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, const void *buf, size_t size,
89 static int ufs_close(struct open_file *f);
90 static int ufs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
91 static off_t ufs_seek(struct open_file *f, off_t offset, int where);
92 static int ufs_stat(struct open_file *f, struct stat *sb);
93 static int ufs_readdir(struct open_file *f, struct dirent *d);
95 struct fs_ops ufs_fsops = {
110 off_t f_seekp; /* seek pointer */
111 struct fs *f_fs; /* pointer to super-block */
113 struct ufs1_dinode di1;
114 struct ufs2_dinode di2;
115 } f_di; /* copy of on-disk inode */
116 int f_nindir[NIADDR];
117 /* number of blocks mapped by
118 indirect block at level i */
119 char *f_blk[NIADDR]; /* buffer for indirect block at
121 size_t f_blksize[NIADDR];
123 ufs2_daddr_t f_blkno[NIADDR];/* disk address of block in buffer */
124 ufs2_daddr_t f_buf_blkno; /* block number of data block */
125 char *f_buf; /* buffer for data block */
126 size_t f_buf_size; /* size of data block */
128 #define DIP(fp, field) \
129 ((fp)->f_fs->fs_magic == FS_UFS1_MAGIC ? \
130 (fp)->f_di.di1.field : (fp)->f_di.di2.field)
132 static int read_inode(ino_t, struct open_file *);
133 static int block_map(struct open_file *, ufs2_daddr_t, ufs2_daddr_t *);
134 static int buf_read_file(struct open_file *, char **, size_t *);
135 static int buf_write_file(struct open_file *, const char *, size_t *);
136 static int search_directory(char *, struct open_file *, ino_t *);
139 * Read a new inode into a file structure.
142 read_inode(inumber, f)
146 struct file *fp = (struct file *)f->f_fsdata;
147 struct fs *fs = fp->f_fs;
156 * Read inode and save it.
158 buf = malloc(fs->fs_bsize);
160 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
161 fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize,
165 if (rsize != fs->fs_bsize) {
170 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
171 fp->f_di.di1 = ((struct ufs1_dinode *)buf)
172 [ino_to_fsbo(fs, inumber)];
174 fp->f_di.di2 = ((struct ufs2_dinode *)buf)
175 [ino_to_fsbo(fs, inumber)];
178 * Clear out the old buffers
183 for (level = 0; level < NIADDR; level++)
184 fp->f_blkno[level] = -1;
185 fp->f_buf_blkno = -1;
194 * Given an offset in a file, find the disk block number that
195 * contains that block.
198 block_map(f, file_block, disk_block_p)
200 ufs2_daddr_t file_block;
201 ufs2_daddr_t *disk_block_p; /* out */
203 struct file *fp = (struct file *)f->f_fsdata;
204 struct fs *fs = fp->f_fs;
207 ufs2_daddr_t ind_block_num;
211 * Index structure of an inode:
213 * di_db[0..NDADDR-1] hold block numbers for blocks
216 * di_ib[0] index block 0 is the single indirect block
217 * holds block numbers for blocks
218 * NDADDR .. NDADDR + NINDIR(fs)-1
220 * di_ib[1] index block 1 is the double indirect block
221 * holds block numbers for INDEX blocks for blocks
222 * NDADDR + NINDIR(fs) ..
223 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
225 * di_ib[2] index block 2 is the triple indirect block
226 * holds block numbers for double-indirect
228 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
229 * NDADDR + NINDIR(fs) + NINDIR(fs)**2
230 * + NINDIR(fs)**3 - 1
233 if (file_block < NDADDR) {
235 *disk_block_p = DIP(fp, di_db[file_block]);
239 file_block -= NDADDR;
243 * nindir[1] = NINDIR**2
244 * nindir[2] = NINDIR**3
247 for (level = 0; level < NIADDR; level++) {
248 if (file_block < fp->f_nindir[level])
250 file_block -= fp->f_nindir[level];
252 if (level == NIADDR) {
253 /* Block number too high */
257 ind_block_num = DIP(fp, di_ib[level]);
259 for (; level >= 0; level--) {
260 if (ind_block_num == 0) {
261 *disk_block_p = 0; /* missing */
265 if (fp->f_blkno[level] != ind_block_num) {
266 if (fp->f_blk[level] == (char *)0)
268 malloc(fs->fs_bsize);
270 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
271 fsbtodb(fp->f_fs, ind_block_num),
274 &fp->f_blksize[level]);
277 if (fp->f_blksize[level] != fs->fs_bsize)
279 fp->f_blkno[level] = ind_block_num;
283 idx = file_block / fp->f_nindir[level - 1];
284 file_block %= fp->f_nindir[level - 1];
288 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
289 ind_block_num = ((ufs1_daddr_t *)fp->f_blk[level])[idx];
291 ind_block_num = ((ufs2_daddr_t *)fp->f_blk[level])[idx];
294 *disk_block_p = ind_block_num;
300 * Write a portion of a file from an internal buffer.
