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Diffstat (limited to 'lib/libstand/ufs.c')
| -rw-r--r-- | lib/libstand/ufs.c | 861 |
1 files changed, 861 insertions, 0 deletions
diff --git a/lib/libstand/ufs.c b/lib/libstand/ufs.c new file mode 100644 index 0000000..b6f7815 --- /dev/null +++ b/lib/libstand/ufs.c @@ -0,0 +1,861 @@ +/* $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. + * 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("$FreeBSD$"); + +/* + * 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" + +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; + } + fp->f_seekp = 0; +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; + fp->f_seekp = 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); +} |
