1 /* 2 * Copyright (c) 2013-2015 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 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 /* 35 * The cluster module collects multiple chains representing the same 36 * information from different nodes into a single entity. It allows direct 37 * access to media data as long as it is not blockref array data (which 38 * will obviously have to be different at each node). 39 * 40 * This module also handles I/O dispatch, status rollup, and various 41 * mastership arrangements including quorum operations. It effectively 42 * presents one topology to the vnops layer. 43 * 44 * Many of the API calls mimic chain API calls but operate on clusters 45 * instead of chains. Please see hammer2_chain.c for more complete code 46 * documentation of the API functions. 47 * 48 * WARNING! This module is *extremely* complex. It must issue asynchronous 49 * locks and I/O, do quorum and/or master-slave processing, and 50 * it must operate properly even if some nodes are broken (which 51 * can also mean indefinite locks). 52 * 53 * CLUSTER OPERATIONS 54 * 55 * Cluster operations can be broken down into three pieces: 56 * 57 * (1) Chain locking and data retrieval. 58 * 59 * - Most complex functions, quorum management on transaction ids. 60 * 61 * - Locking and data accesses must be internally asynchronous. 62 * 63 * - Validate and manage cache coherency primitives (cache state 64 * is stored in chain topologies but must be validated by these 65 * functions). 66 * 67 * (2) Lookups and Scans 68 * hammer2_cluster_lookup() 69 * hammer2_cluster_next() 70 * 71 * - Depend on locking & data retrieval functions, but still complex. 72 * 73 * - Must do quorum management on transaction ids. 74 * 75 * - Lookup and Iteration ops Must be internally asynchronous. 76 * 77 * (3) Modifying Operations 78 * hammer2_cluster_create() 79 * 80 * - Can usually punt on failures, operation continues unless quorum 81 * is lost. If quorum is lost, must wait for resynchronization 82 * (depending on the management mode). 83 * 84 * - Must disconnect node on failures (also not flush), remount, and 85 * resynchronize. 86 * 87 * - Network links (via kdmsg) are relatively easy to issue as the 88 * complex underworkings of hammer2_chain.c don't have to messed 89 * with (the protocol is at a higher level than block-level). 90 * 91 * - Multiple local disk nodes (i.e. block devices) are another matter. 92 * Chain operations have to be dispatched to per-node threads (xN) 93 * because we can't asynchronize potentially very complex chain 94 * operations in hammer2_chain.c (it would be a huge mess). 95 * 96 * (these threads are also used to terminate incoming kdmsg ops from 97 * other machines). 98 * 99 * - Single-node filesystems do not use threads and will simply call 100 * hammer2_chain.c functions directly. This short-cut is handled 101 * at the base of each cluster function. 102 */ 103 #include <sys/cdefs.h> 104 #include <sys/param.h> 105 #include <sys/systm.h> 106 #include <sys/types.h> 107 #include <sys/lock.h> 108 #include <sys/uuid.h> 109 110 #include "hammer2.h" 111 112 /* 113 * Returns the bref type of the cluster's foucs. 114 * 115 * If the cluster is errored, returns HAMMER2_BREF_TYPE_EMPTY (0). 116 * The cluster must be locked. 117 */ 118 uint8_t 119 hammer2_cluster_type(hammer2_cluster_t *cluster) 120 { 121 if (cluster->error == 0) { 122 KKASSERT(cluster->focus != NULL); 123 return(cluster->focus->bref.type); 124 } 125 return 0; 126 } 127 128 /* 129 * Returns non-zero if the cluster's focus is flagged as being modified. 130 * 131 * If the cluster is errored, returns 0. 132 */ 133 static 134 int 135 hammer2_cluster_modified(hammer2_cluster_t *cluster) 136 { 137 if (cluster->error == 0) { 138 KKASSERT(cluster->focus != NULL); 139 return((cluster->focus->flags & HAMMER2_CHAIN_MODIFIED) != 0); 140 } 141 return 0; 142 } 143 144 /* 145 * Returns the bref of the cluster's focus, sans any data-offset information 146 * (since offset information is per-node and wouldn't be useful). 147 * 148 * Callers use this function to access modify_tid, mirror_tid, type, 149 * key, and keybits. 150 * 151 * If the cluster is errored, returns an empty bref. 152 * The cluster must be locked. 