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 * This subsystem implements most of the core support functions for 39 * the hammer2_chain structure. 40 * 41 * Chains are the in-memory version on media objects (volume header, inodes, 42 * indirect blocks, data blocks, etc). Chains represent a portion of the 43 * HAMMER2 topology. 44 * 45 * Chains are no-longer delete-duplicated. Instead, the original in-memory 46 * chain will be moved along with its block reference (e.g. for things like 47 * renames, hardlink operations, modifications, etc), and will be indexed 48 * on a secondary list for flush handling instead of propagating a flag 49 * upward to the root. 50 * 51 * Concurrent front-end operations can still run against backend flushes 52 * as long as they do not cross the current flush boundary. An operation 53 * running above the current flush (in areas not yet flushed) can become 54 * part of the current flush while ano peration running below the current 55 * flush can become part of the next flush. 56 */ 57 /* 58 #include <sys/cdefs.h> 59 #include <sys/param.h> 60 #include <sys/systm.h> 61 #include <sys/types.h> 62 #include <sys/lock.h> 63 #include <sys/buf.h> 64 65 #include <crypto/sha2/sha2.h> 66 */ 67 68 #include "hammer2.h" 69 70 static hammer2_chain_t *hammer2_chain_create_indirect( 71 hammer2_chain_t *parent, 72 hammer2_key_t key, int keybits, 73 hammer2_tid_t mtid, int for_type, int *errorp); 74 static int hammer2_chain_delete_obref(hammer2_chain_t *parent, 75 hammer2_chain_t *chain, 76 hammer2_tid_t mtid, int flags, 77 hammer2_blockref_t *obref); 78 static hammer2_chain_t *hammer2_combined_find( 79 hammer2_chain_t *parent, 80 hammer2_blockref_t *base, int count, 81 hammer2_key_t *key_nextp, 82 hammer2_key_t key_beg, hammer2_key_t key_end, 83 hammer2_blockref_t **brefp); 84 static hammer2_chain_t *hammer2_chain_lastdrop(hammer2_chain_t *chain, 85 int depth); 86 static void hammer2_chain_lru_flush(hammer2_pfs_t *pmp); 87 88 /* 89 * There are many degenerate situations where an extreme rate of console 90 * output can occur from warnings and errors. Make sure this output does 91 * not impede operations. 92 */ 93 /* 94 static struct krate krate_h2chk = { .freq = 5 }; 95 static struct krate krate_h2me = { .freq = 1 }; 96 static struct krate krate_h2em = { .freq = 1 }; 97 */ 98 99 /* 100 * Basic RBTree for chains (core.rbtree). 101 */ 102 RB_GENERATE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp); 103 104 int 105 hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2) 106 { 107 hammer2_key_t c1_beg; 108 hammer2_key_t c1_end; 109 hammer2_key_t c2_beg; 110 hammer2_key_t c2_end; 111 112 /* 113 * Compare chains. Overlaps are not supposed to happen and catch 114 * any software issues early we count overlaps as a match. 115 */ 116 c1_beg = chain1->bref.key; 117 c1_end = c1_beg + ((hammer2_key_t)1 << chain1->bref.keybits) - 1; 118 c2_beg = chain2->bref.key; 119 c2_end = c2_beg + ((hammer2_key_t)1 << chain2->bref.keybits) - 1; 120 121 if (c1_end < c2_beg) /* fully to the left */ 122 return(-1); 123 if (c1_beg > c2_end) /* fully to the right */ 124 return(1); 125 return(0); /* overlap (must not cross edge boundary) */ 126 } 127 128 /* 129 * Assert that a chain has no media data associated with it. 130 */ 131 static __inline void 132 hammer2_chain_assert_no_data(hammer2_chain_t *chain) 133 { 134 KKASSERT(chain->dio == NULL); 135 if (chain->bref.type != HAMMER2_BREF_TYPE_VOLUME && 136 chain->bref.type != HAMMER2_BREF_TYPE_FREEMAP && 137 chain->data) { 138 panic("hammer2_chain_assert_no_data: chain %p still has data", 139 chain); 140 } 141 } 142 143 /* 144 * Make a chain visible to the flusher. The flusher operates using a top-down 145 * recursion based on the ONFLUSH flag. It locates MODIFIED and UPDATE chains, 146 * flushes them, and updates blocks back to the volume root. 147 * 148 * This routine sets the ONFLUSH flag upward from the triggering chain until 149 * it hits an inode root or the volume root. Inode chains serve as inflection 150 * points, requiring the flusher to bridge across trees. Inodes include 151 * regular inodes, PFS roots (pmp->iroot), and the media super root 152 * (spmp->iroot). 153 */ 154 void 155 hammer2_chain_setflush(hammer2_chain_t *chain) 156 { 157 hammer2_chain_t *parent; 158 159 if ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { 160 hammer2_spin_sh(&chain->core.spin); 161 while ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { 162 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); 163 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) 164 break; 165 if ((parent = chain->parent) == NULL) 166 break; 167 hammer2_spin_sh(&parent->core.spin); 168 hammer2_spin_unsh(&chain->core.spin); 169 chain = parent; 170 } 171 hammer2_spin_unsh(&chain->core.spin); 172 } 173 } 174 175 /* 176 * Allocate a new disconnected chain element representing the specified 177 * bref. chain->refs is set to 1 and the passed bref is copied to 178 * chain->bref. chain->bytes is derived from the bref. 179 * 180 * chain->pmp inherits pmp unless the chain is an inode (other than the 181 * super-root inode). 182 * 183 * NOTE: Returns a referenced but unlocked (because there is no core) chain. 184 */ 185 hammer2_chain_t * 186 hammer2_chain_alloc(hammer2_dev_t *hmp, hammer2_pfs_t *pmp, 187 hammer2_blockref_t *bref) 188 { 189 hammer2_chain_t *chain; 190 u_int bytes; 191 192 /* 193 * Special case - radix of 0 indicates a chain that does not 194 * need a data reference (context is completely embedded in the 195 * bref). 196 */ 197 if ((int)(bref->data_off & HAMMER2_OFF_MASK_RADIX)) 198 bytes = 1U << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX); 199 else 200 bytes = 0; 201 202 switch(bref->type) { 203 case HAMMER2_BREF_TYPE_INODE: 204 case HAMMER2_BREF_TYPE_INDIRECT: 205 case HAMMER2_BREF_TYPE_DATA: 206 case HAMMER2_BREF_TYPE_DIRENT: 207 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 208 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 209 case HAMMER2_BREF_TYPE_FREEMAP: 210 case HAMMER2_BREF_TYPE_VOLUME: 211 chain = kmalloc_obj(sizeof(*chain), hmp->mchain, 212 M_WAITOK | M_ZERO); 213 atomic_add_long(&hammer2_chain_allocs, 1); 214 break; 215 case HAMMER2_BREF_TYPE_EMPTY: 216 default: 217 panic("hammer2_chain_alloc: unrecognized blockref type: %d", 218 bref->type); 219 break; 220 } 221 222 /* 223 * Initialize the new chain structure. pmp must be set to NULL for 224 * chains belonging to the super-root topology of a device mount. 225 */ 226 if (pmp == hmp->spmp) 227 chain->pmp = NULL; 228 else 229 chain->pmp = pmp; 230 231 chain->hmp = hmp; 232 chain->bref = *bref; 233 chain->bytes = bytes; 234 chain->refs = 1; 235 chain->flags = HAMMER2_CHAIN_ALLOCATED; 236 lockinit(&chain->diolk, "chdio", 0, 0); 237 238 /* 239 * Set the PFS boundary flag if this chain represents a PFS root. 240 */ 241 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) 242 atomic_set_int(&chain->flags, HAMMER2_CHAIN_PFSBOUNDARY); 243 hammer2_chain_core_init(chain); 244 245 return (chain); 246 } 247 248 /* 249 * Initialize a chain's core structure. This structure used to be allocated 250 * but is now embedded. 251 * 252 * The core is not locked. No additional refs on the chain are made. 253 */ 254 void 255 hammer2_chain_core_init(hammer2_chain_t *chain) 256 { 257 RB_INIT(&chain->core.rbtree); /* live chains */ 258 hammer2_mtx_init(&chain->lock, "h2chain"); 259 hammer2_spin_init(&chain->core.spin, "h2chain"); 260 } 261 262 /* 263 * Add a reference to a chain element, preventing its destruction. 264 * 265 * (can be called with spinlock held) 266 */ 267 void 268 hammer2_chain_ref(hammer2_chain_t *chain) 269 { 270 if (atomic_fetchadd_int(&chain->refs, 1) == 0) { 271 /* 272 * Just flag that the chain was used and should be recycled 273 * on the LRU if it encounters it later. 274 */ 275 if (chain->flags & HAMMER2_CHAIN_ONLRU) 276 atomic_set_int(&chain->flags, HAMMER2_CHAIN_LRUHINT); 277 278 #if 0 279 /* 280 * REMOVED - reduces contention, lru_list is more heuristical 281 * now. 282 * 283 * 0->non-zero transition must ensure that chain is removed 284 * from the LRU list. 285 * 286 * NOTE: Already holding lru_spin here so we cannot call 287 * hammer2_chain_ref() to get it off lru_list, do 288 * it manually. 289 */ 290 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 291 hammer2_pfs_t *pmp = chain->pmp; 292 hammer2_spin_ex(&pmp->lru_spin); 293 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 294 atomic_add_int(&pmp->lru_count, -1); 295 atomic_clear_int(&chain->flags, 296 HAMMER2_CHAIN_ONLRU); 297 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 298 } 299 hammer2_spin_unex(&pmp->lru_spin); 300 } 301 #endif 302 } 303 } 304 305 /* 306 * Ref a locked chain and force the data to be held across an unlock. 307 * Chain must be currently locked. The user of the chain who desires 308 * to release the hold must call hammer2_chain_lock_unhold() to relock 309 * and unhold the chain, then unlock normally, or may simply call 310 * hammer2_chain_drop_unhold() (which is safer against deadlocks). 311 */ 312 void 313 hammer2_chain_ref_hold(hammer2_chain_t *chain) 314 { 315 atomic_add_int(&chain->lockcnt, 1); 316 hammer2_chain_ref(chain); 317 } 318 319 /* 320 * Insert the chain in the core rbtree. 321 * 322 * Normal insertions are placed in the live rbtree. Insertion of a deleted 323 * chain is a special case used by the flush code that is placed on the 324 * unstaged deleted list to avoid confusing the live view. 325 */ 326 #define HAMMER2_CHAIN_INSERT_SPIN 0x0001 327 #define HAMMER2_CHAIN_INSERT_LIVE 0x0002 328 #define HAMMER2_CHAIN_INSERT_RACE 0x0004 329 330 static 331 int 332 hammer2_chain_insert(hammer2_chain_t *parent, hammer2_chain_t *chain, 333 int flags, int generation) 334 { 335 hammer2_chain_t *xchain; 336 int error = 0; 337 338 if (flags & HAMMER2_CHAIN_INSERT_SPIN) 339 hammer2_spin_ex(&parent->core.spin); 340 341 /* 342 * Interlocked by spinlock, check for race 343 */ 344 if ((flags & HAMMER2_CHAIN_INSERT_RACE) && 345 parent->core.generation != generation) { 346 error = HAMMER2_ERROR_EAGAIN; 347 goto failed; 348 } 349 350 /* 351 * Insert chain 352 */ 353 xchain = RB_INSERT(hammer2_chain_tree, &parent->core.rbtree, chain); 354 KASSERT(xchain == NULL, 355 ("hammer2_chain_insert: collision %p %p (key=%016jx)", 356 chain, xchain, chain->bref.key)); 357 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 358 chain->parent = parent; 359 ++parent->core.chain_count; 360 ++parent->core.generation; /* XXX incs for _get() too, XXX */ 361 362 /* 363 * We have to keep track of the effective live-view blockref count 364 * so the create code knows when to push an indirect block. 365 */ 366 if (flags & HAMMER2_CHAIN_INSERT_LIVE) 367 atomic_add_int(&parent->core.live_count, 1); 368 failed: 369 if (flags & HAMMER2_CHAIN_INSERT_SPIN) 370 hammer2_spin_unex(&parent->core.spin); 371 return error; 372 } 373 374 /* 375 * Drop the caller's reference to the chain. When the ref count drops to 376 * zero this function will try to disassociate the chain from its parent and 377 * deallocate it, then recursely drop the parent using the implied ref 378 * from the chain's chain->parent. 379 * 380 * Nobody should own chain's mutex on the 1->0 transition, unless this drop 381 * races an acquisition by another cpu. Therefore we can loop if we are 382 * unable to acquire the mutex, and refs is unlikely to be 1 unless we again 383 * race against another drop. 384 */ 385 void 386 hammer2_chain_drop(hammer2_chain_t *chain) 387 { 388 u_int refs; 389 390 KKASSERT(chain->refs > 0); 391 392 while (chain) { 393 refs = chain->refs; 394 cpu_ccfence(); 395 KKASSERT(refs > 0); 396 397 if (refs == 1) { 398 if (hammer2_mtx_ex_try(&chain->lock) == 0) 399 chain = hammer2_chain_lastdrop(chain, 0); 400 /* retry the same chain, or chain from lastdrop */ 401 } else { 402 if (atomic_cmpset_int(&chain->refs, refs, refs - 1)) 403 break; 404 /* retry the same chain */ 405 } 406 cpu_pause(); 407 } 408 } 409 410 /* 411 * Unhold a held and probably not-locked chain, ensure that the data is 412 * dropped on the 1->0 transition of lockcnt by obtaining an exclusive 413 * lock and then simply unlocking the chain. 414 */ 415 void 416 hammer2_chain_unhold(hammer2_chain_t *chain) 417 { 418 u_int lockcnt; 419 int iter = 0; 420 421 for (;;) { 422 lockcnt = chain->lockcnt; 423 cpu_ccfence(); 424 if (lockcnt > 1) { 425 if (atomic_cmpset_int(&chain->lockcnt, 426 lockcnt, lockcnt - 1)) { 427 break; 428 } 429 } else if (hammer2_mtx_ex_try(&chain->lock) == 0) { 430 hammer2_chain_unlock(chain); 431 break; 432 } else { 433 /* 434 * This situation can easily occur on SMP due to 435 * the gap inbetween the 1->0 transition and the 436 * final unlock. We cannot safely block on the 437 * mutex because lockcnt might go above 1. 438 * 439 * XXX Sleep for one tick if it takes too long. 440 */ 441 if (++iter > 1000) { 442 if (iter > 1000 + hz) { 443 kprintf("hammer2: h2race1 %p\n", chain); 444 iter = 1000; 445 } 446 tsleep(&iter, 0, "h2race1", 1); 447 } 448 cpu_pause(); 449 } 450 } 451 } 452 453 void 454 hammer2_chain_drop_unhold(hammer2_chain_t *chain) 455 { 456 hammer2_chain_unhold(chain); 457 hammer2_chain_drop(chain); 458 } 459 460 void 461 hammer2_chain_rehold(hammer2_chain_t *chain) 462 { 463 hammer2_chain_lock(chain, HAMMER2_RESOLVE_SHARED); 464 atomic_add_int(&chain->lockcnt, 1); 465 hammer2_chain_unlock(chain); 466 } 467 468 /* 469 * Handles the (potential) last drop of chain->refs from 1->0. Called with 470 * the mutex exclusively locked, refs == 1, and lockcnt 0. SMP races are 471 * possible against refs and lockcnt. We must dispose of the mutex on chain. 472 * 473 * This function returns an unlocked chain for recursive drop or NULL. It 474 * can return the same chain if it determines it has raced another ref. 475 * 476 * -- 477 * 478 * When two chains need to be recursively dropped we use the chain we 479 * would otherwise free to placehold the additional chain. It's a bit 480 * convoluted but we can't just recurse without potentially blowing out 481 * the kernel stack. 482 * 483 * The chain cannot be freed if it has any children. 484 * The chain cannot be freed if flagged MODIFIED unless we can dispose of it. 485 * The chain cannot be freed if flagged UPDATE unless we can dispose of it. 486 * Any dedup registration can remain intact. 487 * 488 * The core spinlock is allowed to nest child-to-parent (not parent-to-child). 489 */ 490 static 491 hammer2_chain_t * 492 hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth) 493 { 494 hammer2_pfs_t *pmp; 495 hammer2_dev_t *hmp; 496 hammer2_chain_t *parent; 497 hammer2_chain_t *rdrop; 498 499 /* 500 * We need chain's spinlock to interlock the sub-tree test. 501 * We already have chain's mutex, protecting chain->parent. 502 * 503 * Remember that chain->refs can be in flux. 504 */ 505 hammer2_spin_ex(&chain->core.spin); 506 507 if (chain->parent != NULL) { 508 /* 509 * If the chain has a parent the UPDATE bit prevents scrapping 510 * as the chain is needed to properly flush the parent. Try 511 * to complete the 1->0 transition and return NULL. Retry 512 * (return chain) if we are unable to complete the 1->0 513 * transition, else return NULL (nothing more to do). 514 * 515 * If the chain has a parent the MODIFIED bit prevents 516 * scrapping. 517 * 518 * Chains with UPDATE/MODIFIED are *not* put on the LRU list! 519 */ 520 if (chain->flags & (HAMMER2_CHAIN_UPDATE | 521 HAMMER2_CHAIN_MODIFIED)) { 522 if (atomic_cmpset_int(&chain->refs, 1, 0)) { 523 hammer2_spin_unex(&chain->core.spin); 524 hammer2_chain_assert_no_data(chain); 525 hammer2_mtx_unlock(&chain->lock); 526 chain = NULL; 527 } else { 528 hammer2_spin_unex(&chain->core.spin); 529 hammer2_mtx_unlock(&chain->lock); 530 } 531 return (chain); 532 } 533 /* spinlock still held */ 534 } else if (chain->bref.type == HAMMER2_BREF_TYPE_VOLUME || 535 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP) { 536 /* 537 * Retain the static vchain and fchain. Clear bits that 538 * are not relevant. Do not clear the MODIFIED bit, 539 * and certainly do not put it on the delayed-flush queue. 540 */ 541 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 542 } else { 543 /* 544 * The chain has no parent and can be flagged for destruction. 545 * Since it has no parent, UPDATE can also be cleared. 546 */ 547 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 548 if (chain->flags & HAMMER2_CHAIN_UPDATE) 549 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 550 551 /* 552 * If the chain has children we must propagate the DESTROY 553 * flag downward and rip the disconnected topology apart. 554 * This is accomplished by calling hammer2_flush() on the 555 * chain. 556 * 557 * Any dedup is already handled by the underlying DIO, so 558 * we do not have to specifically flush it here. 559 */ 560 if (chain->core.chain_count) { 561 hammer2_spin_unex(&chain->core.spin); 562 hammer2_flush(chain, HAMMER2_FLUSH_TOP | 563 HAMMER2_FLUSH_ALL); 564 hammer2_mtx_unlock(&chain->lock); 565 566 return(chain); /* retry drop */ 567 } 568 569 /* 570 * Otherwise we can scrap the MODIFIED bit if it is set, 571 * and continue along the freeing path. 572 * 573 * Be sure to clean-out any dedup bits. Without a parent 574 * this chain will no longer be visible to the flush code. 575 * Easy check data_off to avoid the volume root. 576 */ 577 if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 578 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 579 atomic_add_long(&hammer2_count_modified_chains, -1); 580 if (chain->pmp) 581 hammer2_pfs_memory_wakeup(chain->pmp, -1); 582 } 583 /* spinlock still held */ 584 } 585 586 /* spinlock still held */ 587 588 /* 589 * If any children exist we must leave the chain intact with refs == 0. 590 * They exist because chains are retained below us which have refs or 591 * may require flushing. 592 * 593 * Retry (return chain) if we fail to transition the refs to 0, else 594 * return NULL indication nothing more to do. 595 * 596 * Chains with children are NOT put on the LRU list. 597 */ 598 if (chain->core.chain_count) { 599 if (atomic_cmpset_int(&chain->refs, 1, 0)) { 600 hammer2_spin_unex(&chain->core.spin); 601 hammer2_chain_assert_no_data(chain); 602 hammer2_mtx_unlock(&chain->lock); 603 chain = NULL; 604 } else { 605 hammer2_spin_unex(&chain->core.spin); 606 hammer2_mtx_unlock(&chain->lock); 607 } 608 return (chain); 609 } 610 /* spinlock still held */ 611 /* no chains left under us */ 612 613 /* 614 * chain->core has no children left so no accessors can get to our 615 * chain from there. Now we have to lock the parent core to interlock 616 * remaining possible accessors that might bump chain's refs before 617 * we can safely drop chain's refs with intent to free the chain. 618 */ 619 hmp = chain->hmp; 620 pmp = chain->pmp; /* can be NULL */ 621 rdrop = NULL; 622 623 parent = chain->parent; 624 625 /* 626 * WARNING! chain's spin lock is still held here, and other spinlocks 627 * will be acquired and released in the code below. We 628 * cannot be making fancy procedure calls! 629 */ 630 631 /* 632 * We can cache the chain if it is associated with a pmp 633 * and not flagged as being destroyed or requesting a full 634 * release. In this situation the chain is not removed 635 * from its parent, i.e. it can still be looked up. 636 * 637 * We intentionally do not cache DATA chains because these 638 * were likely used to load data into the logical buffer cache 639 * and will not be accessed again for some time. 640 */ 641 if ((chain->flags & 642 (HAMMER2_CHAIN_DESTROY | HAMMER2_CHAIN_RELEASE)) == 0 && 643 chain->pmp && 644 chain->bref.type != HAMMER2_BREF_TYPE_DATA) { 645 if (parent) 646 hammer2_spin_ex(&parent->core.spin); 647 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 648 /* 649 * 1->0 transition failed, retry. Do not drop 650 * the chain's data yet! 651 */ 652 if (parent) 653 hammer2_spin_unex(&parent->core.spin); 654 hammer2_spin_unex(&chain->core.spin); 655 hammer2_mtx_unlock(&chain->lock); 656 657 return(chain); 658 } 659 660 /* 661 * Success 662 */ 663 hammer2_chain_assert_no_data(chain); 664 665 /* 666 * Make sure we are on the LRU list, clean up excessive 667 * LRU entries. We can only really drop one but there might 668 * be other entries that we can remove from the lru_list 669 * without dropping. 670 * 671 * NOTE: HAMMER2_CHAIN_ONLRU may only be safely set when 672 * chain->core.spin AND pmp->lru_spin are held, but 673 * can be safely cleared only holding pmp->lru_spin. 674 */ 675 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) { 676 hammer2_spin_ex(&pmp->lru_spin); 677 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) { 678 atomic_set_int(&chain->flags, 679 HAMMER2_CHAIN_ONLRU); 680 TAILQ_INSERT_TAIL(&pmp->lru_list, 681 chain, lru_node); 682 atomic_add_int(&pmp->lru_count, 1); 683 } 684 if (pmp->lru_count < HAMMER2_LRU_LIMIT) 685 depth = 1; /* disable lru_list flush */ 686 hammer2_spin_unex(&pmp->lru_spin); 687 } else { 688 /* disable lru flush */ 689 depth = 1; 690 } 691 692 if (parent) { 693 hammer2_spin_unex(&parent->core.spin); 694 parent = NULL; /* safety */ 695 } 696 hammer2_spin_unex(&chain->core.spin); 697 hammer2_mtx_unlock(&chain->lock); 698 699 /* 700 * lru_list hysteresis (see above for depth overrides). 701 * Note that depth also prevents excessive lastdrop recursion. 702 */ 703 if (depth == 0) 704 hammer2_chain_lru_flush(pmp); 705 706 return NULL; 707 /* NOT REACHED */ 708 } 709 710 /* 711 * Make sure we are not on the LRU list. 712 */ 713 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 714 hammer2_spin_ex(&pmp->lru_spin); 715 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 716 atomic_add_int(&pmp->lru_count, -1); 717 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 718 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 719 } 720 hammer2_spin_unex(&pmp->lru_spin); 721 } 722 723 /* 724 * Spinlock the parent and try to drop the last ref on chain. 725 * On success determine if we should dispose of the chain 726 * (remove the chain from its parent, etc). 727 * 728 * (normal core locks are top-down recursive but we define 729 * core spinlocks as bottom-up recursive, so this is safe). 730 */ 731 if (parent) { 732 hammer2_spin_ex(&parent->core.spin); 733 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 734 /* 735 * 1->0 transition failed, retry. 736 */ 737 hammer2_spin_unex(&parent->core.spin); 738 hammer2_spin_unex(&chain->core.spin); 739 hammer2_mtx_unlock(&chain->lock); 740 741 return(chain); 742 } 743 744 /* 745 * 1->0 transition successful, parent spin held to prevent 746 * new lookups, chain spinlock held to protect parent field. 747 * Remove chain from the parent. 748 * 749 * If the chain is being removed from the parent's btree but 750 * is not blkmapped, we have to adjust live_count downward. If 751 * it is blkmapped then the blockref is retained in the parent 752 * as is its associated live_count. This case can occur when 753 * a chain added to the topology is unable to flush and is 754 * then later deleted. 755 */ 756 if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { 757 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) && 758 (chain->flags & HAMMER2_CHAIN_BLKMAPPED) == 0) { 759 atomic_add_int(&parent->core.live_count, -1); 760 } 761 RB_REMOVE(hammer2_chain_tree, 762 &parent->core.rbtree, chain); 763 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 764 --parent->core.chain_count; 765 chain->parent = NULL; 766 } 767 768 /* 769 * If our chain was the last chain in the parent's core the 770 * core is now empty and its parent might have to be 771 * re-dropped if it has 0 refs. 772 */ 773 if (parent->core.chain_count == 0) { 774 rdrop = parent; 775 atomic_add_int(&rdrop->refs, 1); 776 /* 777 if (atomic_cmpset_int(&rdrop->refs, 0, 1) == 0) 778 rdrop = NULL; 779 */ 780 } 781 hammer2_spin_unex(&parent->core.spin); 782 parent = NULL; /* safety */ 783 /* FALL THROUGH */ 784 } else { 785 /* 786 * No-parent case. 787 */ 788 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 789 /* 790 * 1->0 transition failed, retry. 