xref: /dragonfly/sys/vfs/udf/udf_vfsops.c (revision d5f516c3)
1 /*-
2  * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/sys/fs/udf/udf_vfsops.c,v 1.16 2003/11/05 06:56:08 scottl Exp $
27  * $DragonFly: src/sys/vfs/udf/udf_vfsops.c,v 1.10 2004/11/12 00:09:51 dillon Exp $
28  */
29 
30 /* udf_vfsops.c */
31 /* Implement the VFS side of things */
32 
33 /*
34  * Ok, here's how it goes.  The UDF specs are pretty clear on how each data
35  * structure is made up, but not very clear on how they relate to each other.
36  * Here is the skinny... This demostrates a filesystem with one file in the
37  * root directory.  Subdirectories are treated just as normal files, but they
38  * have File Id Descriptors of their children as their file data.  As for the
39  * Anchor Volume Descriptor Pointer, it can exist in two of the following three
40  * places: sector 256, sector n (the max sector of the disk), or sector
41  * n - 256.  It's a pretty good bet that one will exist at sector 256 though.
42  * One caveat is unclosed CD media.  For that, sector 256 cannot be written,
43  * so the Anchor Volume Descriptor Pointer can exist at sector 512 until the
44  * media is closed.
45  *
46  *  Sector:
47  *     256:
48  *       n: Anchor Volume Descriptor Pointer
49  * n - 256:	|
50  *		|
51  *		|-->Main Volume Descriptor Sequence
52  *			|	|
53  *			|	|
54  *			|	|-->Logical Volume Descriptor
55  *			|			  |
56  *			|-->Partition Descriptor  |
57  *				|		  |
58  *				|		  |
59  *				|-->Fileset Descriptor
60  *					|
61  *					|
62  *					|-->Root Dir File Entry
63  *						|
64  *						|
65  *						|-->File data:
66  *						    File Id Descriptor
67  *							|
68  *							|
69  *							|-->File Entry
70  *								|
71  *								|
72  *								|-->File data
73  */
74 
75 #include <sys/types.h>
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/uio.h>
79 #include <sys/buf.h>
80 #include <sys/conf.h>
81 #include <sys/dirent.h>
82 #include <sys/fcntl.h>
83 #include <sys/module.h>
84 #include <sys/kernel.h>
85 #include <sys/malloc.h>
86 #include <sys/mount.h>
87 #include <sys/nlookup.h>
88 #include <sys/proc.h>
89 #include <sys/queue.h>
90 #include <sys/vnode.h>
91 
92 #include <vfs/udf/ecma167-udf.h>
93 #include <vfs/udf/osta.h>
94 #include <vfs/udf/udf.h>
95 #include <vfs/udf/udf_mount.h>
96 
97 extern struct vnodeopv_entry_desc udf_vnodeop_entries[];
98 
99 MALLOC_DEFINE(M_UDFNODE, "UDF node", "UDF node structure");
100 MALLOC_DEFINE(M_UDFMOUNT, "UDF mount", "UDF mount structure");
101 MALLOC_DEFINE(M_UDFFENTRY, "UDF fentry", "UDF file entry structure");
102 
103 static int udf_mount(struct mount *, char *, caddr_t, struct thread *);
104 static int udf_unmount(struct mount *, int, struct thread *);
105 static int udf_root(struct mount *, struct vnode **);
106 static int udf_statfs(struct mount *, struct statfs *, struct thread *);
107 static int udf_fhtovp(struct mount *, struct fid *, struct vnode **);
108 static int udf_vptofh(struct vnode *, struct fid *);
109 
110 static int udf_find_partmaps(struct udf_mnt *, struct logvol_desc *);
111 
112 static struct vfsops udf_vfsops = {
113 	udf_mount,
114 	vfs_stdstart,
115 	udf_unmount,
116 	udf_root,
117 	vfs_stdquotactl,
118 	udf_statfs,
119 	vfs_stdsync,
120 	udf_vget,
121 	udf_fhtovp,
122 	vfs_stdcheckexp,
123 	udf_vptofh,
124 	vfs_stdinit,
125 	vfs_stduninit,
126 	vfs_stdextattrctl,
127 };
128 VFS_SET(udf_vfsops, udf, VFCF_READONLY);
129 
130 MODULE_VERSION(udf, 1);
131 
132 static int udf_mountfs(struct vnode *, struct mount *, struct thread *);
133 
134 static int
135 udf_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
136 {
137 	struct vnode *devvp;	/* vnode of the mount device */
138 	struct udf_args args;
139 	struct udf_mnt *imp = 0;
140 	size_t size;
141 	int error;
142 	struct nlookupdata nd;
143 
144 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
145 		return (EROFS);
146 
147 	/*
148 	 * No root filesystem support.  Probably not a big deal, since the
149 	 * bootloader doesn't understand UDF.
