1 /* 2 * Copyright (c) 2011-2018 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 60 /* 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 long diddeferral; 71 int error; /* cumulative error */ 72 int flags; 73 #ifdef HAMMER2_SCAN_DEBUG 74 long scan_count; 75 long scan_mod_count; 76 long scan_upd_count; 77 long scan_onf_count; 78 long scan_del_count; 79 long scan_btype[7]; 80 long flushq_count; 81 #endif 82 struct h2_flush_list flushq; 83 hammer2_chain_t *debug; 84 }; 85 86 typedef struct hammer2_flush_info hammer2_flush_info_t; 87 88 static void hammer2_flush_core(hammer2_flush_info_t *info, 89 hammer2_chain_t *chain, int flags); 90 static int hammer2_flush_recurse(hammer2_chain_t *child, void *data); 91 92 /* 93 * Any per-pfs transaction initialization goes here. 94 */ 95 void 96 hammer2_trans_manage_init(hammer2_pfs_t *pmp) 97 { 98 } 99 100 /* 101 * Transaction support for any modifying operation. Transactions are used 102 * in the pmp layer by the frontend and in the spmp layer by the backend. 103 * 104 * 0 - Normal transaction, interlocked against flush 105 * transaction. 106 * 107 * TRANS_ISFLUSH - Flush transaction, interlocked against normal 108 * transaction. 109 * 110 * TRANS_BUFCACHE - Buffer cache transaction, no interlock. 111 * 112 * Initializing a new transaction allocates a transaction ID. Typically 113 * passed a pmp (hmp passed as NULL), indicating a cluster transaction. Can 114 * be passed a NULL pmp and non-NULL hmp to indicate a transaction on a single 115 * media target. The latter mode is used by the recovery code. 116 * 117 * TWO TRANSACTION IDs can run concurrently, where one is a flush and the 118 * other is a set of any number of concurrent filesystem operations. We 119 * can either have <running_fs_ops> + <waiting_flush> + <blocked_fs_ops> 120 * or we can have <running_flush> + <concurrent_fs_ops>. 121 * 122 * During a flush, new fs_ops are only blocked until the fs_ops prior to 123 * the flush complete. The new fs_ops can then run concurrent with the flush. 124 * 125 * Buffer-cache transactions operate as fs_ops but never block. A 126 * buffer-cache flush will run either before or after the current pending 127 * flush depending on its state. 128 */ 129 void 130 hammer2_trans_init(hammer2_pfs_t *pmp, uint32_t flags) 131 { 132 uint32_t oflags; 133 uint32_t nflags; 134 int dowait; 135 136 for (;;) { 137 oflags = pmp->trans.flags; 138 cpu_ccfence(); 139 dowait = 0; 140 141 if (flags & HAMMER2_TRANS_ISFLUSH) { 142 /* 143 * Requesting flush transaction. Wait for all 144 * currently running transactions to finish. 145 * Afterwords, normal transactions will be 146 * interlocked. 147 */ 148 if (oflags & HAMMER2_TRANS_MASK) { 149 nflags = oflags | HAMMER2_TRANS_FPENDING | 150 HAMMER2_TRANS_WAITING; 151 dowait = 1; 152 } else { 153 nflags = (oflags | flags) + 1; 154 } 155 } else if (flags & HAMMER2_TRANS_BUFCACHE) { 156 /* 157 * Requesting strategy transaction from buffer-cache, 158 * or a VM getpages/putpages through the buffer cache. 159 * We must allow such transactions in all situations 160 * to avoid deadlocks. 161 */ 162 nflags = (oflags | flags) + 1; 163 #if 0 164 /* 165 * (old) previous code interlocked against the main 166 * flush pass. 167 */ 168 if ((oflags & (HAMMER2_TRANS_ISFLUSH | 169 HAMMER2_TRANS_PREFLUSH)) == 170 HAMMER2_TRANS_ISFLUSH) { 171 nflags = oflags | HAMMER2_TRANS_WAITING; 172 dowait = 1; 173 } else { 174 nflags = (oflags | flags) + 1; 175 } 176 #endif 177 } else { 178 /* 179 * Requesting a normal modifying transaction. 180 * Waits for any flush to finish before allowing. 181 * Multiple modifying transactions can run 182 * concurrently. 183 * 184 * If a flush is pending for more than one second 185 * but can't run because many modifying transactions 186 * are active, we wait for the flush to be granted. 187 * 188 * NOTE: Remember that non-modifying operations 189 * such as read, stat, readdir, etc, do 190 * not use transactions. 191 */ 192 if ((oflags & HAMMER2_TRANS_FPENDING) && 193 (u_int)(ticks - pmp->trans.fticks) >= (u_int)hz) { 194 nflags = oflags | HAMMER2_TRANS_WAITING; 195 dowait = 1; 196 } else if (oflags & HAMMER2_TRANS_ISFLUSH) { 197 nflags = oflags | HAMMER2_TRANS_WAITING; 198 dowait = 1; 199 } else { 200 nflags = (oflags | flags) + 1; 201 } 202 } 203 if (dowait) 204 tsleep_interlock(&pmp->trans.sync_wait, 0); 205 if (atomic_cmpset_int(&pmp->trans.flags, oflags, nflags)) { 206 if ((oflags & HAMMER2_TRANS_FPENDING) == 0 && 207 (nflags & HAMMER2_TRANS_FPENDING)) { 208 pmp->trans.fticks = ticks; 209 } 210 if (dowait == 0) 211 break; 212 tsleep(&pmp->trans.sync_wait, PINTERLOCKED, 213 "h2trans", hz); 214 } else { 215 cpu_pause(); 216 } 217 /* retry */ 218 } 219 } 220 221 /* 222 * Start a sub-transaction, there is no 'subdone' function. This will 223 * issue a new modify_tid (mtid) for the current transaction, which is a 224 * CLC (cluster level change) id and not a per-node id. 225 * 226 * This function must be called for each XOP when multiple XOPs are run in 227 * sequence within a transaction. 228 * 229 * Callers typically update the inode with the transaction mtid manually 230 * to enforce sequencing. 231 */ 232 hammer2_tid_t 233 hammer2_trans_sub(hammer2_pfs_t *pmp) 234 { 235 hammer2_tid_t mtid; 236 237 mtid = atomic_fetchadd_64(&pmp->modify_tid, 1); 238 239 return (mtid); 240 } 241 242 void 243 hammer2_trans_done(hammer2_pfs_t *pmp) 244 { 245 uint32_t oflags; 246 uint32_t nflags; 247 248 for (;;) { 249 oflags = pmp->trans.flags; 250 cpu_ccfence(); 251 KKASSERT(oflags & HAMMER2_TRANS_MASK); 252 if ((oflags & HAMMER2_TRANS_MASK) == 1) { 253 /* 254 * This was the last transaction 255 */ 256 nflags = (oflags - 1) & ~(HAMMER2_TRANS_ISFLUSH | 257 HAMMER2_TRANS_BUFCACHE | 258 HAMMER2_TRANS_FPENDING | 259 HAMMER2_TRANS_WAITING); 260 } else { 261 /* 262 * Still transactions pending 263 */ 264 nflags = oflags - 1; 265 } 266 if (atomic_cmpset_int(&pmp->trans.flags, oflags, nflags)) { 267 if ((nflags & HAMMER2_TRANS_MASK) == 0 && 268 (oflags & HAMMER2_TRANS_WAITING)) { 269 wakeup(&pmp->trans.sync_wait); 270 } 271 break; 272 } else { 273 cpu_pause(); 274 } 275 /* retry */ 276 } 277 } 278 279 /* 280 * Obtain new, unique inode number (not serialized by caller). 