replication.c (23753B)
1/* 2 * Replication Block filter 3 * 4 * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. 5 * Copyright (c) 2016 Intel Corporation 6 * Copyright (c) 2016 FUJITSU LIMITED 7 * 8 * Author: 9 * Wen Congyang <wency@cn.fujitsu.com> 10 * 11 * This work is licensed under the terms of the GNU GPL, version 2 or later. 12 * See the COPYING file in the top-level directory. 13 */ 14 15#include "qemu/osdep.h" 16#include "qemu/module.h" 17#include "qemu/option.h" 18#include "block/nbd.h" 19#include "block/blockjob.h" 20#include "block/block_int.h" 21#include "block/block_backup.h" 22#include "sysemu/block-backend.h" 23#include "qapi/error.h" 24#include "qapi/qmp/qdict.h" 25#include "block/replication.h" 26 27typedef enum { 28 BLOCK_REPLICATION_NONE, /* block replication is not started */ 29 BLOCK_REPLICATION_RUNNING, /* block replication is running */ 30 BLOCK_REPLICATION_FAILOVER, /* failover is running in background */ 31 BLOCK_REPLICATION_FAILOVER_FAILED, /* failover failed */ 32 BLOCK_REPLICATION_DONE, /* block replication is done */ 33} ReplicationStage; 34 35typedef struct BDRVReplicationState { 36 ReplicationMode mode; 37 ReplicationStage stage; 38 BlockJob *commit_job; 39 BdrvChild *hidden_disk; 40 BdrvChild *secondary_disk; 41 BlockJob *backup_job; 42 char *top_id; 43 ReplicationState *rs; 44 Error *blocker; 45 bool orig_hidden_read_only; 46 bool orig_secondary_read_only; 47 int error; 48} BDRVReplicationState; 49 50static void replication_start(ReplicationState *rs, ReplicationMode mode, 51 Error **errp); 52static void replication_do_checkpoint(ReplicationState *rs, Error **errp); 53static void replication_get_error(ReplicationState *rs, Error **errp); 54static void replication_stop(ReplicationState *rs, bool failover, 55 Error **errp); 56 57#define REPLICATION_MODE "mode" 58#define REPLICATION_TOP_ID "top-id" 59static QemuOptsList replication_runtime_opts = { 60 .name = "replication", 61 .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head), 62 .desc = { 63 { 64 .name = REPLICATION_MODE, 65 .type = QEMU_OPT_STRING, 66 }, 67 { 68 .name = REPLICATION_TOP_ID, 69 .type = QEMU_OPT_STRING, 70 }, 71 { /* end of list */ } 72 }, 73}; 74 75static ReplicationOps replication_ops = { 76 .start = replication_start, 77 .checkpoint = replication_do_checkpoint, 78 .get_error = replication_get_error, 79 .stop = replication_stop, 80}; 81 82static int replication_open(BlockDriverState *bs, QDict *options, 83 int flags, Error **errp) 84{ 85 int ret; 86 BDRVReplicationState *s = bs->opaque; 87 QemuOpts *opts = NULL; 88 const char *mode; 89 const char *top_id; 90 91 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 92 BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, 93 false, errp); 94 if (!bs->file) { 95 return -EINVAL; 96 } 97 98 ret = -EINVAL; 99 opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort); 100 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 101 goto fail; 102 } 103 104 mode = qemu_opt_get(opts, REPLICATION_MODE); 105 if (!mode) { 106 error_setg(errp, "Missing the option mode"); 107 goto fail; 108 } 109 110 if (!strcmp(mode, "primary")) { 111 s->mode = REPLICATION_MODE_PRIMARY; 112 top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); 113 if (top_id) { 114 error_setg(errp, 115 "The primary side does not support option top-id"); 116 goto fail; 117 } 118 } else if (!strcmp(mode, "secondary")) { 119 s->mode = REPLICATION_MODE_SECONDARY; 120 top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); 121 s->top_id = g_strdup(top_id); 122 if (!s->top_id) { 123 error_setg(errp, "Missing