xref: /illumos-gate/usr/src/common/fs/hsfs.c (revision b5358705b92a175b02aad08cd1c6b83dc69e2ae6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Basic file system reading code for standalone I/O system.
28  * Simulates a primitive UNIX I/O system (read(), write(), open(), etc).
29  * Does not support writes.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/sysmacros.h>
34 #include <sys/vnode.h>
35 #include <sys/fs/ufs_fsdir.h>
36 #include <sys/fs/ufs_fs.h>
37 #include <sys/fs/ufs_inode.h>
38 
39 #include <sys/fs/hsfs_spec.h>
40 #include <sys/fs/hsfs_isospec.h>
41 #include <sys/fs/hsfs_node.h>
42 #include <sys/fs/hsfs_susp.h>
43 #include <sys/fs/hsfs_rrip.h>
44 #include <sys/bootvfs.h>
45 #include <sys/filep.h>
46 
47 #ifdef	_BOOT
48 #include "../common/util.h"
49 #else
50 #include <sys/sunddi.h>
51 #endif
52 
53 #define	hdbtodb(n)	((ISO_SECTOR_SIZE / DEV_BSIZE) * (n))
54 
55 #define	HSFS_NUM_SIG    14
56 
57 #define	SUSP_SP_IX	0
58 #define	SUSP_CE_IX	1
59 #define	SUSP_PD_IX	2
60 #define	SUSP_ST_IX	3
61 #define	SUSP_ER_IX	4
62 #define	RRIP_PX_IX	5
63 #define	RRIP_PN_IX	6
64 #define	RRIP_SL_IX	7
65 #define	RRIP_CL_IX	8
66 #define	RRIP_PL_IX	9
67 #define	RRIP_RE_IX	10
68 #define	RRIP_RF_IX	11
69 #define	RRIP_RR_IX	12
70 #define	RRIP_NM_IX	13
71 
72 #ifdef	_BOOT
73 #define	dprintf	if (bootrd_debug) printf
74 #else
75 #define	printf	kobj_printf
76 #define	dprintf	if (bootrd_debug) kobj_printf
77 
78 /* PRINTFLIKE1 */
79 extern void kobj_printf(char *, ...);
80 #endif
81 
82 extern int bootrd_debug;
83 extern void *bkmem_alloc(size_t);
84 extern void bkmem_free(void *, size_t);
85 extern int cf_check_compressed(fileid_t *);
86 extern void cf_close(fileid_t *);
87 extern void cf_seek(fileid_t *, off_t, int);
88 extern int cf_read(fileid_t *, caddr_t, size_t);
89 
90 struct dirstuff {
91 	int loc;
92 	fileid_t *filep;
93 };
94 
95 struct hs_direct {
96     struct	direct  hs_ufs_dir;
97     struct	hs_direntry hs_dir;
98 };
99 
100 static uint_t root_ino = 0;
101 static struct hs_volume *hsfsp;
102 static fileid_t *head;
103 
104 static char *hsfs_sig_tab[] = {
105 	SUSP_SP,
106 	SUSP_CE,
107 	SUSP_PD,
108 	SUSP_ST,
109 	SUSP_ER,
110 	RRIP_PX,
111 	RRIP_PN,
112 	RRIP_SL,
113 	RRIP_CL,
114 	RRIP_PL,
115 	RRIP_RE,
116 	RRIP_TF,
117 	RRIP_RR,
118 	RRIP_NM
119 };
120 
121 static int hsfs_num_sig = sizeof (hsfs_sig_tab) / sizeof (hsfs_sig_tab[0]);
122 
123 /*
124  *  Local prototypes
125  */
126 static struct hs_direct *readdir(struct dirstuff *);
127 static uint_t parse_dir(fileid_t *, int, struct hs_direct *);
128 static uint_t parse_susp(char *, uint_t *, struct hs_direct *);
129 static ino_t dlook(char *, fileid_t *);
130 static int opendir(ino_t, fileid_t *);
131 static ino_t find(char *, fileid_t *);
132 
133 static int bhsfs_mountroot(char *str);
134 static int bhsfs_unmountroot(void);
135 static int bhsfs_open(char *str, int flags);
136 static int bhsfs_close(int fd);
137 static void bhsfs_closeall(void);
138 static ssize_t bhsfs_read(int fdesc, char *buf, size_t count);
139 static off_t bhsfs_lseek(int fdesc, off_t addr, int whence);
140 static int bhsfs_fstat(int fdesc, struct bootstat *stp);
141 
