1 /* 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2022 Tomohiro Kusumi <tkusumi@netbsd.org> 5 * Copyright (c) 2011-2022 The DragonFly Project. All rights reserved. 6 * 7 * This code is derived from software contributed to The DragonFly Project 8 * by Matthew Dillon <dillon@dragonflybsd.org> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 3. Neither the name of The DragonFly Project nor the names of its 21 * contributors may be used to endorse or promote products derived 22 * from this software without specific, prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 27 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 28 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 30 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 31 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 32 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 33 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 34 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 /* 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <sys/mount.h> 43 */ 44 45 #include "hammer2.h" 46 47 #define FREEMAP_DEBUG 0 48 49 struct hammer2_fiterate { 50 hammer2_off_t bpref; 51 hammer2_off_t bnext; 52 int loops; 53 int relaxed; 54 }; 55 56 typedef struct hammer2_fiterate hammer2_fiterate_t; 57 58 static int hammer2_freemap_try_alloc(hammer2_chain_t **parentp, 59 hammer2_blockref_t *bref, int radix, 60 hammer2_fiterate_t *iter, hammer2_tid_t mtid); 61 static void hammer2_freemap_init(hammer2_dev_t *hmp, 62 hammer2_key_t key, hammer2_chain_t *chain); 63 static int hammer2_bmap_alloc(hammer2_dev_t *hmp, 64 hammer2_bmap_data_t *bmap, uint16_t class, 65 int n, int sub_key, int radix, hammer2_key_t *basep); 66 static int hammer2_freemap_iterate(hammer2_chain_t **parentp, 67 hammer2_chain_t **chainp, 68 hammer2_fiterate_t *iter); 69 70 /* 71 * Calculate the device offset for the specified FREEMAP_NODE or FREEMAP_LEAF 72 * bref. Return a combined media offset and physical size radix. Freemap 73 * chains use fixed storage offsets in the 4MB reserved area at the 74 * beginning of each 1GB zone. 75 * 76 * Rotate between eight possibilities. Theoretically this means we have seven 77 * good freemaps in case of a crash which we can use as a base for the fixup 78 * scan at mount-time. 79 */ 80 static 81 int 82 hammer2_freemap_reserve(hammer2_chain_t *chain, int radix) 83 { 84 hammer2_blockref_t *bref = &chain->bref; 85 hammer2_off_t off; 86 int index; 87 int index_inc; 88 size_t bytes; 89 90 /* 91 * Physical allocation size. 92 */ 93 bytes = (size_t)1 << radix; 94 95 /* 96 * Calculate block selection index 0..7 of current block. If this 97 * is the first allocation of the block (verses a modification of an 98 * existing block), we use index 0, otherwise we use the next rotating 99 * index. 100 */ 101 if ((bref->data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) { 102 index = 0; 103 } else { 104 off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX & 105 HAMMER2_SEGMASK; 106 off = off / HAMMER2_PBUFSIZE; 107 KKASSERT(off >= HAMMER2_ZONE_FREEMAP_00 && 108 off < HAMMER2_ZONE_FREEMAP_END); 109 index = (int)(off - HAMMER2_ZONE_FREEMAP_00) / 110 HAMMER2_ZONE_FREEMAP_INC; 111 KKASSERT(index >= 0 && index < HAMMER2_NFREEMAPS); 112 if (++index == HAMMER2_NFREEMAPS) 113 index = 0; 114 } 115 116 /* 117 * Calculate the block offset of the reserved block. This will 118 * point into the 4MB reserved area at the base of the appropriate 119 * 2GB zone, once added to the FREEMAP_x selection above. 120 */ 121 index_inc = index * HAMMER2_ZONE_FREEMAP_INC; 122 123 switch(bref->keybits) { 124 /* case HAMMER2_FREEMAP_LEVEL6_RADIX: not applicable */ 125 case HAMMER2_FREEMAP_LEVEL5_RADIX: /* 4EB */ 126 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE); 127 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE); 128 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL5_RADIX) + 129 (index_inc + HAMMER2_ZONE_FREEMAP_00 + 130 HAMMER2_ZONEFM_LEVEL5) * HAMMER2_PBUFSIZE; 131 break; 132 case HAMMER2_FREEMAP_LEVEL4_RADIX: /* 16PB */ 133 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE); 134 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE); 135 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL4_RADIX) + 136 (index_inc + HAMMER2_ZONE_FREEMAP_00 + 137 HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE; 138 break; 139 case HAMMER2_FREEMAP_LEVEL3_RADIX: /* 64TB */ 140 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE); 141 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE); 142 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) + 143 (index_inc + HAMMER2_ZONE_FREEMAP_00 + 144 HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE; 145 break; 146 case HAMMER2_FREEMAP_LEVEL2_RADIX: /* 256GB */ 147 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE); 148 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE); 