1 /* 2 * Image mirroring 3 * 4 * Copyright Red Hat, Inc. 2012 5 * 6 * Authors: 7 * Paolo Bonzini <pbonzini@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 10 * See the COPYING.LIB file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "qemu/cutils.h" 16 #include "trace.h" 17 #include "block/blockjob_int.h" 18 #include "block/block_int.h" 19 #include "sysemu/block-backend.h" 20 #include "qapi/error.h" 21 #include "qapi/qmp/qerror.h" 22 #include "qemu/ratelimit.h" 23 #include "qemu/bitmap.h" 24 25 #define SLICE_TIME 100000000ULL /* ns */ 26 #define MAX_IN_FLIGHT 16 27 #define MAX_IO_SECTORS ((1 << 20) >> BDRV_SECTOR_BITS) /* 1 Mb */ 28 #define DEFAULT_MIRROR_BUF_SIZE \ 29 (MAX_IN_FLIGHT * MAX_IO_SECTORS * BDRV_SECTOR_SIZE) 30 31 /* The mirroring buffer is a list of granularity-sized chunks. 32 * Free chunks are organized in a list. 33 */ 34 typedef struct MirrorBuffer { 35 QSIMPLEQ_ENTRY(MirrorBuffer) next; 36 } MirrorBuffer; 37 38 typedef struct MirrorBlockJob { 39 BlockJob common; 40 RateLimit limit; 41 BlockBackend *target; 42 BlockDriverState *mirror_top_bs; 43 BlockDriverState *source; 44 BlockDriverState *base; 45 46 /* The name of the graph node to replace */ 47 char *replaces; 48 /* The BDS to replace */ 49 BlockDriverState *to_replace; 50 /* Used to block operations on the drive-mirror-replace target */ 51 Error *replace_blocker; 52 bool is_none_mode; 53 BlockMirrorBackingMode backing_mode; 54 BlockdevOnError on_source_error, on_target_error; 55 bool synced; 56 bool should_complete; 57 int64_t granularity; 58 size_t buf_size; 59 int64_t bdev_length; 60 unsigned long *cow_bitmap; 61 BdrvDirtyBitmap *dirty_bitmap; 62 BdrvDirtyBitmapIter *dbi; 63 uint8_t *buf; 64 QSIMPLEQ_HEAD(, MirrorBuffer) buf_free; 65 int buf_free_count; 66 67 uint64_t last_pause_ns; 68 unsigned long *in_flight_bitmap; 69 int in_flight; 70 int64_t sectors_in_flight; 71 int ret; 72 bool unmap; 73 bool waiting_for_io; 74 int target_cluster_sectors; 75 int max_iov; 76 bool initial_zeroing_ongoing; 77 } MirrorBlockJob; 78 79 typedef struct MirrorOp { 80 MirrorBlockJob *s; 81 QEMUIOVector qiov; 82 int64_t sector_num; 83 int nb_sectors; 84 } MirrorOp; 85 86 static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, 87 int error) 88 { 89 s->synced = false; 90 if (read) { 91 return block_job_error_action(&s->common, s->on_source_error, 92 true, error); 93 } else { 94 return block_job_error_action(&s->common, s->on_target_error, 95 false, error); 96 } 97 } 98 99 static void mirror_iteration_done(MirrorOp *op, int ret) 100 { 101 MirrorBlockJob *s = op->s; 102 struct iovec *iov; 103 int64_t chunk_num; 104 int i, nb_chunks, sectors_per_chunk; 105 106 trace_mirror_iteration_done(s, op->sector_num, op->nb_sectors, ret); 107 108 s->in_flight--; 109 s->sectors_in_flight -= op->nb_sectors; 110 iov = op->qiov.iov; 111 for (i = 0; i < op->qiov.niov; i++) { 112 MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; 113 QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next); 114 s->buf_free_count++; 115 } 116 117 sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 118 chunk_num = op->sector_num / sectors_per_chunk; 119 nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk); 120 bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); 121 if (ret >= 0) { 122 if (s->cow_bitmap) { 123 bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); 124 } 125 if (!s->initial_zeroing_ongoing) { 126 s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE; 127 } 128 } 129 qemu_iovec_destroy(&op->qiov); 130 g_free(op); 131 132 if (s->waiting_for_io) { 133 qemu_coroutine_enter(s->common.co); 134 } 135 } 136 137 static void mirror_write_complete(void *opaque, int ret) 138 { 139 MirrorOp *op = opaque; 140 MirrorBlockJob *s = op->s; 141 142 aio_context_acquire(blk_get_aio_context(s->common.blk)); 143 if (ret < 0) { 144 BlockErrorAction action; 145 146 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); 147 action = mirror_error_action(s, false, -ret); 148 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 149 s->ret = ret; 150 } 151 } 152 mirror_iteration_done(op, ret); 153 aio_context_release(blk_get_aio_context(s->common.blk)); 154 } 155 156 static void mirror_read_complete(void *opaque, int ret) 157 { 158 MirrorOp *op = opaque; 159 MirrorBlockJob *s = op->s; 160 161 aio_context_acquire(blk_get_aio_context(s->common.blk)); 162 if (ret < 0) { 163 BlockErrorAction action; 164 165 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); 166 action = mirror_error_action(s, true, -ret); 167 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 168 s->ret = ret; 169 } 170 171 mirror_iteration_done(op, ret); 172 } else { 173 blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov, 174 0, mirror_write_complete, op); 175 } 176 aio_context_release(blk_get_aio_context(s->common.blk)); 177 } 178 179 static inline void mirror_clip_sectors(MirrorBlockJob *s, 180 int64_t sector_num, 181 int *nb_sectors) 182 { 183 *nb_sectors = MIN(*nb_sectors, 184 s->bdev_length / BDRV_SECTOR_SIZE - sector_num); 185 } 186 187 /* Round sector_num and/or nb_sectors to target cluster if COW is needed, and 188 * return