ffs.c revision 1.5
1 /* $NetBSD: ffs.c,v 1.5 2002/05/14 06:18:50 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Fredette. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(__RCSID) && !defined(__lint) 41 __RCSID("$NetBSD: ffs.c,v 1.5 2002/05/14 06:18:50 lukem Exp $"); 42 #endif /* !__lint */ 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 47 #include <assert.h> 48 #include <err.h> 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 #include "installboot.h" 58 59 #undef DIRBLKSIZ 60 61 #include <ufs/ufs/dinode.h> 62 #include <ufs/ufs/dir.h> 63 #include <ufs/ffs/fs.h> 64 #include <ufs/ffs/ffs_extern.h> 65 #include <ufs/ufs/ufs_bswap.h> 66 67 static int ffs_read_disk_block(ib_params *, uint32_t, int, char *); 68 static int ffs_find_disk_blocks(ib_params *, uint32_t, 69 int (*)(ib_params *, void *, uint32_t, uint32_t), void *); 70 static int ffs_findstage2_ino(ib_params *, void *, uint32_t, uint32_t); 71 static int ffs_findstage2_blocks(ib_params *, void *, uint32_t, uint32_t); 72 73 74 /* This reads a disk block from the filesystem. */ 75 static int 76 ffs_read_disk_block(ib_params *params, uint32_t blkno, int size, char *blk) 77 { 78 int rv; 79 80 assert(params != NULL); 81 assert(blk != NULL); 82 assert(params->filesystem != NULL); 83 assert(params->fsfd != -1); 84 assert(blkno > 0); 85 assert(size > 0); 86 assert(blk != NULL); 87 88 rv = pread(params->fsfd, blk, size, blkno * DEV_BSIZE); 89 if (rv == -1) { 90 warn("Reading block %d in `%s'", blkno, params->filesystem); 91 return (0); 92 } else if (rv != size) { 93 warnx("Reading block %d in `%s': short read", blkno, 94 params->filesystem); 95 return (0); 96 } 97 98 return (1); 99 } 100 101 /* 102 * This iterates over the data blocks belonging to an inode, 103 * making a callback each iteration with the disk block number 104 * and the size. 105 */ 106 static int 107 ffs_find_disk_blocks(ib_params *params, uint32_t ino, 108 int (*callback)(ib_params *, void *, uint32_t, uint32_t), 109 void *state) 110 { 111 char sbbuf[SBSIZE]; 112 struct fs *fs; 113 char inodebuf[MAXBSIZE]; 114 struct dinode *inode; 115 int level_i; 116 ufs_daddr_t blk, lblk, nblk; 117 int rv; 118 #define LEVELS 4 119 struct { 120 ufs_daddr_t *blknums; 121 unsigned long blkcount; 122 char diskbuf[MAXBSIZE]; 123 } level[LEVELS]; 124 125 assert(params != NULL); 126 assert(params->fstype != NULL); 127 assert(callback != NULL); 128 assert(state != NULL); 129 130 /* Read the superblock. */ 131 if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf)) 132 return (0); 133 fs = (struct fs *)sbbuf; 134 if (params->fstype->needswap) 135 ffs_sb_swap(fs, fs); 136 137 /* Sanity check the superblock. */ 138 if (fs->fs_magic != FS_MAGIC) { 139 warnx("Bad superblock magic number in `%s'", 140 params->filesystem); 141 return (0); 142 } 143 if (fs->fs_inopb <= 0) { 144 warnx("Bad inopb %d in superblock in `%s'", 145 fs->fs_inopb, params->filesystem); 146 return (0); 147 } 148 149 /* Read the inode. */ 150 if (! ffs_read_disk_block(params, fsbtodb(fs, ino_to_fsba(fs, ino)), 151 fs->fs_bsize, inodebuf)) 152 return (0); 153 inode = (struct dinode *)inodebuf; 154 inode += ino_to_fsbo(fs, ino); 155 if (params->fstype->needswap) 156 ffs_dinode_swap(inode, inode); 157 158 /* Get the block count and initialize for our block walk. */ 159 nblk = howmany(inode->di_size, fs->fs_bsize); 160 lblk = 0; 161 level_i = 0; 162 level[0].blknums = &inode->di_db[0]; 163 level[0].blkcount = NDADDR; 164 level[1].blknums = &inode->di_ib[0]; 165 level[1].blkcount = 1; 166 level[2].blknums = &inode->di_ib[1]; 167 level[2].blkcount = 1; 168 level[3].blknums = &inode->di_ib[2]; 169 level[3].blkcount = 1; 170 171 /* Walk the data blocks. */ 172 while (nblk > 0) { 173 174 /* 175 * If there are no more blocks at this indirection 176 * level, move up one indirection level and loop. 177 */ 178 if (level[level_i].blkcount == 0) { 179 if (++level_i == LEVELS) 180 break; 181 continue; 182 } 183 184 /* Get the next block at this level. */ 185 blk = *(level[level_i].blknums++); 186 level[level_i].blkcount--; 187 if (params->fstype->needswap) 188 blk = bswap32(blk); 189 190 #if 0 191 fprintf(stderr, "ino %lu blk %lu level %d\n", ino, blk, 192 level_i); 193 #endif 194 195 /* 196 * If we're not at the direct level, descend one 197 * level, read in that level's new block list, 198 * and loop. 199 */ 200 if (level_i > 0) { 201 level_i--; 202 if (blk == 0) 203 memset(level[level_i].diskbuf, 0, MAXBSIZE); 204 else if (! ffs_read_disk_block(params, 