1 /* 2 * Copyright (c) 2011-2015 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 * by 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 * TRANSACTION AND FLUSH HANDLING 37 * 38 * Deceptively simple but actually fairly difficult to implement properly is 39 * how I would describe it. 40 * 41 * Flushing generally occurs bottom-up but requires a top-down scan to 42 * locate chains with MODIFIED and/or UPDATE bits set. The ONFLUSH flag 43 * tells how to recurse downward to find these chains. 44 */ 45 46 #include <sys/cdefs.h> 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/types.h> 50 #include <sys/lock.h> 51 #include <sys/uuid.h> 52 53 #include "hammer2.h" 54 55 #define FLUSH_DEBUG 0 56 57 #define HAMMER2_FLUSH_DEPTH_LIMIT 10 /* stack recursion limit */ 58 59 60 /* 61 * Recursively flush the specified chain. The chain is locked and 62 * referenced by the caller and will remain so on return. The chain 63 * will remain referenced throughout but can temporarily lose its 64 * lock during the recursion to avoid unnecessarily stalling user 65 * processes. 66 */ 67 struct hammer2_flush_info { 68 hammer2_chain_t *parent; 69 int depth; 70 int diddeferral; 71 int cache_index; 72 int flags; 73 struct h2_flush_list flushq; 74 hammer2_chain_t *debug; 75 }; 76 77 typedef struct hammer2_flush_info hammer2_flush_info_t; 78 79 static void hammer2_flush_core(hammer2_flush_info_t *info, 80 hammer2_chain_t *chain, int flags); 81 static int hammer2_flush_recurse(hammer2_chain_t *child, void *data); 82 83 /* 84 * Any per-pfs transaction initialization goes here. 85 */ 86 void 87 hammer2_trans_manage_init(hammer2_pfs_t *pmp) 88 { 89 } 90 91 /* 92 * Transaction support for any modifying operation. Transactions are used 93 * in the pmp layer by the frontend and in the spmp layer by the backend. 94 * 95 * 0 - Normal transaction, interlocked against flush 96 * transaction. 97 * 98 * TRANS_ISFLUSH - Flush transaction, interlocked against normal 99 * transaction. 100 * 101 * TRANS_BUFCACHE - Buffer cache transaction, no interlock. 102 * 103 * Initializing a new transaction allocates a transaction ID. Typically 104 * passed a pmp (hmp passed as NULL), indicating a cluster transaction. Can 105 * be passed a NULL pmp and non-NULL hmp to indicate a transaction on a single 106 * media target. The latter mode is used by the recovery code. 107 * 108 * TWO TRANSACTION IDs can run concurrently, where one is a flush and the 109 * other is a set of any number of concurrent filesystem operations. We 110 * can either have <running_fs_ops> + <waiting_flush> + <blocked_fs_ops> 111 * or we can have <running_flush> + <concurrent_fs_ops>. 112 * 113 * During a flush, new fs_ops are only blocked until the fs_ops prior to 114 * the flush complete. The new fs_ops can then run concurrent with the flush. 115 * 116 * Buffer-cache transactions operate as fs_ops but never block. A 117 * buffer-cache flush will run either before or after the current pending 118 * flush depending on its state. 119 */ 120 void 121 hammer2_trans_init(hammer2_pfs_t *pmp, uint32_t flags) 122 { 123 uint32_t oflags; 124 uint32_t nflags; 125 int dowait; 126 127 for (;;) { 128 oflags = pmp->trans.flags; 129 cpu_ccfence(); 130 dowait = 0; 131 132 if (flags & HAMMER2_TRANS_ISFLUSH) { 133 /* 134 * Requesting flush transaction. Wait for all 135 * currently running transactions to finish. 136 */ 137 if (oflags & HAMMER2_TRANS_MASK) { 138 nflags = oflags | HAMMER2_TRANS_FPENDING | 139 HAMMER2_TRANS_WAITING; 140 dowait = 1; 141 } else { 142 nflags = (oflags | flags) + 1; 143 } 144 } else if (flags & HAMMER2_TRANS_BUFCACHE) { 145 /* 146 * Requesting strategy transaction. Generally 147 * allowed in all situations unless a flush 148 * is running without the preflush flag. 149 */ 150 if ((oflags & (HAMMER2_TRANS_ISFLUSH | 151 HAMMER2_TRANS_PREFLUSH)) == 152 HAMMER2_TRANS_ISFLUSH) { 153 nflags = oflags | HAMMER2_TRANS_WAITING; 154 dowait = 1; 155 } else { 156 nflags = (oflags | flags) + 1; 157 } 158 } else { 159 /* 160 * Requesting normal transaction. Wait for any 161 * flush to finish before allowing. 162 */ 163 if (oflags & HAMMER2_TRANS_ISFLUSH) { 164 nflags = oflags | HAMMER2_TRANS_WAITING; 165 dowait = 1; 166 } else { 167 nflags = (oflags | flags) + 1; 168 } 169 } 170 if (dowait) 171 tsleep_interlock(&pmp->trans.sync_wait, 0); 172 if (atomic_cmpset_int(&pmp->trans.flags, oflags, nflags)) { 173 if (dowait == 0) 174 break; 175 tsleep(&pmp->trans.sync_wait, PINTERLOCKED, 176 "h2trans", hz); 177 } else { 178 cpu_pause(); 179 } 180 /* retry */ 181 } 182 } 183 184 /* 185 * Start a sub-transaction, there is no 'subdone' function. This will 186 * issue a new modify_tid (mtid) for the current transaction, which is a 187 * CLC (cluster level change) id and not a per-node id. 188 * 189 * This function must be called for each XOP when multiple XOPs are run in 190 * sequence within a transaction. 