149 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) + 150 (index_inc + HAMMER2_ZONE_FREEMAP_00 + 151 HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE; 152 break; 153 case HAMMER2_FREEMAP_LEVEL1_RADIX: /* 1GB */ 154 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF); 155 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE); 156 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) + 157 (index_inc + HAMMER2_ZONE_FREEMAP_00 + 158 HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE; 159 break; 160 default: 161 panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits); 162 /* NOT REACHED */ 163 off = (hammer2_off_t)-1; 164 break; 165 } 166 bref->data_off = off | radix; 167 #if FREEMAP_DEBUG 168 kprintf("FREEMAP BLOCK TYPE %d %016jx/%d DATA_OFF=%016jx\n", 169 bref->type, bref->key, bref->keybits, bref->data_off); 170 #endif 171 return (0); 172 } 173 174 /* 175 * Normal freemap allocator 176 * 177 * Use available hints to allocate space using the freemap. Create missing 178 * freemap infrastructure on-the-fly as needed (including marking initial 179 * allocations using the iterator as allocated, instantiating new 2GB zones, 180 * and dealing with the end-of-media edge case). 181 * 182 * bpref is only used as a heuristic to determine locality of reference. 183 * 184 * This function is a NOP if bytes is 0. 185 */ 186 int 187 hammer2_freemap_alloc(hammer2_chain_t *chain, size_t bytes) 188 { 189 hammer2_dev_t *hmp = chain->hmp; 190 hammer2_blockref_t *bref = &chain->bref; 191 hammer2_chain_t *parent; 192 hammer2_tid_t mtid; 193 int radix; 194 int error; 195 unsigned int hindex; 196 hammer2_fiterate_t iter; 197 198 /* 199 * If allocating or downsizing to zero we just get rid of whatever 200 * data_off we had. 201 */ 202 if (bytes == 0) { 203 chain->bref.data_off = 0; 204 return 0; 205 } 206 207 KKASSERT(hmp->spmp); 208 mtid = hammer2_trans_sub(hmp->spmp); 209 210 /* 211 * Validate the allocation size. It must be a power of 2. 212 * 213 * For now require that the caller be aware of the minimum 214 * allocation (1K). 215 */ 216 radix = hammer2_getradix(bytes); 217 KKASSERT((size_t)1 << radix == bytes); 218 219 if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 220 bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 221 /* 222 * Freemap blocks themselves are assigned from the reserve 223 * area, not allocated from the freemap. 224 */ 225 error = hammer2_freemap_reserve(chain, radix); 226 227 return error; 228 } 229 230 KKASSERT(bytes >= HAMMER2_ALLOC_MIN && bytes <= HAMMER2_ALLOC_MAX); 231 232 /* 233 * Heuristic tracking index. We would like one for each distinct 234 * bref type if possible. heur_freemap[] has room for two classes 235 * for each type. At a minimum we have to break-up our heuristic 236 * by device block sizes. 237 */ 238 hindex = HAMMER2_PBUFRADIX - HAMMER2_LBUFRADIX; 239 KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX); 240 hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX; 241 hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1; 242 KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_SIZE); 243 244 iter.bpref = hmp->heur_freemap[hindex]; 245 iter.relaxed = hmp->freemap_relaxed; 246 247 /* 248 * Make sure bpref is in-bounds. It's ok if bpref covers a zone's 249 * reserved area, the try code will iterate past it. 250 */ 251 if (iter.bpref > hmp->total_size) 252 iter.bpref = hmp->total_size - 1; 253 254 /* 255 * Iterate the freemap looking for free space before and after. 256 */ 257 parent = &hmp->fchain; 258 hammer2_chain_ref(parent); 259 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 260 error = HAMMER2_ERROR_EAGAIN; 261 iter.bnext = iter.bpref; 262 iter.loops = 0; 263 264 while (error == HAMMER2_ERROR_EAGAIN) { 265 error = hammer2_freemap_try_alloc(&parent, bref, radix, 266 &iter, mtid); 267 } 268 hmp->freemap_relaxed |= iter.relaxed; /* heuristical, SMP race ok */ 269 hmp->heur_freemap[hindex] = iter.bnext; 270 hammer2_chain_unlock(parent); 271 hammer2_chain_drop(parent); 272 273 return (error); 274 } 275 276 static int 277 hammer2_freemap_try_alloc(hammer2_chain_t **parentp, 278 hammer2_blockref_t *bref, int radix, 279 hammer2_fiterate_t *iter, hammer2_tid_t mtid) 280 { 281 hammer2_dev_t *hmp = (*parentp)->hmp; 282 hammer2_off_t l0size; 283 hammer2_off_t l1size; 284 hammer2_off_t l1mask; 285 hammer2_key_t key_dummy; 286 hammer2_chain_t *chain; 287 hammer2_off_t key; 288 size_t bytes; 289 uint16_t class; 290 int error; 291 292 /* 293 * Calculate the number of bytes being allocated. 294 */ 295 bytes = (size_t)1 << radix; 296 class = (bref->type << 8) | HAMMER2_PBUFRADIX; 297 298 /* 299 * Lookup the level1 freemap chain, creating and initializing one 300 * if necessary. Intermediate levels will be created automatically 301 * when necessary by hammer2_chain_create(). 