/*- * modified for Lites 1.1 * * Aug 1995, Godmar Back (gback@cs.utah.edu) * University of Utah, Department of Computer Science */ /*- * 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. * 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_subr.c 8.2 (Berkeley) 9/21/93 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KDB void ext2_checkoverlap(struct buf *, struct inode *); #endif /* * Return buffer with the contents of block "offset" from the beginning of * directory "ip". If "res" is non-zero, fill it in with a pointer to the * remaining space in the directory. */ int ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) { struct inode *ip; struct m_ext2fs *fs; struct buf *bp; e2fs_lbn_t lbn; int bsize, error; daddr_t newblk; struct ext4_extent *ep; struct ext4_extent_path path; ip = VTOI(vp); fs = ip->i_e2fs; lbn = lblkno(fs, offset); bsize = blksize(fs, ip, lbn); *bpp = NULL; /* * IN_E4EXTENTS requires special treatment as we can otherwise fall * back to the normal path. */ if (!(ip->i_flag & IN_E4EXTENTS)) goto normal; memset(&path, 0, sizeof(path)); if (ext4_ext_find_extent(fs, ip, lbn, &path) == NULL) goto normal; ep = path.ep_ext; if (ep == NULL) goto normal; newblk = lbn - ep->e_blk + (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32); if (path.ep_bp != NULL) { brelse(path.ep_bp); path.ep_bp = NULL; } error = bread(ip->i_devvp, fsbtodb(fs, newblk), bsize, NOCRED, &bp); if (error != 0) { brelse(bp); return (error); } if (res) *res = (char *)bp->b_data + blkoff(fs, offset); /* * If IN_E4EXTENTS is enabled we would get a wrong offset so * reset b_offset here. */ bp->b_offset = lbn * bsize; *bpp = bp; return (0); normal: if (*bpp == NULL) { if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { brelse(bp); return (error); } if (res) *res = (char *)bp->b_data + blkoff(fs, offset); *bpp = bp; } return (0); } #ifdef KDB void ext2_checkoverlap(struct buf *bp, struct inode *ip) { struct buf *ebp, *ep; e4fs_daddr_t start, last; struct vnode *vp; ebp = &buf[nbuf]; start = bp->b_blkno; last = start + btodb(bp->b_bcount) - 1; for (ep = buf; ep < ebp; ep++) { if (ep == bp || (ep->b_flags & B_INVAL)) continue; vp = ip->i_ump->um_devvp; /* look for overlap */ if (ep->b_bcount == 0 || ep->b_blkno > last || ep->b_blkno + btodb(ep->b_bcount) <= start) continue; vprint("Disk overlap", vp); printf("\tstart %jd, end %jd overlap start %jd, end %jd\n", (intmax_t)start, (intmax_t)last, (intmax_t)ep->b_blkno, (intmax_t)(ep->b_blkno + btodb(ep->b_bcount) - 1)); panic("ext2_checkoverlap: Disk buffer overlap"); } } #endif /* KDB */ /* * Update the cluster map because of an allocation of free like ffs. * * Cnt == 1 means free; cnt == -1 means allocating. */ void ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt) { int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; int32_t *lp; int back, bit, end, forw, i, loc, start; /* Initialize the cluster summary array. */ if (fs->e2fs_clustersum[cg].cs_init == 0) { int run = 0; bit = 1; loc = 0; for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { if ((bbp[loc] & bit) == 0) run++; else if (run != 0) { if (run > fs->e2fs_contigsumsize) run = fs->e2fs_contigsumsize; sump[run]++; run = 0; } if ((i & (NBBY - 1)) != (NBBY - 1)) bit <<= 1; else { loc++; bit = 1; } } if (run != 0) { if (run > fs->e2fs_contigsumsize) run = fs->e2fs_contigsumsize; sump[run]++; } fs->e2fs_clustersum[cg].cs_init = 1; } if (fs->e2fs_contigsumsize <= 0) return; /* Find the size of the cluster going forward. */ start = bno + 1; end = start + fs->e2fs_contigsumsize; if (end > fs->e2fs->e2fs_fpg) end = fs->e2fs->e2fs_fpg; loc = start / NBBY; bit = 1 << (start % NBBY); for (i = start; i < end; i++) { if ((bbp[loc] & bit) != 0) break; if ((i & (NBBY - 1)) != (NBBY - 1)) bit <<= 1; else { loc++; bit = 1; } } forw = i - start; /* Find the size of the cluster going backward. */ start = bno - 1; end = start - fs->e2fs_contigsumsize; if (end < 0) end = -1; loc = start / NBBY; bit = 1 << (start % NBBY); for (i = start; i > end; i--) { if ((bbp[loc] & bit) != 0) break; if ((i & (NBBY - 1)) != 0) bit >>= 1; else { loc--; bit = 1 << (NBBY - 1); } } back = start - i; /* * Account for old cluster and the possibly new forward and * back clusters. */ i = back + forw + 1; if (i > fs->e2fs_contigsumsize) i = fs->e2fs_contigsumsize; sump[i] += cnt; if (back > 0) sump[back] -= cnt; if (forw > 0) sump[forw] -= cnt; /* Update cluster summary information. */ lp = &sump[fs->e2fs_contigsumsize]; for (i = fs->e2fs_contigsumsize; i > 0; i--) if (*lp-- > 0) break; fs->e2fs_maxcluster[cg] = i; }