/* $OpenBSD: ext2fs_balloc.c,v 1.5 2001/06/23 02:07:50 csapuntz Exp $ */ /* $NetBSD: ext2fs_balloc.c,v 1.1 1997/06/11 09:33:44 bouyer Exp $ */ /* * Copyright (c) 1997 Manuel Bouyer. * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * 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. * * @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93 * Modified for ext2fs by Manuel Bouyer. */ #include #include #include #include #include #include #include #include #include #include #include #include /* * Balloc defines the structure of file system storage * by allocating the physical blocks on a device given * the inode and the logical block number in a file. */ int ext2fs_buf_alloc(struct inode *ip, daddr_t bn, int size, struct ucred *cred, struct buf **bpp, int flags) { struct m_ext2fs *fs; daddr_t nb; struct buf *bp, *nbp; struct vnode *vp = ITOV(ip); struct indir indirs[NIADDR + 2]; daddr_t newb, lbn, *bap, pref; int num, i, error; *bpp = NULL; if (bn < 0) return (EFBIG); fs = ip->i_e2fs; lbn = bn; /* * The first NDADDR blocks are direct blocks */ if (bn < NDADDR) { nb = ip->i_e2fs_blocks[bn]; if (nb != 0) { error = bread(vp, bn, fs->e2fs_bsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } *bpp = bp; return (0); } else { error = ext2fs_alloc(ip, bn, ext2fs_blkpref(ip, bn, (int)bn, &ip->i_e2fs_blocks[0]), cred, &newb); if (error) return (error); ip->i_e2fs_last_lblk = lbn; ip->i_e2fs_last_blk = newb; bp = getblk(vp, bn, fs->e2fs_bsize, 0, 0); bp->b_blkno = fsbtodb(fs, newb); if (flags & B_CLRBUF) clrbuf(bp); } ip->i_e2fs_blocks[bn] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE | IN_UPDATE; *bpp = bp; return (0); } /* * Determine the number of levels of indirection. */ pref = 0; if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0) return(error); #ifdef DIAGNOSTIC if (num < 1) panic ("ext2fs_balloc: ufs_getlbns returned indirect block"); #endif /* * Fetch the first indirect block allocating if necessary. */ --num; nb = ip->i_e2fs_blocks[NDADDR + indirs[0].in_off]; if (nb == 0) { pref = ext2fs_blkpref(ip, lbn, 0, (daddr_t *)0); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) return (error); nb = newb; ip->i_e2fs_last_blk = newb; bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0); bp->b_blkno = fsbtodb(fs, newb); clrbuf(bp); /* * Write synchronously so that indirect blocks * never point at garbage. */ if ((error = bwrite(bp)) != 0) { ext2fs_blkfree(ip, nb); return (error); } ip->i_e2fs_blocks[NDADDR + indirs[0].in_off] = newb; ip->i_flag |= IN_CHANGE | IN_UPDATE; } /* * Fetch through the indirect blocks, allocating as necessary. */ for (i = 1;;) { error = bread(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bap = (daddr_t *)bp->b_data; nb = bap[indirs[i].in_off]; if (i == num) break; i += 1; if (nb != 0) { brelse(bp); continue; } pref = ext2fs_blkpref(ip, lbn, 0, (daddr_t *)0); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) { brelse(bp); return (error); } nb = newb; ip->i_e2fs_last_blk = newb; nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); clrbuf(nbp); /* * Write synchronously so that indirect blocks * never point at garbage. */ if ((error = bwrite(nbp)) != 0) { ext2fs_blkfree(ip, nb); brelse(bp); return (error); } bap[indirs[i - 1].in_off] = nb; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & B_SYNC) { bwrite(bp); } else { bdwrite(bp); } } /* * Get the data block, allocating if necessary. */ if (nb == 0) { pref = ext2fs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) { brelse(bp); return (error); } nb = newb; ip->i_e2fs_last_lblk = lbn; ip->i_e2fs_last_blk = newb; nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); if (flags & B_CLRBUF) clrbuf(nbp); bap[indirs[i].in_off] = nb; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & B_SYNC) { bwrite(bp); } else { bdwrite(bp); } *bpp = nbp; return (0); } brelse(bp); if (flags & B_CLRBUF) { error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp); if (error) { brelse(nbp); return (error); } } else { nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); } *bpp = nbp; return (0); }