xref: /freebsd/sys/fs/udf/udf_vnops.c (revision 3a92d97ff0f22d21608e1c19b83104c4937523b6)
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, (const char **)&unibuf,
530 				(size_t *)&unilen, (char **)&destname, &destleft);
531 			/* Unconverted character found */
532 			if (unilen > 0 && destleft > 0) {
533 				*destname++ = '?';
534 				destleft--;
535 				unibuf += 2;
536 				unilen -= 2;
537 			}
538 		}
539 		uma_zfree(udf_zone_trans, unip);
540 		*destname = '\0';
541 		destlen = MAXNAMLEN - (int)destleft;
542 	} else {
543 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
544 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
545 
546 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
547 			printf("udf: Unicode translation failed\n");
548 			uma_zfree(udf_zone_trans, transname);
549 			return 0;
550 		}
551 
552 		for (i = 0; i < unilen ; i++) {
553 			if (transname[i] & 0xff00) {
554 				destname[i] = '.';	/* Fudge the 16bit chars */
555 			} else {
556 				destname[i] = transname[i] & 0xff;
557 			}
558 		}
559 		uma_zfree(udf_zone_trans, transname);
560 		destname[unilen] = 0;
561 		destlen = (int)unilen;
562 	}
563 
564 	return (destlen);
565 }
566 
567 /*
568  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
569  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
570  * here also.
571  */
572 static int
573 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
574 {
575 	char *transname;
576 	int error = 0;
577 
578 	/* This is overkill, but not worth creating a new zone */
579 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
580 
581 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
582 
583 	/* Easy check.  If they aren't the same length, they aren't equal */
584 	if ((cs0len == 0) || (cs0len != cmplen))
585 		error = -1;
586 	else
587 		error = bcmp(transname, cmpname, cmplen);
588 
589 	uma_zfree(udf_zone_trans, transname);
590 	return (error);
591 }
592 
593 struct udf_uiodir {
594 	struct dirent *dirent;
595 	u_long *cookies;
596 	int ncookies;
597 	int acookies;
598 	int eofflag;
599 };
600 
601 static int
602 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
603 {
604 	if (uiodir->cookies != NULL) {
605 		if (++uiodir->acookies > uiodir->ncookies) {
606 			uiodir->eofflag = 0;
607 			return (-1);
608 		}
609 		*uiodir->cookies++ = cookie;
610 	}
611 
612 	if (uio->uio_resid < de_size) {
613 		uiodir->eofflag = 0;
614 		return (-1);
615 	}
616 
617 	return (uiomove(uiodir->dirent, de_size, uio));
618 }
619 
620 static struct udf_dirstream *
621 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
622 {
623 	struct udf_dirstream *ds;
624 
625 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
626 
627 	ds->node = node;
628 	ds->offset = offset;
629 	ds->udfmp = udfmp;
630 	ds->fsize = fsize;
631 
632 	return (ds);
633 }
634 
635 static struct fileid_desc *
636 udf_getfid(struct udf_dirstream *ds)
637 {
638 	struct fileid_desc *fid;
639 	int error, frag_size = 0, total_fid_size;
640 
641 	/* End of directory? */
642 	if (ds->offset + ds->off >= ds->fsize) {
643 		ds->error = 0;
644 		return (NULL);
645 	}
646 
647 	/* Grab the first extent of the directory */
648 	if (ds->off == 0) {
649 		ds->size = 0;
650 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
651 		    &ds->bp, &ds->data);
652 		if (error) {
653 			ds->error = error;
654 			if (ds->bp != NULL)
655 				brelse(ds->bp);
656 			return (NULL);
657 		}
658 	}
659 
660 	/*
661 	 * Clean up from a previous fragmented FID.
662 	 * XXX Is this the right place for this?
663 	 */
664 	if (ds->fid_fragment && ds->buf != NULL) {
665 		ds->fid_fragment = 0;
666 		free(ds->buf, M_UDFFID);
667 	}
668 
669 	fid = (struct fileid_desc*)&ds->data[ds->off];
670 
671 	/*
672 	 * Check to see if the fid is fragmented. The first test
673 	 * ensures that we don't wander off the end of the buffer
674 	 * looking for the l_iu and l_fi fields.
