| 1 | /* $NetBSD: ulfs_bmap.c,v 1.7 2015/09/01 06:08:37 dholland Exp $ */ |
| 2 | /* from NetBSD: ufs_bmap.c,v 1.50 2013/01/22 09:39:18 dholland Exp */ |
| 3 | |
| 4 | /* |
| 5 | * Copyright (c) 1989, 1991, 1993 |
| 6 | * The Regents of the University of California. All rights reserved. |
| 7 | * (c) UNIX System Laboratories, Inc. |
| 8 | * All or some portions of this file are derived from material licensed |
| 9 | * to the University of California by American Telephone and Telegraph |
| 10 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 11 | * the permission of UNIX System Laboratories, Inc. |
| 12 | * |
| 13 | * Redistribution and use in source and binary forms, with or without |
| 14 | * modification, are permitted provided that the following conditions |
| 15 | * are met: |
| 16 | * 1. Redistributions of source code must retain the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer. |
| 18 | * 2. Redistributions in binary form must reproduce the above copyright |
| 19 | * notice, this list of conditions and the following disclaimer in the |
| 20 | * documentation and/or other materials provided with the distribution. |
| 21 | * 3. Neither the name of the University nor the names of its contributors |
| 22 | * may be used to endorse or promote products derived from this software |
| 23 | * without specific prior written permission. |
| 24 | * |
| 25 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 26 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 29 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 30 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 31 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 32 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 33 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 34 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 35 | * SUCH DAMAGE. |
| 36 | * |
| 37 | * @(#)ufs_bmap.c 8.8 (Berkeley) 8/11/95 |
| 38 | */ |
| 39 | |
| 40 | #include <sys/cdefs.h> |
| 41 | __KERNEL_RCSID(0, "$NetBSD: ulfs_bmap.c,v 1.7 2015/09/01 06:08:37 dholland Exp $" ); |
| 42 | |
| 43 | #include <sys/param.h> |
| 44 | #include <sys/systm.h> |
| 45 | #include <sys/stat.h> |
| 46 | #include <sys/buf.h> |
| 47 | #include <sys/proc.h> |
| 48 | #include <sys/vnode.h> |
| 49 | #include <sys/mount.h> |
| 50 | #include <sys/resourcevar.h> |
| 51 | #include <sys/trace.h> |
| 52 | #include <sys/fstrans.h> |
| 53 | |
| 54 | #include <miscfs/specfs/specdev.h> |
| 55 | |
| 56 | #include <ufs/lfs/ulfs_inode.h> |
| 57 | #include <ufs/lfs/ulfsmount.h> |
| 58 | #include <ufs/lfs/ulfs_extern.h> |
| 59 | #include <ufs/lfs/ulfs_bswap.h> |
| 60 | |
| 61 | static bool |
| 62 | ulfs_issequential(const struct lfs *fs, daddr_t daddr0, daddr_t daddr1) |
| 63 | { |
| 64 | |
| 65 | /* for ulfs, blocks in a hole is not 'contiguous'. */ |
| 66 | if (daddr0 == 0) |
| 67 | return false; |
| 68 | |
| 69 | return (daddr0 + fs->um_seqinc == daddr1); |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * This is used for block pointers in inodes and elsewhere, which can |
| 74 | * contain the magic value UNWRITTEN, which is -2. This is mishandled |
| 75 | * by u32 -> u64 promotion unless special-cased. |
