1 /* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 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 * $DragonFly: src/sys/vfs/hammer/hammer_flusher.c,v 1.45 2008/07/31 04:42:04 dillon Exp $ 35 */ 36 /* 37 * HAMMER dependancy flusher thread 38 * 39 * Meta data updates create buffer dependancies which are arranged as a 40 * hierarchy of lists. 41 */ 42 43 #include "hammer.h" 44 45 static void hammer_flusher_master_thread(void *arg); 46 static void hammer_flusher_slave_thread(void *arg); 47 static void hammer_flusher_flush(hammer_mount_t hmp); 48 static void hammer_flusher_flush_inode(hammer_inode_t ip, 49 hammer_transaction_t trans); 50 51 /* 52 * Support structures for the flusher threads. 53 */ 54 struct hammer_flusher_info { 55 TAILQ_ENTRY(hammer_flusher_info) entry; 56 struct hammer_mount *hmp; 57 thread_t td; 58 int runstate; 59 int count; 60 hammer_flush_group_t flg; 61 hammer_inode_t work_array[HAMMER_FLUSH_GROUP_SIZE]; 62 }; 63 64 typedef struct hammer_flusher_info *hammer_flusher_info_t; 65 66 /* 67 * Sync all inodes pending on the flusher. 68 * 69 * All flush groups will be flushed. This does not queue dirty inodes 70 * to the flush groups, it just flushes out what has already been queued! 71 */ 72 void 73 hammer_flusher_sync(hammer_mount_t hmp) 74 { 75 int seq; 76 77 seq = hammer_flusher_async(hmp, NULL); 78 hammer_flusher_wait(hmp, seq); 79 } 80 81 /* 82 * Sync all inodes pending on the flusher - return immediately. 83 * 84 * All flush groups will be flushed. 85 */ 86 int 87 hammer_flusher_async(hammer_mount_t hmp, hammer_flush_group_t close_flg) 88 { 89 hammer_flush_group_t flg; 90 int seq = hmp->flusher.next; 91 92 TAILQ_FOREACH(flg, &hmp->flush_group_list, flush_entry) { 93 if (flg->running == 0) 94 ++seq; 95 flg->closed = 1; 96 if (flg == close_flg) 97 break; 98 } 99 if (hmp->flusher.td) { 100 if (hmp->flusher.signal++ == 0) 101 wakeup(&hmp->flusher.signal); 102 } else { 103 seq = hmp->flusher.done; 104 } 105 return(seq); 106 } 107 108 int 109 hammer_flusher_async_one(hammer_mount_t hmp) 110 { 111 int seq; 112 113 if (hmp->flusher.td) { 114 seq = hmp->flusher.next; 115 if (hmp->flusher.signal++ == 0) 116 wakeup(&hmp->flusher.signal); 117 } else { 118 seq = hmp->flusher.done; 119 } 120 return(seq); 121 } 122 123 /* 124 * Wait for the flusher to get to the specified sequence number. 125 * Signal the flusher as often as necessary to keep it going. 126 */ 127 void 128 hammer_flusher_wait(hammer_mount_t hmp, int seq) 129 { 130 while ((int)(seq - hmp->flusher.done) > 0) { 131 if (hmp->flusher.act != seq) { 132 if (hmp->flusher.signal++ == 0) 133 wakeup(&hmp->flusher.signal); 134 } 135 tsleep(&hmp->flusher.done, 0, "hmrfls", 0); 136 } 137 } 138 139 void 140 hammer_flusher_wait_next(hammer_mount_t hmp) 141 { 142 int seq; 143 144 seq = hammer_flusher_async_one(hmp); 145 hammer_flusher_wait(hmp, seq); 146 } 147 148 void 149 hammer_flusher_create(hammer_mount_t hmp) 150 { 151 hammer_flusher_info_t info; 152 int i; 153 154 hmp->flusher.signal = 0; 155 hmp->flusher.act = 0; 156 hmp->flusher.done = 0; 157 hmp->flusher.next = 1; 158 hammer_ref(&hmp->flusher.finalize_lock); 159 TAILQ_INIT(&hmp->flusher.run_list); 160 TAILQ_INIT(&hmp->flusher.ready_list); 161 162 lwkt_create(hammer_flusher_master_thread, hmp, 163 &hmp->flusher.td, NULL, 