281 */ 282 hammer2_tid_t 283 hammer2_trans_newinum(hammer2_pfs_t *pmp) 284 { 285 hammer2_tid_t tid; 286 287 tid = atomic_fetchadd_64(&pmp->inode_tid, 1); 288 289 return tid; 290 } 291 292 /* 293 * Assert that a strategy call is ok here. Currently we allow strategy 294 * calls in all situations, including during flushes. Previously: 295 * (old) (1) In a normal transaction. 296 * (old) (2) In a flush transaction only if PREFLUSH is also set. 297 */ 298 void 299 hammer2_trans_assert_strategy(hammer2_pfs_t *pmp) 300 { 301 #if 0 302 KKASSERT((pmp->trans.flags & HAMMER2_TRANS_ISFLUSH) == 0 || 303 (pmp->trans.flags & HAMMER2_TRANS_PREFLUSH)); 304 #endif 305 } 306 307 308 /* 309 * Chains undergoing destruction are removed from the in-memory topology. 310 * To avoid getting lost these chains are placed on the delayed flush 311 * queue which will properly dispose of them. 312 * 313 * We do this instead of issuing an immediate flush in order to give 314 * recursive deletions (rm -rf, etc) a chance to remove more of the 315 * hierarchy, potentially allowing an enormous amount of write I/O to 316 * be avoided. 317 * 318 * NOTE: The flush code tests HAMMER2_CHAIN_DESTROY to differentiate 319 * between these chains and the deep-recursion requeue. 320 */ 321 void 322 hammer2_delayed_flush(hammer2_chain_t *chain) 323 { 324 if ((chain->flags & HAMMER2_CHAIN_DELAYED) == 0) { 325 hammer2_spin_ex(&chain->hmp->list_spin); 326 if ((chain->flags & (HAMMER2_CHAIN_DELAYED | 327 HAMMER2_CHAIN_DEFERRED)) == 0) { 328 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELAYED | 329 HAMMER2_CHAIN_DEFERRED); 330 TAILQ_INSERT_TAIL(&chain->hmp->flushq, 331 chain, flush_node); 332 hammer2_chain_ref(chain); 333 } 334 hammer2_spin_unex(&chain->hmp->list_spin); 335 hammer2_voldata_modify(chain->hmp); 336 } 337 } 338 339 /* 340 * Flush the chain and all modified sub-chains through the specified 341 * synchronization point, propagating blockref updates back up. As 342 * part of this propagation, mirror_tid and inode/data usage statistics 343 * propagates back upward. 344 * 345 * Returns a HAMMER2 error code, 0 if no error. Note that I/O errors from 346 * buffers dirtied during the flush operation can occur later. 347 * 348 * modify_tid (clc - cluster level change) is not propagated. 349 * 350 * update_tid (clc) is used for validation and is not propagated by this 351 * function. 352 * 353 * This routine can be called from several places but the most important 354 * is from VFS_SYNC (frontend) via hammer2_inode_xop_flush (backend). 355 * 356 * chain is locked on call and will remain locked on return. The chain's 357 * UPDATE flag indicates that its parent's block table (which is not yet 358 * part of the flush) should be updated. 359 * 360 * flags: 361 * HAMMER2_FLUSH_TOP Indicates that this is the top of the flush. 362 * Is cleared for the recursion. 363 * 364 * HAMMER2_FLUSH_ALL Recurse everything 365 * 366 * HAMMER2_FLUSH_INODE_STOP 367 * Stop at PFS inode or normal inode boundary 368 */ 369 int 370 hammer2_flush(hammer2_chain_t *chain, int flags) 371 { 372 hammer2_chain_t *scan; 373 hammer2_flush_info_t info; 374 hammer2_dev_t *hmp; 375 int loops; 376 377 /* 378 * Execute the recursive flush and handle deferrals. 379 * 380 * Chains can be ridiculously long (thousands deep), so to 381 * avoid blowing out the kernel stack the recursive flush has a 382 * depth limit. Elements at the limit are placed on a list 383 * for re-execution after the stack has been popped. 384 */ 385 bzero(&info, sizeof(info)); 386 TAILQ_INIT(&info.flushq); 387 info.flags = flags & ~HAMMER2_FLUSH_TOP; 388 389 /* 390 * Calculate parent (can be NULL), if not NULL the flush core 391 * expects the parent to be referenced so it can easily lock/unlock 392 * it without it getting ripped up. 393 */ 394 if ((info.parent = chain->parent) != NULL) 395 hammer2_chain_ref(info.parent); 396 397 /* 398 * Extra ref needed because flush_core expects it when replacing 399 * chain. 400 */ 401 hammer2_chain_ref(chain); 402 hmp = chain->hmp; 403 loops = 0; 404 405 for (;;) { 406 /* 407 * Move hmp->flushq to info.flushq if non-empty so it can 408 * be processed. 409 */ 410 if (TAILQ_FIRST(&hmp->flushq) != NULL) { 411 hammer2_spin_ex(&chain->hmp->list_spin); 412 TAILQ_CONCAT(&info.flushq, &hmp->flushq, flush_node); 413 hammer2_spin_unex(&chain->hmp->list_spin); 414 } 415 416 /* 417 * Unwind deep recursions which had been deferred. This 418 * can leave the FLUSH_* bits set for these chains, which 419 * will be handled when we [re]flush chain after the unwind. 420 */ 421 while ((scan = TAILQ_FIRST(&info.flushq)) != NULL) { 422 KKASSERT(scan->flags & HAMMER2_CHAIN_DEFERRED); 423 TAILQ_REMOVE(&info.flushq, scan, flush_node); 424 #ifdef HAMMER2_SCAN_DEBUG 425 ++info.flushq_count; 426 #endif 427 atomic_clear_int(&scan->flags, HAMMER2_CHAIN_DEFERRED | 428 HAMMER2_CHAIN_DELAYED); 429 430 /* 431 * Now that we've popped back up we can do a secondary 432 * recursion on the deferred elements. 433 * 434 * NOTE: hmp->flushq chains (marked DESTROY) must be 435 * handled unconditionally so they can be cleaned 436 * out. 437 * 438 * NOTE: hammer2_flush() may replace scan. 439 */ 440 if (hammer2_debug & 0x0040) 441 kprintf("deferred flush %p\n", scan); 442 hammer2_chain_lock(scan, HAMMER2_RESOLVE_MAYBE); 443 if (scan->error == 0) { 444 if (scan->flags & HAMMER2_CHAIN_DESTROY) { 445 hammer2_flush(scan, 446 flags | 447 HAMMER2_FLUSH_TOP | 448 HAMMER2_FLUSH_ALL); 449 } else { 450 hammer2_flush(scan, 451 flags & ~HAMMER2_FLUSH_TOP); 452 } 453 } else { 454 info.error |= scan->error; 455 } 456 hammer2_chain_unlock(scan); 457 hammer2_chain_drop(scan);/* ref from defer */ 458 } 459 460 /* 461 * [re]flush chain as the deep recursion may have generated 462 * additional modifications. 