205 fsbtodb(fs, blk), 206 fs->fs_bsize, level[level_i].diskbuf)) 207 return (0); 208 level[level_i].blknums = 209 (ufs_daddr_t *)level[level_i].diskbuf; 210 level[level_i].blkcount = NINDIR(fs); 211 continue; 212 } 213 214 /* blk is the next direct level block. */ 215 #if 0 216 fprintf(stderr, "ino %lu db %lu blksize %lu\n", ino, 217 fsbtodb(fs, blk), dblksize(fs, inode, lblk)); 218 #endif 219 rv = (*callback)(params, state, 220 fsbtodb(fs, blk), dblksize(fs, inode, lblk)); 221 lblk++; 222 nblk--; 223 if (rv != 1) 224 return (rv); 225 } 226 227 if (nblk != 0) { 228 warnx("Inode %d in `%s' ran out of blocks?", ino, 229 params->filesystem); 230 return (0); 231 } 232 233 return (1); 234 } 235 236 /* 237 * This callback reads a block of the root directory, 238 * searches for an entry for the secondary bootstrap, 239 * and saves the inode number if one is found. 240 */ 241 static int 242 ffs_findstage2_ino(ib_params *params, void *_ino, 243 uint32_t blk, uint32_t blksize) 244 { 245 char dirbuf[MAXBSIZE]; 246 struct direct *de, *ede; 247 uint32_t ino; 248 249 assert(params != NULL); 250 assert(params->fstype != NULL); 251 assert(params->stage2 != NULL); 252 assert(_ino != NULL); 253 254 /* Skip directory holes. */ 255 if (blk == 0) 256 return (1); 257 258 /* Read the directory block. */ 259 if (! ffs_read_disk_block(params, blk, blksize, dirbuf)) 260 return (0); 261 262 /* Loop over the directory entries. */ 263 de = (struct direct *)&dirbuf[0]; 264 ede = (struct direct *)&dirbuf[blksize]; 265 while (de < ede) { 266 ino = de->d_ino; 267 if (params->fstype->needswap) { 268 ino = bswap32(ino); 269 de->d_reclen = bswap16(de->d_reclen); 270 } 271 if (ino != 0 && strcmp(de->d_name, params->stage2) == 0) { 272 *((uint32_t *)_ino) = ino; 273 return (2); 274 } 275 if (de->d_reclen == 0) 276 break; 277 de = (struct direct *)((char *)de + de->d_reclen); 278 } 279 280 return (1); 281 } 282 283 struct findblks_state { 284 uint32_t maxblk; 285 uint32_t nblk; 286 ib_block *blocks; 287 }; 288 289 /* This callback records the blocks of the secondary bootstrap. */ 290 static int 291 ffs_findstage2_blocks(ib_params *params, void *_state, 292 uint32_t blk, uint32_t blksize) 293 { 294 struct findblks_state *state = _state; 295 296 assert(params != NULL); 297 assert(params->stage2 != NULL); 298 assert(_state != NULL); 299 300 if (state->nblk == state->maxblk) { 301 warnx("Secondary bootstrap `%s' has too many blocks " \ 302 "(max %d)\n", params->stage2, state->maxblk); 303 return (0); 304 } 305 state->blocks[state->nblk].block = blk; 306 state->blocks[state->nblk].blocksize = blksize; 307 state->nblk++; 308 return (1); 309 } 310 311 /* 312 * publically visible functions 313 */ 314 315 int 316 ffs_match(ib_params *params) 317 { 318 char sbbuf[SBSIZE]; 319 struct fs *fs; 320 321 assert(params != NULL); 322 assert(params->fstype != NULL); 323 324 /* Read and check the superblock. */ 325 if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf)) 326 return (0); 327 fs = (struct fs *)sbbuf; 328 if (fs->fs_magic == FS_MAGIC) { 329 params->fstype->needswap = 0; 330 params->fstype->blocksize = fs->fs_bsize; 331 } else if (fs->fs_magic == bswap32(FS_MAGIC)) { 332 params->fstype->needswap = 1; 333 params->fstype->blocksize = bswap32(fs->fs_bsize); 334 } else { 335 return (0); 336 } 337 338 return (1); 339 } 340 341 int 342 ffs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks) 343 { 344 int rv; 345 uint32_t ino; 346 struct findblks_state state; 347 348 assert(params != NULL); 349 assert(params->stage2 != NULL); 350 assert(maxblk != NULL); 351 assert(blocks != NULL); 352 353 if (params->flags & IB_STAGE2START) 354 return (hardcode_stage2(params, maxblk, blocks)); 355 356 /* The secondary bootstrap must be clearly in /. */ 357 if (params->stage2[0] == '/') 358 params->stage2++; 359 if (strchr(params->stage2, '/') != NULL) { 360 warnx("The secondary bootstrap `%s' must be in /", 361 params->stage2); 362 return (0); 363 } 364 365 /* Get the inode number of the secondary bootstrap. */ 366 rv = ffs_find_disk_blocks(params, ROOTINO, ffs_findstage2_ino, &ino); 367 if (rv != 2) 368 return (0); 369 370 /* Record the disk blocks of the secondary bootstrap. */ 371 state.maxblk = *maxblk; 372 state.nblk = 0; 373 state.blocks = blocks; 374 rv = ffs_find_disk_blocks(params, ino, ffs_findstage2_blocks, &state); 375 if (! rv) 376 return (0); 377 378 *maxblk = state.nblk; 379 return (1); 380 } 381
Indexes created Fri Sep 26 20:09:58 GMT 2025