302 */ 303 key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX); 304 l0size = HAMMER2_FREEMAP_LEVEL0_SIZE; 305 l1size = HAMMER2_FREEMAP_LEVEL1_SIZE; 306 l1mask = l1size - 1; 307 308 chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask, 309 &error, 310 HAMMER2_LOOKUP_ALWAYS | 311 HAMMER2_LOOKUP_MATCHIND); 312 313 if (chain == NULL) { 314 /* 315 * Create the missing leaf, be sure to initialize 316 * the auxillary freemap tracking information in 317 * the bref.check.freemap structure. 318 */ 319 #if 0 320 kprintf("freemap create L1 @ %016jx bpref %016jx\n", 321 key, iter->bpref); 322 #endif 323 error = hammer2_chain_create(parentp, &chain, NULL, hmp->spmp, 324 HAMMER2_METH_DEFAULT, 325 key, HAMMER2_FREEMAP_LEVEL1_RADIX, 326 HAMMER2_BREF_TYPE_FREEMAP_LEAF, 327 HAMMER2_FREEMAP_LEVELN_PSIZE, 328 mtid, 0, 0); 329 KKASSERT(error == 0); 330 if (error == 0) { 331 hammer2_chain_modify(chain, mtid, 0, 0); 332 bzero(&chain->data->bmdata[0], 333 HAMMER2_FREEMAP_LEVELN_PSIZE); 334 chain->bref.check.freemap.bigmask = (uint32_t)-1; 335 chain->bref.check.freemap.avail = l1size; 336 /* bref.methods should already be inherited */ 337 338 hammer2_freemap_init(hmp, key, chain); 339 } 340 } else if (chain->error) { 341 /* 342 * Error during lookup. 343 */ 344 kprintf("hammer2_freemap_try_alloc: %016jx: error %s\n", 345 (intmax_t)bref->data_off, 346 hammer2_error_str(chain->error)); 347 error = HAMMER2_ERROR_EIO; 348 } else if ((chain->bref.check.freemap.bigmask & 349 ((size_t)1 << radix)) == 0) { 350 /* 351 * Already flagged as not having enough space 352 */ 353 error = HAMMER2_ERROR_ENOSPC; 354 } else { 355 /* 356 * Modify existing chain to setup for adjustment. 357 */ 358 hammer2_chain_modify(chain, mtid, 0, 0); 359 } 360 361 /* 362 * Scan 4MB entries. 363 */ 364 if (error == 0) { 365 hammer2_bmap_data_t *bmap; 366 hammer2_key_t base_key; 367 int count; 368 int start; 369 int n; 370 371 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF); 372 start = (int)((iter->bnext - key) >> 373 HAMMER2_FREEMAP_LEVEL0_RADIX); 374 KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT); 375 hammer2_chain_modify(chain, mtid, 0, 0); 376 377 error = HAMMER2_ERROR_ENOSPC; 378 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) { 379 int availchk; 380 381 if (start + count >= HAMMER2_FREEMAP_COUNT && 382 start - count < 0) { 383 break; 384 } 385 386 /* 387 * Calculate bmap pointer from thart starting index 388 * forwards. 389 * 390 * NOTE: bmap pointer is invalid if n >= FREEMAP_COUNT. 391 */ 392 n = start + count; 393 bmap = &chain->data->bmdata[n]; 394 395 if (n >= HAMMER2_FREEMAP_COUNT) { 396 availchk = 0; 397 } else if (bmap->avail) { 398 availchk = 1; 399 } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX && 400 (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) { 401 availchk = 1; 402 } else { 403 availchk = 0; 404 } 405 406 /* 407 * Try to allocate from a matching freemap class 408 * superblock. If we are in relaxed mode we allocate 409 * from any freemap class superblock. 410 */ 411 if (availchk && 412 (bmap->class == 0 || bmap->class == class || 413 iter->relaxed)) { 414 base_key = key + n * l0size; 415 error = hammer2_bmap_alloc(hmp, bmap, 416 class, n, 417 (int)bref->key, 418 radix, 419 &base_key); 420 if (error != HAMMER2_ERROR_ENOSPC) { 421 key = base_key; 422 break; 423 } 424 } 425 426 /* 427 * Calculate bmap pointer from the starting index 428 * backwards (locality). 429 * 430 * Must recalculate after potentially having called 431 * hammer2_bmap_alloc() above in case chain was 432 * reallocated. 433 * 434 * NOTE: bmap pointer is invalid if n < 0. 435 */ 436 n = start - count; 437 bmap = &chain->data->bmdata[n]; 438 if (n < 0) { 439 availchk = 0; 440 } else if (bmap->avail) { 441 availchk = 1; 442 } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX && 443 (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) { 444 availchk = 1; 445 } else { 446 availchk = 0; 447 } 448 449 /* 450 * Try to allocate from a matching freemap class 451 * superblock. If we are in relaxed mode we allocate 452 * from any freemap class superblock. 453 */ 454 if (availchk && 455 (bmap->class == 0 || bmap->class == class || 456 iter->relaxed)) { 457 base_key = key + n * l0size; 458 error = hammer2_bmap_alloc(hmp, bmap, 459 class, n, 460 (int)bref->key, 461 radix, 462 &base_key); 463 if (error != HAMMER2_ERROR_ENOSPC) { 464 key = base_key; 465 break; 466 } 467 } 468 } 469 470 /* 471 * We only know for sure that we can clear the bitmap bit 472 * if we scanned the entire array (start == 0) in relaxed 473 * mode. 474 */ 475 if (error == HAMMER2_ERROR_ENOSPC && 476 start == 0 && 477 iter->relaxed) 478 { 479 chain->bref.check.freemap.bigmask &= 480 (uint32_t)~((size_t)1 << radix); 481 } 482 /* XXX also scan down from original count */ 483 } 484 485 if (error == 0) { 486 /* 487 * Assert validity. Must be beyond the static allocator used 488 * by newfs_hammer2 (and thus also beyond the aux area), 489 * not go past the volume size, and must not be in the 490 * reserved segment area for a zone. 491 */ 492 KKASSERT(key >= hmp->voldata.allocator_beg && 493 key + bytes <= hmp->total_size); 494 KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG); 495 bref->data_off = key | radix; 496 497 /* 498 * Record dedupability. The dedup bits are cleared 499 * when bulkfree transitions the freemap from 11->10, 500 * and asserted to be clear on the 10->00 transition. 