1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)ufs_bmap.c 8.7 (Berkeley) 3/21/95 37 * $FreeBSD$ 38 */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/bio.h> 43 #include <sys/buf.h> 44 #include <sys/endian.h> 45 #include <sys/proc.h> 46 #include <sys/vnode.h> 47 #include <sys/mount.h> 48 #include <sys/racct.h> 49 #include <sys/resourcevar.h> 50 #include <sys/stat.h> 51 52 #include <fs/ext2fs/fs.h> 53 #include <fs/ext2fs/inode.h> 54 #include <fs/ext2fs/ext2fs.h> 55 #include <fs/ext2fs/ext2_dinode.h> 56 #include <fs/ext2fs/ext2_extern.h> 57 #include <fs/ext2fs/ext2_mount.h> 58 59 /* 60 * Bmap converts the logical block number of a file to its physical block 61 * number on the disk. The conversion is done by using the logical block 62 * number to index into the array of block pointers described by the dinode. 63 */ 64 int 65 ext2_bmap(struct vop_bmap_args *ap) 66 { 67 daddr_t blkno; 68 int error; 69 70 /* 71 * Check for underlying vnode requests and ensure that logical 72 * to physical mapping is requested. 73 */ 74 if (ap->a_bop != NULL) 75 *ap->a_bop = &VTOI(ap->a_vp)->i_devvp->v_bufobj; 76 if (ap->a_bnp == NULL) 77 return (0); 78 79 if (VTOI(ap->a_vp)->i_flag & IN_E4EXTENTS) 80 error = ext4_bmapext(ap->a_vp, ap->a_bn, &blkno, 81 ap->a_runp, ap->a_runb); 82 else 83 error = ext2_bmaparray(ap->a_vp, ap->a_bn, &blkno, 84 ap->a_runp, ap->a_runb); 85 *ap->a_bnp = blkno; 86 return (error); 87 } 88 89 /* 90 * Convert the logical block number of a file to its physical block number 91 * on the disk within ext4 extents. 92 */ 93 int 94 ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb) 95 { 96 struct inode *ip; 97 struct m_ext2fs *fs; 98 struct mount *mp; 99 struct ext2mount *ump; 100 struct ext4_extent_header *ehp; 101 struct ext4_extent *ep; 102 struct ext4_extent_path *path = NULL; 103 daddr_t lbn; 104 int error, depth, maxrun = 0, bsize; 105 106 ip = VTOI(vp); 107 fs = ip->i_e2fs; 108 mp = vp->v_mount; 109 ump = VFSTOEXT2(mp); 110 lbn = bn; 111 ehp = (struct ext4_extent_header *)ip->i_data; 112 depth = le16toh(ehp->eh_depth); 113 bsize = EXT2_BLOCK_SIZE(ump->um_e2fs); 114 115 *bnp = -1; 116 if (runp != NULL) { 117 maxrun = mp->mnt_iosize_max / bsize - 1; 118 *runp = 0; 119 } 120 if (runb != NULL) 121 *runb = 0; 122 123 error = ext4_ext_find_extent(ip, lbn, &path); 124 if (error) 125 return (error); 126 127 ep = path[depth].ep_ext; 128 if(ep) { 129 if (lbn < le32toh(ep->e_blk)) { 130 if (runp != NULL) { 131 *runp = min(maxrun, le32toh(ep->e_blk) - lbn - 1); 132 } 133 } else if (le32toh(ep->e_blk) <= lbn && 134 lbn < le32toh(ep->e_blk) + le16toh(ep->e_len)) { 135 *bnp = fsbtodb(fs, lbn - le32toh(ep->e_blk) + 136 (le32toh(ep->e_start_lo) | 137 (daddr_t)le16toh(ep->e_start_hi) << 32)); 138 if (runp != NULL) { 139 *runp = min(maxrun, 140 le16toh(ep->e_len) - 141 (lbn - le32toh(ep->e_blk)) - 1); 142 } 143 if (runb != NULL) 144 *runb = min(maxrun, lbn - le32toh(ep->e_blk)); 145 } else { 146 if (runb != NULL) 147 *runb = min(maxrun, le32toh(ep->e_blk) + lbn - 148 le16toh(ep->e_len)); 149 } 150 } 151 152 ext4_ext_path_free(path); 153 154 return (error); 155 } 156 157 static int 158 readindir(struct vnode *vp, e2fs_lbn_t lbn, e2fs_daddr_t