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 MAX_IN_FLIGHT 16 26 #define MAX_IO_BYTES (1 << 20) /* 1 Mb */ 27 #define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES) 28 29 /* The mirroring buffer is a list of granularity-sized chunks. 30 * Free chunks are organized in a list. 31 */ 32 typedef struct MirrorBuffer { 33 QSIMPLEQ_ENTRY(MirrorBuffer) next; 34 } MirrorBuffer; 35 36 typedef struct MirrorBlockJob { 37 BlockJob common; 38 BlockBackend *target; 39 BlockDriverState *mirror_top_bs; 40 BlockDriverState *source; 41 BlockDriverState *base; 42 43 /* The name of the graph node to replace */ 44 char *replaces; 45 /* The BDS to replace */ 46 BlockDriverState *to_replace; 47 /* Used to block operations on the drive-mirror-replace target */ 48 Error *replace_blocker; 49 bool is_none_mode; 50 BlockMirrorBackingMode backing_mode; 51 BlockdevOnError on_source_error, on_target_error; 52 bool synced; 53 bool should_complete; 54 int64_t granularity; 55 size_t buf_size; 56 int64_t bdev_length; 57 unsigned long *cow_bitmap; 58 BdrvDirtyBitmap *dirty_bitmap; 59 BdrvDirtyBitmapIter *dbi; 60 uint8_t *buf; 61 QSIMPLEQ_HEAD(, MirrorBuffer) buf_free; 62 int buf_free_count; 63 64 uint64_t last_pause_ns; 65 unsigned long *in_flight_bitmap; 66 int in_flight; 67 int64_t bytes_in_flight; 68 int ret; 69 bool unmap; 70 bool waiting_for_io; 71 int target_cluster_size; 72 int max_iov; 73 bool initial_zeroing_ongoing; 74 } MirrorBlockJob; 75 76 typedef struct MirrorOp { 77 MirrorBlockJob *s; 78 QEMUIOVector qiov; 79 int64_t offset; 80 uint64_t bytes; 81 } MirrorOp; 82 83 static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, 84 int error) 85 { 86 s->synced = false; 87 if (read) { 88 return block_job_error_action(&s->common, s->on_source_error, 89 true, error); 90 } else { 91 return block_job_error_action(&s->common, s->on_target_error, 92 false, error); 93 } 94 } 95 96 static void mirror_iteration_done(MirrorOp *op, int ret) 97 { 98 MirrorBlockJob *s = op->s; 99 struct iovec *iov; 100 int64_t chunk_num; 101 int i, nb_chunks; 102 103 trace_mirror_iteration_done(s, op->offset, op->bytes, ret); 104 105 s->in_flight--; 106 s->bytes_in_flight -= op->bytes; 107 iov = op->qiov.iov; 108 for (i = 0; i < op->qiov.niov; i++) { 109 MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; 110 QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next); 111 s->buf_free_count++; 112 } 113 114 chunk_num = op->offset / s->granularity; 115 nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity); 116 bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); 117 if (ret >= 0) { 118 if (s->cow_bitmap) { 119 bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); 120 } 121 if (!s->initial_zeroing_ongoing) { 122 job_progress_update(&s->common.job, op->bytes); 123 } 124 } 125 qemu_iovec_destroy(&op->qiov); 126 g_free(op); 127 128 if (s->waiting_for_io) { 129 qemu_coroutine_enter(s->common.job.co); 130 } 131 } 132 133 static void mirror_write_complete(void *opaque, int ret) 134 { 135 MirrorOp *op = opaque; 136 MirrorBlockJob *s = op->s; 137 138 aio_context_acquire(blk_get_aio_context(s->common.blk)); 139 if (ret < 0) { 140 BlockErrorAction action; 141 142 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes); 143 action = mirror_error_action(s, false, -ret); 144 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 145 s->ret = ret; 146 } 147 } 148 mirror_iteration_done(op, ret); 149 aio_context_release(blk_get_aio_context(s->common.blk)); 150 } 151 152 static void mirror_read_complete(void *opaque, int ret) 153 { 154 MirrorOp *op = opaque; 155 MirrorBlockJob *s = op->s; 156 157 aio_context_acquire(blk_get_aio_context(s->common.blk)); 158 if (ret < 0) { 159 BlockErrorAction action; 160 161 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes); 162 action = mirror_error_action(s, true, -ret); 163 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 164 s->ret = ret; 165 } 166 167 mirror_iteration_done(op, ret); 168 } else { 169 blk_aio_pwritev(s->target, op->offset, &op->qiov, 170 0, mirror_write_complete, op); 171 } 172 aio_context_release(blk_get_aio_context(s->common.blk)); 173 } 174 175 /* Clip bytes relative to offset to not exceed end-of-file */ 176 static inline int64_t mirror_clip_bytes(MirrorBlockJob *s, 177 int64_t offset, 178 int64_t bytes) 179 { 180 return MIN(bytes, s->bdev_length - offset); 181 } 182 183 /* Round offset and/or bytes to target cluster if COW is needed, and 184 * return the offset of the adjusted tail against original. */ 185 static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, 186 uint64_t *bytes) 187 { 188 bool need_cow; 189 int ret = 0; 190 int64_t align_offset = *offset; 191 int64_t align_bytes = *bytes; 192 int max_bytes = s->granularity * s->max_iov; 193 194 need_cow = !test_bit(*offset / s->granularity, s->cow_bitmap); 195 need_cow |= !test_bit((*offset + *bytes - 1) / s->granularity, 196 s->cow_bitmap); 197 if (need_cow) { 198 