463 */ 464 info.diddeferral = 0; 465 if (info.parent != chain->parent) { 466 if (hammer2_debug & 0x0040) { 467 kprintf("LOST CHILD4 %p->%p " 468 "(actual parent %p)\n", 469 info.parent, chain, chain->parent); 470 } 471 hammer2_chain_drop(info.parent); 472 info.parent = chain->parent; 473 hammer2_chain_ref(info.parent); 474 } 475 hammer2_flush_core(&info, chain, flags); 476 477 /* 478 * Only loop if deep recursions have been deferred. 479 */ 480 if (TAILQ_EMPTY(&info.flushq)) 481 break; 482 483 if (++loops % 1000 == 0) { 484 kprintf("hammer2_flush: excessive loops on %p\n", 485 chain); 486 if (hammer2_debug & 0x100000) 487 Debugger("hell4"); 488 } 489 } 490 #ifdef HAMMER2_SCAN_DEBUG 491 if (info.scan_count >= 10) 492 kprintf("hammer2_flush: scan_count %ld (%ld,%ld,%ld,%ld) " 493 "bt(%ld,%ld,%ld,%ld,%ld,%ld) flushq %ld\n", 494 info.scan_count, 495 info.scan_mod_count, 496 info.scan_upd_count, 497 info.scan_onf_count, 498 info.scan_del_count, 499 info.scan_btype[1], 500 info.scan_btype[2], 501 info.scan_btype[3], 502 info.scan_btype[4], 503 info.scan_btype[5], 504 info.scan_btype[6], 505 info.flushq_count); 506 #endif 507 hammer2_chain_drop(chain); 508 if (info.parent) 509 hammer2_chain_drop(info.parent); 510 return (info.error); 511 } 512 513 /* 514 * This is the core of the chain flushing code. The chain is locked by the 515 * caller and must also have an extra ref on it by the caller, and remains 516 * locked and will have an extra ref on return. info.parent is referenced 517 * but not locked. 518 * 519 * Upon return, the caller can test the UPDATE bit on the chain to determine 520 * if the parent needs updating. 521 * 522 * (1) Determine if this node is a candidate for the flush, return if it is 523 * not. fchain and vchain are always candidates for the flush. 524 * 525 * (2) If we recurse too deep the chain is entered onto the deferral list and 526 * the current flush stack is aborted until after the deferral list is 527 * run. 528 * 529 * (3) Recursively flush live children (rbtree). This can create deferrals. 530 * A successful flush clears the MODIFIED and UPDATE bits on the children 531 * and typically causes the parent to be marked MODIFIED as the children 532 * update the parent's block table. A parent might already be marked 533 * MODIFIED due to a deletion (whos blocktable update in the parent is 534 * handled by the frontend), or if the parent itself is modified by the 535 * frontend for other reasons. 536 * 537 * (4) Permanently disconnected sub-trees are cleaned up by the front-end. 538 * Deleted-but-open inodes can still be individually flushed via the 539 * filesystem syncer. 540 * 541 * (5) Delete parents on the way back up if they are normal indirect blocks 542 * and have no children. 543 * 544 * (6) Note that an unmodified child may still need the block table in its 545 * parent updated (e.g. rename/move). The child will have UPDATE set 546 * in this case. 547 * 548 * WARNING ON BREF MODIFY_TID/MIRROR_TID 549 * 550 * blockref.modify_tid is consistent only within a PFS, and will not be 551 * consistent during synchronization. mirror_tid is consistent across the 552 * block device regardless of the PFS. 553 */ 554 static void 555 hammer2_flush_core(hammer2_flush_info_t *info, hammer2_chain_t *chain, 556 int flags) 557 { 558 hammer2_chain_t *parent; 559 hammer2_dev_t *hmp; 560 int save_error; 561 562 /* 563 * (1) Optimize downward recursion to locate nodes needing action. 564 * Nothing to do if none of these flags are set. 565 */ 566 if ((chain->flags & HAMMER2_CHAIN_FLUSH_MASK) == 0) { 567 if (hammer2_debug & 0x200) { 568 if (info->debug == NULL) 569 info->debug = chain; 570 } else { 571 return; 572 } 573 } 574 575 hmp = chain->hmp; 576 577 /* 578 * NOTE: parent can be NULL, usually due to destroy races. 579 */ 580 parent = info->parent; 581 KKASSERT(chain->parent == parent); 582 583 /* 584 * Downward search recursion 585 * 586 * We must be careful on cold stops. If CHAIN_UPDATE is set and 587 * we stop cold (verses a deferral which will re-run the chain later), 588 * the update can wind up never being applied. This situation most 589 * typically occurs on inode boundaries due to the way 590 * hammer2_vfs_sync() breaks-up the flush. As a safety, we 591 * flush-through such situations. 592 */ 593 if (chain->flags & (HAMMER2_CHAIN_DEFERRED | HAMMER2_CHAIN_DELAYED)) { 594 /* 595 * Already deferred. 596 */ 597 ++info->diddeferral; 598 } else if ((chain->flags & HAMMER2_CHAIN_PFSBOUNDARY) && 599 (chain->flags & HAMMER2_CHAIN_UPDATE) == 0 && 600 (flags & HAMMER2_FLUSH_ALL) == 0 && 601 (flags & HAMMER2_FLUSH_TOP) == 0 && 602 chain->pmp && chain->pmp->mp) { 603 /* 604 * If FLUSH_ALL is not specified the caller does not want 605 * to recurse through PFS roots that have been mounted. 606 * 607 * (If the PFS has not been mounted there may not be 608 * anything monitoring its chains and its up to us 609 * to flush it). 610 * 611 * The typical sequence is to flush dirty PFS's starting at 612 * their root downward, then flush the device root (vchain). 613 * It is this second flush that typically leaves out the 614 * ALL flag. 615 * 616 * However we must still process the PFSROOT chains for block 617 * table updates in their parent (which IS part of our flush). 618 * 619 * NOTE: The volume root, vchain, does not set PFSBOUNDARY. 620 * 621 * NOTE: This test must be done before the depth-limit test, 622 * else it might become the top on a flushq iteration. 