xref: /freebsd/sys/fs/udf/udf_vnops.c (revision d34048812292b714a0bf99967270d18fe3097c62)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /* udf_vnops.c */
32 /* Take care of the vnode side of things */
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/namei.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/stat.h>
40 #include <sys/bio.h>
41 #include <sys/conf.h>
42 #include <sys/buf.h>
43 #include <sys/iconv.h>
44 #include <sys/mount.h>
45 #include <sys/vnode.h>
46 #include <sys/dirent.h>
47 #include <sys/queue.h>
48 #include <sys/unistd.h>
49 #include <sys/endian.h>
50 
51 #include <vm/uma.h>
52 
53 #include <fs/udf/ecma167-udf.h>
54 #include <fs/udf/osta.h>
55 #include <fs/udf/udf.h>
56 #include <fs/udf/udf_mount.h>
57 
58 extern struct iconv_functions *udf_iconv;
59 
60 static vop_access_t	udf_access;
61 static vop_getattr_t	udf_getattr;
62 static vop_open_t	udf_open;
63 static vop_ioctl_t	udf_ioctl;
64 static vop_pathconf_t	udf_pathconf;
65 static vop_print_t	udf_print;
66 static vop_read_t	udf_read;
67 static vop_readdir_t	udf_readdir;
68 static vop_readlink_t	udf_readlink;
69 static vop_setattr_t	udf_setattr;
70 static vop_strategy_t	udf_strategy;
71 static vop_bmap_t	udf_bmap;
72 static vop_cachedlookup_t	udf_lookup;
73 static vop_reclaim_t	udf_reclaim;
74 static vop_vptofh_t	udf_vptofh;
75 static int udf_readatoffset(struct udf_node *node, int *size, off_t offset,
76     struct buf **bp, uint8_t **data);
77 static int udf_bmap_internal(struct udf_node *node, off_t offset,
78     daddr_t *sector, uint32_t *max_size);
79 
80 static struct vop_vector udf_vnodeops = {
81 	.vop_default =		&default_vnodeops,
82 
83 	.vop_access =		udf_access,
84 	.vop_bmap =		udf_bmap,
85 	.vop_cachedlookup =	udf_lookup,
86 	.vop_getattr =		udf_getattr,
87 	.vop_ioctl =		udf_ioctl,
88 	.vop_lookup =		vfs_cache_lookup,
89 	.vop_open =		udf_open,
90 	.vop_pathconf =		udf_pathconf,
91 	.vop_print =		udf_print,
92 	.vop_read =		udf_read,
93 	.vop_readdir =		udf_readdir,
94 	.vop_readlink =		udf_readlink,
95 	.vop_reclaim =		udf_reclaim,
96 	.vop_setattr =		udf_setattr,
97 	.vop_strategy =		udf_strategy,
98 	.vop_vptofh =		udf_vptofh,
99 };
100 
101 struct vop_vector udf_fifoops = {
102 	.vop_default =		&fifo_specops,
103 	.vop_access =		udf_access,
104 	.vop_getattr =		udf_getattr,
105 	.vop_pathconf =		udf_pathconf,
106 	.vop_print =		udf_print,
107 	.vop_reclaim =		udf_reclaim,
108 	.vop_setattr =		udf_setattr,
109 	.vop_vptofh =		udf_vptofh,
110 };
111 
112 static MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
113 static MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");
114 
115 #define UDF_INVALID_BMAP	-1
116 
117 int
118 udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
119 {
120 	int error;
121 	struct vnode *vp;
122 
123 	error = getnewvnode("udf", mp, &udf_vnodeops, &vp);
124 	if (error) {
125 		printf("udf_allocv: failed to allocate new vnode\n");
126 		return (error);
127 	}
128 
129 	*vpp = vp;
130 	return (0);
131 }
132 
133 /* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
134 static mode_t
135 udf_permtomode(struct udf_node *node)
136 {
137 	uint32_t perm;
138 	uint16_t flags;
139 	mode_t mode;
140 
141 	perm = le32toh(node->fentry->perm);
142 	flags = le16toh(node->fentry->icbtag.flags);
143 
144 	mode = perm & UDF_FENTRY_PERM_USER_MASK;
145 	mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
146 	mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
147 	mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
148 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
149 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);
150 
151 	return (mode);
152 }
153 
154 static int
155 udf_access(struct vop_access_args *a)
156 {
157 	struct vnode *vp;
158 	struct udf_node *node;
159 	accmode_t accmode;
160 	mode_t mode;
161 
162 	vp = a->a_vp;
163 	node = VTON(vp);
164 	accmode = a->a_accmode;
165 
166 	if (accmode & VWRITE) {
167 		switch (vp->v_type) {
168 		case VDIR:
169 		case VLNK:
170 		case VREG:
171 			return (EROFS);
172 			/* NOT REACHED */
173 		default:
174 			break;
175 		}
176 	}
177 
178 	mode = udf_permtomode(node);
179 
180 	return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
181 	    accmode, a->a_cred, NULL));
182 }
183 
184 static int
185 udf_open(struct vop_open_args *ap) {
186 	struct udf_node *np = VTON(ap->a_vp);
187 	off_t fsize;
188 
189 	fsize = le64toh(np->fentry->inf_len);
190 	vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
191 	return 0;
192 }
193 
194 static const int mon_lens[2][12] = {
195 	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
196 	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
197 };
198 
199 static int
200 udf_isaleapyear(int year)
201 {
202 	int i;
203 
204 	i = (year % 4) ? 0 : 1;
205 	i &= (year % 100) ? 1 : 0;
206 	i |= (year % 400) ? 0 : 1;
207 
208 	return i;
209 }
210 
211 /*
212  * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
213  */
214 static void
215 udf_timetotimespec(struct timestamp *time, struct timespec *t)
216 {
217 	int i, lpyear, daysinyear, year, startyear;
218 	union {
219 		uint16_t	u_tz_offset;
220 		int16_t		s_tz_offset;
221 	} tz;
222 
223 	/*
224 	 * DirectCD seems to like using bogus year values.