the offset of the adjusted tail sector against original. */ 189 static int mirror_cow_align(MirrorBlockJob *s, 190 int64_t *sector_num, 191 int *nb_sectors) 192 { 193 bool need_cow; 194 int ret = 0; 195 int chunk_sectors = s->granularity >> BDRV_SECTOR_BITS; 196 int64_t align_sector_num = *sector_num; 197 int align_nb_sectors = *nb_sectors; 198 int max_sectors = chunk_sectors * s->max_iov; 199 200 need_cow = !test_bit(*sector_num / chunk_sectors, s->cow_bitmap); 201 need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors, 202 s->cow_bitmap); 203 if (need_cow) { 204 bdrv_round_sectors_to_clusters(blk_bs(s->target), *sector_num, 205 *nb_sectors, &align_sector_num, 206 &align_nb_sectors); 207 } 208 209 if (align_nb_sectors > max_sectors) { 210 align_nb_sectors = max_sectors; 211 if (need_cow) { 212 align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors, 213 s->target_cluster_sectors); 214 } 215 } 216 /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but 217 * that doesn't matter because it's already the end of source image. */ 218 mirror_clip_sectors(s, align_sector_num, &align_nb_sectors); 219 220 ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors); 221 *sector_num = align_sector_num; 222 *nb_sectors = align_nb_sectors; 223 assert(ret >= 0); 224 return ret; 225 } 226 227 static inline void mirror_wait_for_io(MirrorBlockJob *s) 228 { 229 assert(!s->waiting_for_io); 230 s->waiting_for_io = true; 231 qemu_coroutine_yield(); 232 s->waiting_for_io = false; 233 } 234 235 /* Submit async read while handling COW. 236 * Returns: The number of sectors copied after and including sector_num, 237 * excluding any sectors copied prior to sector_num due to alignment. 238 * This will be nb_sectors if no alignment is necessary, or 239 * (new_end - sector_num) if tail is rounded up or down due to 240 * alignment or buffer limit. 241 */ 242 static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, 243 int nb_sectors) 244 { 245 BlockBackend *source = s->common.blk; 246 int sectors_per_chunk, nb_chunks; 247 int ret; 248 MirrorOp *op; 249 int max_sectors; 250 251 sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 252 max_sectors = sectors_per_chunk * s->max_iov; 253 254 /* We can only handle as much as buf_size at a time. */ 255 nb_sectors = MIN(s->buf_size >> BDRV_SECTOR_BITS, nb_sectors); 256 nb_sectors = MIN(max_sectors, nb_sectors); 257 assert(nb_sectors); 258 ret = nb_sectors; 259 260 if (s->cow_bitmap) { 261 ret += mirror_cow_align(s, §or_num, &nb_sectors); 262 } 263 assert(nb_sectors << BDRV_SECTOR_BITS <= s->buf_size); 264 /* The sector range must meet granularity because: 265 * 1) Caller passes in aligned values; 266 * 2) mirror_cow_align is used only when target cluster is larger. */ 267 assert(!(sector_num % sectors_per_chunk)); 268 nb_chunks = DIV_ROUND_UP(nb_sectors, sectors_per_chunk); 269 270 while (s->buf_free_count < nb_chunks) { 271 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 272 mirror_wait_for_io(s); 273 } 274 275 /* Allocate a MirrorOp that is used as an AIO callback. */ 276 op = g_new(MirrorOp, 1); 277 op->s = s; 278 op->sector_num = sector_num; 279 op->nb_sectors = nb_sectors; 280 281 /* Now make a QEMUIOVector taking enough granularity-sized chunks 282 * from s->buf_free. 283 */ 284 qemu_iovec_init(&op->qiov, nb_chunks); 285 while (nb_chunks-- > 0) { 286 MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); 287 size_t remaining = nb_sectors * BDRV_SECTOR_SIZE - op->qiov.size; 288 289 QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); 290 s->buf_free_count--; 291 qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); 292 } 293 294 /* Copy the dirty cluster. */ 295 s->in_flight++; 296 s->sectors_in_flight += nb_sectors; 297 trace_mirror_one_iteration(s, sector_num, nb_sectors); 298 299 blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov, 0, 300 mirror_read_complete, op); 301 return ret; 302 } 303 304 static void mirror_do_zero_or_discard(MirrorBlockJob *s, 305 int64_t sector_num, 306 int nb_sectors, 307 bool is_discard) 308 { 309 MirrorOp *op; 310 311 /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed 312 * so the freeing in mirror_iteration_done is nop. */ 313 op = g_new0(MirrorOp, 1); 314 op->s = s; 315 op->sector_num = sector_num; 316 op->nb_sectors = nb_sectors; 317 318 s->in_flight++; 319 s->sectors_in_flight += nb_sectors; 320 if (is_discard) { 321 blk_aio_pdiscard(s->target, sector_num << BDRV_SECTOR_BITS, 322 op->nb_sectors << BDRV_SECTOR_BITS, 323 mirror_write_complete, op); 324 } else { 325 blk_aio_pwrite_zeroes(s->target, sector_num * BDRV_SECTOR_SIZE, 326 op->nb_sectors * BDRV_SECTOR_SIZE, 327 s->unmap ? BDRV_REQ_MAY_UNMAP : 0, 328 mirror_write_complete, op); 329 } 330 } 331 332 static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) 333 { 334 BlockDriverState *source = s->source; 335 int64_t sector_num, first_chunk; 336 uint64_t delay_ns = 0; 337 /* At least the first dirty chunk is mirrored in one iteration. */ 338 int nb_chunks = 1; 339 int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; 340 int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 341 bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); 342 int max_io_sectors = MAX((s->buf_size >> BDRV_SECTOR_BITS) / MAX_IN_FLIGHT, 343 MAX_IO_SECTORS); 344 345 sector_num = bdrv_dirty_iter_next(s->dbi); 346 if (sector_num < 0) { 347 bdrv_set_dirty_iter(s->dbi, 0); 348 sector_num = bdrv_dirty_iter_next(s->dbi); 349 trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); 350 assert(sector_num >= 0); 351 } 352 353 first_chunk = sector_num / sectors_per_chunk; 354 while (test_bit(first_chunk, s->in_flight_bitmap)) { 355 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 356 mirror_wait_for_io(s); 357 } 358 359 block_job_pause_point(&s->common); 360 361 /* Find the number of consective dirty chunks following the first dirty 362 * one, and wait for in flight requests in them. */ 363 while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { 364 int64_t next_dirty; 365 int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk; 366 int64_t next_chunk = next_sector / sectors_per_chunk; 367 if (next_sector >= end || 368 !bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) { 369 break; 370 } 371 if (test_bit(next_chunk, s->in_flight_bitmap)) { 372 break; 373 } 374 375 next_dirty = bdrv_dirty_iter_next(s->dbi); 376 if (next_dirty > next_sector || next_dirty < 0) { 377 /* The bitmap iterator's cache is stale, refresh it */ 378 bdrv_set_dirty_iter(s->dbi, next_sector); 379 next_dirty = bdrv_dirty_iter_next(s->dbi); 380 } 381 assert(next_dirty == next_sector); 382 nb_chunks++; 383 } 384 385 /* Clear dirty bits before querying the block status, because 386 * calling bdrv_get_block_status_above could yield - if some blocks are 387 * marked dirty in this window, we need to know. 388 */ 389 bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num, 390 nb_chunks * sectors_per_chunk); 391 bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks); 392 while (nb_chunks > 0 && sector_num < end) { 393 int64_t ret; 394 int io_sectors, io_sectors_acct; 395 BlockDriverState *file; 396 enum MirrorMethod { 397 MIRROR_METHOD_COPY, 398 MIRROR_METHOD_ZERO, 399 MIRROR_METHOD_DISCARD 400 } mirror_method = MIRROR_METHOD_COPY; 401 402 assert(!(sector_num % sectors_per_chunk)); 403 ret = bdrv_get_block_status_above(source, NULL, sector_num, 404 nb_chunks * sectors_per_chunk, 405 &io_sectors, &file); 406 if (ret < 0) { 407 io_sectors = MIN(nb_chunks * sectors_per_chunk, max_io_sectors); 408 } else if (ret & BDRV_BLOCK_DATA) { 409 io_sectors = MIN(io_sectors, max_io_sectors); 410 } 411 412 io_sectors -= io_sectors % sectors_per_chunk; 413 if (io_sectors < sectors_per_chunk) { 414 io_sectors = sectors_per_chunk; 415 } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { 416 int64_t target_sector_num; 417 int target_nb_sectors; 418 bdrv_round_sectors_to_clusters(blk_bs(s->target), sector_num, 419 io_sectors, &target_sector_num, 420 &target_nb_sectors); 421 if (target_sector_num == sector_num && 422 target_nb_sectors == io_sectors) { 423 mirror_method = ret & BDRV_BLOCK_ZERO ? 424 MIRROR_METHOD_ZERO : 425 MIRROR_METHOD_DISCARD; 426 } 427 } 428 429 while (s->in_flight >= MAX_IN_FLIGHT) { 430 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 431 mirror_wait_for_io(s); 432 } 433 434 if (s->ret < 0) { 435 return 0; 436 } 437 438 mirror_clip_sectors(s, sector_num, &io_sectors); 439 switch (mirror_method) { 440 case MIRROR_METHOD_COPY: 441 io_sectors = mirror_do_read(s, sector_num, io_sectors); 442 io_sectors_acct = io_sectors; 443 break; 444 case MIRROR_METHOD_ZERO: 445 case MIRROR_METHOD_DISCARD: 446 mirror_do_zero_or_discard(s, sector_num, io_sectors, 447 mirror_method == MIRROR_METHOD_DISCARD); 448 if (write_zeroes_ok) { 449 io_sectors_acct = 0; 450 } else { 451 io_sectors_acct = io_sectors; 452 } 453 break; 454 default: 455 abort(); 456 } 457 assert(io_sectors); 458 sector_num += io_sectors; 459 nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk); 460 if (s->common.speed) { 461 delay_ns = ratelimit_calculate_delay(&s->limit, io_sectors_acct); 462 } 463 } 464 return delay_ns; 465 } 466 467 static void mirror_free_init(MirrorBlockJob *s) 468 { 469 int granularity = s->granularity; 470 size_t buf_size = s->buf_size; 471 uint8_t *buf = s->buf; 472 473 assert(s->buf_free_count == 0); 474 QSIMPLEQ_INIT(&s->buf_free); 475 while (buf_size != 0) { 476 MirrorBuffer *cur = (MirrorBuffer *)buf; 477 QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); 478 s->buf_free_count++; 479 buf_size -= granularity; 480 buf += granularity; 481 } 482 } 483 484 /* This is also used for the .pause callback. There is no matching 485 * mirror_resume() because mirror_run() will begin iterating again 486 * when the job is resumed. 