bdrv_round_to_clusters(blk_bs(s->target), *offset, *bytes, 199 &align_offset, &align_bytes); 200 } 201 202 if (align_bytes > max_bytes) { 203 align_bytes = max_bytes; 204 if (need_cow) { 205 align_bytes = QEMU_ALIGN_DOWN(align_bytes, s->target_cluster_size); 206 } 207 } 208 /* Clipping may result in align_bytes unaligned to chunk boundary, but 209 * that doesn't matter because it's already the end of source image. */ 210 align_bytes = mirror_clip_bytes(s, align_offset, align_bytes); 211 212 ret = align_offset + align_bytes - (*offset + *bytes); 213 *offset = align_offset; 214 *bytes = align_bytes; 215 assert(ret >= 0); 216 return ret; 217 } 218 219 static inline void mirror_wait_for_io(MirrorBlockJob *s) 220 { 221 assert(!s->waiting_for_io); 222 s->waiting_for_io = true; 223 qemu_coroutine_yield(); 224 s->waiting_for_io = false; 225 } 226 227 /* Submit async read while handling COW. 228 * Returns: The number of bytes copied after and including offset, 229 * excluding any bytes copied prior to offset due to alignment. 230 * This will be @bytes if no alignment is necessary, or 231 * (new_end - offset) if tail is rounded up or down due to 232 * alignment or buffer limit. 233 */ 234 static uint64_t mirror_do_read(MirrorBlockJob *s, int64_t offset, 235 uint64_t bytes) 236 { 237 BlockBackend *source = s->common.blk; 238 int nb_chunks; 239 uint64_t ret; 240 MirrorOp *op; 241 uint64_t max_bytes; 242 243 max_bytes = s->granularity * s->max_iov; 244 245 /* We can only handle as much as buf_size at a time. */ 246 bytes = MIN(s->buf_size, MIN(max_bytes, bytes)); 247 assert(bytes); 248 assert(bytes < BDRV_REQUEST_MAX_BYTES); 249 ret = bytes; 250 251 if (s->cow_bitmap) { 252 ret += mirror_cow_align(s, &offset, &bytes); 253 } 254 assert(bytes <= s->buf_size); 255 /* The offset is granularity-aligned because: 256 * 1) Caller passes in aligned values; 257 * 2) mirror_cow_align is used only when target cluster is larger. */ 258 assert(QEMU_IS_ALIGNED(offset, s->granularity)); 259 /* The range is sector-aligned, since bdrv_getlength() rounds up. */ 260 assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); 261 nb_chunks = DIV_ROUND_UP(bytes, s->granularity); 262 263 while (s->buf_free_count < nb_chunks) { 264 trace_mirror_yield_in_flight(s, offset, s->in_flight); 265 mirror_wait_for_io(s); 266 } 267 268 /* Allocate a MirrorOp that is used as an AIO callback. */ 269 op = g_new(MirrorOp, 1); 270 op->s = s; 271 op->offset = offset; 272 op->bytes = bytes; 273 274 /* Now make a QEMUIOVector taking enough granularity-sized chunks 275 * from s->buf_free. 276 */ 277 qemu_iovec_init(&op->qiov, nb_chunks); 278 while (nb_chunks-- > 0) { 279 MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); 280 size_t remaining = bytes - op->qiov.size; 281 282 QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); 283 s->buf_free_count--; 284 qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); 285 } 286 287 /* Copy the dirty cluster. */ 288 s->in_flight++; 289 s->bytes_in_flight += bytes; 290 trace_mirror_one_iteration(s, offset, bytes); 291 292 blk_aio_preadv(source, offset, &op->qiov, 0, mirror_read_complete, op); 293 return ret; 294 } 295 296 static void mirror_do_zero_or_discard(MirrorBlockJob *s, 297 int64_t offset, 298 uint64_t bytes, 299 bool is_discard) 300 { 301 MirrorOp *op; 302 303 /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed 304 * so the freeing in mirror_iteration_done is nop. */ 305 op = g_new0(MirrorOp, 1); 306 op->s = s; 307 op->offset = offset; 308 op->bytes = bytes; 309 310 s->in_flight++; 311 s->bytes_in_flight += bytes; 312 if (is_discard) { 313 blk_aio_pdiscard(s->target, offset, 314 op->bytes, mirror_write_complete, op); 315 } else { 316 blk_aio_pwrite_zeroes(s->target, offset, 317 op->bytes, s->unmap ? BDRV_REQ_MAY_UNMAP : 0, 318 mirror_write_complete, op); 319 } 320 } 321 322 static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) 323 { 324 BlockDriverState *source = s->source; 325 int64_t offset, first_chunk; 326 uint64_t delay_ns = 0; 327 /* At least the first dirty chunk is mirrored in one iteration. */ 328 int nb_chunks = 1; 329 bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); 330 int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES); 331 332 bdrv_dirty_bitmap_lock(s->dirty_bitmap); 333 offset = bdrv_dirty_iter_next(s->dbi); 334 if (offset < 0) { 335 bdrv_set_dirty_iter(s->dbi, 0); 336 offset = bdrv_dirty_iter_next(s->dbi); 337 trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); 338 assert(offset >= 0); 339 } 340 bdrv_dirty_bitmap_unlock(s->dirty_bitmap); 341 342 first_chunk = offset / s->granularity; 343 while (test_bit(first_chunk, s->in_flight_bitmap)) { 344 trace_mirror_yield_in_flight(s, offset, s->in_flight); 345 mirror_wait_for_io(s); 346 } 347 348 job_pause_point(&s->common.job); 349 350 /* Find the number of consective dirty chunks following the first dirty 351 * one, and wait for in flight requests in