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 7.5 (Berkeley) 06/21/87 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_fs == NULL || mp->m_dev == NODEV) 59 continue; 60 fs = mp->m_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 iupdat(ip, &time, &time, 1); 143 } 144 #endif 145 146 extern int around[9]; 147 extern int inside[9]; 148 extern u_char *fragtbl[]; 149 150 /* 151 * Update the frsum fields to reflect addition or deletion 152 * of some frags. 153 */ 154 fragacct(fs, fragmap, fraglist, cnt) 155 struct fs *fs; 156 int fragmap; 157 long fraglist[]; 158 int cnt; 159 { 160 int inblk; 161 register int field, subfield; 162 register int siz, pos; 163 164 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 165 fragmap <<= 1; 166 for (siz = 1; siz < fs->fs_frag; siz++) { 167 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 168 continue; 169 field = around[siz]; 170 subfield = inside[siz]; 171 for (pos = siz; pos <= fs->fs_frag; pos++) { 172 if ((fragmap & field) == subfield) { 173 fraglist[siz] += cnt; 174 pos += siz; 175 field <<= siz; 176 subfield <<= siz; 177 } 178 field <<= 1; 179 subfield <<= 1; 180 } 181 } 182 } 183 184 #ifdef KERNEL 185 /* 186 * Check that a specified block number is in range. 187 */ 188 badblock(fs, bn) 189 register struct fs *fs; 190 daddr_t bn; 191 { 192 193 if ((unsigned)bn >= fs->fs_size) { 194 printf("bad block %d, ", bn); 195 fserr(fs, "bad block"); 196 return (1); 197 } 198 return (0); 199 } 200 #endif 201 202 /* 203 * block operations 204 * 205 * check if a block is available 206 */ 207 isblock(fs, cp, h) 208 struct fs *fs; 209 unsigned char *cp; 210 daddr_t h; 211 { 212 unsigned char mask; 213 214 switch ((int)fs->fs_frag) { 215 case 8: 216 return (cp[h] == 0xff); 217 case 4: 218 mask = 0x0f << ((h & 0x1) << 2); 219 return ((cp[h >> 1] & mask) == mask); 220 case 2: 221 mask = 0x03 << ((h & 0x3) << 1); 222 return ((cp[h >> 2] & mask) == mask); 223 case 1: 224 mask = 0x01 << (h & 0x7); 225 return ((cp[h >> 3] & mask) == mask); 226 default: 227 panic("isblock"); 228 return (NULL); 229 } 230 } 231 232 /* 233 * take a block out of the map 234 */ 235 clrblock(fs, cp, h) 236 struct fs *fs; 237 u_char *cp; 238 daddr_t h; 239 { 240 241 switch ((int)fs->fs_frag) { 242 case 8: 243 cp[h] = 0; 244 return; 245 case 4: 246 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 247 return; 248 case 2: 249 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 250 return; 251 case 1: 252 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 253 return; 254 default: 255 panic("clrblock"); 256 } 257 } 258 259 /* 260 * put a block into the map 261 */ 262 setblock(fs, cp, h) 263 struct fs *fs; 264 unsigned char *cp; 265 daddr_t h; 266 { 267 268 switch ((int)fs->fs_frag) { 269 270 case 8: 271 cp[h] = 0xff; 272 return; 273 case 4: 274 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 275 return; 276 case 2: 277 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 278 return; 279 case 1: 280 cp[h >> 3] |= (0x01 << (h & 0x7)); 281 return; 282 default: 283 panic("setblock"); 284 } 285 } 286 287 #ifdef KERNEL 288 /* 289 * Getfs maps a device number into a pointer to the incore super block. 290 * 291 * The algorithm is a linear search through the mount table. A 292 * consistency check of the super block magic number is performed. 293 * 294 * panic: no fs -- the device is not mounted. 295 * this "cannot happen" 296 */ 297 struct fs * 298 getfs(dev) 299 dev_t dev; 300 { 301 register struct mount *mp; 302 register struct fs *fs; 303 304 for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) { 305 if (mp->m_fs == NULL || mp->m_dev != dev) 306 continue; 307 fs = mp->m_fs; 308 if (fs->fs_magic != FS_MAGIC) { 309 printf("dev = 0x%x, fs = %s\n", dev, fs->fs_fsmnt); 310 panic("getfs: bad magic"); 311 } 312 return (fs); 313 } 314 printf("dev = 0x%x\n", dev); 315 panic("getfs: no fs"); 316 return (NULL); 317 } 318 319 /* 320 * Getfsx returns the index in the file system 321 * table of the specified device. The swap device 322 * is also assigned a pseudo-index. The index may 323 * be used as a compressed indication of the location 324 * of a block, recording 325 * <getfsx(dev),blkno> 326 * rather than 327 * <dev, blkno> 328 * provided the information need remain valid only 329 * as long as the file system is mounted. 330 */ 331 getfsx(dev) 332 dev_t dev; 333 { 334 register struct mount *mp; 335 336 if (dev == swapdev) 337 return (MSWAPX); 338 for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) 339 if (mp->m_dev == dev) 340 return (mp - &mount[0]); 341 return (-1); 342 } 343 344 /* 345 * Print out statistics on the current allocation of the buffer pool. 346 * Can be enabled to print out on every ``sync'' by setting "syncprt" 347 * above. 348 */ 349 bufstats() 350 { 351 int s, i, j, count; 352 register struct buf *bp, *dp; 353 int counts[MAXBSIZE/CLBYTES+1]; 354 static char *bname[BQUEUES] = { "LOCKED", "LRU", "AGE", "EMPTY" }; 355 356 for (bp = bfreelist, i = 0; bp < &bfreelist[BQUEUES]; bp++, i++) { 357 count = 0; 358 for (j = 0; j <= MAXBSIZE/CLBYTES; j++) 359 counts[j] = 0; 360 s = splbio(); 361 for (dp = bp->av_forw; dp != bp; dp = dp->av_forw) { 362 counts[dp->b_bufsize/CLBYTES]++; 363 count++; 364 } 365 splx(s); 366 printf("%s: total-%d", bname[i], count); 367 for (j = 0; j <= MAXBSIZE/CLBYTES; j++) 368 if (counts[j] != 0) 369 printf(", %d-%d", j * CLBYTES, counts[j]); 370 printf("\n"); 371 } 372 } 373 #endif 374 375 #if (!defined(vax) && !defined(tahoe)) || defined(VAX630) 376 /* 377 * C definitions of special instructions. 378 * Normally expanded with inline. 379 */ 380 scanc(size, cp, table, mask) 381 u_int size; 382 register u_char *cp, table[]; 383 register u_char mask; 384 { 385 register u_char *end = &cp[size]; 386 387 while (cp < end && (table[*cp] & mask) == 0) 388 cp++; 389 return (end - cp); 390 } 391 #endif 392 393 #if !defined(vax) && !defined(tahoe) 394 skpc(mask, size, cp) 395 register u_char mask; 396 u_int size; 397 register u_char *cp; 398 { 399 register u_char *end = &cp[size]; 400 401 while (cp < end && *cp == mask) 402 cp++; 403 return (end - cp); 404 } 405 406 locc(mask, size, cp) 407 register u_char mask; 408 u_int size; 409 register u_char *cp; 410 { 411 register u_char *end = &cp[size]; 412 413 while (cp < end && *cp != mask) 414 cp++; 415 return (end - cp); 416 } 417 #endif 418