487 */ 488 static void mirror_wait_for_all_io(MirrorBlockJob *s) 489 { 490 while (s->in_flight > 0) { 491 mirror_wait_for_io(s); 492 } 493 } 494 495 typedef struct { 496 int ret; 497 } MirrorExitData; 498 499 static void mirror_exit(BlockJob *job, void *opaque) 500 { 501 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 502 MirrorExitData *data = opaque; 503 AioContext *replace_aio_context = NULL; 504 BlockDriverState *src = s->source; 505 BlockDriverState *target_bs = blk_bs(s->target); 506 BlockDriverState *mirror_top_bs = s->mirror_top_bs; 507 Error *local_err = NULL; 508 509 /* Make sure that the source BDS doesn't go away before we called 510 * block_job_completed(). */ 511 bdrv_ref(src); 512 bdrv_ref(mirror_top_bs); 513 bdrv_ref(target_bs); 514 515 /* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before 516 * inserting target_bs at s->to_replace, where we might not be able to get 517 * these permissions. */ 518 blk_unref(s->target); 519 s->target = NULL; 520 521 /* We don't access the source any more. Dropping any WRITE/RESIZE is 522 * required before it could become a backing file of target_bs. */ 523 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 524 &error_abort); 525 if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { 526 BlockDriverState *backing = s->is_none_mode ? src : s->base; 527 if (backing_bs(target_bs) != backing) { 528 bdrv_set_backing_hd(target_bs, backing, &local_err); 529 if (local_err) { 530 error_report_err(local_err); 531 data->ret = -EPERM; 532 } 533 } 534 } 535 536 if (s->to_replace) { 537 replace_aio_context = bdrv_get_aio_context(s->to_replace); 538 aio_context_acquire(replace_aio_context); 539 } 540 541 if (s->should_complete && data->ret == 0) { 542 BlockDriverState *to_replace = src; 543 if (s->to_replace) { 544 to_replace = s->to_replace; 545 } 546 547 if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) { 548 bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL); 549 } 550 551 /* The mirror job has no requests in flight any more, but we need to 552 * drain potential other users of the BDS before changing the graph. */ 553 bdrv_drained_begin(target_bs); 554 bdrv_replace_node(to_replace, target_bs, &local_err); 555 bdrv_drained_end(target_bs); 556 if (local_err) { 557 error_report_err(local_err); 558 data->ret = -EPERM; 559 } 560 } 561 if (s->to_replace) { 562 bdrv_op_unblock_all(s->to_replace, s->replace_blocker); 563 error_free(s->replace_blocker); 564 bdrv_unref(s->to_replace); 565 } 566 if (replace_aio_context) { 567 aio_context_release(replace_aio_context); 568 } 569 g_free(s->replaces); 570 bdrv_unref(target_bs); 571 572 /* Remove the mirror filter driver from the graph. Before this, get rid of 573 * the blockers on the intermediate nodes so that the resulting state is 574 * valid. Also give up permissions on mirror_top_bs->backing, which might 575 * block the removal. */ 576 block_job_remove_all_bdrv(job); 577 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 578 &error_abort); 579 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 580 581 /* We just changed the BDS the job BB refers to (with either or both of the 582 * bdrv_replace_node() calls), so switch the BB back so the cleanup does 583 * the right thing. We don't need any permissions any more now. */ 584 blk_remove_bs(job->blk); 585 blk_set_perm(job->blk, 0, BLK_PERM_ALL, &error_abort); 586 blk_insert_bs(job->blk, mirror_top_bs, &error_abort); 587 588 block_job_completed(&s->common, data->ret); 589 590 g_free(data); 591 bdrv_drained_end(src); 592 bdrv_unref(mirror_top_bs); 593 bdrv_unref(src); 594 } 595 596 static void mirror_throttle(MirrorBlockJob *s) 597 { 598 int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 599 600 if (now - s->last_pause_ns > SLICE_TIME) { 601 s->last_pause_ns = now; 602 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); 603 } else { 604 block_job_pause_point(&s->common); 605 } 606 } 607 608 static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) 609 { 610 int64_t sector_num, end; 611 BlockDriverState *base = s->base; 612 BlockDriverState *bs = s->source; 613 BlockDriverState *target_bs = blk_bs(s->target); 614 int ret, n; 615 616 end = s->bdev_length / BDRV_SECTOR_SIZE; 617 618 if (base == NULL && !bdrv_has_zero_init(target_bs)) { 619 if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { 620 bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end); 621 return 0; 622 } 623 624 s->initial_zeroing_ongoing = true; 625 for (sector_num = 0; sector_num < end; ) { 626 int nb_sectors = MIN(end - sector_num, 627 QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS); 628 629 mirror_throttle(s); 630 631 if (block_job_is_cancelled(&s->common)) { 632 s->initial_zeroing_ongoing = false; 633 return 0; 634 } 635 636 if (s->in_flight >= MAX_IN_FLIGHT) { 637 trace_mirror_yield(s, s->in_flight, s->buf_free_count, -1); 638 mirror_wait_for_io(s); 639 continue; 640 } 641 642 mirror_do_zero_or_discard(s, sector_num, nb_sectors, false); 643 sector_num += nb_sectors; 644 } 645 646 mirror_wait_for_all_io(s); 647 s->initial_zeroing_ongoing = false; 648 } 649 650 /* First part, loop on the sectors and initialize the dirty bitmap. */ 651 for (sector_num = 0; sector_num < end; ) { 652 /* Just to make sure we are not exceeding int limit. */ 653 int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, 654 end - sector_num); 655 656 mirror_throttle(s); 657 658 if (block_job_is_cancelled(&s->common)) { 659 return 0; 660 } 661 662 ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n); 663 if (ret < 0) { 664 return ret; 665 } 666 667 assert(n > 0); 668 if (ret == 1) { 669 bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); 670 } 671 sector_num += n; 672 } 673 return 0; 674 } 675 676 /* Called when going out of the streaming phase to flush the bulk of the 677 * data to the medium, or just before completing. 