153 */ 154 void 155 hammer2_cluster_bref(hammer2_cluster_t *cluster, hammer2_blockref_t *bref) 156 { 157 if (cluster->error == 0) { 158 KKASSERT(cluster->focus != NULL); 159 *bref = cluster->focus->bref; 160 bref->data_off = 0; 161 } else { 162 bzero(bref, sizeof(*bref)); 163 } 164 } 165 166 /* 167 * Create a degenerate cluster with one ref from a single locked chain. 168 * The returned cluster will be focused on the chain and inherit its 169 * error state. 170 * 171 * The chain's lock and reference are transfered to the new cluster, so 172 * the caller should not try to unlock the chain separately. 173 * 174 * We fake the flags. 175 */ 176 hammer2_cluster_t * 177 hammer2_cluster_from_chain(hammer2_chain_t *chain) 178 { 179 hammer2_cluster_t *cluster; 180 181 cluster = kmalloc(sizeof(*cluster), M_HAMMER2, M_WAITOK | M_ZERO); 182 cluster->array[0].chain = chain; 183 cluster->array[0].flags = HAMMER2_CITEM_FEMOD; 184 cluster->nchains = 1; 185 cluster->focus = chain; 186 cluster->focus_index = 0; 187 cluster->pmp = chain->pmp; 188 cluster->refs = 1; 189 cluster->error = chain->error; 190 cluster->flags = HAMMER2_CLUSTER_LOCKED | 191 HAMMER2_CLUSTER_WRHARD | 192 HAMMER2_CLUSTER_RDHARD | 193 HAMMER2_CLUSTER_MSYNCED | 194 HAMMER2_CLUSTER_SSYNCED; 195 196 return cluster; 197 } 198 199 /* 200 * Add a reference to a cluster and its underlying chains. 201 * 202 * We must also ref the underlying chains in order to allow ref/unlock 203 * sequences to later re-lock. 204 */ 205 void 206 hammer2_cluster_ref(hammer2_cluster_t *cluster) 207 { 208 atomic_add_int(&cluster->refs, 1); 209 } 210 211 /* 212 * Drop the caller's reference to the cluster. When the ref count drops to 213 * zero this function frees the cluster and drops all underlying chains. 214 * 215 * In-progress read I/Os are typically detached from the cluster once the 216 * first one returns (the remaining stay attached to the DIOs but are then 217 * ignored and drop naturally). 218 */ 219 void 220 hammer2_cluster_drop(hammer2_cluster_t *cluster) 221 { 222 hammer2_chain_t *chain; 223 int i; 224 225 KKASSERT(cluster->refs > 0); 226 if (atomic_fetchadd_int(&cluster->refs, -1) == 1) { 227 cluster->focus = NULL; /* safety XXX chg to assert */ 228 cluster->focus_index = 0; 229 230 for (i = 0; i < cluster->nchains; ++i) { 231 chain = cluster->array[i].chain; 232 if (chain) { 233 hammer2_chain_drop(chain); 234 cluster->array[i].chain = NULL; /* safety */ 235 } 236 } 237 cluster->nchains = 0; /* safety */ 238 239 kfree(cluster, M_HAMMER2); 240 /* cluster is invalid */ 241 } 242 } 243 244 /* 245 * Lock a cluster. Cluster must already be referenced. Focus is maintained. 246 * 247 * WARNING! This function expects the caller to handle resolution of the 248 * cluster. We never re-resolve the cluster in this function, 249 * because it might be used to temporarily unlock/relock a cparent 250 * in an iteration or recursrion, and the cparents elements do not 251 * necessarily match. 252 */ 253 void 254 hammer2_cluster_lock(hammer2_cluster_t *cluster, int how) 255 { 256 hammer2_chain_t *chain; 257 int i; 258 259 /* cannot be on inode-embedded cluster template, must be on copy */ 260 KKASSERT(cluster->refs > 0); 261 KKASSERT((cluster->flags & HAMMER2_CLUSTER_INODE) == 0); 262 if (cluster->flags & HAMMER2_CLUSTER_LOCKED) { 263 panic("hammer2_cluster_lock: cluster %p already locked!\n", 264 cluster); 265 } 266 atomic_set_int(&cluster->flags, HAMMER2_CLUSTER_LOCKED); 267 268 /* 269 * Lock chains and resolve state. 270 */ 271 for (i = 0; i < cluster->nchains; ++i) { 272 chain = cluster->array[i].chain; 273 if (chain == NULL) 274 continue; 275 hammer2_chain_lock(chain, how); 276 } 277 } 278 279 /* 280 * Calculate the clustering state for the cluster and set its focus. 281 * This routine must be called with care. For example, it should not 282 * normally be called after relocking a non-leaf cluster because parent 283 * clusters help iterations and each element might be at a slightly different 284 * indirect node (each node's topology is independently indexed). 