xref: /freebsd/sys/fs/udf/udf_vnops.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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/fifofs/fifo.h>
52 #include <fs/udf/ecma167-udf.h>
53 #include <fs/udf/osta.h>
54 #include <fs/udf/udf.h>
55 #include <fs/udf/udf_mount.h>
56 
57 extern struct iconv_functions *udf_iconv;
58 
59 static vop_access_t	udf_access;
60 static vop_getattr_t	udf_getattr;
61 static vop_open_t	udf_open;
62 static vop_ioctl_t	udf_ioctl;
63 static vop_pathconf_t	udf_pathconf;
64 static vop_print_t	udf_print;
65 static vop_read_t	udf_read;
66 static vop_readdir_t	udf_readdir;
67 static vop_readlink_t	udf_readlink;
68 static vop_setattr_t	udf_setattr;
69 static vop_strategy_t	udf_strategy;
70 static vop_bmap_t	udf_bmap;
71 static vop_cachedlookup_t	udf_lookup;
72 static vop_reclaim_t	udf_reclaim;
73 static vop_vptofh_t	udf_vptofh;
74 static int udf_readatoffset(struct udf_node *node, int *size, off_t offset,
75     struct buf **bp, uint8_t **data);
76 static int udf_bmap_internal(struct udf_node *node, off_t offset,
77     daddr_t *sector, uint32_t *max_size);
78 
79 static struct vop_vector udf_vnodeops = {
80 	.vop_default =		&default_vnodeops,
81 
82 	.vop_access =		udf_access,
83 	.vop_bmap =		udf_bmap,
84 	.vop_cachedlookup =	udf_lookup,
85 	.vop_getattr =		udf_getattr,
86 	.vop_ioctl =		udf_ioctl,
87 	.vop_lookup =		vfs_cache_lookup,
88 	.vop_open =		udf_open,
89 	.vop_pathconf =		udf_pathconf,
90 	.vop_print =		udf_print,
91 	.vop_read =		udf_read,
92 	.vop_readdir =		udf_readdir,
93 	.vop_readlink =		udf_readlink,
94 	.vop_reclaim =		udf_reclaim,
95 	.vop_setattr =		udf_setattr,
96 	.vop_strategy =		udf_strategy,
97 	.vop_vptofh =		udf_vptofh,
98 };
99 
100 struct vop_vector udf_fifoops = {
101 	.vop_default =		&fifo_specops,
102 	.vop_access =		udf_access,
103 	.vop_getattr =		udf_getattr,
104 	.vop_print =		udf_print,
105 	.vop_reclaim =		udf_reclaim,
106 	.vop_setattr =		udf_setattr,
107 	.vop_vptofh =		udf_vptofh,
108 };
109 
110 MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
111 MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");
112 
113 #define UDF_INVALID_BMAP	-1
114 
115 int
116 udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
117 {
118 	int error;
119 	struct vnode *vp;
120 
121 	error = getnewvnode("udf", mp, &udf_vnodeops, &vp);
122 	if (error) {
123 		printf("udf_allocv: failed to allocate new vnode\n");
124 		return (error);
125 	}
126 
127 	*vpp = vp;
128 	return (0);
129 }
130 
131 /* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
132 static mode_t
133 udf_permtomode(struct udf_node *node)
134 {
135 	uint32_t perm;
136 	uint16_t flags;
137 	mode_t mode;
138 
139 	perm = le32toh(node->fentry->perm);
140 	flags = le16toh(node->fentry->icbtag.flags);
141 
142 	mode = perm & UDF_FENTRY_PERM_USER_MASK;
143 	mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
144 	mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
145 	mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
146 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
147 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);
148 
149 	return (mode);
150 }
151 
152 static int
153 udf_access(struct vop_access_args *a)
154 {
155 	struct vnode *vp;
156 	struct udf_node *node;
157 	accmode_t accmode;
158 	mode_t mode;
159 
160 	vp = a->a_vp;
161 	node = VTON(vp);
162 	accmode = a->a_accmode;
163 
164 	if (accmode & VWRITE) {
165 		switch (vp->v_type) {
166 		case VDIR:
167 		case VLNK:
168 		case VREG:
169 			return (EROFS);
170 			/* NOT REACHED */
171 		default:
172 			break;
173 		}
174 	}
175 
176 	mode = udf_permtomode(node);
177 
178 	return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
179 	    accmode, a->a_cred, NULL));
180 }
181 
182 static int
183 udf_open(struct vop_open_args *ap) {
184 	struct udf_node *np = VTON(ap->a_vp);
185 	off_t fsize;
186 
187 	fsize = le64toh(np->fentry->inf_len);
188 	vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
189 	return 0;
190 }
191 
192 static const int mon_lens[2][12] = {
193 	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
194 	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
195 };
196 
197 static int
198 udf_isaleapyear(int year)
199 {
200 	int i;
201 
202 	i = (year % 4) ? 0 : 1;
203 	i &= (year % 100) ? 1 : 0;
204 	i |= (year % 400) ? 0 : 1;
205 
206 	return i;
207 }
208 
209 /*
210  * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
211  */
212 static void
213 udf_timetotimespec(struct timestamp *time, struct timespec *t)
214 {
215 	int i, lpyear, daysinyear, year, startyear;
216 	union {
217 		uint16_t	u_tz_offset;
218 		int16_t		s_tz_offset;
219 	} tz;
220 
221 	/*
222 	 * DirectCD seems to like using bogus year values.
