1 /* $NetBSD: ufs.c,v 1.15 1996/06/02 13:28:21 ragge Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 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 University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * 39 * Copyright (c) 1990, 1991 Carnegie Mellon University 40 * All Rights Reserved. 41 * 42 * Author: David Golub 43 * 44 * Permission to use, copy, modify and distribute this software and its 45 * documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 52 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * Stand-alone file reading package. 67 */ 68 69 #include <sys/param.h> 70 #include <sys/time.h> 71 #include <ufs/ffs/fs.h> 72 #include <ufs/ufs/dinode.h> 73 #include <ufs/ufs/dir.h> 74 #include <lib/libkern/libkern.h> 75 76 #include <string.h> 77 78 #include "stand.h" 79 80 /* 81 * In-core open file. 82 */ 83 struct file { 84 off_t f_seekp; /* seek pointer */ 85 struct fs *f_fs; /* pointer to super-block */ 86 struct dinode f_di; /* copy of on-disk inode */ 87 int f_nindir[NIADDR]; 88 /* number of blocks mapped by 89 indirect block at level i */ 90 char *f_blk[NIADDR]; /* buffer for indirect block at 91 level i */ 92 size_t f_blksize[NIADDR]; 93 /* size of buffer */ 94 daddr_t f_blkno[NIADDR];/* disk address of block in buffer */ 95 char *f_buf; /* buffer for data block */ 96 size_t f_buf_size; /* size of data block */ 97 daddr_t f_buf_blkno; /* block number of data block */ 98 }; 99 100 static int read_inode __P((ino_t, struct open_file *)); 101 static int block_map __P((struct open_file *, daddr_t, daddr_t *)); 102 static int buf_read_file __P((struct open_file *, char **, size_t *)); 103 static int search_directory __P((char *, struct open_file *, ino_t *)); 104 #ifdef COMPAT_UFS 105 static void ffs_oldfscompat __P((struct fs *)); 106 #endif 107 108 /* 109 * Read a new inode into a file structure. 110 */ 111 static int 112 read_inode(inumber, f) 113 ino_t inumber; 114 struct open_file *f; 115 { 116 register struct file *fp = (struct file *)f->f_fsdata; 117 register struct fs *fs = fp->f_fs; 118 char *buf; 119 size_t rsize; 120 int rc; 121 122 /* 123 * Read inode and save it. 124 */ 125 buf = alloc(fs->fs_bsize); 126 twiddle(); 127 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 128 fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize, 129 buf, &rsize); 130 if (rc) 131 goto out; 132 if (rsize != fs->fs_bsize) { 133 rc = EIO; 134 goto out; 135 } 136 137 { 138 register struct dinode *dp; 139 140 dp = (struct dinode *)buf; 141 fp->f_di = dp[ino_to_fsbo(fs, inumber)]; 142 } 143 144 /* 145 * Clear out the old buffers 146 */ 147 { 148 register int level; 149 150 for (level = 0; level < NIADDR; level++) 151 fp->f_blkno[level] = -1; 152 fp->f_buf_blkno = -1; 153 } 154 out: 155 free(buf, fs->fs_bsize); 156 return (rc); 157 } 158 159 /* 160 * Given an offset in a file, find the disk block number that 161 * contains that block. 162 */ 163 static int 164 block_map(f, file_block, disk_block_p) 165 struct open_file *f; 166 daddr_t file_block; 167 daddr_t *disk_block_p; /* out */ 168 { 169 register struct file *fp = (struct file *)f->f_fsdata; 170 register struct fs *fs = fp->f_fs; 171 int level; 172 int idx; 173 daddr_t ind_block_num; 174 daddr_t *ind_p; 175 int rc; 176 177 /* 178 * Index structure of an inode: 179 * 180 * di_db[0..NDADDR-1] hold block numbers for blocks 181 * 0..NDADDR-1 182 * 183 * di_ib[0] index block 0 is the single indirect block 184 * holds block numbers for blocks 185 * NDADDR .. NDADDR + NINDIR(fs)-1 186 * 187 * di_ib[1] index block 1 is the double indirect block 188 * holds block numbers for INDEX blocks for blocks 189 * NDADDR + NINDIR(fs) .. 