xref: /freebsd/sys/fs/udf/udf_vnops.c (revision 4e8d558c9d1cf3e7e424e3fb123b01979c3d57f2)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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));
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 
293 	vp = a->a_vp;
294 	vap = a->a_vap;
295 	node = VTON(vp);
296 	fentry = node->fentry;
297 
298 	vap->va_fsid = dev2udev(node->udfmp->im_dev);
299 	vap->va_fileid = node->hash_id;
300 	vap->va_mode = udf_permtomode(node);
301 	vap->va_nlink = le16toh(fentry->link_cnt);
302 	/*
303 	 * XXX The spec says that -1 is valid for uid/gid and indicates an
304 	 * invalid uid/gid.  How should this be represented?
305 	 */
306 	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
307 	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
308 	udf_timetotimespec(&fentry->atime, &vap->va_atime);
309 	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
310 	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
311 	vap->va_rdev = NODEV;
312 	if (vp->v_type & VDIR) {
313 		/*
314 		 * Directories that are recorded within their ICB will show
315 		 * as having 0 blocks recorded.  Since tradition dictates
316 		 * that directories consume at least one logical block,
317 		 * make it appear so.
318 		 */
319 		if (fentry->logblks_rec != 0) {
320 			vap->va_size =
321 			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
322 		} else {
323 			vap->va_size = node->udfmp->bsize;
324 		}
325 	} else {
326 		vap->va_size = le64toh(fentry->inf_len);
327 	}
328 	vap->va_flags = 0;
329 	vap->va_gen = 1;
330 	vap->va_blocksize = node->udfmp->bsize;
331 	vap->va_bytes = le64toh(fentry->inf_len);
332 	vap->va_type = vp->v_type;
333 	vap->va_filerev = 0; /* XXX */
334 	return (0);
335 }
336 
337 static int
338 udf_setattr(struct vop_setattr_args *a)
339 {
340 	struct vnode *vp;
341 	struct vattr *vap;
342 
343 	vp = a->a_vp;
344 	vap = a->a_vap;
345 	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
346 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
347 	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
348 		return (EROFS);
349 	if (vap->va_size != (u_quad_t)VNOVAL) {
350 		switch (vp->v_type) {
351 		case VDIR:
352 			return (EISDIR);
353 		case VLNK:
354 		case VREG:
355 			return (EROFS);
356 		case VCHR:
357 		case VBLK:
358 		case VSOCK:
359 		case VFIFO:
360 		case VNON:
361 		case VBAD:
362 		case VMARKER:
363 			return (0);
364 		}
365 	}
366 	return (0);
367 }
368 
369 /*
370  * File specific ioctls.
371  */
372 static int
373 udf_ioctl(struct vop_ioctl_args *a)
374 {
375 	printf("%s called\n", __func__);
376 	return (ENOTTY);
377 }
378 
379 /*
380  * I'm not sure that this has much value in a read-only filesystem, but
381  * cd9660 has it too.
382  */
383 static int
384 udf_pathconf(struct vop_pathconf_args *a)
385 {
386 
387 	switch (a->a_name) {
388 	case _PC_FILESIZEBITS:
389 		*a->a_retval = 64;
390 		return (0);
391 	case _PC_LINK_MAX:
392 		*a->a_retval = 65535;
393 		return (0);
394 	case _PC_NAME_MAX:
395 		*a->a_retval = NAME_MAX;
396 		return (0);
397 	case _PC_SYMLINK_MAX:
398 		*a->a_retval = MAXPATHLEN;
399 		return (0);
400 	case _PC_NO_TRUNC:
401 		*a->a_retval = 1;
402 		return (0);
403 	case _PC_PIPE_BUF:
404 		if (a->a_vp->v_type == VDIR || a->a_vp->v_type == VFIFO) {
405 			*a->a_retval = PIPE_BUF;
406 			return (0);
407 		}
408 		return (EINVAL);
409 	default:
410 		return (vop_stdpathconf(a));
411 	}
412 }
413 
414 static int
415 udf_print(struct vop_print_args *ap)
416 {
417 	struct vnode *vp = ap->a_vp;
418 	struct udf_node *node = VTON(vp);
419 
420 	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
421 	    devtoname(node->udfmp->im_dev));
422 	if (vp->v_type == VFIFO)
423 		fifo_printinfo(vp);
424 	printf("\n");
425 	return (0);
426 }
427 
428 #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
429 #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
430 #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
431 
432 static inline int
433 is_data_in_fentry(const struct udf_node *node)
434 {
435 	const struct file_entry *fentry = node->fentry;
436 
437 	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
438 }
439 