223 	 * Don't trust time->month as it will be used for an array index.
224 	 */
225 	year = le16toh(time->year);
226 	if (year < 1970 || time->month < 1 || time->month > 12) {
227 		t->tv_sec = 0;
228 		t->tv_nsec = 0;
229 		return;
230 	}
231 
232 	/* Calculate the time and day */
233 	t->tv_sec = time->second;
234 	t->tv_sec += time->minute * 60;
235 	t->tv_sec += time->hour * 3600;
236 	t->tv_sec += (time->day - 1) * 3600 * 24;
237 
238 	/* Calculate the month */
239 	lpyear = udf_isaleapyear(year);
240 	t->tv_sec += mon_lens[lpyear][time->month - 1] * 3600 * 24;
241 
242 	/* Speed up the calculation */
243 	startyear = 1970;
244 	if (year > 2009) {
245 		t->tv_sec += 1262304000;
246 		startyear += 40;
247 	} else if (year > 1999) {
248 		t->tv_sec += 946684800;
249 		startyear += 30;
250 	} else if (year > 1989) {
251 		t->tv_sec += 631152000;
252 		startyear += 20;
253 	} else if (year > 1979) {
254 		t->tv_sec += 315532800;
255 		startyear += 10;
256 	}
257 
258 	daysinyear = (year - startyear) * 365;
259 	for (i = startyear; i < year; i++)
260 		daysinyear += udf_isaleapyear(i);
261 	t->tv_sec += daysinyear * 3600 * 24;
262 
263 	/* Calculate microseconds */
264 	t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
265 	    time->usec;
266 
267 	/*
268 	 * Calculate the time zone.  The timezone is 12 bit signed 2's
269 	 * complement, so we gotta do some extra magic to handle it right.
270 	 */
271 	tz.u_tz_offset = le16toh(time->type_tz);
272 	tz.u_tz_offset &= 0x0fff;
273 	if (tz.u_tz_offset & 0x0800)
274 		tz.u_tz_offset |= 0xf000;	/* extend the sign to 16 bits */
275 	if ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
276 		t->tv_sec -= tz.s_tz_offset * 60;
277 
278 	return;
279 }
280 
281 static int
282 udf_getattr(struct vop_getattr_args *a)
283 {
284 	struct vnode *vp;
285 	struct udf_node *node;
286 	struct vattr *vap;
287 	struct file_entry *fentry;
288 	struct timespec ts;
289 
290 	ts.tv_sec = 0;
291 
292 	vp = a->a_vp;
293 	vap = a->a_vap;
294 	node = VTON(vp);
295 	fentry = node->fentry;
296 
297 	vap->va_fsid = dev2udev(node->udfmp->im_dev);
298 	vap->va_fileid = node->hash_id;
299 	vap->va_mode = udf_permtomode(node);
300 	vap->va_nlink = le16toh(fentry->link_cnt);
301 	/*
302 	 * XXX The spec says that -1 is valid for uid/gid and indicates an
303 	 * invalid uid/gid.  How should this be represented?
304 	 */
305 	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
306 	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
307 	udf_timetotimespec(&fentry->atime, &vap->va_atime);
308 	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
309 	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
310 	vap->va_rdev = NODEV;
311 	if (vp->v_type & VDIR) {
312 		/*
313 		 * Directories that are recorded within their ICB will show
314 		 * as having 0 blocks recorded.  Since tradition dictates
315 		 * that directories consume at least one logical block,
316 		 * make it appear so.
317 		 */
318 		if (fentry->logblks_rec != 0) {
319 			vap->va_size =
320 			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
321 		} else {
322 			vap->va_size = node->udfmp->bsize;
323 		}
324 	} else {
325 		vap->va_size = le64toh(fentry->inf_len);
326 	}
327 	vap->va_flags = 0;
328 	vap->va_gen = 1;
329 	vap->va_blocksize = node->udfmp->bsize;
330 	vap->va_bytes = le64toh(fentry->inf_len);
331 	vap->va_type = vp->v_type;
332 	vap->va_filerev = 0; /* XXX */
333 	return (0);
334 }
335 
336 static int
337 udf_setattr(struct vop_setattr_args *a)
338 {
339 	struct vnode *vp;
340 	struct vattr *vap;
341 
342 	vp = a->a_vp;
343 	vap = a->a_vap;
344 	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
345 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
346 	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
347 		return (EROFS);
348 	if (vap->va_size != (u_quad_t)VNOVAL) {
349 		switch (vp->v_type) {
350 		case VDIR:
351 			return (EISDIR);
352 		case VLNK:
353 		case VREG:
354 			return (EROFS);
355 		case VCHR:
356 		case VBLK:
357 		case VSOCK:
358 		case VFIFO:
359 		case VNON:
360 		case VBAD:
361 		case VMARKER:
362 			return (0);
363 		}
364 	}
365 	return (0);
366 }
367 
368 /*
369  * File specific ioctls.
370  */
371 static int
372 udf_ioctl(struct vop_ioctl_args *a)
373 {
374 	printf("%s called\n", __func__);
375 	return (ENOTTY);
376 }
377 
378 /*
379  * I'm not sure that this has much value in a read-only filesystem, but
380  * cd9660 has it too.
