xref: /freebsd/stand/libsa/ufs.c (revision 105fd928b0b5b35ab529e5f6914788dc49582901)
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 __FBSDID("$FreeBSD$");
72 
73 /*
74  *	Stand-alone file reading package.
75  */
76 
77 #include <sys/param.h>
78 #include <sys/disklabel.h>
79 #include <sys/time.h>
80 #include <ufs/ufs/dinode.h>
81 #include <ufs/ufs/dir.h>
82 #include <ufs/ffs/fs.h>
83 #include "stand.h"
84 #include "disk.h"
85 #include "string.h"
86 
87 static int	ufs_open(const char *path, struct open_file *f);
88 static int	ufs_write(struct open_file *f, const void *buf, size_t size,
89 		size_t *resid);
90 static int	ufs_close(struct open_file *f);
91 static int	ufs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
92 static off_t	ufs_seek(struct open_file *f, off_t offset, int where);
93 static int	ufs_stat(struct open_file *f, struct stat *sb);
94 static int	ufs_readdir(struct open_file *f, struct dirent *d);
95 static int	ufs_mount(const char *dev, const char *path, void **data);
96 static int	ufs_unmount(const char *dev, void *data);
97 
98 struct fs_ops ufs_fsops = {
99 	.fs_name = "ufs",
100 	.fo_open = ufs_open,
101 	.fo_close = ufs_close,
102 	.fo_read = ufs_read,
103 	.fo_write = ufs_write,
104 	.fo_seek = ufs_seek,
105 	.fo_stat = ufs_stat,
106 	.fo_readdir = ufs_readdir,
107 	.fo_mount = ufs_mount,
108 	.fo_unmount = ufs_unmount
109 };
110 
111 /*
112  * In-core open file.
113  */
114 struct file {
115 	off_t		f_seekp;	/* seek pointer */
116 	struct fs	*f_fs;		/* pointer to super-block */
117 	union dinode {
118 		struct ufs1_dinode di1;
119 		struct ufs2_dinode di2;
120 	}		f_di;		/* copy of on-disk inode */
121 	int		f_nindir[UFS_NIADDR];
122 					/* number of blocks mapped by
123 					   indirect block at level i */
124 	char		*f_blk[UFS_NIADDR];	/* buffer for indirect block at
125 					   level i */
126 	size_t		f_blksize[UFS_NIADDR];
127 					/* size of buffer */
128 	ufs2_daddr_t	f_blkno[UFS_NIADDR];/* disk address of block in buffer */
129 	ufs2_daddr_t	f_buf_blkno;	/* block number of data block */
130 	char		*f_buf;		/* buffer for data block */
131 	size_t		f_buf_size;	/* size of data block */
132 	int		f_inumber;	/* inumber */
133 };
134 #define DIP(fp, field) \
135 	((fp)->f_fs->fs_magic == FS_UFS1_MAGIC ? \
136 	(fp)->f_di.di1.field : (fp)->f_di.di2.field)
137 
138 typedef struct ufs_mnt {
139 	char			*um_dev;
140 	int			um_fd;
141 	STAILQ_ENTRY(ufs_mnt)	um_link;
142 } ufs_mnt_t;
143 
144 typedef STAILQ_HEAD(ufs_mnt_list, ufs_mnt) ufs_mnt_list_t;
145 static ufs_mnt_list_t mnt_list = STAILQ_HEAD_INITIALIZER(mnt_list);
146 
147 static int	read_inode(ino_t, struct open_file *);
148 static int	block_map(struct open_file *, ufs2_daddr_t, ufs2_daddr_t *);
149 static int	buf_read_file(struct open_file *, char **, size_t *);
150 static int	buf_write_file(struct open_file *, const char *, size_t *);
151 static int	search_directory(char *, struct open_file *, ino_t *);
152 static int	ufs_use_sa_read(void *, off_t, void **, int);
153 
154 /* from ffs_subr.c */
155 int	ffs_sbget(void *, struct fs **, off_t, char *,
156 	    int (*)(void *, off_t, void **, int));
157 /*
158  * Request standard superblock location in ffs_sbget
159  */
160 #define	STDSB			-1	/* Fail if check-hash is bad */
161 #define	STDSB_NOHASHFAIL	-2	/* Ignore check-hash failure */
162 
163 /*
164  * Read a new inode into a file structure.