150 	 */
151 	if (mp->mnt_flag & MNT_ROOTFS)
152 		return (ENOTSUP);
153 
154 	if ((error = copyin(data, (caddr_t)&args, sizeof(struct udf_args))))
155 		return(error);
156 
157 	if (mp->mnt_flag & MNT_UPDATE) {
158 		imp = VFSTOUDFFS(mp);
159 		if (args.fspec == NULL)
160 			return(vfs_export(mp, &imp->im_export, &args.export));
161 	}
162 
163 	/* Check that the mount device exists */
164 	devvp = NULL;
165 	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
166 	if (error == 0)
167 		error = nlookup(&nd);
168 	if (error == 0)
169 		error = cache_vref(nd.nl_ncp, nd.nl_cred, &devvp);
170 	nlookup_done(&nd);
171 	if (error)
172 		return (error);
173 
174 	if (vn_isdisk(devvp, &error) == 0) {
175 		vrele(devvp);
176 		return(error);
177 	}
178 
179 	/* Check the access rights on the mount device */
180 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
181 	error = VOP_ACCESS(devvp, VREAD, td->td_proc->p_ucred, td);
182 	if (error)
183 		error = suser(td);
184 	if (error) {
185 		vput(devvp);
186 		return(error);
187 	}
188 	VOP_UNLOCK(devvp, 0, td);
189 
190 	if ((error = udf_mountfs(devvp, mp, td))) {
191 		vrele(devvp);
192 		return(error);
193 	}
194 
195 	imp = VFSTOUDFFS(mp);
196 
197 	imp->im_flags = args.flags;
198 
199 	copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
200 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
201 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
202 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
203 	udf_statfs(mp, &mp->mnt_stat, td);
204 	return(0);
205 }
206 
207 /*
208  * Check the descriptor tag for both the correct id and correct checksum.
209  * Return zero if all is good, EINVAL if not.
210  */
211 int
212 udf_checktag(struct desc_tag *tag, uint16_t id)
213 {
214 	uint8_t *itag;
215 	uint8_t i, cksum = 0;
216 
217 	itag = (uint8_t *)tag;
218 
219 	if (tag->id != id)
220 		return(EINVAL);
221 
222 	for (i = 0; i < 15; i++)
223 		cksum = cksum + itag[i];
224 	cksum = cksum - itag[4];
225 
226 	if (cksum == tag->cksum)
227 		return(0);
228 
229 	return(EINVAL);
230 }
231 
232 static int
233 udf_mountfs(struct vnode *devvp, struct mount *mp, struct thread *td)
234 {
235 	struct buf *bp = NULL;
236 	struct anchor_vdp avdp;
237 	struct udf_mnt *udfmp = NULL;
238 	struct part_desc *pd;
239 	struct logvol_desc *lvd;
240 	struct fileset_desc *fsd;
241 	struct file_entry *root_fentry;
242 	dev_t dev;
243 	uint32_t sector, size, mvds_start, mvds_end;
244 	uint32_t fsd_offset = 0;
245 	uint16_t part_num = 0, fsd_part = 0;
246 	int error = EINVAL, needclose = 0;
247 	int logvol_found = 0, part_found = 0, fsd_found = 0;
248 	int bsize;
249 
250 	/*
251 	 * Disallow multiple mounts of the same device. Flush the buffer
252 	 * cache for the device.
