xref: /titanic_51/usr/src/boot/lib/libstand/ufs.c (revision e48f27a0bf5ac8d6bcd05e2d0554b4aab53b1059)
1 /*	$NetBSD: ufs.c,v 1.20 1998/03/01 07:15:39 ross Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 Networks Associates Technology, Inc.
5  * All rights reserved.
6  *
7  * This software was developed for the FreeBSD Project by Marshall
8  * Kirk McKusick and Network Associates Laboratories, the Security
9  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
10  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
11  * research program
12  *
13  * Copyright (c) 1982, 1989, 1993
14  *	The Regents of the University of California.  All rights reserved.
15  *
16  * This code is derived from software contributed to Berkeley by
17  * The Mach Operating System project at Carnegie-Mellon University.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  * 3. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  *
44  * Copyright (c) 1990, 1991 Carnegie Mellon University
45  * All Rights Reserved.
46  *
47  * Author: David Golub
48  *
49  * Permission to use, copy, modify and distribute this software and its
50  * documentation is hereby granted, provided that both the copyright
51  * notice and this permission notice appear in all copies of the
52  * software, derivative works or modified versions, and any portions
53  * thereof, and that both notices appear in supporting documentation.
54  *
55  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
56  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
57  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
58  *
59  * Carnegie Mellon requests users of this software to return to
60  *
61  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
62  *  School of Computer Science
63  *  Carnegie Mellon University
64  *  Pittsburgh PA 15213-3890
65  *
66  * any improvements or extensions that they make and grant Carnegie the
67  * rights to redistribute these changes.
68  */
69 
70 #include <sys/cdefs.h>
71 
72 /*
73  *	Stand-alone file reading package.
74  */
75 
76 #include <sys/param.h>
77 #include <sys/disklabel.h>
78 #include <sys/time.h>
79 #include <ufs/ufs/dinode.h>
80 #include <ufs/ufs/dir.h>
81 #include <ufs/ffs/fs.h>
82 #include "stand.h"
83 #include "string.h"
84 
85 static int	ufs_open(const char *path, struct open_file *f);
86 static int	ufs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
87 static int	ufs_close(struct open_file *f);
88 static int	ufs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
89 static off_t	ufs_seek(struct open_file *f, off_t offset, int where);
90 static int	ufs_stat(struct open_file *f, struct stat *sb);
91 static int	ufs_readdir(struct open_file *f, struct dirent *d);
92 
93 struct fs_ops ufs_fsops = {
94 	"ufs",
95 	ufs_open,
96 	ufs_close,
97 	ufs_read,
98 	ufs_write,
99 	ufs_seek,
100 	ufs_stat,
101 	ufs_readdir
102 };
103 
104 /*
105  * In-core open file.
106  */
107 struct file {
108 	off_t		f_seekp;	/* seek pointer */
109 	struct fs	*f_fs;		/* pointer to super-block */
110 	union dinode {
111 		struct ufs1_dinode di1;
112 		struct ufs2_dinode di2;
113 	}		f_di;		/* copy of on-disk inode */
114 	int		f_nindir[NIADDR];
115 					/* number of blocks mapped by
116 					   indirect block at level i */
117 	char		*f_blk[NIADDR];	/* buffer for indirect block at
118 					   level i */
119 	size_t		f_blksize[NIADDR];
120 					/* size of buffer */
121 	ufs2_daddr_t	f_blkno[NIADDR];/* disk address of block in buffer */
122 	ufs2_daddr_t	f_buf_blkno;	/* block number of data block */
123 	char		*f_buf;		/* buffer for data block */
124 	size_t		f_buf_size;	/* size of data block */
125 };
126 #define DIP(fp, field) \
127 	((fp)->f_fs->fs_magic == FS_UFS1_MAGIC ? \
128 	(fp)->f_di.di1.field : (fp)->f_di.di2.field)
129 
130 static int	read_inode(ino_t, struct open_file *);
131 static int	block_map(struct open_file *, ufs2_daddr_t, ufs2_daddr_t *);
132 static int	buf_read_file(struct open_file *, char **, size_t *);
133 static int	buf_write_file(struct open_file *, char *, size_t *);
134 static int	search_directory(char *, struct open_file *, ino_t *);
135 
136 /*
137  * Read a new inode into a file structure.
