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 error = ext2_dir_blk_csum_verify(ip, bp); 83 if (error != 0) { 84 brelse(bp); 85 return (error); 86 } 87 if (res) 88 *res = (char *)bp->b_data + blkoff(fs, offset); 89 90 *bpp = bp; 91 92 return (0); 93 } 94 95 /* 96 * Update the cluster map because of an allocation of free like ffs. 97 * 98 * Cnt == 1 means free; cnt == -1 means allocating. 99 */ 100 void 101 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt) 102 { 103 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 104 int32_t *lp; 105 e4fs_daddr_t start, end, loc, forw, back; 106 int bit, i; 107 108 /* Initialize the cluster summary array. */ 109 if (fs->e2fs_clustersum[cg].cs_init == 0) { 110 int run = 0; 111 112 bit = 1; 113 loc = 0; 114 115 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 116 if ((bbp[loc] & bit) == 0) 117 run++; 118 else if (run != 0) { 119 if (run > fs->e2fs_contigsumsize) 120 run = fs->e2fs_contigsumsize; 121 sump[run]++; 122 run = 0; 123 } 124 if ((i & (NBBY - 1)) != (NBBY - 1)) 125 bit <<= 1; 126 else { 127 loc++; 128 bit = 1; 129 } 130 } 131 if (run != 0) { 132 if (run > fs->e2fs_contigsumsize) 133 run = fs->e2fs_contigsumsize; 134 sump[run]++; 135 } 136 fs->e2fs_clustersum[cg].cs_init = 1; 137 } 138 139 if (fs->e2fs_contigsumsize <= 0) 140 return; 141 142 /* Find the size of the cluster going forward. */ 143 start = bno + 1; 144 end = start + fs->e2fs_contigsumsize; 145 if (end > fs->e2fs->e2fs_fpg) 146 end = fs->e2fs->e2fs_fpg; 147 loc = start / NBBY; 148 bit = 1 << (start % NBBY); 149 for (i = start; i < end; i++) { 150 if ((bbp[loc] & bit) != 0) 151 break; 152 if ((i & (NBBY - 1)) != (NBBY - 1)) 153 bit <<= 1; 154 else { 155 loc++; 156 bit = 1; 157 } 158 } 159 forw = i - start; 160 161 /* Find the size of the cluster going backward. */ 162 start = bno - 1; 163 end = start - fs->e2fs_contigsumsize; 164 if (end < 0) 165 end = -1; 166 loc = start / NBBY; 167 bit = 1 << (start % NBBY); 168 for (i = start; i > end; i--) { 169 if ((bbp[loc] & bit) != 0) 170 break; 171 if ((i & (NBBY - 1)) != 0) 172 bit >>= 1; 173 else { 174 loc--; 175 bit = 1 << (NBBY - 1); 176 } 177 } 178 back = start - i; 179 180 /* 181 * Account for old cluster and the possibly new forward and 182 * back clusters. 183 */ 184 i = back + forw + 1; 185 if (i > fs->e2fs_contigsumsize) 186 i = fs->e2fs_contigsumsize; 187 sump[i] += cnt; 188 if (back > 0) 189 sump[back] -= cnt; 190 if (forw > 0) 191 sump[forw] -= cnt; 192 193 /* Update cluster summary information. */ 194 lp = &sump[fs->e2fs_contigsumsize]; 195 for (i = fs->e2fs_contigsumsize; i > 0; i--) 196 if (*lp-- > 0) 197 break; 198 fs->e2fs_maxcluster[cg] = i; 199 } 200