1 /*- 2 * modified for Lites 1.1 3 * 4 * Aug 1995, Godmar Back (gback@cs.utah.edu) 5 * University of Utah, Department of Computer Science 6 */ 7 /*- 8 * SPDX-License-Identifier: BSD-3-Clause 9 * 10 * Copyright (c) 1982, 1986, 1989, 1993 11 * The Regents of the University of California. All rights reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93 38 * $FreeBSD$ 39 */ 40 41 #include <sys/param.h> 42 43 #include <sys/proc.h> 44 #include <sys/systm.h> 45 #include <sys/bio.h> 46 #include <sys/buf.h> 47 #include <sys/lock.h> 48 #include <sys/ucred.h> 49 #include <sys/vnode.h> 50 51 #include <fs/ext2fs/inode.h> 52 #include <fs/ext2fs/ext2fs.h> 53 #include <fs/ext2fs/ext2_extern.h> 54 #include <fs/ext2fs/fs.h> 55 #include <fs/ext2fs/ext2_extents.h> 56 #include <fs/ext2fs/ext2_mount.h> 57 #include <fs/ext2fs/ext2_dinode.h> 58 59 /* 60 * Return buffer with the contents of block "offset" from the beginning of 61 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 62 * remaining space in the directory. 63 */ 64 int 65 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 66 { 67 struct inode *ip; 68 struct m_ext2fs *fs; 69 struct buf *bp; 70 e2fs_lbn_t lbn; 71 int error, bsize; 72 73 ip = VTOI(vp); 74 fs = ip->i_e2fs; 75 lbn = lblkno(fs, offset); 76 bsize = blksize(fs, ip, lbn); 77 78 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 79 brelse(bp); 80 return (error); 81 } 82 if (res) 83 *res = (char *)bp->b_data + blkoff(fs, offset); 84 85 *bpp = bp; 86 87 return (0); 88 } 89 90 /* 91 * Update the cluster map because of an allocation of free like ffs. 92 * 93 * Cnt == 1 means free; cnt == -1 means allocating. 94 */ 95 void 96 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt) 97 { 98 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 99 int32_t *lp; 100 e4fs_daddr_t start, end, loc, forw, back; 101 int bit, i; 102 103 /* Initialize the cluster summary array. */ 104 if (fs->e2fs_clustersum[cg].cs_init == 0) { 105 int run = 0; 106 107 bit = 1; 108 loc = 0; 109 110 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 111 if ((bbp[loc] & bit) == 0) 112 run++; 113 else if (run != 0) { 114 if (run > fs->e2fs_contigsumsize) 115 run = fs->e2fs_contigsumsize; 116 sump[run]++; 117 run = 0; 118 } 119 if ((i & (NBBY - 1)) != (NBBY - 1)) 120 bit <<= 1; 121 else { 122 loc++; 123 bit = 1; 124 } 125 } 126 if (run != 0) { 127 if (run > fs->e2fs_contigsumsize) 128 run = fs->e2fs_contigsumsize; 129 sump[run]++; 130 } 131 fs->e2fs_clustersum[cg].cs_init = 1; 132 } 133 134 if (fs->e2fs_contigsumsize <= 0) 135 return; 136 137 /* Find the size of the cluster going forward. */ 138 start = bno + 1; 139 end = start + fs->e2fs_contigsumsize; 140 if (end > fs->e2fs->e2fs_fpg) 141 end = fs->e2fs->e2fs_fpg; 142 loc = start / NBBY; 143 bit = 1 << (start % NBBY); 144 for (i = start; i < end; i++) { 145 if ((bbp[loc] & bit) != 0) 146 break; 147 if ((i & (NBBY - 1)) != (NBBY - 1)) 148 bit <<= 1; 149 else { 150 loc++; 151 bit = 1; 152 } 153 } 154 forw = i - start; 155 156 /* Find the size of the cluster going backward. */ 157 start = bno - 1; 158 end = start - fs->e2fs_contigsumsize; 159 if (end < 0) 160 end = -1; 161 loc = start / NBBY; 162 bit = 1 << (start % NBBY); 163 for (i = start; i > end; i--) { 164 if ((bbp[loc] & bit) != 0) 165 break; 166 if ((i & (NBBY - 1)) != 0) 167 bit >>= 1; 168 else { 169 loc--; 170 bit = 1 << (NBBY - 1); 171 } 172 } 173 back = start - i; 174 175 /* 176 * Account for old cluster and the possibly new forward and 177 * back clusters. 178 */ 179 i = back + forw + 1; 180 if (i > fs->e2fs_contigsumsize) 181 i = fs->e2fs_contigsumsize; 182 sump[i] += cnt; 183 if (back > 0) 184 sump[back] -= cnt; 185 if (forw > 0) 186 sump[forw] -= cnt; 187 188 /* Update cluster summary information. */ 189 lp = &sump[fs->e2fs_contigsumsize]; 190 for (i = fs->e2fs_contigsumsize; i > 0; i--) 191 if (*lp-- > 0) 192 break; 193 fs->e2fs_maxcluster[cg] = i; 194 } 195