daddr, struct buf **bpp) 159 { 160 struct buf *bp; 161 struct mount *mp; 162 struct ext2mount *ump; 163 int error; 164 165 mp = vp->v_mount; 166 ump = VFSTOEXT2(mp); 167 168 bp = getblk(vp, lbn, mp->mnt_stat.f_iosize, 0, 0, 0); 169 if ((bp->b_flags & B_CACHE) == 0) { 170 KASSERT(daddr != 0, 171 ("readindir: indirect block not in cache")); 172 173 bp->b_blkno = blkptrtodb(ump, daddr); 174 bp->b_iocmd = BIO_READ; 175 bp->b_flags &= ~B_INVAL; 176 bp->b_ioflags &= ~BIO_ERROR; 177 vfs_busy_pages(bp, 0); 178 bp->b_iooffset = dbtob(bp->b_blkno); 179 bstrategy(bp); 180 #ifdef RACCT 181 if (racct_enable) { 182 PROC_LOCK(curproc); 183 racct_add_buf(curproc, bp, 0); 184 PROC_UNLOCK(curproc); 185 } 186 #endif 187 curthread->td_ru.ru_inblock++; 188 error = bufwait(bp); 189 if (error != 0) { 190 brelse(bp); 191 return (error); 192 } 193 } 194 *bpp = bp; 195 return (0); 196 } 197 198 /* 199 * Indirect blocks are now on the vnode for the file. They are given negative 200 * logical block numbers. Indirect blocks are addressed by the negative 201 * address of the first data block to which they point. Double indirect blocks 202 * are addressed by one less than the address of the first indirect block to 203 * which they point. Triple indirect blocks are addressed by one less than 204 * the address of the first double indirect block to which they point. 205 * 206 * ext2_bmaparray does the bmap conversion, and if requested returns the 207 * array of logical blocks which must be traversed to get to a block. 208 * Each entry contains the offset into that block that gets you to the 209 * next block and the disk address of the block (if it is assigned). 210 */ 211 212 int 213 ext2_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, int *runp, int *runb) 214 { 215 struct inode *ip; 216 struct buf *bp; 217 struct ext2mount *ump; 218 struct mount *mp; 219 struct indir a[EXT2_NIADDR + 1], *ap; 220 daddr_t daddr; 221 e2fs_lbn_t metalbn; 222 int error, num, maxrun = 0, bsize; 223 int *nump; 224 225 ap = NULL; 226 ip = VTOI(vp); 227 mp = vp->v_mount; 228 ump = VFSTOEXT2(mp); 229 230 bsize = EXT2_BLOCK_SIZE(ump->um_e2fs); 231 232 if (runp) { 233 maxrun = mp->mnt_iosize_max / bsize - 1; 234 *runp = 0; 235 } 236 if (runb) 237 *runb = 0; 238 239 ap = a; 240 nump = # 241 error = ext2_getlbns(vp, bn, ap, nump); 242 if (error) 243 return (error); 244 245 num = *nump; 246 if (num == 0) { 247 *bnp = blkptrtodb(ump, ip->i_db[bn]); 248 if (*bnp == 0) { 249 *bnp = -1; 250 } else if (runp) { 251 daddr_t bnb = bn; 252 253 for (++bn; bn < EXT2_NDADDR && *runp < maxrun && 254 is_sequential(ump, ip->i_db[bn - 1], ip->i_db[bn]); 255 ++bn, ++*runp); 256 bn = bnb; 257 if (runb && (bn > 0)) { 258 for (--bn; (bn >= 0) && (*runb < maxrun) && 259 is_sequential(ump, ip->i_db[bn], 260 ip->i_db[bn + 1]); 261 --bn, ++*runb); 262 } 263 } 264 return (0); 265 } 266 267 /* Get disk address out of indirect block array */ 268 daddr = ip->i_ib[ap->in_off]; 269 270 for (bp = NULL, ++ap; --num; ++ap) { 271 /* 272 * Exit the loop if there is no disk address assigned yet and 273 * the indirect block isn't in the cache, or if we were 274 * looking for an indirect block and we've found it. 275 */ 276 277 metalbn = ap->in_lbn; 278 if ((daddr == 0 && !incore(&vp->v_bufobj, metalbn)) || metalbn == bn) 279 break; 280 /* 281 * If we get here, we've either got the block in the cache 282 * or we have a disk address for it, go fetch it. 283 */ 284 if (bp) 285 bqrelse(bp); 286 error = readindir(vp, metalbn, daddr, &bp); 287 if (error != 0) 288 return (error); 289 290 daddr = le32toh(((e2fs_daddr_t *)bp->b_data)[ap->in_off]); 291 if (num == 1 && daddr && runp) { 292 for (bn = ap->in_off + 1; 293 bn < MNINDIR(ump) && *runp < maxrun && 294 is_sequential(ump, 295 ((e2fs_daddr_t *)bp->b_data)[bn - 1], 296 ((e2fs_daddr_t *)bp->b_data)[bn]); 297 ++bn, ++*runp); 298 bn = ap->in_off; 299 if (runb && bn) { 300 for (--bn; bn >= 0 && *runb < maxrun && 301 is_sequential(ump, 302 ((e2fs_daddr_t *)bp->b_data)[bn], 303 ((e2fs_daddr_t *)bp->b_data)[bn + 1]); 304 --bn, ++*runb); 305 } 306 } 307 } 308 if (bp) 309 bqrelse(bp); 310 311 /* 312 * Since this is FFS independent code, we are out of scope for the 313 * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they 314 * will fall in the range 1..um_seqinc, so we use that test and 315 * return a request for a zeroed out buffer if attempts are made 316 * to read a BLK_NOCOPY or BLK_SNAP block. 317 */ 318 if ((ip->i_flags & SF_SNAPSHOT) && daddr > 0 && daddr < ump->um_seqinc) { 319 *bnp = -1; 320 return (0); 321 } 322 *bnp = blkptrtodb(ump, daddr); 323 if (*bnp == 0) { 324 *bnp = -1; 325 } 326 return (0); 327 } 328 329 static e2fs_lbn_t 330 lbn_count(struct ext2mount *ump, int level) 331 332 { 333 e2fs_lbn_t blockcnt; 334 335 for (blockcnt = 1; level > 0; level--) 336 blockcnt *= MNINDIR(ump); 337 return (blockcnt); 338 } 339 340 int 341 ext2_bmap_seekdata(struct vnode *vp, off_t *offp) 342 { 343 struct buf *bp; 344 struct indir a[EXT2_NIADDR + 1], *ap; 345 struct inode *ip; 346 struct mount *mp; 347 struct ext2mount *ump; 348 e2fs_daddr_t bn, daddr, nextbn; 349 uint64_t bsize; 350 off_t numblks; 351 int error, num, num1, off; 352 353 bp = NULL; 354 error = 0; 355 ip = VTOI(vp); 356 mp = vp->v_mount; 357 ump = VFSTOEXT2(mp); 358 359 if (vp->v_type != VREG || (ip->i_flags & SF_SNAPSHOT) != 0) 360 return (EINVAL); 361 if (*offp < 0 || *offp >= ip->i_size) 362 return (ENXIO); 363 364 bsize = mp->mnt_stat.f_iosize; 365 for (bn = *offp / bsize, numblks = howmany(ip->i_size, bsize); 366 bn < numblks; bn = nextbn) { 367 if (bn < EXT2_NDADDR) { 368 daddr = ip->i_db[bn]; 369 if (daddr != 0) 370 break; 371 nextbn = bn + 1; 372 continue; 373 } 374 375 ap = a; 376 error = ext2_getlbns(vp, bn, ap, &num); 377 if (error != 0) 378 break; 379 MPASS(num >= 2); 380 daddr = ip->i_ib[ap->in_off]; 381 ap++, num--; 382 for (nextbn = EXT2_NDADDR, num1 = num - 1; num1 > 0; num1--) 383 nextbn += lbn_count(ump, num1); 384 if (daddr == 0) { 385 nextbn += lbn_count(ump, num); 386 continue; 387 } 388 389 for (; daddr != 0 && num > 0; ap++, num--) { 390 if (bp != NULL) 391 bqrelse(bp); 392 error = readindir(vp, ap->in_lbn, daddr, &bp); 393 if (error != 0) 394 return (error); 395 396 /* 397 * Scan the indirect block until we find a non-zero 398 * pointer. 