225 	 * Don't trust time->month as it will be used for an array index.
226 	 */
227 	year = le16toh(time->year);
228 	if (year < 1970 || time->month < 1 || time->month > 12) {
229 		t->tv_sec = 0;
230 		t->tv_nsec = 0;
231 		return;
232 	}
233 
234 	/* Calculate the time and day */
235 	t->tv_sec = time->second;
236 	t->tv_sec += time->minute * 60;
237 	t->tv_sec += time->hour * 3600;
238 	t->tv_sec += (time->day - 1) * 3600 * 24;
239 
240 	/* Calculate the month */
241 	lpyear = udf_isaleapyear(year);
242 	t->tv_sec += mon_lens[lpyear][time->month - 1] * 3600 * 24;
243 
244 	/* Speed up the calculation */
245 	startyear = 1970;
246 	if (year > 2009) {
247 		t->tv_sec += 1262304000;
248 		startyear += 40;
249 	} else if (year > 1999) {
250 		t->tv_sec += 946684800;
251 		startyear += 30;
252 	} else if (year > 1989) {
253 		t->tv_sec += 631152000;
254 		startyear += 20;
255 	} else if (year > 1979) {
256 		t->tv_sec += 315532800;
257 		startyear += 10;
258 	}
259 
260 	daysinyear = (year - startyear) * 365;
261 	for (i = startyear; i < year; i++)
262 		daysinyear += udf_isaleapyear(i);
263 	t->tv_sec += daysinyear * 3600 * 24;
264 
265 	/* Calculate microseconds */
266 	t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
267 	    time->usec;
268 
269 	/*
270 	 * Calculate the time zone.  The timezone is 12 bit signed 2's
271 	 * complement, so we gotta do some extra magic to handle it right.
272 	 */
273 	tz.u_tz_offset = le16toh(time->type_tz);
274 	tz.u_tz_offset &= 0x0fff;
275 	if (tz.u_tz_offset & 0x0800)
276 		tz.u_tz_offset |= 0xf000;	/* extend the sign to 16 bits */
277 	if ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
278 		t->tv_sec -= tz.s_tz_offset * 60;
279 
280 	return;
281 }
282 
283 static int
284 udf_getattr(struct vop_getattr_args *a)
285 {
286 	struct vnode *vp;
287 	struct udf_node *node;
288 	struct vattr *vap;
289 	struct file_entry *fentry;
290 	struct timespec ts;
291 
292 	ts.tv_sec = 0;
293 
294 	vp = a->a_vp;
295 	vap = a->a_vap;
296 	node = VTON(vp);
297 	fentry = node->fentry;
298 
299 	vap->va_fsid = dev2udev(node->udfmp->im_dev);
300 	vap->va_fileid = node->hash_id;
301 	vap->va_mode = udf_permtomode(node);
302 	vap->va_nlink = le16toh(fentry->link_cnt);
303 	/*
304 	 * XXX The spec says that -1 is valid for uid/gid and indicates an
305 	 * invalid uid/gid.  How should this be represented?
306 	 */
307 	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
308 	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
309 	udf_timetotimespec(&fentry->atime, &vap->va_atime);
310 	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
311 	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
312 	vap->va_rdev = NODEV;
313 	if (vp->v_type & VDIR) {
314 		/*
315 		 * Directories that are recorded within their ICB will show
316 		 * as having 0 blocks recorded.  Since tradition dictates
317 		 * that directories consume at least one logical block,
318 		 * make it appear so.
319 		 */
320 		if (fentry->logblks_rec != 0) {
321 			vap->va_size =
322 			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
323 		} else {
324 			vap->va_size = node->udfmp->bsize;
325 		}
326 	} else {
327 		vap->va_size = le64toh(fentry->inf_len);
328 	}
329 	vap->va_flags = 0;
330 	vap->va_gen = 1;
331 	vap->va_blocksize = node->udfmp->bsize;
332 	vap->va_bytes = le64toh(fentry->inf_len);
333 	vap->va_type = vp->v_type;
334 	vap->va_filerev = 0; /* XXX */
335 	return (0);
336 }
337 
338 static int
339 udf_setattr(struct vop_setattr_args *a)
340 {
341 	struct vnode *vp;
342 	struct vattr *vap;
343 
344 	vp = a->a_vp;
345 	vap = a->a_vap;
346 	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
347 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
348 	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
349 		return (EROFS);
350 	if (vap->va_size != (u_quad_t)VNOVAL) {
351 		switch (vp->v_type) {
352 		case VDIR:
353 			return (EISDIR);
354 		case VLNK:
355 		case VREG:
356 			return (EROFS);
357 		case VCHR:
358 		case VBLK:
359 		case VSOCK:
360 		case VFIFO:
361 		case VNON:
362 		case VBAD:
363 		case VMARKER:
364 			return (0);
365 		}
366 	}
367 	return (0);
368 }
369 
370 /*
371  * File specific ioctls.
372  */
373 static int
374 udf_ioctl(struct vop_ioctl_args *a)
375 {
376 	printf("%s called\n", __func__);
377 	return (ENOTTY);
378 }
379 
380 /*
381  * I'm not sure that this has much value in a read-only filesystem, but
382  * cd9660 has it too.
