ext2fs_bmap.c revision 1.7
1 /* $NetBSD: ext2fs_bmap.c,v 1.7 2001/11/06 07:11:29 simonb Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Manuel Bouyer. 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. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94 42 * Modified for ext2fs by Manuel Bouyer. 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/buf.h> 48 #include <sys/proc.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/resourcevar.h> 52 #include <sys/trace.h> 53 54 #include <miscfs/specfs/specdev.h> 55 56 #include <ufs/ufs/inode.h> 57 #include <ufs/ufs/ufsmount.h> 58 #include <ufs/ufs/ufs_extern.h> 59 #include <ufs/ext2fs/ext2fs.h> 60 #include <ufs/ext2fs/ext2fs_extern.h> 61 62 static int ext2fs_bmaparray __P((struct vnode *, ufs_daddr_t, ufs_daddr_t *, 63 struct indir *, int *, int *)); 64 65 /* 66 * Bmap converts a the logical block number of a file to its physical block 67 * number on the disk. The conversion is done by using the logical block 68 * number to index into the array of block pointers described by the dinode. 69 */ 70 int 71 ext2fs_bmap(v) 72 void *v; 73 { 74 struct vop_bmap_args /* { 75 struct vnode *a_vp; 76 daddr_t a_bn; 77 struct vnode **a_vpp; 78 daddr_t *a_bnp; 79 int *a_runp; 80 } */ *ap = v; 81 /* 82 * Check for underlying vnode requests and ensure that logical 83 * to physical mapping is requested. 84 */ 85 if (ap->a_vpp != NULL) 86 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 87 if (ap->a_bnp == NULL) 88 return (0); 89 90 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 91 ap->a_runp)); 92 } 93 94 /* 95 * Indirect blocks are now on the vnode for the file. They are given negative 96 * logical block numbers. Indirect blocks are addressed by the negative 97 * address of the first data block to which they point. Double indirect blocks 98 * are addressed by one less than the address of the first indirect block to 99 * which they point. Triple indirect blocks are addressed by one less than 100 * the address of the first double indirect block to which they point. 101 * 102 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 103 * array of logical blocks which must be traversed to get to a block. 104 * Each entry contains the offset into that block that gets you to the 105 * next block and the disk address of the block (if it is assigned). 106 */ 107 108 int 109 ext2fs_bmaparray(vp, bn, bnp, ap, nump, runp) 110 struct vnode *vp; 111 ufs_daddr_t bn; 112 ufs_daddr_t *bnp; 113 struct indir *ap; 114 int *nump; 115 int *runp; 116 { 117 struct inode *ip; 118 struct buf *bp; 119 struct ufsmount *ump; 120 struct mount *mp; 121 struct indir a[NIADDR+1], *xap; 122 ufs_daddr_t daddr; 123 long metalbn; 124 int error, maxrun = 0, num; 125 126 ip = VTOI(vp); 127 mp = vp->v_mount; 128 ump = VFSTOUFS(mp); 129 #ifdef DIAGNOSTIC 130 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 131 panic("ext2fs_bmaparray: invalid arguments"); 132 #endif 133 134 if (runp) { 135 /* 136 * XXX 137 * If MAXBSIZE is the largest transfer the disks can handle, 138 * we probably want maxrun to be 1 block less so that we 139 * don't create a block larger than the device can handle. 140 */ 141 *runp = 0; 142 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 143 } 144 145 xap = ap == NULL ? a : ap; 146 if (!nump) 147 nump = # 148 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 149 return (error); 150 151 num = *nump; 152 if (num == 0) { 153 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 154 if (*bnp == 0) 155 *bnp = -1; 156 else if (runp) 157 for (++bn; bn < NDADDR && *runp < maxrun && 158 is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]), 159 fs2h32(ip->i_e2fs_blocks[bn])); 160 ++bn, ++*runp); 161 return (0); 162 } 163 164 165 /* Get disk address out of indirect block array */ 166 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 167 168 #ifdef DIAGNOSTIC 169 if (num > NIADDR + 1 || num < 1) { 170 printf("ext2fs_bmaparray: num=%d\n", num); 171 panic("ext2fs_bmaparray: num"); 172 } 173 #endif 174 for (bp = NULL, ++xap; --num; ++xap) { 175 /* 176 * Exit the loop if there is no disk address assigned yet and 177 * the indirect block isn't in the cache, or if we were 178 * looking for an indirect block and we've found it. 179 */ 180 181 metalbn = xap->in_lbn; 182 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) 183 break; 184 /* 185 * If we get here, we've either got the block in the cache 186 * or we have a disk address for it, go fetch it. 187 */ 188 if (bp) 189 brelse(bp); 190 191 xap->in_exists = 1; 192 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 193 if (bp->b_flags & (B_DONE | B_DELWRI)) { 194 trace(TR_BREADHIT, pack(vp, size), metalbn); 195 } 196 #ifdef DIAGNOSTIC 197 else if (!daddr) 198 panic("ext2fs_bmaparry: indirect block not in cache"); 199 #endif 200 else { 201 trace(TR_BREADMISS, pack(vp, size), metalbn); 202 bp->b_blkno = blkptrtodb(ump, daddr); 203 bp->b_flags |= B_READ; 204 VOP_STRATEGY(bp); 205 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 206 if ((error = biowait(bp)) != 0) { 207 brelse(bp); 208 return (error); 209 } 210 } 211 212 daddr = fs2h32(((ufs_daddr_t *)bp->b_data)[xap->in_off]); 213 if (num == 1 && daddr && runp) 214 for (bn = xap->in_off + 1; 215 bn < MNINDIR(ump) && *runp < maxrun && 216 is_sequential(ump, ((ufs_daddr_t *)bp->b_data)[bn - 1], 217 ((ufs_daddr_t *)bp->b_data)[bn]); 218 ++bn, ++*runp); 219 } 220 if (bp) 221 brelse(bp); 222 223 daddr = blkptrtodb(ump, daddr); 224 *bnp = daddr == 0 ? -1 : daddr; 225 return (0); 226 } 227
Indexes created Sun Oct 19 02:09:48 GMT 2025