142 static fileid_t *
143 find_fp(int fd)
144 {
145 	fileid_t *filep = head;
146 
147 	if (fd >= 0) {
148 		while ((filep = filep->fi_forw) != head)
149 			if (fd == filep->fi_filedes)
150 				return (filep->fi_taken ? filep : 0);
151 	}
152 
153 	return (0);
154 }
155 
156 static int
157 opendir(ino_t inode, fileid_t *filep)
158 {
159 	struct hs_direct hsdep;
160 
161 	dprintf("opendir: inode = %ld\n", inode);
162 	/* Set up the IO request */
163 	filep->fi_offset = 0;
164 	filep->fi_blocknum = hdbtodb(inode);
165 	filep->fi_count = ISO_SECTOR_SIZE;
166 	filep->fi_memp = 0;
167 
168 	if (diskread(filep))
169 		return (0);
170 
171 	filep->fi_offset = 0;
172 	filep->fi_blocknum = hdbtodb(inode);
173 
174 	if (inode != root_ino)
175 		return (0);
176 
177 	if (parse_dir(filep, 0, &hsdep) > 0) {
178 		struct inode *ip;
179 
180 		ip = filep->fi_inode;
181 		if (ip == NULL)
182 			ip = filep->fi_inode = bkmem_alloc(sizeof (*ip));
183 
184 		ip->i_size = hsdep.hs_dir.ext_size;
185 		ip->i_smode = hsdep.hs_dir.mode;
186 		ip->i_number = inode;
187 		return (0);
188 	}
189 	return (1);
190 }
191 
192 static ino_t
193 find(char *path, fileid_t *filep)
194 {
195 	char *q;
196 	char c;
197 	ino_t n;
198 
199 	n = 0;
200 	dprintf("find: %s\n", path);
201 	if (path == NULL || *path == '\0')
202 		return (0);
203 
204 	if (opendir(root_ino, filep))
205 		return (0);
206 
207 	while (*path) {
208 		while (*path == '/')
209 			path++;
210 		q = path;
211 		while (*q != '/' && *q != '\0')
212 			q++;
213 		c = *q;
214 		*q = '\0';
215 		n = dlook(path, filep);
216 		*q = c;
217 		path = q;
218 
219 		if (n != 0) {
220 			if (c == '\0')
221 				break;
222 			if (opendir(n, filep))
223 				return (0);
224 			continue;
225 		} else {
226 			return (0);
227 		}
228 	}
229 	return ((ino_t)n);
230 }
231 
232 static ino_t
233 dlook(char *s, fileid_t *filep)
234 {
235 	struct hs_direct *hsdep;
236 	struct direct *udp;
237 	struct inode *ip;
238 	struct dirstuff dirp;
239 	int len;
240 
241 	dprintf("dlook: %s\n", s);
242 	ip = filep->fi_inode;
243 	if (s == NULL || *s == '\0')
244 		return (0);
245 	if ((ip->i_smode & IFMT) != IFDIR) {
246 		return (0);
247 	}
248 	if (ip->i_size == 0) {
249 		return (0);
250 	}
251 	len = strlen(s);
252 	dirp.loc = 0;
253 	dirp.filep = filep;
254 	for (hsdep = readdir(&dirp); hsdep != NULL; hsdep = readdir(&dirp)) {
255 		udp = &hsdep->hs_ufs_dir;
256 		if (udp->d_namlen == 1 &&
257 		    udp->d_name[0] == '.' &&
258 		    udp->d_name[1] == '\0')
259 			continue;
260 		if (udp->d_namlen == 2 &&
261 		    udp->d_name[0] == '.' &&
262 		    udp->d_name[1] == '.' &&
263 		    udp->d_name[2] == '\0')
264 			continue;
265 		if (udp->d_namlen == len && (strcmp(s, udp->d_name)) == 0) {
266 			struct inode *ip = filep->fi_inode;
267 
268 			filep->fi_offset = 0;
269 			filep->fi_blocknum = hdbtodb(udp->d_ino);
270 
271 			bzero(filep->fi_inode, sizeof (struct inode));
272 			ip->i_size = hsdep->hs_dir.ext_size;
273 			ip->i_smode = hsdep->hs_dir.mode;
274 			ip->i_number = udp->d_ino;
275 			return (udp->d_ino);
276 		}
277 	}
278 	return (0);
279 }
280 
281 /*
282  * get next entry in a directory.