383  */
384 static int
385 udf_pathconf(struct vop_pathconf_args *a)
386 {
387 
388 	switch (a->a_name) {
389 	case _PC_FILESIZEBITS:
390 		*a->a_retval = 64;
391 		return (0);
392 	case _PC_LINK_MAX:
393 		*a->a_retval = 65535;
394 		return (0);
395 	case _PC_NAME_MAX:
396 		*a->a_retval = NAME_MAX;
397 		return (0);
398 	case _PC_SYMLINK_MAX:
399 		*a->a_retval = MAXPATHLEN;
400 		return (0);
401 	case _PC_NO_TRUNC:
402 		*a->a_retval = 1;
403 		return (0);
404 	case _PC_PIPE_BUF:
405 		if (a->a_vp->v_type == VDIR || a->a_vp->v_type == VFIFO) {
406 			*a->a_retval = PIPE_BUF;
407 			return (0);
408 		}
409 		return (EINVAL);
410 	default:
411 		return (vop_stdpathconf(a));
412 	}
413 }
414 
415 static int
416 udf_print(struct vop_print_args *ap)
417 {
418 	struct vnode *vp = ap->a_vp;
419 	struct udf_node *node = VTON(vp);
420 
421 	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
422 	    devtoname(node->udfmp->im_dev));
423 	if (vp->v_type == VFIFO)
424 		fifo_printinfo(vp);
425 	printf("\n");
426 	return (0);
427 }
428 
429 #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
430 #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
431 #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
432 
433 static inline int
434 is_data_in_fentry(const struct udf_node *node)
435 {
436 	const struct file_entry *fentry = node->fentry;
437 
438 	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
439 }
440 
441 static int
442 udf_read(struct vop_read_args *ap)
443 {
444 	struct vnode *vp = ap->a_vp;
445 	struct uio *uio = ap->a_uio;
446 	struct udf_node *node = VTON(vp);
447 	struct udf_mnt *udfmp;
448 	struct file_entry *fentry;
449 	struct buf *bp;
450 	uint8_t *data;
451 	daddr_t lbn, rablock;
452 	off_t diff, fsize;
453 	ssize_t n;
454 	int error = 0;
455 	long size, on;
456 
457 	if (uio->uio_resid == 0)
458 		return (0);
459 	if (uio->uio_offset < 0)
460 		return (EINVAL);
461 
462 	if (is_data_in_fentry(node)) {
463 		fentry = node->fentry;
464 		data = &fentry->data[le32toh(fentry->l_ea)];
465 		fsize = le32toh(fentry->l_ad);
466 
467 		n = uio->uio_resid;
468 		diff = fsize - uio->uio_offset;
469 		if (diff <= 0)
470 			return (0);
471 		if (diff < n)
472 			n = diff;
473 		error = uiomove(data + uio->uio_offset, (int)n, uio);
474 		return (error);
475 	}
476 
477 	fsize = le64toh(node->fentry->inf_len);
478 	udfmp = node->udfmp;
479 	do {
480 		lbn = lblkno(udfmp, uio->uio_offset);
481 		on = blkoff(udfmp, uio->uio_offset);
482 		n = min((u_int)(udfmp->bsize - on),
483 			uio->uio_resid);
484 		diff = fsize - uio->uio_offset;
485 		if (diff <= 0)
486 			return (0);
487 		if (diff < n)
488 			n = diff;
489 		size = udfmp->bsize;
490 		rablock = lbn + 1;
491 		if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
492 			if (lblktosize(udfmp, rablock) < fsize) {
493 				error = cluster_read(vp, fsize, lbn, size,
494 				    NOCRED, uio->uio_resid,
495 				    (ap->a_ioflag >> 16), 0, &bp);
496 			} else {
497 				error = bread(vp, lbn, size, NOCRED, &bp);
498 			}
499 		} else {
500 			error = bread(vp, lbn, size, NOCRED, &bp);
501 		}
502 		if (error != 0) {
503 			brelse(bp);
504 			return (error);
505 		}
506 		n = min(n, size - bp->b_resid);
507 
508 		error = uiomove(bp->b_data + on, (int)n, uio);
509 		brelse(bp);
510 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
511 	return (error);
512 }
513 
514 /*
515  * Call the OSTA routines to translate the name from a CS0 dstring to a
516  * 16-bit Unicode String.  Hooks need to be placed in here to translate from
517  * Unicode to the encoding that the kernel/user expects.  Return the length
518  * of the translated string.
519  */
520 static int
521 udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
522 {
523 	unicode_t *transname;
524 	char *unibuf, *unip;
525 	int i, destlen;
526 	ssize_t unilen = 0;
527 	size_t destleft = MAXNAMLEN;
528 
529 	/* Convert 16-bit Unicode to destname */
530 	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
531 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
532 		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
533 		unip = unibuf;
534 		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
535 			printf("udf: Unicode translation failed\n");
536 			uma_zfree(udf_zone_trans, unibuf);
537 			return 0;
538 		}
539 
540 		while (unilen > 0 && destleft > 0) {
541 			udf_iconv->conv(udfmp->im_d2l, __DECONST(const char **,
542 			    &unibuf), (size_t *)&unilen, (char **)&destname,
543 			    &destleft);
544 			/* Unconverted character found */
545 			if (unilen > 0 && destleft > 0) {
546 				*destname++ = '?';
547 				destleft--;
548 				unibuf += 2;
549 				unilen -= 2;
550 			}
551 		}
552 		uma_zfree(udf_zone_trans, unip);
553 		*destname = '\0';
554 		destlen = MAXNAMLEN - (int)destleft;
555 	} else {
556 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
557 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
558 
559 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
560 			printf("udf: Unicode translation failed\n");
561 			uma_zfree(udf_zone_trans, transname);
562 			return 0;
563 		}
564 
565 		for (i = 0; i < unilen ; i++) {
566 			if (transname[i] & 0xff00) {
567 				destname[i] = '.';	/* Fudge the 16bit chars */
568 			} else {
569 				destname[i] = transname[i] & 0xff;
570 			}
571 		}
572 		uma_zfree(udf_zone_trans, transname);
573 		destname[unilen] = 0;
574 		destlen = (int)unilen;
575 	}
576 
577 	return (destlen);
578 }
579 
580 /*
581  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
582  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
583  * here also.