791 */ 792 hammer2_spin_unex(&parent->core.spin); 793 hammer2_spin_unex(&chain->core.spin); 794 hammer2_mtx_unlock(&chain->lock); 795 796 return(chain); 797 } 798 } 799 800 /* 801 * Successful 1->0 transition, no parent, no children... no way for 802 * anyone to ref this chain any more. We can clean-up and free it. 803 * 804 * We still have the core spinlock, and core's chain_count is 0. 805 * Any parent spinlock is gone. 806 */ 807 hammer2_spin_unex(&chain->core.spin); 808 hammer2_chain_assert_no_data(chain); 809 hammer2_mtx_unlock(&chain->lock); 810 KKASSERT(RB_EMPTY(&chain->core.rbtree) && 811 chain->core.chain_count == 0); 812 813 /* 814 * All locks are gone, no pointers remain to the chain, finish 815 * freeing it. 816 */ 817 KKASSERT((chain->flags & (HAMMER2_CHAIN_UPDATE | 818 HAMMER2_CHAIN_MODIFIED)) == 0); 819 820 /* 821 * Once chain resources are gone we can use the now dead chain 822 * structure to placehold what might otherwise require a recursive 823 * drop, because we have potentially two things to drop and can only 824 * return one directly. 825 */ 826 if (chain->flags & HAMMER2_CHAIN_ALLOCATED) { 827 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ALLOCATED); 828 chain->hmp = NULL; 829 kfree_obj(chain, hmp->mchain); 830 atomic_add_long(&hammer2_chain_allocs, -1); 831 } 832 833 /* 834 * Possible chaining loop when parent re-drop needed. 835 */ 836 return(rdrop); 837 } 838 839 /* 840 * Heuristical flush of the LRU, try to reduce the number of entries 841 * on the LRU to (HAMMER2_LRU_LIMIT * 2 / 3). This procedure is called 842 * only when lru_count exceeds HAMMER2_LRU_LIMIT. 843 */ 844 static 845 void 846 hammer2_chain_lru_flush(hammer2_pfs_t *pmp) 847 { 848 hammer2_chain_t *chain; 849 850 again: 851 chain = NULL; 852 hammer2_spin_ex(&pmp->lru_spin); 853 while (pmp->lru_count > HAMMER2_LRU_LIMIT * 2 / 3) { 854 /* 855 * Pick a chain off the lru_list, just recycle it quickly 856 * if LRUHINT is set (the chain was ref'd but left on 857 * the lru_list, so cycle to the end). 858 */ 859 chain = TAILQ_FIRST(&pmp->lru_list); 860 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 861 862 if (chain->flags & HAMMER2_CHAIN_LRUHINT) { 863 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_LRUHINT); 864 TAILQ_INSERT_TAIL(&pmp->lru_list, chain, lru_node); 865 chain = NULL; 866 continue; 867 } 868 869 /* 870 * Ok, we are off the LRU. We must adjust refs before we 871 * can safely clear the ONLRU flag. 872 */ 873 atomic_add_int(&pmp->lru_count, -1); 874 if (atomic_cmpset_int(&chain->refs, 0, 1)) { 875 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 876 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE); 877 break; 878 } 879 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 880 chain = NULL; 881 } 882 hammer2_spin_unex(&pmp->lru_spin); 883 if (chain == NULL) 884 return; 885 886 /* 887 * If we picked a chain off the lru list we may be able to lastdrop 888 * it. Use a depth of 1 to prevent excessive lastdrop recursion. 889 */ 890 while (chain) { 891 u_int refs; 892 893 refs = chain->refs; 894 cpu_ccfence(); 895 KKASSERT(refs > 0); 896 897 if (refs == 1) { 898 if (hammer2_mtx_ex_try(&chain->lock) == 0) 899 chain = hammer2_chain_lastdrop(chain, 1); 900 /* retry the same chain, or chain from lastdrop */ 901 } else { 902 if (atomic_cmpset_int(&chain->refs, refs, refs - 1)) 903 break; 904 /* retry the same chain */ 905 } 906 cpu_pause(); 907 } 908 goto again; 909 } 910 911 /* 912 * On last lock release. 913 */ 914 static hammer2_io_t * 915 hammer2_chain_drop_data(hammer2_chain_t *chain) 916 { 917 hammer2_io_t *dio; 918 919 if ((dio = chain->dio) != NULL) { 920 chain->dio = NULL; 921 chain->data = NULL; 922 } else { 923 switch(chain->bref.type) { 924 case HAMMER2_BREF_TYPE_VOLUME: 925 case HAMMER2_BREF_TYPE_FREEMAP: 926 break; 927 default: 928 if (chain->data != NULL) { 929 hammer2_spin_unex(&chain->core.spin); 930 panic("chain data not null: " 931 "chain %p bref %016jx.%02x " 932 "refs %d parent %p dio %p data %p", 933 chain, chain->bref.data_off, 934 chain->bref.type, chain->refs, 935 chain->parent, 936 chain->dio, chain->data); 937 } 938 KKASSERT(chain->data == NULL); 939 break; 940 } 941 } 942 return dio; 943 } 944 945 /* 946 * Lock a referenced chain element, acquiring its data with I/O if necessary, 947 * and specify how you would like the data to be resolved. 948 * 949 * If an I/O or other fatal error occurs, chain->error will be set to non-zero. 950 * 951 * The lock is allowed to recurse, multiple locking ops will aggregate 952 * the requested resolve types. Once data is assigned it will not be 953 * removed until the last unlock. 954 * 955 * HAMMER2_RESOLVE_NEVER - Do not resolve the data element. 956 * (typically used to avoid device/logical buffer 957 * aliasing for data) 958 * 959 * HAMMER2_RESOLVE_MAYBE - Do not resolve data elements for chains in 960 * the INITIAL-create state (indirect blocks only). 961 * 962 * Do not resolve data elements for DATA chains. 963 * (typically used to avoid device/logical buffer 964 * aliasing for data) 965 * 966 * HAMMER2_RESOLVE_ALWAYS- Always resolve the data element. 967 * 968 * HAMMER2_RESOLVE_SHARED- (flag) The chain is locked shared, otherwise 969 * it will be locked exclusive. 970 * 971 * HAMMER2_RESOLVE_NONBLOCK- (flag) The chain is locked non-blocking. If 972 * the lock fails, EAGAIN is returned. 973 * 974 * NOTE: Embedded elements (volume header, inodes) are always resolved 975 * regardless. 976 * 977 * NOTE: Specifying HAMMER2_RESOLVE_ALWAYS on a newly-created non-embedded 978 * element will instantiate and zero its buffer, and flush it on 979 * release. 980 * 981 * NOTE: (data) elements are normally locked RESOLVE_NEVER or RESOLVE_MAYBE 982 * so as not to instantiate a device buffer, which could alias against 983 * a logical file buffer. However, if ALWAYS is specified the 984 * device buffer will be instantiated anyway. 985 * 986 * NOTE: The return value is always 0 unless NONBLOCK is specified, in which 987 * case it can be either 0 or EAGAIN. 988 * 989 * WARNING! This function blocks on I/O if data needs to be fetched. This 990 * blocking can run concurrent with other compatible lock holders 991 * who do not need data returning. The lock is not upgraded to 992 * exclusive during a data fetch, a separate bit is used to 993 * interlock I/O. However, an exclusive lock holder can still count 994 * on being interlocked against an I/O fetch managed by a shared 995 * lock holder. 996 */ 997 int 998 hammer2_chain_lock(hammer2_chain_t *chain, int how) 999 { 1000 KKASSERT(chain->refs > 0); 1001 1002 if (how & HAMMER2_RESOLVE_NONBLOCK) { 1003 /* 1004 * We still have to bump lockcnt before acquiring the lock, 1005 * even for non-blocking operation, because the unlock code 1006 * live-loops on lockcnt == 1 when dropping the last lock. 1007 * 1008 * If the non-blocking operation fails we have to use an 1009 * unhold sequence to undo the mess. 1010 * 1011 * NOTE: LOCKAGAIN must always succeed without blocking, 1012 * even if NONBLOCK is specified. 1013 */ 1014 atomic_add_int(&chain->lockcnt, 1); 1015 if (how & HAMMER2_RESOLVE_SHARED) { 1016 if (how & HAMMER2_RESOLVE_LOCKAGAIN) { 1017 hammer2_mtx_sh_again(&chain->lock); 1018 } else { 1019 if (hammer2_mtx_sh_try(&chain->lock) != 0) { 1020 hammer2_chain_unhold(chain); 1021 return EAGAIN; 1022 } 1023 } 1024 } else { 1025 if (hammer2_mtx_ex_try(&chain->lock) != 0) { 1026 hammer2_chain_unhold(chain); 1027 return EAGAIN; 1028 } 1029 } 1030 } else { 1031 /* 1032 * Get the appropriate lock. If LOCKAGAIN is flagged with 1033 * SHARED the caller expects a shared lock to already be 1034 * present and we are giving it another ref. This case must 1035 * importantly not block if there is a pending exclusive lock 1036 * request. 1037 */ 1038 atomic_add_int(&chain->lockcnt, 1); 1039 if (how & HAMMER2_RESOLVE_SHARED) { 1040 if (how & HAMMER2_RESOLVE_LOCKAGAIN) { 1041 hammer2_mtx_sh_again(&chain->lock); 1042 } else { 1043 hammer2_mtx_sh(&chain->lock); 1044 } 1045 } else { 1046 hammer2_mtx_ex(&chain->lock); 1047 } 1048 } 1049 1050 /* 1051 * If we already have a valid data pointer make sure the data is 1052 * synchronized to the current cpu, and then no further action is 1053 * necessary. 1054 */ 1055 if (chain->data) { 1056 if (chain->dio) 1057 hammer2_io_bkvasync(chain->dio); 1058 return 0; 1059 } 1060 1061 /* 1062 * Do we have to resolve the data? This is generally only 1063 * applicable to HAMMER2_BREF_TYPE_DATA which is special-cased. 1064 * Other BREF types expects the data to be there. 1065 */ 1066 switch(how & HAMMER2_RESOLVE_MASK) { 1067 case HAMMER2_RESOLVE_NEVER: 1068 return 0; 1069 case HAMMER2_RESOLVE_MAYBE: 1070 if (chain->flags & HAMMER2_CHAIN_INITIAL) 1071 return 0; 1072 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) 1073 return 0; 1074 #if 0 1075 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) 1076 return 0; 1077 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) 1078 return 0; 1079 #endif 1080 /* fall through */ 1081 case HAMMER2_RESOLVE_ALWAYS: 1082 default: 1083 break; 1084 } 1085 1086 /* 1087 * Caller requires data 1088 */ 1089 hammer2_chain_load_data(chain); 1090 1091 return 0; 1092 } 1093 1094 /* 1095 * Lock the chain, retain the hold, and drop the data persistence count. 1096 * The data should remain valid because we never transitioned lockcnt 1097 * through 0. 1098 */ 1099 void 1100 hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how) 1101 { 1102 hammer2_chain_lock(chain, how); 1103 atomic_add_int(&chain->lockcnt, -1); 1104 } 1105 1106 #if 0 1107 /* 1108 * Downgrade an exclusive chain lock to a shared chain lock. 1109 * 1110 * NOTE: There is no upgrade equivalent due to the ease of 1111 * deadlocks in that direction. 1112 */ 1113 void 1114 hammer2_chain_lock_downgrade(hammer2_chain_t *chain) 1115 { 1116 hammer2_mtx_downgrade(&chain->lock); 1117 } 1118 #endif 1119 1120 /* 1121 * Issue I/O and install chain->data. Caller must hold a chain lock, lock 1122 * may be of any type. 1123 * 1124 * Once chain->data is set it cannot be disposed of until all locks are 1125 * released. 1126 * 1127 * Make sure the data is synchronized to the current cpu. 1128 */ 1129 void 1130 hammer2_chain_load_data(hammer2_chain_t *chain) 1131 { 1132 hammer2_blockref_t *bref; 1133 hammer2_dev_t *hmp; 1134 hammer2_io_t *dio; 1135 char *bdata; 1136 int error; 1137 1138 /* 1139 * Degenerate case, data already present, or chain has no media 1140 * reference to load. 1141 */ 1142 KKASSERT(chain->lock.mtx_lock & MTX_MASK); 1143 if (chain->data) { 1144 if (chain->dio) 1145 hammer2_io_bkvasync(chain->dio); 1146 return; 1147 } 1148 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) 1149 return; 1150 1151 hmp = chain->hmp; 1152 KKASSERT(hmp != NULL); 1153 1154 /* 1155 * Gain the IOINPROG bit, interlocked block. 1156 */ 1157 for (;;) { 1158 u_int oflags; 1159 u_int nflags; 1160 1161 oflags = chain->flags; 1162 cpu_ccfence(); 1163 if (oflags & HAMMER2_CHAIN_IOINPROG) { 1164 nflags = oflags | HAMMER2_CHAIN_IOSIGNAL; 1165 tsleep_interlock(&chain->flags, 0); 1166 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1167 tsleep(&chain->flags, PINTERLOCKED, 1168 "h2iocw", 0); 1169 } 1170 /* retry */ 1171 } else { 1172 nflags = oflags | HAMMER2_CHAIN_IOINPROG; 1173 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1174 break; 1175 } 1176 /* retry */ 1177 } 1178 } 1179 1180 /* 1181 * We own CHAIN_IOINPROG 1182 * 1183 * Degenerate case if we raced another load. 1184 */ 1185 if (chain->data) { 1186 if (chain->dio) 1187 hammer2_io_bkvasync(chain->dio); 1188 goto done; 1189 } 1190 1191 /* 1192 * We must resolve to a device buffer, either by issuing I/O or 1193 * by creating a zero-fill element. We do not mark the buffer 1194 * dirty when creating a zero-fill element (the hammer2_chain_modify() 1195 * API must still be used to do that). 1196 * 1197 * The device buffer is variable-sized in powers of 2 down 1198 * to HAMMER2_MIN_ALLOC (typically 1K). A 64K physical storage 1199 * chunk always contains buffers of the same size. (XXX) 1200 * 1201 * The minimum physical IO size may be larger than the variable 1202 * block size. 1203 */ 1204 bref = &chain->bref; 1205 1206 /* 1207 * The getblk() optimization can only be used on newly created 1208 * elements if the physical block size matches the request. 1209 */ 1210 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1211 error = hammer2_io_new(hmp, bref->type, 1212 bref->data_off, chain->bytes, 1213 &chain->dio); 1214 } else { 1215 error = hammer2_io_bread(hmp, bref->type, 1216 bref->data_off, chain->bytes, 1217 &chain->dio); 1218 hammer2_adjreadcounter(chain->bref.type, chain->bytes); 1219 } 1220 if (error) { 1221 chain->error = HAMMER2_ERROR_EIO; 1222 kprintf("hammer2_chain_load_data: I/O error %016jx: %d\n", 1223 (intmax_t)bref->data_off, error); 1224 hammer2_io_bqrelse(&chain->dio); 1225 goto done; 1226 } 1227 chain->error = 0; 1228 1229 /* 1230 * This isn't perfect and can be ignored on OSs which do not have 1231 * an indication as to whether a buffer is coming from cache or 1232 * if I/O was actually issued for the read. TESTEDGOOD will work 1233 * pretty well without the B_IOISSUED logic because chains are 1234 * cached, but in that situation (without B_IOISSUED) it will not 1235 * detect whether a re-read via I/O is corrupted verses the original 1236 * read. 1237 * 1238 * We can't re-run the CRC on every fresh lock. That would be 1239 * insanely expensive. 1240 * 1241 * If the underlying kernel buffer covers the entire chain we can 1242 * use the B_IOISSUED indication to determine if we have to re-run 1243 * the CRC on chain data for chains that managed to stay cached 1244 * across the kernel disposal of the original buffer. 1245 */ 1246 if ((dio = chain->dio) != NULL && dio->bp) { 1247 //struct buf *bp = dio->bp; 1248 1249 if (dio->psize == chain->bytes //&& 1250 /*(bp->b_flags & B_IOISSUED)*/) { 1251 atomic_clear_int(&chain->flags, 1252 HAMMER2_CHAIN_TESTEDGOOD); 1253 //bp->b_flags &= ~B_IOISSUED; 1254 } 1255 } 1256 1257 /* 1258 * NOTE: A locked chain's data cannot be modified without first 1259 * calling hammer2_chain_modify(). 1260 */ 1261 1262 /* 1263 * NOTE: hammer2_io_data() call issues bkvasync() 1264 */ 1265 bdata = hammer2_io_data(chain->dio, chain->bref.data_off); 1266 1267 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1268 /* 1269 * Clear INITIAL. In this case we used io_new() and the 1270 * buffer has been zero'd and marked dirty. 1271 * 1272 * CHAIN_MODIFIED has not been set yet, and we leave it 1273 * that way for now. Set a temporary CHAIN_NOTTESTED flag 1274 * to prevent hammer2_chain_testcheck() from trying to match 1275 * a check code that has not yet been generated. This bit 1276 * should NOT end up on the actual media. 1277 */ 1278 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 1279 atomic_set_int(&chain->flags, HAMMER2_CHAIN_NOTTESTED); 1280 } else if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 1281 /* 1282 * check data not currently synchronized due to 1283 * modification. XXX assumes data stays in the buffer 1284 * cache, which might not be true (need biodep on flush 1285 * to calculate crc? or simple crc?). 1286 */ 1287 } else if ((chain->flags & HAMMER2_CHAIN_TESTEDGOOD) == 0) { 1288 if (hammer2_chain_testcheck(chain, bdata) == 0) { 1289 chain->error = HAMMER2_ERROR_CHECK; 1290 } else { 1291 atomic_set_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD); 1292 } 1293 } 1294 1295 /* 1296 * Setup the data pointer, either pointing it to an embedded data 1297 * structure and copying the data from the buffer, or pointing it 1298 * into the buffer. 1299 * 1300 * The buffer is not retained when copying to an embedded data 1301 * structure in order to avoid potential deadlocks or recursions 1302 * on the same physical buffer. 1303 * 1304 * WARNING! Other threads can start using the data the instant we 1305 * set chain->data non-NULL. 1306 */ 1307 switch (bref->type) { 1308 case HAMMER2_BREF_TYPE_VOLUME: 1309 case HAMMER2_BREF_TYPE_FREEMAP: 1310 /* 1311 * Copy data from bp to embedded buffer 1312 */ 1313 panic("hammer2_chain_load_data: unresolved volume header"); 1314 break; 1315 case HAMMER2_BREF_TYPE_DIRENT: 1316 KKASSERT(chain->bytes != 0); 1317 /* fall through */ 1318 case HAMMER2_BREF_TYPE_INODE: 1319 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 1320 case HAMMER2_BREF_TYPE_INDIRECT: 1321 case HAMMER2_BREF_TYPE_DATA: 1322 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1323 default: 1324 /* 1325 * Point data at the device buffer and leave dio intact. 1326 */ 1327 chain->data = (void *)bdata; 1328 break; 1329 } 1330 1331 /* 1332 * Release HAMMER2_CHAIN_IOINPROG and signal waiters if requested. 1333 */ 1334 done: 1335 for (;;) { 1336 u_int oflags; 1337 u_int nflags; 1338 1339 oflags = chain->flags; 1340 nflags = oflags & ~(HAMMER2_CHAIN_IOINPROG | 1341 HAMMER2_CHAIN_IOSIGNAL); 1342 KKASSERT(oflags & HAMMER2_CHAIN_IOINPROG); 1343 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1344 if (oflags & HAMMER2_CHAIN_IOSIGNAL) 1345 wakeup(&chain->flags); 1346 break; 1347 } 1348 } 1349 } 1350 1351 /* 1352 * Unlock and deref a chain element. 1353 * 1354 * Remember that the presence of children under chain prevent the chain's 1355 * destruction but do not add additional references, so the dio will still 1356 * be dropped. 1357 */ 1358 void 1359 hammer2_chain_unlock(hammer2_chain_t *chain) 1360 { 1361 hammer2_io_t *dio; 1362 u_int lockcnt; 1363 int iter = 0; 1364 1365 /* 1366 * If multiple locks are present (or being attempted) on this 1367 * particular chain we can just unlock, drop refs, and return. 1368 * 1369 * Otherwise fall-through on the 1->0 transition. 1370 */ 1371 for (;;) { 1372 lockcnt = chain->lockcnt; 1373 KKASSERT(lockcnt > 0); 1374 cpu_ccfence(); 1375 if (lockcnt > 1) { 1376 if (atomic_cmpset_int(&chain->lockcnt, 1377 lockcnt, lockcnt - 1)) { 1378 hammer2_mtx_unlock(&chain->lock); 1379 return; 1380 } 1381 } else if (hammer2_mtx_upgrade_try(&chain->lock) == 0) { 1382 /* while holding the mutex exclusively */ 1383 if (atomic_cmpset_int(&chain->lockcnt, 1, 0)) 1384 break; 1385 } else { 1386 /* 1387 * This situation can easily occur on SMP due to 1388 * the gap inbetween the 1->0 transition and the 1389 * final unlock. We cannot safely block on the 1390 * mutex because lockcnt might go above 1. 1391 * 1392 * XXX Sleep for one tick if it takes too long. 1393 */ 1394 if (++iter > 1000) { 1395 if (iter > 1000 + hz) { 1396 kprintf("hammer2: h2race2 %p\n", chain); 1397 iter = 1000; 1398 } 1399 tsleep(&iter, 0, "h2race2", 1); 1400 } 1401 cpu_pause(); 1402 } 1403 /* retry */ 1404 } 1405 1406 /* 1407 * Last unlock / mutex upgraded to exclusive. Drop the data 1408 * reference. 1409 */ 1410 dio = hammer2_chain_drop_data(chain); 1411 if (dio) 1412 hammer2_io_bqrelse(&dio); 1413 hammer2_mtx_unlock(&chain->lock); 1414 } 1415 1416 /* 1417 * Unlock and hold chain data intact 1418 */ 1419 void 1420 hammer2_chain_unlock_hold(hammer2_chain_t *chain) 1421 { 1422 atomic_add_int(&chain->lockcnt, 1); 1423 hammer2_chain_unlock(chain); 1424 } 1425 1426 /* 1427 * Helper to obtain the blockref[] array base and count for a chain. 1428 * 1429 * XXX Not widely used yet, various use cases need to be validated and 1430 * converted to use this function. 1431 */ 1432 static 1433 hammer2_blockref_t * 1434 hammer2_chain_base_and_count(hammer2_chain_t *parent, int *countp) 1435 { 1436 hammer2_blockref_t *base; 1437 int count; 1438 1439 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 1440 base = NULL; 1441 1442 switch(parent->bref.type) { 1443 case HAMMER2_BREF_TYPE_INODE: 1444 count = HAMMER2_SET_COUNT; 1445 break; 1446 case HAMMER2_BREF_TYPE_INDIRECT: 1447 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1448 count = parent->bytes / sizeof(hammer2_blockref_t); 1449 break; 1450 case HAMMER2_BREF_TYPE_VOLUME: 1451 count = HAMMER2_SET_COUNT; 1452 break; 1453 case HAMMER2_BREF_TYPE_FREEMAP: 1454 count = HAMMER2_SET_COUNT; 1455 break; 1456 default: 1457 panic("hammer2_chain_base_and_count: " 1458 "unrecognized blockref type: %d", 1459 parent->bref.type); 1460 count = 0; 1461 break; 1462 } 1463 } else { 1464 switch(parent->bref.type) { 1465 case HAMMER2_BREF_TYPE_INODE: 1466 base = &parent->data->ipdata.u.blockset.blockref[0]; 1467 count = HAMMER2_SET_COUNT; 1468 break; 1469 case HAMMER2_BREF_TYPE_INDIRECT: 1470 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1471 base = &parent->data->npdata[0]; 1472 count = parent->bytes / sizeof(hammer2_blockref_t); 1473 break; 1474 case HAMMER2_BREF_TYPE_VOLUME: 1475 base = &parent->data->voldata. 1476 sroot_blockset.blockref[0]; 1477 count = HAMMER2_SET_COUNT; 1478 break; 1479 case HAMMER2_BREF_TYPE_FREEMAP: 1480 base = &parent->data->blkset.blockref[0]; 1481 count = HAMMER2_SET_COUNT; 1482 break; 1483 default: 1484 panic("hammer2_chain_base_and_count: " 1485 "unrecognized blockref type: %d", 1486 parent->bref.type); 1487 base = NULL; 1488 count = 0; 1489 break; 1490 } 1491 } 1492 *countp = count; 1493 1494 return base; 1495 } 1496 1497 /* 1498 * This counts the number of live blockrefs in a block array and 1499 * also calculates the point at which all remaining blockrefs are empty. 1500 * This routine can only be called on a live chain. 1501 * 1502 * Caller holds the chain locked, but possibly with a shared lock. We 1503 * must use an exclusive spinlock to prevent corruption. 1504 * 1505 * NOTE: Flag is not set until after the count is complete, allowing 1506 * callers to test the flag without holding the spinlock. 1507 * 1508 * NOTE: If base is NULL the related chain is still in the INITIAL 1509 * state and there are no blockrefs to count. 1510 * 1511 * NOTE: live_count may already have some counts accumulated due to 1512 * creation and deletion and could even be initially negative. 1513 */ 1514 void 1515 hammer2_chain_countbrefs(hammer2_chain_t *chain, 1516 hammer2_blockref_t *base, int count) 1517 { 1518 hammer2_spin_ex(&chain->core.spin); 1519 if ((chain->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) { 1520 if (base) { 1521 while (--count >= 0) { 1522 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) 1523 break; 1524 } 1525 chain->core.live_zero = count + 1; 1526 while (count >= 0) { 1527 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) 1528 atomic_add_int(&chain->core.live_count, 1529 1); 1530 --count; 1531 } 1532 } else { 1533 chain->core.live_zero = 0; 1534 } 1535 /* else do not modify live_count */ 1536 atomic_set_int(&chain->flags, HAMMER2_CHAIN_COUNTEDBREFS); 1537 } 1538 hammer2_spin_unex(&chain->core.spin); 1539 } 1540 1541 /* 1542 * Resize the chain's physical storage allocation in-place. This function does 1543 * not usually adjust the data pointer and must be followed by (typically) a 1544 * hammer2_chain_modify() call to copy any old data over and adjust the 1545 * data pointer. 1546 * 1547 * Chains can be resized smaller without reallocating the storage. Resizing 1548 * larger will reallocate the storage. Excess or prior storage is reclaimed 1549 * asynchronously at a later time. 1550 * 1551 * An nradix value of 0 is special-cased to mean that the storage should 1552 * be disassociated, that is the chain is being resized to 0 bytes (not 1 1553 * byte). 1554 * 1555 * Must be passed an exclusively locked parent and chain. 1556 * 1557 * This function is mostly used with DATA blocks locked RESOLVE_NEVER in order 1558 * to avoid instantiating a device buffer that conflicts with the vnode data 1559 * buffer. However, because H2 can compress or encrypt data, the chain may 1560 * have a dio assigned to it in those situations, and they do not conflict. 1561 * 1562 * XXX return error if cannot resize. 