283  */
284 static struct hs_direct *
285 readdir(struct dirstuff *dirp)
286 {
287 	static struct hs_direct hsdep;
288 	struct direct *udp = &hsdep.hs_ufs_dir;
289 	struct inode *ip;
290 	fileid_t *filep;
291 	daddr_t lbn;
292 	int off;
293 
294 	dprintf("readdir: start\n");
295 	filep = dirp->filep;
296 	ip = filep->fi_inode;
297 	for (;;) {
298 		if (dirp->loc >= ip->i_size) {
299 			return (NULL);
300 		}
301 		off = dirp->loc & ((1 << ISO_SECTOR_SHIFT) - 1);
302 		if (off == 0) {
303 			lbn = hdbtodb(dirp->loc >> ISO_SECTOR_SHIFT);
304 			filep->fi_blocknum = lbn + hdbtodb(ip->i_number);
305 			filep->fi_count = ISO_SECTOR_SIZE;
306 			filep->fi_memp = 0;
307 			if (diskread(filep)) {
308 				dprintf("readdir: diskread failed\n");
309 				return (NULL);
310 			}
311 		}
312 		dirp->loc += parse_dir(filep, off, &hsdep);
313 		if (udp->d_reclen == 0 && dirp->loc <= ip->i_size) {
314 			dirp->loc = roundup(dirp->loc, ISO_SECTOR_SIZE);
315 			continue;
316 		}
317 		return (&hsdep);
318 	}
319 }
320 
321 static int
322 getblock(fileid_t *filep)
323 {
324 	struct inode *ip = filep->fi_inode;
325 	int off, size, diff;
326 	daddr_t lbn;
327 
328 	dprintf("getblock: start\n");
329 	diff = ip->i_size - filep->fi_offset;
330 	if (diff <= 0)
331 		return (-1);
332 
333 	/* which block (or frag) in the file do we read? */
334 	lbn = hdbtodb(filep->fi_offset >> ISO_SECTOR_SHIFT);
335 	filep->fi_blocknum = lbn + hdbtodb(ip->i_number);
336 
337 	off = filep->fi_offset & ((1 << ISO_SECTOR_SHIFT) - 1);
338 	size = filep->fi_count = ISO_SECTOR_SIZE;
339 	filep->fi_memp = 0;
340 	if (diskread(filep))	/* Trap errors */
341 		return (-1);
342 
343 	if (filep->fi_offset - off + size >= ip->i_size)
344 		filep->fi_count = diff + off;
345 	filep->fi_count -= off;
346 	filep->fi_memp += off;
347 	dprintf("getblock: end\n");
348 	return (0);
349 }
350 
351 static ssize_t
352 bhsfs_read(int fd, caddr_t buf, size_t count)
353 {
354 	int i, j;
355 	fileid_t *filep;
356 	struct inode *ip;
357 	caddr_t n;
358 
359 	dprintf("bhsfs_read %d, ", fd);
360 	dprintf("count 0x%lx\n", count);
361 	filep = find_fp(fd);
362 	if (filep == NULL)
363 		return (-1);
364 
365 	ip = filep->fi_inode;
366 	n = buf;
367 	if ((filep->fi_flags & FI_COMPRESSED) == 0 &&
368 	    filep->fi_offset + count > ip->i_size)
369 		count = ip->i_size - filep->fi_offset;
370 
371 	if ((i = count) <= 0)
372 		return (0);
373 
374 	while (i > 0) {
375 		if (filep->fi_flags & FI_COMPRESSED) {
376 			if ((j = cf_read(filep, buf, count)) < 0)