584  */
585 static int
586 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
587 {
588 	char *transname;
589 	int error = 0;
590 
591 	/* This is overkill, but not worth creating a new zone */
592 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
593 
594 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
595 
596 	/* Easy check.  If they aren't the same length, they aren't equal */
597 	if ((cs0len == 0) || (cs0len != cmplen))
598 		error = -1;
599 	else
600 		error = bcmp(transname, cmpname, cmplen);
601 
602 	uma_zfree(udf_zone_trans, transname);
603 	return (error);
604 }
605 
606 struct udf_uiodir {
607 	struct dirent *dirent;
608 	u_long *cookies;
609 	int ncookies;
610 	int acookies;
611 	int eofflag;
612 };
613 
614 static int
615 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
616 {
617 	if (uiodir->cookies != NULL) {
618 		if (++uiodir->acookies > uiodir->ncookies) {
619 			uiodir->eofflag = 0;
620 			return (-1);
621 		}
622 		*uiodir->cookies++ = cookie;
623 	}
624 
625 	if (uio->uio_resid < de_size) {
626 		uiodir->eofflag = 0;
627 		return (-1);
628 	}
629 
630 	return (uiomove(uiodir->dirent, de_size, uio));
631 }
632 
633 static struct udf_dirstream *
634 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
635 {
636 	struct udf_dirstream *ds;
637 
638 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
639 
640 	ds->node = node;
641 	ds->offset = offset;
642 	ds->udfmp = udfmp;
643 	ds->fsize = fsize;
644 
645 	return (ds);
646 }
647 
648 static struct fileid_desc *
649 udf_getfid(struct udf_dirstream *ds)
650 {
651 	struct fileid_desc *fid;
652 	int error, frag_size = 0, total_fid_size;
653 
654 	/* End of directory? */
655 	if (ds->offset + ds->off >= ds->fsize) {
656 		ds->error = 0;
657 		return (NULL);
658 	}
659 
660 	/* Grab the first extent of the directory */
661 	if (ds->off == 0) {
662 		ds->size = 0;
663 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
664 		    &ds->bp, &ds->data);
665 		if (error) {
666 			ds->error = error;
667 			if (ds->bp != NULL)
668 				brelse(ds->bp);
669 			return (NULL);
670 		}
671 	}
672 
673 	/*
674 	 * Clean up from a previous fragmented FID.
675 	 * XXX Is this the right place for this?
676 	 */
677 	if (ds->fid_fragment && ds->buf != NULL) {
678 		ds->fid_fragment = 0;
679 		free(ds->buf, M_UDFFID);
680 	}
681 
682 	fid = (struct fileid_desc*)&ds->data[ds->off];
683 
684 	/*
685 	 * Check to see if the fid is fragmented. The first test
686 	 * ensures that we don't wander off the end of the buffer
687 	 * looking for the l_iu and l_fi fields.
688 	 */
689 	if (ds->off + UDF_FID_SIZE > ds->size ||
690 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
691 
692 		/* Copy what we have of the fid into a buffer */
693 		frag_size = ds->size - ds->off;
694 		if (frag_size >= ds->udfmp->bsize) {
695 			printf("udf: invalid FID fragment\n");
696 			ds->error = EINVAL;
697 			return (NULL);
698 		}
699 
700 		/*
701 		 * File ID descriptors can only be at most one
702 		 * logical sector in size.
703 		 */
704 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
705 		     M_WAITOK | M_ZERO);
706 		bcopy(fid, ds->buf, frag_size);
707 
708 		/* Reduce all of the casting magic */
709 		fid = (struct fileid_desc*)ds->buf;
710 
711 		if (ds->bp != NULL)
712 			brelse(ds->bp);
713 
714 		/* Fetch the next allocation */
715 		ds->offset += ds->size;
716 		ds->size = 0;
717 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
718 		    &ds->bp, &ds->data);
719 		if (error) {
720 			ds->error = error;
721 			return (NULL);
722 		}
723 
724 		/*
725 		 * If the fragment was so small that we didn't get
726 		 * the l_iu and l_fi fields, copy those in.
727 		 */
728 		if (frag_size < UDF_FID_SIZE)
729 			bcopy(ds->data, &ds->buf[frag_size],
730 			    UDF_FID_SIZE - frag_size);
731 
732 		/*
733 		 * Now that we have enough of the fid to work with,
734 		 * copy in the rest of the fid from the new
735 		 * allocation.
736 		 */
737 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
738 		if (total_fid_size > ds->udfmp->bsize) {
739 			printf("udf: invalid FID\n");
740 			ds->error = EIO;
741 			return (NULL);
742 		}
743 		bcopy(ds->data, &ds->buf[frag_size],
744 		    total_fid_size - frag_size);
745 
746 		ds->fid_fragment = 1;
747 	} else {
748 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
749 	}
750 
751 	/*
752 	 * Update the offset. Align on a 4 byte boundary because the
753 	 * UDF spec says so.
