FreeBSD-5.3/lib/libstand/ufs.c
/* $NetBSD: ufs.c,v 1.20 1998/03/01 07:15:39 ross Exp $ */
/*-
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Marshall
* Kirk McKusick and Network Associates Laboratories, the Security
* Research Division of Network Associates, Inc. under DARPA/SPAWAR
* contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
* research program
*
* Copyright (c) 1982, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*
* Copyright (c) 1990, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Author: David Golub
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libstand/ufs.c,v 1.14 2004/01/21 20:12:23 jhb Exp $");
/*
* Stand-alone file reading package.
*/
#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/time.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ffs/fs.h>
#include "stand.h"
#include "string.h"
#ifdef __alpha__
#define COMPAT_UFS /* DUX has old format file systems */
#endif
static int ufs_open(const char *path, struct open_file *f);
static int ufs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
static int ufs_close(struct open_file *f);
static int ufs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
static off_t ufs_seek(struct open_file *f, off_t offset, int where);
static int ufs_stat(struct open_file *f, struct stat *sb);
static int ufs_readdir(struct open_file *f, struct dirent *d);
struct fs_ops ufs_fsops = {
"ufs",
ufs_open,
ufs_close,
ufs_read,
ufs_write,
ufs_seek,
ufs_stat,
ufs_readdir
};
/*
* In-core open file.
*/
struct file {
off_t f_seekp; /* seek pointer */
struct fs *f_fs; /* pointer to super-block */
union dinode {
struct ufs1_dinode di1;
struct ufs2_dinode di2;
} f_di; /* copy of on-disk inode */
int f_nindir[NIADDR];
/* number of blocks mapped by
indirect block at level i */
char *f_blk[NIADDR]; /* buffer for indirect block at
level i */
size_t f_blksize[NIADDR];
/* size of buffer */
ufs2_daddr_t f_blkno[NIADDR];/* disk address of block in buffer */
ufs2_daddr_t f_buf_blkno; /* block number of data block */
char *f_buf; /* buffer for data block */
size_t f_buf_size; /* size of data block */
};
#define DIP(fp, field) \
((fp)->f_fs->fs_magic == FS_UFS1_MAGIC ? \
(fp)->f_di.di1.field : (fp)->f_di.di2.field)
static int read_inode(ino_t, struct open_file *);
static int block_map(struct open_file *, ufs2_daddr_t, ufs2_daddr_t *);
static int buf_read_file(struct open_file *, char **, size_t *);
static int buf_write_file(struct open_file *, char *, size_t *);
static int search_directory(char *, struct open_file *, ino_t *);
/*
* Read a new inode into a file structure.
*/
static int
read_inode(inumber, f)
ino_t inumber;
struct open_file *f;
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
char *buf;
size_t rsize;
int rc;
if (fs == NULL)
panic("fs == NULL");
/*
* Read inode and save it.
*/
buf = malloc(fs->fs_bsize);
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize,
buf, &rsize);
if (rc)
goto out;
if (rsize != fs->fs_bsize) {
rc = EIO;
goto out;
}
if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
fp->f_di.di1 = ((struct ufs1_dinode *)buf)
[ino_to_fsbo(fs, inumber)];
else
fp->f_di.di2 = ((struct ufs2_dinode *)buf)
[ino_to_fsbo(fs, inumber)];
/*
* Clear out the old buffers
*/
{
int level;
for (level = 0; level < NIADDR; level++)
fp->f_blkno[level] = -1;
fp->f_buf_blkno = -1;
}
out:
free(buf);
return (rc);
}
/*
* Given an offset in a file, find the disk block number that
* contains that block.
*/
static int
block_map(f, file_block, disk_block_p)
struct open_file *f;
ufs2_daddr_t file_block;
ufs2_daddr_t *disk_block_p; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
int level;
int idx;
ufs2_daddr_t ind_block_num;
int rc;
/*
* Index structure of an inode:
*
* di_db[0..NDADDR-1] hold block numbers for blocks
* 0..NDADDR-1
*
* di_ib[0] index block 0 is the single indirect block
* holds block numbers for blocks
* NDADDR .. NDADDR + NINDIR(fs)-1
*
* di_ib[1] index block 1 is the double indirect block
* holds block numbers for INDEX blocks for blocks
* NDADDR + NINDIR(fs) ..
* NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
*
* di_ib[2] index block 2 is the triple indirect block
* holds block numbers for double-indirect
* blocks for blocks
* NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
* NDADDR + NINDIR(fs) + NINDIR(fs)**2
* + NINDIR(fs)**3 - 1
*/
if (file_block < NDADDR) {
/* Direct block. */
*disk_block_p = DIP(fp, di_db[file_block]);
return (0);
}
file_block -= NDADDR;
/*
* nindir[0] = NINDIR
* nindir[1] = NINDIR**2
* nindir[2] = NINDIR**3
* etc
*/
for (level = 0; level < NIADDR; level++) {
if (file_block < fp->f_nindir[level])
break;
file_block -= fp->f_nindir[level];
}
if (level == NIADDR) {
/* Block number too high */
return (EFBIG);
}
ind_block_num = DIP(fp, di_ib[level]);
for (; level >= 0; level--) {
if (ind_block_num == 0) {
*disk_block_p = 0; /* missing */
return (0);
}
if (fp->f_blkno[level] != ind_block_num) {
if (fp->f_blk[level] == (char *)0)
fp->f_blk[level] =
malloc(fs->fs_bsize);
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
fsbtodb(fp->f_fs, ind_block_num),
fs->fs_bsize,
fp->f_blk[level],
&fp->f_blksize[level]);
if (rc)
return (rc);
if (fp->f_blksize[level] != fs->fs_bsize)
return (EIO);
fp->f_blkno[level] = ind_block_num;
}
if (level > 0) {
idx = file_block / fp->f_nindir[level - 1];
file_block %= fp->f_nindir[level - 1];
} else
idx = file_block;
if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
ind_block_num = ((ufs1_daddr_t *)fp->f_blk[level])[idx];
else
ind_block_num = ((ufs2_daddr_t *)fp->f_blk[level])[idx];
}
*disk_block_p = ind_block_num;
return (0);
}
/*
* Write a portion of a file from an internal buffer.
*/
static int
buf_write_file(f, buf_p, size_p)
struct open_file *f;
char *buf_p;
size_t *size_p; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
long off;
ufs_lbn_t file_block;
ufs2_daddr_t disk_block;
size_t block_size;
int rc;
/*
* Calculate the starting block address and offset.
*/
off = blkoff(fs, fp->f_seekp);
file_block = lblkno(fs, fp->f_seekp);
block_size = sblksize(fs, DIP(fp, di_size), file_block);
rc = block_map(f, file_block, &disk_block);
if (rc)
return (rc);
if (disk_block == 0)
/* Because we can't allocate space on the drive */
return (EFBIG);
/*
* Truncate buffer at end of file, and at the end of
* this block.
*/
if (*size_p > DIP(fp, di_size) - fp->f_seekp)
*size_p = DIP(fp, di_size) - fp->f_seekp;
if (*size_p > block_size - off)
*size_p = block_size - off;
/*
* If we don't entirely occlude the block and it's not
* in memory already, read it in first.
*/
if (((off > 0) || (*size_p + off < block_size)) &&
(file_block != fp->f_buf_blkno)) {
if (fp->f_buf == (char *)0)
fp->f_buf = malloc(fs->fs_bsize);
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
fsbtodb(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
if (rc)
return (rc);
fp->f_buf_blkno = file_block;
}
/*
* Copy the user data into the cached block.
*/
bcopy(buf_p, fp->f_buf + off, *size_p);
/*
* Write the block out to storage.
*/
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
fsbtodb(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
return (rc);
}
/*
* Read a portion of a file into an internal buffer. Return
* the location in the buffer and the amount in the buffer.
*/
static int
buf_read_file(f, buf_p, size_p)
struct open_file *f;
char **buf_p; /* out */
size_t *size_p; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
long off;
ufs_lbn_t file_block;
ufs2_daddr_t disk_block;
size_t block_size;
int rc;
off = blkoff(fs, fp->f_seekp);
file_block = lblkno(fs, fp->f_seekp);
block_size = sblksize(fs, DIP(fp, di_size), file_block);
if (file_block != fp->f_buf_blkno) {
if (fp->f_buf == (char *)0)
fp->f_buf = malloc(fs->fs_bsize);
rc = block_map(f, file_block, &disk_block);
if (rc)
return (rc);
if (disk_block == 0) {
bzero(fp->f_buf, block_size);
fp->f_buf_size = block_size;
} else {
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
fsbtodb(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
if (rc)
return (rc);
}
fp->f_buf_blkno = file_block;
}
/*
* Return address of byte in buffer corresponding to
* offset, and size of remainder of buffer after that
* byte.
*/
*buf_p = fp->f_buf + off;
*size_p = block_size - off;
/*
* But truncate buffer at end of file.
*/
if (*size_p > DIP(fp, di_size) - fp->f_seekp)
*size_p = DIP(fp, di_size) - fp->f_seekp;
return (0);
}
/*
* Search a directory for a name and return its
* i_number.
