Annotation of sys/ufs/ext2fs/ext2fs_bmap.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: ext2fs_bmap.c,v 1.15 2007/06/17 20:15:25 jasper 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:
! 50: #include <miscfs/specfs/specdev.h>
! 51:
! 52: #include <ufs/ufs/quota.h>
! 53: #include <ufs/ufs/inode.h>
! 54: #include <ufs/ufs/ufsmount.h>
! 55: #include <ufs/ufs/ufs_extern.h>
! 56: #include <ufs/ext2fs/ext2fs.h>
! 57: #include <ufs/ext2fs/ext2fs_extern.h>
! 58:
! 59: static int ext2fs_bmaparray(struct vnode *, int32_t, daddr64_t *,
! 60: struct indir *, int *, int *);
! 61:
! 62: /*
! 63: * Bmap converts a the logical block number of a file to its physical block
! 64: * number on the disk. The conversion is done by using the logical block
! 65: * number to index into the array of block pointers described by the dinode.
! 66: */
! 67: int
! 68: ext2fs_bmap(void *v)
! 69: {
! 70: struct vop_bmap_args *ap = v;
! 71: /*
! 72: * Check for underlying vnode requests and ensure that logical
! 73: * to physical mapping is requested.
! 74: */
! 75: if (ap->a_vpp != NULL)
! 76: *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
! 77: if (ap->a_bnp == NULL)
! 78: return (0);
! 79:
! 80: return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
! 81: ap->a_runp));
! 82: }
! 83:
! 84: /*
! 85: * Indirect blocks are now on the vnode for the file. They are given negative
! 86: * logical block numbers. Indirect blocks are addressed by the negative
! 87: * address of the first data block to which they point. Double indirect blocks
! 88: * are addressed by one less than the address of the first indirect block to
! 89: * which they point. Triple indirect blocks are addressed by one less than
! 90: * the address of the first double indirect block to which they point.
! 91: *
! 92: * ext2fs_bmaparray does the bmap conversion, and if requested returns the
! 93: * array of logical blocks which must be traversed to get to a block.
! 94: * Each entry contains the offset into that block that gets you to the
! 95: * next block and the disk address of the block (if it is assigned).
! 96: */
! 97:
! 98: int
! 99: ext2fs_bmaparray(struct vnode *vp, int32_t bn, daddr64_t *bnp,
! 100: struct indir *ap, int *nump, int *runp)
! 101: {
! 102: struct inode *ip;
! 103: struct buf *bp;
! 104: struct ufsmount *ump;
! 105: struct mount *mp;
! 106: struct vnode *devvp;
! 107: struct indir a[NIADDR+1], *xap;
! 108: int32_t daddr;
! 109: long metalbn;
! 110: int error, maxrun = 0, num;
! 111:
! 112: ip = VTOI(vp);
! 113: mp = vp->v_mount;
! 114: ump = VFSTOUFS(mp);
! 115: #ifdef DIAGNOSTIC
! 116: if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
! 117: panic("ext2fs_bmaparray: invalid arguments");
! 118: #endif
! 119:
! 120: if (runp) {
! 121: /*
! 122: * XXX
! 123: * If MAXBSIZE is the largest transfer the disks can handle,
! 124: * we probably want maxrun to be 1 block less so that we
! 125: * don't create a block larger than the device can handle.
! 126: */
! 127: *runp = 0;
! 128: maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
! 129: }
! 130:
! 131: xap = ap == NULL ? a : ap;
! 132: if (!nump)
! 133: nump = #
! 134: if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
! 135: return (error);
! 136:
! 137: num = *nump;
! 138: if (num == 0) {
! 139: *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn]));
! 140: if (*bnp == 0)
! 141: *bnp = -1;
! 142: else if (runp)
! 143: for (++bn; bn < NDADDR && *runp < maxrun &&
! 144: is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]),
! 145: fs2h32(ip->i_e2fs_blocks[bn]));
! 146: ++bn, ++*runp);
! 147: return (0);
! 148: }
! 149:
! 150:
! 151: /* Get disk address out of indirect block array */
! 152: daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]);
! 153:
! 154: devvp = VFSTOUFS(vp->v_mount)->um_devvp;
! 155:
! 156: #ifdef DIAGNOSTIC
! 157: if (num > NIADDR + 1 || num < 1) {
! 158: printf("ext2fs_bmaparray: num=%d\n", num);
! 159: panic("ext2fs_bmaparray: num");
! 160: }
! 161: #endif
! 162: for (bp = NULL, ++xap; --num; ++xap) {
! 163: /*
! 164: * Exit the loop if there is no disk address assigned yet and
! 165: * the indirect block isn't in the cache, or if we were
! 166: * looking for an indirect block and we've found it.
! 167: */
! 168:
! 169: metalbn = xap->in_lbn;
! 170: if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn)
! 171: break;
! 172: /*
! 173: * If we get here, we've either got the block in the cache
! 174: * or we have a disk address for it, go fetch it.
! 175: */
! 176: if (bp)
! 177: brelse(bp);
! 178:
! 179: xap->in_exists = 1;
! 180: bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
! 181: if (bp->b_flags & (B_DONE | B_DELWRI)) {
! 182: ;
! 183: }
! 184: #ifdef DIAGNOSTIC
! 185: else if (!daddr)
! 186: panic("ext2fs_bmaparry: indirect block not in cache");
! 187: #endif
! 188: else {
! 189: bp->b_blkno = blkptrtodb(ump, daddr);
! 190: bp->b_flags |= B_READ;
! 191: VOP_STRATEGY(bp);
! 192: curproc->p_stats->p_ru.ru_inblock++; /* XXX */
! 193: if ((error = biowait(bp)) != 0) {
! 194: brelse(bp);
! 195: return (error);
! 196: }
! 197: }
! 198:
! 199: daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]);
! 200: if (num == 1 && daddr && runp)
! 201: for (bn = xap->in_off + 1;
! 202: bn < MNINDIR(ump) && *runp < maxrun &&
! 203: is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1],
! 204: ((int32_t *)bp->b_data)[bn]);
! 205: ++bn, ++*runp);
! 206: }
! 207: if (bp)
! 208: brelse(bp);
! 209:
! 210: daddr = blkptrtodb(ump, daddr);
! 211: *bnp = daddr == 0 ? -1 : daddr;
! 212: return (0);
! 213: }
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