190 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1 191 * 192 * di_ib[2] index block 2 is the triple indirect block 193 * holds block numbers for double-indirect 194 * blocks for blocks 195 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 .. 196 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 197 * + NINDIR(fs)**3 - 1 198 */ 199 200 if (file_block < NDADDR) { 201 /* Direct block. */ 202 *disk_block_p = fp->f_di.di_db[file_block]; 203 return (0); 204 } 205 206 file_block -= NDADDR; 207 208 /* 209 * nindir[0] = NINDIR 210 * nindir[1] = NINDIR**2 211 * nindir[2] = NINDIR**3 212 * etc 213 */ 214 for (level = 0; level < NIADDR; level++) { 215 if (file_block < fp->f_nindir[level]) 216 break; 217 file_block -= fp->f_nindir[level]; 218 } 219 if (level == NIADDR) { 220 /* Block number too high */ 221 return (EFBIG); 222 } 223 224 ind_block_num = fp->f_di.di_ib[level]; 225 226 for (; level >= 0; level--) { 227 if (ind_block_num == 0) { 228 *disk_block_p = 0; /* missing */ 229 return (0); 230 } 231 232 if (fp->f_blkno[level] != ind_block_num) { 233 if (fp->f_blk[level] == (char *)0) 234 fp->f_blk[level] = 235 alloc(fs->fs_bsize); 236 twiddle(); 237 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 238 fsbtodb(fp->f_fs, ind_block_num), 239 fs->fs_bsize, 240 fp->f_blk[level], 241 &fp->f_blksize[level]); 242 if (rc) 243 return (rc); 244 if (fp->f_blksize[level] != fs->fs_bsize) 245 return (EIO); 246 fp->f_blkno[level] = ind_block_num; 247 } 248 249 ind_p = (daddr_t *)fp->f_blk[level]; 250 251 if (level > 0) { 252 idx = file_block / fp->f_nindir[level - 1]; 253 file_block %= fp->f_nindir[level - 1]; 254 } else 255 idx = file_block; 256 257 ind_block_num = ind_p[idx]; 258 } 259 260 *disk_block_p = ind_block_num; 261 262 return (0); 263 } 264 265 /* 266 * Read a portion of a file into an internal buffer. Return 267 * the location in the buffer and the amount in the buffer. 268 */ 269 static int 270 buf_read_file(f, buf_p, size_p) 271 struct open_file *f; 272 char **buf_p; /* out */ 273 size_t *size_p; /* out */ 274 { 275 register struct file *fp = (struct file *)f->f_fsdata; 276 register struct fs *fs = fp->f_fs; 277 long off; 278 register daddr_t file_block; 279 daddr_t disk_block; 280 size_t block_size; 281 int rc; 282 283 off = blkoff(fs, fp->f_seekp); 284 file_block = lblkno(fs, fp->f_seekp); 285 block_size = dblksize(fs, &fp->f_di, file_block); 286 287 if (file_block != fp->f_buf_blkno) { 288 rc = block_map(f, file_block, &disk_block); 289 if (rc) 290 return (rc); 291 292 if (fp->f_buf == (char *)0) 293 fp->f_buf = alloc(fs->fs_bsize); 294 295 if (disk_block == 0) { 296 bzero(fp->f_buf, block_size); 297 fp->f_buf_size = block_size; 298 } else { 299 twiddle(); 300 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 301 fsbtodb(fs, disk_block), 302 block_size, fp->f_buf, &fp->f_buf_size); 303 if (rc) 304 return (rc); 305 } 306 307 fp->f_buf_blkno = file_block; 308 } 309 310 /* 311 * Return address of byte in buffer corresponding to 312 * offset, and size of remainder of buffer after that 313 * byte. 314 */ 315 *buf_p = fp->f_buf + off; 316 *size_p = block_size - off; 317 318 /* 319 * But truncate buffer at end of file. 320 */ 321 if (*size_p > fp->f_di.di_size - fp->f_seekp) 322 *size_p = fp->f_di.di_size - fp->f_seekp; 323 324 return (0); 325 } 326 327 /* 328 * Search a directory for a name and return its 329 * i_number. 