*/
static int
search_directory(name, f, inumber_p)
char *name;
struct open_file *f;
ino_t *inumber_p; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
struct direct *dp;
struct direct *edp;
char *buf;
size_t buf_size;
int namlen, length;
int rc;
length = strlen(name);
fp->f_seekp = 0;
while (fp->f_seekp < DIP(fp, di_size)) {
rc = buf_read_file(f, &buf, &buf_size);
if (rc)
return (rc);
dp = (struct direct *)buf;
edp = (struct direct *)(buf + buf_size);
while (dp < edp) {
if (dp->d_ino == (ino_t)0)
goto next;
#if BYTE_ORDER == LITTLE_ENDIAN
if (fp->f_fs->fs_maxsymlinklen <= 0)
namlen = dp->d_type;
else
#endif
namlen = dp->d_namlen;
if (namlen == length &&
!strcmp(name, dp->d_name)) {
/* found entry */
*inumber_p = dp->d_ino;
return (0);
}
next:
dp = (struct direct *)((char *)dp + dp->d_reclen);
}
fp->f_seekp += buf_size;
}
return (ENOENT);
}
static int sblock_try[] = SBLOCKSEARCH;
/*
* Open a file.
*/
static int
ufs_open(upath, f)
const char *upath;
struct open_file *f;
{
char *cp, *ncp;
int c;
ino_t inumber, parent_inumber;
struct file *fp;
struct fs *fs;
int i, rc;
size_t buf_size;
int nlinks = 0;
char namebuf[MAXPATHLEN+1];
char *buf = NULL;
char *path = NULL;
/* allocate file system specific data structure */
fp = malloc(sizeof(struct file));
bzero(fp, sizeof(struct file));
f->f_fsdata = (void *)fp;
/* allocate space and read super block */
fs = malloc(SBLOCKSIZE);
fp->f_fs = fs;
twiddle();
/*
* Try reading the superblock in each of its possible locations.
*/
for (i = 0; sblock_try[i] != -1; i++) {
rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
sblock_try[i] / DEV_BSIZE, SBLOCKSIZE,
(char *)fs, &buf_size);
if (rc)
goto out;
if ((fs->fs_magic == FS_UFS1_MAGIC ||
(fs->fs_magic == FS_UFS2_MAGIC &&
fs->fs_sblockloc == sblock_try[i])) &&
buf_size == SBLOCKSIZE &&
fs->fs_bsize <= MAXBSIZE &&
fs->fs_bsize >= sizeof(struct fs))
break;
}
if (sblock_try[i] == -1) {
rc = EINVAL;
goto out;
}
/*
* Calculate indirect block levels.
*/
{
ufs2_daddr_t mult;
int level;
mult = 1;
for (level = 0; level < NIADDR; level++) {
mult *= NINDIR(fs);
fp->f_nindir[level] = mult;
}
}
inumber = ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
cp = path = strdup(upath);
if (path == NULL) {
rc = ENOMEM;
goto out;
}
while (*cp) {
/*
* Remove extra separators
*/
while (*cp == '/')
cp++;
if (*cp == '\0')
break;
/*
* Check that current node is a directory.
*/
if ((DIP(fp, di_mode) & IFMT) != IFDIR) {
rc = ENOTDIR;
goto out;
}
/*
* Get next component of path name.
*/
{
int len = 0;
ncp = cp;
while ((c = *cp) != '\0' && c != '/') {
if (++len > MAXNAMLEN) {
rc = ENOENT;
goto out;
}
cp++;
}
*cp = '\0';
}
/*
* Look up component in current directory.
* Save directory inumber in case we find a
* symbolic link.
*/
parent_inumber = inumber;
rc = search_directory(ncp, f, &inumber);
*cp = c;
if (rc)
goto out;
/*
* Open next component.
*/
if ((rc = read_inode(inumber, f)) != 0)
goto out;
/*
* Check for symbolic link.
