| File: | ufs/ufs/ufs_bmap.c |
| Warning: | line 280, column 15 Although the value stored to 'off' is used in the enclosing expression, the value is never actually read from 'off' |
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| 1 | /* $OpenBSD: ufs_bmap.c,v 1.37 2021/12/12 09:14:59 visa Exp $ */ |
| 2 | /* $NetBSD: ufs_bmap.c,v 1.3 1996/02/09 22:36:00 christos 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 8.6 (Berkeley) 1/21/94 |
| 38 | */ |
| 39 | |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/systm.h> |
| 42 | #include <sys/buf.h> |
| 43 | #include <sys/proc.h> |
| 44 | #include <sys/vnode.h> |
| 45 | #include <sys/mount.h> |
| 46 | #include <sys/specdev.h> |
| 47 | |
| 48 | #include <ufs/ufs/quota.h> |
| 49 | #include <ufs/ufs/inode.h> |
| 50 | #include <ufs/ufs/ufsmount.h> |
| 51 | #include <ufs/ufs/ufs_extern.h> |
| 52 | |
| 53 | /* |
| 54 | * Bmap converts a the logical block number of a file to its physical block |
| 55 | * number on the disk. The conversion is done by using the logical block |
| 56 | * number to index into the array of block pointers described by the dinode. |
| 57 | */ |
| 58 | int |
| 59 | ufs_bmap(void *v) |
| 60 | { |
| 61 | struct vop_bmap_args *ap = v; |
| 62 | |
| 63 | /* |
| 64 | * Check for underlying vnode requests and ensure that logical |
| 65 | * to physical mapping is requested. |
| 66 | */ |
| 67 | if (ap->a_vpp != NULL((void *)0)) |
| 68 | *ap->a_vpp = VTOI(ap->a_vp)((struct inode *)(ap->a_vp)->v_data)->i_devvpi_ump->um_devvp; |
| 69 | if (ap->a_bnp == NULL((void *)0)) |
| 70 | return (0); |
| 71 | |
| 72 | return (ufs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL((void *)0), NULL((void *)0), |
| 73 | ap->a_runp)); |
| 74 | } |
| 75 | |
| 76 | /* |
| 77 | * Indirect blocks are now on the vnode for the file. They are given negative |
| 78 | * logical block numbers. Indirect blocks are addressed by the negative |
| 79 | * address of the first data block to which they point. Double indirect blocks |
| 80 | * are addressed by one less than the address of the first indirect block to |
| 81 | * which they point. Triple indirect blocks are addressed by one less than |
| 82 | * the address of the first double indirect block to which they point. |
| 83 | * |
| 84 | * ufs_bmaparray does the bmap conversion, and if requested returns the |
| 85 | * array of logical blocks which must be traversed to get to a block. |
| 86 | * Each entry contains the offset into that block that gets you to the |
| 87 | * next block and the disk address of the block (if it is assigned). |
| 88 | */ |
| 89 | int |
| 90 | ufs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, |
| 91 | int *nump, int *runp) |
| 92 | { |
| 93 | struct inode *ip; |
| 94 | struct buf *bp; |
| 95 | struct ufsmount *ump; |
| 96 | struct mount *mp; |
| 97 | struct vnode *devvp; |
| 98 | struct indir a[NIADDR3+1], *xap; |
| 99 | daddr_t daddr, metalbn; |
| 100 | int error, maxrun = 0, num; |
| 101 | |
| 102 | ip = VTOI(vp)((struct inode *)(vp)->v_data); |
| 103 | mp = vp->v_mount; |
| 104 | ump = VFSTOUFS(mp)((struct ufsmount *)((mp)->mnt_data)); |
| 105 | #ifdef DIAGNOSTIC1 |
| 106 | if ((ap != NULL((void *)0) && nump == NULL((void *)0)) || (ap == NULL((void *)0) && nump != NULL((void *)0))) |
| 107 | panic("ufs_bmaparray: invalid arguments"); |
| 108 | #endif |
| 109 | |
| 110 | if (runp) { |
| 111 | /* |
| 112 | * XXX |
| 113 | * If MAXBSIZE is the largest transfer the disks can handle, |
| 114 | * we probably want maxrun to be 1 block less so that we |
| 115 | * don't create a block larger than the device can handle. |
| 116 | */ |
| 117 | *runp = 0; |
| 118 | maxrun = MAXBSIZE(64 * 1024) / mp->mnt_stat.f_iosize - 1; |
| 119 | } |
| 120 | |
| 121 | xap = ap == NULL((void *)0) ? a : ap; |
| 122 | if (!nump) |
| 123 | nump = # |
| 124 | if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) |
| 125 | return (error); |
| 126 | |