1563 */ 1564 int 1565 hammer2_chain_resize(hammer2_chain_t *chain, 1566 hammer2_tid_t mtid, hammer2_off_t dedup_off, 1567 int nradix, int flags) 1568 { 1569 hammer2_dev_t *hmp; 1570 size_t obytes; 1571 size_t nbytes; 1572 int error; 1573 1574 hmp = chain->hmp; 1575 1576 /* 1577 * Only data and indirect blocks can be resized for now. 1578 * (The volu root, inodes, and freemap elements use a fixed size). 1579 */ 1580 KKASSERT(chain != &hmp->vchain); 1581 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1582 chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 1583 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); 1584 1585 /* 1586 * Nothing to do if the element is already the proper size 1587 */ 1588 obytes = chain->bytes; 1589 nbytes = (nradix) ? (1U << nradix) : 0; 1590 if (obytes == nbytes) 1591 return (chain->error); 1592 1593 /* 1594 * Make sure the old data is instantiated so we can copy it. If this 1595 * is a data block, the device data may be superfluous since the data 1596 * might be in a logical block, but compressed or encrypted data is 1597 * another matter. 1598 * 1599 * NOTE: The modify will set BLKMAPUPD for us if BLKMAPPED is set. 1600 */ 1601 error = hammer2_chain_modify(chain, mtid, dedup_off, 0); 1602 if (error) 1603 return error; 1604 1605 /* 1606 * Reallocate the block, even if making it smaller (because different 1607 * block sizes may be in different regions). 1608 * 1609 * NOTE: Operation does not copy the data and may only be used 1610 * to resize data blocks in-place, or directory entry blocks 1611 * which are about to be modified in some manner. 1612 */ 1613 error = hammer2_freemap_alloc(chain, nbytes); 1614 if (error) 1615 return error; 1616 1617 chain->bytes = nbytes; 1618 1619 /* 1620 * We don't want the followup chain_modify() to try to copy data 1621 * from the old (wrong-sized) buffer. It won't know how much to 1622 * copy. This case should only occur during writes when the 1623 * originator already has the data to write in-hand. 1624 */ 1625 if (chain->dio) { 1626 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1627 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); 1628 hammer2_io_brelse(&chain->dio); 1629 chain->data = NULL; 1630 } 1631 return (chain->error); 1632 } 1633 1634 /* 1635 * Set the chain modified so its data can be changed by the caller, or 1636 * install deduplicated data. The caller must call this routine for each 1637 * set of modifications it makes, even if the chain is already flagged 1638 * MODIFIED. 1639 * 1640 * Sets bref.modify_tid to mtid only if mtid != 0. Note that bref.modify_tid 1641 * is a CLC (cluster level change) field and is not updated by parent 1642 * propagation during a flush. 1643 * 1644 * Returns an appropriate HAMMER2_ERROR_* code, which will generally reflect 1645 * chain->error except for HAMMER2_ERROR_ENOSPC. If the allocation fails 1646 * due to no space available, HAMMER2_ERROR_ENOSPC is returned and the chain 1647 * remains unmodified with its old data ref intact and chain->error 1648 * unchanged. 1649 * 1650 * Dedup Handling 1651 * 1652 * If the DEDUPABLE flag is set in the chain the storage must be reallocated 1653 * even if the chain is still flagged MODIFIED. In this case the chain's 1654 * DEDUPABLE flag will be cleared once the new storage has been assigned. 1655 * 1656 * If the caller passes a non-zero dedup_off we will use it to assign the 1657 * new storage. The MODIFIED flag will be *CLEARED* in this case, and 1658 * DEDUPABLE will be set (NOTE: the UPDATE flag is always set). The caller 1659 * must not modify the data content upon return. 1660 */ 1661 int 1662 hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid, 1663 hammer2_off_t dedup_off, int flags) 1664 { 1665 hammer2_dev_t *hmp; 1666 hammer2_io_t *dio; 1667 int error; 1668 int wasinitial; 1669 int setmodified; 1670 int setupdate; 1671 int newmod; 1672 char *bdata; 1673 1674 hmp = chain->hmp; 1675 KKASSERT(chain->lock.mtx_lock & MTX_EXCLUSIVE); 1676 1677 /* 1678 * Data is not optional for freemap chains (we must always be sure 1679 * to copy the data on COW storage allocations). 1680 */ 1681 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 1682 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 1683 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) || 1684 (flags & HAMMER2_MODIFY_OPTDATA) == 0); 1685 } 1686 1687 /* 1688 * Data must be resolved if already assigned, unless explicitly 1689 * flagged otherwise. If we cannot safety load the data the 1690 * modification fails and we return early. 1691 */ 1692 if (chain->data == NULL && chain->bytes != 0 && 1693 (flags & HAMMER2_MODIFY_OPTDATA) == 0 && 1694 (chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX)) { 1695 hammer2_chain_load_data(chain); 1696 if (chain->error) 1697 return (chain->error); 1698 } 1699 error = 0; 1700 1701 /* 1702 * Set MODIFIED to indicate that the chain has been modified. A new 1703 * allocation is required when modifying a chain. 1704 * 1705 * Set UPDATE to ensure that the blockref is updated in the parent. 1706 * 1707 * If MODIFIED is already set determine if we can reuse the assigned 1708 * data block or if we need a new data block. 1709 */ 1710 if ((chain->flags & HAMMER2_CHAIN_MODIFIED) == 0) { 1711 /* 1712 * Must set modified bit. 1713 */ 1714 atomic_add_long(&hammer2_count_modified_chains, 1); 1715 atomic_set_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 1716 hammer2_pfs_memory_inc(chain->pmp); /* can be NULL */ 1717 setmodified = 1; 1718 1719 /* 1720 * We may be able to avoid a copy-on-write if the chain's 1721 * check mode is set to NONE and the chain's current 1722 * modify_tid is beyond the last explicit snapshot tid. 1723 * 1724 * This implements HAMMER2's overwrite-in-place feature. 1725 * 1726 * NOTE! This data-block cannot be used as a de-duplication 1727 * source when the check mode is set to NONE. 1728 */ 1729 if ((chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1730 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT) && 1731 (chain->flags & HAMMER2_CHAIN_INITIAL) == 0 && 1732 (chain->flags & HAMMER2_CHAIN_DEDUPABLE) == 0 && 1733 HAMMER2_DEC_CHECK(chain->bref.methods) == 1734 HAMMER2_CHECK_NONE && 1735 chain->pmp && 1736 chain->bref.modify_tid > 1737 chain->pmp->iroot->meta.pfs_lsnap_tid) { 1738 /* 1739 * Sector overwrite allowed. 1740 */ 1741 newmod = 0; 1742 } else if ((hmp->hflags & HMNT2_EMERG) && 1743 chain->pmp && 1744 chain->bref.modify_tid > 1745 chain->pmp->iroot->meta.pfs_lsnap_tid) { 1746 /* 1747 * If in emergency delete mode then do a modify-in- 1748 * place on any chain type belonging to the PFS as 1749 * long as it doesn't mess up a snapshot. We might 1750 * be forced to do this anyway a little further down 1751 * in the code if the allocation fails. 1752 * 1753 * Also note that in emergency mode, these modify-in- 1754 * place operations are NOT SAFE. A storage failure, 1755 * power failure, or panic can corrupt the filesystem. 1756 */ 1757 newmod = 0; 1758 } else { 1759 /* 1760 * Sector overwrite not allowed, must copy-on-write. 1761 */ 1762 newmod = 1; 1763 } 1764 } else if (chain->flags & HAMMER2_CHAIN_DEDUPABLE) { 1765 /* 1766 * If the modified chain was registered for dedup we need 1767 * a new allocation. This only happens for delayed-flush 1768 * chains (i.e. which run through the front-end buffer 1769 * cache). 1770 */ 1771 newmod = 1; 1772 setmodified = 0; 1773 } else { 1774 /* 1775 * Already flagged modified, no new allocation is needed. 1776 */ 1777 newmod = 0; 1778 setmodified = 0; 1779 } 1780 1781 /* 1782 * Flag parent update required. 1783 */ 1784 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) { 1785 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1786 setupdate = 1; 1787 } else { 1788 setupdate = 0; 1789 } 1790 1791 /* 1792 * The XOP code returns held but unlocked focus chains. This 1793 * prevents the chain from being destroyed but does not prevent 1794 * it from being modified. diolk is used to interlock modifications 1795 * against XOP frontend accesses to the focus. 1796 * 1797 * This allows us to theoretically avoid deadlocking the frontend 1798 * if one of the backends lock up by not formally locking the 1799 * focused chain in the frontend. In addition, the synchronization 1800 * code relies on this mechanism to avoid deadlocking concurrent 1801 * synchronization threads. 1802 */ 1803 lockmgr(&chain->diolk, LK_EXCLUSIVE); 1804 1805 /* 1806 * The modification or re-modification requires an allocation and 1807 * possible COW. If an error occurs, the previous content and data 1808 * reference is retained and the modification fails. 1809 * 1810 * If dedup_off is non-zero, the caller is requesting a deduplication 1811 * rather than a modification. The MODIFIED bit is not set and the 1812 * data offset is set to the deduplication offset. The data cannot 1813 * be modified. 1814 * 1815 * NOTE: The dedup offset is allowed to be in a partially free state 1816 * and we must be sure to reset it to a fully allocated state 1817 * to force two bulkfree passes to free it again. 1818 * 1819 * NOTE: Only applicable when chain->bytes != 0. 1820 * 1821 * XXX can a chain already be marked MODIFIED without a data 1822 * assignment? If not, assert here instead of testing the case. 1823 */ 1824 if (chain != &hmp->vchain && chain != &hmp->fchain && 1825 chain->bytes) { 1826 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0 || 1827 newmod 1828 ) { 1829 /* 1830 * NOTE: We do not have to remove the dedup 1831 * registration because the area is still 1832 * allocated and the underlying DIO will 1833 * still be flushed. 1834 */ 1835 if (dedup_off) { 1836 chain->bref.data_off = dedup_off; 1837 if ((int)(dedup_off & HAMMER2_OFF_MASK_RADIX)) 1838 chain->bytes = 1 << 1839 (int)(dedup_off & 1840 HAMMER2_OFF_MASK_RADIX); 1841 else 1842 chain->bytes = 0; 1843 chain->error = 0; 1844 atomic_clear_int(&chain->flags, 1845 HAMMER2_CHAIN_MODIFIED); 1846 atomic_add_long(&hammer2_count_modified_chains, 1847 -1); 1848 if (chain->pmp) { 1849 hammer2_pfs_memory_wakeup( 1850 chain->pmp, -1); 1851 } 1852 hammer2_freemap_adjust(hmp, &chain->bref, 1853 HAMMER2_FREEMAP_DORECOVER); 1854 atomic_set_int(&chain->flags, 1855 HAMMER2_CHAIN_DEDUPABLE); 1856 } else { 1857 error = hammer2_freemap_alloc(chain, 1858 chain->bytes); 1859 atomic_clear_int(&chain->flags, 1860 HAMMER2_CHAIN_DEDUPABLE); 1861 1862 /* 1863 * If we are unable to allocate a new block 1864 * but we are in emergency mode, issue a 1865 * warning to the console and reuse the same 1866 * block. 1867 * 1868 * We behave as if the allocation were 1869 * successful. 1870 * 1871 * THIS IS IMPORTANT: These modifications 1872 * are virtually guaranteed to corrupt any 1873 * snapshots related to this filesystem. 1874 */ 1875 if (error && (hmp->hflags & HMNT2_EMERG)) { 1876 error = 0; 1877 chain->bref.flags |= 1878 HAMMER2_BREF_FLAG_EMERG_MIP; 1879 1880 krateprintf(&krate_h2em, 1881 "hammer2: Emergency Mode WARNING: " 1882 "Operation will likely corrupt " 1883 "related snapshot: " 1884 "%016jx.%02x key=%016jx\n", 1885 chain->bref.data_off, 1886 chain->bref.type, 1887 chain->bref.key); 1888 } else if (error == 0) { 1889 chain->bref.flags &= 1890 ~HAMMER2_BREF_FLAG_EMERG_MIP; 1891 } 1892 } 1893 } 1894 } 1895 1896 /* 1897 * Stop here if error. We have to undo any flag bits we might 1898 * have set above. 1899 */ 1900 if (error) { 1901 if (setmodified) { 1902 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 1903 atomic_add_long(&hammer2_count_modified_chains, -1); 1904 if (chain->pmp) 1905 hammer2_pfs_memory_wakeup(chain->pmp, -1); 1906 } 1907 if (setupdate) { 1908 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1909 } 1910 lockmgr(&chain->diolk, LK_RELEASE); 1911 1912 return error; 1913 } 1914 1915 /* 1916 * Update mirror_tid and modify_tid. modify_tid is only updated 1917 * if not passed as zero (during flushes, parent propagation passes 1918 * the value 0). 1919 * 1920 * NOTE: chain->pmp could be the device spmp. 1921 */ 1922 chain->bref.mirror_tid = hmp->voldata.mirror_tid + 1; 1923 if (mtid) 1924 chain->bref.modify_tid = mtid; 1925 1926 /* 1927 * Set BLKMAPUPD to tell the flush code that an existing blockmap entry 1928 * requires updating as well as to tell the delete code that the 1929 * chain's blockref might not exactly match (in terms of physical size 1930 * or block offset) the one in the parent's blocktable. The base key 1931 * of course will still match. 1932 */ 1933 if (chain->flags & HAMMER2_CHAIN_BLKMAPPED) 1934 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPUPD); 1935 1936 /* 1937 * Short-cut data block handling when the caller does not need an 1938 * actual data reference to (aka OPTDATA), as long as the chain does 1939 * not already have a data pointer to the data and no de-duplication 1940 * occurred. 1941 * 1942 * This generally means that the modifications are being done via the 1943 * logical buffer cache. 1944 * 1945 * NOTE: If deduplication occurred we have to run through the data 1946 * stuff to clear INITIAL, and the caller will likely want to 1947 * assign the check code anyway. Leaving INITIAL set on a 1948 * dedup can be deadly (it can cause the block to be zero'd!). 1949 * 1950 * This code also handles bytes == 0 (most dirents). 1951 */ 1952 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA && 1953 (flags & HAMMER2_MODIFY_OPTDATA) && 1954 chain->data == NULL) { 1955 if (dedup_off == 0) { 1956 KKASSERT(chain->dio == NULL); 1957 goto skip2; 1958 } 1959 } 1960 1961 /* 1962 * Clearing the INITIAL flag (for indirect blocks) indicates that 1963 * we've processed the uninitialized storage allocation. 1964 * 1965 * If this flag is already clear we are likely in a copy-on-write 1966 * situation but we have to be sure NOT to bzero the storage if 1967 * no data is present. 1968 * 1969 * Clearing of NOTTESTED is allowed if the MODIFIED bit is set, 1970 */ 1971 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1972 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 1973 wasinitial = 1; 1974 } else { 1975 wasinitial = 0; 1976 } 1977 1978 /* 1979 * Instantiate data buffer and possibly execute COW operation 1980 */ 1981 switch(chain->bref.type) { 1982 case HAMMER2_BREF_TYPE_VOLUME: 1983 case HAMMER2_BREF_TYPE_FREEMAP: 1984 /* 1985 * The data is embedded, no copy-on-write operation is 1986 * needed. 1987 */ 1988 KKASSERT(chain->dio == NULL); 1989 break; 1990 case HAMMER2_BREF_TYPE_DIRENT: 1991 /* 1992 * The data might be fully embedded. 1993 */ 1994 if (chain->bytes == 0) { 1995 KKASSERT(chain->dio == NULL); 1996 break; 1997 } 1998 /* fall through */ 1999 case HAMMER2_BREF_TYPE_INODE: 2000 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 2001 case HAMMER2_BREF_TYPE_DATA: 2002 case HAMMER2_BREF_TYPE_INDIRECT: 2003 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 2004 /* 2005 * Perform the copy-on-write operation 2006 * 2007 * zero-fill or copy-on-write depending on whether 2008 * chain->data exists or not and set the dirty state for 2009 * the new buffer. hammer2_io_new() will handle the 2010 * zero-fill. 2011 * 2012 * If a dedup_off was supplied this is an existing block 2013 * and no COW, copy, or further modification is required. 2014 */ 2015 KKASSERT(chain != &hmp->vchain && chain != &hmp->fchain); 2016 2017 if (wasinitial && dedup_off == 0) { 2018 error = hammer2_io_new(hmp, chain->bref.type, 2019 chain->bref.data_off, 2020 chain->bytes, &dio); 2021 } else { 2022 error = hammer2_io_bread(hmp, chain->bref.type, 2023 chain->bref.data_off, 2024 chain->bytes, &dio); 2025 } 2026 hammer2_adjreadcounter(chain->bref.type, chain->bytes); 2027 2028 /* 2029 * If an I/O error occurs make sure callers cannot accidently 2030 * modify the old buffer's contents and corrupt the filesystem. 2031 * 2032 * NOTE: hammer2_io_data() call issues bkvasync() 2033 */ 2034 if (error) { 2035 kprintf("hammer2_chain_modify: hmp=%p I/O error\n", 2036 hmp); 2037 chain->error = HAMMER2_ERROR_EIO; 2038 hammer2_io_brelse(&dio); 2039 hammer2_io_brelse(&chain->dio); 2040 chain->data = NULL; 2041 break; 2042 } 2043 chain->error = 0; 2044 bdata = hammer2_io_data(dio, chain->bref.data_off); 2045 2046 if (chain->data) { 2047 /* 2048 * COW (unless a dedup). 2049 */ 2050 KKASSERT(chain->dio != NULL); 2051 if (chain->data != (void *)bdata && dedup_off == 0) { 2052 bcopy(chain->data, bdata, chain->bytes); 2053 } 2054 } else if (wasinitial == 0 && dedup_off == 0) { 2055 /* 2056 * We have a problem. We were asked to COW but 2057 * we don't have any data to COW with! 2058 */ 2059 panic("hammer2_chain_modify: having a COW %p\n", 2060 chain); 2061 } 2062 2063 /* 2064 * Retire the old buffer, replace with the new. Dirty or 2065 * redirty the new buffer. 2066 * 2067 * WARNING! The system buffer cache may have already flushed 2068 * the buffer, so we must be sure to [re]dirty it 2069 * for further modification. 2070 * 2071 * If dedup_off was supplied, the caller is not 2072 * expected to make any further modification to the 2073 * buffer. 2074 * 2075 * WARNING! hammer2_get_gdata() assumes dio never transitions 2076 * through NULL in order to optimize away unnecessary 2077 * diolk operations. 2078 */ 2079 { 2080 hammer2_io_t *tio; 2081 2082 if ((tio = chain->dio) != NULL) 2083 hammer2_io_bqrelse(&tio); 2084 chain->data = (void *)bdata; 2085 chain->dio = dio; 2086 if (dedup_off == 0) 2087 hammer2_io_setdirty(dio); 2088 } 2089 break; 2090 default: 2091 panic("hammer2_chain_modify: illegal non-embedded type %d", 2092 chain->bref.type); 2093 break; 2094 2095 } 2096 skip2: 2097 /* 2098 * setflush on parent indicating that the parent must recurse down 2099 * to us. Do not call on chain itself which might already have it 2100 * set. 2101 */ 2102 if (chain->parent) 2103 hammer2_chain_setflush(chain->parent); 2104 lockmgr(&chain->diolk, LK_RELEASE); 2105 2106 return (chain->error); 2107 } 2108 2109 /* 2110 * Modify the chain associated with an inode. 2111 */ 2112 int 2113 hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain, 2114 hammer2_tid_t mtid, int flags) 2115 { 2116 int error; 2117 2118 hammer2_inode_modify(ip); 2119 error = hammer2_chain_modify(chain, mtid, 0, flags); 2120 2121 return error; 2122 } 2123 2124 /* 2125 * This function returns the chain at the nearest key within the specified 2126 * range. The returned chain will be referenced but not locked. 2127 * 2128 * This function will recurse through chain->rbtree as necessary and will 2129 * return a *key_nextp suitable for iteration. *key_nextp is only set if 2130 * the iteration value is less than the current value of *key_nextp. 2131 * 2132 * The caller should use (*key_nextp) to calculate the actual range of 2133 * the returned element, which will be (key_beg to *key_nextp - 1), because 2134 * there might be another element which is superior to the returned element 2135 * and overlaps it. 2136 * 2137 * (*key_nextp) can be passed as key_beg in an iteration only while non-NULL 2138 * chains continue to be returned. On EOF (*key_nextp) may overflow since 2139 * it will wind up being (key_end + 1). 2140 * 2141 * WARNING! Must be called with child's spinlock held. Spinlock remains 2142 * held through the operation. 2143 */ 2144 struct hammer2_chain_find_info { 2145 hammer2_chain_t *best; 2146 hammer2_key_t key_beg; 2147 hammer2_key_t key_end; 2148 hammer2_key_t key_next; 2149 }; 2150 2151 static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data); 2152 static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data); 2153 2154 static 2155 hammer2_chain_t * 2156 hammer2_chain_find(hammer2_chain_t *parent, hammer2_key_t *key_nextp, 2157 hammer2_key_t key_beg, hammer2_key_t key_end) 2158 { 2159 struct hammer2_chain_find_info info; 2160 2161 info.best = NULL; 2162 info.key_beg = key_beg; 2163 info.key_end = key_end; 2164 info.key_next = *key_nextp; 2165 2166 RB_SCAN(hammer2_chain_tree, &parent->core.rbtree, 2167 hammer2_chain_find_cmp, hammer2_chain_find_callback, 2168 &info); 2169 *key_nextp = info.key_next; 2170 #if 0 2171 kprintf("chain_find %p %016jx:%016jx next=%016jx\n", 2172 parent, key_beg, key_end, *key_nextp); 2173 #endif 2174 2175 return (info.best); 2176 } 2177 2178 static 2179 int 2180 hammer2_chain_find_cmp(hammer2_chain_t *child, void *data) 2181 { 2182 struct hammer2_chain_find_info *info = data; 2183 hammer2_key_t child_beg; 2184 hammer2_key_t child_end; 2185 2186 child_beg = child->bref.key; 2187 child_end = child_beg + ((hammer2_key_t)1 << child->bref.keybits) - 1; 2188 2189 if (child_end < info->key_beg) 2190 return(-1); 2191 if (child_beg > info->key_end) 2192 return(1); 2193 return(0); 2194 } 2195 2196 static 2197 int 2198 hammer2_chain_find_callback(hammer2_chain_t *child, void *data) 2199 { 2200 struct hammer2_chain_find_info *info = data; 2201 hammer2_chain_t *best; 2202 hammer2_key_t child_end; 2203 2204 /* 2205 * WARNING! Layerq is scanned forwards, exact matches should keep 2206 * the existing info->best. 2207 */ 2208 if ((best = info->best) == NULL) { 2209 /* 2210 * No previous best. Assign best 2211 */ 2212 info->best = child; 2213 } else if (best->bref.key <= info->key_beg && 2214 child->bref.key <= info->key_beg) { 2215 /* 2216 * Illegal overlap. 2217 */ 2218 KKASSERT(0); 2219 /*info->best = child;*/ 2220 } else if (child->bref.key < best->bref.key) { 2221 /* 2222 * Child has a nearer key and best is not flush with key_beg. 2223 * Set best to child. Truncate key_next to the old best key. 2224 */ 2225 info->best = child; 2226 if (info->key_next > best->bref.key || info->key_next == 0) 2227 info->key_next = best->bref.key; 2228 } else if (child->bref.key == best->bref.key) { 2229 /* 2230 * If our current best is flush with the child then this 2231 * is an illegal overlap. 2232 * 2233 * key_next will automatically be limited to the smaller of 2234 * the two end-points. 2235 */ 2236 KKASSERT(0); 2237 info->best = child; 2238 } else { 2239 /* 2240 * Keep the current best but truncate key_next to the child's 2241 * base. 2242 * 2243 * key_next will also automatically be limited to the smaller 2244 * of the two end-points (probably not necessary for this case 2245 * but we do it anyway). 2246 */ 2247 if (info->key_next > child->bref.key || info->key_next == 0) 2248 info->key_next = child->bref.key; 2249 } 2250 2251 /* 2252 * Always truncate key_next based on child's end-of-range. 2253 */ 2254 child_end = child->bref.key + ((hammer2_key_t)1 << child->bref.keybits); 2255 if (child_end && (info->key_next > child_end || info->key_next == 0)) 2256 info->key_next = child_end; 2257 2258 return(0); 2259 } 2260 2261 /* 2262 * Retrieve the specified chain from a media blockref, creating the 2263 * in-memory chain structure which reflects it. The returned chain is 2264 * held and locked according to (how) (HAMMER2_RESOLVE_*). The caller must 2265 * handle crc-checks and so forth, and should check chain->error before 2266 * assuming that the data is good. 2267 * 2268 * To handle insertion races pass the INSERT_RACE flag along with the 2269 * generation number of the core. NULL will be returned if the generation 2270 * number changes before we have a chance to insert the chain. Insert 2271 * races can occur because the parent might be held shared. 2272 * 2273 * Caller must hold the parent locked shared or exclusive since we may 2274 * need the parent's bref array to find our block. 2275 * 2276 * WARNING! chain->pmp is always set to NULL for any chain representing 2277 * part of the super-root topology. 2278 */ 2279 hammer2_chain_t * 2280 hammer2_chain_get(hammer2_chain_t *parent, int generation, 2281 hammer2_blockref_t *bref, int how) 2282 { 2283 hammer2_dev_t *hmp = parent->hmp; 2284 hammer2_chain_t *chain; 2285 int error; 2286 2287 /* 2288 * Allocate a chain structure representing the existing media 2289 * entry. Resulting chain has one ref and is not locked. 