138  */
139 static int
140 read_inode(inumber, f)
141 	ino_t inumber;
142 	struct open_file *f;
143 {
144 	struct file *fp = (struct file *)f->f_fsdata;
145 	struct fs *fs = fp->f_fs;
146 	char *buf;
147 	size_t rsize;
148 	int rc;
149 
150 	if (fs == NULL)
151 	    panic("fs == NULL");
152 
153 	/*
154 	 * Read inode and save it.
155 	 */
156 	buf = malloc(fs->fs_bsize);
157 	twiddle(1);
158 	rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
159 		fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize,
160 		buf, &rsize);
161 	if (rc)
162 		goto out;
163 	if (rsize != fs->fs_bsize) {
164 		rc = EIO;
165 		goto out;
166 	}
167 
168 	if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
169 		fp->f_di.di1 = ((struct ufs1_dinode *)buf)
170 		    [ino_to_fsbo(fs, inumber)];
171 	else
172 		fp->f_di.di2 = ((struct ufs2_dinode *)buf)
173 		    [ino_to_fsbo(fs, inumber)];
174 
175 	/*
176 	 * Clear out the old buffers
177 	 */
178 	{
179 		int level;
180 
181 		for (level = 0; level < NIADDR; level++)
182 			fp->f_blkno[level] = -1;
183 		fp->f_buf_blkno = -1;
184 	}
185 	fp->f_seekp = 0;
186 out:
187 	free(buf);
188 	return (rc);
189 }
190 
191 /*
192  * Given an offset in a file, find the disk block number that
193  * contains that block.
194  */
195 static int
196 block_map(f, file_block, disk_block_p)
197 	struct open_file *f;
198 	ufs2_daddr_t file_block;
199 	ufs2_daddr_t *disk_block_p;	/* out */
200 {
201 	struct file *fp = (struct file *)f->f_fsdata;
202 	struct fs *fs = fp->f_fs;
203 	int level;
204 	int idx;
205 	ufs2_daddr_t ind_block_num;
206 	int rc;
207 
208 	/*
209 	 * Index structure of an inode:
210 	 *
211 	 * di_db[0..NDADDR-1]	hold block numbers for blocks
212 	 *			0..NDADDR-1
213 	 *
214 	 * di_ib[0]		index block 0 is the single indirect block
215 	 *			holds block numbers for blocks
216 	 *			NDADDR .. NDADDR + NINDIR(fs)-1
217 	 *
218 	 * di_ib[1]		index block 1 is the double indirect block
219 	 *			holds block numbers for INDEX blocks for blocks
220 	 *			NDADDR + NINDIR(fs) ..
221 	 *			NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
222 	 *
223 	 * di_ib[2]		index block 2 is the triple indirect block
224 	 *			holds block numbers for double-indirect
225 	 *			blocks for blocks
226 	 *			NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
227 	 *			NDADDR + NINDIR(fs) + NINDIR(fs)**2
228 	 *				+ NINDIR(fs)**3 - 1
229 	 */
230 
231 	if (file_block < NDADDR) {
232 		/* Direct block. */
233 		*disk_block_p = DIP(fp, di_db[file_block]);
234 		return (0);
235 	}
236 
237 	file_block -= NDADDR;
238 
239 	/*
240 	 * nindir[0] = NINDIR
241 	 * nindir[1] = NINDIR**2
242 	 * nindir[2] = NINDIR**3
243 	 *	etc
244 	 */
245 	for (level = 0; level < NIADDR; level++) {
246 		if (file_block < fp->f_nindir[level])
247 			break;
248 		file_block -= fp->f_nindir[level];
249 	}
250 	if (level == NIADDR) {
251 		/* Block number too high */
252 		return (EFBIG);
253 	}
254 
255 	ind_block_num = DIP(fp, di_ib[level]);
256 
257 	for (; level >= 0; level--) {
258 		if (ind_block_num == 0) {
259 			*disk_block_p = 0;	/* missing */
260 			return (0);
261 		}
262 
263 		if (fp->f_blkno[level] != ind_block_num) {
264 			if (fp->f_blk[level] == (char *)0)
265 				fp->f_blk[level] =
266 					malloc(fs->fs_bsize);
267 			twiddle(1);
268 			rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
269 				fsbtodb(fp->f_fs, ind_block_num),
270 				fs->fs_bsize,
271 				fp->f_blk[level],
272 				&fp->f_blksize[level]);
273 			if (rc)
274 				return (rc);
275 			if (fp->f_blksize[level] != fs->fs_bsize)
276 				return (EIO);
277 			fp->f_blkno[level] = ind_block_num;
278 		}
279 
280 		if (level > 0) {
281 			idx = file_block / fp->f_nindir[level - 1];
282 			file_block %= fp->f_nindir[level - 1];
283 		} else
284 			idx = file_block;
285 
286 		if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
287 			ind_block_num = ((ufs1_daddr_t *)fp->f_blk[level])[idx];
288 		else
289 			ind_block_num = ((ufs2_daddr_t *)fp->f_blk[level])[idx];
290 	}
291 
292 	*disk_block_p = ind_block_num;
293 
294 	return (0);
295 }
296 
297 /*
298  * Write a portion of a file from an internal buffer.