381  */
382 static int
383 udf_pathconf(struct vop_pathconf_args *a)
384 {
385 
386 	switch (a->a_name) {
387 	case _PC_LINK_MAX:
388 		*a->a_retval = 65535;
389 		return (0);
390 	case _PC_NAME_MAX:
391 		*a->a_retval = NAME_MAX;
392 		return (0);
393 	case _PC_PATH_MAX:
394 		*a->a_retval = PATH_MAX;
395 		return (0);
396 	case _PC_NO_TRUNC:
397 		*a->a_retval = 1;
398 		return (0);
399 	default:
400 		return (EINVAL);
401 	}
402 }
403 
404 static int
405 udf_print(struct vop_print_args *ap)
406 {
407 	struct vnode *vp = ap->a_vp;
408 	struct udf_node *node = VTON(vp);
409 
410 	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
411 	    devtoname(node->udfmp->im_dev));
412 	if (vp->v_type == VFIFO)
413 		fifo_printinfo(vp);
414 	printf("\n");
415 	return (0);
416 }
417 
418 #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
419 #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
420 #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
421 
422 static inline int
423 is_data_in_fentry(const struct udf_node *node)
424 {
425 	const struct file_entry *fentry = node->fentry;
426 
427 	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
428 }
429 
430 static int
431 udf_read(struct vop_read_args *ap)
432 {
433 	struct vnode *vp = ap->a_vp;
434 	struct uio *uio = ap->a_uio;
435 	struct udf_node *node = VTON(vp);
436 	struct udf_mnt *udfmp;
437 	struct file_entry *fentry;
438 	struct buf *bp;
439 	uint8_t *data;
440 	daddr_t lbn, rablock;
441 	off_t diff, fsize;
442 	int error = 0;
443 	long size, n, 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, NOCRED,
482 					uio->uio_resid, (ap->a_ioflag >> 16), &bp);
483 			} else {
484 				error = bread(vp, lbn, size, NOCRED, &bp);
485 			}
486 		} else {
487 			error = bread(vp, lbn, size, NOCRED, &bp);
488 		}
489 		n = min(n, size - bp->b_resid);
490 		if (error) {
491 			brelse(bp);
492 			return (error);
493 		}
494 
495 		error = uiomove(bp->b_data + on, (int)n, uio);
496 		brelse(bp);
497 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
498 	return (error);
499 }
500 
501 /*
502  * Call the OSTA routines to translate the name from a CS0 dstring to a
503  * 16-bit Unicode String.  Hooks need to be placed in here to translate from
504  * Unicode to the encoding that the kernel/user expects.  Return the length
505  * of the translated string.
506  */
507 static int
508 udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
509 {
510 	unicode_t *transname;
511 	char *unibuf, *unip;
512 	int i, destlen;
513 	ssize_t unilen = 0;
514 	size_t destleft = MAXNAMLEN;
515 
516 	/* Convert 16-bit Unicode to destname */
517 	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
518 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
519 		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
520 		unip = unibuf;
521 		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
522 			printf("udf: Unicode translation failed\n");
523 			uma_zfree(udf_zone_trans, unibuf);
524 			return 0;
525 		}
526 
527 		while (unilen > 0 && destleft > 0) {
528 			udf_iconv->conv(udfmp->im_d2l, (const char **)&unibuf,
529 				(size_t *)&unilen, (char **)&destname, &destleft);
530 			/* Unconverted character found */
531 			if (unilen > 0 && destleft > 0) {
532 				*destname++ = '?';
533 				destleft--;
534 				unibuf += 2;
535 				unilen -= 2;
536 			}
537 		}
538 		uma_zfree(udf_zone_trans, unip);
539 		*destname = '\0';
540 		destlen = MAXNAMLEN - (int)destleft;
541 	} else {
542 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
543 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
544 
545 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
546 			printf("udf: Unicode translation failed\n");
547 			uma_zfree(udf_zone_trans, transname);
548 			return 0;
549 		}
550 
551 		for (i = 0; i < unilen ; i++) {
552 			if (transname[i] & 0xff00) {
553 				destname[i] = '.';	/* Fudge the 16bit chars */
554 			} else {
555 				destname[i] = transname[i] & 0xff;
556 			}
557 		}
558 		uma_zfree(udf_zone_trans, transname);
559 		destname[unilen] = 0;
560 		destlen = (int)unilen;
561 	}
562 
563 	return (destlen);
564 }
565 
566 /*
567  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
568  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
569  * here also.