2290 */ 2291 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) 2292 chain = hammer2_chain_alloc(hmp, NULL, bref); 2293 else 2294 chain = hammer2_chain_alloc(hmp, parent->pmp, bref); 2295 /* ref'd chain returned */ 2296 2297 /* 2298 * Flag that the chain is in the parent's blockmap so delete/flush 2299 * knows what to do with it. 2300 */ 2301 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED); 2302 2303 /* 2304 * chain must be locked to avoid unexpected ripouts 2305 */ 2306 hammer2_chain_lock(chain, how); 2307 2308 /* 2309 * Link the chain into its parent. A spinlock is required to safely 2310 * access the RBTREE, and it is possible to collide with another 2311 * hammer2_chain_get() operation because the caller might only hold 2312 * a shared lock on the parent. 2313 * 2314 * NOTE: Get races can occur quite often when we distribute 2315 * asynchronous read-aheads across multiple threads. 2316 */ 2317 KKASSERT(parent->refs > 0); 2318 error = hammer2_chain_insert(parent, chain, 2319 HAMMER2_CHAIN_INSERT_SPIN | 2320 HAMMER2_CHAIN_INSERT_RACE, 2321 generation); 2322 if (error) { 2323 KKASSERT((chain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); 2324 /*kprintf("chain %p get race\n", chain);*/ 2325 hammer2_chain_unlock(chain); 2326 hammer2_chain_drop(chain); 2327 chain = NULL; 2328 } else { 2329 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); 2330 } 2331 2332 /* 2333 * Return our new chain referenced but not locked, or NULL if 2334 * a race occurred. 2335 */ 2336 return (chain); 2337 } 2338 2339 /* 2340 * Lookup initialization/completion API 2341 */ 2342 hammer2_chain_t * 2343 hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags) 2344 { 2345 hammer2_chain_ref(parent); 2346 if (flags & HAMMER2_LOOKUP_SHARED) { 2347 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS | 2348 HAMMER2_RESOLVE_SHARED); 2349 } else { 2350 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 2351 } 2352 return (parent); 2353 } 2354 2355 void 2356 hammer2_chain_lookup_done(hammer2_chain_t *parent) 2357 { 2358 if (parent) { 2359 hammer2_chain_unlock(parent); 2360 hammer2_chain_drop(parent); 2361 } 2362 } 2363 2364 /* 2365 * Take the locked chain and return a locked parent. The chain remains 2366 * locked on return, but may have to be temporarily unlocked to acquire 2367 * the parent. Because of this, (chain) must be stable and cannot be 2368 * deleted while it was temporarily unlocked (typically means that (chain) 2369 * is an inode). 2370 * 2371 * Pass HAMMER2_RESOLVE_* flags in flags. 2372 * 2373 * This will work even if the chain is errored, and the caller can check 2374 * parent->error on return if desired since the parent will be locked. 2375 * 2376 * This function handles the lock order reversal. 2377 */ 2378 hammer2_chain_t * 2379 hammer2_chain_getparent(hammer2_chain_t *chain, int flags) 2380 { 2381 hammer2_chain_t *parent; 2382 2383 /* 2384 * Be careful of order, chain must be unlocked before parent 2385 * is locked below to avoid a deadlock. Try it trivially first. 2386 */ 2387 parent = chain->parent; 2388 if (parent == NULL) 2389 panic("hammer2_chain_getparent: no parent"); 2390 hammer2_chain_ref(parent); 2391 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) 2392 return parent; 2393 2394 for (;;) { 2395 hammer2_chain_unlock(chain); 2396 hammer2_chain_lock(parent, flags); 2397 hammer2_chain_lock(chain, flags); 2398 2399 /* 2400 * Parent relinking races are quite common. We have to get 2401 * it right or we will blow up the block table. 2402 */ 2403 if (chain->parent == parent) 2404 break; 2405 hammer2_chain_unlock(parent); 2406 hammer2_chain_drop(parent); 2407 cpu_ccfence(); 2408 parent = chain->parent; 2409 if (parent == NULL) 2410 panic("hammer2_chain_getparent: no parent"); 2411 hammer2_chain_ref(parent); 2412 } 2413 return parent; 2414 } 2415 2416 /* 2417 * Take the locked chain and return a locked parent. The chain is unlocked 2418 * and dropped. *chainp is set to the returned parent as a convenience. 2419 * Pass HAMMER2_RESOLVE_* flags in flags. 2420 * 2421 * This will work even if the chain is errored, and the caller can check 2422 * parent->error on return if desired since the parent will be locked. 2423 * 2424 * The chain does NOT need to be stable. We use a tracking structure 2425 * to track the expected parent if the chain is deleted out from under us. 2426 * 2427 * This function handles the lock order reversal. 2428 */ 2429 hammer2_chain_t * 2430 hammer2_chain_repparent(hammer2_chain_t **chainp, int flags) 2431 { 2432 hammer2_chain_t *chain; 2433 hammer2_chain_t *parent; 2434 struct hammer2_reptrack reptrack; 2435 struct hammer2_reptrack **repp; 2436 2437 /* 2438 * Be careful of order, chain must be unlocked before parent 2439 * is locked below to avoid a deadlock. Try it trivially first. 2440 */ 2441 chain = *chainp; 2442 parent = chain->parent; 2443 if (parent == NULL) { 2444 hammer2_spin_unex(&chain->core.spin); 2445 panic("hammer2_chain_repparent: no parent"); 2446 } 2447 hammer2_chain_ref(parent); 2448 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) { 2449 hammer2_chain_unlock(chain); 2450 hammer2_chain_drop(chain); 2451 *chainp = parent; 2452 2453 return parent; 2454 } 2455 2456 /* 2457 * Ok, now it gets a bit nasty. There are multiple situations where 2458 * the parent might be in the middle of a deletion, or where the child 2459 * (chain) might be deleted the instant we let go of its lock. 2460 * We can potentially end up in a no-win situation! 2461 * 2462 * In particular, the indirect_maintenance() case can cause these 2463 * situations. 2464 * 2465 * To deal with this we install a reptrack structure in the parent 2466 * This reptrack structure 'owns' the parent ref and will automatically 2467 * migrate to the parent's parent if the parent is deleted permanently. 2468 */ 2469 hammer2_spin_init(&reptrack.spin, "h2reptrk"); 2470 reptrack.chain = parent; 2471 hammer2_chain_ref(parent); /* for the reptrack */ 2472 2473 hammer2_spin_ex(&parent->core.spin); 2474 reptrack.next = parent->core.reptrack; 2475 parent->core.reptrack = &reptrack; 2476 hammer2_spin_unex(&parent->core.spin); 2477 2478 hammer2_chain_unlock(chain); 2479 hammer2_chain_drop(chain); 2480 chain = NULL; /* gone */ 2481 2482 /* 2483 * At the top of this loop, chain is gone and parent is refd both 2484 * by us explicitly AND via our reptrack. We are attempting to 2485 * lock parent. 2486 */ 2487 for (;;) { 2488 hammer2_chain_lock(parent, flags); 2489 2490 if (reptrack.chain == parent) 2491 break; 2492 hammer2_chain_unlock(parent); 2493 hammer2_chain_drop(parent); 2494 2495 kprintf("hammer2: debug REPTRACK %p->%p\n", 2496 parent, reptrack.chain); 2497 hammer2_spin_ex(&reptrack.spin); 2498 parent = reptrack.chain; 2499 hammer2_chain_ref(parent); 2500 hammer2_spin_unex(&reptrack.spin); 2501 } 2502 2503 /* 2504 * Once parent is locked and matches our reptrack, our reptrack 2505 * will be stable and we have our parent. We can unlink our 2506 * reptrack. 2507 * 2508 * WARNING! Remember that the chain lock might be shared. Chains 2509 * locked shared have stable parent linkages. 2510 */ 2511 hammer2_spin_ex(&parent->core.spin); 2512 repp = &parent->core.reptrack; 2513 while (*repp != &reptrack) 2514 repp = &(*repp)->next; 2515 *repp = reptrack.next; 2516 hammer2_spin_unex(&parent->core.spin); 2517 2518 hammer2_chain_drop(parent); /* reptrack ref */ 2519 *chainp = parent; /* return parent lock+ref */ 2520 2521 return parent; 2522 } 2523 2524 /* 2525 * Dispose of any linked reptrack structures in (chain) by shifting them to 2526 * (parent). Both (chain) and (parent) must be exclusively locked. 2527 * 2528 * This is interlocked against any children of (chain) on the other side. 2529 * No children so remain as-of when this is called so we can test 2530 * core.reptrack without holding the spin-lock. 2531 * 2532 * Used whenever the caller intends to permanently delete chains related 2533 * to topological recursions (BREF_TYPE_INDIRECT, BREF_TYPE_FREEMAP_NODE), 2534 * where the chains underneath the node being deleted are given a new parent 2535 * above the node being deleted. 2536 */ 2537 static 2538 void 2539 hammer2_chain_repchange(hammer2_chain_t *parent, hammer2_chain_t *chain) 2540 { 2541 struct hammer2_reptrack *reptrack; 2542 2543 KKASSERT(chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)); 2544 while (chain->core.reptrack) { 2545 hammer2_spin_ex(&parent->core.spin); 2546 hammer2_spin_ex(&chain->core.spin); 2547 reptrack = chain->core.reptrack; 2548 if (reptrack == NULL) { 2549 hammer2_spin_unex(&chain->core.spin); 2550 hammer2_spin_unex(&parent->core.spin); 2551 break; 2552 } 2553 hammer2_spin_ex(&reptrack->spin); 2554 chain->core.reptrack = reptrack->next; 2555 reptrack->chain = parent; 2556 reptrack->next = parent->core.reptrack; 2557 parent->core.reptrack = reptrack; 2558 hammer2_chain_ref(parent); /* reptrack */ 2559 2560 hammer2_spin_unex(&chain->core.spin); 2561 hammer2_spin_unex(&parent->core.spin); 2562 kprintf("hammer2: debug repchange %p %p->%p\n", 2563 reptrack, chain, parent); 2564 hammer2_chain_drop(chain); /* reptrack */ 2565 } 2566 } 2567 2568 /* 2569 * Locate the first chain whos key range overlaps (key_beg, key_end) inclusive. 2570 * (*parentp) typically points to an inode but can also point to a related 2571 * indirect block and this function will recurse upwards and find the inode 2572 * or the nearest undeleted indirect block covering the key range. 2573 * 2574 * This function unconditionally sets *errorp, replacing any previous value. 2575 * 2576 * (*parentp) must be exclusive or shared locked (depending on flags) and 2577 * referenced and can be an inode or an existing indirect block within the 2578 * inode. 2579 * 2580 * If (*parent) is errored out, this function will not attempt to recurse 2581 * the radix tree and will return NULL along with an appropriate *errorp. 2582 * If NULL is returned and *errorp is 0, the requested lookup could not be 2583 * located. 2584 * 2585 * On return (*parentp) will be modified to point at the deepest parent chain 2586 * element encountered during the search, as a helper for an insertion or 2587 * deletion. 2588 * 2589 * The new (*parentp) will be locked shared or exclusive (depending on flags), 2590 * and referenced, and the old will be unlocked and dereferenced (no change 2591 * if they are both the same). This is particularly important if the caller 2592 * wishes to insert a new chain, (*parentp) will be set properly even if NULL 2593 * is returned, as long as no error occurred. 2594 * 2595 * The matching chain will be returned locked according to flags. 2596 * 2597 * -- 2598 * 2599 * NULL is returned if no match was found, but (*parentp) will still 2600 * potentially be adjusted. 2601 * 2602 * On return (*key_nextp) will point to an iterative value for key_beg. 2603 * (If NULL is returned (*key_nextp) is set to (key_end + 1)). 2604 * 2605 * This function will also recurse up the chain if the key is not within the 2606 * current parent's range. (*parentp) can never be set to NULL. An iteration 2607 * can simply allow (*parentp) to float inside the loop. 2608 * 2609 * NOTE! chain->data is not always resolved. By default it will not be 2610 * resolved for BREF_TYPE_DATA, FREEMAP_NODE, or FREEMAP_LEAF. Use 2611 * HAMMER2_LOOKUP_ALWAYS to force resolution (but be careful w/ 2612 * BREF_TYPE_DATA as the device buffer can alias the logical file 2613 * buffer). 2614 */ 2615 hammer2_chain_t * 2616 hammer2_chain_lookup(hammer2_chain_t **parentp, hammer2_key_t *key_nextp, 2617 hammer2_key_t key_beg, hammer2_key_t key_end, 2618 int *errorp, int flags) 2619 { 2620 hammer2_chain_t *parent; 2621 hammer2_chain_t *chain; 2622 hammer2_blockref_t *base; 2623 hammer2_blockref_t *bref; 2624 hammer2_blockref_t bsave; 2625 hammer2_key_t scan_beg; 2626 hammer2_key_t scan_end; 2627 int count = 0; 2628 int how_always = HAMMER2_RESOLVE_ALWAYS; 2629 int how_maybe = HAMMER2_RESOLVE_MAYBE; 2630 int how; 2631 int generation; 2632 int maxloops = 300000; 2633 2634 if (flags & HAMMER2_LOOKUP_ALWAYS) { 2635 how_maybe = how_always; 2636 how = HAMMER2_RESOLVE_ALWAYS; 2637 } else if (flags & HAMMER2_LOOKUP_NODATA) { 2638 how = HAMMER2_RESOLVE_NEVER; 2639 } else { 2640 how = HAMMER2_RESOLVE_MAYBE; 2641 } 2642 if (flags & HAMMER2_LOOKUP_SHARED) { 2643 how_maybe |= HAMMER2_RESOLVE_SHARED; 2644 how_always |= HAMMER2_RESOLVE_SHARED; 2645 how |= HAMMER2_RESOLVE_SHARED; 2646 } 2647 2648 /* 2649 * Recurse (*parentp) upward if necessary until the parent completely 2650 * encloses the key range or we hit the inode. 2651 * 2652 * Handle races against the flusher deleting indirect nodes on its 2653 * way back up by continuing to recurse upward past the deletion. 2654 */ 2655 parent = *parentp; 2656 *errorp = 0; 2657 2658 while (parent->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 2659 parent->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2660 scan_beg = parent->bref.key; 2661 scan_end = scan_beg + 2662 ((hammer2_key_t)1 << parent->bref.keybits) - 1; 2663 if ((parent->flags & HAMMER2_CHAIN_DELETED) == 0) { 2664 if (key_beg >= scan_beg && key_end <= scan_end) 2665 break; 2666 } 2667 parent = hammer2_chain_repparent(parentp, how_maybe); 2668 } 2669 again: 2670 if (--maxloops == 0) 2671 panic("hammer2_chain_lookup: maxloops"); 2672 2673 /* 2674 * MATCHIND case that does not require parent->data (do prior to 2675 * parent->error check). 2676 */ 2677 switch(parent->bref.type) { 2678 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 2679 case HAMMER2_BREF_TYPE_INDIRECT: 2680 if (flags & HAMMER2_LOOKUP_MATCHIND) { 2681 scan_beg = parent->bref.key; 2682 scan_end = scan_beg + 2683 ((hammer2_key_t)1 << parent->bref.keybits) - 1; 2684 if (key_beg == scan_beg && key_end == scan_end) { 2685 chain = parent; 2686 hammer2_chain_ref(chain); 2687 hammer2_chain_lock(chain, how_maybe); 2688 *key_nextp = scan_end + 1; 2689 goto done; 2690 } 2691 } 2692 break; 2693 default: 2694 break; 2695 } 2696 2697 /* 2698 * No lookup is possible if the parent is errored. We delayed 2699 * this check as long as we could to ensure that the parent backup, 2700 * embedded data, and MATCHIND code could still execute. 2701 */ 2702 if (parent->error) { 2703 *errorp = parent->error; 2704 return NULL; 2705 } 2706 2707 /* 2708 * Locate the blockref array. Currently we do a fully associative 2709 * search through the array. 2710 */ 2711 switch(parent->bref.type) { 2712 case HAMMER2_BREF_TYPE_INODE: 2713 /* 2714 * Special shortcut for embedded data returns the inode 2715 * itself. Callers must detect this condition and access 2716 * the embedded data (the strategy code does this for us). 2717 * 2718 * This is only applicable to regular files and softlinks. 2719 * 2720 * We need a second lock on parent. Since we already have 2721 * a lock we must pass LOCKAGAIN to prevent unexpected 2722 * blocking (we don't want to block on a second shared 2723 * ref if an exclusive lock is pending) 2724 */ 2725 if (parent->data->ipdata.meta.op_flags & 2726 HAMMER2_OPFLAG_DIRECTDATA) { 2727 if (flags & HAMMER2_LOOKUP_NODIRECT) { 2728 chain = NULL; 2729 *key_nextp = key_end + 1; 2730 goto done; 2731 } 2732 hammer2_chain_ref(parent); 2733 hammer2_chain_lock(parent, how_always | 2734 HAMMER2_RESOLVE_LOCKAGAIN); 2735 *key_nextp = key_end + 1; 2736 return (parent); 2737 } 2738 base = &parent->data->ipdata.u.blockset.blockref[0]; 2739 count = HAMMER2_SET_COUNT; 2740 break; 2741 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 2742 case HAMMER2_BREF_TYPE_INDIRECT: 2743 /* 2744 * Optimize indirect blocks in the INITIAL state to avoid 2745 * I/O. 2746 * 2747 * Debugging: Enter permanent wait state instead of 2748 * panicing on unexpectedly NULL data for the moment. 2749 */ 2750 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 2751 base = NULL; 2752 } else { 2753 if (parent->data == NULL) { 2754 kprintf("hammer2: unexpected NULL data " 2755 "on %p\n", parent); 2756 while (1) 2757 tsleep(parent, 0, "xxx", 0); 2758 } 2759 base = &parent->data->npdata[0]; 2760 } 2761 count = parent->bytes / sizeof(hammer2_blockref_t); 2762 break; 2763 case HAMMER2_BREF_TYPE_VOLUME: 2764 base = &parent->data->voldata.sroot_blockset.blockref[0]; 2765 count = HAMMER2_SET_COUNT; 2766 break; 2767 case HAMMER2_BREF_TYPE_FREEMAP: 2768 base = &parent->data->blkset.blockref[0]; 2769 count = HAMMER2_SET_COUNT; 2770 break; 2771 default: 2772 panic("hammer2_chain_lookup: unrecognized " 2773 "blockref(B) type: %d", 2774 parent->bref.type); 2775 base = NULL; /* safety */ 2776 count = 0; /* safety */ 2777 break; 2778 } 2779 2780 /* 2781 * Merged scan to find next candidate. 2782 * 2783 * hammer2_base_*() functions require the parent->core.live_* fields 2784 * to be synchronized. 2785 * 2786 * We need to hold the spinlock to access the block array and RB tree 2787 * and to interlock chain creation. 2788 */ 2789 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 2790 hammer2_chain_countbrefs(parent, base, count); 2791 2792 /* 2793 * Combined search 2794 */ 2795 hammer2_spin_ex(&parent->core.spin); 2796 chain = hammer2_combined_find(parent, base, count, 2797 key_nextp, 2798 key_beg, key_end, 2799 &bref); 2800 generation = parent->core.generation; 2801 2802 /* 2803 * Exhausted parent chain, iterate. 2804 */ 2805 if (bref == NULL) { 2806 KKASSERT(chain == NULL); 2807 hammer2_spin_unex(&parent->core.spin); 2808 if (key_beg == key_end) /* short cut single-key case */ 2809 return (NULL); 2810 2811 /* 2812 * Stop if we reached the end of the iteration. 2813 */ 2814 if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && 2815 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2816 return (NULL); 2817 } 2818 2819 /* 2820 * Calculate next key, stop if we reached the end of the 2821 * iteration, otherwise go up one level and loop. 2822 */ 2823 key_beg = parent->bref.key + 2824 ((hammer2_key_t)1 << parent->bref.keybits); 2825 if (key_beg == 0 || key_beg > key_end) 2826 return (NULL); 2827 parent = hammer2_chain_repparent(parentp, how_maybe); 2828 goto again; 2829 } 2830 2831 /* 2832 * Selected from blockref or in-memory chain. 2833 */ 2834 bsave = *bref; 2835 if (chain == NULL) { 2836 hammer2_spin_unex(&parent->core.spin); 2837 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || 2838 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2839 chain = hammer2_chain_get(parent, generation, 2840 &bsave, how_maybe); 2841 } else { 2842 chain = hammer2_chain_get(parent, generation, 2843 &bsave, how); 2844 } 2845 if (chain == NULL) 2846 goto again; 2847 } else { 2848 hammer2_chain_ref(chain); 2849 hammer2_spin_unex(&parent->core.spin); 2850 2851 /* 2852 * chain is referenced but not locked. We must lock the 2853 * chain to obtain definitive state. 2854 */ 2855 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || 2856 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2857 hammer2_chain_lock(chain, how_maybe); 2858 } else { 2859 hammer2_chain_lock(chain, how); 2860 } 2861 KKASSERT(chain->parent == parent); 2862 } 2863 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || 2864 chain->parent != parent) { 2865 hammer2_chain_unlock(chain); 2866 hammer2_chain_drop(chain); 2867 chain = NULL; /* SAFETY */ 2868 goto again; 2869 } 2870 2871 2872 /* 2873 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) 2874 * 2875 * NOTE: Chain's key range is not relevant as there might be 2876 * one-offs within the range that are not deleted. 2877 * 2878 * NOTE: Lookups can race delete-duplicate because 2879 * delete-duplicate does not lock the parent's core 2880 * (they just use the spinlock on the core). 2881 */ 2882 if (chain->flags & HAMMER2_CHAIN_DELETED) { 2883 kprintf("skip deleted chain %016jx.%02x key=%016jx\n", 2884 chain->bref.data_off, chain->bref.type, 2885 chain->bref.key); 2886 hammer2_chain_unlock(chain); 2887 hammer2_chain_drop(chain); 2888 chain = NULL; /* SAFETY */ 2889 key_beg = *key_nextp; 2890 if (key_beg == 0 || key_beg > key_end) 2891 return(NULL); 2892 goto again; 2893 } 2894 2895 /* 2896 * If the chain element is an indirect block it becomes the new 2897 * parent and we loop on it. We must maintain our top-down locks 2898 * to prevent the flusher from interfering (i.e. doing a 2899 * delete-duplicate and leaving us recursing down a deleted chain). 2900 * 2901 * The parent always has to be locked with at least RESOLVE_MAYBE 2902 * so we can access its data. It might need a fixup if the caller 2903 * passed incompatible flags. Be careful not to cause a deadlock 2904 * as a data-load requires an exclusive lock. 2905 * 2906 * If HAMMER2_LOOKUP_MATCHIND is set and the indirect block's key 2907 * range is within the requested key range we return the indirect 2908 * block and do NOT loop. This is usually only used to acquire 2909 * freemap nodes. 2910 */ 2911 if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 2912 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2913 hammer2_chain_unlock(parent); 2914 hammer2_chain_drop(parent); 2915 *parentp = parent = chain; 2916 chain = NULL; /* SAFETY */ 2917 goto again; 2918 } 2919 done: 2920 /* 2921 * All done, return the locked chain. 2922 * 2923 * If the caller does not want a locked chain, replace the lock with 2924 * a ref. Perhaps this can eventually be optimized to not obtain the 2925 * lock in the first place for situations where the data does not 2926 * need to be resolved. 2927 * 2928 * NOTE! A chain->error must be tested by the caller upon return. 2929 * *errorp is only set based on issues which occur while 2930 * trying to reach the chain. 2931 */ 2932 return (chain); 2933 } 2934 2935 /* 2936 * After having issued a lookup we can iterate all matching keys. 2937 * 2938 * If chain is non-NULL we continue the iteration from just after it's index. 2939 * 2940 * If chain is NULL we assume the parent was exhausted and continue the 2941 * iteration at the next parent. 2942 * 2943 * If a fatal error occurs (typically an I/O error), a dummy chain is 2944 * returned with chain->error and error-identifying information set. This 2945 * chain will assert if you try to do anything fancy with it. 2946 * 2947 * XXX Depending on where the error occurs we should allow continued iteration. 2948 * 2949 * parent must be locked on entry and remains locked throughout. chain's 2950 * lock status must match flags. Chain is always at least referenced. 2951 * 2952 * WARNING! The MATCHIND flag does not apply to this function. 2953 */ 2954 hammer2_chain_t * 2955 hammer2_chain_next(hammer2_chain_t **parentp, hammer2_chain_t *chain, 2956 hammer2_key_t *key_nextp, 2957 hammer2_key_t key_beg, hammer2_key_t key_end, 2958 int *errorp, int flags) 2959 { 2960 hammer2_chain_t *parent; 2961 int how_maybe; 2962 2963 /* 2964 * Calculate locking flags for upward recursion. 2965 */ 2966 how_maybe = HAMMER2_RESOLVE_MAYBE; 2967 if (flags & HAMMER2_LOOKUP_SHARED) 2968 how_maybe |= HAMMER2_RESOLVE_SHARED; 2969 2970 parent = *parentp; 2971 *errorp = 0; 2972 2973 /* 2974 * Calculate the next index and recalculate the parent if necessary. 2975 */ 2976 if (chain) { 2977 key_beg = chain->bref.key + 2978 ((hammer2_key_t)1 << chain->bref.keybits); 2979 hammer2_chain_unlock(chain); 2980 hammer2_chain_drop(chain); 2981 2982 /* 2983 * chain invalid past this point, but we can still do a 2984 * pointer comparison w/parent. 2985 * 2986 * Any scan where the lookup returned degenerate data embedded 2987 * in the inode has an invalid index and must terminate. 2988 */ 2989 if (chain == parent) 2990 return(NULL); 2991 if (key_beg == 0 || key_beg > key_end) 2992 return(NULL); 2993 chain = NULL; 2994 } else if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && 2995 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2996 /* 2997 * We reached the end of the iteration. 2998 */ 2999 return (NULL); 3000 } else { 3001 /* 3002 * Continue iteration with next parent unless the current 3003 * parent covers the range. 3004 * 3005 * (This also handles the case of a deleted, empty indirect 3006 * node). 