0, -1, "hammer-M"); 164 for (i = 0; i < HAMMER_MAX_FLUSHERS; ++i) { 165 info = kmalloc(sizeof(*info), hmp->m_misc, M_WAITOK|M_ZERO); 166 info->hmp = hmp; 167 TAILQ_INSERT_TAIL(&hmp->flusher.ready_list, info, entry); 168 lwkt_create(hammer_flusher_slave_thread, info, 169 &info->td, NULL, 0, -1, "hammer-S%d", i); 170 } 171 } 172 173 void 174 hammer_flusher_destroy(hammer_mount_t hmp) 175 { 176 hammer_flusher_info_t info; 177 178 /* 179 * Kill the master 180 */ 181 hmp->flusher.exiting = 1; 182 while (hmp->flusher.td) { 183 ++hmp->flusher.signal; 184 wakeup(&hmp->flusher.signal); 185 tsleep(&hmp->flusher.exiting, 0, "hmrwex", hz); 186 } 187 188 /* 189 * Kill the slaves 190 */ 191 while ((info = TAILQ_FIRST(&hmp->flusher.ready_list)) != NULL) { 192 KKASSERT(info->runstate == 0); 193 TAILQ_REMOVE(&hmp->flusher.ready_list, info, entry); 194 info->runstate = -1; 195 wakeup(&info->runstate); 196 while (info->td) 197 tsleep(&info->td, 0, "hmrwwc", 0); 198 TAILQ_REMOVE(&hmp->flusher.ready_list, info, entry); 199 kfree(info, hmp->m_misc); 200 } 201 } 202 203 /* 204 * The master flusher thread manages the flusher sequence id and 205 * synchronization with the slave work threads. 206 */ 207 static void 208 hammer_flusher_master_thread(void *arg) 209 { 210 hammer_flush_group_t flg; 211 hammer_mount_t hmp; 212 213 hmp = arg; 214 215 for (;;) { 216 /* 217 * Do at least one flush cycle. We may have to update the 218 * UNDO FIFO even if no inodes are queued. 219 */ 220 for (;;) { 221 while (hmp->flusher.group_lock) 222 tsleep(&hmp->flusher.group_lock, 0, "hmrhld", 0); 223 hmp->flusher.act = hmp->flusher.next; 224 ++hmp->flusher.next; 225 hammer_flusher_clean_loose_ios(hmp); 226 hammer_flusher_flush(hmp); 227 hmp->flusher.done = hmp->flusher.act; 228 wakeup(&hmp->flusher.done); 229 flg = TAILQ_FIRST(&hmp->flush_group_list); 230 if (flg == NULL || flg->closed == 0) 231 break; 232 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 233 break; 234 } 235 236 /* 237 * Wait for activity. 238 */ 239 if (hmp->flusher.exiting && TAILQ_EMPTY(&hmp->flush_group_list)) 240 break; 241 while (hmp->flusher.signal == 0) 242 tsleep(&hmp->flusher.signal, 0, "hmrwwa", 0); 243 244 /* 245 * Flush for each count on signal but only allow one extra 246 * flush request to build up. 247 */ 248 if (--hmp->flusher.signal != 0) 249 hmp->flusher.signal = 1; 250 } 251 252 /* 253 * And we are done. 254 */ 255 hmp->flusher.td = NULL; 256 wakeup(&hmp->flusher.exiting); 257 lwkt_exit(); 258 } 259 260 /* 261 * Flush all inodes in the current flush group. 262 */ 263 static void 264 hammer_flusher_flush(hammer_mount_t hmp) 265 { 266 hammer_flusher_info_t info; 267 hammer_flush_group_t flg; 268 hammer_reserve_t resv; 269 hammer_inode_t ip; 270 hammer_inode_t next_ip; 271 int slave_index; 272 int count; 273 274 /* 275 * Just in-case there's a flush race on mount 276 */ 277 if (TAILQ_FIRST(&hmp->flusher.ready_list) == NULL) 278 return; 279 280 /* 281 * We only do one flg but we may have to loop/retry. 