ext2fs_bmap.c revision 1.26.14.1
1 /* $NetBSD: ext2fs_bmap.c,v 1.26.14.1 2016/07/09 20:25:24 skrll Exp $ */ 2 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 8.6 (Berkeley) 1/21/94 37 * Modified for ext2fs by Manuel Bouyer. 38 */ 39 40 /* 41 * Copyright (c) 1997 Manuel Bouyer. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 53 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 54 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 55 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 56 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 57 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 58 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 59 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 60 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 61 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 62 * 63 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94 64 * Modified for ext2fs by Manuel Bouyer. 65 */ 66 67 #include <sys/cdefs.h> 68 __KERNEL_RCSID(0, "$NetBSD: ext2fs_bmap.c,v 1.26.14.1 2016/07/09 20:25:24 skrll Exp $"); 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/buf.h> 73 #include <sys/proc.h> 74 #include <sys/vnode.h> 75 #include <sys/mount.h> 76 #include <sys/resourcevar.h> 77 #include <sys/trace.h> 78 79 #include <miscfs/specfs/specdev.h> 80 81 #include <ufs/ufs/inode.h> 82 #include <ufs/ufs/ufsmount.h> 83 #include <ufs/ufs/ufs_extern.h> 84 #include <ufs/ext2fs/ext2fs.h> 85 #include <ufs/ext2fs/ext2fs_extern.h> 86 87 88 static int ext4_bmapext(struct vnode *, int32_t, int64_t *, int *, int *); 89 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, struct indir *, 90 int *, int *); 91 92 #define is_sequential(ump, a, b) ((b) == (a) + ump->um_seqinc) 93 94 /* 95 * Bmap converts a the logical block number of a file to its physical block 96 * number on the disk. The conversion is done by using the logical block 97 * number to index into the array of block pointers described by the dinode. 98 */ 99 int 100 ext2fs_bmap(void *v) 101 { 102 struct vop_bmap_args /* { 103 struct vnode *a_vp; 104 daddr_t a_bn; 105 struct vnode **a_vpp; 106 daddr_t *a_bnp; 107 int *a_runp; 108 } */ *ap = v; 109 /* 110 * Check for underlying vnode requests and ensure that logical 111 * to physical mapping is requested. 112 */ 113 if (ap->a_vpp != NULL) 114 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 115 if (ap->a_bnp == NULL) 116 return (0); 117 118 119 if (VTOI(ap->a_vp)->i_din.e2fs_din->e2di_flags & IN_E4EXTENTS) 120 return ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp, 121 ap->a_runp, NULL); 122 else 123 return ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, 124 NULL, ap->a_runp); 125 126 127 } 128 129 /* 130 * Convert the logical block number of a file to its physical block number 131 * on the disk within ext4 extents. 132 */ 133 static int 134 ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb) 135 { 136 struct inode *ip; 137 struct m_ext2fs *fs; 138 struct ext4_extent *ep; 139 struct ext4_extent_path path = { .ep_bp = NULL }; 140 daddr_t lbn; 141 int error = 0; 142 143 ip = VTOI(vp); 144 fs = ip->i_e2fs; 145 lbn = bn; 146 147 /* XXX: Should not initialize on error? */ 148 if (runp != NULL) 149 *runp = 0; 150 151 if (runb != NULL) 152 *runb = 0; 153 154 ext4_ext_find_extent(fs, ip, lbn, &path); 155 if (path.ep_is_sparse) { 156 *bnp = -1; 157 if (runp != NULL) 158 *runp = path.ep_sparse_ext.e_len - 159 (lbn - path.ep_sparse_ext.e_blk) - 1; 160 if (runb != NULL) 161 *runb = lbn - path.ep_sparse_ext.e_blk; 162 } else { 163 if (path.ep_ext == NULL) { 164 error = EIO; 165 goto out; 166 } 167 ep = path.ep_ext; 168 *bnp = fsbtodb(fs, lbn - ep->e_blk 169 + (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32)); 170 171 if (*bnp == 0) 172 *bnp = -1; 173 174 if (runp != NULL) 175 *runp = ep->e_len - (lbn - ep->e_blk) - 1; 176 if (runb != NULL) 177 *runb = lbn - ep->e_blk; 178 } 179 180 out: 181 if (path.ep_bp != NULL) { 182 brelse(path.ep_bp, 0); 183 } 184 185 return error; 186 } 187 188 189 190 /* 191 * Indirect blocks are now on the vnode for the file. They are given negative 192 * logical block numbers. Indirect blocks are addressed by the negative 193 * address of the first data block to which they point. Double indirect blocks 194 * are addressed by one less than the address of the first indirect block to 195 * which they point. Triple indirect blocks are addressed by one less than 196 * the address of the first double indirect block to which they point. 