/* $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 __FBSDID("$FreeBSD$"); /* * Stand-alone file reading package. */ #include #include #include #include #include #include #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, const 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 *, const 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(1); 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(1); 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; const 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(4); 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(4); 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(4); 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(1); /* * 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(1); 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; const void *start; size_t size; size_t *resid; /* out */ { struct file *fp = (struct file *)f->f_fsdata; size_t csize; int rc = 0; const 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); }