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