xref: /freebsd/sys/fs/udf/udf_vnops.c (revision e17f5b1d)
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 VFS_VOP_VECTOR_REGISTER(udf_vnodeops);
101 
102 struct vop_vector udf_fifoops = {
103 	.vop_default =		&fifo_specops,
104 	.vop_access =		udf_access,
105 	.vop_getattr =		udf_getattr,
106 	.vop_pathconf =		udf_pathconf,
107 	.vop_print =		udf_print,
108 	.vop_reclaim =		udf_reclaim,
109 	.vop_setattr =		udf_setattr,
110 	.vop_vptofh =		udf_vptofh,
111 };
112 VFS_VOP_VECTOR_REGISTER(udf_fifoops);
113 
114 static MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
115 static MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");
116 
117 #define UDF_INVALID_BMAP	-1
118 
119 int
120 udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
121 {
122 	int error;
123 	struct vnode *vp;
124 
125 	error = getnewvnode("udf", mp, &udf_vnodeops, &vp);
126 	if (error) {
127 		printf("udf_allocv: failed to allocate new vnode\n");
128 		return (error);
129 	}
130 
131 	*vpp = vp;
132 	return (0);
133 }
134 
135 /* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
136 static mode_t
137 udf_permtomode(struct udf_node *node)
138 {
139 	uint32_t perm;
140 	uint16_t flags;
141 	mode_t mode;
142 
143 	perm = le32toh(node->fentry->perm);
144 	flags = le16toh(node->fentry->icbtag.flags);
145 
146 	mode = perm & UDF_FENTRY_PERM_USER_MASK;
147 	mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
148 	mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
149 	mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
150 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
151 	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);
152 
153 	return (mode);
154 }
155 
156 static int
157 udf_access(struct vop_access_args *a)
158 {
159 	struct vnode *vp;
160 	struct udf_node *node;
161 	accmode_t accmode;
162 	mode_t mode;
163 
164 	vp = a->a_vp;
165 	node = VTON(vp);
166 	accmode = a->a_accmode;
167 
168 	if (accmode & VWRITE) {
169 		switch (vp->v_type) {
170 		case VDIR:
171 		case VLNK:
172 		case VREG:
173 			return (EROFS);
174 			/* NOT REACHED */
175 		default:
176 			break;
177 		}
178 	}
179 
180 	mode = udf_permtomode(node);
181 
182 	return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
183 	    accmode, a->a_cred, NULL));
184 }
185 
186 static int
187 udf_open(struct vop_open_args *ap) {
188 	struct udf_node *np = VTON(ap->a_vp);
189 	off_t fsize;
190 
191 	fsize = le64toh(np->fentry->inf_len);
192 	vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
193 	return 0;
194 }
195 
196 static const int mon_lens[2][12] = {
197 	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
198 	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
199 };
200 
201 static int
202 udf_isaleapyear(int year)
203 {
204 	int i;
205 
206 	i = (year % 4) ? 0 : 1;
207 	i &= (year % 100) ? 1 : 0;
208 	i |= (year % 400) ? 0 : 1;
209 
210 	return i;
211 }
212 
213 /*
214  * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
215  */
216 static void
217 udf_timetotimespec(struct timestamp *time, struct timespec *t)
218 {
219 	int i, lpyear, daysinyear, year, startyear;
220 	union {
221 		uint16_t	u_tz_offset;
222 		int16_t		s_tz_offset;
223 	} tz;
224 
225 	/*
226 	 * DirectCD seems to like using bogus year values.
227 	 * Don't trust time->month as it will be used for an array index.
228 	 */
229 	year = le16toh(time->year);
230 	if (year < 1970 || time->month < 1 || time->month > 12) {
231 		t->tv_sec = 0;
232 		t->tv_nsec = 0;
233 		return;
234 	}
235 
236 	/* Calculate the time and day */
237 	t->tv_sec = time->second;
238 	t->tv_sec += time->minute * 60;
239 	t->tv_sec += time->hour * 3600;
240 	t->tv_sec += (time->day - 1) * 3600 * 24;
241 
242 	/* Calculate the month */
243 	lpyear = udf_isaleapyear(year);
244 	t->tv_sec += mon_lens[lpyear][time->month - 1] * 3600 * 24;
245 
246 	/* Speed up the calculation */
247 	startyear = 1970;
248 	if (year > 2009) {
249 		t->tv_sec += 1262304000;
250 		startyear += 40;
251 	} else if (year > 1999) {
252 		t->tv_sec += 946684800;
253 		startyear += 30;
254 	} else if (year > 1989) {
255 		t->tv_sec += 631152000;
256 		startyear += 20;
257 	} else if (year > 1979) {
258 		t->tv_sec += 315532800;
259 		startyear += 10;
260 	}
261 
262 	daysinyear = (year - startyear) * 365;
263 	for (i = startyear; i < year; i++)
264 		daysinyear += udf_isaleapyear(i);
265 	t->tv_sec += daysinyear * 3600 * 24;
266 
267 	/* Calculate microseconds */
268 	t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
269 	    time->usec;
270 
271 	/*
272 	 * Calculate the time zone.  The timezone is 12 bit signed 2's
273 	 * complement, so we gotta do some extra magic to handle it right.