285 * 286 * HAMMER2_CITEM_FEMOD flags which elements can be modified by normal 287 * operations. Typically this is only set on a quorum of MASTERs or 288 * on a SOFT_MASTER. Also as a degenerate case on SUPROOT. If a SOFT_MASTER 289 * is present, this bit is *not* set on a quorum of MASTERs. The 290 * synchronization code ignores this bit, but all hammer2_cluster_*() calls 291 * that create/modify/delete elements use it. 292 * 293 * The chains making up the cluster may be narrowed down based on quorum 294 * acceptability, and if RESOLVE_RDONLY is specified the chains can be 295 * narrowed down to a single chain as long as the entire subtopology is known 296 * to be intact. So, for example, we can narrow a read-only op to a single 297 * fast SLAVE but if we focus a CACHE chain we must still retain at least 298 * a SLAVE to ensure that the subtopology can be accessed. 299 * 300 * RESOLVE_RDONLY operations are effectively as-of so the quorum does not need 301 * to be maintained once the topology is validated as-of the top level of 302 * the operation. 303 * 304 * If a failure occurs the operation must be aborted by higher-level code and 305 * retried. XXX 306 */ 307 void 308 hammer2_cluster_resolve(hammer2_cluster_t *cluster) 309 { 310 hammer2_chain_t *chain; 311 hammer2_chain_t *focus; 312 hammer2_pfs_t *pmp; 313 hammer2_tid_t quorum_tid; 314 hammer2_tid_t last_best_quorum_tid; 315 int focus_pfs_type; 316 uint32_t nflags; 317 int ttlmasters; 318 int ttlslaves; 319 int nmasters; 320 int nslaves; 321 int nquorum; 322 int smpresent; 323 int i; 324 325 cluster->error = 0; 326 cluster->focus = NULL; 327 328 focus_pfs_type = 0; 329 nflags = 0; 330 ttlmasters = 0; 331 ttlslaves = 0; 332 nmasters = 0; 333 nslaves = 0; 334 335 /* 336 * Calculate quorum 337 */ 338 pmp = cluster->pmp; 339 KKASSERT(pmp != NULL || cluster->nchains == 0); 340 nquorum = pmp ? pmp->pfs_nmasters / 2 + 1 : 0; 341 smpresent = 0; 342 343 /* 344 * Pass 1 345 * 346 * NOTE: A NULL chain is not necessarily an error, it could be 347 * e.g. a lookup failure or the end of an iteration. 348 * Process normally. 349 */ 350 for (i = 0; i < cluster->nchains; ++i) { 351 chain = cluster->array[i].chain; 352 if (chain && chain->error) { 353 if (cluster->focus == NULL || cluster->focus == chain) { 354 /* error will be overridden by valid focus */ 355 cluster->error = chain->error; 356 } 357 358 /* 359 * Must count total masters and slaves whether the 360 * chain is errored or not. 361 */ 362 switch (cluster->pmp->pfs_types[i]) { 363 case HAMMER2_PFSTYPE_SUPROOT: 364 case HAMMER2_PFSTYPE_MASTER: 365 ++ttlmasters; 366 break; 367 case HAMMER2_PFSTYPE_SLAVE: 368 ++ttlslaves; 369 break; 370 } 371 continue; 372 } 373 switch (cluster->pmp->pfs_types[i]) { 374 case HAMMER2_PFSTYPE_MASTER: 375 ++ttlmasters; 376 break; 377 case HAMMER2_PFSTYPE_SLAVE: 378 ++ttlslaves; 379 break; 380 case HAMMER2_PFSTYPE_SOFT_MASTER: 381 nflags |= HAMMER2_CLUSTER_WRSOFT; 382 nflags |= HAMMER2_CLUSTER_RDSOFT; 383 smpresent = 1; 384 break; 385 case HAMMER2_PFSTYPE_SOFT_SLAVE: 386 nflags |= HAMMER2_CLUSTER_RDSOFT; 387 break; 388 case HAMMER2_PFSTYPE_SUPROOT: 389 /* 390 * Degenerate cluster representing the super-root 391 * topology on a single device. Fake stuff so 392 * cluster ops work as expected. 393 */ 394 nflags |= HAMMER2_CLUSTER_WRHARD; 395 nflags |= HAMMER2_CLUSTER_RDHARD; 396 cluster->focus_index = i; 397 cluster->focus = chain; 398 cluster->error = chain ? chain->error : 0; 399 ++ttlmasters; 400 break; 401 default: 402 break; 403 } 404 } 405 406 /* 407 * Pass 2 408 * 409 * Resolve masters. Calculate nmasters for the highest matching 410 * TID, if a quorum cannot be attained try the next lower matching 411 * TID until we exhaust TIDs. 412 * 413 * NOTE: A NULL chain is not necessarily an error, it could be 414 * e.g. a lookup failure or the end of an iteration. 415 * Process normally. 416 */ 417 last_best_quorum_tid = HAMMER2_TID_MAX; 418 quorum_tid = 0; /* fix gcc warning */ 419 420 while (nmasters < nquorum && last_best_quorum_tid != 0) { 421 nmasters = 0; 422 quorum_tid = 0; 423 424 for (i = 0; i < cluster->nchains; ++i) { 425 switch (cluster->pmp->pfs_types[i]) { 426 case HAMMER2_PFSTYPE_SUPROOT: 427 case HAMMER2_PFSTYPE_MASTER: 428 break; 429 default: 430 continue; 431 } 432 chain = cluster->array[i].chain; 433 434 if (cluster->array[i].flags & HAMMER2_CITEM_INVALID) { 435 /* 436 * Invalid as in unsynchronized, cannot be 437 * used to calculate the quorum. 438 */ 439 } else if (chain == NULL && quorum_tid == 0) { 440 /* 441 * NULL chain on master matches NULL chains 442 * on other masters. 