1 /* 2 * Copyright (c) 2011-2019 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@dragonflybsd.org> 6 * and Venkatesh Srinivas <vsrinivas@dragonflybsd.org> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 /* 36 * This subsystem implements most of the core support functions for 37 * the hammer2_chain structure. 38 * 39 * Chains are the in-memory version on media objects (volume header, inodes, 40 * indirect blocks, data blocks, etc). Chains represent a portion of the 41 * HAMMER2 topology. 42 * 43 * Chains are no-longer delete-duplicated. Instead, the original in-memory 44 * chain will be moved along with its block reference (e.g. for things like 45 * renames, hardlink operations, modifications, etc), and will be indexed 46 * on a secondary list for flush handling instead of propagating a flag 47 * upward to the root. 48 * 49 * Concurrent front-end operations can still run against backend flushes 50 * as long as they do not cross the current flush boundary. An operation 51 * running above the current flush (in areas not yet flushed) can become 52 * part of the current flush while ano peration running below the current 53 * flush can become part of the next flush. 54 */ 55 #include <sys/cdefs.h> 56 #include <sys/param.h> 57 #include <sys/systm.h> 58 #include <sys/types.h> 59 #include <sys/lock.h> 60 #include <sys/kern_syscall.h> 61 #include <sys/uuid.h> 62 63 #include <crypto/sha2/sha2.h> 64 65 #include "hammer2.h" 66 67 static hammer2_chain_t *hammer2_chain_create_indirect( 68 hammer2_chain_t *parent, 69 hammer2_key_t key, int keybits, 70 hammer2_tid_t mtid, int for_type, int *errorp); 71 static void hammer2_chain_rename_obref(hammer2_chain_t **parentp, 72 hammer2_chain_t *chain, hammer2_tid_t mtid, 73 int flags, hammer2_blockref_t *obref); 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_io_t *hammer2_chain_drop_data(hammer2_chain_t *chain); 79 static hammer2_chain_t *hammer2_combined_find( 80 hammer2_chain_t *parent, 81 hammer2_blockref_t *base, int count, 82 hammer2_key_t *key_nextp, 83 hammer2_key_t key_beg, hammer2_key_t key_end, 84 hammer2_blockref_t **bresp); 85 86 /* 87 * There are many degenerate situations where an extreme rate of console 88 * output can occur from warnings and errors. Make sure this output does 89 * not impede operations. 90 */ 91 static struct krate krate_h2chk = { .freq = 5 }; 92 static struct krate krate_h2me = { .freq = 1 }; 93 static struct krate krate_h2em = { .freq = 1 }; 94 95 /* 96 * Basic RBTree for chains (core.rbtree). 97 */ 98 RB_GENERATE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp); 99 100 int 101 hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2) 102 { 103 hammer2_key_t c1_beg; 104 hammer2_key_t c1_end; 105 hammer2_key_t c2_beg; 106 hammer2_key_t c2_end; 107 108 /* 109 * Compare chains. Overlaps are not supposed to happen and catch 110 * any software issues early we count overlaps as a match. 111 */ 112 c1_beg = chain1->bref.key; 113 c1_end = c1_beg + ((hammer2_key_t)1 << chain1->bref.keybits) - 1; 114 c2_beg = chain2->bref.key; 115 c2_end = c2_beg + ((hammer2_key_t)1 << chain2->bref.keybits) - 1; 116 117 if (c1_end < c2_beg) /* fully to the left */ 118 return(-1); 119 if (c1_beg > c2_end) /* fully to the right */ 120 return(1); 121 return(0); /* overlap (must not cross edge boundary) */ 122 } 123 124 /* 125 * Assert that a chain has no media data associated with it. 126 */ 127 static __inline void 128 hammer2_chain_assert_no_data(hammer2_chain_t *chain) 129 { 130 KKASSERT(chain->dio == NULL); 131 if (chain->bref.type != HAMMER2_BREF_TYPE_VOLUME && 132 chain->bref.type != HAMMER2_BREF_TYPE_FREEMAP && 133 chain->data) { 134 panic("hammer2_chain_assert_no_data: chain %p still has data", 135 chain); 136 } 137 } 138 139 /* 140 * Make a chain visible to the flusher. The flusher operates using a top-down 141 * recursion based on the ONFLUSH flag. It locates MODIFIED and UPDATE chains, 142 * flushes them, and updates blocks back to the volume root. 143 * 144 * This routine sets the ONFLUSH flag upward from the triggering chain until 145 * it hits an inode root or the volume root. Inode chains serve as inflection 146 * points, requiring the flusher to bridge across trees. Inodes include 147 * regular inodes, PFS roots (pmp->iroot), and the media super root 148 * (spmp->iroot). 149 */ 150 void 151 hammer2_chain_setflush(hammer2_chain_t *chain) 152 { 153 hammer2_chain_t *parent; 154 155 if ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { 156 hammer2_spin_sh(&chain->core.spin); 157 while ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { 158 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); 159 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) 160 break; 161 if ((parent = chain->parent) == NULL) 162 break; 163 hammer2_spin_sh(&parent->core.spin); 164 hammer2_spin_unsh(&chain->core.spin); 165 chain = parent; 166 } 167 hammer2_spin_unsh(&chain->core.spin); 168 } 169 } 170 171 /* 172 * Allocate a new disconnected chain element representing the specified 173 * bref. chain->refs is set to 1 and the passed bref is copied to 174 * chain->bref. chain->bytes is derived from the bref. 175 * 176 * chain->pmp inherits pmp unless the chain is an inode (other than the 177 * super-root inode). 178 * 179 * NOTE: Returns a referenced but unlocked (because there is no core) chain. 180 */ 181 hammer2_chain_t * 182 hammer2_chain_alloc(hammer2_dev_t *hmp, hammer2_pfs_t *pmp, 183 hammer2_blockref_t *bref) 184 { 185 hammer2_chain_t *chain; 186 u_int bytes; 187 188 /* 189 * Special case - radix of 0 indicates a chain that does not 190 * need a data reference (context is completely embedded in the 191 * bref). 192 */ 193 if ((int)(bref->data_off & HAMMER2_OFF_MASK_RADIX)) 194 bytes = 1U << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX); 195 else 196 bytes = 0; 197 198 atomic_add_long(&hammer2_chain_allocs, 1); 199 200 /* 201 * Construct the appropriate system structure. 202 */ 203 switch(bref->type) { 204 case HAMMER2_BREF_TYPE_DIRENT: 205 case HAMMER2_BREF_TYPE_INODE: 206 case HAMMER2_BREF_TYPE_INDIRECT: 207 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 208 case HAMMER2_BREF_TYPE_DATA: 209 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 210 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO); 211 break; 212 case HAMMER2_BREF_TYPE_VOLUME: 213 case HAMMER2_BREF_TYPE_FREEMAP: 214 /* 215 * Only hammer2_chain_bulksnap() calls this function with these 216 * types. 217 */ 218 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO); 219 break; 220 default: 221 chain = NULL; 222 panic("hammer2_chain_alloc: unrecognized blockref type: %d", 223 bref->type); 224 } 225 226 /* 227 * Initialize the new chain structure. pmp must be set to NULL for 228 * chains belonging to the super-root topology of a device mount. 229 */ 230 if (pmp == hmp->spmp) 231 chain->pmp = NULL; 232 else 233 chain->pmp = pmp; 234 235 chain->hmp = hmp; 236 chain->bref = *bref; 237 chain->bytes = bytes; 238 chain->refs = 1; 239 chain->flags = HAMMER2_CHAIN_ALLOCATED; 240 lockinit(&chain->diolk, "chdio", 0, 0); 241 242 /* 243 * Set the PFS boundary flag if this chain represents a PFS root. 244 */ 245 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) 246 atomic_set_int(&chain->flags, HAMMER2_CHAIN_PFSBOUNDARY); 247 hammer2_chain_core_init(chain); 248 249 return (chain); 250 } 251 252 /* 253 * Initialize a chain's core structure. This structure used to be allocated 254 * but is now embedded. 255 * 256 * The core is not locked. No additional refs on the chain are made. 257 * (trans) must not be NULL if (core) is not NULL. 258 */ 259 void 260 hammer2_chain_core_init(hammer2_chain_t *chain) 261 { 262 /* 263 * Fresh core under nchain (no multi-homing of ochain's 264 * sub-tree). 265 */ 266 RB_INIT(&chain->core.rbtree); /* live chains */ 267 hammer2_mtx_init(&chain->lock, "h2chain"); 268 } 269 270 /* 271 * Add a reference to a chain element, preventing its destruction. 272 * 273 * (can be called with spinlock held) 274 */ 275 void 276 hammer2_chain_ref(hammer2_chain_t *chain) 277 { 278 if (atomic_fetchadd_int(&chain->refs, 1) == 0) { 279 /* 280 * Just flag that the chain was used and should be recycled 281 * on the LRU if it encounters it later. 282 */ 283 if (chain->flags & HAMMER2_CHAIN_ONLRU) 284 atomic_set_int(&chain->flags, HAMMER2_CHAIN_LRUHINT); 285 286 #if 0 287 /* 288 * REMOVED - reduces contention, lru_list is more heuristical 289 * now. 290 * 291 * 0->non-zero transition must ensure that chain is removed 292 * from the LRU list. 293 * 294 * NOTE: Already holding lru_spin here so we cannot call 295 * hammer2_chain_ref() to get it off lru_list, do 296 * it manually. 297 */ 298 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 299 hammer2_pfs_t *pmp = chain->pmp; 300 hammer2_spin_ex(&pmp->lru_spin); 301 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 302 atomic_add_int(&pmp->lru_count, -1); 303 atomic_clear_int(&chain->flags, 304 HAMMER2_CHAIN_ONLRU); 305 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 306 } 307 hammer2_spin_unex(&pmp->lru_spin); 308 } 309 #endif 310 } 311 } 312 313 /* 314 * Ref a locked chain and force the data to be held across an unlock. 315 * Chain must be currently locked. The user of the chain who desires 316 * to release the hold must call hammer2_chain_lock_unhold() to relock 317 * and unhold the chain, then unlock normally, or may simply call 318 * hammer2_chain_drop_unhold() (which is safer against deadlocks). 319 */ 320 void 321 hammer2_chain_ref_hold(hammer2_chain_t *chain) 322 { 323 atomic_add_int(&chain->lockcnt, 1); 324 hammer2_chain_ref(chain); 325 } 326 327 /* 328 * Insert the chain in the core rbtree. 329 * 330 * Normal insertions are placed in the live rbtree. Insertion of a deleted 331 * chain is a special case used by the flush code that is placed on the 332 * unstaged deleted list to avoid confusing the live view. 333 */ 334 #define HAMMER2_CHAIN_INSERT_SPIN 0x0001 335 #define HAMMER2_CHAIN_INSERT_LIVE 0x0002 336 #define HAMMER2_CHAIN_INSERT_RACE 0x0004 337 338 static 339 int 340 hammer2_chain_insert(hammer2_chain_t *parent, hammer2_chain_t *chain, 341 int flags, int generation) 342 { 343 hammer2_chain_t *xchain; 344 int error = 0; 345 346 if (flags & HAMMER2_CHAIN_INSERT_SPIN) 347 hammer2_spin_ex(&parent->core.spin); 348 349 /* 350 * Interlocked by spinlock, check for race 351 */ 352 if ((flags & HAMMER2_CHAIN_INSERT_RACE) && 353 parent->core.generation != generation) { 354 error = HAMMER2_ERROR_EAGAIN; 355 goto failed; 356 } 357 358 /* 359 * Insert chain 360 */ 361 xchain = RB_INSERT(hammer2_chain_tree, &parent->core.rbtree, chain); 362 KASSERT(xchain == NULL, 363 ("hammer2_chain_insert: collision %p %p (key=%016jx)", 364 chain, xchain, chain->bref.key)); 365 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 366 chain->parent = parent; 367 ++parent->core.chain_count; 368 ++parent->core.generation; /* XXX incs for _get() too, XXX */ 369 370 /* 371 * We have to keep track of the effective live-view blockref count 372 * so the create code knows when to push an indirect block. 373 */ 374 if (flags & HAMMER2_CHAIN_INSERT_LIVE) 375 atomic_add_int(&parent->core.live_count, 1); 376 failed: 377 if (flags & HAMMER2_CHAIN_INSERT_SPIN) 378 hammer2_spin_unex(&parent->core.spin); 379 return error; 380 } 381 382 /* 383 * Drop the caller's reference to the chain. When the ref count drops to 384 * zero this function will try to disassociate the chain from its parent and 385 * deallocate it, then recursely drop the parent using the implied ref 386 * from the chain's chain->parent. 387 * 388 * Nobody should own chain's mutex on the 1->0 transition, unless this drop 389 * races an acquisition by another cpu. Therefore we can loop if we are 390 * unable to acquire the mutex, and refs is unlikely to be 1 unless we again 391 * race against another drop. 392 */ 393 static hammer2_chain_t *hammer2_chain_lastdrop(hammer2_chain_t *chain, 394 int depth); 395 static void hammer2_chain_lru_flush(hammer2_pfs_t *pmp); 396 397 void 398 hammer2_chain_drop(hammer2_chain_t *chain) 399 { 400 u_int refs; 401 402 if (hammer2_debug & 0x200000) 403 Debugger("drop"); 404 405 KKASSERT(chain->refs > 0); 406 407 while (chain) { 408 refs = chain->refs; 409 cpu_ccfence(); 410 KKASSERT(refs > 0); 411 412 if (refs == 1) { 413 if (hammer2_mtx_ex_try(&chain->lock) == 0) 414 chain = hammer2_chain_lastdrop(chain, 0); 415 /* retry the same chain, or chain from lastdrop */ 416 } else { 417 if (atomic_cmpset_int(&chain->refs, refs, refs - 1)) 418 break; 419 /* retry the same chain */ 420 } 421 cpu_pause(); 422 } 423 } 424 425 /* 426 * Unhold a held and probably not-locked chain, ensure that the data is 427 * dropped on the 1->0 transition of lockcnt by obtaining an exclusive 428 * lock and then simply unlocking the chain. 429 */ 430 void 431 hammer2_chain_unhold(hammer2_chain_t *chain) 432 { 433 u_int lockcnt; 434 int iter = 0; 435 436 for (;;) { 437 lockcnt = chain->lockcnt; 438 cpu_ccfence(); 439 if (lockcnt > 1) { 440 if (atomic_cmpset_int(&chain->lockcnt, 441 lockcnt, lockcnt - 1)) { 442 break; 443 } 444 } else if (hammer2_mtx_ex_try(&chain->lock) == 0) { 445 hammer2_chain_unlock(chain); 446 break; 447 } else { 448 /* 449 * This situation can easily occur on SMP due to 450 * the gap inbetween the 1->0 transition and the 451 * final unlock. We cannot safely block on the 452 * mutex because lockcnt might go above 1. 453 * 454 * XXX Sleep for one tick if it takes too long. 455 */ 456 if (++iter > 1000) { 457 if (iter > 1000 + hz) { 458 kprintf("hammer2: h2race1 %p\n", chain); 459 iter = 1000; 460 } 461 tsleep(&iter, 0, "h2race1", 1); 462 } 463 cpu_pause(); 464 } 465 } 466 } 467 468 void 469 hammer2_chain_drop_unhold(hammer2_chain_t *chain) 470 { 471 hammer2_chain_unhold(chain); 472 hammer2_chain_drop(chain); 473 } 474 475 void 476 hammer2_chain_rehold(hammer2_chain_t *chain) 477 { 478 hammer2_chain_lock(chain, HAMMER2_RESOLVE_SHARED); 479 atomic_add_int(&chain->lockcnt, 1); 480 hammer2_chain_unlock(chain); 481 } 482 483 /* 484 * Handles the (potential) last drop of chain->refs from 1->0. Called with 485 * the mutex exclusively locked, refs == 1, and lockcnt 0. SMP races are 486 * possible against refs and lockcnt. We must dispose of the mutex on chain. 487 * 488 * This function returns an unlocked chain for recursive drop or NULL. It 489 * can return the same chain if it determines it has raced another ref. 490 * 491 * -- 492 * 493 * When two chains need to be recursively dropped we use the chain we 494 * would otherwise free to placehold the additional chain. It's a bit 495 * convoluted but we can't just recurse without potentially blowing out 496 * the kernel stack. 497 * 498 * The chain cannot be freed if it has any children. 499 * The chain cannot be freed if flagged MODIFIED unless we can dispose of it. 500 * The chain cannot be freed if flagged UPDATE unless we can dispose of it. 501 * Any dedup registration can remain intact. 502 * 503 * The core spinlock is allowed to nest child-to-parent (not parent-to-child). 504 */ 505 static 506 hammer2_chain_t * 507 hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth) 508 { 509 hammer2_pfs_t *pmp; 510 hammer2_dev_t *hmp; 511 hammer2_chain_t *parent; 512 hammer2_chain_t *rdrop; 513 514 /* 515 * We need chain's spinlock to interlock the sub-tree test. 516 * We already have chain's mutex, protecting chain->parent. 517 * 518 * Remember that chain->refs can be in flux. 519 */ 520 hammer2_spin_ex(&chain->core.spin); 521 522 if (chain->parent != NULL) { 523 /* 524 * If the chain has a parent the UPDATE bit prevents scrapping 525 * as the chain is needed to properly flush the parent. Try 526 * to complete the 1->0 transition and return NULL. Retry 527 * (return chain) if we are unable to complete the 1->0 528 * transition, else return NULL (nothing more to do). 529 * 530 * If the chain has a parent the MODIFIED bit prevents 531 * scrapping. 532 * 533 * Chains with UPDATE/MODIFIED are *not* put on the LRU list! 534 */ 535 if (chain->flags & (HAMMER2_CHAIN_UPDATE | 536 HAMMER2_CHAIN_MODIFIED)) { 537 if (atomic_cmpset_int(&chain->refs, 1, 0)) { 538 hammer2_spin_unex(&chain->core.spin); 539 hammer2_chain_assert_no_data(chain); 540 hammer2_mtx_unlock(&chain->lock); 541 chain = NULL; 542 } else { 543 hammer2_spin_unex(&chain->core.spin); 544 hammer2_mtx_unlock(&chain->lock); 545 } 546 return (chain); 547 } 548 /* spinlock still held */ 549 } else if (chain->bref.type == HAMMER2_BREF_TYPE_VOLUME || 550 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP) { 551 /* 552 * Retain the static vchain and fchain. Clear bits that 553 * are not relevant. Do not clear the MODIFIED bit, 554 * and certainly do not put it on the delayed-flush queue. 555 */ 556 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 557 } else { 558 /* 559 * The chain has no parent and can be flagged for destruction. 560 * Since it has no parent, UPDATE can also be cleared. 561 */ 562 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 563 if (chain->flags & HAMMER2_CHAIN_UPDATE) 564 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 565 566 /* 567 * If the chain has children we must propagate the DESTROY 568 * flag downward and rip the disconnected topology apart. 569 * This is accomplished by calling hammer2_flush() on the 570 * chain. 571 * 572 * Any dedup is already handled by the underlying DIO, so 573 * we do not have to specifically flush it here. 574 */ 575 if (chain->core.chain_count) { 576 hammer2_spin_unex(&chain->core.spin); 577 hammer2_flush(chain, HAMMER2_FLUSH_TOP | 578 HAMMER2_FLUSH_ALL); 579 hammer2_mtx_unlock(&chain->lock); 580 581 return(chain); /* retry drop */ 582 } 583 584 /* 585 * Otherwise we can scrap the MODIFIED bit if it is set, 586 * and continue along the freeing path. 587 * 588 * Be sure to clean-out any dedup bits. Without a parent 589 * this chain will no longer be visible to the flush code. 590 * Easy check data_off to avoid the volume root. 591 */ 592 if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 593 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 594 atomic_add_long(&hammer2_count_modified_chains, -1); 595 if (chain->pmp) 596 hammer2_pfs_memory_wakeup(chain->pmp); 597 } 598 /* spinlock still held */ 599 } 600 601 /* spinlock still held */ 602 603 /* 604 * If any children exist we must leave the chain intact with refs == 0. 605 * They exist because chains are retained below us which have refs or 606 * may require flushing. 607 * 608 * Retry (return chain) if we fail to transition the refs to 0, else 609 * return NULL indication nothing more to do. 610 * 611 * Chains with children are NOT put on the LRU list. 612 */ 613 if (chain->core.chain_count) { 614 if (atomic_cmpset_int(&chain->refs, 1, 0)) { 615 hammer2_spin_unex(&chain->core.spin); 616 hammer2_chain_assert_no_data(chain); 617 hammer2_mtx_unlock(&chain->lock); 618 chain = NULL; 619 } else { 620 hammer2_spin_unex(&chain->core.spin); 621 hammer2_mtx_unlock(&chain->lock); 622 } 623 return (chain); 624 } 625 /* spinlock still held */ 626 /* no chains left under us */ 627 628 /* 629 * chain->core has no children left so no accessors can get to our 630 * chain from there. Now we have to lock the parent core to interlock 631 * remaining possible accessors that might bump chain's refs before 632 * we can safely drop chain's refs with intent to free the chain. 633 */ 634 hmp = chain->hmp; 635 pmp = chain->pmp; /* can be NULL */ 636 rdrop = NULL; 637 638 parent = chain->parent; 639 640 /* 641 * WARNING! chain's spin lock is still held here, and other spinlocks 642 * will be acquired and released in the code below. We 643 * cannot be making fancy procedure calls! 644 */ 645 646 /* 647 * We can cache the chain if it is associated with a pmp 648 * and not flagged as being destroyed or requesting a full 649 * release. In this situation the chain is not removed 650 * from its parent, i.e. it can still be looked up. 651 * 652 * We intentionally do not cache DATA chains because these 653 * were likely used to load data into the logical buffer cache 654 * and will not be accessed again for some time. 655 */ 656 if ((chain->flags & 657 (HAMMER2_CHAIN_DESTROY | HAMMER2_CHAIN_RELEASE)) == 0 && 658 chain->pmp && 659 chain->bref.type != HAMMER2_BREF_TYPE_DATA) { 660 if (parent) 661 hammer2_spin_ex(&parent->core.spin); 662 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 663 /* 664 * 1->0 transition failed, retry. Do not drop 665 * the chain's data yet! 666 */ 667 if (parent) 668 hammer2_spin_unex(&parent->core.spin); 669 hammer2_spin_unex(&chain->core.spin); 670 hammer2_mtx_unlock(&chain->lock); 671 672 return(chain); 673 } 674 675 /* 676 * Success 677 */ 678 hammer2_chain_assert_no_data(chain); 679 680 /* 681 * Make sure we are on the LRU list, clean up excessive 682 * LRU entries. We can only really drop one but there might 683 * be other entries that we can remove from the lru_list 684 * without dropping. 685 * 686 * NOTE: HAMMER2_CHAIN_ONLRU may only be safely set when 687 * chain->core.spin AND pmp->lru_spin are held, but 688 * can be safely cleared only holding pmp->lru_spin. 689 */ 690 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) { 691 hammer2_spin_ex(&pmp->lru_spin); 692 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) { 693 atomic_set_int(&chain->flags, 694 HAMMER2_CHAIN_ONLRU); 695 TAILQ_INSERT_TAIL(&pmp->lru_list, 696 chain, lru_node); 697 atomic_add_int(&pmp->lru_count, 1); 698 } 699 if (pmp->lru_count < HAMMER2_LRU_LIMIT) 700 depth = 1; /* disable lru_list flush */ 701 hammer2_spin_unex(&pmp->lru_spin); 702 } else { 703 /* disable lru flush */ 704 depth = 1; 705 } 706 707 if (parent) { 708 hammer2_spin_unex(&parent->core.spin); 709 parent = NULL; /* safety */ 710 } 711 hammer2_spin_unex(&chain->core.spin); 712 hammer2_mtx_unlock(&chain->lock); 713 714 /* 715 * lru_list hysteresis (see above for depth overrides). 716 * Note that depth also prevents excessive lastdrop recursion. 717 */ 718 if (depth == 0) 719 hammer2_chain_lru_flush(pmp); 720 721 return NULL; 722 /* NOT REACHED */ 723 } 724 725 /* 726 * Make sure we are not on the LRU list. 727 */ 728 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 729 hammer2_spin_ex(&pmp->lru_spin); 730 if (chain->flags & HAMMER2_CHAIN_ONLRU) { 731 atomic_add_int(&pmp->lru_count, -1); 732 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 733 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 734 } 735 hammer2_spin_unex(&pmp->lru_spin); 736 } 737 738 /* 739 * Spinlock the parent and try to drop the last ref on chain. 740 * On success determine if we should dispose of the chain 741 * (remove the chain from its parent, etc). 742 * 743 * (normal core locks are top-down recursive but we define 744 * core spinlocks as bottom-up recursive, so this is safe). 745 */ 746 if (parent) { 747 hammer2_spin_ex(&parent->core.spin); 748 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 749 /* 750 * 1->0 transition failed, retry. 751 */ 752 hammer2_spin_unex(&parent->core.spin); 753 hammer2_spin_unex(&chain->core.spin); 754 hammer2_mtx_unlock(&chain->lock); 755 756 return(chain); 757 } 758 759 /* 760 * 1->0 transition successful, parent spin held to prevent 761 * new lookups, chain spinlock held to protect parent field. 762 * Remove chain from the parent. 763 * 764 * If the chain is being removed from the parent's btree but 765 * is not bmapped, we have to adjust live_count downward. If 766 * it is bmapped then the blockref is retained in the parent 767 * as is its associated live_count. This case can occur when 768 * a chain added to the topology is unable to flush and is 769 * then later deleted. 