165  */
166 static int
167 read_inode(ino_t inumber, struct open_file *f)
168 {
169 	struct file *fp = (struct file *)f->f_fsdata;
170 	struct fs *fs = fp->f_fs;
171 	char *buf;
172 	size_t rsize;
173 	int rc;
174 
175 	if (fs == NULL)
176 	    panic("fs == NULL");
177 
178 	/*
179 	 * Read inode and save it.
180 	 */
181 	buf = malloc(fs->fs_bsize);
182 	twiddle(1);
183 	rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
184 		fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize,
185 		buf, &rsize);
186 	if (rc)
187 		goto out;
188 	if (rsize != fs->fs_bsize) {
189 		rc = EIO;
190 		goto out;
191 	}
192 
193 	if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
194 		fp->f_di.di1 = ((struct ufs1_dinode *)buf)
195 		    [ino_to_fsbo(fs, inumber)];
196 	else
197 		fp->f_di.di2 = ((struct ufs2_dinode *)buf)
198 		    [ino_to_fsbo(fs, inumber)];
199 
200 	/*
201 	 * Clear out the old buffers
202 	 */
203 	{
204 		int level;
205 
206 		for (level = 0; level < UFS_NIADDR; level++)
207 			fp->f_blkno[level] = -1;
208 		fp->f_buf_blkno = -1;
209 	}
210 	fp->f_seekp = 0;
211 	fp->f_inumber = inumber;
212 out:
213 	free(buf);
214 	return (rc);
215 }
216 
217 /*
218  * Given an offset in a file, find the disk block number that
219  * contains that block.
220  */
221 static int
222 block_map(struct open_file *f, ufs2_daddr_t file_block,
223     ufs2_daddr_t *disk_block_p)
224 {
225 	struct file *fp = (struct file *)f->f_fsdata;
226 	struct fs *fs = fp->f_fs;
227 	int level;
228 	int idx;
229 	ufs2_daddr_t ind_block_num;
230 	int rc;
231 
232 	/*
233 	 * Index structure of an inode:
234 	 *
235 	 * di_db[0..UFS_NDADDR-1] hold block numbers for blocks
236 	 *			0..UFS_NDADDR-1
237 	 *
238 	 * di_ib[0]		index block 0 is the single indirect block
239 	 *			holds block numbers for blocks
240 	 *			UFS_NDADDR .. UFS_NDADDR + NINDIR(fs)-1
241 	 *
242 	 * di_ib[1]		index block 1 is the double indirect block
243 	 *			holds block numbers for INDEX blocks for blocks
244 	 *			UFS_NDADDR + NINDIR(fs) ..
245 	 *			UFS_NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
246 	 *
247 	 * di_ib[2]		index block 2 is the triple indirect block
248 	 *			holds block numbers for double-indirect
249 	 *			blocks for blocks
250 	 *			UFS_NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
251 	 *			UFS_NDADDR + NINDIR(fs) + NINDIR(fs)**2
252 	 *				+ NINDIR(fs)**3 - 1
253 	 */
254 
255 	if (file_block < UFS_NDADDR) {
256 		/* Direct block. */
257 		*disk_block_p = DIP(fp, di_db[file_block]);
258 		return (0);
259 	}
260 
261 	file_block -= UFS_NDADDR;
262 
263 	/*
264 	 * nindir[0] = NINDIR
265 	 * nindir[1] = NINDIR**2
266 	 * nindir[2] = NINDIR**3
267 	 *	etc
268 	 */
269 	for (level = 0; level < UFS_NIADDR; level++) {
270 		if (file_block < fp->f_nindir[level])
271 			break;
272 		file_block -= fp->f_nindir[level];
273 	}
274 	if (level == UFS_NIADDR) {
275 		/* Block number too high */
276 		return (EFBIG);
277 	}
278 
279 	ind_block_num = DIP(fp, di_ib[level]);
280 
281 	for (; level >= 0; level--) {
282 		if (ind_block_num == 0) {
283 			*disk_block_p = 0;	/* missing */
284 			return (0);
285 		}
286 
287 		if (fp->f_blkno[level] != ind_block_num) {
288 			if (fp->f_blk[level] == (char *)0)
289 				fp->f_blk[level] =
290 					malloc(fs->fs_bsize);
291 			twiddle(1);
292 			rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
293 				fsbtodb(fp->f_fs, ind_block_num),
294 				fs->fs_bsize,
295 				fp->f_blk[level],
296 				&fp->f_blksize[level]);
297 			if (rc)
298 				return (rc);
299 			if (fp->f_blksize[level] != fs->fs_bsize)
300 				return (EIO);
301 			fp->f_blkno[level] = ind_block_num;
302 		}
303 
304 		if (level > 0) {
305 			idx = file_block / fp->f_nindir[level - 1];
306 			file_block %= fp->f_nindir[level - 1];
307 		} else
308 			idx = file_block;
309 
310 		if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
311 			ind_block_num = ((ufs1_daddr_t *)fp->f_blk[level])[idx];
312 		else
313 			ind_block_num = ((ufs2_daddr_t *)fp->f_blk[level])[idx];
314 	}
315 
316 	*disk_block_p = ind_block_num;
317 
318 	return (0);
319 }
320 
321 /*
322  * Write a portion of a file from an internal buffer.