274 	 */
275 	tz.u_tz_offset = le16toh(time->type_tz);
276 	tz.u_tz_offset &= 0x0fff;
277 	if (tz.u_tz_offset & 0x0800)
278 		tz.u_tz_offset |= 0xf000;	/* extend the sign to 16 bits */
279 	if ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
280 		t->tv_sec -= tz.s_tz_offset * 60;
281 
282 	return;
283 }
284 
285 static int
286 udf_getattr(struct vop_getattr_args *a)
287 {
288 	struct vnode *vp;
289 	struct udf_node *node;
290 	struct vattr *vap;
291 	struct file_entry *fentry;
292 	struct timespec ts;
293 
294 	ts.tv_sec = 0;
295 
296 	vp = a->a_vp;
297 	vap = a->a_vap;
298 	node = VTON(vp);
299 	fentry = node->fentry;
300 
301 	vap->va_fsid = dev2udev(node->udfmp->im_dev);
302 	vap->va_fileid = node->hash_id;
303 	vap->va_mode = udf_permtomode(node);
304 	vap->va_nlink = le16toh(fentry->link_cnt);
305 	/*
306 	 * XXX The spec says that -1 is valid for uid/gid and indicates an
307 	 * invalid uid/gid.  How should this be represented?
308 	 */
309 	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
310 	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
311 	udf_timetotimespec(&fentry->atime, &vap->va_atime);
312 	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
313 	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
314 	vap->va_rdev = NODEV;
315 	if (vp->v_type & VDIR) {
316 		/*
317 		 * Directories that are recorded within their ICB will show
318 		 * as having 0 blocks recorded.  Since tradition dictates
319 		 * that directories consume at least one logical block,
320 		 * make it appear so.
321 		 */
322 		if (fentry->logblks_rec != 0) {
323 			vap->va_size =
324 			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
325 		} else {
326 			vap->va_size = node->udfmp->bsize;
327 		}
328 	} else {
329 		vap->va_size = le64toh(fentry->inf_len);
330 	}
331 	vap->va_flags = 0;
332 	vap->va_gen = 1;
333 	vap->va_blocksize = node->udfmp->bsize;
334 	vap->va_bytes = le64toh(fentry->inf_len);
335 	vap->va_type = vp->v_type;
336 	vap->va_filerev = 0; /* XXX */
337 	return (0);
338 }
339 
340 static int
341 udf_setattr(struct vop_setattr_args *a)
342 {
343 	struct vnode *vp;
344 	struct vattr *vap;
345 
346 	vp = a->a_vp;
347 	vap = a->a_vap;
348 	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
349 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
350 	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
351 		return (EROFS);
352 	if (vap->va_size != (u_quad_t)VNOVAL) {
353 		switch (vp->v_type) {
354 		case VDIR:
355 			return (EISDIR);
356 		case VLNK:
357 		case VREG:
358 			return (EROFS);
359 		case VCHR:
360 		case VBLK:
361 		case VSOCK:
362 		case VFIFO:
363 		case VNON:
364 		case VBAD:
365 		case VMARKER:
366 			return (0);
367 		}
368 	}
369 	return (0);
370 }
371 
372 /*
373  * File specific ioctls.
374  */
375 static int
376 udf_ioctl(struct vop_ioctl_args *a)
377 {
378 	printf("%s called\n", __func__);
379 	return (ENOTTY);
380 }
381 
382 /*
383  * I'm not sure that this has much value in a read-only filesystem, but
384  * cd9660 has it too.
385  */
386 static int
387 udf_pathconf(struct vop_pathconf_args *a)
388 {
389 
390 	switch (a->a_name) {
391 	case _PC_FILESIZEBITS:
392 		*a->a_retval = 64;
393 		return (0);
394 	case _PC_LINK_MAX:
395 		*a->a_retval = 65535;
396 		return (0);
397 	case _PC_NAME_MAX:
398 		*a->a_retval = NAME_MAX;
399 		return (0);
400 	case _PC_SYMLINK_MAX:
401 		*a->a_retval = MAXPATHLEN;
402 		return (0);
403 	case _PC_NO_TRUNC:
404 		*a->a_retval = 1;
405 		return (0);
406 	case _PC_PIPE_BUF:
407 		if (a->a_vp->v_type == VDIR || a->a_vp->v_type == VFIFO) {
408 			*a->a_retval = PIPE_BUF;
409 			return (0);
410 		}
411 		return (EINVAL);
412 	default:
413 		return (vop_stdpathconf(a));
414 	}
415 }
416 
417 static int
418 udf_print(struct vop_print_args *ap)
419 {
420 	struct vnode *vp = ap->a_vp;
421 	struct udf_node *node = VTON(vp);
422 
423 	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
424 	    devtoname(node->udfmp->im_dev));
425 	if (vp->v_type == VFIFO)
426 		fifo_printinfo(vp);
427 	printf("\n");
428 	return (0);
429 }
430 
431 #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
432 #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
433 #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
434 
435 static inline int
436 is_data_in_fentry(const struct udf_node *node)