501 * 502 * We must record the bitmask with the chain locked 503 * at the time we set the allocation bits to avoid 504 * racing a bulkfree. 505 */ 506 if (bref->type == HAMMER2_BREF_TYPE_DATA) 507 hammer2_io_dedup_set(hmp, bref); 508 #if 0 509 kprintf("alloc cp=%p %016jx %016jx using %016jx\n", 510 chain, 511 bref->key, bref->data_off, chain->bref.data_off); 512 #endif 513 } else if (error == HAMMER2_ERROR_ENOSPC) { 514 /* 515 * Return EAGAIN with next iteration in iter->bnext, or 516 * return ENOSPC if the allocation map has been exhausted. 517 */ 518 error = hammer2_freemap_iterate(parentp, &chain, iter); 519 } 520 521 /* 522 * Cleanup 523 */ 524 if (chain) { 525 hammer2_chain_unlock(chain); 526 hammer2_chain_drop(chain); 527 } 528 return (error); 529 } 530 531 /* 532 * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep). 533 * 534 * If the linear iterator is mid-block we use it directly (the bitmap should 535 * already be marked allocated), otherwise we search for a block in the 536 * bitmap that fits the allocation request. 537 * 538 * A partial bitmap allocation sets the minimum bitmap granularity (16KB) 539 * to fully allocated and adjusts the linear allocator to allow the 540 * remaining space to be allocated. 541 * 542 * sub_key is the lower 32 bits of the chain->bref.key for the chain whos 543 * bref is being allocated. If the radix represents an allocation >= 16KB 544 * (aka HAMMER2_FREEMAP_BLOCK_RADIX) we try to use this key to select the 545 * blocks directly out of the bmap. 546 */ 547 static 548 int 549 hammer2_bmap_alloc(hammer2_dev_t *hmp, hammer2_bmap_data_t *bmap, 550 uint16_t class, int n, int sub_key, 551 int radix, hammer2_key_t *basep) 552 { 553 size_t size; 554 size_t bgsize; 555 int bmradix; 556 hammer2_bitmap_t bmmask; 557 int offset; 558 int i; 559 int j; 560 561 /* 562 * Take into account 2-bits per block when calculating bmradix. 563 */ 564 size = (size_t)1 << radix; 565 566 if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) { 567 bmradix = 2; 568 /* (16K) 2 bits per allocation block */ 569 } else { 570 bmradix = (hammer2_bitmap_t)2 << 571 (radix - HAMMER2_FREEMAP_BLOCK_RADIX); 572 /* (32K-64K) 4, 8 bits per allocation block */ 573 } 574 575 /* 576 * Use the linear iterator to pack small allocations, otherwise 577 * fall-back to finding a free 16KB chunk. The linear iterator 578 * is only valid when *NOT* on a freemap chunking boundary (16KB). 579 * If it is the bitmap must be scanned. It can become invalid 580 * once we pack to the boundary. We adjust it after a bitmap 581 * allocation only for sub-16KB allocations (so the perfectly good 582 * previous value can still be used for fragments when 16KB+ 583 * allocations are made inbetween fragmentary allocations). 584 * 585 * Beware of hardware artifacts when bmradix == 64 (intermediate 586 * result can wind up being '1' instead of '0' if hardware masks 587 * bit-count & 63). 588 * 589 * NOTE: j needs to be even in the j= calculation. As an artifact 590 * of the /2 division, our bitmask has to clear bit 0. 591 * 592 * NOTE: TODO this can leave little unallocatable fragments lying 593 * around. 594 */ 595 if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <= 596 HAMMER2_FREEMAP_BLOCK_SIZE && 597 (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) && 598 bmap->linear < HAMMER2_SEGSIZE) { 599 /* 600 * Use linear iterator if it is not block-aligned to avoid 601 * wasting space. 602 * 603 * Calculate the bitmapq[] index (i) and calculate the 604 * shift count within the 64-bit bitmapq[] entry. 605 * 606 * The freemap block size is 16KB, but each bitmap 607 * entry is two bits so use a little trick to get 608 * a (j) shift of 0, 2, 4, ... 62 in 16KB chunks. 609 */ 610 KKASSERT(bmap->linear >= 0 && 611 bmap->linear + size <= HAMMER2_SEGSIZE && 612 (bmap->linear & (HAMMER2_ALLOC_MIN - 1)) == 0); 613 offset = bmap->linear; 614 i = offset / (HAMMER2_SEGSIZE / HAMMER2_BMAP_ELEMENTS); 615 j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 62; 616 bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ? 617 HAMMER2_BMAP_ALLONES : 618 ((hammer2_bitmap_t)1 << bmradix) - 1; 619 bmmask <<= j; 620 bmap->linear = offset + size; 621 } else { 622 /* 623 * Try to index a starting point based on sub_key. This 624 * attempts to restore sequential block ordering on-disk 625 * whenever possible, even if data is committed out of 626 * order. 