303 buf_write_file(f, buf_p, size_p)
306 size_t *size_p; /* out */
308 struct file *fp = (struct file *)f->f_fsdata;
309 struct fs *fs = fp->f_fs;
311 ufs_lbn_t file_block;
312 ufs2_daddr_t disk_block;
317 * Calculate the starting block address and offset.
319 off = blkoff(fs, fp->f_seekp);
320 file_block = lblkno(fs, fp->f_seekp);
321 block_size = sblksize(fs, DIP(fp, di_size), file_block);
323 rc = block_map(f, file_block, &disk_block);
328 /* Because we can't allocate space on the drive */
332 * Truncate buffer at end of file, and at the end of
335 if (*size_p > DIP(fp, di_size) - fp->f_seekp)
336 *size_p = DIP(fp, di_size) - fp->f_seekp;
337 if (*size_p > block_size - off)
338 *size_p = block_size - off;
341 * If we don't entirely occlude the block and it's not
342 * in memory already, read it in first.
344 if (((off > 0) || (*size_p + off < block_size)) &&
345 (file_block != fp->f_buf_blkno)) {
347 if (fp->f_buf == (char *)0)
348 fp->f_buf = malloc(fs->fs_bsize);
351 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
352 fsbtodb(fs, disk_block),
353 block_size, fp->f_buf, &fp->f_buf_size);
357 fp->f_buf_blkno = file_block;
361 * Copy the user data into the cached block.
363 bcopy(buf_p, fp->f_buf + off, *size_p);
366 * Write the block out to storage.
370 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
371 fsbtodb(fs, disk_block),
372 block_size, fp->f_buf, &fp->f_buf_size);
377 * Read a portion of a file into an internal buffer. Return
378 * the location in the buffer and the amount in the buffer.
381 buf_read_file(f, buf_p, size_p)
383 char **buf_p; /* out */
384 size_t *size_p; /* out */
386 struct file *fp = (struct file *)f->f_fsdata;
387 struct fs *fs = fp->f_fs;
389 ufs_lbn_t file_block;
390 ufs2_daddr_t disk_block;
394 off = blkoff(fs, fp->f_seekp);
395 file_block = lblkno(fs, fp->f_seekp);
396 block_size = sblksize(fs, DIP(fp, di_size), file_block);
398 if (file_block != fp->f_buf_blkno) {
399 if (fp->f_buf == (char *)0)
400 fp->f_buf = malloc(fs->fs_bsize);
402 rc = block_map(f, file_block, &disk_block);
406 if (disk_block == 0) {
407 bzero(fp->f_buf, block_size);
408 fp->f_buf_size = block_size;
411 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
412 fsbtodb(fs, disk_block),
413 block_size, fp->f_buf, &fp->f_buf_size);
418 fp->f_buf_blkno = file_block;
422 * Return address of byte in buffer corresponding to
423 * offset, and size of remainder of buffer after that
426 *buf_p = fp->f_buf + off;
427 *size_p = block_size - off;
430 * But truncate buffer at end of file.
432 if (*size_p > DIP(fp, di_size) - fp->f_seekp)
433 *size_p = DIP(fp, di_size) - fp->f_seekp;
439 * Search a directory for a name and return its
443 search_directory(name, f, inumber_p)
446 ino_t *inumber_p; /* out */
448 struct file *fp = (struct file *)f->f_fsdata;
456 length = strlen(name);
459 while (fp->f_seekp < DIP(fp, di_size)) {
460 rc = buf_read_file(f, &buf, &buf_size);
464 dp = (struct direct *)buf;
465 edp = (struct direct *)(buf + buf_size);
467 if (dp->d_ino == (ino_t)0)
469 #if BYTE_ORDER == LITTLE_ENDIAN
470 if (fp->f_fs->fs_maxsymlinklen <= 0)
474 namlen = dp->d_namlen;
475 if (namlen == length &&
476 !strcmp(name, dp->d_name)) {
478 *inumber_p = dp->d_ino;
482 dp = (struct direct *)((char *)dp + dp->d_reclen);
484 fp->f_seekp += buf_size;
489 static int sblock_try[] = SBLOCKSEARCH;
501 ino_t inumber, parent_inumber;
507 char namebuf[MAXPATHLEN+1];
511 /* allocate file system specific data structure */
512 fp = malloc(sizeof(struct file));
513 bzero(fp, sizeof(struct file));
514 f->f_fsdata = (void *)fp;
516 /* allocate space and read super block */
517 fs = malloc(SBLOCKSIZE);
521 * Try reading the superblock in each of its possible locations.