770 */ 771 if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { 772 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) && 773 (chain->flags & HAMMER2_CHAIN_BMAPPED) == 0) { 774 atomic_add_int(&parent->core.live_count, -1); 775 } 776 RB_REMOVE(hammer2_chain_tree, 777 &parent->core.rbtree, chain); 778 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 779 --parent->core.chain_count; 780 chain->parent = NULL; 781 } 782 783 /* 784 * If our chain was the last chain in the parent's core the 785 * core is now empty and its parent might have to be 786 * re-dropped if it has 0 refs. 787 */ 788 if (parent->core.chain_count == 0) { 789 rdrop = parent; 790 atomic_add_int(&rdrop->refs, 1); 791 /* 792 if (atomic_cmpset_int(&rdrop->refs, 0, 1) == 0) 793 rdrop = NULL; 794 */ 795 } 796 hammer2_spin_unex(&parent->core.spin); 797 parent = NULL; /* safety */ 798 /* FALL THROUGH */ 799 } else { 800 /* 801 * No-parent case. 802 */ 803 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { 804 /* 805 * 1->0 transition failed, retry. 806 */ 807 hammer2_spin_unex(&parent->core.spin); 808 hammer2_spin_unex(&chain->core.spin); 809 hammer2_mtx_unlock(&chain->lock); 810 811 return(chain); 812 } 813 } 814 815 /* 816 * Successful 1->0 transition, no parent, no children... no way for 817 * anyone to ref this chain any more. We can clean-up and free it. 818 * 819 * We still have the core spinlock, and core's chain_count is 0. 820 * Any parent spinlock is gone. 821 */ 822 hammer2_spin_unex(&chain->core.spin); 823 hammer2_chain_assert_no_data(chain); 824 hammer2_mtx_unlock(&chain->lock); 825 KKASSERT(RB_EMPTY(&chain->core.rbtree) && 826 chain->core.chain_count == 0); 827 828 /* 829 * All locks are gone, no pointers remain to the chain, finish 830 * freeing it. 831 */ 832 KKASSERT((chain->flags & (HAMMER2_CHAIN_UPDATE | 833 HAMMER2_CHAIN_MODIFIED)) == 0); 834 835 /* 836 * Once chain resources are gone we can use the now dead chain 837 * structure to placehold what might otherwise require a recursive 838 * drop, because we have potentially two things to drop and can only 839 * return one directly. 840 */ 841 if (chain->flags & HAMMER2_CHAIN_ALLOCATED) { 842 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ALLOCATED); 843 chain->hmp = NULL; 844 kfree(chain, hmp->mchain); 845 } 846 847 /* 848 * Possible chaining loop when parent re-drop needed. 849 */ 850 return(rdrop); 851 } 852 853 /* 854 * Heuristical flush of the LRU, try to reduce the number of entries 855 * on the LRU to (HAMMER2_LRU_LIMIT * 2 / 3). This procedure is called 856 * only when lru_count exceeds HAMMER2_LRU_LIMIT. 857 */ 858 static 859 void 860 hammer2_chain_lru_flush(hammer2_pfs_t *pmp) 861 { 862 hammer2_chain_t *chain; 863 864 again: 865 chain = NULL; 866 hammer2_spin_ex(&pmp->lru_spin); 867 while (pmp->lru_count > HAMMER2_LRU_LIMIT * 2 / 3) { 868 /* 869 * Pick a chain off the lru_list, just recycle it quickly 870 * if LRUHINT is set (the chain was ref'd but left on 871 * the lru_list, so cycle to the end). 872 */ 873 chain = TAILQ_FIRST(&pmp->lru_list); 874 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node); 875 876 if (chain->flags & HAMMER2_CHAIN_LRUHINT) { 877 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_LRUHINT); 878 TAILQ_INSERT_TAIL(&pmp->lru_list, chain, lru_node); 879 chain = NULL; 880 continue; 881 } 882 883 /* 884 * Ok, we are off the LRU. We must adjust refs before we 885 * can safely clear the ONLRU flag. 886 */ 887 atomic_add_int(&pmp->lru_count, -1); 888 if (atomic_cmpset_int(&chain->refs, 0, 1)) { 889 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 890 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE); 891 break; 892 } 893 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU); 894 chain = NULL; 895 } 896 hammer2_spin_unex(&pmp->lru_spin); 897 if (chain == NULL) 898 return; 899 900 /* 901 * If we picked a chain off the lru list we may be able to lastdrop 902 * it. Use a depth of 1 to prevent excessive lastdrop recursion. 903 */ 904 while (chain) { 905 u_int refs; 906 907 refs = chain->refs; 908 cpu_ccfence(); 909 KKASSERT(refs > 0); 910 911 if (refs == 1) { 912 if (hammer2_mtx_ex_try(&chain->lock) == 0) 913 chain = hammer2_chain_lastdrop(chain, 1); 914 /* retry the same chain, or chain from lastdrop */ 915 } else { 916 if (atomic_cmpset_int(&chain->refs, refs, refs - 1)) 917 break; 918 /* retry the same chain */ 919 } 920 cpu_pause(); 921 } 922 goto again; 923 } 924 925 /* 926 * On last lock release. 927 */ 928 static hammer2_io_t * 929 hammer2_chain_drop_data(hammer2_chain_t *chain) 930 { 931 hammer2_io_t *dio; 932 933 if ((dio = chain->dio) != NULL) { 934 chain->dio = NULL; 935 chain->data = NULL; 936 } else { 937 switch(chain->bref.type) { 938 case HAMMER2_BREF_TYPE_VOLUME: 939 case HAMMER2_BREF_TYPE_FREEMAP: 940 break; 941 default: 942 if (chain->data != NULL) { 943 hammer2_spin_unex(&chain->core.spin); 944 panic("chain data not null: " 945 "chain %p bref %016jx.%02x " 946 "refs %d parent %p dio %p data %p", 947 chain, chain->bref.data_off, 948 chain->bref.type, chain->refs, 949 chain->parent, 950 chain->dio, chain->data); 951 } 952 KKASSERT(chain->data == NULL); 953 break; 954 } 955 } 956 return dio; 957 } 958 959 /* 960 * Lock a referenced chain element, acquiring its data with I/O if necessary, 961 * and specify how you would like the data to be resolved. 962 * 963 * If an I/O or other fatal error occurs, chain->error will be set to non-zero. 964 * 965 * The lock is allowed to recurse, multiple locking ops will aggregate 966 * the requested resolve types. Once data is assigned it will not be 967 * removed until the last unlock. 968 * 969 * HAMMER2_RESOLVE_NEVER - Do not resolve the data element. 970 * (typically used to avoid device/logical buffer 971 * aliasing for data) 972 * 973 * HAMMER2_RESOLVE_MAYBE - Do not resolve data elements for chains in 974 * the INITIAL-create state (indirect blocks only). 975 * 976 * Do not resolve data elements for DATA chains. 977 * (typically used to avoid device/logical buffer 978 * aliasing for data) 979 * 980 * HAMMER2_RESOLVE_ALWAYS- Always resolve the data element. 981 * 982 * HAMMER2_RESOLVE_SHARED- (flag) The chain is locked shared, otherwise 983 * it will be locked exclusive. 984 * 985 * HAMMER2_RESOLVE_NONBLOCK- (flag) The chain is locked non-blocking. If 986 * the lock fails, EAGAIN is returned. 987 * 988 * NOTE: Embedded elements (volume header, inodes) are always resolved 989 * regardless. 990 * 991 * NOTE: Specifying HAMMER2_RESOLVE_ALWAYS on a newly-created non-embedded 992 * element will instantiate and zero its buffer, and flush it on 993 * release. 994 * 995 * NOTE: (data) elements are normally locked RESOLVE_NEVER or RESOLVE_MAYBE 996 * so as not to instantiate a device buffer, which could alias against 997 * a logical file buffer. However, if ALWAYS is specified the 998 * device buffer will be instantiated anyway. 999 * 1000 * NOTE: The return value is always 0 unless NONBLOCK is specified, in which 1001 * case it can be either 0 or EAGAIN. 1002 * 1003 * WARNING! This function blocks on I/O if data needs to be fetched. This 1004 * blocking can run concurrent with other compatible lock holders 1005 * who do not need data returning. The lock is not upgraded to 1006 * exclusive during a data fetch, a separate bit is used to 1007 * interlock I/O. However, an exclusive lock holder can still count 1008 * on being interlocked against an I/O fetch managed by a shared 1009 * lock holder. 1010 */ 1011 int 1012 hammer2_chain_lock(hammer2_chain_t *chain, int how) 1013 { 1014 KKASSERT(chain->refs > 0); 1015 1016 if (how & HAMMER2_RESOLVE_NONBLOCK) { 1017 /* 1018 * We still have to bump lockcnt before acquiring the lock, 1019 * even for non-blocking operation, because the unlock code 1020 * live-loops on lockcnt == 1 when dropping the last lock. 1021 * 1022 * If the non-blocking operation fails we have to use an 1023 * unhold sequence to undo the mess. 1024 * 1025 * NOTE: LOCKAGAIN must always succeed without blocking, 1026 * even if NONBLOCK is specified. 1027 */ 1028 atomic_add_int(&chain->lockcnt, 1); 1029 if (how & HAMMER2_RESOLVE_SHARED) { 1030 if (how & HAMMER2_RESOLVE_LOCKAGAIN) { 1031 hammer2_mtx_sh_again(&chain->lock); 1032 } else { 1033 if (hammer2_mtx_sh_try(&chain->lock) != 0) { 1034 hammer2_chain_unhold(chain); 1035 return EAGAIN; 1036 } 1037 } 1038 } else { 1039 if (hammer2_mtx_ex_try(&chain->lock) != 0) { 1040 hammer2_chain_unhold(chain); 1041 return EAGAIN; 1042 } 1043 } 1044 } else { 1045 /* 1046 * Get the appropriate lock. If LOCKAGAIN is flagged with 1047 * SHARED the caller expects a shared lock to already be 1048 * present and we are giving it another ref. This case must 1049 * importantly not block if there is a pending exclusive lock 1050 * request. 1051 */ 1052 atomic_add_int(&chain->lockcnt, 1); 1053 if (how & HAMMER2_RESOLVE_SHARED) { 1054 if (how & HAMMER2_RESOLVE_LOCKAGAIN) { 1055 hammer2_mtx_sh_again(&chain->lock); 1056 } else { 1057 hammer2_mtx_sh(&chain->lock); 1058 } 1059 } else { 1060 hammer2_mtx_ex(&chain->lock); 1061 } 1062 } 1063 1064 /* 1065 * If we already have a valid data pointer make sure the data is 1066 * synchronized to the current cpu, and then no further action is 1067 * necessary. 1068 */ 1069 if (chain->data) { 1070 if (chain->dio) 1071 hammer2_io_bkvasync(chain->dio); 1072 return 0; 1073 } 1074 1075 /* 1076 * Do we have to resolve the data? This is generally only 1077 * applicable to HAMMER2_BREF_TYPE_DATA which is special-cased. 1078 * Other BREF types expects the data to be there. 1079 */ 1080 switch(how & HAMMER2_RESOLVE_MASK) { 1081 case HAMMER2_RESOLVE_NEVER: 1082 return 0; 1083 case HAMMER2_RESOLVE_MAYBE: 1084 if (chain->flags & HAMMER2_CHAIN_INITIAL) 1085 return 0; 1086 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) 1087 return 0; 1088 #if 0 1089 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) 1090 return 0; 1091 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) 1092 return 0; 1093 #endif 1094 /* fall through */ 1095 case HAMMER2_RESOLVE_ALWAYS: 1096 default: 1097 break; 1098 } 1099 1100 /* 1101 * Caller requires data 1102 */ 1103 hammer2_chain_load_data(chain); 1104 1105 return 0; 1106 } 1107 1108 /* 1109 * Lock the chain, retain the hold, and drop the data persistence count. 1110 * The data should remain valid because we never transitioned lockcnt 1111 * through 0. 1112 */ 1113 void 1114 hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how) 1115 { 1116 hammer2_chain_lock(chain, how); 1117 atomic_add_int(&chain->lockcnt, -1); 1118 } 1119 1120 #if 0 1121 /* 1122 * Downgrade an exclusive chain lock to a shared chain lock. 1123 * 1124 * NOTE: There is no upgrade equivalent due to the ease of 1125 * deadlocks in that direction. 1126 */ 1127 void 1128 hammer2_chain_lock_downgrade(hammer2_chain_t *chain) 1129 { 1130 hammer2_mtx_downgrade(&chain->lock); 1131 } 1132 #endif 1133 1134 /* 1135 * Issue I/O and install chain->data. Caller must hold a chain lock, lock 1136 * may be of any type. 1137 * 1138 * Once chain->data is set it cannot be disposed of until all locks are 1139 * released. 1140 * 1141 * Make sure the data is synchronized to the current cpu. 1142 */ 1143 void 1144 hammer2_chain_load_data(hammer2_chain_t *chain) 1145 { 1146 hammer2_blockref_t *bref; 1147 hammer2_dev_t *hmp; 1148 hammer2_io_t *dio; 1149 char *bdata; 1150 int error; 1151 1152 /* 1153 * Degenerate case, data already present, or chain has no media 1154 * reference to load. 1155 */ 1156 KKASSERT(chain->lock.mtx_lock & MTX_MASK); 1157 if (chain->data) { 1158 if (chain->dio) 1159 hammer2_io_bkvasync(chain->dio); 1160 return; 1161 } 1162 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) 1163 return; 1164 1165 hmp = chain->hmp; 1166 KKASSERT(hmp != NULL); 1167 1168 /* 1169 * Gain the IOINPROG bit, interlocked block. 1170 */ 1171 for (;;) { 1172 u_int oflags; 1173 u_int nflags; 1174 1175 oflags = chain->flags; 1176 cpu_ccfence(); 1177 if (oflags & HAMMER2_CHAIN_IOINPROG) { 1178 nflags = oflags | HAMMER2_CHAIN_IOSIGNAL; 1179 tsleep_interlock(&chain->flags, 0); 1180 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1181 tsleep(&chain->flags, PINTERLOCKED, 1182 "h2iocw", 0); 1183 } 1184 /* retry */ 1185 } else { 1186 nflags = oflags | HAMMER2_CHAIN_IOINPROG; 1187 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1188 break; 1189 } 1190 /* retry */ 1191 } 1192 } 1193 1194 /* 1195 * We own CHAIN_IOINPROG 1196 * 1197 * Degenerate case if we raced another load. 1198 */ 1199 if (chain->data) { 1200 if (chain->dio) 1201 hammer2_io_bkvasync(chain->dio); 1202 goto done; 1203 } 1204 1205 /* 1206 * We must resolve to a device buffer, either by issuing I/O or 1207 * by creating a zero-fill element. We do not mark the buffer 1208 * dirty when creating a zero-fill element (the hammer2_chain_modify() 1209 * API must still be used to do that). 1210 * 1211 * The device buffer is variable-sized in powers of 2 down 1212 * to HAMMER2_MIN_ALLOC (typically 1K). A 64K physical storage 1213 * chunk always contains buffers of the same size. (XXX) 1214 * 1215 * The minimum physical IO size may be larger than the variable 1216 * block size. 1217 */ 1218 bref = &chain->bref; 1219 1220 /* 1221 * The getblk() optimization can only be used on newly created 1222 * elements if the physical block size matches the request. 1223 */ 1224 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1225 error = hammer2_io_new(hmp, bref->type, 1226 bref->data_off, chain->bytes, 1227 &chain->dio); 1228 } else { 1229 error = hammer2_io_bread(hmp, bref->type, 1230 bref->data_off, chain->bytes, 1231 &chain->dio); 1232 hammer2_adjreadcounter(&chain->bref, chain->bytes); 1233 } 1234 if (error) { 1235 chain->error = HAMMER2_ERROR_EIO; 1236 kprintf("hammer2_chain_lock: I/O error %016jx: %d\n", 1237 (intmax_t)bref->data_off, error); 1238 hammer2_io_bqrelse(&chain->dio); 1239 goto done; 1240 } 1241 chain->error = 0; 1242 1243 /* 1244 * This isn't perfect and can be ignored on OSs which do not have 1245 * an indication as to whether a buffer is coming from cache or 1246 * if I/O was actually issued for the read. TESTEDGOOD will work 1247 * pretty well without the B_IOISSUED logic because chains are 1248 * cached, but in that situation (without B_IOISSUED) it will not 1249 * detect whether a re-read via I/O is corrupted verses the original 1250 * read. 1251 * 1252 * We can't re-run the CRC on every fresh lock. That would be 1253 * insanely expensive. 1254 * 1255 * If the underlying kernel buffer covers the entire chain we can 1256 * use the B_IOISSUED indication to determine if we have to re-run 1257 * the CRC on chain data for chains that managed to stay cached 1258 * across the kernel disposal of the original buffer. 1259 */ 1260 if ((dio = chain->dio) != NULL && dio->bp) { 1261 struct buf *bp = dio->bp; 1262 1263 if (dio->psize == chain->bytes && 1264 (bp->b_flags & B_IOISSUED)) { 1265 atomic_clear_int(&chain->flags, 1266 HAMMER2_CHAIN_TESTEDGOOD); 1267 bp->b_flags &= ~B_IOISSUED; 1268 } 1269 } 1270 1271 /* 1272 * NOTE: A locked chain's data cannot be modified without first 1273 * calling hammer2_chain_modify(). 1274 */ 1275 1276 /* 1277 * Clear INITIAL. In this case we used io_new() and the buffer has 1278 * been zero'd and marked dirty. 1279 * 1280 * NOTE: hammer2_io_data() call issues bkvasync() 1281 */ 1282 bdata = hammer2_io_data(chain->dio, chain->bref.data_off); 1283 1284 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1285 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 1286 chain->bref.flags |= HAMMER2_BREF_FLAG_ZERO; 1287 } else if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 1288 /* 1289 * check data not currently synchronized due to 1290 * modification. XXX assumes data stays in the buffer 1291 * cache, which might not be true (need biodep on flush 1292 * to calculate crc? or simple crc?). 1293 */ 1294 } else if ((chain->flags & HAMMER2_CHAIN_TESTEDGOOD) == 0) { 1295 if (hammer2_chain_testcheck(chain, bdata) == 0) { 1296 chain->error = HAMMER2_ERROR_CHECK; 1297 } else { 1298 atomic_set_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD); 1299 } 1300 } 1301 1302 /* 1303 * Setup the data pointer, either pointing it to an embedded data 1304 * structure and copying the data from the buffer, or pointing it 1305 * into the buffer. 1306 * 1307 * The buffer is not retained when copying to an embedded data 1308 * structure in order to avoid potential deadlocks or recursions 1309 * on the same physical buffer. 1310 * 1311 * WARNING! Other threads can start using the data the instant we 1312 * set chain->data non-NULL. 1313 */ 1314 switch (bref->type) { 1315 case HAMMER2_BREF_TYPE_VOLUME: 1316 case HAMMER2_BREF_TYPE_FREEMAP: 1317 /* 1318 * Copy data from bp to embedded buffer 1319 */ 1320 panic("hammer2_chain_load_data: unresolved volume header"); 1321 break; 1322 case HAMMER2_BREF_TYPE_DIRENT: 1323 KKASSERT(chain->bytes != 0); 1324 /* fall through */ 1325 case HAMMER2_BREF_TYPE_INODE: 1326 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 1327 case HAMMER2_BREF_TYPE_INDIRECT: 1328 case HAMMER2_BREF_TYPE_DATA: 1329 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1330 default: 1331 /* 1332 * Point data at the device buffer and leave dio intact. 1333 */ 1334 chain->data = (void *)bdata; 1335 break; 1336 } 1337 1338 /* 1339 * Release HAMMER2_CHAIN_IOINPROG and signal waiters if requested. 1340 */ 1341 done: 1342 for (;;) { 1343 u_int oflags; 1344 u_int nflags; 1345 1346 oflags = chain->flags; 1347 nflags = oflags & ~(HAMMER2_CHAIN_IOINPROG | 1348 HAMMER2_CHAIN_IOSIGNAL); 1349 KKASSERT(oflags & HAMMER2_CHAIN_IOINPROG); 1350 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { 1351 if (oflags & HAMMER2_CHAIN_IOSIGNAL) 1352 wakeup(&chain->flags); 1353 break; 1354 } 1355 } 1356 } 1357 1358 /* 1359 * Unlock and deref a chain element. 1360 * 1361 * Remember that the presence of children under chain prevent the chain's 1362 * destruction but do not add additional references, so the dio will still 1363 * be dropped. 1364 */ 1365 void 1366 hammer2_chain_unlock(hammer2_chain_t *chain) 1367 { 1368 hammer2_io_t *dio; 1369 u_int lockcnt; 1370 int iter = 0; 1371 1372 /* 1373 * If multiple locks are present (or being attempted) on this 1374 * particular chain we can just unlock, drop refs, and return. 1375 * 1376 * Otherwise fall-through on the 1->0 transition. 1377 */ 1378 for (;;) { 1379 lockcnt = chain->lockcnt; 1380 KKASSERT(lockcnt > 0); 1381 cpu_ccfence(); 1382 if (lockcnt > 1) { 1383 if (atomic_cmpset_int(&chain->lockcnt, 1384 lockcnt, lockcnt - 1)) { 1385 hammer2_mtx_unlock(&chain->lock); 1386 return; 1387 } 1388 } else if (hammer2_mtx_upgrade_try(&chain->lock) == 0) { 1389 /* while holding the mutex exclusively */ 1390 if (atomic_cmpset_int(&chain->lockcnt, 1, 0)) 1391 break; 1392 } else { 1393 /* 1394 * This situation can easily occur on SMP due to 1395 * the gap inbetween the 1->0 transition and the 1396 * final unlock. We cannot safely block on the 1397 * mutex because lockcnt might go above 1. 1398 * 1399 * XXX Sleep for one tick if it takes too long. 1400 */ 1401 if (++iter > 1000) { 1402 if (iter > 1000 + hz) { 1403 kprintf("hammer2: h2race2 %p\n", chain); 1404 iter = 1000; 1405 } 1406 tsleep(&iter, 0, "h2race2", 1); 1407 } 1408 cpu_pause(); 1409 } 1410 /* retry */ 1411 } 1412 1413 /* 1414 * Last unlock / mutex upgraded to exclusive. Drop the data 1415 * reference. 1416 */ 1417 dio = hammer2_chain_drop_data(chain); 1418 if (dio) 1419 hammer2_io_bqrelse(&dio); 1420 hammer2_mtx_unlock(&chain->lock); 1421 } 1422 1423 /* 1424 * Unlock and hold chain data intact 1425 */ 1426 void 1427 hammer2_chain_unlock_hold(hammer2_chain_t *chain) 1428 { 1429 atomic_add_int(&chain->lockcnt, 1); 1430 hammer2_chain_unlock(chain); 1431 } 1432 1433 /* 1434 * Helper to obtain the blockref[] array base and count for a chain. 1435 * 1436 * XXX Not widely used yet, various use cases need to be validated and 1437 * converted to use this function. 1438 */ 1439 static 1440 hammer2_blockref_t * 1441 hammer2_chain_base_and_count(hammer2_chain_t *parent, int *countp) 1442 { 1443 hammer2_blockref_t *base; 1444 int count; 1445 1446 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 1447 base = NULL; 1448 1449 switch(parent->bref.type) { 1450 case HAMMER2_BREF_TYPE_INODE: 1451 count = HAMMER2_SET_COUNT; 1452 break; 1453 case HAMMER2_BREF_TYPE_INDIRECT: 1454 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1455 count = parent->bytes / sizeof(hammer2_blockref_t); 1456 break; 1457 case HAMMER2_BREF_TYPE_VOLUME: 1458 count = HAMMER2_SET_COUNT; 1459 break; 1460 case HAMMER2_BREF_TYPE_FREEMAP: 1461 count = HAMMER2_SET_COUNT; 1462 break; 1463 default: 1464 panic("hammer2_chain_base_and_count: " 1465 "unrecognized blockref type: %d", 1466 parent->bref.type); 1467 count = 0; 1468 break; 1469 } 1470 } else { 1471 switch(parent->bref.type) { 1472 case HAMMER2_BREF_TYPE_INODE: 1473 base = &parent->data->ipdata.u.blockset.blockref[0]; 1474 count = HAMMER2_SET_COUNT; 1475 break; 1476 case HAMMER2_BREF_TYPE_INDIRECT: 1477 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1478 base = &parent->data->npdata[0]; 1479 count = parent->bytes / sizeof(hammer2_blockref_t); 1480 break; 1481 case HAMMER2_BREF_TYPE_VOLUME: 1482 base = &parent->data->voldata. 1483 sroot_blockset.blockref[0]; 1484 count = HAMMER2_SET_COUNT; 1485 break; 1486 case HAMMER2_BREF_TYPE_FREEMAP: 1487 base = &parent->data->blkset.blockref[0]; 1488 count = HAMMER2_SET_COUNT; 1489 break; 1490 default: 1491 panic("hammer2_chain_base_and_count: " 1492 "unrecognized blockref type: %d", 1493 parent->bref.type); 1494 count = 0; 1495 break; 1496 } 1497 } 1498 *countp = count; 1499 1500 return base; 1501 } 1502 1503 /* 1504 * This counts the number of live blockrefs in a block array and 1505 * also calculates the point at which all remaining blockrefs are empty. 1506 * This routine can only be called on a live chain. 1507 * 1508 * Caller holds the chain locked, but possibly with a shared lock. We 1509 * must use an exclusive spinlock to prevent corruption. 1510 * 1511 * NOTE: Flag is not set until after the count is complete, allowing 1512 * callers to test the flag without holding the spinlock. 1513 * 1514 * NOTE: If base is NULL the related chain is still in the INITIAL 1515 * state and there are no blockrefs to count. 1516 * 1517 * NOTE: live_count may already have some counts accumulated due to 1518 * creation and deletion and could even be initially negative. 1519 */ 1520 void 1521 hammer2_chain_countbrefs(hammer2_chain_t *chain, 1522 hammer2_blockref_t *base, int count) 1523 { 1524 hammer2_spin_ex(&chain->core.spin); 1525 if ((chain->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) { 1526 if (base) { 1527 while (--count >= 0) { 1528 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) 1529 break; 1530 } 1531 chain->core.live_zero = count + 1; 1532 while (count >= 0) { 1533 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) 1534 atomic_add_int(&chain->core.live_count, 1535 1); 1536 --count; 1537 } 1538 } else { 1539 chain->core.live_zero = 0; 1540 } 1541 /* else do not modify live_count */ 1542 atomic_set_int(&chain->flags, HAMMER2_CHAIN_COUNTEDBREFS); 1543 } 1544 hammer2_spin_unex(&chain->core.spin); 1545 } 1546 1547 /* 1548 * Resize the chain's physical storage allocation in-place. This function does 1549 * not usually adjust the data pointer and must be followed by (typically) a 1550 * hammer2_chain_modify() call to copy any old data over and adjust the 1551 * data pointer. 1552 * 1553 * Chains can be resized smaller without reallocating the storage. Resizing 1554 * larger will reallocate the storage. Excess or prior storage is reclaimed 1555 * asynchronously at a later time. 1556 * 1557 * An nradix value of 0 is special-cased to mean that the storage should 1558 * be disassociated, that is the chain is being resized to 0 bytes (not 1 1559 * byte). 1560 * 1561 * Must be passed an exclusively locked parent and chain. 1562 * 1563 * This function is mostly used with DATA blocks locked RESOLVE_NEVER in order 1564 * to avoid instantiating a device buffer that conflicts with the vnode data 1565 * buffer. However, because H2 can compress or encrypt data, the chain may 1566 * have a dio assigned to it in those situations, and they do not conflict. 1567 * 1568 * XXX return error if cannot resize. 1569 */ 1570 int 1571 hammer2_chain_resize(hammer2_chain_t *chain, 1572 hammer2_tid_t mtid, hammer2_off_t dedup_off, 1573 int nradix, int flags) 1574 { 1575 hammer2_dev_t *hmp; 1576 size_t obytes; 1577 size_t nbytes; 1578 int error; 1579 1580 hmp = chain->hmp; 1581 1582 /* 1583 * Only data and indirect blocks can be resized for now. 1584 * (The volu root, inodes, and freemap elements use a fixed size). 