443 */ 444 ++nmasters; 445 } else if (quorum_tid < last_best_quorum_tid && 446 chain != NULL && 447 (quorum_tid < chain->bref.modify_tid || 448 nmasters == 0)) { 449 /* 450 * Better TID located, reset nmasters count. 451 */ 452 nmasters = 1; 453 quorum_tid = chain->bref.modify_tid; 454 } else if (chain && 455 quorum_tid == chain->bref.modify_tid) { 456 /* 457 * TID matches current collection. 458 */ 459 ++nmasters; 460 } 461 } 462 if (nmasters >= nquorum) 463 break; 464 last_best_quorum_tid = quorum_tid; 465 } 466 467 /* 468 * Pass 3 469 * 470 * NOTE: A NULL chain is not necessarily an error, it could be 471 * e.g. a lookup failure or the end of an iteration. 472 * Process normally. 473 */ 474 for (i = 0; i < cluster->nchains; ++i) { 475 cluster->array[i].flags &= ~HAMMER2_CITEM_FEMOD; 476 chain = cluster->array[i].chain; 477 if (chain && chain->error) { 478 if (cluster->focus == NULL || cluster->focus == chain) { 479 /* error will be overridden by valid focus */ 480 cluster->error = chain->error; 481 } 482 continue; 483 } 484 485 switch (cluster->pmp->pfs_types[i]) { 486 case HAMMER2_PFSTYPE_MASTER: 487 /* 488 * We must have enough up-to-date masters to reach 489 * a quorum and the master modify_tid must match 490 * the quorum's modify_tid. 491 * 492 * Do not select an errored or out-of-sync master. 493 */ 494 if (cluster->array[i].flags & HAMMER2_CITEM_INVALID) { 495 nflags |= HAMMER2_CLUSTER_UNHARD; 496 } else if (nmasters >= nquorum && 497 (chain == NULL || chain->error == 0) && 498 ((chain == NULL && quorum_tid == 0) || 499 (chain != NULL && quorum_tid == 500 chain->bref.modify_tid))) { 501 nflags |= HAMMER2_CLUSTER_WRHARD; 502 nflags |= HAMMER2_CLUSTER_RDHARD; 503 if (!smpresent) { 504 cluster->array[i].flags |= 505 HAMMER2_CITEM_FEMOD; 506 } 507 if (cluster->focus == NULL || 508 focus_pfs_type == HAMMER2_PFSTYPE_SLAVE) { 509 focus_pfs_type = HAMMER2_PFSTYPE_MASTER; 510 cluster->focus_index = i; 511 cluster->focus = chain; /* NULL ok */ 512 cluster->error = chain ? chain->error : 513 0; 514 } 515 } else if (chain == NULL || chain->error == 0) { 516 nflags |= HAMMER2_CLUSTER_UNHARD; 517 } 518 break; 519 case HAMMER2_PFSTYPE_SLAVE: 520 /* 521 * We must have enough up-to-date masters to reach 522 * a quorum and the slave modify_tid must match the 523 * quorum's modify_tid. 524 * 525 * Do not select an errored slave. 526 */ 527 if (cluster->array[i].flags & HAMMER2_CITEM_INVALID) { 528 nflags |= HAMMER2_CLUSTER_UNHARD; 529 } else if (nmasters >= nquorum && 530 (chain == NULL || chain->error == 0) && 531 ((chain == NULL && quorum_tid == 0) || 532 (chain && quorum_tid == 533 chain->bref.modify_tid))) { 534 ++nslaves; 535 nflags |= HAMMER2_CLUSTER_RDHARD; 536 #if 0 537 /* XXX optimize for RESOLVE_RDONLY */ 538 if (cluster->focus == NULL) { 539 focus_pfs_type = HAMMER2_PFSTYPE_SLAVE; 540 cluster->focus_index = i; 541 cluster->focus = chain; /* NULL ok */ 542 cluster->error = chain ? chain->error : 543 0; 544 } 545 #endif 546 } else if (chain == NULL || chain->error == 0) { 547 nflags |= HAMMER2_CLUSTER_UNSOFT; 548 } 549 break; 550 case HAMMER2_PFSTYPE_SOFT_MASTER: 551 /* 552 * Directly mounted soft master always wins. There 553 * should be only one. 554 */ 555 KKASSERT(focus_pfs_type != HAMMER2_PFSTYPE_SOFT_MASTER); 556 cluster->focus_index = i; 557 cluster->focus = chain; 558 cluster->error = chain ? chain->error : 0; 559 focus_pfs_type = HAMMER2_PFSTYPE_SOFT_MASTER; 560 cluster->array[i].flags |= HAMMER2_CITEM_FEMOD; 561 break; 562 case HAMMER2_PFSTYPE_SOFT_SLAVE: 563 /* 564 * Directly mounted soft slave always wins. There 565 * should be only one. 566 */ 567 KKASSERT(focus_pfs_type != HAMMER2_PFSTYPE_SOFT_SLAVE); 568 if (focus_pfs_type != HAMMER2_PFSTYPE_SOFT_MASTER) { 569 cluster->focus_index = i; 570 cluster->focus = chain; 571 cluster->error = chain ? chain->error : 0; 572 focus_pfs_type = HAMMER2_PFSTYPE_SOFT_SLAVE; 573 } 574 break; 575 case HAMMER2_PFSTYPE_SUPROOT: 576 /* 577 * spmp (degenerate case) 578 */ 579 KKASSERT(i == 0); 580 cluster->focus_index = i; 581 cluster->focus = chain; 582 cluster->error = chain ? chain->error : 0; 583 focus_pfs_type = HAMMER2_PFSTYPE_SUPROOT; 584 cluster->array[i].flags |= HAMMER2_CITEM_FEMOD; 585 break; 586 default: 587 break; 588 } 589 } 590 591 /* 592 * Focus now set, adjust ddflag. Skip this pass if the focus 593 * is bad or if we are at the PFS root (the bref won't match at 594 * the PFS root, obviously). 