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(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 67 { 68 struct inode *ip; 69 struct m_ext2fs *fs; 70 struct buf *bp; 71 e2fs_lbn_t lbn; 72 int bsize, error; 73 74 ip = VTOI(vp); 75 fs = ip->i_e2fs; 76 lbn = lblkno(fs, offset); 77 bsize = blksize(fs, ip, lbn); 78 79 *bpp = NULL; 80 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 81 brelse(bp); 82 return (error); 83 } 84 if (res) 85 *res = (char *)bp->b_data + blkoff(fs, offset); 86 *bpp = bp; 87 return (0); 88 } 89 90 #ifdef KDB 91 void 92 ext2_checkoverlap(struct buf *bp, struct inode *ip) 93 { 94 struct buf *ebp, *ep; 95 int32_t start, last; 96 struct vnode *vp; 97 98 ebp = &buf[nbuf]; 99 start = bp->b_blkno; 100 last = start + btodb(bp->b_bcount) - 1; 101 for (ep = buf; ep < ebp; ep++) { 102 if (ep == bp || (ep->b_flags & B_INVAL)) 103 continue; 104 vp = ip->i_ump->um_devvp; 105 /* look for overlap */ 106 if (ep->b_bcount == 0 || ep->b_blkno > last || 107 ep->b_blkno + btodb(ep->b_bcount) <= start) 108 continue; 109 vprint("Disk overlap", vp); 110 (void)printf("\tstart %d, end %d overlap start %lld, end %ld\n", 111 start, last, (long long)ep->b_blkno, 112 (long)(ep->b_blkno + btodb(ep->b_bcount) - 1)); 113 panic("Disk buffer overlap"); 114 } 115 } 116 #endif /* KDB */ 117 118 /* 119 * Update the cluster map because of an allocation of free like ffs. 120 * 121 * Cnt == 1 means free; cnt == -1 means allocating. 122 */ 123 void 124 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt) 125 { 126 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 127 int32_t *lp; 128 int back, bit, end, forw, i, loc, start; 129 130 /* Initialize the cluster summary array. */ 131 if (fs->e2fs_clustersum[cg].cs_init == 0) { 132 int run = 0; 133 bit = 1; 134 loc = 0; 135 136 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 137 if ((bbp[loc] & bit) == 0) 138 run++; 139 else if (run != 0) { 140 if (run > fs->e2fs_contigsumsize) 141 run = fs->e2fs_contigsumsize; 142 sump[run]++; 143 run = 0; 144 } 145 if ((i & (NBBY - 1)) != (NBBY - 1)) 146 bit <<= 1; 147 else { 148 loc++; 149 bit = 1; 150 } 151 } 152 if (run != 0) { 153 if (run > fs->e2fs_contigsumsize) 154 run = fs->e2fs_contigsumsize; 155 sump[run]++; 156 } 157 fs->e2fs_clustersum[cg].cs_init = 1; 158 } 159 160 if (fs->e2fs_contigsumsize <= 0) 161 return; 162 163 /* Find the size of the cluster going forward. */ 164 start = bno + 1; 165 end = start + fs->e2fs_contigsumsize; 166 if (end > fs->e2fs->e2fs_fpg) 167 end = fs->e2fs->e2fs_fpg; 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)) != (NBBY - 1)) 174 bit <<= 1; 175 else { 176 loc++; 177 bit = 1; 178 } 179 } 180 forw = i - start; 181 182 /* Find the size of the cluster going backward. */ 183 start = bno - 1; 184 end = start - fs->e2fs_contigsumsize; 185 if (end < 0) 186 end = -1; 187 loc = start / NBBY; 188 bit = 1 << (start % NBBY); 189 for (i = start; i > end; i--) { 190 if ((bbp[loc] & bit) != 0) 191 break; 192 if ((i & (NBBY - 1)) != 0) 193 bit >>= 1; 194 else { 195 loc--; 196 bit = 1 << (NBBY - 1); 197 } 198 } 199 back = start - i; 200 201 /* 202 * Account for old cluster and the possibly new forward and 203 * back clusters. 204 */ 205 i = back + forw + 1; 206 if (i > fs->e2fs_contigsumsize) 207 i = fs->e2fs_contigsumsize; 208 sump[i] += cnt; 209 if (back > 0) 210 sump[back] -= cnt; 211 if (forw > 0) 212 sump[forw] -= cnt; 213 214 /* Update cluster summary information. */ 215 lp = &sump[fs->e2fs_contigsumsize]; 216 for (i = fs->e2fs_contigsumsize; i > 0; i--) 217 if (*lp-- > 0) 218 break; 219 fs->e2fs_maxcluster[cg] = i; 220 } 221