440 static int
441 udf_read(struct vop_read_args *ap)
442 {
443 	struct vnode *vp = ap->a_vp;
444 	struct uio *uio = ap->a_uio;
445 	struct udf_node *node = VTON(vp);
446 	struct udf_mnt *udfmp;
447 	struct file_entry *fentry;
448 	struct buf *bp;
449 	uint8_t *data;
450 	daddr_t lbn, rablock;
451 	off_t diff, fsize;
452 	ssize_t n;
453 	int error = 0;
454 	long size, on;
455 
456 	if (uio->uio_resid == 0)
457 		return (0);
458 	if (uio->uio_offset < 0)
459 		return (EINVAL);
460 
461 	if (is_data_in_fentry(node)) {
462 		fentry = node->fentry;
463 		data = &fentry->data[le32toh(fentry->l_ea)];
464 		fsize = le32toh(fentry->l_ad);
465 
466 		n = uio->uio_resid;
467 		diff = fsize - uio->uio_offset;
468 		if (diff <= 0)
469 			return (0);
470 		if (diff < n)
471 			n = diff;
472 		error = uiomove(data + uio->uio_offset, (int)n, uio);
473 		return (error);
474 	}
475 
476 	fsize = le64toh(node->fentry->inf_len);
477 	udfmp = node->udfmp;
478 	do {
479 		lbn = lblkno(udfmp, uio->uio_offset);
480 		on = blkoff(udfmp, uio->uio_offset);
481 		n = min((u_int)(udfmp->bsize - on),
482 			uio->uio_resid);
483 		diff = fsize - uio->uio_offset;
484 		if (diff <= 0)
485 			return (0);
486 		if (diff < n)
487 			n = diff;
488 		size = udfmp->bsize;
489 		rablock = lbn + 1;
490 		if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
491 			if (lblktosize(udfmp, rablock) < fsize) {
492 				error = cluster_read(vp, fsize, lbn, size,
493 				    NOCRED, uio->uio_resid,
494 				    (ap->a_ioflag >> 16), 0, &bp);
495 			} else {
496 				error = bread(vp, lbn, size, NOCRED, &bp);
497 			}
498 		} else {
499 			error = bread(vp, lbn, size, NOCRED, &bp);
500 		}
501 		if (error != 0) {
502 			brelse(bp);
503 			return (error);
504 		}
505 		n = min(n, size - bp->b_resid);
506 
507 		error = uiomove(bp->b_data + on, (int)n, uio);
508 		brelse(bp);
509 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
510 	return (error);
511 }
512 
513 /*
514  * Call the OSTA routines to translate the name from a CS0 dstring to a
515  * 16-bit Unicode String.  Hooks need to be placed in here to translate from
516  * Unicode to the encoding that the kernel/user expects.  Return the length
517  * of the translated string.
518  */
519 static int
520 udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
521 {
522 	unicode_t *transname;
523 	char *unibuf, *unip;
524 	int i, destlen;
525 	ssize_t unilen = 0;
526 	size_t destleft = MAXNAMLEN;
527 
528 	/* Convert 16-bit Unicode to destname */
529 	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
530 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
531 		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
532 		unip = unibuf;
533 		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
534 			printf("udf: Unicode translation failed\n");
535 			uma_zfree(udf_zone_trans, unibuf);
536 			return 0;
537 		}
538 
539 		while (unilen > 0 && destleft > 0) {
540 			udf_iconv->conv(udfmp->im_d2l, __DECONST(const char **,
541 			    &unibuf), (size_t *)&unilen, (char **)&destname,
542 			    &destleft);
543 			/* Unconverted character found */
544 			if (unilen > 0 && destleft > 0) {
545 				*destname++ = '?';
546 				destleft--;
547 				unibuf += 2;
548 				unilen -= 2;
549 			}
550 		}
551 		uma_zfree(udf_zone_trans, unip);
552 		*destname = '\0';
553 		destlen = MAXNAMLEN - (int)destleft;
554 	} else {
555 		/* allocate a buffer big enough to hold an 8->16 bit expansion */
556 		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
557 
558 		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
559 			printf("udf: Unicode translation failed\n");
560 			uma_zfree(udf_zone_trans, transname);
561 			return 0;
562 		}
563 
564 		for (i = 0; i < unilen ; i++) {
565 			if (transname[i] & 0xff00) {
566 				destname[i] = '.';	/* Fudge the 16bit chars */
567 			} else {
568 				destname[i] = transname[i] & 0xff;
569 			}
570 		}
571 		uma_zfree(udf_zone_trans, transname);
572 		destname[unilen] = 0;
573 		destlen = (int)unilen;
574 	}
575 
576 	return (destlen);
577 }
578 
579 /*
580  * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
581  * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
582  * here also.
