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, daddr_t bno, int cnt) 95 { 96 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 97 int32_t *lp; 98 int back, bit, end, forw, i, loc, start; 99 100 /* Initialize the cluster summary array. */ 101 if (fs->e2fs_clustersum[cg].cs_init == 0) { 102 int run = 0; 103 104 bit = 1; 105 loc = 0; 106 107 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 108 if ((bbp[loc] & bit) == 0) 109 run++; 110 else if (run != 0) { 111 if (run > fs->e2fs_contigsumsize) 112 run = fs->e2fs_contigsumsize; 113 sump[run]++; 114 run = 0; 115 } 116 if ((i & (NBBY - 1)) != (NBBY - 1)) 117 bit <<= 1; 118 else { 119 loc++; 120 bit = 1; 121 } 122 } 123 if (run != 0) { 124 if (run > fs->e2fs_contigsumsize) 125 run = fs->e2fs_contigsumsize; 126 sump[run]++; 127 } 128 fs->e2fs_clustersum[cg].cs_init = 1; 129 } 130 131 if (fs->e2fs_contigsumsize <= 0) 132 return; 133 134 /* Find the size of the cluster going forward. */ 135 start = bno + 1; 136 end = start + fs->e2fs_contigsumsize; 137 if (end > fs->e2fs->e2fs_fpg) 138 end = fs->e2fs->e2fs_fpg; 139 loc = start / NBBY; 140 bit = 1 << (start % NBBY); 141 for (i = start; i < end; i++) { 142 if ((bbp[loc] & bit) != 0) 143 break; 144 if ((i & (NBBY - 1)) != (NBBY - 1)) 145 bit <<= 1; 146 else { 147 loc++; 148 bit = 1; 149 } 150 } 151 forw = i - start; 152 153 /* Find the size of the cluster going backward. */ 154 start = bno - 1; 155 end = start - fs->e2fs_contigsumsize; 156 if (end < 0) 157 end = -1; 158 loc = start / NBBY; 159 bit = 1 << (start % NBBY); 160 for (i = start; i > end; i--) { 161 if ((bbp[loc] & bit) != 0) 162 break; 163 if ((i & (NBBY - 1)) != 0) 164 bit >>= 1; 165 else { 166 loc--; 167 bit = 1 << (NBBY - 1); 168 } 169 } 170 back = start - i; 171 172 /* 173 * Account for old cluster and the possibly new forward and 174 * back clusters. 175 */ 176 i = back + forw + 1; 177 if (i > fs->e2fs_contigsumsize) 178 i = fs->e2fs_contigsumsize; 179 sump[i] += cnt; 180 if (back > 0) 181 sump[back] -= cnt; 182 if (forw > 0) 183 sump[forw] -= cnt; 184 185 /* Update cluster summary information. */ 186 lp = &sump[fs->e2fs_contigsumsize]; 187 for (i = fs->e2fs_contigsumsize; i > 0; i--) 188 if (*lp-- > 0) 189 break; 190 fs->e2fs_maxcluster[cg] = i; 191 } 192