1 // SPDX-License-Identifier: GPL-2.0-only 2 /* -*- mode: c; c-basic-offset: 8; -*- 3 * vim: noexpandtab sw=8 ts=8 sts=0: 4 * 5 * reservations.c 6 * 7 * Allocation reservations implementation 8 * 9 * Some code borrowed from fs/ext3/balloc.c and is: 10 * 11 * Copyright (C) 1992, 1993, 1994, 1995 12 * Remy Card (card@masi.ibp.fr) 13 * Laboratoire MASI - Institut Blaise Pascal 14 * Universite Pierre et Marie Curie (Paris VI) 15 * 16 * The rest is copyright (C) 2010 Novell. All rights reserved. 17 */ 18 19 #include <linux/fs.h> 20 #include <linux/types.h> 21 #include <linux/highmem.h> 22 #include <linux/bitops.h> 23 #include <linux/list.h> 24 25 #include <cluster/masklog.h> 26 27 #include "ocfs2.h" 28 #include "ocfs2_trace.h" 29 30 #ifdef CONFIG_OCFS2_DEBUG_FS 31 #define OCFS2_CHECK_RESERVATIONS 32 #endif 33 34 static DEFINE_SPINLOCK(resv_lock); 35 36 int ocfs2_dir_resv_allowed(struct ocfs2_super *osb) 37 { 38 return (osb->osb_resv_level && osb->osb_dir_resv_level); 39 } 40 41 static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap, 42 struct ocfs2_alloc_reservation *resv) 43 { 44 struct ocfs2_super *osb = resmap->m_osb; 45 unsigned int bits; 46 47 if (!(resv->r_flags & OCFS2_RESV_FLAG_DIR)) { 48 /* 8, 16, 32, 64, 128, 256, 512, 1024 */ 49 bits = 4 << osb->osb_resv_level; 50 } else { 51 bits = 4 << osb->osb_dir_resv_level; 52 } 53 return bits; 54 } 55 56 static inline unsigned int ocfs2_resv_end(struct ocfs2_alloc_reservation *resv) 57 { 58 if (resv->r_len) 59 return resv->r_start + resv->r_len - 1; 60 return resv->r_start; 61 } 62 63 static inline int ocfs2_resv_empty(struct ocfs2_alloc_reservation *resv) 64 { 65 return !!(resv->r_len == 0); 66 } 67 68 static inline int ocfs2_resmap_disabled(struct ocfs2_reservation_map *resmap) 69 { 70 if (resmap->m_osb->osb_resv_level == 0) 71 return 1; 72 return 0; 73 } 74 75 static void ocfs2_dump_resv(struct ocfs2_reservation_map *resmap) 76 { 77 struct ocfs2_super *osb = resmap->m_osb; 78 struct rb_node *node; 79 struct ocfs2_alloc_reservation *resv; 80 int i = 0; 81 82 mlog(ML_NOTICE, "Dumping resmap for device %s. Bitmap length: %u\n", 83 osb->dev_str, resmap->m_bitmap_len); 84 85 node = rb_first(&resmap->m_reservations); 86 while (node) { 87 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node); 88 89 mlog(ML_NOTICE, "start: %u\tend: %u\tlen: %u\tlast_start: %u" 90 "\tlast_len: %u\n", resv->r_start, 91 ocfs2_resv_end(resv), resv->r_len, resv->r_last_start, 92 resv->r_last_len); 93 94 node = rb_next(node); 95 i++; 96 } 97 98 mlog(ML_NOTICE, "%d reservations found. LRU follows\n", i); 99 100 i = 0; 101 list_for_each_entry(resv, &resmap->m_lru, r_lru) { 102 mlog(ML_NOTICE, "LRU(%d) start: %u\tend: %u\tlen: %u\t" 103 "last_start: %u\tlast_len: %u\n", i, resv->r_start, 104 ocfs2_resv_end(resv), resv->r_len, resv->r_last_start, 105 resv->r_last_len); 106 107 i++; 108 } 109 } 110 111 #ifdef OCFS2_CHECK_RESERVATIONS 112 static int ocfs2_validate_resmap_bits(struct ocfs2_reservation_map *resmap, 113 int i, 114 struct ocfs2_alloc_reservation *resv) 115 { 116 char *disk_bitmap = resmap->m_disk_bitmap; 117 unsigned int start = resv->r_start; 118 unsigned int end = ocfs2_resv_end(resv); 119 120 while (start <= end) { 121 if (ocfs2_test_bit(start, disk_bitmap)) { 122 mlog(ML_ERROR, 123 "reservation %d covers an allocated area " 124 "starting at bit %u!\n", i, start); 125 return 1; 126 } 127 128 start++; 129 } 130 return 0; 131 } 132 133 static void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap) 134 { 135 unsigned int off = 0; 136 int i = 0; 137 struct rb_node *node; 138 struct ocfs2_alloc_reservation *resv; 139 140 node = rb_first(&resmap->m_reservations); 141 while (node) { 142 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node); 143 144 if (i > 0 && resv->r_start <= off) { 145 mlog(ML_ERROR, "reservation %d has bad start off!