678 */ 679 static int mirror_flush(MirrorBlockJob *s) 680 { 681 int ret = blk_flush(s->target); 682 if (ret < 0) { 683 if (mirror_error_action(s, false, -ret) == BLOCK_ERROR_ACTION_REPORT) { 684 s->ret = ret; 685 } 686 } 687 return ret; 688 } 689 690 static void coroutine_fn mirror_run(void *opaque) 691 { 692 MirrorBlockJob *s = opaque; 693 MirrorExitData *data; 694 BlockDriverState *bs = s->source; 695 BlockDriverState *target_bs = blk_bs(s->target); 696 bool need_drain = true; 697 int64_t length; 698 BlockDriverInfo bdi; 699 char backing_filename[2]; /* we only need 2 characters because we are only 700 checking for a NULL string */ 701 int ret = 0; 702 int target_cluster_size = BDRV_SECTOR_SIZE; 703 704 if (block_job_is_cancelled(&s->common)) { 705 goto immediate_exit; 706 } 707 708 s->bdev_length = bdrv_getlength(bs); 709 if (s->bdev_length < 0) { 710 ret = s->bdev_length; 711 goto immediate_exit; 712 } 713 714 /* Active commit must resize the base image if its size differs from the 715 * active layer. */ 716 if (s->base == blk_bs(s->target)) { 717 int64_t base_length; 718 719 base_length = blk_getlength(s->target); 720 if (base_length < 0) { 721 ret = base_length; 722 goto immediate_exit; 723 } 724 725 if (s->bdev_length > base_length) { 726 ret = blk_truncate(s->target, s->bdev_length); 727 if (ret < 0) { 728 goto immediate_exit; 729 } 730 } 731 } 732 733 if (s->bdev_length == 0) { 734 /* Report BLOCK_JOB_READY and wait for complete. */ 735 block_job_event_ready(&s->common); 736 s->synced = true; 737 while (!block_job_is_cancelled(&s->common) && !s->should_complete) { 738 block_job_yield(&s->common); 739 } 740 s->common.cancelled = false; 741 goto immediate_exit; 742 } 743 744 length = DIV_ROUND_UP(s->bdev_length, s->granularity); 745 s->in_flight_bitmap = bitmap_new(length); 746 747 /* If we have no backing file yet in the destination, we cannot let 748 * the destination do COW. Instead, we copy sectors around the 749 * dirty data if needed. We need a bitmap to do that. 750 */ 751 bdrv_get_backing_filename(target_bs, backing_filename, 752 sizeof(backing_filename)); 753 if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) { 754 target_cluster_size = bdi.cluster_size; 755 } 756 if (backing_filename[0] && !target_bs->backing 757 && s->granularity < target_cluster_size) { 758 s->buf_size = MAX(s->buf_size, target_cluster_size); 759 s->cow_bitmap = bitmap_new(length); 760 } 761 s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS; 762 s->max_iov = MIN(bs->bl.max_iov, target_bs->bl.max_iov); 763 764 s->buf = qemu_try_blockalign(bs, s->buf_size); 765 if (s->buf == NULL) { 766 ret = -ENOMEM; 767 goto immediate_exit; 768 } 769 770 mirror_free_init(s); 771 772 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 773 if (!s->is_none_mode) { 774 ret = mirror_dirty_init(s); 775 if (ret < 0 || block_job_is_cancelled(&s->common)) { 776 goto immediate_exit; 777 } 778 } 779 780 assert(!s->dbi); 781 s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap, 0); 782 for (;;) { 783 uint64_t delay_ns = 0; 784 int64_t cnt, delta; 785 bool should_complete; 786 787 if (s->ret < 0) { 788 ret = s->ret; 789 goto immediate_exit; 790 } 791 792 block_job_pause_point(&s->common); 793 794 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 795 /* s->common.offset contains the number of bytes already processed so 796 * far, cnt is the number of dirty sectors remaining and 797 * s->sectors_in_flight is the number of sectors currently being 798 * processed; together those are the current total operation length */ 799 s->common.len = s->common.offset + 800 (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE; 801 802 /* Note that even when no rate limit is applied we need to yield 803 * periodically with no pending I/O so that bdrv_drain_all() returns. 804 * We do so every SLICE_TIME nanoseconds, or when there is an error, 805 * or when the source is clean, whichever comes first. 806 */ 807 delta = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->last_pause_ns; 808 if (delta < SLICE_TIME && 809 s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 810 if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || 811 (cnt == 0 && s->in_flight > 0)) { 812 trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt); 813 mirror_wait_for_io(s); 814 continue; 815 } else if (cnt != 0) { 816 delay_ns = mirror_iteration(s); 817 } 818 } 819 820 should_complete = false; 821 if (s->in_flight == 0 && cnt == 0) { 822 trace_mirror_before_flush(s); 823 if (!s->synced) { 824 if (mirror_flush(s) < 0) { 825 /* Go check s->ret. */ 826 continue; 827 } 828 /* We're out of the streaming phase. From now on, if the job 829 * is cancelled we will actually complete all pending I/O and 830 * report completion. This way, block-job-cancel will leave 831 * the target in a consistent state. 