ext2fs_bmap.c revision 1.24
1 /* $NetBSD: ext2fs_bmap.c,v 1.24 2008/03/27 19:06:52 ad 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 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by Manuel Bouyer. 54 * 4. The name of the author may not be used to endorse or promote products 55 * derived from this software without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 58 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 59 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 60 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 61 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 62 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 63 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 64 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 65 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 66 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 67 * 68 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94 69 * Modified for ext2fs by Manuel Bouyer. 70 */ 71 72 #include <sys/cdefs.h> 73 __KERNEL_RCSID(0, "$NetBSD: ext2fs_bmap.c,v 1.24 2008/03/27 19:06:52 ad Exp $"); 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/buf.h> 78 #include <sys/proc.h> 79 #include <sys/vnode.h> 80 #include <sys/mount.h> 81 #include <sys/resourcevar.h> 82 #include <sys/trace.h> 83 84 #include <miscfs/specfs/specdev.h> 85 86 #include <ufs/ufs/inode.h> 87 #include <ufs/ufs/ufsmount.h> 88 #include <ufs/ufs/ufs_extern.h> 89 #include <ufs/ext2fs/ext2fs.h> 90 #include <ufs/ext2fs/ext2fs_extern.h> 91 92 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, 93 struct indir *, int *, int *); 94 95 #define is_sequential(ump, a, b) ((b) == (a) + ump->um_seqinc) 96 97 /* 98 * Bmap converts a the logical block number of a file to its physical block 99 * number on the disk. The conversion is done by using the logical block 100 * number to index into the array of block pointers described by the dinode. 101 */ 102 int 103 ext2fs_bmap(void *v) 104 { 105 struct vop_bmap_args /* { 106 struct vnode *a_vp; 107 daddr_t a_bn; 108 struct vnode **a_vpp; 109 daddr_t *a_bnp; 110 int *a_runp; 111 } */ *ap = v; 112 /* 113 * Check for underlying vnode requests and ensure that logical 114 * to physical mapping is requested. 115 */ 116 if (ap->a_vpp != NULL) 117 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 118 if (ap->a_bnp == NULL) 119 return (0); 120 121 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 122 ap->a_runp)); 123 } 124 125 /* 126 * Indirect blocks are now on the vnode for the file. They are given negative 127 * logical block numbers. Indirect blocks are addressed by the negative 128 * address of the first data block to which they point. Double indirect blocks 129 * are addressed by one less than the address of the first indirect block to 130 * which they point. Triple indirect blocks are addressed by one less than 131 * the address of the first double indirect block to which they point. 132 * 133 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 134 * array of logical blocks which must be traversed to get to a block. 135 * Each entry contains the offset into that block that gets you to the 136 * next block and the disk address of the block (if it is assigned). 137 */ 138 139 int 140 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, 141 int *nump, int *runp) 142 { 143 struct inode *ip; 144 struct buf *bp, *cbp; 145 struct ufsmount *ump; 146 struct mount *mp; 147 struct indir a[NIADDR+1], *xap; 148 daddr_t daddr; 149 daddr_t metalbn; 150 int error, maxrun = 0, num; 151 152 ip = VTOI(vp); 153 mp = vp->v_mount; 154 ump = ip->i_ump; 155 #ifdef DIAGNOSTIC 156 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 157 panic("ext2fs_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 = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 169 } 170 171 if (bn >= 0 && bn < NDADDR) { 172 /* XXX ondisk32 */ 173 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 174 if (*bnp == 0) 175 *bnp = -1; 176 else if (runp) 177 /* XXX ondisk32 */ 178 for (++bn; bn < NDADDR && *runp < maxrun && 179 is_sequential(ump, (daddr_t)fs2h32(ip->i_e2fs_blocks[bn - 1]), 180 (daddr_t)fs2h32(ip->i_e2fs_blocks[bn])); 181 ++bn, ++*runp); 182 return (0); 183 } 184 185 xap = ap == NULL ? a : ap; 186 if (!nump) 187 nump = # 188 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 189 return (error); 190 191 num = *nump; 192 193 /* Get disk address out of indirect block array */ 194 /* XXX ondisk32 */ 195 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 196 197 #ifdef DIAGNOSTIC 198 if (num > NIADDR + 1 || num < 1) { 199 printf("ext2fs_bmaparray: num=%d\n", num); 200 panic("ext2fs_bmaparray: num"); 201 } 202 #endif 203 for (bp = NULL, ++xap; --num; ++xap) { 204 /* 205 * Exit the loop if there is no disk address assigned yet and 206 * the indirect block isn't in the cache, or if we were 207 * looking for an indirect block and we've found it. 208 */ 209 210 metalbn = xap->in_lbn; 211 if (metalbn == bn) 212 break; 213 if (daddr == 0) { 214 mutex_enter(&bufcache_lock); 215 cbp = incore(vp, metalbn); 216 mutex_exit(&bufcache_lock); 217 if (cbp == NULL) 218 break; 219 } 220 /* 221 * If we get here, we've either got the block in the cache 222 * or we have a disk address for it, go fetch it. 223 */ 224 if (bp) 225 brelse(bp, 0); 226 227 xap->in_exists = 1; 228 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 229 if (bp == NULL) { 230 231 /* 232 * getblk() above returns NULL only iff we are 233 * pagedaemon. See the implementation of getblk 234 * for detail. 235 */ 236 237 return (ENOMEM); 238 } 239 if (bp->b_oflags & (BO_DONE | BO_DELWRI)) { 240 trace(TR_BREADHIT, pack(vp, size), metalbn); 241 } 242 #ifdef DIAGNOSTIC 243 else if (!daddr) 244 panic("ext2fs_bmaparry: indirect block not in cache"); 245 #endif 246 else { 247 trace(TR_BREADMISS, pack(vp, size), metalbn); 248 bp->b_blkno = blkptrtodb(ump, daddr); 249 bp->b_flags |= B_READ; 250 VOP_STRATEGY(vp, bp); 251 curlwp->l_ru.ru_inblock++; /* XXX */ 252 if ((error = biowait(bp)) != 0) { 253 brelse(bp, 0); 254 return (error); 255 } 256 } 257 258 /* XXX ondisk32 */ 259 daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]); 260 if (num == 1 && daddr && runp) 261 /* XXX ondisk32 */ 262 for (bn = xap->in_off + 1; 263 bn < MNINDIR(ump) && *runp < maxrun && 264 is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1], 265 ((int32_t *)bp->b_data)[bn]); 266 ++bn, ++*runp); 267 } 268 if (bp) 269 brelse(bp, 0); 270 271 daddr = blkptrtodb(ump, daddr); 272 *bnp = daddr == 0 ? -1 : daddr; 273 return (0); 274 } 275
Indexes created Wed Sep 24 05:09:52 GMT 2025