*/
if ((DIP(fp, di_mode) & IFMT) == IFLNK) {
int link_len = DIP(fp, di_size);
int len;
len = strlen(cp);
if (link_len + len > MAXPATHLEN ||
++nlinks > MAXSYMLINKS) {
rc = ENOENT;
goto out;
}
bcopy(cp, &namebuf[link_len], len + 1);
if (link_len < fs->fs_maxsymlinklen) {
if (fp->f_fs->fs_magic == FS_UFS1_MAGIC)
cp = (caddr_t)(fp->f_di.di1.di_db);
else
cp = (caddr_t)(fp->f_di.di2.di_db);
bcopy(cp, namebuf, (unsigned) link_len);
} else {
/*
* Read file for symbolic link
*/
size_t buf_size;
ufs2_daddr_t disk_block;
struct fs *fs = fp->f_fs;
if (!buf)
buf = malloc(fs->fs_bsize);
rc = block_map(f, (ufs2_daddr_t)0, &disk_block);
if (rc)
goto out;
twiddle();
rc = (f->f_dev->dv_strategy)(f->f_devdata,
F_READ, fsbtodb(fs, disk_block),
fs->fs_bsize, buf, &buf_size);
if (rc)
goto out;
bcopy((char *)buf, namebuf, (unsigned)link_len);
}
/*
* If relative pathname, restart at parent directory.
* If absolute pathname, restart at root.
*/
cp = namebuf;
if (*cp != '/')
inumber = parent_inumber;
else
inumber = (ino_t)ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
}
}
/*
* Found terminal component.
*/
rc = 0;
out:
if (buf)
free(buf);
if (path)
free(path);
if (rc) {
if (fp->f_buf)
free(fp->f_buf);
free(fp->f_fs);
free(fp);
}
return (rc);
}
static int
ufs_close(f)
struct open_file *f;
{
struct file *fp = (struct file *)f->f_fsdata;
int level;
f->f_fsdata = (void *)0;
if (fp == (struct file *)0)
return (0);
for (level = 0; level < NIADDR; level++) {
if (fp->f_blk[level])
free(fp->f_blk[level]);
}
if (fp->f_buf)
free(fp->f_buf);
free(fp->f_fs);
free(fp);
return (0);
}
/*
* Copy a portion of a file into kernel memory.
* Cross block boundaries when necessary.
*/
static int
ufs_read(f, start, size, resid)
struct open_file *f;
void *start;
size_t size;
size_t *resid; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
size_t csize;
char *buf;
size_t buf_size;
int rc = 0;
char *addr = start;
while (size != 0) {
if (fp->f_seekp >= DIP(fp, di_size))
break;
rc = buf_read_file(f, &buf, &buf_size);
if (rc)
break;
csize = size;
if (csize > buf_size)
csize = buf_size;
bcopy(buf, addr, csize);
fp->f_seekp += csize;
addr += csize;
size -= csize;
}
if (resid)
*resid = size;
return (rc);
}
/*
* Write to a portion of an already allocated file.
* Cross block boundaries when necessary. Can not
* extend the file.
*/
static int
ufs_write(f, start, size, resid)
struct open_file *f;
void *start;
size_t size;
size_t *resid; /* out */
{
struct file *fp = (struct file *)f->f_fsdata;
size_t csize;
int rc = 0;
char *addr = start;
csize = size;
while ((size != 0) && (csize != 0)) {
if (fp->f_seekp >= DIP(fp, di_size))
break;
if (csize >= 512) csize = 512; /* XXX */
rc = buf_write_file(f, addr, &csize);
if (rc)
break;
fp->f_seekp += csize;
addr += csize;
size -= csize;
}
if (resid)
*resid = size;
return (rc);
}
static off_t
ufs_seek(f, offset, where)
struct open_file *f;
off_t offset;
int where;
{
struct file *fp = (struct file *)f->f_fsdata;
switch (where) {
case SEEK_SET:
fp->f_seekp = offset;
break;
case SEEK_CUR:
fp->f_seekp += offset;
break;
case SEEK_END:
fp->f_seekp = DIP(fp, di_size) - offset;
break;
default:
errno = EINVAL;
return (-1);
}
return (fp->f_seekp);
}
static int
ufs_stat(f, sb)
struct open_file *f;
struct stat *sb;
{
struct file *fp = (struct file *)f->f_fsdata;
/* only important stuff */
sb->st_mode = DIP(fp, di_mode);
sb->st_uid = DIP(fp, di_uid);
sb->st_gid = DIP(fp, di_gid);
sb->st_size = DIP(fp, di_size);
return (0);
}
static int
ufs_readdir(struct open_file *f, struct dirent *d)
{
struct file *fp = (struct file *)f->f_fsdata;
struct direct *dp;
char *buf;
size_t buf_size;
int error;
/*
* assume that a directory entry will not be split across blocks
*/
again:
if (fp->f_seekp >= DIP(fp, di_size))
return (ENOENT);
error = buf_read_file(f, &buf, &buf_size);
if (error)
return (error);
dp = (struct direct *)buf;
fp->f_seekp += dp->d_reclen;
if (dp->d_ino == (ino_t)0)
goto again;
d->d_type = dp->d_type;
strcpy(d->d_name, dp->d_name);
return (0);
}