/* $OpenBSD: ufs_bmap.c,v 1.37 2021/12/12 09:14:59 visa Exp $ */ /* $NetBSD: ufs_bmap.c,v 1.3 1996/02/09 22:36:00 christos Exp $ */ /* * 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 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/buf.h> #include <sys/proc.h> #include <sys/vnode.h> #include <sys/mount.h> #include <sys/specdev.h> #include <ufs/ufs/quota.h> #include <ufs/ufs/inode.h> #include <ufs/ufs/ufsmount.h> #include <ufs/ufs/ufs_extern.h> /* * 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(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 (ufs_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. * * 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(struct vnode *vp, daddr_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; daddr_t daddr, 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) { /* * 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, DIP(ip, db[bn])); if (*bnp == 0) *bnp = -1; else if (runp) for (++bn; bn < NDADDR && *runp < maxrun && is_sequential(ump, DIP(ip, db[bn - 1]), DIP(ip, db[bn])); ++bn, ++*runp); return (0); } /* Get disk address out of indirect block array */ daddr = DIP(ip, 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) brelse(bp); xap->in_exists = 1; bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, INFSLP); if (bp->b_flags & (B_DONE | B_DELWRI)) { ; } #ifdef DIAGNOSTIC else if (!daddr) panic("ufs_bmaparray: indirect block not in cache"); #endif else { bp->b_blkno = blkptrtodb(ump, daddr); bp->b_flags |= B_READ; bcstats.pendingreads++; bcstats.numreads++; VOP_STRATEGY(bp->b_vp, bp); curproc->p_ru.ru_inblock++; /* XXX */ if ((error = biowait(bp)) != 0) { brelse(bp); return (error); } } #ifdef FFS2 if (ip->i_ump->um_fstype == UM_UFS2) { daddr = ((int64_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, ((int64_t *)bp->b_data)[bn - 1], ((int64_t *)bp->b_data)[bn]); ++bn, ++*runp); continue; } #endif /* FFS2 */ daddr = ((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); } /* * 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_ffs_ib and * once with the offset into the page itself. */ int ufs_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) { daddr_t metalbn, realbn; struct ufsmount *ump; int64_t blockcnt; int i, numlevels, off; ump = VFSTOUFS(vp->v_mount); if (nump) *nump = 0; numlevels = 0; realbn = bn; if (bn < 0) bn = -bn; #ifdef DIAGNOSTIC if (realbn < 0 && realbn > -NDADDR) { panic ("ufs_getlbns: Invalid indirect block %lld specified", (long long)realbn); } #endif /* 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 given 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); blockcnt *= MNINDIR(ump); if (bn < blockcnt) break; } /* 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; blockcnt /= MNINDIR(ump); off = (bn / blockcnt) % MNINDIR(ump); ++numlevels; ap->in_lbn = metalbn; ap->in_off = off; ap->in_exists = 0; ++ap; metalbn -= -1 + off * blockcnt; } #ifdef DIAGNOSTIC if (realbn < 0 && metalbn != realbn) { panic("ufs_getlbns: indirect block %lld not found", (long long)realbn); } #endif if (nump) *nump = numlevels; return (0); }