299  */
300 static int
301 buf_write_file(f, buf_p, size_p)
302 	struct open_file *f;
303 	char *buf_p;
304 	size_t *size_p;		/* out */
305 {
306 	struct file *fp = (struct file *)f->f_fsdata;
307 	struct fs *fs = fp->f_fs;
308 	long off;
309 	ufs_lbn_t file_block;
310 	ufs2_daddr_t disk_block;
311 	size_t block_size;
312 	int rc;
313 
314 	/*
315 	 * Calculate the starting block address and offset.
316 	 */
317 	off = blkoff(fs, fp->f_seekp);
318 	file_block = lblkno(fs, fp->f_seekp);
319 	block_size = sblksize(fs, DIP(fp, di_size), file_block);
320 
321 	rc = block_map(f, file_block, &disk_block);
322 	if (rc)
323 		return (rc);
324 
325  	if (disk_block == 0)
326 		/* Because we can't allocate space on the drive */
327 		return (EFBIG);
328 
329 	/*
330 	 * Truncate buffer at end of file, and at the end of
331 	 * this block.
332 	 */
333 	if (*size_p > DIP(fp, di_size) - fp->f_seekp)
334 		*size_p = DIP(fp, di_size) - fp->f_seekp;
335 	if (*size_p > block_size - off)
336 		*size_p = block_size - off;
337 
338 	/*
339 	 * If we don't entirely occlude the block and it's not
340 	 * in memory already, read it in first.
341 	 */
342 	if (((off > 0) || (*size_p + off < block_size)) &&
343 	    (file_block != fp->f_buf_blkno)) {
344 
345 		if (fp->f_buf == (char *)0)
346 			fp->f_buf = malloc(fs->fs_bsize);
347 
348 		twiddle(8);
349 		rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
350 			fsbtodb(fs, disk_block),
351 			block_size, fp->f_buf, &fp->f_buf_size);
352 		if (rc)
353 			return (rc);
354 
355 		fp->f_buf_blkno = file_block;
356 	}
357 
358 	/*
359 	 *	Copy the user data into the cached block.
360 	 */
361 	bcopy(buf_p, fp->f_buf + off, *size_p);
362 
363 	/*
364 	 *	Write the block out to storage.
365 	 */
366 
367 	twiddle(4);
368 	rc = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
369 		fsbtodb(fs, disk_block),
370 		block_size, fp->f_buf, &fp->f_buf_size);
371 	return (rc);
372 }
373 
374 /*
375  * Read a portion of a file into an internal buffer.  Return
376  * the location in the buffer and the amount in the buffer.
377  */
378 static int
379 buf_read_file(f, buf_p, size_p)
380 	struct open_file *f;
381 	char **buf_p;		/* out */
382 	size_t *size_p;		/* out */
383 {
384 	struct file *fp = (struct file *)f->f_fsdata;
385 	struct fs *fs = fp->f_fs;
386 	long off;
387 	ufs_lbn_t file_block;
388 	ufs2_daddr_t disk_block;
389 	size_t block_size;
390 	int rc;
391 
392 	off = blkoff(fs, fp->f_seekp);
393 	file_block = lblkno(fs, fp->f_seekp);
394 	block_size = sblksize(fs, DIP(fp, di_size), file_block);
395 
396 	if (file_block != fp->f_buf_blkno) {
397 		if (fp->f_buf == (char *)0)
398 			fp->f_buf = malloc(fs->fs_bsize);
399 
400 		rc = block_map(f, file_block, &disk_block);
401 		if (rc)
402 			return (rc);
403 
404 		if (disk_block == 0) {
405 			bzero(fp->f_buf, block_size);
406 			fp->f_buf_size = block_size;
407 		} else {
408 			twiddle(4);
409 			rc = (f->f_dev->dv_strategy)(f->f_devdata,
410 				F_READ, fsbtodb(fs, disk_block),
411 				block_size, fp->f_buf, &fp->f_buf_size);
412 			if (rc)
413 				return (rc);
414 		}
415 
416 		fp->f_buf_blkno = file_block;
417 	}
418 
419 	/*
420 	 * Return address of byte in buffer corresponding to
421 	 * offset, and size of remainder of buffer after that
422 	 * byte.
