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 */ 39 40 #include <sys/param.h> 41 42 #include <sys/proc.h> 43 #include <sys/sdt.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/fs.h> 52 #include <fs/ext2fs/inode.h> 53 #include <fs/ext2fs/ext2fs.h> 54 #include <fs/ext2fs/ext2_extern.h> 55 #include <fs/ext2fs/fs.h> 56 #include <fs/ext2fs/ext2_extents.h> 57 #include <fs/ext2fs/ext2_mount.h> 58 #include <fs/ext2fs/ext2_dinode.h> 59 60 /* 61 * Return buffer with the contents of block "offset" from the beginning of 62 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 63 * remaining space in the directory. 64 */ 65 int 66 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 67 { 68 struct inode *ip; 69 struct m_ext2fs *fs; 70 struct buf *bp; 71 e2fs_lbn_t lbn; 72 int error, bsize; 73 74 ip = VTOI(vp); 75 fs = ip->i_e2fs; 76 lbn = lblkno(fs, offset); 77 bsize = blksize(fs, ip, lbn); 78 79 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 80 brelse(bp); 81 return (error); 82 } 83 error = ext2_dir_blk_csum_verify(ip, bp); 84 if (error != 0) { 85 brelse(bp); 86 return (error); 87 } 88 if (res) 89 *res = (char *)bp->b_data + blkoff(fs, offset); 90 91 *bpp = bp; 92 93 return (0); 94 } 95 96 /* 97 * Update the cluster map because of an allocation of free like ffs. 98 * 99 * Cnt == 1 means free; cnt == -1 means allocating. 100 */ 101 void 102 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt) 103 { 104 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 105 int32_t *lp; 106 e4fs_daddr_t start, end, loc, forw, back; 107 int bit, i; 108 109 /* Initialize the cluster summary array. */ 110 if (fs->e2fs_clustersum[cg].cs_init == 0) { 111 int run = 0; 112 113 bit = 1; 114 loc = 0; 115 116 for (i = 0; i < fs->e2fs_fpg; i++) { 117 if ((bbp[loc] & bit) == 0) 118 run++; 119 else if (run != 0) { 120 if (run > fs->e2fs_contigsumsize) 121 run = fs->e2fs_contigsumsize; 122 sump[run]++; 123 run = 0; 124 } 125 if ((i & (NBBY - 1)) != (NBBY - 1)) 126 bit <<= 1; 127 else { 128 loc++; 129 bit = 1; 130 } 131 } 132 if (run != 0) { 133 if (run > fs->e2fs_contigsumsize) 134 run = fs->e2fs_contigsumsize; 135 sump[run]++; 136 } 137 fs->e2fs_clustersum[cg].cs_init = 1; 138 } 139 140 if (fs->e2fs_contigsumsize <= 0) 141 return; 142 143 /* Find the size of the cluster going forward. */ 144 start = bno + 1; 145 end = start + fs->e2fs_contigsumsize; 146 if (end > fs->e2fs_fpg) 147 end = fs->e2fs_fpg; 148 loc = start / NBBY; 149 bit = 1 << (start % NBBY); 150 for (i = start; i < end; i++) { 151 if ((bbp[loc] & bit) != 0) 152 break; 153 if ((i & (NBBY - 1)) != (NBBY - 1)) 154 bit <<= 1; 155 else { 156 loc++; 157 bit = 1; 158 } 159 } 160 forw = i - start; 161 162 /* Find the size of the cluster going backward. */ 163 start = bno - 1; 164 end = start - fs->e2fs_contigsumsize; 165 if (end < 0) 166 end = -1; 167 loc = start / NBBY; 168 bit = 1 << (start % NBBY); 169 for (i = start; i > end; i--) { 170 if ((bbp[loc] & bit) != 0) 171 break; 172 if ((i & (NBBY - 1)) != 0) 173 bit >>= 1; 174 else { 175 loc--; 176 bit = 1 << (NBBY - 1); 177 } 178 } 179 back = start - i; 180 181 /* 182 * Account for old cluster and the possibly new forward and 183 * back clusters. 184 */ 185 i = back + forw + 1; 186 if (i > fs->e2fs_contigsumsize) 187 i = fs->e2fs_contigsumsize; 188 sump[i] += cnt; 189 if (back > 0) 190 sump[back] -= cnt; 191 if (forw > 0) 192 sump[forw] -= cnt; 193 194 /* Update cluster summary information. */ 195 lp = &sump[fs->e2fs_contigsumsize]; 196 for (i = fs->e2fs_contigsumsize; i > 0; i--) 197 if (*lp-- > 0) 198 break; 199 fs->e2fs_maxcluster[cg] = i; 200 } 201