1 /* $NetBSD: ufs.c,v 1.20 1998/03/01 07:15:39 ross Exp $ */
4 * Copyright (c) 2002 Networks Associates Technology, Inc.
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
13 * Copyright (c) 1982, 1989, 1993
14 * The Regents of the University of California. All rights reserved.
16 * This code is derived from software contributed to Berkeley by
17 * The Mach Operating System project at Carnegie-Mellon University.
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
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 * 4. 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.
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
44 * Copyright (c) 1990, 1991 Carnegie Mellon University
45 * All Rights Reserved.
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.
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.
59 * Carnegie Mellon requests users of this software to return to
61 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
62 * School of Computer Science
63 * Carnegie Mellon University
64 * Pittsburgh PA 15213-3890
66 * any improvements or extensions that they make and grant Carnegie the
67 * rights to redistribute these changes.
70 #include <sys/cdefs.h>
71 __FBSDID("$FreeBSD$");
74 * Stand-alone file reading package.
77 #include <sys/param.h>
78 #include <sys/disklabel.h>
80 #include <ufs/ufs/dinode.h>
81 #include <ufs/ufs/dir.h>
82 #include <ufs/ffs/fs.h>
86 static int ufs_open(const char *path, struct open_file *f);
87 static int ufs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
88 static int ufs_close(struct open_file *f);
89 static int ufs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
90 static off_t ufs_seek(struct open_file *f, off_t offset, int where);
91 static int ufs_stat(struct open_file *f, struct stat *sb);
92 static int ufs_readdir(struct open_file *f, struct dirent *d);
94 struct fs_ops ufs_fsops = {
109 off_t f_seekp; /* seek pointer */
110 struct fs *f_fs; /* pointer to super-block */
112 struct ufs1_dinode di1;
113 struct ufs2_dinode di2;
114 } f_di; /* copy of on-disk inode */
115 int f_nindir[NIADDR];
116 /* number of blocks mapped by
117 indirect block at level i */
118 char *f_blk[NIADDR]; /* buffer for indirect block at
120 size_t f_blksize[NIADDR];
122 ufs2_daddr_t f_blkno[NIADDR];/* disk address of block in buffer */
123 ufs2_daddr_t f_buf_blkno; /* block number of data block */
124 char *f_buf; /* buffer for data block */
125 size_t f_buf_size; /* size of data block */
127 #define DIP(fp, field) \
128 ((fp)->f_fs->fs_magic == FS_UFS1_MAGIC ? \
129 (fp)->f_di.di1.field : (fp)->f_di.di2.field)
131 static int read_inode(ino_t, struct open_file *);
132 static int block_map(struct open_file *, ufs2_daddr_t, ufs2_daddr_t *);
133 static int buf_read_file(struct open_file *, char **, size_t *);
134 static int buf_write_file(struct open_file *, char *, size_t *);
135 static int search_directory(char *, struct open_file *, ino_t *);
138 * Read a new inode into a file structure.
141 read_inode(inumber, f)
145 struct file *fp = (struct file *)f->f_fsdata;
146 struct fs *fs = fp->f_fs;
155 * Read inode and save it.
157 buf = malloc(fs->fs_bsize);
159 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
160 fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize,
164 if (rsize != fs->fs_bsize) {
169 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
170 fp->f_di.di1 = ((struct ufs1_dinode *)buf)
171 [ino_to_fsbo(fs, inumber)];
173 fp->f_di.di2 = ((struct ufs2_dinode *)buf)
174 [ino_to_fsbo(fs, inumber)];
177 * Clear out the old buffers
182 for (level = 0; level < NIADDR; level++)
183 fp->f_blkno[level] = -1;
184 fp->f_buf_blkno = -1;
193 * Given an offset in a file, find the disk block number that
194 * contains that block.
