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 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/bio.h> 40#include <sys/buf.h> 41#include <sys/endian.h> 42#include <sys/proc.h> 43#include <sys/vnode.h> 44#include <sys/mount.h> 45#include <sys/racct.h> 46#include <sys/resourcevar.h> 47#include <sys/stat.h> 48 49#include <fs/ext2fs/fs.h> 50#include <fs/ext2fs/inode.h> 51#include <fs/ext2fs/ext2fs.h> 52#include <fs/ext2fs/ext2_dinode.h> 53#include <fs/ext2fs/ext2_extern.h> 54#include <fs/ext2fs/ext2_mount.h> 55 56/* 57 * Bmap converts the logical block number of a file to its physical block 58 * number on the disk. The conversion is done by using the logical block 59 * number to index into the array of block pointers described by the dinode. 60 */ 61int 62ext2_bmap(struct vop_bmap_args *ap) 63{ 64 daddr_t blkno; 65 int error; 66 67 /* 68 * Check for underlying vnode requests and ensure that logical 69 * to physical mapping is requested. 70 */ 71 if (ap->a_bop != NULL) 72 *ap->a_bop = &VTOI(ap->a_vp)->i_devvp->v_bufobj; 73 if (ap->a_bnp == NULL) 74 return (0); 75 76 if (VTOI(ap->a_vp)->i_flag & IN_E4EXTENTS) 77 error = ext4_bmapext(ap->a_vp, ap->a_bn, &blkno, 78 ap->a_runp, ap->a_runb); 79 else 80 error = ext2_bmaparray(ap->a_vp, ap->a_bn, &blkno, 81 ap->a_runp, ap->a_runb); 82 *ap->a_bnp = blkno; 83 return (error); 84} 85 86/* 87 * Convert the logical block number of a file to its physical block number 88 * on the disk within ext4 extents. 89 */ 90int 91ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb) 92{ 93 struct inode *ip; 94 struct m_ext2fs *fs; 95 struct mount *mp; 96 struct ext2mount *ump; 97 struct ext4_extent_header *ehp; 98 struct ext4_extent *ep; 99 struct ext4_extent_path *path = NULL; 100 daddr_t lbn; 101 int error, depth, maxrun = 0, bsize; 102 103 ip = VTOI(vp); 104 fs = ip->i_e2fs; 105 mp = vp->v_mount; 106 ump = VFSTOEXT2(mp); 107 lbn = bn; 108 ehp = (struct ext4_extent_header *)ip->i_data; 109 depth = le16toh(ehp->eh_depth); 110 bsize = EXT2_BLOCK_SIZE(ump->um_e2fs); 111 112 *bnp = -1; 113 if (runp != NULL) { 114 maxrun = mp->mnt_iosize_max / bsize - 1; 115 *runp = 0; 116 } 117 if (runb != NULL) 118 *runb = 0; 119 120 error = ext4_ext_find_extent(ip, lbn, &path); 121 if (error) 122 return (error); 123 124 ep = path[depth].ep_ext; 125 if(ep) { 126 if (lbn < le32toh(ep->e_blk)) { 127 if (runp != NULL) { 128 *runp = min(maxrun, le32toh(ep->e_blk) - lbn - 1); 129 } 130 } else if (le32toh(ep->e_blk) <= lbn && 131 lbn < le32toh(ep->e_blk) + le16toh(ep->e_len)) { 132 *bnp = fsbtodb(fs, lbn - le32toh(ep->e_blk) + 133 (le32toh(ep->e_start_lo) | 134 (daddr_t)le16toh(ep->e_start_hi) << 32)); 135 if (runp != NULL) { 136 *runp = min(maxrun, 137 le16toh(ep->e_len) - 138 (lbn - le32toh(ep->e_blk)) - 1); 139 } 140 if (runb != NULL) 141 *runb = min(maxrun, lbn - le32toh(ep->e_blk)); 142 } else { 143 if (runb != NULL) 144 *runb = min(maxrun, le32toh(ep->e_blk) + lbn - 145 le16toh(ep->e_len)); 146 } 147 } 148 149 ext4_ext_path_free(path); 150 151 return (error); 152} 153 