191 * 192 * Callers typically update the inode with the transaction mtid manually 193 * to enforce sequencing. 194 */ 195 hammer2_tid_t 196 hammer2_trans_sub(hammer2_pfs_t *pmp) 197 { 198 hammer2_tid_t mtid; 199 200 mtid = atomic_fetchadd_64(&pmp->modify_tid, 1); 201 202 return (mtid); 203 } 204 205 /* 206 * Clears the PREFLUSH stage, called during a flush transaction after all 207 * logical buffer I/O has completed. 208 */ 209 void 210 hammer2_trans_clear_preflush(hammer2_pfs_t *pmp) 211 { 212 atomic_clear_int(&pmp->trans.flags, HAMMER2_TRANS_PREFLUSH); 213 } 214 215 void 216 hammer2_trans_done(hammer2_pfs_t *pmp) 217 { 218 uint32_t oflags; 219 uint32_t nflags; 220 221 for (;;) { 222 oflags = pmp->trans.flags; 223 cpu_ccfence(); 224 KKASSERT(oflags & HAMMER2_TRANS_MASK); 225 if ((oflags & HAMMER2_TRANS_MASK) == 1) { 226 /* 227 * This was the last transaction 228 */ 229 nflags = (oflags - 1) & ~(HAMMER2_TRANS_ISFLUSH | 230 HAMMER2_TRANS_BUFCACHE | 231 HAMMER2_TRANS_PREFLUSH | 232 HAMMER2_TRANS_FPENDING | 233 HAMMER2_TRANS_WAITING); 234 } else { 235 /* 236 * Still transactions pending 237 */ 238 nflags = oflags - 1; 239 } 240 if (atomic_cmpset_int(&pmp->trans.flags, oflags, nflags)) { 241 if ((nflags & HAMMER2_TRANS_MASK) == 0 && 242 (oflags & HAMMER2_TRANS_WAITING)) { 243 wakeup(&pmp->trans.sync_wait); 244 } 245 break; 246 } else { 247 cpu_pause(); 248 } 249 /* retry */ 250 } 251 } 252 253 /* 254 * Obtain new, unique inode number (not serialized by caller). 255 */ 256 hammer2_tid_t 257 hammer2_trans_newinum(hammer2_pfs_t *pmp) 258 { 259 hammer2_tid_t tid; 260 261 tid = atomic_fetchadd_64(&pmp->inode_tid, 1); 262 263 return tid; 264 } 265 266 /* 267 * Assert that a strategy call is ok here. Strategy calls are legal 268 * 269 * (1) In a normal transaction. 270 * (2) In a flush transaction only if PREFLUSH is also set. 271 */ 272 void 273 hammer2_trans_assert_strategy(hammer2_pfs_t *pmp) 274 { 275 KKASSERT((pmp->trans.flags & HAMMER2_TRANS_ISFLUSH) == 0 || 276 (pmp->trans.flags & HAMMER2_TRANS_PREFLUSH)); 277 } 278 279 280 /* 281 * Chains undergoing destruction are removed from the in-memory topology. 282 * To avoid getting lost these chains are placed on the delayed flush 283 * queue which will properly dispose of them. 284 * 285 * We do this instead of issuing an immediate flush in order to give 286 * recursive deletions (rm -rf, etc) a chance to remove more of the 287 * hierarchy, potentially allowing an enormous amount of write I/O to 288 * be avoided. 289 */ 290 void 291 hammer2_delayed_flush(hammer2_chain_t *chain) 292 { 293 if ((chain->flags & HAMMER2_CHAIN_DELAYED) == 0) { 294 hammer2_spin_ex(&chain->hmp->list_spin); 295 if ((chain->flags & (HAMMER2_CHAIN_DELAYED | 296 HAMMER2_CHAIN_DEFERRED)) == 0) { 297 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELAYED | 298 HAMMER2_CHAIN_DEFERRED); 299 TAILQ_INSERT_TAIL(&chain->hmp->flushq, 300 chain, flush_node); 301 hammer2_chain_ref(chain); 302 } 303 hammer2_spin_unex(&chain->hmp->list_spin); 304 hammer2_voldata_modify(chain->hmp); 305 } 306 } 307 308 /* 309 * Flush the chain and all modified sub-chains through the specified 310 * synchronization point, propagating blockref updates back up. As 311 * part of this propagation, mirror_tid and inode/data usage statistics 312 * propagates back upward. 313 * 314 * modify_tid (clc - cluster level change) is not propagated. 315 * 316 * update_tid (clc) is used for validation and is not propagated by this 317 * function. 318 * 319 * This routine can be called from several places but the most important 320 * is from VFS_SYNC (frontend) via hammer2_inode_xop_flush (backend). 321 * 322 * chain is locked on call and will remain locked on return. The chain's 323 * UPDATE flag indicates that its parent's block table (which is not yet 324 * part of the flush) should be updated. The chain may be replaced by 325 * the call if it was modified. 326 */ 327 void 328 hammer2_flush(hammer2_chain_t *chain, int flags) 329 { 330 hammer2_chain_t *scan; 331 hammer2_flush_info_t info; 332 hammer2_dev_t *hmp; 333 int loops; 334 335 /* 336 * Execute the recursive flush and handle deferrals. 337 * 338 * Chains can be ridiculously long (thousands deep), so to 339 * avoid blowing out the kernel stack the recursive flush has a 340 * depth limit. Elements at the limit are placed on a list 341 * for re-execution after the stack has been popped. 