1/*- 2 * Copyright (c) 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)ufs_bmap.c 8.7 (Berkeley) 3/21/95 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD$"); 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/bio.h> 43#include <sys/buf.h> 44#include <sys/proc.h> 45#include <sys/vnode.h> 46#include <sys/mount.h> 47#include <sys/resourcevar.h> 48#include <sys/stat.h> 49 50#include <ufs/ufs/extattr.h> 51#include <ufs/ufs/quota.h> 52#include <ufs/ufs/inode.h> 53#include <ufs/ufs/ufsmount.h> 54#include <ufs/ufs/ufs_extern.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 62ufs_bmap(ap) 63 struct vop_bmap_args /* { 64 struct vnode *a_vp; 65 daddr_t a_bn; 66 struct bufobj **a_bop; 67 daddr_t *a_bnp; 68 int *a_runp; 69 int *a_runb; 70 } */ *ap; 71{ 72 ufs2_daddr_t blkno; 73 int error; 74 75 /* 76 * Check for underlying vnode requests and ensure that logical 77 * to physical mapping is requested. 78 */ 79 if (ap->a_bop != NULL) 80 *ap->a_bop = &VTOI(ap->a_vp)->i_devvp->v_bufobj; 81 if (ap->a_bnp == NULL) 82 return (0); 83 84 error = ufs_bmaparray(ap->a_vp, ap->a_bn, &blkno, NULL, 85 ap->a_runp, ap->a_runb); 86 *ap->a_bnp = blkno; 87 return (error); 88} 89 90/* 91 * Indirect blocks are now on the vnode for the file. They are given negative 92 * logical block numbers. Indirect blocks are addressed by the negative 93 * address of the first data block to which they point. Double indirect blocks 94 * are addressed by one less than the address of the first indirect block to 95 * which they point. Triple indirect blocks are addressed by one less than 96 * the address of the first double indirect block to which they point. 97 * 98 * ufs_bmaparray does the bmap conversion, and if requested returns the 99 * array of logical blocks which must be traversed to get to a block. 100 * Each entry contains the offset into that block that gets you to the 101 * next block and the disk address of the block (if it is assigned). 102 */ 103 104int 105ufs_bmaparray(vp, bn, bnp, nbp, runp, runb) 106 struct vnode *vp; 107 ufs2_daddr_t bn; 108 ufs2_daddr_t *bnp; 109 struct buf *nbp; 110 int *runp; 111 int *runb; 112{ 113 struct inode *ip; 114 struct buf *bp; 115 struct ufsmount *ump; 116 struct mount *mp; 117 struct vnode *devvp; 118 struct indir a[NIADDR+1], *ap; 119 ufs2_daddr_t daddr; 120 ufs_lbn_t metalbn; 121 int error, num, maxrun = 0; 122 int *nump; 123 124 ap = NULL; 125 ip = VTOI(vp); 126 mp = vp->v_mount; 127 ump = VFSTOUFS(mp); 128 devvp = ump->um_devvp; 129 130 if (runp) { 131 maxrun = mp->mnt_iosize_max / mp->mnt_stat.f_iosize - 1; 132 *runp = 0; 133 } 134 135 if (runb) { 136 *runb = 0; 137 } 138 139 140 ap = a; 141 nump = # 142 error = ufs_getlbns(vp, bn, ap, nump); 143 if (error) 144 return (error); 145 146 num = *nump; 147 if (num == 0) { 148 if (bn >= 0 && bn < NDADDR) { 149 *bnp = blkptrtodb(ump, DIP(ip, i_db[bn])); 150 } else if (bn < 0 && bn >= -NXADDR) { 151 *bnp = blkptrtodb(ump, ip->i_din2->di_extb[-1 - bn]); 152 if (*bnp == 0) 153 *bnp = -1; 154 if (nbp == NULL) 155 panic("ufs_bmaparray: mapping ext data"); 156 nbp->b_xflags |= BX_ALTDATA; 157 return (0); 158 } else { 159 panic("ufs_bmaparray: blkno out of range"); 160 } 161 /* 162 * Since this is FFS independent code, we are out of 163 * scope for the definitions of BLK_NOCOPY and 164 * BLK_SNAP, but we do know that they will fall in 165 * the range 1..um_seqinc, so we use that test and 166 * return a request for a zeroed out buffer if attempts 167 * are made to read a BLK_NOCOPY or BLK_SNAP block. 