282 */ 283 count = 0; 284 while ((flg = TAILQ_FIRST(&hmp->flush_group_list)) != NULL) { 285 ++count; 286 if (hammer_debug_general & 0x0001) { 287 kprintf("hammer_flush %d ttl=%d recs=%d\n", 288 hmp->flusher.act, 289 flg->total_count, flg->refs); 290 } 291 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 292 break; 293 hammer_start_transaction_fls(&hmp->flusher.trans, hmp); 294 295 /* 296 * If the previous flush cycle just about exhausted our 297 * UNDO space we may have to do a dummy cycle to move the 298 * first_offset up before actually digging into a new cycle, 299 * or the new cycle will not have sufficient undo space. 300 */ 301 if (hammer_flusher_undo_exhausted(&hmp->flusher.trans, 3)) 302 hammer_flusher_finalize(&hmp->flusher.trans, 0); 303 304 /* 305 * Ok, we are running this flush group now (this prevents new 306 * additions to it). 307 */ 308 flg->running = 1; 309 if (hmp->next_flush_group == flg) 310 hmp->next_flush_group = TAILQ_NEXT(flg, flush_entry); 311 312 /* 313 * Iterate the inodes in the flg's flush_list and assign 314 * them to slaves. 315 */ 316 slave_index = 0; 317 info = TAILQ_FIRST(&hmp->flusher.ready_list); 318 next_ip = TAILQ_FIRST(&flg->flush_list); 319 320 while ((ip = next_ip) != NULL) { 321 next_ip = TAILQ_NEXT(ip, flush_entry); 322 323 /* 324 * Add ip to the slave's work array. The slave is 325 * not currently running. 326 */ 327 info->work_array[info->count++] = ip; 328 if (info->count != HAMMER_FLUSH_GROUP_SIZE) 329 continue; 330 331 /* 332 * Get the slave running 333 */ 334 TAILQ_REMOVE(&hmp->flusher.ready_list, info, entry); 335 TAILQ_INSERT_TAIL(&hmp->flusher.run_list, info, entry); 336 info->flg = flg; 337 info->runstate = 1; 338 wakeup(&info->runstate); 339 340 /* 341 * Get a new slave. We may have to wait for one to 342 * finish running. 343 */ 344 while ((info = TAILQ_FIRST(&hmp->flusher.ready_list)) == NULL) { 345 tsleep(&hmp->flusher.ready_list, 0, "hmrfcc", 0); 346 } 347 } 348 349 /* 350 * Run the current slave if necessary 351 */ 352 if (info->count) { 353 TAILQ_REMOVE(&hmp->flusher.ready_list, info, entry); 354 TAILQ_INSERT_TAIL(&hmp->flusher.run_list, info, entry); 355 info->flg = flg; 356 info->runstate = 1; 357 wakeup(&info->runstate); 358 } 359 360 /* 361 * Wait for all slaves to finish running 362 */ 363 while (TAILQ_FIRST(&hmp->flusher.run_list) != NULL) 364 tsleep(&hmp->flusher.ready_list, 0, "hmrfcc", 0); 365 366 /* 367 * Do the final finalization, clean up 368 */ 369 hammer_flusher_finalize(&hmp->flusher.trans, 1); 370 hmp->flusher.tid = hmp->flusher.trans.tid; 371 372 hammer_done_transaction(&hmp->flusher.trans); 373 374 /* 375 * Loop up on the same flg. If the flg is done clean it up 376 * and break out. We only flush one flg. 377 */ 378 if (TAILQ_FIRST(&flg->flush_list) == NULL) { 379 KKASSERT(TAILQ_EMPTY(&flg->flush_list)); 380 KKASSERT(flg->refs == 0); 381 TAILQ_REMOVE(&hmp->flush_group_list, flg, flush_entry); 382 kfree(flg, hmp->m_misc); 383 break; 384 } 385 } 386 387 /* 388 * We may have pure meta-data to flush, or we may have to finish 389 * cycling the UNDO FIFO, even if there were no flush groups. 390 */ 391 if (count == 0 && hammer_flusher_haswork(hmp)) { 392 hammer_start_transaction_fls(&hmp->flusher.trans, hmp); 393 hammer_flusher_finalize(&hmp->flusher.trans, 1); 394 hammer_done_transaction(&hmp->flusher.trans); 395 } 396 397 /* 398 * Clean up any freed big-blocks (typically zone-2). 399 * resv->flush_group is typically set several flush groups ahead 400 * of the free to ensure that the freed block is not reused until 401 * it can no longer be reused. 