570  */
571 static int
572 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
573 {
574 	char *transname;
575 	int error = 0;
576 
577 	/* This is overkill, but not worth creating a new zone */
578 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
579 
580 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
581 
582 	/* Easy check.  If they aren't the same length, they aren't equal */
583 	if ((cs0len == 0) || (cs0len != cmplen))
584 		error = -1;
585 	else
586 		error = bcmp(transname, cmpname, cmplen);
587 
588 	uma_zfree(udf_zone_trans, transname);
589 	return (error);
590 }
591 
592 struct udf_uiodir {
593 	struct dirent *dirent;
594 	u_long *cookies;
595 	int ncookies;
596 	int acookies;
597 	int eofflag;
598 };
599 
600 static int
601 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
602 {
603 	if (uiodir->cookies != NULL) {
604 		if (++uiodir->acookies > uiodir->ncookies) {
605 			uiodir->eofflag = 0;
606 			return (-1);
607 		}
608 		*uiodir->cookies++ = cookie;
609 	}
610 
611 	if (uio->uio_resid < de_size) {
612 		uiodir->eofflag = 0;
613 		return (-1);
614 	}
615 
616 	return (uiomove(uiodir->dirent, de_size, uio));
617 }
618 
619 static struct udf_dirstream *
620 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
621 {
622 	struct udf_dirstream *ds;
623 
624 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
625 
626 	ds->node = node;
627 	ds->offset = offset;
628 	ds->udfmp = udfmp;
629 	ds->fsize = fsize;
630 
631 	return (ds);
632 }
633 
634 static struct fileid_desc *
635 udf_getfid(struct udf_dirstream *ds)
636 {
637 	struct fileid_desc *fid;
638 	int error, frag_size = 0, total_fid_size;
639 
640 	/* End of directory? */
641 	if (ds->offset + ds->off >= ds->fsize) {
642 		ds->error = 0;
643 		return (NULL);
644 	}
645 
646 	/* Grab the first extent of the directory */
647 	if (ds->off == 0) {
648 		ds->size = 0;
649 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
650 		    &ds->bp, &ds->data);
651 		if (error) {
652 			ds->error = error;
653 			if (ds->bp != NULL)
654 				brelse(ds->bp);
655 			return (NULL);
656 		}
657 	}
658 
659 	/*
660 	 * Clean up from a previous fragmented FID.
661 	 * XXX Is this the right place for this?
662 	 */
663 	if (ds->fid_fragment && ds->buf != NULL) {
664 		ds->fid_fragment = 0;
665 		free(ds->buf, M_UDFFID);
666 	}
667 
668 	fid = (struct fileid_desc*)&ds->data[ds->off];
669 
670 	/*
671 	 * Check to see if the fid is fragmented. The first test
672 	 * ensures that we don't wander off the end of the buffer
673 	 * looking for the l_iu and l_fi fields.
674 	 */
675 	if (ds->off + UDF_FID_SIZE > ds->size ||
676 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
677 
678 		/* Copy what we have of the fid into a buffer */
679 		frag_size = ds->size - ds->off;
680 		if (frag_size >= ds->udfmp->bsize) {
681 			printf("udf: invalid FID fragment\n");
682 			ds->error = EINVAL;
683 			return (NULL);
684 		}
685 
686 		/*
687 		 * File ID descriptors can only be at most one
688 		 * logical sector in size.
689 		 */
690 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
691 		     M_WAITOK | M_ZERO);
692 		bcopy(fid, ds->buf, frag_size);
693 
694 		/* Reduce all of the casting magic */
695 		fid = (struct fileid_desc*)ds->buf;
696 
697 		if (ds->bp != NULL)
698 			brelse(ds->bp);
699 
700 		/* Fetch the next allocation */
701 		ds->offset += ds->size;
702 		ds->size = 0;
703 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
704 		    &ds->bp, &ds->data);
705 		if (error) {
706 			ds->error = error;
707 			return (NULL);
708 		}
709 
710 		/*
711 		 * If the fragment was so small that we didn't get
712 		 * the l_iu and l_fi fields, copy those in.
713 		 */
714 		if (frag_size < UDF_FID_SIZE)
715 			bcopy(ds->data, &ds->buf[frag_size],
716 			    UDF_FID_SIZE - frag_size);
717 
718 		/*
719 		 * Now that we have enough of the fid to work with,
720 		 * copy in the rest of the fid from the new
721 		 * allocation.
722 		 */
723 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
724 		if (total_fid_size > ds->udfmp->bsize) {
725 			printf("udf: invalid FID\n");
726 			ds->error = EIO;
727 			return (NULL);
728 		}
729 		bcopy(ds->data, &ds->buf[frag_size],
730 		    total_fid_size - frag_size);
731 
732 		ds->fid_fragment = 1;
733 	} else {
734 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
735 	}
736 
737 	/*
738 	 * Update the offset. Align on a 4 byte boundary because the
739 	 * UDF spec says so.
740 	 */
741 	ds->this_off = ds->offset + ds->off;
742 	if (!ds->fid_fragment) {
743 		ds->off += (total_fid_size + 3) & ~0x03;
744 	} else {
745 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
746 	}
747 
748 	return (fid);
749 }
750 
751 static void
752 udf_closedir(struct udf_dirstream *ds)
753 {
754 
755 	if (ds->bp != NULL)
756 		brelse(ds->bp);
757 
758 	if (ds->fid_fragment && ds->buf != NULL)
759 		free(ds->buf, M_UDFFID);
760 
761 	uma_zfree(udf_zone_ds, ds);
762 }
763 
764 static int
765 udf_readdir(struct vop_readdir_args *a)
766 {
767 	struct vnode *vp;
768 	struct uio *uio;
769 	struct dirent dir;
770 	struct udf_node *node;
771 	struct udf_mnt *udfmp;
772 	struct fileid_desc *fid;
773 	struct udf_uiodir uiodir;
774 	struct udf_dirstream *ds;
775 	u_long *cookies = NULL;
776 	int ncookies;
777 	int error = 0;
778 
779 	vp = a->a_vp;
780 	uio = a->a_uio;
781 	node = VTON(vp);
782 	udfmp = node->udfmp;
783 	uiodir.eofflag = 1;
784 
785 	if (a->a_ncookies != NULL) {
786 		/*
787 		 * Guess how many entries are needed.  If we run out, this
788 		 * function will be called again and thing will pick up were
789 		 * it left off.