197 block_map(f, file_block, disk_block_p)
199 ufs2_daddr_t file_block;
200 ufs2_daddr_t *disk_block_p; /* out */
202 struct file *fp = (struct file *)f->f_fsdata;
203 struct fs *fs = fp->f_fs;
206 ufs2_daddr_t ind_block_num;
210 * Index structure of an inode:
212 * di_db[0..NDADDR-1] hold block numbers for blocks
215 * di_ib[0] index block 0 is the single indirect block
216 * holds block numbers for blocks
217 * NDADDR .. NDADDR + NINDIR(fs)-1
219 * di_ib[1] index block 1 is the double indirect block
220 * holds block numbers for INDEX blocks for blocks
221 * NDADDR + NINDIR(fs) ..
222 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
224 * di_ib[2] index block 2 is the triple indirect block
225 * holds block numbers for double-indirect
227 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
228 * NDADDR + NINDIR(fs) + NINDIR(fs)**2
229 * + NINDIR(fs)**3 - 1
232 if (file_block < NDADDR) {
234 *disk_block_p = DIP(fp, di_db[file_block]);
238 file_block -= NDADDR;
242 * nindir[1] = NINDIR**2
243 * nindir[2] = NINDIR**3
246 for (level = 0; level < NIADDR; level++) {
247 if (file_block < fp->f_nindir[level])
249 file_block -= fp->f_nindir[level];
251 if (level == NIADDR) {
252 /* Block number too high */
256 ind_block_num = DIP(fp, di_ib[level]);
258 for (; level >= 0; level--) {
259 if (ind_block_num == 0) {
260 *disk_block_p = 0; /* missing */
264 if (fp->f_blkno[level] != ind_block_num) {
265 if (fp->f_blk[level] == (char *)0)
267 malloc(fs->fs_bsize);
269 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
270 fsbtodb(fp->f_fs, ind_block_num),
273 &fp->f_blksize[level]);
276 if (fp->f_blksize[level] != fs->fs_bsize)
278 fp->f_blkno[level] = ind_block_num;
282 idx = file_block / fp->f_nindir[level - 1];
283 file_block %= fp->f_nindir[level - 1];
287 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
288 ind_block_num = ((ufs1_daddr_t *)fp->f_blk[level])[idx];
290 ind_block_num = ((ufs2_daddr_t *)fp->f_blk[level])[idx];
293 *disk_block_p = ind_block_num;
299 * Write a portion of a file from an internal buffer.
302 buf_write_file(f, buf_p, size_p)
305 size_t *size_p; /* out */
307 struct file *fp = (struct file *)f->f_fsdata;
308 struct fs *fs = fp->f_fs;
310 ufs_lbn_t file_block;
311 ufs2_daddr_t disk_block;
316 * Calculate the starting block address and offset.
318 off = blkoff(fs, fp->f_seekp);
319 file_block = lblkno(fs, fp->f_seekp);
320 block_size = sblksize(fs, DIP(fp, di_size), file_block);
322 rc = block_map(f, file_block, &disk_block);
327 /* Because we can't allocate space on the drive */
331 * Truncate buffer at end of file, and at the end of
334 if (*size_p > DIP(fp, di_size) - fp->f_seekp)
335 *size_p = DIP(fp, di_size) - fp->f_seekp;
336 if (*size_p > block_size - off)
337 *size_p = block_size - off;
340 * If we don't entirely occlude the block and it's not
341 * in memory already, read it in first.
343 if (((off > 0) || (*size_p + off < block_size)) &&
344 (file_block != fp->f_buf_blkno)) {
346 if (fp->f_buf == (char *)0)
347 fp->f_buf = malloc(fs->fs_bsize);
350 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
351 fsbtodb(fs, disk_block),
352 block_size, fp->f_buf, &fp->f_buf_size);
356 fp->f_buf_blkno = file_block;
360 * Copy the user data into the cached block.
362 bcopy(buf_p, fp->f_buf + off, *size_p);
365 * Write the block out to storage.
369 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
370 fsbtodb(fs, disk_block),
371 block_size, fp->f_buf, &fp->f_buf_size);
376 * Read a portion of a file into an internal buffer. Return
377 * the location in the buffer and the amount in the buffer.