| 127 | num = *nump; |
| 128 | if (num == 0) { |
| 129 | *bnp = blkptrtodb(ump, DIP(ip, db[bn]))(((((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_db[bn] : (ip)->dinode_u.ffs2_din->di_db[bn])) << (ump)->um_bptrtodb); |
| 130 | if (*bnp == 0) |
| 131 | *bnp = -1; |
| 132 | else if (runp) |
| 133 | for (++bn; bn < NDADDR12 && *runp < maxrun && |
| 134 | is_sequential(ump, DIP(ip, db[bn - 1]),(((((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_db[bn] : (ip)->dinode_u.ffs2_din->di_db[bn])) == ((((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_db[bn - 1] : (ip)->dinode_u.ffs2_din->di_db[bn - 1])) + ump->um_seqinc) |
| 135 | DIP(ip, db[bn]))(((((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_db[bn] : (ip)->dinode_u.ffs2_din->di_db[bn])) == ((((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_db[bn - 1] : (ip)->dinode_u.ffs2_din->di_db[bn - 1])) + ump->um_seqinc); |
| 136 | ++bn, ++*runp); |
| 137 | return (0); |
| 138 | } |
| 139 | |
| 140 | |
| 141 | /* Get disk address out of indirect block array */ |
| 142 | daddr = DIP(ip, ib[xap->in_off])(((ip)->i_ump->um_fstype == 1) ? (ip)->dinode_u.ffs1_din ->di_ib[xap->in_off] : (ip)->dinode_u.ffs2_din->di_ib [xap->in_off]); |
| 143 | |
| 144 | devvp = VFSTOUFS(vp->v_mount)((struct ufsmount *)((vp->v_mount)->mnt_data))->um_devvp; |
| 145 | for (bp = NULL((void *)0), ++xap; --num; ++xap) { |
| 146 | /* |
| 147 | * Exit the loop if there is no disk address assigned yet and |
| 148 | * the indirect block isn't in the cache, or if we were |
| 149 | * looking for an indirect block and we've found it. |
| 150 | */ |
| 151 | |
| 152 | metalbn = xap->in_lbn; |
| 153 | if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) |
| 154 | break; |
| 155 | /* |
| 156 | * If we get here, we've either got the block in the cache |
| 157 | * or we have a disk address for it, go fetch it. |
| 158 | */ |
| 159 | if (bp) |
| 160 | brelse(bp); |
| 161 | |
| 162 | xap->in_exists = 1; |
| 163 | bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, INFSLP0xffffffffffffffffULL); |
| 164 | if (bp->b_flags & (B_DONE0x00000100 | B_DELWRI0x00000080)) { |
| 165 | ; |
| 166 | } |
| 167 | #ifdef DIAGNOSTIC1 |
| 168 | else if (!daddr) |
| 169 | panic("ufs_bmaparray: indirect block not in cache"); |
| 170 | #endif |
| 171 | else { |
| 172 | bp->b_blkno = blkptrtodb(ump, daddr)((daddr) << (ump)->um_bptrtodb); |
| 173 | bp->b_flags |= B_READ0x00008000; |
| 174 | bcstats.pendingreads++; |
| 175 | bcstats.numreads++; |
| 176 | VOP_STRATEGY(bp->b_vp, bp); |
| 177 | curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc->p_ru.ru_inblock++; /* XXX */ |
| 178 | if ((error = biowait(bp)) != 0) { |
| 179 | brelse(bp); |
| 180 | return (error); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | #ifdef FFS21 |
| 185 | if (ip->i_ump->um_fstype == UM_UFS22) { |
| 186 | daddr = ((int64_t *)bp->b_data)[xap->in_off]; |
| 187 | if (num == 1 && daddr && runp) |
| 188 | for (bn = xap->in_off + 1; |
| 189 | bn < MNINDIR(ump)((ump)->um_nindir) && *runp < maxrun && |
| 190 | is_sequential(ump,((((int64_t *)bp->b_data)[bn]) == (((int64_t *)bp->b_data )[bn - 1]) + ump->um_seqinc) |
| 191 | ((int64_t *)bp->b_data)[bn - 1],((((int64_t *)bp->b_data)[bn]) == (((int64_t *)bp->b_data )[bn - 1]) + ump->um_seqinc) |
| 192 | ((int64_t *)bp->b_data)[bn])((((int64_t *)bp->b_data)[bn]) == (((int64_t *)bp->b_data )[bn - 1]) + ump->um_seqinc); |
| 193 | ++bn, ++*runp); |
| 194 | |
| 195 | continue; |
| 196 | } |
| 197 | |
| 198 | #endif /* FFS2 */ |
| 199 | |
| 200 | daddr = ((int32_t *)bp->b_data)[xap->in_off]; |
| 201 | if (num == 1 && daddr && runp) |
| 202 | for (bn = xap->in_off + 1; |
| 203 | bn < MNINDIR(ump)((ump)->um_nindir) && *runp < maxrun && |
| 204 | is_sequential(ump,((((int32_t *)bp->b_data)[bn]) == (((int32_t *)bp->b_data )[bn - 1]) + ump->um_seqinc) |
| 205 | ((int32_t *)bp->b_data)[bn - 1],((((int32_t *)bp->b_data)[bn]) == (((int32_t *)bp->b_data )[bn - 1]) + ump->um_seqinc) |
