/* $OpenBSD: ext2fs_balloc.c,v 1.21 2014/07/08 17:19:26 deraadt Exp $ */ /* $NetBSD: ext2fs_balloc.c,v 1.10 2001/07/04 21:16:01 chs 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. 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 /* * 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; struct buf *bp, *nbp; struct vnode *vp = ITOV(ip); struct indir indirs[NIADDR + 2]; int32_t nb, newb, *bap; int num, i, error; u_int deallocated; int32_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1]; int unwindidx = -1; daddr_t lbn, pref; *bpp = NULL; if (bn < 0) return (EFBIG); fs = ip->i_e2fs; lbn = bn; /* * The first NDADDR blocks are direct blocks */ if (bn < NDADDR) { nb = fs2h32(ip->i_e2fs_blocks[bn]); if (nb != 0) { error = bread(vp, bn, fs->e2fs_bsize, &bp); if (error) { brelse(bp); return (error); } *bpp = bp; return (0); } /* * allocate a new direct block. */ 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; ip->i_e2fs_blocks[bn] = h2fs32(newb); ip->i_flag |= IN_CHANGE | IN_UPDATE; bp = getblk(vp, bn, fs->e2fs_bsize, 0, 0); bp->b_blkno = fsbtodb(fs, newb); if (flags & B_CLRBUF) clrbuf(bp); *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 = fs2h32(ip->i_e2fs_blocks[NDADDR + indirs[0].in_off]); allocib = NULL; allocblk = allociblk; if (nb == 0) { pref = ext2fs_blkpref(ip, lbn, 0, (int32_t *)0); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) return (error); nb = newb; *allocblk++ = nb; 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) goto fail; unwindidx = 0; allocib = &ip->i_e2fs_blocks[NDADDR + indirs[0].in_off]; *allocib = h2fs32(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, &bp); if (error) { brelse(bp); goto fail; } bap = (int32_t *)bp->b_data; nb = fs2h32(bap[indirs[i].in_off]); if (i == num) break; i++; if (nb != 0) { brelse(bp); continue; } pref = ext2fs_blkpref(ip, lbn, 0, (int32_t *)0); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) { brelse(bp); goto fail; } nb = newb; *allocblk++ = nb; 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) { brelse(bp); goto fail; } if (unwindidx < 0) unwindidx = i - 1; bap[indirs[i - 1].in_off] = h2fs32(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[num].in_off, &bap[0]); error = ext2fs_alloc(ip, lbn, pref, cred, &newb); if (error) { brelse(bp); goto fail; } nb = newb; *allocblk++ = nb; ip->i_e2fs_last_lblk = lbn; ip->i_e2fs_last_blk = newb; bap[indirs[num].in_off] = h2fs32(nb); /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & B_SYNC) { bwrite(bp); } else { bdwrite(bp); } nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); if (flags & B_CLRBUF) clrbuf(nbp); *bpp = nbp; return (0); } brelse(bp); if (flags & B_CLRBUF) { error = bread(vp, lbn, (int)fs->e2fs_bsize, &nbp); if (error) { brelse(nbp); goto fail; } } else { nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); } *bpp = nbp; return (0); fail: /* * If we have failed part way through block allocation, we * have to deallocate any indirect blocks that we have allocated. */ for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) { ext2fs_blkfree(ip, *blkp); deallocated += fs->e2fs_bsize; } if (unwindidx >= 0) { if (unwindidx == 0) { *allocib = 0; } else { int r; r = bread(vp, indirs[unwindidx].in_lbn, (int)fs->e2fs_bsize, &bp); if (r) { panic("Could not unwind indirect block, error %d", r); } else { bap = (int32_t *)bp->b_data; bap[indirs[unwindidx].in_off] = 0; if (flags & B_SYNC) bwrite(bp); else bdwrite(bp); } } for (i = unwindidx + 1; i <= num; i++) { bp = getblk(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize, 0, 0); bp->b_flags |= B_INVAL; brelse(bp); } } if (deallocated) { ip->i_e2fs_nblock -= btodb(deallocated); ip->i_e2fs_flags |= IN_CHANGE | IN_UPDATE; } return error; }