754 	 */
755 	ds->this_off = ds->offset + ds->off;
756 	if (!ds->fid_fragment) {
757 		ds->off += (total_fid_size + 3) & ~0x03;
758 	} else {
759 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
760 	}
761 
762 	return (fid);
763 }
764 
765 static void
766 udf_closedir(struct udf_dirstream *ds)
767 {
768 
769 	if (ds->bp != NULL)
770 		brelse(ds->bp);
771 
772 	if (ds->fid_fragment && ds->buf != NULL)
773 		free(ds->buf, M_UDFFID);
774 
775 	uma_zfree(udf_zone_ds, ds);
776 }
777 
778 static int
779 udf_readdir(struct vop_readdir_args *a)
780 {
781 	struct vnode *vp;
782 	struct uio *uio;
783 	struct dirent dir;
784 	struct udf_node *node;
785 	struct udf_mnt *udfmp;
786 	struct fileid_desc *fid;
787 	struct udf_uiodir uiodir;
788 	struct udf_dirstream *ds;
789 	u_long *cookies = NULL;
790 	int ncookies;
791 	int error = 0;
792 
793 	vp = a->a_vp;
794 	uio = a->a_uio;
795 	node = VTON(vp);
796 	udfmp = node->udfmp;
797 	uiodir.eofflag = 1;
798 
799 	if (a->a_ncookies != NULL) {
800 		/*
801 		 * Guess how many entries are needed.  If we run out, this
802 		 * function will be called again and thing will pick up were
803 		 * it left off.
804 		 */
805 		ncookies = uio->uio_resid / 8;
806 		cookies = malloc(sizeof(u_long) * ncookies,
807 		    M_TEMP, M_WAITOK);
808 		if (cookies == NULL)
809 			return (ENOMEM);
810 		uiodir.ncookies = ncookies;
811 		uiodir.cookies = cookies;
812 		uiodir.acookies = 0;
813 	} else {
814 		uiodir.cookies = NULL;
815 	}
816 
817 	/*
818 	 * Iterate through the file id descriptors.  Give the parent dir
819 	 * entry special attention.
820 	 */
821 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
822 	    node->udfmp);
823 
824 	while ((fid = udf_getfid(ds)) != NULL) {
825 
826 		/* XXX Should we return an error on a bad fid? */
827 		if (udf_checktag(&fid->tag, TAGID_FID)) {
828 			printf("Invalid FID tag\n");
829 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
830 			error = EIO;
831 			break;
832 		}
833 
834 		/* Is this a deleted file? */
835 		if (fid->file_char & UDF_FILE_CHAR_DEL)
836 			continue;
837 
838 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
839 			/* Do up the '.' and '..' entries.  Dummy values are
840 			 * used for the cookies since the offset here is
841 			 * usually zero, and NFS doesn't like that value
842 			 */
843 			dir.d_fileno = node->hash_id;
844 			dir.d_type = DT_DIR;
845 			dir.d_name[0] = '.';
846 			dir.d_namlen = 1;
847 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
848 			dir.d_off = 1;
849 			dirent_terminate(&dir);
850 			uiodir.dirent = &dir;
851 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
852 			if (error)
853 				break;
854 
855 			dir.d_fileno = udf_getid(&fid->icb);
856 			dir.d_type = DT_DIR;
857 			dir.d_name[0] = '.';
858 			dir.d_name[1] = '.';
859 			dir.d_namlen = 2;
860 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
861 			dir.d_off = 2;
862 			dirent_terminate(&dir);
863 			uiodir.dirent = &dir;
864 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
865 		} else {
866 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
867 			    &dir.d_name[0], fid->l_fi, udfmp);
868 			dir.d_fileno = udf_getid(&fid->icb);
869 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
870 			    DT_DIR : DT_UNKNOWN;
871 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
872 			dir.d_off = ds->this_off;
873 			dirent_terminate(&dir);
874 			uiodir.dirent = &dir;
875 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
876 			    ds->this_off);
877 		}
878 		if (error)
879 			break;
880 		uio->uio_offset = ds->offset + ds->off;
881 	}
882 
883 	/* tell the calling layer whether we need to be called again */
884 	*a->a_eofflag = uiodir.eofflag;
885 
886 	if (error < 0)
887 		error = 0;
888 	if (!error)
889 		error = ds->error;
890 
891 	udf_closedir(ds);
892 
893 	if (a->a_ncookies != NULL) {
894 		if (error)
895 			free(cookies, M_TEMP);
896 		else {
897 			*a->a_ncookies = uiodir.acookies;
898 			*a->a_cookies = cookies;
899 		}
900 	}
901 
902 	return (error);
903 }
904 
905 static int
906 udf_readlink(struct vop_readlink_args *ap)
907 {
908 	struct path_component *pc, *end;
909 	struct vnode *vp;
910 	struct uio uio;
911 	struct iovec iov[1];
912 	struct udf_node *node;
913 	void *buf;
914 	char *cp;
915 	int error, len, root;
916 
917 	/*
918 	 * A symbolic link in UDF is a list of variable-length path
919 	 * component structures.  We build a pathname in the caller's
920 	 * uio by traversing this list.
921 	 */
922 	vp = ap->a_vp;
923 	node = VTON(vp);
924 	len = le64toh(node->fentry->inf_len);
925 	buf = malloc(len, M_DEVBUF, M_WAITOK);
926 	iov[0].iov_len = len;
927 	iov[0].iov_base = buf;
928 	uio.uio_iov = iov;
929 	uio.uio_iovcnt = 1;
930 	uio.uio_offset = 0;
931 	uio.uio_resid = iov[0].iov_len;
932 	uio.uio_segflg = UIO_SYSSPACE;
933 	uio.uio_rw = UIO_READ;
934 	uio.uio_td = curthread;
935 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
936 	if (error)
937 		goto error;
938 
939 	pc = buf;
940 	end = (void *)((char *)buf + len);
941 	root = 0;
942 	while (pc < end) {
943 		switch (pc->type) {
944 		case UDF_PATH_ROOT:
945 			/* Only allow this at the beginning of a path. */
946 			if ((void *)pc != buf) {
947 				error = EINVAL;
948 				goto error;
949 			}
950 			cp = "/";
951 			len = 1;
952 			root = 1;
953 			break;
954 		case UDF_PATH_DOT:
955 			cp = ".";
956 			len = 1;
957 			break;
958 		case UDF_PATH_DOTDOT:
959 			cp = "..";
960 			len = 2;
961 			break;
962 		case UDF_PATH_PATH:
963 			if (pc->length == 0) {
964 				error = EINVAL;
965 				goto error;
966 			}
967 			/*
968 			 * XXX: We only support CS8 which appears to map
969 			 * to ASCII directly.