3007 */ 3008 key_beg = parent->bref.key + 3009 ((hammer2_key_t)1 << parent->bref.keybits); 3010 if (key_beg == 0 || key_beg > key_end) 3011 return (NULL); 3012 parent = hammer2_chain_repparent(parentp, how_maybe); 3013 } 3014 3015 /* 3016 * And execute 3017 */ 3018 return (hammer2_chain_lookup(parentp, key_nextp, 3019 key_beg, key_end, 3020 errorp, flags)); 3021 } 3022 3023 /* 3024 * Caller wishes to iterate chains under parent, loading new chains into 3025 * chainp. Caller must initialize *chainp to NULL and *firstp to 1, and 3026 * then call hammer2_chain_scan() repeatedly until a non-zero return. 3027 * During the scan, *firstp will be set to 0 and (*chainp) will be replaced 3028 * with the returned chain for the scan. The returned *chainp will be 3029 * locked and referenced. Any prior contents will be unlocked and dropped. 3030 * 3031 * Caller should check the return value. A normal scan EOF will return 3032 * exactly HAMMER2_ERROR_EOF. Any other non-zero value indicates an 3033 * error trying to access parent data. Any error in the returned chain 3034 * must be tested separately by the caller. 3035 * 3036 * (*chainp) is dropped on each scan, but will only be set if the returned 3037 * element itself can recurse. Leaf elements are NOT resolved, loaded, or 3038 * returned via *chainp. The caller will get their bref only. 3039 * 3040 * The raw scan function is similar to lookup/next but does not seek to a key. 3041 * Blockrefs are iterated via first_bref = (parent, NULL) and 3042 * next_chain = (parent, bref). 3043 * 3044 * The passed-in parent must be locked and its data resolved. The function 3045 * nominally returns a locked and referenced *chainp != NULL for chains 3046 * the caller might need to recurse on (and will dipose of any *chainp passed 3047 * in). The caller must check the chain->bref.type either way. 3048 */ 3049 int 3050 hammer2_chain_scan(hammer2_chain_t *parent, hammer2_chain_t **chainp, 3051 hammer2_blockref_t *bref, int *firstp, 3052 int flags) 3053 { 3054 hammer2_blockref_t *base; 3055 hammer2_blockref_t *bref_ptr; 3056 hammer2_key_t key; 3057 hammer2_key_t next_key; 3058 hammer2_chain_t *chain = NULL; 3059 int count = 0; 3060 int how; 3061 int generation; 3062 int maxloops = 300000; 3063 int error; 3064 3065 error = 0; 3066 3067 /* 3068 * Scan flags borrowed from lookup. 3069 */ 3070 if (flags & HAMMER2_LOOKUP_ALWAYS) { 3071 how = HAMMER2_RESOLVE_ALWAYS; 3072 } else if (flags & HAMMER2_LOOKUP_NODATA) { 3073 how = HAMMER2_RESOLVE_NEVER; 3074 } else { 3075 how = HAMMER2_RESOLVE_MAYBE; 3076 } 3077 if (flags & HAMMER2_LOOKUP_SHARED) { 3078 how |= HAMMER2_RESOLVE_SHARED; 3079 } 3080 3081 /* 3082 * Calculate key to locate first/next element, unlocking the previous 3083 * element as we go. Be careful, the key calculation can overflow. 3084 * 3085 * (also reset bref to NULL) 3086 */ 3087 if (*firstp) { 3088 key = 0; 3089 *firstp = 0; 3090 } else { 3091 key = bref->key + ((hammer2_key_t)1 << bref->keybits); 3092 if ((chain = *chainp) != NULL) { 3093 *chainp = NULL; 3094 hammer2_chain_unlock(chain); 3095 hammer2_chain_drop(chain); 3096 chain = NULL; 3097 } 3098 if (key == 0) { 3099 error |= HAMMER2_ERROR_EOF; 3100 goto done; 3101 } 3102 } 3103 3104 again: 3105 if (parent->error) { 3106 error = parent->error; 3107 goto done; 3108 } 3109 if (--maxloops == 0) 3110 panic("hammer2_chain_scan: maxloops"); 3111 3112 /* 3113 * Locate the blockref array. Currently we do a fully associative 3114 * search through the array. 3115 */ 3116 switch(parent->bref.type) { 3117 case HAMMER2_BREF_TYPE_INODE: 3118 /* 3119 * An inode with embedded data has no sub-chains. 3120 * 3121 * WARNING! Bulk scan code may pass a static chain marked 3122 * as BREF_TYPE_INODE with a copy of the volume 3123 * root blockset to snapshot the volume. 3124 */ 3125 if (parent->data->ipdata.meta.op_flags & 3126 HAMMER2_OPFLAG_DIRECTDATA) { 3127 error |= HAMMER2_ERROR_EOF; 3128 goto done; 3129 } 3130 base = &parent->data->ipdata.u.blockset.blockref[0]; 3131 count = HAMMER2_SET_COUNT; 3132 break; 3133 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3134 case HAMMER2_BREF_TYPE_INDIRECT: 3135 /* 3136 * Optimize indirect blocks in the INITIAL state to avoid 3137 * I/O. 3138 */ 3139 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 3140 base = NULL; 3141 } else { 3142 if (parent->data == NULL) 3143 panic("parent->data is NULL"); 3144 base = &parent->data->npdata[0]; 3145 } 3146 count = parent->bytes / sizeof(hammer2_blockref_t); 3147 break; 3148 case HAMMER2_BREF_TYPE_VOLUME: 3149 base = &parent->data->voldata.sroot_blockset.blockref[0]; 3150 count = HAMMER2_SET_COUNT; 3151 break; 3152 case HAMMER2_BREF_TYPE_FREEMAP: 3153 base = &parent->data->blkset.blockref[0]; 3154 count = HAMMER2_SET_COUNT; 3155 break; 3156 default: 3157 panic("hammer2_chain_scan: unrecognized blockref type: %d", 3158 parent->bref.type); 3159 base = NULL; /* safety */ 3160 count = 0; /* safety */ 3161 break; 3162 } 3163 3164 /* 3165 * Merged scan to find next candidate. 3166 * 3167 * hammer2_base_*() functions require the parent->core.live_* fields 3168 * to be synchronized. 3169 * 3170 * We need to hold the spinlock to access the block array and RB tree 3171 * and to interlock chain creation. 3172 */ 3173 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 3174 hammer2_chain_countbrefs(parent, base, count); 3175 3176 next_key = 0; 3177 bref_ptr = NULL; 3178 hammer2_spin_ex(&parent->core.spin); 3179 chain = hammer2_combined_find(parent, base, count, 3180 &next_key, 3181 key, HAMMER2_KEY_MAX, 3182 &bref_ptr); 3183 generation = parent->core.generation; 3184 3185 /* 3186 * Exhausted parent chain, we're done. 3187 */ 3188 if (bref_ptr == NULL) { 3189 hammer2_spin_unex(&parent->core.spin); 3190 KKASSERT(chain == NULL); 3191 error |= HAMMER2_ERROR_EOF; 3192 goto done; 3193 } 3194 3195 /* 3196 * Copy into the supplied stack-based blockref. 3197 */ 3198 *bref = *bref_ptr; 3199 3200 /* 3201 * Selected from blockref or in-memory chain. 3202 */ 3203 if (chain == NULL) { 3204 switch(bref->type) { 3205 case HAMMER2_BREF_TYPE_INODE: 3206 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3207 case HAMMER2_BREF_TYPE_INDIRECT: 3208 case HAMMER2_BREF_TYPE_VOLUME: 3209 case HAMMER2_BREF_TYPE_FREEMAP: 3210 /* 3211 * Recursion, always get the chain 3212 */ 3213 hammer2_spin_unex(&parent->core.spin); 3214 chain = hammer2_chain_get(parent, generation, 3215 bref, how); 3216 if (chain == NULL) 3217 goto again; 3218 break; 3219 default: 3220 /* 3221 * No recursion, do not waste time instantiating 3222 * a chain, just iterate using the bref. 3223 */ 3224 hammer2_spin_unex(&parent->core.spin); 3225 break; 3226 } 3227 } else { 3228 /* 3229 * Recursion or not we need the chain in order to supply 3230 * the bref. 3231 */ 3232 hammer2_chain_ref(chain); 3233 hammer2_spin_unex(&parent->core.spin); 3234 hammer2_chain_lock(chain, how); 3235 } 3236 if (chain && 3237 (bcmp(bref, &chain->bref, sizeof(*bref)) || 3238 chain->parent != parent)) { 3239 hammer2_chain_unlock(chain); 3240 hammer2_chain_drop(chain); 3241 chain = NULL; 3242 goto again; 3243 } 3244 3245 /* 3246 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) 3247 * 3248 * NOTE: chain's key range is not relevant as there might be 3249 * one-offs within the range that are not deleted. 3250 * 3251 * NOTE: XXX this could create problems with scans used in 3252 * situations other than mount-time recovery. 3253 * 3254 * NOTE: Lookups can race delete-duplicate because 3255 * delete-duplicate does not lock the parent's core 3256 * (they just use the spinlock on the core). 3257 */ 3258 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 3259 hammer2_chain_unlock(chain); 3260 hammer2_chain_drop(chain); 3261 chain = NULL; 3262 3263 key = next_key; 3264 if (key == 0) { 3265 error |= HAMMER2_ERROR_EOF; 3266 goto done; 3267 } 3268 goto again; 3269 } 3270 3271 done: 3272 /* 3273 * All done, return the bref or NULL, supply chain if necessary. 3274 */ 3275 if (chain) 3276 *chainp = chain; 3277 return (error); 3278 } 3279 3280 /* 3281 * Create and return a new hammer2 system memory structure of the specified 3282 * key, type and size and insert it under (*parentp). This is a full 3283 * insertion, based on the supplied key/keybits, and may involve creating 3284 * indirect blocks and moving other chains around via delete/duplicate. 3285 * 3286 * This call can be made with parent == NULL as long as a non -1 methods 3287 * is supplied. hmp must also be supplied in this situation (otherwise 3288 * hmp is extracted from the supplied parent). The chain will be detached 3289 * from the topology. A later call with both parent and chain can be made 3290 * to attach it. 3291 * 3292 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (*parentp) TO THE INSERTION 3293 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING 3294 * FULL. This typically means that the caller is creating the chain after 3295 * doing a hammer2_chain_lookup(). 3296 * 3297 * (*parentp) must be exclusive locked and may be replaced on return 3298 * depending on how much work the function had to do. 3299 * 3300 * (*parentp) must not be errored or this function will assert. 3301 * 3302 * (*chainp) usually starts out NULL and returns the newly created chain, 3303 * but if the caller desires the caller may allocate a disconnected chain 3304 * and pass it in instead. 3305 * 3306 * This function should NOT be used to insert INDIRECT blocks. It is 3307 * typically used to create/insert inodes and data blocks. 3308 * 3309 * Caller must pass-in an exclusively locked parent the new chain is to 3310 * be inserted under, and optionally pass-in a disconnected, exclusively 3311 * locked chain to insert (else we create a new chain). The function will 3312 * adjust (*parentp) as necessary, create or connect the chain, and 3313 * return an exclusively locked chain in *chainp. 3314 * 3315 * When creating a PFSROOT inode under the super-root, pmp is typically NULL 3316 * and will be reassigned. 3317 * 3318 * NOTE: returns HAMMER_ERROR_* flags 3319 */ 3320 int 3321 hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp, 3322 hammer2_dev_t *hmp, hammer2_pfs_t *pmp, int methods, 3323 hammer2_key_t key, int keybits, int type, size_t bytes, 3324 hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags) 3325 { 3326 hammer2_chain_t *chain; 3327 hammer2_chain_t *parent; 3328 hammer2_blockref_t *base; 3329 hammer2_blockref_t dummy; 3330 int allocated = 0; 3331 int error = 0; 3332 int count; 3333 int maxloops = 300000; 3334 3335 /* 3336 * Topology may be crossing a PFS boundary. 3337 */ 3338 parent = *parentp; 3339 if (parent) { 3340 KKASSERT(hammer2_mtx_owned(&parent->lock)); 3341 KKASSERT(parent->error == 0); 3342 hmp = parent->hmp; 3343 } 3344 chain = *chainp; 3345 3346 if (chain == NULL) { 3347 /* 3348 * First allocate media space and construct the dummy bref, 3349 * then allocate the in-memory chain structure. Set the 3350 * INITIAL flag for fresh chains which do not have embedded 3351 * data. 3352 */ 3353 bzero(&dummy, sizeof(dummy)); 3354 dummy.type = type; 3355 dummy.key = key; 3356 dummy.keybits = keybits; 3357 dummy.data_off = hammer2_getradix(bytes); 3358 3359 /* 3360 * Inherit methods from parent by default. Primarily used 3361 * for BREF_TYPE_DATA. Non-data types *must* be set to 3362 * a non-NONE check algorithm. 3363 */ 3364 if (methods == HAMMER2_METH_DEFAULT) 3365 dummy.methods = parent->bref.methods; 3366 else 3367 dummy.methods = (uint8_t)methods; 3368 3369 if (type != HAMMER2_BREF_TYPE_DATA && 3370 HAMMER2_DEC_CHECK(dummy.methods) == HAMMER2_CHECK_NONE) { 3371 dummy.methods |= 3372 HAMMER2_ENC_CHECK(HAMMER2_CHECK_DEFAULT); 3373 } 3374 3375 chain = hammer2_chain_alloc(hmp, pmp, &dummy); 3376 3377 /* 3378 * Lock the chain manually, chain_lock will load the chain 3379 * which we do NOT want to do. (note: chain->refs is set 3380 * to 1 by chain_alloc() for us, but lockcnt is not). 3381 */ 3382 chain->lockcnt = 1; 3383 hammer2_mtx_ex(&chain->lock); 3384 allocated = 1; 3385 3386 /* 3387 * Set INITIAL to optimize I/O. The flag will generally be 3388 * processed when we call hammer2_chain_modify(). 3389 */ 3390 switch(type) { 3391 case HAMMER2_BREF_TYPE_VOLUME: 3392 case HAMMER2_BREF_TYPE_FREEMAP: 3393 panic("hammer2_chain_create: called with volume type"); 3394 break; 3395 case HAMMER2_BREF_TYPE_INDIRECT: 3396 panic("hammer2_chain_create: cannot be used to" 3397 "create indirect block"); 3398 break; 3399 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3400 panic("hammer2_chain_create: cannot be used to" 3401 "create freemap root or node"); 3402 break; 3403 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 3404 KKASSERT(bytes == sizeof(chain->data->bmdata)); 3405 /* fall through */ 3406 case HAMMER2_BREF_TYPE_DIRENT: 3407 case HAMMER2_BREF_TYPE_INODE: 3408 case HAMMER2_BREF_TYPE_DATA: 3409 default: 3410 /* 3411 * leave chain->data NULL, set INITIAL 3412 */ 3413 KKASSERT(chain->data == NULL); 3414 atomic_set_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 3415 break; 3416 } 3417 } else { 3418 /* 3419 * We are reattaching a previously deleted chain, possibly 3420 * under a new parent and possibly with a new key/keybits. 3421 * The chain does not have to be in a modified state. The 3422 * UPDATE flag will be set later on in this routine. 3423 * 3424 * Do NOT mess with the current state of the INITIAL flag. 3425 */ 3426 chain->bref.key = key; 3427 chain->bref.keybits = keybits; 3428 if (chain->flags & HAMMER2_CHAIN_DELETED) 3429 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3430 KKASSERT(chain->parent == NULL); 3431 } 3432 3433 /* 3434 * Set the appropriate bref flag if requested. 3435 * 3436 * NOTE! Callers can call this function to move chains without 3437 * knowing about special flags, so don't clear bref flags 3438 * here! 3439 */ 3440 if (flags & HAMMER2_INSERT_PFSROOT) 3441 chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT; 3442 3443 if (parent == NULL) 3444 goto skip; 3445 3446 /* 3447 * Calculate how many entries we have in the blockref array and 3448 * determine if an indirect block is required when inserting into 3449 * the parent. 3450 */ 3451 again: 3452 if (--maxloops == 0) 3453 panic("hammer2_chain_create: maxloops"); 3454 3455 switch(parent->bref.type) { 3456 case HAMMER2_BREF_TYPE_INODE: 3457 if ((parent->data->ipdata.meta.op_flags & 3458 HAMMER2_OPFLAG_DIRECTDATA) != 0) { 3459 kprintf("hammer2: parent set for direct-data! " 3460 "pkey=%016jx ckey=%016jx\n", 3461 parent->bref.key, 3462 chain->bref.key); 3463 } 3464 KKASSERT((parent->data->ipdata.meta.op_flags & 3465 HAMMER2_OPFLAG_DIRECTDATA) == 0); 3466 KKASSERT(parent->data != NULL); 3467 base = &parent->data->ipdata.u.blockset.blockref[0]; 3468 count = HAMMER2_SET_COUNT; 3469 break; 3470 case HAMMER2_BREF_TYPE_INDIRECT: 3471 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3472 if (parent->flags & HAMMER2_CHAIN_INITIAL) 3473 base = NULL; 3474 else 3475 base = &parent->data->npdata[0]; 3476 count = parent->bytes / sizeof(hammer2_blockref_t); 3477 break; 3478 case HAMMER2_BREF_TYPE_VOLUME: 3479 KKASSERT(parent->data != NULL); 3480 base = &parent->data->voldata.sroot_blockset.blockref[0]; 3481 count = HAMMER2_SET_COUNT; 3482 break; 3483 case HAMMER2_BREF_TYPE_FREEMAP: 3484 KKASSERT(parent->data != NULL); 3485 base = &parent->data->blkset.blockref[0]; 3486 count = HAMMER2_SET_COUNT; 3487 break; 3488 default: 3489 panic("hammer2_chain_create: unrecognized blockref type: %d", 3490 parent->bref.type); 3491 base = NULL; 3492 count = 0; 3493 break; 3494 } 3495 3496 /* 3497 * Make sure we've counted the brefs 3498 */ 3499 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 3500 hammer2_chain_countbrefs(parent, base, count); 3501 3502 KASSERT(parent->core.live_count >= 0 && 3503 parent->core.live_count <= count, 3504 ("bad live_count %d/%d (%02x, %d)", 3505 parent->core.live_count, count, 3506 parent->bref.type, parent->bytes)); 3507 3508 /* 3509 * If no free blockref could be found we must create an indirect 3510 * block and move a number of blockrefs into it. With the parent 3511 * locked we can safely lock each child in order to delete+duplicate 3512 * it without causing a deadlock. 3513 * 3514 * This may return the new indirect block or the old parent depending 3515 * on where the key falls. NULL is returned on error. 3516 */ 3517 if (parent->core.live_count == count) { 3518 hammer2_chain_t *nparent; 3519 3520 KKASSERT((flags & HAMMER2_INSERT_SAMEPARENT) == 0); 3521 3522 nparent = hammer2_chain_create_indirect(parent, key, keybits, 3523 mtid, type, &error); 3524 if (nparent == NULL) { 3525 if (allocated) 3526 hammer2_chain_drop(chain); 3527 chain = NULL; 3528 goto done; 3529 } 3530 if (parent != nparent) { 3531 hammer2_chain_unlock(parent); 3532 hammer2_chain_drop(parent); 3533 parent = *parentp = nparent; 3534 } 3535 goto again; 3536 } 3537 3538 /* 3539 * fall through if parent, or skip to here if no parent. 3540 */ 3541 skip: 3542 if (chain->flags & HAMMER2_CHAIN_DELETED) 3543 kprintf("Inserting deleted chain @%016jx\n", 3544 chain->bref.key); 3545 3546 /* 3547 * Link the chain into its parent. 3548 */ 3549 if (chain->parent != NULL) 3550 panic("hammer2: hammer2_chain_create: chain already connected"); 3551 KKASSERT(chain->parent == NULL); 3552 if (parent) { 3553 KKASSERT(parent->core.live_count < count); 3554 hammer2_chain_insert(parent, chain, 3555 HAMMER2_CHAIN_INSERT_SPIN | 3556 HAMMER2_CHAIN_INSERT_LIVE, 3557 0); 3558 } 3559 3560 if (allocated) { 3561 /* 3562 * Mark the newly created chain modified. This will cause 3563 * UPDATE to be set and process the INITIAL flag. 3564 * 3565 * Device buffers are not instantiated for DATA elements 3566 * as these are handled by logical buffers. 3567 * 3568 * Indirect and freemap node indirect blocks are handled 3569 * by hammer2_chain_create_indirect() and not by this 3570 * function. 3571 * 3572 * Data for all other bref types is expected to be 3573 * instantiated (INODE, LEAF). 3574 */ 3575 switch(chain->bref.type) { 3576 case HAMMER2_BREF_TYPE_DATA: 3577 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 3578 case HAMMER2_BREF_TYPE_DIRENT: 3579 case HAMMER2_BREF_TYPE_INODE: 3580 error = hammer2_chain_modify(chain, mtid, dedup_off, 3581 HAMMER2_MODIFY_OPTDATA); 3582 break; 3583 default: 3584 /* 3585 * Remaining types are not supported by this function. 3586 * In particular, INDIRECT and LEAF_NODE types are 3587 * handled by create_indirect(). 3588 */ 3589 panic("hammer2_chain_create: bad type: %d", 3590 chain->bref.type); 3591 /* NOT REACHED */ 3592 break; 3593 } 3594 } else { 3595 /* 3596 * When reconnecting a chain we must set UPDATE and 3597 * setflush so the flush recognizes that it must update 3598 * the bref in the parent. 3599 */ 3600 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) 3601 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 3602 } 3603 3604 /* 3605 * We must setflush(parent) to ensure that it recurses through to 3606 * chain. setflush(chain) might not work because ONFLUSH is possibly 3607 * already set in the chain (so it won't recurse up to set it in the 3608 * parent). 3609 */ 3610 if (parent) 3611 hammer2_chain_setflush(parent); 3612 3613 done: 3614 *chainp = chain; 3615 3616 return (error); 3617 } 3618 3619 /* 3620 * Move the chain from its old parent to a new parent. The chain must have 3621 * already been deleted or already disconnected (or never associated) with 3622 * a parent. The chain is reassociated with the new parent and the deleted 3623 * flag will be cleared (no longer deleted). The chain's modification state 3624 * is not altered. 3625 * 3626 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (parent) TO THE INSERTION 3627 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING 3628 * FULL. This typically means that the caller is creating the chain after 3629 * doing a hammer2_chain_lookup(). 3630 * 3631 * Neither (parent) or (chain) can be errored. 3632 * 3633 * If (parent) is non-NULL then the chain is inserted under the parent. 3634 * 3635 * If (parent) is NULL then the newly duplicated chain is not inserted 3636 * anywhere, similar to if it had just been chain_alloc()'d (suitable for 3637 * passing into hammer2_chain_create() after this function returns). 3638 * 3639 * WARNING! This function calls create which means it can insert indirect 3640 * blocks. This can cause other unrelated chains in the parent to 3641 * be moved to a newly inserted indirect block in addition to the 3642 * specific chain. 3643 */ 3644 void 3645 hammer2_chain_rename(hammer2_chain_t **parentp, hammer2_chain_t *chain, 3646 hammer2_tid_t mtid, int flags) 3647 { 3648 hammer2_blockref_t *bref; 3649 hammer2_chain_t *parent; 3650 3651 /* 3652 * WARNING! We should never resolve DATA to device buffers 3653 * (XXX allow it if the caller did?), and since 3654 * we currently do not have the logical buffer cache 3655 * buffer in-hand to fix its cached physical offset 3656 * we also force the modify code to not COW it. XXX 3657 * 3658 * NOTE! We allow error'd chains to be renamed. The bref itself 3659 * is good and can be renamed. The content, however, may 3660 * be inaccessible. 3661 */ 3662 KKASSERT(chain->parent == NULL); 3663 /*KKASSERT(chain->error == 0); allow */ 3664 bref = &chain->bref; 3665 3666 /* 3667 * If parent is not NULL the duplicated chain will be entered under 3668 * the parent and the UPDATE bit set to tell flush to update 3669 * the blockref. 3670 * 3671 * We must setflush(parent) to ensure that it recurses through to 3672 * chain. setflush(chain) might not work because ONFLUSH is possibly 3673 * already set in the chain (so it won't recurse up to set it in the 3674 * parent). 3675 * 3676 * Having both chains locked is extremely important for atomicy. 3677 */ 3678 if (parentp && (parent = *parentp) != NULL) { 3679 KKASSERT(hammer2_mtx_owned(&parent->lock)); 3680 KKASSERT(parent->refs > 0); 3681 KKASSERT(parent->error == 0); 3682 3683 hammer2_chain_create(parentp, &chain, NULL, chain->pmp, 3684 HAMMER2_METH_DEFAULT, 3685 bref->key, bref->keybits, bref->type, 3686 chain->bytes, mtid, 0, flags); 3687 KKASSERT(chain->flags & HAMMER2_CHAIN_UPDATE); 3688 hammer2_chain_setflush(*parentp); 3689 } 3690 } 3691 3692 /* 3693 * This works in tandem with delete_obref() to install a blockref in 3694 * (typically) an indirect block that is associated with the chain being 3695 * moved to *parentp. 3696 * 3697 * The reason we need this function is that the caller needs to maintain 3698 * the blockref as it was, and not generate a new blockref for what might 3699 * be a modified chain. Otherwise stuff will leak into the flush that 3700 * the flush code's FLUSH_INODE_STOP flag is unable to catch. 3701 * 3702 * It is EXTREMELY important that we properly set CHAIN_BLKMAPUPD and 3703 * CHAIN_UPDATE. We must set BLKMAPUPD if the bref does not match, and 3704 * we must clear CHAIN_UPDATE (that was likely set by the chain_rename) if 3705 * it does. Otherwise we can end up in a situation where H2 is unable to 3706 * clean up the in-memory chain topology. 3707 * 3708 * The reason for this is that flushes do not generally flush through 3709 * BREF_TYPE_INODE chains and depend on a hammer2_inode_t queued to syncq 3710 * or sideq to properly flush and dispose of the related inode chain's flags. 3711 * Situations where the inode is not actually modified by the frontend, 3712 * but where we have to move the related chains around as we insert or cleanup 3713 * indirect blocks, can leave us with a 'dirty' (non-disposable) in-memory 3714 * inode chain that does not have a hammer2_inode_t associated with it. 3715 */ 3716 static void 3717 hammer2_chain_rename_obref(hammer2_chain_t **parentp, hammer2_chain_t *chain, 3718 hammer2_tid_t mtid, int flags, 3719 hammer2_blockref_t *obref) 3720 { 3721 hammer2_chain_rename(parentp, chain, mtid, flags); 3722 3723 if (obref->type != HAMMER2_BREF_TYPE_EMPTY) { 3724 hammer2_blockref_t *tbase; 3725 int tcount; 3726 3727 KKASSERT((chain->flags & HAMMER2_CHAIN_BLKMAPPED) == 0); 3728 hammer2_chain_modify(*parentp, mtid, 0, 0); 3729 tbase = hammer2_chain_base_and_count(*parentp, &tcount); 3730 hammer2_base_insert(*parentp, tbase, tcount, chain, obref); 3731 if (bcmp(obref, &chain->bref, sizeof(chain->bref))) { 3732 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPUPD | 3733 HAMMER2_CHAIN_UPDATE); 3734 } else { 3735 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 3736 } 3737 } 3738 } 3739 3740 /* 3741 * Helper function for deleting chains. 