423 	 */
424 	*buf_p = fp->f_buf + off;
425 	*size_p = block_size - off;
426 
427 	/*
428 	 * But truncate buffer at end of file.
429 	 */
430 	if (*size_p > DIP(fp, di_size) - fp->f_seekp)
431 		*size_p = DIP(fp, di_size) - fp->f_seekp;
432 
433 	return (0);
434 }
435 
436 /*
437  * Search a directory for a name and return its
438  * i_number.
439  */
440 static int
441 search_directory(name, f, inumber_p)
442 	char *name;
443 	struct open_file *f;
444 	ino_t *inumber_p;		/* out */
445 {
446 	struct file *fp = (struct file *)f->f_fsdata;
447 	struct direct *dp;
448 	struct direct *edp;
449 	char *buf;
450 	size_t buf_size;
451 	int namlen, length;
452 	int rc;
453 
454 	length = strlen(name);
455 
456 	fp->f_seekp = 0;
457 	while (fp->f_seekp < DIP(fp, di_size)) {
458 		rc = buf_read_file(f, &buf, &buf_size);
459 		if (rc)
460 			return (rc);
461 
462 		dp = (struct direct *)buf;
463 		edp = (struct direct *)(buf + buf_size);
464 		while (dp < edp) {
465 			if (dp->d_ino == (ino_t)0)
466 				goto next;
467 			namlen = dp->d_namlen;
468 			if (namlen == length &&
469 			    !strcmp(name, dp->d_name)) {
470 				/* found entry */
471 				*inumber_p = dp->d_ino;
472 				return (0);
473 			}
474 		next:
475 			dp = (struct direct *)((char *)dp + dp->d_reclen);
476 		}
477 		fp->f_seekp += buf_size;
478 	}
479 	return (ENOENT);
480 }
481 
482 static int sblock_try[] = SBLOCKSEARCH;
483 
484 /*
485  * Open a file.
486  */
487 static int
488 ufs_open(upath, f)
489 	const char *upath;
490 	struct open_file *f;
491 {
492 	char *cp, *ncp;
493 	int c;
494 	ino_t inumber, parent_inumber;
495 	struct file *fp;
496 	struct fs *fs;
497 	int i, rc;
498 	size_t buf_size;
499 	int nlinks = 0;
500 	char namebuf[MAXPATHLEN+1];
501 	char *buf = NULL;
502 	char *path = NULL;
503 
504 	/* allocate file system specific data structure */
505 	fp = malloc(sizeof(struct file));
506 	bzero(fp, sizeof(struct file));
507 	f->f_fsdata = (void *)fp;
508 
509 	/* allocate space and read super block */
510 	fs = malloc(SBLOCKSIZE);
511 	fp->f_fs = fs;
512 	twiddle(1);
513 	/*
514 	 * Try reading the superblock in each of its possible locations.
515 	 */
516 	for (i = 0; sblock_try[i] != -1; i++) {
517 		rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
518 		    sblock_try[i] / DEV_BSIZE, SBLOCKSIZE,
519 		    (char *)fs, &buf_size);
520 		if (rc)
521 			goto out;
522 		if ((fs->fs_magic == FS_UFS1_MAGIC ||
523 		     (fs->fs_magic == FS_UFS2_MAGIC &&
524 		      fs->fs_sblockloc == sblock_try[i])) &&
525 		    buf_size == SBLOCKSIZE &&
526 		    fs->fs_bsize <= MAXBSIZE &&
527 		    fs->fs_bsize >= sizeof(struct fs))
528 			break;
529 	}
530 	if (sblock_try[i] == -1) {
531 		rc = EINVAL;
532 		goto out;
533 	}
534 	/*
535 	 * Calculate indirect block levels.