583  */
584 static int
585 udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
586 {
587 	char *transname;
588 	int error = 0;
589 
590 	/* This is overkill, but not worth creating a new zone */
591 	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
592 
593 	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
594 
595 	/* Easy check.  If they aren't the same length, they aren't equal */
596 	if ((cs0len == 0) || (cs0len != cmplen))
597 		error = -1;
598 	else
599 		error = bcmp(transname, cmpname, cmplen);
600 
601 	uma_zfree(udf_zone_trans, transname);
602 	return (error);
603 }
604 
605 struct udf_uiodir {
606 	struct dirent *dirent;
607 	uint64_t *cookies;
608 	int ncookies;
609 	int acookies;
610 	int eofflag;
611 };
612 
613 static int
614 udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
615 {
616 	if (uiodir->cookies != NULL) {
617 		if (++uiodir->acookies > uiodir->ncookies) {
618 			uiodir->eofflag = 0;
619 			return (-1);
620 		}
621 		*uiodir->cookies++ = cookie;
622 	}
623 
624 	if (uio->uio_resid < de_size) {
625 		uiodir->eofflag = 0;
626 		return (-1);
627 	}
628 
629 	return (uiomove(uiodir->dirent, de_size, uio));
630 }
631 
632 static struct udf_dirstream *
633 udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
634 {
635 	struct udf_dirstream *ds;
636 
637 	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
638 
639 	ds->node = node;
640 	ds->offset = offset;
641 	ds->udfmp = udfmp;
642 	ds->fsize = fsize;
643 
644 	return (ds);
645 }
646 
647 static struct fileid_desc *
648 udf_getfid(struct udf_dirstream *ds)
649 {
650 	struct fileid_desc *fid;
651 	int error, frag_size = 0, total_fid_size;
652 
653 	/* End of directory? */
654 	if (ds->offset + ds->off >= ds->fsize) {
655 		ds->error = 0;
656 		return (NULL);
657 	}
658 
659 	/* Grab the first extent of the directory */
660 	if (ds->off == 0) {
661 		ds->size = 0;
662 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
663 		    &ds->bp, &ds->data);
664 		if (error) {
665 			ds->error = error;
666 			if (ds->bp != NULL)
667 				brelse(ds->bp);
668 			return (NULL);
669 		}
670 	}
671 
672 	/*
673 	 * Clean up from a previous fragmented FID.
674 	 * XXX Is this the right place for this?
675 	 */
676 	if (ds->fid_fragment && ds->buf != NULL) {
677 		ds->fid_fragment = 0;
678 		free(ds->buf, M_UDFFID);
679 	}
680 
681 	fid = (struct fileid_desc*)&ds->data[ds->off];
682 
683 	/*
684 	 * Check to see if the fid is fragmented. The first test
685 	 * ensures that we don't wander off the end of the buffer
686 	 * looking for the l_iu and l_fi fields.
687 	 */
688 	if (ds->off + UDF_FID_SIZE > ds->size ||
689 	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
690 		/* Copy what we have of the fid into a buffer */
691 		frag_size = ds->size - ds->off;
692 		if (frag_size >= ds->udfmp->bsize) {
693 			printf("udf: invalid FID fragment\n");
694 			ds->error = EINVAL;
695 			return (NULL);
696 		}
697 
698 		/*
699 		 * File ID descriptors can only be at most one
700 		 * logical sector in size.
701 		 */
702 		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
703 		     M_WAITOK | M_ZERO);
704 		bcopy(fid, ds->buf, frag_size);
705 
706 		/* Reduce all of the casting magic */
707 		fid = (struct fileid_desc*)ds->buf;
708 
709 		if (ds->bp != NULL)
710 			brelse(ds->bp);
711 
712 		/* Fetch the next allocation */
713 		ds->offset += ds->size;
714 		ds->size = 0;
715 		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
716 		    &ds->bp, &ds->data);
717 		if (error) {
718 			ds->error = error;
719 			return (NULL);
720 		}
721 
722 		/*
723 		 * If the fragment was so small that we didn't get
724 		 * the l_iu and l_fi fields, copy those in.
725 		 */
726 		if (frag_size < UDF_FID_SIZE)
727 			bcopy(ds->data, &ds->buf[frag_size],
728 			    UDF_FID_SIZE - frag_size);
729 
730 		/*
731 		 * Now that we have enough of the fid to work with,
732 		 * copy in the rest of the fid from the new
733 		 * allocation.
734 		 */
735 		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
736 		if (total_fid_size > ds->udfmp->bsize) {
737 			printf("udf: invalid FID\n");
738 			ds->error = EIO;
739 			return (NULL);
740 		}
741 		bcopy(ds->data, &ds->buf[frag_size],
742 		    total_fid_size - frag_size);
743 
744 		ds->fid_fragment = 1;
745 	} else {
746 		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
747 	}
748 
749 	/*
750 	 * Update the offset. Align on a 4 byte boundary because the
751 	 * UDF spec says so.