168 */ 169 if ((ip->i_flags & SF_SNAPSHOT) && DIP(ip, i_db[bn]) > 0 && 170 DIP(ip, i_db[bn]) < ump->um_seqinc) { 171 *bnp = -1; 172 } else if (*bnp == 0) { 173 if (ip->i_flags & SF_SNAPSHOT) 174 *bnp = blkptrtodb(ump, bn * ump->um_seqinc); 175 else 176 *bnp = -1; 177 } else if (runp) { 178 ufs2_daddr_t bnb = bn; 179 for (++bn; bn < NDADDR && *runp < maxrun && 180 is_sequential(ump, DIP(ip, i_db[bn - 1]), 181 DIP(ip, i_db[bn])); 182 ++bn, ++*runp); 183 bn = bnb; 184 if (runb && (bn > 0)) { 185 for (--bn; (bn >= 0) && (*runb < maxrun) && 186 is_sequential(ump, DIP(ip, i_db[bn]), 187 DIP(ip, i_db[bn+1])); 188 --bn, ++*runb); 189 } 190 } 191 return (0); 192 } 193 194 195 /* Get disk address out of indirect block array */ 196 daddr = DIP(ip, i_ib[ap->in_off]); 197 198 for (bp = NULL, ++ap; --num; ++ap) { 199 /* 200 * Exit the loop if there is no disk address assigned yet and 201 * the indirect block isn't in the cache, or if we were 202 * looking for an indirect block and we've found it. 203 */ 204 205 metalbn = ap->in_lbn; 206 if ((daddr == 0 && !incore(&vp->v_bufobj, metalbn)) || metalbn == bn) 207 break; 208 /* 209 * If we get here, we've either got the block in the cache 210 * or we have a disk address for it, go fetch it. 211 */ 212 if (bp) 213 bqrelse(bp); 214 215 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0, 0); 216 if ((bp->b_flags & B_CACHE) == 0) { 217#ifdef INVARIANTS 218 if (!daddr) 219 panic("ufs_bmaparray: indirect block not in cache"); 220#endif 221 bp->b_blkno = blkptrtodb(ump, daddr); 222 bp->b_iocmd = BIO_READ; 223 bp->b_flags &= ~B_INVAL; 224 bp->b_ioflags &= ~BIO_ERROR; 225 vfs_busy_pages(bp, 0); 226 bp->b_iooffset = dbtob(bp->b_blkno); 227 bstrategy(bp); 228 curthread->td_ru.ru_inblock++; 229 error = bufwait(bp); 230 if (error) { 231 brelse(bp); 232 return (error); 233 } 234 } 235 236 if (ip->i_ump->um_fstype == UFS1) { 237 daddr = ((ufs1_daddr_t *)bp->b_data)[ap->in_off]; 238 if (num == 1 && daddr && runp) { 239 for (bn = ap->in_off + 1; 240 bn < MNINDIR(ump) && *runp < maxrun && 241 is_sequential(ump, 242 ((ufs1_daddr_t *)bp->b_data)[bn - 1], 243 ((ufs1_daddr_t *)bp->b_data)[bn]); 244 ++bn, ++*runp); 245 bn = ap->in_off; 246 if (runb && bn) { 247 for (--bn; bn >= 0 && *runb < maxrun && 248 is_sequential(ump, 249 ((ufs1_daddr_t *)bp->b_data)[bn], 250 ((ufs1_daddr_t *)bp->b_data)[bn+1]); 251 --bn, ++*runb); 252 } 253 } 254 continue; 255 } 256 daddr = ((ufs2_daddr_t *)bp->b_data)[ap->in_off]; 257 if (num == 1 && daddr && runp) { 258 for (bn = ap->in_off + 1; 259 bn < MNINDIR(ump) && *runp < maxrun && 260 is_sequential(ump, 261 ((ufs2_daddr_t *)bp->b_data)[bn - 1], 262 ((ufs2_daddr_t *)bp->b_data)[bn]); 263 ++bn, ++*runp); 264 bn = ap->in_off; 265 if (runb && bn) { 266 for (--bn; bn >= 0 && *runb < maxrun && 267 is_sequential(ump, 268 ((ufs2_daddr_t *)bp->b_data)[bn], 269 ((ufs2_daddr_t *)bp->b_data)[bn + 1]); 270 --bn, ++*runb); 271 } 272 } 273 } 274 if (bp) 275 bqrelse(bp); 276 277 /* 278 * Since this is FFS independent code, we are out of scope for the 279 * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they 280 * will fall in the range 1..um_seqinc, so we use that test and 281 * return a request for a zeroed out buffer if attempts are made 282 * to read a BLK_NOCOPY or BLK_SNAP block. 