437 {
438 	const struct file_entry *fentry = node->fentry;
439 
440 	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
441 }
442 
443 static int
444 udf_read(struct vop_read_args *ap)
445 {
446 	struct vnode *vp = ap->a_vp;
447 	struct uio *uio = ap->a_uio;
448 	struct udf_node *node = VTON(vp);
449 	struct udf_mnt *udfmp;
450 	struct file_entry *fentry;
451 	struct buf *bp;
452 	uint8_t *data;
453 	daddr_t lbn, rablock;
454 	off_t diff, fsize;
455 	ssize_t n;
456 	int error = 0;
457 	long size, on;
458 
459 	if (uio->uio_resid == 0)
460 		return (0);
461 	if (uio->uio_offset < 0)
462 		return (EINVAL);
463 
464 	if (is_data_in_fentry(node)) {
465 		fentry = node->fentry;
466 		data = &fentry->data[le32toh(fentry->l_ea)];
467 		fsize = le32toh(fentry->l_ad);
468 
469 		n = uio->uio_resid;
470 		diff = fsize - uio->uio_offset;
471 		if (diff <= 0)
472 			return (0);
473 		if (diff < n)
474 			n = diff;
475 		error = uiomove(data + uio->uio_offset, (int)n, uio);
476 		return (error);
477 	}
478 
479 	fsize = le64toh(node->fentry->inf_len);
480 	udfmp = node->udfmp;
481 	do {
482 		lbn = lblkno(udfmp, uio->uio_offset);
483 		on = blkoff(udfmp, uio->uio_offset);
484 		n = min((u_int)(udfmp->bsize - on),
485 			uio->uio_resid);
486 		diff = fsize - uio->uio_offset;
487 		if (diff <= 0)
488 			return (0);
489 		if (diff < n)
490 			n = diff;
491 		size = udfmp->bsize;
492 		rablock = lbn + 1;
493 		if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
494 			if (lblktosize(udfmp, rablock) < fsize) {
495 				error = cluster_read(vp, fsize, lbn, size,
496 				    NOCRED, uio->uio_resid,
497 				    (ap->a_ioflag >> 16), 0, &bp);
498 			} else {
499 				error = bread(vp, lbn, size, NOCRED, &bp);
500 			}
501 		} else {
502 			error = bread(vp, lbn, size, NOCRED, &bp);
503 		}
504 		if (error != 0) {
505 			brelse(bp);
506 			return (error);
507 		}
508 		n = min(n, size - bp->b_resid);
509 
510 		error = uiomove(bp->b_data + on, (int)n, uio);
511 		brelse(bp);
512 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
513 	return (error);
514 }
515 
516 /*
517  * Call the OSTA routines to translate the name from a CS0 dstring to a
518  * 16-bit Unicode String.  Hooks need to be placed in here to translate from
519  * Unicode to the encoding that the kernel/user expects.  Return the length
520  * of the translated string.
521  */
522 static int
523 udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
524 {
525 	unicode_t *transname;
526 	char *unibuf, *unip;
527 	int i, destlen;
528 	ssize_t unilen = 0;
529 	size_t destleft = MAXNAMLEN;
530 
531 	/* Convert 16-bit Unicode to destname */
532 	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
533 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
534 		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
535 		unip = unibuf;
536 		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
537 			printf("udf: Unicode translation failed\n");
538 			uma_zfree(udf_zone_trans, unibuf);
539 			return 0;
540 		}
541 
542 		while (unilen > 0 && destleft > 0) {
543 			udf_iconv->conv(udfmp->im_d2l, __DECONST(const char **,
544 			    &unibuf), (size_t *)&unilen, (char **)&destname,
545 			    &destleft);
546 			/* Unconverted character found */
547 			if (unilen > 0 && destleft > 0) {
548 				*destname++ = '?';
549 				destleft--;
550 				unibuf += 2;
551 				unilen -= 2;
552 			}
553 		}
554 		uma_zfree(udf_zone_trans, unip);
555 		*destname = '\0';
556 		destlen = MAXNAMLEN - (int)destleft;
557 	} else {
558 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
559 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
560 
561 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
562 			printf("udf: Unicode translation failed\n");
563 			uma_zfree(udf_zone_trans, transname);
564 			return 0;
565 		}
566 
567 		for (i = 0; i < unilen ; i++) {
568 			if (transname[i] & 0xff00) {
569 				destname[i] = '.';	/* Fudge the 16bit chars */
570 			} else {
571 				destname[i] = transname[i] & 0xff;
572 			}
573 		}
574 		uma_zfree(udf_zone_trans, transname);
575 		destname[unilen] = 0;
576 		destlen = (int)unilen;
577 	}
578 
579 	return (destlen);
580 }
581 
582 /*
583  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
584  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
585  * here also.