790 		 */
791 		ncookies = uio->uio_resid / 8;
792 		cookies = malloc(sizeof(u_long) * ncookies,
793 		    M_TEMP, M_WAITOK);
794 		if (cookies == NULL)
795 			return (ENOMEM);
796 		uiodir.ncookies = ncookies;
797 		uiodir.cookies = cookies;
798 		uiodir.acookies = 0;
799 	} else {
800 		uiodir.cookies = NULL;
801 	}
802 
803 	/*
804 	 * Iterate through the file id descriptors.  Give the parent dir
805 	 * entry special attention.
806 	 */
807 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
808 	    node->udfmp);
809 
810 	while ((fid = udf_getfid(ds)) != NULL) {
811 
812 		/* XXX Should we return an error on a bad fid? */
813 		if (udf_checktag(&fid->tag, TAGID_FID)) {
814 			printf("Invalid FID tag\n");
815 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
816 			error = EIO;
817 			break;
818 		}
819 
820 		/* Is this a deleted file? */
821 		if (fid->file_char & UDF_FILE_CHAR_DEL)
822 			continue;
823 
824 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
825 			/* Do up the '.' and '..' entries.  Dummy values are
826 			 * used for the cookies since the offset here is
827 			 * usually zero, and NFS doesn't like that value
828 			 */
829 			dir.d_fileno = node->hash_id;
830 			dir.d_type = DT_DIR;
831 			dir.d_name[0] = '.';
832 			dir.d_name[1] = '\0';
833 			dir.d_namlen = 1;
834 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
835 			uiodir.dirent = &dir;
836 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
837 			if (error)
838 				break;
839 
840 			dir.d_fileno = udf_getid(&fid->icb);
841 			dir.d_type = DT_DIR;
842 			dir.d_name[0] = '.';
843 			dir.d_name[1] = '.';
844 			dir.d_name[2] = '\0';
845 			dir.d_namlen = 2;
846 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
847 			uiodir.dirent = &dir;
848 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
849 		} else {
850 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
851 			    &dir.d_name[0], fid->l_fi, udfmp);
852 			dir.d_fileno = udf_getid(&fid->icb);
853 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
854 			    DT_DIR : DT_UNKNOWN;
855 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
856 			uiodir.dirent = &dir;
857 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
858 			    ds->this_off);
859 		}
860 		if (error)
861 			break;
862 		uio->uio_offset = ds->offset + ds->off;
863 	}
864 
865 	/* tell the calling layer whether we need to be called again */
866 	*a->a_eofflag = uiodir.eofflag;
867 
868 	if (error < 0)
869 		error = 0;
870 	if (!error)
871 		error = ds->error;
872 
873 	udf_closedir(ds);
874 
875 	if (a->a_ncookies != NULL) {
876 		if (error)
877 			free(cookies, M_TEMP);
878 		else {
879 			*a->a_ncookies = uiodir.acookies;
880 			*a->a_cookies = cookies;
881 		}
882 	}
883 
884 	return (error);
885 }
886 
887 static int
888 udf_readlink(struct vop_readlink_args *ap)
889 {
890 	struct path_component *pc, *end;
891 	struct vnode *vp;
892 	struct uio uio;
893 	struct iovec iov[1];
894 	struct udf_node *node;
895 	void *buf;
896 	char *cp;
897 	int error, len, root;
898 
899 	/*
900 	 * A symbolic link in UDF is a list of variable-length path
901 	 * component structures.  We build a pathname in the caller's
902 	 * uio by traversing this list.
903 	 */
904 	vp = ap->a_vp;
905 	node = VTON(vp);
906 	len = le64toh(node->fentry->inf_len);
907 	buf = malloc(len, M_DEVBUF, M_WAITOK);
908 	iov[0].iov_len = len;
909 	iov[0].iov_base = buf;
910 	uio.uio_iov = iov;
911 	uio.uio_iovcnt = 1;
912 	uio.uio_offset = 0;
913 	uio.uio_resid = iov[0].iov_len;
914 	uio.uio_segflg = UIO_SYSSPACE;
915 	uio.uio_rw = UIO_READ;
916 	uio.uio_td = curthread;
917 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
918 	if (error)
919 		goto error;
920 
921 	pc = buf;
922 	end = (void *)((char *)buf + len);
923 	root = 0;
924 	while (pc < end) {
925 		switch (pc->type) {
926 		case UDF_PATH_ROOT:
927 			/* Only allow this at the beginning of a path. */
928 			if ((void *)pc != buf) {
929 				error = EINVAL;
930 				goto error;
931 			}
932 			cp = "/";
933 			len = 1;
934 			root = 1;
935 			break;
936 		case UDF_PATH_DOT:
937 			cp = ".";
938 			len = 1;
939 			break;
940 		case UDF_PATH_DOTDOT:
941 			cp = "..";
942 			len = 2;
943 			break;
944 		case UDF_PATH_PATH:
945 			if (pc->length == 0) {
946 				error = EINVAL;
947 				goto error;
948 			}
949 			/*
950 			 * XXX: We only support CS8 which appears to map
951 			 * to ASCII directly.
952 			 */
953 			switch (pc->identifier[0]) {
954 			case 8:
955 				cp = pc->identifier + 1;
956 				len = pc->length - 1;
957 				break;
958 			default:
959 				error = EOPNOTSUPP;
960 				goto error;
961 			}
962 			break;
963 		default:
964 			error = EINVAL;
965 			goto error;
966 		}
967 
968 		/*
969 		 * If this is not the first component, insert a path
970 		 * separator.