1585 */ 1586 KKASSERT(chain != &hmp->vchain); 1587 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1588 chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 1589 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); 1590 1591 /* 1592 * Nothing to do if the element is already the proper size 1593 */ 1594 obytes = chain->bytes; 1595 nbytes = (nradix) ? (1U << nradix) : 0; 1596 if (obytes == nbytes) 1597 return (chain->error); 1598 1599 /* 1600 * Make sure the old data is instantiated so we can copy it. If this 1601 * is a data block, the device data may be superfluous since the data 1602 * might be in a logical block, but compressed or encrypted data is 1603 * another matter. 1604 * 1605 * NOTE: The modify will set BMAPUPD for us if BMAPPED is set. 1606 */ 1607 error = hammer2_chain_modify(chain, mtid, dedup_off, 0); 1608 if (error) 1609 return error; 1610 1611 /* 1612 * Relocate the block, even if making it smaller (because different 1613 * block sizes may be in different regions). 1614 * 1615 * NOTE: Operation does not copy the data and may only be used 1616 * to resize data blocks in-place, or directory entry blocks 1617 * which are about to be modified in some manner. 1618 */ 1619 error = hammer2_freemap_alloc(chain, nbytes); 1620 if (error) 1621 return error; 1622 1623 chain->bytes = nbytes; 1624 1625 /* 1626 * We don't want the followup chain_modify() to try to copy data 1627 * from the old (wrong-sized) buffer. It won't know how much to 1628 * copy. This case should only occur during writes when the 1629 * originator already has the data to write in-hand. 1630 */ 1631 if (chain->dio) { 1632 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1633 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); 1634 hammer2_io_brelse(&chain->dio); 1635 chain->data = NULL; 1636 } 1637 return (chain->error); 1638 } 1639 1640 /* 1641 * Set the chain modified so its data can be changed by the caller, or 1642 * install deduplicated data. The caller must call this routine for each 1643 * set of modifications it makes, even if the chain is already flagged 1644 * MODIFIED. 1645 * 1646 * Sets bref.modify_tid to mtid only if mtid != 0. Note that bref.modify_tid 1647 * is a CLC (cluster level change) field and is not updated by parent 1648 * propagation during a flush. 1649 * 1650 * Returns an appropriate HAMMER2_ERROR_* code, which will generally reflect 1651 * chain->error except for HAMMER2_ERROR_ENOSPC. If the allocation fails 1652 * due to no space available, HAMMER2_ERROR_ENOSPC is returned and the chain 1653 * remains unmodified with its old data ref intact and chain->error 1654 * unchanged. 1655 * 1656 * Dedup Handling 1657 * 1658 * If the DEDUPABLE flag is set in the chain the storage must be reallocated 1659 * even if the chain is still flagged MODIFIED. In this case the chain's 1660 * DEDUPABLE flag will be cleared once the new storage has been assigned. 1661 * 1662 * If the caller passes a non-zero dedup_off we will use it to assign the 1663 * new storage. The MODIFIED flag will be *CLEARED* in this case, and 1664 * DEDUPABLE will be set (NOTE: the UPDATE flag is always set). The caller 1665 * must not modify the data content upon return. 1666 */ 1667 int 1668 hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid, 1669 hammer2_off_t dedup_off, int flags) 1670 { 1671 hammer2_blockref_t obref; 1672 hammer2_dev_t *hmp; 1673 hammer2_io_t *dio; 1674 int error; 1675 int wasinitial; 1676 int setmodified; 1677 int setupdate; 1678 int newmod; 1679 char *bdata; 1680 1681 hmp = chain->hmp; 1682 obref = chain->bref; 1683 KKASSERT((chain->flags & HAMMER2_CHAIN_FICTITIOUS) == 0); 1684 KKASSERT(chain->lock.mtx_lock & MTX_EXCLUSIVE); 1685 1686 /* 1687 * Data is not optional for freemap chains (we must always be sure 1688 * to copy the data on COW storage allocations). 1689 */ 1690 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 1691 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 1692 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) || 1693 (flags & HAMMER2_MODIFY_OPTDATA) == 0); 1694 } 1695 1696 /* 1697 * Data must be resolved if already assigned, unless explicitly 1698 * flagged otherwise. If we cannot safety load the data the 1699 * modification fails and we return early. 1700 */ 1701 if (chain->data == NULL && chain->bytes != 0 && 1702 (flags & HAMMER2_MODIFY_OPTDATA) == 0 && 1703 (chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX)) { 1704 hammer2_chain_load_data(chain); 1705 if (chain->error) 1706 return (chain->error); 1707 } 1708 error = 0; 1709 1710 /* 1711 * Set MODIFIED to indicate that the chain has been modified. A new 1712 * allocation is required when modifying a chain. 1713 * 1714 * Set UPDATE to ensure that the blockref is updated in the parent. 1715 * 1716 * If MODIFIED is already set determine if we can reuse the assigned 1717 * data block or if we need a new data block. 1718 */ 1719 if ((chain->flags & HAMMER2_CHAIN_MODIFIED) == 0) { 1720 /* 1721 * Must set modified bit. 1722 */ 1723 atomic_add_long(&hammer2_count_modified_chains, 1); 1724 atomic_set_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 1725 hammer2_pfs_memory_inc(chain->pmp); /* can be NULL */ 1726 setmodified = 1; 1727 1728 /* 1729 * We may be able to avoid a copy-on-write if the chain's 1730 * check mode is set to NONE and the chain's current 1731 * modify_tid is beyond the last explicit snapshot tid. 1732 * 1733 * This implements HAMMER2's overwrite-in-place feature. 1734 * 1735 * NOTE! This data-block cannot be used as a de-duplication 1736 * source when the check mode is set to NONE. 1737 */ 1738 if ((chain->bref.type == HAMMER2_BREF_TYPE_DATA || 1739 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT) && 1740 (chain->flags & HAMMER2_CHAIN_INITIAL) == 0 && 1741 (chain->flags & HAMMER2_CHAIN_DEDUPABLE) == 0 && 1742 HAMMER2_DEC_CHECK(chain->bref.methods) == 1743 HAMMER2_CHECK_NONE && 1744 chain->pmp && 1745 chain->bref.modify_tid > 1746 chain->pmp->iroot->meta.pfs_lsnap_tid) { 1747 /* 1748 * Sector overwrite allowed. 1749 */ 1750 newmod = 0; 1751 } else if ((hmp->hflags & HMNT2_EMERG) && 1752 chain->pmp && 1753 chain->bref.modify_tid > 1754 chain->pmp->iroot->meta.pfs_lsnap_tid) { 1755 /* 1756 * If in emergency delete mode then do a modify-in- 1757 * place on any chain type belonging to the PFS as 1758 * long as it doesn't mess up a snapshot. We might 1759 * be forced to do this anyway a little further down 1760 * in the code if the allocation fails. 1761 * 1762 * Also note that in emergency mode, these modify-in- 1763 * place operations are NOT SAFE. A storage failure, 1764 * power failure, or panic can corrupt the filesystem. 1765 */ 1766 newmod = 0; 1767 } else { 1768 /* 1769 * Sector overwrite not allowed, must copy-on-write. 1770 */ 1771 newmod = 1; 1772 } 1773 } else if (chain->flags & HAMMER2_CHAIN_DEDUPABLE) { 1774 /* 1775 * If the modified chain was registered for dedup we need 1776 * a new allocation. This only happens for delayed-flush 1777 * chains (i.e. which run through the front-end buffer 1778 * cache). 1779 */ 1780 newmod = 1; 1781 setmodified = 0; 1782 } else { 1783 /* 1784 * Already flagged modified, no new allocation is needed. 1785 */ 1786 newmod = 0; 1787 setmodified = 0; 1788 } 1789 1790 /* 1791 * Flag parent update required. 1792 */ 1793 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) { 1794 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1795 setupdate = 1; 1796 } else { 1797 setupdate = 0; 1798 } 1799 1800 /* 1801 * The XOP code returns held but unlocked focus chains. This 1802 * prevents the chain from being destroyed but does not prevent 1803 * it from being modified. diolk is used to interlock modifications 1804 * against XOP frontend accesses to the focus. 1805 * 1806 * This allows us to theoretically avoid deadlocking the frontend 1807 * if one of the backends lock up by not formally locking the 1808 * focused chain in the frontend. In addition, the synchronization 1809 * code relies on this mechanism to avoid deadlocking concurrent 1810 * synchronization threads. 1811 */ 1812 lockmgr(&chain->diolk, LK_EXCLUSIVE); 1813 1814 /* 1815 * The modification or re-modification requires an allocation and 1816 * possible COW. If an error occurs, the previous content and data 1817 * reference is retained and the modification fails. 1818 * 1819 * If dedup_off is non-zero, the caller is requesting a deduplication 1820 * rather than a modification. The MODIFIED bit is not set and the 1821 * data offset is set to the deduplication offset. The data cannot 1822 * be modified. 1823 * 1824 * NOTE: The dedup offset is allowed to be in a partially free state 1825 * and we must be sure to reset it to a fully allocated state 1826 * to force two bulkfree passes to free it again. 1827 * 1828 * NOTE: Only applicable when chain->bytes != 0. 1829 * 1830 * XXX can a chain already be marked MODIFIED without a data 1831 * assignment? If not, assert here instead of testing the case. 1832 */ 1833 if (chain != &hmp->vchain && chain != &hmp->fchain && 1834 chain->bytes) { 1835 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0 || 1836 newmod 1837 ) { 1838 /* 1839 * NOTE: We do not have to remove the dedup 1840 * registration because the area is still 1841 * allocated and the underlying DIO will 1842 * still be flushed. 1843 */ 1844 if (dedup_off) { 1845 chain->bref.data_off = dedup_off; 1846 chain->bytes = 1 << (dedup_off & 1847 HAMMER2_OFF_MASK_RADIX); 1848 chain->error = 0; 1849 atomic_clear_int(&chain->flags, 1850 HAMMER2_CHAIN_MODIFIED); 1851 atomic_add_long(&hammer2_count_modified_chains, 1852 -1); 1853 if (chain->pmp) 1854 hammer2_pfs_memory_wakeup(chain->pmp); 1855 hammer2_freemap_adjust(hmp, &chain->bref, 1856 HAMMER2_FREEMAP_DORECOVER); 1857 atomic_set_int(&chain->flags, 1858 HAMMER2_CHAIN_DEDUPABLE); 1859 } else { 1860 error = hammer2_freemap_alloc(chain, 1861 chain->bytes); 1862 atomic_clear_int(&chain->flags, 1863 HAMMER2_CHAIN_DEDUPABLE); 1864 1865 /* 1866 * If we are unable to allocate a new block 1867 * but we are in emergency mode, issue a 1868 * warning to the console and reuse the same 1869 * block. 1870 * 1871 * We behave as if the allocation were 1872 * successful. 1873 * 1874 * THIS IS IMPORTANT: These modifications 1875 * are virtually guaranteed to corrupt any 1876 * snapshots related to this filesystem. 1877 */ 1878 if (error && (hmp->hflags & HMNT2_EMERG)) { 1879 error = 0; 1880 chain->bref.flags |= 1881 HAMMER2_BREF_FLAG_EMERG_MIP; 1882 1883 krateprintf(&krate_h2em, 1884 "hammer2: Emergency Mode WARNING: " 1885 "Operation will likely corrupt " 1886 "related snapshot: " 1887 "%016jx.%02x key=%016jx\n", 1888 chain->bref.data_off, 1889 chain->bref.type, 1890 chain->bref.key); 1891 } else if (error == 0) { 1892 chain->bref.flags &= 1893 ~HAMMER2_BREF_FLAG_EMERG_MIP; 1894 } 1895 } 1896 } 1897 } 1898 1899 /* 1900 * Stop here if error. We have to undo any flag bits we might 1901 * have set above. 1902 */ 1903 if (error) { 1904 if (setmodified) { 1905 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 1906 atomic_add_long(&hammer2_count_modified_chains, -1); 1907 if (chain->pmp) 1908 hammer2_pfs_memory_wakeup(chain->pmp); 1909 } 1910 if (setupdate) { 1911 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1912 } 1913 lockmgr(&chain->diolk, LK_RELEASE); 1914 1915 return error; 1916 } 1917 1918 /* 1919 * Update mirror_tid and modify_tid. modify_tid is only updated 1920 * if not passed as zero (during flushes, parent propagation passes 1921 * the value 0). 1922 * 1923 * NOTE: chain->pmp could be the device spmp. 1924 */ 1925 chain->bref.mirror_tid = hmp->voldata.mirror_tid + 1; 1926 if (mtid) 1927 chain->bref.modify_tid = mtid; 1928 1929 /* 1930 * Set BMAPUPD to tell the flush code that an existing blockmap entry 1931 * requires updating as well as to tell the delete code that the 1932 * chain's blockref might not exactly match (in terms of physical size 1933 * or block offset) the one in the parent's blocktable. The base key 1934 * of course will still match. 1935 */ 1936 if (chain->flags & HAMMER2_CHAIN_BMAPPED) 1937 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD); 1938 1939 /* 1940 * Short-cut data blocks which the caller does not need an actual 1941 * data reference to (aka OPTDATA), as long as the chain does not 1942 * already have a data pointer to the data. This generally means 1943 * that the modifications are being done via the logical buffer cache. 1944 * The INITIAL flag relates only to the device data buffer and thus 1945 * remains unchange in this situation. 1946 * 1947 * This code also handles bytes == 0 (most dirents). 1948 */ 1949 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA && 1950 (flags & HAMMER2_MODIFY_OPTDATA) && 1951 chain->data == NULL) { 1952 KKASSERT(chain->dio == NULL); 1953 goto skip2; 1954 } 1955 1956 /* 1957 * Clearing the INITIAL flag (for indirect blocks) indicates that 1958 * we've processed the uninitialized storage allocation. 1959 * 1960 * If this flag is already clear we are likely in a copy-on-write 1961 * situation but we have to be sure NOT to bzero the storage if 1962 * no data is present. 1963 */ 1964 if (chain->flags & HAMMER2_CHAIN_INITIAL) { 1965 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 1966 wasinitial = 1; 1967 } else { 1968 wasinitial = 0; 1969 } 1970 1971 /* 1972 * Instantiate data buffer and possibly execute COW operation 1973 */ 1974 switch(chain->bref.type) { 1975 case HAMMER2_BREF_TYPE_VOLUME: 1976 case HAMMER2_BREF_TYPE_FREEMAP: 1977 /* 1978 * The data is embedded, no copy-on-write operation is 1979 * needed. 1980 */ 1981 KKASSERT(chain->dio == NULL); 1982 break; 1983 case HAMMER2_BREF_TYPE_DIRENT: 1984 /* 1985 * The data might be fully embedded. 1986 */ 1987 if (chain->bytes == 0) { 1988 KKASSERT(chain->dio == NULL); 1989 break; 1990 } 1991 /* fall through */ 1992 case HAMMER2_BREF_TYPE_INODE: 1993 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 1994 case HAMMER2_BREF_TYPE_DATA: 1995 case HAMMER2_BREF_TYPE_INDIRECT: 1996 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1997 /* 1998 * Perform the copy-on-write operation 1999 * 2000 * zero-fill or copy-on-write depending on whether 2001 * chain->data exists or not and set the dirty state for 2002 * the new buffer. hammer2_io_new() will handle the 2003 * zero-fill. 2004 * 2005 * If a dedup_off was supplied this is an existing block 2006 * and no COW, copy, or further modification is required. 2007 */ 2008 KKASSERT(chain != &hmp->vchain && chain != &hmp->fchain); 2009 2010 if (wasinitial && dedup_off == 0) { 2011 error = hammer2_io_new(hmp, chain->bref.type, 2012 chain->bref.data_off, 2013 chain->bytes, &dio); 2014 } else { 2015 error = hammer2_io_bread(hmp, chain->bref.type, 2016 chain->bref.data_off, 2017 chain->bytes, &dio); 2018 } 2019 hammer2_adjreadcounter(&chain->bref, chain->bytes); 2020 2021 /* 2022 * If an I/O error occurs make sure callers cannot accidently 2023 * modify the old buffer's contents and corrupt the filesystem. 2024 * 2025 * NOTE: hammer2_io_data() call issues bkvasync() 2026 */ 2027 if (error) { 2028 kprintf("hammer2_chain_modify: hmp=%p I/O error\n", 2029 hmp); 2030 chain->error = HAMMER2_ERROR_EIO; 2031 hammer2_io_brelse(&dio); 2032 hammer2_io_brelse(&chain->dio); 2033 chain->data = NULL; 2034 break; 2035 } 2036 chain->error = 0; 2037 bdata = hammer2_io_data(dio, chain->bref.data_off); 2038 2039 if (chain->data) { 2040 /* 2041 * COW (unless a dedup). 2042 */ 2043 KKASSERT(chain->dio != NULL); 2044 if (chain->data != (void *)bdata && dedup_off == 0) { 2045 bcopy(chain->data, bdata, chain->bytes); 2046 } 2047 } else if (wasinitial == 0) { 2048 /* 2049 * We have a problem. We were asked to COW but 2050 * we don't have any data to COW with! 2051 */ 2052 panic("hammer2_chain_modify: having a COW %p\n", 2053 chain); 2054 } 2055 2056 /* 2057 * Retire the old buffer, replace with the new. Dirty or 2058 * redirty the new buffer. 2059 * 2060 * WARNING! The system buffer cache may have already flushed 2061 * the buffer, so we must be sure to [re]dirty it 2062 * for further modification. 2063 * 2064 * If dedup_off was supplied, the caller is not 2065 * expected to make any further modification to the 2066 * buffer. 2067 * 2068 * WARNING! hammer2_get_gdata() assumes dio never transitions 2069 * through NULL in order to optimize away unnecessary 2070 * diolk operations. 2071 */ 2072 { 2073 hammer2_io_t *tio; 2074 2075 if ((tio = chain->dio) != NULL) 2076 hammer2_io_bqrelse(&tio); 2077 chain->data = (void *)bdata; 2078 chain->dio = dio; 2079 if (dedup_off == 0) 2080 hammer2_io_setdirty(dio); 2081 } 2082 break; 2083 default: 2084 panic("hammer2_chain_modify: illegal non-embedded type %d", 2085 chain->bref.type); 2086 break; 2087 2088 } 2089 skip2: 2090 /* 2091 * setflush on parent indicating that the parent must recurse down 2092 * to us. Do not call on chain itself which might already have it 2093 * set. 2094 */ 2095 if (chain->parent) 2096 hammer2_chain_setflush(chain->parent); 2097 lockmgr(&chain->diolk, LK_RELEASE); 2098 2099 return (chain->error); 2100 } 2101 2102 /* 2103 * Modify the chain associated with an inode. 2104 */ 2105 int 2106 hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain, 2107 hammer2_tid_t mtid, int flags) 2108 { 2109 int error; 2110 2111 hammer2_inode_modify(ip); 2112 error = hammer2_chain_modify(chain, mtid, 0, flags); 2113 2114 return error; 2115 } 2116 2117 /* 2118 * Volume header data locks 2119 */ 2120 void 2121 hammer2_voldata_lock(hammer2_dev_t *hmp) 2122 { 2123 lockmgr(&hmp->vollk, LK_EXCLUSIVE); 2124 } 2125 2126 void 2127 hammer2_voldata_unlock(hammer2_dev_t *hmp) 2128 { 2129 lockmgr(&hmp->vollk, LK_RELEASE); 2130 } 2131 2132 void 2133 hammer2_voldata_modify(hammer2_dev_t *hmp) 2134 { 2135 if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) { 2136 atomic_add_long(&hammer2_count_modified_chains, 1); 2137 atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED); 2138 hammer2_pfs_memory_inc(hmp->vchain.pmp); 2139 } 2140 } 2141 2142 /* 2143 * This function returns the chain at the nearest key within the specified 2144 * range. The returned chain will be referenced but not locked. 2145 * 2146 * This function will recurse through chain->rbtree as necessary and will 2147 * return a *key_nextp suitable for iteration. *key_nextp is only set if 2148 * the iteration value is less than the current value of *key_nextp. 2149 * 2150 * The caller should use (*key_nextp) to calculate the actual range of 2151 * the returned element, which will be (key_beg to *key_nextp - 1), because 2152 * there might be another element which is superior to the returned element 2153 * and overlaps it. 2154 * 2155 * (*key_nextp) can be passed as key_beg in an iteration only while non-NULL 2156 * chains continue to be returned. On EOF (*key_nextp) may overflow since 2157 * it will wind up being (key_end + 1). 2158 * 2159 * WARNING! Must be called with child's spinlock held. Spinlock remains 2160 * held through the operation. 2161 */ 2162 struct hammer2_chain_find_info { 2163 hammer2_chain_t *best; 2164 hammer2_key_t key_beg; 2165 hammer2_key_t key_end; 2166 hammer2_key_t key_next; 2167 }; 2168 2169 static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data); 2170 static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data); 2171 2172 static 2173 hammer2_chain_t * 2174 hammer2_chain_find(hammer2_chain_t *parent, hammer2_key_t *key_nextp, 2175 hammer2_key_t key_beg, hammer2_key_t key_end) 2176 { 2177 struct hammer2_chain_find_info info; 2178 2179 info.best = NULL; 2180 info.key_beg = key_beg; 2181 info.key_end = key_end; 2182 info.key_next = *key_nextp; 2183 2184 RB_SCAN(hammer2_chain_tree, &parent->core.rbtree, 2185 hammer2_chain_find_cmp, hammer2_chain_find_callback, 2186 &info); 2187 *key_nextp = info.key_next; 2188 #if 0 2189 kprintf("chain_find %p %016jx:%016jx next=%016jx\n", 2190 parent, key_beg, key_end, *key_nextp); 2191 #endif 2192 2193 return (info.best); 2194 } 2195 2196 static 2197 int 2198 hammer2_chain_find_cmp(hammer2_chain_t *child, void *data) 2199 { 2200 struct hammer2_chain_find_info *info = data; 2201 hammer2_key_t child_beg; 2202 hammer2_key_t child_end; 2203 2204 child_beg = child->bref.key; 2205 child_end = child_beg + ((hammer2_key_t)1 << child->bref.keybits) - 1; 2206 2207 if (child_end < info->key_beg) 2208 return(-1); 2209 if (child_beg > info->key_end) 2210 return(1); 2211 return(0); 2212 } 2213 2214 static 2215 int 2216 hammer2_chain_find_callback(hammer2_chain_t *child, void *data) 2217 { 2218 struct hammer2_chain_find_info *info = data; 2219 hammer2_chain_t *best; 2220 hammer2_key_t child_end; 2221 2222 /* 2223 * WARNING! Layerq is scanned forwards, exact matches should keep 2224 * the existing info->best. 2225 */ 2226 if ((best = info->best) == NULL) { 2227 /* 2228 * No previous best. Assign best 2229 */ 2230 info->best = child; 2231 } else if (best->bref.key <= info->key_beg && 2232 child->bref.key <= info->key_beg) { 2233 /* 2234 * Illegal overlap. 2235 */ 2236 KKASSERT(0); 2237 /*info->best = child;*/ 2238 } else if (child->bref.key < best->bref.key) { 2239 /* 2240 * Child has a nearer key and best is not flush with key_beg. 2241 * Set best to child. Truncate key_next to the old best key. 2242 */ 2243 info->best = child; 2244 if (info->key_next > best->bref.key || info->key_next == 0) 2245 info->key_next = best->bref.key; 2246 } else if (child->bref.key == best->bref.key) { 2247 /* 2248 * If our current best is flush with the child then this 2249 * is an illegal overlap. 2250 * 2251 * key_next will automatically be limited to the smaller of 2252 * the two end-points. 2253 */ 2254 KKASSERT(0); 2255 info->best = child; 2256 } else { 2257 /* 2258 * Keep the current best but truncate key_next to the child's 2259 * base. 2260 * 2261 * key_next will also automatically be limited to the smaller 2262 * of the two end-points (probably not necessary for this case 2263 * but we do it anyway). 2264 */ 2265 if (info->key_next > child->bref.key || info->key_next == 0) 2266 info->key_next = child->bref.key; 2267 } 2268 2269 /* 2270 * Always truncate key_next based on child's end-of-range. 2271 */ 2272 child_end = child->bref.key + ((hammer2_key_t)1 << child->bref.keybits); 2273 if (child_end && (info->key_next > child_end || info->key_next == 0)) 2274 info->key_next = child_end; 2275 2276 return(0); 2277 } 2278 2279 /* 2280 * Retrieve the specified chain from a media blockref, creating the 2281 * in-memory chain structure which reflects it. The returned chain is 2282 * held and locked according to (how) (HAMMER2_RESOLVE_*). The caller must 2283 * handle crc-checks and so forth, and should check chain->error before 2284 * assuming that the data is good. 2285 * 2286 * To handle insertion races pass the INSERT_RACE flag along with the 2287 * generation number of the core. NULL will be returned if the generation 2288 * number changes before we have a chance to insert the chain. Insert 2289 * races can occur because the parent might be held shared. 2290 * 2291 * Caller must hold the parent locked shared or exclusive since we may 2292 * need the parent's bref array to find our block. 2293 * 2294 * WARNING! chain->pmp is always set to NULL for any chain representing 2295 * part of the super-root topology. 2296 */ 2297 hammer2_chain_t * 2298 hammer2_chain_get(hammer2_chain_t *parent, int generation, 2299 hammer2_blockref_t *bref, int how) 2300 { 2301 hammer2_dev_t *hmp = parent->hmp; 2302 hammer2_chain_t *chain; 2303 int error; 2304 2305 /* 2306 * Allocate a chain structure representing the existing media 2307 * entry. Resulting chain has one ref and is not locked. 2308 */ 2309 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) 2310 chain = hammer2_chain_alloc(hmp, NULL, bref); 2311 else 2312 chain = hammer2_chain_alloc(hmp, parent->pmp, bref); 2313 /* ref'd chain returned */ 2314 2315 /* 2316 * Flag that the chain is in the parent's blockmap so delete/flush 2317 * knows what to do with it. 2318 */ 2319 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED); 2320 2321 /* 2322 * chain must be locked to avoid unexpected ripouts 2323 */ 2324 hammer2_chain_lock(chain, how); 2325 2326 /* 2327 * Link the chain into its parent. A spinlock is required to safely 2328 * access the RBTREE, and it is possible to collide with another 2329 * hammer2_chain_get() operation because the caller might only hold 2330 * a shared lock on the parent. 