330 */ 331 static int 332 search_directory(name, f, inumber_p) 333 char *name; 334 struct open_file *f; 335 ino_t *inumber_p; /* out */ 336 { 337 register struct file *fp = (struct file *)f->f_fsdata; 338 register struct direct *dp; 339 struct direct *edp; 340 char *buf; 341 size_t buf_size; 342 int namlen, length; 343 int rc; 344 345 length = strlen(name); 346 347 fp->f_seekp = 0; 348 while (fp->f_seekp < fp->f_di.di_size) { 349 rc = buf_read_file(f, &buf, &buf_size); 350 if (rc) 351 return (rc); 352 353 dp = (struct direct *)buf; 354 edp = (struct direct *)(buf + buf_size); 355 while (dp < edp) { 356 if (dp->d_ino == (ino_t)0) 357 goto next; 358 #if BYTE_ORDER == LITTLE_ENDIAN 359 if (fp->f_fs->fs_maxsymlinklen <= 0) 360 namlen = dp->d_type; 361 else 362 #endif 363 namlen = dp->d_namlen; 364 if (namlen == length && 365 !strcmp(name, dp->d_name)) { 366 /* found entry */ 367 *inumber_p = dp->d_ino; 368 return (0); 369 } 370 next: 371 dp = (struct direct *)((char *)dp + dp->d_reclen); 372 } 373 fp->f_seekp += buf_size; 374 } 375 return (ENOENT); 376 } 377 378 /* 379 * Open a file. 380 */ 381 int 382 ufs_open(path, f) 383 char *path; 384 struct open_file *f; 385 { 386 register char *cp, *ncp; 387 register int c; 388 ino_t inumber, parent_inumber; 389 struct file *fp; 390 struct fs *fs; 391 int rc; 392 size_t buf_size; 393 int nlinks = 0; 394 char namebuf[MAXPATHLEN+1]; 395 char *buf = NULL; 396 397 /* allocate file system specific data structure */ 398 fp = alloc(sizeof(struct file)); 399 bzero(fp, sizeof(struct file)); 400 f->f_fsdata = (void *)fp; 401 402 /* allocate space and read super block */ 403 fs = alloc(SBSIZE); 404 fp->f_fs = fs; 405 twiddle(); 406 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 407 SBLOCK, SBSIZE, (char *)fs, &buf_size); 408 if (rc) 409 goto out; 410 411 if (buf_size != SBSIZE || fs->fs_magic != FS_MAGIC || 412 fs->fs_bsize > MAXBSIZE || fs->fs_bsize < sizeof(struct fs)) { 413 rc = EINVAL; 414 goto out; 415 } 416 #ifdef COMPAT_UFS 417 ffs_oldfscompat(fs); 418 #endif 419 420 /* 421 * Calculate indirect block levels. 422 */ 423 { 424 register int mult; 425 register int level; 426 427 mult = 1; 428 for (level = 0; level < NIADDR; level++) { 429 mult *= NINDIR(fs); 430 fp->f_nindir[level] = mult; 431 } 432 } 433 434 inumber = ROOTINO; 435 if ((rc = read_inode(inumber, f)) != 0) 436 goto out; 437 438 cp = path; 439 while (*cp) { 440 441 /* 442 * Remove extra separators 443 */ 444 while (*cp == '/') 445 cp++; 446 if (*cp == '\0') 447 break; 448 449 /* 450 * Check that current node is a directory. 451 */ 452 if ((fp->f_di.di_mode & IFMT) != IFDIR) { 453 rc = ENOTDIR; 454 goto out; 455 } 456 457 /* 458 * Get next component of path name. 459 */ 460 { 461 register int len = 0; 462 463 ncp = cp; 464 while ((c = *cp) != '\0' && c != '/') { 465 if (++len > MAXNAMLEN) { 466 rc = ENOENT; 467 goto out; 468 } 469 cp++; 470 } 471 *cp = '\0'; 472 } 473 474 /* 475 * Look up component in current directory. 476 * Save directory inumber in case we find a 477 * symbolic link. 478 */ 479 parent_inumber = inumber; 480 rc = search_directory(ncp, f, &inumber); 481 *cp = c; 482 if (rc) 483 goto out; 484 485 /* 486 * Open next component. 487 */ 488 if ((rc = read_inode(inumber, f)) != 0) 489 goto out; 490 491 /* 492 * Check for symbolic link. 493 */ 494 if ((fp->f_di.di_mode & IFMT) == IFLNK) { 495 int link_len = fp->f_di.di_size; 496 int len; 497 498 len = strlen(cp); 499 500 if (link_len + len > MAXPATHLEN || 501 ++nlinks > MAXSYMLINKS) { 502 rc = ENOENT; 503 goto out; 504 } 505 506 bcopy(cp, &namebuf[link_len], len + 1); 507 508 if (link_len < fs->fs_maxsymlinklen) { 509 bcopy(fp->f_di.di_shortlink, namebuf, 510 (unsigned) link_len); 511 } else { 512 /* 513 * Read file for symbolic link 514 */ 515 size_t buf_size; 516 daddr_t disk_block; 517 register struct fs *fs = fp->f_fs; 518 519 if (!buf) 520 buf = alloc(fs->fs_bsize); 521 rc = block_map(f, (daddr_t)0, &disk_block); 522 if (rc) 523 goto out; 524 525 twiddle(); 526 rc = (f->f_dev->dv_strategy)(f->f_devdata, 527 F_READ, fsbtodb(fs, disk_block), 528 fs->fs_bsize, buf, &buf_size); 529 if (rc) 530 goto out; 531 532 bcopy((char *)buf, namebuf, (unsigned)link_len); 533 } 534 535 /* 536 * If relative pathname, restart at parent directory. 