ext2fs_bmap.c revision 1.5.6.2
1 /* $NetBSD: ext2fs_bmap.c,v 1.5.6.2 2001/11/14 19:18:53 nathanw 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/cdefs.h> 46 __KERNEL_RCSID(0, "$NetBSD: ext2fs_bmap.c,v 1.5.6.2 2001/11/14 19:18:53 nathanw Exp $"); 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/buf.h> 51 #include <sys/lwp.h> 52 #include <sys/proc.h> 53 #include <sys/vnode.h> 54 #include <sys/mount.h> 55 #include <sys/resourcevar.h> 56 #include <sys/trace.h> 57 58 #include <miscfs/specfs/specdev.h> 59 60 #include <ufs/ufs/inode.h> 61 #include <ufs/ufs/ufsmount.h> 62 #include <ufs/ufs/ufs_extern.h> 63 #include <ufs/ext2fs/ext2fs.h> 64 #include <ufs/ext2fs/ext2fs_extern.h> 65 66 static int ext2fs_bmaparray __P((struct vnode *, ufs_daddr_t, ufs_daddr_t *, 67 struct indir *, int *, int *)); 68 69 /* 70 * Bmap converts a the logical block number of a file to its physical block 71 * number on the disk. The conversion is done by using the logical block 72 * number to index into the array of block pointers described by the dinode. 73 */ 74 int 75 ext2fs_bmap(v) 76 void *v; 77 { 78 struct vop_bmap_args /* { 79 struct vnode *a_vp; 80 daddr_t a_bn; 81 struct vnode **a_vpp; 82 daddr_t *a_bnp; 83 int *a_runp; 84 } */ *ap = v; 85 /* 86 * Check for underlying vnode requests and ensure that logical 87 * to physical mapping is requested. 88 */ 89 if (ap->a_vpp != NULL) 90 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 91 if (ap->a_bnp == NULL) 92 return (0); 93 94 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 95 ap->a_runp)); 96 } 97 98 /* 99 * Indirect blocks are now on the vnode for the file. They are given negative 100 * logical block numbers. Indirect blocks are addressed by the negative 101 * address of the first data block to which they point. Double indirect blocks 102 * are addressed by one less than the address of the first indirect block to 103 * which they point. Triple indirect blocks are addressed by one less than 104 * the address of the first double indirect block to which they point. 105 * 106 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 107 * array of logical blocks which must be traversed to get to a block. 108 * Each entry contains the offset into that block that gets you to the 109 * next block and the disk address of the block (if it is assigned). 110 */ 111 112 int 113 ext2fs_bmaparray(vp, bn, bnp, ap, nump, runp) 114 struct vnode *vp; 115 ufs_daddr_t bn; 116 ufs_daddr_t *bnp; 117 struct indir *ap; 118 int *nump; 119 int *runp; 120 { 121 struct inode *ip; 122 struct buf *bp; 123 struct ufsmount *ump; 124 struct mount *mp; 125 struct indir a[NIADDR+1], *xap; 126 ufs_daddr_t daddr; 127 long metalbn; 128 int error, maxrun = 0, num; 129 130 ip = VTOI(vp); 131 mp = vp->v_mount; 132 ump = VFSTOUFS(mp); 133 #ifdef DIAGNOSTIC 134 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 135 panic("ext2fs_bmaparray: invalid arguments"); 136 #endif 137 138 if (runp) { 139 /* 140 * XXX 141 * If MAXBSIZE is the largest transfer the disks can handle, 142 * we probably want maxrun to be 1 block less so that we 143 * don't create a block larger than the device can handle. 144 */ 145 *runp = 0; 146 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 147 } 148 149 if (bn >= 0 && bn < NDADDR) { 150 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 151 if (*bnp == 0) 152 *bnp = -1; 153 else if (runp) 154 for (++bn; bn < NDADDR && *runp < maxrun && 155 is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]), 156 fs2h32(ip->i_e2fs_blocks[bn])); 157 ++bn, ++*runp); 158 return (0); 159 } 160 161 xap = ap == NULL ? a : ap; 162 if (!nump) 163 nump = # 164 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 165 return (error); 166 167 num = *nump; 168 169 /* Get disk address out of indirect block array */ 170 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 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->l_proc->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(((ufs_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, ((ufs_daddr_t *)bp->b_data)[bn - 1], 221 ((ufs_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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