\n", 146 i); 147 goto bad; 148 } 149 150 if (resv->r_len == 0) { 151 mlog(ML_ERROR, "reservation %d has no length!\n", 152 i); 153 goto bad; 154 } 155 156 if (resv->r_start > ocfs2_resv_end(resv)) { 157 mlog(ML_ERROR, "reservation %d has invalid range!\n", 158 i); 159 goto bad; 160 } 161 162 if (ocfs2_resv_end(resv) >= resmap->m_bitmap_len) { 163 mlog(ML_ERROR, "reservation %d extends past bitmap!\n", 164 i); 165 goto bad; 166 } 167 168 if (ocfs2_validate_resmap_bits(resmap, i, resv)) 169 goto bad; 170 171 off = ocfs2_resv_end(resv); 172 node = rb_next(node); 173 174 i++; 175 } 176 return; 177 178 bad: 179 ocfs2_dump_resv(resmap); 180 BUG(); 181 } 182 #else 183 static inline void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap) 184 { 185 186 } 187 #endif 188 189 void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv) 190 { 191 memset(resv, 0, sizeof(*resv)); 192 INIT_LIST_HEAD(&resv->r_lru); 193 } 194 195 void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv, 196 unsigned int flags) 197 { 198 BUG_ON(flags & ~OCFS2_RESV_TYPES); 199 200 resv->r_flags |= flags; 201 } 202 203 int ocfs2_resmap_init(struct ocfs2_super *osb, 204 struct ocfs2_reservation_map *resmap) 205 { 206 memset(resmap, 0, sizeof(*resmap)); 207 208 resmap->m_osb = osb; 209 resmap->m_reservations = RB_ROOT; 210 /* m_bitmap_len is initialized to zero by the above memset. */ 211 INIT_LIST_HEAD(&resmap->m_lru); 212 213 return 0; 214 } 215 216 static void ocfs2_resv_mark_lru(struct ocfs2_reservation_map *resmap, 217 struct ocfs2_alloc_reservation *resv) 218 { 219 assert_spin_locked(&resv_lock); 220 221 if (!list_empty(&resv->r_lru)) 222 list_del_init(&resv->r_lru); 223 224 list_add_tail(&resv->r_lru, &resmap->m_lru); 225 } 226 227 static void __ocfs2_resv_trunc(struct ocfs2_alloc_reservation *resv) 228 { 229 resv->r_len = 0; 230 resv->r_start = 0; 231 } 232 233 static void ocfs2_resv_remove(struct ocfs2_reservation_map *resmap, 234 struct ocfs2_alloc_reservation *resv) 235 { 236 if (resv->r_flags & OCFS2_RESV_FLAG_INUSE) { 237 list_del_init(&resv->r_lru); 238 rb_erase(&resv->r_node, &resmap->m_reservations); 239 resv->r_flags &= ~OCFS2_RESV_FLAG_INUSE; 240 } 241 } 242 243 static void __ocfs2_resv_discard(struct ocfs2_reservation_map *resmap, 244 struct ocfs2_alloc_reservation *resv) 245 { 246 assert_spin_locked(&resv_lock); 247 248 __ocfs2_resv_trunc(resv); 249 /* 250 * last_len and last_start no longer make sense if 251 * we're changing the range of our allocations. 252 */ 253 resv->r_last_len = resv->r_last_start = 0; 254 255 ocfs2_resv_remove(resmap, resv); 256 } 257 258 /* does nothing if 'resv' is null */ 259 void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap, 260 struct ocfs2_alloc_reservation *resv) 261 { 262 if (resv) { 263 spin_lock(&resv_lock); 264 __ocfs2_resv_discard(resmap, resv); 265 spin_unlock(&resv_lock); 266 } 267 } 268 269 static void ocfs2_resmap_clear_all_resv(struct ocfs2_reservation_map *resmap) 270 { 271 struct rb_node *node; 272 struct ocfs2_alloc_reservation *resv; 273 274 assert_spin_locked(&resv_lock); 275 276 while ((node = rb_last(&resmap->m_reservations)) != NULL) { 277 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node); 278 279 __ocfs2_resv_discard(resmap, resv); 280 } 281 } 282 283 void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap, 284 unsigned int clen, char *disk_bitmap) 285 { 286 if (ocfs2_resmap_disabled(resmap)) 287 return; 288 289 spin_lock(&resv_lock); 290 291 