832 */ 833 block_job_event_ready(&s->common); 834 s->synced = true; 835 } 836 837 should_complete = s->should_complete || 838 block_job_is_cancelled(&s->common); 839 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 840 } 841 842 if (cnt == 0 && should_complete) { 843 /* The dirty bitmap is not updated while operations are pending. 844 * If we're about to exit, wait for pending operations before 845 * calling bdrv_get_dirty_count(bs), or we may exit while the 846 * source has dirty data to copy! 847 * 848 * Note that I/O can be submitted by the guest while 849 * mirror_populate runs, so pause it now. Before deciding 850 * whether to switch to target check one last time if I/O has 851 * come in the meanwhile, and if not flush the data to disk. 852 */ 853 trace_mirror_before_drain(s, cnt); 854 855 bdrv_drained_begin(bs); 856 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 857 if (cnt > 0 || mirror_flush(s) < 0) { 858 bdrv_drained_end(bs); 859 continue; 860 } 861 862 /* The two disks are in sync. Exit and report successful 863 * completion. 864 */ 865 assert(QLIST_EMPTY(&bs->tracked_requests)); 866 s->common.cancelled = false; 867 need_drain = false; 868 break; 869 } 870 871 ret = 0; 872 trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); 873 if (!s->synced) { 874 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 875 if (block_job_is_cancelled(&s->common)) { 876 break; 877 } 878 } else if (!should_complete) { 879 delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0); 880 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 881 } 882 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 883 } 884 885 immediate_exit: 886 if (s->in_flight > 0) { 887 /* We get here only if something went wrong. Either the job failed, 888 * or it was cancelled prematurely so that we do not guarantee that 889 * the target is a copy of the source. 890 */ 891 assert(ret < 0 || (!s->synced && block_job_is_cancelled(&s->common))); 892 assert(need_drain); 893 mirror_wait_for_all_io(s); 894 } 895 896 assert(s->in_flight == 0); 897 qemu_vfree(s->buf); 898 g_free(s->cow_bitmap); 899 g_free(s->in_flight_bitmap); 900 bdrv_dirty_iter_free(s->dbi); 901 bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); 902 903 data = g_malloc(sizeof(*data)); 904 data->ret = ret; 905 906 if (need_drain) { 907 bdrv_drained_begin(bs); 908 } 909 block_job_defer_to_main_loop(&s->common, mirror_exit, data); 910 } 911 912 static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp) 913 { 914 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 915 916 if (speed < 0) { 917 error_setg(errp, QERR_INVALID_PARAMETER, "speed"); 918 return; 919 } 920 ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); 921 } 922 923 static void mirror_complete(BlockJob *job, Error **errp) 924 { 925 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 926 BlockDriverState *target; 927 928 target = blk_bs(s->target); 929 930 if (!s->synced) { 931 error_setg(errp, "The active block job '%s' cannot be completed", 932 job->id); 933 return; 934 } 935 936 if (s->backing_mode == MIRROR_OPEN_BACKING_CHAIN) { 937 int ret; 938 939 assert(!target->backing); 940 ret = bdrv_open_backing_file(target, NULL, "backing", errp); 941 if (ret < 0) { 942 return; 943 } 944 } 945 946 /* block all operations on to_replace bs */ 947 if (s->replaces) { 948 AioContext *replace_aio_context; 949 950 s->to_replace = bdrv_find_node(s->replaces); 951 if (!s->to_replace) { 952 error_setg(errp, "Node name '%s' not found", s->replaces); 953 return; 954 } 955 956 replace_aio_context = bdrv_get_aio_context(s->to_replace); 957 aio_context_acquire(replace_aio_context); 958 959 /* TODO Translate this into permission system. Current definition of 960 * GRAPH_MOD would require to request it for the parents; they might 961 * not even be BlockDriverStates, however, so a BdrvChild can't address 962 * them. May need redefinition of GRAPH_MOD. */ 963 error_setg(&s->replace_blocker, 964 "block device is in use by block-job-complete"); 965 bdrv_op_block_all(s->to_replace, s->replace_blocker); 966 bdrv_ref(s->to_replace); 967 968 aio_context_release(replace_aio_context); 969 } 970 971 s->should_complete = true; 972 block_job_enter(&s->common); 973 } 974 975 static void mirror_pause(BlockJob *job) 976 { 977 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 978 979 mirror_wait_for_all_io(s); 980 } 981 982 static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context) 983 { 984 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 985 986 blk_set_aio_context(s->target, new_context); 987 } 988 989 static void mirror_drain(BlockJob *job) 990 { 991 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 992 993 /* Need to keep a reference in case blk_drain triggers execution 994 * of mirror_complete... 