623 * 624 * NOTE: We must re-set ONFLUSH in the parent to retain if 625 * this chain (that we are skipping) requires work. 626 */ 627 if (chain->flags & (HAMMER2_CHAIN_ONFLUSH | 628 HAMMER2_CHAIN_DESTROY | 629 HAMMER2_CHAIN_MODIFIED)) { 630 hammer2_chain_setflush(parent); 631 } 632 } else if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && 633 (chain->flags & HAMMER2_CHAIN_UPDATE) == 0 && 634 (flags & HAMMER2_FLUSH_INODE_STOP) && 635 (flags & HAMMER2_FLUSH_ALL) == 0 && 636 (flags & HAMMER2_FLUSH_TOP) == 0 && 637 chain->pmp && chain->pmp->mp) { 638 /* 639 * If FLUSH_INODE_STOP is specified and both ALL and TOP 640 * are clear, we must not flush the chain. The chain should 641 * have already been flushed and any further ONFLUSH/UPDATE 642 * setting will be related to the next flush. 643 * 644 * This features allows us to flush inodes independently of 645 * each other and meta-data above the inodes separately. 646 */ 647 if (chain->flags & (HAMMER2_CHAIN_ONFLUSH | 648 HAMMER2_CHAIN_DESTROY | 649 HAMMER2_CHAIN_MODIFIED)) { 650 if (parent) 651 hammer2_chain_setflush(parent); 652 } 653 } else if (info->depth == HAMMER2_FLUSH_DEPTH_LIMIT) { 654 /* 655 * Recursion depth reached. 656 */ 657 KKASSERT((chain->flags & HAMMER2_CHAIN_DELAYED) == 0); 658 hammer2_chain_ref(chain); 659 TAILQ_INSERT_TAIL(&info->flushq, chain, flush_node); 660 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEFERRED); 661 ++info->diddeferral; 662 } else if (chain->flags & (HAMMER2_CHAIN_ONFLUSH | 663 HAMMER2_CHAIN_DESTROY)) { 664 /* 665 * Downward recursion search (actual flush occurs bottom-up). 666 * pre-clear ONFLUSH. It can get set again due to races or 667 * flush errors, which we want so the scan finds us again in 668 * the next flush. 669 * 670 * We must also recurse if DESTROY is set so we can finally 671 * get rid of the related children, otherwise the node will 672 * just get re-flushed on lastdrop. 673 * 674 * WARNING! The recursion will unlock/relock info->parent 675 * (which is 'chain'), potentially allowing it 676 * to be ripped up. 677 */ 678 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); 679 save_error = info->error; 680 info->error = 0; 681 info->parent = chain; 682 683 /* 684 * We may have to do this twice to catch any indirect 685 * block maintenance that occurs. Other conditions which 686 * can keep setting ONFLUSH (such as deferrals) ought to 687 * be handled by the flushq code. XXX needs more help 688 */ 689 hammer2_spin_ex(&chain->core.spin); 690 RB_SCAN(hammer2_chain_tree, &chain->core.rbtree, 691 NULL, hammer2_flush_recurse, info); 692 if (chain->flags & HAMMER2_CHAIN_ONFLUSH) { 693 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); 694 RB_SCAN(hammer2_chain_tree, &chain->core.rbtree, 695 NULL, hammer2_flush_recurse, info); 696 } 697 hammer2_spin_unex(&chain->core.spin); 698 info->parent = parent; 699 700 /* 701 * Re-set the flush bits if the flush was incomplete or 702 * an error occurred. If an error occurs it is typically 703 * an allocation error. Errors do not cause deferrals. 704 */ 705 if (info->error) 706 hammer2_chain_setflush(chain); 707 info->error |= save_error; 708 if (info->diddeferral) 709 hammer2_chain_setflush(chain); 710 711 /* 712 * If we lost the parent->chain association we have to 713 * stop processing this chain because it is no longer 714 * in this recursion. If it moved, it will be handled 715 * by the ONFLUSH flag elsewhere. 716 */ 717 if (chain->parent != parent) { 718 kprintf("LOST CHILD2 %p->%p (actual parent %p)\n", 719 parent, chain, chain->parent); 720 goto done; 721 } 722 } 723 724 /* 725 * Now we are in the bottom-up part of the recursion. 726 * 727 * Do not update chain if lower layers were deferred. We continue 728 * to try to update the chain on lower-level errors, but the flush 729 * code may decide not to flush the volume root. 730 * 731 * XXX should we continue to try to update the chain if an error 732 * occurred? 733 */ 734 if (info->diddeferral) 735 goto done; 736 737 /* 738 * Both parent and chain must be locked in order to flush chain, 739 * in order to properly update the parent under certain conditions. 740 * 741 * In addition, we can't safely unlock/relock the chain once we 742 * start flushing the chain itself, which we would have to do later 743 * on in order to lock the parent if we didn't do that now. 744 */ 745 hammer2_chain_ref_hold(chain); 746 hammer2_chain_unlock(chain); 747 if (parent) 748 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); 749 hammer2_chain_lock(chain, HAMMER2_RESOLVE_MAYBE); 750 hammer2_chain_drop_unhold(chain); 751 752 /* 753 * Can't process if we can't access their content. 754 */ 755 if ((parent && parent->error) || chain->error) { 756 kprintf("hammer2: chain error during flush\n"); 757 info->error |= chain->error; 758 if (parent) { 759 info->error |= parent->error; 760 hammer2_chain_unlock(parent); 761 } 762 goto done; 763 } 764 765 if (chain->parent != parent) { 766 if (hammer2_debug & 0x0040) { 767 kprintf("LOST CHILD3 %p->%p (actual parent %p)\n", 768 parent, chain, chain->parent); 769 } 770 KKASSERT(parent != NULL); 771 hammer2_chain_unlock(parent); 772 if ((chain->flags & HAMMER2_CHAIN_DELAYED) == 0) { 773 hammer2_chain_ref(chain); 774 TAILQ_INSERT_TAIL(&info->flushq, chain, flush_node); 775 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEFERRED); 776 ++info->diddeferral; 777 } 778 goto done; 779 } 780 781 /* 782 * Propagate the DESTROY flag downwards. This dummies up the flush 783 * code and tries to invalidate related buffer cache buffers to 784 * avoid the disk write. 785 */ 786 if (parent && (parent->flags & HAMMER2_CHAIN_DESTROY)) 787 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); 788 789 /* 790 * Dispose of the modified bit. 791 * 792 * If parent is present, the UPDATE bit should already be set. 793 * UPDATE should already be set. 794 * bref.mirror_tid should already be set. 795 */ 796 if (chain->flags & HAMMER2_CHAIN_MODIFIED) { 797 KKASSERT((chain->flags & HAMMER2_CHAIN_UPDATE) || 798 chain->parent == NULL); 799 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); 800 atomic_add_long(&hammer2_count_modified_chains, -1); 801 802 /* 803 * Manage threads waiting for excessive dirty memory to 804 * be retired. 