| 76 | * |
| 77 | * XXX this should be rolled into better inode accessors and go away. |
| 78 | */ |
| 79 | static inline uint64_t |
| 80 | ulfs_fix_unwritten(uint32_t val) |
| 81 | { |
| 82 | if (val == (uint32_t)UNWRITTEN) { |
| 83 | return (uint64_t)(int64_t)UNWRITTEN; |
| 84 | } else { |
| 85 | return val; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | |
| 90 | /* |
| 91 | * Bmap converts the logical block number of a file to its physical block |
| 92 | * number on the disk. The conversion is done by using the logical block |
| 93 | * number to index into the array of block pointers described by the dinode. |
| 94 | */ |
| 95 | int |
| 96 | ulfs_bmap(void *v) |
| 97 | { |
| 98 | struct vop_bmap_args /* { |
| 99 | struct vnode *a_vp; |
| 100 | daddr_t a_bn; |
| 101 | struct vnode **a_vpp; |
| 102 | daddr_t *a_bnp; |
| 103 | int *a_runp; |
| 104 | } */ *ap = v; |
| 105 | int error; |
| 106 | |
| 107 | /* |
| 108 | * Check for underlying vnode requests and ensure that logical |
| 109 | * to physical mapping is requested. |
| 110 | */ |
| 111 | if (ap->a_vpp != NULL) |
| 112 | *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; |
| 113 | if (ap->a_bnp == NULL) |
| 114 | return (0); |
| 115 | |
| 116 | fstrans_start(ap->a_vp->v_mount, FSTRANS_SHARED); |
| 117 | error = ulfs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, |
| 118 | ap->a_runp, ulfs_issequential); |
| 119 | fstrans_done(ap->a_vp->v_mount); |
| 120 | return error; |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * Indirect blocks are now on the vnode for the file. They are given negative |
| 125 | * logical block numbers. Indirect blocks are addressed by the negative |
| 126 | * address of the first data block to which they point. Double indirect blocks |
| 127 | * are addressed by one less than the address of the first indirect block to |
| 128 | * which they point. Triple indirect blocks are addressed by one less than |
| 129 | * the address of the first double indirect block to which they point. |
| 130 | * |
| 131 | * ulfs_bmaparray does the bmap conversion, and if requested returns the |
| 132 | * array of logical blocks which must be traversed to get to a block. |
| 133 | * Each entry contains the offset into that block that gets you to the |
| 134 | * next block and the disk address of the block (if it is assigned). |
| 135 | */ |
| 136 | |
| 137 | int |
| 138 | ulfs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, |
| 139 | int *nump, int *runp, ulfs_issequential_callback_t is_sequential) |
| 140 | { |
| 141 | struct inode *ip; |
| 142 | struct buf *bp, *cbp; |
| 143 | struct ulfsmount *ump; |
| 144 | struct lfs *fs; |
| 145 | struct mount *mp; |
| 146 | struct indir a[ULFS_NIADDR + 1], *xap; |
| 147 | daddr_t daddr; |
| 148 | daddr_t metalbn; |
| 149 | int error, maxrun = 0, num; |
| 150 | |
| 151 | ip = VTOI(vp); |
| 152 | mp = vp->v_mount; |
| 153 | ump = ip->i_ump; |
| 154 | fs = ip->i_lfs; |
| 155 | #ifdef DIAGNOSTIC |
| 156 | if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) |
| 157 | panic("ulfs_bmaparray: invalid arguments" ); |
| 158 | #endif |
| 159 | |
| 160 | if (runp) { |