675 	 */
676 	if (ds->off + UDF_FID_SIZE > ds->size ||
677 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
678 
679 		/* Copy what we have of the fid into a buffer */
680 		frag_size = ds->size - ds->off;
681 		if (frag_size >= ds->udfmp->bsize) {
682 			printf("udf: invalid FID fragment\n");
683 			ds->error = EINVAL;
684 			return (NULL);
685 		}
686 
687 		/*
688 		 * File ID descriptors can only be at most one
689 		 * logical sector in size.
690 		 */
691 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
692 		     M_WAITOK | M_ZERO);
693 		bcopy(fid, ds->buf, frag_size);
694 
695 		/* Reduce all of the casting magic */
696 		fid = (struct fileid_desc*)ds->buf;
697 
698 		if (ds->bp != NULL)
699 			brelse(ds->bp);
700 
701 		/* Fetch the next allocation */
702 		ds->offset += ds->size;
703 		ds->size = 0;
704 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
705 		    &ds->bp, &ds->data);
706 		if (error) {
707 			ds->error = error;
708 			return (NULL);
709 		}
710 
711 		/*
712 		 * If the fragment was so small that we didn't get
713 		 * the l_iu and l_fi fields, copy those in.
714 		 */
715 		if (frag_size < UDF_FID_SIZE)
716 			bcopy(ds->data, &ds->buf[frag_size],
717 			    UDF_FID_SIZE - frag_size);
718 
719 		/*
720 		 * Now that we have enough of the fid to work with,
721 		 * copy in the rest of the fid from the new
722 		 * allocation.
723 		 */
724 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
725 		if (total_fid_size > ds->udfmp->bsize) {
726 			printf("udf: invalid FID\n");
727 			ds->error = EIO;
728 			return (NULL);
729 		}
730 		bcopy(ds->data, &ds->buf[frag_size],
731 		    total_fid_size - frag_size);
732 
733 		ds->fid_fragment = 1;
734 	} else {
735 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
736 	}
737 
738 	/*
739 	 * Update the offset. Align on a 4 byte boundary because the
740 	 * UDF spec says so.
741 	 */
742 	ds->this_off = ds->offset + ds->off;
743 	if (!ds->fid_fragment) {
744 		ds->off += (total_fid_size + 3) & ~0x03;
745 	} else {
746 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
747 	}
748 
749 	return (fid);
750 }
751 
752 static void
753 udf_closedir(struct udf_dirstream *ds)
754 {
755 
756 	if (ds->bp != NULL)
757 		brelse(ds->bp);
758 
759 	if (ds->fid_fragment && ds->buf != NULL)
760 		free(ds->buf, M_UDFFID);
761 
762 	uma_zfree(udf_zone_ds, ds);
763 }
764 
765 static int
766 udf_readdir(struct vop_readdir_args *a)
767 {
768 	struct vnode *vp;
769 	struct uio *uio;
770 	struct dirent dir;
771 	struct udf_node *node;
772 	struct udf_mnt *udfmp;
773 	struct fileid_desc *fid;
774 	struct udf_uiodir uiodir;
775 	struct udf_dirstream *ds;
776 	u_long *cookies = NULL;
777 	int ncookies;
778 	int error = 0;
779 
780 	vp = a->a_vp;
781 	uio = a->a_uio;
782 	node = VTON(vp);
783 	udfmp = node->udfmp;
784 	uiodir.eofflag = 1;
785 
786 	if (a->a_ncookies != NULL) {
787 		/*
788 		 * Guess how many entries are needed.  If we run out, this
789 		 * function will be called again and thing will pick up were
790 		 * it left off.
791 		 */
792 		ncookies = uio->uio_resid / 8;
793 		cookies = malloc(sizeof(u_long) * ncookies,
794 		    M_TEMP, M_WAITOK);
795 		if (cookies == NULL)
796 			return (ENOMEM);
797 		uiodir.ncookies = ncookies;
798 		uiodir.cookies = cookies;
799 		uiodir.acookies = 0;
800 	} else {
801 		uiodir.cookies = NULL;
802 	}
803 
804 	/*
805 	 * Iterate through the file id descriptors.  Give the parent dir
806 	 * entry special attention.