586  */
587 static int
588 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
589 {
590 	char *transname;
591 	int error = 0;
592 
593 	/* This is overkill, but not worth creating a new zone */
594 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
595 
596 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
597 
598 	/* Easy check.  If they aren't the same length, they aren't equal */
599 	if ((cs0len == 0) || (cs0len != cmplen))
600 		error = -1;
601 	else
602 		error = bcmp(transname, cmpname, cmplen);
603 
604 	uma_zfree(udf_zone_trans, transname);
605 	return (error);
606 }
607 
608 struct udf_uiodir {
609 	struct dirent *dirent;
610 	u_long *cookies;
611 	int ncookies;
612 	int acookies;
613 	int eofflag;
614 };
615 
616 static int
617 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
618 {
619 	if (uiodir->cookies != NULL) {
620 		if (++uiodir->acookies > uiodir->ncookies) {
621 			uiodir->eofflag = 0;
622 			return (-1);
623 		}
624 		*uiodir->cookies++ = cookie;
625 	}
626 
627 	if (uio->uio_resid < de_size) {
628 		uiodir->eofflag = 0;
629 		return (-1);
630 	}
631 
632 	return (uiomove(uiodir->dirent, de_size, uio));
633 }
634 
635 static struct udf_dirstream *
636 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
637 {
638 	struct udf_dirstream *ds;
639 
640 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
641 
642 	ds->node = node;
643 	ds->offset = offset;
644 	ds->udfmp = udfmp;
645 	ds->fsize = fsize;
646 
647 	return (ds);
648 }
649 
650 static struct fileid_desc *
651 udf_getfid(struct udf_dirstream *ds)
652 {
653 	struct fileid_desc *fid;
654 	int error, frag_size = 0, total_fid_size;
655 
656 	/* End of directory? */
657 	if (ds->offset + ds->off >= ds->fsize) {
658 		ds->error = 0;
659 		return (NULL);
660 	}
661 
662 	/* Grab the first extent of the directory */
663 	if (ds->off == 0) {
664 		ds->size = 0;
665 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
666 		    &ds->bp, &ds->data);
667 		if (error) {
668 			ds->error = error;
669 			if (ds->bp != NULL)
670 				brelse(ds->bp);
671 			return (NULL);
672 		}
673 	}
674 
675 	/*
676 	 * Clean up from a previous fragmented FID.
677 	 * XXX Is this the right place for this?
678 	 */
679 	if (ds->fid_fragment && ds->buf != NULL) {
680 		ds->fid_fragment = 0;
681 		free(ds->buf, M_UDFFID);
682 	}
683 
684 	fid = (struct fileid_desc*)&ds->data[ds->off];
685 
686 	/*
687 	 * Check to see if the fid is fragmented. The first test
688 	 * ensures that we don't wander off the end of the buffer
689 	 * looking for the l_iu and l_fi fields.
690 	 */
691 	if (ds->off + UDF_FID_SIZE > ds->size ||
692 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
693 
694 		/* Copy what we have of the fid into a buffer */
695 		frag_size = ds->size - ds->off;
696 		if (frag_size >= ds->udfmp->bsize) {
697 			printf("udf: invalid FID fragment\n");
698 			ds->error = EINVAL;
699 			return (NULL);
700 		}
701 
702 		/*
703 		 * File ID descriptors can only be at most one
704 		 * logical sector in size.
705 		 */
706 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
707 		     M_WAITOK | M_ZERO);
708 		bcopy(fid, ds->buf, frag_size);
709 
710 		/* Reduce all of the casting magic */
711 		fid = (struct fileid_desc*)ds->buf;
712 
713 		if (ds->bp != NULL)
714 			brelse(ds->bp);
715 
716 		/* Fetch the next allocation */
717 		ds->offset += ds->size;
718 		ds->size = 0;
719 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
720 		    &ds->bp, &ds->data);
721 		if (error) {
722 			ds->error = error;
723 			return (NULL);
724 		}
725 
726 		/*
727 		 * If the fragment was so small that we didn't get
728 		 * the l_iu and l_fi fields, copy those in.
729 		 */
730 		if (frag_size < UDF_FID_SIZE)
731 			bcopy(ds->data, &ds->buf[frag_size],
732 			    UDF_FID_SIZE - frag_size);
733 
734 		/*
735 		 * Now that we have enough of the fid to work with,
736 		 * copy in the rest of the fid from the new
737 		 * allocation.
738 		 */
739 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
740 		if (total_fid_size > ds->udfmp->bsize) {
741 			printf("udf: invalid FID\n");
742 			ds->error = EIO;
743 			return (NULL);
744 		}
745 		bcopy(ds->data, &ds->buf[frag_size],
746 		    total_fid_size - frag_size);
747 
748 		ds->fid_fragment = 1;
749 	} else {
750 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
751 	}
752 
753 	/*
754 	 * Update the offset. Align on a 4 byte boundary because the
755 	 * UDF spec says so.
756 	 */
757 	ds->this_off = ds->offset + ds->off;
758 	if (!ds->fid_fragment) {
759 		ds->off += (total_fid_size + 3) & ~0x03;
760 	} else {
761 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
762 	}
763 
764 	return (fid);
765 }
766 
767 static void
768 udf_closedir(struct udf_dirstream *ds)
769 {
770 
771 	if (ds->bp != NULL)
772 		brelse(ds->bp);
773 
774 	if (ds->fid_fragment && ds->buf != NULL)
775 		free(ds->buf, M_UDFFID);
776 
777 	uma_zfree(udf_zone_ds, ds);
778 }
779 
780 static int
781 udf_readdir(struct vop_readdir_args *a)
782 {
783 	struct vnode *vp;
784 	struct uio *uio;
785 	struct dirent dir;
786 	struct udf_node *node;
787 	struct udf_mnt *udfmp;
788 	struct fileid_desc *fid;
789 	struct udf_uiodir uiodir;
790 	struct udf_dirstream *ds;
791 	u_long *cookies = NULL;
792 	int ncookies;
793 	int error = 0;
794 
795 	vp = a->a_vp;
796 	uio = a->a_uio;
797 	node = VTON(vp);
798 	udfmp = node->udfmp;
799 	uiodir.eofflag = 1;
800 
801 	if (a->a_ncookies != NULL) {
802 		/*
803 		 * Guess how many entries are needed.  If we run out, this
804 		 * function will be called again and thing will pick up were
805 		 * it left off.
