1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 * 6 * @(#)ffs_subr.c 7.2 (Berkeley) 11/03/86 7 */ 8 9 #ifdef KERNEL 10 #include "param.h" 11 #include "systm.h" 12 #include "mount.h" 13 #include "fs.h" 14 #include "buf.h" 15 #include "inode.h" 16 #include "dir.h" 17 #include "user.h" 18 #include "quota.h" 19 #include "kernel.h" 20 #else 21 #include <sys/param.h> 22 #include <sys/systm.h> 23 #include <sys/mount.h> 24 #include <sys/fs.h> 25 #include <sys/buf.h> 26 #include <sys/inode.h> 27 #include <sys/dir.h> 28 #include <sys/user.h> 29 #include <sys/quota.h> 30 #endif 31 32 #ifdef KERNEL 33 int syncprt = 0; 34 35 /* 36 * Update is the internal name of 'sync'. It goes through the disk 37 * queues to initiate sandbagged IO; goes through the inodes to write 38 * modified nodes; and it goes through the mount table to initiate 39 * the writing of the modified super blocks. 40 */ 41 update() 42 { 43 register struct inode *ip; 44 register struct mount *mp; 45 struct fs *fs; 46 47 if (syncprt) 48 bufstats(); 49 if (updlock) 50 return; 51 updlock++; 52 /* 53 * Write back modified superblocks. 54 * Consistency check that the superblock 55 * of each file system is still in the buffer cache. 56 */ 57 for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) { 58 if (mp->m_bufp == NULL || mp->m_dev == NODEV) 59 continue; 60 fs = mp->m_bufp->b_un.b_fs; 61 if (fs->fs_fmod == 0) 62 continue; 63 if (fs->fs_ronly != 0) { /* XXX */ 64 printf("fs = %s\n", fs->fs_fsmnt); 65 panic("update: rofs mod"); 66 } 67 fs->fs_fmod = 0; 68 fs->fs_time = time.tv_sec; 69 sbupdate(mp); 70 } 71 /* 72 * Write back each (modified) inode. 73 */ 74 for (ip = inode; ip < inodeNINODE; ip++) { 75 if ((ip->i_flag & ILOCKED) != 0 || ip->i_count == 0 || 76 (ip->i_flag & (IMOD|IACC|IUPD|ICHG)) == 0) 77 continue; 78 ip->i_flag |= ILOCKED; 79 ip->i_count++; 80 iupdat(ip, &time, &time, 0); 81 iput(ip); 82 } 83 updlock = 0; 84 /* 85 * Force stale buffer cache information to be flushed, 86 * for all devices. 87 */ 88 bflush(NODEV); 89 } 90 91 /* 92 * Flush all the blocks associated with an inode. 93 * There are two strategies based on the size of the file; 94 * large files are those with more than (nbuf / 2) blocks. 95 * Large files 96 * Walk through the buffer pool and push any dirty pages 97 * associated with the device on which the file resides. 98 * Small files 99 * Look up each block in the file to see if it is in the 100 * buffer pool writing any that are found to disk. 101 * Note that we make a more stringent check of 102 * writing out any block in the buffer pool that may 103 * overlap the inode. This brings the inode up to 104 * date with recent mods to the cooked device. 105 */ 106 syncip(ip) 107 register struct inode *ip; 108 { 109 register struct fs *fs; 110 register struct buf *bp; 111 struct buf *lastbufp; 112 long lbn, lastlbn; 113 int s; 114 daddr_t blkno; 115 116 fs = ip->i_fs; 117 lastlbn = howmany(ip->i_size, fs->fs_bsize); 118 if (lastlbn < nbuf / 2) { 119 for (lbn = 0; lbn < lastlbn; lbn++) { 120 blkno = fsbtodb(fs, bmap(ip, lbn, B_READ)); 121 blkflush(ip->i_dev, blkno, blksize(fs, ip, lbn)); 122 } 123 } else { 124 lastbufp = &buf[nbuf]; 125 for (bp = buf; bp < lastbufp; bp++) { 126 if (bp->b_dev != ip->i_dev || 127 (bp->b_flags & B_DELWRI) == 0) 128 continue; 129 s = splbio(); 130 if (bp->b_flags & B_BUSY) { 131 bp->b_flags |= B_WANTED; 132 sleep((caddr_t)bp, PRIBIO+1); 133 splx(s); 134 bp--; 135 continue; 136 } 137 splx(s); 138 notavail(bp); 139 bwrite(bp); 140 } 141 } 142 ip->i_flag |= ICHG; 143 iupdat(ip, &time, &time, 1); 144 } 145 #endif 146 147 extern int around[9]; 148 extern int inside[9]; 149 extern u_char *fragtbl[]; 150 151 /* 152 * Update the frsum fields to reflect addition or deletion 153 * of some frags. 154 */ 155 fragacct(fs, fragmap, fraglist, cnt) 156 struct fs *fs; 157 int fragmap; 158 long fraglist[]; 159 int cnt; 160 { 161 int inblk; 162 register int field, subfield; 163 register int siz, pos; 164 165 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 166 fragmap <<= 1; 167 for (siz = 1; siz < fs->fs_frag; siz++) { 168 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 169 continue; 170 field = around[siz]; 171 subfield = inside[siz]; 172 for (pos = siz; pos <= fs->fs_frag; pos++) { 173 if ((fragmap & field) == subfield) { 174 fraglist[siz] += cnt; 175 pos += siz; 176 field <<= siz; 177 subfield <<= siz; 178 } 179 field <<= 1; 180 subfield <<= 1; 181 } 182 } 183 } 184 185 #ifdef KERNEL 186 /* 187 * Check that a specified block number is in range. 188 */ 189 badblock(fs, bn) 190 register struct fs *fs; 191 daddr_t bn; 192 { 193 194 if ((unsigned)bn >= fs->fs_size) { 195 printf("bad block %d, ", bn); 196 fserr(fs, "bad block"); 197 return (1); 198 } 199 return (0); 200 } 201 #endif 202 203 /* 204 * block operations 205 * 206 * check if a block is available 207 */ 208 isblock(fs, cp, h) 209 struct fs *fs; 210 unsigned char *cp; 211 daddr_t h; 212 { 213 unsigned char mask; 214 215 switch ((int)fs->fs_frag) { 216 case 8: 217 return (cp[h] == 0xff); 218 case 4: 219 mask = 0x0f << ((h & 0x1) << 2); 220 return ((cp[h >> 1] & mask) == mask); 221 case 2: 222 mask = 0x03 << ((h & 0x3) << 1); 223 return ((cp[h >> 2] & mask) == mask); 224 case 1: 225 mask = 0x01 << (h & 0x7); 226 return ((cp[h >> 3] & mask) == mask); 227 default: 228 panic("isblock"); 229 return (NULL); 230 } 231 } 232 233 /* 234 * take a block out of the map 235 */ 236 clrblock(fs, cp, h) 237 struct fs *fs; 238 u_char *cp; 239 daddr_t h; 240 { 241 242 switch ((int)fs->fs_frag) { 243 case 8: 244 cp[h] = 0; 245 return; 246 case 4: 247 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 248 return; 249 case 2: 250 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 251 return; 252 case 1: 253 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 254 return; 255 default: 256 panic("clrblock"); 257 } 258 } 259 260 /* 261 * put a block into the map 262 */ 263 setblock(fs, cp, h) 264 struct fs *fs; 265 unsigned char *cp; 266 daddr_t h; 267 { 268 269 switch ((int)fs->fs_frag) { 270 271 case 8: 272 cp[h] = 0xff; 273 return; 274 case 4: 275 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 276 return; 277 case 2: 278 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 279 return; 280 case 1: 281 cp[h >> 3] |= (0x01 << (h & 0x7)); 282 return; 283 default: 284 panic("setblock"); 285 } 286 } 287 288 #ifdef KERNEL 289 /* 290 * Getfs maps a device number into a pointer to the incore super block. 