342 */ 343 bzero(&info, sizeof(info)); 344 TAILQ_INIT(&info.flushq); 345 info.cache_index = -1; 346 info.flags = flags & ~HAMMER2_FLUSH_TOP; 347 348 /* 349 * Calculate parent (can be NULL), if not NULL the flush core 350 * expects the parent to be referenced so it can easily lock/unlock 351 * it without it getting ripped up. 352 */ 353 if ((info.parent = chain->parent) != NULL) 354 hammer2_chain_ref(info.parent); 355 356 /* 357 * Extra ref needed because flush_core expects it when replacing 358 * chain. 359 */ 360 hammer2_chain_ref(chain); 361 hmp = chain->hmp; 362 loops = 0; 363 364 for (;;) { 365 /* 366 * Move hmp->flushq to info.flushq if non-empty so it can 367 * be processed. 368 */ 369 if (TAILQ_FIRST(&hmp->flushq) != NULL) { 370 hammer2_spin_ex(&chain->hmp->list_spin); 371 TAILQ_CONCAT(&info.flushq, &hmp->flushq, flush_node); 372 hammer2_spin_unex(&chain->hmp->list_spin); 373 } 374 375 /* 376 * Unwind deep recursions which had been deferred. This 377 * can leave the FLUSH_* bits set for these chains, which 378 * will be handled when we [re]flush chain after the unwind. 379 */ 380 while ((scan = TAILQ_FIRST(&info.flushq)) != NULL) { 381 KKASSERT(scan->flags & HAMMER2_CHAIN_DEFERRED); 382 TAILQ_REMOVE(&info.flushq, scan, flush_node); 383 atomic_clear_int(&scan->flags, HAMMER2_CHAIN_DEFERRED | 384 HAMMER2_CHAIN_DELAYED); 385 386 /* 387 * Now that we've popped back up we can do a secondary 388 * recursion on the deferred elements. 389 * 390 * NOTE: hammer2_flush() may replace scan. 391 */ 392 if (hammer2_debug & 0x0040) 393 kprintf("deferred flush %p\n", scan); 394 hammer2_chain_lock(scan, HAMMER2_RESOLVE_MAYBE); 395 hammer2_flush(scan, flags & ~HAMMER2_FLUSH_TOP); 396 hammer2_chain_unlock(scan); 397 hammer2_chain_drop(scan); /* ref from deferral */ 398 } 399 400 /* 401 * [re]flush chain. 402 */ 403 info.diddeferral = 0; 404 hammer2_flush_core(&info, chain, flags); 405 406 /* 407 * Only loop if deep recursions have been deferred. 408 */ 409 if (TAILQ_EMPTY(&info.flushq)) 410 break; 411 412 if (++loops % 1000 == 0) { 413 kprintf("hammer2_flush: excessive loops on %p\n", 414 chain); 415 if (hammer2_debug & 0x100000) 416 Debugger("hell4"); 417 } 418 } 419 hammer2_chain_drop(chain); 420 if (info.parent) 421 hammer2_chain_drop(info.parent); 422 } 423 424 /* 425 * This is the core of the chain flushing code. The chain is locked by the 426 * caller and must also have an extra ref on it by the caller, and remains 427 * locked and will have an extra ref on return. Upon return, the caller can 428 * test the UPDATE bit on the child to determine if the parent needs updating. 429 * 430 * (1) Determine if this node is a candidate for the flush, return if it is 431 * not. fchain and vchain are always candidates for the flush. 432 * 433 * (2) If we recurse too deep the chain is entered onto the deferral list and 434 * the current flush stack is aborted until after the deferral list is 435 * run. 436 * 437 * (3) Recursively flush live children (rbtree). This can create deferrals. 438 * A successful flush clears the MODIFIED and UPDATE bits on the children 439 * and typically causes the parent to be marked MODIFIED as the children 440 * update the parent's block table. A parent might already be marked 441 * MODIFIED due to a deletion (whos blocktable update in the parent is 442 * handled by the frontend), or if the parent itself is modified by the 443 * frontend for other reasons. 444 * 445 * (4) Permanently disconnected sub-trees are cleaned up by the front-end. 446 * Deleted-but-open inodes can still be individually flushed via the 447 * filesystem syncer. 448 * 449 * (5) Note that an unmodified child may still need the block table in its 450 * parent updated (e.g. rename/move). The child will have UPDATE set 451 * in this case. 452 * 453 * WARNING ON BREF MODIFY_TID/MIRROR_TID 454 * 455 * blockref.modify_tid is consistent only within a PFS, and will not be 456 * consistent during synchronization. mirror_tid is consistent across the 457 * block device regardless of the PFS. 458 */ 459 static void 460 hammer2_flush_core(hammer2_flush_info_t *info, hammer2_chain_t *chain, 461 int flags) 462 { 463 hammer2_chain_t *parent; 464 hammer2_dev_t *hmp; 465 int diddeferral; 466 467 /* 468 * (1) Optimize downward recursion to locate nodes needing action. 469 * Nothing to do if none of these flags are set. 470 */ 471 if ((chain->flags & HAMMER2_CHAIN_FLUSH_MASK) == 0) { 472 if (hammer2_debug & 0x200) { 473 if (info->debug == NULL) 474 info->debug = chain; 475 } else { 476 return; 477 } 478 } 479 480 hmp = chain->hmp; 481 diddeferral = info->diddeferral; 482 parent = info->parent; /* can be NULL */ 483 484 /* 485 * Downward search recursion 486 */ 487 if (chain->flags & (HAMMER2_CHAIN_DEFERRED | HAMMER2_CHAIN_DELAYED)) { 488 /* 489 * Already deferred. 