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 * 4. 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 54 #ifdef KDB 55 #include <fs/ext2fs/ext2_mount.h> 56 57 void ext2_checkoverlap(struct buf *, struct inode *); 58 #endif 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(vp, offset, res, bpp) 67 struct vnode *vp; 68 off_t offset; 69 char **res; 70 struct buf **bpp; 71 { 72 struct inode *ip; 73 struct m_ext2fs *fs; 74 struct buf *bp; 75 int32_t lbn; 76 int bsize, error; 77 78 ip = VTOI(vp); 79 fs = ip->i_e2fs; 80 lbn = lblkno(fs, offset); 81 bsize = blksize(fs, ip, lbn); 82 83 *bpp = NULL; 84 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 85 brelse(bp); 86 return (error); 87 } 88 if (res) 89 *res = (char *)bp->b_data + blkoff(fs, offset); 90 *bpp = bp; 91 return (0); 92 } 93 94 #ifdef KDB 95 void 96 ext2_checkoverlap(bp, ip) 97 struct buf *bp; 98 struct inode *ip; 99 { 100 struct buf *ebp, *ep; 101 int32_t start, last; 102 struct vnode *vp; 103 104 ebp = &buf[nbuf]; 105 start = bp->b_blkno; 106 last = start + btodb(bp->b_bcount) - 1; 107 for (ep = buf; ep < ebp; ep++) { 108 if (ep == bp || (ep->b_flags & B_INVAL)) 109 continue; 110 vp = ip->i_ump->um_devvp; 111 /* look for overlap */ 112 if (ep->b_bcount == 0 || ep->b_blkno > last || 113 ep->b_blkno + btodb(ep->b_bcount) <= start) 114 continue; 115 vprint("Disk overlap", vp); 116 (void)printf("\tstart %d, end %d overlap start %lld, end %ld\n", 117 start, last, (long long)ep->b_blkno, 118 (long)(ep->b_blkno + btodb(ep->b_bcount) - 1)); 119 panic("Disk buffer overlap"); 120 } 121 } 122 #endif /* KDB */ 123 124 /* 125 * Update the cluster map because of an allocation of free like ffs. 126 * 127 * Cnt == 1 means free; cnt == -1 means allocating. 128 */ 129 void 130 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt) 131 { 132 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 133 int32_t *lp; 134 int back, bit, end, forw, i, loc, start; 135 136 /* Initialize the cluster summary array. */ 137 if (fs->e2fs_clustersum[cg].cs_init == 0) { 138 int run = 0; 139 bit = 1; 140 loc = 0; 141 142 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 143 if ((bbp[loc] & bit) == 0) 144 run++; 145 else if (run != 0) { 146 if (run > fs->e2fs_contigsumsize) 147 run = fs->e2fs_contigsumsize; 148 sump[run]++; 149 run = 0; 150 } 151 if ((i & (NBBY - 1)) != (NBBY - 1)) 152 bit <<= 1; 153 else { 154 loc++; 155 bit = 1; 156 } 157 } 158 if (run != 0) { 159 if (run > fs->e2fs_contigsumsize) 160 run = fs->e2fs_contigsumsize; 161 sump[run]++; 162 } 163 fs->e2fs_clustersum[cg].cs_init = 1; 164 } 165 166 if (fs->e2fs_contigsumsize <= 0) 167 return; 168 169 /* Find the size of the cluster going forward. */ 170 start = bno + 1; 171 end = start + fs->e2fs_contigsumsize; 172 if (end > fs->e2fs->e2fs_fpg) 173 end = fs->e2fs->e2fs_fpg; 174 loc = start / NBBY; 175 bit = 1 << (start % NBBY); 176 for (i = start; i < end; i++) { 177 if ((bbp[loc] & bit) != 0) 178 break; 179 if ((i & (NBBY - 1)) != (NBBY - 1)) 180 bit <<= 1; 181 else { 182 loc++; 183 bit = 1; 184 } 185 } 186 forw = i - start; 187 188 /* Find the size of the cluster going backward. */ 189 start = bno - 1; 190 end = start - fs->e2fs_contigsumsize; 191 if (end < 0) 192 end = -1; 193 loc = start / NBBY; 194 bit = 1 << (start % NBBY); 195 for (i = start; i > end; i--) { 196 if ((bbp[loc] & bit) != 0) 197 break; 198 if ((i & (NBBY - 1)) != 0) 199 bit >>= 1; 200 else { 201 loc--; 202 bit = 1 << (NBBY - 1); 203 } 204 } 205 back = start - i; 206 207 /* 208 * Account for old cluster and the possibly new forward and 209 * back clusters. 210 */ 211 i = back + forw + 1; 212 if (i > fs->e2fs_contigsumsize) 213 i = fs->e2fs_contigsumsize; 214 sump[i] += cnt; 215 if (back > 0) 216 sump[back] -= cnt; 217 if (forw > 0) 218 sump[forw] -= cnt; 219 220 /* Update cluster summary information. */ 221 lp = &sump[fs->e2fs_contigsumsize]; 222 for (i = fs->e2fs_contigsumsize; i > 0; i--) 223 if (*lp-- > 0) 224 break; 225 fs->e2fs_maxcluster[cg] = i; 226 } 227