2331 * 2332 * NOTE: Get races can occur quite often when we distribute 2333 * asynchronous read-aheads across multiple threads. 2334 */ 2335 KKASSERT(parent->refs > 0); 2336 error = hammer2_chain_insert(parent, chain, 2337 HAMMER2_CHAIN_INSERT_SPIN | 2338 HAMMER2_CHAIN_INSERT_RACE, 2339 generation); 2340 if (error) { 2341 KKASSERT((chain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); 2342 /*kprintf("chain %p get race\n", chain);*/ 2343 hammer2_chain_unlock(chain); 2344 hammer2_chain_drop(chain); 2345 chain = NULL; 2346 } else { 2347 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); 2348 } 2349 2350 /* 2351 * Return our new chain referenced but not locked, or NULL if 2352 * a race occurred. 2353 */ 2354 return (chain); 2355 } 2356 2357 /* 2358 * Lookup initialization/completion API 2359 */ 2360 hammer2_chain_t * 2361 hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags) 2362 { 2363 hammer2_chain_ref(parent); 2364 if (flags & HAMMER2_LOOKUP_SHARED) { 2365 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS | 2366 HAMMER2_RESOLVE_SHARED); 2367 } else { 2368 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 2369 } 2370 return (parent); 2371 } 2372 2373 void 2374 hammer2_chain_lookup_done(hammer2_chain_t *parent) 2375 { 2376 if (parent) { 2377 hammer2_chain_unlock(parent); 2378 hammer2_chain_drop(parent); 2379 } 2380 } 2381 2382 /* 2383 * Take the locked chain and return a locked parent. The chain remains 2384 * locked on return, but may have to be temporarily unlocked to acquire 2385 * the parent. Because of this, (chain) must be stable and cannot be 2386 * deleted while it was temporarily unlocked (typically means that (chain) 2387 * is an inode). 2388 * 2389 * Pass HAMMER2_RESOLVE_* flags in flags. 2390 * 2391 * This will work even if the chain is errored, and the caller can check 2392 * parent->error on return if desired since the parent will be locked. 2393 * 2394 * This function handles the lock order reversal. 2395 */ 2396 hammer2_chain_t * 2397 hammer2_chain_getparent(hammer2_chain_t *chain, int flags) 2398 { 2399 hammer2_chain_t *parent; 2400 2401 /* 2402 * Be careful of order, chain must be unlocked before parent 2403 * is locked below to avoid a deadlock. Try it trivially first. 2404 */ 2405 parent = chain->parent; 2406 if (parent == NULL) 2407 panic("hammer2_chain_getparent: no parent"); 2408 hammer2_chain_ref(parent); 2409 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) 2410 return parent; 2411 2412 for (;;) { 2413 hammer2_chain_unlock(chain); 2414 hammer2_chain_lock(parent, flags); 2415 hammer2_chain_lock(chain, flags); 2416 2417 /* 2418 * Parent relinking races are quite common. We have to get 2419 * it right or we will blow up the block table. 2420 */ 2421 if (chain->parent == parent) 2422 break; 2423 hammer2_chain_unlock(parent); 2424 hammer2_chain_drop(parent); 2425 cpu_ccfence(); 2426 parent = chain->parent; 2427 if (parent == NULL) 2428 panic("hammer2_chain_getparent: no parent"); 2429 hammer2_chain_ref(parent); 2430 } 2431 return parent; 2432 } 2433 2434 /* 2435 * Take the locked chain and return a locked parent. The chain is unlocked 2436 * and dropped. *chainp is set to the returned parent as a convenience. 2437 * Pass HAMMER2_RESOLVE_* flags in flags. 2438 * 2439 * This will work even if the chain is errored, and the caller can check 2440 * parent->error on return if desired since the parent will be locked. 2441 * 2442 * The chain does NOT need to be stable. We use a tracking structure 2443 * to track the expected parent if the chain is deleted out from under us. 2444 * 2445 * This function handles the lock order reversal. 2446 */ 2447 hammer2_chain_t * 2448 hammer2_chain_repparent(hammer2_chain_t **chainp, int flags) 2449 { 2450 hammer2_chain_t *chain; 2451 hammer2_chain_t *parent; 2452 struct hammer2_reptrack reptrack; 2453 struct hammer2_reptrack **repp; 2454 2455 /* 2456 * Be careful of order, chain must be unlocked before parent 2457 * is locked below to avoid a deadlock. Try it trivially first. 2458 */ 2459 chain = *chainp; 2460 parent = chain->parent; 2461 if (parent == NULL) { 2462 hammer2_spin_unex(&chain->core.spin); 2463 panic("hammer2_chain_repparent: no parent"); 2464 } 2465 hammer2_chain_ref(parent); 2466 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) { 2467 hammer2_chain_unlock(chain); 2468 hammer2_chain_drop(chain); 2469 *chainp = parent; 2470 2471 return parent; 2472 } 2473 2474 /* 2475 * Ok, now it gets a bit nasty. There are multiple situations where 2476 * the parent might be in the middle of a deletion, or where the child 2477 * (chain) might be deleted the instant we let go of its lock. 2478 * We can potentially end up in a no-win situation! 2479 * 2480 * In particular, the indirect_maintenance() case can cause these 2481 * situations. 2482 * 2483 * To deal with this we install a reptrack structure in the parent 2484 * This reptrack structure 'owns' the parent ref and will automatically 2485 * migrate to the parent's parent if the parent is deleted permanently. 2486 */ 2487 hammer2_spin_init(&reptrack.spin, "h2reptrk"); 2488 reptrack.chain = parent; 2489 hammer2_chain_ref(parent); /* for the reptrack */ 2490 2491 hammer2_spin_ex(&parent->core.spin); 2492 reptrack.next = parent->core.reptrack; 2493 parent->core.reptrack = &reptrack; 2494 hammer2_spin_unex(&parent->core.spin); 2495 2496 hammer2_chain_unlock(chain); 2497 hammer2_chain_drop(chain); 2498 chain = NULL; /* gone */ 2499 2500 /* 2501 * At the top of this loop, chain is gone and parent is refd both 2502 * by us explicitly AND via our reptrack. We are attempting to 2503 * lock parent. 2504 */ 2505 for (;;) { 2506 hammer2_chain_lock(parent, flags); 2507 2508 if (reptrack.chain == parent) 2509 break; 2510 hammer2_chain_unlock(parent); 2511 hammer2_chain_drop(parent); 2512 2513 kprintf("hammer2: debug REPTRACK %p->%p\n", 2514 parent, reptrack.chain); 2515 hammer2_spin_ex(&reptrack.spin); 2516 parent = reptrack.chain; 2517 hammer2_chain_ref(parent); 2518 hammer2_spin_unex(&reptrack.spin); 2519 } 2520 2521 /* 2522 * Once parent is locked and matches our reptrack, our reptrack 2523 * will be stable and we have our parent. We can unlink our 2524 * reptrack. 2525 * 2526 * WARNING! Remember that the chain lock might be shared. Chains 2527 * locked shared have stable parent linkages. 2528 */ 2529 hammer2_spin_ex(&parent->core.spin); 2530 repp = &parent->core.reptrack; 2531 while (*repp != &reptrack) 2532 repp = &(*repp)->next; 2533 *repp = reptrack.next; 2534 hammer2_spin_unex(&parent->core.spin); 2535 2536 hammer2_chain_drop(parent); /* reptrack ref */ 2537 *chainp = parent; /* return parent lock+ref */ 2538 2539 return parent; 2540 } 2541 2542 /* 2543 * Dispose of any linked reptrack structures in (chain) by shifting them to 2544 * (parent). Both (chain) and (parent) must be exclusively locked. 2545 * 2546 * This is interlocked against any children of (chain) on the other side. 2547 * No children so remain as-of when this is called so we can test 2548 * core.reptrack without holding the spin-lock. 2549 * 2550 * Used whenever the caller intends to permanently delete chains related 2551 * to topological recursions (BREF_TYPE_INDIRECT, BREF_TYPE_FREEMAP_NODE), 2552 * where the chains underneath the node being deleted are given a new parent 2553 * above the node being deleted. 2554 */ 2555 static 2556 void 2557 hammer2_chain_repchange(hammer2_chain_t *parent, hammer2_chain_t *chain) 2558 { 2559 struct hammer2_reptrack *reptrack; 2560 2561 KKASSERT(chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)); 2562 while (chain->core.reptrack) { 2563 hammer2_spin_ex(&parent->core.spin); 2564 hammer2_spin_ex(&chain->core.spin); 2565 reptrack = chain->core.reptrack; 2566 if (reptrack == NULL) { 2567 hammer2_spin_unex(&chain->core.spin); 2568 hammer2_spin_unex(&parent->core.spin); 2569 break; 2570 } 2571 hammer2_spin_ex(&reptrack->spin); 2572 chain->core.reptrack = reptrack->next; 2573 reptrack->chain = parent; 2574 reptrack->next = parent->core.reptrack; 2575 parent->core.reptrack = reptrack; 2576 hammer2_chain_ref(parent); /* reptrack */ 2577 2578 hammer2_spin_unex(&chain->core.spin); 2579 hammer2_spin_unex(&parent->core.spin); 2580 kprintf("hammer2: debug repchange %p %p->%p\n", 2581 reptrack, chain, parent); 2582 hammer2_chain_drop(chain); /* reptrack */ 2583 } 2584 } 2585 2586 /* 2587 * Locate the first chain whos key range overlaps (key_beg, key_end) inclusive. 2588 * (*parentp) typically points to an inode but can also point to a related 2589 * indirect block and this function will recurse upwards and find the inode 2590 * or the nearest undeleted indirect block covering the key range. 2591 * 2592 * This function unconditionally sets *errorp, replacing any previous value. 2593 * 2594 * (*parentp) must be exclusive or shared locked (depending on flags) and 2595 * referenced and can be an inode or an existing indirect block within the 2596 * inode. 2597 * 2598 * If (*parent) is errored out, this function will not attempt to recurse 2599 * the radix tree and will return NULL along with an appropriate *errorp. 2600 * If NULL is returned and *errorp is 0, the requested lookup could not be 2601 * located. 2602 * 2603 * On return (*parentp) will be modified to point at the deepest parent chain 2604 * element encountered during the search, as a helper for an insertion or 2605 * deletion. 2606 * 2607 * The new (*parentp) will be locked shared or exclusive (depending on flags), 2608 * and referenced, and the old will be unlocked and dereferenced (no change 2609 * if they are both the same). This is particularly important if the caller 2610 * wishes to insert a new chain, (*parentp) will be set properly even if NULL 2611 * is returned, as long as no error occurred. 2612 * 2613 * The matching chain will be returned locked according to flags. 2614 * 2615 * -- 2616 * 2617 * NULL is returned if no match was found, but (*parentp) will still 2618 * potentially be adjusted. 2619 * 2620 * On return (*key_nextp) will point to an iterative value for key_beg. 2621 * (If NULL is returned (*key_nextp) is set to (key_end + 1)). 2622 * 2623 * This function will also recurse up the chain if the key is not within the 2624 * current parent's range. (*parentp) can never be set to NULL. An iteration 2625 * can simply allow (*parentp) to float inside the loop. 2626 * 2627 * NOTE! chain->data is not always resolved. By default it will not be 2628 * resolved for BREF_TYPE_DATA, FREEMAP_NODE, or FREEMAP_LEAF. Use 2629 * HAMMER2_LOOKUP_ALWAYS to force resolution (but be careful w/ 2630 * BREF_TYPE_DATA as the device buffer can alias the logical file 2631 * buffer). 2632 */ 2633 2634 hammer2_chain_t * 2635 hammer2_chain_lookup(hammer2_chain_t **parentp, hammer2_key_t *key_nextp, 2636 hammer2_key_t key_beg, hammer2_key_t key_end, 2637 int *errorp, int flags) 2638 { 2639 hammer2_dev_t *hmp; 2640 hammer2_chain_t *parent; 2641 hammer2_chain_t *chain; 2642 hammer2_blockref_t *base; 2643 hammer2_blockref_t *bref; 2644 hammer2_blockref_t bsave; 2645 hammer2_key_t scan_beg; 2646 hammer2_key_t scan_end; 2647 int count = 0; 2648 int how_always = HAMMER2_RESOLVE_ALWAYS; 2649 int how_maybe = HAMMER2_RESOLVE_MAYBE; 2650 int how; 2651 int generation; 2652 int maxloops = 300000; 2653 volatile hammer2_mtx_t save_mtx; 2654 2655 if (flags & HAMMER2_LOOKUP_ALWAYS) { 2656 how_maybe = how_always; 2657 how = HAMMER2_RESOLVE_ALWAYS; 2658 } else if (flags & HAMMER2_LOOKUP_NODATA) { 2659 how = HAMMER2_RESOLVE_NEVER; 2660 } else { 2661 how = HAMMER2_RESOLVE_MAYBE; 2662 } 2663 if (flags & HAMMER2_LOOKUP_SHARED) { 2664 how_maybe |= HAMMER2_RESOLVE_SHARED; 2665 how_always |= HAMMER2_RESOLVE_SHARED; 2666 how |= HAMMER2_RESOLVE_SHARED; 2667 } 2668 2669 /* 2670 * Recurse (*parentp) upward if necessary until the parent completely 2671 * encloses the key range or we hit the inode. 2672 * 2673 * Handle races against the flusher deleting indirect nodes on its 2674 * way back up by continuing to recurse upward past the deletion. 2675 */ 2676 parent = *parentp; 2677 hmp = parent->hmp; 2678 *errorp = 0; 2679 2680 while (parent->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 2681 parent->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2682 scan_beg = parent->bref.key; 2683 scan_end = scan_beg + 2684 ((hammer2_key_t)1 << parent->bref.keybits) - 1; 2685 if ((parent->flags & HAMMER2_CHAIN_DELETED) == 0) { 2686 if (key_beg >= scan_beg && key_end <= scan_end) 2687 break; 2688 } 2689 parent = hammer2_chain_repparent(parentp, how_maybe); 2690 } 2691 again: 2692 if (--maxloops == 0) 2693 panic("hammer2_chain_lookup: maxloops"); 2694 2695 /* 2696 * MATCHIND case that does not require parent->data (do prior to 2697 * parent->error check). 2698 */ 2699 switch(parent->bref.type) { 2700 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 2701 case HAMMER2_BREF_TYPE_INDIRECT: 2702 if (flags & HAMMER2_LOOKUP_MATCHIND) { 2703 scan_beg = parent->bref.key; 2704 scan_end = scan_beg + 2705 ((hammer2_key_t)1 << parent->bref.keybits) - 1; 2706 if (key_beg == scan_beg && key_end == scan_end) { 2707 chain = parent; 2708 hammer2_chain_ref(chain); 2709 hammer2_chain_lock(chain, how_maybe); 2710 *key_nextp = scan_end + 1; 2711 goto done; 2712 } 2713 } 2714 break; 2715 default: 2716 break; 2717 } 2718 2719 /* 2720 * No lookup is possible if the parent is errored. We delayed 2721 * this check as long as we could to ensure that the parent backup, 2722 * embedded data, and MATCHIND code could still execute. 2723 */ 2724 if (parent->error) { 2725 *errorp = parent->error; 2726 return NULL; 2727 } 2728 2729 /* 2730 * Locate the blockref array. Currently we do a fully associative 2731 * search through the array. 2732 */ 2733 switch(parent->bref.type) { 2734 case HAMMER2_BREF_TYPE_INODE: 2735 /* 2736 * Special shortcut for embedded data returns the inode 2737 * itself. Callers must detect this condition and access 2738 * the embedded data (the strategy code does this for us). 2739 * 2740 * This is only applicable to regular files and softlinks. 2741 * 2742 * We need a second lock on parent. Since we already have 2743 * a lock we must pass LOCKAGAIN to prevent unexpected 2744 * blocking (we don't want to block on a second shared 2745 * ref if an exclusive lock is pending) 2746 */ 2747 if (parent->data->ipdata.meta.op_flags & 2748 HAMMER2_OPFLAG_DIRECTDATA) { 2749 if (flags & HAMMER2_LOOKUP_NODIRECT) { 2750 chain = NULL; 2751 *key_nextp = key_end + 1; 2752 goto done; 2753 } 2754 hammer2_chain_ref(parent); 2755 hammer2_chain_lock(parent, how_always | 2756 HAMMER2_RESOLVE_LOCKAGAIN); 2757 *key_nextp = key_end + 1; 2758 return (parent); 2759 } 2760 base = &parent->data->ipdata.u.blockset.blockref[0]; 2761 count = HAMMER2_SET_COUNT; 2762 break; 2763 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 2764 case HAMMER2_BREF_TYPE_INDIRECT: 2765 /* 2766 * Optimize indirect blocks in the INITIAL state to avoid 2767 * I/O. 2768 * 2769 * Debugging: Enter permanent wait state instead of 2770 * panicing on unexpectedly NULL data for the moment. 2771 */ 2772 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 2773 base = NULL; 2774 } else { 2775 if (parent->data == NULL) { 2776 kprintf("hammer2: unexpected NULL data " 2777 "on %p\n", parent); 2778 while (1) 2779 tsleep(parent, 0, "xxx", 0); 2780 } 2781 base = &parent->data->npdata[0]; 2782 } 2783 count = parent->bytes / sizeof(hammer2_blockref_t); 2784 break; 2785 case HAMMER2_BREF_TYPE_VOLUME: 2786 base = &parent->data->voldata.sroot_blockset.blockref[0]; 2787 count = HAMMER2_SET_COUNT; 2788 break; 2789 case HAMMER2_BREF_TYPE_FREEMAP: 2790 base = &parent->data->blkset.blockref[0]; 2791 count = HAMMER2_SET_COUNT; 2792 break; 2793 default: 2794 kprintf("hammer2_chain_lookup: unrecognized " 2795 "blockref(B) type: %d", 2796 parent->bref.type); 2797 while (1) 2798 tsleep(&base, 0, "dead", 0); 2799 panic("hammer2_chain_lookup: unrecognized " 2800 "blockref(B) type: %d", 2801 parent->bref.type); 2802 base = NULL; /* safety */ 2803 count = 0; /* safety */ 2804 } 2805 2806 /* 2807 * Merged scan to find next candidate. 2808 * 2809 * hammer2_base_*() functions require the parent->core.live_* fields 2810 * to be synchronized. 2811 * 2812 * We need to hold the spinlock to access the block array and RB tree 2813 * and to interlock chain creation. 2814 */ 2815 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 2816 hammer2_chain_countbrefs(parent, base, count); 2817 2818 /* 2819 * Combined search 2820 */ 2821 hammer2_spin_ex(&parent->core.spin); 2822 chain = hammer2_combined_find(parent, base, count, 2823 key_nextp, 2824 key_beg, key_end, 2825 &bref); 2826 generation = parent->core.generation; 2827 2828 /* 2829 * Exhausted parent chain, iterate. 2830 */ 2831 if (bref == NULL) { 2832 KKASSERT(chain == NULL); 2833 hammer2_spin_unex(&parent->core.spin); 2834 if (key_beg == key_end) /* short cut single-key case */ 2835 return (NULL); 2836 2837 /* 2838 * Stop if we reached the end of the iteration. 2839 */ 2840 if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && 2841 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2842 return (NULL); 2843 } 2844 2845 /* 2846 * Calculate next key, stop if we reached the end of the 2847 * iteration, otherwise go up one level and loop. 2848 */ 2849 key_beg = parent->bref.key + 2850 ((hammer2_key_t)1 << parent->bref.keybits); 2851 if (key_beg == 0 || key_beg > key_end) 2852 return (NULL); 2853 parent = hammer2_chain_repparent(parentp, how_maybe); 2854 goto again; 2855 } 2856 2857 /* 2858 * Selected from blockref or in-memory chain. 2859 */ 2860 bsave = *bref; 2861 if (chain == NULL) { 2862 hammer2_spin_unex(&parent->core.spin); 2863 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || 2864 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2865 chain = hammer2_chain_get(parent, generation, 2866 &bsave, how_maybe); 2867 } else { 2868 chain = hammer2_chain_get(parent, generation, 2869 &bsave, how); 2870 } 2871 if (chain == NULL) 2872 goto again; 2873 } else { 2874 hammer2_chain_ref(chain); 2875 hammer2_spin_unex(&parent->core.spin); 2876 2877 /* 2878 * chain is referenced but not locked. We must lock the 2879 * chain to obtain definitive state. 2880 */ 2881 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || 2882 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2883 hammer2_chain_lock(chain, how_maybe); 2884 } else { 2885 hammer2_chain_lock(chain, how); 2886 } 2887 KKASSERT(chain->parent == parent); 2888 } 2889 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || 2890 chain->parent != parent) { 2891 hammer2_chain_unlock(chain); 2892 hammer2_chain_drop(chain); 2893 chain = NULL; /* SAFETY */ 2894 goto again; 2895 } 2896 2897 2898 /* 2899 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) 2900 * 2901 * NOTE: Chain's key range is not relevant as there might be 2902 * one-offs within the range that are not deleted. 2903 * 2904 * NOTE: Lookups can race delete-duplicate because 2905 * delete-duplicate does not lock the parent's core 2906 * (they just use the spinlock on the core). 2907 */ 2908 if (chain->flags & HAMMER2_CHAIN_DELETED) { 2909 kprintf("skip deleted chain %016jx.%02x key=%016jx\n", 2910 chain->bref.data_off, chain->bref.type, 2911 chain->bref.key); 2912 hammer2_chain_unlock(chain); 2913 hammer2_chain_drop(chain); 2914 chain = NULL; /* SAFETY */ 2915 key_beg = *key_nextp; 2916 if (key_beg == 0 || key_beg > key_end) 2917 return(NULL); 2918 goto again; 2919 } 2920 2921 /* 2922 * If the chain element is an indirect block it becomes the new 2923 * parent and we loop on it. We must maintain our top-down locks 2924 * to prevent the flusher from interfering (i.e. doing a 2925 * delete-duplicate and leaving us recursing down a deleted chain). 2926 * 2927 * The parent always has to be locked with at least RESOLVE_MAYBE 2928 * so we can access its data. It might need a fixup if the caller 2929 * passed incompatible flags. Be careful not to cause a deadlock 2930 * as a data-load requires an exclusive lock. 2931 * 2932 * If HAMMER2_LOOKUP_MATCHIND is set and the indirect block's key 2933 * range is within the requested key range we return the indirect 2934 * block and do NOT loop. This is usually only used to acquire 2935 * freemap nodes. 2936 */ 2937 if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || 2938 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { 2939 save_mtx = parent->lock; 2940 hammer2_chain_unlock(parent); 2941 hammer2_chain_drop(parent); 2942 *parentp = parent = chain; 2943 chain = NULL; /* SAFETY */ 2944 goto again; 2945 } 2946 done: 2947 /* 2948 * All done, return the locked chain. 2949 * 2950 * If the caller does not want a locked chain, replace the lock with 2951 * a ref. Perhaps this can eventually be optimized to not obtain the 2952 * lock in the first place for situations where the data does not 2953 * need to be resolved. 2954 * 2955 * NOTE! A chain->error must be tested by the caller upon return. 2956 * *errorp is only set based on issues which occur while 2957 * trying to reach the chain. 2958 */ 2959 return (chain); 2960 } 2961 2962 /* 2963 * After having issued a lookup we can iterate all matching keys. 2964 * 2965 * If chain is non-NULL we continue the iteration from just after it's index. 2966 * 2967 * If chain is NULL we assume the parent was exhausted and continue the 2968 * iteration at the next parent. 2969 * 2970 * If a fatal error occurs (typically an I/O error), a dummy chain is 2971 * returned with chain->error and error-identifying information set. This 2972 * chain will assert if you try to do anything fancy with it. 2973 * 2974 * XXX Depending on where the error occurs we should allow continued iteration. 2975 * 2976 * parent must be locked on entry and remains locked throughout. chain's 2977 * lock status must match flags. Chain is always at least referenced. 2978 * 2979 * WARNING! The MATCHIND flag does not apply to this function. 2980 */ 2981 hammer2_chain_t * 2982 hammer2_chain_next(hammer2_chain_t **parentp, hammer2_chain_t *chain, 2983 hammer2_key_t *key_nextp, 2984 hammer2_key_t key_beg, hammer2_key_t key_end, 2985 int *errorp, int flags) 2986 { 2987 hammer2_chain_t *parent; 2988 int how_maybe; 2989 2990 /* 2991 * Calculate locking flags for upward recursion. 2992 */ 2993 how_maybe = HAMMER2_RESOLVE_MAYBE; 2994 if (flags & HAMMER2_LOOKUP_SHARED) 2995 how_maybe |= HAMMER2_RESOLVE_SHARED; 2996 2997 parent = *parentp; 2998 *errorp = 0; 2999 3000 /* 3001 * Calculate the next index and recalculate the parent if necessary. 3002 */ 3003 if (chain) { 3004 key_beg = chain->bref.key + 3005 ((hammer2_key_t)1 << chain->bref.keybits); 3006 hammer2_chain_unlock(chain); 3007 hammer2_chain_drop(chain); 3008 3009 /* 3010 * chain invalid past this point, but we can still do a 3011 * pointer comparison w/parent. 3012 * 3013 * Any scan where the lookup returned degenerate data embedded 3014 * in the inode has an invalid index and must terminate. 3015 */ 3016 if (chain == parent) 3017 return(NULL); 3018 if (key_beg == 0 || key_beg > key_end) 3019 return(NULL); 3020 chain = NULL; 3021 } else if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && 3022 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { 3023 /* 3024 * We reached the end of the iteration. 3025 */ 3026 return (NULL); 3027 } else { 3028 /* 3029 * Continue iteration with next parent unless the current 3030 * parent covers the range. 3031 * 3032 * (This also handles the case of a deleted, empty indirect 3033 * node). 