402 */ 403 while ((resv = TAILQ_FIRST(&hmp->delay_list)) != NULL) { 404 if (resv->flush_group != hmp->flusher.act) 405 break; 406 hammer_reserve_clrdelay(hmp, resv); 407 } 408 } 409 410 411 /* 412 * The slave flusher thread pulls work off the master flush_list until no 413 * work is left. 414 */ 415 static void 416 hammer_flusher_slave_thread(void *arg) 417 { 418 hammer_flush_group_t flg; 419 hammer_flusher_info_t info; 420 hammer_mount_t hmp; 421 hammer_inode_t ip; 422 int i; 423 424 info = arg; 425 hmp = info->hmp; 426 427 for (;;) { 428 while (info->runstate == 0) 429 tsleep(&info->runstate, 0, "hmrssw", 0); 430 if (info->runstate < 0) 431 break; 432 flg = info->flg; 433 434 for (i = 0; i < info->count; ++i) { 435 ip = info->work_array[i]; 436 hammer_flusher_flush_inode(ip, &hmp->flusher.trans); 437 ++hammer_stats_inode_flushes; 438 } 439 info->count = 0; 440 info->runstate = 0; 441 TAILQ_REMOVE(&hmp->flusher.run_list, info, entry); 442 TAILQ_INSERT_TAIL(&hmp->flusher.ready_list, info, entry); 443 wakeup(&hmp->flusher.ready_list); 444 } 445 info->td = NULL; 446 wakeup(&info->td); 447 lwkt_exit(); 448 } 449 450 void 451 hammer_flusher_clean_loose_ios(hammer_mount_t hmp) 452 { 453 hammer_buffer_t buffer; 454 hammer_io_t io; 455 456 /* 457 * loose ends - buffers without bp's aren't tracked by the kernel 458 * and can build up, so clean them out. This can occur when an 459 * IO completes on a buffer with no references left. 460 */ 461 if ((io = TAILQ_FIRST(&hmp->lose_list)) != NULL) { 462 crit_enter(); /* biodone() race */ 463 while ((io = TAILQ_FIRST(&hmp->lose_list)) != NULL) { 464 KKASSERT(io->mod_list == &hmp->lose_list); 465 TAILQ_REMOVE(&hmp->lose_list, io, mod_entry); 466 io->mod_list = NULL; 467 if (io->lock.refs == 0) 468 ++hammer_count_refedbufs; 469 hammer_ref(&io->lock); 470 buffer = (void *)io; 471 hammer_rel_buffer(buffer, 0); 472 } 473 crit_exit(); 474 } 475 } 476 477 /* 478 * Flush a single inode that is part of a flush group. 479 * 480 * Flusher errors are extremely serious, even ENOSPC shouldn't occur because 481 * the front-end should have reserved sufficient space on the media. Any 482 * error other then EWOULDBLOCK will force the mount to be read-only. 483 */ 484 static 485 void 486 hammer_flusher_flush_inode(hammer_inode_t ip, hammer_transaction_t trans) 487 { 488 hammer_mount_t hmp = ip->hmp; 489 int error; 490 491 hammer_flusher_clean_loose_ios(hmp); 492 error = hammer_sync_inode(trans, ip); 493 494 /* 495 * EWOULDBLOCK can happen under normal operation, all other errors 496 * are considered extremely serious. We must set WOULDBLOCK 497 * mechanics to deal with the mess left over from the abort of the 498 * previous flush. 499 */ 500 if (error) { 501 ip->flags |= HAMMER_INODE_WOULDBLOCK; 502 if (error == EWOULDBLOCK) 503 error = 0; 504 } 505 hammer_flush_inode_done(ip, error); 506 while (hmp->flusher.finalize_want) 507 tsleep(&hmp->flusher.finalize_want, 0, "hmrsxx", 0); 508 if (hammer_flusher_undo_exhausted(trans, 1)) { 509 kprintf("HAMMER: Warning: UNDO area too small!\n"); 510 hammer_flusher_finalize(trans, 1); 511 } else if (hammer_flusher_meta_limit(trans->hmp)) { 512 hammer_flusher_finalize(trans, 0); 513 } 514 } 515 516 /* 517 * Return non-zero if the UNDO area has less then (QUARTER / 4) of its 518 * space left. 519 * 520 * 1/4 - Emergency free undo space level. Below this point the flusher 521 * will finalize even if directory dependancies have not been resolved. 