them. */ 352 bdrv_dirty_bitmap_lock(s->dirty_bitmap); 353 while (nb_chunks * s->granularity < s->buf_size) { 354 int64_t next_dirty; 355 int64_t next_offset = offset + nb_chunks * s->granularity; 356 int64_t next_chunk = next_offset / s->granularity; 357 if (next_offset >= s->bdev_length || 358 !bdrv_get_dirty_locked(source, s->dirty_bitmap, next_offset)) { 359 break; 360 } 361 if (test_bit(next_chunk, s->in_flight_bitmap)) { 362 break; 363 } 364 365 next_dirty = bdrv_dirty_iter_next(s->dbi); 366 if (next_dirty > next_offset || next_dirty < 0) { 367 /* The bitmap iterator's cache is stale, refresh it */ 368 bdrv_set_dirty_iter(s->dbi, next_offset); 369 next_dirty = bdrv_dirty_iter_next(s->dbi); 370 } 371 assert(next_dirty == next_offset); 372 nb_chunks++; 373 } 374 375 /* Clear dirty bits before querying the block status, because 376 * calling bdrv_block_status_above could yield - if some blocks are 377 * marked dirty in this window, we need to know. 378 */ 379 bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, offset, 380 nb_chunks * s->granularity); 381 bdrv_dirty_bitmap_unlock(s->dirty_bitmap); 382 383 bitmap_set(s->in_flight_bitmap, offset / s->granularity, nb_chunks); 384 while (nb_chunks > 0 && offset < s->bdev_length) { 385 int ret; 386 int64_t io_bytes; 387 int64_t io_bytes_acct; 388 enum MirrorMethod { 389 MIRROR_METHOD_COPY, 390 MIRROR_METHOD_ZERO, 391 MIRROR_METHOD_DISCARD 392 } mirror_method = MIRROR_METHOD_COPY; 393 394 assert(!(offset % s->granularity)); 395 ret = bdrv_block_status_above(source, NULL, offset, 396 nb_chunks * s->granularity, 397 &io_bytes, NULL, NULL); 398 if (ret < 0) { 399 io_bytes = MIN(nb_chunks * s->granularity, max_io_bytes); 400 } else if (ret & BDRV_BLOCK_DATA) { 401 io_bytes = MIN(io_bytes, max_io_bytes); 402 } 403 404 io_bytes -= io_bytes % s->granularity; 405 if (io_bytes < s->granularity) { 406 io_bytes = s->granularity; 407 } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { 408 int64_t target_offset; 409 int64_t target_bytes; 410 bdrv_round_to_clusters(blk_bs(s->target), offset, io_bytes, 411 &target_offset, &target_bytes); 412 if (target_offset == offset && 413 target_bytes == io_bytes) { 414 mirror_method = ret & BDRV_BLOCK_ZERO ? 415 MIRROR_METHOD_ZERO : 416 MIRROR_METHOD_DISCARD; 417 } 418 } 419 420 while (s->in_flight >= MAX_IN_FLIGHT) { 421 trace_mirror_yield_in_flight(s, offset, s->in_flight); 422 mirror_wait_for_io(s); 423 } 424 425 if (s->ret < 0) { 426 return 0; 427 } 428 429 io_bytes = mirror_clip_bytes(s, offset, io_bytes); 430 switch (mirror_method) { 431 case MIRROR_METHOD_COPY: 432 io_bytes = io_bytes_acct = mirror_do_read(s, offset, io_bytes); 433 break; 434 case MIRROR_METHOD_ZERO: 435 case MIRROR_METHOD_DISCARD: 436 mirror_do_zero_or_discard(s, offset, io_bytes, 437 mirror_method == MIRROR_METHOD_DISCARD); 438 if (write_zeroes_ok) { 439 io_bytes_acct = 0; 440 } else { 441 io_bytes_acct = io_bytes; 442 } 443 break; 444 default: 445 abort(); 446 } 447 assert(io_bytes); 448 offset += io_bytes; 449 nb_chunks -= DIV_ROUND_UP(io_bytes, s->granularity); 450 delay_ns = block_job_ratelimit_get_delay(&s->common, io_bytes_acct); 451 } 452 return delay_ns; 453 } 454 455 static void mirror_free_init(MirrorBlockJob *s) 456 { 457 int granularity = s->granularity; 458 size_t buf_size = s->buf_size; 459 uint8_t *buf = s->buf; 460 461 assert(s->buf_free_count == 0); 462 QSIMPLEQ_INIT(&s->buf_free); 463 while (buf_size != 0) { 464 MirrorBuffer *cur = (MirrorBuffer *)buf; 465 QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); 466 s->buf_free_count++; 467 buf_size -= granularity; 468 buf += granularity; 469 } 470 } 471 472 /* This is also used for the .pause callback. There is no matching 473 * mirror_resume() because mirror_run() will begin iterating again 474 * when the job is resumed. 475 */ 476 static void mirror_wait_for_all_io(MirrorBlockJob *s) 477 { 478 while (s->in_flight > 0) { 479 mirror_wait_for_io(s); 480 } 481 } 482 483 typedef struct { 484 int ret; 485 } MirrorExitData; 486 487 static void mirror_exit(Job *job, void *opaque) 488 { 489 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job); 490 BlockJob *bjob = &s->common; 491 MirrorExitData *data = opaque; 492 AioContext *replace_aio_context = NULL; 493 BlockDriverState *src = s->source; 494 BlockDriverState *target_bs = blk_bs(s->target); 495 BlockDriverState *mirror_top_bs = s->mirror_top_bs; 496 Error *local_err = NULL; 497 498 bdrv_release_dirty_bitmap(src, s->dirty_bitmap); 499 500 /* Make sure that the source BDS doesn't go away before we called 501 * job_completed(). */ 502 bdrv_ref(src); 503 bdrv_ref(mirror_top_bs); 504 bdrv_ref(target_bs); 505 506 /* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before 507 * inserting target_bs at s->to_replace, where we might not be able to get 508 * these permissions. 