/* $OpenBSD: ext2fs_bmap.c,v 1.21 2013/06/11 16:42:18 deraadt Exp $ */ /* $NetBSD: ext2fs_bmap.c,v 1.5 2000/03/30 12:41:11 augustss Exp $ */ /* * Copyright (c) 1997 Manuel Bouyer. * Copyright (c) 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94 * Modified for ext2fs by Manuel Bouyer. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int ext2fs_bmaparray(struct vnode *, int32_t, daddr_t *, struct indir *, int *, int *); /* * Bmap converts a the logical block number of a file to its physical block * number on the disk. The conversion is done by using the logical block * number to index into the array of block pointers described by the dinode. */ int ext2fs_bmap(void *v) { struct vop_bmap_args *ap = v; /* * Check for underlying vnode requests and ensure that logical * to physical mapping is requested. */ if (ap->a_vpp != NULL) *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; if (ap->a_bnp == NULL) return (0); return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, ap->a_runp)); } /* * Indirect blocks are now on the vnode for the file. They are given negative * logical block numbers. Indirect blocks are addressed by the negative * address of the first data block to which they point. Double indirect blocks * are addressed by one less than the address of the first indirect block to * which they point. Triple indirect blocks are addressed by one less than * the address of the first double indirect block to which they point. * * ext2fs_bmaparray does the bmap conversion, and if requested returns the * array of logical blocks which must be traversed to get to a block. * Each entry contains the offset into that block that gets you to the * next block and the disk address of the block (if it is assigned). */ int ext2fs_bmaparray(struct vnode *vp, int32_t bn, daddr_t *bnp, struct indir *ap, int *nump, int *runp) { struct inode *ip; struct buf *bp; struct ufsmount *ump; struct mount *mp; struct vnode *devvp; struct indir a[NIADDR+1], *xap; int32_t daddr; long metalbn; int error, maxrun = 0, num; ip = VTOI(vp); mp = vp->v_mount; ump = VFSTOUFS(mp); #ifdef DIAGNOSTIC if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) panic("ext2fs_bmaparray: invalid arguments"); #endif if (runp) { /* * XXX * If MAXBSIZE is the largest transfer the disks can handle, * we probably want maxrun to be 1 block less so that we * don't create a block larger than the device can handle. */ *runp = 0; maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1; } xap = ap == NULL ? a : ap; if (!nump) nump = # if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) return (error); num = *nump; if (num == 0) { *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn])); if (*bnp == 0) *bnp = -1; else if (runp) for (++bn; bn < NDADDR && *runp < maxrun && is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]), fs2h32(ip->i_e2fs_blocks[bn])); ++bn, ++*runp); return (0); } /* Get disk address out of indirect block array */ daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]); devvp = VFSTOUFS(vp->v_mount)->um_devvp; #ifdef DIAGNOSTIC if (num > NIADDR + 1 || num < 1) { printf("ext2fs_bmaparray: num=%d\n", num); panic("ext2fs_bmaparray: num"); } #endif for (bp = NULL, ++xap; --num; ++xap) { /* * Exit the loop if there is no disk address assigned yet and * the indirect block isn't in the cache, or if we were * looking for an indirect block and we've found it. */ metalbn = xap->in_lbn; if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn) break; /* * If we get here, we've either got the block in the cache * or we have a disk address for it, go fetch it. */ if (bp) brelse(bp); xap->in_exists = 1; bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); if (bp->b_flags & (B_DONE | B_DELWRI)) { ; } #ifdef DIAGNOSTIC else if (!daddr) panic("ext2fs_bmaparry: indirect block not in cache"); #endif else { bp->b_blkno = blkptrtodb(ump, daddr); bp->b_flags |= B_READ; VOP_STRATEGY(bp); curproc->p_ru.ru_inblock++; /* XXX */ bcstats.pendingreads++; if ((error = biowait(bp)) != 0) { brelse(bp); return (error); } } daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]); if (num == 1 && daddr && runp) for (bn = xap->in_off + 1; bn < MNINDIR(ump) && *runp < maxrun && is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1], ((int32_t *)bp->b_data)[bn]); ++bn, ++*runp); } if (bp) brelse(bp); daddr = blkptrtodb(ump, daddr); *bnp = daddr == 0 ? -1 : daddr; return (0); }