805 */ 806 if (chain->pmp) 807 hammer2_pfs_memory_wakeup(chain->pmp); 808 809 #if 0 810 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0 && 811 chain != &hmp->vchain && 812 chain != &hmp->fchain) { 813 /* 814 * Set UPDATE bit indicating that the parent block 815 * table requires updating. 816 */ 817 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 818 } 819 #endif 820 821 /* 822 * Issue the flush. This is indirect via the DIO. 823 * 824 * NOTE: A DELETED node that reaches this point must be 825 * flushed for synchronization point consistency. 826 * 827 * NOTE: Even though MODIFIED was already set, the related DIO 828 * might not be dirty due to a system buffer cache 829 * flush and must be set dirty if we are going to make 830 * further modifications to the buffer. Chains with 831 * embedded data don't need this. 832 */ 833 if (hammer2_debug & 0x1000) { 834 kprintf("Flush %p.%d %016jx/%d data=%016jx\n", 835 chain, chain->bref.type, 836 (uintmax_t)chain->bref.key, 837 chain->bref.keybits, 838 (uintmax_t)chain->bref.data_off); 839 } 840 if (hammer2_debug & 0x2000) { 841 Debugger("Flush hell"); 842 } 843 844 /* 845 * Update chain CRCs for flush. 846 * 847 * NOTE: Volume headers are NOT flushed here as they require 848 * special processing. 849 */ 850 switch(chain->bref.type) { 851 case HAMMER2_BREF_TYPE_FREEMAP: 852 /* 853 * Update the volume header's freemap_tid to the 854 * freemap's flushing mirror_tid. 855 * 856 * (note: embedded data, do not call setdirty) 857 */ 858 KKASSERT(hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED); 859 KKASSERT(chain == &hmp->fchain); 860 hmp->voldata.freemap_tid = chain->bref.mirror_tid; 861 if (hammer2_debug & 0x8000) { 862 /* debug only, avoid syslogd loop */ 863 kprintf("sync freemap mirror_tid %08jx\n", 864 (intmax_t)chain->bref.mirror_tid); 865 } 866 867 /* 868 * The freemap can be flushed independently of the 869 * main topology, but for the case where it is 870 * flushed in the same transaction, and flushed 871 * before vchain (a case we want to allow for 872 * performance reasons), make sure modifications 873 * made during the flush under vchain use a new 874 * transaction id. 875 * 876 * Otherwise the mount recovery code will get confused. 877 */ 878 ++hmp->voldata.mirror_tid; 879 break; 880 case HAMMER2_BREF_TYPE_VOLUME: 881 /* 882 * The free block table is flushed by 883 * hammer2_vfs_sync() before it flushes vchain. 884 * We must still hold fchain locked while copying 885 * voldata to volsync, however. 886 * 887 * These do not error per-say since their data does 888 * not need to be re-read from media on lock. 889 * 890 * (note: embedded data, do not call setdirty) 891 */ 892 hammer2_chain_lock(&hmp->fchain, 893 HAMMER2_RESOLVE_ALWAYS); 894 hammer2_voldata_lock(hmp); 895 if (hammer2_debug & 0x8000) { 896 /* debug only, avoid syslogd loop */ 897 kprintf("sync volume mirror_tid %08jx\n", 898 (intmax_t)chain->bref.mirror_tid); 899 } 900 901 /* 902 * Update the volume header's mirror_tid to the 903 * main topology's flushing mirror_tid. It is 904 * possible that voldata.mirror_tid is already 905 * beyond bref.mirror_tid due to the bump we made 906 * above in BREF_TYPE_FREEMAP. 907 */ 908 if (hmp->voldata.mirror_tid < chain->bref.mirror_tid) { 909 hmp->voldata.mirror_tid = 910 chain->bref.mirror_tid; 911 } 912 913 /* 914 * The volume header is flushed manually by the 915 * syncer, not here. All we do here is adjust the 916 * crc's. 917 */ 918 KKASSERT(chain->data != NULL); 919 KKASSERT(chain->dio == NULL); 920 921 hmp->voldata.icrc_sects[HAMMER2_VOL_ICRC_SECT1]= 922 hammer2_icrc32( 923 (char *)&hmp->voldata + 924 HAMMER2_VOLUME_ICRC1_OFF, 925 HAMMER2_VOLUME_ICRC1_SIZE); 926 hmp->voldata.icrc_sects[HAMMER2_VOL_ICRC_SECT0]= 927 hammer2_icrc32( 928 (char *)&hmp->voldata + 929 HAMMER2_VOLUME_ICRC0_OFF, 930 HAMMER2_VOLUME_ICRC0_SIZE); 931 hmp->voldata.icrc_volheader = 932 hammer2_icrc32( 933 (char *)&hmp->voldata + 934 HAMMER2_VOLUME_ICRCVH_OFF, 935 HAMMER2_VOLUME_ICRCVH_SIZE); 936 937 if (hammer2_debug & 0x8000) { 938 /* debug only, avoid syslogd loop */ 939 kprintf("syncvolhdr %016jx %016jx\n", 940 hmp->voldata.mirror_tid, 941 hmp->vchain.bref.mirror_tid); 942 } 943 hmp->volsync = hmp->voldata; 944 atomic_set_int(&chain->flags, HAMMER2_CHAIN_VOLUMESYNC); 945 hammer2_voldata_unlock(hmp); 946 hammer2_chain_unlock(&hmp->fchain); 947 break; 948 case HAMMER2_BREF_TYPE_DATA: 949 /* 950 * Data elements have already been flushed via the 951 * logical file buffer cache. Their hash was set in 952 * the bref by the vop_write code. Do not re-dirty. 953 * 954 * Make sure any device buffer(s) have been flushed 955 * out here (there aren't usually any to flush) XXX. 956 */ 957 break; 958 case HAMMER2_BREF_TYPE_INDIRECT: 959 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 960 case HAMMER2_BREF_TYPE_FREEMAP_LEAF: 961 /* 962 * Buffer I/O will be cleaned up when the volume is 963 * flushed (but the kernel is free to flush it before 964 * then, as well). 965 */ 966 KKASSERT((chain->flags & HAMMER2_CHAIN_EMBEDDED) == 0); 967 hammer2_chain_setcheck(chain, chain->data); 968 break; 969 case HAMMER2_BREF_TYPE_DIRENT: 970 /* 971 * A directory entry can use the check area to store 972 * the filename for filenames <= 64 bytes, don't blow 973 * it up! 974 */ 975 KKASSERT((chain->flags & HAMMER2_CHAIN_EMBEDDED) == 0); 976 if (chain->bytes) 977 hammer2_chain_setcheck(chain, chain->data); 978 break; 979 case HAMMER2_BREF_TYPE_INODE: 980 /* 981 * NOTE: We must call io_setdirty() to make any late 982 * changes to the inode data, the system might 983 * have already flushed the buffer. 