3034 */ 3035 key_beg = parent->bref.key + 3036 ((hammer2_key_t)1 << parent->bref.keybits); 3037 if (key_beg == 0 || key_beg > key_end) 3038 return (NULL); 3039 parent = hammer2_chain_repparent(parentp, how_maybe); 3040 } 3041 3042 /* 3043 * And execute 3044 */ 3045 return (hammer2_chain_lookup(parentp, key_nextp, 3046 key_beg, key_end, 3047 errorp, flags)); 3048 } 3049 3050 /* 3051 * Caller wishes to iterate chains under parent, loading new chains into 3052 * chainp. Caller must initialize *chainp to NULL and *firstp to 1, and 3053 * then call hammer2_chain_scan() repeatedly until a non-zero return. 3054 * During the scan, *firstp will be set to 0 and (*chainp) will be replaced 3055 * with the returned chain for the scan. The returned *chainp will be 3056 * locked and referenced. Any prior contents will be unlocked and dropped. 3057 * 3058 * Caller should check the return value. A normal scan EOF will return 3059 * exactly HAMMER2_ERROR_EOF. Any other non-zero value indicates an 3060 * error trying to access parent data. Any error in the returned chain 3061 * must be tested separately by the caller. 3062 * 3063 * (*chainp) is dropped on each scan, but will only be set if the returned 3064 * element itself can recurse. Leaf elements are NOT resolved, loaded, or 3065 * returned via *chainp. The caller will get their bref only. 3066 * 3067 * The raw scan function is similar to lookup/next but does not seek to a key. 3068 * Blockrefs are iterated via first_bref = (parent, NULL) and 3069 * next_chain = (parent, bref). 3070 * 3071 * The passed-in parent must be locked and its data resolved. The function 3072 * nominally returns a locked and referenced *chainp != NULL for chains 3073 * the caller might need to recurse on (and will dipose of any *chainp passed 3074 * in). The caller must check the chain->bref.type either way. 3075 */ 3076 int 3077 hammer2_chain_scan(hammer2_chain_t *parent, hammer2_chain_t **chainp, 3078 hammer2_blockref_t *bref, int *firstp, 3079 int flags) 3080 { 3081 hammer2_dev_t *hmp; 3082 hammer2_blockref_t *base; 3083 hammer2_blockref_t *bref_ptr; 3084 hammer2_key_t key; 3085 hammer2_key_t next_key; 3086 hammer2_chain_t *chain = NULL; 3087 int count = 0; 3088 int how_always = HAMMER2_RESOLVE_ALWAYS; 3089 int how_maybe = HAMMER2_RESOLVE_MAYBE; 3090 int how; 3091 int generation; 3092 int maxloops = 300000; 3093 int error; 3094 3095 hmp = parent->hmp; 3096 error = 0; 3097 3098 /* 3099 * Scan flags borrowed from lookup. 3100 */ 3101 if (flags & HAMMER2_LOOKUP_ALWAYS) { 3102 how_maybe = how_always; 3103 how = HAMMER2_RESOLVE_ALWAYS; 3104 } else if (flags & HAMMER2_LOOKUP_NODATA) { 3105 how = HAMMER2_RESOLVE_NEVER; 3106 } else { 3107 how = HAMMER2_RESOLVE_MAYBE; 3108 } 3109 if (flags & HAMMER2_LOOKUP_SHARED) { 3110 how_maybe |= HAMMER2_RESOLVE_SHARED; 3111 how_always |= HAMMER2_RESOLVE_SHARED; 3112 how |= HAMMER2_RESOLVE_SHARED; 3113 } 3114 3115 /* 3116 * Calculate key to locate first/next element, unlocking the previous 3117 * element as we go. Be careful, the key calculation can overflow. 3118 * 3119 * (also reset bref to NULL) 3120 */ 3121 if (*firstp) { 3122 key = 0; 3123 *firstp = 0; 3124 } else { 3125 key = bref->key + ((hammer2_key_t)1 << bref->keybits); 3126 if ((chain = *chainp) != NULL) { 3127 *chainp = NULL; 3128 hammer2_chain_unlock(chain); 3129 hammer2_chain_drop(chain); 3130 chain = NULL; 3131 } 3132 if (key == 0) { 3133 error |= HAMMER2_ERROR_EOF; 3134 goto done; 3135 } 3136 } 3137 3138 again: 3139 if (parent->error) { 3140 error = parent->error; 3141 goto done; 3142 } 3143 if (--maxloops == 0) 3144 panic("hammer2_chain_scan: maxloops"); 3145 3146 /* 3147 * Locate the blockref array. Currently we do a fully associative 3148 * search through the array. 3149 */ 3150 switch(parent->bref.type) { 3151 case HAMMER2_BREF_TYPE_INODE: 3152 /* 3153 * An inode with embedded data has no sub-chains. 3154 * 3155 * WARNING! Bulk scan code may pass a static chain marked 3156 * as BREF_TYPE_INODE with a copy of the volume 3157 * root blockset to snapshot the volume. 3158 */ 3159 if (parent->data->ipdata.meta.op_flags & 3160 HAMMER2_OPFLAG_DIRECTDATA) { 3161 error |= HAMMER2_ERROR_EOF; 3162 goto done; 3163 } 3164 base = &parent->data->ipdata.u.blockset.blockref[0]; 3165 count = HAMMER2_SET_COUNT; 3166 break; 3167 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3168 case HAMMER2_BREF_TYPE_INDIRECT: 3169 /* 3170 * Optimize indirect blocks in the INITIAL state to avoid 3171 * I/O. 3172 */ 3173 if (parent->flags & HAMMER2_CHAIN_INITIAL) { 3174 base = NULL; 3175 } else { 3176 if (parent->data == NULL) 3177 panic("parent->data is NULL"); 3178 base = &parent->data->npdata[0]; 3179 } 3180 count = parent->bytes / sizeof(hammer2_blockref_t); 3181 break; 3182 case HAMMER2_BREF_TYPE_VOLUME: 3183 base = &parent->data->voldata.sroot_blockset.blockref[0]; 3184 count = HAMMER2_SET_COUNT; 3185 break; 3186 case HAMMER2_BREF_TYPE_FREEMAP: 3187 base = &parent->data->blkset.blockref[0]; 3188 count = HAMMER2_SET_COUNT; 3189 break; 3190 default: 3191 panic("hammer2_chain_scan: unrecognized blockref type: %d", 3192 parent->bref.type); 3193 base = NULL; /* safety */ 3194 count = 0; /* safety */ 3195 } 3196 3197 /* 3198 * Merged scan to find next candidate. 3199 * 3200 * hammer2_base_*() functions require the parent->core.live_* fields 3201 * to be synchronized. 3202 * 3203 * We need to hold the spinlock to access the block array and RB tree 3204 * and to interlock chain creation. 3205 */ 3206 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 3207 hammer2_chain_countbrefs(parent, base, count); 3208 3209 next_key = 0; 3210 bref_ptr = NULL; 3211 hammer2_spin_ex(&parent->core.spin); 3212 chain = hammer2_combined_find(parent, base, count, 3213 &next_key, 3214 key, HAMMER2_KEY_MAX, 3215 &bref_ptr); 3216 generation = parent->core.generation; 3217 3218 /* 3219 * Exhausted parent chain, we're done. 3220 */ 3221 if (bref_ptr == NULL) { 3222 hammer2_spin_unex(&parent->core.spin); 3223 KKASSERT(chain == NULL); 3224 error |= HAMMER2_ERROR_EOF; 3225 goto done; 3226 } 3227 3228 /* 3229 * Copy into the supplied stack-based blockref. 3230 */ 3231 *bref = *bref_ptr; 3232 3233 /* 3234 * Selected from blockref or in-memory chain. 3235 */ 3236 if (chain == NULL) { 3237 switch(bref->type) { 3238 case HAMMER2_BREF_TYPE_INODE: 3239 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3240 case HAMMER2_BREF_TYPE_INDIRECT: 3241 case HAMMER2_BREF_TYPE_VOLUME: 3242 case HAMMER2_BREF_TYPE_FREEMAP: 3243 /* 3244 * Recursion, always get the chain 3245 */ 3246 hammer2_spin_unex(&parent->core.spin); 3247 chain = hammer2_chain_get(parent, generation, 3248 bref, how); 3249 if (chain == NULL) 3250 goto again; 3251 break; 3252 default: 3253 /* 3254 * No recursion, do not waste time instantiating 3255 * a chain, just iterate using the bref. 3256 */ 3257 hammer2_spin_unex(&parent->core.spin); 3258 break; 3259 } 3260 } else { 3261 /* 3262 * Recursion or not we need the chain in order to supply 3263 * the bref. 3264 */ 3265 hammer2_chain_ref(chain); 3266 hammer2_spin_unex(&parent->core.spin); 3267 hammer2_chain_lock(chain, how); 3268 } 3269 if (chain && 3270 (bcmp(bref, &chain->bref, sizeof(*bref)) || 3271 chain->parent != parent)) { 3272 hammer2_chain_unlock(chain); 3273 hammer2_chain_drop(chain); 3274 chain = NULL; 3275 goto again; 3276 } 3277 3278 /* 3279 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) 3280 * 3281 * NOTE: chain's key range is not relevant as there might be 3282 * one-offs within the range that are not deleted. 3283 * 3284 * NOTE: XXX this could create problems with scans used in 3285 * situations other than mount-time recovery. 3286 * 3287 * NOTE: Lookups can race delete-duplicate because 3288 * delete-duplicate does not lock the parent's core 3289 * (they just use the spinlock on the core). 3290 */ 3291 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 3292 hammer2_chain_unlock(chain); 3293 hammer2_chain_drop(chain); 3294 chain = NULL; 3295 3296 key = next_key; 3297 if (key == 0) { 3298 error |= HAMMER2_ERROR_EOF; 3299 goto done; 3300 } 3301 goto again; 3302 } 3303 3304 done: 3305 /* 3306 * All done, return the bref or NULL, supply chain if necessary. 3307 */ 3308 if (chain) 3309 *chainp = chain; 3310 return (error); 3311 } 3312 3313 /* 3314 * Create and return a new hammer2 system memory structure of the specified 3315 * key, type and size and insert it under (*parentp). This is a full 3316 * insertion, based on the supplied key/keybits, and may involve creating 3317 * indirect blocks and moving other chains around via delete/duplicate. 3318 * 3319 * This call can be made with parent == NULL as long as a non -1 methods 3320 * is supplied. hmp must also be supplied in this situation (otherwise 3321 * hmp is extracted from the supplied parent). The chain will be detached 3322 * from the topology. A later call with both parent and chain can be made 3323 * to attach it. 3324 * 3325 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (*parentp) TO THE INSERTION 3326 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING 3327 * FULL. This typically means that the caller is creating the chain after 3328 * doing a hammer2_chain_lookup(). 3329 * 3330 * (*parentp) must be exclusive locked and may be replaced on return 3331 * depending on how much work the function had to do. 3332 * 3333 * (*parentp) must not be errored or this function will assert. 3334 * 3335 * (*chainp) usually starts out NULL and returns the newly created chain, 3336 * but if the caller desires the caller may allocate a disconnected chain 3337 * and pass it in instead. 3338 * 3339 * This function should NOT be used to insert INDIRECT blocks. It is 3340 * typically used to create/insert inodes and data blocks. 3341 * 3342 * Caller must pass-in an exclusively locked parent the new chain is to 3343 * be inserted under, and optionally pass-in a disconnected, exclusively 3344 * locked chain to insert (else we create a new chain). The function will 3345 * adjust (*parentp) as necessary, create or connect the chain, and 3346 * return an exclusively locked chain in *chainp. 3347 * 3348 * When creating a PFSROOT inode under the super-root, pmp is typically NULL 3349 * and will be reassigned. 3350 * 3351 * NOTE: returns HAMMER_ERROR_* flags 3352 */ 3353 int 3354 hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp, 3355 hammer2_dev_t *hmp, hammer2_pfs_t *pmp, int methods, 3356 hammer2_key_t key, int keybits, int type, size_t bytes, 3357 hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags) 3358 { 3359 hammer2_chain_t *chain; 3360 hammer2_chain_t *parent; 3361 hammer2_blockref_t *base; 3362 hammer2_blockref_t dummy; 3363 int allocated = 0; 3364 int error = 0; 3365 int count; 3366 int maxloops = 300000; 3367 3368 /* 3369 * Topology may be crossing a PFS boundary. 3370 */ 3371 parent = *parentp; 3372 if (parent) { 3373 KKASSERT(hammer2_mtx_owned(&parent->lock)); 3374 KKASSERT(parent->error == 0); 3375 hmp = parent->hmp; 3376 } 3377 chain = *chainp; 3378 3379 if (chain == NULL) { 3380 /* 3381 * First allocate media space and construct the dummy bref, 3382 * then allocate the in-memory chain structure. Set the 3383 * INITIAL flag for fresh chains which do not have embedded 3384 * data. 3385 * 3386 * XXX for now set the check mode of the child based on 3387 * the parent or, if the parent is an inode, the 3388 * specification in the inode. 3389 */ 3390 bzero(&dummy, sizeof(dummy)); 3391 dummy.type = type; 3392 dummy.key = key; 3393 dummy.keybits = keybits; 3394 dummy.data_off = hammer2_getradix(bytes); 3395 3396 /* 3397 * Inherit methods from parent by default. Primarily used 3398 * for BREF_TYPE_DATA. Non-data types *must* be set to 3399 * a non-NONE check algorithm. 3400 */ 3401 if (methods == -1) 3402 dummy.methods = parent->bref.methods; 3403 else 3404 dummy.methods = (uint8_t)methods; 3405 3406 if (type != HAMMER2_BREF_TYPE_DATA && 3407 HAMMER2_DEC_CHECK(dummy.methods) == HAMMER2_CHECK_NONE) { 3408 dummy.methods |= 3409 HAMMER2_ENC_CHECK(HAMMER2_CHECK_DEFAULT); 3410 } 3411 3412 chain = hammer2_chain_alloc(hmp, pmp, &dummy); 3413 3414 /* 3415 * Lock the chain manually, chain_lock will load the chain 3416 * which we do NOT want to do. (note: chain->refs is set 3417 * to 1 by chain_alloc() for us, but lockcnt is not). 3418 */ 3419 chain->lockcnt = 1; 3420 hammer2_mtx_ex(&chain->lock); 3421 allocated = 1; 3422 3423 /* 3424 * Set INITIAL to optimize I/O. The flag will generally be 3425 * processed when we call hammer2_chain_modify(). 3426 * 3427 * Recalculate bytes to reflect the actual media block 3428 * allocation. Handle special case radix 0 == 0 bytes. 3429 */ 3430 bytes = (size_t)(chain->bref.data_off & HAMMER2_OFF_MASK_RADIX); 3431 if (bytes) 3432 bytes = (hammer2_off_t)1 << bytes; 3433 chain->bytes = bytes; 3434 3435 switch(type) { 3436 case HAMMER2_BREF_TYPE_VOLUME: 3437 case HAMMER2_BREF_TYPE_FREEMAP: 3438 panic("hammer2_chain_create: called with volume type"); 3439 break; 3440 case HAMMER2_BREF_TYPE_INDIRECT: 3441 panic("hammer2_chain_create: cannot be used to" 3442 "create indirect block"); 3443 break; 3444 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3445 panic("hammer2_chain_create: cannot be used to" 3446 "create freemap root or node"); 3447 break; 3448 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 3449 KKASSERT(bytes == sizeof(chain->data->bmdata)); 3450 /* fall through */ 3451 case HAMMER2_BREF_TYPE_DIRENT: 3452 case HAMMER2_BREF_TYPE_INODE: 3453 case HAMMER2_BREF_TYPE_DATA: 3454 default: 3455 /* 3456 * leave chain->data NULL, set INITIAL 3457 */ 3458 KKASSERT(chain->data == NULL); 3459 atomic_set_int(&chain->flags, HAMMER2_CHAIN_INITIAL); 3460 break; 3461 } 3462 } else { 3463 /* 3464 * We are reattaching a previously deleted chain, possibly 3465 * under a new parent and possibly with a new key/keybits. 3466 * The chain does not have to be in a modified state. The 3467 * UPDATE flag will be set later on in this routine. 3468 * 3469 * Do NOT mess with the current state of the INITIAL flag. 3470 */ 3471 chain->bref.key = key; 3472 chain->bref.keybits = keybits; 3473 if (chain->flags & HAMMER2_CHAIN_DELETED) 3474 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3475 KKASSERT(chain->parent == NULL); 3476 } 3477 3478 /* 3479 * Set the appropriate bref flag if requested. 3480 * 3481 * NOTE! Callers can call this function to move chains without 3482 * knowing about special flags, so don't clear bref flags 3483 * here! 3484 */ 3485 if (flags & HAMMER2_INSERT_PFSROOT) 3486 chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT; 3487 3488 if (parent == NULL) 3489 goto skip; 3490 3491 /* 3492 * Calculate how many entries we have in the blockref array and 3493 * determine if an indirect block is required when inserting into 3494 * the parent. 3495 */ 3496 again: 3497 if (--maxloops == 0) 3498 panic("hammer2_chain_create: maxloops"); 3499 3500 switch(parent->bref.type) { 3501 case HAMMER2_BREF_TYPE_INODE: 3502 if ((parent->data->ipdata.meta.op_flags & 3503 HAMMER2_OPFLAG_DIRECTDATA) != 0) { 3504 kprintf("hammer2: parent set for direct-data! " 3505 "pkey=%016jx ckey=%016jx\n", 3506 parent->bref.key, 3507 chain->bref.key); 3508 } 3509 KKASSERT((parent->data->ipdata.meta.op_flags & 3510 HAMMER2_OPFLAG_DIRECTDATA) == 0); 3511 KKASSERT(parent->data != NULL); 3512 base = &parent->data->ipdata.u.blockset.blockref[0]; 3513 count = HAMMER2_SET_COUNT; 3514 break; 3515 case HAMMER2_BREF_TYPE_INDIRECT: 3516 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3517 if (parent->flags & HAMMER2_CHAIN_INITIAL) 3518 base = NULL; 3519 else 3520 base = &parent->data->npdata[0]; 3521 count = parent->bytes / sizeof(hammer2_blockref_t); 3522 break; 3523 case HAMMER2_BREF_TYPE_VOLUME: 3524 KKASSERT(parent->data != NULL); 3525 base = &parent->data->voldata.sroot_blockset.blockref[0]; 3526 count = HAMMER2_SET_COUNT; 3527 break; 3528 case HAMMER2_BREF_TYPE_FREEMAP: 3529 KKASSERT(parent->data != NULL); 3530 base = &parent->data->blkset.blockref[0]; 3531 count = HAMMER2_SET_COUNT; 3532 break; 3533 default: 3534 panic("hammer2_chain_create: unrecognized blockref type: %d", 3535 parent->bref.type); 3536 base = NULL; 3537 count = 0; 3538 break; 3539 } 3540 3541 /* 3542 * Make sure we've counted the brefs 3543 */ 3544 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) 3545 hammer2_chain_countbrefs(parent, base, count); 3546 3547 KASSERT(parent->core.live_count >= 0 && 3548 parent->core.live_count <= count, 3549 ("bad live_count %d/%d (%02x, %d)", 3550 parent->core.live_count, count, 3551 parent->bref.type, parent->bytes)); 3552 3553 /* 3554 * If no free blockref could be found we must create an indirect 3555 * block and move a number of blockrefs into it. With the parent 3556 * locked we can safely lock each child in order to delete+duplicate 3557 * it without causing a deadlock. 3558 * 3559 * This may return the new indirect block or the old parent depending 3560 * on where the key falls. NULL is returned on error. 3561 */ 3562 if (parent->core.live_count == count) { 3563 hammer2_chain_t *nparent; 3564 3565 KKASSERT((flags & HAMMER2_INSERT_SAMEPARENT) == 0); 3566 3567 nparent = hammer2_chain_create_indirect(parent, key, keybits, 3568 mtid, type, &error); 3569 if (nparent == NULL) { 3570 if (allocated) 3571 hammer2_chain_drop(chain); 3572 chain = NULL; 3573 goto done; 3574 } 3575 if (parent != nparent) { 3576 hammer2_chain_unlock(parent); 3577 hammer2_chain_drop(parent); 3578 parent = *parentp = nparent; 3579 } 3580 goto again; 3581 } 3582 3583 /* 3584 * fall through if parent, or skip to here if no parent. 3585 */ 3586 skip: 3587 if (chain->flags & HAMMER2_CHAIN_DELETED) 3588 kprintf("Inserting deleted chain @%016jx\n", 3589 chain->bref.key); 3590 3591 /* 3592 * Link the chain into its parent. 3593 */ 3594 if (chain->parent != NULL) 3595 panic("hammer2: hammer2_chain_create: chain already connected"); 3596 KKASSERT(chain->parent == NULL); 3597 if (parent) { 3598 KKASSERT(parent->core.live_count < count); 3599 hammer2_chain_insert(parent, chain, 3600 HAMMER2_CHAIN_INSERT_SPIN | 3601 HAMMER2_CHAIN_INSERT_LIVE, 3602 0); 3603 } 3604 3605 if (allocated) { 3606 /* 3607 * Mark the newly created chain modified. This will cause 3608 * UPDATE to be set and process the INITIAL flag. 3609 * 3610 * Device buffers are not instantiated for DATA elements 3611 * as these are handled by logical buffers. 3612 * 3613 * Indirect and freemap node indirect blocks are handled 3614 * by hammer2_chain_create_indirect() and not by this 3615 * function. 3616 * 3617 * Data for all other bref types is expected to be 3618 * instantiated (INODE, LEAF). 3619 */ 3620 switch(chain->bref.type) { 3621 case HAMMER2_BREF_TYPE_DATA: 3622 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 3623 case HAMMER2_BREF_TYPE_DIRENT: 3624 case HAMMER2_BREF_TYPE_INODE: 3625 error = hammer2_chain_modify(chain, mtid, dedup_off, 3626 HAMMER2_MODIFY_OPTDATA); 3627 break; 3628 default: 3629 /* 3630 * Remaining types are not supported by this function. 3631 * In particular, INDIRECT and LEAF_NODE types are 3632 * handled by create_indirect(). 3633 */ 3634 panic("hammer2_chain_create: bad type: %d", 3635 chain->bref.type); 3636 /* NOT REACHED */ 3637 break; 3638 } 3639 } else { 3640 /* 3641 * When reconnecting a chain we must set UPDATE and 3642 * setflush so the flush recognizes that it must update 3643 * the bref in the parent. 3644 */ 3645 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) 3646 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 3647 } 3648 3649 /* 3650 * We must setflush(parent) to ensure that it recurses through to 3651 * chain. setflush(chain) might not work because ONFLUSH is possibly 3652 * already set in the chain (so it won't recurse up to set it in the 3653 * parent). 3654 */ 3655 if (parent) 3656 hammer2_chain_setflush(parent); 3657 3658 done: 3659 *chainp = chain; 3660 3661 return (error); 3662 } 3663 3664 /* 3665 * Move the chain from its old parent to a new parent. The chain must have 3666 * already been deleted or already disconnected (or never associated) with 3667 * a parent. The chain is reassociated with the new parent and the deleted 3668 * flag will be cleared (no longer deleted). The chain's modification state 3669 * is not altered. 3670 * 3671 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (parent) TO THE INSERTION 3672 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING 3673 * FULL. This typically means that the caller is creating the chain after 3674 * doing a hammer2_chain_lookup(). 3675 * 3676 * Neither (parent) or (chain) can be errored. 3677 * 3678 * If (parent) is non-NULL then the chain is inserted under the parent. 3679 * 3680 * If (parent) is NULL then the newly duplicated chain is not inserted 3681 * anywhere, similar to if it had just been chain_alloc()'d (suitable for 3682 * passing into hammer2_chain_create() after this function returns). 3683 * 3684 * WARNING! This function calls create which means it can insert indirect 3685 * blocks. This can cause other unrelated chains in the parent to 3686 * be moved to a newly inserted indirect block in addition to the 3687 * specific chain. 3688 */ 3689 void 3690 hammer2_chain_rename(hammer2_chain_t **parentp, hammer2_chain_t *chain, 3691 hammer2_tid_t mtid, int flags) 3692 { 3693 hammer2_blockref_t *bref; 3694 hammer2_dev_t *hmp; 3695 hammer2_chain_t *parent; 3696 size_t bytes; 3697 3698 /* 3699 * WARNING! We should never resolve DATA to device buffers 3700 * (XXX allow it if the caller did?), and since 3701 * we currently do not have the logical buffer cache 3702 * buffer in-hand to fix its cached physical offset 3703 * we also force the modify code to not COW it. XXX 3704 * 3705 * NOTE! We allow error'd chains to be renamed. The bref itself 3706 * is good and can be renamed. The content, however, may 3707 * be inaccessible. 3708 */ 3709 hmp = chain->hmp; 3710 KKASSERT(chain->parent == NULL); 3711 /*KKASSERT(chain->error == 0); allow */ 3712 3713 /* 3714 * Now create a duplicate of the chain structure, associating 3715 * it with the same core, making it the same size, pointing it 3716 * to the same bref (the same media block). 3717 * 3718 * NOTE: Handle special radix == 0 case (means 0 bytes). 3719 */ 3720 bref = &chain->bref; 3721 bytes = (size_t)(bref->data_off & HAMMER2_OFF_MASK_RADIX); 3722 if (bytes) 3723 bytes = (hammer2_off_t)1 << bytes; 3724 3725 /* 3726 * If parent is not NULL the duplicated chain will be entered under 3727 * the parent and the UPDATE bit set to tell flush to update 3728 * the blockref. 3729 * 3730 * We must setflush(parent) to ensure that it recurses through to 3731 * chain. setflush(chain) might not work because ONFLUSH is possibly 3732 * already set in the chain (so it won't recurse up to set it in the 3733 * parent). 3734 * 3735 * Having both chains locked is extremely important for atomicy. 3736 */ 3737 if (parentp && (parent = *parentp) != NULL) { 3738 KKASSERT(hammer2_mtx_owned(&parent->lock)); 3739 KKASSERT(parent->refs > 0); 3740 KKASSERT(parent->error == 0); 3741 3742 hammer2_chain_create(parentp, &chain, NULL, chain->pmp, 3743 HAMMER2_METH_DEFAULT, 3744 bref->key, bref->keybits, bref->type, 3745 chain->bytes, mtid, 0, flags); 3746 KKASSERT(chain->flags & HAMMER2_CHAIN_UPDATE); 3747 hammer2_chain_setflush(*parentp); 3748 } 3749 } 3750 3751 /* 3752 * This works in tandem with delete_obref() to install a blockref in 3753 * (typically) an indirect block that is associated with the chain being 3754 * moved to *parentp. 3755 * 3756 * The reason we need this function is that the caller needs to maintain 3757 * the blockref as it was, and not generate a new blockref for what might 3758 * be a modified chain. Otherwise stuff will leak into the flush that 3759 * the flush code's FLUSH_INODE_STOP flag is unable to catch. 3760 * 3761 * It is EXTREMELY important that we properly set CHAIN_BMAPUPD and 3762 * CHAIN_UPDATE. We must set BMAPUPD if the bref does not match, and 3763 * we must clear CHAIN_UPDATE (that was likely set by the chain_rename) if 3764 * it does. Otherwise we can end up in a situation where H2 is unable to 3765 * clean up the in-memory chain topology. 3766 * 3767 * The reason for this is that flushes do not generally flush through 3768 * BREF_TYPE_INODE chains and depend on a hammer2_inode_t queued to syncq 3769 * or sideq to properly flush and dispose of the related inode chain's flags. 