1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) International Business Machines Corp., 2000-2004 4 * Portions Copyright (C) Tino Reichardt, 2012 5 */ 6 7 #include <linux/fs.h> 8 #include <linux/slab.h> 9 #include "jfs_incore.h" 10 #include "jfs_superblock.h" 11 #include "jfs_dmap.h" 12 #include "jfs_imap.h" 13 #include "jfs_lock.h" 14 #include "jfs_metapage.h" 15 #include "jfs_debug.h" 16 #include "jfs_discard.h" 17 18 /* 19 * SERIALIZATION of the Block Allocation Map. 20 * 21 * the working state of the block allocation map is accessed in 22 * two directions: 23 * 24 * 1) allocation and free requests that start at the dmap 25 * level and move up through the dmap control pages (i.e. 26 * the vast majority of requests). 27 * 28 * 2) allocation requests that start at dmap control page 29 * level and work down towards the dmaps. 30 * 31 * the serialization scheme used here is as follows. 32 * 33 * requests which start at the bottom are serialized against each 34 * other through buffers and each requests holds onto its buffers 35 * as it works it way up from a single dmap to the required level 36 * of dmap control page. 37 * requests that start at the top are serialized against each other 38 * and request that start from the bottom by the multiple read/single 39 * write inode lock of the bmap inode. requests starting at the top 40 * take this lock in write mode while request starting at the bottom 41 * take the lock in read mode. a single top-down request may proceed 42 * exclusively while multiple bottoms-up requests may proceed 43 * simultaneously (under the protection of busy buffers). 44 * 45 * in addition to information found in dmaps and dmap control pages, 46 * the working state of the block allocation map also includes read/ 47 * write information maintained in the bmap descriptor (i.e. total 48 * free block count, allocation group level free block counts). 49 * a single exclusive lock (BMAP_LOCK) is used to guard this information 50 * in the face of multiple-bottoms up requests. 51 * (lock ordering: IREAD_LOCK, BMAP_LOCK); 52 * 53 * accesses to the persistent state of the block allocation map (limited 54 * to the persistent bitmaps in dmaps) is guarded by (busy) buffers. 55 */ 56 57 #define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock) 58 #define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock) 59 #define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock) 60 61 /* 62 * forward references 63 */ 64 static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, 65 int nblocks); 66 static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl); 67 static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl); 68 static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl); 69 static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl); 70 static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, 71 int level); 72 static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); 73 static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, 74 int nblocks); 75 static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, 76 int nblocks, 77 int l2nb, s64 * results); 78 static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, 79 int nblocks); 80 static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, 81 int l2nb, 82 s64 * results); 83 static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, 84 s64 * results); 85 static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, 86 s64 * results); 87 static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); 88 static int dbFindBits(u32 word, int l2nb); 89 static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); 90 static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl); 91 static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, 92 int nblocks); 93 static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, 94 int nblocks); 95 static int dbMaxBud(u8 * cp); 96 static int blkstol2(s64 nb); 97 98 static int cntlz(u32 value); 99 static int cnttz(u32 word); 100 101 static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, 102 int nblocks); 103 static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); 104 static int dbInitDmapTree(struct dmap * dp); 105 static int dbInitTree(struct dmaptree * dtp); 106 static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); 107 static int dbGetL2AGSize(s64 nblocks); 108 109 /* 110 * buddy table 111 * 112 * table used for determining buddy sizes within characters of 113 * dmap bitmap words. the characters themselves serve as indexes 114 * into the table, with the table elements yielding the maximum 115 * binary buddy of free bits within the character. 116 */ 117 static const s8 budtab[256] = { 118 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 119 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 120 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 121 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 122 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 123 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 124 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 125 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 126 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 127 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 128 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 129 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 130 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 131 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 132 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 133 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1 134 }; 135 136 /* 137 * NAME: dbMount() 138 * 139 * FUNCTION: initializate the block allocation map. 140 * 141 * memory is allocated for the in-core bmap descriptor and 142 * the in-core descriptor is initialized from disk. 143 * 144 * PARAMETERS: 145 * ipbmap - pointer to in-core inode for the block map. 146 * 147 * RETURN VALUES: 148 * 0 - success 149 * -ENOMEM - insufficient memory 150 * -EIO - i/o error 151 * -EINVAL - wrong bmap data 152 */ dbMount(struct inode * ipbmap)153 int dbMount(struct inode *ipbmap) 154 { 155 struct bmap *bmp; 156 struct dbmap_disk *dbmp_le; 157 struct metapage *mp; 158 int i, err; 159 160 /* 161 * allocate/initialize the in-memory bmap descriptor 162 */ 163 /* allocate memory for the in-memory bmap descriptor */ 164 bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); 165 if (bmp == NULL) 166 return -ENOMEM; 167 168 /* read the on-disk bmap descriptor. */ 169 mp = read_metapage(ipbmap, 170 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, 171 PSIZE, 0); 172 if (mp == NULL) { 173 err = -EIO; 174 goto err_kfree_bmp; 175 } 176 177 /* copy the on-disk bmap descriptor to its in-memory version. */ 178 dbmp_le = (struct dbmap_disk *) mp->data; 179 bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); 180 bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); 181 182 bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); 183 if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE || 184 bmp->db_l2nbperpage < 0) { 185 err = -EINVAL; 186 goto err_release_metapage; 187 } 188 189 bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); 190 if (!bmp->db_numag || bmp->db_numag > MAXAG) { 191 err = -EINVAL; 192 goto err_release_metapage; 193 } 194 195 bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); 196 bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); 197 bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); 198 if (bmp->db_maxag >= MAXAG || bmp->db_maxag < 0 || 199 bmp->db_agpref >= MAXAG || bmp->db_agpref < 0) { 200 err = -EINVAL; 201 goto err_release_metapage; 202 } 203 204 bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); 205 bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); 206 bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); 207 bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); 208 bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); 209 if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG || 210 bmp->db_agl2size < 0) { 211 err = -EINVAL; 212 goto err_release_metapage; 213 } 214 215 if (((bmp->db_mapsize - 1) >> bmp->db_agl2size) > MAXAG) { 216 err = -EINVAL; 217 goto err_release_metapage; 218 } 219 220 for (i = 0; i < MAXAG; i++) 221 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); 222 bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); 223 bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; 224 225 /* release the buffer. */ 226 release_metapage(mp); 227 228 /* bind the bmap inode and the bmap descriptor to each other. */ 229 bmp->db_ipbmap = ipbmap; 230 JFS_SBI(ipbmap->i_sb)->bmap = bmp; 231 232 memset(bmp->db_active, 0, sizeof(bmp->db_active)); 233 234 /* 235 * allocate/initialize the bmap lock 236 */ 237 BMAP_LOCK_INIT(bmp); 238 239 return (0); 240 241 err_release_metapage: 242 release_metapage(mp); 243 err_kfree_bmp: 244 kfree(bmp); 245 return err; 246 } 247 248 249 /* 250 * NAME: dbUnmount() 251 * 252 * FUNCTION: terminate the block allocation map in preparation for 253 * file system unmount. 254 * 255 * the in-core bmap descriptor is written to disk and 256 * the memory for this descriptor is freed. 257 * 258 * PARAMETERS: 259 * ipbmap - pointer to in-core inode for the block map. 260 * 261 * RETURN VALUES: 262 * 0 - success 263 * -EIO - i/o error 264 */ dbUnmount(struct inode * ipbmap,int mounterror)265 int dbUnmount(struct inode *ipbmap, int mounterror) 266 { 267 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; 268 269 if (!(mounterror || isReadOnly(ipbmap))) 270 dbSync(ipbmap); 271 272 /* 273 * Invalidate the page cache buffers 274 */ 275 truncate_inode_pages(ipbmap->i_mapping, 0); 276 277 /* free the memory for the in-memory bmap. */ 278 kfree(bmp); 279 JFS_SBI(ipbmap->i_sb)->bmap = NULL; 280 281 return (0); 282 } 283 284 /* 285 * dbSync() 286 */ dbSync(struct inode * ipbmap)287 int dbSync(struct inode *ipbmap) 288 { 289 struct dbmap_disk *dbmp_le; 290 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; 291 struct metapage *mp; 292 int i; 293 294 /* 295 * write bmap global control page 296 */ 297 /* get the buffer for the on-disk bmap descriptor. */ 298 mp = read_metapage(ipbmap, 299 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, 300 PSIZE, 0); 301 if (mp == NULL) { 302 jfs_err("dbSync: read_metapage failed!"); 303 return -EIO; 304 } 305 /* copy the in-memory version of the bmap to the on-disk version */ 306 dbmp_le = (struct dbmap_disk *) mp->data; 307 dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); 308 dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); 309 dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); 310 dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); 311 dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); 312 dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); 313 dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); 314 dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); 315 dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight); 316 dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); 317 dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); 318 dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); 319 for (i = 0; i < MAXAG; i++) 320 dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); 321 dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); 322 dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; 323 324 /* write the buffer */ 325 write_metapage(mp); 326 327 /* 328 * write out dirty pages of bmap 329 */ 330 filemap_write_and_wait(ipbmap->i_mapping); 331 332 diWriteSpecial(ipbmap, 0); 333 334 return (0); 335 } 336 337 /* 338 * NAME: dbFree() 339 * 340 * FUNCTION: free the specified block range from the working block 341 * allocation map. 342 * 343 * the blocks will be free from the working map one dmap 344 * at a time. 345 * 346 * PARAMETERS: 347 * ip - pointer to in-core inode; 348 * blkno - starting block number to be freed. 349 * nblocks - number of blocks to be freed. 350 * 351 * RETURN VALUES: 352 * 0 - success 353 * -EIO - i/o error 354 */ dbFree(struct inode * ip,s64 blkno,s64 nblocks)355 int dbFree(struct inode *ip, s64 blkno, s64 nblocks) 356 { 357 struct metapage *mp; 358 struct dmap *dp; 359 int nb, rc; 360 s64 lblkno, rem; 361 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; 362 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; 363 struct super_block *sb = ipbmap->i_sb; 364 365 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); 366 367 /* block to be freed better be within the mapsize. */ 368 if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { 369 IREAD_UNLOCK(ipbmap); 370 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", 371 (unsigned long long) blkno, 372 (unsigned long long) nblocks); 373 jfs_error(ip->i_sb, "block to be freed is outside the map\n"); 374 return -EIO; 375 } 376 377 /** 378 * TRIM the blocks, when mounted with discard option 379 */ 380 if (JFS_SBI(sb)->flag & JFS_DISCARD) 381 if (JFS_SBI(sb)->minblks_trim <= nblocks) 382 jfs_issue_discard(ipbmap, blkno, nblocks); 383 384 /* 385 * free the blocks a dmap at a time. 386 */ 387 mp = NULL; 388 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { 389 /* release previous dmap if any */ 390 if (mp) { 391 write_metapage(mp); 392 } 393 394 /* get the buffer for the current dmap. */ 395 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); 396 mp = read_metapage(ipbmap, lblkno, PSIZE, 0); 397 if (mp == NULL) { 398 IREAD_UNLOCK(ipbmap); 399 return -EIO; 400 } 401 dp = (struct dmap *) mp->data; 402 403 /* determine the number of blocks to be freed from 404 * this dmap. 405 */ 406 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); 407 408 /* free the blocks. */ 409 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { 410 jfs_error(ip->i_sb, "error in block map\n"); 411 release_metapage(mp); 412 IREAD_UNLOCK(ipbmap); 413 return (rc); 414 } 415 } 416 417 /* write the last buffer. */ 418 if (mp) 419 write_metapage(mp); 420 421 IREAD_UNLOCK(ipbmap); 422 423 return (0); 424 } 425 426 427 /* 428 * NAME: dbUpdatePMap() 429 * 430 * FUNCTION: update the allocation state (free or allocate) of the 431 * specified block range in the persistent block allocation map. 432 * 433 * the blocks will be updated in the persistent map one 434 * dmap at a time. 435 * 436 * PARAMETERS: 437 * ipbmap - pointer to in-core inode for the block map. 438 * free - 'true' if block range is to be freed from the persistent 439 * map; 'false' if it is to be allocated. 440 * blkno - starting block number of the range. 441 * nblocks - number of contiguous blocks in the range. 442 * tblk - transaction block; 443 * 444 * RETURN VALUES: 445 * 0 - success 446 * -EIO - i/o error 447 */ 448 int dbUpdatePMap(struct inode * ipbmap,int free,s64 blkno,s64 nblocks,struct tblock * tblk)449 dbUpdatePMap(struct inode *ipbmap, 450 int free, s64 blkno, s64 nblocks, struct tblock * tblk) 451 { 452 int nblks, dbitno, wbitno, rbits; 453 int word, nbits, nwords; 454 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; 455 s64 lblkno, rem, lastlblkno; 456 u32 mask; 457 struct dmap *dp; 458 struct metapage *mp; 459 struct jfs_log *log; 460 int lsn, difft, diffp; 461 unsigned long flags; 462 463 /* the blocks better be within the mapsize. */ 464 if (blkno + nblocks > bmp->db_mapsize) { 465 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", 466 (unsigned long long) blkno, 467 (unsigned long long) nblocks); 468 jfs_error(ipbmap->i_sb, "blocks are outside the map\n"); 469 return -EIO; 470 } 471 472 /* compute delta of transaction lsn from log syncpt */ 473 lsn = tblk->lsn; 474 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; 475 logdiff(difft, lsn, log); 476 477 /* 478 * update the block state a dmap at a time. 479 */ 480 mp = NULL; 481 lastlblkno = 0; 482 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { 483 /* get the buffer for the current dmap. */ 484 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); 485 if (lblkno != lastlblkno) { 486 if (mp) { 487 write_metapage(mp); 488 } 489 490 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 491 0); 492 if (mp == NULL) 493 return -EIO; 494 metapage_wait_for_io(mp); 495 } 496 dp = (struct dmap *) mp->data; 497 498 /* determine the bit number and word within the dmap of 499 * the starting block. also determine how many blocks 500 * are to be updated within this dmap. 501 */ 502 dbitno = blkno & (BPERDMAP - 1); 503 word = dbitno >> L2DBWORD; 504 nblks = min(rem, (s64)BPERDMAP - dbitno); 505 506 /* update the bits of the dmap words. the first and last 507 * words may only have a subset of their bits updated. if 508 * this is the case, we'll work against that word (i.e. 509 * partial first and/or last) only in a single pass. a 510 * single pass will also be used to update all words that 511 * are to have all their bits updated. 