0) {
948 				error = EINVAL;
949 				goto error;
950 			}
951 			/*
952 			 * XXX: We only support CS8 which appears to map
953 			 * to ASCII directly.
954 			 */
955 			switch (pc->identifier[0]) {
956 			case 8:
957 				cp = pc->identifier + 1;
958 				len = pc->length - 1;
959 				break;
960 			default:
961 				error = EOPNOTSUPP;
962 				goto error;
963 			}
964 			break;
965 		default:
966 			error = EINVAL;
967 			goto error;
968 		}
969 
970 		/*
971 		 * If this is not the first component, insert a path
972 		 * separator.
973 		 */
974 		if (pc != buf) {
975 			/* If we started with root we already have a "/". */
976 			if (root)
977 				goto skipslash;
978 			root = 0;
979 			if (ap->a_uio->uio_resid < 1) {
980 				error = ENAMETOOLONG;
981 				goto error;
982 			}
983 			error = uiomove("/", 1, ap->a_uio);
984 			if (error)
985 				break;
986 		}
987 	skipslash:
988 
989 		/* Append string at 'cp' of length 'len' to our path. */
990 		if (len > ap->a_uio->uio_resid) {
991 			error = ENAMETOOLONG;
992 			goto error;
993 		}
994 		error = uiomove(cp, len, ap->a_uio);
995 		if (error)
996 			break;
997 
998 		/* Advance to next component. */
999 		pc = (void *)((char *)pc + 4 + pc->length);
1000 	}
1001 error:
1002 	free(buf, M_DEVBUF);
1003 	return (error);
1004 }
1005 
1006 static int
1007 udf_strategy(struct vop_strategy_args *a)
1008 {
1009 	struct buf *bp;
1010 	struct vnode *vp;
1011 	struct udf_node *node;
1012 	struct bufobj *bo;
1013 	off_t offset;
1014 	uint32_t maxsize;
1015 	daddr_t sector;
1016 	int error;
1017 
1018 	bp = a->a_bp;
1019 	vp = a->a_vp;
1020 	node = VTON(vp);
1021 
1022 	if (bp->b_blkno == bp->b_lblkno) {
1023 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1024 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1025 		if (error) {
1026 			clrbuf(bp);
1027 			bp->b_blkno = -1;
1028 			bufdone(bp);
1029 			return (0);
1030 		}
1031 		/* bmap gives sector numbers, bio works with device blocks */
1032 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1033 	}
1034 	bo = node->udfmp->im_bo;
1035 	bp->b_iooffset = dbtob(bp->b_blkno);
1036 	BO_STRATEGY(bo, bp);
1037 	return (0);
1038 }
1039 
1040 static int
1041 udf_bmap(struct vop_bmap_args *a)
1042 {
1043 	struct udf_node *node;
1044 	uint32_t max_size;
1045 	daddr_t lsector;
1046 	int nblk;
1047 	int error;
1048 
1049 	node = VTON(a->a_vp);
1050 
1051 	if (a->a_bop != NULL)
1052 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1053 	if (a->a_bnp == NULL)
1054 		return (0);
1055 	if (a->a_runb)
1056 		*a->a_runb = 0;
1057 
1058 	/*
1059 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1060 	 * error that should not be propagated to calling code.
1061 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1062 	 * translate block numbers in this case.
1063 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1064 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1065 	 * thing for this kind of files.
1066 	 */
1067 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1068 	    &lsector, &max_size);
1069 	if (error == UDF_INVALID_BMAP)
1070 		return (EOPNOTSUPP);
1071 	if (error)
1072 		return (error);
1073 
1074 	/* Translate logical to physical sector number */
1075 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1076 
1077 	/*
1078 	 * Determine maximum number of readahead blocks following the
1079 	 * requested block.
1080 	 */
1081 	if (a->a_runp) {
1082 		nblk = (max_size >> node->udfmp->bshift) - 1;
1083 		if (nblk <= 0)
1084 			*a->a_runp = 0;
1085 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1086 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1087 		else
1088 			*a->a_runp = nblk;
1089 	}
1090 
1091 	if (a->a_runb) {
1092 		*a->a_runb = 0;
1093 	}
1094 
1095 	return (0);
1096 }
1097 
1098 /*
1099  * The all powerful VOP_LOOKUP().