984 */ 985 if (chain->data->ipdata.meta.op_flags & 986 HAMMER2_OPFLAG_PFSROOT) { 987 /* 988 * non-NULL pmp if mounted as a PFS. We must 989 * sync fields cached in the pmp? XXX 990 */ 991 hammer2_inode_data_t *ipdata; 992 993 hammer2_io_setdirty(chain->dio); 994 ipdata = &chain->data->ipdata; 995 if (chain->pmp) { 996 ipdata->meta.pfs_inum = 997 chain->pmp->inode_tid; 998 } 999 } else { 1000 /* can't be mounted as a PFS */ 1001 } 1002 1003 KKASSERT((chain->flags & HAMMER2_CHAIN_EMBEDDED) == 0); 1004 hammer2_chain_setcheck(chain, chain->data); 1005 1006 hammer2_inode_data_t *ipdata; 1007 ipdata = &chain->data->ipdata; 1008 break; 1009 default: 1010 KKASSERT(chain->flags & HAMMER2_CHAIN_EMBEDDED); 1011 panic("hammer2_flush_core: unsupported " 1012 "embedded bref %d", 1013 chain->bref.type); 1014 /* NOT REACHED */ 1015 } 1016 1017 /* 1018 * If the chain was destroyed try to avoid unnecessary I/O 1019 * that might not have yet occurred. Remove the data range 1020 * from dedup candidacy and attempt to invalidation that 1021 * potentially dirty portion of the I/O buffer. 1022 */ 1023 if (chain->flags & HAMMER2_CHAIN_DESTROY) { 1024 hammer2_io_dedup_delete(hmp, 1025 chain->bref.type, 1026 chain->bref.data_off, 1027 chain->bytes); 1028 #if 0 1029 hammer2_io_t *dio; 1030 if (chain->dio) { 1031 hammer2_io_inval(chain->dio, 1032 chain->bref.data_off, 1033 chain->bytes); 1034 } else if ((dio = hammer2_io_getquick(hmp, 1035 chain->bref.data_off, 1036 chain->bytes, 1037 1)) != NULL) { 1038 hammer2_io_inval(dio, 1039 chain->bref.data_off, 1040 chain->bytes); 1041 hammer2_io_putblk(&dio); 1042 } 1043 #endif 1044 } 1045 } 1046 1047 /* 1048 * If UPDATE is set the parent block table may need to be updated. 1049 * This can fail if the hammer2_chain_modify() fails. 1050 * 1051 * NOTE: UPDATE may be set on vchain or fchain in which case 1052 * parent could be NULL. It's easiest to allow the case 1053 * and test for NULL. parent can also wind up being NULL 1054 * due to a deletion so we need to handle the case anyway. 1055 * 1056 * If no parent exists we can just clear the UPDATE bit. If the 1057 * chain gets reattached later on the bit will simply get set 1058 * again. 1059 */ 1060 if ((chain->flags & HAMMER2_CHAIN_UPDATE) && parent == NULL) 1061 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1062 1063 /* 1064 * The chain may need its blockrefs updated in the parent. 1065 */ 1066 if (chain->flags & HAMMER2_CHAIN_UPDATE) { 1067 hammer2_blockref_t *base; 1068 int count; 1069 1070 /* 1071 * Clear UPDATE flag, mark parent modified, update its 1072 * modify_tid if necessary, and adjust the parent blockmap. 1073 */ 1074 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1075 1076 /* 1077 * (optional code) 1078 * 1079 * Avoid actually modifying and updating the parent if it 1080 * was flagged for destruction. This can greatly reduce 1081 * disk I/O in large tree removals because the 1082 * hammer2_io_setinval() call in the upward recursion 1083 * (see MODIFIED code above) can only handle a few cases. 1084 */ 1085 if (parent->flags & HAMMER2_CHAIN_DESTROY) { 1086 if (parent->bref.modify_tid < chain->bref.modify_tid) { 1087 parent->bref.modify_tid = 1088 chain->bref.modify_tid; 1089 } 1090 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BMAPPED | 1091 HAMMER2_CHAIN_BMAPUPD); 1092 goto skipupdate; 1093 } 1094 1095 /* 1096 * The flusher is responsible for deleting empty indirect 1097 * blocks at this point. If we don't do this, no major harm 1098 * will be done but the empty indirect blocks will stay in 1099 * the topology and make it a messy and inefficient. 1100 * 1101 * The flusher is also responsible for collapsing the 1102 * content of an indirect block into its parent whenever 1103 * possible (with some hysteresis). Not doing this will also 1104 * not harm the topology, but would make it messy and 1105 * inefficient. 1106 */ 1107 if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT) { 1108 if (hammer2_chain_indirect_maintenance(parent, chain)) 1109 goto skipupdate; 1110 } 1111 1112 /* 1113 * We are updating the parent's blockmap, the parent must 1114 * be set modified. If this fails we re-set the UPDATE flag 1115 * in the child. 1116 * 1117 * NOTE! A modification error can be ENOSPC. We still want 1118 * to flush modified chains recursively, not break out, 1119 * so we just skip the update in this situation and 1120 * continue. That is, we still need to try to clean 1121 * out dirty chains and buffers. 1122 * 1123 * This may not help bulkfree though. XXX 1124 */ 1125 save_error = hammer2_chain_modify(parent, 0, 0, 0); 1126 if (save_error) { 1127 info->error |= save_error; 1128 kprintf("hammer2_flush: %016jx.%02x error=%08x\n", 1129 parent->bref.data_off, parent->bref.type, 1130 save_error); 1131 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); 1132 goto skipupdate; 1133 } 1134 if (parent->bref.modify_tid < chain->bref.modify_tid) 1135 parent->bref.modify_tid = chain->bref.modify_tid; 1136 1137 /* 1138 * Calculate blockmap pointer 1139 */ 1140 switch(parent->bref.type) { 1141 case HAMMER2_BREF_TYPE_INODE: 1142 /* 1143 * Access the inode's block array. However, there is 1144 * no block array if the inode is flagged DIRECTDATA. 1145 */ 1146 if (parent->data && 1147 (parent->data->ipdata.meta.op_flags & 1148 HAMMER2_OPFLAG_DIRECTDATA) == 0) { 1149 base = &parent->data-> 1150 ipdata.u.blockset.blockref[0]; 1151 } else { 1152 base = NULL; 1153 } 1154 count = HAMMER2_SET_COUNT; 1155 break; 1156 case HAMMER2_BREF_TYPE_INDIRECT: 1157 case HAMMER2_BREF_TYPE_FREEMAP_NODE: 1158 if (parent->data) 1159 base = &parent->data->npdata[0]; 1160 else 1161 base = NULL; 1162 count = parent->bytes / sizeof(hammer2_blockref_t); 1163 break; 1164 case HAMMER2_BREF_TYPE_VOLUME: 1165 base = &chain->hmp->voldata.sroot_blockset.blockref[0]; 1166 count = HAMMER2_SET_COUNT; 1167 break; 1168 case HAMMER2_BREF_TYPE_FREEMAP: 1169 base = &parent->data->npdata[0]; 1170 count = HAMMER2_SET_COUNT; 1171 break; 1172 default: 1173 base = NULL; 1174 count = 0; 1175 panic("hammer2_flush_core: " 1176 "unrecognized blockref type: %d", 1177 parent->bref.type); 1178 } 1179 1180 /* 1181 * Blocktable updates 1182 * 1183 * We synchronize pending statistics at this time. Delta 1184 * adjustments designated for the current and upper level 1185 * are synchronized. 