512 */ 513 for (rbits = nblks; rbits > 0; 514 rbits -= nbits, dbitno += nbits) { 515 /* determine the bit number within the word and 516 * the number of bits within the word. 517 */ 518 wbitno = dbitno & (DBWORD - 1); 519 nbits = min(rbits, DBWORD - wbitno); 520 521 /* check if only part of the word is to be updated. */ 522 if (nbits < DBWORD) { 523 /* update (free or allocate) the bits 524 * in this word. 525 */ 526 mask = 527 (ONES << (DBWORD - nbits) >> wbitno); 528 if (free) 529 dp->pmap[word] &= 530 cpu_to_le32(~mask); 531 else 532 dp->pmap[word] |= 533 cpu_to_le32(mask); 534 535 word += 1; 536 } else { 537 /* one or more words are to have all 538 * their bits updated. determine how 539 * many words and how many bits. 540 */ 541 nwords = rbits >> L2DBWORD; 542 nbits = nwords << L2DBWORD; 543 544 /* update (free or allocate) the bits 545 * in these words. 546 */ 547 if (free) 548 memset(&dp->pmap[word], 0, 549 nwords * 4); 550 else 551 memset(&dp->pmap[word], (int) ONES, 552 nwords * 4); 553 554 word += nwords; 555 } 556 } 557 558 /* 559 * update dmap lsn 560 */ 561 if (lblkno == lastlblkno) 562 continue; 563 564 lastlblkno = lblkno; 565 566 LOGSYNC_LOCK(log, flags); 567 if (mp->lsn != 0) { 568 /* inherit older/smaller lsn */ 569 logdiff(diffp, mp->lsn, log); 570 if (difft < diffp) { 571 mp->lsn = lsn; 572 573 /* move bp after tblock in logsync list */ 574 list_move(&mp->synclist, &tblk->synclist); 575 } 576 577 /* inherit younger/larger clsn */ 578 logdiff(difft, tblk->clsn, log); 579 logdiff(diffp, mp->clsn, log); 580 if (difft > diffp) 581 mp->clsn = tblk->clsn; 582 } else { 583 mp->log = log; 584 mp->lsn = lsn; 585 586 /* insert bp after tblock in logsync list */ 587 log->count++; 588 list_add(&mp->synclist, &tblk->synclist); 589 590 mp->clsn = tblk->clsn; 591 } 592 LOGSYNC_UNLOCK(log, flags); 593 } 594 595 /* write the last buffer. */ 596 if (mp) { 597 write_metapage(mp); 598 } 599 600 return (0); 601 } 602 603 604 /* 605 * NAME: dbNextAG() 606 * 607 * FUNCTION: find the preferred allocation group for new allocations. 608 * 609 * Within the allocation groups, we maintain a preferred 610 * allocation group which consists of a group with at least 611 * average free space. It is the preferred group that we target 612 * new inode allocation towards. The tie-in between inode 613 * allocation and block allocation occurs as we allocate the 614 * first (data) block of an inode and specify the inode (block) 615 * as the allocation hint for this block. 616 * 617 * We try to avoid having more than one open file growing in 618 * an allocation group, as this will lead to fragmentation. 619 * This differs from the old OS/2 method of trying to keep 620 * empty ags around for large allocations. 621 * 622 * PARAMETERS: 623 * ipbmap - pointer to in-core inode for the block map. 624 * 625 * RETURN VALUES: 626 * the preferred allocation group number. 627 */ dbNextAG(struct inode * ipbmap)628 int dbNextAG(struct inode *ipbmap) 629 { 630 s64 avgfree; 631 int agpref; 632 s64 hwm = 0; 633 int i; 634 int next_best = -1; 635 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; 636 637 BMAP_LOCK(bmp); 638 639 /* determine the average number of free blocks within the ags. */ 640 avgfree = (u32)bmp->db_nfree / bmp->db_numag; 641 642 /* 643 * if the current preferred ag does not have an active allocator 644 * and has at least average freespace, return it 645 */ 646 agpref = bmp->db_agpref; 647 if ((atomic_read(&bmp->db_active[agpref]) == 0) && 648 (bmp->db_agfree[agpref] >= avgfree)) 649 goto unlock; 650 651 /* From the last preferred ag, find the next one with at least 652 * average free space. 653 */ 654 for (i = 0 ; i < bmp->db_numag; i++, agpref++) { 655 if (agpref >= bmp->db_numag) 656 agpref = 0; 657 658 if (atomic_read(&bmp->db_active[agpref])) 659 /* open file is currently growing in this ag */ 660 continue; 661 if (bmp->db_agfree[agpref] >= avgfree) { 662 /* Return this one */ 663 bmp->db_agpref = agpref; 664 goto unlock; 665 } else if (bmp->db_agfree[agpref] > hwm) { 666 /* Less than avg. freespace, but best so far */ 667 hwm = bmp->db_agfree[agpref]; 668 next_best = agpref; 669 } 670 } 671 672 /* 673 * If no inactive ag was found with average freespace, use the 674 * next best 675 */ 676 if (next_best != -1) 677 bmp->db_agpref = next_best; 678 /* else leave db_agpref unchanged */ 679 unlock: 680 BMAP_UNLOCK(bmp); 681 682 /* return the preferred group. 683 */ 684 return (bmp->db_agpref); 685 } 686 687 /* 688 * NAME: dbAlloc() 689 * 690 * FUNCTION: attempt to allocate a specified number of contiguous free 691 * blocks from the working allocation block map. 692 * 693 * the block allocation policy uses hints and a multi-step 694 * approach. 695 * 696 * for allocation requests smaller than the number of blocks 697 * per dmap, we first try to allocate the new blocks 698 * immediately following the hint. if these blocks are not 699 * available, we try to allocate blocks near the hint. if 700 * no blocks near the hint are available, we next try to 701 * allocate within the same dmap as contains the hint. 702 * 703 * if no blocks are available in the dmap or the allocation 704 * request is larger than the dmap size, we try to allocate 705 * within the same allocation group as contains the hint. if 706 * this does not succeed, we finally try to allocate anywhere 707 * within the aggregate. 708 * 709 * we also try to allocate anywhere within the aggregate 710 * for allocation requests larger than the allocation group 711 * size or requests that specify no hint value. 712 * 713 * PARAMETERS: 714 * ip - pointer to in-core inode; 715 * hint - allocation hint. 716 * nblocks - number of contiguous blocks in the range. 717 * results - on successful return, set to the starting block number 718 * of the newly allocated contiguous range. 719 * 720 * RETURN VALUES: 721 * 0 - success 722 * -ENOSPC - insufficient disk resources 723 * -EIO - i/o error 724 */ dbAlloc(struct inode * ip,s64 hint,s64 nblocks,s64 * results)725 int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) 726 { 727 int rc, agno; 728 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; 729 struct bmap *bmp; 730 struct metapage *mp; 731 s64 lblkno, blkno; 732 struct dmap *dp; 733 int l2nb; 734 s64 mapSize; 735 int writers; 736 737 /* assert that nblocks is valid */ 738 assert(nblocks > 0); 739 740 /* get the log2 number of blocks to be allocated. 741 * if the number of blocks is not a log2 multiple, 742 * it will be rounded up to the next log2 multiple. 743 */ 744 l2nb = BLKSTOL2(nblocks); 745 746 bmp = JFS_SBI(ip->i_sb)->bmap; 747 748 mapSize = bmp->db_mapsize; 749 750 /* the hint should be within the map */ 751 if (hint >= mapSize) { 752 jfs_error(ip->i_sb, "the hint is outside the map\n"); 753 return -EIO; 754 } 755 756 /* if the number of blocks to be allocated is greater than the 757 * allocation group size, try to allocate anywhere. 758 */ 759 if (l2nb > bmp->db_agl2size) { 760 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); 761 762 rc = dbAllocAny(bmp, nblocks, l2nb, results); 763 764 goto write_unlock; 765 } 766 767 /* 768 * If no hint, let dbNextAG recommend an allocation group 769 */ 770 if (hint == 0) 771 goto pref_ag; 772 773 /* we would like to allocate close to the hint. adjust the 774 * hint to the block following the hint since the allocators 775 * will start looking for free space starting at this point. 776 */ 777 blkno = hint + 1; 778 779 if (blkno >= bmp->db_mapsize) 780 goto pref_ag; 781 782 agno = blkno >> bmp->db_agl2size; 783 784 /* check if blkno crosses over into a new allocation group. 785 * if so, check if we should allow allocations within this 786 * allocation group. 787 */ 788 if ((blkno & (bmp->db_agsize - 1)) == 0) 789 /* check if the AG is currently being written to. 790 * if so, call dbNextAG() to find a non-busy 791 * AG with sufficient free space. 792 */ 793 if (atomic_read(&bmp->db_active[agno])) 794 goto pref_ag; 795 796 /* check if the allocation request size can be satisfied from a 797 * single dmap. if so, try to allocate from the dmap containing 798 * the hint using a tiered strategy. 799 */ 800 if (nblocks <= BPERDMAP) { 801 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); 802 803 /* get the buffer for the dmap containing the hint. 804 */ 805 rc = -EIO; 806 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); 807 mp = read_metapage(ipbmap, lblkno, PSIZE, 0); 808 if (mp == NULL) 809 goto read_unlock; 810 811 dp = (struct dmap *) mp->data; 812 813 /* first, try to satisfy the allocation request with the 814 * blocks beginning at the hint. 815 */ 816 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) 817 != -ENOSPC) { 818 if (rc == 0) { 819 *results = blkno; 820 mark_metapage_dirty(mp); 821 } 822 823 release_metapage(mp); 824 goto read_unlock; 825 } 826 827 writers = atomic_read(&bmp->db_active[agno]); 828 if ((writers > 1) || 829 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { 830 /* 831 * Someone else is writing in this allocation 832 * group. To avoid fragmenting, try another ag 833 */ 834 release_metapage(mp); 835 IREAD_UNLOCK(ipbmap); 836 goto pref_ag; 837 } 838 839 /* next, try to satisfy the allocation request with blocks 840 * near the hint. 841 */ 842 if ((rc = 843 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) 844 != -ENOSPC) { 845 if (rc == 0) 846 mark_metapage_dirty(mp); 847 848 release_metapage(mp); 849 goto read_unlock; 850 } 851 852 /* try to satisfy the allocation request with blocks within 853 * the same dmap as the hint. 854 */ 855 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) 856 != -ENOSPC) { 857 if (rc == 0) 858 mark_metapage_dirty(mp); 859 860 release_metapage(mp); 861 goto read_unlock; 862 } 863 864 release_metapage(mp); 865 IREAD_UNLOCK(ipbmap); 866 } 867 868 /* try to satisfy the allocation request with blocks within 869 * the same allocation group as the hint. 870 */ 871 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); 872 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) 873 goto write_unlock; 874 875 IWRITE_UNLOCK(ipbmap); 876 877 878 pref_ag: 879 /* 880 * Let dbNextAG recommend a preferred allocation group 881 */ 882 agno = dbNextAG(ipbmap); 883 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); 884 885 /* Try to allocate within this allocation group. if that fails, try to 886 * allocate anywhere in the map. 887 */ 888 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) 889 rc = dbAllocAny(bmp, nblocks, l2nb, results); 890 891 write_unlock: 892 IWRITE_UNLOCK(ipbmap); 893 894 return (rc); 895 896 read_unlock: 897 IREAD_UNLOCK(ipbmap); 898 899 return (rc); 900 } 901 902 /* 903 * NAME: dbReAlloc() 904 * 905 * FUNCTION: attempt to extend a current allocation by a specified 906 * number of blocks. 907 * 908 * this routine attempts to satisfy the allocation request 909 * by first trying to extend the existing allocation in 910 * place by allocating the additional blocks as the blocks 911 * immediately following the current allocation. if these 912 * blocks are not available, this routine will attempt to 913 * allocate a new set of contiguous blocks large enough 914 * to cover the existing allocation plus the additional 915 * number of blocks required. 916 * 917 * PARAMETERS: 918 * ip - pointer to in-core inode requiring allocation. 919 * blkno - starting block of the current allocation. 920 * nblocks - number of contiguous blocks within the current 921 * allocation. 922 * addnblocks - number of blocks to add to the allocation. 923 * results - on successful return, set to the starting block number 924 * of the existing allocation if the existing allocation 925 * was extended in place or to a newly allocated contiguous 926 * range if the existing allocation could not be extended 927 * in place. 928 * 929 * RETURN VALUES: 930 * 0 - success 931 * -ENOSPC - insufficient disk resources 932 * -EIO - i/o error 933 */ 934 int dbReAlloc(struct inode * ip,s64 blkno,s64 nblocks,s64 addnblocks,s64 * results)935 dbReAlloc(struct inode *ip, 936 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) 937 { 938 int rc; 939 940 /* try to extend the allocation in place. 941 */ 942 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { 943 *results = blkno; 944 return (0); 945 } else { 946 if (rc != -ENOSPC) 947 return (rc); 948 } 949 950 /* could not extend the allocation in place, so allocate a 951 * new set of blocks for the entire request (i.e. try to get 952 * a range of contiguous blocks large enough to cover the 953 * existing allocation plus the additional blocks.) 954 */ 955 return (dbAlloc 956 (ip, blkno + nblocks - 1, addnblocks + nblocks, results)); 957 } 958 959 960 /* 961 * NAME: dbExtend() 962 * 963 * FUNCTION: attempt to extend a current allocation by a specified 964 * number of blocks. 965 * 966 * this routine attempts to satisfy the allocation request 967 * by first trying to extend the existing allocation in 968 * place by allocating the additional blocks as the blocks 969 * immediately following the current allocation. 970 * 971 * PARAMETERS: 972 * ip - pointer to in-core inode requiring allocation. 973 * blkno - starting block of the current allocation. 974 * nblocks - number of contiguous blocks within the current 975 * allocation. 976 * addnblocks - number of blocks to add to the allocation. 977 * 978 * RETURN VALUES: 979 * 0 - success 980 * -ENOSPC - insufficient disk resources 981 * -EIO - i/o error 982 */ dbExtend(struct inode * ip,s64 blkno,s64 nblocks,s64 addnblocks)983 static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) 984 { 985 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); 986 s64 lblkno, lastblkno, extblkno; 987 uint rel_block; 988 struct metapage *mp; 989 struct dmap *dp; 990 int rc; 991 struct inode *ipbmap = sbi->ipbmap; 992 struct bmap *bmp; 993 994 /* 995 * We don't want a non-aligned extent to cross a page boundary 996 */ 997 if (((rel_block = blkno & (sbi->nbperpage - 1))) && 998 (rel_block + nblocks + addnblocks > sbi->nbperpage)) 999 return -ENOSPC; 1000 1001 /* get the last block of the current allocation */ 1002 lastblkno = blkno + nblocks - 1; 1003 1004 /* determine the block number of the block following 1005 * the existing allocation. 1006 */ 1007 extblkno = lastblkno + 1; 1008 1009 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); 1010 1011 /* better be within the file system */ 1012 bmp = sbi->bmap; 1013 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { 1014 IREAD_UNLOCK(ipbmap); 1015 jfs_error(ip->i_sb, "the block is outside the filesystem\n"); 1016 return -EIO; 1017 } 1018 1019 /* we'll attempt to extend the current allocation in place by 1020 * allocating the additional blocks as the blocks immediately 1021 * following the current allocation. we only try to extend the 1022 * current allocation in place if the number of additional blocks 1023 * can fit into a dmap, the last block of the current allocation 1024 * is not the last block of the file system, and the start of the 1025 * inplace extension is not on an allocation group boundary. 