| 161 | /* |
| 162 | * XXX |
| 163 | * If MAXBSIZE is the largest transfer the disks can handle, |
| 164 | * we probably want maxrun to be 1 block less so that we |
| 165 | * don't create a block larger than the device can handle. |
| 166 | */ |
| 167 | *runp = 0; |
| 168 | maxrun = MAXPHYS / mp->mnt_stat.f_iosize - 1; |
| 169 | } |
| 170 | |
| 171 | if (bn >= 0 && bn < ULFS_NDADDR) { |
| 172 | if (nump != NULL) |
| 173 | *nump = 0; |
| 174 | if (ump->um_fstype == ULFS1) |
| 175 | daddr = ulfs_fix_unwritten(ulfs_rw32(ip->i_din->u_32.di_db[bn], |
| 176 | ULFS_MPNEEDSWAP(fs))); |
| 177 | else |
| 178 | daddr = ulfs_rw64(ip->i_din->u_64.di_db[bn], |
| 179 | ULFS_MPNEEDSWAP(fs)); |
| 180 | *bnp = blkptrtodb(fs, daddr); |
| 181 | /* |
| 182 | * Since this is FFS independent code, we are out of |
| 183 | * scope for the definitions of BLK_NOCOPY and |
| 184 | * BLK_SNAP, but we do know that they will fall in |
| 185 | * the range 1..um_seqinc, so we use that test and |
| 186 | * return a request for a zeroed out buffer if attempts |
| 187 | * are made to read a BLK_NOCOPY or BLK_SNAP block. |
| 188 | */ |
| 189 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) == SF_SNAPSHOT |
| 190 | && daddr > 0 && |
| 191 | daddr < fs->um_seqinc) { |
| 192 | *bnp = -1; |
| 193 | } else if (*bnp == 0) { |
| 194 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) |
| 195 | == SF_SNAPSHOT) { |
| 196 | *bnp = blkptrtodb(fs, bn * fs->um_seqinc); |
| 197 | } else { |
| 198 | *bnp = -1; |
| 199 | } |
| 200 | } else if (runp) { |
| 201 | if (ump->um_fstype == ULFS1) { |
| 202 | for (++bn; bn < ULFS_NDADDR && *runp < maxrun && |
| 203 | is_sequential(fs, |
| 204 | ulfs_fix_unwritten(ulfs_rw32(ip->i_din->u_32.di_db[bn - 1], |
| 205 | ULFS_MPNEEDSWAP(fs))), |
| 206 | ulfs_fix_unwritten(ulfs_rw32(ip->i_din->u_32.di_db[bn], |
| 207 | ULFS_MPNEEDSWAP(fs)))); |
| 208 | ++bn, ++*runp); |
| 209 | } else { |
| 210 | for (++bn; bn < ULFS_NDADDR && *runp < maxrun && |
| 211 | is_sequential(fs, |
| 212 | ulfs_rw64(ip->i_din->u_64.di_db[bn - 1], |
| 213 | ULFS_MPNEEDSWAP(fs)), |
| 214 | ulfs_rw64(ip->i_din->u_64.di_db[bn], |
| 215 | ULFS_MPNEEDSWAP(fs))); |
| 216 | ++bn, ++*runp); |
| 217 | } |
| 218 | } |
| 219 | return (0); |
| 220 | } |
| 221 | |
| 222 | xap = ap == NULL ? a : ap; |
| 223 | if (!nump) |
| 224 | nump = # |
| 225 | if ((error = ulfs_getlbns(vp, bn, xap, nump)) != 0) |
| 226 | return (error); |
| 227 | |
| 228 | num = *nump; |
| 229 | |
| 230 | /* Get disk address out of indirect block array */ |
| 231 | // XXX clean this up |
| 232 | if (ump->um_fstype == ULFS1) |
| 233 | daddr = ulfs_fix_unwritten(ulfs_rw32(ip->i_din->u_32.di_ib[xap->in_off], |
| 234 | ULFS_MPNEEDSWAP(fs))); |
| 235 | else |
| 236 | daddr = ulfs_rw64(ip->i_din->u_64.di_ib[xap->in_off], |
| 237 | ULFS_MPNEEDSWAP(fs)); |
| 238 | |
| 239 | for (bp = NULL, ++xap; --num; ++xap) { |
| 240 | /* |
| 241 | * Exit the loop if there is no disk address assigned yet and |
| 242 | * the indirect block isn't in the cache, or if we were |
| 243 | * looking for an indirect block and we've found it. |
| 244 | */ |
| 245 | |
| 246 | metalbn = xap->in_lbn; |
| 247 | if (metalbn == bn) |