1100  */
1101 static int
1102 udf_lookup(struct vop_cachedlookup_args *a)
1103 {
1104 	struct vnode *dvp;
1105 	struct vnode *tdp = NULL;
1106 	struct vnode **vpp = a->a_vpp;
1107 	struct udf_node *node;
1108 	struct udf_mnt *udfmp;
1109 	struct fileid_desc *fid = NULL;
1110 	struct udf_dirstream *ds;
1111 	u_long nameiop;
1112 	u_long flags;
1113 	char *nameptr;
1114 	long namelen;
1115 	ino_t id = 0;
1116 	int offset, error = 0;
1117 	int fsize, lkflags, ltype, numdirpasses;
1118 
1119 	dvp = a->a_dvp;
1120 	node = VTON(dvp);
1121 	udfmp = node->udfmp;
1122 	nameiop = a->a_cnp->cn_nameiop;
1123 	flags = a->a_cnp->cn_flags;
1124 	lkflags = a->a_cnp->cn_lkflags;
1125 	nameptr = a->a_cnp->cn_nameptr;
1126 	namelen = a->a_cnp->cn_namelen;
1127 	fsize = le64toh(node->fentry->inf_len);
1128 
1129 	/*
1130 	 * If this is a LOOKUP and we've already partially searched through
1131 	 * the directory, pick up where we left off and flag that the
1132 	 * directory may need to be searched twice.  For a full description,
1133 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1134 	 */
1135 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1136 		offset = 0;
1137 		numdirpasses = 1;
1138 	} else {
1139 		offset = node->diroff;
1140 		numdirpasses = 2;
1141 		nchstats.ncs_2passes++;
1142 	}
1143 
1144 lookloop:
1145 	ds = udf_opendir(node, offset, fsize, udfmp);
1146 
1147 	while ((fid = udf_getfid(ds)) != NULL) {
1148 
1149 		/* XXX Should we return an error on a bad fid? */
1150 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1151 			printf("udf_lookup: Invalid tag\n");
1152 			error = EIO;
1153 			break;
1154 		}
1155 
1156 		/* Is this a deleted file? */
1157 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1158 			continue;
1159 
1160 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1161 			if (flags & ISDOTDOT) {
1162 				id = udf_getid(&fid->icb);
1163 				break;
1164 			}
1165 		} else {
1166 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1167 			    nameptr, fid->l_fi, namelen, udfmp))) {
1168 				id = udf_getid(&fid->icb);
1169 				break;
1170 			}
1171 		}
1172 	}
1173 
1174 	if (!error)
1175 		error = ds->error;
1176 
1177 	/* XXX Bail out here? */
1178 	if (error) {
1179 		udf_closedir(ds);
1180 		return (error);
1181 	}
1182 
1183 	/* Did we have a match? */
1184 	if (id) {
1185 		/*
1186 		 * Remember where this entry was if it's the final
1187 		 * component.
1188 		 */
1189 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1190 			node->diroff = ds->offset + ds->off;
1191 		if (numdirpasses == 2)
1192 			nchstats.ncs_pass2++;
1193 		udf_closedir(ds);
1194 
1195 		if (flags & ISDOTDOT) {
1196 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1197 		} else if (node->hash_id == id) {
1198 			VREF(dvp);	/* we want ourself, ie "." */
1199 			/*
1200 			 * When we lookup "." we still can be asked to lock it
1201 			 * differently.