399 */ 400 off = ap->in_off; 401 do { 402 daddr = le32toh(((e2fs_daddr_t *)bp->b_data)[off]); 403 } while (daddr == 0 && ++off < MNINDIR(ump)); 404 nextbn += off * lbn_count(ump, num - 1); 405 406 /* 407 * We need to recompute the LBNs of indirect 408 * blocks, so restart with the updated block offset. 409 */ 410 if (off != ap->in_off) 411 break; 412 } 413 if (num == 0) { 414 /* 415 * We found a data block. 416 */ 417 bn = nextbn; 418 break; 419 } 420 } 421 if (bp != NULL) 422 bqrelse(bp); 423 if (bn >= numblks) 424 error = ENXIO; 425 if (error == 0 && *offp < bn * bsize) 426 *offp = bn * bsize; 427 return (error); 428 } 429 430 /* 431 * Create an array of logical block number/offset pairs which represent the 432 * path of indirect blocks required to access a data block. The first "pair" 433 * contains the logical block number of the appropriate single, double or 434 * triple indirect block and the offset into the inode indirect block array. 435 * Note, the logical block number of the inode single/double/triple indirect 436 * block appears twice in the array, once with the offset into the i_ib and 437 * once with the offset into the page itself. 438 */ 439 int 440 ext2_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) 441 { 442 long blockcnt; 443 e2fs_lbn_t metalbn, realbn; 444 struct ext2mount *ump; 445 int i, numlevels, off; 446 int64_t qblockcnt; 447 448 ump = VFSTOEXT2(vp->v_mount); 449 if (nump) 450 *nump = 0; 451 numlevels = 0; 452 realbn = bn; 453 if ((long)bn < 0) 454 bn = -(long)bn; 455 456 /* The first EXT2_NDADDR blocks are direct blocks. */ 457 if (bn < EXT2_NDADDR) 458 return (0); 459 460 /* 461 * Determine the number of levels of indirection. After this loop 462 * is done, blockcnt indicates the number of data blocks possible 463 * at the previous level of indirection, and EXT2_NIADDR - i is the 464 * number of levels of indirection needed to locate the requested block. 465 */ 466 for (blockcnt = 1, i = EXT2_NIADDR, bn -= EXT2_NDADDR; ; 467 i--, bn -= blockcnt) { 468 if (i == 0) 469 return (EFBIG); 470 /* 471 * Use int64_t's here to avoid overflow for triple indirect 472 * blocks when longs have 32 bits and the block size is more 473 * than 4K. 474 */ 475 qblockcnt = (int64_t)blockcnt * MNINDIR(ump); 476 if (bn < qblockcnt) 477 break; 478 blockcnt = qblockcnt; 479 } 480 481 /* Calculate the address of the first meta-block. */ 482 if (realbn >= 0) 483 metalbn = -(realbn - bn + EXT2_NIADDR - i); 484 else 485 metalbn = -(-realbn - bn + EXT2_NIADDR - i); 486 487 /* 488 * At each iteration, off is the offset into the bap array which is 489 * an array of disk addresses at the current level of indirection. 490 * The logical block number and the offset in that block are stored 491 * into the argument array. 492 */ 493 ap->in_lbn = metalbn; 494 ap->in_off = off = EXT2_NIADDR - i; 495 ap++; 496 for (++numlevels; i <= EXT2_NIADDR; i++) { 497 /* If searching for a meta-data block, quit when found. */ 498 if (metalbn == realbn) 499 break; 500 501 off = (bn / blockcnt) % MNINDIR(ump); 502 503 ++numlevels; 504 ap->in_lbn = metalbn; 505 ap->in_off = off; 506 ++ap; 507 508 metalbn -= -1 + off * blockcnt; 509 blockcnt /= MNINDIR(ump); 510 } 511 if (nump) 512 *nump = numlevels; 513 return (0); 514 } 515