323  */
324 static int
325 buf_write_file(struct open_file *f, const char *buf_p, size_t *size_p)
326 {
327 	struct file *fp = (struct file *)f->f_fsdata;
328 	struct fs *fs = fp->f_fs;
329 	long off;
330 	ufs_lbn_t file_block;
331 	ufs2_daddr_t disk_block;
332 	size_t block_size;
333 	int rc;
334 
335 	/*
336 	 * Calculate the starting block address and offset.
337 	 */
338 	off = blkoff(fs, fp->f_seekp);
339 	file_block = lblkno(fs, fp->f_seekp);
340 	block_size = sblksize(fs, DIP(fp, di_size), file_block);
341 
342 	rc = block_map(f, file_block, &disk_block);
343 	if (rc)
344 		return (rc);
345 
346  	if (disk_block == 0)
347 		/* Because we can't allocate space on the drive */
348 		return (EFBIG);
349 
350 	/*
351 	 * Truncate buffer at end of file, and at the end of
352 	 * this block.
353 	 */
354 	if (*size_p > DIP(fp, di_size) - fp->f_seekp)
355 		*size_p = DIP(fp, di_size) - fp->f_seekp;
356 	if (*size_p > block_size - off)
357 		*size_p = block_size - off;
358 
359 	/*
360 	 * If we don't entirely occlude the block and it's not
361 	 * in memory already, read it in first.
362 	 */
363 	if (((off > 0) || (*size_p + off < block_size)) &&
364 	    (file_block != fp->f_buf_blkno)) {
365 
366 		if (fp->f_buf == (char *)0)
367 			fp->f_buf = malloc(fs->fs_bsize);
368 
369 		twiddle(4);
370 		rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
371 			fsbtodb(fs, disk_block),
372 			block_size, fp->f_buf, &fp->f_buf_size);
373 		if (rc)
374 			return (rc);
375 
376 		fp->f_buf_blkno = file_block;
377 	}
378 
379 	/*
380 	 *	Copy the user data into the cached block.
381 	 */
382 	bcopy(buf_p, fp->f_buf + off, *size_p);
383 
384 	/*
385 	 *	Write the block out to storage.
386 	 */
387 
388 	twiddle(4);
389 	rc = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
390 		fsbtodb(fs, disk_block),
391 		block_size, fp->f_buf, &fp->f_buf_size);
392 	return (rc);
393 }
394 
395 /*
396  * Read a portion of a file into an internal buffer.  Return
397  * the location in the buffer and the amount in the buffer.