752 	 */
753 	ds->this_off = ds->offset + ds->off;
754 	if (!ds->fid_fragment) {
755 		ds->off += (total_fid_size + 3) & ~0x03;
756 	} else {
757 		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
758 	}
759 
760 	return (fid);
761 }
762 
763 static void
764 udf_closedir(struct udf_dirstream *ds)
765 {
766 
767 	if (ds->bp != NULL)
768 		brelse(ds->bp);
769 
770 	if (ds->fid_fragment && ds->buf != NULL)
771 		free(ds->buf, M_UDFFID);
772 
773 	uma_zfree(udf_zone_ds, ds);
774 }
775 
776 static int
777 udf_readdir(struct vop_readdir_args *a)
778 {
779 	struct vnode *vp;
780 	struct uio *uio;
781 	struct dirent dir;
782 	struct udf_node *node;
783 	struct udf_mnt *udfmp;
784 	struct fileid_desc *fid;
785 	struct udf_uiodir uiodir;
786 	struct udf_dirstream *ds;
787 	uint64_t *cookies = NULL;
788 	int ncookies;
789 	int error = 0;
790 
791 	vp = a->a_vp;
792 	uio = a->a_uio;
793 	node = VTON(vp);
794 	udfmp = node->udfmp;
795 	uiodir.eofflag = 1;
796 
797 	if (a->a_ncookies != NULL) {
798 		/*
799 		 * Guess how many entries are needed.  If we run out, this
800 		 * function will be called again and thing will pick up were
801 		 * it left off.
802 		 */
803 		ncookies = uio->uio_resid / 8;
804 		cookies = malloc(sizeof(*cookies) * ncookies, M_TEMP, M_WAITOK);
805 		if (cookies == NULL)
806 			return (ENOMEM);
807 		uiodir.ncookies = ncookies;
808 		uiodir.cookies = cookies;
809 		uiodir.acookies = 0;
810 	} else {
811 		uiodir.cookies = NULL;
812 	}
813 
814 	/*
815 	 * Iterate through the file id descriptors.  Give the parent dir
816 	 * entry special attention.
817 	 */
818 	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
819 	    node->udfmp);
820 
821 	while ((fid = udf_getfid(ds)) != NULL) {
822 		/* XXX Should we return an error on a bad fid? */
823 		if (udf_checktag(&fid->tag, TAGID_FID)) {
824 			printf("Invalid FID tag\n");
825 			hexdump(fid, UDF_FID_SIZE, NULL, 0);
826 			error = EIO;
827 			break;
828 		}
829 
830 		/* Is this a deleted file? */
831 		if (fid->file_char & UDF_FILE_CHAR_DEL)
832 			continue;
833 
834 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
835 			/* Do up the '.' and '..' entries.  Dummy values are
836 			 * used for the cookies since the offset here is
837 			 * usually zero, and NFS doesn't like that value
838 			 */
839 			dir.d_fileno = node->hash_id;
840 			dir.d_type = DT_DIR;
841 			dir.d_name[0] = '.';
842 			dir.d_namlen = 1;
843 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
844 			dir.d_off = 1;
845 			dirent_terminate(&dir);
846 			uiodir.dirent = &dir;
847 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
848 			if (error)
849 				break;
850 
851 			dir.d_fileno = udf_getid(&fid->icb);
852 			dir.d_type = DT_DIR;
853 			dir.d_name[0] = '.';
854 			dir.d_name[1] = '.';
855 			dir.d_namlen = 2;
856 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
857 			dir.d_off = 2;
858 			dirent_terminate(&dir);
859 			uiodir.dirent = &dir;
860 			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
861 		} else {
862 			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
863 			    &dir.d_name[0], fid->l_fi, udfmp);
864 			dir.d_fileno = udf_getid(&fid->icb);
865 			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
866 			    DT_DIR : DT_UNKNOWN;
867 			dir.d_reclen = GENERIC_DIRSIZ(&dir);
868 			dir.d_off = ds->this_off;
869 			dirent_terminate(&dir);
870 			uiodir.dirent = &dir;
871 			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
872 			    ds->this_off);
873 		}
874 		if (error)
875 			break;
876 		uio->uio_offset = ds->offset + ds->off;
877 	}
878 
879 	/* tell the calling layer whether we need to be called again */
880 	*a->a_eofflag = uiodir.eofflag;
881 
882 	if (error < 0)
883 		error = 0;
884 	if (!error)
885 		error = ds->error;
886 
887 	udf_closedir(ds);
888 
889 	if (a->a_ncookies != NULL) {
890 		if (error)
891 			free(cookies, M_TEMP);
892 		else {
893 			*a->a_ncookies = uiodir.acookies;
894 			*a->a_cookies = cookies;
895 		}
896 	}
897 
898 	return (error);
899 }
900 
901 static int
902 udf_readlink(struct vop_readlink_args *ap)
903 {
904 	struct path_component *pc, *end;
905 	struct vnode *vp;
906 	struct uio uio;
907 	struct iovec iov[1];
908 	struct udf_node *node;
909 	void *buf;
910 	char *cp;
911 	int error, len, root;
912 
913 	/*
914 	 * A symbolic link in UDF is a list of variable-length path
915 	 * component structures.  We build a pathname in the caller's
916 	 * uio by traversing this list.