| 248 | break; |
| 249 | if (daddr == 0) { |
| 250 | mutex_enter(&bufcache_lock); |
| 251 | cbp = incore(vp, metalbn); |
| 252 | mutex_exit(&bufcache_lock); |
| 253 | if (cbp == NULL) |
| 254 | break; |
| 255 | } |
| 256 | |
| 257 | /* |
| 258 | * If we get here, we've either got the block in the cache |
| 259 | * or we have a disk address for it, go fetch it. |
| 260 | */ |
| 261 | if (bp) |
| 262 | brelse(bp, 0); |
| 263 | |
| 264 | xap->in_exists = 1; |
| 265 | bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); |
| 266 | if (bp == NULL) { |
| 267 | |
| 268 | /* |
| 269 | * getblk() above returns NULL only iff we are |
| 270 | * pagedaemon. See the implementation of getblk |
| 271 | * for detail. |
| 272 | */ |
| 273 | |
| 274 | return (ENOMEM); |
| 275 | } |
| 276 | if (bp->b_oflags & (BO_DONE | BO_DELWRI)) { |
| 277 | trace(TR_BREADHIT, pack(vp, size), metalbn); |
| 278 | } |
| 279 | #ifdef DIAGNOSTIC |
| 280 | else if (!daddr) |
| 281 | panic("ulfs_bmaparray: indirect block not in cache" ); |
| 282 | #endif |
| 283 | else { |
| 284 | trace(TR_BREADMISS, pack(vp, size), metalbn); |
| 285 | bp->b_blkno = blkptrtodb(fs, daddr); |
| 286 | bp->b_flags |= B_READ; |
| 287 | BIO_SETPRIO(bp, BPRIO_TIMECRITICAL); |
| 288 | VOP_STRATEGY(vp, bp); |
| 289 | curlwp->l_ru.ru_inblock++; /* XXX */ |
| 290 | if ((error = biowait(bp)) != 0) { |
| 291 | brelse(bp, 0); |
| 292 | return (error); |
| 293 | } |
| 294 | } |
| 295 | if (ump->um_fstype == ULFS1) { |
| 296 | daddr = ulfs_fix_unwritten(ulfs_rw32(((u_int32_t *)bp->b_data)[xap->in_off], |
| 297 | ULFS_MPNEEDSWAP(fs))); |
| 298 | if (num == 1 && daddr && runp) { |
| 299 | for (bn = xap->in_off + 1; |
| 300 | bn < MNINDIR(fs) && *runp < maxrun && |
| 301 | is_sequential(fs, |
| 302 | ulfs_fix_unwritten(ulfs_rw32(((int32_t *)bp->b_data)[bn-1], |
| 303 | ULFS_MPNEEDSWAP(fs))), |
| 304 | ulfs_fix_unwritten(ulfs_rw32(((int32_t *)bp->b_data)[bn], |
| 305 | ULFS_MPNEEDSWAP(fs)))); |
| 306 | ++bn, ++*runp); |
| 307 | } |
| 308 | } else { |
| 309 | daddr = ulfs_rw64(((u_int64_t *)bp->b_data)[xap->in_off], |
| 310 | ULFS_MPNEEDSWAP(fs)); |
| 311 | if (num == 1 && daddr && runp) { |
| 312 | for (bn = xap->in_off + 1; |
| 313 | bn < MNINDIR(fs) && *runp < maxrun && |
| 314 | is_sequential(fs, |
| 315 | ulfs_rw64(((int64_t *)bp->b_data)[bn-1], |
| 316 | ULFS_MPNEEDSWAP(fs)), |
| 317 | ulfs_rw64(((int64_t *)bp->b_data)[bn], |
| 318 | ULFS_MPNEEDSWAP(fs))); |
| 319 | ++bn, ++*runp); |
| 320 | } |
| 321 | } |
| 322 | } |
| 323 | if (bp) |
| 324 | brelse(bp, 0); |
| 325 | |
| 326 | /* |
| 327 | * Since this is FFS independent code, we are out of scope for the |
| 328 | * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they |
| 329 | * will fall in the range 1..um_seqinc, so we use that test and |
| 330 | * return a request for a zeroed out buffer if attempts are made |
| 331 | * to read a BLK_NOCOPY or BLK_SNAP block. |
| 332 | */ |
| 333 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) == SF_SNAPSHOT |
| 334 | && daddr > 0 && daddr < fs->um_seqinc) { |
| 335 | *bnp = -1; |
| 336 | return (0); |
| 337 | } |
| 338 | *bnp = blkptrtodb(fs, daddr); |
| 339 | if (*bnp == 0) { |