595 */ 596 focus = cluster->focus; 597 if (focus) { 598 cluster->ddflag = 599 (cluster->focus->bref.type == HAMMER2_BREF_TYPE_INODE); 600 } else { 601 cluster->ddflag = 0; 602 goto skip4; 603 } 604 if (cluster->focus->flags & HAMMER2_CHAIN_PFSBOUNDARY) 605 goto skip4; 606 607 /* 608 * Pass 4 609 * 610 * Validate the elements that were not marked invalid. They should 611 * match. 612 */ 613 for (i = 0; i < cluster->nchains; ++i) { 614 int ddflag; 615 616 chain = cluster->array[i].chain; 617 618 if (chain == NULL) 619 continue; 620 if (chain == focus) 621 continue; 622 if (cluster->array[i].flags & HAMMER2_CITEM_INVALID) 623 continue; 624 625 ddflag = (chain->bref.type == HAMMER2_BREF_TYPE_INODE); 626 if (chain->bref.type != focus->bref.type || 627 chain->bref.key != focus->bref.key || 628 chain->bref.keybits != focus->bref.keybits || 629 chain->bref.modify_tid != focus->bref.modify_tid || 630 chain->bytes != focus->bytes || 631 ddflag != cluster->ddflag) { 632 cluster->array[i].flags |= HAMMER2_CITEM_INVALID; 633 if (hammer2_debug & 1) 634 kprintf("cluster_resolve: matching modify_tid failed " 635 "bref test: idx=%d type=%02x/%02x " 636 "key=%016jx/%d-%016jx/%d " 637 "mod=%016jx/%016jx bytes=%u/%u\n", 638 i, 639 chain->bref.type, focus->bref.type, 640 chain->bref.key, chain->bref.keybits, 641 focus->bref.key, focus->bref.keybits, 642 chain->bref.modify_tid, focus->bref.modify_tid, 643 chain->bytes, focus->bytes); 644 if (hammer2_debug & 0x4000) 645 panic("cluster_resolve"); 646 /* flag issue and force resync? */ 647 } 648 } 649 skip4: 650 651 if (ttlslaves == 0) 652 nflags |= HAMMER2_CLUSTER_NOSOFT; 653 if (ttlmasters == 0) 654 nflags |= HAMMER2_CLUSTER_NOHARD; 655 656 /* 657 * Set SSYNCED or MSYNCED for slaves and masters respectively if 658 * all available nodes (even if 0 are available) are fully 659 * synchronized. This is used by the synchronization thread to 660 * determine if there is work it could potentially accomplish. 661 */ 662 if (nslaves == ttlslaves) 663 nflags |= HAMMER2_CLUSTER_SSYNCED; 664 if (nmasters == ttlmasters) 665 nflags |= HAMMER2_CLUSTER_MSYNCED; 666 667 /* 668 * Determine if the cluster was successfully locked for the 669 * requested operation and generate an error code. The cluster 670 * will not be locked (or ref'd) if an error is returned. 671 */ 672 atomic_set_int(&cluster->flags, nflags); 673 atomic_clear_int(&cluster->flags, HAMMER2_CLUSTER_ZFLAGS & ~nflags); 674 } 675 676 /* 677 * This is used by the XOPS subsystem to calculate the state of 678 * the collection and tell hammer2_xop_collect() what to do with it. 679 * The collection can be in various states of desynchronization, the 680 * caller specifically wants to resolve the passed-in key. 681 * 682 * Return values: 683 * 0 - Quorum agreement, key is valid 684 * 685 * ENOENT - Quorum agreement, end of scan 686 * 687 * ESRCH - Quorum agreement, key is INVALID (caller should 688 * skip key). 689 * 690 * EIO - Quorum agreement but all elements had errors. 691 * 692 * EDEADLK - No quorum agreement possible for key, a repair 693 * may be needed. Caller has to decide what to do, 694 * possibly iterating the key or generating an EIO. 695 * 696 * EINPROGRESS - No quorum agreement yet, but agreement is still 697 * possible if caller waits for more responses. Caller 698 * should not iterate key. 699 * 700 * NOTE! If the pmp is in HMNT2_LOCAL mode, the cluster check always succeeds. 701 * 702 * XXX needs to handle SOFT_MASTER and SOFT_SLAVE 703 */ 704 int 705 hammer2_cluster_check(hammer2_cluster_t *cluster, hammer2_key_t key, int flags) 706 { 707 hammer2_chain_t *chain; 708 hammer2_chain_t *focus; 709 hammer2_pfs_t *pmp; 710 hammer2_tid_t quorum_tid; 711 hammer2_tid_t last_best_quorum_tid; 712 uint32_t nflags; 713 int ttlmasters; 714 int ttlslaves; 715 int nmasters; 716 int nmasters_keymatch; 717 int nslaves; 718 int nquorum; 719 int umasters; /* unknown masters (still in progress) */ 720 int smpresent; 721 int error; 722 int i; 723 724 cluster->error = 0; 725 cluster->focus = NULL; 726 727 pmp = cluster->pmp; 728 KKASSERT(pmp != NULL || cluster->nchains == 0); 729 730 /* 731 * Calculate quorum 732 */ 733 nquorum = pmp ? pmp->pfs_nmasters / 2 + 1 : 0; 734 smpresent = 0; 735 nflags = 0; 736 ttlmasters = 0; 737 ttlslaves = 0; 738 nmasters = 0; 739 nmasters_keymatch = 0; 740 umasters = 0; 741 nslaves = 0; 742 743 744 /* 745 * Pass 1 746 * 747 * NOTE: A NULL chain is not necessarily an error, it could be 748 * e.g. a lookup failure or the end of an iteration. 