509 * 510 * Note that blk_unref() alone doesn't necessarily drop permissions because 511 * we might be running nested inside mirror_drain(), which takes an extra 512 * reference, so use an explicit blk_set_perm() first. */ 513 blk_set_perm(s->target, 0, BLK_PERM_ALL, &error_abort); 514 blk_unref(s->target); 515 s->target = NULL; 516 517 /* We don't access the source any more. Dropping any WRITE/RESIZE is 518 * required before it could become a backing file of target_bs. */ 519 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 520 &error_abort); 521 if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { 522 BlockDriverState *backing = s->is_none_mode ? src : s->base; 523 if (backing_bs(target_bs) != backing) { 524 bdrv_set_backing_hd(target_bs, backing, &local_err); 525 if (local_err) { 526 error_report_err(local_err); 527 data->ret = -EPERM; 528 } 529 } 530 } 531 532 if (s->to_replace) { 533 replace_aio_context = bdrv_get_aio_context(s->to_replace); 534 aio_context_acquire(replace_aio_context); 535 } 536 537 if (s->should_complete && data->ret == 0) { 538 BlockDriverState *to_replace = src; 539 if (s->to_replace) { 540 to_replace = s->to_replace; 541 } 542 543 if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) { 544 bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL); 545 } 546 547 /* The mirror job has no requests in flight any more, but we need to 548 * drain potential other users of the BDS before changing the graph. */ 549 bdrv_drained_begin(target_bs); 550 bdrv_replace_node(to_replace, target_bs, &local_err); 551 bdrv_drained_end(target_bs); 552 if (local_err) { 553 error_report_err(local_err); 554 data->ret = -EPERM; 555 } 556 } 557 if (s->to_replace) { 558 bdrv_op_unblock_all(s->to_replace, s->replace_blocker); 559 error_free(s->replace_blocker); 560 bdrv_unref(s->to_replace); 561 } 562 if (replace_aio_context) { 563 aio_context_release(replace_aio_context); 564 } 565 g_free(s->replaces); 566 bdrv_unref(target_bs); 567 568 /* Remove the mirror filter driver from the graph. Before this, get rid of 569 * the blockers on the intermediate nodes so that the resulting state is 570 * valid. Also give up permissions on mirror_top_bs->backing, which might 571 * block the removal. */ 572 block_job_remove_all_bdrv(bjob); 573 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 574 &error_abort); 575 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 576 577 /* We just changed the BDS the job BB refers to (with either or both of the 578 * bdrv_replace_node() calls), so switch the BB back so the cleanup does 579 * the right thing. We don't need any permissions any more now. */ 580 blk_remove_bs(bjob->blk); 581 blk_set_perm(bjob->blk, 0, BLK_PERM_ALL, &error_abort); 582 blk_insert_bs(bjob->blk, mirror_top_bs, &error_abort); 583 584 job_completed(job, data->ret); 585 586 g_free(data); 587 bdrv_drained_end(src); 588 bdrv_unref(mirror_top_bs); 589 bdrv_unref(src); 590 } 591 592 static void mirror_throttle(MirrorBlockJob *s) 593 { 594 int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 595 596 if (now - s->last_pause_ns > BLOCK_JOB_SLICE_TIME) { 597 s->last_pause_ns = now; 598 job_sleep_ns(&s->common.job, 0); 599 } else { 600 job_pause_point(&s->common.job); 601 } 602 } 603 604 static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) 605 { 606 int64_t offset; 607 BlockDriverState *base = s->base; 608 BlockDriverState *bs = s->source; 609 BlockDriverState *target_bs = blk_bs(s->target); 610 int ret; 611 int64_t count; 612 613 if (base == NULL && !bdrv_has_zero_init(target_bs)) { 614 if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { 615 bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length); 616 return 0; 617 } 618 619 s->initial_zeroing_ongoing = true; 620 for (offset = 0; offset < s->bdev_length; ) { 621 int bytes = MIN(s->bdev_length - offset, 622 QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); 623 624 mirror_throttle(s); 625 626 if (job_is_cancelled(&s->common.job)) { 627 s->initial_zeroing_ongoing = false; 628 return 0; 629 } 630 631 if (s->in_flight >= MAX_IN_FLIGHT) { 632 trace_mirror_yield(s, UINT64_MAX, s->buf_free_count, 633 s->in_flight); 634 mirror_wait_for_io(s); 635 continue; 636 } 637 638 mirror_do_zero_or_discard(s, offset, bytes, false); 639 offset += bytes; 640 } 641 642 mirror_wait_for_all_io(s); 643 s->initial_zeroing_ongoing = false; 644 } 645 646 /* First part, loop on the sectors and initialize the dirty bitmap. */ 647 for (offset = 0; offset < s->bdev_length; ) { 648 /* Just to make sure we are not exceeding int limit. */ 649 int bytes = MIN(s->bdev_length - offset, 650 QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); 651 652 mirror_throttle(s); 653 654 if (job_is_cancelled(&s->common.job)) { 655 return 0; 656 } 657 658 ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count); 659 if (ret < 0) { 660 return ret; 661 } 662 663 assert(count); 664 if (ret == 1) { 665 bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count); 666 } 667 offset += count; 668 } 669 return 0; 670 } 671 672 /* Called when going out of the streaming phase to flush the bulk of the 673 * data to the medium, or just before completing. 