490 */ 491 ++info->diddeferral; 492 } else if ((chain->flags & HAMMER2_CHAIN_PFSBOUNDARY) && 493 (flags & HAMMER2_FLUSH_ALL) == 0 && 494 (flags & HAMMER2_FLUSH_TOP) == 0) { 495 /* 496 * We do not recurse through PFSROOTs. PFSROOT flushes are 497 * handled by the related pmp's (whether mounted or not, 498 * including during recovery). 499 * 500 * But we must still process the PFSROOT chains for block 501 * table updates in their parent (which IS part of our flush). 502 * 503 * Note that the volume root, vchain, does not set this flag. 504 * Note the logic here requires that this test be done before 505 * the depth-limit test, else it might become the top on a 506 * flushq iteration. 507 */ 508 ; 509 } else if (info->depth == HAMMER2_FLUSH_DEPTH_LIMIT) { 510 /* 511 * Recursion depth reached. 512 */ 513 KKASSERT((chain->flags & HAMMER2_CHAIN_DELAYED) == 0); 514 hammer2_chain_ref(chain); 515 TAILQ_INSERT_TAIL(&info->flushq, chain, flush_node); 516 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEFERRED); 517 ++info->diddeferral; 518 } else if (chain->flags & HAMMER2_CHAIN_ONFLUSH) { 519 /* 520 * Downward recursion search (actual flush occurs bottom-up). 521 * pre-clear ONFLUSH. It can get set again due to races, 522 * which we want so the scan finds us again in the next flush. 523 */ 524 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); 525 info->parent = chain; 526 hammer2_spin_ex(&chain->core.spin); 527 RB_SCAN(hammer2_chain_tree, &chain->core.rbtree, 528 NULL, hammer2_flush_recurse, info); 529 hammer2_spin_unex(&chain->core.spin); 530 info->parent = parent; 531 if (info->diddeferral) 532 hammer2_chain_setflush(chain); 533 } 534 535 /* 536 * Now we are in the bottom-up part of the recursion. 537 * 538 * Do not update chain if lower layers were deferred. 539 */ 540 if (info->diddeferral) 541 goto done; 542 543 /* 544 * Propagate the DESTROY flag downwards. This dummies up the flush 545 * code and tries to invalidate related buffer cache buffers to 546 * avoid the disk write. 547 */ 548 if (parent && (parent->flags & HAMMER2_CHAIN_DESTROY)) 549 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 550 551 /* 552 * Chain was already modified or has become modified, flush it out. 553 */ 554 again: 555 if ((hammer2_debug & 0x200) && 556 info->debug && 557 (chain->flags & (HAMMER2_CHAIN_MODIFIED | HAMMER2_CHAIN_UPDATE))) { 558 hammer2_chain_t *scan = chain; 559 560 kprintf("DISCONNECTED FLUSH %p->%p\n", info->debug, chain); 561 while (scan) { 562 kprintf(" chain %p [%08x] bref=%016jx:%02x\n", 563 scan, scan->flags, 564 scan->bref.key, scan->bref.type); 565 if (scan == info->debug) 566 break; 567 scan = scan->parent; 568 } 569 } 570 571 if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 572 /* 573 * Dispose of the modified bit. 574 * 575 * If parent is present, the UPDATE bit should already be set. 576 * UPDATE should already be set. 577 * bref.mirror_tid should already be set. 578 */ 579 KKASSERT((chain->flags & HAMMER2_CHAIN_UPDATE) || 580 chain->parent == NULL); 581 if (hammer2_debug & 0x800000) { 582 hammer2_chain_t *pp; 583 584 for (pp = chain; pp->parent; pp = pp->parent) 585 ; 586 kprintf("FLUSH CHAIN %p (p=%p pp=%p/%d) TYPE %d FLAGS %08x (%s)\n", 587 chain, chain->parent, pp, pp->bref.type, 588 chain->bref.type, chain->flags, 589 (chain->bref.type == 1 ? (const char *)chain->data->ipdata.filename : "?") 590 591 ); 592 print_backtrace(10); 593 } 594 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 595 atomic_add_long(&hammer2_count_modified_chains, -1); 596 597 /* 598 * Manage threads waiting for excessive dirty memory to 599 * be retired. 600 */ 601 if (chain->pmp) 602 hammer2_pfs_memory_wakeup(chain->pmp); 603 604 #if 0 605 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0 && 606 chain != &hmp->vchain && 607 chain != &hmp->fchain) { 608 /* 609 * Set UPDATE bit indicating that the parent block 610 * table requires updating. 611 */ 612 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 613 } 614 #endif 615 616 /* 617 * Issue the flush. This is indirect via the DIO. 618 * 619 * NOTE: A DELETED node that reaches this point must be 620 * flushed for synchronization point consistency. 621 * 622 * NOTE: Even though MODIFIED was already set, the related DIO 623 * might not be dirty due to a system buffer cache 624 * flush and must be set dirty if we are going to make 625 * further modifications to the buffer. Chains with 626 * embedded data don't need this. 627 */ 628 if (hammer2_debug & 0x1000) { 629 kprintf("Flush %p.