1202 			 */
1203 			ltype = lkflags & LK_TYPE_MASK;
1204 			if (ltype != VOP_ISLOCKED(dvp)) {
1205 				if (ltype == LK_EXCLUSIVE)
1206 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1207 				else /* if (ltype == LK_SHARED) */
1208 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1209 			}
1210 			tdp = dvp;
1211 		} else
1212 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1213 		if (!error) {
1214 			*vpp = tdp;
1215 			/* Put this entry in the cache */
1216 			if (flags & MAKEENTRY)
1217 				cache_enter(dvp, *vpp, a->a_cnp);
1218 		}
1219 	} else {
1220 		/* Name wasn't found on this pass.  Do another pass? */
1221 		if (numdirpasses == 2) {
1222 			numdirpasses--;
1223 			offset = 0;
1224 			udf_closedir(ds);
1225 			goto lookloop;
1226 		}
1227 		udf_closedir(ds);
1228 
1229 		/* Enter name into cache as non-existant */
1230 		if (flags & MAKEENTRY)
1231 			cache_enter(dvp, *vpp, a->a_cnp);
1232 
1233 		if ((flags & ISLASTCN) &&
1234 		    (nameiop == CREATE || nameiop == RENAME)) {
1235 			error = EROFS;
1236 		} else {
1237 			error = ENOENT;
1238 		}
1239 	}
1240 
1241 	return (error);
1242 }
1243 
1244 static int
1245 udf_reclaim(struct vop_reclaim_args *a)
1246 {
1247 	struct vnode *vp;
1248 	struct udf_node *unode;
1249 
1250 	vp = a->a_vp;
1251 	unode = VTON(vp);
1252 
1253 	/*
1254 	 * Destroy the vm object and flush associated pages.
1255 	 */
1256 	vnode_destroy_vobject(vp);
1257 
1258 	if (unode != NULL) {
1259 		vfs_hash_remove(vp);
1260 
1261 		if (unode->fentry != NULL)
1262 			free(unode->fentry, M_UDFFENTRY);
1263 		uma_zfree(udf_zone_node, unode);
1264 		vp->v_data = NULL;
1265 	}
1266 
1267 	return (0);
1268 }
1269 
1270 static int
1271 udf_vptofh(struct vop_vptofh_args *a)
1272 {
1273 	struct udf_node *node;
1274 	struct ifid *ifhp;
1275 
1276 	node = VTON(a->a_vp);
1277 	ifhp = (struct ifid *)a->a_fhp;
1278 	ifhp->ifid_len = sizeof(struct ifid);
1279 	ifhp->ifid_ino = node->hash_id;
1280 
1281 	return (0);
1282 }
1283 
1284 /*
1285  * Read the block and then set the data pointer to correspond with the
1286  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1287  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1288  * whole extent.
1289  *
1290  * Note that *bp may be assigned error or not.
1291  *
1292  */
1293 static int
1294 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1295     struct buf **bp, uint8_t **data)
1296 {
1297 	struct udf_mnt *udfmp = node->udfmp;
1298 	struct vnode *vp = node->i_vnode;
1299 	struct file_entry *fentry;
1300 	struct buf *bp1;
1301 	uint32_t max_size;
1302 	daddr_t sector;
1303 	off_t off;
1304 	int adj_size;
1305 	int error;
1306 
1307 	/*
1308 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1309 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1310 	 */
1311 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1312 	if (error == UDF_INVALID_BMAP) {
1313 		/*
1314 		 * This error means that the file *data* is stored in the
1315 		 * allocation descriptor field of the file entry.
1316 		 */
1317 		fentry = node->fentry;
1318 		*data = &fentry->data[le32toh(fentry->l_ea)];
1319 		*size = le32toh(fentry->l_ad);
1320 		if (offset >= *size)
1321 			*size = 0;
1322 		else {
1323 			*data += offset;
1324 			*size -= offset;
1325 		}
1326 		return (0);
1327 	} else if (error != 0) {
1328 		return (error);
1329 	}
1330 
1331 	/* Adjust the size so that it is within range */
1332 	if (*size == 0 || *size > max_size)
1333 		*size = max_size;
1334 
1335 	/*
1336 	 * Because we will read starting at block boundary, we need to adjust
1337 	 * how much we need to read so that all promised data is in.
1338 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1339 	 * from block boundary, so adjust what we promise too.
1340 	 */
1341 	off = blkoff(udfmp, offset);
1342 	*size = min(*size, MAXBSIZE - off);
1343 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1344 	*bp = NULL;
1345 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1346 		printf("warning: udf_readlblks returned error %d\n", error);
1347 		/* note: *bp may be non-NULL */
1348 		return (error);
1349 	}
1350 
1351 	bp1 = *bp;
1352 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1353 	return (0);
1354 }
1355 
1356 /*
1357  * Translate a file offset into a logical block and then into a physical
1358  * block.