1026 */ 1027 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || 1028 (extblkno & (bmp->db_agsize - 1)) == 0) { 1029 IREAD_UNLOCK(ipbmap); 1030 return -ENOSPC; 1031 } 1032 1033 /* get the buffer for the dmap containing the first block 1034 * of the extension. 1035 */ 1036 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); 1037 mp = read_metapage(ipbmap, lblkno, PSIZE, 0); 1038 if (mp == NULL) { 1039 IREAD_UNLOCK(ipbmap); 1040 return -EIO; 1041 } 1042 1043 dp = (struct dmap *) mp->data; 1044 1045 /* try to allocate the blocks immediately following the 1046 * current allocation. 1047 */ 1048 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); 1049 1050 IREAD_UNLOCK(ipbmap); 1051 1052 /* were we successful ? */ 1053 if (rc == 0) 1054 write_metapage(mp); 1055 else 1056 /* we were not successful */ 1057 release_metapage(mp); 1058 1059 return (rc); 1060 } 1061 1062 1063 /* 1064 * NAME: dbAllocNext() 1065 * 1066 * FUNCTION: attempt to allocate the blocks of the specified block 1067 * range within a dmap. 1068 * 1069 * PARAMETERS: 1070 * bmp - pointer to bmap descriptor 1071 * dp - pointer to dmap. 1072 * blkno - starting block number of the range. 1073 * nblocks - number of contiguous free blocks of the range. 1074 * 1075 * RETURN VALUES: 1076 * 0 - success 1077 * -ENOSPC - insufficient disk resources 1078 * -EIO - i/o error 1079 * 1080 * serialization: IREAD_LOCK(ipbmap) held on entry/exit; 1081 */ dbAllocNext(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)1082 static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, 1083 int nblocks) 1084 { 1085 int dbitno, word, rembits, nb, nwords, wbitno, nw; 1086 int l2size; 1087 s8 *leaf; 1088 u32 mask; 1089 1090 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { 1091 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); 1092 return -EIO; 1093 } 1094 1095 /* pick up a pointer to the leaves of the dmap tree. 1096 */ 1097 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); 1098 1099 /* determine the bit number and word within the dmap of the 1100 * starting block. 1101 */ 1102 dbitno = blkno & (BPERDMAP - 1); 1103 word = dbitno >> L2DBWORD; 1104 1105 /* check if the specified block range is contained within 1106 * this dmap. 1107 */ 1108 if (dbitno + nblocks > BPERDMAP) 1109 return -ENOSPC; 1110 1111 /* check if the starting leaf indicates that anything 1112 * is free. 1113 */ 1114 if (leaf[word] == NOFREE) 1115 return -ENOSPC; 1116 1117 /* check the dmaps words corresponding to block range to see 1118 * if the block range is free. not all bits of the first and 1119 * last words may be contained within the block range. if this 1120 * is the case, we'll work against those words (i.e. partial first 1121 * and/or last) on an individual basis (a single pass) and examine 1122 * the actual bits to determine if they are free. a single pass 1123 * will be used for all dmap words fully contained within the 1124 * specified range. within this pass, the leaves of the dmap 1125 * tree will be examined to determine if the blocks are free. a 1126 * single leaf may describe the free space of multiple dmap 1127 * words, so we may visit only a subset of the actual leaves 1128 * corresponding to the dmap words of the block range. 1129 */ 1130 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { 1131 /* determine the bit number within the word and 1132 * the number of bits within the word. 1133 */ 1134 wbitno = dbitno & (DBWORD - 1); 1135 nb = min(rembits, DBWORD - wbitno); 1136 1137 /* check if only part of the word is to be examined. 1138 */ 1139 if (nb < DBWORD) { 1140 /* check if the bits are free. 1141 */ 1142 mask = (ONES << (DBWORD - nb) >> wbitno); 1143 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) 1144 return -ENOSPC; 1145 1146 word += 1; 1147 } else { 1148 /* one or more dmap words are fully contained 1149 * within the block range. determine how many 1150 * words and how many bits. 1151 */ 1152 nwords = rembits >> L2DBWORD; 1153 nb = nwords << L2DBWORD; 1154 1155 /* now examine the appropriate leaves to determine 1156 * if the blocks are free. 1157 */ 1158 while (nwords > 0) { 1159 /* does the leaf describe any free space ? 1160 */ 1161 if (leaf[word] < BUDMIN) 1162 return -ENOSPC; 1163 1164 /* determine the l2 number of bits provided 1165 * by this leaf. 1166 */ 1167 l2size = 1168 min_t(int, leaf[word], NLSTOL2BSZ(nwords)); 1169 1170 /* determine how many words were handled. 1171 */ 1172 nw = BUDSIZE(l2size, BUDMIN); 1173 1174 nwords -= nw; 1175 word += nw; 1176 } 1177 } 1178 } 1179 1180 /* allocate the blocks. 1181 */ 1182 return (dbAllocDmap(bmp, dp, blkno, nblocks)); 1183 } 1184 1185 1186 /* 1187 * NAME: dbAllocNear() 1188 * 1189 * FUNCTION: attempt to allocate a number of contiguous free blocks near 1190 * a specified block (hint) within a dmap. 1191 * 1192 * starting with the dmap leaf that covers the hint, we'll 1193 * check the next four contiguous leaves for sufficient free 1194 * space. if sufficient free space is found, we'll allocate 1195 * the desired free space. 1196 * 1197 * PARAMETERS: 1198 * bmp - pointer to bmap descriptor 1199 * dp - pointer to dmap. 1200 * blkno - block number to allocate near. 1201 * nblocks - actual number of contiguous free blocks desired. 1202 * l2nb - log2 number of contiguous free blocks desired. 1203 * results - on successful return, set to the starting block number 1204 * of the newly allocated range. 1205 * 1206 * RETURN VALUES: 1207 * 0 - success 1208 * -ENOSPC - insufficient disk resources 1209 * -EIO - i/o error 1210 * 1211 * serialization: IREAD_LOCK(ipbmap) held on entry/exit; 1212 */ 1213 static int dbAllocNear(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks,int l2nb,s64 * results)1214 dbAllocNear(struct bmap * bmp, 1215 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) 1216 { 1217 int word, lword, rc; 1218 s8 *leaf; 1219 1220 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { 1221 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); 1222 return -EIO; 1223 } 1224 1225 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); 1226 1227 /* determine the word within the dmap that holds the hint 1228 * (i.e. blkno). also, determine the last word in the dmap 1229 * that we'll include in our examination. 1230 */ 1231 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; 1232 lword = min(word + 4, LPERDMAP); 1233 1234 /* examine the leaves for sufficient free space. 1235 */ 1236 for (; word < lword; word++) { 1237 /* does the leaf describe sufficient free space ? 1238 */ 1239 if (leaf[word] < l2nb) 1240 continue; 1241 1242 /* determine the block number within the file system 1243 * of the first block described by this dmap word. 1244 */ 1245 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); 1246 1247 /* if not all bits of the dmap word are free, get the 1248 * starting bit number within the dmap word of the required 1249 * string of free bits and adjust the block number with the 1250 * value. 1251 */ 1252 if (leaf[word] < BUDMIN) 1253 blkno += 1254 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); 1255 1256 /* allocate the blocks. 1257 */ 1258 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) 1259 *results = blkno; 1260 1261 return (rc); 1262 } 1263 1264 return -ENOSPC; 1265 } 1266 1267 1268 /* 1269 * NAME: dbAllocAG() 1270 * 1271 * FUNCTION: attempt to allocate the specified number of contiguous 1272 * free blocks within the specified allocation group. 1273 * 1274 * unless the allocation group size is equal to the number 1275 * of blocks per dmap, the dmap control pages will be used to 1276 * find the required free space, if available. we start the 1277 * search at the highest dmap control page level which 1278 * distinctly describes the allocation group's free space 1279 * (i.e. the highest level at which the allocation group's 1280 * free space is not mixed in with that of any other group). 1281 * in addition, we start the search within this level at a 1282 * height of the dmapctl dmtree at which the nodes distinctly 1283 * describe the allocation group's free space. at this height, 1284 * the allocation group's free space may be represented by 1 1285 * or two sub-trees, depending on the allocation group size. 1286 * we search the top nodes of these subtrees left to right for 1287 * sufficient free space. if sufficient free space is found, 1288 * the subtree is searched to find the leftmost leaf that 1289 * has free space. once we have made it to the leaf, we 1290 * move the search to the next lower level dmap control page 1291 * corresponding to this leaf. we continue down the dmap control 1292 * pages until we find the dmap that contains or starts the 1293 * sufficient free space and we allocate at this dmap. 1294 * 1295 * if the allocation group size is equal to the dmap size, 1296 * we'll start at the dmap corresponding to the allocation 1297 * group and attempt the allocation at this level. 1298 * 1299 * the dmap control page search is also not performed if the 1300 * allocation group is completely free and we go to the first 1301 * dmap of the allocation group to do the allocation. this is 1302 * done because the allocation group may be part (not the first 1303 * part) of a larger binary buddy system, causing the dmap 1304 * control pages to indicate no free space (NOFREE) within 1305 * the allocation group. 1306 * 1307 * PARAMETERS: 1308 * bmp - pointer to bmap descriptor 1309 * agno - allocation group number. 1310 * nblocks - actual number of contiguous free blocks desired. 1311 * l2nb - log2 number of contiguous free blocks desired. 1312 * results - on successful return, set to the starting block number 1313 * of the newly allocated range. 1314 * 1315 * RETURN VALUES: 1316 * 0 - success 1317 * -ENOSPC - insufficient disk resources 1318 * -EIO - i/o error 1319 * 1320 * note: IWRITE_LOCK(ipmap) held on entry/exit; 1321 */ 1322 static int dbAllocAG(struct bmap * bmp,int agno,s64 nblocks,int l2nb,s64 * results)1323 dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) 1324 { 1325 struct metapage *mp; 1326 struct dmapctl *dcp; 1327 int rc, ti, i, k, m, n, agperlev; 1328 s64 blkno, lblkno; 1329 int budmin; 1330 1331 /* allocation request should not be for more than the 1332 * allocation group size. 1333 */ 1334 if (l2nb > bmp->db_agl2size) { 1335 jfs_error(bmp->db_ipbmap->i_sb, 1336 "allocation request is larger than the allocation group size\n"); 1337 return -EIO; 1338 } 1339 1340 /* determine the starting block number of the allocation 1341 * group. 1342 */ 1343 blkno = (s64) agno << bmp->db_agl2size; 1344 1345 /* check if the allocation group size is the minimum allocation 1346 * group size or if the allocation group is completely free. if 1347 * the allocation group size is the minimum size of BPERDMAP (i.e. 1348 * 1 dmap), there is no need to search the dmap control page (below) 1349 * that fully describes the allocation group since the allocation 1350 * group is already fully described by a dmap. in this case, we 1351 * just call dbAllocCtl() to search the dmap tree and allocate the 1352 * required space if available. 1353 * 1354 * if the allocation group is completely free, dbAllocCtl() is 1355 * also called to allocate the required space. this is done for 1356 * two reasons. first, it makes no sense searching the dmap control 1357 * pages for free space when we know that free space exists. second, 1358 * the dmap control pages may indicate that the allocation group 1359 * has no free space if the allocation group is part (not the first 1360 * part) of a larger binary buddy system. 1361 */ 1362 if (bmp->db_agsize == BPERDMAP 1363 || bmp->db_agfree[agno] == bmp->db_agsize) { 1364 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); 1365 if ((rc == -ENOSPC) && 1366 (bmp->db_agfree[agno] == bmp->db_agsize)) { 1367 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", 1368 (unsigned long long) blkno, 1369 (unsigned long long) nblocks); 1370 jfs_error(bmp->db_ipbmap->i_sb, 1371 "dbAllocCtl failed in free AG\n"); 1372 } 1373 return (rc); 1374 } 1375 1376 /* the buffer for the dmap control page that fully describes the 1377 * allocation group. 1378 */ 1379 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); 1380 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 1381 if (mp == NULL) 1382 return -EIO; 1383 dcp = (struct dmapctl *) mp->data; 1384 budmin = dcp->budmin; 1385 1386 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { 1387 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); 1388 release_metapage(mp); 1389 return -EIO; 1390 } 1391 1392 /* search the subtree(s) of the dmap control page that describes 1393 * the allocation group, looking for sufficient free space. to begin, 1394 * determine how many allocation groups are represented in a dmap 1395 * control page at the control page level (i.e. L0, L1, L2) that 1396 * fully describes an allocation group. next, determine the starting 1397 * tree index of this allocation group within the control page. 1398 */ 1399 agperlev = 1400 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth; 1401 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); 1402 1403 /* dmap control page trees fan-out by 4 and a single allocation 1404 * group may be described by 1 or 2 subtrees within the ag level 1405 * dmap control page, depending upon the ag size. examine the ag's 1406 * subtrees for sufficient free space, starting with the leftmost 1407 * subtree. 1408 */ 1409 for (i = 0; i < bmp->db_agwidth; i++, ti++) { 1410 /* is there sufficient free space ? 1411 */ 1412 if (l2nb > dcp->stree[ti]) 1413 continue; 1414 1415 /* sufficient free space found in a subtree. now search down 1416 * the subtree to find the leftmost leaf that describes this 1417 * free space. 1418 */ 1419 for (k = bmp->db_agheight; k > 0; k--) { 1420 for (n = 0, m = (ti << 2) + 1; n < 4; n++) { 1421 if (l2nb <= dcp->stree[m + n]) { 1422 ti = m + n; 1423 break; 1424 } 1425 } 1426 if (n == 4) { 1427 jfs_error(bmp->db_ipbmap->i_sb, 1428 "failed descending stree\n"); 1429 release_metapage(mp); 1430 return -EIO; 1431 } 1432 } 1433 1434 /* determine the block number within the file system 1435 * that corresponds to this leaf. 1436 */ 1437 if (bmp->db_aglevel == 2) 1438 blkno = 0; 1439 else if (bmp->db_aglevel == 1) 1440 blkno &= ~(MAXL1SIZE - 1); 1441 else /* bmp->db_aglevel == 0 */ 1442 blkno &= ~(MAXL0SIZE - 1); 1443 1444 blkno += 1445 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; 1446 1447 /* release the buffer in preparation for going down 1448 * the next level of dmap control pages. 1449 */ 1450 release_metapage(mp); 1451 1452 /* check if we need to continue to search down the lower 1453 * level dmap control pages. we need to if the number of 1454 * blocks required is less than maximum number of blocks 1455 * described at the next lower level. 1456 */ 1457 if (l2nb < budmin) { 1458 1459 /* search the lower level dmap control pages to get 1460 * the starting block number of the dmap that 1461 * contains or starts off the free space. 1462 */ 1463 if ((rc = 1464 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, 1465 &blkno))) { 1466 if (rc == -ENOSPC) { 1467 jfs_error(bmp->db_ipbmap->i_sb, 1468 "control page inconsistent\n"); 1469 return -EIO; 1470 } 1471 return (rc); 1472 } 1473 } 1474 1475 /* allocate the blocks. 1476 */ 1477 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); 1478 if (rc == -ENOSPC) { 1479 jfs_error(bmp->db_ipbmap->i_sb, 1480 "unable to allocate blocks\n"); 1481 rc = -EIO; 1482 } 1483 return (rc); 1484 } 1485 1486 /* no space in the allocation group. release the buffer and 1487 * return -ENOSPC. 1488 */ 1489 release_metapage(mp); 1490 1491 return -ENOSPC; 1492 } 1493 1494 1495 /* 1496 * NAME: dbAllocAny() 1497 * 1498 * FUNCTION: attempt to allocate the specified number of contiguous 1499 * free blocks anywhere in the file system. 