917 	 */
918 	vp = ap->a_vp;
919 	node = VTON(vp);
920 	len = le64toh(node->fentry->inf_len);
921 	buf = malloc(len, M_DEVBUF, M_WAITOK);
922 	iov[0].iov_len = len;
923 	iov[0].iov_base = buf;
924 	uio.uio_iov = iov;
925 	uio.uio_iovcnt = 1;
926 	uio.uio_offset = 0;
927 	uio.uio_resid = iov[0].iov_len;
928 	uio.uio_segflg = UIO_SYSSPACE;
929 	uio.uio_rw = UIO_READ;
930 	uio.uio_td = curthread;
931 	error = VOP_READ(vp, &uio, 0, ap->a_cred);
932 	if (error)
933 		goto error;
934 
935 	pc = buf;
936 	end = (void *)((char *)buf + len);
937 	root = 0;
938 	while (pc < end) {
939 		switch (pc->type) {
940 		case UDF_PATH_ROOT:
941 			/* Only allow this at the beginning of a path. */
942 			if ((void *)pc != buf) {
943 				error = EINVAL;
944 				goto error;
945 			}
946 			cp = "/";
947 			len = 1;
948 			root = 1;
949 			break;
950 		case UDF_PATH_DOT:
951 			cp = ".";
952 			len = 1;
953 			break;
954 		case UDF_PATH_DOTDOT:
955 			cp = "..";
956 			len = 2;
957 			break;
958 		case UDF_PATH_PATH:
959 			if (pc->length == 0) {
960 				error = EINVAL;
961 				goto error;
962 			}
963 			/*
964 			 * XXX: We only support CS8 which appears to map
965 			 * to ASCII directly.
966 			 */
967 			switch (pc->identifier[0]) {
968 			case 8:
969 				cp = pc->identifier + 1;
970 				len = pc->length - 1;
971 				break;
972 			default:
973 				error = EOPNOTSUPP;
974 				goto error;
975 			}
976 			break;
977 		default:
978 			error = EINVAL;
979 			goto error;
980 		}
981 
982 		/*
983 		 * If this is not the first component, insert a path
984 		 * separator.
985 		 */
986 		if (pc != buf) {
987 			/* If we started with root we already have a "/". */
988 			if (root)
989 				goto skipslash;
990 			root = 0;
991 			if (ap->a_uio->uio_resid < 1) {
992 				error = ENAMETOOLONG;
993 				goto error;
994 			}
995 			error = uiomove("/", 1, ap->a_uio);
996 			if (error)
997 				break;
998 		}
999 	skipslash:
1000 
1001 		/* Append string at 'cp' of length 'len' to our path. */
1002 		if (len > ap->a_uio->uio_resid) {
1003 			error = ENAMETOOLONG;
1004 			goto error;
1005 		}
1006 		error = uiomove(cp, len, ap->a_uio);
1007 		if (error)
1008 			break;
1009 
1010 		/* Advance to next component. */
1011 		pc = (void *)((char *)pc + 4 + pc->length);
1012 	}
1013 error:
1014 	free(buf, M_DEVBUF);
1015 	return (error);
1016 }
1017 
1018 static int
1019 udf_strategy(struct vop_strategy_args *a)
1020 {
1021 	struct buf *bp;
1022 	struct vnode *vp;
1023 	struct udf_node *node;
1024 	struct bufobj *bo;
1025 	off_t offset;
1026 	uint32_t maxsize;
1027 	daddr_t sector;
1028 	int error;
1029 
1030 	bp = a->a_bp;
1031 	vp = a->a_vp;
1032 	node = VTON(vp);
1033 
1034 	if (bp->b_blkno == bp->b_lblkno) {
1035 		offset = lblktosize(node->udfmp, bp->b_lblkno);
1036 		error = udf_bmap_internal(node, offset, &sector, &maxsize);
1037 		if (error) {
1038 			clrbuf(bp);
1039 			bp->b_blkno = -1;
1040 			bufdone(bp);
1041 			return (0);
1042 		}
1043 		/* bmap gives sector numbers, bio works with device blocks */
1044 		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
1045 	}
1046 	bo = node->udfmp->im_bo;
1047 	bp->b_iooffset = dbtob(bp->b_blkno);
1048 	BO_STRATEGY(bo, bp);
1049 	return (0);
1050 }
1051 
1052 static int
1053 udf_bmap(struct vop_bmap_args *a)
1054 {
1055 	struct udf_node *node;
1056 	uint32_t max_size;
1057 	daddr_t lsector;
1058 	int nblk;
1059 	int error;
1060 
1061 	node = VTON(a->a_vp);
1062 
1063 	if (a->a_bop != NULL)
1064 		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
1065 	if (a->a_bnp == NULL)
1066 		return (0);
1067 	if (a->a_runb)
1068 		*a->a_runb = 0;
1069 
1070 	/*
1071 	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
1072 	 * error that should not be propagated to calling code.