ocfs2_resmap_clear_all_resv(resmap); 292 resmap->m_bitmap_len = clen; 293 resmap->m_disk_bitmap = disk_bitmap; 294 295 spin_unlock(&resv_lock); 296 } 297 298 void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap) 299 { 300 /* Does nothing for now. Keep this around for API symmetry */ 301 } 302 303 static void ocfs2_resv_insert(struct ocfs2_reservation_map *resmap, 304 struct ocfs2_alloc_reservation *new) 305 { 306 struct rb_root *root = &resmap->m_reservations; 307 struct rb_node *parent = NULL; 308 struct rb_node **p = &root->rb_node; 309 struct ocfs2_alloc_reservation *tmp; 310 311 assert_spin_locked(&resv_lock); 312 313 trace_ocfs2_resv_insert(new->r_start, new->r_len); 314 315 while (*p) { 316 parent = *p; 317 318 tmp = rb_entry(parent, struct ocfs2_alloc_reservation, r_node); 319 320 if (new->r_start < tmp->r_start) { 321 p = &(*p)->rb_left; 322 323 /* 324 * This is a good place to check for 325 * overlapping reservations. 326 */ 327 BUG_ON(ocfs2_resv_end(new) >= tmp->r_start); 328 } else if (new->r_start > ocfs2_resv_end(tmp)) { 329 p = &(*p)->rb_right; 330 } else { 331 /* This should never happen! */ 332 mlog(ML_ERROR, "Duplicate reservation window!\n"); 333 BUG(); 334 } 335 } 336 337 rb_link_node(&new->r_node, parent, p); 338 rb_insert_color(&new->r_node, root); 339 new->r_flags |= OCFS2_RESV_FLAG_INUSE; 340 341 ocfs2_resv_mark_lru(resmap, new); 342 343 ocfs2_check_resmap(resmap); 344 } 345 346 /** 347 * ocfs2_find_resv_lhs() - find the window which contains goal 348 * @resmap: reservation map to search 349 * @goal: which bit to search for 350 * 351 * If a window containing that goal is not found, we return the window 352 * which comes before goal. Returns NULL on empty rbtree or no window 353 * before goal. 354 */ 355 static struct ocfs2_alloc_reservation * 356 ocfs2_find_resv_lhs(struct ocfs2_reservation_map *resmap, unsigned int goal) 357 { 358 struct ocfs2_alloc_reservation *resv = NULL; 359 struct ocfs2_alloc_reservation *prev_resv = NULL; 360 struct rb_node *node = resmap->m_reservations.rb_node; 361 362 assert_spin_locked(&resv_lock); 363 364 if (!node) 365 return NULL; 366 367 node = rb_first(&resmap->m_reservations); 368 while (node) { 369 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node); 370 371 if (resv->r_start <= goal && ocfs2_resv_end(resv) >= goal) 372 break; 373 374 /* Check if we overshot the reservation just before goal? */ 375 if (resv->r_start > goal) { 376 resv = prev_resv; 377 break; 378 } 379 380 prev_resv = resv; 381 node = rb_next(node); 382 } 383 384 return resv; 385 } 386 387 /* 388 * We are given a range within the bitmap, which corresponds to a gap 389 * inside the reservations tree (search_start, search_len). The range 390 * can be anything from the whole bitmap, to a gap between 391 * reservations. 392 * 393 * The start value of *rstart is insignificant. 394 * 395 * This function searches the bitmap range starting at search_start 396 * with length search_len for a set of contiguous free bits. We try 397 * to find up to 'wanted' bits, but can sometimes return less. 398 * 399 * Returns the length of allocation, 0 if no free bits are found. 400 * 401 * *cstart and *clen will also be populated with the result. 