377 				return (0); /* encountered an error */
378 			if (j < i)
379 				i = j; /* short read, must have hit EOF */
380 		} else {
381 			if (filep->fi_count == 0) {
382 				if (getblock(filep) == -1)
383 					return (0);
384 			}
385 			j = MIN(i, filep->fi_count);
386 			bcopy(filep->fi_memp, buf, (uint_t)j);
387 		}
388 		filep->fi_memp += j;
389 		filep->fi_offset += j;
390 		filep->fi_count -= j;
391 		buf += j;
392 		i -= j;
393 	}
394 
395 	dprintf("bhsfs_read: read 0x%x\n", (int)(buf - n));
396 	return (buf - n);
397 }
398 
399 /*ARGSUSED*/
400 static int
401 bhsfs_mountroot(char *str)
402 {
403 	char *bufp;
404 
405 	if (hsfsp != NULL)
406 		return (0);	/* already mounted */
407 
408 	dprintf("mounting ramdisk as hsfs\n");
409 
410 	hsfsp = bkmem_alloc(sizeof (*hsfsp));
411 	bzero(hsfsp, sizeof (*hsfsp));
412 	head = bkmem_alloc(sizeof (*head));
413 	bzero(head, sizeof (*head));
414 	head->fi_back = head->fi_forw = head;
415 
416 	/* now read the superblock. */
417 	head->fi_blocknum = hdbtodb(ISO_VOLDESC_SEC);
418 	head->fi_offset = 0;
419 	head->fi_count = ISO_SECTOR_SIZE;
420 	head->fi_memp = head->fi_buf;
421 	if (diskread(head)) {
422 		printf("failed to read superblock\n");
423 		bhsfs_closeall();
424 		return (-1);
425 	}
426 
427 	/* Since RRIP is based on ISO9660, that's where we start */
428 	bufp = head->fi_buf;
429 	if ((ISO_DESC_TYPE(bufp) != ISO_VD_PVD) ||
430 	    (strncmp((const char *)ISO_std_id(bufp), ISO_ID_STRING,
431 	    ISO_ID_STRLEN) != 0) || (ISO_STD_VER(bufp) != ISO_ID_VER)) {
432 		dprintf("volume type does not match\n");
433 		bhsfs_closeall();
434 		return (-1);
435 	}
436 
437 	/* Now we fill in the volume descriptor */
438 	hsfsp->vol_size = ISO_VOL_SIZE(bufp);
439 	hsfsp->lbn_size = ISO_BLK_SIZE(bufp);
440 	hsfsp->lbn_shift = ISO_SECTOR_SHIFT;
441 	hsfsp->lbn_secshift = ISO_SECTOR_SHIFT;
442 	hsfsp->vol_set_size = (ushort_t)ISO_SET_SIZE(bufp);
443 	hsfsp->vol_set_seq = (ushort_t)ISO_SET_SEQ(bufp);
444 
445 	/* Make sure we have a valid logical block size */
446 	if (hsfsp->lbn_size & ~(1 << hsfsp->lbn_shift)) {
447 		printf("%d invalid logical block size\n", hsfsp->lbn_size);
448 		bhsfs_closeall();
449 		return (-1);
450 	}
451 
452 	/* Since an HSFS root could be located anywhere on the media! */
453 	root_ino = IDE_EXT_LBN(ISO_root_dir(bufp));
454 	return (0);
455 }
456 
457 static int
458 bhsfs_unmountroot(void)
459 {
460 	if (hsfsp == NULL)
461 		return (-1);
462 
463 	bhsfs_closeall();
464 
465 	return (0);
466 }
467 
468 /*
469  * Open a file.