971 		 */
972 		if (pc != buf) {
973 			/* If we started with root we already have a "/". */
974 			if (root)
975 				goto skipslash;
976 			root = 0;
977 			if (ap->a_uio->uio_resid < 1) {
978 				error = ENAMETOOLONG;
979 				goto error;
980 			}
981 			error = uiomove("/", 1, ap->a_uio);
982 			if (error)
983 				break;
984 		}
985 	skipslash:
986 
987 		/* Append string at 'cp' of length 'len' to our path. */
988 		if (len > ap->a_uio->uio_resid) {
989 			error = ENAMETOOLONG;
990 			goto error;
991 		}
992 		error = uiomove(cp, len, ap->a_uio);
993 		if (error)
994 			break;
995 
996 		/* Advance to next component. */
997 		pc = (void *)((char *)pc + 4 + pc->length);
998 	}
999 error:
1000 	free(buf, M_DEVBUF);
1001 	return (error);
1002 }
1003 
1004 static int
1005 udf_strategy(struct vop_strategy_args *a)
1006 {
1007 	struct buf *bp;
1008 	struct vnode *vp;
1009 	struct udf_node *node;
1010 	struct bufobj *bo;
1011 	off_t offset;
1012 	uint32_t maxsize;
1013 	daddr_t sector;
1014 	int error;
1015 
1016 	bp = a->a_bp;
1017 	vp = a->a_vp;
1018 	node = VTON(vp);
1019 
1020 	if (bp->b_blkno == bp->b_lblkno) {
1021 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1022 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1023 		if (error) {
1024 			clrbuf(bp);
1025 			bp->b_blkno = -1;
1026 			bufdone(bp);
1027 			return (0);
1028 		}
1029 		/* bmap gives sector numbers, bio works with device blocks */
1030 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1031 	}
1032 	bo = node->udfmp->im_bo;
1033 	bp->b_iooffset = dbtob(bp->b_blkno);
1034 	BO_STRATEGY(bo, bp);
1035 	return (0);
1036 }
1037 
1038 static int
1039 udf_bmap(struct vop_bmap_args *a)
1040 {
1041 	struct udf_node *node;
1042 	uint32_t max_size;
1043 	daddr_t lsector;
1044 	int nblk;
1045 	int error;
1046 
1047 	node = VTON(a->a_vp);
1048 
1049 	if (a->a_bop != NULL)
1050 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1051 	if (a->a_bnp == NULL)
1052 		return (0);
1053 	if (a->a_runb)
1054 		*a->a_runb = 0;
1055 
1056 	/*
1057 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1058 	 * error that should not be propagated to calling code.
1059 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1060 	 * translate block numbers in this case.
1061 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1062 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1063 	 * thing for this kind of files.
1064 	 */
1065 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1066 	    &lsector, &max_size);
1067 	if (error == UDF_INVALID_BMAP)
1068 		return (EOPNOTSUPP);
1069 	if (error)
1070 		return (error);
1071 
1072 	/* Translate logical to physical sector number */
1073 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1074 
1075 	/*
1076 	 * Determine maximum number of readahead blocks following the
1077 	 * requested block.
1078 	 */
1079 	if (a->a_runp) {
1080 		nblk = (max_size >> node->udfmp->bshift) - 1;
1081 		if (nblk <= 0)
1082 			*a->a_runp = 0;
1083 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1084 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1085 		else
1086 			*a->a_runp = nblk;
1087 	}
1088 
1089 	if (a->a_runb) {
1090 		*a->a_runb = 0;
1091 	}
1092 
1093 	return (0);
1094 }
1095 
1096 /*
1097  * The all powerful VOP_LOOKUP().
1098  */
1099 static int
1100 udf_lookup(struct vop_cachedlookup_args *a)
1101 {
1102 	struct vnode *dvp;
1103 	struct vnode *tdp = NULL;
1104 	struct vnode **vpp = a->a_vpp;
1105 	struct udf_node *node;
1106 	struct udf_mnt *udfmp;
1107 	struct fileid_desc *fid = NULL;
1108 	struct udf_dirstream *ds;
1109 	u_long nameiop;
1110 	u_long flags;
1111 	char *nameptr;
1112 	long namelen;
1113 	ino_t id = 0;
1114 	int offset, error = 0;
1115 	int fsize, lkflags, ltype, numdirpasses;
1116 
1117 	dvp = a->a_dvp;
1118 	node = VTON(dvp);
1119 	udfmp = node->udfmp;
1120 	nameiop = a->a_cnp->cn_nameiop;
1121 	flags = a->a_cnp->cn_flags;
1122 	lkflags = a->a_cnp->cn_lkflags;
1123 	nameptr = a->a_cnp->cn_nameptr;
1124 	namelen = a->a_cnp->cn_namelen;
1125 	fsize = le64toh(node->fentry->inf_len);
1126 
1127 	/*
1128 	 * If this is a LOOKUP and we've already partially searched through
1129 	 * the directory, pick up where we left off and flag that the
1130 	 * directory may need to be searched twice.  For a full description,
1131 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1132 	 */
1133 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1134 		offset = 0;
1135 		numdirpasses = 1;
1136 	} else {
1137 		offset = node->diroff;
1138 		numdirpasses = 2;
1139 		nchstats.ncs_2passes++;
1140 	}
1141 
1142 lookloop:
1143 	ds = udf_opendir(node, offset, fsize, udfmp);
1144 
1145 	while ((fid = udf_getfid(ds)) != NULL) {
1146 
1147 		/* XXX Should we return an error on a bad fid? */
1148 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1149 			printf("udf_lookup: Invalid tag\n");
1150 			error = EIO;
1151 			break;
1152 		}
1153 
1154 		/* Is this a deleted file? */
1155 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1156 			continue;
1157 
1158 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1159 			if (flags & ISDOTDOT) {
1160 				id = udf_getid(&fid->icb);
1161 				break;
1162 			}
1163 		} else {
1164 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1165 			    nameptr, fid->l_fi, namelen, udfmp))) {
1166 				id = udf_getid(&fid->icb);
1167 				break;
1168 			}
1169 		}
1170 	}
1171 
1172 	if (!error)
1173 		error = ds->error;
1174 
1175 	/* XXX Bail out here? */
1176 	if (error) {
1177 		udf_closedir(ds);
1178 		return (error);
1179 	}
1180 
1181 	/* Did we have a match? */
1182 	if (id) {
1183 		/*
1184 		 * Remember where this entry was if it's the final
1185 		 * component.