1500 * 1501 * dbAllocAny() attempts to find the sufficient free space by 1502 * searching down the dmap control pages, starting with the 1503 * highest level (i.e. L0, L1, L2) control page. if free space 1504 * large enough to satisfy the desired free space is found, the 1505 * desired free space is allocated. 1506 * 1507 * PARAMETERS: 1508 * bmp - pointer to bmap descriptor 1509 * nblocks - actual number of contiguous free blocks desired. 1510 * l2nb - log2 number of contiguous free blocks desired. 1511 * results - on successful return, set to the starting block number 1512 * of the newly allocated range. 1513 * 1514 * RETURN VALUES: 1515 * 0 - success 1516 * -ENOSPC - insufficient disk resources 1517 * -EIO - i/o error 1518 * 1519 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; 1520 */ dbAllocAny(struct bmap * bmp,s64 nblocks,int l2nb,s64 * results)1521 static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) 1522 { 1523 int rc; 1524 s64 blkno = 0; 1525 1526 /* starting with the top level dmap control page, search 1527 * down the dmap control levels for sufficient free space. 1528 * if free space is found, dbFindCtl() returns the starting 1529 * block number of the dmap that contains or starts off the 1530 * range of free space. 1531 */ 1532 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) 1533 return (rc); 1534 1535 /* allocate the blocks. 1536 */ 1537 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); 1538 if (rc == -ENOSPC) { 1539 jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n"); 1540 return -EIO; 1541 } 1542 return (rc); 1543 } 1544 1545 1546 /* 1547 * NAME: dbDiscardAG() 1548 * 1549 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG 1550 * 1551 * algorithm: 1552 * 1) allocate blocks, as large as possible and save them 1553 * while holding IWRITE_LOCK on ipbmap 1554 * 2) trim all these saved block/length values 1555 * 3) mark the blocks free again 1556 * 1557 * benefit: 1558 * - we work only on one ag at some time, minimizing how long we 1559 * need to lock ipbmap 1560 * - reading / writing the fs is possible most time, even on 1561 * trimming 1562 * 1563 * downside: 1564 * - we write two times to the dmapctl and dmap pages 1565 * - but for me, this seems the best way, better ideas? 1566 * /TR 2012 1567 * 1568 * PARAMETERS: 1569 * ip - pointer to in-core inode 1570 * agno - ag to trim 1571 * minlen - minimum value of contiguous blocks 1572 * 1573 * RETURN VALUES: 1574 * s64 - actual number of blocks trimmed 1575 */ dbDiscardAG(struct inode * ip,int agno,s64 minlen)1576 s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen) 1577 { 1578 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; 1579 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; 1580 s64 nblocks, blkno; 1581 u64 trimmed = 0; 1582 int rc, l2nb; 1583 struct super_block *sb = ipbmap->i_sb; 1584 1585 struct range2trim { 1586 u64 blkno; 1587 u64 nblocks; 1588 } *totrim, *tt; 1589 1590 /* max blkno / nblocks pairs to trim */ 1591 int count = 0, range_cnt; 1592 u64 max_ranges; 1593 1594 /* prevent others from writing new stuff here, while trimming */ 1595 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); 1596 1597 nblocks = bmp->db_agfree[agno]; 1598 max_ranges = nblocks; 1599 do_div(max_ranges, minlen); 1600 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024); 1601 totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS); 1602 if (totrim == NULL) { 1603 jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n"); 1604 IWRITE_UNLOCK(ipbmap); 1605 return 0; 1606 } 1607 1608 tt = totrim; 1609 while (nblocks >= minlen) { 1610 l2nb = BLKSTOL2(nblocks); 1611 1612 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */ 1613 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno); 1614 if (rc == 0) { 1615 tt->blkno = blkno; 1616 tt->nblocks = nblocks; 1617 tt++; count++; 1618 1619 /* the whole ag is free, trim now */ 1620 if (bmp->db_agfree[agno] == 0) 1621 break; 1622 1623 /* give a hint for the next while */ 1624 nblocks = bmp->db_agfree[agno]; 1625 continue; 1626 } else if (rc == -ENOSPC) { 1627 /* search for next smaller log2 block */ 1628 l2nb = BLKSTOL2(nblocks) - 1; 1629 if (unlikely(l2nb < 0)) 1630 break; 1631 nblocks = 1LL << l2nb; 1632 } else { 1633 /* Trim any already allocated blocks */ 1634 jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n"); 1635 break; 1636 } 1637 1638 /* check, if our trim array is full */ 1639 if (unlikely(count >= range_cnt - 1)) 1640 break; 1641 } 1642 IWRITE_UNLOCK(ipbmap); 1643 1644 tt->nblocks = 0; /* mark the current end */ 1645 for (tt = totrim; tt->nblocks != 0; tt++) { 1646 /* when mounted with online discard, dbFree() will 1647 * call jfs_issue_discard() itself */ 1648 if (!(JFS_SBI(sb)->flag & JFS_DISCARD)) 1649 jfs_issue_discard(ip, tt->blkno, tt->nblocks); 1650 dbFree(ip, tt->blkno, tt->nblocks); 1651 trimmed += tt->nblocks; 1652 } 1653 kfree(totrim); 1654 1655 return trimmed; 1656 } 1657 1658 /* 1659 * NAME: dbFindCtl() 1660 * 1661 * FUNCTION: starting at a specified dmap control page level and block 1662 * number, search down the dmap control levels for a range of 1663 * contiguous free blocks large enough to satisfy an allocation 1664 * request for the specified number of free blocks. 1665 * 1666 * if sufficient contiguous free blocks are found, this routine 1667 * returns the starting block number within a dmap page that 1668 * contains or starts a range of contiqious free blocks that 1669 * is sufficient in size. 1670 * 1671 * PARAMETERS: 1672 * bmp - pointer to bmap descriptor 1673 * level - starting dmap control page level. 1674 * l2nb - log2 number of contiguous free blocks desired. 1675 * *blkno - on entry, starting block number for conducting the search. 1676 * on successful return, the first block within a dmap page 1677 * that contains or starts a range of contiguous free blocks. 1678 * 1679 * RETURN VALUES: 1680 * 0 - success 1681 * -ENOSPC - insufficient disk resources 1682 * -EIO - i/o error 1683 * 1684 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; 1685 */ dbFindCtl(struct bmap * bmp,int l2nb,int level,s64 * blkno)1686 static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) 1687 { 1688 int rc, leafidx, lev; 1689 s64 b, lblkno; 1690 struct dmapctl *dcp; 1691 int budmin; 1692 struct metapage *mp; 1693 1694 /* starting at the specified dmap control page level and block 1695 * number, search down the dmap control levels for the starting 1696 * block number of a dmap page that contains or starts off 1697 * sufficient free blocks. 1698 */ 1699 for (lev = level, b = *blkno; lev >= 0; lev--) { 1700 /* get the buffer of the dmap control page for the block 1701 * number and level (i.e. L0, L1, L2). 1702 */ 1703 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); 1704 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 1705 if (mp == NULL) 1706 return -EIO; 1707 dcp = (struct dmapctl *) mp->data; 1708 budmin = dcp->budmin; 1709 1710 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { 1711 jfs_error(bmp->db_ipbmap->i_sb, 1712 "Corrupt dmapctl page\n"); 1713 release_metapage(mp); 1714 return -EIO; 1715 } 1716 1717 /* search the tree within the dmap control page for 1718 * sufficient free space. if sufficient free space is found, 1719 * dbFindLeaf() returns the index of the leaf at which 1720 * free space was found. 1721 */ 1722 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx, true); 1723 1724 /* release the buffer. 1725 */ 1726 release_metapage(mp); 1727 1728 /* space found ? 1729 */ 1730 if (rc) { 1731 if (lev != level) { 1732 jfs_error(bmp->db_ipbmap->i_sb, 1733 "dmap inconsistent\n"); 1734 return -EIO; 1735 } 1736 return -ENOSPC; 1737 } 1738 1739 /* adjust the block number to reflect the location within 1740 * the dmap control page (i.e. the leaf) at which free 1741 * space was found. 1742 */ 1743 b += (((s64) leafidx) << budmin); 1744 1745 /* we stop the search at this dmap control page level if 1746 * the number of blocks required is greater than or equal 1747 * to the maximum number of blocks described at the next 1748 * (lower) level. 1749 */ 1750 if (l2nb >= budmin) 1751 break; 1752 } 1753 1754 *blkno = b; 1755 return (0); 1756 } 1757 1758 1759 /* 1760 * NAME: dbAllocCtl() 1761 * 1762 * FUNCTION: attempt to allocate a specified number of contiguous 1763 * blocks starting within a specific dmap. 1764 * 1765 * this routine is called by higher level routines that search 1766 * the dmap control pages above the actual dmaps for contiguous 1767 * free space. the result of successful searches by these 1768 * routines are the starting block numbers within dmaps, with 1769 * the dmaps themselves containing the desired contiguous free 1770 * space or starting a contiguous free space of desired size 1771 * that is made up of the blocks of one or more dmaps. these 1772 * calls should not fail due to insufficent resources. 1773 * 1774 * this routine is called in some cases where it is not known 1775 * whether it will fail due to insufficient resources. more 1776 * specifically, this occurs when allocating from an allocation 1777 * group whose size is equal to the number of blocks per dmap. 1778 * in this case, the dmap control pages are not examined prior 1779 * to calling this routine (to save pathlength) and the call 1780 * might fail. 1781 * 1782 * for a request size that fits within a dmap, this routine relies 1783 * upon the dmap's dmtree to find the requested contiguous free 1784 * space. for request sizes that are larger than a dmap, the 1785 * requested free space will start at the first block of the 1786 * first dmap (i.e. blkno). 1787 * 1788 * PARAMETERS: 1789 * bmp - pointer to bmap descriptor 1790 * nblocks - actual number of contiguous free blocks to allocate. 1791 * l2nb - log2 number of contiguous free blocks to allocate. 1792 * blkno - starting block number of the dmap to start the allocation 1793 * from. 1794 * results - on successful return, set to the starting block number 1795 * of the newly allocated range. 1796 * 1797 * RETURN VALUES: 1798 * 0 - success 1799 * -ENOSPC - insufficient disk resources 1800 * -EIO - i/o error 1801 * 1802 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; 1803 */ 1804 static int dbAllocCtl(struct bmap * bmp,s64 nblocks,int l2nb,s64 blkno,s64 * results)1805 dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) 1806 { 1807 int rc, nb; 1808 s64 b, lblkno, n; 1809 struct metapage *mp; 1810 struct dmap *dp; 1811 1812 /* check if the allocation request is confined to a single dmap. 1813 */ 1814 if (l2nb <= L2BPERDMAP) { 1815 /* get the buffer for the dmap. 1816 */ 1817 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); 1818 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 1819 if (mp == NULL) 1820 return -EIO; 1821 dp = (struct dmap *) mp->data; 1822 1823 if (dp->tree.budmin < 0) 1824 return -EIO; 1825 1826 /* try to allocate the blocks. 1827 */ 1828 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); 1829 if (rc == 0) 1830 mark_metapage_dirty(mp); 1831 1832 release_metapage(mp); 1833 1834 return (rc); 1835 } 1836 1837 /* allocation request involving multiple dmaps. it must start on 1838 * a dmap boundary. 1839 */ 1840 assert((blkno & (BPERDMAP - 1)) == 0); 1841 1842 /* allocate the blocks dmap by dmap. 1843 */ 1844 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { 1845 /* get the buffer for the dmap. 1846 */ 1847 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); 1848 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 1849 if (mp == NULL) { 1850 rc = -EIO; 1851 goto backout; 1852 } 1853 dp = (struct dmap *) mp->data; 1854 1855 /* the dmap better be all free. 1856 */ 1857 if (dp->tree.stree[ROOT] != L2BPERDMAP) { 1858 release_metapage(mp); 1859 jfs_error(bmp->db_ipbmap->i_sb, 1860 "the dmap is not all free\n"); 1861 rc = -EIO; 1862 goto backout; 1863 } 1864 1865 /* determine how many blocks to allocate from this dmap. 1866 */ 1867 nb = min_t(s64, n, BPERDMAP); 1868 1869 /* allocate the blocks from the dmap. 1870 */ 1871 if ((rc = dbAllocDmap(bmp, dp, b, nb))) { 1872 release_metapage(mp); 1873 goto backout; 1874 } 1875 1876 /* write the buffer. 1877 */ 1878 write_metapage(mp); 1879 } 1880 1881 /* set the results (starting block number) and return. 1882 */ 1883 *results = blkno; 1884 return (0); 1885 1886 /* something failed in handling an allocation request involving 1887 * multiple dmaps. we'll try to clean up by backing out any 1888 * allocation that has already happened for this request. if 1889 * we fail in backing out the allocation, we'll mark the file 1890 * system to indicate that blocks have been leaked. 1891 */ 1892 backout: 1893 1894 /* try to backout the allocations dmap by dmap. 1895 */ 1896 for (n = nblocks - n, b = blkno; n > 0; 1897 n -= BPERDMAP, b += BPERDMAP) { 1898 /* get the buffer for this dmap. 1899 */ 1900 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); 1901 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 1902 if (mp == NULL) { 1903 /* could not back out. mark the file system 1904 * to indicate that we have leaked blocks. 1905 */ 1906 jfs_error(bmp->db_ipbmap->i_sb, 1907 "I/O Error: Block Leakage\n"); 1908 continue; 1909 } 1910 dp = (struct dmap *) mp->data; 1911 1912 /* free the blocks is this dmap. 1913 */ 1914 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { 1915 /* could not back out. mark the file system 1916 * to indicate that we have leaked blocks. 1917 */ 1918 release_metapage(mp); 1919 jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n"); 1920 continue; 1921 } 1922 1923 /* write the buffer. 1924 */ 1925 write_metapage(mp); 1926 } 1927 1928 return (rc); 1929 } 1930 1931 1932 /* 1933 * NAME: dbAllocDmapLev() 1934 * 1935 * FUNCTION: attempt to allocate a specified number of contiguous blocks 1936 * from a specified dmap. 1937 * 1938 * this routine checks if the contiguous blocks are available. 1939 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is 1940 * returned. 1941 * 1942 * PARAMETERS: 1943 * mp - pointer to bmap descriptor 1944 * dp - pointer to dmap to attempt to allocate blocks from. 1945 * l2nb - log2 number of contiguous block desired. 1946 * nblocks - actual number of contiguous block desired. 1947 * results - on successful return, set to the starting block number 1948 * of the newly allocated range. 1949 * 1950 * RETURN VALUES: 1951 * 0 - success 1952 * -ENOSPC - insufficient disk resources 1953 * -EIO - i/o error 1954 * 1955 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or 1956 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; 1957 */ 1958 static int dbAllocDmapLev(struct bmap * bmp,struct dmap * dp,int nblocks,int l2nb,s64 * results)1959 dbAllocDmapLev(struct bmap * bmp, 1960 struct dmap * dp, int nblocks, int l2nb, s64 * results) 1961 { 1962 s64 blkno; 1963 int leafidx, rc; 1964 1965 /* can't be more than a dmaps worth of blocks */ 1966 assert(l2nb <= L2BPERDMAP); 1967 1968 /* search the tree within the dmap page for sufficient 1969 * free space. if sufficient free space is found, dbFindLeaf() 1970 * returns the index of the leaf at which free space was found. 1971 */ 1972 if (dbFindLeaf((dmtree_t *) &dp->tree, l2nb, &leafidx, false)) 1973 return -ENOSPC; 1974 1975 if (leafidx < 0) 1976 return -EIO; 1977 1978 /* determine the block number within the file system corresponding 1979 * to the leaf at which free space was found. 1980 */ 1981 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); 1982 1983 /* if not all bits of the dmap word are free, get the starting 1984 * bit number within the dmap word of the required string of free 1985 * bits and adjust the block number with this value. 