/* * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 8.7 (Berkeley) 3/21/95 * $Id: ufs_bmap.c,v 1.21 1998/07/04 20:45:39 julian Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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 ufs_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; ufs_daddr_t a_bn; struct vnode **a_vpp; ufs_daddr_t *a_bnp; int *a_runp; int *a_runb; } */ *ap; { /* * 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 (ufs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, ap->a_runp, ap->a_runb)); } /* * 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. * * ufs_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 ufs_bmaparray(vp, bn, bnp, ap, nump, runp, runb) struct vnode *vp; ufs_daddr_t bn; ufs_daddr_t *bnp; struct indir *ap; int *nump; int *runp; int *runb; { register struct inode *ip; struct buf *bp; struct ufsmount *ump; struct mount *mp; struct vnode *devvp; struct indir a[NIADDR+1], *xap; ufs_daddr_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("ufs_bmaparray: invalid arguments"); #endif if (runp) { *runp = 0; } if (runb) { *runb = 0; } maxrun = 0; if (runp || runb || (vp->v_maxio == 0)) { struct vnode *devvp; int blksize; blksize = mp->mnt_stat.f_iosize; /* * XXX * If MAXPHYS 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. */ devvp = ip->i_devvp; if (devvp && devvp->v_type == VBLK && (devvp->v_rdev != NODEV) && (major(devvp->v_rdev) < nblkdev)) { if (bdevsw[major(devvp->v_rdev)]->d_maxio > MAXPHYS) { maxrun = MAXPHYS; vp->v_maxio = MAXPHYS; } else { maxrun = bdevsw[major(devvp->v_rdev)]->d_maxio; vp->v_maxio = bdevsw[major(devvp->v_rdev)]->d_maxio; } maxrun = maxrun / blksize; maxrun -= 1; } if (maxrun <= 0) { vp->v_maxio = DFLTPHYS; maxrun = DFLTPHYS / blksize; maxrun -= 1; } } xap = ap == NULL ? a : ap; if (!nump) nump = # error = ufs_getlbns(vp, bn, xap, nump); if (error) return (error); num = *nump; if (num == 0) { *bnp = blkptrtodb(ump, ip->i_db[bn]); if (*bnp == 0) *bnp = -1; else if (runp) { daddr_t bnb = bn; for (++bn; bn < NDADDR && *runp < maxrun && is_sequential(ump, ip->i_db[bn - 1], ip->i_db[bn]); ++bn, ++*runp); bn = bnb; if (runb && (bn > 0)) { for (--bn; (bn >= 0) && (*runb < maxrun) && is_sequential(ump, ip->i_db[bn], ip->i_db[bn+1]); --bn, ++*runb); } } return (0); } /* Get disk address out of indirect block array */ daddr = ip->i_ib[xap->in_off]; devvp = VFSTOUFS(vp->v_mount)->um_devvp; 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) bqrelse(bp); xap->in_exists = 1; bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); if ((bp->b_flags & B_CACHE) == 0) { #ifdef DIAGNOSTIC if (!daddr) panic("ufs_bmaparray: indirect block not in cache"); #endif bp->b_blkno = blkptrtodb(ump, daddr); bp->b_flags |= B_READ; vfs_busy_pages(bp, 0); VOP_STRATEGY(bp->b_vp, bp); curproc->p_stats->p_ru.ru_inblock++; /* XXX */ error = biowait(bp); if (error) { brelse(bp); return (error); } } daddr = ((ufs_daddr_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, ((ufs_daddr_t *)bp->b_data)[bn - 1], ((ufs_daddr_t *)bp->b_data)[bn]); ++bn, ++*runp); bn = xap->in_off; if (runb && bn) { for(--bn; bn > 0 && *runb < maxrun && is_sequential(ump, ((daddr_t *)bp->b_data)[bn], ((daddr_t *)bp->b_data)[bn+1]); --bn, ++*runb); } } } if (bp) bqrelse(bp); daddr = blkptrtodb(ump, daddr); *bnp = daddr == 0 ? -1 : daddr; return (0); } /* * Create an array of logical block number/offset pairs which represent the * path of indirect blocks required to access a data block. The first "pair" * contains the logical block number of the appropriate single, double or * triple indirect block and the offset into the inode indirect block array. * Note, the logical block number of the inode single/double/triple indirect * block appears twice in the array, once with the offset into the i_ib and * once with the offset into the page itself. */ int ufs_getlbns(vp, bn, ap, nump) struct vnode *vp; ufs_daddr_t bn; struct indir *ap; int *nump; { long blockcnt, metalbn, realbn; struct ufsmount *ump; int i, numlevels, off; int64_t qblockcnt; ump = VFSTOUFS(vp->v_mount); if (nump) *nump = 0; numlevels = 0; realbn = bn; if ((long)bn < 0) bn = -(long)bn; /* The first NDADDR blocks are direct blocks. */ if (bn < NDADDR) return (0); /* * Determine the number of levels of indirection. After this loop * is done, blockcnt indicates the number of data blocks possible * at the previous level of indirection, and NIADDR - i is the number * of levels of indirection needed to locate the requested block. */ for (blockcnt = 1, i = NIADDR, bn -= NDADDR;; i--, bn -= blockcnt) { if (i == 0) return (EFBIG); /* * Use int64_t's here to avoid overflow for triple indirect * blocks when longs have 32 bits and the block size is more * than 4K. */ qblockcnt = (int64_t)blockcnt * MNINDIR(ump); if (bn < qblockcnt) break; blockcnt = qblockcnt; } /* Calculate the address of the first meta-block. */ if (realbn >= 0) metalbn = -(realbn - bn + NIADDR - i); else metalbn = -(-realbn - bn + NIADDR - i); /* * At each iteration, off is the offset into the bap array which is * an array of disk addresses at the current level of indirection. * The logical block number and the offset in that block are stored * into the argument array. */ ap->in_lbn = metalbn; ap->in_off = off = NIADDR - i; ap->in_exists = 0; ap++; for (++numlevels; i <= NIADDR; i++) { /* If searching for a meta-data block, quit when found. */ if (metalbn == realbn) break; off = (bn / blockcnt) % MNINDIR(ump); ++numlevels; ap->in_lbn = metalbn; ap->in_off = off; ap->in_exists = 0; ++ap; metalbn -= -1 + off * blockcnt; blockcnt /= MNINDIR(ump); } if (nump) *nump = numlevels; return (0); }