1186 		 */
1187 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1188 			node->diroff = ds->offset + ds->off;
1189 		if (numdirpasses == 2)
1190 			nchstats.ncs_pass2++;
1191 		udf_closedir(ds);
1192 
1193 		if (flags & ISDOTDOT) {
1194 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1195 		} else if (node->hash_id == id) {
1196 			VREF(dvp);	/* we want ourself, ie "." */
1197 			/*
1198 			 * When we lookup "." we still can be asked to lock it
1199 			 * differently.
1200 			 */
1201 			ltype = lkflags & LK_TYPE_MASK;
1202 			if (ltype != VOP_ISLOCKED(dvp)) {
1203 				if (ltype == LK_EXCLUSIVE)
1204 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1205 				else /* if (ltype == LK_SHARED) */
1206 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1207 			}
1208 			tdp = dvp;
1209 		} else
1210 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1211 		if (!error) {
1212 			*vpp = tdp;
1213 			/* Put this entry in the cache */
1214 			if (flags & MAKEENTRY)
1215 				cache_enter(dvp, *vpp, a->a_cnp);
1216 		}
1217 	} else {
1218 		/* Name wasn't found on this pass.  Do another pass? */
1219 		if (numdirpasses == 2) {
1220 			numdirpasses--;
1221 			offset = 0;
1222 			udf_closedir(ds);
1223 			goto lookloop;
1224 		}
1225 		udf_closedir(ds);
1226 
1227 		/* Enter name into cache as non-existant */
1228 		if (flags & MAKEENTRY)
1229 			cache_enter(dvp, *vpp, a->a_cnp);
1230 
1231 		if ((flags & ISLASTCN) &&
1232 		    (nameiop == CREATE || nameiop == RENAME)) {
1233 			error = EROFS;
1234 		} else {
1235 			error = ENOENT;
1236 		}
1237 	}
1238 
1239 	return (error);
1240 }
1241 
1242 static int
1243 udf_reclaim(struct vop_reclaim_args *a)
1244 {
1245 	struct vnode *vp;
1246 	struct udf_node *unode;
1247 
1248 	vp = a->a_vp;
1249 	unode = VTON(vp);
1250 
1251 	/*
1252 	 * Destroy the vm object and flush associated pages.
1253 	 */
1254 	vnode_destroy_vobject(vp);
1255 
1256 	if (unode != NULL) {
1257 		vfs_hash_remove(vp);
1258 
1259 		if (unode->fentry != NULL)
1260 			free(unode->fentry, M_UDFFENTRY);
1261 		uma_zfree(udf_zone_node, unode);
1262 		vp->v_data = NULL;
1263 	}
1264 
1265 	return (0);
1266 }
1267 
1268 static int
1269 udf_vptofh(struct vop_vptofh_args *a)
1270 {
1271 	struct udf_node *node;
1272 	struct ifid *ifhp;
1273 
1274 	node = VTON(a->a_vp);
1275 	ifhp = (struct ifid *)a->a_fhp;
1276 	ifhp->ifid_len = sizeof(struct ifid);
1277 	ifhp->ifid_ino = node->hash_id;
1278 
1279 	return (0);
1280 }
1281 
1282 /*
1283  * Read the block and then set the data pointer to correspond with the
1284  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1285  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1286  * whole extent.
1287  *
1288  * Note that *bp may be assigned error or not.
1289  *
1290  */
1291 static int
1292 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1293     struct buf **bp, uint8_t **data)
1294 {
1295 	struct udf_mnt *udfmp = node->udfmp;
1296 	struct vnode *vp = node->i_vnode;
1297 	struct file_entry *fentry;
1298 	struct buf *bp1;
1299 	uint32_t max_size;
1300 	daddr_t sector;
1301 	off_t off;
1302 	int adj_size;
1303 	int error;
1304 
1305 	/*
1306 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1307 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1308 	 */
1309 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1310 	if (error == UDF_INVALID_BMAP) {
1311 		/*
1312 		 * This error means that the file *data* is stored in the
1313 		 * allocation descriptor field of the file entry.