398  */
399 static int
400 buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
401 {
402 	struct file *fp = (struct file *)f->f_fsdata;
403 	struct fs *fs = fp->f_fs;
404 	long off;
405 	ufs_lbn_t file_block;
406 	ufs2_daddr_t disk_block;
407 	size_t block_size;
408 	int rc;
409 
410 	off = blkoff(fs, fp->f_seekp);
411 	file_block = lblkno(fs, fp->f_seekp);
412 	block_size = sblksize(fs, DIP(fp, di_size), file_block);
413 
414 	if (file_block != fp->f_buf_blkno) {
415 		if (fp->f_buf == (char *)0)
416 			fp->f_buf = malloc(fs->fs_bsize);
417 
418 		rc = block_map(f, file_block, &disk_block);
419 		if (rc)
420 			return (rc);
421 
422 		if (disk_block == 0) {
423 			bzero(fp->f_buf, block_size);
424 			fp->f_buf_size = block_size;
425 		} else {
426 			twiddle(4);
427 			rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
428 				fsbtodb(fs, disk_block),
429 				block_size, fp->f_buf, &fp->f_buf_size);
430 			if (rc)
431 				return (rc);
432 		}
433 
434 		fp->f_buf_blkno = file_block;
435 	}
436 
437 	/*
438 	 * Return address of byte in buffer corresponding to
439 	 * offset, and size of remainder of buffer after that
440 	 * byte.
441 	 */
442 	*buf_p = fp->f_buf + off;
443 	*size_p = block_size - off;
444 
445 	/*
446 	 * But truncate buffer at end of file.
447 	 */
448 	if (*size_p > DIP(fp, di_size) - fp->f_seekp)
449 		*size_p = DIP(fp, di_size) - fp->f_seekp;
450 
451 	return (0);
452 }
453 
454 /*
455  * Search a directory for a name and return its
456  * i_number.
457  */
458 static int
459 search_directory(char *name, struct open_file *f, ino_t *inumber_p)
460 {
461 	struct file *fp = (struct file *)f->f_fsdata;
462 	struct direct *dp;
463 	struct direct *edp;
464 	char *buf;
465 	size_t buf_size;
466 	int namlen, length;
467 	int rc;
468 
469 	length = strlen(name);
470 
471 	fp->f_seekp = 0;
472 	while (fp->f_seekp < DIP(fp, di_size)) {
473 		rc = buf_read_file(f, &buf, &buf_size);
474 		if (rc)
475 			return (rc);
476 
477 		dp = (struct direct *)buf;
478 		edp = (struct direct *)(buf + buf_size);
479 		while (dp < edp) {
480 			if (dp->d_ino == (ino_t)0)
481 				goto next;
482 #if BYTE_ORDER == LITTLE_ENDIAN
483 			if (fp->f_fs->fs_maxsymlinklen <= 0)
484 				namlen = dp->d_type;
485 			else
486 #endif
487 				namlen = dp->d_namlen;
488 			if (namlen == length &&
489 			    !strcmp(name, dp->d_name)) {
490 				/* found entry */
491 				*inumber_p = dp->d_ino;
492 				return (0);
493 			}
494 		next:
495 			dp = (struct direct *)((char *)dp + dp->d_reclen);
496 		}
497 		fp->f_seekp += buf_size;
498 	}
499 	return (ENOENT);
500 }
501 
502 /*
503  * Open a file.
504  */
505 static int
506 ufs_open(const char *upath, struct open_file *f)
507 {
508 	char *cp, *ncp;
509 	int c;
510 	ino_t inumber, parent_inumber;
511 	struct file *fp;
512 	struct fs *fs;
513 	int rc;
514 	int nlinks = 0;
515 	char namebuf[MAXPATHLEN+1];
516 	char *buf = NULL;
517 	char *path = NULL;
518 	const char *dev;
519 	ufs_mnt_t *mnt;
520 
521 	/* allocate file system specific data structure */
522 	errno = 0;
523 	fp = calloc(1, sizeof(struct file));
524 	if (fp == NULL)
525 		return (errno);
526 	f->f_fsdata = (void *)fp;
527 
528 	dev = disk_fmtdev(f->f_devdata);
529 	/* Is this device mounted? */
530 	STAILQ_FOREACH(mnt, &mnt_list, um_link) {
531 		if (strcmp(dev, mnt->um_dev) == 0)
532 			break;
533 	}
534 
535 	if (mnt == NULL) {
536 		/* read super block */
537 		twiddle(1);
538 		if ((rc = ffs_sbget(f, &fs, STDSB_NOHASHFAIL, "stand",
539 		     ufs_use_sa_read)) != 0) {
540 			goto out;
541 		}
542 	} else {
543 		struct open_file *sbf;
544 		struct file *sfp;
545 
546 		/* get superblock from mounted file system */
547 		sbf = fd2open_file(mnt->um_fd);
548 		sfp = sbf->f_fsdata;
549 		fs = sfp->f_fs;
550 	}
551 	fp->f_fs = fs;
552 
553 	/*
554 	 * Calculate indirect block levels.