970 			 */
971 			switch (pc->identifier[0]) {
972 			case 8:
973 				cp = pc->identifier + 1;
974 				len = pc->length - 1;
975 				break;
976 			default:
977 				error = EOPNOTSUPP;
978 				goto error;
979 			}
980 			break;
981 		default:
982 			error = EINVAL;
983 			goto error;
984 		}
985 
986 		/*
987 		 * If this is not the first component, insert a path
988 		 * separator.
989 		 */
990 		if (pc != buf) {
991 			/* If we started with root we already have a "/". */
992 			if (root)
993 				goto skipslash;
994 			root = 0;
995 			if (ap->a_uio->uio_resid < 1) {
996 				error = ENAMETOOLONG;
997 				goto error;
998 			}
999 			error = uiomove("/", 1, ap->a_uio);
1000 			if (error)
1001 				break;
1002 		}
1003 	skipslash:
1004 
1005 		/* Append string at 'cp' of length 'len' to our path. */
1006 		if (len > ap->a_uio->uio_resid) {
1007 			error = ENAMETOOLONG;
1008 			goto error;
1009 		}
1010 		error = uiomove(cp, len, ap->a_uio);
1011 		if (error)
1012 			break;
1013 
1014 		/* Advance to next component. */
1015 		pc = (void *)((char *)pc + 4 + pc->length);
1016 	}
1017 error:
1018 	free(buf, M_DEVBUF);
1019 	return (error);
1020 }
1021 
1022 static int
1023 udf_strategy(struct vop_strategy_args *a)
1024 {
1025 	struct buf *bp;
1026 	struct vnode *vp;
1027 	struct udf_node *node;
1028 	struct bufobj *bo;
1029 	off_t offset;
1030 	uint32_t maxsize;
1031 	daddr_t sector;
1032 	int error;
1033 
1034 	bp = a->a_bp;
1035 	vp = a->a_vp;
1036 	node = VTON(vp);
1037 
1038 	if (bp->b_blkno == bp->b_lblkno) {
1039 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1040 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1041 		if (error) {
1042 			clrbuf(bp);
1043 			bp->b_blkno = -1;
1044 			bufdone(bp);
1045 			return (0);
1046 		}
1047 		/* bmap gives sector numbers, bio works with device blocks */
1048 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1049 	}
1050 	bo = node->udfmp->im_bo;
1051 	bp->b_iooffset = dbtob(bp->b_blkno);
1052 	BO_STRATEGY(bo, bp);
1053 	return (0);
1054 }
1055 
1056 static int
1057 udf_bmap(struct vop_bmap_args *a)
1058 {
1059 	struct udf_node *node;
1060 	uint32_t max_size;
1061 	daddr_t lsector;
1062 	int nblk;
1063 	int error;
1064 
1065 	node = VTON(a->a_vp);
1066 
1067 	if (a->a_bop != NULL)
1068 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1069 	if (a->a_bnp == NULL)
1070 		return (0);
1071 	if (a->a_runb)
1072 		*a->a_runb = 0;
1073 
1074 	/*
1075 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1076 	 * error that should not be propagated to calling code.
1077 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1078 	 * translate block numbers in this case.
1079 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1080 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1081 	 * thing for this kind of files.
1082 	 */
1083 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1084 	    &lsector, &max_size);
1085 	if (error == UDF_INVALID_BMAP)
1086 		return (EOPNOTSUPP);
1087 	if (error)
1088 		return (error);
1089 
1090 	/* Translate logical to physical sector number */
1091 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1092 
1093 	/*
1094 	 * Determine maximum number of readahead blocks following the
1095 	 * requested block.
1096 	 */
1097 	if (a->a_runp) {
1098 		nblk = (max_size >> node->udfmp->bshift) - 1;
1099 		if (nblk <= 0)
1100 			*a->a_runp = 0;
1101 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1102 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1103 		else
1104 			*a->a_runp = nblk;
1105 	}
1106 
1107 	if (a->a_runb) {
1108 		*a->a_runb = 0;
1109 	}
1110 
1111 	return (0);
1112 }
1113 
1114 /*
1115  * The all powerful VOP_LOOKUP().