253 	 */
254 	if ((error = vfs_mountedon(devvp)))
255 		return(error);
256 	if (count_udev(devvp->v_udev) > 0)
257 		return(EBUSY);
258 	if ((error = vinvalbuf(devvp, V_SAVE, td, 0, 0)))
259 		return(error);
260 
261 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
262 	error = VOP_OPEN(devvp, FREAD, FSCRED, NULL, td);
263 	VOP_UNLOCK(devvp, 0, td);
264 	if (error)
265 		return(error);
266 	needclose = 1;
267 	dev = devvp->v_rdev;
268 
269 	udfmp = malloc(sizeof(*udfmp), M_UDFMOUNT, M_WAITOK | M_ZERO);
270 
271 	mp->mnt_data = (qaddr_t)udfmp;
272 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
273 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
274 	mp->mnt_maxsymlinklen = 0;
275 	mp->mnt_flag |= MNT_LOCAL;
276 	udfmp->im_mountp = mp;
277 	udfmp->im_dev = dev;
278 	udfmp->im_devvp = devvp;
279 
280 	bsize = 2048;	/* XXX Should probe the media for it's size */
281 
282 	/*
283 	 * Get the Anchor Volume Descriptor Pointer from sector 256.
284 	 * XXX Should also check sector n - 256, n, and 512.
285 	 */
286 	sector = 256;
287 	if ((error = bread(devvp, sector * btodb(bsize), bsize, &bp)) != 0)
288 		goto bail;
289 	if ((error = udf_checktag((struct desc_tag *)bp->b_data, TAGID_ANCHOR)))
290 		goto bail;
291 
292 	bcopy(bp->b_data, &avdp, sizeof(struct anchor_vdp));
293 	brelse(bp);
294 	bp = NULL;
295 
296 	/*
297 	 * Extract the Partition Descriptor and Logical Volume Descriptor
298 	 * from the Volume Descriptor Sequence.
299 	 * XXX Should we care about the partition type right now?
300 	 * XXX What about multiple partitions?
301 	 */
302 	mvds_start = avdp.main_vds_ex.loc;
303 	mvds_end = mvds_start + (avdp.main_vds_ex.len - 1) / bsize;
304 	for (sector = mvds_start; sector < mvds_end; sector++) {
305 		if ((error = bread(devvp, sector * btodb(bsize), bsize,
306 				   &bp)) != 0) {
307 			printf("Can't read sector %d of VDS\n", sector);
308 			goto bail;
309 		}
310 		lvd = (struct logvol_desc *)bp->b_data;
311 		if (!udf_checktag(&lvd->tag, TAGID_LOGVOL)) {
312 			udfmp->bsize = lvd->lb_size;
313 			udfmp->bmask = udfmp->bsize - 1;
314 			udfmp->bshift = ffs(udfmp->bsize) - 1;
315 			fsd_part = lvd->_lvd_use.fsd_loc.loc.part_num;
316 			fsd_offset = lvd->_lvd_use.fsd_loc.loc.lb_num;
317 			if (udf_find_partmaps(udfmp, lvd))
318 				break;
319 			logvol_found = 1;
320 		}
321 		pd = (struct part_desc *)bp->b_data;
322 		if (!udf_checktag(&pd->tag, TAGID_PARTITION)) {
323 			part_found = 1;
324 			part_num = pd->part_num;
325 			udfmp->part_len = pd->part_len;
326 			udfmp->part_start = pd->start_loc;
327 		}
328 
329 		brelse(bp);
330 		bp = NULL;
331 		if ((part_found) && (logvol_found))
332 			break;
333 	}
334 
335 	if (!part_found || !logvol_found) {
336 		error = EINVAL;
337 		goto bail;
338 	}
339 
340 	if (fsd_part != part_num) {
341 		printf("FSD does not lie within the partition!\n");
342 		error = EINVAL;
343 		goto bail;
344 	}
345 
346 
347 	/*
348 	 * Grab the Fileset Descriptor
349 	 * Thanks to Chuck McCrobie <mccrobie@cablespeed.com> for pointing
350 	 * me in the right direction here.