537 * If absolute pathname, restart at root. 538 */ 539 cp = namebuf; 540 if (*cp != '/') 541 inumber = parent_inumber; 542 else 543 inumber = (ino_t)ROOTINO; 544 545 if ((rc = read_inode(inumber, f)) != 0) 546 goto out; 547 } 548 } 549 550 /* 551 * Found terminal component. 552 */ 553 rc = 0; 554 out: 555 if (buf) 556 free(buf, fs->fs_bsize); 557 if (rc) 558 free(fp, sizeof(struct file)); 559 return (rc); 560 } 561 562 int 563 ufs_close(f) 564 struct open_file *f; 565 { 566 register struct file *fp = (struct file *)f->f_fsdata; 567 int level; 568 569 f->f_fsdata = (void *)0; 570 if (fp == (struct file *)0) 571 return (0); 572 573 for (level = 0; level < NIADDR; level++) { 574 if (fp->f_blk[level]) 575 free(fp->f_blk[level], fp->f_fs->fs_bsize); 576 } 577 if (fp->f_buf) 578 free(fp->f_buf, fp->f_fs->fs_bsize); 579 free(fp->f_fs, SBSIZE); 580 free(fp, sizeof(struct file)); 581 return (0); 582 } 583 584 /* 585 * Copy a portion of a file into kernel memory. 586 * Cross block boundaries when necessary. 587 */ 588 int 589 ufs_read(f, start, size, resid) 590 struct open_file *f; 591 void *start; 592 size_t size; 593 size_t *resid; /* out */ 594 { 595 register struct file *fp = (struct file *)f->f_fsdata; 596 register size_t csize; 597 char *buf; 598 size_t buf_size; 599 int rc = 0; 600 register char *addr = start; 601 602 while (size != 0) { 603 if (fp->f_seekp >= fp->f_di.di_size) 604 break; 605 606 rc = buf_read_file(f, &buf, &buf_size); 607 if (rc) 608 break; 609 610 csize = size; 611 if (csize > buf_size) 612 csize = buf_size; 613 614 bcopy(buf, addr, csize); 615 616 fp->f_seekp += csize; 617 addr += csize; 618 size -= csize; 619 } 620 if (resid) 621 *resid = size; 622 return (rc); 623 } 624 625 /* 626 * Not implemented. 627 */ 628 int 629 ufs_write(f, start, size, resid) 630 struct open_file *f; 631 void *start; 632 size_t size; 633 size_t *resid; /* out */ 634 { 635 636 return (EROFS); 637 } 638 639 off_t 640 ufs_seek(f, offset, where) 641 struct open_file *f; 642 off_t offset; 643 int where; 644 { 645 register struct file *fp = (struct file *)f->f_fsdata; 646 647 switch (where) { 648 case SEEK_SET: 649 fp->f_seekp = offset; 650 break; 651 case SEEK_CUR: 652 fp->f_seekp += offset; 653 break; 654 case SEEK_END: 655 fp->f_seekp = fp->f_di.di_size - offset; 656 break; 657 default: 658 return (-1); 659 } 660 return (fp->f_seekp); 661 } 662 663 int 664 ufs_stat(f, sb) 665 struct open_file *f; 666 struct stat *sb; 667 { 668 register struct file *fp = (struct file *)f->f_fsdata; 669 670 /* only important stuff */ 671 sb->st_mode = fp->f_di.di_mode; 672 sb->st_uid = fp->f_di.di_uid; 673 sb->st_gid = fp->f_di.di_gid; 674 sb->st_size = fp->f_di.di_size; 675 return (0); 676 } 677 678 #ifdef COMPAT_UFS 679 /* 680 * Sanity checks for old file systems. 681 * 682 * XXX - goes away some day. 683 */ 684 static void 685 ffs_oldfscompat(fs) 686 struct fs *fs; 687 { 688 int i; 689 690 fs->fs_npsect = max(fs->fs_npsect, fs->fs_nsect); /* XXX */ 691 fs->fs_interleave = max(fs->fs_interleave, 1); /* XXX */ 692 if (fs->fs_postblformat == FS_42POSTBLFMT) /* XXX */ 693 fs->fs_nrpos = 8; /* XXX */ 694 if (fs->fs_inodefmt < FS_44INODEFMT) { /* XXX */ 695 quad_t sizepb = fs->fs_bsize; /* XXX */ 696 /* XXX */ 697 fs->fs_maxfilesize = fs->fs_bsize * NDADDR - 1; /* XXX */ 698 for (i = 0; i < NIADDR; i++) { /* XXX */ 699 sizepb *= NINDIR(fs); /* XXX */ 700 fs->fs_maxfilesize += sizepb; /* XXX */ 701 } /* XXX */ 702 fs->fs_qbmask = ~fs->fs_bmask; /* XXX */ 703 fs->fs_qfmask = ~fs->fs_fmask; /* XXX */ 704 } /* XXX */ 705 } 706 #endif 707