/* $NetBSD: ufs.c,v 1.53.10.1 2009/05/04 08:13:52 yamt Exp $ */ /*- * Copyright (c) 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. 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. */ /* * Stand-alone file reading package for UFS and LFS filesystems. */ #include #include #include #include #ifdef LIBSA_LFS #include #include #include /* XXX for MNAMELEN */ #include #else #include #endif #ifdef _STANDALONE #include #else #include #endif #include "stand.h" #ifdef LIBSA_LFS #include "lfs.h" #else #include "ufs.h" #endif /* If this file is compiled by itself, build ufs (aka ffsv1) support */ #if !defined(LIBSA_FFSv2) && !defined(LIBSA_LFS) #define LIBSA_FFSv1 #endif #if defined(LIBSA_FS_SINGLECOMPONENT) && !defined(LIBSA_NO_FS_SYMLINK) #define LIBSA_NO_FS_SYMLINK #endif #if defined(COMPAT_UFS) && defined(LIBSA_NO_COMPAT_UFS) #undef COMPAT_UFS #endif #ifdef LIBSA_LFS /* * In-core LFS superblock. This exists only to placate the macros in lfs.h, */ struct fs { struct dlfs lfs_dlfs; }; #define fs_magic lfs_magic #define fs_maxsymlinklen lfs_maxsymlinklen #define FS_MAGIC LFS_MAGIC #define SBLOCKSIZE LFS_SBPAD #define SBLOCKOFFSET LFS_LABELPAD #else /* NB ufs2 doesn't use the common suberblock code... */ #define FS_MAGIC FS_UFS1_MAGIC #define SBLOCKOFFSET SBLOCK_UFS1 #endif #if defined(LIBSA_NO_TWIDDLE) #define twiddle() #endif #undef cgstart #if defined(LIBSA_FFSv2) #define cgstart(fc, c) cgstart_ufs2((fs), (c)) #else #define cgstart(fc, c) cgstart_ufs1((fs), (c)) #endif #ifndef ufs_dinode #define ufs_dinode ufs1_dinode #endif #ifndef indp_t #define indp_t int32_t #endif typedef uint32_t ino32_t; #ifndef FSBTODB #define FSBTODB(fs, indp) fsbtodb(fs, indp) #endif /* * To avoid having a lot of filesystem-block sized buffers lurking (which * could be 32k) we only keep a few entries of the indirect block map. * With 8k blocks, 2^8 blocks is ~500k so we reread the indirect block * ~13 times pulling in a 6M kernel. * The cache size must be smaller than the smallest filesystem block, * so LN2_IND_CACHE_SZ <= 9 (UFS2 and 4k blocks). */ #define LN2_IND_CACHE_SZ 6 #define IND_CACHE_SZ (1 << LN2_IND_CACHE_SZ) #define IND_CACHE_MASK (IND_CACHE_SZ - 1) /* * In-core open file. */ struct file { off_t f_seekp; /* seek pointer */ struct fs *f_fs; /* pointer to super-block */ struct ufs_dinode f_di; /* copy of on-disk inode */ uint f_nishift; /* for blocks in indirect block */ indp_t f_ind_cache_block; indp_t f_ind_cache[IND_CACHE_SZ]; char *f_buf; /* buffer for data block */ size_t f_buf_size; /* size of data block */ daddr_t f_buf_blkno; /* block number of data block */ }; static int read_inode(ino32_t, struct open_file *); static int block_map(struct open_file *, indp_t, indp_t *); static int buf_read_file(struct open_file *, char **, size_t *); static int search_directory(const char *, int, struct open_file *, ino32_t *); #ifdef LIBSA_FFSv1 static void ffs_oldfscompat(struct fs *); #endif #ifdef LIBSA_FFSv2 static int ffs_find_superblock(struct open_file *, struct fs *); #endif #ifdef LIBSA_LFS /* * Find an inode's block. Look it up in the ifile. Whee! */ static int find_inode_sector(ino32_t inumber, struct open_file *f, daddr_t *isp) { struct file *fp = (struct file *)f->f_fsdata; struct fs *fs = fp->f_fs; daddr_t ifileent_blkno; char *ent_in_buf; size_t buf_after_ent; int rc; rc = read_inode(fs->lfs_ifile, f); if (rc) return rc; ifileent_blkno = (inumber / fs->lfs_ifpb) + fs->lfs_cleansz + fs->lfs_segtabsz; fp->f_seekp = (off_t)ifileent_blkno * fs->fs_bsize + (inumber % fs->lfs_ifpb) * sizeof (IFILE_Vx); rc = buf_read_file(f, &ent_in_buf, &buf_after_ent); if (rc) return rc; /* make sure something's not badly wrong, but don't panic. */ if (buf_after_ent < sizeof (IFILE_Vx)) return