402 */ 403 static int ocfs2_resmap_find_free_bits(struct ocfs2_reservation_map *resmap, 404 unsigned int wanted, 405 unsigned int search_start, 406 unsigned int search_len, 407 unsigned int *rstart, 408 unsigned int *rlen) 409 { 410 void *bitmap = resmap->m_disk_bitmap; 411 unsigned int best_start, best_len = 0; 412 int offset, start, found; 413 414 trace_ocfs2_resmap_find_free_bits_begin(search_start, search_len, 415 wanted, resmap->m_bitmap_len); 416 417 found = best_start = best_len = 0; 418 419 start = search_start; 420 while ((offset = ocfs2_find_next_zero_bit(bitmap, resmap->m_bitmap_len, 421 start)) != -1) { 422 /* Search reached end of the region */ 423 if (offset >= (search_start + search_len)) 424 break; 425 426 if (offset == start) { 427 /* we found a zero */ 428 found++; 429 /* move start to the next bit to test */ 430 start++; 431 } else { 432 /* got a zero after some ones */ 433 found = 1; 434 start = offset + 1; 435 } 436 if (found > best_len) { 437 best_len = found; 438 best_start = start - found; 439 } 440 441 if (found >= wanted) 442 break; 443 } 444 445 if (best_len == 0) 446 return 0; 447 448 if (best_len >= wanted) 449 best_len = wanted; 450 451 *rlen = best_len; 452 *rstart = best_start; 453 454 trace_ocfs2_resmap_find_free_bits_end(best_start, best_len); 455 456 return *rlen; 457 } 458 459 static void __ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap, 460 struct ocfs2_alloc_reservation *resv, 461 unsigned int goal, unsigned int wanted) 462 { 463 struct rb_root *root = &resmap->m_reservations; 464 unsigned int gap_start, gap_end, gap_len; 465 struct ocfs2_alloc_reservation *prev_resv, *next_resv; 466 struct rb_node *prev, *next; 467 unsigned int cstart, clen; 468 unsigned int best_start = 0, best_len = 0; 469 470 /* 471 * Nasty cases to consider: 472 * 473 * - rbtree is empty 474 * - our window should be first in all reservations 475 * - our window should be last in all reservations 476 * - need to make sure we don't go past end of bitmap 477 */ 478 trace_ocfs2_resv_find_window_begin(resv->r_start, ocfs2_resv_end(resv), 479 goal, wanted, RB_EMPTY_ROOT(root)); 480 481 assert_spin_locked(&resv_lock); 482 483 if (RB_EMPTY_ROOT(root)) { 484 /* 485 * Easiest case - empty tree. We can just take 486 * whatever window of free bits we want. 487 */ 488 clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal, 489 resmap->m_bitmap_len - goal, 490 &cstart, &clen); 491 492 /* 493 * This should never happen - the local alloc window 494 * will always have free bits when we're called. 495 */ 496 BUG_ON(goal == 0 && clen == 0); 497 498 if (clen == 0) 499 return; 500 501 resv->r_start = cstart; 502 resv->r_len = clen; 503 504 ocfs2_resv_insert(resmap, resv); 505 return; 506 } 507 508 prev_resv = ocfs2_find_resv_lhs(resmap, goal); 509 510 if (prev_resv == NULL) { 511 /* 512 * A NULL here means that the search code couldn't 513 * find a window that starts before goal. 514 * 515 * However, we can take the first window after goal, 516 * which is also by definition, the leftmost window in 517 * the entire tree. If we can find free bits in the 518 * gap between goal and the LHS window, then the 519 * reservation can safely be placed there. 520 * 521 * Otherwise we fall back to a linear search, checking 522 * the gaps in between windows for a place to 523 * allocate. 524 */ 525 526 next = rb_first(root); 527 next_resv = rb_entry(next, struct ocfs2_alloc_reservation, 528 r_node); 529 530 /* 531 * The search should never return such a window. (see 532 * comment above 533 */ 534 if (next_resv->r_start <= goal) { 535 mlog(ML_ERROR, "goal: %u next_resv: start %u len %u\n", 536 goal, next_resv->r_start, next_resv->r_len); 537 ocfs2_dump_resv(resmap); 538 BUG(); 539 } 540 541 clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal, 542 next_resv->r_start - goal, 543 &cstart, &clen); 544 if (clen) { 545 best_len = clen; 546 best_start = cstart; 547 if (best_len == wanted) 548 goto out_insert; 549 } 550 551 prev_resv = next_resv; 552 next_resv = NULL; 553 } 554 555 trace_ocfs2_resv_find_window_prev(prev_resv->r_start, 556 