627 * 628 * i - Index bitmapq[], full data range represented is 629 * HAMMER2_BMAP_SIZE. 630 * 631 * j - Index within bitmapq[i], full data range represented is 632 * HAMMER2_BMAP_INDEX_SIZE. 633 * 634 * WARNING! 635 */ 636 i = -1; 637 j = -1; 638 639 switch(class >> 8) { 640 case HAMMER2_BREF_TYPE_DATA: 641 if (radix >= HAMMER2_FREEMAP_BLOCK_RADIX) { 642 i = (sub_key & HAMMER2_BMAP_MASK) / 643 (HAMMER2_BMAP_SIZE / HAMMER2_BMAP_ELEMENTS); 644 j = (sub_key & HAMMER2_BMAP_INDEX_MASK) / 645 (HAMMER2_BMAP_INDEX_SIZE / 646 HAMMER2_BMAP_BLOCKS_PER_ELEMENT); 647 j = j * 2; 648 } 649 break; 650 case HAMMER2_BREF_TYPE_INODE: 651 break; 652 default: 653 break; 654 } 655 if (i >= 0) { 656 KKASSERT(i < HAMMER2_BMAP_ELEMENTS && 657 j < 2 * HAMMER2_BMAP_BLOCKS_PER_ELEMENT); 658 KKASSERT(j + bmradix <= HAMMER2_BMAP_BITS_PER_ELEMENT); 659 bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ? 660 HAMMER2_BMAP_ALLONES : 661 ((hammer2_bitmap_t)1 << bmradix) - 1; 662 bmmask <<= j; 663 664 if ((bmap->bitmapq[i] & bmmask) == 0) 665 goto success; 666 } 667 668 /* 669 * General element scan. 670 * 671 * WARNING: (j) is iterating a bit index (by 2's) 672 */ 673 for (i = 0; i < HAMMER2_BMAP_ELEMENTS; ++i) { 674 bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ? 675 HAMMER2_BMAP_ALLONES : 676 ((hammer2_bitmap_t)1 << bmradix) - 1; 677 for (j = 0; 678 j < HAMMER2_BMAP_BITS_PER_ELEMENT; 679 j += bmradix) { 680 if ((bmap->bitmapq[i] & bmmask) == 0) 681 goto success; 682 bmmask <<= bmradix; 683 } 684 } 685 /*fragments might remain*/ 686 /*KKASSERT(bmap->avail == 0);*/ 687 return (HAMMER2_ERROR_ENOSPC); 688 success: 689 offset = i * (HAMMER2_SEGSIZE / HAMMER2_BMAP_ELEMENTS) + 690 (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2)); 691 if (size & HAMMER2_FREEMAP_BLOCK_MASK) 692 bmap->linear = offset + size; 693 } 694 695 /* 8 x (64/2) -> 256 x 16K -> 4MB */ 696 KKASSERT(i >= 0 && i < HAMMER2_BMAP_ELEMENTS); 697 698 /* 699 * Optimize the buffer cache to avoid unnecessary read-before-write 700 * operations. 701 * 702 * The device block size could be larger than the allocation size 703 * so the actual bitmap test is somewhat more involved. We have 704 * to use a compatible buffer size for this operation. 705 */ 706 if ((bmap->bitmapq[i] & bmmask) == 0 && 707 HAMMER2_PBUFSIZE != size) { 708 size_t psize = HAMMER2_PBUFSIZE; 709 hammer2_off_t pmask = (hammer2_off_t)psize - 1; 710 int pbmradix = (hammer2_bitmap_t)2 << 711 (HAMMER2_PBUFRADIX - 712 HAMMER2_FREEMAP_BLOCK_RADIX); 713 hammer2_bitmap_t pbmmask; 714 int pradix = hammer2_getradix(psize); 715 716 pbmmask = (pbmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ? 717 HAMMER2_BMAP_ALLONES : 718 ((hammer2_bitmap_t)1 << pbmradix) - 1; 719 while ((pbmmask & bmmask) == 0) 720 pbmmask <<= pbmradix; 721 722 #if 0 723 kprintf("%016jx mask %016jx %016jx %016jx (%zd/%zd)\n", 724 *basep + offset, bmap->bitmapq[i], 725 pbmmask, bmmask, size, psize); 726 #endif 727 728 if ((bmap->bitmapq[i] & pbmmask) == 0) { 729 hammer2_io_t *dio; 730 731 hammer2_io_newnz(hmp, class >> 8, 732 (*basep + (offset & ~pmask)) | 733 pradix, psize, &dio); 734 hammer2_io_putblk(&dio); 735 } 736 } 737 738 #if 0 739 /* 740 * When initializing a new inode segment also attempt to initialize 741 * an adjacent segment. Be careful not to index beyond the array 742 * bounds. 743 * 744 * We do this to try to localize inode accesses to improve 745 * directory scan rates. XXX doesn't improve scan rates. 746 */ 747 if (size == HAMMER2_INODE_BYTES) { 748 if (n & 1) { 749 if (bmap[-1].radix == 0 && bmap[-1].avail) 750 bmap[-1].radix = radix; 751 } else { 752 if (bmap[1].radix == 0 && bmap[1].avail) 753 bmap[1].radix = radix; 754 } 755 } 756 #endif 757 /* 758 * Calculate the bitmap-granular change in bgsize for the volume 759 * header. We cannot use the fine-grained change here because 760 * the bulkfree code can't undo it. If the bitmap element is already 761 * marked allocated it has already been accounted for. 762 */ 763 if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) { 764 if (bmap->bitmapq[i] & bmmask) 765 bgsize = 0; 766 else 767 bgsize = HAMMER2_FREEMAP_BLOCK_SIZE; 768 } else { 769 bgsize = size; 770 } 771 772 /* 773 * Adjust the bitmap, set the class (it might have been 0), 774 * and available bytes, update the allocation offset (*basep) 775 * from the L0 base to the actual offset. 776 * 777 * Do not override the class if doing a relaxed class allocation. 778 * 779 * avail must reflect the bitmap-granular availability. The allocator 780 * tests will also check the linear iterator. 