1073 	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
1074 	 * translate block numbers in this case.
1075 	 * Incidentally, this return code will make vnode pager to use VOP_READ
1076 	 * to get data for mmap-ed pages and udf_read knows how to do the right
1077 	 * thing for this kind of files.
1078 	 */
1079 	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
1080 	    &lsector, &max_size);
1081 	if (error == UDF_INVALID_BMAP)
1082 		return (EOPNOTSUPP);
1083 	if (error)
1084 		return (error);
1085 
1086 	/* Translate logical to physical sector number */
1087 	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
1088 
1089 	/*
1090 	 * Determine maximum number of readahead blocks following the
1091 	 * requested block.
1092 	 */
1093 	if (a->a_runp) {
1094 		nblk = (max_size >> node->udfmp->bshift) - 1;
1095 		if (nblk <= 0)
1096 			*a->a_runp = 0;
1097 		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
1098 			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
1099 		else
1100 			*a->a_runp = nblk;
1101 	}
1102 
1103 	if (a->a_runb) {
1104 		*a->a_runb = 0;
1105 	}
1106 
1107 	return (0);
1108 }
1109 
1110 /*
1111  * The all powerful VOP_LOOKUP().
1112  */
1113 static int
1114 udf_lookup(struct vop_cachedlookup_args *a)
1115 {
1116 	struct vnode *dvp;
1117 	struct vnode *tdp = NULL;
1118 	struct vnode **vpp = a->a_vpp;
1119 	struct udf_node *node;
1120 	struct udf_mnt *udfmp;
1121 	struct fileid_desc *fid = NULL;
1122 	struct udf_dirstream *ds;
1123 	u_long nameiop;
1124 	u_long flags;
1125 	char *nameptr;
1126 	long namelen;
1127 	ino_t id = 0;
1128 	int offset, error = 0;
1129 	int fsize, lkflags, ltype, numdirpasses;
1130 
1131 	dvp = a->a_dvp;
1132 	node = VTON(dvp);
1133 	udfmp = node->udfmp;
1134 	nameiop = a->a_cnp->cn_nameiop;
1135 	flags = a->a_cnp->cn_flags;
1136 	lkflags = a->a_cnp->cn_lkflags;
1137 	nameptr = a->a_cnp->cn_nameptr;
1138 	namelen = a->a_cnp->cn_namelen;
1139 	fsize = le64toh(node->fentry->inf_len);
1140 
1141 	/*
1142 	 * If this is a LOOKUP and we've already partially searched through
1143 	 * the directory, pick up where we left off and flag that the
1144 	 * directory may need to be searched twice.  For a full description,
1145 	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
1146 	 */
1147 	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
1148 		offset = 0;
1149 		numdirpasses = 1;
1150 	} else {
1151 		offset = node->diroff;
1152 		numdirpasses = 2;
1153 		nchstats.ncs_2passes++;
1154 	}
1155 
1156 lookloop:
1157 	ds = udf_opendir(node, offset, fsize, udfmp);
1158 
1159 	while ((fid = udf_getfid(ds)) != NULL) {
1160 		/* XXX Should we return an error on a bad fid? */
1161 		if (udf_checktag(&fid->tag, TAGID_FID)) {
1162 			printf("udf_lookup: Invalid tag\n");
1163 			error = EIO;
1164 			break;
1165 		}
1166 
1167 		/* Is this a deleted file? */
1168 		if (fid->file_char & UDF_FILE_CHAR_DEL)
1169 			continue;
1170 
1171 		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
1172 			if (flags & ISDOTDOT) {
1173 				id = udf_getid(&fid->icb);
1174 				break;
1175 			}
1176 		} else {
1177 			if (!(udf_cmpname(&fid->data[fid->l_iu],
1178 			    nameptr, fid->l_fi, namelen, udfmp))) {
1179 				id = udf_getid(&fid->icb);
1180 				break;
1181 			}
1182 		}
1183 	}
1184 
1185 	if (!error)
1186 		error = ds->error;
1187 
1188 	/* XXX Bail out here? */
1189 	if (error) {
1190 		udf_closedir(ds);
1191 		return (error);
1192 	}
1193 
1194 	/* Did we have a match? */
1195 	if (id) {
1196 		/*
1197 		 * Remember where this entry was if it's the final
1198 		 * component.
