/*- * 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. * 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 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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. */ int ufs_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; daddr_t a_bn; struct bufobj **a_bop; daddr_t *a_bnp; int *a_runp; int *a_runb; } */ *ap; { ufs2_daddr_t blkno; int error; /* * Check for underlying vnode requests and ensure that logical * to physical mapping is requested. */ if (ap->a_bop != NULL) *ap->a_bop = &VTOI(ap->a_vp)->i_devvp->v_bufobj; if (ap->a_bnp == NULL) return (0); error = ufs_bmaparray(ap->a_vp, ap->a_bn, &blkno, NULL, ap->a_runp, ap->a_runb); *ap->a_bnp = blkno; 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(vp, bn, bnp, nbp, runp, runb) struct vnode *vp; ufs2_daddr_t bn; ufs2_daddr_t *bnp; struct buf *nbp; int *runp; int *runb; { struct inode *ip; struct buf *bp; struct ufsmount *ump; struct mount *mp; struct vnode *devvp; struct indir a[NIADDR+1], *ap; ufs2_daddr_t daddr; ufs_lbn_t metalbn; int error, num, maxrun = 0; int *nump; ap = NULL; ip = VTOI(vp); mp = vp->v_mount; ump = VFSTOUFS(mp); devvp = ump->um_devvp; if (runp) { maxrun = mp->mnt_iosize_max / mp->mnt_stat.f_iosize - 1; *runp = 0; } if (runb) { *runb = 0; } ap = a; nump = # error = ufs_getlbns(vp, bn, ap, nump); if (error) return (error); num = *nump; if (num == 0) { if (bn >= 0 && bn < NDADDR) { *bnp = blkptrtodb(ump, DIP(ip, i_db[bn])); } else if (bn < 0 && bn >= -NXADDR) { *bnp = blkptrtodb(ump, ip->i_din2->di_extb[-1 - bn]); if (*bnp == 0) *bnp = -1; if (nbp == NULL) panic("ufs_bmaparray: mapping ext data"); nbp->b_xflags |= BX_ALTDATA; return (0); } else { panic("ufs_bmaparray: blkno out of range"); } /* * Since this is FFS independent code, we are out of * scope for the definitions of BLK_NOCOPY and * BLK_SNAP, but we do know that they will fall in * the range 1..um_seqinc, so we use that test and * return a request for a zeroed out buffer if attempts * are made to read a BLK_NOCOPY or BLK_SNAP block. */ if ((ip->i_flags & SF_SNAPSHOT) && DIP(ip, i_db[bn]) > 0 && DIP(ip, i_db[bn]) < ump->um_seqinc) { *bnp = -1; } else if (*bnp == 0) { if (ip->i_flags & SF_SNAPSHOT) *bnp = blkptrtodb(ump, bn * ump->um_seqinc); else *bnp = -1; } else if (runp) { ufs2_daddr_t bnb = bn; for (++bn; bn < NDADDR && *runp < maxrun && is_sequential(ump, DIP(ip, i_db[bn - 1]), DIP(ip, i_db[bn])); ++bn, ++*runp); bn = bnb; if (runb && (bn > 0)) { for (--bn; (bn >= 0) && (*runb < maxrun) && is_sequential(ump, DIP(ip, i_db[bn]), DIP(ip, i_db[bn+1])); --bn, ++*runb); } } return (0); } /* Get disk address out of indirect block array */ daddr = DIP(ip, i_ib[ap->in_off]); for (bp = NULL, ++ap; --num; ++ap) { /* * 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 = ap->in_lbn; if ((daddr == 0 && !incore(&vp->v_bufobj, 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); bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0, 0); if ((bp->b_flags & B_CACHE) == 0) { #ifdef INVARIANTS if (!daddr) panic("ufs_bmaparray: indirect block not in cache"); #endif bp->b_blkno = blkptrtodb(ump, daddr); bp->b_iocmd = BIO_READ; bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; vfs_busy_pages(bp, 0); bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); curthread->td_ru.ru_inblock++; error = bufwait(bp); if (error) { brelse(bp); return (error); } } if (ip->i_ump->um_fstype == UFS1) { daddr = ((ufs1_daddr_t *)bp->b_data)[ap->in_off]; if (num == 1 && daddr && runp) { for (bn = ap->in_off + 1; bn < MNINDIR(ump) && *runp < maxrun && is_sequential(ump, ((ufs1_daddr_t *)bp->b_data)[bn - 1], ((ufs1_daddr_t *)bp->b_data)[bn]); ++bn, ++*runp); bn = ap->in_off; if (runb && bn) { for (--bn; bn >= 0 && *runb < maxrun && is_sequential(ump, ((ufs1_daddr_t *)bp->b_data)[bn], ((ufs1_daddr_t *)bp->b_data)[bn+1]); --bn, ++*runb); } } continue; } daddr = ((ufs2_daddr_t *)bp->b_data)[ap->in_off]; if (num == 1 && daddr && runp) { for (bn = ap->in_off + 1; bn < MNINDIR(ump) && *runp < maxrun && is_sequential(ump, ((ufs2_daddr_t *)bp->b_data)[bn - 1], ((ufs2_daddr_t *)bp->b_data)[bn]); ++bn, ++*runp); bn = ap->in_off; if (runb && bn) { for (--bn; bn >= 0 && *runb < maxrun && is_sequential(ump, ((ufs2_daddr_t *)bp->b_data)[bn], ((ufs2_daddr_t *)bp->b_data)[bn + 1]); --bn, ++*runb); } } } if (bp) bqrelse(bp); /* * Since this is FFS independent code, we are out of scope for the * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they * will fall in the range 1..um_seqinc, so we use that test and * return a request for a zeroed out buffer if attempts are made * to read a BLK_NOCOPY or BLK_SNAP block. */ if ((ip->i_flags & SF_SNAPSHOT) && daddr > 0 && daddr < ump->um_seqinc){ *bnp = -1; return (0); } *bnp = blkptrtodb(ump, daddr); if (*bnp == 0) { if (ip->i_flags & SF_SNAPSHOT) *bnp = blkptrtodb(ump, bn * ump->um_seqinc); else *bnp = -1; } 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; ufs2_daddr_t bn; struct indir *ap; int *nump; { ufs2_daddr_t blockcnt; ufs_lbn_t metalbn, realbn; struct ufsmount *ump; int i, numlevels, off; ump = VFSTOUFS(vp->v_mount); if (nump) *nump = 0; numlevels = 0; realbn = bn; if (bn < 0) bn = -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); 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++; 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; metalbn -= -1 + off * blockcnt; } if (nump) *nump = numlevels; return (0); }