154static int 155readindir(struct vnode *vp, e2fs_lbn_t lbn, e2fs_daddr_t daddr, struct buf **bpp) 156{ 157 struct buf *bp; 158 struct mount *mp; 159 struct ext2mount *ump; 160 int error; 161 162 mp = vp->v_mount; 163 ump = VFSTOEXT2(mp); 164 165 bp = getblk(vp, lbn, mp->mnt_stat.f_iosize, 0, 0, 0); 166 if ((bp->b_flags & B_CACHE) == 0) { 167 KASSERT(daddr != 0, 168 ("readindir: indirect block not in cache")); 169 170 bp->b_blkno = blkptrtodb(ump, daddr); 171 bp->b_iocmd = BIO_READ; 172 bp->b_flags &= ~B_INVAL; 173 bp->b_ioflags &= ~BIO_ERROR; 174 vfs_busy_pages(bp, 0); 175 bp->b_iooffset = dbtob(bp->b_blkno); 176 bstrategy(bp); 177#ifdef RACCT 178 if (racct_enable) { 179 PROC_LOCK(curproc); 180 racct_add_buf(curproc, bp, 0); 181 PROC_UNLOCK(curproc); 182 } 183#endif 184 curthread->td_ru.ru_inblock++; 185 error = bufwait(bp); 186 if (error != 0) { 187 brelse(bp); 188 return (error); 189 } 190 } 191 *bpp = bp; 192 return (0); 193} 194 195/* 196 * Indirect blocks are now on the vnode for the file. They are given negative 197 * logical block numbers. Indirect blocks are addressed by the negative 198 * address of the first data block to which they point. Double indirect blocks 199 * are addressed by one less than the address of the first indirect block to 200 * which they point. Triple indirect blocks are addressed by one less than 201 * the address of the first double indirect block to which they point. 202 * 203 * ext2_bmaparray does the bmap conversion, and if requested returns the 204 * array of logical blocks which must be traversed to get to a block. 205 * Each entry contains the offset into that block that gets you to the 206 * next block and the disk address of the block (if it is assigned). 207 */ 208 209int 210ext2_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, int *runp, int *runb) 211{ 212 struct inode *ip; 213 struct buf *bp; 214 struct ext2mount *ump; 215 struct mount *mp; 216 struct indir a[EXT2_NIADDR + 1], *ap; 217 daddr_t daddr; 218 e2fs_lbn_t metalbn; 219 int error, num, maxrun = 0, bsize; 220 int *nump; 221 222 ap = NULL; 223 ip = VTOI(vp); 224 mp = vp->v_mount; 225 ump = VFSTOEXT2(mp); 226 227 bsize = EXT2_BLOCK_SIZE(ump->um_e2fs); 228 229 if (runp) { 230 maxrun = mp->mnt_iosize_max / bsize - 1; 231 *runp = 0; 232 } 233 if (runb) 234 *runb = 0; 235 236 ap = a; 237 nump = # 238 error = ext2_getlbns(vp, bn, ap, nump); 239 if (error) 240 return (error); 241 242 num = *nump; 243 if (num == 0) { 244 *bnp = blkptrtodb(ump, ip->i_db[bn]); 245 if (*bnp == 0) { 246 *bnp = -1; 247 } else if (runp) { 248 daddr_t bnb = bn; 249 250 for (++bn; bn < EXT2_NDADDR && *runp < maxrun && 251 is_sequential(ump, ip->i_db[bn - 1], ip->i_db[bn]); 252 ++bn, ++*runp); 253 bn = bnb; 254 if (runb && (bn > 0)) { 255 for (--bn; (bn >= 0) && (*runb < maxrun) && 256 is_sequential(ump, ip->i_db[bn], 257 ip->i_db[bn + 1]); 258 --bn, ++*runb); 259 } 260 } 261 return (0); 262 } 263 264 /* Get disk address out of indirect block array */ 265 daddr = ip->i_ib[ap->in_off]; 266 267 for (bp = NULL, ++ap; --num; ++ap) { 