995 */ 996 if (s->target) { 997 BlockBackend *target = s->target; 998 blk_ref(target); 999 blk_drain(target); 1000 blk_unref(target); 1001 } 1002 } 1003 1004 static const BlockJobDriver mirror_job_driver = { 1005 .instance_size = sizeof(MirrorBlockJob), 1006 .job_type = BLOCK_JOB_TYPE_MIRROR, 1007 .set_speed = mirror_set_speed, 1008 .start = mirror_run, 1009 .complete = mirror_complete, 1010 .pause = mirror_pause, 1011 .attached_aio_context = mirror_attached_aio_context, 1012 .drain = mirror_drain, 1013 }; 1014 1015 static const BlockJobDriver commit_active_job_driver = { 1016 .instance_size = sizeof(MirrorBlockJob), 1017 .job_type = BLOCK_JOB_TYPE_COMMIT, 1018 .set_speed = mirror_set_speed, 1019 .start = mirror_run, 1020 .complete = mirror_complete, 1021 .pause = mirror_pause, 1022 .attached_aio_context = mirror_attached_aio_context, 1023 .drain = mirror_drain, 1024 }; 1025 1026 static int coroutine_fn bdrv_mirror_top_preadv(BlockDriverState *bs, 1027 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1028 { 1029 return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); 1030 } 1031 1032 static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs, 1033 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1034 { 1035 return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); 1036 } 1037 1038 static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) 1039 { 1040 return bdrv_co_flush(bs->backing->bs); 1041 } 1042 1043 static int64_t coroutine_fn bdrv_mirror_top_get_block_status( 1044 BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum, 1045 BlockDriverState **file) 1046 { 1047 *pnum = nb_sectors; 1048 *file = bs->backing->bs; 1049 return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | 1050 (sector_num << BDRV_SECTOR_BITS); 1051 } 1052 1053 static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, 1054 int64_t offset, int count, BdrvRequestFlags flags) 1055 { 1056 return bdrv_co_pwrite_zeroes(bs->backing, offset, count, flags); 1057 } 1058 1059 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, 1060 int64_t offset, int count) 1061 { 1062 return bdrv_co_pdiscard(bs->backing->bs, offset, count); 1063 } 1064 1065 static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts) 1066 { 1067 bdrv_refresh_filename(bs->backing->bs); 1068 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), 1069 bs->backing->bs->filename); 1070 } 1071 1072 static void bdrv_mirror_top_close(BlockDriverState *bs) 1073 { 1074 } 1075 1076 static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c, 1077 const BdrvChildRole *role, 1078 uint64_t perm, uint64_t shared, 1079 uint64_t *nperm, uint64_t *nshared) 1080 { 1081 /* Must be able to forward guest writes to the real image */ 1082 *nperm = 0; 1083 if (perm & BLK_PERM_WRITE) { 1084 *nperm |= BLK_PERM_WRITE; 1085 } 1086 1087 *nshared = BLK_PERM_ALL; 1088 } 1089 1090 /* Dummy node that provides consistent read to its users without requiring it 1091 * from its backing file and that allows writes on the backing file chain. */ 1092 static BlockDriver bdrv_mirror_top = { 1093 .format_name = "mirror_top", 1094 .bdrv_co_preadv = bdrv_mirror_top_preadv, 1095 .bdrv_co_pwritev = bdrv_mirror_top_pwritev, 1096 .bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes, 1097 .bdrv_co_pdiscard = bdrv_mirror_top_pdiscard, 1098 .bdrv_co_flush = bdrv_mirror_top_flush, 1099 .bdrv_co_get_block_status = bdrv_mirror_top_get_block_status, 1100 .bdrv_refresh_filename = bdrv_mirror_top_refresh_filename, 1101 .bdrv_close = bdrv_mirror_top_close, 1102 .bdrv_child_perm = bdrv_mirror_top_child_perm, 1103 }; 1104 1105 static void mirror_start_job(const char *job_id, BlockDriverState *bs, 1106 int creation_flags, BlockDriverState *target, 1107 const char *replaces, int64_t speed, 1108 uint32_t granularity, int64_t buf_size, 1109 BlockMirrorBackingMode backing_mode, 1110 BlockdevOnError on_source_error, 1111 BlockdevOnError on_target_error, 1112 bool unmap, 1113 BlockCompletionFunc *cb, 1114 void *opaque, Error **errp, 1115 const BlockJobDriver *driver, 1116 bool is_none_mode, BlockDriverState *base, 1117 bool auto_complete, const char *filter_node_name) 1118 { 1119 MirrorBlockJob *s; 1120 BlockDriverState *mirror_top_bs; 1121 bool target_graph_mod; 1122 bool target_is_backing; 1123 Error *local_err = NULL; 1124 int ret; 1125 1126 if (granularity == 0) { 1127 granularity = bdrv_get_default_bitmap_granularity(target); 1128 } 1129 1130 assert ((granularity & (granularity - 1)) == 0); 1131 1132 if (buf_size < 0) { 1133 error_setg(errp, "Invalid parameter 'buf-size'"); 1134 return; 1135 } 1136 1137 if (buf_size == 0) { 1138 buf_size = DEFAULT_MIRROR_BUF_SIZE; 1139 } 1140 1141 /* In the case of active commit, add dummy driver to provide consistent 1142 * reads on the top, while disabling it in the intermediate nodes, and make 1143 * the backing chain writable. */ 1144 mirror_top_bs = bdrv_new_open_driver(&bdrv_mirror_top, filter_node_name, 1145 BDRV_O_RDWR, errp); 1146 if (mirror_top_bs == NULL) { 1147 return; 1148 } 1149 mirror_top_bs->total_sectors = bs->total_sectors; 1150 1151 /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep 1152 * it alive until block_job_create() even if bs has no parent. */ 1153 bdrv_ref(mirror_top_bs); 1154 bdrv_drained_begin(bs); 1155 bdrv_append(mirror_top_bs, bs, &local_err); 1156 bdrv_drained_end(bs); 1157 1158 if (local_err) { 1159 bdrv_unref(mirror_top_bs); 1160 error_propagate(errp, local_err); 1161 return; 1162 } 1163 1164 /* Make sure that the source is not resized while the job is