781 */ 782 bmap->bitmapq[i] |= bmmask; 783 if (bmap->class == 0) 784 bmap->class = class; 785 bmap->avail -= bgsize; 786 *basep += offset; 787 788 /* 789 * Adjust the volume header's allocator_free parameter. This 790 * parameter has to be fixed up by bulkfree which has no way to 791 * figure out sub-16K chunking, so it must be adjusted by the 792 * bitmap-granular size. 793 */ 794 if (bgsize) { 795 hammer2_voldata_lock(hmp); 796 hammer2_voldata_modify(hmp); 797 hmp->voldata.allocator_free -= bgsize; 798 hammer2_voldata_unlock(hmp); 799 } 800 801 return(0); 802 } 803 804 /* 805 * Initialize a freemap for the storage area (in bytes) that begins at (key). 806 */ 807 static 808 void 809 hammer2_freemap_init(hammer2_dev_t *hmp, hammer2_key_t key, 810 hammer2_chain_t *chain) 811 { 812 hammer2_off_t lokey; 813 hammer2_off_t hikey; 814 hammer2_bmap_data_t *bmap; 815 int count; 816 817 /* 818 * Calculate the portion of the 1GB map that should be initialized 819 * as free. Portions below or after will be initialized as allocated. 820 * SEGMASK-align the areas so we don't have to worry about sub-scans 821 * or endianess when using memset. 822 * 823 * WARNING! It is possible for lokey to be larger than hikey if the 824 * entire 2GB segment is within the static allocation. 825 */ 826 /* 827 * (1) Ensure that all statically allocated space from newfs_hammer2 828 * is marked allocated, and take it up to the level1 base for 829 * this key. 830 */ 831 lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) & 832 ~HAMMER2_SEGMASK64; 833 if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX)) 834 lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX); 835 836 /* 837 * (2) Ensure that the reserved area is marked allocated (typically 838 * the first 4MB of each 2GB area being represented). Since 839 * each LEAF represents 1GB of storage and the zone is 2GB, we 840 * have to adjust lowkey upward every other LEAF sequentially. 841 */ 842 if (lokey < H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64) 843 lokey = H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64; 844 845 /* 846 * (3) Ensure that any trailing space at the end-of-volume is marked 847 * allocated. 848 */ 849 hikey = key + HAMMER2_FREEMAP_LEVEL1_SIZE; 850 if (hikey > hmp->total_size) { 851 hikey = hmp->total_size & ~HAMMER2_SEGMASK64; 852 } 853 854 /* 855 * Heuristic highest possible value 856 */ 857 chain->bref.check.freemap.avail = HAMMER2_FREEMAP_LEVEL1_SIZE; 858 bmap = &chain->data->bmdata[0]; 859 860 /* 861 * Initialize bitmap (bzero'd by caller) 862 */ 863 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) { 864 if (key < lokey || key >= hikey) { 865 memset(bmap->bitmapq, -1, 866 sizeof(bmap->bitmapq)); 867 bmap->avail = 0; 868 bmap->linear = HAMMER2_SEGSIZE; 869 chain->bref.check.freemap.avail -= 870 HAMMER2_FREEMAP_LEVEL0_SIZE; 871 } else { 872 bmap->avail = HAMMER2_FREEMAP_LEVEL0_SIZE; 873 } 874 key += HAMMER2_FREEMAP_LEVEL0_SIZE; 875 ++bmap; 876 } 877 } 878 879 /* 880 * The current Level 1 freemap has been exhausted, iterate to the next 881 * one, return ENOSPC if no freemaps remain. 882 * 883 * At least two loops are required. If we are not in relaxed mode and 884 * we run out of storage we enter relaxed mode and do a third loop. 885 * The relaxed mode is recorded back in the hmp so once we enter the mode 886 * we remain relaxed until stuff begins to get freed and only do 2 loops. 887 * 888 * XXX this should rotate back to the beginning to handle freed-up space 889 * XXX or use intermediate entries to locate free space. TODO 890 */ 891 static int 892 hammer2_freemap_iterate(hammer2_chain_t **parentp, hammer2_chain_t **chainp, 893 hammer2_fiterate_t *iter) 894 { 895 hammer2_dev_t *hmp = (*parentp)->hmp; 896 897 iter->bnext &= ~HAMMER2_FREEMAP_LEVEL1_MASK; 898 iter->bnext += HAMMER2_FREEMAP_LEVEL1_SIZE; 899 if (iter->bnext >= hmp->total_size) { 900 iter->bnext = 0; 901 if (++iter->loops >= 2) { 902 if (iter->relaxed == 0) 903 iter->relaxed = 1; 904 else 905 return (HAMMER2_ERROR_ENOSPC); 906 } 907 } 908 return(HAMMER2_ERROR_EAGAIN); 909 } 910 911 /* 912 * Adjust the bit-pattern for data in the freemap bitmap according to 913 * (how). This code is called from on-mount recovery to fixup (mark 914 * as allocated) blocks whos freemap upates might not have been committed 915 * in the last crash and is used by the bulk freemap scan to stage frees. 916 * 917 * WARNING! Cannot be called with a empty-data bref (radix == 0). 