522 * 523 * 2/4 - Used by the pruning and reblocking code. These functions may be 524 * running in parallel with a flush and cannot be allowed to drop 525 * available undo space to emergency levels. 526 * 527 * 3/4 - Used at the beginning of a flush to force-sync the volume header 528 * to give the flush plenty of runway to work in. 529 */ 530 int 531 hammer_flusher_undo_exhausted(hammer_transaction_t trans, int quarter) 532 { 533 if (hammer_undo_space(trans) < 534 hammer_undo_max(trans->hmp) * quarter / 4) { 535 return(1); 536 } else { 537 return(0); 538 } 539 } 540 541 /* 542 * Flush all pending UNDOs, wait for write completion, update the volume 543 * header with the new UNDO end position, and flush it. Then 544 * asynchronously flush the meta-data. 545 * 546 * If this is the last finalization in a flush group we also synchronize 547 * our cached blockmap and set hmp->flusher_undo_start and our cached undo 548 * fifo first_offset so the next flush resets the FIFO pointers. 549 * 550 * If this is not final it is being called because too many dirty meta-data 551 * buffers have built up and must be flushed with UNDO synchronization to 552 * avoid a buffer cache deadlock. 553 */ 554 void 555 hammer_flusher_finalize(hammer_transaction_t trans, int final) 556 { 557 hammer_volume_t root_volume; 558 hammer_blockmap_t cundomap, dundomap; 559 hammer_mount_t hmp; 560 hammer_io_t io; 561 int count; 562 int i; 563 564 hmp = trans->hmp; 565 root_volume = trans->rootvol; 566 567 /* 568 * Exclusively lock the flusher. This guarantees that all dirty 569 * buffers will be idled (have a mod-count of 0). 570 */ 571 ++hmp->flusher.finalize_want; 572 hammer_lock_ex(&hmp->flusher.finalize_lock); 573 574 /* 575 * If this isn't the final sync several threads may have hit the 576 * meta-limit at the same time and raced. Only sync if we really 577 * have to, after acquiring the lock. 578 */ 579 if (final == 0 && !hammer_flusher_meta_limit(hmp)) 580 goto done; 581 582 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 583 goto done; 584 585 /* 586 * Flush data buffers. This can occur asynchronously and at any 587 * time. We must interlock against the frontend direct-data write 588 * but do not have to acquire the sync-lock yet. 589 */ 590 count = 0; 591 while ((io = TAILQ_FIRST(&hmp->data_list)) != NULL) { 592 if (io->ioerror) 593 break; 594 if (io->lock.refs == 0) 595 ++hammer_count_refedbufs; 596 hammer_ref(&io->lock); 597 hammer_io_write_interlock(io); 598 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME); 599 hammer_io_flush(io); 600 hammer_io_done_interlock(io); 601 hammer_rel_buffer((hammer_buffer_t)io, 0); 602 ++count; 603 } 604 605 /* 606 * The sync-lock is required for the remaining sequence. This lock 607 * prevents meta-data from being modified. 608 */ 609 hammer_sync_lock_ex(trans); 610 611 /* 612 * If we have been asked to finalize the volume header sync the 613 * cached blockmap to the on-disk blockmap. Generate an UNDO 614 * record for the update. 