470  */
471 /*ARGSUSED*/
472 int
473 bhsfs_open(char *str, int flags)
474 {
475 	static int filedes = 1;
476 
477 	fileid_t *filep;
478 	ino_t ino;
479 
480 	dprintf("open %s\n", str);
481 	filep = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
482 	filep->fi_back = head->fi_back;
483 	filep->fi_forw = head;
484 	head->fi_back->fi_forw = filep;
485 	head->fi_back = filep;
486 	filep->fi_filedes = filedes++;
487 	filep->fi_taken = 1;
488 	filep->fi_path = (char *)bkmem_alloc(strlen(str) + 1);
489 	(void) strcpy(filep->fi_path, str);
490 	filep->fi_inode = NULL;
491 	bzero(filep->fi_buf, MAXBSIZE);
492 	filep->fi_getblock = getblock;
493 	filep->fi_flags = 0;
494 
495 	ino = find(str, filep);
496 	if (ino == 0) {
497 		(void) bhsfs_close(filep->fi_filedes);
498 		return (-1);
499 	}
500 
501 	filep->fi_blocknum = hdbtodb(ino);
502 	filep->fi_offset = 0;
503 	filep->fi_count = 0;
504 	filep->fi_memp = 0;
505 
506 	if (cf_check_compressed(filep) != 0)
507 		return (-1);
508 	dprintf("open done\n");
509 	return (filep->fi_filedes);
510 }
511 
512 int
513 bhsfs_close(int fd)
514 {
515 	fileid_t *filep;
516 
517 	dprintf("close %d\n", fd);
518 	if (!(filep = find_fp(fd)))
519 		return (-1);
520 
521 	if (filep->fi_taken == 0 || filep == head) {
522 		printf("File descripter %d not allocated!\n", fd);
523 		return (-1);
524 	}
525 
526 	cf_close(filep);
527 	/* unlink and deallocate node */
528 	filep->fi_forw->fi_back = filep->fi_back;
529 	filep->fi_back->fi_forw = filep->fi_forw;
530 	if (filep->fi_inode)
531 		bkmem_free(filep->fi_inode, sizeof (struct inode));
532 	bkmem_free(filep->fi_path, strlen(filep->fi_path) + 1);
533 	bkmem_free((char *)filep, sizeof (fileid_t));
534 	dprintf("close done\n");
535 	return (0);
536 }
537 
538 static void
539 bhsfs_closeall(void)
540 {
541 	fileid_t *filep;
542 
543 	while ((filep = head->fi_forw) != head)
544 		if (filep->fi_taken && bhsfs_close(filep->fi_filedes))
545 			printf("Filesystem may be inconsistent.\n");
546 
547 	bkmem_free(hsfsp, sizeof (*hsfsp));
548 	bkmem_free(head, sizeof (fileid_t));
549 	hsfsp = NULL;
550 	head = NULL;
551 }
552 
553 /*
554  * This version of seek() only performs absolute seeks (whence == 0).
555  */
556 static off_t
557 bhsfs_lseek(int fd, off_t addr, int whence)
558 {
559 	fileid_t *filep;
560 
561 	dprintf("lseek %d, ", fd);
562 	dprintf("off = %lx\n", addr);
563 	if (!(filep = find_fp(fd)))
564 		return (-1);
565 
566 	if (filep->fi_flags & FI_COMPRESSED) {
567 		cf_seek(filep, addr, whence);
568 	} else {
569 		switch (whence) {
570 		case SEEK_CUR:
571 			filep->fi_offset += addr;
572 			break;
573 		case SEEK_SET:
574 			filep->fi_offset = addr;
575 			break;
576 		default:
577 		case SEEK_END:
578 			printf("lseek(): invalid whence value %d\n", whence);
579 			break;
580 		}
581 		filep->fi_blocknum = addr / DEV_BSIZE;
582 	}
583 
584 	filep->fi_count = 0;
585 	return (0);
586 }
587 
588 static int
589 bhsfs_fstat(int fd, struct bootstat *stp)
590 {
591 	fileid_t	*filep;
592 	struct inode	*ip;
593 
594 	if (!(filep = find_fp(fd)))
595 		return (-1);
596 
597 	ip = filep->fi_inode;
598 
599 	stp->st_mode = 0;
600 	stp->st_size = 0;
601 
602 	if (ip == NULL)
603 		return (0);
604 
605 	switch (ip->i_smode & IFMT) {
606 	case IFDIR:
607 		stp->st_mode = S_IFDIR;
608 		break;
609 	case IFREG:
610 		stp->st_mode = S_IFREG;
611 		break;
612 	default:
613 		break;
614 	}
615 	/*
616 	 * NOTE: this size will be the compressed size for a compressed file
617 	 * This could confuse the caller since we decompress the file behind
618 	 * the scenes when the file is read.