%d %016jx/%d data=%016jx", 630 chain, chain->bref.type, 631 (uintmax_t)chain->bref.key, 632 chain->bref.keybits, 633 (uintmax_t)chain->bref.data_off); 634 } 635 if (hammer2_debug & 0x2000) { 636 Debugger("Flush hell"); 637 } 638 639 /* 640 * Update chain CRCs for flush. 641 * 642 * NOTE: Volume headers are NOT flushed here as they require 643 * special processing. 644 */ 645 switch(chain->bref.type) { 646 case HAMMER2_BREF_TYPE_FREEMAP: 647 /* 648 * Update the volume header's freemap_tid to the 649 * freemap's flushing mirror_tid. 650 * 651 * (note: embedded data, do not call setdirty) 652 */ 653 KKASSERT(hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED); 654 KKASSERT(chain == &hmp->fchain); 655 hmp->voldata.freemap_tid = chain->bref.mirror_tid; 656 if (hammer2_debug & 0x8000) { 657 /* debug only, avoid syslogd loop */ 658 kprintf("sync freemap mirror_tid %08jx\n", 659 (intmax_t)chain->bref.mirror_tid); 660 } 661 662 /* 663 * The freemap can be flushed independently of the 664 * main topology, but for the case where it is 665 * flushed in the same transaction, and flushed 666 * before vchain (a case we want to allow for 667 * performance reasons), make sure modifications 668 * made during the flush under vchain use a new 669 * transaction id. 670 * 671 * Otherwise the mount recovery code will get confused. 672 */ 673 ++hmp->voldata.mirror_tid; 674 break; 675 case HAMMER2_BREF_TYPE_VOLUME: 676 /* 677 * The free block table is flushed by 678 * hammer2_vfs_sync() before it flushes vchain. 679 * We must still hold fchain locked while copying 680 * voldata to volsync, however. 681 * 682 * (note: embedded data, do not call setdirty) 683 */ 684 hammer2_chain_lock(&hmp->fchain, 685 HAMMER2_RESOLVE_ALWAYS); 686 hammer2_voldata_lock(hmp); 687 if (hammer2_debug & 0x8000) { 688 /* debug only, avoid syslogd loop */ 689 kprintf("sync volume mirror_tid %08jx\n", 690 (intmax_t)chain->bref.mirror_tid); 691 } 692 693 /* 694 * Update the volume header's mirror_tid to the 695 * main topology's flushing mirror_tid. It is 696 * possible that voldata.mirror_tid is already 697 * beyond bref.mirror_tid due to the bump we made 698 * above in BREF_TYPE_FREEMAP. 699 */ 700 if (hmp->voldata.mirror_tid < chain->bref.mirror_tid) { 701 hmp->voldata.mirror_tid = 702 chain->bref.mirror_tid; 703 } 704 705 /* 706 * The volume header is flushed manually by the 707 * syncer, not here. All we do here is adjust the 708 * crc's. 709 */ 710 KKASSERT(chain->data != NULL); 711 KKASSERT(chain->dio == NULL); 712 713 hmp->voldata.icrc_sects[HAMMER2_VOL_ICRC_SECT1]= 714 hammer2_icrc32( 715 (char *)&hmp->voldata + 716 HAMMER2_VOLUME_ICRC1_OFF, 717 HAMMER2_VOLUME_ICRC1_SIZE); 718 hmp->voldata.icrc_sects[HAMMER2_VOL_ICRC_SECT0]= 719 hammer2_icrc32( 720 (char *)&hmp->voldata + 721 HAMMER2_VOLUME_ICRC0_OFF, 722 HAMMER2_VOLUME_ICRC0_SIZE); 723 hmp->voldata.icrc_volheader = 724 hammer2_icrc32( 725 (char *)&hmp->voldata + 726 HAMMER2_VOLUME_ICRCVH_OFF, 727 HAMMER2_VOLUME_ICRCVH_SIZE); 728 729 if (hammer2_debug & 0x8000) { 730 /* debug only, avoid syslogd loop */ 731 kprintf("syncvolhdr %016jx %016jx\n", 732 hmp->voldata.mirror_tid, 733 hmp->vchain.bref.mirror_tid); 734 } 735 hmp->volsync = hmp->voldata; 736 atomic_set_int(&chain->flags, HAMMER2_CHAIN_VOLUMESYNC); 737 hammer2_voldata_unlock(hmp); 738 hammer2_chain_unlock(&hmp->fchain); 739 break; 740 case HAMMER2_BREF_TYPE_DATA: 741 /* 742 * Data elements have already been flushed via the 743 * logical file buffer cache. Their hash was set in 744 * the bref by the vop_write code. Do not re-dirty. 745 * 746 * Make sure any device buffer(s) have been flushed 747 * out here (there aren't usually any to flush) XXX. 748 */ 749 break; 750 case HAMMER2_BREF_TYPE_INDIRECT: 751 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 752 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 753 /* 754 * Buffer I/O will be cleaned up when the volume is 755 * flushed (but the kernel is free to flush it before 756 * then, as well). 757 */ 758 KKASSERT((chain->flags & HAMMER2_CHAIN_EMBEDDED) == 0); 759 hammer2_chain_setcheck(chain, chain->data); 760 break; 761 case HAMMER2_BREF_TYPE_INODE: 762 /* 763 * NOTE: We must call io_setdirty() to make any late 764 * changes to the inode data, the system might 765 * have already flushed the buffer. 766 */ 767 if (chain->data->ipdata.meta.op_flags & 768 HAMMER2_OPFLAG_PFSROOT) { 769 /* 770 * non-NULL pmp if mounted as a PFS. We must 771 * sync fields cached in the pmp? XXX 772 */ 773 hammer2_inode_data_t *ipdata; 774 775 hammer2_io_setdirty(chain->dio); 776 ipdata = &chain->data->ipdata; 777 if (chain->pmp) { 778 ipdata->meta.pfs_inum = 779 chain->pmp->inode_tid; 780 } 781 } else { 782 /* can't be mounted as a PFS */ 783 } 784 785 KKASSERT((chain->flags & HAMMER2_CHAIN_EMBEDDED) == 0); 786 hammer2_chain_setcheck(chain, chain->data); 787 break; 788 default: 789 KKASSERT(chain->flags & HAMMER2_CHAIN_EMBEDDED); 790 panic("hammer2_flush_core: unsupported " 791 "embedded bref %d", 792 chain->bref.type); 793 /* NOT REACHED */ 794 } 795 796 /* 797 * If the chain was destroyed try to avoid unnecessary I/O. 798 * (this only really works if the DIO system buffer is the 799 * same size as chain->bytes). 