351 	 */
352 	sector = udfmp->part_start + fsd_offset;
353 	if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
354 		printf("Cannot read sector %d of FSD\n", sector);
355 		goto bail;
356 	}
357 	fsd = (struct fileset_desc *)bp->b_data;
358 	if (!udf_checktag(&fsd->tag, TAGID_FSD)) {
359 		fsd_found = 1;
360 		bcopy(&fsd->rootdir_icb, &udfmp->root_icb,
361 		      sizeof(struct long_ad));
362 	}
363 
364 	brelse(bp);
365 	bp = NULL;
366 
367 	if (!fsd_found) {
368 		printf("Couldn't find the fsd\n");
369 		error = EINVAL;
370 		goto bail;
371 	}
372 
373 	vfs_add_vnodeops(&mp->mnt_vn_ops, udf_vnodeop_entries);
374 
375 	/*
376 	 * Find the file entry for the root directory.
377 	 */
378 	sector = udfmp->root_icb.loc.lb_num + udfmp->part_start;
379 	size = udfmp->root_icb.len;
380 	if ((error = udf_readlblks(udfmp, sector, size, &bp)) != 0) {
381 		printf("Cannot read sector %d\n", sector);
382 		goto bail;
383 	}
384 
385 	root_fentry = (struct file_entry *)bp->b_data;
386 	if ((error = udf_checktag(&root_fentry->tag, TAGID_FENTRY))) {
387 		printf("Invalid root file entry!\n");
388 		goto bail;
389 	}
390 
391 	brelse(bp);
392 	bp = NULL;
393 
394 	lwkt_token_init(&udfmp->hash_token);
395 	udfmp->hashtbl = phashinit(UDF_HASHTBLSIZE, M_UDFMOUNT, &udfmp->hashsz);
396 
397 	return(0);
398 
399 bail:
400 	if (udfmp != NULL)
401 		free(udfmp, M_UDFMOUNT);
402 	if (bp != NULL)
403 		brelse(bp);
404 	if (needclose)
405 		VOP_CLOSE(devvp, FREAD, td);
406 	return(error);
407 }
408 
409 static int
410 udf_unmount(struct mount *mp, int mntflags, struct thread *td)
411 {
412 	struct udf_mnt *udfmp;
413 	int error, flags = 0;
414 
415 	udfmp = VFSTOUDFFS(mp);
416 
417 	if (mntflags & MNT_FORCE)
418 		flags |= FORCECLOSE;
419 
420 	if ((error = vflush(mp, 0, flags)))
421 		return (error);
422 
423 	udfmp->im_devvp->v_rdev->si_mountpoint = NULL;
424 	error = VOP_CLOSE(udfmp->im_devvp, FREAD, td);
425 	vrele(udfmp->im_devvp);
426 
427 	if (udfmp->s_table)
428 		free(udfmp->s_table, M_UDFMOUNT);
429 	if (udfmp->hashtbl)
430 		free(udfmp->hashtbl, M_UDFMOUNT);
431 	free(udfmp, M_UDFMOUNT);
432 
433 	mp->mnt_data = (qaddr_t)0;
434 	mp->mnt_flag &= ~MNT_LOCAL;
435 
436 	return (error);
437 }
438 
439 static int
440 udf_root(struct mount *mp, struct vnode **vpp)
441 {
442 	struct udf_mnt *udfmp;
443 	struct vnode *vp;
444 	ino_t id;
445 	int error;
446 
447 	udfmp = VFSTOUDFFS(mp);
448 
449 	id = udf_getid(&udfmp->root_icb);
450 
451 	error = udf_vget(mp, id, vpp);
452 	if (error)
453 		return(error);
454 
455 	vp = *vpp;
456 	vp->v_flag |= VROOT;
457 	udfmp->root_vp = vp;
458 
459 	return(0);
460 }
461 
462 static int
463 udf_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
464 {
465 	struct udf_mnt *udfmp;
466 
467 	udfmp = VFSTOUDFFS(mp);
468 
469 	sbp->f_bsize = udfmp->bsize;
470 	sbp->f_iosize = udfmp->bsize;
471 	sbp->f_blocks = udfmp->part_len;
472 	sbp->f_bfree = 0;
473 	sbp->f_bavail = 0;