1314 		 */
1315 		fentry = node->fentry;
1316 		*data = &fentry->data[le32toh(fentry->l_ea)];
1317 		*size = le32toh(fentry->l_ad);
1318 		if (offset >= *size)
1319 			*size = 0;
1320 		else {
1321 			*data += offset;
1322 			*size -= offset;
1323 		}
1324 		return (0);
1325 	} else if (error != 0) {
1326 		return (error);
1327 	}
1328 
1329 	/* Adjust the size so that it is within range */
1330 	if (*size == 0 || *size > max_size)
1331 		*size = max_size;
1332 
1333 	/*
1334 	 * Because we will read starting at block boundary, we need to adjust
1335 	 * how much we need to read so that all promised data is in.
1336 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1337 	 * from block boundary, so adjust what we promise too.
1338 	 */
1339 	off = blkoff(udfmp, offset);
1340 	*size = min(*size, MAXBSIZE - off);
1341 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1342 	*bp = NULL;
1343 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1344 		printf("warning: udf_readlblks returned error %d\n", error);
1345 		/* note: *bp may be non-NULL */
1346 		return (error);
1347 	}
1348 
1349 	bp1 = *bp;
1350 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1351 	return (0);
1352 }
1353 
1354 /*
1355  * Translate a file offset into a logical block and then into a physical
1356  * block.
1357  * max_size - maximum number of bytes that can be read starting from given
1358  * offset, rather than beginning of calculated sector number
1359  */
1360 static int
1361 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1362     uint32_t *max_size)
1363 {
1364 	struct udf_mnt *udfmp;
1365 	struct file_entry *fentry;
1366 	void *icb;
1367 	struct icb_tag *tag;
1368 	uint32_t icblen = 0;
1369 	daddr_t lsector;
1370 	int ad_offset, ad_num = 0;
1371 	int i, p_offset;
1372 
1373 	udfmp = node->udfmp;
1374 	fentry = node->fentry;
1375 	tag = &fentry->icbtag;
1376 
1377 	switch (le16toh(tag->strat_type)) {
1378 	case 4:
1379 		break;
1380 
1381 	case 4096:
1382 		printf("Cannot deal with strategy4096 yet!\n");
1383 		return (ENODEV);
1384 
1385 	default:
1386 		printf("Unknown strategy type %d\n", tag->strat_type);
1387 		return (ENODEV);
1388 	}
1389 
1390 	switch (le16toh(tag->flags) & 0x7) {
1391 	case 0:
1392 		/*
1393 		 * The allocation descriptor field is filled with short_ad's.
1394 		 * If the offset is beyond the current extent, look for the
1395 		 * next extent.
1396 		 */
1397 		do {
1398 			offset -= icblen;
1399 			ad_offset = sizeof(struct short_ad) * ad_num;
1400 			if (ad_offset > le32toh(fentry->l_ad)) {
1401 				printf("File offset out of bounds\n");
1402 				return (EINVAL);
1403 			}
1404 			icb = GETICB(short_ad, fentry,
1405 			    le32toh(fentry->l_ea) + ad_offset);
1406 			icblen = GETICBLEN(short_ad, icb);
1407 			ad_num++;
1408 		} while(offset >= icblen);
1409 
1410 		lsector = (offset  >> udfmp->bshift) +
1411 		    le32toh(((struct short_ad *)(icb))->pos);
1412 
1413 		*max_size = icblen - offset;
1414 
1415 		break;
1416 	case 1:
1417 		/*
1418 		 * The allocation descriptor field is filled with long_ad's
1419 		 * If the offset is beyond the current extent, look for the
1420 		 * next extent.
1421 		 */
1422 		do {
1423 			offset -= icblen;
1424 			ad_offset = sizeof(struct long_ad) * ad_num;
1425 			if (ad_offset > le32toh(fentry->l_ad)) {
1426 				printf("File offset out of bounds\n");
1427 				return (EINVAL);
1428 			}
1429 			icb = GETICB(long_ad, fentry,
1430 			    le32toh(fentry->l_ea) + ad_offset);
1431 			icblen = GETICBLEN(long_ad, icb);
1432 			ad_num++;
1433 		} while(offset >= icblen);
1434 
1435 		lsector = (offset >> udfmp->bshift) +
1436 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1437 
1438 		*max_size = icblen - offset;
1439 
1440 		break;
1441 	case 3:
1442 		/*
1443 		 * This type means that the file *data* is stored in the
1444 		 * allocation descriptor field of the file entry.
1445 		 */
1446 		*max_size = 0;
1447 		*sector = node->hash_id + udfmp->part_start;
1448 
1449 		return (UDF_INVALID_BMAP);
1450 	case 2:
1451 		/* DirectCD does not use extended_ad's */
1452 	default:
1453 		printf("Unsupported allocation descriptor %d\n",
1454 		       tag->flags & 0x7);
1455 		return (ENODEV);
1456 	}
1457 
1458 	*sector = lsector + udfmp->part_start;
1459 
1460 	/*
1461 	 * Check the sparing table.  Each entry represents the beginning of
1462 	 * a packet.
1463 	 */
1464 	if (udfmp->s_table != NULL) {
1465 		for (i = 0; i< udfmp->s_table_entries; i++) {
1466 			p_offset =
1467 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1468 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1469 				*sector =
1470 				   le32toh(udfmp->s_table->entries[i].map) +
1471 				    p_offset;
1472 				break;
1473 			}
1474 		}
1475 	}
1476 
1477 	return (0);
1478 }
1479