800 */ 801 if ((chain->flags & HAMMER2_CHAIN_DESTROY) && 802 (chain->flags & HAMMER2_CHAIN_DEDUP) == 0 && 803 chain->dio) { 804 hammer2_io_setinval(chain->dio, chain->bytes); 805 } 806 } 807 808 /* 809 * If UPDATE is set the parent block table may need to be updated. 810 * 811 * NOTE: UPDATE may be set on vchain or fchain in which case 812 * parent could be NULL. It's easiest to allow the case 813 * and test for NULL. parent can also wind up being NULL 814 * due to a deletion so we need to handle the case anyway. 815 * 816 * If no parent exists we can just clear the UPDATE bit. If the 817 * chain gets reattached later on the bit will simply get set 818 * again. 819 */ 820 if ((chain->flags & HAMMER2_CHAIN_UPDATE) && parent == NULL) 821 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 822 823 /* 824 * The chain may need its blockrefs updated in the parent. This 825 * requires some fancy footwork. 826 */ 827 if (chain->flags & HAMMER2_CHAIN_UPDATE) { 828 hammer2_blockref_t *base; 829 int count; 830 831 /* 832 * Both parent and chain must be locked. This requires 833 * temporarily unlocking the chain. We have to deal with 834 * the case where the chain might be reparented or modified 835 * while it was unlocked. 836 */ 837 hammer2_chain_unlock(chain); 838 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 839 hammer2_chain_lock(chain, HAMMER2_RESOLVE_MAYBE); 840 if (chain->parent != parent) { 841 kprintf("PARENT MISMATCH ch=%p p=%p/%p\n", 842 chain, chain->parent, parent); 843 hammer2_chain_unlock(parent); 844 goto done; 845 } 846 847 /* 848 * Check race condition. If someone got in and modified 849 * it again while it was unlocked, we have to loop up. 850 */ 851 if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 852 hammer2_chain_unlock(parent); 853 kprintf("hammer2_flush: chain %p flush-mod race\n", 854 chain); 855 goto again; 856 } 857 858 /* 859 * Clear UPDATE flag, mark parent modified, update its 860 * modify_tid if necessary, and adjust the parent blockmap. 861 */ 862 if (chain->flags & HAMMER2_CHAIN_UPDATE) 863 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 864 865 /* 866 * (optional code) 867 * 868 * Avoid actually modifying and updating the parent if it 869 * was flagged for destruction. This can greatly reduce 870 * disk I/O in large tree removals because the 871 * hammer2_io_setinval() call in the upward recursion 872 * (see MODIFIED code above) can only handle a few cases. 873 */ 874 if (parent->flags & HAMMER2_CHAIN_DESTROY) { 875 if (parent->bref.modify_tid < chain->bref.modify_tid) { 876 parent->bref.modify_tid = 877 chain->bref.modify_tid; 878 } 879 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BMAPPED | 880 HAMMER2_CHAIN_BMAPUPD); 881 hammer2_chain_unlock(parent); 882 goto skipupdate; 883 } 884 885 /* 886 * We are updating the parent's blockmap, the parent must 887 * be set modified. 888 */ 889 hammer2_chain_modify(parent, 0, 0, 0); 890 if (parent->bref.modify_tid < chain->bref.modify_tid) 891 parent->bref.modify_tid = chain->bref.modify_tid; 892 893 /* 894 * Calculate blockmap pointer 895 */ 896 switch(parent->bref.type) { 897 case HAMMER2_BREF_TYPE_INODE: 898 /* 899 * Access the inode's block array. However, there is 900 * no block array if the inode is flagged DIRECTDATA. 901 */ 902 if (parent->data && 903 (parent->data->ipdata.meta.op_flags & 904 HAMMER2_OPFLAG_DIRECTDATA) == 0) { 905 base = &parent->data-> 906 ipdata.u.blockset.blockref[0]; 907 } else { 908 base = NULL; 909 } 910 count = HAMMER2_SET_COUNT; 911 break; 912 case HAMMER2_BREF_TYPE_INDIRECT: 913 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 914 if (parent->data) 915 base = &parent->data->npdata[0]; 916 else 917 base = NULL; 918 count = parent->bytes / sizeof(hammer2_blockref_t); 919 break; 920 case HAMMER2_BREF_TYPE_VOLUME: 921 base = &chain->hmp->voldata.sroot_blockset.blockref[0]; 922 count = HAMMER2_SET_COUNT; 923 break; 924 case HAMMER2_BREF_TYPE_FREEMAP: 925 base = &parent->data->npdata[0]; 926 count = HAMMER2_SET_COUNT; 927 break; 928 default: 929 base = NULL; 930 count = 0; 931 panic("hammer2_flush_core: " 932 "unrecognized blockref type: %d", 933 parent->bref.type); 934 } 935 936 /* 937 * Blocktable updates 938 * 939 * We synchronize pending statistics at this time. Delta 940 * adjustments designated for the current and upper level 941 * are synchronized. 