197 * 198 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 199 * array of logical blocks which must be traversed to get to a block. 200 * Each entry contains the offset into that block that gets you to the 201 * next block and the disk address of the block (if it is assigned). 202 */ 203 204 int 205 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, 206 int *nump, int *runp) 207 { 208 struct inode *ip; 209 struct buf *bp, *cbp; 210 struct ufsmount *ump; 211 struct mount *mp; 212 struct indir a[EXT2FS_NIADDR+1], *xap; 213 daddr_t daddr; 214 daddr_t metalbn; 215 int error, maxrun = 0, num; 216 217 ip = VTOI(vp); 218 mp = vp->v_mount; 219 ump = ip->i_ump; 220 #ifdef DIAGNOSTIC 221 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 222 panic("ext2fs_bmaparray: invalid arguments"); 223 #endif 224 225 if (runp) { 226 /* 227 * XXX 228 * If MAXBSIZE is the largest transfer the disks can handle, 229 * we probably want maxrun to be 1 block less so that we 230 * don't create a block larger than the device can handle. 231 */ 232 *runp = 0; 233 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 234 } 235 236 if (bn >= 0 && bn < EXT2FS_NDADDR) { 237 /* XXX ondisk32 */ 238 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 239 if (*bnp == 0) 240 *bnp = -1; 241 else if (runp) 242 /* XXX ondisk32 */ 243 for (++bn; bn < EXT2FS_NDADDR && *runp < maxrun && 244 is_sequential(ump, (daddr_t)fs2h32(ip->i_e2fs_blocks[bn - 1]), 245 (daddr_t)fs2h32(ip->i_e2fs_blocks[bn])); 246 ++bn, ++*runp); 247 return (0); 248 } 249 250 xap = ap == NULL ? a : ap; 251 if (!nump) 252 nump = # 253 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 254 return (error); 255 256 num = *nump; 257 258 /* Get disk address out of indirect block array */ 259 /* XXX ondisk32 */ 260 daddr = fs2h32(ip->i_e2fs_blocks[EXT2FS_NDADDR + xap->in_off]); 261 262 #ifdef DIAGNOSTIC 263 if (num > EXT2FS_NIADDR + 1 || num < 1) { 264 printf("ext2fs_bmaparray: num=%d\n", num); 265 panic("ext2fs_bmaparray: num"); 266 } 267 #endif 268 for (bp = NULL, ++xap; --num; ++xap) { 269 /* 270 * Exit the loop if there is no disk address assigned yet and 271 * the indirect block isn't in the cache, or if we were 272 * looking for an indirect block and we've found it. 273 */ 274 275 metalbn = xap->in_lbn; 276 if (metalbn == bn) 277 break; 278 if (daddr == 0) { 279 mutex_enter(&bufcache_lock); 280 cbp = incore(vp, metalbn); 281 mutex_exit(&bufcache_lock); 282 if (cbp == NULL) 283 break; 284 } 285 /* 286 * If we get here, we've either got the block in the cache 287 * or we have a disk address for it, go fetch it. 288 */ 289 if (bp) 290 brelse(bp, 0); 291 292 xap->in_exists = 1; 293 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 294 if (bp == NULL) { 295 296 /* 297 * getblk() above returns NULL only iff we are 298 * pagedaemon. See the implementation of getblk 299 * for detail. 300 */ 301 302 return (ENOMEM); 303 } 304 if (bp->b_oflags & (BO_DONE | BO_DELWRI)) { 305 trace(TR_BREADHIT, pack(vp, size), metalbn); 306 } 307 #ifdef DIAGNOSTIC 308 else if (!daddr) 309 panic("ext2fs_bmaparry: indirect block not in cache"); 310 #endif 311 else { 312 trace(TR_BREADMISS, pack(vp, size), metalbn); 313 bp->b_blkno = blkptrtodb(ump, daddr); 314 bp->b_flags |= B_READ; 315 VOP_STRATEGY(vp, bp); 316 curlwp->l_ru.ru_inblock++; /* XXX */ 317 if ((error = biowait(bp)) != 0) { 318 brelse(bp, 0); 319 return (error); 320 } 321 } 322 323 /* XXX ondisk32 */ 324 daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]); 325 if (num == 1 && daddr && runp) 326 /* XXX ondisk32 */ 327 for (bn = xap->in_off + 1; 328 bn < MNINDIR(ump) && *runp < maxrun && 329 is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1], 330 ((int32_t *)bp->b_data)[bn]); 331 ++bn, ++*runp); 332 } 333 if (bp) 334 brelse(bp, 0); 335 336 daddr = blkptrtodb(ump, daddr); 337 *bnp = daddr == 0 ? -1 : daddr; 338 return (0); 339 } 340
Indexes created Sat Oct 18 17:09:52 GMT 2025