807 	 */
808 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
809 	    node->udfmp);
810 
811 	while ((fid = udf_getfid(ds)) != NULL) {
812 
813 		/* XXX Should we return an error on a bad fid? */
814 		if (udf_checktag(&fid->tag, TAGID_FID)) {
815 			printf("Invalid FID tag\n");
816 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
817 			error = EIO;
818 			break;
819 		}
820 
821 		/* Is this a deleted file? */
822 		if (fid->file_char & UDF_FILE_CHAR_DEL)
823 			continue;
824 
825 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
826 			/* Do up the '.' and '..' entries.  Dummy values are
827 			 * used for the cookies since the offset here is
828 			 * usually zero, and NFS doesn't like that value
829 			 */
830 			dir.d_fileno = node->hash_id;
831 			dir.d_type = DT_DIR;
832 			dir.d_name[0] = '.';
833 			dir.d_name[1] = '\0';
834 			dir.d_namlen = 1;
835 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
836 			uiodir.dirent = &dir;
837 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
838 			if (error)
839 				break;
840 
841 			dir.d_fileno = udf_getid(&fid->icb);
842 			dir.d_type = DT_DIR;
843 			dir.d_name[0] = '.';
844 			dir.d_name[1] = '.';
845 			dir.d_name[2] = '\0';
846 			dir.d_namlen = 2;
847 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
848 			uiodir.dirent = &dir;
849 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
850 		} else {
851 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
852 			    &dir.d_name[0], fid->l_fi, udfmp);
853 			dir.d_fileno = udf_getid(&fid->icb);
854 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
855 			    DT_DIR : DT_UNKNOWN;
856 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
857 			uiodir.dirent = &dir;
858 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
859 			    ds->this_off);
860 		}
861 		if (error)
862 			break;
863 		uio->uio_offset = ds->offset + ds->off;
864 	}
865 
866 	/* tell the calling layer whether we need to be called again */
867 	*a->a_eofflag = uiodir.eofflag;
868 
869 	if (error < 0)
870 		error = 0;
871 	if (!error)
872 		error = ds->error;
873 
874 	udf_closedir(ds);
875 
876 	if (a->a_ncookies != NULL) {
877 		if (error)
878 			free(cookies, M_TEMP);
879 		else {
880 			*a->a_ncookies = uiodir.acookies;
881 			*a->a_cookies = cookies;
882 		}
883 	}
884 
885 	return (error);
886 }
887 
888 static int
889 udf_readlink(struct vop_readlink_args *ap)
890 {
891 	struct path_component *pc, *end;
892 	struct vnode *vp;
893 	struct uio uio;
894 	struct iovec iov[1];
895 	struct udf_node *node;
896 	void *buf;
897 	char *cp;
898 	int error, len, root;
899 
900 	/*
901 	 * A symbolic link in UDF is a list of variable-length path
902 	 * component structures.  We build a pathname in the caller's
903 	 * uio by traversing this list.
904 	 */
905 	vp = ap->a_vp;
906 	node = VTON(vp);
907 	len = le64toh(node->fentry->inf_len);
908 	buf = malloc(len, M_DEVBUF, M_WAITOK);
909 	iov[0].iov_len = len;
910 	iov[0].iov_base = buf;
911 	uio.uio_iov = iov;
912 	uio.uio_iovcnt = 1;
913 	uio.uio_offset = 0;
914 	uio.uio_resid = iov[0].iov_len;
915 	uio.uio_segflg = UIO_SYSSPACE;
916 	uio.uio_rw = UIO_READ;
917 	uio.uio_td = curthread;
918 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
919 	if (error)
920 		goto error;
921 
922 	pc = buf;
923 	end = (void *)((char *)buf + len);
924 	root = 0;
925 	while (pc < end) {
926 		switch (pc->type) {
927 		case UDF_PATH_ROOT:
928 			/* Only allow this at the beginning of a path. */
929 			if ((void *)pc != buf) {
930 				error = EINVAL;
931 				goto error;
932 			}
933 			cp = "/";
934 			len = 1;
935 			root = 1;
936 			break;
937 		case UDF_PATH_DOT:
938 			cp = ".";
939 			len = 1;
940 			break;
941 		case UDF_PATH_DOTDOT:
942 			cp = "..";
943 			len = 2;
944 			break;
945 		case UDF_PATH_PATH:
946 			if (pc->length == 0) {
947 				error = EINVAL;
948 				goto error;
949 			}
950 			/*
951 			 * XXX: We only support CS8 which appears to map
952 			 * to ASCII directly.