942 */ 943 if (base && (chain->flags & HAMMER2_CHAIN_BMAPUPD)) { 944 if (chain->flags & HAMMER2_CHAIN_BMAPPED) { 945 hammer2_spin_ex(&parent->core.spin); 946 hammer2_base_delete(parent, base, count, 947 &info->cache_index, chain); 948 hammer2_spin_unex(&parent->core.spin); 949 /* base_delete clears both bits */ 950 } else { 951 atomic_clear_int(&chain->flags, 952 HAMMER2_CHAIN_BMAPUPD); 953 } 954 } 955 if (base && (chain->flags & HAMMER2_CHAIN_BMAPPED) == 0) { 956 hammer2_spin_ex(&parent->core.spin); 957 hammer2_base_insert(parent, base, count, 958 &info->cache_index, chain); 959 hammer2_spin_unex(&parent->core.spin); 960 /* base_insert sets BMAPPED */ 961 } 962 hammer2_chain_unlock(parent); 963 } 964 skipupdate: 965 ; 966 967 /* 968 * Final cleanup after flush 969 */ 970 done: 971 KKASSERT(chain->refs > 0); 972 if (hammer2_debug & 0x200) { 973 if (info->debug == chain) 974 info->debug = NULL; 975 } 976 } 977 978 /* 979 * Flush recursion helper, called from flush_core, calls flush_core. 980 * 981 * Flushes the children of the caller's chain (info->parent), restricted 982 * by sync_tid. Set info->domodify if the child's blockref must propagate 983 * back up to the parent. 984 * 985 * Ripouts can move child from rbtree to dbtree or dbq but the caller's 986 * flush scan order prevents any chains from being lost. A child can be 987 * executes more than once. 988 * 989 * WARNING! If we do not call hammer2_flush_core() we must update 990 * bref.mirror_tid ourselves to indicate that the flush has 991 * processed the child. 992 * 993 * WARNING! parent->core spinlock is held on entry and return. 994 */ 995 static int 996 hammer2_flush_recurse(hammer2_chain_t *child, void *data) 997 { 998 hammer2_flush_info_t *info = data; 999 hammer2_chain_t *parent = info->parent; 1000 1001 /* 1002 * (child can never be fchain or vchain so a special check isn't 1003 * needed). 1004 * 1005 * We must ref the child before unlocking the spinlock. 1006 * 1007 * The caller has added a ref to the parent so we can temporarily 1008 * unlock it in order to lock the child. 1009 */ 1010 hammer2_chain_ref(child); 1011 hammer2_spin_unex(&parent->core.spin); 1012 1013 hammer2_chain_unlock(parent); 1014 hammer2_chain_lock(child, HAMMER2_RESOLVE_MAYBE); 1015 1016 /* 1017 * Recurse and collect deferral data. We're in the media flush, 1018 * this can cross PFS boundaries. 1019 */ 1020 if (child->flags & HAMMER2_CHAIN_FLUSH_MASK) { 1021 ++info->depth; 1022 hammer2_flush_core(info, child, info->flags); 1023 --info->depth; 1024 } else if (hammer2_debug & 0x200) { 1025 if (info->debug == NULL) 1026 info->debug = child; 1027 ++info->depth; 1028 hammer2_flush_core(info, child, info->flags); 1029 --info->depth; 1030 if (info->debug == child) 1031 info->debug = NULL; 1032 } 1033 1034 /* 1035 * Relock to continue the loop 1036 */ 1037 hammer2_chain_unlock(child); 1038 hammer2_chain_lock(parent, HAMMER2_RESOLVE_MAYBE); 1039 hammer2_chain_drop(child); 1040 KKASSERT(info->parent == parent); 1041 hammer2_spin_ex(&parent->core.spin); 1042 1043 return (0); 1044 } 1045 1046 /* 1047 * flush helper (direct) 1048 * 1049 * Quickly flushes any dirty chains for a device. This will update our 1050 * concept of the volume root but does NOT flush the actual volume root 1051 * and does not flush dirty device buffers. 1052 * 1053 * This function is primarily used by the bulkfree code to allow it to 1054 * create a snapshot for the pass. It doesn't care about any pending 1055 * work (dirty vnodes, dirty inodes, dirty logical buffers) for which blocks 1056 * have not yet been allocated. 1057 */ 1058 void 1059 hammer2_flush_quick(hammer2_dev_t *hmp) 1060 { 1061 hammer2_chain_t *chain; 1062 1063 hammer2_trans_init(hmp->spmp, HAMMER2_TRANS_ISFLUSH); 1064 1065 hammer2_chain_ref(&hmp->vchain); 1066 hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS); 1067 if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) { 1068 chain = &hmp->vchain; 1069 hammer2_flush(chain, HAMMER2_FLUSH_TOP | 1070 HAMMER2_FLUSH_ALL); 1071 KKASSERT(chain == &hmp->vchain); 1072 } 1073 hammer2_chain_unlock(&hmp->vchain); 1074 hammer2_chain_drop(&hmp->vchain); 1075 1076 hammer2_trans_done(hmp->spmp); /* spmp trans */ 1077 } 1078 1079 /* 1080 * flush helper (backend threaded) 1081 * 1082 * Flushes core chains, issues disk sync, flushes volume roots. 1083 * 1084 * Primarily called from vfs_sync(). 