536 	 */
537 	{
538 		ufs2_daddr_t mult;
539 		int level;
540 
541 		mult = 1;
542 		for (level = 0; level < NIADDR; level++) {
543 			mult *= NINDIR(fs);
544 			fp->f_nindir[level] = mult;
545 		}
546 	}
547 
548 	inumber = ROOTINO;
549 	if ((rc = read_inode(inumber, f)) != 0)
550 		goto out;
551 
552 	cp = path = strdup(upath);
553 	if (path == NULL) {
554 	    rc = ENOMEM;
555 	    goto out;
556 	}
557 	while (*cp) {
558 
559 		/*
560 		 * Remove extra separators
561 		 */
562 		while (*cp == '/')
563 			cp++;
564 		if (*cp == '\0')
565 			break;
566 
567 		/*
568 		 * Check that current node is a directory.
569 		 */
570 		if ((DIP(fp, di_mode) & IFMT) != IFDIR) {
571 			rc = ENOTDIR;
572 			goto out;
573 		}
574 
575 		/*
576 		 * Get next component of path name.
577 		 */
578 		{
579 			int len = 0;
580 
581 			ncp = cp;
582 			while ((c = *cp) != '\0' && c != '/') {
583 				if (++len > UFS_MAXNAMLEN) {
584 					rc = ENOENT;
585 					goto out;
586 				}
587 				cp++;
588 			}
589 			*cp = '\0';
590 		}
591 
592 		/*
593 		 * Look up component in current directory.
594 		 * Save directory inumber in case we find a
595 		 * symbolic link.
596 		 */
597 		parent_inumber = inumber;
598 		rc = search_directory(ncp, f, &inumber);
599 		*cp = c;
600 		if (rc)
601 			goto out;
602 
603 		/*
604 		 * Open next component.
605 		 */
606 		if ((rc = read_inode(inumber, f)) != 0)
607 			goto out;
608 
609 		/*
610 		 * Check for symbolic link.
611 		 */
612 		if ((DIP(fp, di_mode) & IFMT) == IFLNK) {
613 			int link_len = DIP(fp, di_size);
614 			int len;
615 
616 			len = strlen(cp);
617 
618 			if (link_len + len > MAXPATHLEN ||
619 			    ++nlinks > MAXSYMLINKS) {
620 				rc = ENOENT;
621 				goto out;
622 			}
623 
624 			bcopy(cp, &namebuf[link_len], len + 1);
625 
626 			if (link_len < fs->fs_maxsymlinklen) {
627 				if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
628 					cp = (caddr_t)(fp->f_di.di1.di_db);
629 				else
630 					cp = (caddr_t)(fp->f_di.di2.di_db);
631 				bcopy(cp, namebuf, (unsigned) link_len);
632 			} else {
633 				/*
634 				 * Read file for symbolic link
635 				 */
636 				size_t buf_size;
637 				ufs2_daddr_t disk_block;
638 				struct fs *fs = fp->f_fs;
639 
640 				if (!buf)
641 					buf = malloc(fs->fs_bsize);
642 				rc = block_map(f, (ufs2_daddr_t)0, &disk_block);
643 				if (rc)
644 					goto out;
645 
646 				twiddle(1);
647 				rc = (f->f_dev->dv_strategy)(f->f_devdata,
648 					F_READ, fsbtodb(fs, disk_block),
649 					fs->fs_bsize, buf, &buf_size);
650 				if (rc)
651 					goto out;
652 
653 				bcopy((char *)buf, namebuf, (unsigned)link_len);
654 			}
655 
656 			/*
657 			 * If relative pathname, restart at parent directory.
658 			 * If absolute pathname, restart at root.
659 			 */
660 			cp = namebuf;
661 			if (*cp != '/')
662 				inumber = parent_inumber;
663 			else
664 				inumber = (ino_t)ROOTINO;
665 
666 			if ((rc = read_inode(inumber, f)) != 0)
667 				goto out;
668 		}
669 	}
670 
671 	/*
672 	 * Found terminal component.
673 	 */
674 	rc = 0;
675 	fp->f_seekp = 0;
676 out:
677 	if (buf)
678 		free(buf);
679 	if (path)
680 		free(path);
681 	if (rc) {
682 		if (fp->f_buf)
683 			free(fp->f_buf);
684 		free(fp->f_fs);
685 		free(fp);
686 	}
687 	return (rc);
688 }
689 
690 static int
691 ufs_close(f)
692 	struct open_file *f;
693 {
694 	struct file *fp = (struct file *)f->f_fsdata;
695 	int level;
696 
697 	f->f_fsdata = (void *)0;
698 	if (fp == (struct file *)0)
699 		return (0);
700 
701 	for (level = 0; level < NIADDR; level++) {
702 		if (fp->f_blk[level])
703 			free(fp->f_blk[level]);
704 	}
705 	if (fp->f_buf)
706 		free(fp->f_buf);
707 	free(fp->f_fs);
708 	free(fp);
709 	return (0);
710 }
711 
712 /*
713  * Copy a portion of a file into kernel memory.