674 */ 675 static int mirror_flush(MirrorBlockJob *s) 676 { 677 int ret = blk_flush(s->target); 678 if (ret < 0) { 679 if (mirror_error_action(s, false, -ret) == BLOCK_ERROR_ACTION_REPORT) { 680 s->ret = ret; 681 } 682 } 683 return ret; 684 } 685 686 static void coroutine_fn mirror_run(void *opaque) 687 { 688 MirrorBlockJob *s = opaque; 689 MirrorExitData *data; 690 BlockDriverState *bs = s->source; 691 BlockDriverState *target_bs = blk_bs(s->target); 692 bool need_drain = true; 693 int64_t length; 694 BlockDriverInfo bdi; 695 char backing_filename[2]; /* we only need 2 characters because we are only 696 checking for a NULL string */ 697 int ret = 0; 698 699 if (job_is_cancelled(&s->common.job)) { 700 goto immediate_exit; 701 } 702 703 s->bdev_length = bdrv_getlength(bs); 704 if (s->bdev_length < 0) { 705 ret = s->bdev_length; 706 goto immediate_exit; 707 } 708 709 /* Active commit must resize the base image if its size differs from the 710 * active layer. */ 711 if (s->base == blk_bs(s->target)) { 712 int64_t base_length; 713 714 base_length = blk_getlength(s->target); 715 if (base_length < 0) { 716 ret = base_length; 717 goto immediate_exit; 718 } 719 720 if (s->bdev_length > base_length) { 721 ret = blk_truncate(s->target, s->bdev_length, PREALLOC_MODE_OFF, 722 NULL); 723 if (ret < 0) { 724 goto immediate_exit; 725 } 726 } 727 } 728 729 if (s->bdev_length == 0) { 730 /* Transition to the READY state and wait for complete. */ 731 job_transition_to_ready(&s->common.job); 732 s->synced = true; 733 while (!job_is_cancelled(&s->common.job) && !s->should_complete) { 734 job_yield(&s->common.job); 735 } 736 s->common.job.cancelled = false; 737 goto immediate_exit; 738 } 739 740 length = DIV_ROUND_UP(s->bdev_length, s->granularity); 741 s->in_flight_bitmap = bitmap_new(length); 742 743 /* If we have no backing file yet in the destination, we cannot let 744 * the destination do COW. Instead, we copy sectors around the 745 * dirty data if needed. We need a bitmap to do that. 746 */ 747 bdrv_get_backing_filename(target_bs, backing_filename, 748 sizeof(backing_filename)); 749 if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) { 750 s->target_cluster_size = bdi.cluster_size; 751 } else { 752 s->target_cluster_size = BDRV_SECTOR_SIZE; 753 } 754 if (backing_filename[0] && !target_bs->backing && 755 s->granularity < s->target_cluster_size) { 756 s->buf_size = MAX(s->buf_size, s->target_cluster_size); 757 s->cow_bitmap = bitmap_new(length); 758 } 759 s->max_iov = MIN(bs->bl.max_iov, target_bs->bl.max_iov); 760 761 s->buf = qemu_try_blockalign(bs, s->buf_size); 762 if (s->buf == NULL) { 763 ret = -ENOMEM; 764 goto immediate_exit; 765 } 766 767 mirror_free_init(s); 768 769 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 770 if (!s->is_none_mode) { 771 ret = mirror_dirty_init(s); 772 if (ret < 0 || job_is_cancelled(&s->common.job)) { 773 goto immediate_exit; 774 } 775 } 776 777 assert(!s->dbi); 778 s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap); 779 for (;;) { 780 uint64_t delay_ns = 0; 781 int64_t cnt, delta; 782 bool should_complete; 783 784 if (s->ret < 0) { 785 ret = s->ret; 786 goto immediate_exit; 787 } 788 789 job_pause_point(&s->common.job); 790 791 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 792 /* cnt is the number of dirty bytes remaining and s->bytes_in_flight is 793 * the number of bytes currently being processed; together those are 794 * the current remaining operation length */ 795 job_progress_set_remaining(&s->common.job, s->bytes_in_flight + cnt); 796 797 /* Note that even when no rate limit is applied we need to yield 798 * periodically with no pending I/O so that bdrv_drain_all() returns. 799 * We do so every BLKOCK_JOB_SLICE_TIME nanoseconds, or when there is 800 * an error, or when the source is clean, whichever comes first. */ 801 delta = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->last_pause_ns; 802 if (delta < BLOCK_JOB_SLICE_TIME && 803 s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 804 if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || 805 (cnt == 0 && s->in_flight > 0)) { 806 trace_mirror_yield(s, cnt, s->buf_free_count, s->in_flight); 807 mirror_wait_for_io(s); 808 continue; 809 } else if (cnt != 0) { 810 delay_ns = mirror_iteration(s); 811 } 812 } 813 814 should_complete = false; 815 if (s->in_flight == 0 && cnt == 0) { 816 trace_mirror_before_flush(s); 817 if (!s->synced) { 818 if (mirror_flush(s) < 0) { 819 /* Go check s->ret. */ 820 continue; 821 } 822 /* We're out of the streaming phase. From now on, if the job 823 * is cancelled we will actually complete all pending I/O and 824 * report completion. This way, block-job-cancel will leave 825 * the target in a consistent state. 