806 		 */
807 		ncookies = uio->uio_resid / 8;
808 		cookies = malloc(sizeof(u_long) * ncookies,
809 		    M_TEMP, M_WAITOK);
810 		if (cookies == NULL)
811 			return (ENOMEM);
812 		uiodir.ncookies = ncookies;
813 		uiodir.cookies = cookies;
814 		uiodir.acookies = 0;
815 	} else {
816 		uiodir.cookies = NULL;
817 	}
818 
819 	/*
820 	 * Iterate through the file id descriptors.  Give the parent dir
821 	 * entry special attention.
822 	 */
823 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
824 	    node->udfmp);
825 
826 	while ((fid = udf_getfid(ds)) != NULL) {
827 
828 		/* XXX Should we return an error on a bad fid? */
829 		if (udf_checktag(&fid->tag, TAGID_FID)) {
830 			printf("Invalid FID tag\n");
831 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
832 			error = EIO;
833 			break;
834 		}
835 
836 		/* Is this a deleted file? */
837 		if (fid->file_char & UDF_FILE_CHAR_DEL)
838 			continue;
839 
840 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
841 			/* Do up the '.' and '..' entries.  Dummy values are
842 			 * used for the cookies since the offset here is
843 			 * usually zero, and NFS doesn't like that value
844 			 */
845 			dir.d_fileno = node->hash_id;
846 			dir.d_type = DT_DIR;
847 			dir.d_name[0] = '.';
848 			dir.d_namlen = 1;
849 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
850 			dir.d_off = 1;
851 			dirent_terminate(&dir);
852 			uiodir.dirent = &dir;
853 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
854 			if (error)
855 				break;
856 
857 			dir.d_fileno = udf_getid(&fid->icb);
858 			dir.d_type = DT_DIR;
859 			dir.d_name[0] = '.';
860 			dir.d_name[1] = '.';
861 			dir.d_namlen = 2;
862 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
863 			dir.d_off = 2;
864 			dirent_terminate(&dir);
865 			uiodir.dirent = &dir;
866 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
867 		} else {
868 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
869 			    &dir.d_name[0], fid->l_fi, udfmp);
870 			dir.d_fileno = udf_getid(&fid->icb);
871 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
872 			    DT_DIR : DT_UNKNOWN;
873 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
874 			dir.d_off = ds->this_off;
875 			dirent_terminate(&dir);
876 			uiodir.dirent = &dir;
877 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
878 			    ds->this_off);
879 		}
880 		if (error)
881 			break;
882 		uio->uio_offset = ds->offset + ds->off;
883 	}
884 
885 	/* tell the calling layer whether we need to be called again */
886 	*a->a_eofflag = uiodir.eofflag;
887 
888 	if (error < 0)
889 		error = 0;
890 	if (!error)
891 		error = ds->error;
892 
893 	udf_closedir(ds);
894 
895 	if (a->a_ncookies != NULL) {
896 		if (error)
897 			free(cookies, M_TEMP);
898 		else {
899 			*a->a_ncookies = uiodir.acookies;
900 			*a->a_cookies = cookies;
901 		}
902 	}
903 
904 	return (error);
905 }
906 
907 static int
908 udf_readlink(struct vop_readlink_args *ap)
909 {
910 	struct path_component *pc, *end;
911 	struct vnode *vp;
912 	struct uio uio;
913 	struct iovec iov[1];
914 	struct udf_node *node;
915 	void *buf;
916 	char *cp;
917 	int error, len, root;
918 
919 	/*
920 	 * A symbolic link in UDF is a list of variable-length path
921 	 * component structures.  We build a pathname in the caller's
922 	 * uio by traversing this list.
923 	 */
924 	vp = ap->a_vp;
925 	node = VTON(vp);
926 	len = le64toh(node->fentry->inf_len);
927 	buf = malloc(len, M_DEVBUF, M_WAITOK);
928 	iov[0].iov_len = len;
929 	iov[0].iov_base = buf;
930 	uio.uio_iov = iov;
931 	uio.uio_iovcnt = 1;
932 	uio.uio_offset = 0;
933 	uio.uio_resid = iov[0].iov_len;
934 	uio.uio_segflg = UIO_SYSSPACE;
935 	uio.uio_rw = UIO_READ;
936 	uio.uio_td = curthread;
937 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
938 	if (error)
939 		goto error;
940 
941 	pc = buf;
942 	end = (void *)((char *)buf + len);
943 	root = 0;
944 	while (pc < end) {
945 		switch (pc->type) {
946 		case UDF_PATH_ROOT:
947 			/* Only allow this at the beginning of a path. */
948 			if ((void *)pc != buf) {
949 				error = EINVAL;
950 				goto error;
951 			}
952 			cp = "/";
953 			len = 1;
954 			root = 1;
955 			break;
956 		case UDF_PATH_DOT:
957 			cp = ".";
958 			len = 1;
959 			break;
960 		case UDF_PATH_DOTDOT:
961 			cp = "..";
962 			len = 2;
963 			break;
964 		case UDF_PATH_PATH:
965 			if (pc->length == 0) {
966 				error = EINVAL;
967 				goto error;
968 			}
969 			/*
970 			 * XXX: We only support CS8 which appears to map
971 			 * to ASCII directly.
972 			 */
973 			switch (pc->identifier[0]) {
974 			case 8:
975 				cp = pc->identifier + 1;
976 				len = pc->length - 1;
977 				break;
978 			default:
979 				error = EOPNOTSUPP;
980 				goto error;
981 			}
982 			break;
983 		default:
984 			error = EINVAL;
985 			goto error;
986 		}
987 
988 		/*
989 		 * If this is not the first component, insert a path
990 		 * separator.
