1 /* $OpenBSD: ext2fs_bmap.c,v 1.25 2014/07/14 08:54:13 pelikan Exp $ */ 2 /* $NetBSD: ext2fs_bmap.c,v 1.5 2000/03/30 12:41:11 augustss Exp $ */ 3 4 /* 5 * Copyright (c) 1997 Manuel Bouyer. 6 * Copyright (c) 1989, 1991, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94 39 * Modified for ext2fs by Manuel Bouyer. 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/buf.h> 45 #include <sys/proc.h> 46 #include <sys/vnode.h> 47 #include <sys/mount.h> 48 #include <sys/resourcevar.h> 49 #include <sys/specdev.h> 50 51 #include <ufs/ufs/quota.h> 52 #include <ufs/ufs/inode.h> 53 #include <ufs/ufs/ufsmount.h> 54 #include <ufs/ufs/ufs_extern.h> 55 #include <ufs/ext2fs/ext2fs.h> 56 #include <ufs/ext2fs/ext2fs_extents.h> 57 #include <ufs/ext2fs/ext2fs_extern.h> 58 59 static int ext4_bmapext(struct vnode *, daddr_t, daddr_t *, struct indir *, 60 int *, int *); 61 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, struct indir *, 62 int *, int *); 63 64 /* 65 * Bmap converts a the logical block number of a file to its physical block 66 * number on the disk. The conversion is done by using the logical block 67 * number to index into the array of block pointers described by the dinode. 68 */ 69 int 70 ext2fs_bmap(void *v) 71 { 72 struct vop_bmap_args *ap = v; 73 74 /* 75 * Check for underlying vnode requests and ensure that logical 76 * to physical mapping is requested. 77 */ 78 if (ap->a_vpp != NULL) 79 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; 80 if (ap->a_bnp == NULL) 81 return (0); 82 83 if (VTOI(ap->a_vp)->i_e2din->e2di_flags & EXT4_EXTENTS) { 84 return (ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 85 ap->a_runp)); 86 } 87 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, 88 ap->a_runp)); 89 } 90 91 /* 92 * Logical block number of a file -> physical block number on disk within ext4 extents. 93 */ 94 int 95 ext4_bmapext(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, int *nump, int *runp) 96 { 97 struct inode *ip; 98 struct m_ext2fs *fs; 99 struct ext4_extent *ep; 100 struct ext4_extent_path path; 101 daddr_t pos; 102 103 ip = VTOI(vp); 104 fs = ip->i_e2fs; 105 106 if (runp != NULL) 107 *runp = 0; 108 if (nump != NULL) 109 *nump = 0; 110 111 ext4_ext_find_extent(fs, ip, bn, &path); 112 if ((ep = path.ep_ext) == NULL) 113 return (EIO); 114 115 pos = bn - ep->e_blk + (((daddr_t)ep->e_start_hi << 32) | ep->e_start_lo); 116 if ((*bnp = fsbtodb(fs, pos)) == 0) 117 *bnp = -1; 118 return (0); 119 } 120 121 /* 122 * Indirect blocks are now on the vnode for the file. They are given negative 123 * logical block numbers. Indirect blocks are addressed by the negative 124 * address of the first data block to which they point. Double indirect blocks 125 * are addressed by one less than the address of the first indirect block to 126 * which they point. Triple indirect blocks are addressed by one less than 127 * the address of the first double indirect block to which they point. 128 * 129 * ext2fs_bmaparray does the bmap conversion, and if requested returns the 130 * array of logical blocks which must be traversed to get to a block. 131 * Each entry contains the offset into that block that gets you to the 132 * next block and the disk address of the block (if it is assigned). 133 */ 134 135 int 136 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, 137 struct indir *ap, int *nump, int *runp) 138 { 139 struct inode *ip; 140 struct buf *bp; 141 struct ufsmount *ump; 142 struct mount *mp; 143 struct vnode *devvp; 144 struct indir a[NIADDR+1], *xap; 145 int32_t daddr; 146 long metalbn; 147 int error, maxrun = 0, num; 148 149 ip = VTOI(vp); 150 mp = vp->v_mount; 151 ump = VFSTOUFS(mp); 152 #ifdef DIAGNOSTIC 153 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) 154 panic("ext2fs_bmaparray: invalid arguments"); 155 #endif 156 157 if (runp) { 158 /* 159 * XXX 160 * If MAXBSIZE is the largest transfer the disks can handle, 161 * we probably want maxrun to be 1 block less so that we 162 * don't create a block larger than the device can handle. 163 */ 164 *runp = 0; 165 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; 166 } 167 168 xap = ap == NULL ? a : ap; 169 if (!nump) 170 nump = # 171 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) 172 return (error); 173 174 num = *nump; 175 if (num == 0) { 176 *bnp = blkptrtodb(ump, letoh32(ip->i_e2fs_blocks[bn])); 177 if (*bnp == 0) 178 *bnp = -1; 179 else if (runp) 180 for (++bn; bn < NDADDR && *runp < maxrun && 181 is_sequential(ump, 182 letoh32(ip->i_e2fs_blocks[bn - 1]), 183 letoh32(ip->i_e2fs_blocks[bn])); 184 ++bn, ++*runp) 185 /* nothing */; 186 return (0); 187 } 188 189 190 /* Get disk address out of indirect block array */ 191 daddr = letoh32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); 192 193 devvp = VFSTOUFS(vp->v_mount)->um_devvp; 194 195 #ifdef DIAGNOSTIC 196 if (num > NIADDR + 1 || num < 1) { 197 printf("ext2fs_bmaparray: num=%d\n", num); 198 panic("ext2fs_bmaparray: num"); 199 } 200 #endif 201 for (bp = NULL, ++xap; --num; ++xap) { 202 /* 203 * Exit the loop if there is no disk address assigned yet and 204 * the indirect block isn't in the cache, or if we were 205 * looking for an indirect block and we've found it. 206 */ 207 208 metalbn = xap->in_lbn; 209 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) 210 break; 211 /* 212 * If we get here, we've either got the block in the cache 213 * or we have a disk address for it, go fetch it. 214 */ 215 if (bp) 216 brelse(bp); 217 218 xap->in_exists = 1; 219 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); 220 if (bp->b_flags & (B_DONE | B_DELWRI)) { 221 ; 222 } 223 #ifdef DIAGNOSTIC 224 else if (!daddr) 225 panic("ext2fs_bmaparry: indirect block not in cache"); 226 #endif 227 else { 228 bp->b_blkno = blkptrtodb(ump, daddr); 229 bp->b_flags |= B_READ; 230 VOP_STRATEGY(bp); 231 curproc->p_ru.ru_inblock++; /* XXX */ 232 bcstats.pendingreads++; 233 if ((error = biowait(bp)) != 0) { 234 brelse(bp); 235 return (error); 236 } 237 } 238 239 daddr = letoh32(((int32_t *)bp->b_data)[xap->in_off]); 240 if (num == 1 && daddr && runp) 241 for (bn = xap->in_off + 1; 242 bn < MNINDIR(ump) && *runp < maxrun && 243 is_sequential(ump, ((u_int32_t *)bp->b_data)[bn - 1], 244 ((u_int32_t *)bp->b_data)[bn]); 245 ++bn, ++*runp) 246 /* nothing */; 247 } 248 if (bp) 249 brelse(bp); 250 251 daddr = blkptrtodb(ump, daddr); 252 *bnp = daddr == 0 ? -1 : daddr; 253 return (0); 254 } 255