1359  * max_size - maximum number of bytes that can be read starting from given
1360  * offset, rather than beginning of calculated sector number
1361  */
1362 static int
1363 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1364     uint32_t *max_size)
1365 {
1366 	struct udf_mnt *udfmp;
1367 	struct file_entry *fentry;
1368 	void *icb;
1369 	struct icb_tag *tag;
1370 	uint32_t icblen = 0;
1371 	daddr_t lsector;
1372 	int ad_offset, ad_num = 0;
1373 	int i, p_offset;
1374 
1375 	udfmp = node->udfmp;
1376 	fentry = node->fentry;
1377 	tag = &fentry->icbtag;
1378 
1379 	switch (le16toh(tag->strat_type)) {
1380 	case 4:
1381 		break;
1382 
1383 	case 4096:
1384 		printf("Cannot deal with strategy4096 yet!\n");
1385 		return (ENODEV);
1386 
1387 	default:
1388 		printf("Unknown strategy type %d\n", tag->strat_type);
1389 		return (ENODEV);
1390 	}
1391 
1392 	switch (le16toh(tag->flags) & 0x7) {
1393 	case 0:
1394 		/*
1395 		 * The allocation descriptor field is filled with short_ad's.
1396 		 * If the offset is beyond the current extent, look for the
1397 		 * next extent.
1398 		 */
1399 		do {
1400 			offset -= icblen;
1401 			ad_offset = sizeof(struct short_ad) * ad_num;
1402 			if (ad_offset > le32toh(fentry->l_ad)) {
1403 				printf("File offset out of bounds\n");
1404 				return (EINVAL);
1405 			}
1406 			icb = GETICB(short_ad, fentry,
1407 			    le32toh(fentry->l_ea) + ad_offset);
1408 			icblen = GETICBLEN(short_ad, icb);
1409 			ad_num++;
1410 		} while(offset >= icblen);
1411 
1412 		lsector = (offset  >> udfmp->bshift) +
1413 		    le32toh(((struct short_ad *)(icb))->pos);
1414 
1415 		*max_size = icblen - offset;
1416 
1417 		break;
1418 	case 1:
1419 		/*
1420 		 * The allocation descriptor field is filled with long_ad's
1421 		 * If the offset is beyond the current extent, look for the
1422 		 * next extent.
1423 		 */
1424 		do {
1425 			offset -= icblen;
1426 			ad_offset = sizeof(struct long_ad) * ad_num;
1427 			if (ad_offset > le32toh(fentry->l_ad)) {
1428 				printf("File offset out of bounds\n");
1429 				return (EINVAL);
1430 			}
1431 			icb = GETICB(long_ad, fentry,
1432 			    le32toh(fentry->l_ea) + ad_offset);
1433 			icblen = GETICBLEN(long_ad, icb);
1434 			ad_num++;
1435 		} while(offset >= icblen);
1436 
1437 		lsector = (offset >> udfmp->bshift) +
1438 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1439 
1440 		*max_size = icblen - offset;
1441 
1442 		break;
1443 	case 3:
1444 		/*
1445 		 * This type means that the file *data* is stored in the
1446 		 * allocation descriptor field of the file entry.
1447 		 */
1448 		*max_size = 0;
1449 		*sector = node->hash_id + udfmp->part_start;
1450 
1451 		return (UDF_INVALID_BMAP);
1452 	case 2:
1453 		/* DirectCD does not use extended_ad's */
1454 	default:
1455 		printf("Unsupported allocation descriptor %d\n",
1456 		       tag->flags & 0x7);
1457 		return (ENODEV);
1458 	}
1459 
1460 	*sector = lsector + udfmp->part_start;
1461 
1462 	/*
1463 	 * Check the sparing table.  Each entry represents the beginning of
1464 	 * a packet.
1465 	 */
1466 	if (udfmp->s_table != NULL) {
1467 		for (i = 0; i< udfmp->s_table_entries; i++) {
1468 			p_offset =
1469 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1470 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1471 				*sector =
1472 				   le32toh(udfmp->s_table->entries[i].map) +
1473 				    p_offset;
1474 				break;
1475 			}
1476 		}
1477 	}
1478 
1479 	return (0);
1480 }
1481