380 buf_read_file(f, buf_p, size_p)
382 char **buf_p; /* out */
383 size_t *size_p; /* out */
385 struct file *fp = (struct file *)f->f_fsdata;
386 struct fs *fs = fp->f_fs;
388 ufs_lbn_t file_block;
389 ufs2_daddr_t disk_block;
393 off = blkoff(fs, fp->f_seekp);
394 file_block = lblkno(fs, fp->f_seekp);
395 block_size = sblksize(fs, DIP(fp, di_size), file_block);
397 if (file_block != fp->f_buf_blkno) {
398 if (fp->f_buf == (char *)0)
399 fp->f_buf = malloc(fs->fs_bsize);
401 rc = block_map(f, file_block, &disk_block);
405 if (disk_block == 0) {
406 bzero(fp->f_buf, block_size);
407 fp->f_buf_size = block_size;
410 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
411 fsbtodb(fs, disk_block),
412 block_size, fp->f_buf, &fp->f_buf_size);
417 fp->f_buf_blkno = file_block;
421 * Return address of byte in buffer corresponding to
422 * offset, and size of remainder of buffer after that
425 *buf_p = fp->f_buf + off;
426 *size_p = block_size - off;
429 * But truncate buffer at end of file.
431 if (*size_p > DIP(fp, di_size) - fp->f_seekp)
432 *size_p = DIP(fp, di_size) - fp->f_seekp;
438 * Search a directory for a name and return its
442 search_directory(name, f, inumber_p)
445 ino_t *inumber_p; /* out */
447 struct file *fp = (struct file *)f->f_fsdata;
455 length = strlen(name);
458 while (fp->f_seekp < DIP(fp, di_size)) {
459 rc = buf_read_file(f, &buf, &buf_size);
463 dp = (struct direct *)buf;
464 edp = (struct direct *)(buf + buf_size);
466 if (dp->d_ino == (ino_t)0)
468 #if BYTE_ORDER == LITTLE_ENDIAN
469 if (fp->f_fs->fs_maxsymlinklen <= 0)
473 namlen = dp->d_namlen;
474 if (namlen == length &&
475 !strcmp(name, dp->d_name)) {
477 *inumber_p = dp->d_ino;
481 dp = (struct direct *)((char *)dp + dp->d_reclen);
483 fp->f_seekp += buf_size;
488 static int sblock_try[] = SBLOCKSEARCH;
500 ino_t inumber, parent_inumber;
506 char namebuf[MAXPATHLEN+1];
510 /* allocate file system specific data structure */
511 fp = malloc(sizeof(struct file));
512 bzero(fp, sizeof(struct file));
513 f->f_fsdata = (void *)fp;
515 /* allocate space and read super block */
516 fs = malloc(SBLOCKSIZE);
520 * Try reading the superblock in each of its possible locations.
522 for (i = 0; sblock_try[i] != -1; i++) {
523 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
524 sblock_try[i] / DEV_BSIZE, SBLOCKSIZE,
525 (char *)fs, &buf_size);
528 if ((fs->fs_magic == FS_UFS1_MAGIC ||
529 (fs->fs_magic == FS_UFS2_MAGIC &&
530 fs->fs_sblockloc == sblock_try[i])) &&
531 buf_size == SBLOCKSIZE &&
532 fs->fs_bsize <= MAXBSIZE &&
533 fs->fs_bsize >= sizeof(struct fs))
536 if (sblock_try[i] == -1) {
541 * Calculate indirect block levels.
548 for (level = 0; level < NIADDR; level++) {
550 fp->f_nindir[level] = mult;
555 if ((rc = read_inode(inumber, f)) != 0)
558 cp = path = strdup(upath);
566 * Remove extra separators
574 * Check that current node is a directory.
576 if ((DIP(fp, di_mode) & IFMT) != IFDIR) {
582 * Get next component of path name.
588 while ((c = *cp) != '\0' && c != '/') {
589 if (++len > MAXNAMLEN) {
599 * Look up component in current directory.