1986 */ 1987 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) 1988 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); 1989 1990 /* allocate the blocks */ 1991 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) 1992 *results = blkno; 1993 1994 return (rc); 1995 } 1996 1997 1998 /* 1999 * NAME: dbAllocDmap() 2000 * 2001 * FUNCTION: adjust the disk allocation map to reflect the allocation 2002 * of a specified block range within a dmap. 2003 * 2004 * this routine allocates the specified blocks from the dmap 2005 * through a call to dbAllocBits(). if the allocation of the 2006 * block range causes the maximum string of free blocks within 2007 * the dmap to change (i.e. the value of the root of the dmap's 2008 * dmtree), this routine will cause this change to be reflected 2009 * up through the appropriate levels of the dmap control pages 2010 * by a call to dbAdjCtl() for the L0 dmap control page that 2011 * covers this dmap. 2012 * 2013 * PARAMETERS: 2014 * bmp - pointer to bmap descriptor 2015 * dp - pointer to dmap to allocate the block range from. 2016 * blkno - starting block number of the block to be allocated. 2017 * nblocks - number of blocks to be allocated. 2018 * 2019 * RETURN VALUES: 2020 * 0 - success 2021 * -EIO - i/o error 2022 * 2023 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2024 */ dbAllocDmap(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)2025 static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, 2026 int nblocks) 2027 { 2028 s8 oldroot; 2029 int rc; 2030 2031 /* save the current value of the root (i.e. maximum free string) 2032 * of the dmap tree. 2033 */ 2034 oldroot = dp->tree.stree[ROOT]; 2035 2036 /* allocate the specified (blocks) bits */ 2037 dbAllocBits(bmp, dp, blkno, nblocks); 2038 2039 /* if the root has not changed, done. */ 2040 if (dp->tree.stree[ROOT] == oldroot) 2041 return (0); 2042 2043 /* root changed. bubble the change up to the dmap control pages. 2044 * if the adjustment of the upper level control pages fails, 2045 * backout the bit allocation (thus making everything consistent). 2046 */ 2047 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) 2048 dbFreeBits(bmp, dp, blkno, nblocks); 2049 2050 return (rc); 2051 } 2052 2053 2054 /* 2055 * NAME: dbFreeDmap() 2056 * 2057 * FUNCTION: adjust the disk allocation map to reflect the allocation 2058 * of a specified block range within a dmap. 2059 * 2060 * this routine frees the specified blocks from the dmap through 2061 * a call to dbFreeBits(). if the deallocation of the block range 2062 * causes the maximum string of free blocks within the dmap to 2063 * change (i.e. the value of the root of the dmap's dmtree), this 2064 * routine will cause this change to be reflected up through the 2065 * appropriate levels of the dmap control pages by a call to 2066 * dbAdjCtl() for the L0 dmap control page that covers this dmap. 2067 * 2068 * PARAMETERS: 2069 * bmp - pointer to bmap descriptor 2070 * dp - pointer to dmap to free the block range from. 2071 * blkno - starting block number of the block to be freed. 2072 * nblocks - number of blocks to be freed. 2073 * 2074 * RETURN VALUES: 2075 * 0 - success 2076 * -EIO - i/o error 2077 * 2078 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2079 */ dbFreeDmap(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)2080 static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, 2081 int nblocks) 2082 { 2083 s8 oldroot; 2084 int rc = 0, word; 2085 2086 /* save the current value of the root (i.e. maximum free string) 2087 * of the dmap tree. 2088 */ 2089 oldroot = dp->tree.stree[ROOT]; 2090 2091 /* free the specified (blocks) bits */ 2092 rc = dbFreeBits(bmp, dp, blkno, nblocks); 2093 2094 /* if error or the root has not changed, done. */ 2095 if (rc || (dp->tree.stree[ROOT] == oldroot)) 2096 return (rc); 2097 2098 /* root changed. bubble the change up to the dmap control pages. 2099 * if the adjustment of the upper level control pages fails, 2100 * backout the deallocation. 2101 */ 2102 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { 2103 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; 2104 2105 /* as part of backing out the deallocation, we will have 2106 * to back split the dmap tree if the deallocation caused 2107 * the freed blocks to become part of a larger binary buddy 2108 * system. 2109 */ 2110 if (dp->tree.stree[word] == NOFREE) 2111 dbBackSplit((dmtree_t *)&dp->tree, word, false); 2112 2113 dbAllocBits(bmp, dp, blkno, nblocks); 2114 } 2115 2116 return (rc); 2117 } 2118 2119 2120 /* 2121 * NAME: dbAllocBits() 2122 * 2123 * FUNCTION: allocate a specified block range from a dmap. 2124 * 2125 * this routine updates the dmap to reflect the working 2126 * state allocation of the specified block range. it directly 2127 * updates the bits of the working map and causes the adjustment 2128 * of the binary buddy system described by the dmap's dmtree 2129 * leaves to reflect the bits allocated. it also causes the 2130 * dmap's dmtree, as a whole, to reflect the allocated range. 2131 * 2132 * PARAMETERS: 2133 * bmp - pointer to bmap descriptor 2134 * dp - pointer to dmap to allocate bits from. 2135 * blkno - starting block number of the bits to be allocated. 2136 * nblocks - number of bits to be allocated. 2137 * 2138 * RETURN VALUES: none 2139 * 2140 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2141 */ dbAllocBits(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)2142 static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, 2143 int nblocks) 2144 { 2145 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; 2146 dmtree_t *tp = (dmtree_t *) & dp->tree; 2147 int size; 2148 s8 *leaf; 2149 2150 /* pick up a pointer to the leaves of the dmap tree */ 2151 leaf = dp->tree.stree + LEAFIND; 2152 2153 /* determine the bit number and word within the dmap of the 2154 * starting block. 2155 */ 2156 dbitno = blkno & (BPERDMAP - 1); 2157 word = dbitno >> L2DBWORD; 2158 2159 /* block range better be within the dmap */ 2160 assert(dbitno + nblocks <= BPERDMAP); 2161 2162 /* allocate the bits of the dmap's words corresponding to the block 2163 * range. not all bits of the first and last words may be contained 2164 * within the block range. if this is the case, we'll work against 2165 * those words (i.e. partial first and/or last) on an individual basis 2166 * (a single pass), allocating the bits of interest by hand and 2167 * updating the leaf corresponding to the dmap word. a single pass 2168 * will be used for all dmap words fully contained within the 2169 * specified range. within this pass, the bits of all fully contained 2170 * dmap words will be marked as free in a single shot and the leaves 2171 * will be updated. a single leaf may describe the free space of 2172 * multiple dmap words, so we may update only a subset of the actual 2173 * leaves corresponding to the dmap words of the block range. 2174 */ 2175 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { 2176 /* determine the bit number within the word and 2177 * the number of bits within the word. 2178 */ 2179 wbitno = dbitno & (DBWORD - 1); 2180 nb = min(rembits, DBWORD - wbitno); 2181 2182 /* check if only part of a word is to be allocated. 2183 */ 2184 if (nb < DBWORD) { 2185 /* allocate (set to 1) the appropriate bits within 2186 * this dmap word. 2187 */ 2188 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) 2189 >> wbitno); 2190 2191 /* update the leaf for this dmap word. in addition 2192 * to setting the leaf value to the binary buddy max 2193 * of the updated dmap word, dbSplit() will split 2194 * the binary system of the leaves if need be. 2195 */ 2196 dbSplit(tp, word, BUDMIN, 2197 dbMaxBud((u8 *)&dp->wmap[word]), false); 2198 2199 word += 1; 2200 } else { 2201 /* one or more dmap words are fully contained 2202 * within the block range. determine how many 2203 * words and allocate (set to 1) the bits of these 2204 * words. 2205 */ 2206 nwords = rembits >> L2DBWORD; 2207 memset(&dp->wmap[word], (int) ONES, nwords * 4); 2208 2209 /* determine how many bits. 2210 */ 2211 nb = nwords << L2DBWORD; 2212 2213 /* now update the appropriate leaves to reflect 2214 * the allocated words. 2215 */ 2216 for (; nwords > 0; nwords -= nw) { 2217 if (leaf[word] < BUDMIN) { 2218 jfs_error(bmp->db_ipbmap->i_sb, 2219 "leaf page corrupt\n"); 2220 break; 2221 } 2222 2223 /* determine what the leaf value should be 2224 * updated to as the minimum of the l2 number 2225 * of bits being allocated and the l2 number 2226 * of bits currently described by this leaf. 2227 */ 2228 size = min_t(int, leaf[word], 2229 NLSTOL2BSZ(nwords)); 2230 2231 /* update the leaf to reflect the allocation. 2232 * in addition to setting the leaf value to 2233 * NOFREE, dbSplit() will split the binary 2234 * system of the leaves to reflect the current 2235 * allocation (size). 2236 */ 2237 dbSplit(tp, word, size, NOFREE, false); 2238 2239 /* get the number of dmap words handled */ 2240 nw = BUDSIZE(size, BUDMIN); 2241 word += nw; 2242 } 2243 } 2244 } 2245 2246 /* update the free count for this dmap */ 2247 le32_add_cpu(&dp->nfree, -nblocks); 2248 2249 BMAP_LOCK(bmp); 2250 2251 /* if this allocation group is completely free, 2252 * update the maximum allocation group number if this allocation 2253 * group is the new max. 2254 */ 2255 agno = blkno >> bmp->db_agl2size; 2256 if (agno > bmp->db_maxag) 2257 bmp->db_maxag = agno; 2258 2259 /* update the free count for the allocation group and map */ 2260 bmp->db_agfree[agno] -= nblocks; 2261 bmp->db_nfree -= nblocks; 2262 2263 BMAP_UNLOCK(bmp); 2264 } 2265 2266 2267 /* 2268 * NAME: dbFreeBits() 2269 * 2270 * FUNCTION: free a specified block range from a dmap. 2271 * 2272 * this routine updates the dmap to reflect the working 2273 * state allocation of the specified block range. it directly 2274 * updates the bits of the working map and causes the adjustment 2275 * of the binary buddy system described by the dmap's dmtree 2276 * leaves to reflect the bits freed. it also causes the dmap's 2277 * dmtree, as a whole, to reflect the deallocated range. 2278 * 2279 * PARAMETERS: 2280 * bmp - pointer to bmap descriptor 2281 * dp - pointer to dmap to free bits from. 2282 * blkno - starting block number of the bits to be freed. 2283 * nblocks - number of bits to be freed. 2284 * 2285 * RETURN VALUES: 0 for success 2286 * 2287 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2288 */ dbFreeBits(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)2289 static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, 2290 int nblocks) 2291 { 2292 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; 2293 dmtree_t *tp = (dmtree_t *) & dp->tree; 2294 int rc = 0; 2295 int size; 2296 2297 /* determine the bit number and word within the dmap of the 2298 * starting block. 2299 */ 2300 dbitno = blkno & (BPERDMAP - 1); 2301 word = dbitno >> L2DBWORD; 2302 2303 /* block range better be within the dmap. 2304 */ 2305 assert(dbitno + nblocks <= BPERDMAP); 2306 2307 /* free the bits of the dmaps words corresponding to the block range. 2308 * not all bits of the first and last words may be contained within 2309 * the block range. if this is the case, we'll work against those 2310 * words (i.e. partial first and/or last) on an individual basis 2311 * (a single pass), freeing the bits of interest by hand and updating 2312 * the leaf corresponding to the dmap word. a single pass will be used 2313 * for all dmap words fully contained within the specified range. 2314 * within this pass, the bits of all fully contained dmap words will 2315 * be marked as free in a single shot and the leaves will be updated. a 2316 * single leaf may describe the free space of multiple dmap words, 2317 * so we may update only a subset of the actual leaves corresponding 2318 * to the dmap words of the block range. 2319 * 2320 * dbJoin() is used to update leaf values and will join the binary 2321 * buddy system of the leaves if the new leaf values indicate this 2322 * should be done. 2323 */ 2324 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { 2325 /* determine the bit number within the word and 2326 * the number of bits within the word. 2327 */ 2328 wbitno = dbitno & (DBWORD - 1); 2329 nb = min(rembits, DBWORD - wbitno); 2330 2331 /* check if only part of a word is to be freed. 2332 */ 2333 if (nb < DBWORD) { 2334 /* free (zero) the appropriate bits within this 2335 * dmap word. 2336 */ 2337 dp->wmap[word] &= 2338 cpu_to_le32(~(ONES << (DBWORD - nb) 2339 >> wbitno)); 2340 2341 /* update the leaf for this dmap word. 2342 */ 2343 rc = dbJoin(tp, word, 2344 dbMaxBud((u8 *)&dp->wmap[word]), false); 2345 if (rc) 2346 return rc; 2347 2348 word += 1; 2349 } else { 2350 /* one or more dmap words are fully contained 2351 * within the block range. determine how many 2352 * words and free (zero) the bits of these words. 2353 */ 2354 nwords = rembits >> L2DBWORD; 2355 memset(&dp->wmap[word], 0, nwords * 4); 2356 2357 /* determine how many bits. 2358 */ 2359 nb = nwords << L2DBWORD; 2360 2361 /* now update the appropriate leaves to reflect 2362 * the freed words. 2363 */ 2364 for (; nwords > 0; nwords -= nw) { 2365 /* determine what the leaf value should be 2366 * updated to as the minimum of the l2 number 2367 * of bits being freed and the l2 (max) number 2368 * of bits that can be described by this leaf. 2369 */ 2370 size = 2371 min(LITOL2BSZ 2372 (word, L2LPERDMAP, BUDMIN), 2373 NLSTOL2BSZ(nwords)); 2374 2375 /* update the leaf. 2376 */ 2377 rc = dbJoin(tp, word, size, false); 2378 if (rc) 2379 return rc; 2380 2381 /* get the number of dmap words handled. 2382 */ 2383 nw = BUDSIZE(size, BUDMIN); 2384 word += nw; 2385 } 2386 } 2387 } 2388 2389 /* update the free count for this dmap. 2390 */ 2391 le32_add_cpu(&dp->nfree, nblocks); 2392 2393 BMAP_LOCK(bmp); 2394 2395 /* update the free count for the allocation group and 2396 * map. 2397 */ 2398 agno = blkno >> bmp->db_agl2size; 2399 bmp->db_nfree += nblocks; 2400 bmp->db_agfree[agno] += nblocks; 2401 2402 /* check if this allocation group is not completely free and 2403 * if it is currently the maximum (rightmost) allocation group. 2404 * if so, establish the new maximum allocation group number by 2405 * searching left for the first allocation group with allocation. 2406 */ 2407 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || 2408 (agno == bmp->db_numag - 1 && 2409 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { 2410 while (bmp->db_maxag > 0) { 2411 bmp->db_maxag -= 1; 2412 if (bmp->db_agfree[bmp->db_maxag] != 2413 bmp->db_agsize) 2414 break; 2415 } 2416 2417 /* re-establish the allocation group preference if the 2418 * current preference is right of the maximum allocation 2419 * group. 2420 */ 2421 if (bmp->db_agpref > bmp->db_maxag) 2422 bmp->db_agpref = bmp->db_maxag; 2423 } 2424 2425 BMAP_UNLOCK(bmp); 2426 2427 return 0; 2428 } 2429 2430 2431 /* 2432 * NAME: dbAdjCtl() 2433 * 2434 * FUNCTION: adjust a dmap control page at a specified level to reflect 2435 * the change in a lower level dmap or dmap control page's 2436 * maximum string of free blocks (i.e. a change in the root 2437 * of the lower level object's dmtree) due to the allocation 2438 * or deallocation of a range of blocks with a single dmap. 2439 * 2440 * on entry, this routine is provided with the new value of 2441 * the lower level dmap or dmap control page root and the 2442 * starting block number of the block range whose allocation 2443 * or deallocation resulted in the root change. this range 2444 * is respresented by a single leaf of the current dmapctl 2445 * and the leaf will be updated with this value, possibly 2446 * causing a binary buddy system within the leaves to be 2447 * split or joined. the update may also cause the dmapctl's 2448 * dmtree to be updated. 2449 * 2450 * if the adjustment of the dmap control page, itself, causes its 2451 * root to change, this change will be bubbled up to the next dmap 2452 * control level by a recursive call to this routine, specifying 2453 * the new root value and the next dmap control page level to 2454 * be adjusted. 2455 * PARAMETERS: 2456 * bmp - pointer to bmap descriptor 2457 * blkno - the first block of a block range within a dmap. it is 2458 * the allocation or deallocation of this block range that 2459 * requires the dmap control page to be adjusted. 