615 */ 616 if (final) { 617 cundomap = &hmp->blockmap[0]; 618 dundomap = &root_volume->ondisk->vol0_blockmap[0]; 619 if (root_volume->io.modified) { 620 hammer_modify_volume(trans, root_volume, 621 dundomap, sizeof(hmp->blockmap)); 622 for (i = 0; i < HAMMER_MAX_ZONES; ++i) 623 hammer_crc_set_blockmap(&cundomap[i]); 624 bcopy(cundomap, dundomap, sizeof(hmp->blockmap)); 625 hammer_modify_volume_done(root_volume); 626 } 627 } 628 629 /* 630 * Flush UNDOs 631 */ 632 count = 0; 633 while ((io = TAILQ_FIRST(&hmp->undo_list)) != NULL) { 634 if (io->ioerror) 635 break; 636 KKASSERT(io->modify_refs == 0); 637 if (io->lock.refs == 0) 638 ++hammer_count_refedbufs; 639 hammer_ref(&io->lock); 640 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME); 641 hammer_io_flush(io); 642 hammer_rel_buffer((hammer_buffer_t)io, 0); 643 ++count; 644 } 645 646 /* 647 * Wait for I/Os to complete 648 */ 649 hammer_flusher_clean_loose_ios(hmp); 650 hammer_io_wait_all(hmp, "hmrfl1"); 651 652 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 653 goto failed; 654 655 /* 656 * Update the on-disk volume header with new UNDO FIFO end position 657 * (do not generate new UNDO records for this change). We have to 658 * do this for the UNDO FIFO whether (final) is set or not. 659 * 660 * Also update the on-disk next_tid field. This does not require 661 * an UNDO. However, because our TID is generated before we get 662 * the sync lock another sync may have beat us to the punch. 663 * 664 * This also has the side effect of updating first_offset based on 665 * a prior finalization when the first finalization of the next flush 666 * cycle occurs, removing any undo info from the prior finalization 667 * from consideration. 668 * 669 * The volume header will be flushed out synchronously. 670 */ 671 dundomap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; 672 cundomap = &hmp->blockmap[HAMMER_ZONE_UNDO_INDEX]; 673 674 if (dundomap->first_offset != cundomap->first_offset || 675 dundomap->next_offset != cundomap->next_offset) { 676 hammer_modify_volume(NULL, root_volume, NULL, 0); 677 dundomap->first_offset = cundomap->first_offset; 678 dundomap->next_offset = cundomap->next_offset; 679 hammer_crc_set_blockmap(dundomap); 680 hammer_modify_volume_done(root_volume); 681 } 682 683 /* 684 * vol0_next_tid is used for TID selection and is updated without 685 * an UNDO so we do not reuse a TID that may have been rolled-back. 686 * 687 * vol0_last_tid is the highest fully-synchronized TID. It is 688 * set-up when the UNDO fifo is fully synced, later on (not here). 689 */ 690 if (root_volume->io.modified) { 691 hammer_modify_volume(NULL, root_volume, NULL, 0); 692 if (root_volume->ondisk->vol0_next_tid < trans->tid) 693 root_volume->ondisk->vol0_next_tid = trans->tid; 694 hammer_crc_set_volume(root_volume->ondisk); 695 hammer_modify_volume_done(root_volume); 696 hammer_io_flush(&root_volume->io); 697 } 698 699 /* 700 * Wait for I/Os to complete 701 */ 702 hammer_flusher_clean_loose_ios(hmp); 703 hammer_io_wait_all(hmp, "hmrfl2"); 704 705 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 706 goto failed; 707 708 /* 709 * Flush meta-data. The meta-data will be undone if we crash 710 * so we can safely flush it asynchronously. 