1085 */ 1086 void 1087 hammer2_inode_xop_flush(hammer2_xop_t *arg, int clindex) 1088 { 1089 hammer2_xop_flush_t *xop = &arg->xop_flush; 1090 hammer2_chain_t *chain; 1091 hammer2_chain_t *parent; 1092 hammer2_dev_t *hmp; 1093 int error = 0; 1094 int total_error = 0; 1095 int j; 1096 1097 /* 1098 * Flush core chains 1099 */ 1100 chain = hammer2_inode_chain(xop->head.ip1, clindex, 1101 HAMMER2_RESOLVE_ALWAYS); 1102 if (chain) { 1103 hmp = chain->hmp; 1104 if ((chain->flags & HAMMER2_CHAIN_FLUSH_MASK) || 1105 TAILQ_FIRST(&hmp->flushq) != NULL) { 1106 hammer2_flush(chain, HAMMER2_FLUSH_TOP); 1107 parent = chain->parent; 1108 KKASSERT(chain->pmp != parent->pmp); 1109 hammer2_chain_setflush(parent); 1110 } 1111 hammer2_chain_unlock(chain); 1112 hammer2_chain_drop(chain); 1113 chain = NULL; 1114 } else { 1115 hmp = NULL; 1116 } 1117 1118 /* 1119 * Flush volume roots. Avoid replication, we only want to 1120 * flush each hammer2_dev (hmp) once. 1121 */ 1122 for (j = clindex - 1; j >= 0; --j) { 1123 if ((chain = xop->head.ip1->cluster.array[j].chain) != NULL) { 1124 if (chain->hmp == hmp) { 1125 chain = NULL; /* safety */ 1126 goto skip; 1127 } 1128 } 1129 } 1130 chain = NULL; /* safety */ 1131 1132 /* 1133 * spmp transaction. The super-root is never directly mounted so 1134 * there shouldn't be any vnodes, let alone any dirty vnodes 1135 * associated with it, so we shouldn't have to mess around with any 1136 * vnode flushes here. 1137 */ 1138 hammer2_trans_init(hmp->spmp, HAMMER2_TRANS_ISFLUSH); 1139 1140 /* 1141 * Media mounts have two 'roots', vchain for the topology 1142 * and fchain for the free block table. Flush both. 1143 * 1144 * Note that the topology and free block table are handled 1145 * independently, so the free block table can wind up being 1146 * ahead of the topology. We depend on the bulk free scan 1147 * code to deal with any loose ends. 1148 */ 1149 hammer2_chain_ref(&hmp->vchain); 1150 hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS); 1151 hammer2_chain_ref(&hmp->fchain); 1152 hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS); 1153 if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) { 1154 /* 1155 * This will also modify vchain as a side effect, 1156 * mark vchain as modified now. 1157 */ 1158 hammer2_voldata_modify(hmp); 1159 chain = &hmp->fchain; 1160 hammer2_flush(chain, HAMMER2_FLUSH_TOP); 1161 KKASSERT(chain == &hmp->fchain); 1162 } 1163 hammer2_chain_unlock(&hmp->fchain); 1164 hammer2_chain_unlock(&hmp->vchain); 1165 hammer2_chain_drop(&hmp->fchain); 1166 /* vchain dropped down below */ 1167 1168 hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS); 1169 if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) { 1170 chain = &hmp->vchain; 1171 hammer2_flush(chain, HAMMER2_FLUSH_TOP); 1172 KKASSERT(chain == &hmp->vchain); 1173 } 1174 hammer2_chain_unlock(&hmp->vchain); 1175 hammer2_chain_drop(&hmp->vchain); 1176 1177 error = 0; 1178 1179 /* 1180 * We can't safely flush the volume header until we have 1181 * flushed any device buffers which have built up. 1182 * 1183 * XXX this isn't being incremental 1184 */ 1185 vn_lock(hmp->devvp, LK_EXCLUSIVE | LK_RETRY); 1186 error = VOP_FSYNC(hmp->devvp, MNT_WAIT, 0); 1187 vn_unlock(hmp->devvp); 1188 1189 /* 1190 * The flush code sets CHAIN_VOLUMESYNC to indicate that the 1191 * volume header needs synchronization via hmp->volsync. 1192 * 1193 * XXX synchronize the flag & data with only this flush XXX 1194 */ 1195 if (error == 0 && 1196 (hmp->vchain.flags & HAMMER2_CHAIN_VOLUMESYNC)) { 1197 struct buf *bp; 1198 1199 /* 1200 * Synchronize the disk before flushing the volume 1201 * header. 1202 */ 1203 bp = getpbuf(NULL); 1204 bp->b_bio1.bio_offset = 0; 1205 bp->b_bufsize = 0; 1206 bp->b_bcount = 0; 1207 bp->b_cmd = BUF_CMD_FLUSH; 1208 bp->b_bio1.bio_done = biodone_sync; 1209 bp->b_bio1.bio_flags |= BIO_SYNC; 1210 vn_strategy(hmp->devvp, &bp->b_bio1); 1211 biowait(&bp->b_bio1, "h2vol"); 1212 relpbuf(bp, NULL); 1213 1214 /* 1215 * Then we can safely flush the version of the 1216 * volume header synchronized by the flush code. 1217 */ 1218 j = hmp->volhdrno + 1; 1219 if (j >= HAMMER2_NUM_VOLHDRS) 1220 j = 0; 1221 if (j * HAMMER2_ZONE_BYTES64 + HAMMER2_SEGSIZE > 1222 hmp->volsync.volu_size) { 1223 j = 0; 1224 } 1225 if (hammer2_debug & 0x8000) { 1226 /* debug only, avoid syslogd loop */ 1227 kprintf("sync volhdr %d %jd\n", 1228 j, (intmax_t)hmp->volsync.volu_size); 1229 } 1230 bp = getblk(hmp->devvp, j * HAMMER2_ZONE_BYTES64, 1231 HAMMER2_PBUFSIZE, 0, 0); 1232 atomic_clear_int(&hmp->vchain.flags, 1233 HAMMER2_CHAIN_VOLUMESYNC); 1234 bcopy(&hmp->volsync, bp->b_data, HAMMER2_PBUFSIZE); 1235 bawrite(bp); 1236 hmp->volhdrno = j; 1237 } 1238 if (error) 1239 total_error = error; 1240 1241 hammer2_trans_done(hmp->spmp); /* spmp trans */ 1242 skip: 1243 error = hammer2_xop_feed(&xop->head, NULL, clindex, total_error); 1244 } 1245