268 /* 269 * Exit the loop if there is no disk address assigned yet and 270 * the indirect block isn't in the cache, or if we were 271 * looking for an indirect block and we've found it. 272 */ 273 274 metalbn = ap->in_lbn; 275 if ((daddr == 0 && !incore(&vp->v_bufobj, metalbn)) || metalbn == bn) 276 break; 277 /* 278 * If we get here, we've either got the block in the cache 279 * or we have a disk address for it, go fetch it. 280 */ 281 if (bp) 282 bqrelse(bp); 283 error = readindir(vp, metalbn, daddr, &bp); 284 if (error != 0) 285 return (error); 286 287 daddr = le32toh(((e2fs_daddr_t *)bp->b_data)[ap->in_off]); 288 if (num == 1 && daddr && runp) { 289 for (bn = ap->in_off + 1; 290 bn < MNINDIR(ump) && *runp < maxrun && 291 is_sequential(ump, 292 ((e2fs_daddr_t *)bp->b_data)[bn - 1], 293 ((e2fs_daddr_t *)bp->b_data)[bn]); 294 ++bn, ++*runp); 295 bn = ap->in_off; 296 if (runb && bn) { 297 for (--bn; bn >= 0 && *runb < maxrun && 298 is_sequential(ump, 299 ((e2fs_daddr_t *)bp->b_data)[bn], 300 ((e2fs_daddr_t *)bp->b_data)[bn + 1]); 301 --bn, ++*runb); 302 } 303 } 304 } 305 if (bp) 306 bqrelse(bp); 307 308 *bnp = blkptrtodb(ump, daddr); 309 if (*bnp == 0) { 310 *bnp = -1; 311 } 312 return (0); 313} 314 315static e2fs_lbn_t 316lbn_count(struct ext2mount *ump, int level) 317 318{ 319 e2fs_lbn_t blockcnt; 320 321 for (blockcnt = 1; level > 0; level--) 322 blockcnt *= MNINDIR(ump); 323 return (blockcnt); 324} 325 326int 327ext2_bmap_seekdata(struct vnode *vp, off_t *offp) 328{ 329 struct buf *bp; 330 struct indir a[EXT2_NIADDR + 1], *ap; 331 struct inode *ip; 332 struct mount *mp; 333 struct ext2mount *ump; 334 e2fs_daddr_t bn, daddr, nextbn; 335 uint64_t bsize; 336 off_t numblks; 337 int error, num, num1, off; 338 339 bp = NULL; 340 error = 0; 341 ip = VTOI(vp); 342 mp = vp->v_mount; 343 ump = VFSTOEXT2(mp); 344 345 if (vp->v_type != VREG) 346 return (EINVAL); 347 if (*offp < 0 || *offp >= ip->i_size) 348 return (ENXIO); 349 350 bsize = mp->mnt_stat.f_iosize; 351 for (bn = *offp / bsize, numblks = howmany(ip->i_size, bsize); 352 bn < numblks; bn = nextbn) { 353 if (bn < EXT2_NDADDR) { 354 daddr = ip->i_db[bn]; 355 if (daddr != 0) 356 break; 357 nextbn = bn + 1; 358 continue; 359 } 360 361 ap = a; 362 error = ext2_getlbns(vp, bn, ap, &num); 363 if (error != 0) 364 break; 365 MPASS(num >= 2); 366 daddr = ip->i_ib[ap->in_off]; 367 ap++, num--; 368 for (nextbn = EXT2_NDADDR, num1 = num - 1; num1 > 0; num1--) 369 nextbn += lbn_count(ump, num1); 370 if (daddr == 0) { 371 nextbn += lbn_count(ump, num); 372 continue; 373 } 374 375 for (; daddr != 0 && num > 0; ap++, num--) { 376 if (bp != NULL) 377 bqrelse(bp); 378 error = readindir(vp, ap->in_lbn, daddr, &bp); 379 if (error != 0) 380 return (error); 381 382 /* 383 * Scan the indirect block until we find a non-zero 384 * pointer. 385 */ 386 off = ap->in_off; 387 do { 388 daddr = le32toh(((e2fs_daddr_t *)bp->b_data)[off]); 389 } while (daddr == 0 && ++off < MNINDIR(ump)); 390 nextbn += off * lbn_count(ump, num - 1); 391 392 /* 393 * We need to recompute the LBNs of indirect 394 * blocks, so restart with the updated block offset. 