953 			 */
954 			switch (pc->identifier[0]) {
955 			case 8:
956 				cp = pc->identifier + 1;
957 				len = pc->length - 1;
958 				break;
959 			default:
960 				error = EOPNOTSUPP;
961 				goto error;
962 			}
963 			break;
964 		default:
965 			error = EINVAL;
966 			goto error;
967 		}
968 
969 		/*
970 		 * If this is not the first component, insert a path
971 		 * separator.
972 		 */
973 		if (pc != buf) {
974 			/* If we started with root we already have a "/". */
975 			if (root)
976 				goto skipslash;
977 			root = 0;
978 			if (ap->a_uio->uio_resid < 1) {
979 				error = ENAMETOOLONG;
980 				goto error;
981 			}
982 			error = uiomove("/", 1, ap->a_uio);
983 			if (error)
984 				break;
985 		}
986 	skipslash:
987 
988 		/* Append string at 'cp' of length 'len' to our path. */
989 		if (len > ap->a_uio->uio_resid) {
990 			error = ENAMETOOLONG;
991 			goto error;
992 		}
993 		error = uiomove(cp, len, ap->a_uio);
994 		if (error)
995 			break;
996 
997 		/* Advance to next component. */
998 		pc = (void *)((char *)pc + 4 + pc->length);
999 	}
1000 error:
1001 	free(buf, M_DEVBUF);
1002 	return (error);
1003 }
1004 
1005 static int
1006 udf_strategy(struct vop_strategy_args *a)
1007 {
1008 	struct buf *bp;
1009 	struct vnode *vp;
1010 	struct udf_node *node;
1011 	struct bufobj *bo;
1012 	off_t offset;
1013 	uint32_t maxsize;
1014 	daddr_t sector;
1015 	int error;
1016 
1017 	bp = a->a_bp;
1018 	vp = a->a_vp;
1019 	node = VTON(vp);
1020 
1021 	if (bp->b_blkno == bp->b_lblkno) {
1022 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1023 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1024 		if (error) {
1025 			clrbuf(bp);
1026 			bp->b_blkno = -1;
1027 			bufdone(bp);
1028 			return (0);
1029 		}
1030 		/* bmap gives sector numbers, bio works with device blocks */
1031 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1032 	}
1033 	bo = node->udfmp->im_bo;
1034 	bp->b_iooffset = dbtob(bp->b_blkno);
1035 	BO_STRATEGY(bo, bp);
1036 	return (0);
1037 }
1038 
1039 static int
1040 udf_bmap(struct vop_bmap_args *a)
1041 {
1042 	struct udf_node *node;
1043 	uint32_t max_size;
1044 	daddr_t lsector;
1045 	int nblk;
1046 	int error;
1047 
1048 	node = VTON(a->a_vp);
1049 
1050 	if (a->a_bop != NULL)
1051 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1052 	if (a->a_bnp == NULL)
1053 		return (0);
1054 	if (a->a_runb)
1055 		*a->a_runb = 0;
1056 
1057 	/*
1058 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1059 	 * error that should not be propagated to calling code.
1060 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1061 	 * translate block numbers in this case.
1062 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1063 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1064 	 * thing for this kind of files.
1065 	 */
1066 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1067 	    &lsector, &max_size);
1068 	if (error == UDF_INVALID_BMAP)
1069 		return (EOPNOTSUPP);
1070 	if (error)
1071 		return (error);
1072 
1073 	/* Translate logical to physical sector number */
1074 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1075 
1076 	/*
1077 	 * Determine maximum number of readahead blocks following the
1078 	 * requested block.
1079 	 */
1080 	if (a->a_runp) {
1081 		nblk = (max_size >> node->udfmp->bshift) - 1;
1082 		if (nblk <= 0)
1083 			*a->a_runp = 0;
1084 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1085 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1086 		else
1087 			*a->a_runp = nblk;
1088 	}
1089 
1090 	if (a->a_runb) {
1091 		*a->a_runb = 0;
1092 	}
1093 
1094 	return (0);
1095 }
1096 
1097 /*
1098  * The all powerful VOP_LOOKUP().
