/* * 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 8.7 (Berkeley) 3/21/95 * $FreeBSD: src/sys/ufs/ufs/ufs_bmap.c,v 1.34.2.1 2000/03/17 10:12:14 ps Exp $ */ #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/resourcevar.h> #include <sys/conf.h> #include "quota.h" #include "inode.h" #include "ufsmount.h" #include "ufs_extern.h" #include "fs.h" /* * Bmap converts 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. * * BMAP must return the contiguous before and after run in bytes, inclusive * of the returned block. * * ufs_bmap(struct vnode *a_vp, off_t a_loffset, * off_t *a_doffsetp, int *a_runp, int *a_runb) */ int ufs_bmap(struct vop_bmap_args *ap) { struct fs *fs; ufs_daddr_t lbn; ufs_daddr_t dbn; int error; /* * Check for underlying vnode requests and ensure that logical * to physical mapping is requested. */ if (ap->a_doffsetp == NULL) return (0); fs = VTOI(ap->a_vp)->i_fs; KKASSERT(((int)ap->a_loffset & ((1 << fs->fs_bshift) - 1)) == 0); lbn = ap->a_loffset >> fs->fs_bshift; error = ufs_bmaparray(ap->a_vp, lbn, &dbn, NULL, NULL, ap->a_runp, ap->a_runb); if (error || dbn == (ufs_daddr_t)-1) { *ap->a_doffsetp = NOOFFSET; } else { *ap->a_doffsetp = dbtodoff(fs, dbn); if (ap->a_runp) *ap->a_runp = (*ap->a_runp + 1) << fs->fs_bshift; if (ap->a_runb) *ap->a_runb = *ap->a_runb << fs->fs_bshift; } return (error); } /* * 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, ufs_daddr_t bn, ufs_daddr_t *bnp, struct indir *ap, int *nump, int *runp, int *runb) { struct inode *ip; struct buf *bp; struct ufsmount *ump; struct mount *mp; struct fs *fs; struct indir a[UFS_NIADDR+1], *xap; ufs_daddr_t daddr; long metalbn; int error, maxrun, num; ip = VTOI(vp); mp = vp->v_mount; ump = VFSTOUFS(mp); fs = ip->i_fs; #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 = mp->mnt_iosize_max / mp->mnt_stat.f_iosize - 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 < UFS_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]; 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 && !findblk(vp, dbtodoff(fs, metalbn), FINDBLK_TEST)) || 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); bp = getblk(vp, lblktodoff(fs, 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 /* * cached disk addr in bio2, do I/O on bio1. It * will probably hit the vfs's strategy function * which will then use the cached offset in bio2. */ bp->b_bio1.bio_done = biodone_sync; bp->b_bio1.bio_flags |= BIO_SYNC; bp->b_bio2.bio_offset = fsbtodoff(fs, daddr); bp->b_flags &= ~(B_INVAL|B_ERROR); bp->b_cmd = BUF_CMD_READ; vfs_busy_pages(bp->b_vp, bp); vn_strategy(bp->b_vp, &bp->b_bio1); error = biowait(&bp->b_bio1, "biord"); 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(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 UFS_NDADDR blocks are direct blocks. */ if (bn < UFS_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 UFS_NIADDR-i is the number * of levels of indirection needed to locate the requested block. */ for (blockcnt = 1, i = UFS_NIADDR, bn -= UFS_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 + UFS_NIADDR - i); else metalbn = -(-realbn - bn + UFS_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 = UFS_NIADDR - i; ap++; for (++numlevels; i <= UFS_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; metalbn -= -1 + off * blockcnt; blockcnt /= MNINDIR(ump); } if (nump) *nump = numlevels; return (0); }