474 	sbp->f_files = 0;
475 	sbp->f_ffree = 0;
476 	if (sbp != &mp->mnt_stat) {
477 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
478 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
479 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
480 	}
481 
482 	return(0);
483 }
484 
485 int
486 udf_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
487 {
488 	struct buf *bp;
489 	struct vnode *devvp;
490 	struct udf_mnt *udfmp;
491 	struct thread *td;
492 	struct vnode *vp;
493 	struct udf_node *unode;
494 	struct file_entry *fe;
495 	int error, sector, size;
496 
497 	td = curthread;
498 	udfmp = VFSTOUDFFS(mp);
499 
500 	/* See if we already have this in the cache */
501 	if ((error = udf_hashlookup(udfmp, ino, vpp)) != 0)
502 		return(error);
503 	if (*vpp != NULL) {
504 		return(0);
505 	}
506 
507 	/*
508 	 * Allocate memory and check the tag id's before grabbing a new
509 	 * vnode, since it's hard to roll back if there is a problem.
510 	 */
511 	unode = malloc(sizeof(*unode), M_UDFNODE, M_WAITOK | M_ZERO);
512 
513 	/*
514 	 * Copy in the file entry.  Per the spec, the size can only be 1 block.
515 	 */
516 	sector = ino + udfmp->part_start;
517 	devvp = udfmp->im_devvp;
518 	if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
519 		printf("Cannot read sector %d\n", sector);
520 		free(unode, M_UDFNODE);
521 		return(error);
522 	}
523 
524 	fe = (struct file_entry *)bp->b_data;
525 	if (udf_checktag(&fe->tag, TAGID_FENTRY)) {
526 		printf("Invalid file entry!\n");
527 		free(unode, M_UDFNODE);
528 		brelse(bp);
529 		return(ENOMEM);
530 	}
531 	size = UDF_FENTRY_SIZE + fe->l_ea + fe->l_ad;
532 	unode->fentry = malloc(size, M_UDFFENTRY, M_WAITOK | M_ZERO);
533 
534 	bcopy(bp->b_data, unode->fentry, size);
535 
536 	brelse(bp);
537 	bp = NULL;
538 
539 	if ((error = udf_allocv(mp, &vp))) {
540 		printf("Error from udf_allocv\n");
541 		free(unode, M_UDFNODE);
542 		return(error);
543 	}
544 
545 	unode->i_vnode = vp;
546 	unode->hash_id = ino;
547 	unode->i_devvp = udfmp->im_devvp;
548 	unode->i_dev = udfmp->im_dev;
549 	unode->udfmp = udfmp;
550 	vp->v_data = unode;
551 	vref(udfmp->im_devvp);
552 	udf_hashins(unode);
553 
554 	switch (unode->fentry->icbtag.file_type) {
555 	default:
556 		vp->v_type = VBAD;
557 		break;
558 	case 4:
559 		vp->v_type = VDIR;
560 		break;
561 	case 5:
562 		vp->v_type = VREG;
563 		break;
564 	case 6:
565 		vp->v_type = VBLK;
566 		break;
567 	case 7:
568 		vp->v_type = VCHR;
569 		break;
570 	case 9:
571 		vp->v_type = VFIFO;
572 		break;
573 	case 10:
574 		vp->v_type = VSOCK;
575 		break;
576 	case 12:
577 		vp->v_type = VLNK;
578 		break;
579 	}
580 	/*
581 	 * Locked and refd vnode returned
582 	 */
583 	*vpp = vp;
584 
585 	return(0);
586 }
587 
588 struct ifid {
589 	u_short	ifid_len;
590 	u_short	ifid_pad;
591 	int	ifid_ino;
592 	long	ifid_start;
593 };
594 
595 static int
596 udf_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
597 {