395 */ 396 if (off != ap->in_off) 397 break; 398 } 399 if (num == 0) { 400 /* 401 * We found a data block. 402 */ 403 bn = nextbn; 404 break; 405 } 406 } 407 if (bp != NULL) 408 bqrelse(bp); 409 if (bn >= numblks) 410 error = ENXIO; 411 if (error == 0 && *offp < bn * bsize) 412 *offp = bn * bsize; 413 return (error); 414} 415 416/* 417 * Create an array of logical block number/offset pairs which represent the 418 * path of indirect blocks required to access a data block. The first "pair" 419 * contains the logical block number of the appropriate single, double or 420 * triple indirect block and the offset into the inode indirect block array. 421 * Note, the logical block number of the inode single/double/triple indirect 422 * block appears twice in the array, once with the offset into the i_ib and 423 * once with the offset into the page itself. 424 */ 425int 426ext2_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) 427{ 428 long blockcnt; 429 e2fs_lbn_t metalbn, realbn; 430 struct ext2mount *ump; 431 int i, numlevels, off; 432 int64_t qblockcnt; 433 434 ump = VFSTOEXT2(vp->v_mount); 435 if (nump) 436 *nump = 0; 437 numlevels = 0; 438 realbn = bn; 439 if ((long)bn < 0) 440 bn = -(long)bn; 441 442 /* The first EXT2_NDADDR blocks are direct blocks. */ 443 if (bn < EXT2_NDADDR) 444 return (0); 445 446 /* 447 * Determine the number of levels of indirection. After this loop 448 * is done, blockcnt indicates the number of data blocks possible 449 * at the previous level of indirection, and EXT2_NIADDR - i is the 450 * number of levels of indirection needed to locate the requested block. 451 */ 452 for (blockcnt = 1, i = EXT2_NIADDR, bn -= EXT2_NDADDR; ; 453 i--, bn -= blockcnt) { 454 if (i == 0) 455 return (EFBIG); 456 /* 457 * Use int64_t's here to avoid overflow for triple indirect 458 * blocks when longs have 32 bits and the block size is more 459 * than 4K. 460 */ 461 qblockcnt = (int64_t)blockcnt * MNINDIR(ump); 462 if (bn < qblockcnt) 463 break; 464 blockcnt = qblockcnt; 465 } 466 467 /* Calculate the address of the first meta-block. */ 468 if (realbn >= 0) 469 metalbn = -(realbn - bn + EXT2_NIADDR - i); 470 else 471 metalbn = -(-realbn - bn + EXT2_NIADDR - i); 472 473 /* 474 * At each iteration, off is the offset into the bap array which is 475 * an array of disk addresses at the current level of indirection. 476 * The logical block number and the offset in that block are stored 477 * into the argument array. 478 */ 479 ap->in_lbn = metalbn; 480 ap->in_off = off = EXT2_NIADDR - i; 481 ap++; 482 for (++numlevels; i <= EXT2_NIADDR; i++) { 483 /* If searching for a meta-data block, quit when found. */ 484 if (metalbn == realbn) 485 break; 486 487 off = (bn / blockcnt) % MNINDIR(ump); 488 489 ++numlevels; 490 ap->in_lbn = metalbn; 491 ap->in_off = off; 492 ++ap; 493 494 metalbn -= -1 + off * blockcnt; 495 blockcnt /= MNINDIR(ump); 496 } 497 if (nump) 498 *nump = numlevels; 499 return (0); 500} 501