| 340 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) |
| 341 | == SF_SNAPSHOT) { |
| 342 | *bnp = blkptrtodb(fs, bn * fs->um_seqinc); |
| 343 | } else { |
| 344 | *bnp = -1; |
| 345 | } |
| 346 | } |
| 347 | return (0); |
| 348 | } |
| 349 | |
| 350 | /* |
| 351 | * Create an array of logical block number/offset pairs which represent the |
| 352 | * path of indirect blocks required to access a data block. The first "pair" |
| 353 | * contains the logical block number of the appropriate single, double or |
| 354 | * triple indirect block and the offset into the inode indirect block array. |
| 355 | * Note, the logical block number of the inode single/double/triple indirect |
| 356 | * block appears twice in the array, once with the offset into the i_ffs1_ib and |
| 357 | * once with the offset into the page itself. |
| 358 | */ |
| 359 | int |
| 360 | ulfs_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) |
| 361 | { |
| 362 | daddr_t metalbn, realbn; |
| 363 | struct ulfsmount *ump; |
| 364 | struct lfs *fs; |
| 365 | int64_t blockcnt; |
| 366 | int lbc; |
| 367 | int i, numlevels, off; |
| 368 | |
| 369 | ump = VFSTOULFS(vp->v_mount); |
| 370 | fs = ump->um_lfs; |
| 371 | if (nump) |
| 372 | *nump = 0; |
| 373 | numlevels = 0; |
| 374 | realbn = bn; |
| 375 | if (bn < 0) |
| 376 | bn = -bn; |
| 377 | KASSERT(bn >= ULFS_NDADDR); |
| 378 | |
| 379 | /* |
| 380 | * Determine the number of levels of indirection. After this loop |
| 381 | * is done, blockcnt indicates the number of data blocks possible |
| 382 | * at the given level of indirection, and ULFS_NIADDR - i is the number |
| 383 | * of levels of indirection needed to locate the requested block. |
| 384 | */ |
| 385 | |
| 386 | bn -= ULFS_NDADDR; |
| 387 | for (lbc = 0, i = ULFS_NIADDR;; i--, bn -= blockcnt) { |
| 388 | if (i == 0) |
| 389 | return (EFBIG); |
| 390 | |
| 391 | lbc += fs->um_lognindir; |
| 392 | blockcnt = (int64_t)1 << lbc; |
| 393 | |
| 394 | if (bn < blockcnt) |
| 395 | break; |
| 396 | } |
| 397 | |
| 398 | /* Calculate the address of the first meta-block. */ |
| 399 | metalbn = -((realbn >= 0 ? realbn : -realbn) - bn + ULFS_NIADDR - i); |
| 400 | |
| 401 | /* |
| 402 | * At each iteration, off is the offset into the bap array which is |
| 403 | * an array of disk addresses at the current level of indirection. |
| 404 | * The logical block number and the offset in that block are stored |
| 405 | * into the argument array. |
| 406 | */ |
| 407 | ap->in_lbn = metalbn; |
| 408 | ap->in_off = off = ULFS_NIADDR - i; |
| 409 | ap->in_exists = 0; |
| 410 | ap++; |
| 411 | for (++numlevels; i <= ULFS_NIADDR; i++) { |
| 412 | /* If searching for a meta-data block, quit when found. */ |
| 413 | if (metalbn == realbn) |
| 414 | break; |
| 415 | |
| 416 | lbc -= fs->um_lognindir; |
| 417 | off = (bn >> lbc) & (MNINDIR(fs) - 1); |
| 418 | |
| 419 | ++numlevels; |
| 420 | ap->in_lbn = metalbn; |
| 421 | ap->in_off = off; |
| 422 | ap->in_exists = 0; |
| 423 | ++ap; |
| 424 | |
| 425 | metalbn -= -1 + ((int64_t)off << lbc); |
| 426 | } |
| 427 | if (nump) |
| 428 | *nump = numlevels; |
| 429 | return (0); |
| 430 | } |
| 431 | |