1116  */
1117 static int
1118 udf_lookup(struct vop_cachedlookup_args *a)
1119 {
1120 	struct vnode *dvp;
1121 	struct vnode *tdp = NULL;
1122 	struct vnode **vpp = a->a_vpp;
1123 	struct udf_node *node;
1124 	struct udf_mnt *udfmp;
1125 	struct fileid_desc *fid = NULL;
1126 	struct udf_dirstream *ds;
1127 	u_long nameiop;
1128 	u_long flags;
1129 	char *nameptr;
1130 	long namelen;
1131 	ino_t id = 0;
1132 	int offset, error = 0;
1133 	int fsize, lkflags, ltype, numdirpasses;
1134 
1135 	dvp = a->a_dvp;
1136 	node = VTON(dvp);
1137 	udfmp = node->udfmp;
1138 	nameiop = a->a_cnp->cn_nameiop;
1139 	flags = a->a_cnp->cn_flags;
1140 	lkflags = a->a_cnp->cn_lkflags;
1141 	nameptr = a->a_cnp->cn_nameptr;
1142 	namelen = a->a_cnp->cn_namelen;
1143 	fsize = le64toh(node->fentry->inf_len);
1144 
1145 	/*
1146 	 * If this is a LOOKUP and we've already partially searched through
1147 	 * the directory, pick up where we left off and flag that the
1148 	 * directory may need to be searched twice.  For a full description,
1149 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1150 	 */
1151 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1152 		offset = 0;
1153 		numdirpasses = 1;
1154 	} else {
1155 		offset = node->diroff;
1156 		numdirpasses = 2;
1157 		nchstats.ncs_2passes++;
1158 	}
1159 
1160 lookloop:
1161 	ds = udf_opendir(node, offset, fsize, udfmp);
1162 
1163 	while ((fid = udf_getfid(ds)) != NULL) {
1164 
1165 		/* XXX Should we return an error on a bad fid? */
1166 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1167 			printf("udf_lookup: Invalid tag\n");
1168 			error = EIO;
1169 			break;
1170 		}
1171 
1172 		/* Is this a deleted file? */
1173 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1174 			continue;
1175 
1176 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1177 			if (flags & ISDOTDOT) {
1178 				id = udf_getid(&fid->icb);
1179 				break;
1180 			}
1181 		} else {
1182 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1183 			    nameptr, fid->l_fi, namelen, udfmp))) {
1184 				id = udf_getid(&fid->icb);
1185 				break;
1186 			}
1187 		}
1188 	}
1189 
1190 	if (!error)
1191 		error = ds->error;
1192 
1193 	/* XXX Bail out here? */
1194 	if (error) {
1195 		udf_closedir(ds);
1196 		return (error);
1197 	}
1198 
1199 	/* Did we have a match? */
1200 	if (id) {
1201 		/*
1202 		 * Remember where this entry was if it's the final
1203 		 * component.
1204 		 */
1205 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1206 			node->diroff = ds->offset + ds->off;
1207 		if (numdirpasses == 2)
1208 			nchstats.ncs_pass2++;
1209 		udf_closedir(ds);
1210 
1211 		if (flags & ISDOTDOT) {
1212 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1213 		} else if (node->hash_id == id) {
1214 			VREF(dvp);	/* we want ourself, ie "." */
1215 			/*
1216 			 * When we lookup "." we still can be asked to lock it
1217 			 * differently.
1218 			 */
1219 			ltype = lkflags & LK_TYPE_MASK;
1220 			if (ltype != VOP_ISLOCKED(dvp)) {
1221 				if (ltype == LK_EXCLUSIVE)
1222 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1223 				else /* if (ltype == LK_SHARED) */
1224 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1225 			}
1226 			tdp = dvp;
1227 		} else
1228 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1229 		if (!error) {
1230 			*vpp = tdp;
1231 			/* Put this entry in the cache */
1232 			if (flags & MAKEENTRY)
1233 				cache_enter(dvp, *vpp, a->a_cnp);
1234 		}
1235 	} else {
1236 		/* Name wasn't found on this pass.  Do another pass? */
1237 		if (numdirpasses == 2) {
1238 			numdirpasses--;
1239 			offset = 0;
1240 			udf_closedir(ds);
1241 			goto lookloop;
1242 		}
1243 		udf_closedir(ds);
1244 
1245 		/* Enter name into cache as non-existant */
1246 		if (flags & MAKEENTRY)
1247 			cache_enter(dvp, *vpp, a->a_cnp);
1248 
1249 		if ((flags & ISLASTCN) &&
1250 		    (nameiop == CREATE || nameiop == RENAME)) {
1251 			error = EROFS;
1252 		} else {
1253 			error = ENOENT;
1254 		}
1255 	}
1256 
1257 	return (error);
1258 }
1259 
1260 static int
1261 udf_reclaim(struct vop_reclaim_args *a)
1262 {
1263 	struct vnode *vp;
1264 	struct udf_node *unode;
1265 
1266 	vp = a->a_vp;
1267 	unode = VTON(vp);
1268 
1269 	/*
1270 	 * Destroy the vm object and flush associated pages.
1271 	 */
1272 	vnode_destroy_vobject(vp);
1273 
1274 	if (unode != NULL) {
1275 		vfs_hash_remove(vp);
1276 
1277 		if (unode->fentry != NULL)
1278 			free(unode->fentry, M_UDFFENTRY);
1279 		uma_zfree(udf_zone_node, unode);
1280 		vp->v_data = NULL;
1281 	}
1282 
1283 	return (0);
1284 }
1285 
1286 static int
1287 udf_vptofh(struct vop_vptofh_args *a)
1288 {
1289 	struct udf_node *node;
1290 	struct ifid *ifhp;
1291 
1292 	node = VTON(a->a_vp);
1293 	ifhp = (struct ifid *)a->a_fhp;
1294 	ifhp->ifid_len = sizeof(struct ifid);
1295 	ifhp->ifid_ino = node->hash_id;
1296 
1297 	return (0);
1298 }
1299 
1300 /*
1301  * Read the block and then set the data pointer to correspond with the
1302  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1303  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1304  * whole extent.
1305  *
1306  * Note that *bp may be assigned error or not.
1307  *
1308  */
1309 static int
1310 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1311     struct buf **bp, uint8_t **data)
1312 {
1313 	struct udf_mnt *udfmp = node->udfmp;
1314 	struct vnode *vp = node->i_vnode;
1315 	struct file_entry *fentry;
1316 	struct buf *bp1;
1317 	uint32_t max_size;
1318 	daddr_t sector;
1319 	off_t off;
1320 	int adj_size;
1321 	int error;
1322 
1323 	/*
1324 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1325 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1326 	 */
1327 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1328 	if (error == UDF_INVALID_BMAP) {
1329 		/*
1330 		 * This error means that the file *data* is stored in the
1331 		 * allocation descriptor field of the file entry.