1186 */ 1187 if (base && (chain->flags & HAMMER2_CHAIN_BMAPUPD)) { 1188 if (chain->flags & HAMMER2_CHAIN_BMAPPED) { 1189 hammer2_spin_ex(&parent->core.spin); 1190 hammer2_base_delete(parent, base, count, chain); 1191 hammer2_spin_unex(&parent->core.spin); 1192 /* base_delete clears both bits */ 1193 } else { 1194 atomic_clear_int(&chain->flags, 1195 HAMMER2_CHAIN_BMAPUPD); 1196 } 1197 } 1198 if (base && (chain->flags & HAMMER2_CHAIN_BMAPPED) == 0) { 1199 hammer2_spin_ex(&parent->core.spin); 1200 hammer2_base_insert(parent, base, count, 1201 chain, &chain->bref); 1202 hammer2_spin_unex(&parent->core.spin); 1203 /* base_insert sets BMAPPED */ 1204 } 1205 } 1206 skipupdate: 1207 if (parent) 1208 hammer2_chain_unlock(parent); 1209 1210 /* 1211 * Final cleanup after flush 1212 */ 1213 done: 1214 KKASSERT(chain->refs > 0); 1215 if (hammer2_debug & 0x200) { 1216 if (info->debug == chain) 1217 info->debug = NULL; 1218 } 1219 } 1220 1221 /* 1222 * Flush recursion helper, called from flush_core, calls flush_core. 1223 * 1224 * Flushes the children of the caller's chain (info->parent), restricted 1225 * by sync_tid. Set info->domodify if the child's blockref must propagate 1226 * back up to the parent. 1227 * 1228 * This function may set info->error as a side effect. 1229 * 1230 * Ripouts can move child from rbtree to dbtree or dbq but the caller's 1231 * flush scan order prevents any chains from being lost. A child can be 1232 * executes more than once. 1233 * 1234 * WARNING! If we do not call hammer2_flush_core() we must update 1235 * bref.mirror_tid ourselves to indicate that the flush has 1236 * processed the child. 1237 * 1238 * WARNING! parent->core spinlock is held on entry and return. 1239 */ 1240 static int 1241 hammer2_flush_recurse(hammer2_chain_t *child, void *data) 1242 { 1243 hammer2_flush_info_t *info = data; 1244 hammer2_chain_t *parent = info->parent; 1245 1246 #ifdef HAMMER2_SCAN_DEBUG 1247 ++info->scan_count; 1248 if (child->flags & HAMMER2_CHAIN_MODIFIED) 1249 ++info->scan_mod_count; 1250 if (child->flags & HAMMER2_CHAIN_UPDATE) 1251 ++info->scan_upd_count; 1252 if (child->flags & HAMMER2_CHAIN_ONFLUSH) 1253 ++info->scan_onf_count; 1254 #endif 1255 1256 /* 1257 * (child can never be fchain or vchain so a special check isn't 1258 * needed). 1259 * 1260 * We must ref the child before unlocking the spinlock. 1261 * 1262 * The caller has added a ref to the parent so we can temporarily 1263 * unlock it in order to lock the child. However, if it no longer 1264 * winds up being the child of the parent we must skip this child. 1265 * 1266 * NOTE! chain locking errors are fatal. They are never out-of-space 1267 * errors. 1268 */ 1269 hammer2_chain_ref(child); 1270 hammer2_spin_unex(&parent->core.spin); 1271 1272 hammer2_chain_ref_hold(parent); 1273 hammer2_chain_unlock(parent); 1274 hammer2_chain_lock(child, HAMMER2_RESOLVE_MAYBE); 1275 if (child->parent != parent) { 1276 kprintf("LOST CHILD1 %p->%p (actual parent %p)\n", 1277 parent, child, child->parent); 1278 goto done; 1279 } 1280 if (child->error) { 1281 kprintf("CHILD ERROR DURING FLUSH LOCK %p->%p\n", 1282 parent, child); 1283 info->error |= child->error; 1284 goto done; 1285 } 1286 1287 /* 1288 * Must propagate the DESTROY flag downwards, otherwise the 1289 * parent could end up never being removed because it will 1290 * be requeued to the flusher if it survives this run due to 1291 * the flag. 1292 */ 1293 if (parent && (parent->flags & HAMMER2_CHAIN_DESTROY)) 1294 atomic_set_int(&child->flags, HAMMER2_CHAIN_DESTROY); 1295 #ifdef HAMMER2_SCAN_DEBUG 1296 if (child->flags & HAMMER2_CHAIN_DESTROY) 1297 ++info->scan_del_count; 1298 #endif 1299 1300 /* 1301 * Recurse and collect deferral data. We're in the media flush, 1302 * this can cross PFS boundaries. 1303 */ 1304 if (child->flags & HAMMER2_CHAIN_FLUSH_MASK) { 1305 #ifdef HAMMER2_SCAN_DEBUG 1306 if (child->bref.type < 7) 1307 ++info->scan_btype[child->bref.type]; 1308 #endif 1309 ++info->depth; 1310 hammer2_flush_core(info, child, info->flags); 1311 --info->depth; 1312 } else if (hammer2_debug & 0x200) { 1313 if (info->debug == NULL) 1314 info->debug = child; 1315 ++info->depth; 1316 hammer2_flush_core(info, child, info->flags); 1317 --info->depth; 1318 if (info->debug == child) 1319 info->debug = NULL; 1320 } 1321 1322 done: 1323 /* 1324 * Relock to continue the loop. 1325 */ 1326 hammer2_chain_unlock(child); 1327 hammer2_chain_lock(parent, HAMMER2_RESOLVE_MAYBE); 1328 hammer2_chain_drop_unhold(parent); 1329 if (parent->error) { 1330 kprintf("PARENT ERROR DURING FLUSH LOCK %p->%p\n", 1331 parent, child); 1332 info->error |= parent->error; 1333 } 1334 hammer2_chain_drop(child); 1335 KKASSERT(info->parent == parent); 1336 hammer2_spin_ex(&parent->core.spin); 1337 1338 return (0); 1339 } 1340 1341 /* 1342 * flush helper (backend threaded) 1343 * 1344 * Flushes chain topology for the specified inode. 1345 * 1346 * If HAMMER2_XOP_FLUSH is set we flush all chains from the current inode 1347 * through but stop at sub-inodes (we flush the inode chains for sub-inodes, 1348 * but do not go further as deeper modifications do not belong to the current 1349 * flush cycle). 1350 * 1351 * If HAMMER2_XOP_FLUSH is not set we flush the current inode's chains only 1352 * and do not recurse through sub-inodes, including not including those 1353 * sub-inodes. 1354 * 1355 * Remember that HAMMER2 is currently using a flat inode model, so directory 1356 * hierarchies do not translate to inode hierarchies. PFS ROOTs, however, 1357 * do. 1358 * 1359 * chain->parent can be NULL, usually due to destroy races. 1360 * 1361 * Primarily called from vfs_sync(). 