555 	 */
556 	{
557 		ufs2_daddr_t mult;
558 		int level;
559 
560 		mult = 1;
561 		for (level = 0; level < UFS_NIADDR; level++) {
562 			mult *= NINDIR(fs);
563 			fp->f_nindir[level] = mult;
564 		}
565 	}
566 
567 	inumber = UFS_ROOTINO;
568 	if ((rc = read_inode(inumber, f)) != 0)
569 		goto out;
570 
571 	cp = path = strdup(upath);
572 	if (path == NULL) {
573 	    rc = ENOMEM;
574 	    goto out;
575 	}
576 	while (*cp) {
577 
578 		/*
579 		 * Remove extra separators
580 		 */
581 		while (*cp == '/')
582 			cp++;
583 		if (*cp == '\0')
584 			break;
585 
586 		/*
587 		 * Check that current node is a directory.
588 		 */
589 		if ((DIP(fp, di_mode) & IFMT) != IFDIR) {
590 			rc = ENOTDIR;
591 			goto out;
592 		}
593 
594 		/*
595 		 * Get next component of path name.
596 		 */
597 		{
598 			int len = 0;
599 
600 			ncp = cp;
601 			while ((c = *cp) != '\0' && c != '/') {
602 				if (++len > UFS_MAXNAMLEN) {
603 					rc = ENOENT;
604 					goto out;
605 				}
606 				cp++;
607 			}
608 			*cp = '\0';
609 		}
610 
611 		/*
612 		 * Look up component in current directory.
613 		 * Save directory inumber in case we find a
614 		 * symbolic link.
615 		 */
616 		parent_inumber = inumber;
617 		rc = search_directory(ncp, f, &inumber);
618 		*cp = c;
619 		if (rc)
620 			goto out;
621 
622 		/*
623 		 * Open next component.
624 		 */
625 		if ((rc = read_inode(inumber, f)) != 0)
626 			goto out;
627 
628 		/*
629 		 * Check for symbolic link.
630 		 */
631 		if ((DIP(fp, di_mode) & IFMT) == IFLNK) {
632 			int link_len = DIP(fp, di_size);
633 			int len;
634 
635 			len = strlen(cp);
636 
637 			if (link_len + len > MAXPATHLEN ||
638 			    ++nlinks > MAXSYMLINKS) {
639 				rc = ENOENT;
640 				goto out;
641 			}
642 
643 			bcopy(cp, &namebuf[link_len], len + 1);
644 
645 			if (link_len < fs->fs_maxsymlinklen) {
646 				if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
647 					cp = (caddr_t)(fp->f_di.di1.di_db);
648 				else
649 					cp = (caddr_t)(fp->f_di.di2.di_db);
650 				bcopy(cp, namebuf, (unsigned) link_len);
651 			} else {
652 				/*
653 				 * Read file for symbolic link
654 				 */
655 				size_t buf_size;
656 				ufs2_daddr_t disk_block;
657 				struct fs *fs = fp->f_fs;
658 
659 				if (!buf)
660 					buf = malloc(fs->fs_bsize);
661 				rc = block_map(f, (ufs2_daddr_t)0, &disk_block);
662 				if (rc)
663 					goto out;
664 
665 				twiddle(1);
666 				rc = (f->f_dev->dv_strategy)(f->f_devdata,
667 					F_READ, fsbtodb(fs, disk_block),
668 					fs->fs_bsize, buf, &buf_size);
669 				if (rc)
670 					goto out;
671 
672 				bcopy((char *)buf, namebuf, (unsigned)link_len);
673 			}
674 
675 			/*
676 			 * If relative pathname, restart at parent directory.
677 			 * If absolute pathname, restart at root.
678 			 */
679 			cp = namebuf;
680 			if (*cp != '/')
681 				inumber = parent_inumber;
682 			else
683 				inumber = (ino_t)UFS_ROOTINO;
684 
685 			if ((rc = read_inode(inumber, f)) != 0)
686 				goto out;
687 		}
688 	}
689 
690 	/*
691 	 * Found terminal component.