the option top-id"); 124 goto fail; 125 } 126 } else { 127 error_setg(errp, 128 "The option mode's value should be primary or secondary"); 129 goto fail; 130 } 131 132 s->rs = replication_new(bs, &replication_ops); 133 134 ret = 0; 135 136fail: 137 qemu_opts_del(opts); 138 return ret; 139} 140 141static void replication_close(BlockDriverState *bs) 142{ 143 BDRVReplicationState *s = bs->opaque; 144 Job *commit_job; 145 146 if (s->stage == BLOCK_REPLICATION_RUNNING) { 147 replication_stop(s->rs, false, NULL); 148 } 149 if (s->stage == BLOCK_REPLICATION_FAILOVER) { 150 commit_job = &s->commit_job->job; 151 assert(commit_job->aio_context == qemu_get_current_aio_context()); 152 job_cancel_sync(commit_job, false); 153 } 154 155 if (s->mode == REPLICATION_MODE_SECONDARY) { 156 g_free(s->top_id); 157 } 158 159 replication_remove(s->rs); 160} 161 162static void replication_child_perm(BlockDriverState *bs, BdrvChild *c, 163 BdrvChildRole role, 164 BlockReopenQueue *reopen_queue, 165 uint64_t perm, uint64_t shared, 166 uint64_t *nperm, uint64_t *nshared) 167{ 168 if (role & BDRV_CHILD_PRIMARY) { 169 *nperm = BLK_PERM_CONSISTENT_READ; 170 } else { 171 *nperm = 0; 172 } 173 174 if ((bs->open_flags & (BDRV_O_INACTIVE | BDRV_O_RDWR)) == BDRV_O_RDWR) { 175 *nperm |= BLK_PERM_WRITE; 176 } 177 *nshared = BLK_PERM_CONSISTENT_READ 178 | BLK_PERM_WRITE 179 | BLK_PERM_WRITE_UNCHANGED; 180 return; 181} 182 183static int64_t replication_getlength(BlockDriverState *bs) 184{ 185 return bdrv_getlength(bs->file->bs); 186} 187 188static int replication_get_io_status(BDRVReplicationState *s) 189{ 190 switch (s->stage) { 191 case BLOCK_REPLICATION_NONE: 192 return -EIO; 193 case BLOCK_REPLICATION_RUNNING: 194 return 0; 195 case BLOCK_REPLICATION_FAILOVER: 196 return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; 197 case BLOCK_REPLICATION_FAILOVER_FAILED: 198 return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 1; 199 case BLOCK_REPLICATION_DONE: 200 /* 201 * active commit job completes, and active disk and secondary_disk 202 * is swapped, so we can operate bs->file directly 203 */ 204 return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; 205 default: 206 abort(); 207 } 208} 209 210static int replication_return_value(BDRVReplicationState *s, int ret) 211{ 212 if (s->mode == REPLICATION_MODE_SECONDARY) { 213 return ret; 214 } 215 216 if (ret < 0) { 217 s->error = ret; 218 ret = 0; 219 } 220 221 return ret; 222} 223 224static coroutine_fn int replication_co_readv(BlockDriverState *bs, 225 int64_t sector_num, 226 int remaining_sectors, 227 QEMUIOVector *qiov) 228{ 229 BDRVReplicationState *s = bs->opaque; 230 int ret; 231 232 if (s->mode == REPLICATION_MODE_PRIMARY) { 233 /* We only use it to forward primary write requests */ 234 return -EIO; 235 } 236 237 ret = replication_get_io_status(s); 238 if (ret < 0) { 239 return ret; 240 } 241 242 ret = bdrv_co_preadv(bs->file, sector_num * BDRV_SECTOR_SIZE, 243 remaining_sectors * BDRV_SECTOR_SIZE, qiov, 0); 244 245 return replication_return_value(s, ret); 246} 247 248static coroutine_fn int replication_co_writev(BlockDriverState *bs, 249 int64_t sector_num, 250 int remaining_sectors, 251 QEMUIOVector *qiov, 252 int flags) 253{ 254 BDRVReplicationState *s = bs->opaque; 255 QEMUIOVector hd_qiov; 256 uint64_t bytes_done = 0; 257 BdrvChild *top = bs->file; 258 BdrvChild *base = s->secondary_disk; 259 BdrvChild *target; 260 int ret; 261 int64_t n; 262 263 assert(!flags); 264 ret = replication_get_io_status(s); 265 if (ret < 0) { 266 goto out; 267 } 268 269 if (ret == 0) { 270 ret = bdrv_co_pwritev(top, sector_num * BDRV_SECTOR_SIZE, 271 remaining_sectors * BDRV_SECTOR_SIZE, qiov, 0); 272 return replication_return_value(s, ret); 273 } 274 275 /* 276 * Failover failed, only write to active disk if the sectors 277 * have already been allocated in active disk/hidden disk. 278 */ 279 qemu_iovec_init(&hd_qiov, qiov->niov); 280 while (remaining_sectors > 0) { 281 int64_t count; 282 283 ret = bdrv_is_allocated_above(top->bs, base->bs, false, 284 sector_num * BDRV_SECTOR_SIZE, 285 remaining_sectors * BDRV_SECTOR_SIZE, 286 &count); 287 if (ret < 0) { 288 goto out1; 289 } 290 291 assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)); 292 n = count >> BDRV_SECTOR_BITS; 293 qemu_iovec_reset(&hd_qiov); 294 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, count); 295 296 target = ret ? top : base; 297 ret = bdrv_co_pwritev(target, sector_num * BDRV_SECTOR_SIZE, 298 n * BDRV_SECTOR_SIZE, &hd_qiov, 0); 299 if (ret < 0) { 300 goto out1; 301 } 302 303 remaining_sectors -= n; 304 sector_num += n; 305 bytes_done += count; 306 } 307 308out1: 309 qemu_iovec_destroy(&hd_qiov); 310out: 311 return ret; 312} 313 314static void secondary_do_checkpoint(BlockDriverState *bs, Error **errp) 315{ 316 BDRVReplicationState *s = bs->opaque; 317 BdrvChild *active_disk = bs->file; 318 Error *local_err = NULL; 319 int ret; 320 321 if (!s->backup_job) { 322 error_setg(errp, "Backup job was cancelled unexpectedly"); 323 return; 324 } 325 326 backup_do_checkpoint(s->backup_job, &local_err); 327 if (local_err) { 328 error_propagate(errp, local_err); 329 return; 330 } 331 332 if (!active_disk->bs->drv) { 333 error_setg(errp, "Active disk %s is ejected", 334 active_disk->bs->node_name); 335 return; 336 } 337 338 ret = bdrv_make_empty(active_disk, errp); 339 if (ret < 0) { 340 return; 341 } 342 343 if (!s->hidden_disk->bs->drv) { 344 error_setg(errp, "Hidden disk %s is ejected", 345 s->hidden_disk->bs->node_name); 346 return; 347 } 348 349 ret = bdrv_make_empty(s->hidden_disk, errp); 350 if (ret < 0) { 351 return; 352 } 353} 354 355/* This function is supposed to be called twice: 356 * first with writable = true, then with writable = false. 357 * The first call puts s->hidden_disk and s->secondary_disk in 358 * r/w mode, and the second puts them back in their original state. 359 */ 360static void reopen_backing_file(BlockDriverState *bs, bool writable, 361 Error **errp) 362{ 363 BDRVReplicationState *s = bs->opaque; 364 BdrvChild *hidden_disk, *secondary_disk; 365 BlockReopenQueue *reopen_queue = NULL; 366 367 /* 368 * s->hidden_disk and s->secondary_disk may not be set yet, as they will 369 * only be set after the children are writable. 370 */ 371 hidden_disk = bs->file->bs->backing; 372 secondary_disk = hidden_disk->bs->backing; 373 374 if (writable) { 375 s->orig_hidden_read_only = bdrv_is_read_only(hidden_disk->bs); 376 s->orig_secondary_read_only = bdrv_is_read_only(secondary_disk->bs); 377 } 378 379 bdrv_subtree_drained_begin(hidden_disk->bs); 380 bdrv_subtree_drained_begin(secondary_disk->bs); 381 382 if (s->orig_hidden_read_only) { 383 QDict *opts = qdict_new(); 384 qdict_put_bool(opts, BDRV_OPT_READ_ONLY, !writable); 385 reopen_queue = bdrv_reopen_queue(reopen_queue, hidden_disk->bs, 386 opts, true); 387 } 388 389 if (s->orig_secondary_read_only) { 390 QDict *opts = qdict_new(); 391 qdict_put_bool(opts, BDRV_OPT_READ_ONLY, !writable); 392 reopen_queue = bdrv_reopen_queue(reopen_queue, secondary_disk->bs, 393 opts, true); 394 } 395 396 if (reopen_queue) { 397 AioContext *ctx = bdrv_get_aio_context(bs); 398 if (ctx != qemu_get_aio_context()) { 399 aio_context_release(ctx); 400 } 401 bdrv_reopen_multiple(reopen_queue, errp); 402 if (ctx != qemu_get_aio_context()) { 403 aio_context_acquire(ctx); 404 } 405 } 406 407 bdrv_subtree_drained_end(hidden_disk->bs); 408 bdrv_subtree_drained_end(secondary_disk->bs); 409} 410 411static void backup_job_cleanup(BlockDriverState *bs) 412{ 413 BDRVReplicationState *s = bs->opaque; 414 BlockDriverState *top_bs; 415 416 s->backup_job = NULL; 417 418 top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); 419 if (!top_bs) { 420 return; 421 } 422 bdrv_op_unblock_all(top_bs, s->blocker); 423 error_free(s->blocker); 424 reopen_backing_file(bs, false, NULL); 425} 426 427static void backup_job_completed(void *opaque, int ret) 428{ 429 BlockDriverState *bs = opaque; 430 BDRVReplicationState *s = bs->opaque; 431 432 if (s->stage != BLOCK_REPLICATION_FAILOVER) { 433 /* The backup job is cancelled unexpectedly */ 434 s->error = -EIO; 435 } 436 437 backup_job_cleanup(bs); 438} 439 440static bool check_top_bs(BlockDriverState *top_bs, BlockDriverState *bs) 441{ 442 BdrvChild *child; 443 444 /* The bs itself is the top_bs */ 445 if (top_bs == bs) { 446 return true; 447 } 448 449 /* Iterate over top_bs's children */ 450 QLIST_FOREACH(child, &top_bs->children, next) { 451 if (child->bs == bs || check_top_bs(child->bs, bs)) { 452 return true; 453 } 454 } 455 456 return false; 457} 458 459static void replication_start(ReplicationState *rs, ReplicationMode mode, 460 Error **errp) 461{ 462 BlockDriverState *bs = rs->opaque; 463 BDRVReplicationState *s; 464 BlockDriverState *top_bs; 465 BdrvChild *active_disk, *hidden_disk, *secondary_disk; 466 int64_t active_length, hidden_length, disk_length; 467 AioContext *aio_context; 468 Error *local_err = NULL; 469 BackupPerf perf = { .use_copy_range = true, .max_workers = 1 }; 470 471 aio_context = bdrv_get_aio_context(bs); 472 aio_context_acquire(aio_context); 473 s = bs->opaque; 474 475 if (s->stage == BLOCK_REPLICATION_DONE || 476 s->stage == BLOCK_REPLICATION_FAILOVER) { 477 /* 478 * This case happens when a secondary is promoted to primary. 479 * Ignore the request because the secondary side of replication 480 * doesn't have to do anything anymore. 481 */ 482 aio_context_release(aio_context); 483 return; 484 } 485 486 if (s->stage != BLOCK_REPLICATION_NONE) { 487 error_setg(errp, "Block replication is running or done"); 488 aio_context_release(aio_context); 489 return; 490 } 491 492 if (s->mode != mode) { 493 error_setg(errp, "The parameter mode's value is invalid, needs %d," 494 " but got %d", s->mode, mode); 495 aio_context_release(aio_context); 496 return; 497 } 498 499 switch (s->mode) { 500 case REPLICATION_MODE_PRIMARY: 501 break; 502 case REPLICATION_MODE_SECONDARY: 503 active_disk = bs->file; 504 if (!active_disk || !active_disk->bs || !active_disk->bs->backing) { 505 error_setg(errp, "Active disk doesn't have backing file"); 506 aio_context_release(aio_context); 507 return; 508 } 509 510 hidden_disk = active_disk->bs->backing; 511 if (!hidden_disk->bs || !hidden_disk->bs->backing) { 512 error_setg(errp, "Hidden disk doesn't have backing file"); 513 aio_context_release(aio_context); 514 return; 515 } 516 517 secondary_disk = hidden_disk->bs->backing; 518 if (!secondary_disk->bs || !bdrv_has_blk(secondary_disk->bs)) { 519 error_setg(errp, "The secondary disk doesn't have block backend"); 520 aio_context_release(aio_context); 521 return; 522 } 523 524 /* verify the length */ 525 active_length = bdrv_getlength(active_disk->bs); 526 hidden_length = bdrv_getlength(hidden_disk->bs); 