619 	 */
620 	stp->st_size = ip->i_size;
621 
622 	/* file times */
623 	stp->st_atim.tv_sec = ip->i_atime.tv_sec;
624 	stp->st_atim.tv_nsec = ip->i_atime.tv_usec * 1000;
625 	stp->st_mtim.tv_sec = ip->i_mtime.tv_sec;
626 	stp->st_mtim.tv_nsec = ip->i_mtime.tv_usec * 1000;
627 	stp->st_ctim.tv_sec = ip->i_ctime.tv_sec;
628 	stp->st_ctim.tv_nsec = ip->i_ctime.tv_usec * 1000;
629 
630 	return (0);
631 
632 }
633 
634 
635 /*
636  * Parse a directory entry.
637  *
638  */
639 static uint_t
640 parse_dir(fileid_t *filep, int offset, struct hs_direct *hsdep)
641 {
642 	char *bufp = (char *)(filep->fi_memp + offset);
643 	struct direct *udp = &hsdep->hs_ufs_dir;  /* ufs-style dir info */
644 	struct hs_direntry *hdp = &hsdep->hs_dir; /* hsfs-style dir info */
645 	uint_t ce_lbn;
646 	uint_t ce_len;
647 	uint_t nmlen;
648 	uint_t i;
649 	uchar_t c;
650 
651 	dprintf("parse_dir: offset = %d\n", offset);
652 	/* a zero length dir entry terminates the dir block */
653 	udp->d_reclen = IDE_DIR_LEN(bufp);
654 	if (udp->d_reclen == 0)
655 		return (0);
656 
657 	/* fill in some basic hsfs info */
658 	hdp->ext_lbn  = IDE_EXT_LBN(bufp);
659 	hdp->ext_size = IDE_EXT_SIZE(bufp);
660 	hdp->xar_len  = IDE_XAR_LEN(bufp);
661 	hdp->intlf_sz = IDE_INTRLV_SIZE(bufp);
662 	hdp->intlf_sk = IDE_INTRLV_SKIP(bufp);
663 	hdp->sym_link = NULL;
664 
665 	/* we use lbn of data extent as an inode # equivalent */
666 	udp->d_ino	= hdp->ext_lbn;
667 
668 	c = IDE_FLAGS(bufp);
669 	if (IDE_REGULAR_FILE(c)) {
670 		hdp->type = VREG;
671 		hdp->mode = IFREG;
672 		hdp->nlink = 1;
673 	} else if (IDE_REGULAR_DIR(c)) {
674 		hdp->type = VDIR;
675 		hdp->mode = IFDIR;
676 		hdp->nlink = 2;
677 	} else {
678 		printf("pd(): file type=0x%x unknown.\n", c);
679 	}
680 
681 	/*
682 	 * Massage hsfs name, recognizing special entries for . and ..
683 	 * else lopping off version junk.
684 	 */
685 
686 	/* Some initial conditions */
687 	nmlen = IDE_NAME_LEN(bufp);
688 	c = *IDE_NAME(bufp);
689 	/* Special Case: Current Directory */
690 	if (nmlen == 1 && c == '\0') {
691 		udp->d_name[0] = '.';
692 		udp->d_name[1] = '\0';
693 		udp->d_namlen = 1;
694 	/* Special Case: Parent Directory */
695 	} else if (nmlen == 1 && c == '\001') {
696 		udp->d_name[0] = '.';
697 		udp->d_name[1] = '.';
698 		udp->d_name[2] = '\0';
699 		udp->d_namlen = 2;
700 	/* Other file name */
701 	} else {
702 		udp->d_namlen = 0;
703 		for (i = 0; i < nmlen; i++) {
704 			c = *(IDE_name(bufp)+i);
705 			if (c == ';')
706 				break;
707 			else if (c == ' ')
708 				continue;
709 			else
710 				udp->d_name[udp->d_namlen++] = c;
711 		}
712 		udp->d_name[udp->d_namlen] = '\0';
713 	}
714 
715 	/* System Use Fields */
716 	ce_len = IDE_SUA_LEN(bufp);
717 
718 	if (ce_len == 0)
719 		return (udp->d_reclen);
720 
721 	/* there is an SUA for this dir entry; go parse it */
722 	ce_lbn = parse_susp((char *)IDE_sys_use_area(bufp), &ce_len, hsdep);
723 
724 	if (ce_lbn) {
725 		/*
726 		 * store away current position in dir,
727 		 * as we will be using the iobuf to reading SUA.