692 	 */
693 	rc = 0;
694 	fp->f_seekp = 0;
695 out:
696 	free(buf);
697 	free(path);
698 	if (rc) {
699 		free(fp->f_buf);
700 
701 		if (mnt == NULL && fp->f_fs != NULL) {
702 			free(fp->f_fs->fs_csp);
703 			free(fp->f_fs->fs_si);
704 			free(fp->f_fs);
705 		}
706 		free(fp);
707 	}
708 	return (rc);
709 }
710 
711 /*
712  * A read function for use by standalone-layer routines.
713  */
714 static int
715 ufs_use_sa_read(void *devfd, off_t loc, void **bufp, int size)
716 {
717 	struct open_file *f;
718 	size_t buf_size;
719 	int error;
720 
721 	f = (struct open_file *)devfd;
722 	if ((*bufp = malloc(size)) == NULL)
723 		return (ENOSPC);
724 	error = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, loc / DEV_BSIZE,
725 	    size, *bufp, &buf_size);
726 	if (error != 0)
727 		return (error);
728 	if (buf_size != size)
729 		return (EIO);
730 	return (0);
731 }
732 
733 static int
734 ufs_close(struct open_file *f)
735 {
736 	ufs_mnt_t *mnt;
737 	struct file *fp = (struct file *)f->f_fsdata;
738 	int level;
739 	char *dev;
740 
741 	f->f_fsdata = NULL;
742 	if (fp == NULL)
743 		return (0);
744 
745 	for (level = 0; level < UFS_NIADDR; level++) {
746 		free(fp->f_blk[level]);
747 	}
748 	free(fp->f_buf);
749 
750 	dev = disk_fmtdev(f->f_devdata);
751 	STAILQ_FOREACH(mnt, &mnt_list, um_link) {
752 		if (strcmp(dev, mnt->um_dev) == 0)
753 			break;
754 	}
755 
756 	if (mnt == NULL && fp->f_fs != NULL) {
757 		free(fp->f_fs->fs_csp);
758 		free(fp->f_fs->fs_si);
759 		free(fp->f_fs);
760 	}
761 
762 	free(fp);
763 	return (0);
764 }
765 
766 /*
767  * Copy a portion of a file into kernel memory.
768  * Cross block boundaries when necessary.
769  */
770 static int
771 ufs_read(struct open_file *f, void *start, size_t size, size_t *resid)
772 {
773 	struct file *fp = (struct file *)f->f_fsdata;
774 	size_t csize;
775 	char *buf;
776 	size_t buf_size;
777 	int rc = 0;
778 	char *addr = start;
779 
780 	while (size != 0) {
781 		if (fp->f_seekp >= DIP(fp, di_size))
782 			break;
783 
784 		rc = buf_read_file(f, &buf, &buf_size);
785 		if (rc)
786 			break;
787 
788 		csize = size;
789 		if (csize > buf_size)
790 			csize = buf_size;
791 
792 		bcopy(buf, addr, csize);
793 
794 		fp->f_seekp += csize;
795 		addr += csize;
796 		size -= csize;
797 	}
798 	if (resid)
799 		*resid = size;
800 	return (rc);
801 }
802 
803 /*
804  * Write to a portion of an already allocated file.
805  * Cross block boundaries when necessary. Can not
806  * extend the file.