1099  */
1100 static int
1101 udf_lookup(struct vop_cachedlookup_args *a)
1102 {
1103 	struct vnode *dvp;
1104 	struct vnode *tdp = NULL;
1105 	struct vnode **vpp = a->a_vpp;
1106 	struct udf_node *node;
1107 	struct udf_mnt *udfmp;
1108 	struct fileid_desc *fid = NULL;
1109 	struct udf_dirstream *ds;
1110 	u_long nameiop;
1111 	u_long flags;
1112 	char *nameptr;
1113 	long namelen;
1114 	ino_t id = 0;
1115 	int offset, error = 0;
1116 	int fsize, lkflags, ltype, numdirpasses;
1117 
1118 	dvp = a->a_dvp;
1119 	node = VTON(dvp);
1120 	udfmp = node->udfmp;
1121 	nameiop = a->a_cnp->cn_nameiop;
1122 	flags = a->a_cnp->cn_flags;
1123 	lkflags = a->a_cnp->cn_lkflags;
1124 	nameptr = a->a_cnp->cn_nameptr;
1125 	namelen = a->a_cnp->cn_namelen;
1126 	fsize = le64toh(node->fentry->inf_len);
1127 
1128 	/*
1129 	 * If this is a LOOKUP and we've already partially searched through
1130 	 * the directory, pick up where we left off and flag that the
1131 	 * directory may need to be searched twice.  For a full description,
1132 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1133 	 */
1134 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1135 		offset = 0;
1136 		numdirpasses = 1;
1137 	} else {
1138 		offset = node->diroff;
1139 		numdirpasses = 2;
1140 		nchstats.ncs_2passes++;
1141 	}
1142 
1143 lookloop:
1144 	ds = udf_opendir(node, offset, fsize, udfmp);
1145 
1146 	while ((fid = udf_getfid(ds)) != NULL) {
1147 
1148 		/* XXX Should we return an error on a bad fid? */
1149 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1150 			printf("udf_lookup: Invalid tag\n");
1151 			error = EIO;
1152 			break;
1153 		}
1154 
1155 		/* Is this a deleted file? */
1156 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1157 			continue;
1158 
1159 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1160 			if (flags & ISDOTDOT) {
1161 				id = udf_getid(&fid->icb);
1162 				break;
1163 			}
1164 		} else {
1165 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1166 			    nameptr, fid->l_fi, namelen, udfmp))) {
1167 				id = udf_getid(&fid->icb);
1168 				break;
1169 			}
1170 		}
1171 	}
1172 
1173 	if (!error)
1174 		error = ds->error;
1175 
1176 	/* XXX Bail out here? */
1177 	if (error) {
1178 		udf_closedir(ds);
1179 		return (error);
1180 	}
1181 
1182 	/* Did we have a match? */
1183 	if (id) {
1184 		/*
1185 		 * Remember where this entry was if it's the final
1186 		 * component.
1187 		 */
1188 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1189 			node->diroff = ds->offset + ds->off;
1190 		if (numdirpasses == 2)
1191 			nchstats.ncs_pass2++;
1192 		udf_closedir(ds);
1193 
1194 		if (flags & ISDOTDOT) {
1195 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1196 		} else if (node->hash_id == id) {
1197 			VREF(dvp);	/* we want ourself, ie "." */
1198 			/*
1199 			 * When we lookup "." we still can be asked to lock it
1200 			 * differently.