2460 * newval - the new value of the lower level dmap or dmap control 2461 * page root. 2462 * alloc - 'true' if adjustment is due to an allocation. 2463 * level - current level of dmap control page (i.e. L0, L1, L2) to 2464 * be adjusted. 2465 * 2466 * RETURN VALUES: 2467 * 0 - success 2468 * -EIO - i/o error 2469 * 2470 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2471 */ 2472 static int dbAdjCtl(struct bmap * bmp,s64 blkno,int newval,int alloc,int level)2473 dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) 2474 { 2475 struct metapage *mp; 2476 s8 oldroot; 2477 int oldval; 2478 s64 lblkno; 2479 struct dmapctl *dcp; 2480 int rc, leafno, ti; 2481 2482 /* get the buffer for the dmap control page for the specified 2483 * block number and control page level. 2484 */ 2485 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); 2486 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); 2487 if (mp == NULL) 2488 return -EIO; 2489 dcp = (struct dmapctl *) mp->data; 2490 2491 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { 2492 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); 2493 release_metapage(mp); 2494 return -EIO; 2495 } 2496 2497 /* determine the leaf number corresponding to the block and 2498 * the index within the dmap control tree. 2499 */ 2500 leafno = BLKTOCTLLEAF(blkno, dcp->budmin); 2501 ti = leafno + le32_to_cpu(dcp->leafidx); 2502 2503 /* save the current leaf value and the current root level (i.e. 2504 * maximum l2 free string described by this dmapctl). 2505 */ 2506 oldval = dcp->stree[ti]; 2507 oldroot = dcp->stree[ROOT]; 2508 2509 /* check if this is a control page update for an allocation. 2510 * if so, update the leaf to reflect the new leaf value using 2511 * dbSplit(); otherwise (deallocation), use dbJoin() to update 2512 * the leaf with the new value. in addition to updating the 2513 * leaf, dbSplit() will also split the binary buddy system of 2514 * the leaves, if required, and bubble new values within the 2515 * dmapctl tree, if required. similarly, dbJoin() will join 2516 * the binary buddy system of leaves and bubble new values up 2517 * the dmapctl tree as required by the new leaf value. 2518 */ 2519 if (alloc) { 2520 /* check if we are in the middle of a binary buddy 2521 * system. this happens when we are performing the 2522 * first allocation out of an allocation group that 2523 * is part (not the first part) of a larger binary 2524 * buddy system. if we are in the middle, back split 2525 * the system prior to calling dbSplit() which assumes 2526 * that it is at the front of a binary buddy system. 2527 */ 2528 if (oldval == NOFREE) { 2529 rc = dbBackSplit((dmtree_t *)dcp, leafno, true); 2530 if (rc) { 2531 release_metapage(mp); 2532 return rc; 2533 } 2534 oldval = dcp->stree[ti]; 2535 } 2536 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval, true); 2537 } else { 2538 rc = dbJoin((dmtree_t *) dcp, leafno, newval, true); 2539 if (rc) { 2540 release_metapage(mp); 2541 return rc; 2542 } 2543 } 2544 2545 /* check if the root of the current dmap control page changed due 2546 * to the update and if the current dmap control page is not at 2547 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e. 2548 * root changed and this is not the top level), call this routine 2549 * again (recursion) for the next higher level of the mapping to 2550 * reflect the change in root for the current dmap control page. 2551 */ 2552 if (dcp->stree[ROOT] != oldroot) { 2553 /* are we below the top level of the map. if so, 2554 * bubble the root up to the next higher level. 2555 */ 2556 if (level < bmp->db_maxlevel) { 2557 /* bubble up the new root of this dmap control page to 2558 * the next level. 2559 */ 2560 if ((rc = 2561 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, 2562 level + 1))) { 2563 /* something went wrong in bubbling up the new 2564 * root value, so backout the changes to the 2565 * current dmap control page. 2566 */ 2567 if (alloc) { 2568 dbJoin((dmtree_t *) dcp, leafno, 2569 oldval, true); 2570 } else { 2571 /* the dbJoin() above might have 2572 * caused a larger binary buddy system 2573 * to form and we may now be in the 2574 * middle of it. if this is the case, 2575 * back split the buddies. 2576 */ 2577 if (dcp->stree[ti] == NOFREE) 2578 dbBackSplit((dmtree_t *) 2579 dcp, leafno, true); 2580 dbSplit((dmtree_t *) dcp, leafno, 2581 dcp->budmin, oldval, true); 2582 } 2583 2584 /* release the buffer and return the error. 2585 */ 2586 release_metapage(mp); 2587 return (rc); 2588 } 2589 } else { 2590 /* we're at the top level of the map. update 2591 * the bmap control page to reflect the size 2592 * of the maximum free buddy system. 2593 */ 2594 assert(level == bmp->db_maxlevel); 2595 if (bmp->db_maxfreebud != oldroot) { 2596 jfs_error(bmp->db_ipbmap->i_sb, 2597 "the maximum free buddy is not the old root\n"); 2598 } 2599 bmp->db_maxfreebud = dcp->stree[ROOT]; 2600 } 2601 } 2602 2603 /* write the buffer. 2604 */ 2605 write_metapage(mp); 2606 2607 return (0); 2608 } 2609 2610 2611 /* 2612 * NAME: dbSplit() 2613 * 2614 * FUNCTION: update the leaf of a dmtree with a new value, splitting 2615 * the leaf from the binary buddy system of the dmtree's 2616 * leaves, as required. 2617 * 2618 * PARAMETERS: 2619 * tp - pointer to the tree containing the leaf. 2620 * leafno - the number of the leaf to be updated. 2621 * splitsz - the size the binary buddy system starting at the leaf 2622 * must be split to, specified as the log2 number of blocks. 2623 * newval - the new value for the leaf. 2624 * 2625 * RETURN VALUES: none 2626 * 2627 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2628 */ dbSplit(dmtree_t * tp,int leafno,int splitsz,int newval,bool is_ctl)2629 static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl) 2630 { 2631 int budsz; 2632 int cursz; 2633 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); 2634 2635 /* check if the leaf needs to be split. 2636 */ 2637 if (leaf[leafno] > tp->dmt_budmin) { 2638 /* the split occurs by cutting the buddy system in half 2639 * at the specified leaf until we reach the specified 2640 * size. pick up the starting split size (current size 2641 * - 1 in l2) and the corresponding buddy size. 2642 */ 2643 cursz = leaf[leafno] - 1; 2644 budsz = BUDSIZE(cursz, tp->dmt_budmin); 2645 2646 /* split until we reach the specified size. 2647 */ 2648 while (cursz >= splitsz) { 2649 /* update the buddy's leaf with its new value. 2650 */ 2651 dbAdjTree(tp, leafno ^ budsz, cursz, is_ctl); 2652 2653 /* on to the next size and buddy. 2654 */ 2655 cursz -= 1; 2656 budsz >>= 1; 2657 } 2658 } 2659 2660 /* adjust the dmap tree to reflect the specified leaf's new 2661 * value. 2662 */ 2663 dbAdjTree(tp, leafno, newval, is_ctl); 2664 } 2665 2666 2667 /* 2668 * NAME: dbBackSplit() 2669 * 2670 * FUNCTION: back split the binary buddy system of dmtree leaves 2671 * that hold a specified leaf until the specified leaf 2672 * starts its own binary buddy system. 2673 * 2674 * the allocators typically perform allocations at the start 2675 * of binary buddy systems and dbSplit() is used to accomplish 2676 * any required splits. in some cases, however, allocation 2677 * may occur in the middle of a binary system and requires a 2678 * back split, with the split proceeding out from the middle of 2679 * the system (less efficient) rather than the start of the 2680 * system (more efficient). the cases in which a back split 2681 * is required are rare and are limited to the first allocation 2682 * within an allocation group which is a part (not first part) 2683 * of a larger binary buddy system and a few exception cases 2684 * in which a previous join operation must be backed out. 2685 * 2686 * PARAMETERS: 2687 * tp - pointer to the tree containing the leaf. 2688 * leafno - the number of the leaf to be updated. 2689 * 2690 * RETURN VALUES: none 2691 * 2692 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; 2693 */ dbBackSplit(dmtree_t * tp,int leafno,bool is_ctl)2694 static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl) 2695 { 2696 int budsz, bud, w, bsz, size; 2697 int cursz; 2698 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); 2699 2700 /* leaf should be part (not first part) of a binary 2701 * buddy system. 2702 */ 2703 assert(leaf[leafno] == NOFREE); 2704 2705 /* the back split is accomplished by iteratively finding the leaf 2706 * that starts the buddy system that contains the specified leaf and 2707 * splitting that system in two. this iteration continues until 2708 * the specified leaf becomes the start of a buddy system. 2709 * 2710 * determine maximum possible l2 size for the specified leaf. 2711 */ 2712 size = 2713 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), 2714 tp->dmt_budmin); 2715 2716 /* determine the number of leaves covered by this size. this 2717 * is the buddy size that we will start with as we search for 2718 * the buddy system that contains the specified leaf. 2719 */ 2720 budsz = BUDSIZE(size, tp->dmt_budmin); 2721 2722 /* back split. 2723 */ 2724 while (leaf[leafno] == NOFREE) { 2725 /* find the leftmost buddy leaf. 2726 */ 2727 for (w = leafno, bsz = budsz;; bsz <<= 1, 2728 w = (w < bud) ? w : bud) { 2729 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { 2730 jfs_err("JFS: block map error in dbBackSplit"); 2731 return -EIO; 2732 } 2733 2734 /* determine the buddy. 2735 */ 2736 bud = w ^ bsz; 2737 2738 /* check if this buddy is the start of the system. 2739 */ 2740 if (leaf[bud] != NOFREE) { 2741 /* split the leaf at the start of the 2742 * system in two. 2743 */ 2744 cursz = leaf[bud] - 1; 2745 dbSplit(tp, bud, cursz, cursz, is_ctl); 2746 break; 2747 } 2748 } 2749 } 2750 2751 if (leaf[leafno] != size) { 2752 jfs_err("JFS: wrong leaf value in dbBackSplit"); 2753 return -EIO; 2754 } 2755 return 0; 2756 } 2757 2758 2759 /* 2760 * NAME: dbJoin() 2761 * 2762 * FUNCTION: update the leaf of a dmtree with a new value, joining 2763 * the leaf with other leaves of the dmtree into a multi-leaf 2764 * binary buddy system, as required. 2765 * 2766 * PARAMETERS: 2767 * tp - pointer to the tree containing the leaf. 2768 * leafno - the number of the leaf to be updated. 2769 * newval - the new value for the leaf. 2770 * 2771 * RETURN VALUES: none 2772 */ dbJoin(dmtree_t * tp,int leafno,int newval,bool is_ctl)2773 static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl) 2774 { 2775 int budsz, buddy; 2776 s8 *leaf; 2777 2778 /* can the new leaf value require a join with other leaves ? 2779 */ 2780 if (newval >= tp->dmt_budmin) { 2781 /* pickup a pointer to the leaves of the tree. 2782 */ 2783 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); 2784 2785 /* try to join the specified leaf into a large binary 2786 * buddy system. the join proceeds by attempting to join 2787 * the specified leafno with its buddy (leaf) at new value. 2788 * if the join occurs, we attempt to join the left leaf 2789 * of the joined buddies with its buddy at new value + 1. 2790 * we continue to join until we find a buddy that cannot be 2791 * joined (does not have a value equal to the size of the 2792 * last join) or until all leaves have been joined into a 2793 * single system. 2794 * 2795 * get the buddy size (number of words covered) of 2796 * the new value. 2797 */ 2798 budsz = BUDSIZE(newval, tp->dmt_budmin); 2799 2800 /* try to join. 2801 */ 2802 while (budsz < le32_to_cpu(tp->dmt_nleafs)) { 2803 /* get the buddy leaf. 2804 */ 2805 buddy = leafno ^ budsz; 2806 2807 /* if the leaf's new value is greater than its 2808 * buddy's value, we join no more. 2809 */ 2810 if (newval > leaf[buddy]) 2811 break; 2812 2813 /* It shouldn't be less */ 2814 if (newval < leaf[buddy]) 2815 return -EIO; 2816 2817 /* check which (leafno or buddy) is the left buddy. 2818 * the left buddy gets to claim the blocks resulting 2819 * from the join while the right gets to claim none. 2820 * the left buddy is also eligible to participate in 2821 * a join at the next higher level while the right 2822 * is not. 2823 * 2824 */ 2825 if (leafno < buddy) { 2826 /* leafno is the left buddy. 2827 */ 2828 dbAdjTree(tp, buddy, NOFREE, is_ctl); 2829 } else { 2830 /* buddy is the left buddy and becomes 2831 * leafno. 2832 */ 2833 dbAdjTree(tp, leafno, NOFREE, is_ctl); 2834 leafno = buddy; 2835 } 2836 2837 /* on to try the next join. 2838 */ 2839 newval += 1; 2840 budsz <<= 1; 2841 } 2842 } 2843 2844 /* update the leaf value. 2845 */ 2846 dbAdjTree(tp, leafno, newval, is_ctl); 2847 2848 return 0; 2849 } 2850 2851 2852 /* 2853 * NAME: dbAdjTree() 2854 * 2855 * FUNCTION: update a leaf of a dmtree with a new value, adjusting 2856 * the dmtree, as required, to reflect the new leaf value. 2857 * the combination of any buddies must already be done before 2858 * this is called. 2859 * 2860 * PARAMETERS: 2861 * tp - pointer to the tree to be adjusted. 2862 * leafno - the number of the leaf to be updated. 2863 * newval - the new value for the leaf. 2864 * 2865 * RETURN VALUES: none 2866 */ dbAdjTree(dmtree_t * tp,int leafno,int newval,bool is_ctl)2867 static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl) 2868 { 2869 int lp, pp, k; 2870 int max, size; 2871 2872 size = is_ctl ? CTLTREESIZE : TREESIZE; 2873 2874 /* pick up the index of the leaf for this leafno. 2875 */ 2876 lp = leafno + le32_to_cpu(tp->dmt_leafidx); 2877 2878 if (WARN_ON_ONCE(lp >= size || lp < 0)) 2879 return; 2880 2881 /* is the current value the same as the old value ? if so, 2882 * there is nothing to do. 2883 */ 2884 if (tp->dmt_stree[lp] == newval) 2885 return; 2886 2887 /* set the new value. 2888 */ 2889 tp->dmt_stree[lp] = newval; 2890 2891 /* bubble the new value up the tree as required. 2892 */ 2893 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { 2894 if (lp == 0) 2895 break; 2896 2897 /* get the index of the first leaf of the 4 leaf 2898 * group containing the specified leaf (leafno). 2899 */ 2900 lp = ((lp - 1) & ~0x03) + 1; 2901 2902 /* get the index of the parent of this 4 leaf group. 2903 */ 2904 pp = (lp - 1) >> 2; 2905 2906 /* determine the maximum of the 4 leaves. 2907 */ 2908 max = TREEMAX(&tp->dmt_stree[lp]); 2909 2910 /* if the maximum of the 4 is the same as the 2911 * parent's value, we're done. 2912 */ 2913 if (tp->dmt_stree[pp] == max) 2914 break; 2915 2916 /* parent gets new value. 2917 */ 2918 tp->dmt_stree[pp] = max; 2919 2920 /* parent becomes leaf for next go-round. 2921 */ 2922 lp = pp; 2923 } 2924 } 2925 2926 2927 /* 2928 * NAME: dbFindLeaf() 2929 * 2930 * FUNCTION: search a dmtree_t for sufficient free blocks, returning 2931 * the index of a leaf describing the free blocks if 2932 * sufficient free blocks are found. 2933 * 2934 * the search starts at the top of the dmtree_t tree and 2935 * proceeds down the tree to the leftmost leaf with sufficient 2936 * free space. 2937 * 2938 * PARAMETERS: 2939 * tp - pointer to the tree to be searched. 2940 * l2nb - log2 number of free blocks to search for. 2941 * leafidx - return pointer to be set to the index of the leaf 2942 * describing at least l2nb free blocks if sufficient 2943 * free blocks are found. 2944 * is_ctl - determines if the tree is of type ctl 2945 * 2946 * RETURN VALUES: 2947 * 0 - success 2948 * -ENOSPC - insufficient free blocks. 2949 */ dbFindLeaf(dmtree_t * tp,int l2nb,int * leafidx,bool is_ctl)2950 static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl) 2951 { 2952 int ti, n = 0, k, x = 0; 2953 int max_size, max_idx; 2954 2955 max_size = is_ctl ? CTLTREESIZE : TREESIZE; 2956 max_idx = is_ctl ? LPERCTL : LPERDMAP; 2957 2958 /* first check the root of the tree to see if there is 2959 * sufficient free space. 2960 */ 2961 if (l2nb > tp->dmt_stree[ROOT]) 2962 return -ENOSPC; 2963 2964 /* sufficient free space available. now search down the tree 2965 * starting at the next level for the leftmost leaf that 2966 * describes sufficient free space. 