749 * Process normally. 750 */ 751 for (i = 0; i < cluster->nchains; ++i) { 752 cluster->array[i].flags &= ~HAMMER2_CITEM_FEMOD; 753 cluster->array[i].flags |= HAMMER2_CITEM_INVALID; 754 755 chain = cluster->array[i].chain; 756 error = cluster->array[i].error; 757 if (chain && error) { 758 if (cluster->focus == NULL || cluster->focus == chain) { 759 /* error will be overridden by valid focus */ 760 /* XXX */ 761 } 762 763 /* 764 * Must count total masters and slaves whether the 765 * chain is errored or not. 766 */ 767 switch (cluster->pmp->pfs_types[i]) { 768 case HAMMER2_PFSTYPE_SUPROOT: 769 case HAMMER2_PFSTYPE_MASTER: 770 ++ttlmasters; 771 break; 772 case HAMMER2_PFSTYPE_SLAVE: 773 ++ttlslaves; 774 break; 775 } 776 continue; 777 } 778 switch (cluster->pmp->pfs_types[i]) { 779 case HAMMER2_PFSTYPE_MASTER: 780 ++ttlmasters; 781 break; 782 case HAMMER2_PFSTYPE_SLAVE: 783 ++ttlslaves; 784 break; 785 case HAMMER2_PFSTYPE_SOFT_MASTER: 786 nflags |= HAMMER2_CLUSTER_WRSOFT; 787 nflags |= HAMMER2_CLUSTER_RDSOFT; 788 smpresent = 1; 789 break; 790 case HAMMER2_PFSTYPE_SOFT_SLAVE: 791 nflags |= HAMMER2_CLUSTER_RDSOFT; 792 break; 793 case HAMMER2_PFSTYPE_SUPROOT: 794 /* 795 * Degenerate cluster representing the super-root 796 * topology on a single device. Fake stuff so 797 * cluster ops work as expected. 798 */ 799 ++ttlmasters; 800 nflags |= HAMMER2_CLUSTER_WRHARD; 801 nflags |= HAMMER2_CLUSTER_RDHARD; 802 cluster->focus_index = i; 803 cluster->focus = chain; 804 cluster->error = error; 805 break; 806 default: 807 break; 808 } 809 } 810 811 /* 812 * Pass 2 813 * 814 * Resolve nmasters - master nodes fully match 815 * 816 * Resolve umasters - master nodes operation still 817 * in progress 818 * 819 * Resolve nmasters_keymatch - master nodes match the passed-in 820 * key and may or may not match 821 * the quorum-agreed tid. 822 * 823 * The quorum-agreed TID is the highest matching TID. 824 */ 825 last_best_quorum_tid = HAMMER2_TID_MAX; 826 quorum_tid = 0; /* fix gcc warning */ 827 828 while (nmasters < nquorum && last_best_quorum_tid != 0) { 829 nmasters = 0; 830 quorum_tid = 0; 831 832 for (i = 0; i < cluster->nchains; ++i) { 833 /* XXX SOFT smpresent handling */ 834 switch(cluster->pmp->pfs_types[i]) { 835 case HAMMER2_PFSTYPE_MASTER: 836 case HAMMER2_PFSTYPE_SUPROOT: 837 break; 838 default: 839 continue; 840 } 841 842 chain = cluster->array[i].chain; 843 error = cluster->array[i].error; 844 845 /* 846 * Skip elements still in progress. umasters keeps 847 * track of masters that might still be in-progress. 848 */ 849 if (chain == NULL && (cluster->array[i].flags & 850 HAMMER2_CITEM_NULL) == 0) { 851 ++umasters; 852 continue; 853 } 854 855 /* 856 * Key match? 857 */ 858 if (flags & HAMMER2_CHECK_NULL) { 859 if (chain == NULL) { 860 ++nmasters; 861 ++nmasters_keymatch; 862 if (cluster->error == 0) 863 cluster->error = error; 864 } 865 } else if (chain && 866 (key == (hammer2_key_t)-1 || 867 chain->bref.key == key)) { 868 ++nmasters_keymatch; 869 if (quorum_tid < last_best_quorum_tid && 870 (quorum_tid < chain->bref.modify_tid || 871 nmasters == 0)) { 872 /* 873 * Better TID located, reset 874 * nmasters count. 875 */ 876 nmasters = 0; 877 quorum_tid = chain->bref.modify_tid; 878 } 879 if (quorum_tid == chain->bref.modify_tid) { 880 /* 881 * TID matches current collection. 882 * 883 * (error handled in next pass) 884 */ 885 ++nmasters; 886 if (chain->error == 0) { 887 cluster->focus = chain; 888 cluster->focus_index = i; 889 } 890 } 891 } 892 } 893 if (nmasters >= nquorum) 894 break; 895 last_best_quorum_tid = quorum_tid; 896 } 897 898 /* 899 kprintf("nmasters %d/%d nmaster_keymatch=%d umasters=%d\n", 900 nmasters, nquorum, nmasters_keymatch, umasters); 901 */ 902 903 /* 904 * Early return if we do not have enough masters. 905 */ 906 if (nmasters < nquorum) { 907 if (nmasters + umasters >= nquorum) 908 return EINPROGRESS; 909 if (nmasters_keymatch < nquorum) 910 return ESRCH; 911 return EDEADLK; 912 } 913 914 /* 915 * Validated end of scan. 916 */ 917 if (flags & HAMMER2_CHECK_NULL) { 918 if (cluster->error == 0) 919 cluster->error = ENOENT; 920 return cluster->error; 921 } 922 923 /* 924 * If we have a NULL focus at this point the agreeing quorum all 925 * had chain errors. 