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/sdt.h> 45 #include <sys/systm.h> 46 #include <sys/bio.h> 47 #include <sys/buf.h> 48 #include <sys/lock.h> 49 #include <sys/ucred.h> 50 #include <sys/vnode.h> 51 52 #include <fs/ext2fs/fs.h> 53 #include <fs/ext2fs/inode.h> 54 #include <fs/ext2fs/ext2fs.h> 55 #include <fs/ext2fs/ext2_extern.h> 56 #include <fs/ext2fs/fs.h> 57 #include <fs/ext2fs/ext2_extents.h> 58 #include <fs/ext2fs/ext2_mount.h> 59 #include <fs/ext2fs/ext2_dinode.h> 60 61 /* 62 * Return buffer with the contents of block "offset" from the beginning of 63 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 64 * remaining space in the directory. 65 */ 66 int 67 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 68 { 69 struct inode *ip; 70 struct m_ext2fs *fs; 71 struct buf *bp; 72 e2fs_lbn_t lbn; 73 int error, bsize; 74 75 ip = VTOI(vp); 76 fs = ip->i_e2fs; 77 lbn = lblkno(fs, offset); 78 bsize = blksize(fs, ip, lbn); 79 80 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 81 brelse(bp); 82 return (error); 83 } 84 error = ext2_dir_blk_csum_verify(ip, bp); 85 if (error != 0) { 86 brelse(bp); 87 return (error); 88 } 89 if (res) 90 *res = (char *)bp->b_data + blkoff(fs, offset); 91 92 *bpp = bp; 93 94 return (0); 95 } 96 97 /* 98 * Update the cluster map because of an allocation of free like ffs. 99 * 100 * Cnt == 1 means free; cnt == -1 means allocating. 101 */ 102 void 103 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt) 104 { 105 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 106 int32_t *lp; 107 e4fs_daddr_t start, end, loc, forw, back; 108 int bit, i; 109 110 /* Initialize the cluster summary array. */ 111 if (fs->e2fs_clustersum[cg].cs_init == 0) { 112 int run = 0; 113 114 bit = 1; 115 loc = 0; 116 117 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 118 if ((bbp[loc] & bit) == 0) 119 run++; 120 else if (run != 0) { 121 if (run > fs->e2fs_contigsumsize) 122 run = fs->e2fs_contigsumsize; 123 sump[run]++; 124 run = 0; 125 } 126 if ((i & (NBBY - 1)) != (NBBY - 1)) 127 bit <<= 1; 128 else { 129 loc++; 130 bit = 1; 131 } 132 } 133 if (run != 0) { 134 if (run > fs->e2fs_contigsumsize) 135 run = fs->e2fs_contigsumsize; 136 sump[run]++; 137 } 138 fs->e2fs_clustersum[cg].cs_init = 1; 139 } 140 141 if (fs->e2fs_contigsumsize <= 0) 142 return; 143 144 /* Find the size of the cluster going forward. */ 145 start = bno + 1; 146 end = start + fs->e2fs_contigsumsize; 147 if (end > fs->e2fs->e2fs_fpg) 148 end = fs->e2fs->e2fs_fpg; 149 loc = start / NBBY; 150 bit = 1 << (start % NBBY); 151 for (i = start; i < end; i++) { 152 if ((bbp[loc] & bit) != 0) 153 break; 154 if ((i & (NBBY - 1)) != (NBBY - 1)) 155 bit <<= 1; 156 else { 157 loc++; 158 bit = 1; 159 } 160 } 161 forw = i - start; 162 163 /* Find the size of the cluster going backward. */ 164 start = bno - 1; 165 end = start - fs->e2fs_contigsumsize; 166 if (end < 0) 167 end = -1; 168 loc = start / NBBY; 169 bit = 1 << (start % NBBY); 170 for (i = start; i > end; i--) { 171 if ((bbp[loc] & bit) != 0) 172 break; 173 if ((i & (NBBY - 1)) != 0) 174 bit >>= 1; 175 else { 176 loc--; 177 bit = 1 << (NBBY - 1); 178 } 179 } 180 back = start - i; 181 182 /* 183 * Account for old cluster and the possibly new forward and 184 * back clusters. 185 */ 186 i = back + forw + 1; 187 if (i > fs->e2fs_contigsumsize) 188 i = fs->e2fs_contigsumsize; 189 sump[i] += cnt; 190 if (back > 0) 191 sump[back] -= cnt; 192 if (forw > 0) 193 sump[forw] -= cnt; 194 195 /* Update cluster summary information. */ 196 lp = &sump[fs->e2fs_contigsumsize]; 197 for (i = fs->e2fs_contigsumsize; i > 0; i--) 198 if (*lp-- > 0) 199 break; 200 fs->e2fs_maxcluster[cg] = i; 201 } 202