3770 * Situations where the inode is not actually modified by the frontend, 3771 * but where we have to move the related chains around as we insert or cleanup 3772 * indirect blocks, can leave us with a 'dirty' (non-disposable) in-memory 3773 * inode chain that does not have a hammer2_inode_t associated with it. 3774 */ 3775 void 3776 hammer2_chain_rename_obref(hammer2_chain_t **parentp, hammer2_chain_t *chain, 3777 hammer2_tid_t mtid, int flags, 3778 hammer2_blockref_t *obref) 3779 { 3780 hammer2_chain_rename(parentp, chain, mtid, flags); 3781 3782 if (obref->type != HAMMER2_BREF_TYPE_EMPTY) { 3783 hammer2_blockref_t *tbase; 3784 int tcount; 3785 3786 KKASSERT((chain->flags & HAMMER2_CHAIN_BMAPPED) == 0); 3787 hammer2_chain_modify(*parentp, mtid, 0, 0); 3788 tbase = hammer2_chain_base_and_count(*parentp, &tcount); 3789 hammer2_base_insert(*parentp, tbase, tcount, chain, obref); 3790 if (bcmp(obref, &chain->bref, sizeof(chain->bref))) { 3791 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD | 3792 HAMMER2_CHAIN_UPDATE); 3793 } else { 3794 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 3795 } 3796 } 3797 } 3798 3799 /* 3800 * Helper function for deleting chains. 3801 * 3802 * The chain is removed from the live view (the RBTREE) as well as the parent's 3803 * blockmap. Both chain and its parent must be locked. 3804 * 3805 * parent may not be errored. chain can be errored. 3806 */ 3807 static int 3808 _hammer2_chain_delete_helper(hammer2_chain_t *parent, hammer2_chain_t *chain, 3809 hammer2_tid_t mtid, int flags, 3810 hammer2_blockref_t *obref) 3811 { 3812 hammer2_dev_t *hmp; 3813 int error = 0; 3814 3815 KKASSERT((chain->flags & (HAMMER2_CHAIN_DELETED | 3816 HAMMER2_CHAIN_FICTITIOUS)) == 0); 3817 KKASSERT(chain->parent == parent); 3818 hmp = chain->hmp; 3819 3820 if (chain->flags & HAMMER2_CHAIN_BMAPPED) { 3821 /* 3822 * Chain is blockmapped, so there must be a parent. 3823 * Atomically remove the chain from the parent and remove 3824 * the blockmap entry. The parent must be set modified 3825 * to remove the blockmap entry. 3826 */ 3827 hammer2_blockref_t *base; 3828 int count; 3829 3830 KKASSERT(parent != NULL); 3831 KKASSERT(parent->error == 0); 3832 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); 3833 error = hammer2_chain_modify(parent, mtid, 0, 0); 3834 if (error) 3835 goto done; 3836 3837 /* 3838 * Calculate blockmap pointer 3839 */ 3840 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); 3841 hammer2_spin_ex(&chain->core.spin); 3842 hammer2_spin_ex(&parent->core.spin); 3843 3844 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3845 atomic_add_int(&parent->core.live_count, -1); 3846 ++parent->core.generation; 3847 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); 3848 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 3849 --parent->core.chain_count; 3850 chain->parent = NULL; 3851 3852 switch(parent->bref.type) { 3853 case HAMMER2_BREF_TYPE_INODE: 3854 /* 3855 * Access the inode's block array. However, there 3856 * is no block array if the inode is flagged 3857 * DIRECTDATA. 3858 */ 3859 if (parent->data && 3860 (parent->data->ipdata.meta.op_flags & 3861 HAMMER2_OPFLAG_DIRECTDATA) == 0) { 3862 base = 3863 &parent->data->ipdata.u.blockset.blockref[0]; 3864 } else { 3865 base = NULL; 3866 } 3867 count = HAMMER2_SET_COUNT; 3868 break; 3869 case HAMMER2_BREF_TYPE_INDIRECT: 3870 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 3871 if (parent->data) 3872 base = &parent->data->npdata[0]; 3873 else 3874 base = NULL; 3875 count = parent->bytes / sizeof(hammer2_blockref_t); 3876 break; 3877 case HAMMER2_BREF_TYPE_VOLUME: 3878 base = &parent->data->voldata. 3879 sroot_blockset.blockref[0]; 3880 count = HAMMER2_SET_COUNT; 3881 break; 3882 case HAMMER2_BREF_TYPE_FREEMAP: 3883 base = &parent->data->blkset.blockref[0]; 3884 count = HAMMER2_SET_COUNT; 3885 break; 3886 default: 3887 base = NULL; 3888 count = 0; 3889 panic("_hammer2_chain_delete_helper: " 3890 "unrecognized blockref type: %d", 3891 parent->bref.type); 3892 } 3893 3894 /* 3895 * delete blockmapped chain from its parent. 3896 * 3897 * The parent is not affected by any statistics in chain 3898 * which are pending synchronization. That is, there is 3899 * nothing to undo in the parent since they have not yet 3900 * been incorporated into the parent. 3901 * 3902 * The parent is affected by statistics stored in inodes. 3903 * Those have already been synchronized, so they must be 3904 * undone. XXX split update possible w/delete in middle? 3905 */ 3906 if (base) { 3907 hammer2_base_delete(parent, base, count, chain, obref); 3908 } 3909 hammer2_spin_unex(&parent->core.spin); 3910 hammer2_spin_unex(&chain->core.spin); 3911 } else if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { 3912 /* 3913 * Chain is not blockmapped but a parent is present. 3914 * Atomically remove the chain from the parent. There is 3915 * no blockmap entry to remove. 3916 * 3917 * Because chain was associated with a parent but not 3918 * synchronized, the chain's *_count_up fields contain 3919 * inode adjustment statistics which must be undone. 3920 */ 3921 hammer2_spin_ex(&chain->core.spin); 3922 hammer2_spin_ex(&parent->core.spin); 3923 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3924 atomic_add_int(&parent->core.live_count, -1); 3925 ++parent->core.generation; 3926 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); 3927 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); 3928 --parent->core.chain_count; 3929 chain->parent = NULL; 3930 hammer2_spin_unex(&parent->core.spin); 3931 hammer2_spin_unex(&chain->core.spin); 3932 } else { 3933 /* 3934 * Chain is not blockmapped and has no parent. This 3935 * is a degenerate case. 3936 */ 3937 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); 3938 } 3939 done: 3940 return error; 3941 } 3942 3943 /* 3944 * Create an indirect block that covers one or more of the elements in the 3945 * current parent. Either returns the existing parent with no locking or 3946 * ref changes or returns the new indirect block locked and referenced 3947 * and leaving the original parent lock/ref intact as well. 3948 * 3949 * If an error occurs, NULL is returned and *errorp is set to the H2 error. 3950 * 3951 * The returned chain depends on where the specified key falls. 3952 * 3953 * The key/keybits for the indirect mode only needs to follow three rules: 3954 * 3955 * (1) That all elements underneath it fit within its key space and 3956 * 3957 * (2) That all elements outside it are outside its key space. 3958 * 3959 * (3) When creating the new indirect block any elements in the current 3960 * parent that fit within the new indirect block's keyspace must be 3961 * moved into the new indirect block. 3962 * 3963 * (4) The keyspace chosen for the inserted indirect block CAN cover a wider 3964 * keyspace the the current parent, but lookup/iteration rules will 3965 * ensure (and must ensure) that rule (2) for all parents leading up 3966 * to the nearest inode or the root volume header is adhered to. This 3967 * is accomplished by always recursing through matching keyspaces in 3968 * the hammer2_chain_lookup() and hammer2_chain_next() API. 3969 * 3970 * The current implementation calculates the current worst-case keyspace by 3971 * iterating the current parent and then divides it into two halves, choosing 3972 * whichever half has the most elements (not necessarily the half containing 3973 * the requested key). 3974 * 3975 * We can also opt to use the half with the least number of elements. This 3976 * causes lower-numbered keys (aka logical file offsets) to recurse through 3977 * fewer indirect blocks and higher-numbered keys to recurse through more. 3978 * This also has the risk of not moving enough elements to the new indirect 3979 * block and being forced to create several indirect blocks before the element 3980 * can be inserted. 3981 * 3982 * Must be called with an exclusively locked parent. 3983 * 3984 * NOTE: *errorp set to HAMMER_ERROR_* flags 3985 */ 3986 static int hammer2_chain_indkey_freemap(hammer2_chain_t *parent, 3987 hammer2_key_t *keyp, int keybits, 3988 hammer2_blockref_t *base, int count); 3989 static int hammer2_chain_indkey_file(hammer2_chain_t *parent, 3990 hammer2_key_t *keyp, int keybits, 3991 hammer2_blockref_t *base, int count, 3992 int ncount); 3993 static int hammer2_chain_indkey_dir(hammer2_chain_t *parent, 3994 hammer2_key_t *keyp, int keybits, 3995 hammer2_blockref_t *base, int count, 3996 int ncount); 3997 static 3998 hammer2_chain_t * 3999 hammer2_chain_create_indirect(hammer2_chain_t *parent, 4000 hammer2_key_t create_key, int create_bits, 4001 hammer2_tid_t mtid, int for_type, int *errorp) 4002 { 4003 hammer2_dev_t *hmp; 4004 hammer2_blockref_t *base; 4005 hammer2_blockref_t *bref; 4006 hammer2_blockref_t bsave; 4007 hammer2_blockref_t dummy; 4008 hammer2_chain_t *chain; 4009 hammer2_chain_t *ichain; 4010 hammer2_key_t key = create_key; 4011 hammer2_key_t key_beg; 4012 hammer2_key_t key_end; 4013 hammer2_key_t key_next; 4014 int keybits = create_bits; 4015 int count; 4016 int ncount; 4017 int nbytes; 4018 int loops; 4019 int error; 4020 int reason; 4021 int generation; 4022 int maxloops = 300000; 4023 4024 /* 4025 * Calculate the base blockref pointer or NULL if the chain 4026 * is known to be empty. We need to calculate the array count 4027 * for RB lookups either way. 4028 */ 4029 hmp = parent->hmp; 4030 KKASSERT(hammer2_mtx_owned(&parent->lock)); 4031 4032 /* 4033 * Pre-modify the parent now to avoid having to deal with error 4034 * processing if we tried to later (in the middle of our loop). 4035 * 4036 * We are going to be moving bref's around, the indirect blocks 4037 * cannot be in an initial state. Do not pass MODIFY_OPTDATA. 4038 */ 4039 *errorp = hammer2_chain_modify(parent, mtid, 0, 0); 4040 if (*errorp) { 4041 kprintf("hammer2_create_indirect: error %08x %s\n", 4042 *errorp, hammer2_error_str(*errorp)); 4043 return NULL; 4044 } 4045 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); 4046 4047 /*hammer2_chain_modify(&parent, HAMMER2_MODIFY_OPTDATA);*/ 4048 base = hammer2_chain_base_and_count(parent, &count); 4049 4050 /* 4051 * How big should our new indirect block be? It has to be at least 4052 * as large as its parent for splits to work properly. 4053 * 4054 * The freemap uses a specific indirect block size. The number of 4055 * levels are built dynamically and ultimately depend on the size 4056 * volume. Because freemap blocks are taken from the reserved areas 4057 * of the volume our goal is efficiency (fewer levels) and not so 4058 * much to save disk space. 4059 * 4060 * The first indirect block level for a directory usually uses 4061 * HAMMER2_IND_BYTES_MIN (4KB = 32 directory entries). Due to 4062 * the hash mechanism, this typically gives us a nominal 4063 * 32 * 4 entries with one level of indirection. 4064 * 4065 * We use HAMMER2_IND_BYTES_NOM (16KB = 128 blockrefs) for FILE 4066 * indirect blocks. The initial 4 entries in the inode gives us 4067 * 256KB. Up to 4 indirect blocks gives us 32MB. Three levels 4068 * of indirection gives us 137GB, and so forth. H2 can support 4069 * huge file sizes but they are not typical, so we try to stick 4070 * with compactness and do not use a larger indirect block size. 4071 * 4072 * We could use 64KB (PBUFSIZE), giving us 512 blockrefs, but 4073 * due to the way indirect blocks are created this usually winds 4074 * up being extremely inefficient for small files. Even though 4075 * 16KB requires more levels of indirection for very large files, 4076 * the 16KB records can be ganged together into 64KB DIOs. 4077 */ 4078 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 4079 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 4080 nbytes = HAMMER2_FREEMAP_LEVELN_PSIZE; 4081 } else if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { 4082 if (parent->data->ipdata.meta.type == 4083 HAMMER2_OBJTYPE_DIRECTORY) 4084 nbytes = HAMMER2_IND_BYTES_MIN; /* 4KB = 32 entries */ 4085 else 4086 nbytes = HAMMER2_IND_BYTES_NOM; /* 16KB = ~8MB file */ 4087 4088 } else { 4089 nbytes = HAMMER2_IND_BYTES_NOM; 4090 } 4091 if (nbytes < count * sizeof(hammer2_blockref_t)) { 4092 KKASSERT(for_type != HAMMER2_BREF_TYPE_FREEMAP_NODE && 4093 for_type != HAMMER2_BREF_TYPE_FREEMAP_LEAF); 4094 nbytes = count * sizeof(hammer2_blockref_t); 4095 } 4096 ncount = nbytes / sizeof(hammer2_blockref_t); 4097 4098 /* 4099 * When creating an indirect block for a freemap node or leaf 4100 * the key/keybits must be fitted to static radix levels because 4101 * particular radix levels use particular reserved blocks in the 4102 * related zone. 4103 * 4104 * This routine calculates the key/radix of the indirect block 4105 * we need to create, and whether it is on the high-side or the 4106 * low-side. 4107 */ 4108 switch(for_type) { 4109 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 4110 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 4111 keybits = hammer2_chain_indkey_freemap(parent, &key, keybits, 4112 base, count); 4113 break; 4114 case HAMMER2_BREF_TYPE_DATA: 4115 keybits = hammer2_chain_indkey_file(parent, &key, keybits, 4116 base, count, ncount); 4117 break; 4118 case HAMMER2_BREF_TYPE_DIRENT: 4119 case HAMMER2_BREF_TYPE_INODE: 4120 keybits = hammer2_chain_indkey_dir(parent, &key, keybits, 4121 base, count, ncount); 4122 break; 4123 default: 4124 panic("illegal indirect block for bref type %d", for_type); 4125 break; 4126 } 4127 4128 /* 4129 * Normalize the key for the radix being represented, keeping the 4130 * high bits and throwing away the low bits. 4131 */ 4132 key &= ~(((hammer2_key_t)1 << keybits) - 1); 4133 4134 /* 4135 * Ok, create our new indirect block 4136 */ 4137 bzero(&dummy, sizeof(dummy)); 4138 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || 4139 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { 4140 dummy.type = HAMMER2_BREF_TYPE_FREEMAP_NODE; 4141 } else { 4142 dummy.type = HAMMER2_BREF_TYPE_INDIRECT; 4143 } 4144 dummy.key = key; 4145 dummy.keybits = keybits; 4146 dummy.data_off = hammer2_getradix(nbytes); 4147 dummy.methods = 4148 HAMMER2_ENC_CHECK(HAMMER2_DEC_CHECK(parent->bref.methods)) | 4149 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE); 4150 4151 ichain = hammer2_chain_alloc(hmp, parent->pmp, &dummy); 4152 atomic_set_int(&ichain->flags, HAMMER2_CHAIN_INITIAL); 4153 hammer2_chain_lock(ichain, HAMMER2_RESOLVE_MAYBE); 4154 /* ichain has one ref at this point */ 4155 4156 /* 4157 * We have to mark it modified to allocate its block, but use 4158 * OPTDATA to allow it to remain in the INITIAL state. Otherwise 4159 * it won't be acted upon by the flush code. 4160 * 4161 * XXX remove OPTDATA, we need a fully initialized indirect block to 4162 * be able to move the original blockref. 4163 */ 4164 *errorp = hammer2_chain_modify(ichain, mtid, 0, 0); 4165 if (*errorp) { 4166 kprintf("hammer2_alloc_indirect: error %08x %s\n", 4167 *errorp, hammer2_error_str(*errorp)); 4168 hammer2_chain_unlock(ichain); 4169 hammer2_chain_drop(ichain); 4170 return NULL; 4171 } 4172 KKASSERT((ichain->flags & HAMMER2_CHAIN_INITIAL) == 0); 4173 4174 /* 4175 * Iterate the original parent and move the matching brefs into 4176 * the new indirect block. 4177 * 4178 * XXX handle flushes. 4179 */ 4180 key_beg = 0; 4181 key_end = HAMMER2_KEY_MAX; 4182 key_next = 0; /* avoid gcc warnings */ 4183 hammer2_spin_ex(&parent->core.spin); 4184 loops = 0; 4185 reason = 0; 4186 4187 for (;;) { 4188 /* 4189 * Parent may have been modified, relocating its block array. 4190 * Reload the base pointer. 4191 */ 4192 base = hammer2_chain_base_and_count(parent, &count); 4193 4194 if (++loops > 100000) { 4195 hammer2_spin_unex(&parent->core.spin); 4196 panic("excessive loops r=%d p=%p base/count %p:%d %016jx\n", 4197 reason, parent, base, count, key_next); 4198 } 4199 4200 /* 4201 * NOTE: spinlock stays intact, returned chain (if not NULL) 4202 * is not referenced or locked which means that we 4203 * cannot safely check its flagged / deletion status 4204 * until we lock it. 4205 */ 4206 chain = hammer2_combined_find(parent, base, count, 4207 &key_next, 4208 key_beg, key_end, 4209 &bref); 4210 generation = parent->core.generation; 4211 if (bref == NULL) 4212 break; 4213 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4214 4215 /* 4216 * Skip keys that are not within the key/radix of the new 4217 * indirect block. They stay in the parent. 4218 */ 4219 if (rounddown2(key ^ bref->key, (hammer2_key_t)1 << keybits) != 0) { 4220 goto next_key_spinlocked; 4221 } 4222 4223 /* 4224 * Load the new indirect block by acquiring the related 4225 * chains (potentially from media as it might not be 4226 * in-memory). Then move it to the new parent (ichain). 4227 * 4228 * chain is referenced but not locked. We must lock the 4229 * chain to obtain definitive state. 4230 */ 4231 bsave = *bref; 4232 if (chain) { 4233 /* 4234 * Use chain already present in the RBTREE 4235 */ 4236 hammer2_chain_ref(chain); 4237 hammer2_spin_unex(&parent->core.spin); 4238 hammer2_chain_lock(chain, HAMMER2_RESOLVE_NEVER); 4239 } else { 4240 /* 4241 * Get chain for blockref element. _get returns NULL 4242 * on insertion race. 4243 */ 4244 hammer2_spin_unex(&parent->core.spin); 4245 chain = hammer2_chain_get(parent, generation, &bsave, 4246 HAMMER2_RESOLVE_NEVER); 4247 if (chain == NULL) { 4248 reason = 1; 4249 hammer2_spin_ex(&parent->core.spin); 4250 continue; 4251 } 4252 } 4253 4254 /* 4255 * This is always live so if the chain has been deleted 4256 * we raced someone and we have to retry. 4257 * 4258 * NOTE: Lookups can race delete-duplicate because 4259 * delete-duplicate does not lock the parent's core 4260 * (they just use the spinlock on the core). 4261 * 4262 * (note reversed logic for this one) 4263 */ 4264 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || 4265 chain->parent != parent || 4266 (chain->flags & HAMMER2_CHAIN_DELETED)) { 4267 hammer2_chain_unlock(chain); 4268 hammer2_chain_drop(chain); 4269 if (hammer2_debug & 0x0040) { 4270 kprintf("LOST PARENT RETRY " 4271 "RETRY (%p,%p)->%p %08x\n", 4272 parent, chain->parent, chain, chain->flags); 4273 } 4274 hammer2_spin_ex(&parent->core.spin); 4275 continue; 4276 } 4277 4278 /* 4279 * Shift the chain to the indirect block. 4280 * 4281 * WARNING! No reason for us to load chain data, pass NOSTATS 4282 * to prevent delete/insert from trying to access 4283 * inode stats (and thus asserting if there is no 4284 * chain->data loaded). 4285 * 4286 * WARNING! The (parent, chain) deletion may modify the parent 4287 * and invalidate the base pointer. 4288 * 4289 * WARNING! Parent must already be marked modified, so we 4290 * can assume that chain_delete always suceeds. 4291 * 4292 * WARNING! hammer2_chain_repchange() does not have to be 4293 * called (and doesn't work anyway because we are 4294 * only doing a partial shift). A recursion that is 4295 * in-progress can continue at the current parent 4296 * and will be able to properly find its next key. 4297 */ 4298 error = hammer2_chain_delete_obref(parent, chain, mtid, 0, 4299 &bsave); 4300 KKASSERT(error == 0); 4301 hammer2_chain_rename_obref(&ichain, chain, mtid, 0, &bsave); 4302 hammer2_chain_unlock(chain); 4303 hammer2_chain_drop(chain); 4304 KKASSERT(parent->refs > 0); 4305 chain = NULL; 4306 base = NULL; /* safety */ 4307 hammer2_spin_ex(&parent->core.spin); 4308 next_key_spinlocked: 4309 if (--maxloops == 0) 4310 panic("hammer2_chain_create_indirect: maxloops"); 4311 reason = 4; 4312 if (key_next == 0 || key_next > key_end) 4313 break; 4314 key_beg = key_next; 4315 /* loop */ 4316 } 4317 hammer2_spin_unex(&parent->core.spin); 4318 4319 /* 4320 * Insert the new indirect block into the parent now that we've 4321 * cleared out some entries in the parent. We calculated a good 4322 * insertion index in the loop above (ichain->index). 4323 * 4324 * We don't have to set UPDATE here because we mark ichain 4325 * modified down below (so the normal modified -> flush -> set-moved 4326 * sequence applies). 4327 * 4328 * The insertion shouldn't race as this is a completely new block 4329 * and the parent is locked. 4330 */ 4331 base = NULL; /* safety, parent modify may change address */ 4332 KKASSERT((ichain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); 4333 KKASSERT(parent->core.live_count < count); 4334 hammer2_chain_insert(parent, ichain, 4335 HAMMER2_CHAIN_INSERT_SPIN | 4336 HAMMER2_CHAIN_INSERT_LIVE, 4337 0); 4338 4339 /* 4340 * Make sure flushes propogate after our manual insertion. 4341 */ 4342 hammer2_chain_setflush(ichain); 4343 hammer2_chain_setflush(parent); 4344 4345 /* 4346 * Figure out what to return. 4347 */ 4348 if (rounddown2(create_key ^ key, (hammer2_key_t)1 << keybits)) { 4349 /* 4350 * Key being created is outside the key range, 4351 * return the original parent. 4352 */ 4353 hammer2_chain_unlock(ichain); 4354 hammer2_chain_drop(ichain); 4355 } else { 4356 /* 4357 * Otherwise its in the range, return the new parent. 4358 * (leave both the new and old parent locked). 4359 */ 4360 parent = ichain; 4361 } 4362 4363 return(parent); 4364 } 4365 4366 /* 4367 * Do maintenance on an indirect chain. Both parent and chain are locked. 4368 * 4369 * Returns non-zero if (chain) is deleted, either due to being empty or 4370 * because its children were safely moved into the parent. 4371 */ 4372 int 4373 hammer2_chain_indirect_maintenance(hammer2_chain_t *parent, 4374 hammer2_chain_t *chain) 4375 { 4376 hammer2_blockref_t *chain_base; 4377 hammer2_blockref_t *base; 4378 hammer2_blockref_t *bref; 4379 hammer2_blockref_t bsave; 4380 hammer2_key_t key_next; 4381 hammer2_key_t key_beg; 4382 hammer2_key_t key_end; 4383 hammer2_chain_t *sub; 4384 int chain_count; 4385 int count; 4386 int error; 4387 int generation; 4388 4389 /* 4390 * Make sure we have an accurate live_count 4391 */ 4392 if ((chain->flags & (HAMMER2_CHAIN_INITIAL | 4393 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { 4394 base = &chain->data->npdata[0]; 4395 count = chain->bytes / sizeof(hammer2_blockref_t); 4396 hammer2_chain_countbrefs(chain, base, count); 4397 } 4398 4399 /* 4400 * If the indirect block is empty we can delete it. 4401 * (ignore deletion error) 4402 */ 4403 if (chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)) { 4404 hammer2_chain_delete(parent, chain, 4405 chain->bref.modify_tid, 4406 HAMMER2_DELETE_PERMANENT); 4407 hammer2_chain_repchange(parent, chain); 4408 return 1; 4409 } 4410 4411 base = hammer2_chain_base_and_count(parent, &count); 4412 4413 if ((parent->flags & (HAMMER2_CHAIN_INITIAL | 4414 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { 4415 hammer2_chain_countbrefs(parent, base, count); 4416 } 4417 4418 /* 4419 * Determine if we can collapse chain into parent, calculate 4420 * hysteresis for chain emptiness. 4421 */ 4422 if (parent->core.live_count + chain->core.live_count - 1 > count) 4423 return 0; 4424 chain_count = chain->bytes / sizeof(hammer2_blockref_t); 4425 if (chain->core.live_count > chain_count * 3 / 4) 4426 return 0; 4427 4428 /* 4429 * Ok, theoretically we can collapse chain's contents into 4430 * parent. chain is locked, but any in-memory children of chain 4431 * are not. For this to work, we must be able to dispose of any 4432 * in-memory children of chain. 4433 * 4434 * For now require that there are no in-memory children of chain. 4435 * 4436 * WARNING! Both chain and parent must remain locked across this 4437 * entire operation. 4438 */ 4439 4440 /* 4441 * Parent must be marked modified. Don't try to collapse it if we 4442 * can't mark it modified. Once modified, destroy chain to make room 4443 * and to get rid of what will be a conflicting key (this is included 4444 * in the calculation above). Finally, move the children of chain 4445 * into chain's parent. 