826 */ 827 job_transition_to_ready(&s->common.job); 828 s->synced = true; 829 } 830 831 should_complete = s->should_complete || 832 job_is_cancelled(&s->common.job); 833 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 834 } 835 836 if (cnt == 0 && should_complete) { 837 /* The dirty bitmap is not updated while operations are pending. 838 * If we're about to exit, wait for pending operations before 839 * calling bdrv_get_dirty_count(bs), or we may exit while the 840 * source has dirty data to copy! 841 * 842 * Note that I/O can be submitted by the guest while 843 * mirror_populate runs, so pause it now. Before deciding 844 * whether to switch to target check one last time if I/O has 845 * come in the meanwhile, and if not flush the data to disk. 846 */ 847 trace_mirror_before_drain(s, cnt); 848 849 bdrv_drained_begin(bs); 850 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 851 if (cnt > 0 || mirror_flush(s) < 0) { 852 bdrv_drained_end(bs); 853 continue; 854 } 855 856 /* The two disks are in sync. Exit and report successful 857 * completion. 858 */ 859 assert(QLIST_EMPTY(&bs->tracked_requests)); 860 s->common.job.cancelled = false; 861 need_drain = false; 862 break; 863 } 864 865 ret = 0; 866 867 if (s->synced && !should_complete) { 868 delay_ns = (s->in_flight == 0 && 869 cnt == 0 ? BLOCK_JOB_SLICE_TIME : 0); 870 } 871 trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); 872 job_sleep_ns(&s->common.job, delay_ns); 873 if (job_is_cancelled(&s->common.job) && 874 (!s->synced || s->common.job.force_cancel)) 875 { 876 break; 877 } 878 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 879 } 880 881 immediate_exit: 882 if (s->in_flight > 0) { 883 /* We get here only if something went wrong. Either the job failed, 884 * or it was cancelled prematurely so that we do not guarantee that 885 * the target is a copy of the source. 886 */ 887 assert(ret < 0 || ((s->common.job.force_cancel || !s->synced) && 888 job_is_cancelled(&s->common.job))); 889 assert(need_drain); 890 mirror_wait_for_all_io(s); 891 } 892 893 assert(s->in_flight == 0); 894 qemu_vfree(s->buf); 895 g_free(s->cow_bitmap); 896 g_free(s->in_flight_bitmap); 897 bdrv_dirty_iter_free(s->dbi); 898 899 data = g_malloc(sizeof(*data)); 900 data->ret = ret; 901 902 if (need_drain) { 903 bdrv_drained_begin(bs); 904 } 905 job_defer_to_main_loop(&s->common.job, mirror_exit, data); 906 } 907 908 static void mirror_complete(Job *job, Error **errp) 909 { 910 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job); 911 BlockDriverState *target; 912 913 target = blk_bs(s->target); 914 915 if (!s->synced) { 916 error_setg(errp, "The active block job '%s' cannot be completed", 917 job->id); 918 return; 919 } 920 921 if (s->backing_mode == MIRROR_OPEN_BACKING_CHAIN) { 922 int ret; 923 924 assert(!target->backing); 925 ret = bdrv_open_backing_file(target, NULL, "backing", errp); 926 if (ret < 0) { 927 return; 928 } 929 } 930 931 /* block all operations on to_replace bs */ 932 if (s->replaces) { 933 AioContext *replace_aio_context; 934 935 s->to_replace = bdrv_find_node(s->replaces); 936 if (!s->to_replace) { 937 error_setg(errp, "Node name '%s' not found", s->replaces); 938 return; 939 } 940 941 replace_aio_context = bdrv_get_aio_context(s->to_replace); 942 aio_context_acquire(replace_aio_context); 943 944 /* TODO Translate this into permission system. Current definition of 945 * GRAPH_MOD would require to request it for the parents; they might 946 * not even be BlockDriverStates, however, so a BdrvChild can't address 947 * them. May need redefinition of GRAPH_MOD. */ 948 error_setg(&s->replace_blocker, 949 "block device is in use by block-job-complete"); 950 bdrv_op_block_all(s->to_replace, s->replace_blocker); 951 bdrv_ref(s->to_replace); 952 953 aio_context_release(replace_aio_context); 954 } 955 956 s->should_complete = true; 957 job_enter(job); 958 } 959 960 static void mirror_pause(Job *job) 961 { 962 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job); 963 964 mirror_wait_for_all_io(s); 965 } 966 967 static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context) 968 { 969 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 970 971 blk_set_aio_context(s->target, new_context); 972 } 973 974 static void mirror_drain(BlockJob *job) 975 { 976 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 977 978 /* Need to keep a reference in case blk_drain triggers execution 979 * of mirror_complete... 