991 		 */
992 		if (pc != buf) {
993 			/* If we started with root we already have a "/". */
994 			if (root)
995 				goto skipslash;
996 			root = 0;
997 			if (ap->a_uio->uio_resid < 1) {
998 				error = ENAMETOOLONG;
999 				goto error;
1000 			}
1001 			error = uiomove("/", 1, ap->a_uio);
1002 			if (error)
1003 				break;
1004 		}
1005 	skipslash:
1006 
1007 		/* Append string at 'cp' of length 'len' to our path. */
1008 		if (len > ap->a_uio->uio_resid) {
1009 			error = ENAMETOOLONG;
1010 			goto error;
1011 		}
1012 		error = uiomove(cp, len, ap->a_uio);
1013 		if (error)
1014 			break;
1015 
1016 		/* Advance to next component. */
1017 		pc = (void *)((char *)pc + 4 + pc->length);
1018 	}
1019 error:
1020 	free(buf, M_DEVBUF);
1021 	return (error);
1022 }
1023 
1024 static int
1025 udf_strategy(struct vop_strategy_args *a)
1026 {
1027 	struct buf *bp;
1028 	struct vnode *vp;
1029 	struct udf_node *node;
1030 	struct bufobj *bo;
1031 	off_t offset;
1032 	uint32_t maxsize;
1033 	daddr_t sector;
1034 	int error;
1035 
1036 	bp = a->a_bp;
1037 	vp = a->a_vp;
1038 	node = VTON(vp);
1039 
1040 	if (bp->b_blkno == bp->b_lblkno) {
1041 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1042 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1043 		if (error) {
1044 			clrbuf(bp);
1045 			bp->b_blkno = -1;
1046 			bufdone(bp);
1047 			return (0);
1048 		}
1049 		/* bmap gives sector numbers, bio works with device blocks */
1050 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1051 	}
1052 	bo = node->udfmp->im_bo;
1053 	bp->b_iooffset = dbtob(bp->b_blkno);
1054 	BO_STRATEGY(bo, bp);
1055 	return (0);
1056 }
1057 
1058 static int
1059 udf_bmap(struct vop_bmap_args *a)
1060 {
1061 	struct udf_node *node;
1062 	uint32_t max_size;
1063 	daddr_t lsector;
1064 	int nblk;
1065 	int error;
1066 
1067 	node = VTON(a->a_vp);
1068 
1069 	if (a->a_bop != NULL)
1070 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1071 	if (a->a_bnp == NULL)
1072 		return (0);
1073 	if (a->a_runb)
1074 		*a->a_runb = 0;
1075 
1076 	/*
1077 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1078 	 * error that should not be propagated to calling code.
1079 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1080 	 * translate block numbers in this case.
1081 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1082 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1083 	 * thing for this kind of files.
1084 	 */
1085 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1086 	    &lsector, &max_size);
1087 	if (error == UDF_INVALID_BMAP)
1088 		return (EOPNOTSUPP);
1089 	if (error)
1090 		return (error);
1091 
1092 	/* Translate logical to physical sector number */
1093 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1094 
1095 	/*
1096 	 * Determine maximum number of readahead blocks following the
1097 	 * requested block.
1098 	 */
1099 	if (a->a_runp) {
1100 		nblk = (max_size >> node->udfmp->bshift) - 1;
1101 		if (nblk <= 0)
1102 			*a->a_runp = 0;
1103 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1104 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1105 		else
1106 			*a->a_runp = nblk;
1107 	}
1108 
1109 	if (a->a_runb) {
1110 		*a->a_runb = 0;
1111 	}
1112 
1113 	return (0);
1114 }
1115 
1116 /*
1117  * The all powerful VOP_LOOKUP().
1118  */
1119 static int
1120 udf_lookup(struct vop_cachedlookup_args *a)
1121 {
1122 	struct vnode *dvp;
1123 	struct vnode *tdp = NULL;
1124 	struct vnode **vpp = a->a_vpp;
1125 	struct udf_node *node;
1126 	struct udf_mnt *udfmp;
1127 	struct fileid_desc *fid = NULL;
1128 	struct udf_dirstream *ds;
1129 	u_long nameiop;
1130 	u_long flags;
1131 	char *nameptr;
1132 	long namelen;
1133 	ino_t id = 0;
1134 	int offset, error = 0;
1135 	int fsize, lkflags, ltype, numdirpasses;
1136 
1137 	dvp = a->a_dvp;
1138 	node = VTON(dvp);
1139 	udfmp = node->udfmp;
1140 	nameiop = a->a_cnp->cn_nameiop;
1141 	flags = a->a_cnp->cn_flags;
1142 	lkflags = a->a_cnp->cn_lkflags;
1143 	nameptr = a->a_cnp->cn_nameptr;
1144 	namelen = a->a_cnp->cn_namelen;
1145 	fsize = le64toh(node->fentry->inf_len);
1146 
1147 	/*
1148 	 * If this is a LOOKUP and we've already partially searched through
1149 	 * the directory, pick up where we left off and flag that the
1150 	 * directory may need to be searched twice.  For a full description,
1151 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1152 	 */
1153 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1154 		offset = 0;
1155 		numdirpasses = 1;
1156 	} else {
1157 		offset = node->diroff;
1158 		numdirpasses = 2;
1159 		nchstats.ncs_2passes++;
1160 	}
1161 
1162 lookloop:
1163 	ds = udf_opendir(node, offset, fsize, udfmp);
1164 
1165 	while ((fid = udf_getfid(ds)) != NULL) {
1166 
1167 		/* XXX Should we return an error on a bad fid? */
1168 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1169 			printf("udf_lookup: Invalid tag\n");
1170 			error = EIO;
1171 			break;
1172 		}
1173 
1174 		/* Is this a deleted file? */
1175 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1176 			continue;
1177 
1178 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1179 			if (flags & ISDOTDOT) {
1180 				id = udf_getid(&fid->icb);
1181 				break;
1182 			}
1183 		} else {
1184 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1185 			    nameptr, fid->l_fi, namelen, udfmp))) {
1186 				id = udf_getid(&fid->icb);
1187 				break;
1188 			}
1189 		}
1190 	}
1191 
1192 	if (!error)
1193 		error = ds->error;
1194 
1195 	/* XXX Bail out here? */
1196 	if (error) {
1197 		udf_closedir(ds);
1198 		return (error);
1199 	}
1200 
1201 	/* Did we have a match? */
1202 	if (id) {
1203 		/*
1204 		 * Remember where this entry was if it's the final
1205 		 * component.