714  * Cross block boundaries when necessary.
715  */
716 static int
717 ufs_read(f, start, size, resid)
718 	struct open_file *f;
719 	void *start;
720 	size_t size;
721 	size_t *resid;	/* out */
722 {
723 	struct file *fp = (struct file *)f->f_fsdata;
724 	size_t csize;
725 	char *buf;
726 	size_t buf_size;
727 	int rc = 0;
728 	char *addr = start;
729 
730 	while (size != 0) {
731 		if (fp->f_seekp >= DIP(fp, di_size))
732 			break;
733 
734 		rc = buf_read_file(f, &buf, &buf_size);
735 		if (rc)
736 			break;
737 
738 		csize = size;
739 		if (csize > buf_size)
740 			csize = buf_size;
741 
742 		bcopy(buf, addr, csize);
743 
744 		fp->f_seekp += csize;
745 		addr += csize;
746 		size -= csize;
747 	}
748 	if (resid)
749 		*resid = size;
750 	return (rc);
751 }
752 
753 /*
754  * Write to a portion of an already allocated file.
755  * Cross block boundaries when necessary. Can not
756  * extend the file.
757  */
758 static int
759 ufs_write(f, start, size, resid)
760 	struct open_file *f;
761 	void *start;
762 	size_t size;
763 	size_t *resid;	/* out */
764 {
765 	struct file *fp = (struct file *)f->f_fsdata;
766 	size_t csize;
767 	int rc = 0;
768 	char *addr = start;
769 
770 	csize = size;
771 	while ((size != 0) && (csize != 0)) {
772 		if (fp->f_seekp >= DIP(fp, di_size))
773 			break;
774 
775 		if (csize >= 512) csize = 512; /* XXX */
776 
777 		rc = buf_write_file(f, addr, &csize);
778 		if (rc)
779 			break;
780 
781 		fp->f_seekp += csize;
782 		addr += csize;
783 		size -= csize;
784 	}
785 	if (resid)
786 		*resid = size;
787 	return (rc);
788 }
789 
790 static off_t
791 ufs_seek(f, offset, where)
792 	struct open_file *f;
793 	off_t offset;
794 	int where;
795 {
796 	struct file *fp = (struct file *)f->f_fsdata;
797 
798 	switch (where) {
799 	case SEEK_SET:
800 		fp->f_seekp = offset;
801 		break;
802 	case SEEK_CUR:
803 		fp->f_seekp += offset;
804 		break;
805 	case SEEK_END:
806 		fp->f_seekp = DIP(fp, di_size) - offset;
807 		break;
808 	default:
809 		errno = EINVAL;
810 		return (-1);
811 	}
812 	return (fp->f_seekp);
813 }
814 
815 static int
816 ufs_stat(f, sb)
817 	struct open_file *f;
818 	struct stat *sb;
819 {
820 	struct file *fp = (struct file *)f->f_fsdata;
821 
822 	/* only important stuff */
823 	sb->st_mode = DIP(fp, di_mode);
824 	sb->st_uid = DIP(fp, di_uid);
825 	sb->st_gid = DIP(fp, di_gid);
826 	sb->st_size = DIP(fp, di_size);
827 	return (0);
828 }
829 
830 static int
831 ufs_readdir(struct open_file *f, struct dirent *d)
832 {
833 	struct file *fp = (struct file *)f->f_fsdata;
834 	struct direct *dp;
835 	char *buf;
836 	size_t buf_size;
837 	int error;
838 
839 	/*
840 	 * assume that a directory entry will not be split across blocks
841 	 */
842 again:
843 	if (fp->f_seekp >= DIP(fp, di_size))
844 		return (ENOENT);
845 	error = buf_read_file(f, &buf, &buf_size);
846 	if (error)
847 		return (error);
848 	dp = (struct direct *)buf;
849 	fp->f_seekp += dp->d_reclen;
850 	if (dp->d_ino == (ino_t)0)
851 		goto again;
852 
853 	d->d_type = 0;		/* illumos ufs does not have type in direct */
854 	strcpy(d->d_name, dp->d_name);
855 	return (0);
856 }
857