291 * 292 * The algorithm is a linear search through the mount table. A 293 * consistency check of the super block magic number is performed. 294 * 295 * panic: no fs -- the device is not mounted. 296 * this "cannot happen" 297 */ 298 struct fs * 299 getfs(dev) 300 dev_t dev; 301 { 302 register struct mount *mp; 303 register struct fs *fs; 304 305 for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) { 306 if (mp->m_bufp == NULL || mp->m_dev != dev) 307 continue; 308 fs = mp->m_bufp->b_un.b_fs; 309 if (fs->fs_magic != FS_MAGIC) { 310 printf("dev = 0x%x, fs = %s\n", dev, fs->fs_fsmnt); 311 panic("getfs: bad magic"); 312 } 313 return (fs); 314 } 315 printf("dev = 0x%x\n", dev); 316 panic("getfs: no fs"); 317 return (NULL); 318 } 319 320 /* 321 * Getfsx returns the index in the file system 322 * table of the specified device. The swap device 323 * is also assigned a pseudo-index. The index may 324 * be used as a compressed indication of the location 325 * of a block, recording 326 * <getfsx(dev),blkno> 327 * rather than 328 * <dev, blkno> 329 * provided the information need remain valid only 330 * as long as the file system is mounted. 331 */ 332 getfsx(dev) 333 dev_t dev; 334 { 335 register struct mount *mp; 336 337 if (dev == swapdev) 338 return (MSWAPX); 339 for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) 340 if (mp->m_dev == dev) 341 return (mp - &mount[0]); 342 return (-1); 343 } 344 345 /* 346 * Print out statistics on the current allocation of the buffer pool. 347 * Can be enabled to print out on every ``sync'' by setting "syncprt" 348 * above. 349 */ 350 bufstats() 351 { 352 int s, i, j, count; 353 register struct buf *bp, *dp; 354 int counts[MAXBSIZE/CLBYTES+1]; 355 static char *bname[BQUEUES] = { "LOCKED", "LRU", "AGE", "EMPTY" }; 356 357 for (bp = bfreelist, i = 0; bp < &bfreelist[BQUEUES]; bp++, i++) { 358 count = 0; 359 for (j = 0; j <= MAXBSIZE/CLBYTES; j++) 360 counts[j] = 0; 361 s = splbio(); 362 for (dp = bp->av_forw; dp != bp; dp = dp->av_forw) { 363 counts[dp->b_bufsize/CLBYTES]++; 364 count++; 365 } 366 splx(s); 367 printf("%s: total-%d", bname[i], count); 368 for (j = 0; j <= MAXBSIZE/CLBYTES; j++) 369 if (counts[j] != 0) 370 printf(", %d-%d", j * CLBYTES, counts[j]); 371 printf("\n"); 372 } 373 } 374 #endif 375 376 #if (!defined(vax) && !defined(tahoe)) || defined(VAX630) 377 /* 378 * C definitions of special instructions. 379 * Normally expanded with inline. 380 */ 381 scanc(size, cp, table, mask) 382 u_int size; 383 register u_char *cp, table[]; 384 register u_char mask; 385 { 386 register u_char *end = &cp[size]; 387 388 while (cp < end && (table[*cp] & mask) == 0) 389 cp++; 390 return (end - cp); 391 } 392 #endif 393 394 #if !defined(vax) && !defined(tahoe) 395 skpc(mask, size, cp) 396 register u_char mask; 397 u_int size; 398 register u_char *cp; 399 { 400 register u_char *end = &cp[size]; 401 402 while (cp < end && *cp == mask) 403 cp++; 404 return (end - cp); 405 } 406 407 locc(mask, size, cp) 408 register u_char mask; 409 u_int size; 410 register u_char *cp; 411 { 412 register u_char *end = &cp[size]; 413 414 while (cp < end && *cp != mask) 415 cp++; 416 return (end - cp); 417 } 418 #endif 419