918 * 919 * XXX currently disabled when how == 0 (the normal real-time case). At 920 * the moment we depend on the bulk freescan to actually free blocks. It 921 * will still call this routine with a non-zero how to stage possible frees 922 * and to do the actual free. 923 */ 924 void 925 hammer2_freemap_adjust(hammer2_dev_t *hmp, hammer2_blockref_t *bref, 926 int how) 927 { 928 hammer2_off_t data_off = bref->data_off; 929 hammer2_chain_t *chain; 930 hammer2_chain_t *parent; 931 hammer2_bmap_data_t *bmap; 932 hammer2_key_t key; 933 hammer2_key_t key_dummy; 934 hammer2_off_t l1size; 935 hammer2_off_t l1mask; 936 hammer2_tid_t mtid; 937 hammer2_bitmap_t *bitmap; 938 const hammer2_bitmap_t bmmask00 = 0; 939 //hammer2_bitmap_t bmmask01; 940 //hammer2_bitmap_t bmmask10; 941 hammer2_bitmap_t bmmask11; 942 size_t bytes; 943 uint16_t class; 944 int radix; 945 int start; 946 int count; 947 int modified = 0; 948 int error; 949 size_t bgsize = 0; 950 951 KKASSERT(how == HAMMER2_FREEMAP_DORECOVER); 952 953 KKASSERT(hmp->spmp); 954 mtid = hammer2_trans_sub(hmp->spmp); 955 956 radix = (int)data_off & HAMMER2_OFF_MASK_RADIX; 957 KKASSERT(radix != 0); 958 data_off &= ~HAMMER2_OFF_MASK_RADIX; 959 KKASSERT(radix <= HAMMER2_RADIX_MAX); 960 961 if (radix) 962 bytes = (size_t)1 << radix; 963 else 964 bytes = 0; 965 class = (bref->type << 8) | HAMMER2_PBUFRADIX; 966 967 /* 968 * We can't adjust the freemap for data allocations made by 969 * newfs_hammer2. 970 */ 971 if (data_off < hmp->voldata.allocator_beg) 972 return; 973 974 KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG); 975 976 /* 977 * Lookup the level1 freemap chain. The chain must exist. 978 */ 979 key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX); 980 l1size = HAMMER2_FREEMAP_LEVEL1_SIZE; 981 l1mask = l1size - 1; 982 983 parent = &hmp->fchain; 984 hammer2_chain_ref(parent); 985 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 986 987 chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask, 988 &error, 989 HAMMER2_LOOKUP_ALWAYS | 990 HAMMER2_LOOKUP_MATCHIND); 991 992 /* 993 * Stop early if we are trying to free something but no leaf exists. 994 */ 995 if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) { 996 kprintf("hammer2_freemap_adjust: %016jx: no chain\n", 997 (intmax_t)bref->data_off); 998 goto done; 999 } 1000 if (chain->error) { 1001 kprintf("hammer2_freemap_adjust: %016jx: error %s\n", 1002 (intmax_t)bref->data_off, 1003 hammer2_error_str(chain->error)); 1004 hammer2_chain_unlock(chain); 1005 hammer2_chain_drop(chain); 1006 chain = NULL; 1007 goto done; 1008 } 1009 1010 /* 1011 * Create any missing leaf(s) if we are doing a recovery (marking 1012 * the block(s) as being allocated instead of being freed). Be sure 1013 * to initialize the auxillary freemap tracking info in the 1014 * bref.check.freemap structure. 1015 */ 1016 if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) { 1017 error = hammer2_chain_create(&parent, &chain, NULL, hmp->spmp, 1018 HAMMER2_METH_DEFAULT, 1019 key, HAMMER2_FREEMAP_LEVEL1_RADIX, 1020 HAMMER2_BREF_TYPE_FREEMAP_LEAF, 1021 HAMMER2_FREEMAP_LEVELN_PSIZE, 1022 mtid, 0, 0); 1023 1024 if (hammer2_debug & 0x0040) { 1025 kprintf("fixup create chain %p %016jx:%d\n", 1026 chain, chain->bref.key, chain->bref.keybits); 1027 } 1028 1029 if (error == 0) { 1030 error = hammer2_chain_modify(chain, mtid, 0, 0); 1031 KKASSERT(error == 0); 1032 bzero(&chain->data->bmdata[0], 1033 HAMMER2_FREEMAP_LEVELN_PSIZE); 1034 chain->bref.check.freemap.bigmask = (uint32_t)-1; 1035 chain->bref.check.freemap.avail = l1size; 1036 /* bref.methods should already be inherited */ 1037 1038 hammer2_freemap_init(hmp, key, chain); 1039 } 1040 /* XXX handle error */ 1041 } 1042 1043 #if FREEMAP_DEBUG 1044 kprintf("FREEMAP ADJUST TYPE %d %016jx/%d DATA_OFF=%016jx\n", 1045 chain->bref.type, chain->bref.key, 1046 chain->bref.keybits, chain->bref.data_off); 1047 #endif 1048 1049 /* 1050 * Calculate the bitmask (runs in 2-bit pairs). 1051 */ 1052 start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2; 1053 //bmmask01 = (hammer2_bitmap_t)1 << start; 1054 //bmmask10 = (hammer2_bitmap_t)2 << start; 1055 bmmask11 = (hammer2_bitmap_t)3 << start; 1056 1057 /* 1058 * Fixup the bitmap. Partial blocks cannot be fully freed unless 1059 * a bulk scan is able to roll them up. 1060 */ 1061 if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) { 1062 count = 1; 1063 #if 0 1064 if (how == HAMMER2_FREEMAP_DOREALFREE) 1065 how = HAMMER2_FREEMAP_DOMAYFREE; 1066 #endif 1067 } else { 1068 count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX); 1069 } 1070 1071 /* 1072 * [re]load the bmap and bitmap pointers. Each bmap entry covers 1073 * a 4MB swath. The bmap itself (LEVEL1) covers 2GB. 1074 * 1075 * Be sure to reset the linear iterator to ensure that the adjustment 1076 * is not ignored. 1077 */ 1078 again: 1079 bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) & 1080 (HAMMER2_FREEMAP_COUNT - 1)]; 1081 bitmap = &bmap->bitmapq[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7]; 1082 1083 if (modified) 1084 bmap->linear = 0; 1085 1086 while (count) { 1087 KKASSERT(bmmask11); 1088 if (how == HAMMER2_FREEMAP_DORECOVER) { 1089 /* 1090 * Recovery request, mark as allocated. 