ext2fs_bmap.c revision 1.3
1 /* $NetBSD: ext2fs_bmap.c,v 1.3 1997/10/09 15:42:48 bouyer 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/quota.h> 57 #include <ufs/ufs/inode.h> 58 #include <ufs/ufs/ufsmount.h> 59 #include <ufs/ufs/ufs_extern.h> 60 #include <ufs/ext2fs/ext2fs.h> 61 #include <ufs/ext2fs/ext2fs_extern.h> 62 63 static int ext2fs_bmaparray __P((struct vnode *, daddr_t, daddr_t *, 64 struct indir *, int *, int *)); 65 66 /* 67 * Bmap converts a the logical block number of a file to its physical block 68 * number on the disk. The conversion is done by using the logical block 69 * number to index into the array of block pointers described by the dinode. 70 */ 71 int 72 ext2fs_bmap(v) 73 void *v; 74 { 75 struct vop_bmap_args /* { 76 struct vnode *a_vp; 77 daddr_t a_bn; 78 struct vnode **a_vpp; 79 daddr_t *a_bnp; 80 int *a_runp; 81 } */ *ap = v; 82 /* 83 * Check for underlying vnode requests and ensure that logical 84 * to physical mapping is requested. 85 */ 86 if (ap->a_vpp != NULL) 87 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 88 if (ap->a_bnp == NULL) 89 return (0); 90 91 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 92 ap->a_runp)); 93 } 94 95 /* 96 * Indirect blocks are now on the vnode for the file. They are given negative 97 * logical block numbers. Indirect blocks are addressed by the negative 98 * address of the first data block to which they point. Double indirect blocks 99 * are addressed by one less than the address of the first indirect block to 100 * which they point. Triple indirect blocks are addressed by one less than 101 * the address of the first double indirect block to which they point. 102 * 103 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 104 * array of logical blocks which must be traversed to get to a block. 105 * Each entry contains the offset into that block that gets you to the 106 * next block and the disk address of the block (if it is assigned). 107 */ 108 109 int 110 ext2fs_bmaparray(vp, bn, bnp, ap, nump, runp) 111 struct vnode *vp; 112 register daddr_t bn; 113 daddr_t *bnp; 114 struct indir *ap; 115 int *nump; 116 int *runp; 117 { 118 register struct inode *ip; 119 struct buf *bp; 120 struct ufsmount *ump; 121 struct mount *mp; 122 struct vnode *devvp; 123 struct indir a[NIADDR+1], *xap; 124 daddr_t daddr; 125 long metalbn; 126 int error, maxrun = 0, num; 127 128 ip = VTOI(vp); 129 mp = vp->v_mount; 130 ump = VFSTOUFS(mp); 131 #ifdef DIAGNOSTIC 132 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 133 panic("ext2fs_bmaparray: invalid arguments"); 134 #endif 135 136 if (runp) { 137 /* 138 * XXX 139 * If MAXBSIZE is the largest transfer the disks can handle, 140 * we probably want maxrun to be 1 block less so that we 141 * don't create a block larger than the device can handle. 142 */ 143 *runp = 0; 144 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 145 } 146 147 xap = ap == NULL ? a : ap; 148 if (!nump) 149 nump = # 150 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 151 return (error); 152 153 num = *nump; 154 if (num == 0) { 155 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 156 if (*bnp == 0) 157 *bnp = -1; 158 else if (runp) 159 for (++bn; bn < NDADDR && *runp < maxrun && 160 is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]), 161 fs2h32(ip->i_e2fs_blocks[bn])); 162 ++bn, ++*runp); 163 return (0); 164 } 165 166 167 /* Get disk address out of indirect block array */ 168 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 169 170 devvp = VFSTOUFS(vp->v_mount)->um_devvp; 171 172 #ifdef DIAGNOSTIC 173 if (num > NIADDR + 1 || num < 1) { 174 printf("ext2fs_bmaparray: num=%d\n", num); 175 panic("ext2fs_bmaparray: num"); 176 } 177 #endif 178 for (bp = NULL, ++xap; --num; ++xap) { 179 /* 180 * Exit the loop if there is no disk address assigned yet and 181 * the indirect block isn't in the cache, or if we were 182 * looking for an indirect block and we've found it. 183 */ 184 185 metalbn = xap->in_lbn; 186 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) 187 break; 188 /* 189 * If we get here, we've either got the block in the cache 190 * or we have a disk address for it, go fetch it. 191 */ 192 if (bp) 193 brelse(bp); 194 195 xap->in_exists = 1; 196 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 197 if (bp->b_flags & (B_DONE | B_DELWRI)) { 198 trace(TR_BREADHIT, pack(vp, size), metalbn); 199 } 200 #ifdef DIAGNOSTIC 201 else if (!daddr) 202 panic("ext2fs_bmaparry: indirect block not in cache"); 203 #endif 204 else { 205 trace(TR_BREADMISS, pack(vp, size), metalbn); 206 bp->b_blkno = blkptrtodb(ump, daddr); 207 bp->b_flags |= B_READ; 208 VOP_STRATEGY(bp); 209 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 210 if ((error = biowait(bp)) != 0) { 211 brelse(bp); 212 return (error); 213 } 214 } 215 216 daddr = fs2h32(((daddr_t *)bp->b_data)[xap->in_off]); 217 if (num == 1 && daddr && runp) 218 for (bn = xap->in_off + 1; 219 bn < MNINDIR(ump) && *runp < maxrun && 220 is_sequential(ump, ((daddr_t *)bp->b_data)[bn - 1], 221 ((daddr_t *)bp->b_data)[bn]); 222 ++bn, ++*runp); 223 } 224 if (bp) 225 brelse(bp); 226 227 daddr = blkptrtodb(ump, daddr); 228 *bnp = daddr == 0 ? -1 : daddr; 229 return (0); 230 } 231
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