4446 * 4447 * This order creates an accounting problem for bref.embed.stats 4448 * because we destroy chain before we remove its children. Any 4449 * elements whos blockref is already synchronized will be counted 4450 * twice. To deal with the problem we clean out chain's stats prior 4451 * to deleting it. 4452 */ 4453 error = hammer2_chain_modify(parent, 0, 0, 0); 4454 if (error) { 4455 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", 4456 hammer2_error_str(error)); 4457 return 0; 4458 } 4459 error = hammer2_chain_modify(chain, chain->bref.modify_tid, 0, 0); 4460 if (error) { 4461 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", 4462 hammer2_error_str(error)); 4463 return 0; 4464 } 4465 4466 chain->bref.embed.stats.inode_count = 0; 4467 chain->bref.embed.stats.data_count = 0; 4468 error = hammer2_chain_delete(parent, chain, 4469 chain->bref.modify_tid, 4470 HAMMER2_DELETE_PERMANENT); 4471 KKASSERT(error == 0); 4472 4473 /* 4474 * The combined_find call requires core.spin to be held. One would 4475 * think there wouldn't be any conflicts since we hold chain 4476 * exclusively locked, but the caching mechanism for 0-ref children 4477 * does not require a chain lock. 4478 */ 4479 hammer2_spin_ex(&chain->core.spin); 4480 4481 key_next = 0; 4482 key_beg = 0; 4483 key_end = HAMMER2_KEY_MAX; 4484 for (;;) { 4485 chain_base = &chain->data->npdata[0]; 4486 chain_count = chain->bytes / sizeof(hammer2_blockref_t); 4487 sub = hammer2_combined_find(chain, chain_base, chain_count, 4488 &key_next, 4489 key_beg, key_end, 4490 &bref); 4491 generation = chain->core.generation; 4492 if (bref == NULL) 4493 break; 4494 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4495 4496 bsave = *bref; 4497 if (sub) { 4498 hammer2_chain_ref(sub); 4499 hammer2_spin_unex(&chain->core.spin); 4500 hammer2_chain_lock(sub, HAMMER2_RESOLVE_NEVER); 4501 } else { 4502 hammer2_spin_unex(&chain->core.spin); 4503 sub = hammer2_chain_get(chain, generation, &bsave, 4504 HAMMER2_RESOLVE_NEVER); 4505 if (sub == NULL) { 4506 hammer2_spin_ex(&chain->core.spin); 4507 continue; 4508 } 4509 } 4510 if (bcmp(&bsave, &sub->bref, sizeof(bsave)) || 4511 sub->parent != chain || 4512 (sub->flags & HAMMER2_CHAIN_DELETED)) { 4513 hammer2_chain_unlock(sub); 4514 hammer2_chain_drop(sub); 4515 hammer2_spin_ex(&chain->core.spin); 4516 sub = NULL; /* safety */ 4517 continue; 4518 } 4519 error = hammer2_chain_delete_obref(chain, sub, 4520 sub->bref.modify_tid, 0, 4521 &bsave); 4522 KKASSERT(error == 0); 4523 hammer2_chain_rename_obref(&parent, sub, 4524 sub->bref.modify_tid, 4525 HAMMER2_INSERT_SAMEPARENT, &bsave); 4526 hammer2_chain_unlock(sub); 4527 hammer2_chain_drop(sub); 4528 hammer2_spin_ex(&chain->core.spin); 4529 4530 if (key_next == 0) 4531 break; 4532 key_beg = key_next; 4533 } 4534 hammer2_spin_unex(&chain->core.spin); 4535 4536 hammer2_chain_repchange(parent, chain); 4537 4538 return 1; 4539 } 4540 4541 /* 4542 * Freemap indirect blocks 4543 * 4544 * Calculate the keybits and highside/lowside of the freemap node the 4545 * caller is creating. 4546 * 4547 * This routine will specify the next higher-level freemap key/radix 4548 * representing the lowest-ordered set. By doing so, eventually all 4549 * low-ordered sets will be moved one level down. 4550 * 4551 * We have to be careful here because the freemap reserves a limited 4552 * number of blocks for a limited number of levels. So we can't just 4553 * push indiscriminately. 4554 */ 4555 int 4556 hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp, 4557 int keybits, hammer2_blockref_t *base, int count) 4558 { 4559 hammer2_chain_t *chain; 4560 hammer2_blockref_t *bref; 4561 hammer2_key_t key; 4562 hammer2_key_t key_beg; 4563 hammer2_key_t key_end; 4564 hammer2_key_t key_next; 4565 int locount; 4566 int hicount; 4567 int maxloops = 300000; 4568 4569 key = *keyp; 4570 locount = 0; 4571 hicount = 0; 4572 keybits = 64; 4573 4574 /* 4575 * Calculate the range of keys in the array being careful to skip 4576 * slots which are overridden with a deletion. 4577 */ 4578 key_beg = 0; 4579 key_end = HAMMER2_KEY_MAX; 4580 hammer2_spin_ex(&parent->core.spin); 4581 4582 for (;;) { 4583 if (--maxloops == 0) { 4584 panic("indkey_freemap shit %p %p:%d\n", 4585 parent, base, count); 4586 } 4587 chain = hammer2_combined_find(parent, base, count, 4588 &key_next, 4589 key_beg, key_end, 4590 &bref); 4591 4592 /* 4593 * Exhausted search 4594 */ 4595 if (bref == NULL) 4596 break; 4597 4598 /* 4599 * Skip deleted chains. 4600 */ 4601 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4602 if (key_next == 0 || key_next > key_end) 4603 break; 4604 key_beg = key_next; 4605 continue; 4606 } 4607 4608 /* 4609 * Use the full live (not deleted) element for the scan 4610 * iteration. HAMMER2 does not allow partial replacements. 4611 * 4612 * XXX should be built into hammer2_combined_find(). 4613 */ 4614 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4615 4616 if (keybits > bref->keybits) { 4617 key = bref->key; 4618 keybits = bref->keybits; 4619 } else if (keybits == bref->keybits && bref->key < key) { 4620 key = bref->key; 4621 } 4622 if (key_next == 0) 4623 break; 4624 key_beg = key_next; 4625 } 4626 hammer2_spin_unex(&parent->core.spin); 4627 4628 /* 4629 * Return the keybits for a higher-level FREEMAP_NODE covering 4630 * this node. 4631 */ 4632 switch(keybits) { 4633 case HAMMER2_FREEMAP_LEVEL0_RADIX: 4634 keybits = HAMMER2_FREEMAP_LEVEL1_RADIX; 4635 break; 4636 case HAMMER2_FREEMAP_LEVEL1_RADIX: 4637 keybits = HAMMER2_FREEMAP_LEVEL2_RADIX; 4638 break; 4639 case HAMMER2_FREEMAP_LEVEL2_RADIX: 4640 keybits = HAMMER2_FREEMAP_LEVEL3_RADIX; 4641 break; 4642 case HAMMER2_FREEMAP_LEVEL3_RADIX: 4643 keybits = HAMMER2_FREEMAP_LEVEL4_RADIX; 4644 break; 4645 case HAMMER2_FREEMAP_LEVEL4_RADIX: 4646 keybits = HAMMER2_FREEMAP_LEVEL5_RADIX; 4647 break; 4648 case HAMMER2_FREEMAP_LEVEL5_RADIX: 4649 panic("hammer2_chain_indkey_freemap: level too high"); 4650 break; 4651 default: 4652 panic("hammer2_chain_indkey_freemap: bad radix"); 4653 break; 4654 } 4655 *keyp = key; 4656 4657 return (keybits); 4658 } 4659 4660 /* 4661 * File indirect blocks 4662 * 4663 * Calculate the key/keybits for the indirect block to create by scanning 4664 * existing keys. The key being created is also passed in *keyp and can be 4665 * inside or outside the indirect block. Regardless, the indirect block 4666 * must hold at least two keys in order to guarantee sufficient space. 4667 * 4668 * We use a modified version of the freemap's fixed radix tree, but taylored 4669 * for file data. Basically we configure an indirect block encompassing the 4670 * smallest key. 4671 */ 4672 static int 4673 hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp, 4674 int keybits, hammer2_blockref_t *base, int count, 4675 int ncount) 4676 { 4677 hammer2_chain_t *chain; 4678 hammer2_blockref_t *bref; 4679 hammer2_key_t key; 4680 hammer2_key_t key_beg; 4681 hammer2_key_t key_end; 4682 hammer2_key_t key_next; 4683 int nradix; 4684 int locount; 4685 int hicount; 4686 int maxloops = 300000; 4687 4688 key = *keyp; 4689 locount = 0; 4690 hicount = 0; 4691 keybits = 64; 4692 4693 /* 4694 * Calculate the range of keys in the array being careful to skip 4695 * slots which are overridden with a deletion. 4696 * 4697 * Locate the smallest key. 4698 */ 4699 key_beg = 0; 4700 key_end = HAMMER2_KEY_MAX; 4701 hammer2_spin_ex(&parent->core.spin); 4702 4703 for (;;) { 4704 if (--maxloops == 0) { 4705 panic("indkey_freemap shit %p %p:%d\n", 4706 parent, base, count); 4707 } 4708 chain = hammer2_combined_find(parent, base, count, 4709 &key_next, 4710 key_beg, key_end, 4711 &bref); 4712 4713 /* 4714 * Exhausted search 4715 */ 4716 if (bref == NULL) 4717 break; 4718 4719 /* 4720 * Skip deleted chains. 4721 */ 4722 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4723 if (key_next == 0 || key_next > key_end) 4724 break; 4725 key_beg = key_next; 4726 continue; 4727 } 4728 4729 /* 4730 * Use the full live (not deleted) element for the scan 4731 * iteration. HAMMER2 does not allow partial replacements. 4732 * 4733 * XXX should be built into hammer2_combined_find(). 4734 */ 4735 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4736 4737 if (keybits > bref->keybits) { 4738 key = bref->key; 4739 keybits = bref->keybits; 4740 } else if (keybits == bref->keybits && bref->key < key) { 4741 key = bref->key; 4742 } 4743 if (key_next == 0) 4744 break; 4745 key_beg = key_next; 4746 } 4747 hammer2_spin_unex(&parent->core.spin); 4748 4749 /* 4750 * Calculate the static keybits for a higher-level indirect block 4751 * that contains the key. 4752 */ 4753 *keyp = key; 4754 4755 switch(ncount) { 4756 case HAMMER2_IND_BYTES_MIN / sizeof(hammer2_blockref_t): 4757 nradix = HAMMER2_IND_RADIX_MIN - HAMMER2_BLOCKREF_RADIX; 4758 break; 4759 case HAMMER2_IND_BYTES_NOM / sizeof(hammer2_blockref_t): 4760 nradix = HAMMER2_IND_RADIX_NOM - HAMMER2_BLOCKREF_RADIX; 4761 break; 4762 case HAMMER2_IND_BYTES_MAX / sizeof(hammer2_blockref_t): 4763 nradix = HAMMER2_IND_RADIX_MAX - HAMMER2_BLOCKREF_RADIX; 4764 break; 4765 default: 4766 panic("bad ncount %d\n", ncount); 4767 nradix = 0; 4768 break; 4769 } 4770 4771 /* 4772 * The largest radix that can be returned for an indirect block is 4773 * 63 bits. (The largest practical indirect block radix is actually 4774 * 62 bits because the top-level inode or volume root contains four 4775 * entries, but allow 63 to be returned). 4776 */ 4777 if (nradix >= 64) 4778 nradix = 63; 4779 4780 return keybits + nradix; 4781 } 4782 4783 #if 1 4784 4785 /* 4786 * Directory indirect blocks. 4787 * 4788 * Covers both the inode index (directory of inodes), and directory contents 4789 * (filenames hardlinked to inodes). 4790 * 4791 * Because directory keys are hashed we generally try to cut the space in 4792 * half. We accomodate the inode index (which tends to have linearly 4793 * increasing inode numbers) by ensuring that the keyspace is at least large 4794 * enough to fill up the indirect block being created. 4795 */ 4796 static int 4797 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, 4798 int keybits, hammer2_blockref_t *base, int count, 4799 int ncount) 4800 { 4801 hammer2_blockref_t *bref; 4802 hammer2_chain_t *chain; 4803 hammer2_key_t key_beg; 4804 hammer2_key_t key_end; 4805 hammer2_key_t key_next; 4806 hammer2_key_t key; 4807 int nkeybits; 4808 int locount; 4809 int hicount; 4810 int maxloops = 300000; 4811 4812 /* 4813 * NOTE: We can't take a shortcut here anymore for inodes because 4814 * the root directory can contain a mix of inodes and directory 4815 * entries (we used to just return 63 if parent->bref.type was 4816 * HAMMER2_BREF_TYPE_INODE. 4817 */ 4818 key = *keyp; 4819 locount = 0; 4820 hicount = 0; 4821 4822 /* 4823 * Calculate the range of keys in the array being careful to skip 4824 * slots which are overridden with a deletion. 4825 */ 4826 key_beg = 0; 4827 key_end = HAMMER2_KEY_MAX; 4828 hammer2_spin_ex(&parent->core.spin); 4829 4830 for (;;) { 4831 if (--maxloops == 0) { 4832 panic("indkey_freemap shit %p %p:%d\n", 4833 parent, base, count); 4834 } 4835 chain = hammer2_combined_find(parent, base, count, 4836 &key_next, 4837 key_beg, key_end, 4838 &bref); 4839 4840 /* 4841 * Exhausted search 4842 */ 4843 if (bref == NULL) 4844 break; 4845 4846 /* 4847 * Deleted object 4848 */ 4849 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 4850 if (key_next == 0 || key_next > key_end) 4851 break; 4852 key_beg = key_next; 4853 continue; 4854 } 4855 4856 /* 4857 * Use the full live (not deleted) element for the scan 4858 * iteration. HAMMER2 does not allow partial replacements. 4859 * 4860 * XXX should be built into hammer2_combined_find(). 4861 */ 4862 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 4863 4864 /* 4865 * Expand our calculated key range (key, keybits) to fit 4866 * the scanned key. nkeybits represents the full range 4867 * that we will later cut in half (two halves @ nkeybits - 1). 4868 */ 4869 nkeybits = keybits; 4870 if (nkeybits < bref->keybits) { 4871 if (bref->keybits > 64) { 4872 kprintf("bad bref chain %p bref %p\n", 4873 chain, bref); 4874 Debugger("fubar"); 4875 } 4876 nkeybits = bref->keybits; 4877 } 4878 while (nkeybits < 64 && 4879 rounddown2(key ^ bref->key, (hammer2_key_t)1 << nkeybits) != 0) { 4880 ++nkeybits; 4881 } 4882 4883 /* 4884 * If the new key range is larger we have to determine 4885 * which side of the new key range the existing keys fall 4886 * under by checking the high bit, then collapsing the 4887 * locount into the hicount or vise-versa. 4888 */ 4889 if (keybits != nkeybits) { 4890 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { 4891 hicount += locount; 4892 locount = 0; 4893 } else { 4894 locount += hicount; 4895 hicount = 0; 4896 } 4897 keybits = nkeybits; 4898 } 4899 4900 /* 4901 * The newly scanned key will be in the lower half or the 4902 * upper half of the (new) key range. 4903 */ 4904 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) 4905 ++hicount; 4906 else 4907 ++locount; 4908 4909 if (key_next == 0) 4910 break; 4911 key_beg = key_next; 4912 } 4913 hammer2_spin_unex(&parent->core.spin); 4914 bref = NULL; /* now invalid (safety) */ 4915 4916 /* 4917 * Adjust keybits to represent half of the full range calculated 4918 * above (radix 63 max) for our new indirect block. 4919 */ 4920 --keybits; 4921 4922 /* 4923 * Expand keybits to hold at least ncount elements. ncount will be 4924 * a power of 2. This is to try to completely fill leaf nodes (at 4925 * least for keys which are not hashes). 4926 * 4927 * We aren't counting 'in' or 'out', we are counting 'high side' 4928 * and 'low side' based on the bit at (1LL << keybits). We want 4929 * everything to be inside in these cases so shift it all to 4930 * the low or high side depending on the new high bit. 4931 */ 4932 while (((hammer2_key_t)1 << keybits) < ncount) { 4933 ++keybits; 4934 if (key & ((hammer2_key_t)1 << keybits)) { 4935 hicount += locount; 4936 locount = 0; 4937 } else { 4938 locount += hicount; 4939 hicount = 0; 4940 } 4941 } 4942 4943 if (hicount > locount) 4944 key |= (hammer2_key_t)1 << keybits; 4945 else 4946 key &= ~(hammer2_key_t)1 << keybits; 4947 4948 *keyp = key; 4949 4950 return (keybits); 4951 } 4952 4953 #else 4954 4955 /* 4956 * Directory indirect blocks. 4957 * 4958 * Covers both the inode index (directory of inodes), and directory contents 4959 * (filenames hardlinked to inodes). 4960 * 4961 * Because directory keys are hashed we generally try to cut the space in 4962 * half. We accomodate the inode index (which tends to have linearly 4963 * increasing inode numbers) by ensuring that the keyspace is at least large 4964 * enough to fill up the indirect block being created. 4965 */ 4966 static int 4967 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, 4968 int keybits, hammer2_blockref_t *base, int count, 4969 int ncount) 4970 { 4971 hammer2_blockref_t *bref; 4972 hammer2_chain_t *chain; 4973 hammer2_key_t key_beg; 4974 hammer2_key_t key_end; 4975 hammer2_key_t key_next; 4976 hammer2_key_t key; 4977 int nkeybits; 4978 int locount; 4979 int hicount; 4980 int maxloops = 300000; 4981 4982 /* 4983 * Shortcut if the parent is the inode. In this situation the 4984 * parent has 4+1 directory entries and we are creating an indirect 4985 * block capable of holding many more. 4986 */ 4987 if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { 4988 return 63; 4989 } 4990 4991 key = *keyp; 4992 locount = 0; 4993 hicount = 0; 4994 4995 /* 4996 * Calculate the range of keys in the array being careful to skip 4997 * slots which are overridden with a deletion. 4998 */ 4999 key_beg = 0; 5000 key_end = HAMMER2_KEY_MAX; 5001 hammer2_spin_ex(&parent->core.spin); 5002 5003 for (;;) { 5004 if (--maxloops == 0) { 5005 panic("indkey_freemap shit %p %p:%d\n", 5006 parent, base, count); 5007 } 5008 chain = hammer2_combined_find(parent, base, count, 5009 &key_next, 5010 key_beg, key_end, 5011 &bref); 5012 5013 /* 5014 * Exhausted search 5015 */ 5016 if (bref == NULL) 5017 break; 5018 5019 /* 5020 * Deleted object 5021 */ 5022 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { 5023 if (key_next == 0 || key_next > key_end) 5024 break; 5025 key_beg = key_next; 5026 continue; 5027 } 5028 5029 /* 5030 * Use the full live (not deleted) element for the scan 5031 * iteration. HAMMER2 does not allow partial replacements. 5032 * 5033 * XXX should be built into hammer2_combined_find(). 5034 */ 5035 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); 5036 5037 /* 5038 * Expand our calculated key range (key, keybits) to fit 5039 * the scanned key. nkeybits represents the full range 5040 * that we will later cut in half (two halves @ nkeybits - 1). 5041 */ 5042 nkeybits = keybits; 5043 if (nkeybits < bref->keybits) { 5044 if (bref->keybits > 64) { 5045 kprintf("bad bref chain %p bref %p\n", 5046 chain, bref); 5047 Debugger("fubar"); 5048 } 5049 nkeybits = bref->keybits; 5050 } 5051 while (nkeybits < 64 && 5052 (~(((hammer2_key_t)1 << nkeybits) - 1) & 5053 (key ^ bref->key)) != 0) { 5054 ++nkeybits; 5055 } 5056 5057 /* 5058 * If the new key range is larger we have to determine 5059 * which side of the new key range the existing keys fall 5060 * under by checking the high bit, then collapsing the 5061 * locount into the hicount or vise-versa. 5062 */ 5063 if (keybits != nkeybits) { 5064 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { 5065 hicount += locount; 5066 locount = 0; 5067 } else { 5068 locount += hicount; 5069 hicount = 0; 5070 } 5071 keybits = nkeybits; 5072 } 5073 5074 /* 5075 * The newly scanned key will be in the lower half or the 5076 * upper half of the (new) key range. 5077 */ 5078 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) 5079 ++hicount; 5080 else 5081 ++locount; 5082 5083 if (key_next == 0) 5084 break; 5085 key_beg = key_next; 5086 } 5087 hammer2_spin_unex(&parent->core.spin); 5088 bref = NULL; /* now invalid (safety) */ 5089 5090 /* 5091 * Adjust keybits to represent half of the full range calculated 5092 * above (radix 63 max) for our new indirect block. 5093 */ 5094 --keybits; 5095 5096 /* 5097 * Expand keybits to hold at least ncount elements. ncount will be 5098 * a power of 2. This is to try to completely fill leaf nodes (at 5099 * least for keys which are not hashes). 5100 * 5101 * We aren't counting 'in' or 'out', we are counting 'high side' 5102 * and 'low side' based on the bit at (1LL << keybits). We want 5103 * everything to be inside in these cases so shift it all to 5104 * the low or high side depending on the new high bit. 5105 */ 5106 while (((hammer2_key_t)1 << keybits) < ncount) { 5107 ++keybits; 5108 if (key & ((hammer2_key_t)1 << keybits)) { 5109 hicount += locount; 5110 locount = 0; 5111 } else { 5112 locount += hicount; 5113 hicount = 0; 5114 } 5115 } 5116 5117 if (hicount > locount) 5118 key |= (hammer2_key_t)1 << keybits; 5119 else 5120 key &= ~(hammer2_key_t)1 << keybits; 5121 5122 *keyp = key; 5123 5124 return (keybits); 5125 } 5126 5127 #endif 5128 5129 /* 5130 * Sets CHAIN_DELETED and remove the chain's blockref from the parent if 5131 * it exists. 5132 * 5133 * Both parent and chain must be locked exclusively. 5134 * 5135 * This function will modify the parent if the blockref requires removal 5136 * from the parent's block table. 5137 * 5138 * This function is NOT recursive. Any entity already pushed into the 5139 * chain (such as an inode) may still need visibility into its contents, 5140 * as well as the ability to read and modify the contents. For example, 5141 * for an unlinked file which is still open. 5142 * 5143 * Also note that the flusher is responsible for cleaning up empty 5144 * indirect blocks. 5145 */ 5146 int 5147 hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain, 5148 hammer2_tid_t mtid, int flags) 5149 { 5150 int error = 0; 5151 5152 KKASSERT(hammer2_mtx_owned(&chain->lock)); 5153 5154 /* 5155 * Nothing to do if already marked. 5156 * 5157 * We need the spinlock on the core whos RBTREE contains chain 5158 * to protect against races. 5159 */ 5160 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { 5161 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && 5162 chain->parent == parent); 5163 error = _hammer2_chain_delete_helper(parent, chain, 5164 mtid, flags, NULL); 5165 } 5166 5167 /* 5168 * Permanent deletions mark the chain as destroyed. 5169 * 5170 * NOTE: We do not setflush the chain unless the deletion is 5171 * permanent, since the deletion of a chain does not actually 5172 * require it to be flushed. 5173 */ 5174 if (error == 0) { 5175 if (flags & HAMMER2_DELETE_PERMANENT) { 5176 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 5177 hammer2_chain_setflush(chain); 5178 } 5179 } 5180 5181 return error; 5182 } 5183 5184 static int 5185 hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain, 5186 hammer2_tid_t mtid, int flags, 5187 hammer2_blockref_t *obref) 5188 { 5189 int error = 0; 5190 5191 KKASSERT(hammer2_mtx_owned(&chain->lock)); 5192 5193 /* 5194 * Nothing to do if already marked. 5195 * 5196 * We need the spinlock on the core whos RBTREE contains chain 5197 * to protect against races. 5198 */ 5199 obref->type = HAMMER2_BREF_TYPE_EMPTY; 5200 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { 5201 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && 5202 chain->parent == parent); 5203 error = _hammer2_chain_delete_helper(parent, chain, 5204 mtid, flags, obref); 5205 } 5206 5207 /* 5208 * Permanent deletions mark the chain as destroyed. 5209 * 5210 * NOTE: We do not setflush the chain unless the deletion is 5211 * permanent, since the deletion of a chain does not actually 5212 * require it to be flushed. 5213 */ 5214 if (error == 0) { 5215 if (flags & HAMMER2_DELETE_PERMANENT) { 5216 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 5217 hammer2_chain_setflush(chain); 5218 } 5219 } 5220 5221 return error; 5222 } 5223 5224 /* 5225 * Returns the index of the nearest element in the blockref array >= elm. 5226 * Returns (count) if no element could be found. 5227 * 5228 * Sets *key_nextp to the next key for loop purposes but does not modify 5229 * it if the next key would be higher than the current value of *key_nextp. 5230 * Note that *key_nexp can overflow to 0, which should be tested by the 5231 * caller. 5232 * 5233 * WARNING! Must be called with parent's spinlock held. Spinlock remains 5234 * held through the operation. 5235 */ 5236 static int 5237 hammer2_base_find(hammer2_chain_t *parent, 5238 hammer2_blockref_t *base, int count, 5239 hammer2_key_t *key_nextp, 5240 hammer2_key_t key_beg, hammer2_key_t key_end) 5241 { 5242 hammer2_blockref_t *scan; 5243 hammer2_key_t scan_end; 5244 int i; 5245 int limit; 5246 5247 /* 5248 * Require the live chain's already have their core's counted 5249 * so we can optimize operations. 5250 */ 5251 KKASSERT(parent->flags & HAMMER2_CHAIN_COUNTEDBREFS); 5252 5253 /* 5254 * Degenerate case 5255 */ 5256 if (count == 0 || base == NULL) 5257 return(count); 5258 5259 /* 5260 * Sequential optimization using parent->cache_index. This is 5261 * the most likely scenario. 5262 * 5263 * We can avoid trailing empty entries on live chains, otherwise 5264 * we might have to check the whole block array. 5265 */ 5266 i = parent->cache_index; /* SMP RACE OK */ 5267 cpu_ccfence(); 5268 limit = parent->core.live_zero; 5269 if (i >= limit) 5270 i = limit - 1; 5271 if (i < 0) 5272 i = 0; 5273 KKASSERT(i < count); 5274 5275 /* 5276 * Search backwards 5277 */ 5278 scan = &base[i]; 5279 while (i > 0 && (scan->type == HAMMER2_BREF_TYPE_EMPTY || 5280 scan->key > key_beg)) { 5281 --scan; 5282 --i; 5283 } 5284 parent->cache_index = i; 5285 5286 /* 5287 * Search forwards, stop when we find a scan element which 5288 * encloses the key or until we know that there are no further 5289 * elements. 5290 */ 5291 while (i < count) { 5292 if (scan->type != HAMMER2_BREF_TYPE_EMPTY) { 5293 scan_end = scan->key + 5294 ((hammer2_key_t)1 << scan->keybits) - 1; 5295 if (scan->key > key_beg || scan_end >= key_beg) 5296 break; 5297 } 5298 if (i >= limit) 5299 return (count); 5300 ++scan; 5301 ++i; 5302 } 5303 if (i != count) { 5304 parent->cache_index = i; 5305 if (i >= limit) { 5306 i = count; 5307 } else { 5308 scan_end = scan->key + 5309 ((hammer2_key_t)1 << scan->keybits); 5310 if (scan_end && (*key_nextp > scan_end || 5311 *key_nextp == 0)) { 5312 *key_nextp = scan_end; 5313 } 5314 } 5315 } 5316 return (i); 5317 } 5318 5319 /* 5320 * Do a combined search and return the next match either from the blockref 5321 * array or from the in-memory chain. Sets *bresp to the returned bref in 5322 * both cases, or sets it to NULL if the search exhausted. Only returns 5323 * a non-NULL chain if the search matched from the in-memory chain. 