1 /* $NetBSD: ext2fs_bmap.c,v 1.9 2001/11/10 17:46:23 chs 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 1.9 2001/11/10 17:46:23 chs Exp $"); 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/buf.h> 51 #include <sys/proc.h> 52 #include <sys/vnode.h> 53 #include <sys/mount.h> 54 #include <sys/resourcevar.h> 55 #include <sys/trace.h> 56 57 #include <miscfs/specfs/specdev.h> 58 59 #include <ufs/ufs/inode.h> 60 #include <ufs/ufs/ufsmount.h> 61 #include <ufs/ufs/ufs_extern.h> 62 #include <ufs/ext2fs/ext2fs.h> 63 #include <ufs/ext2fs/ext2fs_extern.h> 64 65 static int ext2fs_bmaparray __P((struct vnode *, ufs_daddr_t, ufs_daddr_t *, 66 struct indir *, int *, int *)); 67 68 /* 69 * Bmap converts a the logical block number of a file to its physical block 70 * number on the disk. The conversion is done by using the logical block 71 * number to index into the array of block pointers described by the dinode. 72 */ 73 int 74 ext2fs_bmap(v) 75 void *v; 76 { 77 struct vop_bmap_args /* { 78 struct vnode *a_vp; 79 daddr_t a_bn; 80 struct vnode **a_vpp; 81 daddr_t *a_bnp; 82 int *a_runp; 83 } */ *ap = v; 84 /* 85 * Check for underlying vnode requests and ensure that logical 86 * to physical mapping is requested. 87 */ 88 if (ap->a_vpp != NULL) 89 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 90 if (ap->a_bnp == NULL) 91 return (0); 92 93 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 94 ap->a_runp)); 95 } 96 97 /* 98 * Indirect blocks are now on the vnode for the file. They are given negative 99 * logical block numbers. Indirect blocks are addressed by the negative 100 * address of the first data block to which they point. Double indirect blocks 101 * are addressed by one less than the address of the first indirect block to 102 * which they point. Triple indirect blocks are addressed by one less than 103 * the address of the first double indirect block to which they point. 104 * 105 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 106 * array of logical blocks which must be traversed to get to a block. 107 * Each entry contains the offset into that block that gets you to the 108 * next block and the disk address of the block (if it is assigned). 109 */ 110 111 int 112 ext2fs_bmaparray(vp, bn, bnp, ap, nump, runp) 113 struct vnode *vp; 114 ufs_daddr_t bn; 115 ufs_daddr_t *bnp; 116 struct indir *ap; 117 int *nump; 118 int *runp; 119 { 120 struct inode *ip; 121 struct buf *bp; 122 struct ufsmount *ump; 123 struct mount *mp; 124 struct indir a[NIADDR+1], *xap; 125 ufs_daddr_t daddr; 126 long metalbn; 127 int error, maxrun = 0, num; 128 129 ip = VTOI(vp); 130 mp = vp->v_mount; 131 ump = VFSTOUFS(mp); 132 #ifdef DIAGNOSTIC 133 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 134 panic("ext2fs_bmaparray: invalid arguments"); 135 #endif 136 137 if (runp) { 138 /* 139 * XXX 140 * If MAXBSIZE is the largest transfer the disks can handle, 141 * we probably want maxrun to be 1 block less so that we 142 * don't create a block larger than the device can handle. 143 */ 144 *runp = 0; 145 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 146 } 147 148 if (bn >= 0 && bn < NDADDR) { 149 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); 150 if (*bnp == 0) 151 *bnp = -1; 152 else if (runp) 153 for (++bn; bn < NDADDR && *runp < maxrun && 154 is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]), 155 fs2h32(ip->i_e2fs_blocks[bn])); 156 ++bn, ++*runp); 157 return (0); 158 } 159 160 xap = ap == NULL ? a : ap; 161 if (!nump) 162 nump = # 163 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 164 return (error); 165 166 num = *nump; 167 168 /* Get disk address out of indirect block array */ 169 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 170 171 #ifdef DIAGNOSTIC 172 if (num > NIADDR + 1 || num < 1) { 173 printf("ext2fs_bmaparray: num=%d\n", num); 174 panic("ext2fs_bmaparray: num"); 175 } 176 #endif 177 for (bp = NULL, ++xap; --num; ++xap) { 178 /* 179 * Exit the loop if there is no disk address assigned yet and 180 * the indirect block isn't in the cache, or if we were 181 * looking for an indirect block and we've found it. 182 */ 183 184 metalbn = xap->in_lbn; 185 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) 186 break; 187 /* 188 * If we get here, we've either got the block in the cache 189 * or we have a disk address for it, go fetch it. 190 */ 191 if (bp) 192 brelse(bp); 193 194 xap->in_exists = 1; 195 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 196 if (bp->b_flags & (B_DONE | B_DELWRI)) { 197 trace(TR_BREADHIT, pack(vp, size), metalbn); 198 } 199 #ifdef DIAGNOSTIC 200 else if (!daddr) 201 panic("ext2fs_bmaparry: indirect block not in cache"); 202 #endif 203 else { 204 trace(TR_BREADMISS, pack(vp, size), metalbn); 205 bp->b_blkno = blkptrtodb(ump, daddr); 206 bp->b_flags |= B_READ; 207 VOP_STRATEGY(bp); 208 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 209 if ((error = biowait(bp)) != 0) { 210 brelse(bp); 211 return (error); 212 } 213 } 214 215 daddr = fs2h32(((ufs_daddr_t *)bp->b_data)[xap->in_off]); 216 if (num == 1 && daddr && runp) 217 for (bn = xap->in_off + 1; 218 bn < MNINDIR(ump) && *runp < maxrun && 219 is_sequential(ump, ((ufs_daddr_t *)bp->b_data)[bn - 1], 220 ((ufs_daddr_t *)bp->b_data)[bn]); 221 ++bn, ++*runp); 222 } 223 if (bp) 224 brelse(bp); 225 226 daddr = blkptrtodb(ump, daddr); 227 *bnp = daddr == 0 ? -1 : daddr; 228 return (0); 229 } 230