1332 		 */
1333 		fentry = node->fentry;
1334 		*data = &fentry->data[le32toh(fentry->l_ea)];
1335 		*size = le32toh(fentry->l_ad);
1336 		if (offset >= *size)
1337 			*size = 0;
1338 		else {
1339 			*data += offset;
1340 			*size -= offset;
1341 		}
1342 		return (0);
1343 	} else if (error != 0) {
1344 		return (error);
1345 	}
1346 
1347 	/* Adjust the size so that it is within range */
1348 	if (*size == 0 || *size > max_size)
1349 		*size = max_size;
1350 
1351 	/*
1352 	 * Because we will read starting at block boundary, we need to adjust
1353 	 * how much we need to read so that all promised data is in.
1354 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1355 	 * from block boundary, so adjust what we promise too.
1356 	 */
1357 	off = blkoff(udfmp, offset);
1358 	*size = min(*size, MAXBSIZE - off);
1359 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1360 	*bp = NULL;
1361 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1362 		printf("warning: udf_readlblks returned error %d\n", error);
1363 		/* note: *bp may be non-NULL */
1364 		return (error);
1365 	}
1366 
1367 	bp1 = *bp;
1368 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1369 	return (0);
1370 }
1371 
1372 /*
1373  * Translate a file offset into a logical block and then into a physical
1374  * block.
1375  * max_size - maximum number of bytes that can be read starting from given
1376  * offset, rather than beginning of calculated sector number
1377  */
1378 static int
1379 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1380     uint32_t *max_size)
1381 {
1382 	struct udf_mnt *udfmp;
1383 	struct file_entry *fentry;
1384 	void *icb;
1385 	struct icb_tag *tag;
1386 	uint32_t icblen = 0;
1387 	daddr_t lsector;
1388 	int ad_offset, ad_num = 0;
1389 	int i, p_offset;
1390 
1391 	udfmp = node->udfmp;
1392 	fentry = node->fentry;
1393 	tag = &fentry->icbtag;
1394 
1395 	switch (le16toh(tag->strat_type)) {
1396 	case 4:
1397 		break;
1398 
1399 	case 4096:
1400 		printf("Cannot deal with strategy4096 yet!\n");
1401 		return (ENODEV);
1402 
1403 	default:
1404 		printf("Unknown strategy type %d\n", tag->strat_type);
1405 		return (ENODEV);
1406 	}
1407 
1408 	switch (le16toh(tag->flags) & 0x7) {
1409 	case 0:
1410 		/*
1411 		 * The allocation descriptor field is filled with short_ad's.
1412 		 * If the offset is beyond the current extent, look for the
1413 		 * next extent.
1414 		 */
1415 		do {
1416 			offset -= icblen;
1417 			ad_offset = sizeof(struct short_ad) * ad_num;
1418 			if (ad_offset > le32toh(fentry->l_ad)) {
1419 				printf("File offset out of bounds\n");
1420 				return (EINVAL);
1421 			}
1422 			icb = GETICB(short_ad, fentry,
1423 			    le32toh(fentry->l_ea) + ad_offset);
1424 			icblen = GETICBLEN(short_ad, icb);
1425 			ad_num++;
1426 		} while(offset >= icblen);
1427 
1428 		lsector = (offset  >> udfmp->bshift) +
1429 		    le32toh(((struct short_ad *)(icb))->pos);
1430 
1431 		*max_size = icblen - offset;
1432 
1433 		break;
1434 	case 1:
1435 		/*
1436 		 * The allocation descriptor field is filled with long_ad's
1437 		 * If the offset is beyond the current extent, look for the
1438 		 * next extent.
1439 		 */
1440 		do {
1441 			offset -= icblen;
1442 			ad_offset = sizeof(struct long_ad) * ad_num;
1443 			if (ad_offset > le32toh(fentry->l_ad)) {
1444 				printf("File offset out of bounds\n");
1445 				return (EINVAL);
1446 			}
1447 			icb = GETICB(long_ad, fentry,
1448 			    le32toh(fentry->l_ea) + ad_offset);
1449 			icblen = GETICBLEN(long_ad, icb);
1450 			ad_num++;
1451 		} while(offset >= icblen);
1452 
1453 		lsector = (offset >> udfmp->bshift) +
1454 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1455 
1456 		*max_size = icblen - offset;
1457 
1458 		break;
1459 	case 3:
1460 		/*
1461 		 * This type means that the file *data* is stored in the
1462 		 * allocation descriptor field of the file entry.
1463 		 */
1464 		*max_size = 0;
1465 		*sector = node->hash_id + udfmp->part_start;
1466 
1467 		return (UDF_INVALID_BMAP);
1468 	case 2:
1469 		/* DirectCD does not use extended_ad's */
1470 	default:
1471 		printf("Unsupported allocation descriptor %d\n",
1472 		       tag->flags & 0x7);
1473 		return (ENODEV);
1474 	}
1475 
1476 	*sector = lsector + udfmp->part_start;
1477 
1478 	/*
1479 	 * Check the sparing table.  Each entry represents the beginning of
1480 	 * a packet.
1481 	 */
1482 	if (udfmp->s_table != NULL) {
1483 		for (i = 0; i< udfmp->s_table_entries; i++) {
1484 			p_offset =
1485 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1486 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1487 				*sector =
1488 				   le32toh(udfmp->s_table->entries[i].map) +
1489 				    p_offset;
1490 				break;
1491 			}
1492 		}
1493 	}
1494 
1495 	return (0);
1496 }
1497