600 * Save directory inumber in case we find a
603 parent_inumber = inumber;
604 rc = search_directory(ncp, f, &inumber);
610 * Open next component.
612 if ((rc = read_inode(inumber, f)) != 0)
616 * Check for symbolic link.
618 if ((DIP(fp, di_mode) & IFMT) == IFLNK) {
619 int link_len = DIP(fp, di_size);
624 if (link_len + len > MAXPATHLEN ||
625 ++nlinks > MAXSYMLINKS) {
630 bcopy(cp, &namebuf[link_len], len + 1);
632 if (link_len < fs->fs_maxsymlinklen) {
633 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
634 cp = (caddr_t)(fp->f_di.di1.di_db);
636 cp = (caddr_t)(fp->f_di.di2.di_db);
637 bcopy(cp, namebuf, (unsigned) link_len);
640 * Read file for symbolic link
643 ufs2_daddr_t disk_block;
644 struct fs *fs = fp->f_fs;
647 buf = malloc(fs->fs_bsize);
648 rc = block_map(f, (ufs2_daddr_t)0, &disk_block);
653 rc = (f->f_dev->dv_strategy)(f->f_devdata,
654 F_READ, fsbtodb(fs, disk_block),
655 fs->fs_bsize, buf, &buf_size);
659 bcopy((char *)buf, namebuf, (unsigned)link_len);
663 * If relative pathname, restart at parent directory.
664 * If absolute pathname, restart at root.
668 inumber = parent_inumber;
670 inumber = (ino_t)ROOTINO;
672 if ((rc = read_inode(inumber, f)) != 0)
678 * Found terminal component.
700 struct file *fp = (struct file *)f->f_fsdata;
703 f->f_fsdata = (void *)0;
704 if (fp == (struct file *)0)
707 for (level = 0; level < NIADDR; level++) {
708 if (fp->f_blk[level])
709 free(fp->f_blk[level]);
719 * Copy a portion of a file into kernel memory.
720 * Cross block boundaries when necessary.
723 ufs_read(f, start, size, resid)
727 size_t *resid; /* out */
729 struct file *fp = (struct file *)f->f_fsdata;
737 if (fp->f_seekp >= DIP(fp, di_size))
740 rc = buf_read_file(f, &buf, &buf_size);
745 if (csize > buf_size)
748 bcopy(buf, addr, csize);
750 fp->f_seekp += csize;
760 * Write to a portion of an already allocated file.
761 * Cross block boundaries when necessary. Can not
765 ufs_write(f, start, size, resid)
769 size_t *resid; /* out */
771 struct file *fp = (struct file *)f->f_fsdata;
777 while ((size != 0) && (csize != 0)) {
778 if (fp->f_seekp >= DIP(fp, di_size))
781 if (csize >= 512) csize = 512; /* XXX */
783 rc = buf_write_file(f, addr, &csize);
787 fp->f_seekp += csize;
797 ufs_seek(f, offset, where)
802 struct file *fp = (struct file *)f->f_fsdata;
806 fp->f_seekp = offset;
809 fp->f_seekp += offset;
812 fp->f_seekp = DIP(fp, di_size) - offset;
818 return (fp->f_seekp);
826 struct file *fp = (struct file *)f->f_fsdata;
828 /* only important stuff */
829 sb->st_mode = DIP(fp, di_mode);
830 sb->st_uid = DIP(fp, di_uid);
831 sb->st_gid = DIP(fp, di_gid);
832 sb->st_size = DIP(fp, di_size);
837 ufs_readdir(struct open_file *f, struct dirent *d)
839 struct file *fp = (struct file *)f->f_fsdata;
846 * assume that a directory entry will not be split across blocks
849 if (fp->f_seekp >= DIP(fp, di_size))
851 error = buf_read_file(f, &buf, &buf_size);
854 dp = (struct direct *)buf;
855 fp->f_seekp += dp->d_reclen;
856 if (dp->d_ino == (ino_t)0)
858 d->d_type = dp->d_type;
859 strcpy(d->d_name, dp->d_name);