1362 */ 1363 void 1364 hammer2_inode_xop_flush(hammer2_thread_t *thr, hammer2_xop_t *arg) 1365 { 1366 hammer2_xop_flush_t *xop = &arg->xop_flush; 1367 hammer2_chain_t *chain; 1368 hammer2_chain_t *parent; 1369 hammer2_dev_t *hmp; 1370 int flush_error = 0; 1371 int fsync_error = 0; 1372 int total_error = 0; 1373 int j; 1374 int xflags; 1375 int ispfsroot = 0; 1376 1377 xflags = HAMMER2_FLUSH_TOP; 1378 if (xop->head.flags & HAMMER2_XOP_INODE_STOP) 1379 xflags |= HAMMER2_FLUSH_INODE_STOP; 1380 1381 /* 1382 * Flush core chains 1383 */ 1384 chain = hammer2_inode_chain(xop->head.ip1, thr->clindex, 1385 HAMMER2_RESOLVE_ALWAYS); 1386 if (chain) { 1387 hmp = chain->hmp; 1388 if ((chain->flags & HAMMER2_CHAIN_FLUSH_MASK) || 1389 TAILQ_FIRST(&hmp->flushq) != NULL) { 1390 hammer2_flush(chain, xflags); 1391 parent = chain->parent; 1392 if (parent) 1393 hammer2_chain_setflush(parent); 1394 } 1395 if (chain->flags & HAMMER2_CHAIN_PFSBOUNDARY) 1396 ispfsroot = 1; 1397 hammer2_chain_unlock(chain); 1398 hammer2_chain_drop(chain); 1399 chain = NULL; 1400 } else { 1401 hmp = NULL; 1402 } 1403 1404 /* 1405 * Only flush the volume header if asked to, plus the inode must also 1406 * be the PFS root. 1407 */ 1408 if ((xop->head.flags & HAMMER2_XOP_VOLHDR) == 0) 1409 goto skip; 1410 if (ispfsroot == 0) 1411 goto skip; 1412 1413 /* 1414 * Flush volume roots. Avoid replication, we only want to 1415 * flush each hammer2_dev (hmp) once. 1416 */ 1417 for (j = thr->clindex - 1; j >= 0; --j) { 1418 if ((chain = xop->head.ip1->cluster.array[j].chain) != NULL) { 1419 if (chain->hmp == hmp) { 1420 chain = NULL; /* safety */ 1421 goto skip; 1422 } 1423 } 1424 } 1425 chain = NULL; /* safety */ 1426 1427 /* 1428 * spmp transaction. The super-root is never directly mounted so 1429 * there shouldn't be any vnodes, let alone any dirty vnodes 1430 * associated with it, so we shouldn't have to mess around with any 1431 * vnode flushes here. 1432 */ 1433 hammer2_trans_init(hmp->spmp, HAMMER2_TRANS_ISFLUSH); 1434 1435 /* 1436 * Media mounts have two 'roots', vchain for the topology 1437 * and fchain for the free block table. Flush both. 1438 * 1439 * Note that the topology and free block table are handled 1440 * independently, so the free block table can wind up being 1441 * ahead of the topology. We depend on the bulk free scan 1442 * code to deal with any loose ends. 1443 * 1444 * vchain and fchain do not error on-lock since their data does 1445 * not have to be re-read from media. 1446 */ 1447 hammer2_chain_ref(&hmp->vchain); 1448 hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS); 1449 hammer2_chain_ref(&hmp->fchain); 1450 hammer2_chain_lock(&hmp->fchain, HAMMER2_RESOLVE_ALWAYS); 1451 if (hmp->fchain.flags & HAMMER2_CHAIN_FLUSH_MASK) { 1452 /* 1453 * This will also modify vchain as a side effect, 1454 * mark vchain as modified now. 1455 */ 1456 hammer2_voldata_modify(hmp); 1457 chain = &hmp->fchain; 1458 flush_error |= hammer2_flush(chain, HAMMER2_FLUSH_TOP); 1459 KKASSERT(chain == &hmp->fchain); 1460 } 1461 hammer2_chain_unlock(&hmp->fchain); 1462 hammer2_chain_unlock(&hmp->vchain); 1463 hammer2_chain_drop(&hmp->fchain); 1464 /* vchain dropped down below */ 1465 1466 hammer2_chain_lock(&hmp->vchain, HAMMER2_RESOLVE_ALWAYS); 1467 if (hmp->vchain.flags & HAMMER2_CHAIN_FLUSH_MASK) { 1468 chain = &hmp->vchain; 1469 flush_error |= hammer2_flush(chain, HAMMER2_FLUSH_TOP); 1470 KKASSERT(chain == &hmp->vchain); 1471 } 1472 hammer2_chain_unlock(&hmp->vchain); 1473 hammer2_chain_drop(&hmp->vchain); 1474 1475 /* 1476 * We can't safely flush the volume header until we have 1477 * flushed any device buffers which have built up. 1478 * 1479 * XXX this isn't being incremental 1480 */ 1481 vn_lock(hmp->devvp, LK_EXCLUSIVE | LK_RETRY); 1482 fsync_error = VOP_FSYNC(hmp->devvp, MNT_WAIT, 0); 1483 vn_unlock(hmp->devvp); 1484 if (fsync_error || flush_error) { 1485 kprintf("hammer2: sync error fsync=%d h2flush=0x%04x dev=%s\n", 1486 fsync_error, flush_error, hmp->devrepname); 1487 } 1488 1489 /* 1490 * The flush code sets CHAIN_VOLUMESYNC to indicate that the 1491 * volume header needs synchronization via hmp->volsync. 1492 * 1493 * XXX synchronize the flag & data with only this flush XXX 1494 */ 1495 if (fsync_error == 0 && flush_error == 0 && 1496 (hmp->vchain.flags & HAMMER2_CHAIN_VOLUMESYNC)) { 1497 struct buf *bp; 1498 int vol_error = 0; 1499 1500 /* 1501 * Synchronize the disk before flushing the volume 1502 * header. 1503 */ 1504 bp = getpbuf(NULL); 1505 bp->b_bio1.bio_offset = 0; 1506 bp->b_bufsize = 0; 1507 bp->b_bcount = 0; 1508 bp->b_cmd = BUF_CMD_FLUSH; 1509 bp->b_bio1.bio_done = biodone_sync; 1510 bp->b_bio1.bio_flags |= BIO_SYNC; 1511 vn_strategy(hmp->devvp, &bp->b_bio1); 1512 fsync_error = biowait(&bp->b_bio1, "h2vol"); 1513 relpbuf(bp, NULL); 1514 1515 /* 1516 * Then we can safely flush the version of the 1517 * volume header synchronized by the flush code. 1518 */ 1519 j = hmp->volhdrno + 1; 1520 if (j < 0) 1521 j = 0; 1522 if (j >= HAMMER2_NUM_VOLHDRS) 1523 j = 0; 1524 if (j * HAMMER2_ZONE_BYTES64 + HAMMER2_SEGSIZE > 1525 hmp->volsync.volu_size) { 1526 j = 0; 1527 } 1528 if (hammer2_debug & 0x8000) { 1529 /* debug only, avoid syslogd loop */ 1530 kprintf("sync volhdr %d %jd\n", 1531 j, (intmax_t)hmp->volsync.volu_size); 1532 } 1533 bp = getblk(hmp->devvp, j * HAMMER2_ZONE_BYTES64, 1534 HAMMER2_PBUFSIZE, GETBLK_KVABIO, 0); 1535 atomic_clear_int(&hmp->vchain.flags, 1536 HAMMER2_CHAIN_VOLUMESYNC); 1537 bkvasync(bp); 1538 bcopy(&hmp->volsync, bp->b_data, HAMMER2_PBUFSIZE); 1539 vol_error = bwrite(bp); 1540 hmp->volhdrno = j; 1541 if (vol_error) 1542 fsync_error = vol_error; 1543 } 1544 if (flush_error) 1545 total_error = flush_error; 1546 if (fsync_error) 1547 total_error = hammer2_errno_to_error(fsync_error); 1548 1549 hammer2_trans_done(hmp->spmp); /* spmp trans */ 1550 skip: 1551 hammer2_xop_feed(&xop->head, NULL, thr->clindex, total_error); 1552 } 1553