1201 			 */
1202 			ltype = lkflags & LK_TYPE_MASK;
1203 			if (ltype != VOP_ISLOCKED(dvp)) {
1204 				if (ltype == LK_EXCLUSIVE)
1205 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1206 				else /* if (ltype == LK_SHARED) */
1207 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1208 			}
1209 			tdp = dvp;
1210 		} else
1211 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1212 		if (!error) {
1213 			*vpp = tdp;
1214 			/* Put this entry in the cache */
1215 			if (flags & MAKEENTRY)
1216 				cache_enter(dvp, *vpp, a->a_cnp);
1217 		}
1218 	} else {
1219 		/* Name wasn't found on this pass.  Do another pass? */
1220 		if (numdirpasses == 2) {
1221 			numdirpasses--;
1222 			offset = 0;
1223 			udf_closedir(ds);
1224 			goto lookloop;
1225 		}
1226 		udf_closedir(ds);
1227 
1228 		/* Enter name into cache as non-existant */
1229 		if (flags & MAKEENTRY)
1230 			cache_enter(dvp, *vpp, a->a_cnp);
1231 
1232 		if ((flags & ISLASTCN) &&
1233 		    (nameiop == CREATE || nameiop == RENAME)) {
1234 			error = EROFS;
1235 		} else {
1236 			error = ENOENT;
1237 		}
1238 	}
1239 
1240 	return (error);
1241 }
1242 
1243 static int
1244 udf_reclaim(struct vop_reclaim_args *a)
1245 {
1246 	struct vnode *vp;
1247 	struct udf_node *unode;
1248 
1249 	vp = a->a_vp;
1250 	unode = VTON(vp);
1251 
1252 	/*
1253 	 * Destroy the vm object and flush associated pages.
1254 	 */
1255 	vnode_destroy_vobject(vp);
1256 
1257 	if (unode != NULL) {
1258 		vfs_hash_remove(vp);
1259 
1260 		if (unode->fentry != NULL)
1261 			free(unode->fentry, M_UDFFENTRY);
1262 		uma_zfree(udf_zone_node, unode);
1263 		vp->v_data = NULL;
1264 	}
1265 
1266 	return (0);
1267 }
1268 
1269 static int
1270 udf_vptofh(struct vop_vptofh_args *a)
1271 {
1272 	struct udf_node *node;
1273 	struct ifid *ifhp;
1274 
1275 	node = VTON(a->a_vp);
1276 	ifhp = (struct ifid *)a->a_fhp;
1277 	ifhp->ifid_len = sizeof(struct ifid);
1278 	ifhp->ifid_ino = node->hash_id;
1279 
1280 	return (0);
1281 }
1282 
1283 /*
1284  * Read the block and then set the data pointer to correspond with the
1285  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1286  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1287  * whole extent.
1288  *
1289  * Note that *bp may be assigned error or not.
1290  *
1291  */
1292 static int
1293 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1294     struct buf **bp, uint8_t **data)
1295 {
1296 	struct udf_mnt *udfmp = node->udfmp;
1297 	struct vnode *vp = node->i_vnode;
1298 	struct file_entry *fentry;
1299 	struct buf *bp1;
1300 	uint32_t max_size;
1301 	daddr_t sector;
1302 	off_t off;
1303 	int adj_size;
1304 	int error;
1305 
1306 	/*
1307 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1308 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1309 	 */
1310 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1311 	if (error == UDF_INVALID_BMAP) {
1312 		/*
1313 		 * This error means that the file *data* is stored in the
1314 		 * allocation descriptor field of the file entry.
1315 		 */
1316 		fentry = node->fentry;
1317 		*data = &fentry->data[le32toh(fentry->l_ea)];
1318 		*size = le32toh(fentry->l_ad);
1319 		if (offset >= *size)
1320 			*size = 0;
1321 		else {
1322 			*data += offset;
1323 			*size -= offset;
1324 		}
1325 		return (0);
1326 	} else if (error != 0) {
1327 		return (error);
1328 	}
1329 
1330 	/* Adjust the size so that it is within range */
1331 	if (*size == 0 || *size > max_size)
1332 		*size = max_size;
1333 
1334 	/*
1335 	 * Because we will read starting at block boundary, we need to adjust
1336 	 * how much we need to read so that all promised data is in.
1337 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1338 	 * from block boundary, so adjust what we promise too.
1339 	 */
1340 	off = blkoff(udfmp, offset);
1341 	*size = min(*size, MAXBSIZE - off);
1342 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1343 	*bp = NULL;
1344 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1345 		printf("warning: udf_readlblks returned error %d\n", error);
1346 		/* note: *bp may be non-NULL */
1347 		return (error);
1348 	}
1349 
1350 	bp1 = *bp;
1351 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1352 	return (0);
1353 }
1354 
1355 /*
1356  * Translate a file offset into a logical block and then into a physical
1357  * block.