1199 		 */
1200 		if ((flags & ISLASTCN) && nameiop == LOOKUP)
1201 			node->diroff = ds->offset + ds->off;
1202 		if (numdirpasses == 2)
1203 			nchstats.ncs_pass2++;
1204 		udf_closedir(ds);
1205 
1206 		if (flags & ISDOTDOT) {
1207 			error = vn_vget_ino(dvp, id, lkflags, &tdp);
1208 		} else if (node->hash_id == id) {
1209 			VREF(dvp);	/* we want ourself, ie "." */
1210 			/*
1211 			 * When we lookup "." we still can be asked to lock it
1212 			 * differently.
1213 			 */
1214 			ltype = lkflags & LK_TYPE_MASK;
1215 			if (ltype != VOP_ISLOCKED(dvp)) {
1216 				if (ltype == LK_EXCLUSIVE)
1217 					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
1218 				else /* if (ltype == LK_SHARED) */
1219 					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
1220 			}
1221 			tdp = dvp;
1222 		} else
1223 			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
1224 		if (!error) {
1225 			*vpp = tdp;
1226 			/* Put this entry in the cache */
1227 			if (flags & MAKEENTRY)
1228 				cache_enter(dvp, *vpp, a->a_cnp);
1229 		}
1230 	} else {
1231 		/* Name wasn't found on this pass.  Do another pass? */
1232 		if (numdirpasses == 2) {
1233 			numdirpasses--;
1234 			offset = 0;
1235 			udf_closedir(ds);
1236 			goto lookloop;
1237 		}
1238 		udf_closedir(ds);
1239 
1240 		/* Enter name into cache as non-existant */
1241 		if (flags & MAKEENTRY)
1242 			cache_enter(dvp, *vpp, a->a_cnp);
1243 
1244 		if ((flags & ISLASTCN) &&
1245 		    (nameiop == CREATE || nameiop == RENAME)) {
1246 			error = EROFS;
1247 		} else {
1248 			error = ENOENT;
1249 		}
1250 	}
1251 
1252 	return (error);
1253 }
1254 
1255 static int
1256 udf_reclaim(struct vop_reclaim_args *a)
1257 {
1258 	struct vnode *vp;
1259 	struct udf_node *unode;
1260 
1261 	vp = a->a_vp;
1262 	unode = VTON(vp);
1263 
1264 	if (unode != NULL) {
1265 		vfs_hash_remove(vp);
1266 
1267 		if (unode->fentry != NULL)
1268 			free(unode->fentry, M_UDFFENTRY);
1269 		uma_zfree(udf_zone_node, unode);
1270 		vp->v_data = NULL;
1271 	}
1272 
1273 	return (0);
1274 }
1275 
1276 static int
1277 udf_vptofh(struct vop_vptofh_args *a)
1278 {
1279 	struct udf_node *node;
1280 	struct ifid *ifhp;
1281 
1282 	node = VTON(a->a_vp);
1283 	ifhp = (struct ifid *)a->a_fhp;
1284 	ifhp->ifid_len = sizeof(struct ifid);
1285 	ifhp->ifid_ino = node->hash_id;
1286 
1287 	return (0);
1288 }
1289 
1290 /*
1291  * Read the block and then set the data pointer to correspond with the
1292  * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
1293  * to the number of bytes pointed to.  If 'size' is zero, try to read in a
1294  * whole extent.
1295  *
1296  * Note that *bp may be assigned error or not.
1297  *
1298  */
1299 static int
1300 udf_readatoffset(struct udf_node *node, int *size, off_t offset,
1301     struct buf **bp, uint8_t **data)
1302 {
1303 	struct udf_mnt *udfmp = node->udfmp;
1304 	struct vnode *vp = node->i_vnode;
1305 	struct file_entry *fentry;
1306 	struct buf *bp1;
1307 	uint32_t max_size;
1308 	daddr_t sector;
1309 	off_t off;
1310 	int adj_size;
1311 	int error;
1312 
1313 	/*
1314 	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
1315 	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
1316 	 */
1317 	error = udf_bmap_internal(node, offset, &sector, &max_size);
1318 	if (error == UDF_INVALID_BMAP) {
1319 		/*
1320 		 * This error means that the file *data* is stored in the
1321 		 * allocation descriptor field of the file entry.
1322 		 */
1323 		fentry = node->fentry;
1324 		*data = &fentry->data[le32toh(fentry->l_ea)];
1325 		*size = le32toh(fentry->l_ad);
1326 		if (offset >= *size)
1327 			*size = 0;
1328 		else {
1329 			*data += offset;
1330 			*size -= offset;
1331 		}
1332 		return (0);
1333 	} else if (error != 0) {
1334 		return (error);
1335 	}
1336 
1337 	/* Adjust the size so that it is within range */
1338 	if (*size == 0 || *size > max_size)
1339 		*size = max_size;
1340 
1341 	/*
1342 	 * Because we will read starting at block boundary, we need to adjust
1343 	 * how much we need to read so that all promised data is in.
1344 	 * Also, we can't promise to read more than MAXBSIZE bytes starting
1345 	 * from block boundary, so adjust what we promise too.