283 */ 284 if ((ip->i_flags & SF_SNAPSHOT) && daddr > 0 && daddr < ump->um_seqinc){ 285 *bnp = -1; 286 return (0); 287 } 288 *bnp = blkptrtodb(ump, daddr); 289 if (*bnp == 0) { 290 if (ip->i_flags & SF_SNAPSHOT) 291 *bnp = blkptrtodb(ump, bn * ump->um_seqinc); 292 else 293 *bnp = -1; 294 } 295 return (0); 296} 297 298/* 299 * Create an array of logical block number/offset pairs which represent the 300 * path of indirect blocks required to access a data block. The first "pair" 301 * contains the logical block number of the appropriate single, double or 302 * triple indirect block and the offset into the inode indirect block array. 303 * Note, the logical block number of the inode single/double/triple indirect 304 * block appears twice in the array, once with the offset into the i_ib and 305 * once with the offset into the page itself. 306 */ 307int 308ufs_getlbns(vp, bn, ap, nump) 309 struct vnode *vp; 310 ufs2_daddr_t bn; 311 struct indir *ap; 312 int *nump; 313{ 314 ufs2_daddr_t blockcnt; 315 ufs_lbn_t metalbn, realbn; 316 struct ufsmount *ump; 317 int i, numlevels, off; 318 319 ump = VFSTOUFS(vp->v_mount); 320 if (nump) 321 *nump = 0; 322 numlevels = 0; 323 realbn = bn; 324 if (bn < 0) 325 bn = -bn; 326 327 /* The first NDADDR blocks are direct blocks. */ 328 if (bn < NDADDR) 329 return (0); 330 331 /* 332 * Determine the number of levels of indirection. After this loop 333 * is done, blockcnt indicates the number of data blocks possible 334 * at the previous level of indirection, and NIADDR - i is the number 335 * of levels of indirection needed to locate the requested block. 336 */ 337 for (blockcnt = 1, i = NIADDR, bn -= NDADDR;; i--, bn -= blockcnt) { 338 if (i == 0) 339 return (EFBIG); 340 blockcnt *= MNINDIR(ump); 341 if (bn < blockcnt) 342 break; 343 } 344 345 /* Calculate the address of the first meta-block. */ 346 if (realbn >= 0) 347 metalbn = -(realbn - bn + NIADDR - i); 348 else 349 metalbn = -(-realbn - bn + NIADDR - i); 350 351 /* 352 * At each iteration, off is the offset into the bap array which is 353 * an array of disk addresses at the current level of indirection. 354 * The logical block number and the offset in that block are stored 355 * into the argument array. 356 */ 357 ap->in_lbn = metalbn; 358 ap->in_off = off = NIADDR - i; 359 ap++; 360 for (++numlevels; i <= NIADDR; i++) { 361 /* If searching for a meta-data block, quit when found. */ 362 if (metalbn == realbn) 363 break; 364 365 blockcnt /= MNINDIR(ump); 366 off = (bn / blockcnt) % MNINDIR(ump); 367 368 ++numlevels; 369 ap->in_lbn = metalbn; 370 ap->in_off = off; 371 ++ap; 372 373 metalbn -= -1 + off * blockcnt; 374 } 375 if (nump) 376 *nump = numlevels; 377 return (0); 378} 379