926 */ 927 if (cluster->focus == NULL) 928 return EIO; 929 930 /* 931 * Pass 3 932 * 933 * We have quorum agreement, validate elements, not end of scan. 934 */ 935 cluster->error = 0; 936 for (i = 0; i < cluster->nchains; ++i) { 937 chain = cluster->array[i].chain; 938 error = cluster->array[i].error; 939 if (chain == NULL || 940 chain->bref.key != key || 941 chain->bref.modify_tid != quorum_tid) { 942 continue; 943 } 944 945 /* 946 * Quorum Match 947 * 948 * XXX for now, cumulative error. 949 */ 950 if (cluster->error == 0) 951 cluster->error = error; 952 953 switch (cluster->pmp->pfs_types[i]) { 954 case HAMMER2_PFSTYPE_MASTER: 955 cluster->array[i].flags |= HAMMER2_CITEM_FEMOD; 956 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 957 nflags |= HAMMER2_CLUSTER_WRHARD; 958 nflags |= HAMMER2_CLUSTER_RDHARD; 959 break; 960 case HAMMER2_PFSTYPE_SLAVE: 961 /* 962 * We must have enough up-to-date masters to reach 963 * a quorum and the slave modify_tid must match the 964 * quorum's modify_tid. 965 * 966 * Do not select an errored slave. 967 */ 968 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 969 nflags |= HAMMER2_CLUSTER_RDHARD; 970 ++nslaves; 971 break; 972 case HAMMER2_PFSTYPE_SOFT_MASTER: 973 /* 974 * Directly mounted soft master always wins. There 975 * should be only one. 976 */ 977 cluster->array[i].flags |= HAMMER2_CITEM_FEMOD; 978 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 979 break; 980 case HAMMER2_PFSTYPE_SOFT_SLAVE: 981 /* 982 * Directly mounted soft slave always wins. There 983 * should be only one. 984 * 985 * XXX 986 */ 987 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 988 break; 989 case HAMMER2_PFSTYPE_SUPROOT: 990 /* 991 * spmp (degenerate case) 992 */ 993 cluster->array[i].flags |= HAMMER2_CITEM_FEMOD; 994 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 995 nflags |= HAMMER2_CLUSTER_WRHARD; 996 nflags |= HAMMER2_CLUSTER_RDHARD; 997 break; 998 default: 999 break; 1000 } 1001 } 1002 1003 /* 1004 * Focus now set, adjust ddflag. Skip this pass if the focus 1005 * is bad or if we are at the PFS root (the bref won't match at 1006 * the PFS root, obviously). 1007 */ 1008 focus = cluster->focus; 1009 if (focus) { 1010 cluster->ddflag = 1011 (cluster->focus->bref.type == HAMMER2_BREF_TYPE_INODE); 1012 } else { 1013 cluster->ddflag = 0; 1014 goto skip4; 1015 } 1016 if (cluster->focus->flags & HAMMER2_CHAIN_PFSBOUNDARY) 1017 goto skip4; 1018 1019 /* 1020 * Pass 4 1021 * 1022 * Validate the elements that were not marked invalid. They should 1023 * match. 1024 */ 1025 for (i = 0; i < cluster->nchains; ++i) { 1026 int ddflag; 1027 1028 chain = cluster->array[i].chain; 1029 1030 if (chain == NULL) 1031 continue; 1032 if (chain == focus) 1033 continue; 1034 if (cluster->array[i].flags & HAMMER2_CITEM_INVALID) 1035 continue; 1036 1037 ddflag = (chain->bref.type == HAMMER2_BREF_TYPE_INODE); 1038 if (chain->bref.type != focus->bref.type || 1039 chain->bref.key != focus->bref.key || 1040 chain->bref.keybits != focus->bref.keybits || 1041 chain->bref.modify_tid != focus->bref.modify_tid || 1042 chain->bytes != focus->bytes || 1043 ddflag != cluster->ddflag) { 1044 cluster->array[i].flags |= HAMMER2_CITEM_INVALID; 1045 if (hammer2_debug & 1) 1046 kprintf("cluster_resolve: matching modify_tid failed " 1047 "bref test: idx=%d type=%02x/%02x " 1048 "key=%016jx/%d-%016jx/%d " 1049 "mod=%016jx/%016jx bytes=%u/%u\n", 1050 i, 1051 chain->bref.type, focus->bref.type, 1052 chain->bref.key, chain->bref.keybits, 1053 focus->bref.key, focus->bref.keybits, 1054 chain->bref.modify_tid, focus->bref.modify_tid, 1055 chain->bytes, focus->bytes); 1056 if (hammer2_debug & 0x4000) 1057 panic("cluster_resolve"); 1058 /* flag issue and force resync? */ 1059 } 1060 } 1061 skip4: 1062 1063 if (ttlslaves == 0) 1064 nflags |= HAMMER2_CLUSTER_NOSOFT; 1065 if (ttlmasters == 0) 1066 nflags |= HAMMER2_CLUSTER_NOHARD; 1067 1068 /* 1069 * Set SSYNCED or MSYNCED for slaves and masters respectively if 1070 * all available nodes (even if 0 are available) are fully 1071 * synchronized. This is used by the synchronization thread to 1072 * determine if there is work it could potentially accomplish. 