1091 */ 1092 if ((*bitmap & bmmask11) != bmmask11) { 1093 if (modified == 0) { 1094 hammer2_chain_modify(chain, mtid, 0, 0); 1095 modified = 1; 1096 goto again; 1097 } 1098 if ((*bitmap & bmmask11) == bmmask00) { 1099 bmap->avail -= 1100 HAMMER2_FREEMAP_BLOCK_SIZE; 1101 bgsize += HAMMER2_FREEMAP_BLOCK_SIZE; 1102 } 1103 if (bmap->class == 0) 1104 bmap->class = class; 1105 *bitmap |= bmmask11; 1106 if (hammer2_debug & 0x0040) { 1107 kprintf("hammer2_freemap_adjust: " 1108 "fixup type=%02x " 1109 "block=%016jx/%zd\n", 1110 bref->type, data_off, bytes); 1111 } 1112 } else { 1113 /* 1114 kprintf("hammer2_freemap_adjust: good " 1115 "type=%02x block=%016jx/%zd\n", 1116 bref->type, data_off, bytes); 1117 */ 1118 } 1119 } 1120 #if 0 1121 /* 1122 * XXX this stuff doesn't work, avail is miscalculated and 1123 * code 10 means something else now. 1124 */ 1125 else if ((*bitmap & bmmask11) == bmmask11) { 1126 /* 1127 * Mayfree/Realfree request and bitmap is currently 1128 * marked as being fully allocated. 1129 */ 1130 if (!modified) { 1131 hammer2_chain_modify(chain, 0); 1132 modified = 1; 1133 goto again; 1134 } 1135 if (how == HAMMER2_FREEMAP_DOREALFREE) 1136 *bitmap &= ~bmmask11; 1137 else 1138 *bitmap = (*bitmap & ~bmmask11) | bmmask10; 1139 } else if ((*bitmap & bmmask11) == bmmask10) { 1140 /* 1141 * Mayfree/Realfree request and bitmap is currently 1142 * marked as being possibly freeable. 1143 */ 1144 if (how == HAMMER2_FREEMAP_DOREALFREE) { 1145 if (!modified) { 1146 hammer2_chain_modify(chain, 0); 1147 modified = 1; 1148 goto again; 1149 } 1150 *bitmap &= ~bmmask11; 1151 } 1152 } else { 1153 /* 1154 * 01 - Not implemented, currently illegal state 1155 * 00 - Not allocated at all, illegal free. 1156 */ 1157 panic("hammer2_freemap_adjust: " 1158 "Illegal state %08x(%08x)", 1159 *bitmap, *bitmap & bmmask11); 1160 } 1161 #endif 1162 --count; 1163 //bmmask01 <<= 2; 1164 //bmmask10 <<= 2; 1165 bmmask11 <<= 2; 1166 } 1167 #if 0 1168 #if HAMMER2_BMAP_ELEMENTS != 8 1169 #error "hammer2_freemap.c: HAMMER2_BMAP_ELEMENTS expected to be 8" 1170 #endif 1171 if (how == HAMMER2_FREEMAP_DOREALFREE && modified) { 1172 bmap->avail += 1 << radix; 1173 KKASSERT(bmap->avail <= HAMMER2_SEGSIZE); 1174 if (bmap->avail == HAMMER2_SEGSIZE && 1175 bmap->bitmapq[0] == 0 && 1176 bmap->bitmapq[1] == 0 && 1177 bmap->bitmapq[2] == 0 && 1178 bmap->bitmapq[3] == 0 && 1179 bmap->bitmapq[4] == 0 && 1180 bmap->bitmapq[5] == 0 && 1181 bmap->bitmapq[6] == 0 && 1182 bmap->bitmapq[7] == 0) { 1183 key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX); 1184 kprintf("Freeseg %016jx\n", (intmax_t)key); 1185 bmap->class = 0; 1186 } 1187 } 1188 #endif 1189 1190 /* 1191 * chain->bref.check.freemap.bigmask (XXX) 1192 * 1193 * Setting bigmask is a hint to the allocation code that there might 1194 * be something allocatable. We also set this in recovery... it 1195 * doesn't hurt and we might want to use the hint for other validation 1196 * operations later on. 1197 * 1198 * We could calculate the largest possible allocation and set the 1199 * radixes that could fit, but its easier just to set bigmask to -1. 1200 */ 1201 if (modified) { 1202 chain->bref.check.freemap.bigmask = -1; 1203 hmp->freemap_relaxed = 0; /* reset heuristic */ 1204 } 1205 1206 hammer2_chain_unlock(chain); 1207 hammer2_chain_drop(chain); 1208 done: 1209 hammer2_chain_unlock(parent); 1210 hammer2_chain_drop(parent); 1211 1212 if (bgsize) { 1213 hammer2_voldata_lock(hmp); 1214 hammer2_voldata_modify(hmp); 1215 hmp->voldata.allocator_free -= bgsize; 1216 hammer2_voldata_unlock(hmp); 1217 } 1218 } 1219 1220 /* 1221 * Validate the freemap, in three stages. 1222 * 1223 * stage-1 ALLOCATED -> POSSIBLY FREE 1224 * POSSIBLY FREE -> POSSIBLY FREE (type corrected) 1225 * 1226 * This transitions bitmap entries from ALLOCATED to POSSIBLY FREE. 1227 * The POSSIBLY FREE state does not mean that a block is actually free 1228 * and may be transitioned back to ALLOCATED in stage-2. 1229 * 1230 * This is typically done during normal filesystem operations when 1231 * something is deleted or a block is replaced. 1232 * 1233 * This is done by bulkfree in-bulk after a memory-bounded meta-data 1234 * scan to try to determine what might be freeable. 1235 * 1236 * This can be done unconditionally through a freemap scan when the 1237 * intention is to brute-force recover the proper state of the freemap. 1238 * 1239 * stage-2 POSSIBLY FREE -> ALLOCATED (scan metadata topology) 1240 * 1241 * This is done by bulkfree during a meta-data scan to ensure that 1242 * all blocks still actually allocated by the filesystem are marked 1243 * as such. 1244 * 1245 * NOTE! Live filesystem transitions to POSSIBLY FREE can occur while 1246 * the bulkfree stage-2 and stage-3 is running. The live filesystem 1247 * will use the alternative POSSIBLY FREE type (2) to prevent 1248 * stage-3 from improperly transitioning unvetted possibly-free 1249 * blocks to FREE. 1250 * 1251 * stage-3 POSSIBLY FREE (type 1) -> FREE (scan freemap) 1252 * 1253 * This is done by bulkfree to finalize POSSIBLY FREE states. 1254 * 1255 */ 1256