1206 		 */
1207 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1208 			node->diroff = ds->offset + ds->off;
1209 		if (numdirpasses == 2)
1210 			nchstats.ncs_pass2++;
1211 		udf_closedir(ds);
1212 
1213 		if (flags & ISDOTDOT) {
1214 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1215 		} else if (node->hash_id == id) {
1216 			VREF(dvp);	/* we want ourself, ie "." */
1217 			/*
1218 			 * When we lookup "." we still can be asked to lock it
1219 			 * differently.
1220 			 */
1221 			ltype = lkflags & LK_TYPE_MASK;
1222 			if (ltype != VOP_ISLOCKED(dvp)) {
1223 				if (ltype == LK_EXCLUSIVE)
1224 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1225 				else /* if (ltype == LK_SHARED) */
1226 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1227 			}
1228 			tdp = dvp;
1229 		} else
1230 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1231 		if (!error) {
1232 			*vpp = tdp;
1233 			/* Put this entry in the cache */
1234 			if (flags & MAKEENTRY)
1235 				cache_enter(dvp, *vpp, a->a_cnp);
1236 		}
1237 	} else {
1238 		/* Name wasn't found on this pass.  Do another pass? */
1239 		if (numdirpasses == 2) {
1240 			numdirpasses--;
1241 			offset = 0;
1242 			udf_closedir(ds);
1243 			goto lookloop;
1244 		}
1245 		udf_closedir(ds);
1246 
1247 		/* Enter name into cache as non-existant */
1248 		if (flags & MAKEENTRY)
1249 			cache_enter(dvp, *vpp, a->a_cnp);
1250 
1251 		if ((flags & ISLASTCN) &&
1252 		    (nameiop == CREATE || nameiop == RENAME)) {
1253 			error = EROFS;
1254 		} else {
1255 			error = ENOENT;
1256 		}
1257 	}
1258 
1259 	return (error);
1260 }
1261 
1262 static int
1263 udf_reclaim(struct vop_reclaim_args *a)
1264 {
1265 	struct vnode *vp;
1266 	struct udf_node *unode;
1267 
1268 	vp = a->a_vp;
1269 	unode = VTON(vp);
1270 
1271 	if (unode != NULL) {
1272 		vfs_hash_remove(vp);
1273 
1274 		if (unode->fentry != NULL)
1275 			free(unode->fentry, M_UDFFENTRY);
1276 		uma_zfree(udf_zone_node, unode);
1277 		vp->v_data = NULL;
1278 	}
1279 
1280 	return (0);
1281 }
1282 
1283 static int
1284 udf_vptofh(struct vop_vptofh_args *a)
1285 {
1286 	struct udf_node *node;
1287 	struct ifid *ifhp;
1288 
1289 	node = VTON(a->a_vp);
1290 	ifhp = (struct ifid *)a->a_fhp;
1291 	ifhp->ifid_len = sizeof(struct ifid);
1292 	ifhp->ifid_ino = node->hash_id;
1293 
1294 	return (0);
1295 }
1296 
1297 /*
1298  * Read the block and then set the data pointer to correspond with the
1299  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1300  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1301  * whole extent.
1302  *
1303  * Note that *bp may be assigned error or not.
1304  *
1305  */
1306 static int
1307 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1308     struct buf **bp, uint8_t **data)
1309 {
1310 	struct udf_mnt *udfmp = node->udfmp;
1311 	struct vnode *vp = node->i_vnode;
1312 	struct file_entry *fentry;
1313 	struct buf *bp1;
1314 	uint32_t max_size;
1315 	daddr_t sector;
1316 	off_t off;
1317 	int adj_size;
1318 	int error;
1319 
1320 	/*
1321 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1322 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1323 	 */
1324 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1325 	if (error == UDF_INVALID_BMAP) {
1326 		/*
1327 		 * This error means that the file *data* is stored in the
1328 		 * allocation descriptor field of the file entry.