523 for (i = 0; sblock_try[i] != -1; i++) {
524 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
525 sblock_try[i] / DEV_BSIZE, SBLOCKSIZE,
526 (char *)fs, &buf_size);
529 if ((fs->fs_magic == FS_UFS1_MAGIC ||
530 (fs->fs_magic == FS_UFS2_MAGIC &&
531 fs->fs_sblockloc == sblock_try[i])) &&
532 buf_size == SBLOCKSIZE &&
533 fs->fs_bsize <= MAXBSIZE &&
534 fs->fs_bsize >= sizeof(struct fs))
537 if (sblock_try[i] == -1) {
542 * Calculate indirect block levels.
549 for (level = 0; level < NIADDR; level++) {
551 fp->f_nindir[level] = mult;
556 if ((rc = read_inode(inumber, f)) != 0)
559 cp = path = strdup(upath);
567 * Remove extra separators
575 * Check that current node is a directory.
577 if ((DIP(fp, di_mode) & IFMT) != IFDIR) {
583 * Get next component of path name.
589 while ((c = *cp) != '\0' && c != '/') {
590 if (++len > MAXNAMLEN) {
600 * Look up component in current directory.
601 * Save directory inumber in case we find a
604 parent_inumber = inumber;
605 rc = search_directory(ncp, f, &inumber);
611 * Open next component.
613 if ((rc = read_inode(inumber, f)) != 0)
617 * Check for symbolic link.
619 if ((DIP(fp, di_mode) & IFMT) == IFLNK) {
620 int link_len = DIP(fp, di_size);
625 if (link_len + len > MAXPATHLEN ||
626 ++nlinks > MAXSYMLINKS) {
631 bcopy(cp, &namebuf[link_len], len + 1);
633 if (link_len < fs->fs_maxsymlinklen) {
634 if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
635 cp = (caddr_t)(fp->f_di.di1.di_db);
637 cp = (caddr_t)(fp->f_di.di2.di_db);
638 bcopy(cp, namebuf, (unsigned) link_len);
641 * Read file for symbolic link
644 ufs2_daddr_t disk_block;
645 struct fs *fs = fp->f_fs;
648 buf = malloc(fs->fs_bsize);
649 rc = block_map(f, (ufs2_daddr_t)0, &disk_block);
654 rc = (f->f_dev->dv_strategy)(f->f_devdata,
655 F_READ, fsbtodb(fs, disk_block),
656 fs->fs_bsize, buf, &buf_size);
660 bcopy((char *)buf, namebuf, (unsigned)link_len);
664 * If relative pathname, restart at parent directory.
665 * If absolute pathname, restart at root.
669 inumber = parent_inumber;
671 inumber = (ino_t)ROOTINO;
673 if ((rc = read_inode(inumber, f)) != 0)
679 * Found terminal component.
701 struct file *fp = (struct file *)f->f_fsdata;
704 f->f_fsdata = (void *)0;
705 if (fp == (struct file *)0)
708 for (level = 0; level < NIADDR; level++) {
709 if (fp->f_blk[level])
710 free(fp->f_blk[level]);
720 * Copy a portion of a file into kernel memory.
721 * Cross block boundaries when necessary.
724 ufs_read(f, start, size, resid)
728 size_t *resid; /* out */
730 struct file *fp = (struct file *)f->f_fsdata;
738 if (fp->f_seekp >= DIP(fp, di_size))
741 rc = buf_read_file(f, &buf, &buf_size);
746 if (csize > buf_size)
749 bcopy(buf, addr, csize);
751 fp->f_seekp += csize;
761 * Write to a portion of an already allocated file.
762 * Cross block boundaries when necessary. Can not
766 ufs_write(f, start, size, resid)
770 size_t *resid; /* out */
772 struct file *fp = (struct file *)f->f_fsdata;
775 const char *addr = start;
778 while ((size != 0) && (csize != 0)) {
779 if (fp->f_seekp >= DIP(fp, di_size))
782 if (csize >= 512) csize = 512; /* XXX */
784 rc = buf_write_file(f, addr, &csize);
788 fp->f_seekp += csize;
798 ufs_seek(f, offset, where)
803 struct file *fp = (struct file *)f->f_fsdata;
807 fp->f_seekp = offset;
810 fp->f_seekp += offset;
813 fp->f_seekp = DIP(fp, di_size) - offset;
819 return (fp->f_seekp);
827 struct file *fp = (struct file *)f->f_fsdata;
829 /* only important stuff */
830 sb->st_mode = DIP(fp, di_mode);
831 sb->st_uid = DIP(fp, di_uid);
832 sb->st_gid = DIP(fp, di_gid);
833 sb->st_size = DIP(fp, di_size);
838 ufs_readdir(struct open_file *f, struct dirent *d)
840 struct file *fp = (struct file *)f->f_fsdata;
847 * assume that a directory entry will not be split across blocks
850 if (fp->f_seekp >= DIP(fp, di_size))
852 error = buf_read_file(f, &buf, &buf_size);
855 dp = (struct direct *)buf;
856 fp->f_seekp += dp->d_reclen;
857 if (dp->d_ino == (ino_t)0)
859 d->d_type = dp->d_type;
860 strcpy(d->d_name, dp->d_name);