3742 * 3743 * The chain is removed from the live view (the RBTREE) as well as the parent's 3744 * blockmap. Both chain and its parent must be locked. 3745 * 3746 * parent may not be errored. chain can be errored. 3747 */ 3748 static int 3749 _hammer2_chain_delete_helper(hammer2_chain_t *parent, hammer2_chain_t *chain, 3750 hammer2_tid_t mtid, int flags, 3751 hammer2_blockref_t *obref) 3752 { 3753 int error = 0; 3754 3755 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0); 3756 KKASSERT(chain->parent == parent); 3757 3758 if (chain->flags & HAMMER2_CHAIN_BLKMAPPED) { 3759 /* 3760 * Chain is blockmapped, so there must be a parent. 3761 * Atomically remove the chain from the parent and remove 3762 * the blockmap entry. The parent must be set modified 3763 * to remove the blockmap entry. 3764 */ 3765 hammer2_blockref_t *base; 3766 int count; 3767 3768 KKASSERT(parent != NULL); 3769 KKASSERT(parent->error == 0); 3770 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); 3771 error = hammer2_chain_modify(parent, mtid, 0, 0); 3772 if (error) 3773 goto done; 3774 3775 /* 3776 * Calculate blockmap pointer 3777 */ 3778 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); 3779 hammer2_spin_ex(&chain->core.spin); 3780 hammer2_spin_ex(&parent->core.spin); 3781 3782 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3783 atomic_add_int(&parent->core.live_count, -1); 3784 ++parent->core.generation; 3785 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); 3786 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 3787 --parent->core.chain_count; 3788 chain->parent = NULL; 3789 3790 switch(parent->bref.type) { 3791 case HAMMER2_BREF_TYPE_INODE: 3792 /* 3793 * Access the inode's block array. However, there 3794 * is no block array if the inode is flagged 3795 * DIRECTDATA. 3796 */ 3797 if (parent->data && 3798 (parent->data->ipdata.meta.op_flags & 3799 HAMMER2_OPFLAG_DIRECTDATA) == 0) { 3800 base = 3801 &parent->data->ipdata.u.blockset.blockref[0]; 3802 } else { 3803 base = NULL; 3804 } 3805 count = HAMMER2_SET_COUNT; 3806 break; 3807 case HAMMER2_BREF_TYPE_INDIRECT: 3808 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3809 if (parent->data) 3810 base = &parent->data->npdata[0]; 3811 else 3812 base = NULL; 3813 count = parent->bytes / sizeof(hammer2_blockref_t); 3814 break; 3815 case HAMMER2_BREF_TYPE_VOLUME: 3816 base = &parent->data->voldata. 3817 sroot_blockset.blockref[0]; 3818 count = HAMMER2_SET_COUNT; 3819 break; 3820 case HAMMER2_BREF_TYPE_FREEMAP: 3821 base = &parent->data->blkset.blockref[0]; 3822 count = HAMMER2_SET_COUNT; 3823 break; 3824 default: 3825 base = NULL; 3826 count = 0; 3827 panic("_hammer2_chain_delete_helper: " 3828 "unrecognized blockref type: %d", 3829 parent->bref.type); 3830 break; 3831 } 3832 3833 /* 3834 * delete blockmapped chain from its parent. 3835 * 3836 * The parent is not affected by any statistics in chain 3837 * which are pending synchronization. That is, there is 3838 * nothing to undo in the parent since they have not yet 3839 * been incorporated into the parent. 3840 * 3841 * The parent is affected by statistics stored in inodes. 3842 * Those have already been synchronized, so they must be 3843 * undone. XXX split update possible w/delete in middle? 3844 */ 3845 if (base) { 3846 hammer2_base_delete(parent, base, count, chain, obref); 3847 } 3848 hammer2_spin_unex(&parent->core.spin); 3849 hammer2_spin_unex(&chain->core.spin); 3850 } else if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { 3851 /* 3852 * Chain is not blockmapped but a parent is present. 3853 * Atomically remove the chain from the parent. There is 3854 * no blockmap entry to remove. 3855 * 3856 * Because chain was associated with a parent but not 3857 * synchronized, the chain's *_count_up fields contain 3858 * inode adjustment statistics which must be undone. 3859 */ 3860 hammer2_spin_ex(&chain->core.spin); 3861 hammer2_spin_ex(&parent->core.spin); 3862 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3863 atomic_add_int(&parent->core.live_count, -1); 3864 ++parent->core.generation; 3865 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); 3866 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 3867 --parent->core.chain_count; 3868 chain->parent = NULL; 3869 hammer2_spin_unex(&parent->core.spin); 3870 hammer2_spin_unex(&chain->core.spin); 3871 } else { 3872 /* 3873 * Chain is not blockmapped and has no parent. This 3874 * is a degenerate case. 3875 */ 3876 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3877 } 3878 done: 3879 return error; 3880 } 3881 3882 /* 3883 * Create an indirect block that covers one or more of the elements in the 3884 * current parent. Either returns the existing parent with no locking or 3885 * ref changes or returns the new indirect block locked and referenced 3886 * and leaving the original parent lock/ref intact as well. 3887 * 3888 * If an error occurs, NULL is returned and *errorp is set to the H2 error. 3889 * 3890 * The returned chain depends on where the specified key falls. 3891 * 3892 * The key/keybits for the indirect mode only needs to follow three rules: 3893 * 3894 * (1) That all elements underneath it fit within its key space and 3895 * 3896 * (2) That all elements outside it are outside its key space. 3897 * 3898 * (3) When creating the new indirect block any elements in the current 3899 * parent that fit within the new indirect block's keyspace must be 3900 * moved into the new indirect block. 3901 * 3902 * (4) The keyspace chosen for the inserted indirect block CAN cover a wider 3903 * keyspace the the current parent, but lookup/iteration rules will 3904 * ensure (and must ensure) that rule (2) for all parents leading up 3905 * to the nearest inode or the root volume header is adhered to. This 3906 * is accomplished by always recursing through matching keyspaces in 3907 * the hammer2_chain_lookup() and hammer2_chain_next() API. 3908 * 3909 * The current implementation calculates the current worst-case keyspace by 3910 * iterating the current parent and then divides it into two halves, choosing 3911 * whichever half has the most elements (not necessarily the half containing 3912 * the requested key). 3913 * 3914 * We can also opt to use the half with the least number of elements. This 3915 * causes lower-numbered keys (aka logical file offsets) to recurse through 3916 * fewer indirect blocks and higher-numbered keys to recurse through more. 3917 * This also has the risk of not moving enough elements to the new indirect 3918 * block and being forced to create several indirect blocks before the element 3919 * can be inserted. 3920 * 3921 * Must be called with an exclusively locked parent. 3922 * 3923 * NOTE: *errorp set to HAMMER_ERROR_* flags 3924 */ 3925 static int hammer2_chain_indkey_freemap(hammer2_chain_t *parent, 3926 hammer2_key_t *keyp, int keybits, 3927 hammer2_blockref_t *base, int count); 3928 static int hammer2_chain_indkey_file(hammer2_chain_t *parent, 3929 hammer2_key_t *keyp, int keybits, 3930 hammer2_blockref_t *base, int count, 3931 int ncount); 3932 static int hammer2_chain_indkey_dir(hammer2_chain_t *parent, 3933 hammer2_key_t *keyp, int keybits, 3934 hammer2_blockref_t *base, int count, 3935 int ncount); 3936 static 3937 hammer2_chain_t * 3938 hammer2_chain_create_indirect(hammer2_chain_t *parent, 3939 hammer2_key_t create_key, int create_bits, 3940 hammer2_tid_t mtid, int for_type, int *errorp) 3941 { 3942 hammer2_dev_t *hmp; 3943 hammer2_blockref_t *base; 3944 hammer2_blockref_t *bref; 3945 hammer2_blockref_t bsave; 3946 hammer2_blockref_t dummy; 3947 hammer2_chain_t *chain; 3948 hammer2_chain_t *ichain; 3949 hammer2_key_t key = create_key; 3950 hammer2_key_t key_beg; 3951 hammer2_key_t key_end; 3952 hammer2_key_t key_next; 3953 int keybits = create_bits; 3954 int count; 3955 int ncount; 3956 int nbytes; 3957 int loops; 3958 int error; 3959 int reason; 3960 int generation; 3961 int maxloops = 300000; 3962 3963 /* 3964 * Calculate the base blockref pointer or NULL if the chain 3965 * is known to be empty. We need to calculate the array count 3966 * for RB lookups either way. 3967 */ 3968 hmp = parent->hmp; 3969 KKASSERT(hammer2_mtx_owned(&parent->lock)); 3970 3971 /* 3972 * Pre-modify the parent now to avoid having to deal with error 3973 * processing if we tried to later (in the middle of our loop). 3974 * 3975 * We are going to be moving bref's around, the indirect blocks 3976 * cannot be in an initial state. Do not pass MODIFY_OPTDATA. 3977 */ 3978 *errorp = hammer2_chain_modify(parent, mtid, 0, 0); 3979 if (*errorp) { 3980 kprintf("hammer2_chain_create_indirect: error %08x %s\n", 3981 *errorp, hammer2_error_str(*errorp)); 3982 return NULL; 3983 } 3984 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); 3985 3986 /*hammer2_chain_modify(&parent, HAMMER2_MODIFY_OPTDATA);*/ 3987 base = hammer2_chain_base_and_count(parent, &count); 3988 3989 /* 3990 * How big should our new indirect block be? It has to be at least 3991 * as large as its parent for splits to work properly. 3992 * 3993 * The freemap uses a specific indirect block size. The number of 3994 * levels are built dynamically and ultimately depend on the size 3995 * volume. Because freemap blocks are taken from the reserved areas 3996 * of the volume our goal is efficiency (fewer levels) and not so 3997 * much to save disk space. 3998 * 3999 * The first indirect block level for a directory usually uses 4000 * HAMMER2_IND_BYTES_MIN (4KB = 32 directory entries). Due to 4001 * the hash mechanism, this typically gives us a nominal 4002 * 32 * 4 entries with one level of indirection. 4003 * 4004 * We use HAMMER2_IND_BYTES_NOM (16KB = 128 blockrefs) for FILE 4005 * indirect blocks. The initial 4 entries in the inode gives us 4006 * 256KB. Up to 4 indirect blocks gives us 32MB. Three levels 4007 * of indirection gives us 137GB, and so forth. H2 can support 4008 * huge file sizes but they are not typical, so we try to stick 4009 * with compactness and do not use a larger indirect block size. 4010 * 4011 * We could use 64KB (PBUFSIZE), giving us 512 blockrefs, but 4012 * due to the way indirect blocks are created this usually winds 4013 * up being extremely inefficient for small files. Even though 4014 * 16KB requires more levels of indirection for very large files, 4015 * the 16KB records can be ganged together into 64KB DIOs. 4016 */ 4017 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 4018 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 4019 nbytes = HAMMER2_FREEMAP_LEVELN_PSIZE; 4020 } else if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { 4021 if (parent->data->ipdata.meta.type == 4022 HAMMER2_OBJTYPE_DIRECTORY) 4023 nbytes = HAMMER2_IND_BYTES_MIN; /* 4KB = 32 entries */ 4024 else 4025 nbytes = HAMMER2_IND_BYTES_NOM; /* 16KB = ~8MB file */ 4026 4027 } else { 4028 nbytes = HAMMER2_IND_BYTES_NOM; 4029 } 4030 if (nbytes < count * sizeof(hammer2_blockref_t)) { 4031 KKASSERT(for_type != HAMMER2_BREF_TYPE_FREEMAP_NODE && 4032 for_type != HAMMER2_BREF_TYPE_FREEMAP_LEAF); 4033 nbytes = count * sizeof(hammer2_blockref_t); 4034 } 4035 ncount = nbytes / sizeof(hammer2_blockref_t); 4036 4037 /* 4038 * When creating an indirect block for a freemap node or leaf 4039 * the key/keybits must be fitted to static radix levels because 4040 * particular radix levels use particular reserved blocks in the 4041 * related zone. 4042 * 4043 * This routine calculates the key/radix of the indirect block 4044 * we need to create, and whether it is on the high-side or the 4045 * low-side. 4046 */ 4047 switch(for_type) { 4048 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 4049 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 4050 keybits = hammer2_chain_indkey_freemap(parent, &key, keybits, 4051 base, count); 4052 break; 4053 case HAMMER2_BREF_TYPE_DATA: 4054 keybits = hammer2_chain_indkey_file(parent, &key, keybits, 4055 base, count, ncount); 4056 break; 4057 case HAMMER2_BREF_TYPE_DIRENT: 4058 case HAMMER2_BREF_TYPE_INODE: 4059 keybits = hammer2_chain_indkey_dir(parent, &key, keybits, 4060 base, count, ncount); 4061 break; 4062 default: 4063 panic("illegal indirect block for bref type %d", for_type); 4064 break; 4065 } 4066 4067 /* 4068 * Normalize the key for the radix being represented, keeping the 4069 * high bits and throwing away the low bits. 4070 */ 4071 key &= ~(((hammer2_key_t)1 << keybits) - 1); 4072 4073 /* 4074 * Ok, create our new indirect block 4075 */ 4076 bzero(&dummy, sizeof(dummy)); 4077 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 4078 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 4079 dummy.type = HAMMER2_BREF_TYPE_FREEMAP_NODE; 4080 } else { 4081 dummy.type = HAMMER2_BREF_TYPE_INDIRECT; 4082 } 4083 dummy.key = key; 4084 dummy.keybits = keybits; 4085 dummy.data_off = hammer2_getradix(nbytes); 4086 dummy.methods = 4087 HAMMER2_ENC_CHECK(HAMMER2_DEC_CHECK(parent->bref.methods)) | 4088 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE); 4089 4090 ichain = hammer2_chain_alloc(hmp, parent->pmp, &dummy); 4091 atomic_set_int(&ichain->flags, HAMMER2_CHAIN_INITIAL); 4092 hammer2_chain_lock(ichain, HAMMER2_RESOLVE_MAYBE); 4093 /* ichain has one ref at this point */ 4094 4095 /* 4096 * We have to mark it modified to allocate its block, but use 4097 * OPTDATA to allow it to remain in the INITIAL state. Otherwise 4098 * it won't be acted upon by the flush code. 4099 * 4100 * XXX remove OPTDATA, we need a fully initialized indirect block to 4101 * be able to move the original blockref. 4102 */ 4103 *errorp = hammer2_chain_modify(ichain, mtid, 0, 0); 4104 if (*errorp) { 4105 kprintf("hammer2_chain_create_indirect: error %08x %s\n", 4106 *errorp, hammer2_error_str(*errorp)); 4107 hammer2_chain_unlock(ichain); 4108 hammer2_chain_drop(ichain); 4109 return NULL; 4110 } 4111 KKASSERT((ichain->flags & HAMMER2_CHAIN_INITIAL) == 0); 4112 4113 /* 4114 * Iterate the original parent and move the matching brefs into 4115 * the new indirect block. 4116 * 4117 * XXX handle flushes. 4118 */ 4119 key_beg = 0; 4120 key_end = HAMMER2_KEY_MAX; 4121 key_next = 0; /* avoid gcc warnings */ 4122 hammer2_spin_ex(&parent->core.spin); 4123 loops = 0; 4124 reason = 0; 4125 4126 for (;;) { 4127 /* 4128 * Parent may have been modified, relocating its block array. 4129 * Reload the base pointer. 4130 */ 4131 base = hammer2_chain_base_and_count(parent, &count); 4132 4133 if (++loops > 100000) { 4134 hammer2_spin_unex(&parent->core.spin); 4135 panic("excessive loops r=%d p=%p base/count %p:%d %016jx\n", 4136 reason, parent, base, count, key_next); 4137 } 4138 4139 /* 4140 * NOTE: spinlock stays intact, returned chain (if not NULL) 4141 * is not referenced or locked which means that we 4142 * cannot safely check its flagged / deletion status 4143 * until we lock it. 4144 */ 4145 chain = hammer2_combined_find(parent, base, count, 4146 &key_next, 4147 key_beg, key_end, 4148 &bref); 4149 generation = parent->core.generation; 4150 if (bref == NULL) 4151 break; 4152 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4153 4154 /* 4155 * Skip keys that are not within the key/radix of the new 4156 * indirect block. They stay in the parent. 4157 */ 4158 if (rounddown2(key ^ bref->key, (hammer2_key_t)1 << keybits) != 0) { 4159 goto next_key_spinlocked; 4160 } 4161 4162 /* 4163 * Load the new indirect block by acquiring the related 4164 * chains (potentially from media as it might not be 4165 * in-memory). Then move it to the new parent (ichain). 4166 * 4167 * chain is referenced but not locked. We must lock the 4168 * chain to obtain definitive state. 4169 */ 4170 bsave = *bref; 4171 if (chain) { 4172 /* 4173 * Use chain already present in the RBTREE 4174 */ 4175 hammer2_chain_ref(chain); 4176 hammer2_spin_unex(&parent->core.spin); 4177 hammer2_chain_lock(chain, HAMMER2_RESOLVE_NEVER); 4178 } else { 4179 /* 4180 * Get chain for blockref element. _get returns NULL 4181 * on insertion race. 4182 */ 4183 hammer2_spin_unex(&parent->core.spin); 4184 chain = hammer2_chain_get(parent, generation, &bsave, 4185 HAMMER2_RESOLVE_NEVER); 4186 if (chain == NULL) { 4187 reason = 1; 4188 hammer2_spin_ex(&parent->core.spin); 4189 continue; 4190 } 4191 } 4192 4193 /* 4194 * This is always live so if the chain has been deleted 4195 * we raced someone and we have to retry. 4196 * 4197 * NOTE: Lookups can race delete-duplicate because 4198 * delete-duplicate does not lock the parent's core 4199 * (they just use the spinlock on the core). 4200 * 4201 * (note reversed logic for this one) 4202 */ 4203 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || 4204 chain->parent != parent || 4205 (chain->flags & HAMMER2_CHAIN_DELETED)) { 4206 hammer2_chain_unlock(chain); 4207 hammer2_chain_drop(chain); 4208 if (hammer2_debug & 0x0040) { 4209 kprintf("LOST PARENT RETRY " 4210 "RETRY (%p,%p)->%p %08x\n", 4211 parent, chain->parent, chain, chain->flags); 4212 } 4213 hammer2_spin_ex(&parent->core.spin); 4214 continue; 4215 } 4216 4217 /* 4218 * Shift the chain to the indirect block. 4219 * 4220 * WARNING! No reason for us to load chain data, pass NOSTATS 4221 * to prevent delete/insert from trying to access 4222 * inode stats (and thus asserting if there is no 4223 * chain->data loaded). 4224 * 4225 * WARNING! The (parent, chain) deletion may modify the parent 4226 * and invalidate the base pointer. 4227 * 4228 * WARNING! Parent must already be marked modified, so we 4229 * can assume that chain_delete always suceeds. 4230 * 4231 * WARNING! hammer2_chain_repchange() does not have to be 4232 * called (and doesn't work anyway because we are 4233 * only doing a partial shift). A recursion that is 4234 * in-progress can continue at the current parent 4235 * and will be able to properly find its next key. 4236 */ 4237 error = hammer2_chain_delete_obref(parent, chain, mtid, 0, 4238 &bsave); 4239 KKASSERT(error == 0); 4240 hammer2_chain_rename_obref(&ichain, chain, mtid, 0, &bsave); 4241 hammer2_chain_unlock(chain); 4242 hammer2_chain_drop(chain); 4243 KKASSERT(parent->refs > 0); 4244 chain = NULL; 4245 base = NULL; /* safety */ 4246 hammer2_spin_ex(&parent->core.spin); 4247 next_key_spinlocked: 4248 if (--maxloops == 0) 4249 panic("hammer2_chain_create_indirect: maxloops"); 4250 reason = 4; 4251 if (key_next == 0 || key_next > key_end) 4252 break; 4253 key_beg = key_next; 4254 /* loop */ 4255 } 4256 hammer2_spin_unex(&parent->core.spin); 4257 4258 /* 4259 * Insert the new indirect block into the parent now that we've 4260 * cleared out some entries in the parent. We calculated a good 4261 * insertion index in the loop above (ichain->index). 4262 * 4263 * We don't have to set UPDATE here because we mark ichain 4264 * modified down below (so the normal modified -> flush -> set-moved 4265 * sequence applies). 4266 * 4267 * The insertion shouldn't race as this is a completely new block 4268 * and the parent is locked. 4269 */ 4270 base = NULL; /* safety, parent modify may change address */ 4271 KKASSERT((ichain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); 4272 KKASSERT(parent->core.live_count < count); 4273 hammer2_chain_insert(parent, ichain, 4274 HAMMER2_CHAIN_INSERT_SPIN | 4275 HAMMER2_CHAIN_INSERT_LIVE, 4276 0); 4277 4278 /* 4279 * Make sure flushes propogate after our manual insertion. 4280 */ 4281 hammer2_chain_setflush(ichain); 4282 hammer2_chain_setflush(parent); 4283 4284 /* 4285 * Figure out what to return. 4286 */ 4287 if (rounddown2(create_key ^ key, (hammer2_key_t)1 << keybits)) { 4288 /* 4289 * Key being created is outside the key range, 4290 * return the original parent. 4291 */ 4292 hammer2_chain_unlock(ichain); 4293 hammer2_chain_drop(ichain); 4294 } else { 4295 /* 4296 * Otherwise its in the range, return the new parent. 4297 * (leave both the new and old parent locked). 4298 */ 4299 parent = ichain; 4300 } 4301 4302 return(parent); 4303 } 4304 4305 /* 4306 * Do maintenance on an indirect chain. Both parent and chain are locked. 4307 * 4308 * Returns non-zero if (chain) is deleted, either due to being empty or 4309 * because its children were safely moved into the parent. 4310 */ 4311 int 4312 hammer2_chain_indirect_maintenance(hammer2_chain_t *parent, 4313 hammer2_chain_t *chain) 4314 { 4315 hammer2_blockref_t *chain_base; 4316 hammer2_blockref_t *base; 4317 hammer2_blockref_t *bref; 4318 hammer2_blockref_t bsave; 4319 hammer2_key_t key_next; 4320 hammer2_key_t key_beg; 4321 hammer2_key_t key_end; 4322 hammer2_chain_t *sub; 4323 int chain_count; 4324 int count; 4325 int error; 4326 int generation; 4327 4328 /* 4329 * Make sure we have an accurate live_count 4330 */ 4331 if ((chain->flags & (HAMMER2_CHAIN_INITIAL | 4332 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { 4333 base = &chain->data->npdata[0]; 4334 count = chain->bytes / sizeof(hammer2_blockref_t); 4335 hammer2_chain_countbrefs(chain, base, count); 4336 } 4337 4338 /* 4339 * If the indirect block is empty we can delete it. 4340 * (ignore deletion error) 4341 */ 4342 if (chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)) { 4343 hammer2_chain_delete(parent, chain, 4344 chain->bref.modify_tid, 4345 HAMMER2_DELETE_PERMANENT); 4346 hammer2_chain_repchange(parent, chain); 4347 return 1; 4348 } 4349 4350 base = hammer2_chain_base_and_count(parent, &count); 4351 4352 if ((parent->flags & (HAMMER2_CHAIN_INITIAL | 4353 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { 4354 hammer2_chain_countbrefs(parent, base, count); 4355 } 4356 4357 /* 4358 * Determine if we can collapse chain into parent, calculate 4359 * hysteresis for chain emptiness. 4360 */ 4361 if (parent->core.live_count + chain->core.live_count - 1 > count) 4362 return 0; 4363 chain_count = chain->bytes / sizeof(hammer2_blockref_t); 4364 if (chain->core.live_count > chain_count * 3 / 4) 4365 return 0; 4366 4367 /* 4368 * Ok, theoretically we can collapse chain's contents into 4369 * parent. chain is locked, but any in-memory children of chain 4370 * are not. For this to work, we must be able to dispose of any 4371 * in-memory children of chain. 4372 * 4373 * For now require that there are no in-memory children of chain. 4374 * 4375 * WARNING! Both chain and parent must remain locked across this 4376 * entire operation. 4377 */ 4378 4379 /* 4380 * Parent must be marked modified. Don't try to collapse it if we 4381 * can't mark it modified. Once modified, destroy chain to make room 4382 * and to get rid of what will be a conflicting key (this is included 4383 * in the calculation above). Finally, move the children of chain 4384 * into chain's parent. 