1358  * max_size - maximum number of bytes that can be read starting from given
1359  * offset, rather than beginning of calculated sector number
1360  */
1361 static int
1362 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1363     uint32_t *max_size)
1364 {
1365 	struct udf_mnt *udfmp;
1366 	struct file_entry *fentry;
1367 	void *icb;
1368 	struct icb_tag *tag;
1369 	uint32_t icblen = 0;
1370 	daddr_t lsector;
1371 	int ad_offset, ad_num = 0;
1372 	int i, p_offset;
1373 
1374 	udfmp = node->udfmp;
1375 	fentry = node->fentry;
1376 	tag = &fentry->icbtag;
1377 
1378 	switch (le16toh(tag->strat_type)) {
1379 	case 4:
1380 		break;
1381 
1382 	case 4096:
1383 		printf("Cannot deal with strategy4096 yet!\n");
1384 		return (ENODEV);
1385 
1386 	default:
1387 		printf("Unknown strategy type %d\n", tag->strat_type);
1388 		return (ENODEV);
1389 	}
1390 
1391 	switch (le16toh(tag->flags) & 0x7) {
1392 	case 0:
1393 		/*
1394 		 * The allocation descriptor field is filled with short_ad's.
1395 		 * If the offset is beyond the current extent, look for the
1396 		 * next extent.
1397 		 */
1398 		do {
1399 			offset -= icblen;
1400 			ad_offset = sizeof(struct short_ad) * ad_num;
1401 			if (ad_offset > le32toh(fentry->l_ad)) {
1402 				printf("File offset out of bounds\n");
1403 				return (EINVAL);
1404 			}
1405 			icb = GETICB(short_ad, fentry,
1406 			    le32toh(fentry->l_ea) + ad_offset);
1407 			icblen = GETICBLEN(short_ad, icb);
1408 			ad_num++;
1409 		} while(offset >= icblen);
1410 
1411 		lsector = (offset  >> udfmp->bshift) +
1412 		    le32toh(((struct short_ad *)(icb))->pos);
1413 
1414 		*max_size = icblen - offset;
1415 
1416 		break;
1417 	case 1:
1418 		/*
1419 		 * The allocation descriptor field is filled with long_ad's
1420 		 * If the offset is beyond the current extent, look for the
1421 		 * next extent.
1422 		 */
1423 		do {
1424 			offset -= icblen;
1425 			ad_offset = sizeof(struct long_ad) * ad_num;
1426 			if (ad_offset > le32toh(fentry->l_ad)) {
1427 				printf("File offset out of bounds\n");
1428 				return (EINVAL);
1429 			}
1430 			icb = GETICB(long_ad, fentry,
1431 			    le32toh(fentry->l_ea) + ad_offset);
1432 			icblen = GETICBLEN(long_ad, icb);
1433 			ad_num++;
1434 		} while(offset >= icblen);
1435 
1436 		lsector = (offset >> udfmp->bshift) +
1437 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1438 
1439 		*max_size = icblen - offset;
1440 
1441 		break;
1442 	case 3:
1443 		/*
1444 		 * This type means that the file *data* is stored in the
1445 		 * allocation descriptor field of the file entry.
1446 		 */
1447 		*max_size = 0;
1448 		*sector = node->hash_id + udfmp->part_start;
1449 
1450 		return (UDF_INVALID_BMAP);
1451 	case 2:
1452 		/* DirectCD does not use extended_ad's */
1453 	default:
1454 		printf("Unsupported allocation descriptor %d\n",
1455 		       tag->flags & 0x7);
1456 		return (ENODEV);
1457 	}
1458 
1459 	*sector = lsector + udfmp->part_start;
1460 
1461 	/*
1462 	 * Check the sparing table.  Each entry represents the beginning of
1463 	 * a packet.
1464 	 */
1465 	if (udfmp->s_table != NULL) {
1466 		for (i = 0; i< udfmp->s_table_entries; i++) {
1467 			p_offset =
1468 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1469 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1470 				*sector =
1471 				   le32toh(udfmp->s_table->entries[i].map) +
1472 				    p_offset;
1473 				break;
1474 			}
1475 		}
1476 	}
1477 
1478 	return (0);
1479 }
1480