2967 */ 2968 for (k = le32_to_cpu(tp->dmt_height), ti = 1; 2969 k > 0; k--, ti = ((ti + n) << 2) + 1) { 2970 /* search the four nodes at this level, starting from 2971 * the left. 2972 */ 2973 for (x = ti, n = 0; n < 4; n++) { 2974 /* sufficient free space found. move to the next 2975 * level (or quit if this is the last level). 2976 */ 2977 if (x + n > max_size) 2978 return -ENOSPC; 2979 if (l2nb <= tp->dmt_stree[x + n]) 2980 break; 2981 } 2982 2983 /* better have found something since the higher 2984 * levels of the tree said it was here. 2985 */ 2986 assert(n < 4); 2987 } 2988 if (le32_to_cpu(tp->dmt_leafidx) >= max_idx) 2989 return -ENOSPC; 2990 2991 /* set the return to the leftmost leaf describing sufficient 2992 * free space. 2993 */ 2994 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); 2995 2996 return (0); 2997 } 2998 2999 3000 /* 3001 * NAME: dbFindBits() 3002 * 3003 * FUNCTION: find a specified number of binary buddy free bits within a 3004 * dmap bitmap word value. 3005 * 3006 * this routine searches the bitmap value for (1 << l2nb) free 3007 * bits at (1 << l2nb) alignments within the value. 3008 * 3009 * PARAMETERS: 3010 * word - dmap bitmap word value. 3011 * l2nb - number of free bits specified as a log2 number. 3012 * 3013 * RETURN VALUES: 3014 * starting bit number of free bits. 3015 */ dbFindBits(u32 word,int l2nb)3016 static int dbFindBits(u32 word, int l2nb) 3017 { 3018 int bitno, nb; 3019 u32 mask; 3020 3021 /* get the number of bits. 3022 */ 3023 nb = 1 << l2nb; 3024 assert(nb <= DBWORD); 3025 3026 /* complement the word so we can use a mask (i.e. 0s represent 3027 * free bits) and compute the mask. 3028 */ 3029 word = ~word; 3030 mask = ONES << (DBWORD - nb); 3031 3032 /* scan the word for nb free bits at nb alignments. 3033 */ 3034 for (bitno = 0; mask != 0; bitno += nb, mask = (mask >> nb)) { 3035 if ((mask & word) == mask) 3036 break; 3037 } 3038 3039 ASSERT(bitno < 32); 3040 3041 /* return the bit number. 3042 */ 3043 return (bitno); 3044 } 3045 3046 3047 /* 3048 * NAME: dbMaxBud(u8 *cp) 3049 * 3050 * FUNCTION: determine the largest binary buddy string of free 3051 * bits within 32-bits of the map. 3052 * 3053 * PARAMETERS: 3054 * cp - pointer to the 32-bit value. 3055 * 3056 * RETURN VALUES: 3057 * largest binary buddy of free bits within a dmap word. 3058 */ dbMaxBud(u8 * cp)3059 static int dbMaxBud(u8 * cp) 3060 { 3061 signed char tmp1, tmp2; 3062 3063 /* check if the wmap word is all free. if so, the 3064 * free buddy size is BUDMIN. 3065 */ 3066 if (*((uint *) cp) == 0) 3067 return (BUDMIN); 3068 3069 /* check if the wmap word is half free. if so, the 3070 * free buddy size is BUDMIN-1. 3071 */ 3072 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) 3073 return (BUDMIN - 1); 3074 3075 /* not all free or half free. determine the free buddy 3076 * size thru table lookup using quarters of the wmap word. 3077 */ 3078 tmp1 = max(budtab[cp[2]], budtab[cp[3]]); 3079 tmp2 = max(budtab[cp[0]], budtab[cp[1]]); 3080 return (max(tmp1, tmp2)); 3081 } 3082 3083 3084 /* 3085 * NAME: cnttz(uint word) 3086 * 3087 * FUNCTION: determine the number of trailing zeros within a 32-bit 3088 * value. 3089 * 3090 * PARAMETERS: 3091 * value - 32-bit value to be examined. 3092 * 3093 * RETURN VALUES: 3094 * count of trailing zeros 3095 */ cnttz(u32 word)3096 static int cnttz(u32 word) 3097 { 3098 int n; 3099 3100 for (n = 0; n < 32; n++, word >>= 1) { 3101 if (word & 0x01) 3102 break; 3103 } 3104 3105 return (n); 3106 } 3107 3108 3109 /* 3110 * NAME: cntlz(u32 value) 3111 * 3112 * FUNCTION: determine the number of leading zeros within a 32-bit 3113 * value. 3114 * 3115 * PARAMETERS: 3116 * value - 32-bit value to be examined. 3117 * 3118 * RETURN VALUES: 3119 * count of leading zeros 3120 */ cntlz(u32 value)3121 static int cntlz(u32 value) 3122 { 3123 int n; 3124 3125 for (n = 0; n < 32; n++, value <<= 1) { 3126 if (value & HIGHORDER) 3127 break; 3128 } 3129 return (n); 3130 } 3131 3132 3133 /* 3134 * NAME: blkstol2(s64 nb) 3135 * 3136 * FUNCTION: convert a block count to its log2 value. if the block 3137 * count is not a l2 multiple, it is rounded up to the next 3138 * larger l2 multiple. 3139 * 3140 * PARAMETERS: 3141 * nb - number of blocks 3142 * 3143 * RETURN VALUES: 3144 * log2 number of blocks 3145 */ blkstol2(s64 nb)3146 static int blkstol2(s64 nb) 3147 { 3148 int l2nb; 3149 s64 mask; /* meant to be signed */ 3150 3151 mask = (s64) 1 << (64 - 1); 3152 3153 /* count the leading bits. 3154 */ 3155 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { 3156 /* leading bit found. 3157 */ 3158 if (nb & mask) { 3159 /* determine the l2 value. 3160 */ 3161 l2nb = (64 - 1) - l2nb; 3162 3163 /* check if we need to round up. 3164 */ 3165 if (~mask & nb) 3166 l2nb++; 3167 3168 return (l2nb); 3169 } 3170 } 3171 assert(0); 3172 return 0; /* fix compiler warning */ 3173 } 3174 3175 3176 /* 3177 * NAME: dbAllocBottomUp() 3178 * 3179 * FUNCTION: alloc the specified block range from the working block 3180 * allocation map. 3181 * 3182 * the blocks will be alloc from the working map one dmap 3183 * at a time. 3184 * 3185 * PARAMETERS: 3186 * ip - pointer to in-core inode; 3187 * blkno - starting block number to be freed. 3188 * nblocks - number of blocks to be freed. 3189 * 3190 * RETURN VALUES: 3191 * 0 - success 3192 * -EIO - i/o error 3193 */ dbAllocBottomUp(struct inode * ip,s64 blkno,s64 nblocks)3194 int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) 3195 { 3196 struct metapage *mp; 3197 struct dmap *dp; 3198 int nb, rc; 3199 s64 lblkno, rem; 3200 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; 3201 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; 3202 3203 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); 3204 3205 /* block to be allocated better be within the mapsize. */ 3206 ASSERT(nblocks <= bmp->db_mapsize - blkno); 3207 3208 /* 3209 * allocate the blocks a dmap at a time. 3210 */ 3211 mp = NULL; 3212 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { 3213 /* release previous dmap if any */ 3214 if (mp) { 3215 write_metapage(mp); 3216 } 3217 3218 /* get the buffer for the current dmap. */ 3219 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); 3220 mp = read_metapage(ipbmap, lblkno, PSIZE, 0); 3221 if (mp == NULL) { 3222 IREAD_UNLOCK(ipbmap); 3223 return -EIO; 3224 } 3225 dp = (struct dmap *) mp->data; 3226 3227 /* determine the number of blocks to be allocated from 3228 * this dmap. 3229 */ 3230 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); 3231 3232 /* allocate the blocks. */ 3233 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { 3234 release_metapage(mp); 3235 IREAD_UNLOCK(ipbmap); 3236 return (rc); 3237 } 3238 } 3239 3240 /* write the last buffer. */ 3241 write_metapage(mp); 3242 3243 IREAD_UNLOCK(ipbmap); 3244 3245 return (0); 3246 } 3247 3248 dbAllocDmapBU(struct bmap * bmp,struct dmap * dp,s64 blkno,int nblocks)3249 static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, 3250 int nblocks) 3251 { 3252 int rc; 3253 int dbitno, word, rembits, nb, nwords, wbitno, agno; 3254 s8 oldroot; 3255 struct dmaptree *tp = (struct dmaptree *) & dp->tree; 3256 3257 /* save the current value of the root (i.e. maximum free string) 3258 * of the dmap tree. 3259 */ 3260 oldroot = tp->stree[ROOT]; 3261 3262 /* determine the bit number and word within the dmap of the 3263 * starting block. 3264 */ 3265 dbitno = blkno & (BPERDMAP - 1); 3266 word = dbitno >> L2DBWORD; 3267 3268 /* block range better be within the dmap */ 3269 assert(dbitno + nblocks <= BPERDMAP); 3270 3271 /* allocate the bits of the dmap's words corresponding to the block 3272 * range. not all bits of the first and last words may be contained 3273 * within the block range. if this is the case, we'll work against 3274 * those words (i.e. partial first and/or last) on an individual basis 3275 * (a single pass), allocating the bits of interest by hand and 3276 * updating the leaf corresponding to the dmap word. a single pass 3277 * will be used for all dmap words fully contained within the 3278 * specified range. within this pass, the bits of all fully contained 3279 * dmap words will be marked as free in a single shot and the leaves 3280 * will be updated. a single leaf may describe the free space of 3281 * multiple dmap words, so we may update only a subset of the actual 3282 * leaves corresponding to the dmap words of the block range. 3283 */ 3284 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { 3285 /* determine the bit number within the word and 3286 * the number of bits within the word. 3287 */ 3288 wbitno = dbitno & (DBWORD - 1); 3289 nb = min(rembits, DBWORD - wbitno); 3290 3291 /* check if only part of a word is to be allocated. 3292 */ 3293 if (nb < DBWORD) { 3294 /* allocate (set to 1) the appropriate bits within 3295 * this dmap word. 3296 */ 3297 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) 3298 >> wbitno); 3299 3300 word++; 3301 } else { 3302 /* one or more dmap words are fully contained 3303 * within the block range. determine how many 3304 * words and allocate (set to 1) the bits of these 3305 * words. 3306 */ 3307 nwords = rembits >> L2DBWORD; 3308 memset(&dp->wmap[word], (int) ONES, nwords * 4); 3309 3310 /* determine how many bits */ 3311 nb = nwords << L2DBWORD; 3312 word += nwords; 3313 } 3314 } 3315 3316 /* update the free count for this dmap */ 3317 le32_add_cpu(&dp->nfree, -nblocks); 3318 3319 /* reconstruct summary tree */ 3320 dbInitDmapTree(dp); 3321 3322 BMAP_LOCK(bmp); 3323 3324 /* if this allocation group is completely free, 3325 * update the highest active allocation group number 3326 * if this allocation group is the new max. 3327 */ 3328 agno = blkno >> bmp->db_agl2size; 3329 if (agno > bmp->db_maxag) 3330 bmp->db_maxag = agno; 3331 3332 /* update the free count for the allocation group and map */ 3333 bmp->db_agfree[agno] -= nblocks; 3334 bmp->db_nfree -= nblocks; 3335 3336 BMAP_UNLOCK(bmp); 3337 3338 /* if the root has not changed, done. */ 3339 if (tp->stree[ROOT] == oldroot) 3340 return (0); 3341 3342 /* root changed. bubble the change up to the dmap control pages. 3343 * if the adjustment of the upper level control pages fails, 3344 * backout the bit allocation (thus making everything consistent). 3345 */ 3346 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) 3347 dbFreeBits(bmp, dp, blkno, nblocks); 3348 3349 return (rc); 3350 } 3351 3352 3353 /* 3354 * NAME: dbExtendFS() 3355 * 3356 * FUNCTION: extend bmap from blkno for nblocks; 3357 * dbExtendFS() updates bmap ready for dbAllocBottomUp(); 3358 * 3359 * L2 3360 * | 3361 * L1---------------------------------L1 3362 * | | 3363 * L0---------L0---------L0 L0---------L0---------L0 3364 * | | | | | | 3365 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; 3366 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm 3367 * 3368 * <---old---><----------------------------extend-----------------------> 3369 */ dbExtendFS(struct inode * ipbmap,s64 blkno,s64 nblocks)3370 int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) 3371 { 3372 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); 3373 int nbperpage = sbi->nbperpage; 3374 int i, i0 = true, j, j0 = true, k, n; 3375 s64 newsize; 3376 s64 p; 3377 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; 3378 struct dmapctl *l2dcp, *l1dcp, *l0dcp; 3379 struct dmap *dp; 3380 s8 *l0leaf, *l1leaf, *l2leaf; 3381 struct bmap *bmp = sbi->bmap; 3382 int agno, l2agsize, oldl2agsize; 3383 s64 ag_rem; 3384 3385 newsize = blkno + nblocks; 3386 3387 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", 3388 (long long) blkno, (long long) nblocks, (long long) newsize); 3389 3390 /* 3391 * initialize bmap control page. 3392 * 3393 * all the data in bmap control page should exclude 3394 * the mkfs hidden dmap page. 3395 */ 3396 3397 /* update mapsize */ 3398 bmp->db_mapsize = newsize; 3399 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); 3400 3401 /* compute new AG size */ 3402 l2agsize = dbGetL2AGSize(newsize); 3403 oldl2agsize = bmp->db_agl2size; 3404 3405 bmp->db_agl2size = l2agsize; 3406 bmp->db_agsize = 1 << l2agsize; 3407 3408 /* compute new number of AG */ 3409 agno = bmp->db_numag; 3410 bmp->db_numag = newsize >> l2agsize; 3411 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; 3412 3413 /* 3414 * reconfigure db_agfree[] 3415 * from old AG configuration to new AG configuration; 3416 * 3417 * coalesce contiguous k (newAGSize/oldAGSize) AGs; 3418 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; 3419 * note: new AG size = old AG size * (2**x). 3420 */ 3421 if (l2agsize == oldl2agsize) 3422 goto extend; 3423 k = 1 << (l2agsize - oldl2agsize); 3424 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ 3425 for (i = 0, n = 0; i < agno; n++) { 3426 bmp->db_agfree[n] = 0; /* init collection point */ 3427 3428 /* coalesce contiguous k AGs; */ 3429 for (j = 0; j < k && i < agno; j++, i++) { 3430 /* merge AGi to AGn */ 3431 bmp->db_agfree[n] += bmp->db_agfree[i]; 3432 } 3433 } 3434 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ 3435 3436 for (; n < MAXAG; n++) 3437 bmp->db_agfree[n] = 0; 3438 3439 /* 3440 * update highest active ag number 3441 */ 3442 3443 bmp->db_maxag = bmp->db_maxag / k; 3444 3445 /* 3446 * extend bmap 3447 * 3448 * update bit maps and corresponding level control pages; 3449 * global control page db_nfree, db_agfree[agno], db_maxfreebud; 3450 */ 3451 extend: 3452 /* get L2 page */ 3453 p = BMAPBLKNO + nbperpage; /* L2 page */ 3454 l2mp = read_metapage(ipbmap, p, PSIZE, 0); 3455 if (!l2mp) { 3456 jfs_error(ipbmap->i_sb, "L2 page could not be read\n"); 3457 return -EIO; 3458 } 3459 l2dcp = (struct dmapctl *) l2mp->data; 3460 3461 /* compute start L1 */ 3462 k = blkno >> L2MAXL1SIZE; 3463 l2leaf = l2dcp->stree + CTLLEAFIND + k; 3464 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ 3465 3466 /* 3467 * extend each L1 in L2 3468 */ 3469 for (; k < LPERCTL; k++, p += nbperpage) { 3470 /* get L1 page */ 3471 if (j0) { 3472 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ 3473 l1mp = read_metapage(ipbmap, p, PSIZE, 0); 3474 if (l1mp == NULL) 3475 goto errout; 3476 l1dcp = (struct dmapctl *) l1mp->data; 3477 3478 /* compute start L0 */ 3479 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; 3480 l1leaf = l1dcp->stree + CTLLEAFIND + j; 3481 p = BLKTOL0(blkno, sbi->l2nbperpage); 3482 j0 = false; 3483 } else { 3484 /* assign/init L1 page */ 3485 l1mp = get_metapage(ipbmap, p, PSIZE, 0); 3486 if (l1mp == NULL) 3487 goto errout; 3488 3489 l1dcp = (struct dmapctl *) l1mp->data; 3490 3491 /* compute start L0 */ 3492 j = 0; 3493 l1leaf = l1dcp->stree + CTLLEAFIND; 3494 p += nbperpage; /* 1st L0 of L1.k */ 3495 } 3496 3497 /* 3498 * extend each L0 in L1 3499 */ 3500 for (; j < LPERCTL; j++) { 3501 /* get L0 page */ 3502 if (i0) { 3503 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ 3504 3505 l0mp = read_metapage(ipbmap, p, PSIZE, 0); 3506 if (l0mp == NULL) 3507 goto errout; 3508 l0dcp = (struct dmapctl *) l0mp->data; 3509 3510 /* compute start dmap */ 3511 i = (blkno & (MAXL0SIZE - 1)) >> 3512 L2BPERDMAP; 3513 l0leaf = l0dcp->stree + CTLLEAFIND + i; 3514 p = BLKTODMAP(blkno, 3515 sbi->l2nbperpage); 3516 i0 = false; 3517 } else { 3518 /* assign/init L0 page */ 3519 l0mp = get_metapage(ipbmap, p, PSIZE, 0); 3520 if (l0mp == NULL) 3521 goto errout; 3522 3523 l0dcp = (struct dmapctl *) l0mp->data; 3524 3525 /* compute start dmap */ 3526 i = 0; 3527 l0leaf = l0dcp->stree + CTLLEAFIND; 3528 p += nbperpage; /* 1st dmap of L0.j */ 3529 } 3530 3531 /* 3532 * extend each dmap in L0 3533 */ 3534 for (; i < LPERCTL; i++) { 3535 /* 3536 * reconstruct the dmap page, and 3537 * initialize corresponding parent L0 leaf 3538 */ 3539 if ((n = blkno & (BPERDMAP - 1))) { 3540 /* read in dmap page: */ 3541 mp = read_metapage(ipbmap, p, 3542 PSIZE, 0); 3543 if (mp == NULL) 3544 goto errout; 3545 n = min(nblocks, (s64)BPERDMAP - n); 3546 } else { 3547 /* assign/init dmap page */ 3548 mp = read_metapage(ipbmap, p, 3549 PSIZE, 0); 3550 if (mp == NULL) 3551 goto errout; 3552 3553 n = min_t(s64, nblocks, BPERDMAP); 3554 } 3555 3556 dp = (struct dmap *) mp->data; 3557 *l0leaf = dbInitDmap(dp, blkno, n); 3558 3559 bmp->db_nfree += n; 3560 agno = le64_to_cpu(dp->start) >> l2agsize; 3561 bmp->db_agfree[agno] += n; 3562 3563 write_metapage(mp); 3564 3565 l0leaf++; 3566 p += nbperpage; 3567 3568 blkno += n; 3569 nblocks -= n; 3570 if (nblocks == 0) 3571 break; 3572 } /* for each dmap in a L0 */ 3573 3574 /* 3575 * build current L0 page from its leaves, and 3576 * initialize corresponding parent L1 leaf 3577 */ 3578 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); 3579 write_metapage(l0mp); 3580 l0mp = NULL; 3581 3582 if (nblocks) 3583 l1leaf++; /* continue for next L0 */ 3584 else { 3585 /* more than 1 L0 ? */ 3586 if (j > 0) 3587 break; /* build L1 page */ 3588 else { 3589 /* summarize in global bmap page */ 3590 bmp->db_maxfreebud = *l1leaf; 3591 release_metapage(l1mp); 3592 release_metapage(l2mp); 3593 goto finalize; 3594 } 3595 } 3596 } /* for each L0 in a L1 */ 3597 3598 /* 3599 * build current L1 page from its leaves, and 3600 * initialize corresponding parent L2 leaf 3601 */ 3602 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); 3603 write_metapage(l1mp); 3604 l1mp = NULL; 3605 3606 if (nblocks) 3607 l2leaf++; /* continue for next L1 */ 3608 else { 3609 /* more than 1 L1 ? */ 3610 if (k > 0) 3611 break; /* build L2 page */ 3612 else { 3613 /* summarize in global bmap page */ 3614 bmp->db_maxfreebud = *l2leaf; 3615 release_metapage(l2mp); 3616 goto finalize; 3617 } 3618 } 3619 } /* for each L1 in a L2 */ 3620 3621 jfs_error(ipbmap->i_sb, "function has not returned as expected\n"); 3622 errout: 3623 if (l0mp) 3624 release_metapage(l0mp); 3625 if (l1mp) 3626 release_metapage(l1mp); 3627 release_metapage(l2mp); 3628 return -EIO; 3629 3630 /* 3631 * finalize bmap control page 3632 */ 3633 finalize: 3634 3635 return 0; 3636 } 3637 3638 3639 /* 3640 * dbFinalizeBmap() 3641 */ dbFinalizeBmap(struct inode * ipbmap)3642 void dbFinalizeBmap(struct inode *ipbmap) 3643 { 3644 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; 3645 int actags, inactags, l2nl; 3646 s64 ag_rem, actfree, inactfree, avgfree; 3647 int i, n; 3648 3649 /* 3650 * finalize bmap control page 3651 */ 3652 //finalize: 3653 /* 3654 * compute db_agpref: preferred ag to allocate from 3655 * (the leftmost ag with average free space in it); 3656 */ 3657 //agpref: 3658 /* get the number of active ags and inactive ags */ 3659 actags = bmp->db_maxag + 1; 3660 inactags = bmp->db_numag - actags; 3661 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ 3662 3663 /* determine how many blocks are in the inactive allocation 3664 * groups. in doing this, we must account for the fact that 3665 * the rightmost group might be a partial group (i.e. file 3666 * system size is not a multiple of the group size). 3667 */ 3668 inactfree = (inactags && ag_rem) ? 3669 ((inactags - 1) << bmp->db_agl2size) + ag_rem 3670 : inactags << bmp->db_agl2size; 3671 3672 /* determine how many free blocks are in the active 3673 * allocation groups plus the average number of free blocks 3674 * within the active ags. 3675 */ 3676 actfree = bmp->db_nfree - inactfree; 3677 avgfree = (u32) actfree / (u32) actags; 3678 3679 /* if the preferred allocation group has not average free space. 3680 * re-establish the preferred group as the leftmost 3681 * group with average free space. 3682 */ 3683 if (bmp->db_agfree[bmp->db_agpref] < avgfree) { 3684 for (bmp->db_agpref = 0; bmp->db_agpref < actags; 3685 bmp->db_agpref++) { 3686 if (bmp->db_agfree[bmp->db_agpref] >= avgfree) 3687 break; 3688 } 3689 if (bmp->db_agpref >= bmp->db_numag) { 3690 jfs_error(ipbmap->i_sb, 3691 "cannot find ag with average freespace\n"); 3692 } 3693 } 3694 3695 /* 3696 * compute db_aglevel, db_agheight, db_width, db_agstart: 3697 * an ag is covered in aglevel dmapctl summary tree, 3698 * at agheight level height (from leaf) with agwidth number of nodes 3699 * each, which starts at agstart index node of the smmary tree node 3700 * array; 3701 */ 3702 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); 3703 l2nl = 3704 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); 3705 bmp->db_agheight = l2nl >> 1; 3706 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1)); 3707 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0; 3708 i--) { 3709 bmp->db_agstart += n; 3710 n <<= 2; 3711 } 3712 3713 } 3714 3715 3716 /* 3717 * NAME: dbInitDmap()/ujfs_idmap_page() 3718 * 3719 * FUNCTION: initialize working/persistent bitmap of the dmap page 3720 * for the specified number of blocks: 3721 * 3722 * at entry, the bitmaps had been initialized as free (ZEROS); 3723 * The number of blocks will only account for the actually 3724 * existing blocks. Blocks which don't actually exist in 3725 * the aggregate will be marked as allocated (ONES); 3726 * 3727 * PARAMETERS: 3728 * dp - pointer to page of map 3729 * nblocks - number of blocks this page 3730 * 3731 * RETURNS: NONE 3732 */ dbInitDmap(struct dmap * dp,s64 Blkno,int nblocks)3733 static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) 3734 { 3735 int blkno, w, b, r, nw, nb, i; 3736 3737 /* starting block number within the dmap */ 3738 blkno = Blkno & (BPERDMAP - 1); 3739 3740 if (blkno == 0) { 3741 dp->nblocks = dp->nfree = cpu_to_le32(nblocks); 3742 dp->start = cpu_to_le64(Blkno); 3743 3744 if (nblocks == BPERDMAP) { 3745 memset(&dp->wmap[0], 0, LPERDMAP * 4); 3746 memset(&dp->pmap[0], 0, LPERDMAP * 4); 3747 goto initTree; 3748 } 3749 } else { 3750 le32_add_cpu(&dp->nblocks, nblocks); 3751 le32_add_cpu(&dp->nfree, nblocks); 3752 } 3753 3754 /* word number containing start block number */ 3755 w = blkno >> L2DBWORD; 3756 3757 /* 3758 * free the bits corresponding to the block range (ZEROS): 3759 * note: not all bits of the first and last words may be contained 3760 * within the block range. 3761 */ 3762 for (r = nblocks; r > 0; r -= nb, blkno += nb) { 3763 /* number of bits preceding range to be freed in the word */ 3764 b = blkno & (DBWORD - 1); 3765 /* number of bits to free in the word */ 3766 nb = min(r, DBWORD - b); 3767 3768 /* is partial word to be freed ? */ 3769 if (nb < DBWORD) { 3770 /* free (set to 0) from the bitmap word */ 3771 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) 3772 >> b)); 3773 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) 3774 >> b)); 3775 3776 /* skip the word freed */ 3777 w++; 3778 } else { 3779 /* free (set to 0) contiguous bitmap words */ 3780 nw = r >> L2DBWORD; 3781 memset(&dp->wmap[w], 0, nw * 4); 3782 memset(&dp->pmap[w], 0, nw * 4); 3783 3784 /* skip the words freed */ 3785 nb = nw << L2DBWORD; 3786 w += nw; 3787 } 3788 } 3789 3790 /* 3791 * mark bits following the range to be freed (non-existing 3792 * blocks) as allocated (ONES) 3793 */ 3794 3795 if (blkno == BPERDMAP) 3796 goto initTree; 3797 3798 /* the first word beyond the end of existing blocks */ 3799 w = blkno >> L2DBWORD; 3800 3801 /* does nblocks fall on a 32-bit boundary ? */ 3802 b = blkno & (DBWORD - 1); 3803 if (b) { 3804 /* mark a partial word allocated */ 3805 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); 3806 w++; 3807 } 3808 3809 /* set the rest of the words in the page to allocated (ONES) */ 3810 for (i = w; i < LPERDMAP; i++) 3811 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); 3812 3813 /* 3814 * init tree 3815 */ 3816 initTree: 3817 return (dbInitDmapTree(dp)); 3818 } 3819 3820 3821 /* 3822 * NAME: dbInitDmapTree()/ujfs_complete_dmap() 3823 * 3824 * FUNCTION: initialize summary tree of the specified dmap: 3825 * 3826 * at entry, bitmap of the dmap has been initialized; 3827 * 3828 * PARAMETERS: 3829 * dp - dmap to complete 3830 * blkno - starting block number for this dmap 3831 * treemax - will be filled in with max free for this dmap 3832 * 3833 * RETURNS: max free string at the root of the tree 3834 */ dbInitDmapTree(struct dmap * dp)3835 static int dbInitDmapTree(struct dmap * dp) 3836 { 3837 struct dmaptree *tp; 3838 s8 *cp; 3839 int i; 3840 3841 /* init fixed info of tree */ 3842 tp = &dp->tree; 3843 tp->nleafs = cpu_to_le32(LPERDMAP); 3844 tp->l2nleafs = cpu_to_le32(L2LPERDMAP); 3845 tp->leafidx = cpu_to_le32(LEAFIND); 3846 tp->height = cpu_to_le32(4); 3847 tp->budmin = BUDMIN; 3848 3849 /* init each leaf from corresponding wmap word: 3850 * note: leaf is set to NOFREE(-1) if all blocks of corresponding 3851 * bitmap word are allocated. 3852 */ 3853 cp = tp->stree + le32_to_cpu(tp->leafidx); 3854 for (i = 0; i < LPERDMAP; i++) 3855 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]); 3856 3857 /* build the dmap's binary buddy summary tree */ 3858 return (dbInitTree(tp)); 3859 } 3860 3861 3862 /* 3863 * NAME: dbInitTree()/ujfs_adjtree() 3864 * 3865 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. 3866 * 3867 * at entry, the leaves of the tree has been initialized 3868 * from corresponding bitmap word or root of summary tree 3869 * of the child control page; 3870 * configure binary buddy system at the leaf level, then 3871 * bubble up the values of the leaf nodes up the tree. 3872 * 3873 * PARAMETERS: 3874 * cp - Pointer to the root of the tree 3875 * l2leaves- Number of leaf nodes as a power of 2 3876 * l2min - Number of blocks that can be covered by a leaf 3877 * as a power of 2 3878 * 3879 * RETURNS: max free string at the root of the tree 3880 */ dbInitTree(struct dmaptree * dtp)3881 static int dbInitTree(struct dmaptree * dtp) 3882 { 3883 int l2max, l2free, bsize, nextb, i; 3884 int child, parent, nparent; 3885 s8 *tp, *cp, *cp1; 3886 3887 tp = dtp->stree; 3888 3889 /* Determine the maximum free string possible for the leaves */ 3890 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; 3891 3892 /* 3893 * configure the leaf level into binary buddy system 3894 * 3895 * Try to combine buddies starting with a buddy size of 1 3896 * (i.e. two leaves). At a buddy size of 1 two buddy leaves 3897 * can be combined if both buddies have a maximum free of l2min; 3898 * the combination will result in the left-most buddy leaf having 3899 * a maximum free of l2min+1. 3900 * After processing all buddies for a given size, process buddies 3901 * at the next higher buddy size (i.e. current size * 2) and 3902 * the next maximum free (current free + 1). 3903 * This continues until the maximum possible buddy combination 3904 * yields maximum free. 3905 */ 3906 for (l2free = dtp->budmin, bsize = 1; l2free < l2max; 3907 l2free++, bsize = nextb) { 3908 /* get next buddy size == current buddy pair size */ 3909 nextb = bsize << 1; 3910 3911 /* scan each adjacent buddy pair at current buddy size */ 3912 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); 3913 i < le32_to_cpu(dtp->nleafs); 3914 i += nextb, cp += nextb) { 3915 /* coalesce if both adjacent buddies are max free */ 3916 if (*cp == l2free && *(cp + bsize) == l2free) { 3917 *cp = l2free + 1; /* left take right */ 3918 *(cp + bsize) = -1; /* right give left */ 3919 } 3920 } 3921 } 3922 3923 /* 3924 * bubble summary information of leaves up the tree. 3925 * 3926 * Starting at the leaf node level, the four nodes described by 3927 * the higher level parent node are compared for a maximum free and 3928 * this maximum becomes the value of the parent node. 3929 * when all lower level nodes are processed in this fashion then 3930 * move up to the next level (parent becomes a lower level node) and 3931 * continue the process for that level. 3932 */ 3933 for (child = le32_to_cpu(dtp->leafidx), 3934 nparent = le32_to_cpu(dtp->nleafs) >> 2; 3935 nparent > 0; nparent >>= 2, child = parent) { 3936 /* get index of 1st node of parent level */ 3937 parent = (child - 1) >> 2; 3938 3939 /* set the value of the parent node as the maximum 3940 * of the four nodes of the current level. 3941 */ 3942 for (i = 0, cp = tp + child, cp1 = tp + parent; 3943 i < nparent; i++, cp += 4, cp1++) 3944 *cp1 = TREEMAX(cp); 3945 } 3946 3947 return (*tp); 3948 } 3949 3950 3951 /* 3952 * dbInitDmapCtl() 3953 * 3954 * function: initialize dmapctl page 3955 */ dbInitDmapCtl(struct dmapctl * dcp,int level,int i)3956 static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) 3957 { /* start leaf index not covered by range */ 3958 s8 *cp; 3959 3960 dcp->nleafs = cpu_to_le32(LPERCTL); 3961 dcp->l2nleafs = cpu_to_le32(L2LPERCTL); 3962 dcp->leafidx = cpu_to_le32(CTLLEAFIND); 3963 dcp->height = cpu_to_le32(5); 3964 dcp->budmin = L2BPERDMAP + L2LPERCTL * level; 3965 3966 /* 3967 * initialize the leaves of current level that were not covered 3968 * by the specified input block range (i.e. the leaves have no 3969 * low level dmapctl or dmap). 3970 */ 3971 cp = &dcp->stree[CTLLEAFIND + i]; 3972 for (; i < LPERCTL; i++) 3973 *cp++ = NOFREE; 3974 3975 /* build the dmap's binary buddy summary tree */ 3976 return (dbInitTree((struct dmaptree *) dcp)); 3977 } 3978 3979 3980 /* 3981 * NAME: dbGetL2AGSize()/ujfs_getagl2size() 3982 * 3983 * FUNCTION: Determine log2(allocation group size) from aggregate size 3984 * 3985 * PARAMETERS: 3986 * nblocks - Number of blocks in aggregate 3987 * 3988 * RETURNS: log2(allocation group size) in aggregate blocks 3989 */ dbGetL2AGSize(s64 nblocks)3990 static int dbGetL2AGSize(s64 nblocks) 3991 { 3992 s64 sz; 3993 s64 m; 3994 int l2sz; 3995 3996 if (nblocks < BPERDMAP * MAXAG) 3997 return (L2BPERDMAP); 3998 3999 /* round up aggregate size to power of 2 */ 4000 m = ((u64) 1 << (64 - 1)); 4001 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { 4002 if (m & nblocks) 4003 break; 4004 } 4005 4006 sz = (s64) 1 << l2sz; 4007 if (sz < nblocks) 4008 l2sz += 1; 4009 4010 /* agsize = roundupSize/max_number_of_ag */ 4011 return (l2sz - L2MAXAG); 4012 } 4013 4014 4015 /* 4016 * NAME: dbMapFileSizeToMapSize() 4017 * 4018 * FUNCTION: compute number of blocks the block allocation map file 4019 * can cover from the map file size; 4020 * 4021 * RETURNS: Number of blocks which can be covered by this block map file; 4022 */ 4023 4024 /* 4025 * maximum number of map pages at each level including control pages 4026 */ 4027 #define MAXL0PAGES (1 + LPERCTL) 4028 #define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) 4029 4030 /* 4031 * convert number of map pages to the zero origin top dmapctl level 4032 */ 4033 #define BMAPPGTOLEV(npages) \ 4034 (((npages) <= 3 + MAXL0PAGES) ? 0 : \ 4035 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2) 4036 dbMapFileSizeToMapSize(struct inode * ipbmap)4037 s64 dbMapFileSizeToMapSize(struct inode * ipbmap) 4038 { 4039 struct super_block *sb = ipbmap->i_sb; 4040 s64 nblocks; 4041 s64 npages, ndmaps; 4042 int level, i; 4043 int complete, factor; 4044 4045 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; 4046 npages = nblocks >> JFS_SBI(sb)->l2nbperpage; 4047 level = BMAPPGTOLEV(npages); 4048 4049 /* At each level, accumulate the number of dmap pages covered by 4050 * the number of full child levels below it; 4051 * repeat for the last incomplete child level. 4052 */ 4053 ndmaps = 0; 4054 npages--; /* skip the first global control page */ 4055 /* skip higher level control pages above top level covered by map */ 4056 npages -= (2 - level); 4057 npages--; /* skip top level's control page */ 4058 for (i = level; i >= 0; i--) { 4059 factor = 4060 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); 4061 complete = (u32) npages / factor; 4062 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL : 4063 ((i == 1) ? LPERCTL : 1)); 4064 4065 /* pages in last/incomplete child */ 4066 npages = (u32) npages % factor; 4067 /* skip incomplete child's level control page */ 4068 npages--; 4069 } 4070 4071 /* convert the number of dmaps into the number of blocks 4072 * which can be covered by the dmaps; 4073 */ 4074 nblocks = ndmaps << L2BPERDMAP; 4075 4076 return (nblocks); 4077 } 4078