980 */ 981 if (s->target) { 982 BlockBackend *target = s->target; 983 blk_ref(target); 984 blk_drain(target); 985 blk_unref(target); 986 } 987 } 988 989 static const BlockJobDriver mirror_job_driver = { 990 .job_driver = { 991 .instance_size = sizeof(MirrorBlockJob), 992 .job_type = JOB_TYPE_MIRROR, 993 .free = block_job_free, 994 .user_resume = block_job_user_resume, 995 .drain = block_job_drain, 996 .start = mirror_run, 997 .pause = mirror_pause, 998 .complete = mirror_complete, 999 }, 1000 .attached_aio_context = mirror_attached_aio_context, 1001 .drain = mirror_drain, 1002 }; 1003 1004 static const BlockJobDriver commit_active_job_driver = { 1005 .job_driver = { 1006 .instance_size = sizeof(MirrorBlockJob), 1007 .job_type = JOB_TYPE_COMMIT, 1008 .free = block_job_free, 1009 .user_resume = block_job_user_resume, 1010 .drain = block_job_drain, 1011 .start = mirror_run, 1012 .pause = mirror_pause, 1013 .complete = mirror_complete, 1014 }, 1015 .attached_aio_context = mirror_attached_aio_context, 1016 .drain = mirror_drain, 1017 }; 1018 1019 static int coroutine_fn bdrv_mirror_top_preadv(BlockDriverState *bs, 1020 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1021 { 1022 return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); 1023 } 1024 1025 static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs, 1026 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1027 { 1028 return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); 1029 } 1030 1031 static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) 1032 { 1033 if (bs->backing == NULL) { 1034 /* we can be here after failed bdrv_append in mirror_start_job */ 1035 return 0; 1036 } 1037 return bdrv_co_flush(bs->backing->bs); 1038 } 1039 1040 static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, 1041 int64_t offset, int bytes, BdrvRequestFlags flags) 1042 { 1043 return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags); 1044 } 1045 1046 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, 1047 int64_t offset, int bytes) 1048 { 1049 return bdrv_co_pdiscard(bs->backing->bs, offset, bytes); 1050 } 1051 1052 static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts) 1053 { 1054 if (bs->backing == NULL) { 1055 /* we can be here after failed bdrv_attach_child in 1056 * bdrv_set_backing_hd */ 1057 return; 1058 } 1059 bdrv_refresh_filename(bs->backing->bs); 1060 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), 1061 bs->backing->bs->filename); 1062 } 1063 1064 static void bdrv_mirror_top_close(BlockDriverState *bs) 1065 { 1066 } 1067 1068 static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c, 1069 const BdrvChildRole *role, 1070 BlockReopenQueue *reopen_queue, 1071 uint64_t perm, uint64_t shared, 1072 uint64_t *nperm, uint64_t *nshared) 1073 { 1074 /* Must be able to forward guest writes to the real image */ 1075 *nperm = 0; 1076 if (perm & BLK_PERM_WRITE) { 1077 *nperm |= BLK_PERM_WRITE; 1078 } 1079 1080 *nshared = BLK_PERM_ALL; 1081 } 1082 1083 /* Dummy node that provides consistent read to its users without requiring it 1084 * from its backing file and that allows writes on the backing file chain. */ 1085 static BlockDriver bdrv_mirror_top = { 1086 .format_name = "mirror_top", 1087 .bdrv_co_preadv = bdrv_mirror_top_preadv, 1088 .bdrv_co_pwritev = bdrv_mirror_top_pwritev, 1089 .bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes, 1090 .bdrv_co_pdiscard = bdrv_mirror_top_pdiscard, 1091 .bdrv_co_flush = bdrv_mirror_top_flush, 1092 .bdrv_co_block_status = bdrv_co_block_status_from_backing, 1093 .bdrv_refresh_filename = bdrv_mirror_top_refresh_filename, 1094 .bdrv_close = bdrv_mirror_top_close, 1095 .bdrv_child_perm = bdrv_mirror_top_child_perm, 1096 }; 1097 1098 static void mirror_start_job(const char *job_id, BlockDriverState *bs, 1099 int creation_flags, BlockDriverState *target, 1100 const char *replaces, int64_t speed, 1101 uint32_t granularity, int64_t buf_size, 1102 BlockMirrorBackingMode backing_mode, 1103 BlockdevOnError on_source_error, 1104 BlockdevOnError on_target_error, 1105 bool unmap, 1106 BlockCompletionFunc *cb, 1107 void *opaque, 1108 const BlockJobDriver *driver, 1109 bool is_none_mode, BlockDriverState *base, 1110 bool auto_complete, const char *filter_node_name, 1111 bool is_mirror, 1112 Error **errp) 1113 { 1114 MirrorBlockJob *s; 1115 BlockDriverState *mirror_top_bs; 1116 bool target_graph_mod; 1117 bool target_is_backing; 1118 Error *local_err = NULL; 1119 int ret; 1120 1121 if (granularity == 0) { 1122 granularity = bdrv_get_default_bitmap_granularity(target); 1123 } 1124 1125 assert(is_power_of_2(granularity)); 1126 1127 if (buf_size < 0) { 1128 error_setg(errp, "Invalid parameter 'buf-size'"); 1129 return; 1130 } 1131 1132 if (buf_size == 0) { 1133 buf_size = DEFAULT_MIRROR_BUF_SIZE; 1134 } 1135 1136 /* In the case of active commit, add dummy driver to provide consistent 1137 * reads on the top, while disabling it in the intermediate nodes, and make 1138 * the backing chain writable. */ 1139 mirror_top_bs = bdrv_new_open_driver(&bdrv_mirror_top, filter_node_name, 1140 BDRV_O_RDWR, errp); 1141 if (mirror_top_bs == NULL) { 1142 return; 1143 } 1144 if (!filter_node_name) { 1145 mirror_top_bs->implicit = true; 1146 } 1147 mirror_top_bs->total_sectors = bs->total_sectors; 1148 mirror_top_bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED; 1149 mirror_top_bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED; 1150 bdrv_set_aio_context(mirror_top_bs, bdrv_get_aio_context(bs)); 1151 