598 	struct ifid *ifhp;
599 	struct vnode *nvp;
600 	int error;
601 
602 	ifhp = (struct ifid *)fhp;
603 
604 	if ((error = VFS_VGET(mp, ifhp->ifid_ino, &nvp)) != 0) {
605 		*vpp = NULLVP;
606 		return(error);
607 	}
608 
609 	*vpp = nvp;
610 	return(0);
611 }
612 
613 static int
614 udf_vptofh (struct vnode *vp, struct fid *fhp)
615 {
616 	struct udf_node *node;
617 	struct ifid *ifhp;
618 
619 	node = VTON(vp);
620 	ifhp = (struct ifid *)fhp;
621 	ifhp->ifid_len = sizeof(struct ifid);
622 	ifhp->ifid_ino = node->hash_id;
623 
624 	return(0);
625 }
626 
627 static int
628 udf_find_partmaps(struct udf_mnt *udfmp, struct logvol_desc *lvd)
629 {
630 	union udf_pmap *pmap;
631 	struct part_map_spare *pms;
632 	struct regid *pmap_id;
633 	struct buf *bp;
634 	unsigned char regid_id[UDF_REGID_ID_SIZE + 1];
635 	int ptype, psize, error;
636 	unsigned int i;
637 
638 	for (i = 0; i < lvd->n_pm; i++) {
639 		pmap = (union udf_pmap *)&lvd->maps[i * UDF_PMAP_SIZE];
640 		ptype = pmap->data[0];
641 		psize = pmap->data[1];
642 		if (((ptype != 1) && (ptype != 2)) ||
643 		    ((psize != UDF_PMAP_SIZE) && (psize != 6))) {
644 			printf("Invalid partition map found\n");
645 			return(1);
646 		}
647 
648 		if (ptype == 1) {
649 			/* Type 1 map.  We don't care */
650 			continue;
651 		}
652 
653 		/* Type 2 map.  Gotta find out the details */
654 		pmap_id = (struct regid *)&pmap->data[4];
655 		bzero(&regid_id[0], UDF_REGID_ID_SIZE);
656 		bcopy(&pmap_id->id[0], &regid_id[0], UDF_REGID_ID_SIZE);
657 
658 		if (bcmp(&regid_id[0], "*UDF Sparable Partition",
659 		    UDF_REGID_ID_SIZE)) {
660 			printf("Unsupported partition map: %s\n", &regid_id[0]);
661 			return(1);
662 		}
663 
664 		pms = &pmap->pms;
665 		udfmp->s_table = malloc(pms->st_size, M_UDFMOUNT,
666 					M_WAITOK | M_ZERO);
667 		if (udfmp->s_table == NULL)
668 			return(ENOMEM);
669 
670 		/* Calculate the number of sectors per packet. */
671 		/* XXX Logical or physical? */
672 		udfmp->p_sectors = pms->packet_len / udfmp->bsize;
673 
674 		/*
675 		 * XXX If reading the first Sparing Table fails, should look
676 		 * for another table.
677 		 */
678 		if ((error = udf_readlblks(udfmp, pms->st_loc[0], pms->st_size,
679 		    &bp)) != 0) {
680 			if (bp)
681 				brelse(bp);
682 			printf("Failed to read Sparing Table at sector %d\n",
683 			    pms->st_loc[0]);
684 			return(error);
685 		}
686 		bcopy(bp->b_data, udfmp->s_table, pms->st_size);
687 		brelse(bp);
688 
689 		if (udf_checktag(&udfmp->s_table->tag, 0)) {
690 			printf("Invalid sparing table found\n");
691 			return(EINVAL);
692 		}
693 
694 		/* See how many valid entries there are here.  The list is
695 		 * supposed to be sorted. 0xfffffff0 and higher are not valid
696 		 */
697 		for (i = 0; i < udfmp->s_table->rt_l; i++) {
698 			udfmp->s_table_entries = i;
699 			if (udfmp->s_table->entries[i].org >= 0xfffffff0)
700 				break;
701 		}
702 	}
703 
704 	return(0);
705 }
706