ext2fs_bmap.c revision 1.25.22.1
1 /* $NetBSD: ext2fs_bmap.c,v 1.25.22.1 2013/02/25 00:30:14 tls 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 1.25.22.1 2013/02/25 00:30:14 tls 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 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, 88 struct indir *, int *, int *); 89 90 #define is_sequential(ump, a, b) ((b) == (a) + ump->um_seqinc) 91 92 /* 93 * Bmap converts a the logical block number of a file to its physical block 94 * number on the disk. The conversion is done by using the logical block 95 * number to index into the array of block pointers described by the dinode. 96 */ 97 int 98 ext2fs_bmap(void *v) 99 { 100 struct vop_bmap_args /* { 101 struct vnode *a_vp; 102 daddr_t a_bn; 103 struct vnode **a_vpp; 104 daddr_t *a_bnp; 105 int *a_runp; 106 } */ *ap = v; 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 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 117 ap->a_runp)); 118 } 119 120 /* 121 * Indirect blocks are now on the vnode for the file. They are given negative 122 * logical block numbers. Indirect blocks are addressed by the negative 123 * address of the first data block to which they point. Double indirect blocks 124 * are addressed by one less than the address of the first indirect block to 125 * which they point. Triple indirect blocks are addressed by one less than 126 * the address of the first double indirect block to which they point. 127 * 128 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 129 * array of logical blocks which must be traversed to get to a block. 130 * Each entry contains the offset into that block that gets you to the 131 * next block and the disk address of the block (if it is assigned). 132 */ 133 134 int 135 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, 136 int *nump, int *runp) 137 { 138 struct inode *ip; 139 struct buf *bp, *cbp; 140 struct ufsmount *ump; 141 struct mount *mp; 142 struct indir a[EXT2FS_NIADDR+1], *xap; 143 daddr_t daddr; 144 daddr_t metalbn; 145 int error, maxrun = 0, num; 146 147 ip = VTOI(vp); 148 mp = vp->v_mount; 149 ump = ip->i_ump; 150 #ifdef DIAGNOSTIC 151 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 152 panic("ext2fs_bmaparray: invalid arguments"); 153 #endif 154 155 if (runp) { 156 /* 157 * XXX 158 * If MAXBSIZE is the largest transfer the disks can handle, 159 * we probably want maxrun to be 1 block less so that we 160 * don't create a block larger than the device can handle. 161 */ 162 *runp = 0; 163 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 164 } 165 166 if (bn >= 0 && bn < EXT2FS_NDADDR) { 167 /* XXX ondisk32 */ 168 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 169 if (*bnp == 0) 170 *bnp = -1; 171 else if (runp) 172 /* XXX ondisk32 */ 173 for (++bn; bn < EXT2FS_NDADDR && *runp < maxrun && 174 is_sequential(ump, (daddr_t)fs2h32(ip->i_e2fs_blocks[bn - 1]), 175 (daddr_t)fs2h32(ip->i_e2fs_blocks[bn])); 176 ++bn, ++*runp); 177 return (0); 178 } 179 180 xap = ap == NULL ? a : ap; 181 if (!nump) 182 nump = # 183 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 184 return (error); 185 186 num = *nump; 187 188 /* Get disk address out of indirect block array */ 189 /* XXX ondisk32 */ 190 daddr = fs2h32(ip->i_e2fs_blocks[EXT2FS_NDADDR + xap->in_off]); 191 192 #ifdef DIAGNOSTIC 193 if (num > EXT2FS_NIADDR + 1 || num < 1) { 194 printf("ext2fs_bmaparray: num=%d\n", num); 195 panic("ext2fs_bmaparray: num"); 196 } 197 #endif 198 for (bp = NULL, ++xap; --num; ++xap) { 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 = xap->in_lbn; 206 if (metalbn == bn) 207 break; 208 if (daddr == 0) { 209 mutex_enter(&bufcache_lock); 210 cbp = incore(vp, metalbn); 211 mutex_exit(&bufcache_lock); 212 if (cbp == NULL) 213 break; 214 } 215 /* 216 * If we get here, we've either got the block in the cache 217 * or we have a disk address for it, go fetch it. 218 */ 219 if (bp) 220 brelse(bp, 0); 221 222 xap->in_exists = 1; 223 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 224 if (bp == NULL) { 225 226 /* 227 * getblk() above returns NULL only iff we are 228 * pagedaemon. See the implementation of getblk 229 * for detail. 230 */ 231 232 return (ENOMEM); 233 } 234 if (bp->b_oflags & (BO_DONE | BO_DELWRI)) { 235 trace(TR_BREADHIT, pack(vp, size), metalbn); 236 } 237 #ifdef DIAGNOSTIC 238 else if (!daddr) 239 panic("ext2fs_bmaparry: indirect block not in cache"); 240 #endif 241 else { 242 trace(TR_BREADMISS, pack(vp, size), metalbn); 243 bp->b_blkno = blkptrtodb(ump, daddr); 244 bp->b_flags |= B_READ; 245 VOP_STRATEGY(vp, bp); 246 curlwp->l_ru.ru_inblock++; /* XXX */ 247 if ((error = biowait(bp)) != 0) { 248 brelse(bp, 0); 249 return (error); 250 } 251 } 252 253 /* XXX ondisk32 */ 254 daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]); 255 if (num == 1 && daddr && runp) 256 /* XXX ondisk32 */ 257 for (bn = xap->in_off + 1; 258 bn < MNINDIR(ump) && *runp < maxrun && 259 is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1], 260 ((int32_t *)bp->b_data)[bn]); 261 ++bn, ++*runp); 262 } 263 if (bp) 264 brelse(bp, 0); 265 266 daddr = blkptrtodb(ump, daddr); 267 *bnp = daddr == 0 ? -1 : daddr; 268 return (0); 269 } 270
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