807  */
808 static int
809 ufs_write(struct open_file *f, const void *start, size_t size, size_t *resid)
810 {
811 	struct file *fp = (struct file *)f->f_fsdata;
812 	size_t csize;
813 	int rc = 0;
814 	const char *addr = start;
815 
816 	csize = size;
817 	while ((size != 0) && (csize != 0)) {
818 		if (fp->f_seekp >= DIP(fp, di_size))
819 			break;
820 
821 		if (csize >= 512) csize = 512; /* XXX */
822 
823 		rc = buf_write_file(f, addr, &csize);
824 		if (rc)
825 			break;
826 
827 		fp->f_seekp += csize;
828 		addr += csize;
829 		size -= csize;
830 	}
831 	if (resid)
832 		*resid = size;
833 	return (rc);
834 }
835 
836 static off_t
837 ufs_seek(struct open_file *f, off_t offset, int where)
838 {
839 	struct file *fp = (struct file *)f->f_fsdata;
840 
841 	switch (where) {
842 	case SEEK_SET:
843 		fp->f_seekp = offset;
844 		break;
845 	case SEEK_CUR:
846 		fp->f_seekp += offset;
847 		break;
848 	case SEEK_END:
849 		fp->f_seekp = DIP(fp, di_size) - offset;
850 		break;
851 	default:
852 		errno = EINVAL;
853 		return (-1);
854 	}
855 	return (fp->f_seekp);
856 }
857 
858 static int
859 ufs_stat(struct open_file *f, struct stat *sb)
860 {
861 	struct file *fp = (struct file *)f->f_fsdata;
862 
863 	/* only important stuff */
864 	sb->st_mode = DIP(fp, di_mode);
865 	sb->st_uid = DIP(fp, di_uid);
866 	sb->st_gid = DIP(fp, di_gid);
867 	sb->st_size = DIP(fp, di_size);
868 	sb->st_mtime = DIP(fp, di_mtime);
869 	/*
870 	 * The items below are ufs specific!
871 	 * Other fs types will need their own solution
872 	 * if these fields are needed.
873 	 */
874 	sb->st_ino = fp->f_inumber;
875 	/*
876 	 * We need something to differentiate devs.
877 	 * fs_id is unique but 64bit, we xor the two
878 	 * halves to squeeze it into 32bits.
879 	 */
880 	sb->st_dev = (dev_t)(fp->f_fs->fs_id[0] ^ fp->f_fs->fs_id[1]);
881 
882 	return (0);
883 }
884 
885 static int
886 ufs_readdir(struct open_file *f, struct dirent *d)
887 {
888 	struct file *fp = (struct file *)f->f_fsdata;
889 	struct direct *dp;
890 	char *buf;
891 	size_t buf_size;
892 	int error;
893 
894 	/*
895 	 * assume that a directory entry will not be split across blocks
896 	 */
897 again:
898 	if (fp->f_seekp >= DIP(fp, di_size))
899 		return (ENOENT);
900 	error = buf_read_file(f, &buf, &buf_size);
901 	if (error)
902 		return (error);
903 	dp = (struct direct *)buf;
904 	fp->f_seekp += dp->d_reclen;
905 	if (dp->d_ino == (ino_t)0)
906 		goto again;
907 	d->d_type = dp->d_type;
908 	strcpy(d->d_name, dp->d_name);
909 	return (0);
910 }
911 
912 static int
913 ufs_mount(const char *dev, const char *path, void **data)
914 {
915 	char *fs;
916 	ufs_mnt_t *mnt;
917 	struct open_file *f;
918 
919 	errno = 0;
920 	mnt = calloc(1, sizeof(*mnt));
921 	if (mnt == NULL)
922 		return (errno);
923 	mnt->um_fd = -1;
924 	mnt->um_dev = strdup(dev);
925 	if (mnt->um_dev == NULL)
926 		goto done;
927 
928 	if (asprintf(&fs, "%s%s", dev, path) < 0)
929 		goto done;
930 
931 	mnt->um_fd = open(fs, O_RDONLY);
932 	free(fs);
933 	if (mnt->um_fd == -1)
934 		goto done;
935 
936 	/* Is it ufs file system? */
937 	f = fd2open_file(mnt->um_fd);
938 	if (strcmp(f->f_ops->fs_name, "ufs") == 0)
939 		STAILQ_INSERT_TAIL(&mnt_list, mnt, um_link);
940 	else
941 		errno = ENXIO;
942 
943 done:
944 	if (errno != 0) {
945 		free(mnt->um_dev);
946 		if (mnt->um_fd >= 0)
947 			close(mnt->um_fd);
948 		free(mnt);
949 	} else {
950 		*data = mnt;
951 	}
952 
953 	return (errno);
954 }
955 
956 static int
957 ufs_unmount(const char *dev __unused, void *data)
958 {
959 	ufs_mnt_t *mnt = data;
960 
961 	STAILQ_REMOVE(&mnt_list, mnt, ufs_mnt, um_link);
962 	free(mnt->um_dev);
963 	close(mnt->um_fd);
964 	free(mnt);
965 	return (0);
966 }
967