527 disk_length = bdrv_getlength(secondary_disk->bs); 528 if (active_length < 0 || hidden_length < 0 || disk_length < 0 || 529 active_length != hidden_length || hidden_length != disk_length) { 530 error_setg(errp, "Active disk, hidden disk, secondary disk's length" 531 " are not the same"); 532 aio_context_release(aio_context); 533 return; 534 } 535 536 /* Must be true, or the bdrv_getlength() calls would have failed */ 537 assert(active_disk->bs->drv && hidden_disk->bs->drv); 538 539 if (!active_disk->bs->drv->bdrv_make_empty || 540 !hidden_disk->bs->drv->bdrv_make_empty) { 541 error_setg(errp, 542 "Active disk or hidden disk doesn't support make_empty"); 543 aio_context_release(aio_context); 544 return; 545 } 546 547 /* reopen the backing file in r/w mode */ 548 reopen_backing_file(bs, true, &local_err); 549 if (local_err) { 550 error_propagate(errp, local_err); 551 aio_context_release(aio_context); 552 return; 553 } 554 555 bdrv_ref(hidden_disk->bs); 556 s->hidden_disk = bdrv_attach_child(bs, hidden_disk->bs, "hidden disk", 557 &child_of_bds, BDRV_CHILD_DATA, 558 &local_err); 559 if (local_err) { 560 error_propagate(errp, local_err); 561 aio_context_release(aio_context); 562 return; 563 } 564 565 bdrv_ref(secondary_disk->bs); 566 s->secondary_disk = bdrv_attach_child(bs, secondary_disk->bs, 567 "secondary disk", &child_of_bds, 568 BDRV_CHILD_DATA, &local_err); 569 if (local_err) { 570 error_propagate(errp, local_err); 571 aio_context_release(aio_context); 572 return; 573 } 574 575 /* start backup job now */ 576 error_setg(&s->blocker, 577 "Block device is in use by internal backup job"); 578 579 top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); 580 if (!top_bs || !bdrv_is_root_node(top_bs) || 581 !check_top_bs(top_bs, bs)) { 582 error_setg(errp, "No top_bs or it is invalid"); 583 reopen_backing_file(bs, false, NULL); 584 aio_context_release(aio_context); 585 return; 586 } 587 bdrv_op_block_all(top_bs, s->blocker); 588 bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); 589 590 s->backup_job = backup_job_create( 591 NULL, s->secondary_disk->bs, s->hidden_disk->bs, 592 0, MIRROR_SYNC_MODE_NONE, NULL, 0, false, NULL, 593 &perf, 594 BLOCKDEV_ON_ERROR_REPORT, 595 BLOCKDEV_ON_ERROR_REPORT, JOB_INTERNAL, 596 backup_job_completed, bs, NULL, &local_err); 597 if (local_err) { 598 error_propagate(errp, local_err); 599 backup_job_cleanup(bs); 600 aio_context_release(aio_context); 601 return; 602 } 603 job_start(&s->backup_job->job); 604 break; 605 default: 606 aio_context_release(aio_context); 607 abort(); 608 } 609 610 s->stage = BLOCK_REPLICATION_RUNNING; 611 612 if (s->mode == REPLICATION_MODE_SECONDARY) { 613 secondary_do_checkpoint(bs, errp); 614 } 615 616 s->error = 0; 617 aio_context_release(aio_context); 618} 619 620static void replication_do_checkpoint(ReplicationState *rs, Error **errp) 621{ 622 BlockDriverState *bs = rs->opaque; 623 BDRVReplicationState *s; 624 AioContext *aio_context; 625 626 aio_context = bdrv_get_aio_context(bs); 627 aio_context_acquire(aio_context); 628 s = bs->opaque; 629 630 if (s->stage == BLOCK_REPLICATION_DONE || 631 s->stage == BLOCK_REPLICATION_FAILOVER) { 632 /* 633 * This case happens when a secondary was promoted to primary. 634 * Ignore the request because the secondary side of replication 635 * doesn't have to do anything anymore. 