EINVAL; *isp = FSBTODB(fs, ((IFILE_Vx *)ent_in_buf)->if_daddr); if (*isp == LFS_UNUSED_DADDR) /* again, something badly wrong */ return EINVAL; return 0; } #endif /* * Read a new inode into a file structure. */ static int read_inode(ino32_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; daddr_t inode_sector; #ifdef LIBSA_LFS struct ufs_dinode *dip; int cnt; #endif #ifdef LIBSA_LFS if (inumber == fs->lfs_ifile) inode_sector = FSBTODB(fs, fs->lfs_idaddr); else if ((rc = find_inode_sector(inumber, f, &inode_sector)) != 0) return rc; #else inode_sector = FSBTODB(fs, ino_to_fsba(fs, inumber)); #endif /* * Read inode and save it. */ buf = fp->f_buf; twiddle(); rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, inode_sector, fs->fs_bsize, buf, &rsize); if (rc) return rc; if (rsize != fs->fs_bsize) return EIO; #ifdef LIBSA_LFS cnt = INOPBx(fs); dip = (struct ufs_dinode *)buf + (cnt - 1); for (; dip->di_inumber != inumber; --dip) { /* kernel code panics, but boot blocks which panic are Bad. */ if (--cnt == 0) return EINVAL; } fp->f_di = *dip; #else fp->f_di = ((struct ufs_dinode *)buf)[ino_to_fsbo(fs, inumber)]; #endif /* * Clear out the old buffers */ fp->f_ind_cache_block = ~0; fp->f_buf_blkno = -1; return rc; } /* * Given an offset in a file, find the disk block number that * contains that block. */ static int block_map(struct open_file *f, indp_t file_block, indp_t *disk_block_p) { struct file *fp = (struct file *)f->f_fsdata; struct fs *fs = fp->f_fs; uint level; indp_t ind_cache; indp_t ind_block_num; size_t rsize; int rc; indp_t *buf = (void *)fp->f_buf; /* * 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 = fp->f_di.di_db[file_block]; return 0; } file_block -= NDADDR; ind_cache = file_block >> LN2_IND_CACHE_SZ; if (ind_cache == fp->f_ind_cache_block) { *disk_block_p = fp->f_ind_cache[file_block & IND_CACHE_MASK]; return 0; } for (level = 0;;) { level += fp->f_nishift; if (file_block < (indp_t)1 << level) break; if (level > NIADDR * fp->f_nishift) /* Block number too high */ return EFBIG; file_block -= (indp_t)1 << level; } ind_block_num = fp->f_di.di_ib[level / fp->f_nishift - 1]; for (;;) { level -= fp->f_nishift; if (ind_block_num == 0) { *disk_block_p = 0; /* missing */ return 0; } twiddle(); /* * If we were feeling brave, we could work out the number * of the disk sector and read a single disk sector instead * of a filesystem block. * However we don't do this very often anyway... */ rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, FSBTODB(fp->f_fs, ind_block_num), fs->fs_bsize, buf, &rsize); if (rc) return rc; if (rsize != fs->fs_bsize) return EIO; ind_block_num = buf[file_block >> level]; if (level == 0) break; file_block &= (1 << level) - 1; } /* Save the part of the block that contains this sector */ memcpy(fp->f_ind_cache, &buf[file_block & ~IND_CACHE_MASK], IND_CACHE_SZ * sizeof fp->f_ind_cache[0]); fp->f_ind_cache_block = ind_cache; *disk_block_p = ind_block_num; return 0; } /* * 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(struct open_file *f, char **buf_p, size_t *size_p) { struct file *fp = (struct file *)f->f_fsdata; struct fs *fs = fp->f_fs; long off; indp_t file_block; indp_t disk_block; size_t block_size; int rc; off = blkoff(fs, fp->f_seekp); file_block = lblkno(fs, fp->f_seekp); #ifdef LIBSA_LFS block_size = dblksize(fs, &fp->f_di, file_block); #else block_size = sblksize(fs, (int64_t)fp->f_di.di_size, file_block); #endif if (file_block != fp->f_buf_blkno) { rc = block_map(f, file_block, &disk_block); if (rc) return rc; if (disk_block == 0) { memset(fp->f_buf, 0, block_size); fp->f_buf_size = block_size; } else { twiddle(); rc = DEV_STRATEGY(f->f_dev)(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 > fp->f_di.di_size - fp->f_seekp) *size_p = fp->f_di.di_size - fp->f_seekp; return 0; } /* * Search a directory for a name and return its * inode number. */ static int search_directory(const char *name, int length, struct open_file *f, ino32_t *inumber_p) { struct file *fp = (struct file *)f->f_fsdata; struct direct *dp; struct direct *edp; char *buf; size_t buf_size; int namlen; int rc; fp->f_seekp = 0; while (fp->f_seekp < (off_t)fp->f_di.di_size) { rc = buf_read_file(f, &buf, &buf_size); if (rc) return rc; dp = (struct direct *)buf; edp = (struct direct *)(buf + buf_size); for (;dp < edp; dp = (void *)((char *)dp + dp->d_reclen)) { if (dp->d_reclen <= 0) break; if (dp->d_ino == (ino32_t)0) continue; #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 && !memcmp(name, dp->d_name, length)) { /* found entry */ *inumber_p = dp->d_ino; return 0; } } fp->f_seekp += buf_size; } return ENOENT; } #ifdef LIBSA_FFSv2 daddr_t sblock_try[] = SBLOCKSEARCH; static int ffs_find_superblock(struct open_file *f, struct fs *fs) { int i, rc; size_t buf_size; for (i = 0; sblock_try[i] != -1; i++) { rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, sblock_try[i] / DEV_BSIZE, SBLOCKSIZE, fs, &buf_size); if (rc != 0 || buf_size != SBLOCKSIZE) return rc; if (fs->fs_sblockloc != sblock_try[i]) /* an alternate superblock - try again */ continue; if (fs->fs_magic == FS_UFS2_MAGIC) { return 0; } } return EINVAL; } #endif /* * Open a file. */ int ufs_open(const char *path, struct open_file *f) { #ifndef LIBSA_FS_SINGLECOMPONENT const char *cp, *ncp; int c; #endif ino32_t inumber; struct file *fp; struct fs *fs; int rc; #ifndef LIBSA_NO_FS_SYMLINK ino32_t parent_inumber; int nlinks = 0; char namebuf[MAXPATHLEN+1]; char *buf; #endif /* allocate file system specific data structure */ fp = alloc(sizeof(struct file)); memset(fp, 0, sizeof(struct file)); f->f_fsdata = (void *)fp; /* allocate space and read super block */ fs = alloc(SBLOCKSIZE); fp->f_fs = fs; twiddle(); #ifdef LIBSA_FFSv2 rc = ffs_find_superblock(f, fs); if (rc) goto out; #else { size_t buf_size; rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, SBLOCKOFFSET / DEV_BSIZE, SBLOCKSIZE, fs, &buf_size); if (rc) goto out; if (buf_size != SBLOCKSIZE || #ifdef LIBSA_FFS fs->lfs_version != REQUIRED_LFS_VERSION || #endif fs->fs_magic != FS_MAGIC) { rc = EINVAL; goto out; } } #if defined(LIBSA_LFS) && REQUIRED_LFS_VERSION == 2 /* * XXX We should check the second superblock and use the eldest * of the two. See comments near the top of lfs_mountfs() * in sys/ufs/lfs/lfs_vfsops.c. * This may need a LIBSA_LFS_SMALL check as well. */ #endif #endif #ifdef LIBSA_FFSv1 ffs_oldfscompat(fs); #endif if (fs->fs_bsize > MAXBSIZE || (size_t)fs->fs_bsize < sizeof(struct fs)) { rc = EINVAL; goto out; } /* * Calculate indirect block levels. */ { indp_t mult; int ln2; /* * We note that the number of indirect blocks is always * a power of 2. This lets us use shifts and masks instead * of divide and remainder and avoinds pulling in the * 64bit division routine into the boot code. */ mult = NINDIR(fs); #ifdef DEBUG if (mult & (mult - 1)) { /* Hummm was't a power of 2 */ rc = EINVAL; goto out; } #endif for (ln2 = 0; mult != 1; ln2++) mult >>= 1; fp->f_nishift = ln2; } /* alloc a block sized buffer used for all fs transfers */ fp->f_buf = alloc(fs->fs_bsize); inumber = ROOTINO; if ((rc = read_inode(inumber, f)) != 0) goto out; #ifndef LIBSA_FS_SINGLECOMPONENT cp = path; while (*cp) { /* * Remove extra separators */ while (*cp == '/') cp++; if (*cp == '\0') break; /* * Check that current node is a directory. */ if ((fp->f_di.di_mode & IFMT) != IFDIR) { rc = ENOTDIR; goto out; } /* * Get next component of path name. */ ncp = cp; while ((c = *cp) != '\0' && c != '/') cp++; /* * Look up component in current directory. * Save directory inumber in case we find a * symbolic link. */ #ifndef LIBSA_NO_FS_SYMLINK parent_inumber = inumber; #endif rc = search_directory(ncp, cp - ncp, f, &inumber); if (rc) goto out; /* * Open next component. */ if ((rc = read_inode(inumber, f)) != 0) goto out; #ifndef LIBSA_NO_FS_SYMLINK /* * Check for symbolic link. */ if ((fp->f_di.di_mode & IFMT) == IFLNK) { int link_len = fp->f_di.di_size; int len; len = strlen(cp); if (link_len + len > MAXPATHLEN || ++nlinks > MAXSYMLINKS) { rc = ENOENT; goto out; } memmove(&namebuf[link_len], cp, len + 1); if (link_len < fs->fs_maxsymlinklen) { memcpy(namebuf, fp->f_di.di_db, link_len); } else { /* * Read file for symbolic link */ size_t buf_size; indp_t disk_block; buf = fp->f_buf; rc = block_map(f, (indp_t)0, &disk_block); if (rc) goto out; twiddle(); rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, FSBTODB(fs, disk_block), fs->fs_bsize, buf, &buf_size); if (rc) goto out; memcpy(namebuf, buf, link_len); } /* * If relative pathname, restart at parent directory. * If absolute pathname, restart at root. */ cp = namebuf; if (*cp != '/') inumber = parent_inumber; else inumber = (ino32_t)ROOTINO; if ((rc = read_inode(inumber, f)) != 0) goto out; } #endif /* !LIBSA_NO_FS_SYMLINK */ } /* * Found terminal component. */ rc = 0; #else /* !LIBSA_FS_SINGLECOMPONENT */ /* look up component in the current (root) directory */ rc = search_directory(path, strlen(path), f, &inumber); if (rc) goto out; /* open it */ rc = read_inode(inumber, f); #endif /* !LIBSA_FS_SINGLECOMPONENT */ fp->f_seekp = 0; /* reset seek pointer */ out: if (rc) ufs_close(f); else { #ifdef FSMOD fsmod = FSMOD; #endif #ifdef FSMOD2 fsmod2 = FSMOD2; #endif } return rc; } int ufs_close(struct open_file *f) { struct file *fp = (struct file *)f->f_fsdata; f->f_fsdata = NULL; if (fp == NULL) return 0; if (fp->f_buf) dealloc(fp->f_buf, fp->f_fs->fs_bsize); dealloc(fp->f_fs, SBLOCKSIZE); dealloc(fp, sizeof(struct file)); return 0; } /* * Copy a portion of a file into kernel memory. * Cross block boundaries when necessary. */ int ufs_read(struct open_file *f, void *start, size_t size, size_t *resid) { 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 >= (off_t)fp->f_di.di_size) break; rc = buf_read_file(f, &buf, &buf_size); if (rc) break; csize = size; if (csize > buf_size) csize = buf_size; memcpy(addr, buf, csize); fp->f_seekp += csize; addr += csize; size -= csize; } if (resid) *resid = size; return rc; } /* * Not implemented. */ #ifndef LIBSA_NO_FS_WRITE int ufs_write(struct open_file *f, void *start, size_t size, size_t *resid) { return EROFS; } #endif /* !LIBSA_NO_FS_WRITE */ #ifndef LIBSA_NO_FS_SEEK off_t ufs_seek(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 = fp->f_di.di_size - offset; break; default: return -1; } return fp->f_seekp; } #endif /* !LIBSA_NO_FS_SEEK */ int ufs_stat(struct open_file *f, struct stat *sb) { struct file *fp = (struct file *)f->f_fsdata; /* only important stuff */ memset(sb, 0, sizeof *sb); sb->st_mode = fp->f_di.di_mode; sb->st_uid = fp->f_di.di_uid; sb->st_gid = fp->f_di.di_gid; sb->st_size = fp->f_di.di_size; return 0; } #ifdef LIBSA_FFSv1 /* * Sanity checks for old file systems. * * XXX - goes away some day. * Stripped of stuff libsa doesn't need..... */ static void ffs_oldfscompat(struct fs *fs) { #ifdef COMPAT_UFS /* * Newer Solaris versions have a slightly incompatible * superblock - so always calculate this values on the fly, which * is good enough for libsa purposes */ if (fs->fs_magic == FS_UFS1_MAGIC #ifndef COMPAT_SOLARIS_UFS && fs->fs_old_inodefmt < FS_44INODEFMT #endif ) { fs->fs_qbmask = ~fs->fs_bmask; fs->fs_qfmask = ~fs->fs_fmask; } #endif } #endif