4385 * 4386 * This order creates an accounting problem for bref.embed.stats 4387 * because we destroy chain before we remove its children. Any 4388 * elements whos blockref is already synchronized will be counted 4389 * twice. To deal with the problem we clean out chain's stats prior 4390 * to deleting it. 4391 */ 4392 error = hammer2_chain_modify(parent, 0, 0, 0); 4393 if (error) { 4394 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", 4395 hammer2_error_str(error)); 4396 return 0; 4397 } 4398 error = hammer2_chain_modify(chain, chain->bref.modify_tid, 0, 0); 4399 if (error) { 4400 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", 4401 hammer2_error_str(error)); 4402 return 0; 4403 } 4404 4405 chain->bref.embed.stats.inode_count = 0; 4406 chain->bref.embed.stats.data_count = 0; 4407 error = hammer2_chain_delete(parent, chain, 4408 chain->bref.modify_tid, 4409 HAMMER2_DELETE_PERMANENT); 4410 KKASSERT(error == 0); 4411 4412 /* 4413 * The combined_find call requires core.spin to be held. One would 4414 * think there wouldn't be any conflicts since we hold chain 4415 * exclusively locked, but the caching mechanism for 0-ref children 4416 * does not require a chain lock. 4417 */ 4418 hammer2_spin_ex(&chain->core.spin); 4419 4420 key_next = 0; 4421 key_beg = 0; 4422 key_end = HAMMER2_KEY_MAX; 4423 for (;;) { 4424 chain_base = &chain->data->npdata[0]; 4425 chain_count = chain->bytes / sizeof(hammer2_blockref_t); 4426 sub = hammer2_combined_find(chain, chain_base, chain_count, 4427 &key_next, 4428 key_beg, key_end, 4429 &bref); 4430 generation = chain->core.generation; 4431 if (bref == NULL) 4432 break; 4433 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4434 4435 bsave = *bref; 4436 if (sub) { 4437 hammer2_chain_ref(sub); 4438 hammer2_spin_unex(&chain->core.spin); 4439 hammer2_chain_lock(sub, HAMMER2_RESOLVE_NEVER); 4440 } else { 4441 hammer2_spin_unex(&chain->core.spin); 4442 sub = hammer2_chain_get(chain, generation, &bsave, 4443 HAMMER2_RESOLVE_NEVER); 4444 if (sub == NULL) { 4445 hammer2_spin_ex(&chain->core.spin); 4446 continue; 4447 } 4448 } 4449 if (bcmp(&bsave, &sub->bref, sizeof(bsave)) || 4450 sub->parent != chain || 4451 (sub->flags & HAMMER2_CHAIN_DELETED)) { 4452 hammer2_chain_unlock(sub); 4453 hammer2_chain_drop(sub); 4454 hammer2_spin_ex(&chain->core.spin); 4455 sub = NULL; /* safety */ 4456 continue; 4457 } 4458 error = hammer2_chain_delete_obref(chain, sub, 4459 sub->bref.modify_tid, 0, 4460 &bsave); 4461 KKASSERT(error == 0); 4462 hammer2_chain_rename_obref(&parent, sub, 4463 sub->bref.modify_tid, 4464 HAMMER2_INSERT_SAMEPARENT, &bsave); 4465 hammer2_chain_unlock(sub); 4466 hammer2_chain_drop(sub); 4467 hammer2_spin_ex(&chain->core.spin); 4468 4469 if (key_next == 0) 4470 break; 4471 key_beg = key_next; 4472 } 4473 hammer2_spin_unex(&chain->core.spin); 4474 4475 hammer2_chain_repchange(parent, chain); 4476 4477 return 1; 4478 } 4479 4480 /* 4481 * Freemap indirect blocks 4482 * 4483 * Calculate the keybits and highside/lowside of the freemap node the 4484 * caller is creating. 4485 * 4486 * This routine will specify the next higher-level freemap key/radix 4487 * representing the lowest-ordered set. By doing so, eventually all 4488 * low-ordered sets will be moved one level down. 4489 * 4490 * We have to be careful here because the freemap reserves a limited 4491 * number of blocks for a limited number of levels. So we can't just 4492 * push indiscriminately. 4493 */ 4494 int 4495 hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp, 4496 int keybits, hammer2_blockref_t *base, int count) 4497 { 4498 hammer2_chain_t *chain; 4499 hammer2_blockref_t *bref; 4500 hammer2_key_t key; 4501 hammer2_key_t key_beg; 4502 hammer2_key_t key_end; 4503 hammer2_key_t key_next; 4504 int maxloops = 300000; 4505 4506 key = *keyp; 4507 keybits = 64; 4508 4509 /* 4510 * Calculate the range of keys in the array being careful to skip 4511 * slots which are overridden with a deletion. 4512 */ 4513 key_beg = 0; 4514 key_end = HAMMER2_KEY_MAX; 4515 hammer2_spin_ex(&parent->core.spin); 4516 4517 for (;;) { 4518 if (--maxloops == 0) { 4519 panic("indkey_freemap shit %p %p:%d\n", 4520 parent, base, count); 4521 } 4522 chain = hammer2_combined_find(parent, base, count, 4523 &key_next, 4524 key_beg, key_end, 4525 &bref); 4526 4527 /* 4528 * Exhausted search 4529 */ 4530 if (bref == NULL) 4531 break; 4532 4533 /* 4534 * Skip deleted chains. 4535 */ 4536 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4537 if (key_next == 0 || key_next > key_end) 4538 break; 4539 key_beg = key_next; 4540 continue; 4541 } 4542 4543 /* 4544 * Use the full live (not deleted) element for the scan 4545 * iteration. HAMMER2 does not allow partial replacements. 4546 * 4547 * XXX should be built into hammer2_combined_find(). 4548 */ 4549 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4550 4551 if (keybits > bref->keybits) { 4552 key = bref->key; 4553 keybits = bref->keybits; 4554 } else if (keybits == bref->keybits && bref->key < key) { 4555 key = bref->key; 4556 } 4557 if (key_next == 0) 4558 break; 4559 key_beg = key_next; 4560 } 4561 hammer2_spin_unex(&parent->core.spin); 4562 4563 /* 4564 * Return the keybits for a higher-level FREEMAP_NODE covering 4565 * this node. 4566 */ 4567 switch(keybits) { 4568 case HAMMER2_FREEMAP_LEVEL0_RADIX: 4569 keybits = HAMMER2_FREEMAP_LEVEL1_RADIX; 4570 break; 4571 case HAMMER2_FREEMAP_LEVEL1_RADIX: 4572 keybits = HAMMER2_FREEMAP_LEVEL2_RADIX; 4573 break; 4574 case HAMMER2_FREEMAP_LEVEL2_RADIX: 4575 keybits = HAMMER2_FREEMAP_LEVEL3_RADIX; 4576 break; 4577 case HAMMER2_FREEMAP_LEVEL3_RADIX: 4578 keybits = HAMMER2_FREEMAP_LEVEL4_RADIX; 4579 break; 4580 case HAMMER2_FREEMAP_LEVEL4_RADIX: 4581 keybits = HAMMER2_FREEMAP_LEVEL5_RADIX; 4582 break; 4583 case HAMMER2_FREEMAP_LEVEL5_RADIX: 4584 panic("hammer2_chain_indkey_freemap: level too high"); 4585 break; 4586 default: 4587 panic("hammer2_chain_indkey_freemap: bad radix"); 4588 break; 4589 } 4590 *keyp = key; 4591 4592 return (keybits); 4593 } 4594 4595 /* 4596 * File indirect blocks 4597 * 4598 * Calculate the key/keybits for the indirect block to create by scanning 4599 * existing keys. The key being created is also passed in *keyp and can be 4600 * inside or outside the indirect block. Regardless, the indirect block 4601 * must hold at least two keys in order to guarantee sufficient space. 4602 * 4603 * We use a modified version of the freemap's fixed radix tree, but taylored 4604 * for file data. Basically we configure an indirect block encompassing the 4605 * smallest key. 4606 */ 4607 static int 4608 hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp, 4609 int keybits, hammer2_blockref_t *base, int count, 4610 int ncount) 4611 { 4612 hammer2_chain_t *chain; 4613 hammer2_blockref_t *bref; 4614 hammer2_key_t key; 4615 hammer2_key_t key_beg; 4616 hammer2_key_t key_end; 4617 hammer2_key_t key_next; 4618 int nradix; 4619 int maxloops = 300000; 4620 4621 key = *keyp; 4622 keybits = 64; 4623 4624 /* 4625 * Calculate the range of keys in the array being careful to skip 4626 * slots which are overridden with a deletion. 4627 * 4628 * Locate the smallest key. 4629 */ 4630 key_beg = 0; 4631 key_end = HAMMER2_KEY_MAX; 4632 hammer2_spin_ex(&parent->core.spin); 4633 4634 for (;;) { 4635 if (--maxloops == 0) { 4636 panic("indkey_freemap shit %p %p:%d\n", 4637 parent, base, count); 4638 } 4639 chain = hammer2_combined_find(parent, base, count, 4640 &key_next, 4641 key_beg, key_end, 4642 &bref); 4643 4644 /* 4645 * Exhausted search 4646 */ 4647 if (bref == NULL) 4648 break; 4649 4650 /* 4651 * Skip deleted chains. 4652 */ 4653 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4654 if (key_next == 0 || key_next > key_end) 4655 break; 4656 key_beg = key_next; 4657 continue; 4658 } 4659 4660 /* 4661 * Use the full live (not deleted) element for the scan 4662 * iteration. HAMMER2 does not allow partial replacements. 4663 * 4664 * XXX should be built into hammer2_combined_find(). 4665 */ 4666 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4667 4668 if (keybits > bref->keybits) { 4669 key = bref->key; 4670 keybits = bref->keybits; 4671 } else if (keybits == bref->keybits && bref->key < key) { 4672 key = bref->key; 4673 } 4674 if (key_next == 0) 4675 break; 4676 key_beg = key_next; 4677 } 4678 hammer2_spin_unex(&parent->core.spin); 4679 4680 /* 4681 * Calculate the static keybits for a higher-level indirect block 4682 * that contains the key. 4683 */ 4684 *keyp = key; 4685 4686 switch(ncount) { 4687 case HAMMER2_IND_COUNT_MIN: 4688 nradix = HAMMER2_IND_RADIX_MIN - HAMMER2_BLOCKREF_RADIX; 4689 break; 4690 case HAMMER2_IND_COUNT_NOM: 4691 nradix = HAMMER2_IND_RADIX_NOM - HAMMER2_BLOCKREF_RADIX; 4692 break; 4693 case HAMMER2_IND_COUNT_MAX: 4694 nradix = HAMMER2_IND_RADIX_MAX - HAMMER2_BLOCKREF_RADIX; 4695 break; 4696 default: 4697 panic("bad ncount %d\n", ncount); 4698 nradix = 0; 4699 break; 4700 } 4701 4702 /* 4703 * The largest radix that can be returned for an indirect block is 4704 * 63 bits. (The largest practical indirect block radix is actually 4705 * 62 bits because the top-level inode or volume root contains four 4706 * entries, but allow 63 to be returned). 4707 */ 4708 if (nradix >= 64) 4709 nradix = 63; 4710 4711 return keybits + nradix; 4712 } 4713 4714 #if 1 4715 4716 /* 4717 * Directory indirect blocks. 4718 * 4719 * Covers both the inode index (directory of inodes), and directory contents 4720 * (filenames hardlinked to inodes). 4721 * 4722 * Because directory keys are hashed we generally try to cut the space in 4723 * half. We accomodate the inode index (which tends to have linearly 4724 * increasing inode numbers) by ensuring that the keyspace is at least large 4725 * enough to fill up the indirect block being created. 4726 */ 4727 static int 4728 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, 4729 int keybits, hammer2_blockref_t *base, int count, 4730 int ncount) 4731 { 4732 hammer2_blockref_t *bref; 4733 hammer2_chain_t *chain; 4734 hammer2_key_t key_beg; 4735 hammer2_key_t key_end; 4736 hammer2_key_t key_next; 4737 hammer2_key_t key; 4738 int nkeybits; 4739 int locount; 4740 int hicount; 4741 int maxloops = 300000; 4742 4743 /* 4744 * NOTE: We can't take a shortcut here anymore for inodes because 4745 * the root directory can contain a mix of inodes and directory 4746 * entries (we used to just return 63 if parent->bref.type was 4747 * HAMMER2_BREF_TYPE_INODE. 4748 */ 4749 key = *keyp; 4750 locount = 0; 4751 hicount = 0; 4752 4753 /* 4754 * Calculate the range of keys in the array being careful to skip 4755 * slots which are overridden with a deletion. 4756 */ 4757 key_beg = 0; 4758 key_end = HAMMER2_KEY_MAX; 4759 hammer2_spin_ex(&parent->core.spin); 4760 4761 for (;;) { 4762 if (--maxloops == 0) { 4763 panic("indkey_freemap shit %p %p:%d\n", 4764 parent, base, count); 4765 } 4766 chain = hammer2_combined_find(parent, base, count, 4767 &key_next, 4768 key_beg, key_end, 4769 &bref); 4770 4771 /* 4772 * Exhausted search 4773 */ 4774 if (bref == NULL) 4775 break; 4776 4777 /* 4778 * Deleted object 4779 */ 4780 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4781 if (key_next == 0 || key_next > key_end) 4782 break; 4783 key_beg = key_next; 4784 continue; 4785 } 4786 4787 /* 4788 * Use the full live (not deleted) element for the scan 4789 * iteration. HAMMER2 does not allow partial replacements. 4790 * 4791 * XXX should be built into hammer2_combined_find(). 4792 */ 4793 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4794 4795 /* 4796 * Expand our calculated key range (key, keybits) to fit 4797 * the scanned key. nkeybits represents the full range 4798 * that we will later cut in half (two halves @ nkeybits - 1). 4799 */ 4800 nkeybits = keybits; 4801 if (nkeybits < bref->keybits) { 4802 if (bref->keybits > 64) { 4803 kprintf("bad bref chain %p bref %p\n", 4804 chain, bref); 4805 Debugger("fubar"); 4806 } 4807 nkeybits = bref->keybits; 4808 } 4809 while (nkeybits < 64 && 4810 rounddown2(key ^ bref->key, (hammer2_key_t)1 << nkeybits) != 0) { 4811 ++nkeybits; 4812 } 4813 4814 /* 4815 * If the new key range is larger we have to determine 4816 * which side of the new key range the existing keys fall 4817 * under by checking the high bit, then collapsing the 4818 * locount into the hicount or vise-versa. 4819 */ 4820 if (keybits != nkeybits) { 4821 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { 4822 hicount += locount; 4823 locount = 0; 4824 } else { 4825 locount += hicount; 4826 hicount = 0; 4827 } 4828 keybits = nkeybits; 4829 } 4830 4831 /* 4832 * The newly scanned key will be in the lower half or the 4833 * upper half of the (new) key range. 4834 */ 4835 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) 4836 ++hicount; 4837 else 4838 ++locount; 4839 4840 if (key_next == 0) 4841 break; 4842 key_beg = key_next; 4843 } 4844 hammer2_spin_unex(&parent->core.spin); 4845 bref = NULL; /* now invalid (safety) */ 4846 4847 /* 4848 * Adjust keybits to represent half of the full range calculated 4849 * above (radix 63 max) for our new indirect block. 4850 */ 4851 --keybits; 4852 4853 /* 4854 * Expand keybits to hold at least ncount elements. ncount will be 4855 * a power of 2. This is to try to completely fill leaf nodes (at 4856 * least for keys which are not hashes). 4857 * 4858 * We aren't counting 'in' or 'out', we are counting 'high side' 4859 * and 'low side' based on the bit at (1LL << keybits). We want 4860 * everything to be inside in these cases so shift it all to 4861 * the low or high side depending on the new high bit. 4862 */ 4863 while (((hammer2_key_t)1 << keybits) < ncount) { 4864 ++keybits; 4865 if (key & ((hammer2_key_t)1 << keybits)) { 4866 hicount += locount; 4867 locount = 0; 4868 } else { 4869 locount += hicount; 4870 hicount = 0; 4871 } 4872 } 4873 4874 if (hicount > locount) 4875 key |= (hammer2_key_t)1 << keybits; 4876 else 4877 key &= ~(hammer2_key_t)1 << keybits; 4878 4879 *keyp = key; 4880 4881 return (keybits); 4882 } 4883 4884 #else 4885 4886 /* 4887 * Directory indirect blocks. 4888 * 4889 * Covers both the inode index (directory of inodes), and directory contents 4890 * (filenames hardlinked to inodes). 4891 * 4892 * Because directory keys are hashed we generally try to cut the space in 4893 * half. We accomodate the inode index (which tends to have linearly 4894 * increasing inode numbers) by ensuring that the keyspace is at least large 4895 * enough to fill up the indirect block being created. 4896 */ 4897 static int 4898 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, 4899 int keybits, hammer2_blockref_t *base, int count, 4900 int ncount) 4901 { 4902 hammer2_blockref_t *bref; 4903 hammer2_chain_t *chain; 4904 hammer2_key_t key_beg; 4905 hammer2_key_t key_end; 4906 hammer2_key_t key_next; 4907 hammer2_key_t key; 4908 int nkeybits; 4909 int locount; 4910 int hicount; 4911 int maxloops = 300000; 4912 4913 /* 4914 * Shortcut if the parent is the inode. In this situation the 4915 * parent has 4+1 directory entries and we are creating an indirect 4916 * block capable of holding many more. 4917 */ 4918 if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { 4919 return 63; 4920 } 4921 4922 key = *keyp; 4923 locount = 0; 4924 hicount = 0; 4925 4926 /* 4927 * Calculate the range of keys in the array being careful to skip 4928 * slots which are overridden with a deletion. 4929 */ 4930 key_beg = 0; 4931 key_end = HAMMER2_KEY_MAX; 4932 hammer2_spin_ex(&parent->core.spin); 4933 4934 for (;;) { 4935 if (--maxloops == 0) { 4936 panic("indkey_freemap shit %p %p:%d\n", 4937 parent, base, count); 4938 } 4939 chain = hammer2_combined_find(parent, base, count, 4940 &key_next, 4941 key_beg, key_end, 4942 &bref); 4943 4944 /* 4945 * Exhausted search 4946 */ 4947 if (bref == NULL) 4948 break; 4949 4950 /* 4951 * Deleted object 4952 */ 4953 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4954 if (key_next == 0 || key_next > key_end) 4955 break; 4956 key_beg = key_next; 4957 continue; 4958 } 4959 4960 /* 4961 * Use the full live (not deleted) element for the scan 4962 * iteration. HAMMER2 does not allow partial replacements. 4963 * 4964 * XXX should be built into hammer2_combined_find(). 4965 */ 4966 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4967 4968 /* 4969 * Expand our calculated key range (key, keybits) to fit 4970 * the scanned key. nkeybits represents the full range 4971 * that we will later cut in half (two halves @ nkeybits - 1). 4972 */ 4973 nkeybits = keybits; 4974 if (nkeybits < bref->keybits) { 4975 if (bref->keybits > 64) { 4976 kprintf("bad bref chain %p bref %p\n", 4977 chain, bref); 4978 Debugger("fubar"); 4979 } 4980 nkeybits = bref->keybits; 4981 } 4982 while (nkeybits < 64 && 4983 (~(((hammer2_key_t)1 << nkeybits) - 1) & 4984 (key ^ bref->key)) != 0) { 4985 ++nkeybits; 4986 } 4987 4988 /* 4989 * If the new key range is larger we have to determine 4990 * which side of the new key range the existing keys fall 4991 * under by checking the high bit, then collapsing the 4992 * locount into the hicount or vise-versa. 4993 */ 4994 if (keybits != nkeybits) { 4995 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { 4996 hicount += locount; 4997 locount = 0; 4998 } else { 4999 locount += hicount; 5000 hicount = 0; 5001 } 5002 keybits = nkeybits; 5003 } 5004 5005 /* 5006 * The newly scanned key will be in the lower half or the 5007 * upper half of the (new) key range. 5008 */ 5009 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) 5010 ++hicount; 5011 else 5012 ++locount; 5013 5014 if (key_next == 0) 5015 break; 5016 key_beg = key_next; 5017 } 5018 hammer2_spin_unex(&parent->core.spin); 5019 bref = NULL; /* now invalid (safety) */ 5020 5021 /* 5022 * Adjust keybits to represent half of the full range calculated 5023 * above (radix 63 max) for our new indirect block. 5024 */ 5025 --keybits; 5026 5027 /* 5028 * Expand keybits to hold at least ncount elements. ncount will be 5029 * a power of 2. This is to try to completely fill leaf nodes (at 5030 * least for keys which are not hashes). 5031 * 5032 * We aren't counting 'in' or 'out', we are counting 'high side' 5033 * and 'low side' based on the bit at (1LL << keybits). We want 5034 * everything to be inside in these cases so shift it all to 5035 * the low or high side depending on the new high bit. 5036 */ 5037 while (((hammer2_key_t)1 << keybits) < ncount) { 5038 ++keybits; 5039 if (key & ((hammer2_key_t)1 << keybits)) { 5040 hicount += locount; 5041 locount = 0; 5042 } else { 5043 locount += hicount; 5044 hicount = 0; 5045 } 5046 } 5047 5048 if (hicount > locount) 5049 key |= (hammer2_key_t)1 << keybits; 5050 else 5051 key &= ~(hammer2_key_t)1 << keybits; 5052 5053 *keyp = key; 5054 5055 return (keybits); 5056 } 5057 5058 #endif 5059 5060 /* 5061 * Sets CHAIN_DELETED and remove the chain's blockref from the parent if 5062 * it exists. 5063 * 5064 * Both parent and chain must be locked exclusively. 5065 * 5066 * This function will modify the parent if the blockref requires removal 5067 * from the parent's block table. 5068 * 5069 * This function is NOT recursive. Any entity already pushed into the 5070 * chain (such as an inode) may still need visibility into its contents, 5071 * as well as the ability to read and modify the contents. For example, 5072 * for an unlinked file which is still open. 5073 * 5074 * Also note that the flusher is responsible for cleaning up empty 5075 * indirect blocks. 5076 */ 5077 int 5078 hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain, 5079 hammer2_tid_t mtid, int flags) 5080 { 5081 int error = 0; 5082 5083 KKASSERT(hammer2_mtx_owned(&chain->lock)); 5084 5085 /* 5086 * Nothing to do if already marked. 5087 * 5088 * We need the spinlock on the core whos RBTREE contains chain 5089 * to protect against races. 5090 */ 5091 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { 5092 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && 5093 chain->parent == parent); 5094 error = _hammer2_chain_delete_helper(parent, chain, 5095 mtid, flags, NULL); 5096 } 5097 5098 /* 5099 * Permanent deletions mark the chain as destroyed. 5100 * 5101 * NOTE: We do not setflush the chain unless the deletion is 5102 * permanent, since the deletion of a chain does not actually 5103 * require it to be flushed. 5104 */ 5105 if (error == 0) { 5106 if (flags & HAMMER2_DELETE_PERMANENT) { 5107 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 5108 hammer2_chain_setflush(chain); 5109 } 5110 } 5111 5112 return error; 5113 } 5114 5115 static int 5116 hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain, 5117 hammer2_tid_t mtid, int flags, 5118 hammer2_blockref_t *obref) 5119 { 5120 int error = 0; 5121 5122 KKASSERT(hammer2_mtx_owned(&chain->lock)); 5123 5124 /* 5125 * Nothing to do if already marked. 5126 * 5127 * We need the spinlock on the core whos RBTREE contains chain 5128 * to protect against races. 5129 */ 5130 obref->type = HAMMER2_BREF_TYPE_EMPTY; 5131 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { 5132 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && 5133 chain->parent == parent); 5134 error = _hammer2_chain_delete_helper(parent, chain, 5135 mtid, flags, obref); 5136 } 5137 5138 /* 5139 * Permanent deletions mark the chain as destroyed. 5140 * 5141 * NOTE: We do not setflush the chain unless the deletion is 5142 * permanent, since the deletion of a chain does not actually 5143 * require it to be flushed. 5144 */ 5145 if (error == 0) { 5146 if (flags & HAMMER2_DELETE_PERMANENT) { 5147 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 5148 hammer2_chain_setflush(chain); 5149 } 5150 } 5151 5152 return error; 5153 } 5154 5155 /* 5156 * Returns the index of the nearest element in the blockref array >= elm. 5157 * Returns (count) if no element could be found. 5158 * 5159 * Sets *key_nextp to the next key for loop purposes but does not modify 5160 * it if the next key would be higher than the current value of *key_nextp. 5161 * Note that *key_nexp can overflow to 0, which should be tested by the 5162 * caller. 5163 * 5164 * WARNING! Must be called with parent's spinlock held. Spinlock remains 5165 * held through the operation. 5166 */ 5167 static int 5168 hammer2_base_find(hammer2_chain_t *parent, 5169 hammer2_blockref_t *base, int count, 5170 hammer2_key_t *key_nextp, 5171 hammer2_key_t key_beg, hammer2_key_t key_end) 5172 { 5173 hammer2_blockref_t *scan; 5174 hammer2_key_t scan_end; 5175 int i; 5176 int limit; 5177 5178 /* 5179 * Require the live chain's already have their core's counted 5180 * so we can optimize operations. 5181 */ 5182 KKASSERT(parent->flags & HAMMER2_CHAIN_COUNTEDBREFS); 5183 5184 /* 5185 * Degenerate case 5186 */ 5187 if (count == 0 || base == NULL) 5188 return(count); 5189 5190 /* 5191 * Sequential optimization using parent->cache_index. This is 5192 * the most likely scenario. 5193 * 5194 * We can avoid trailing empty entries on live chains, otherwise 5195 * we might have to check the whole block array. 5196 */ 5197 i = parent->cache_index; /* SMP RACE OK */ 5198 cpu_ccfence(); 5199 limit = parent->core.live_zero; 5200 if (i >= limit) 5201 i = limit - 1; 5202 if (i < 0) 5203 i = 0; 5204 KKASSERT(i < count); 5205 5206 /* 5207 * Search backwards 5208 */ 5209 scan = &base[i]; 5210 while (i > 0 && (scan->type == HAMMER2_BREF_TYPE_EMPTY || 5211 scan->key > key_beg)) { 5212 --scan; 5213 --i; 5214 } 5215 parent->cache_index = i; 5216 5217 /* 5218 * Search forwards, stop when we find a scan element which 5219 * encloses the key or until we know that there are no further 5220 * elements. 5221 */ 5222 while (i < count) { 5223 if (scan->type != HAMMER2_BREF_TYPE_EMPTY) { 5224 scan_end = scan->key + 5225 ((hammer2_key_t)1 << scan->keybits) - 1; 5226 if (scan->key > key_beg || scan_end >= key_beg) 5227 break; 5228 } 5229 if (i >= limit) 5230 return (count); 5231 ++scan; 5232 ++i; 5233 } 5234 if (i != count) { 5235 parent->cache_index = i; 5236 if (i >= limit) { 5237 i = count; 5238 } else { 5239 scan_end = scan->key + 5240 ((hammer2_key_t)1 << scan->keybits); 5241 if (scan_end && (*key_nextp > scan_end || 5242 *key_nextp == 0)) { 5243 *key_nextp = scan_end; 5244 } 5245 } 5246 } 5247 return (i); 5248 } 5249 5250 /* 5251 * Do a combined search and return the next match either from the blockref 5252 * array or from the in-memory chain. Sets *brefp to the returned bref in 5253 * both cases, or sets it to NULL if the search exhausted. Only returns 5254 * a non-NULL chain if the search matched from the in-memory chain. 5255 * 5256 * When no in-memory chain has been found and a non-NULL bref is returned 5257 * in *brefp. 5258 * 5259 * 5260 * The returned chain is not locked or referenced. Use the returned bref 5261 * to determine if the search exhausted or not. Iterate if the base find 5262 * is chosen but matches a deleted chain. 5263 * 5264 * WARNING! Must be called with parent's spinlock held. Spinlock remains 5265 * held through the operation. 