711 * 712 * Repeated catchups will wind up flushing this update's meta-data 713 * and the UNDO buffers for the next update simultaniously. This 714 * is ok. 715 */ 716 count = 0; 717 while ((io = TAILQ_FIRST(&hmp->meta_list)) != NULL) { 718 if (io->ioerror) 719 break; 720 KKASSERT(io->modify_refs == 0); 721 if (io->lock.refs == 0) 722 ++hammer_count_refedbufs; 723 hammer_ref(&io->lock); 724 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME); 725 hammer_io_flush(io); 726 hammer_rel_buffer((hammer_buffer_t)io, 0); 727 ++count; 728 } 729 730 /* 731 * If this is the final finalization for the flush group set 732 * up for the next sequence by setting a new first_offset in 733 * our cached blockmap and clearing the undo history. 734 * 735 * Even though we have updated our cached first_offset, the on-disk 736 * first_offset still governs available-undo-space calculations. 737 */ 738 if (final) { 739 cundomap = &hmp->blockmap[HAMMER_ZONE_UNDO_INDEX]; 740 if (cundomap->first_offset == cundomap->next_offset) { 741 hmp->hflags &= ~HMNT_UNDO_DIRTY; 742 } else { 743 cundomap->first_offset = cundomap->next_offset; 744 hmp->hflags |= HMNT_UNDO_DIRTY; 745 } 746 hammer_clear_undo_history(hmp); 747 748 /* 749 * Flush tid sequencing. flush_tid1 is fully synchronized, 750 * meaning a crash will not roll it back. flush_tid2 has 751 * been written out asynchronously and a crash will roll 752 * it back. flush_tid1 is used for all mirroring masters. 753 */ 754 if (hmp->flush_tid1 != hmp->flush_tid2) { 755 hmp->flush_tid1 = hmp->flush_tid2; 756 wakeup(&hmp->flush_tid1); 757 } 758 hmp->flush_tid2 = trans->tid; 759 } 760 761 /* 762 * Cleanup. Report any critical errors. 763 */ 764 failed: 765 hammer_sync_unlock(trans); 766 767 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) { 768 kprintf("HAMMER(%s): Critical write error during flush, " 769 "refusing to sync UNDO FIFO\n", 770 root_volume->ondisk->vol_name); 771 } 772 773 done: 774 hammer_unlock(&hmp->flusher.finalize_lock); 775 776 if (--hmp->flusher.finalize_want == 0) 777 wakeup(&hmp->flusher.finalize_want); 778 hammer_stats_commits += final; 779 } 780 781 /* 782 * Return non-zero if too many dirty meta-data buffers have built up. 783 * 784 * Since we cannot allow such buffers to flush until we have dealt with 785 * the UNDOs, we risk deadlocking the kernel's buffer cache. 786 */ 787 int 788 hammer_flusher_meta_limit(hammer_mount_t hmp) 789 { 790 if (hmp->locked_dirty_space + hmp->io_running_space > 791 hammer_limit_dirtybufspace) { 792 return(1); 793 } 794 return(0); 795 } 796 797 /* 798 * Return non-zero if too many dirty meta-data buffers have built up. 799 * 800 * This version is used by background operations (mirror, prune, reblock) 801 * to leave room for foreground operations. 802 */ 803 int 804 hammer_flusher_meta_halflimit(hammer_mount_t hmp) 805 { 806 if (hmp->locked_dirty_space + hmp->io_running_space > 807 hammer_limit_dirtybufspace / 2) { 808 return(1); 809 } 810 return(0); 811 } 812 813 /* 814 * Return non-zero if the flusher still has something to flush. 815 */ 816 int 817 hammer_flusher_haswork(hammer_mount_t hmp) 818 { 819 if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) 820 return(0); 821 if (TAILQ_FIRST(&hmp->flush_group_list) || /* dirty inodes */ 822 TAILQ_FIRST(&hmp->volu_list) || /* dirty bufffers */ 823 TAILQ_FIRST(&hmp->undo_list) || 824 TAILQ_FIRST(&hmp->data_list) || 825 TAILQ_FIRST(&hmp->meta_list) || 826 (hmp->hflags & HMNT_UNDO_DIRTY) /* UNDO FIFO sync */ 827 ) { 828 return(1); 829 } 830 return(0); 831 } 832 833