5324 * 5325 * When no in-memory chain has been found and a non-NULL bref is returned 5326 * in *bresp. 5327 * 5328 * 5329 * The returned chain is not locked or referenced. Use the returned bref 5330 * to determine if the search exhausted or not. Iterate if the base find 5331 * is chosen but matches a deleted chain. 5332 * 5333 * WARNING! Must be called with parent's spinlock held. Spinlock remains 5334 * held through the operation. 5335 */ 5336 hammer2_chain_t * 5337 hammer2_combined_find(hammer2_chain_t *parent, 5338 hammer2_blockref_t *base, int count, 5339 hammer2_key_t *key_nextp, 5340 hammer2_key_t key_beg, hammer2_key_t key_end, 5341 hammer2_blockref_t **bresp) 5342 { 5343 hammer2_blockref_t *bref; 5344 hammer2_chain_t *chain; 5345 int i; 5346 5347 /* 5348 * Lookup in block array and in rbtree. 5349 */ 5350 *key_nextp = key_end + 1; 5351 i = hammer2_base_find(parent, base, count, key_nextp, 5352 key_beg, key_end); 5353 chain = hammer2_chain_find(parent, key_nextp, key_beg, key_end); 5354 5355 /* 5356 * Neither matched 5357 */ 5358 if (i == count && chain == NULL) { 5359 *bresp = NULL; 5360 return(NULL); 5361 } 5362 5363 /* 5364 * Only chain matched. 5365 */ 5366 if (i == count) { 5367 bref = &chain->bref; 5368 goto found; 5369 } 5370 5371 /* 5372 * Only blockref matched. 5373 */ 5374 if (chain == NULL) { 5375 bref = &base[i]; 5376 goto found; 5377 } 5378 5379 /* 5380 * Both in-memory and blockref matched, select the nearer element. 5381 * 5382 * If both are flush with the left-hand side or both are the 5383 * same distance away, select the chain. In this situation the 5384 * chain must have been loaded from the matching blockmap. 5385 */ 5386 if ((chain->bref.key <= key_beg && base[i].key <= key_beg) || 5387 chain->bref.key == base[i].key) { 5388 KKASSERT(chain->bref.key == base[i].key); 5389 bref = &chain->bref; 5390 goto found; 5391 } 5392 5393 /* 5394 * Select the nearer key 5395 */ 5396 if (chain->bref.key < base[i].key) { 5397 bref = &chain->bref; 5398 } else { 5399 bref = &base[i]; 5400 chain = NULL; 5401 } 5402 5403 /* 5404 * If the bref is out of bounds we've exhausted our search. 5405 */ 5406 found: 5407 if (bref->key > key_end) { 5408 *bresp = NULL; 5409 chain = NULL; 5410 } else { 5411 *bresp = bref; 5412 } 5413 return(chain); 5414 } 5415 5416 /* 5417 * Locate the specified block array element and delete it. The element 5418 * must exist. 5419 * 5420 * The spin lock on the related chain must be held. 5421 * 5422 * NOTE: live_count was adjusted when the chain was deleted, so it does not 5423 * need to be adjusted when we commit the media change. 5424 */ 5425 void 5426 hammer2_base_delete(hammer2_chain_t *parent, 5427 hammer2_blockref_t *base, int count, 5428 hammer2_chain_t *chain, 5429 hammer2_blockref_t *obref) 5430 { 5431 hammer2_blockref_t *elm = &chain->bref; 5432 hammer2_blockref_t *scan; 5433 hammer2_key_t key_next; 5434 int i; 5435 5436 /* 5437 * Delete element. Expect the element to exist. 5438 * 5439 * XXX see caller, flush code not yet sophisticated enough to prevent 5440 * re-flushed in some cases. 5441 */ 5442 key_next = 0; /* max range */ 5443 i = hammer2_base_find(parent, base, count, &key_next, 5444 elm->key, elm->key); 5445 scan = &base[i]; 5446 if (i == count || scan->type == HAMMER2_BREF_TYPE_EMPTY || 5447 scan->key != elm->key || 5448 ((chain->flags & HAMMER2_CHAIN_BMAPUPD) == 0 && 5449 scan->keybits != elm->keybits)) { 5450 hammer2_spin_unex(&parent->core.spin); 5451 panic("delete base %p element not found at %d/%d elm %p\n", 5452 base, i, count, elm); 5453 return; 5454 } 5455 5456 /* 5457 * Update stats and zero the entry. 5458 * 5459 * NOTE: Handle radix == 0 (0 bytes) case. 5460 */ 5461 if ((int)(scan->data_off & HAMMER2_OFF_MASK_RADIX)) { 5462 parent->bref.embed.stats.data_count -= (hammer2_off_t)1 << 5463 (int)(scan->data_off & HAMMER2_OFF_MASK_RADIX); 5464 } 5465 switch(scan->type) { 5466 case HAMMER2_BREF_TYPE_INODE: 5467 --parent->bref.embed.stats.inode_count; 5468 /* fall through */ 5469 case HAMMER2_BREF_TYPE_DATA: 5470 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5471 atomic_set_int(&chain->flags, 5472 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5473 } else { 5474 if (parent->bref.leaf_count) 5475 --parent->bref.leaf_count; 5476 } 5477 /* fall through */ 5478 case HAMMER2_BREF_TYPE_INDIRECT: 5479 if (scan->type != HAMMER2_BREF_TYPE_DATA) { 5480 parent->bref.embed.stats.data_count -= 5481 scan->embed.stats.data_count; 5482 parent->bref.embed.stats.inode_count -= 5483 scan->embed.stats.inode_count; 5484 } 5485 if (scan->type == HAMMER2_BREF_TYPE_INODE) 5486 break; 5487 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5488 atomic_set_int(&chain->flags, 5489 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5490 } else { 5491 if (parent->bref.leaf_count <= scan->leaf_count) 5492 parent->bref.leaf_count = 0; 5493 else 5494 parent->bref.leaf_count -= scan->leaf_count; 5495 } 5496 break; 5497 case HAMMER2_BREF_TYPE_DIRENT: 5498 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { 5499 atomic_set_int(&chain->flags, 5500 HAMMER2_CHAIN_HINT_LEAF_COUNT); 5501 } else { 5502 if (parent->bref.leaf_count) 5503 --parent->bref.leaf_count; 5504 } 5505 default: 5506 break; 5507 } 5508 5509 if (obref) 5510 *obref = *scan; 5511 bzero(scan, sizeof(*scan)); 5512 5513 /* 5514 * We can only optimize parent->core.live_zero for live chains. 5515 */ 5516 if (parent->core.live_zero == i + 1) { 5517 while (--i >= 0 && base[i].type == HAMMER2_BREF_TYPE_EMPTY) 5518 ; 5519 parent->core.live_zero = i + 1; 5520 } 5521 5522 /* 5523 * Clear appropriate blockmap flags in chain. 5524 */ 5525 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BMAPPED | 5526 HAMMER2_CHAIN_BMAPUPD); 5527 } 5528 5529 /* 5530 * Insert the specified element. The block array must not already have the 5531 * element and must have space available for the insertion. 5532 * 5533 * The spin lock on the related chain must be held. 5534 * 5535 * NOTE: live_count was adjusted when the chain was deleted, so it does not 5536 * need to be adjusted when we commit the media change. 5537 */ 5538 void 5539 hammer2_base_insert(hammer2_chain_t *parent, 5540 hammer2_blockref_t *base, int count, 5541 hammer2_chain_t *chain, hammer2_blockref_t *elm) 5542 { 5543 hammer2_key_t key_next; 5544 hammer2_key_t xkey; 5545 int i; 5546 int j; 5547 int k; 5548 int l; 5549 int u = 1; 5550 5551 /* 5552 * Insert new element. Expect the element to not already exist 5553 * unless we are replacing it. 5554 * 5555 * XXX see caller, flush code not yet sophisticated enough to prevent 5556 * re-flushed in some cases. 5557 */ 5558 key_next = 0; /* max range */ 5559 i = hammer2_base_find(parent, base, count, &key_next, 5560 elm->key, elm->key); 5561 5562 /* 5563 * Shortcut fill optimization, typical ordered insertion(s) may not 5564 * require a search. 5565 */ 5566 KKASSERT(i >= 0 && i <= count); 5567 5568 /* 5569 * Set appropriate blockmap flags in chain (if not NULL) 5570 */ 5571 if (chain) 5572 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED); 5573 5574 /* 5575 * Update stats and zero the entry 5576 */ 5577 if ((int)(elm->data_off & HAMMER2_OFF_MASK_RADIX)) { 5578 parent->bref.embed.stats.data_count += (hammer2_off_t)1 << 5579 (int)(elm->data_off & HAMMER2_OFF_MASK_RADIX); 5580 } 5581 switch(elm->type) { 5582 case HAMMER2_BREF_TYPE_INODE: 5583 ++parent->bref.embed.stats.inode_count; 5584 /* fall through */ 5585 case HAMMER2_BREF_TYPE_DATA: 5586 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) 5587 ++parent->bref.leaf_count; 5588 /* fall through */ 5589 case HAMMER2_BREF_TYPE_INDIRECT: 5590 if (elm->type != HAMMER2_BREF_TYPE_DATA) { 5591 parent->bref.embed.stats.data_count += 5592 elm->embed.stats.data_count; 5593 parent->bref.embed.stats.inode_count += 5594 elm->embed.stats.inode_count; 5595 } 5596 if (elm->type == HAMMER2_BREF_TYPE_INODE) 5597 break; 5598 if (parent->bref.leaf_count + elm->leaf_count < 5599 HAMMER2_BLOCKREF_LEAF_MAX) { 5600 parent->bref.leaf_count += elm->leaf_count; 5601 } else { 5602 parent->bref.leaf_count = HAMMER2_BLOCKREF_LEAF_MAX; 5603 } 5604 break; 5605 case HAMMER2_BREF_TYPE_DIRENT: 5606 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) 5607 ++parent->bref.leaf_count; 5608 break; 5609 default: 5610 break; 5611 } 5612 5613 5614 /* 5615 * We can only optimize parent->core.live_zero for live chains. 5616 */ 5617 if (i == count && parent->core.live_zero < count) { 5618 i = parent->core.live_zero++; 5619 base[i] = *elm; 5620 return; 5621 } 5622 5623 xkey = elm->key + ((hammer2_key_t)1 << elm->keybits) - 1; 5624 if (i != count && (base[i].key < elm->key || xkey >= base[i].key)) { 5625 hammer2_spin_unex(&parent->core.spin); 5626 panic("insert base %p overlapping elements at %d elm %p\n", 5627 base, i, elm); 5628 } 5629 5630 /* 5631 * Try to find an empty slot before or after. 5632 */ 5633 j = i; 5634 k = i; 5635 while (j > 0 || k < count) { 5636 --j; 5637 if (j >= 0 && base[j].type == HAMMER2_BREF_TYPE_EMPTY) { 5638 if (j == i - 1) { 5639 base[j] = *elm; 5640 } else { 5641 bcopy(&base[j+1], &base[j], 5642 (i - j - 1) * sizeof(*base)); 5643 base[i - 1] = *elm; 5644 } 5645 goto validate; 5646 } 5647 ++k; 5648 if (k < count && base[k].type == HAMMER2_BREF_TYPE_EMPTY) { 5649 bcopy(&base[i], &base[i+1], 5650 (k - i) * sizeof(hammer2_blockref_t)); 5651 base[i] = *elm; 5652 5653 /* 5654 * We can only update parent->core.live_zero for live 5655 * chains. 5656 */ 5657 if (parent->core.live_zero <= k) 5658 parent->core.live_zero = k + 1; 5659 u = 2; 5660 goto validate; 5661 } 5662 } 5663 panic("hammer2_base_insert: no room!"); 5664 5665 /* 5666 * Debugging 5667 */ 5668 validate: 5669 key_next = 0; 5670 for (l = 0; l < count; ++l) { 5671 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { 5672 key_next = base[l].key + 5673 ((hammer2_key_t)1 << base[l].keybits) - 1; 5674 break; 5675 } 5676 } 5677 while (++l < count) { 5678 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { 5679 if (base[l].key <= key_next) 5680 panic("base_insert %d %d,%d,%d fail %p:%d", u, i, j, k, base, l); 5681 key_next = base[l].key + 5682 ((hammer2_key_t)1 << base[l].keybits) - 1; 5683 5684 } 5685 } 5686 5687 } 5688 5689 #if 0 5690 5691 /* 5692 * Sort the blockref array for the chain. Used by the flush code to 5693 * sort the blockref[] array. 5694 * 5695 * The chain must be exclusively locked AND spin-locked. 5696 */ 5697 typedef hammer2_blockref_t *hammer2_blockref_p; 5698 5699 static 5700 int 5701 hammer2_base_sort_callback(const void *v1, const void *v2) 5702 { 5703 hammer2_blockref_p bref1 = *(const hammer2_blockref_p *)v1; 5704 hammer2_blockref_p bref2 = *(const hammer2_blockref_p *)v2; 5705 5706 /* 5707 * Make sure empty elements are placed at the end of the array 5708 */ 5709 if (bref1->type == HAMMER2_BREF_TYPE_EMPTY) { 5710 if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) 5711 return(0); 5712 return(1); 5713 } else if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) { 5714 return(-1); 5715 } 5716 5717 /* 5718 * Sort by key 5719 */ 5720 if (bref1->key < bref2->key) 5721 return(-1); 5722 if (bref1->key > bref2->key) 5723 return(1); 5724 return(0); 5725 } 5726 5727 void 5728 hammer2_base_sort(hammer2_chain_t *chain) 5729 { 5730 hammer2_blockref_t *base; 5731 int count; 5732 5733 switch(chain->bref.type) { 5734 case HAMMER2_BREF_TYPE_INODE: 5735 /* 5736 * Special shortcut for embedded data returns the inode 5737 * itself. Callers must detect this condition and access 5738 * the embedded data (the strategy code does this for us). 5739 * 5740 * This is only applicable to regular files and softlinks. 5741 */ 5742 if (chain->data->ipdata.meta.op_flags & 5743 HAMMER2_OPFLAG_DIRECTDATA) { 5744 return; 5745 } 5746 base = &chain->data->ipdata.u.blockset.blockref[0]; 5747 count = HAMMER2_SET_COUNT; 5748 break; 5749 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 5750 case HAMMER2_BREF_TYPE_INDIRECT: 5751 /* 5752 * Optimize indirect blocks in the INITIAL state to avoid 5753 * I/O. 5754 */ 5755 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) == 0); 5756 base = &chain->data->npdata[0]; 5757 count = chain->bytes / sizeof(hammer2_blockref_t); 5758 break; 5759 case HAMMER2_BREF_TYPE_VOLUME: 5760 base = &chain->data->voldata.sroot_blockset.blockref[0]; 5761 count = HAMMER2_SET_COUNT; 5762 break; 5763 case HAMMER2_BREF_TYPE_FREEMAP: 5764 base = &chain->data->blkset.blockref[0]; 5765 count = HAMMER2_SET_COUNT; 5766 break; 5767 default: 5768 kprintf("hammer2_chain_lookup: unrecognized " 5769 "blockref(A) type: %d", 5770 chain->bref.type); 5771 while (1) 5772 tsleep(&base, 0, "dead", 0); 5773 panic("hammer2_base_sort: unrecognized " 5774 "blockref(A) type: %d", 5775 chain->bref.type); 5776 base = NULL; /* safety */ 5777 count = 0; /* safety */ 5778 } 5779 kqsort(base, count, sizeof(*base), hammer2_base_sort_callback); 5780 } 5781 5782 #endif 5783 5784 /* 5785 * Chain memory management 5786 */ 5787 void 5788 hammer2_chain_wait(hammer2_chain_t *chain) 5789 { 5790 tsleep(chain, 0, "chnflw", 1); 5791 } 5792 5793 const hammer2_media_data_t * 5794 hammer2_chain_rdata(hammer2_chain_t *chain) 5795 { 5796 KKASSERT(chain->data != NULL); 5797 return (chain->data); 5798 } 5799 5800 hammer2_media_data_t * 5801 hammer2_chain_wdata(hammer2_chain_t *chain) 5802 { 5803 KKASSERT(chain->data != NULL); 5804 return (chain->data); 5805 } 5806 5807 /* 5808 * Set the check data for a chain. This can be a heavy-weight operation 5809 * and typically only runs on-flush. For file data check data is calculated 5810 * when the logical buffers are flushed. 5811 */ 5812 void 5813 hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata) 5814 { 5815 chain->bref.flags &= ~HAMMER2_BREF_FLAG_ZERO; 5816 5817 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { 5818 case HAMMER2_CHECK_NONE: 5819 break; 5820 case HAMMER2_CHECK_DISABLED: 5821 break; 5822 case HAMMER2_CHECK_ISCSI32: 5823 chain->bref.check.iscsi32.value = 5824 hammer2_icrc32(bdata, chain->bytes); 5825 break; 5826 case HAMMER2_CHECK_XXHASH64: 5827 chain->bref.check.xxhash64.value = 5828 XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); 5829 break; 5830 case HAMMER2_CHECK_SHA192: 5831 { 5832 SHA256_CTX hash_ctx; 5833 union { 5834 uint8_t digest[SHA256_DIGEST_LENGTH]; 5835 uint64_t digest64[SHA256_DIGEST_LENGTH/8]; 5836 } u; 5837 5838 SHA256_Init(&hash_ctx); 5839 SHA256_Update(&hash_ctx, bdata, chain->bytes); 5840 SHA256_Final(u.digest, &hash_ctx); 5841 u.digest64[2] ^= u.digest64[3]; 5842 bcopy(u.digest, 5843 chain->bref.check.sha192.data, 5844 sizeof(chain->bref.check.sha192.data)); 5845 } 5846 break; 5847 case HAMMER2_CHECK_FREEMAP: 5848 chain->bref.check.freemap.icrc32 = 5849 hammer2_icrc32(bdata, chain->bytes); 5850 break; 5851 default: 5852 kprintf("hammer2_chain_setcheck: unknown check type %02x\n", 5853 chain->bref.methods); 5854 break; 5855 } 5856 } 5857 5858 /* 5859 * Characterize a failed check code and try to trace back to the inode. 5860 */ 5861 static void 5862 hammer2_characterize_failed_chain(hammer2_chain_t *chain, uint64_t check, 5863 int bits) 5864 { 5865 hammer2_chain_t *lchain; 5866 hammer2_chain_t *ochain; 5867 int did; 5868 5869 did = krateprintf(&krate_h2chk, 5870 "chain %016jx.%02x (%s) meth=%02x CHECK FAIL " 5871 "(flags=%08x, bref/data ", 5872 chain->bref.data_off, 5873 chain->bref.type, 5874 hammer2_bref_type_str(&chain->bref), 5875 chain->bref.methods, 5876 chain->flags); 5877 if (did == 0) 5878 return; 5879 5880 if (bits == 32) { 5881 kprintf("%08x/%08x)\n", 5882 chain->bref.check.iscsi32.value, 5883 (uint32_t)check); 5884 } else { 5885 kprintf("%016jx/%016jx)\n", 5886 chain->bref.check.xxhash64.value, 5887 check); 5888 } 5889 5890 /* 5891 * Run up the chains to try to find the governing inode so we 5892 * can report it. 5893 * 5894 * XXX This error reporting is not really MPSAFE 5895 */ 5896 ochain = chain; 5897 lchain = chain; 5898 while (chain && chain->bref.type != HAMMER2_BREF_TYPE_INODE) { 5899 lchain = chain; 5900 chain = chain->parent; 5901 } 5902 5903 if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE && 5904 ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) == 0 || 5905 (lchain->bref.key & HAMMER2_DIRHASH_VISIBLE))) { 5906 kprintf(" Resides at/in inode %ld\n", 5907 chain->bref.key); 5908 } else if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE) { 5909 kprintf(" Resides in inode index - CRITICAL!!!\n"); 5910 } else { 5911 kprintf(" Resides in root index - CRITICAL!!!\n"); 5912 } 5913 if (ochain->hmp) { 5914 const char *pfsname = "UNKNOWN"; 5915 int i; 5916 5917 if (ochain->pmp) { 5918 for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) { 5919 if (ochain->pmp->pfs_hmps[i] == ochain->hmp && 5920 ochain->pmp->pfs_names[i]) { 5921 pfsname = ochain->pmp->pfs_names[i]; 5922 break; 5923 } 5924 } 5925 } 5926 kprintf(" In pfs %s on device %s\n", 5927 pfsname, ochain->hmp->devrepname); 5928 } 5929 } 5930 5931 /* 5932 * Returns non-zero on success, 0 on failure. 5933 */ 5934 int 5935 hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata) 5936 { 5937 uint32_t check32; 5938 uint64_t check64; 5939 int r; 5940 5941 if (chain->bref.flags & HAMMER2_BREF_FLAG_ZERO) 5942 return 1; 5943 5944 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { 5945 case HAMMER2_CHECK_NONE: 5946 r = 1; 5947 break; 5948 case HAMMER2_CHECK_DISABLED: 5949 r = 1; 5950 break; 5951 case HAMMER2_CHECK_ISCSI32: 5952 check32 = hammer2_icrc32(bdata, chain->bytes); 5953 r = (chain->bref.check.iscsi32.value == check32); 5954 if (r == 0) { 5955 hammer2_characterize_failed_chain(chain, check32, 32); 5956 } 5957 hammer2_process_icrc32 += chain->bytes; 5958 break; 5959 case HAMMER2_CHECK_XXHASH64: 5960 check64 = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); 5961 r = (chain->bref.check.xxhash64.value == check64); 5962 if (r == 0) { 5963 hammer2_characterize_failed_chain(chain, check64, 64); 5964 } 5965 hammer2_process_xxhash64 += chain->bytes; 5966 break; 5967 case HAMMER2_CHECK_SHA192: 5968 { 5969 SHA256_CTX hash_ctx; 5970 union { 5971 uint8_t digest[SHA256_DIGEST_LENGTH]; 5972 uint64_t digest64[SHA256_DIGEST_LENGTH/8]; 5973 } u; 5974 5975 SHA256_Init(&hash_ctx); 5976 SHA256_Update(&hash_ctx, bdata, chain->bytes); 5977 SHA256_Final(u.digest, &hash_ctx); 5978 u.digest64[2] ^= u.digest64[3]; 5979 if (bcmp(u.digest, 5980 chain->bref.check.sha192.data, 5981 sizeof(chain->bref.check.sha192.data)) == 0) { 5982 r = 1; 5983 } else { 5984 r = 0; 5985 krateprintf(&krate_h2chk, 5986 "chain %016jx.%02x meth=%02x " 5987 "CHECK FAIL\n", 5988 chain->bref.data_off, 5989 chain->bref.type, 5990 chain->bref.methods); 5991 } 5992 } 5993 break; 5994 case HAMMER2_CHECK_FREEMAP: 5995 r = (chain->bref.check.freemap.icrc32 == 5996 hammer2_icrc32(bdata, chain->bytes)); 5997 if (r == 0) { 5998 int did; 5999 6000 did = krateprintf(&krate_h2chk, 6001 "chain %016jx.%02x meth=%02x " 6002 "CHECK FAIL\n", 6003 chain->bref.data_off, 6004 chain->bref.type, 6005 chain->bref.methods); 6006 if (did) { 6007 kprintf("freemap.icrc %08x icrc32 %08x (%d)\n", 6008 chain->bref.check.freemap.icrc32, 6009 hammer2_icrc32(bdata, chain->bytes), 6010 chain->bytes); 6011 if (chain->dio) { 6012 kprintf("dio %p buf %016jx,%d " 6013 "bdata %p/%p\n", 6014 chain->dio, 6015 chain->dio->bp->b_loffset, 6016 chain->dio->bp->b_bufsize, 6017 bdata, 6018 chain->dio->bp->b_data); 6019 } 6020 } 6021 } 6022 break; 6023 default: 6024 kprintf("hammer2_chain_setcheck: unknown check type %02x\n", 6025 chain->bref.methods); 6026 r = 1; 6027 break; 6028 } 6029 return r; 6030 } 6031 6032 /* 6033 * Acquire the chain and parent representing the specified inode for the 6034 * device at the specified cluster index. 6035 * 6036 * The flags passed in are LOOKUP flags, not RESOLVE flags. 6037 * 6038 * If we are unable to locate the inode, HAMMER2_ERROR_EIO is returned and 6039 * *chainp will be NULL. *parentp may still be set error or not, or NULL 6040 * if the parent itself could not be resolved. 6041 * 6042 * The caller may pass-in a locked *parentp and/or *chainp, or neither. 6043 * They will be unlocked and released by this function. The *parentp and 6044 * *chainp representing the located inode are returned locked. 6045 */ 6046 int 6047 hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum, 6048 int clindex, int flags, 6049 hammer2_chain_t **parentp, hammer2_chain_t **chainp) 6050 { 6051 hammer2_chain_t *parent; 6052 hammer2_chain_t *rchain; 6053 hammer2_key_t key_dummy; 6054 hammer2_inode_t *ip; 6055 int resolve_flags; 6056 int error; 6057 6058 resolve_flags = (flags & HAMMER2_LOOKUP_SHARED) ? 6059 HAMMER2_RESOLVE_SHARED : 0; 6060 6061 /* 6062 * Caller expects us to replace these. 6063 */ 6064 if (*chainp) { 6065 hammer2_chain_unlock(*chainp); 6066 hammer2_chain_drop(*chainp); 6067 *chainp = NULL; 6068 } 6069 if (*parentp) { 6070 hammer2_chain_unlock(*parentp); 6071 hammer2_chain_drop(*parentp); 6072 *parentp = NULL; 6073 } 6074 6075 /* 6076 * Be very careful, this is a backend function and we CANNOT 6077 * lock any frontend inode structure we find. But we have to 6078 * look the inode up this way first in case it exists but is 6079 * detached from the radix tree. 6080 */ 6081 ip = hammer2_inode_lookup(pmp, inum); 6082 if (ip) { 6083 *chainp = hammer2_inode_chain_and_parent(ip, clindex, 6084 parentp, 6085 resolve_flags); 6086 hammer2_inode_drop(ip); 6087 if (*chainp) 6088 return 0; 6089 hammer2_chain_unlock(*chainp); 6090 hammer2_chain_drop(*chainp); 6091 *chainp = NULL; 6092 if (*parentp) { 6093 hammer2_chain_unlock(*parentp); 6094 hammer2_chain_drop(*parentp); 6095 *parentp = NULL; 6096 } 6097 } 6098 6099 /* 6100 * Inodes hang off of the iroot (bit 63 is clear, differentiating 6101 * inodes from root directory entries in the key lookup). 6102 */ 6103 parent = hammer2_inode_chain(pmp->iroot, clindex, resolve_flags); 6104 rchain = NULL; 6105 if (parent) { 6106 rchain = hammer2_chain_lookup(&parent, &key_dummy, 6107 inum, inum, 6108 &error, flags); 6109 } else { 6110 error = HAMMER2_ERROR_EIO; 6111 } 6112 *parentp = parent; 6113 *chainp = rchain; 6114 6115 return error; 6116 } 6117 6118 /* 6119 * Used by the bulkscan code to snapshot the synchronized storage for 6120 * a volume, allowing it to be scanned concurrently against normal 6121 * operation. 6122 */ 6123 hammer2_chain_t * 6124 hammer2_chain_bulksnap(hammer2_dev_t *hmp) 6125 { 6126 hammer2_chain_t *copy; 6127 6128 copy = hammer2_chain_alloc(hmp, hmp->spmp, &hmp->vchain.bref); 6129 copy->data = kmalloc(sizeof(copy->data->voldata), 6130 hmp->mchain, 6131 M_WAITOK | M_ZERO); 6132 hammer2_voldata_lock(hmp); 6133 copy->data->voldata = hmp->volsync; 6134 hammer2_voldata_unlock(hmp); 6135 6136 return copy; 6137 } 6138 6139 void 6140 hammer2_chain_bulkdrop(hammer2_chain_t *copy) 6141 { 6142 KKASSERT(copy->bref.type == HAMMER2_BREF_TYPE_VOLUME); 6143 KKASSERT(copy->data); 6144 kfree(copy->data, copy->hmp->mchain); 6145 copy->data = NULL; 6146 atomic_add_long(&hammer2_chain_allocs, -1); 6147 hammer2_chain_drop(copy); 6148 } 6149 6150 /* 6151 * Returns non-zero if the chain (INODE or DIRENT) matches the 6152 * filename. 6153 */ 6154 int 6155 hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name, 6156 size_t name_len) 6157 { 6158 const hammer2_inode_data_t *ripdata; 6159 const hammer2_dirent_head_t *den; 6160 6161 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) { 6162 ripdata = &chain->data->ipdata; 6163 if (ripdata->meta.name_len == name_len && 6164 bcmp(ripdata->filename, name, name_len) == 0) { 6165 return 1; 6166 } 6167 } 6168 if (chain->bref.type == HAMMER2_BREF_TYPE_DIRENT && 6169 chain->bref.embed.dirent.namlen == name_len) { 6170 den = &chain->bref.embed.dirent; 6171 if (name_len > sizeof(chain->bref.check.buf) && 6172 bcmp(chain->data->buf, name, name_len) == 0) { 6173 return 1; 6174 } 6175 if (name_len <= sizeof(chain->bref.check.buf) && 6176 bcmp(chain->bref.check.buf, name, name_len) == 0) { 6177 return 1; 6178 } 6179 } 6180 return 0; 6181 } 6182