| 206 | ((int32_t *)bp->b_data)[bn])((((int32_t *)bp->b_data)[bn]) == (((int32_t *)bp->b_data )[bn - 1]) + ump->um_seqinc); |
| 207 | ++bn, ++*runp); |
| 208 | } |
| 209 | if (bp) |
| 210 | brelse(bp); |
| 211 | |
| 212 | daddr = blkptrtodb(ump, daddr)((daddr) << (ump)->um_bptrtodb); |
| 213 | *bnp = daddr == 0 ? -1 : daddr; |
| 214 | return (0); |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * Create an array of logical block number/offset pairs which represent the |
| 219 | * path of indirect blocks required to access a data block. The first "pair" |
| 220 | * contains the logical block number of the appropriate single, double or |
| 221 | * triple indirect block and the offset into the inode indirect block array. |
| 222 | * Note, the logical block number of the inode single/double/triple indirect |
| 223 | * block appears twice in the array, once with the offset into the i_ffs_ib and |
| 224 | * once with the offset into the page itself. |
| 225 | */ |
| 226 | int |
| 227 | ufs_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) |
| 228 | { |
| 229 | daddr_t metalbn, realbn; |
| 230 | struct ufsmount *ump; |
| 231 | int64_t blockcnt; |
| 232 | int i, numlevels, off; |
| 233 | |
| 234 | ump = VFSTOUFS(vp->v_mount)((struct ufsmount *)((vp->v_mount)->mnt_data)); |
| 235 | if (nump) |
| 236 | *nump = 0; |
| 237 | numlevels = 0; |
| 238 | realbn = bn; |
| 239 | if (bn < 0) |
| 240 | bn = -bn; |
| 241 | |
| 242 | #ifdef DIAGNOSTIC1 |
| 243 | if (realbn < 0 && realbn > -NDADDR12) { |
| 244 | panic ("ufs_getlbns: Invalid indirect block %lld specified", |
| 245 | (long long)realbn); |
| 246 | } |
| 247 | #endif |
| 248 | |
| 249 | /* The first NDADDR blocks are direct blocks. */ |
| 250 | if (bn < NDADDR12) |
| 251 | return (0); |
| 252 | |
| 253 | /* |
| 254 | * Determine the number of levels of indirection. After this loop |
| 255 | * is done, blockcnt indicates the number of data blocks possible |
| 256 | * at the given level of indirection, and NIADDR - i is the number |
| 257 | * of levels of indirection needed to locate the requested block. |
| 258 | */ |
| 259 | for (blockcnt = 1, i = NIADDR3, bn -= NDADDR12;; i--, bn -= blockcnt) { |
| 260 | if (i == 0) |
| 261 | return (EFBIG27); |
| 262 | blockcnt *= MNINDIR(ump)((ump)->um_nindir); |
| 263 | if (bn < blockcnt) |
| 264 | break; |
| 265 | } |
| 266 | |
| 267 | /* Calculate the address of the first meta-block. */ |
| 268 | if (realbn >= 0) |
| 269 | metalbn = -(realbn - bn + NIADDR3 - i); |
| 270 | else |
| 271 | metalbn = -(-realbn - bn + NIADDR3 - i); |
| 272 | |
| 273 | /* |
| 274 | * At each iteration, off is the offset into the bap array which is |
| 275 | * an array of disk addresses at the current level of indirection. |
| 276 | * The logical block number and the offset in that block are stored |
| 277 | * into the argument array. |
| 278 | */ |
| 279 | ap->in_lbn = metalbn; |
| 280 | ap->in_off = off = NIADDR3 - i; |
Although the value stored to 'off' is used in the enclosing expression, the value is never actually read from 'off' | |
| 281 | ap->in_exists = 0; |
| 282 | ap++; |
| 283 | for (++numlevels; i <= NIADDR3; i++) { |
| 284 | /* If searching for a meta-data block, quit when found. */ |
| 285 | if (metalbn == realbn) |
| 286 | break; |
| 287 | |
| 288 | blockcnt /= MNINDIR(ump)((ump)->um_nindir); |
| 289 | off = (bn / blockcnt) % MNINDIR(ump)((ump)->um_nindir); |
| 290 | |
| 291 | ++numlevels; |
| 292 | ap->in_lbn = metalbn; |
| 293 | ap->in_off = off; |
| 294 | ap->in_exists = 0; |
| 295 | ++ap; |
| 296 | |
| 297 | metalbn -= -1 + off * blockcnt; |
| 298 | } |
| 299 | #ifdef DIAGNOSTIC1 |
| 300 | if (realbn < 0 && metalbn != realbn) { |
| 301 | panic("ufs_getlbns: indirect block %lld not found", |
| 302 | (long long)realbn); |
| 303 | } |
| 304 | #endif |
| 305 | if (nump) |
| 306 | *nump = numlevels; |
| 307 | return (0); |
| 308 | } |