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 38 #include <sys/param.h> 39 40 #include <sys/proc.h> 41 #include <sys/sdt.h> 42 #include <sys/systm.h> 43 #include <sys/bio.h> 44 #include <sys/buf.h> 45 #include <sys/lock.h> 46 #include <sys/ucred.h> 47 #include <sys/vnode.h> 48 49 #include <fs/ext2fs/fs.h> 50 #include <fs/ext2fs/inode.h> 51 #include <fs/ext2fs/ext2fs.h> 52 #include <fs/ext2fs/ext2_extern.h> 53 #include <fs/ext2fs/fs.h> 54 #include <fs/ext2fs/ext2_extents.h> 55 #include <fs/ext2fs/ext2_mount.h> 56 #include <fs/ext2fs/ext2_dinode.h> 57 58 /* 59 * Return buffer with the contents of block "offset" from the beginning of 60 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 61 * remaining space in the directory. 62 */ 63 int 64 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 65 { 66 struct inode *ip; 67 struct m_ext2fs *fs; 68 struct buf *bp; 69 e2fs_lbn_t lbn; 70 int error, bsize; 71 72 ip = VTOI(vp); 73 fs = ip->i_e2fs; 74 lbn = lblkno(fs, offset); 75 bsize = blksize(fs, ip, lbn); 76 77 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 78 brelse(bp); 79 return (error); 80 } 81 error = ext2_dir_blk_csum_verify(ip, bp); 82 if (error != 0) { 83 brelse(bp); 84 return (error); 85 } 86 if (res) 87 *res = (char *)bp->b_data + blkoff(fs, offset); 88 89 *bpp = bp; 90 91 return (0); 92 } 93 94 /* 95 * Update the cluster map because of an allocation of free like ffs. 96 * 97 * Cnt == 1 means free; cnt == -1 means allocating. 98 */ 99 void 100 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt) 101 { 102 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 103 int32_t *lp; 104 e4fs_daddr_t start, end, loc, forw, back; 105 int bit, i; 106 107 /* Initialize the cluster summary array. */ 108 if (fs->e2fs_clustersum[cg].cs_init == 0) { 109 int run = 0; 110 111 bit = 1; 112 loc = 0; 113 114 for (i = 0; i < fs->e2fs_fpg; i++) { 115 if ((bbp[loc] & bit) == 0) 116 run++; 117 else if (run != 0) { 118 if (run > fs->e2fs_contigsumsize) 119 run = fs->e2fs_contigsumsize; 120 sump[run]++; 121 run = 0; 122 } 123 if ((i & (NBBY - 1)) != (NBBY - 1)) 124 bit <<= 1; 125 else { 126 loc++; 127 bit = 1; 128 } 129 } 130 if (run != 0) { 131 if (run > fs->e2fs_contigsumsize) 132 run = fs->e2fs_contigsumsize; 133 sump[run]++; 134 } 135 fs->e2fs_clustersum[cg].cs_init = 1; 136 } 137 138 if (fs->e2fs_contigsumsize <= 0) 139 return; 140 141 /* Find the size of the cluster going forward. */ 142 start = bno + 1; 143 end = start + fs->e2fs_contigsumsize; 144 if (end > fs->e2fs_fpg) 145 end = fs->e2fs_fpg; 146 loc = start / NBBY; 147 bit = 1 << (start % NBBY); 148 for (i = start; i < end; i++) { 149 if ((bbp[loc] & bit) != 0) 150 break; 151 if ((i & (NBBY - 1)) != (NBBY - 1)) 152 bit <<= 1; 153 else { 154 loc++; 155 bit = 1; 156 } 157 } 158 forw = i - start; 159 160 /* Find the size of the cluster going backward. */ 161 start = bno - 1; 162 end = start - fs->e2fs_contigsumsize; 163 if (end < 0) 164 end = -1; 165 loc = start / NBBY; 166 bit = 1 << (start % NBBY); 167 for (i = start; i > end; i--) { 168 if ((bbp[loc] & bit) != 0) 169 break; 170 if ((i & (NBBY - 1)) != 0) 171 bit >>= 1; 172 else { 173 loc--; 174 bit = 1 << (NBBY - 1); 175 } 176 } 177 back = start - i; 178 179 /* 180 * Account for old cluster and the possibly new forward and 181 * back clusters. 182 */ 183 i = back + forw + 1; 184 if (i > fs->e2fs_contigsumsize) 185 i = fs->e2fs_contigsumsize; 186 sump[i] += cnt; 187 if (back > 0) 188 sump[back] -= cnt; 189 if (forw > 0) 190 sump[forw] -= cnt; 191 192 /* Update cluster summary information. */ 193 lp = &sump[fs->e2fs_contigsumsize]; 194 for (i = fs->e2fs_contigsumsize; i > 0; i--) 195 if (*lp-- > 0) 196 break; 197 fs->e2fs_maxcluster[cg] = i; 198 } 199