1329 		 */
1330 		fentry = node->fentry;
1331 		*data = &fentry->data[le32toh(fentry->l_ea)];
1332 		*size = le32toh(fentry->l_ad);
1333 		if (offset >= *size)
1334 			*size = 0;
1335 		else {
1336 			*data += offset;
1337 			*size -= offset;
1338 		}
1339 		return (0);
1340 	} else if (error != 0) {
1341 		return (error);
1342 	}
1343 
1344 	/* Adjust the size so that it is within range */
1345 	if (*size == 0 || *size > max_size)
1346 		*size = max_size;
1347 
1348 	/*
1349 	 * Because we will read starting at block boundary, we need to adjust
1350 	 * how much we need to read so that all promised data is in.
1351 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1352 	 * from block boundary, so adjust what we promise too.
1353 	 */
1354 	off = blkoff(udfmp, offset);
1355 	*size = min(*size, MAXBSIZE - off);
1356 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1357 	*bp = NULL;
1358 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1359 		printf("warning: udf_readlblks returned error %d\n", error);
1360 		/* note: *bp may be non-NULL */
1361 		return (error);
1362 	}
1363 
1364 	bp1 = *bp;
1365 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1366 	return (0);
1367 }
1368 
1369 /*
1370  * Translate a file offset into a logical block and then into a physical
1371  * block.
1372  * max_size - maximum number of bytes that can be read starting from given
1373  * offset, rather than beginning of calculated sector number
1374  */
1375 static int
1376 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1377     uint32_t *max_size)
1378 {
1379 	struct udf_mnt *udfmp;
1380 	struct file_entry *fentry;
1381 	void *icb;
1382 	struct icb_tag *tag;
1383 	uint32_t icblen = 0;
1384 	daddr_t lsector;
1385 	int ad_offset, ad_num = 0;
1386 	int i, p_offset;
1387 
1388 	udfmp = node->udfmp;
1389 	fentry = node->fentry;
1390 	tag = &fentry->icbtag;
1391 
1392 	switch (le16toh(tag->strat_type)) {
1393 	case 4:
1394 		break;
1395 
1396 	case 4096:
1397 		printf("Cannot deal with strategy4096 yet!\n");
1398 		return (ENODEV);
1399 
1400 	default:
1401 		printf("Unknown strategy type %d\n", tag->strat_type);
1402 		return (ENODEV);
1403 	}
1404 
1405 	switch (le16toh(tag->flags) & 0x7) {
1406 	case 0:
1407 		/*
1408 		 * The allocation descriptor field is filled with short_ad's.
1409 		 * If the offset is beyond the current extent, look for the
1410 		 * next extent.
1411 		 */
1412 		do {
1413 			offset -= icblen;
1414 			ad_offset = sizeof(struct short_ad) * ad_num;
1415 			if (ad_offset > le32toh(fentry->l_ad)) {
1416 				printf("File offset out of bounds\n");
1417 				return (EINVAL);
1418 			}
1419 			icb = GETICB(short_ad, fentry,
1420 			    le32toh(fentry->l_ea) + ad_offset);
1421 			icblen = GETICBLEN(short_ad, icb);
1422 			ad_num++;
1423 		} while(offset >= icblen);
1424 
1425 		lsector = (offset  >> udfmp->bshift) +
1426 		    le32toh(((struct short_ad *)(icb))->pos);
1427 
1428 		*max_size = icblen - offset;
1429 
1430 		break;
1431 	case 1:
1432 		/*
1433 		 * The allocation descriptor field is filled with long_ad's
1434 		 * If the offset is beyond the current extent, look for the
1435 		 * next extent.
1436 		 */
1437 		do {
1438 			offset -= icblen;
1439 			ad_offset = sizeof(struct long_ad) * ad_num;
1440 			if (ad_offset > le32toh(fentry->l_ad)) {
1441 				printf("File offset out of bounds\n");
1442 				return (EINVAL);
1443 			}
1444 			icb = GETICB(long_ad, fentry,
1445 			    le32toh(fentry->l_ea) + ad_offset);
1446 			icblen = GETICBLEN(long_ad, icb);
1447 			ad_num++;
1448 		} while(offset >= icblen);
1449 
1450 		lsector = (offset >> udfmp->bshift) +
1451 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1452 
1453 		*max_size = icblen - offset;
1454 
1455 		break;
1456 	case 3:
1457 		/*
1458 		 * This type means that the file *data* is stored in the
1459 		 * allocation descriptor field of the file entry.
1460 		 */
1461 		*max_size = 0;
1462 		*sector = node->hash_id + udfmp->part_start;
1463 
1464 		return (UDF_INVALID_BMAP);
1465 	case 2:
1466 		/* DirectCD does not use extended_ad's */
1467 	default:
1468 		printf("Unsupported allocation descriptor %d\n",
1469 		       tag->flags & 0x7);
1470 		return (ENODEV);
1471 	}
1472 
1473 	*sector = lsector + udfmp->part_start;
1474 
1475 	/*
1476 	 * Check the sparing table.  Each entry represents the beginning of
1477 	 * a packet.
1478 	 */
1479 	if (udfmp->s_table != NULL) {
1480 		for (i = 0; i< udfmp->s_table_entries; i++) {
1481 			p_offset =
1482 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1483 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1484 				*sector =
1485 				   le32toh(udfmp->s_table->entries[i].map) +
1486 				    p_offset;
1487 				break;
1488 			}
1489 		}
1490 	}
1491 
1492 	return (0);
1493 }
1494