ocfs2_resv_end(prev_resv)); 557 558 prev = &prev_resv->r_node; 559 560 /* Now we do a linear search for a window, starting at 'prev_rsv' */ 561 while (1) { 562 next = rb_next(prev); 563 if (next) { 564 next_resv = rb_entry(next, 565 struct ocfs2_alloc_reservation, 566 r_node); 567 568 gap_start = ocfs2_resv_end(prev_resv) + 1; 569 gap_end = next_resv->r_start - 1; 570 gap_len = gap_end - gap_start + 1; 571 } else { 572 /* 573 * We're at the rightmost edge of the 574 * tree. See if a reservation between this 575 * window and the end of the bitmap will work. 576 */ 577 gap_start = ocfs2_resv_end(prev_resv) + 1; 578 gap_len = resmap->m_bitmap_len - gap_start; 579 gap_end = resmap->m_bitmap_len - 1; 580 } 581 582 trace_ocfs2_resv_find_window_next(next ? next_resv->r_start: -1, 583 next ? ocfs2_resv_end(next_resv) : -1); 584 /* 585 * No need to check this gap if we have already found 586 * a larger region of free bits. 587 */ 588 if (gap_len <= best_len) 589 goto next_resv; 590 591 clen = ocfs2_resmap_find_free_bits(resmap, wanted, gap_start, 592 gap_len, &cstart, &clen); 593 if (clen == wanted) { 594 best_len = clen; 595 best_start = cstart; 596 goto out_insert; 597 } else if (clen > best_len) { 598 best_len = clen; 599 best_start = cstart; 600 } 601 602 next_resv: 603 if (!next) 604 break; 605 606 prev = next; 607 prev_resv = rb_entry(prev, struct ocfs2_alloc_reservation, 608 r_node); 609 } 610 611 out_insert: 612 if (best_len) { 613 resv->r_start = best_start; 614 resv->r_len = best_len; 615 ocfs2_resv_insert(resmap, resv); 616 } 617 } 618 619 static void ocfs2_cannibalize_resv(struct ocfs2_reservation_map *resmap, 620 struct ocfs2_alloc_reservation *resv, 621 unsigned int wanted) 622 { 623 struct ocfs2_alloc_reservation *lru_resv; 624 int tmpwindow = !!(resv->r_flags & OCFS2_RESV_FLAG_TMP); 625 unsigned int min_bits; 626 627 if (!tmpwindow) 628 min_bits = ocfs2_resv_window_bits(resmap, resv) >> 1; 629 else 630 min_bits = wanted; /* We at know the temp window will use all 631 * of these bits */ 632 633 /* 634 * Take the first reservation off the LRU as our 'target'. We 635 * don't try to be smart about it. There might be a case for 636 * searching based on size but I don't have enough data to be 637 * sure. --Mark (3/16/2010) 638 */ 639 lru_resv = list_first_entry(&resmap->m_lru, 640 struct ocfs2_alloc_reservation, r_lru); 641 642 trace_ocfs2_cannibalize_resv_begin(lru_resv->r_start, 643 lru_resv->r_len, 644 ocfs2_resv_end(lru_resv)); 645 646 /* 647 * Cannibalize (some or all) of the target reservation and 648 * feed it to the current window. 649 */ 650 if (lru_resv->r_len <= min_bits) { 651 /* 652 * Discard completely if size is less than or equal to a 653 * reasonable threshold - 50% of window bits for non temporary 654 * windows. 655 */ 656 resv->r_start = lru_resv->r_start; 657 resv->r_len = lru_resv->r_len; 658 659 __ocfs2_resv_discard(resmap, lru_resv); 660 } else { 661 unsigned int shrink; 662 if (tmpwindow) 663 shrink = min_bits; 664 else 665 shrink = lru_resv->r_len / 2; 666 667 lru_resv->r_len -= shrink; 668 669 resv->r_start = ocfs2_resv_end(lru_resv) + 1; 670 resv->r_len = shrink; 671 } 672 673 trace_ocfs2_cannibalize_resv_end(resv->r_start, ocfs2_resv_end(resv), 674 resv->r_len, resv->r_last_start, 675 resv->r_last_len); 676 677 ocfs2_resv_insert(resmap, resv); 678 } 679 680 static void ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap, 681 struct ocfs2_alloc_reservation *resv, 682 unsigned int wanted) 683 { 684 unsigned int goal = 0; 685 686 BUG_ON(!ocfs2_resv_empty(resv)); 687 688 /* 689 * Begin by trying to get a window as close to the previous 690 * one as possible. Using the most recent allocation as a 691 * start goal makes sense. 