1073 */ 1074 if (nslaves == ttlslaves) 1075 nflags |= HAMMER2_CLUSTER_SSYNCED; 1076 if (nmasters == ttlmasters) 1077 nflags |= HAMMER2_CLUSTER_MSYNCED; 1078 1079 /* 1080 * Determine if the cluster was successfully locked for the 1081 * requested operation and generate an error code. The cluster 1082 * will not be locked (or ref'd) if an error is returned. 1083 */ 1084 atomic_set_int(&cluster->flags, nflags); 1085 atomic_clear_int(&cluster->flags, HAMMER2_CLUSTER_ZFLAGS & ~nflags); 1086 1087 return cluster->error; 1088 } 1089 1090 /* 1091 * This is used by the sync thread to force non-NULL elements of a copy 1092 * of the pmp->iroot cluster to be good which is required to prime the 1093 * sync. 1094 */ 1095 void 1096 hammer2_cluster_forcegood(hammer2_cluster_t *cluster) 1097 { 1098 int i; 1099 1100 for (i = 0; i < cluster->nchains; ++i) { 1101 if (cluster->array[i].chain) 1102 cluster->array[i].flags &= ~HAMMER2_CITEM_INVALID; 1103 } 1104 } 1105 1106 /* 1107 * Copy a cluster, returned a ref'd cluster. All underlying chains 1108 * are also ref'd, but not locked. Focus state is also copied. 1109 * 1110 * Original cluster does not have to be locked but usually is. 1111 * New cluster will not be flagged as locked. 1112 * 1113 * Callers using this function to initialize a new cluster from an inode 1114 * generally lock and resolve the resulting cluster. 1115 * 1116 * Callers which use this function to save/restore a cluster structure 1117 * generally retain the focus state and do not re-resolve it. Caller should 1118 * not try to re-resolve internal (cparent) node state during an iteration 1119 * as the individual tracking elements of cparent in an iteration may not 1120 * match even though they are correct. 1121 */ 1122 hammer2_cluster_t * 1123 hammer2_cluster_copy(hammer2_cluster_t *ocluster) 1124 { 1125 hammer2_pfs_t *pmp = ocluster->pmp; 1126 hammer2_cluster_t *ncluster; 1127 hammer2_chain_t *chain; 1128 int i; 1129 1130 ncluster = kmalloc(sizeof(*ncluster), M_HAMMER2, M_WAITOK | M_ZERO); 1131 ncluster->pmp = pmp; 1132 ncluster->nchains = ocluster->nchains; 1133 ncluster->refs = 1; 1134 1135 for (i = 0; i < ocluster->nchains; ++i) { 1136 chain = ocluster->array[i].chain; 1137 ncluster->array[i].chain = chain; 1138 ncluster->array[i].flags = ocluster->array[i].flags; 1139 if (chain) 1140 hammer2_chain_ref(chain); 1141 } 1142 ncluster->focus_index = ocluster->focus_index; 1143 ncluster->focus = ocluster->focus; 1144 ncluster->flags = ocluster->flags & ~(HAMMER2_CLUSTER_LOCKED | 1145 HAMMER2_CLUSTER_INODE); 1146 1147 return (ncluster); 1148 } 1149 1150 /* 1151 * Unlock a cluster. Refcount and focus is maintained. 1152 */ 1153 void 1154 hammer2_cluster_unlock(hammer2_cluster_t *cluster) 1155 { 1156 hammer2_chain_t *chain; 1157 int i; 1158 1159 if ((cluster->flags & HAMMER2_CLUSTER_LOCKED) == 0) { 1160 kprintf("hammer2_cluster_unlock: cluster %p not locked\n", 1161 cluster); 1162 } 1163 KKASSERT(cluster->flags & HAMMER2_CLUSTER_LOCKED); 1164 KKASSERT(cluster->refs > 0); 1165 atomic_clear_int(&cluster->flags, HAMMER2_CLUSTER_LOCKED); 1166 1167 for (i = 0; i < cluster->nchains; ++i) { 1168 chain = cluster->array[i].chain; 1169 if (chain) 1170 hammer2_chain_unlock(chain); 1171 } 1172 } 1173 1174 /************************************************************************ 1175 * CLUSTER I/O * 1176 ************************************************************************ 1177 * 1178 * 1179 * WARNING! blockref[] array data is not universal. These functions should 1180 * only be used to access universal data. 1181 * 1182 * NOTE! The rdata call will wait for at least one of the chain I/Os to 1183 * complete if necessary. The I/O's should have already been 1184 * initiated by the cluster_lock/chain_lock operation. 1185 * 1186 * The cluster must already be in a modified state before wdata 1187 * is called. The data will already be available for this case. 1188 */ 1189 const hammer2_media_data_t * 1190 hammer2_cluster_rdata(hammer2_cluster_t *cluster) 1191 { 1192 KKASSERT(cluster->focus != NULL); 1193 return(cluster->focus->data); 1194 } 1195 1196 hammer2_media_data_t * 1197 hammer2_cluster_wdata(hammer2_cluster_t *cluster) 1198 { 1199 KKASSERT(cluster->focus != NULL); 1200 KKASSERT(hammer2_cluster_modified(cluster)); 1201 return(cluster->focus->data); 1202 } 1203