running */ 1165 s = block_job_create(job_id, driver, mirror_top_bs, 1166 BLK_PERM_CONSISTENT_READ, 1167 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED | 1168 BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD, speed, 1169 creation_flags, cb, opaque, errp); 1170 bdrv_unref(mirror_top_bs); 1171 if (!s) { 1172 goto fail; 1173 } 1174 s->source = bs; 1175 s->mirror_top_bs = mirror_top_bs; 1176 1177 /* No resize for the target either; while the mirror is still running, a 1178 * consistent read isn't necessarily possible. We could possibly allow 1179 * writes and graph modifications, though it would likely defeat the 1180 * purpose of a mirror, so leave them blocked for now. 1181 * 1182 * In the case of active commit, things look a bit different, though, 1183 * because the target is an already populated backing file in active use. 1184 * We can allow anything except resize there.*/ 1185 target_is_backing = bdrv_chain_contains(bs, target); 1186 target_graph_mod = (backing_mode != MIRROR_LEAVE_BACKING_CHAIN); 1187 s->target = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE | 1188 (target_graph_mod ? BLK_PERM_GRAPH_MOD : 0), 1189 BLK_PERM_WRITE_UNCHANGED | 1190 (target_is_backing ? BLK_PERM_CONSISTENT_READ | 1191 BLK_PERM_WRITE | 1192 BLK_PERM_GRAPH_MOD : 0)); 1193 ret = blk_insert_bs(s->target, target, errp); 1194 if (ret < 0) { 1195 goto fail; 1196 } 1197 1198 s->replaces = g_strdup(replaces); 1199 s->on_source_error = on_source_error; 1200 s->on_target_error = on_target_error; 1201 s->is_none_mode = is_none_mode; 1202 s->backing_mode = backing_mode; 1203 s->base = base; 1204 s->granularity = granularity; 1205 s->buf_size = ROUND_UP(buf_size, granularity); 1206 s->unmap = unmap; 1207 if (auto_complete) { 1208 s->should_complete = true; 1209 } 1210 1211 s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); 1212 if (!s->dirty_bitmap) { 1213 goto fail; 1214 } 1215 1216 /* Required permissions are already taken with blk_new() */ 1217 block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL, 1218 &error_abort); 1219 1220 /* In commit_active_start() all intermediate nodes disappear, so 1221 * any jobs in them must be blocked */ 1222 if (target_is_backing) { 1223 BlockDriverState *iter; 1224 for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) { 1225 /* XXX BLK_PERM_WRITE needs to be allowed so we don't block 1226 * ourselves at s->base (if writes are blocked for a node, they are 1227 * also blocked for its backing file). The other options would be a 1228 * second filter driver above s->base (== target). */ 1229 ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, 1230 BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, 1231 errp); 1232 if (ret < 0) { 1233 goto fail; 1234 } 1235 } 1236 } 1237 1238 trace_mirror_start(bs, s, opaque); 1239 block_job_start(&s->common); 1240 return; 1241 1242 fail: 1243 if (s) { 1244 g_free(s->replaces); 1245 blk_unref(s->target); 1246 block_job_unref(&s->common); 1247 } 1248 1249 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 1250 &error_abort); 1251 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 1252 } 1253 1254 void mirror_start(const char *job_id, BlockDriverState *bs, 1255 BlockDriverState *target, const char *replaces, 1256 int64_t speed, uint32_t granularity, int64_t buf_size, 1257 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, 1258 BlockdevOnError on_source_error, 1259 BlockdevOnError on_target_error, 1260 bool unmap, const char *filter_node_name, Error **errp) 1261 { 1262 bool is_none_mode; 1263 BlockDriverState *base; 1264 1265 if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { 1266 error_setg(errp, "Sync mode 'incremental' not supported"); 1267 return; 1268 } 1269 is_none_mode = mode == MIRROR_SYNC_MODE_NONE; 1270 base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; 1271 mirror_start_job(job_id, bs, BLOCK_JOB_DEFAULT, target, replaces, 1272 speed, granularity, buf_size, backing_mode, 1273 on_source_error, on_target_error, unmap, NULL, NULL, errp, 1274 &mirror_job_driver, is_none_mode, base, false, 1275 filter_node_name); 1276 } 1277 1278 void commit_active_start(const char *job_id, BlockDriverState *bs, 1279 BlockDriverState *base, int creation_flags, 1280 int64_t speed, BlockdevOnError on_error, 1281 const char *filter_node_name, 1282 BlockCompletionFunc *cb, void *opaque, Error **errp, 1283 bool auto_complete) 1284 { 1285 int orig_base_flags; 1286 Error *local_err = NULL; 1287 1288 orig_base_flags = bdrv_get_flags(base); 1289 1290 if (bdrv_reopen(base, bs->open_flags, errp)) { 1291 return; 1292 } 1293 1294 mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0, 1295 MIRROR_LEAVE_BACKING_CHAIN, 1296 on_error, on_error, true, cb, opaque, &local_err, 1297 &commit_active_job_driver, false, base, auto_complete, 1298 filter_node_name); 1299 if (local_err) { 1300 error_propagate(errp, local_err); 1301 goto error_restore_flags; 1302 } 1303 1304 return; 1305 1306 error_restore_flags: 1307 /* ignore error and errp for bdrv_reopen, because we want to propagate 1308 * the original error */ 1309 bdrv_reopen(base, orig_base_flags, NULL); 1310 return; 1311 } 1312