692 */ 693 if (resv->r_last_len) { 694 goal = resv->r_last_start + resv->r_last_len; 695 if (goal >= resmap->m_bitmap_len) 696 goal = 0; 697 } 698 699 __ocfs2_resv_find_window(resmap, resv, goal, wanted); 700 701 /* Search from last alloc didn't work, try once more from beginning. */ 702 if (ocfs2_resv_empty(resv) && goal != 0) 703 __ocfs2_resv_find_window(resmap, resv, 0, wanted); 704 705 if (ocfs2_resv_empty(resv)) { 706 /* 707 * Still empty? Pull oldest one off the LRU, remove it from 708 * tree, put this one in it's place. 709 */ 710 ocfs2_cannibalize_resv(resmap, resv, wanted); 711 } 712 713 BUG_ON(ocfs2_resv_empty(resv)); 714 } 715 716 int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap, 717 struct ocfs2_alloc_reservation *resv, 718 int *cstart, int *clen) 719 { 720 if (resv == NULL || ocfs2_resmap_disabled(resmap)) 721 return -ENOSPC; 722 723 spin_lock(&resv_lock); 724 725 if (ocfs2_resv_empty(resv)) { 726 /* 727 * We don't want to over-allocate for temporary 728 * windows. Otherwise, we run the risk of fragmenting the 729 * allocation space. 730 */ 731 unsigned int wanted = ocfs2_resv_window_bits(resmap, resv); 732 733 if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen) 734 wanted = *clen; 735 736 /* 737 * Try to get a window here. If it works, we must fall 738 * through and test the bitmap . This avoids some 739 * ping-ponging of windows due to non-reserved space 740 * being allocation before we initialize a window for 741 * that inode. 742 */ 743 ocfs2_resv_find_window(resmap, resv, wanted); 744 trace_ocfs2_resmap_resv_bits(resv->r_start, resv->r_len); 745 } 746 747 BUG_ON(ocfs2_resv_empty(resv)); 748 749 *cstart = resv->r_start; 750 *clen = resv->r_len; 751 752 spin_unlock(&resv_lock); 753 return 0; 754 } 755 756 static void 757 ocfs2_adjust_resv_from_alloc(struct ocfs2_reservation_map *resmap, 758 struct ocfs2_alloc_reservation *resv, 759 unsigned int start, unsigned int end) 760 { 761 unsigned int rhs = 0; 762 unsigned int old_end = ocfs2_resv_end(resv); 763 764 BUG_ON(start != resv->r_start || old_end < end); 765 766 /* 767 * Completely used? We can remove it then. 768 */ 769 if (old_end == end) { 770 __ocfs2_resv_discard(resmap, resv); 771 return; 772 } 773 774 rhs = old_end - end; 775 776 /* 777 * This should have been trapped above. 778 */ 779 BUG_ON(rhs == 0); 780 781 resv->r_start = end + 1; 782 resv->r_len = old_end - resv->r_start + 1; 783 } 784 785 void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap, 786 struct ocfs2_alloc_reservation *resv, 787 u32 cstart, u32 clen) 788 { 789 unsigned int cend = cstart + clen - 1; 790 791 if (resmap == NULL || ocfs2_resmap_disabled(resmap)) 792 return; 793 794 if (resv == NULL) 795 return; 796 797 BUG_ON(cstart != resv->r_start); 798 799 spin_lock(&resv_lock); 800 801 trace_ocfs2_resmap_claimed_bits_begin(cstart, cend, clen, resv->r_start, 802 ocfs2_resv_end(resv), resv->r_len, 803 resv->r_last_start, 804 resv->r_last_len); 805 806 BUG_ON(cstart < resv->r_start); 807 BUG_ON(cstart > ocfs2_resv_end(resv)); 808 BUG_ON(cend > ocfs2_resv_end(resv)); 809 810 ocfs2_adjust_resv_from_alloc(resmap, resv, cstart, cend); 811 resv->r_last_start = cstart; 812 resv->r_last_len = clen; 813 814 /* 815 * May have been discarded above from 816 * ocfs2_adjust_resv_from_alloc(). 817 */ 818 if (!ocfs2_resv_empty(resv)) 819 ocfs2_resv_mark_lru(resmap, resv); 820 821 trace_ocfs2_resmap_claimed_bits_end(resv->r_start, ocfs2_resv_end(resv), 822 resv->r_len, resv->r_last_start, 823 resv->r_last_len); 824 825 ocfs2_check_resmap(resmap); 826 827 spin_unlock(&resv_lock); 828 } 829