1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ffs_subr.c 8.5 (Berkeley) 3/21/95 34 * $FreeBSD: src/sys/ufs/ffs/ffs_subr.c,v 1.25 1999/12/29 04:55:04 peter Exp $ 35 * $DragonFly: src/sys/vfs/ufs/ffs_subr.c,v 1.7 2004/05/18 00:16:46 cpressey Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include "fs.h" 40 41 #ifndef _KERNEL 42 #include "dinode.h" 43 #else 44 #include "opt_ddb.h" 45 46 #include <sys/systm.h> 47 #include <sys/lock.h> 48 #include <sys/vnode.h> 49 #include <sys/buf.h> 50 #include <sys/ucred.h> 51 52 #include "quota.h" 53 #include "inode.h" 54 #include "ffs_extern.h" 55 56 #ifdef DDB 57 void ffs_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 ffs_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 67 { 68 struct inode *ip; 69 struct fs *fs; 70 struct buf *bp; 71 ufs_daddr_t lbn; 72 int bsize, error; 73 74 ip = VTOI(vp); 75 fs = ip->i_fs; 76 lbn = lblkno(fs, offset); 77 bsize = blksize(fs, ip, lbn); 78 79 *bpp = NULL; 80 error = bread(vp, lbn, bsize, &bp); 81 if (error) { 82 brelse(bp); 83 return (error); 84 } 85 if (res) 86 *res = (char *)bp->b_data + blkoff(fs, offset); 87 *bpp = bp; 88 return (0); 89 } 90 #endif 91 92 /* 93 * Update the frsum fields to reflect addition or deletion 94 * of some frags. 95 */ 96 void 97 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt) 98 { 99 int inblk; 100 int field, subfield; 101 int siz, pos; 102 103 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 104 fragmap <<= 1; 105 for (siz = 1; siz < fs->fs_frag; siz++) { 106 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 107 continue; 108 field = around[siz]; 109 subfield = inside[siz]; 110 for (pos = siz; pos <= fs->fs_frag; pos++) { 111 if ((fragmap & field) == subfield) { 112 fraglist[siz] += cnt; 113 pos += siz; 114 field <<= siz; 115 subfield <<= siz; 116 } 117 field <<= 1; 118 subfield <<= 1; 119 } 120 } 121 } 122 123 #ifdef DDB 124 void 125 ffs_checkoverlap(struct buf *bp, struct inode *ip) 126 { 127 struct buf *ebp, *ep; 128 ufs_daddr_t start, last; 129 struct vnode *vp; 130 131 ebp = &buf[nbuf]; 132 start = bp->b_blkno; 133 last = start + btodb(bp->b_bcount) - 1; 134 for (ep = buf; ep < ebp; ep++) { 135 if (ep == bp || (ep->b_flags & B_INVAL) || 136 ep->b_vp == NULLVP) 137 continue; 138 if (VOP_BMAP(ep->b_vp, (ufs_daddr_t)0, &vp, (ufs_daddr_t *)NULL, 139 (int *)NULL, (int *)NULL)) 140 continue; 141 if (vp != ip->i_devvp) 142 continue; 143 /* look for overlap */ 144 if (ep->b_bcount == 0 || ep->b_blkno > last || 145 ep->b_blkno + btodb(ep->b_bcount) <= start) 146 continue; 147 vprint("Disk overlap", vp); 148 (void)printf("\tstart %lu, end %lu overlap start %lu, end %lu\n", 149 (u_long)start, (u_long)last, (u_long)ep->b_blkno, 150 (u_long)(ep->b_blkno + btodb(ep->b_bcount) - 1)); 151 panic("ffs_checkoverlap: Disk buffer overlap"); 152 } 153 } 154 #endif /* DDB */ 155 156 /* 157 * block operations 158 * 159 * check if a block is available 160 */ 161 int 162 ffs_isblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 163 { 164 unsigned char mask; 165 166 switch ((int)fs->fs_frag) { 167 case 8: 168 return (cp[h] == 0xff); 169 case 4: 170 mask = 0x0f << ((h & 0x1) << 2); 171 return ((cp[h >> 1] & mask) == mask); 172 case 2: 173 mask = 0x03 << ((h & 0x3) << 1); 174 return ((cp[h >> 2] & mask) == mask); 175 case 1: 176 mask = 0x01 << (h & 0x7); 177 return ((cp[h >> 3] & mask) == mask); 178 default: 179 panic("ffs_isblock"); 180 } 181 } 182 183 /* 184 * check if a block is free 185 */ 186 int 187 ffs_isfreeblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 188 { 189 switch ((int)fs->fs_frag) { 190 case 8: 191 return (cp[h] == 0); 192 case 4: 193 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); 194 case 2: 195 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); 196 case 1: 197 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); 198 default: 199 panic("ffs_isfreeblock"); 200 } 201 } 202 203 /* 204 * take a block out of the map 205 */ 206 void 207 ffs_clrblock(struct fs *fs, u_char *cp, ufs_daddr_t h) 208 { 209 switch ((int)fs->fs_frag) { 210 case 8: 211 cp[h] = 0; 212 return; 213 case 4: 214 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 215 return; 216 case 2: 217 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 218 return; 219 case 1: 220 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 221 return; 222 default: 223 panic("ffs_clrblock"); 224 } 225 } 226 227 /* 228 * put a block into the map 229 */ 230 void 231 ffs_setblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 232 { 233 switch ((int)fs->fs_frag) { 234 case 8: 235 cp[h] = 0xff; 236 return; 237 case 4: 238 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 239 return; 240 case 2: 241 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 242 return; 243 case 1: 244 cp[h >> 3] |= (0x01 << (h & 0x7)); 245 return; 246 default: 247 panic("ffs_setblock"); 248 } 249 } 250