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 1.9 2006/02/17 19:18:08 dillon 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 /* 104 * inblk represents a bitmap of fragment sizes which may be 105 * contained in the data 'fragmap'. e.g. if a fragment of size 106 * 1 is available, bit 0 would be set. inblk is shifted left 107 * by one so we do not have to calculate (1 << (siz - 1)). 108 * 109 * fragment represents the data pattern we are trying to decipher, 110 * we shift it left by one to align it with the 'around' and 'inside' 111 * masks. 112 * 113 * around represents the bits around the subfield and is a mask. 114 * inside represents what we must match within the mask, it is 115 * basically the mask with the first and last bit set to 0, allowing 116 * us to represent a whole fragment. 117 * 118 * When we find a match we bump our position by the size of the 119 * matching fragment, then bump the position again: 120 * 121 * 010101010 fragmap (shifted left by 1) 122 * 111 around mask 123 * 010 inside mask 124 * 111 (shifted by siz) 125 * 010 126 * 111 (shifted again) 127 * 010 128 */ 129 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 130 fragmap <<= 1; 131 for (siz = 1; siz < fs->fs_frag; siz++) { 132 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 133 continue; 134 field = around[siz]; 135 subfield = inside[siz]; 136 for (pos = siz; pos <= fs->fs_frag; pos++) { 137 if ((fragmap & field) == subfield) { 138 fraglist[siz] += cnt; 139 pos += siz; 140 field <<= siz; 141 subfield <<= siz; 142 } 143 field <<= 1; 144 subfield <<= 1; 145 } 146 } 147 } 148 149 #ifdef DDB 150 void 151 ffs_checkoverlap(struct buf *bp, struct inode *ip) 152 { 153 struct buf *ebp, *ep; 154 ufs_daddr_t start, last; 155 struct vnode *vp; 156 157 ebp = &buf[nbuf]; 158 start = bp->b_bio2.bio_blkno; 159 last = start + btodb(bp->b_bcount) - 1; 160 for (ep = buf; ep < ebp; ep++) { 161 if (ep == bp || (ep->b_flags & B_INVAL) || 162 ep->b_vp == NULLVP) 163 continue; 164 if (VOP_BMAP(ep->b_vp, (ufs_daddr_t)0, &vp, (ufs_daddr_t *)NULL, 165 (int *)NULL, (int *)NULL)) 166 continue; 167 if (vp != ip->i_devvp) 168 continue; 169 /* look for overlap */ 170 if (ep->b_bcount == 0 || ep->b_bio2.bio_blkno == (daddr_t)-1 || 171 ep->b_bio2.bio_blkno > last || 172 ep->b_bio2.bio_blkno + btodb(ep->b_bcount) <= start) 173 continue; 174 vprint("Disk overlap", vp); 175 (void)printf("\tstart %lu, end %lu overlap start %lu, end %lu\n", 176 (u_long)start, (u_long)last, 177 (u_long)ep->b_bio2.bio_blkno, 178 (u_long)(ep->b_bio2.bio_blkno + btodb(ep->b_bcount) - 1)); 179 panic("ffs_checkoverlap: Disk buffer overlap"); 180 } 181 } 182 #endif /* DDB */ 183 184 /* 185 * block operations 186 * 187 * check if a block is available 188 */ 189 int 190 ffs_isblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 191 { 192 unsigned char mask; 193 194 switch ((int)fs->fs_frag) { 195 case 8: 196 return (cp[h] == 0xff); 197 case 4: 198 mask = 0x0f << ((h & 0x1) << 2); 199 return ((cp[h >> 1] & mask) == mask); 200 case 2: 201 mask = 0x03 << ((h & 0x3) << 1); 202 return ((cp[h >> 2] & mask) == mask); 203 case 1: 204 mask = 0x01 << (h & 0x7); 205 return ((cp[h >> 3] & mask) == mask); 206 default: 207 panic("ffs_isblock"); 208 } 209 } 210 211 /* 212 * check if a block is free 213 */ 214 int 215 ffs_isfreeblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 216 { 217 switch ((int)fs->fs_frag) { 218 case 8: 219 return (cp[h] == 0); 220 case 4: 221 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); 222 case 2: 223 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); 224 case 1: 225 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); 226 default: 227 panic("ffs_isfreeblock"); 228 } 229 } 230 231 /* 232 * take a block out of the map 233 */ 234 void 235 ffs_clrblock(struct fs *fs, u_char *cp, ufs_daddr_t h) 236 { 237 switch ((int)fs->fs_frag) { 238 case 8: 239 cp[h] = 0; 240 return; 241 case 4: 242 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 243 return; 244 case 2: 245 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 246 return; 247 case 1: 248 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 249 return; 250 default: 251 panic("ffs_clrblock"); 252 } 253 } 254 255 /* 256 * put a block into the map 257 */ 258 void 259 ffs_setblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h) 260 { 261 switch ((int)fs->fs_frag) { 262 case 8: 263 cp[h] = 0xff; 264 return; 265 case 4: 266 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 267 return; 268 case 2: 269 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 270 return; 271 case 1: 272 cp[h >> 3] |= (0x01 << (h & 0x7)); 273 return; 274 default: 275 panic("ffs_setblock"); 276 } 277 } 278