728 		 */
729 		daddr_t save_bn = filep->fi_blocknum;
730 		daddr_t save_offset = filep->fi_offset;
731 		caddr_t save_ma = filep->fi_memp;
732 		int save_cc = filep->fi_count;
733 		do {
734 			filep->fi_count = ISO_SECTOR_SIZE;
735 			filep->fi_offset = 0;
736 			filep->fi_blocknum = hdbtodb(ce_lbn);
737 			filep->fi_memp = 0;
738 			if (diskread(filep)) {
739 				printf("failed to read cont. area\n");
740 				ce_len = 0;
741 				ce_lbn = 0;
742 				break;
743 			}
744 			ce_lbn = parse_susp(filep->fi_memp, &ce_len,
745 			    hsdep);
746 		} while (ce_lbn);
747 		filep->fi_count = save_cc;
748 		filep->fi_offset = save_offset;
749 		filep->fi_blocknum = save_bn;
750 		filep->fi_memp = save_ma;
751 	}
752 	return (udp->d_reclen);
753 }
754 
755 /*
756  * Parse the System Use Fields in this System Use Area.
757  * Return blk number of continuation/SUA, or 0 if no continuation/not a SUA.
758  */
759 static uint_t
760 parse_susp(char *bufp, uint_t *len, struct hs_direct *hsdep)
761 {
762 	struct direct *udp = &hsdep->hs_ufs_dir; /* ufs-style info */
763 	char *susp;
764 	uint_t cur_off = 0;
765 	uint_t blk_len = *len;
766 	uint_t susp_len = 0;
767 	uint_t ce_lbn = 0;
768 	uint_t i;
769 
770 	dprintf("parse_susp: len = %d\n", *len);
771 	while (cur_off < blk_len) {
772 		susp = (char *)(bufp + cur_off);
773 
774 		/*
775 		 * A null entry, or an entry with zero length
776 		 * terminates the SUSP.
777 		 */
778 		if (susp[0] == '\0' || susp[1] == '\0' ||
779 		    (susp_len = SUF_LEN(susp)) == 0)
780 			break;
781 
782 		/*
783 		 * Compare current entry to all known signatures.
784 		 */
785 		for (i = 0; i < hsfs_num_sig; i++)
786 			if (strncmp(hsfs_sig_tab[i], susp, SUF_SIG_LEN) == 0)
787 				break;
788 		switch (i) {
789 		case SUSP_CE_IX:
790 			/*
791 			 * CE signature: continuation of SUSP.
792 			 * will want to return new lbn, len.
793 			 */
794 			ce_lbn = CE_BLK_LOC(susp);
795 			*len = CE_CONT_LEN(susp);
796 			break;
797 		case RRIP_NM_IX:
798 			/* NM signature: POSIX-style file name */
799 			if (!RRIP_NAME_FLAGS(susp)) {
800 				udp->d_namlen = RRIP_NAME_LEN(susp);
801 				bcopy((char *)RRIP_name(susp),
802 				    udp->d_name, udp->d_namlen);
803 				udp->d_name[udp->d_namlen] = '\0';
804 			}
805 			break;
806 		case HSFS_NUM_SIG:
807 			/* couldn't find a legit susp, terminate loop */
808 		case SUSP_ST_IX:
809 			/* ST signature: terminates SUSP */
810 			return (ce_lbn);
811 		case SUSP_SP_IX:
812 		case RRIP_RR_IX:
813 		default:
814 			break;
815 		}
816 		cur_off += susp_len;
817 	}
818 	return (ce_lbn);
819 }
820 
821 struct boot_fs_ops bhsfs_ops = {
822 	"boot_hsfs",
823 	bhsfs_mountroot,
824 	bhsfs_unmountroot,
825 	bhsfs_open,
826 	bhsfs_close,
827 	bhsfs_read,
828 	bhsfs_lseek,
829 	bhsfs_fstat,
830 	NULL
831 };
832