636 */ 637 aio_context_release(aio_context); 638 return; 639 } 640 641 if (s->mode == REPLICATION_MODE_SECONDARY) { 642 secondary_do_checkpoint(bs, errp); 643 } 644 aio_context_release(aio_context); 645} 646 647static void replication_get_error(ReplicationState *rs, Error **errp) 648{ 649 BlockDriverState *bs = rs->opaque; 650 BDRVReplicationState *s; 651 AioContext *aio_context; 652 653 aio_context = bdrv_get_aio_context(bs); 654 aio_context_acquire(aio_context); 655 s = bs->opaque; 656 657 if (s->stage == BLOCK_REPLICATION_NONE) { 658 error_setg(errp, "Block replication is not running"); 659 aio_context_release(aio_context); 660 return; 661 } 662 663 if (s->error) { 664 error_setg(errp, "I/O error occurred"); 665 aio_context_release(aio_context); 666 return; 667 } 668 aio_context_release(aio_context); 669} 670 671static void replication_done(void *opaque, int ret) 672{ 673 BlockDriverState *bs = opaque; 674 BDRVReplicationState *s = bs->opaque; 675 676 if (ret == 0) { 677 s->stage = BLOCK_REPLICATION_DONE; 678 679 bdrv_unref_child(bs, s->secondary_disk); 680 s->secondary_disk = NULL; 681 bdrv_unref_child(bs, s->hidden_disk); 682 s->hidden_disk = NULL; 683 s->error = 0; 684 } else { 685 s->stage = BLOCK_REPLICATION_FAILOVER_FAILED; 686 s->error = -EIO; 687 } 688} 689 690static void replication_stop(ReplicationState *rs, bool failover, Error **errp) 691{ 692 BlockDriverState *bs = rs->opaque; 693 BDRVReplicationState *s; 694 AioContext *aio_context; 695 696 aio_context = bdrv_get_aio_context(bs); 697 aio_context_acquire(aio_context); 698 s = bs->opaque; 699 700 if (s->stage == BLOCK_REPLICATION_DONE || 701 s->stage == BLOCK_REPLICATION_FAILOVER) { 702 /* 703 * This case happens when a secondary was promoted to primary. 704 * Ignore the request because the secondary side of replication 705 * doesn't have to do anything anymore. 706 */ 707 aio_context_release(aio_context); 708 return; 709 } 710 711 if (s->stage != BLOCK_REPLICATION_RUNNING) { 712 error_setg(errp, "Block replication is not running"); 713 aio_context_release(aio_context); 714 return; 715 } 716 717 switch (s->mode) { 718 case REPLICATION_MODE_PRIMARY: 719 s->stage = BLOCK_REPLICATION_DONE; 720 s->error = 0; 721 break; 722 case REPLICATION_MODE_SECONDARY: 723 /* 724 * This BDS will be closed, and the job should be completed 725 * before the BDS is closed, because we will access hidden 726 * disk, secondary disk in backup_job_completed(). 727 */ 728 if (s->backup_job) { 729 job_cancel_sync(&s->backup_job->job, true); 730 } 731 732 if (!failover) { 733 secondary_do_checkpoint(bs, errp); 734 s->stage = BLOCK_REPLICATION_DONE; 735 aio_context_release(aio_context); 736 return; 737 } 738 739 s->stage = BLOCK_REPLICATION_FAILOVER; 740 s->commit_job = commit_active_start( 741 NULL, bs->file->bs, s->secondary_disk->bs, 742 JOB_INTERNAL, 0, BLOCKDEV_ON_ERROR_REPORT, 743 NULL, replication_done, bs, true, errp); 744 break; 745 default: 746 aio_context_release(aio_context); 747 abort(); 748 } 749 aio_context_release(aio_context); 750} 751 752static const char *const replication_strong_runtime_opts[] = { 753 REPLICATION_MODE, 754 REPLICATION_TOP_ID, 755 756 NULL 757}; 758 759static BlockDriver bdrv_replication = { 760 .format_name = "replication", 761 .instance_size = sizeof(BDRVReplicationState), 762 763 .bdrv_open = replication_open, 764 .bdrv_close = replication_close, 765 .bdrv_child_perm = replication_child_perm, 766 767 .bdrv_getlength = replication_getlength, 768 .bdrv_co_readv = replication_co_readv, 769 .bdrv_co_writev = replication_co_writev, 770 771 .is_filter = true, 772 773 .has_variable_length = true, 774 .strong_runtime_opts = replication_strong_runtime_opts, 775}; 776 777static void bdrv_replication_init(void) 778{ 779 bdrv_register(&bdrv_replication); 780} 781 782block_init(bdrv_replication_init);