1346 	 */
1347 	off = blkoff(udfmp, offset);
1348 	*size = min(*size, MAXBSIZE - off);
1349 	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
1350 	*bp = NULL;
1351 	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
1352 		printf("warning: udf_readlblks returned error %d\n", error);
1353 		/* note: *bp may be non-NULL */
1354 		return (error);
1355 	}
1356 
1357 	bp1 = *bp;
1358 	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
1359 	return (0);
1360 }
1361 
1362 /*
1363  * Translate a file offset into a logical block and then into a physical
1364  * block.
1365  * max_size - maximum number of bytes that can be read starting from given
1366  * offset, rather than beginning of calculated sector number
1367  */
1368 static int
1369 udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
1370     uint32_t *max_size)
1371 {
1372 	struct udf_mnt *udfmp;
1373 	struct file_entry *fentry;
1374 	void *icb;
1375 	struct icb_tag *tag;
1376 	uint32_t icblen = 0;
1377 	daddr_t lsector;
1378 	int ad_offset, ad_num = 0;
1379 	int i, p_offset;
1380 
1381 	udfmp = node->udfmp;
1382 	fentry = node->fentry;
1383 	tag = &fentry->icbtag;
1384 
1385 	switch (le16toh(tag->strat_type)) {
1386 	case 4:
1387 		break;
1388 
1389 	case 4096:
1390 		printf("Cannot deal with strategy4096 yet!\n");
1391 		return (ENODEV);
1392 
1393 	default:
1394 		printf("Unknown strategy type %d\n", tag->strat_type);
1395 		return (ENODEV);
1396 	}
1397 
1398 	switch (le16toh(tag->flags) & 0x7) {
1399 	case 0:
1400 		/*
1401 		 * The allocation descriptor field is filled with short_ad's.
1402 		 * If the offset is beyond the current extent, look for the
1403 		 * next extent.
1404 		 */
1405 		do {
1406 			offset -= icblen;
1407 			ad_offset = sizeof(struct short_ad) * ad_num;
1408 			if (ad_offset > le32toh(fentry->l_ad)) {
1409 				printf("File offset out of bounds\n");
1410 				return (EINVAL);
1411 			}
1412 			icb = GETICB(short_ad, fentry,
1413 			    le32toh(fentry->l_ea) + ad_offset);
1414 			icblen = GETICBLEN(short_ad, icb);
1415 			ad_num++;
1416 		} while(offset >= icblen);
1417 
1418 		lsector = (offset  >> udfmp->bshift) +
1419 		    le32toh(((struct short_ad *)(icb))->pos);
1420 
1421 		*max_size = icblen - offset;
1422 
1423 		break;
1424 	case 1:
1425 		/*
1426 		 * The allocation descriptor field is filled with long_ad's
1427 		 * If the offset is beyond the current extent, look for the
1428 		 * next extent.
1429 		 */
1430 		do {
1431 			offset -= icblen;
1432 			ad_offset = sizeof(struct long_ad) * ad_num;
1433 			if (ad_offset > le32toh(fentry->l_ad)) {
1434 				printf("File offset out of bounds\n");
1435 				return (EINVAL);
1436 			}
1437 			icb = GETICB(long_ad, fentry,
1438 			    le32toh(fentry->l_ea) + ad_offset);
1439 			icblen = GETICBLEN(long_ad, icb);
1440 			ad_num++;
1441 		} while(offset >= icblen);
1442 
1443 		lsector = (offset >> udfmp->bshift) +
1444 		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
1445 
1446 		*max_size = icblen - offset;
1447 
1448 		break;
1449 	case 3:
1450 		/*
1451 		 * This type means that the file *data* is stored in the
1452 		 * allocation descriptor field of the file entry.
1453 		 */
1454 		*max_size = 0;
1455 		*sector = node->hash_id + udfmp->part_start;
1456 
1457 		return (UDF_INVALID_BMAP);
1458 	case 2:
1459 		/* DirectCD does not use extended_ad's */
1460 	default:
1461 		printf("Unsupported allocation descriptor %d\n",
1462 		       tag->flags & 0x7);
1463 		return (ENODEV);
1464 	}
1465 
1466 	*sector = lsector + udfmp->part_start;
1467 
1468 	/*
1469 	 * Check the sparing table.  Each entry represents the beginning of
1470 	 * a packet.
1471 	 */
1472 	if (udfmp->s_table != NULL) {
1473 		for (i = 0; i< udfmp->s_table_entries; i++) {
1474 			p_offset =
1475 			    lsector - le32toh(udfmp->s_table->entries[i].org);
1476 			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
1477 				*sector =
1478 				   le32toh(udfmp->s_table->entries[i].map) +
1479 				    p_offset;
1480 				break;
1481 			}
1482 		}
1483 	}
1484 
1485 	return (0);
1486 }
1487