5266 */ 5267 static hammer2_chain_t * 5268 hammer2_combined_find(hammer2_chain_t *parent, 5269 hammer2_blockref_t *base, int count, 5270 hammer2_key_t *key_nextp, 5271 hammer2_key_t key_beg, hammer2_key_t key_end, 5272 hammer2_blockref_t **brefp) 5273 { 5274 hammer2_blockref_t *bref; 5275 hammer2_chain_t *chain; 5276 int i; 5277 5278 /* 5279 * Lookup in block array and in rbtree. 5280 */ 5281 *key_nextp = key_end + 1; 5282 i = hammer2_base_find(parent, base, count, key_nextp, 5283 key_beg, key_end); 5284 chain = hammer2_chain_find(parent, key_nextp, key_beg, key_end); 5285 5286 /* 5287 * Neither matched 5288 */ 5289 if (i == count && chain == NULL) { 5290 *brefp = NULL; 5291 return(NULL); 5292 } 5293 5294 /* 5295 * Only chain matched. 5296 */ 5297 if (i == count) { 5298 bref = &chain->bref; 5299 goto found; 5300 } 5301 5302 /* 5303 * Only blockref matched. 5304 */ 5305 if (chain == NULL) { 5306 bref = &base[i]; 5307 goto found; 5308 } 5309 5310 /* 5311 * Both in-memory and blockref matched, select the nearer element. 5312 * 5313 * If both are flush with the left-hand side or both are the 5314 * same distance away, select the chain. In this situation the 5315 * chain must have been loaded from the matching blockmap. 5316 */ 5317 if ((chain->bref.key <= key_beg && base[i].key <= key_beg) || 5318 chain->bref.key == base[i].key) { 5319 KKASSERT(chain->bref.key == base[i].key); 5320 bref = &chain->bref; 5321 goto found; 5322 } 5323 5324 /* 5325 * Select the nearer key 5326 */ 5327 if (chain->bref.key < base[i].key) { 5328 bref = &chain->bref; 5329 } else { 5330 bref = &base[i]; 5331 chain = NULL; 5332 } 5333 5334 /* 5335 * If the bref is out of bounds we've exhausted our search. 5336 */ 5337 found: 5338 if (bref->key > key_end) { 5339 *brefp = NULL; 5340 chain = NULL; 5341 } else { 5342 *brefp = bref; 5343 } 5344 return(chain); 5345 } 5346 5347 /* 5348 * Locate the specified block array element and delete it. The element 5349 * must exist. 5350 * 5351 * The spin lock on the related chain must be held. 5352 * 5353 * NOTE: live_count was adjusted when the chain was deleted, so it does not 5354 * need to be adjusted when we commit the media change. 5355 */ 5356 void 5357 hammer2_base_delete(hammer2_chain_t *parent, 5358 hammer2_blockref_t *base, int count, 5359 hammer2_chain_t *chain, 5360 hammer2_blockref_t *obref) 5361 { 5362 hammer2_blockref_t *elm = &chain->bref; 5363 hammer2_blockref_t *scan; 5364 hammer2_key_t key_next; 5365 int i; 5366 5367 /* 5368 * Delete element. Expect the element to exist. 5369 * 5370 * XXX see caller, flush code not yet sophisticated enough to prevent 5371 * re-flushed in some cases. 5372 */ 5373 key_next = 0; /* max range */ 5374 i = hammer2_base_find(parent, base, count, &key_next, 5375 elm->key, elm->key); 5376 scan = &base[i]; 5377 if (i == count || scan->type == HAMMER2_BREF_TYPE_EMPTY || 5378 scan->key != elm->key || 5379 ((chain->flags & HAMMER2_CHAIN_BLKMAPUPD) == 0 && 5380 scan->keybits != elm->keybits)) { 5381 hammer2_spin_unex(&parent->core.spin); 5382 panic("delete base %p element not found at %d/%d elm %p\n", 5383 base, i, count, elm); 5384 return; 5385 } 5386 5387 /* 5388 * Update stats and zero the entry. 5389 * 5390 * NOTE: Handle radix == 0 (0 bytes) case. 5391 */ 5392 if ((int)(scan->data_off & HAMMER2_OFF_MASK_RADIX)) { 5393 parent->bref.embed.stats.data_count -= (hammer2_off_t)1 << 5394 (int)(scan->data_off & HAMMER2_OFF_MASK_RADIX); 5395 } 5396 switch(scan->type) { 5397 case HAMMER2_BREF_TYPE_INODE: 5398 --parent->bref.embed.stats.inode_count; 5399 /* fall through */ 5400 case HAMMER2_BREF_TYPE_DATA: 5401 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5402 atomic_set_int(&chain->flags, 5403 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5404 } else { 5405 if (parent->bref.leaf_count) 5406 --parent->bref.leaf_count; 5407 } 5408 /* fall through */ 5409 case HAMMER2_BREF_TYPE_INDIRECT: 5410 if (scan->type != HAMMER2_BREF_TYPE_DATA) { 5411 parent->bref.embed.stats.data_count -= 5412 scan->embed.stats.data_count; 5413 parent->bref.embed.stats.inode_count -= 5414 scan->embed.stats.inode_count; 5415 } 5416 if (scan->type == HAMMER2_BREF_TYPE_INODE) 5417 break; 5418 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5419 atomic_set_int(&chain->flags, 5420 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5421 } else { 5422 if (parent->bref.leaf_count <= scan->leaf_count) 5423 parent->bref.leaf_count = 0; 5424 else 5425 parent->bref.leaf_count -= scan->leaf_count; 5426 } 5427 break; 5428 case HAMMER2_BREF_TYPE_DIRENT: 5429 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5430 atomic_set_int(&chain->flags, 5431 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5432 } else { 5433 if (parent->bref.leaf_count) 5434 --parent->bref.leaf_count; 5435 } 5436 default: 5437 break; 5438 } 5439 5440 if (obref) 5441 *obref = *scan; 5442 bzero(scan, sizeof(*scan)); 5443 5444 /* 5445 * We can only optimize parent->core.live_zero for live chains. 5446 */ 5447 if (parent->core.live_zero == i + 1) { 5448 while (--i >= 0 && base[i].type == HAMMER2_BREF_TYPE_EMPTY) 5449 ; 5450 parent->core.live_zero = i + 1; 5451 } 5452 5453 /* 5454 * Clear appropriate blockmap flags in chain. 5455 */ 5456 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED | 5457 HAMMER2_CHAIN_BLKMAPUPD); 5458 } 5459 5460 /* 5461 * Insert the specified element. The block array must not already have the 5462 * element and must have space available for the insertion. 5463 * 5464 * The spin lock on the related chain must be held. 5465 * 5466 * NOTE: live_count was adjusted when the chain was deleted, so it does not 5467 * need to be adjusted when we commit the media change. 5468 */ 5469 void 5470 hammer2_base_insert(hammer2_chain_t *parent, 5471 hammer2_blockref_t *base, int count, 5472 hammer2_chain_t *chain, hammer2_blockref_t *elm) 5473 { 5474 hammer2_key_t key_next; 5475 hammer2_key_t xkey; 5476 int i; 5477 int j; 5478 int k; 5479 int l; 5480 int u = 1; 5481 5482 /* 5483 * Insert new element. Expect the element to not already exist 5484 * unless we are replacing it. 5485 * 5486 * XXX see caller, flush code not yet sophisticated enough to prevent 5487 * re-flushed in some cases. 5488 */ 5489 key_next = 0; /* max range */ 5490 i = hammer2_base_find(parent, base, count, &key_next, 5491 elm->key, elm->key); 5492 5493 /* 5494 * Shortcut fill optimization, typical ordered insertion(s) may not 5495 * require a search. 5496 */ 5497 KKASSERT(i >= 0 && i <= count); 5498 5499 /* 5500 * Set appropriate blockmap flags in chain (if not NULL) 5501 */ 5502 if (chain) 5503 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED); 5504 5505 /* 5506 * Update stats and zero the entry 5507 */ 5508 if ((int)(elm->data_off & HAMMER2_OFF_MASK_RADIX)) { 5509 parent->bref.embed.stats.data_count += (hammer2_off_t)1 << 5510 (int)(elm->data_off & HAMMER2_OFF_MASK_RADIX); 5511 } 5512 switch(elm->type) { 5513 case HAMMER2_BREF_TYPE_INODE: 5514 ++parent->bref.embed.stats.inode_count; 5515 /* fall through */ 5516 case HAMMER2_BREF_TYPE_DATA: 5517 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) 5518 ++parent->bref.leaf_count; 5519 /* fall through */ 5520 case HAMMER2_BREF_TYPE_INDIRECT: 5521 if (elm->type != HAMMER2_BREF_TYPE_DATA) { 5522 parent->bref.embed.stats.data_count += 5523 elm->embed.stats.data_count; 5524 parent->bref.embed.stats.inode_count += 5525 elm->embed.stats.inode_count; 5526 } 5527 if (elm->type == HAMMER2_BREF_TYPE_INODE) 5528 break; 5529 if (parent->bref.leaf_count + elm->leaf_count < 5530 HAMMER2_BLOCKREF_LEAF_MAX) { 5531 parent->bref.leaf_count += elm->leaf_count; 5532 } else { 5533 parent->bref.leaf_count = HAMMER2_BLOCKREF_LEAF_MAX; 5534 } 5535 break; 5536 case HAMMER2_BREF_TYPE_DIRENT: 5537 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) 5538 ++parent->bref.leaf_count; 5539 break; 5540 default: 5541 break; 5542 } 5543 5544 5545 /* 5546 * We can only optimize parent->core.live_zero for live chains. 5547 */ 5548 if (i == count && parent->core.live_zero < count) { 5549 i = parent->core.live_zero++; 5550 base[i] = *elm; 5551 return; 5552 } 5553 5554 xkey = elm->key + ((hammer2_key_t)1 << elm->keybits) - 1; 5555 if (i != count && (base[i].key < elm->key || xkey >= base[i].key)) { 5556 hammer2_spin_unex(&parent->core.spin); 5557 panic("insert base %p overlapping elements at %d elm %p\n", 5558 base, i, elm); 5559 } 5560 5561 /* 5562 * Try to find an empty slot before or after. 5563 */ 5564 j = i; 5565 k = i; 5566 while (j > 0 || k < count) { 5567 --j; 5568 if (j >= 0 && base[j].type == HAMMER2_BREF_TYPE_EMPTY) { 5569 if (j == i - 1) { 5570 base[j] = *elm; 5571 } else { 5572 bcopy(&base[j+1], &base[j], 5573 (i - j - 1) * sizeof(*base)); 5574 base[i - 1] = *elm; 5575 } 5576 goto validate; 5577 } 5578 ++k; 5579 if (k < count && base[k].type == HAMMER2_BREF_TYPE_EMPTY) { 5580 bcopy(&base[i], &base[i+1], 5581 (k - i) * sizeof(hammer2_blockref_t)); 5582 base[i] = *elm; 5583 5584 /* 5585 * We can only update parent->core.live_zero for live 5586 * chains. 5587 */ 5588 if (parent->core.live_zero <= k) 5589 parent->core.live_zero = k + 1; 5590 u = 2; 5591 goto validate; 5592 } 5593 } 5594 panic("hammer2_base_insert: no room!"); 5595 5596 /* 5597 * Debugging 5598 */ 5599 validate: 5600 key_next = 0; 5601 for (l = 0; l < count; ++l) { 5602 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { 5603 key_next = base[l].key + 5604 ((hammer2_key_t)1 << base[l].keybits) - 1; 5605 break; 5606 } 5607 } 5608 while (++l < count) { 5609 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { 5610 if (base[l].key <= key_next) 5611 panic("base_insert %d %d,%d,%d fail %p:%d", u, i, j, k, base, l); 5612 key_next = base[l].key + 5613 ((hammer2_key_t)1 << base[l].keybits) - 1; 5614 5615 } 5616 } 5617 5618 } 5619 5620 #if 0 5621 5622 /* 5623 * Sort the blockref array for the chain. Used by the flush code to 5624 * sort the blockref[] array. 5625 * 5626 * The chain must be exclusively locked AND spin-locked. 5627 */ 5628 typedef hammer2_blockref_t *hammer2_blockref_p; 5629 5630 static 5631 int 5632 hammer2_base_sort_callback(const void *v1, const void *v2) 5633 { 5634 hammer2_blockref_p bref1 = *(const hammer2_blockref_p *)v1; 5635 hammer2_blockref_p bref2 = *(const hammer2_blockref_p *)v2; 5636 5637 /* 5638 * Make sure empty elements are placed at the end of the array 5639 */ 5640 if (bref1->type == HAMMER2_BREF_TYPE_EMPTY) { 5641 if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) 5642 return(0); 5643 return(1); 5644 } else if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) { 5645 return(-1); 5646 } 5647 5648 /* 5649 * Sort by key 5650 */ 5651 if (bref1->key < bref2->key) 5652 return(-1); 5653 if (bref1->key > bref2->key) 5654 return(1); 5655 return(0); 5656 } 5657 5658 void 5659 hammer2_base_sort(hammer2_chain_t *chain) 5660 { 5661 hammer2_blockref_t *base; 5662 int count; 5663 5664 switch(chain->bref.type) { 5665 case HAMMER2_BREF_TYPE_INODE: 5666 /* 5667 * Special shortcut for embedded data returns the inode 5668 * itself. Callers must detect this condition and access 5669 * the embedded data (the strategy code does this for us). 5670 * 5671 * This is only applicable to regular files and softlinks. 5672 */ 5673 if (chain->data->ipdata.meta.op_flags & 5674 HAMMER2_OPFLAG_DIRECTDATA) { 5675 return; 5676 } 5677 base = &chain->data->ipdata.u.blockset.blockref[0]; 5678 count = HAMMER2_SET_COUNT; 5679 break; 5680 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 5681 case HAMMER2_BREF_TYPE_INDIRECT: 5682 /* 5683 * Optimize indirect blocks in the INITIAL state to avoid 5684 * I/O. 5685 */ 5686 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) == 0); 5687 base = &chain->data->npdata[0]; 5688 count = chain->bytes / sizeof(hammer2_blockref_t); 5689 break; 5690 case HAMMER2_BREF_TYPE_VOLUME: 5691 base = &chain->data->voldata.sroot_blockset.blockref[0]; 5692 count = HAMMER2_SET_COUNT; 5693 break; 5694 case HAMMER2_BREF_TYPE_FREEMAP: 5695 base = &chain->data->blkset.blockref[0]; 5696 count = HAMMER2_SET_COUNT; 5697 break; 5698 default: 5699 panic("hammer2_base_sort: unrecognized " 5700 "blockref(A) type: %d", 5701 chain->bref.type); 5702 base = NULL; /* safety */ 5703 count = 0; /* safety */ 5704 break; 5705 } 5706 kqsort(base, count, sizeof(*base), hammer2_base_sort_callback); 5707 } 5708 5709 #endif 5710 5711 /* 5712 * Set the check data for a chain. This can be a heavy-weight operation 5713 * and typically only runs on-flush. For file data check data is calculated 5714 * when the logical buffers are flushed. 5715 */ 5716 void 5717 hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata) 5718 { 5719 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_NOTTESTED); 5720 5721 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { 5722 case HAMMER2_CHECK_NONE: 5723 break; 5724 case HAMMER2_CHECK_DISABLED: 5725 break; 5726 case HAMMER2_CHECK_ISCSI32: 5727 chain->bref.check.iscsi32.value = 5728 hammer2_icrc32(bdata, chain->bytes); 5729 break; 5730 case HAMMER2_CHECK_XXHASH64: 5731 chain->bref.check.xxhash64.value = 5732 XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); 5733 break; 5734 case HAMMER2_CHECK_SHA192: 5735 assert(0); /* XXX unsupported */ 5736 /* 5737 { 5738 SHA256_CTX hash_ctx; 5739 union { 5740 uint8_t digest[SHA256_DIGEST_LENGTH]; 5741 uint64_t digest64[SHA256_DIGEST_LENGTH/8]; 5742 } u; 5743 5744 SHA256_Init(&hash_ctx); 5745 SHA256_Update(&hash_ctx, bdata, chain->bytes); 5746 SHA256_Final(u.digest, &hash_ctx); 5747 u.digest64[2] ^= u.digest64[3]; 5748 bcopy(u.digest, 5749 chain->bref.check.sha192.data, 5750 sizeof(chain->bref.check.sha192.data)); 5751 } 5752 */ 5753 break; 5754 case HAMMER2_CHECK_FREEMAP: 5755 chain->bref.check.freemap.icrc32 = 5756 hammer2_icrc32(bdata, chain->bytes); 5757 break; 5758 default: 5759 kprintf("hammer2_chain_setcheck: unknown check type %02x\n", 5760 chain->bref.methods); 5761 break; 5762 } 5763 } 5764 5765 /* 5766 * Characterize a failed check code and try to trace back to the inode. 5767 */ 5768 static void 5769 hammer2_characterize_failed_chain(hammer2_chain_t *chain, uint64_t check, 5770 int bits) 5771 { 5772 hammer2_chain_t *lchain; 5773 hammer2_chain_t *ochain; 5774 int did; 5775 5776 did = krateprintf(&krate_h2chk, 5777 "chain %016jx.%02x (%s) meth=%02x CHECK FAIL " 5778 "(flags=%08x, bref/data ", 5779 chain->bref.data_off, 5780 chain->bref.type, 5781 hammer2_bref_type_str(chain->bref.type), 5782 chain->bref.methods, 5783 chain->flags); 5784 if (did == 0) 5785 return; 5786 5787 if (bits == 32) { 5788 kprintf("%08x/%08x)\n", 5789 chain->bref.check.iscsi32.value, 5790 (uint32_t)check); 5791 } else { 5792 kprintf("%016jx/%016jx)\n", 5793 chain->bref.check.xxhash64.value, 5794 check); 5795 } 5796 5797 /* 5798 * Run up the chains to try to find the governing inode so we 5799 * can report it. 5800 * 5801 * XXX This error reporting is not really MPSAFE 5802 */ 5803 ochain = chain; 5804 lchain = chain; 5805 while (chain && chain->bref.type != HAMMER2_BREF_TYPE_INODE) { 5806 lchain = chain; 5807 chain = chain->parent; 5808 } 5809 5810 if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE && 5811 ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) == 0 || 5812 (lchain->bref.key & HAMMER2_DIRHASH_VISIBLE))) { 5813 kprintf(" Resides at/in inode %ld\n", 5814 chain->bref.key); 5815 } else if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE) { 5816 kprintf(" Resides in inode index - CRITICAL!!!\n"); 5817 } else { 5818 kprintf(" Resides in root index - CRITICAL!!!\n"); 5819 } 5820 if (ochain->hmp) { 5821 const char *pfsname = "UNKNOWN"; 5822 int i; 5823 5824 if (ochain->pmp) { 5825 for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) { 5826 if (ochain->pmp->pfs_hmps[i] == ochain->hmp && 5827 ochain->pmp->pfs_names[i]) { 5828 pfsname = ochain->pmp->pfs_names[i]; 5829 break; 5830 } 5831 } 5832 } 5833 kprintf(" In pfs %s on device %s\n", 5834 pfsname, ochain->hmp->devrepname); 5835 } 5836 } 5837 5838 /* 5839 * Returns non-zero on success, 0 on failure. 5840 */ 5841 int 5842 hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata) 5843 { 5844 uint32_t check32; 5845 uint64_t check64; 5846 int r; 5847 5848 if (chain->flags & HAMMER2_CHAIN_NOTTESTED) 5849 return 1; 5850 5851 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { 5852 case HAMMER2_CHECK_NONE: 5853 r = 1; 5854 break; 5855 case HAMMER2_CHECK_DISABLED: 5856 r = 1; 5857 break; 5858 case HAMMER2_CHECK_ISCSI32: 5859 check32 = hammer2_icrc32(bdata, chain->bytes); 5860 r = (chain->bref.check.iscsi32.value == check32); 5861 if (r == 0) { 5862 hammer2_characterize_failed_chain(chain, check32, 32); 5863 } 5864 hammer2_process_icrc32 += chain->bytes; 5865 break; 5866 case HAMMER2_CHECK_XXHASH64: 5867 check64 = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); 5868 r = (chain->bref.check.xxhash64.value == check64); 5869 if (r == 0) { 5870 hammer2_characterize_failed_chain(chain, check64, 64); 5871 } 5872 hammer2_process_xxhash64 += chain->bytes; 5873 break; 5874 case HAMMER2_CHECK_SHA192: 5875 assert(0); /* XXX unsupported */ 5876 /* 5877 { 5878 SHA256_CTX hash_ctx; 5879 union { 5880 uint8_t digest[SHA256_DIGEST_LENGTH]; 5881 uint64_t digest64[SHA256_DIGEST_LENGTH/8]; 5882 } u; 5883 5884 SHA256_Init(&hash_ctx); 5885 SHA256_Update(&hash_ctx, bdata, chain->bytes); 5886 SHA256_Final(u.digest, &hash_ctx); 5887 u.digest64[2] ^= u.digest64[3]; 5888 if (bcmp(u.digest, 5889 chain->bref.check.sha192.data, 5890 sizeof(chain->bref.check.sha192.data)) == 0) { 5891 r = 1; 5892 } else { 5893 r = 0; 5894 krateprintf(&krate_h2chk, 5895 "chain %016jx.%02x meth=%02x " 5896 "CHECK FAIL\n", 5897 chain->bref.data_off, 5898 chain->bref.type, 5899 chain->bref.methods); 5900 } 5901 } 5902 */ 5903 break; 5904 case HAMMER2_CHECK_FREEMAP: 5905 r = (chain->bref.check.freemap.icrc32 == 5906 hammer2_icrc32(bdata, chain->bytes)); 5907 if (r == 0) { 5908 int did; 5909 5910 did = krateprintf(&krate_h2chk, 5911 "chain %016jx.%02x meth=%02x " 5912 "CHECK FAIL\n", 5913 chain->bref.data_off, 5914 chain->bref.type, 5915 chain->bref.methods); 5916 if (did) { 5917 kprintf("freemap.icrc %08x icrc32 %08x (%d)\n", 5918 chain->bref.check.freemap.icrc32, 5919 hammer2_icrc32(bdata, chain->bytes), 5920 chain->bytes); 5921 if (chain->dio) { 5922 kprintf("dio %p buf %016jx,%ld " 5923 "bdata %p/%p\n", 5924 chain->dio, 5925 chain->dio->bp->b_loffset, 5926 chain->dio->bp->b_bufsize, 5927 bdata, 5928 chain->dio->bp->b_data); 5929 } 5930 } 5931 } 5932 break; 5933 default: 5934 kprintf("hammer2_chain_testcheck: unknown check type %02x\n", 5935 chain->bref.methods); 5936 r = 1; 5937 break; 5938 } 5939 return r; 5940 } 5941 5942 /* 5943 * Acquire the chain and parent representing the specified inode for the 5944 * device at the specified cluster index. 5945 * 5946 * The flags passed in are LOOKUP flags, not RESOLVE flags. 5947 * 5948 * If we are unable to locate the inode, HAMMER2_ERROR_EIO or HAMMER2_ERROR_CHECK 5949 * is returned. In case of error, *chainp and/or *parentp may still be returned 5950 * non-NULL. 5951 * 5952 * The caller may pass-in a locked *parentp and/or *chainp, or neither. 5953 * They will be unlocked and released by this function. The *parentp and 5954 * *chainp representing the located inode are returned locked. 5955 * 5956 * The returned error includes any error on the returned chain in addition to 5957 * errors incurred while trying to lookup the inode. However, a chain->error 5958 * might not be recognized if HAMMER2_LOOKUP_NODATA is passed. This flag may 5959 * not be passed to this function. 5960 */ 5961 int 5962 hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum, 5963 int clindex, int flags, 5964 hammer2_chain_t **parentp, hammer2_chain_t **chainp) 5965 { 5966 hammer2_chain_t *parent; 5967 hammer2_chain_t *rchain; 5968 hammer2_key_t key_dummy; 5969 hammer2_inode_t *ip; 5970 int resolve_flags; 5971 int error; 5972 5973 KKASSERT((flags & HAMMER2_LOOKUP_NODATA) == 0); 5974 5975 resolve_flags = (flags & HAMMER2_LOOKUP_SHARED) ? 5976 HAMMER2_RESOLVE_SHARED : 0; 5977 5978 /* 5979 * Caller expects us to replace these. 5980 */ 5981 if (*chainp) { 5982 hammer2_chain_unlock(*chainp); 5983 hammer2_chain_drop(*chainp); 5984 *chainp = NULL; 5985 } 5986 if (*parentp) { 5987 hammer2_chain_unlock(*parentp); 5988 hammer2_chain_drop(*parentp); 5989 *parentp = NULL; 5990 } 5991 5992 /* 5993 * Be very careful, this is a backend function and we CANNOT 5994 * lock any frontend inode structure we find. But we have to 5995 * look the inode up this way first in case it exists but is 5996 * detached from the radix tree. 5997 */ 5998 ip = hammer2_inode_lookup(pmp, inum); 5999 if (ip) { 6000 *chainp = hammer2_inode_chain_and_parent(ip, clindex, 6001 parentp, 6002 resolve_flags); 6003 hammer2_inode_drop(ip); 6004 if (*chainp) 6005 return (*chainp)->error; 6006 hammer2_chain_unlock(*chainp); 6007 hammer2_chain_drop(*chainp); 6008 *chainp = NULL; 6009 if (*parentp) { 6010 hammer2_chain_unlock(*parentp); 6011 hammer2_chain_drop(*parentp); 6012 *parentp = NULL; 6013 } 6014 } 6015 6016 /* 6017 * Inodes hang off of the iroot (bit 63 is clear, differentiating 6018 * inodes from root directory entries in the key lookup). 6019 */ 6020 parent = hammer2_inode_chain(pmp->iroot, clindex, resolve_flags); 6021 rchain = NULL; 6022 if (parent) { 6023 /* 6024 * NOTE: rchain can be returned as NULL even if error == 0 6025 * (i.e. not found) 6026 */ 6027 rchain = hammer2_chain_lookup(&parent, &key_dummy, 6028 inum, inum, 6029 &error, flags); 6030 /* 6031 * Propagate a chain-specific error to caller. 6032 * 6033 * If the chain is not errored, we must still validate that the inode 6034 * number is correct, because all hell will break loose if it isn't 6035 * correct. It should always be correct so print to the console and 6036 * simulate a CHECK error if it is not. 6037 */ 6038 if (error == 0 && rchain) { 6039 error = rchain->error; 6040 if (error == 0 && rchain->data) { 6041 if (inum != rchain->data->ipdata.meta.inum) { 6042 kprintf("hammer2_chain_inode_find: lookup inum %ld, " 6043 "got valid inode but with inum %ld\n", 6044 inum, rchain->data->ipdata.meta.inum); 6045 error = HAMMER2_ERROR_CHECK; 6046 rchain->error = error; 6047 } 6048 } 6049 } 6050 } else { 6051 error = HAMMER2_ERROR_EIO; 6052 } 6053 *parentp = parent; 6054 *chainp = rchain; 6055 6056 return error; 6057 } 6058 6059 /* 6060 * Used by the bulkscan code to snapshot the synchronized storage for 6061 * a volume, allowing it to be scanned concurrently against normal 6062 * operation. 6063 */ 6064 hammer2_chain_t * 6065 hammer2_chain_bulksnap(hammer2_dev_t *hmp) 6066 { 6067 hammer2_chain_t *copy; 6068 6069 copy = hammer2_chain_alloc(hmp, hmp->spmp, &hmp->vchain.bref); 6070 copy->data = kmalloc(sizeof(copy->data->voldata), 6071 hmp->mmsg, M_WAITOK | M_ZERO); 6072 hammer2_voldata_lock(hmp); 6073 copy->data->voldata = hmp->volsync; 6074 hammer2_voldata_unlock(hmp); 6075 6076 return copy; 6077 } 6078 6079 void 6080 hammer2_chain_bulkdrop(hammer2_chain_t *copy) 6081 { 6082 KKASSERT(copy->bref.type == HAMMER2_BREF_TYPE_VOLUME); 6083 KKASSERT(copy->data); 6084 kfree(copy->data, copy->hmp->mmsg); 6085 copy->data = NULL; 6086 hammer2_chain_drop(copy); 6087 } 6088 6089 /* 6090 * Returns non-zero if the chain (INODE or DIRENT) matches the 6091 * filename. 6092 */ 6093 int 6094 hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name, 6095 size_t name_len) 6096 { 6097 const hammer2_inode_data_t *ripdata; 6098 6099 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) { 6100 ripdata = &chain->data->ipdata; 6101 if (ripdata->meta.name_len == name_len && 6102 bcmp(ripdata->filename, name, name_len) == 0) { 6103 return 1; 6104 } 6105 } 6106 if (chain->bref.type == HAMMER2_BREF_TYPE_DIRENT && 6107 chain->bref.embed.dirent.namlen == name_len) { 6108 if (name_len > sizeof(chain->bref.check.buf) && 6109 bcmp(chain->data->buf, name, name_len) == 0) { 6110 return 1; 6111 } 6112 if (name_len <= sizeof(chain->bref.check.buf) && 6113 bcmp(chain->bref.check.buf, name, name_len) == 0) { 6114 return 1; 6115 } 6116 } 6117 return 0; 6118 } 6119