1152 /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep 1153 * it alive until block_job_create() succeeds even if bs has no parent. */ 1154 bdrv_ref(mirror_top_bs); 1155 bdrv_drained_begin(bs); 1156 bdrv_append(mirror_top_bs, bs, &local_err); 1157 bdrv_drained_end(bs); 1158 1159 if (local_err) { 1160 bdrv_unref(mirror_top_bs); 1161 error_propagate(errp, local_err); 1162 return; 1163 } 1164 1165 /* Make sure that the source is not resized while the job is running */ 1166 s = block_job_create(job_id, driver, NULL, mirror_top_bs, 1167 BLK_PERM_CONSISTENT_READ, 1168 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED | 1169 BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD, speed, 1170 creation_flags, cb, opaque, errp); 1171 if (!s) { 1172 goto fail; 1173 } 1174 /* The block job now has a reference to this node */ 1175 bdrv_unref(mirror_top_bs); 1176 1177 s->source = bs; 1178 s->mirror_top_bs = mirror_top_bs; 1179 1180 /* No resize for the target either; while the mirror is still running, a 1181 * consistent read isn't necessarily possible. We could possibly allow 1182 * writes and graph modifications, though it would likely defeat the 1183 * purpose of a mirror, so leave them blocked for now. 1184 * 1185 * In the case of active commit, things look a bit different, though, 1186 * because the target is an already populated backing file in active use. 1187 * We can allow anything except resize there.*/ 1188 target_is_backing = bdrv_chain_contains(bs, target); 1189 target_graph_mod = (backing_mode != MIRROR_LEAVE_BACKING_CHAIN); 1190 s->target = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE | 1191 (target_graph_mod ? BLK_PERM_GRAPH_MOD : 0), 1192 BLK_PERM_WRITE_UNCHANGED | 1193 (target_is_backing ? BLK_PERM_CONSISTENT_READ | 1194 BLK_PERM_WRITE | 1195 BLK_PERM_GRAPH_MOD : 0)); 1196 ret = blk_insert_bs(s->target, target, errp); 1197 if (ret < 0) { 1198 goto fail; 1199 } 1200 if (is_mirror) { 1201 /* XXX: Mirror target could be a NBD server of target QEMU in the case 1202 * of non-shared block migration. To allow migration completion, we 1203 * have to allow "inactivate" of the target BB. When that happens, we 1204 * know the job is drained, and the vcpus are stopped, so no write 1205 * operation will be performed. Block layer already has assertions to 1206 * ensure that. */ 1207 blk_set_force_allow_inactivate(s->target); 1208 } 1209 1210 s->replaces = g_strdup(replaces); 1211 s->on_source_error = on_source_error; 1212 s->on_target_error = on_target_error; 1213 s->is_none_mode = is_none_mode; 1214 s->backing_mode = backing_mode; 1215 s->base = base; 1216 s->granularity = granularity; 1217 s->buf_size = ROUND_UP(buf_size, granularity); 1218 s->unmap = unmap; 1219 if (auto_complete) { 1220 s->should_complete = true; 1221 } 1222 1223 s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); 1224 if (!s->dirty_bitmap) { 1225 goto fail; 1226 } 1227 1228 /* Required permissions are already taken with blk_new() */ 1229 block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL, 1230 &error_abort); 1231 1232 /* In commit_active_start() all intermediate nodes disappear, so 1233 * any jobs in them must be blocked */ 1234 if (target_is_backing) { 1235 BlockDriverState *iter; 1236 for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) { 1237 /* XXX BLK_PERM_WRITE needs to be allowed so we don't block 1238 * ourselves at s->base (if writes are blocked for a node, they are 1239 * also blocked for its backing file). The other options would be a 1240 * second filter driver above s->base (== target). */ 1241 ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, 1242 BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, 1243 errp); 1244 if (ret < 0) { 1245 goto fail; 1246 } 1247 } 1248 } 1249 1250 trace_mirror_start(bs, s, opaque); 1251 job_start(&s->common.job); 1252 return; 1253 1254 fail: 1255 if (s) { 1256 /* Make sure this BDS does not go away until we have completed the graph 1257 * changes below */ 1258 bdrv_ref(mirror_top_bs); 1259 1260 g_free(s->replaces); 1261 blk_unref(s->target); 1262 job_early_fail(&s->common.job); 1263 } 1264 1265 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 1266 &error_abort); 1267 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 1268 1269 bdrv_unref(mirror_top_bs); 1270 } 1271 1272 void mirror_start(const char *job_id, BlockDriverState *bs, 1273 BlockDriverState *target, const char *replaces, 1274 int64_t speed, uint32_t granularity, int64_t buf_size, 1275 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, 1276 BlockdevOnError on_source_error, 1277 BlockdevOnError on_target_error, 1278 bool unmap, const char *filter_node_name, Error **errp) 1279 { 1280 bool is_none_mode; 1281 BlockDriverState *base; 1282 1283 if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { 1284 error_setg(errp, "Sync mode 'incremental' not supported"); 1285 return; 1286 } 1287 is_none_mode = mode == MIRROR_SYNC_MODE_NONE; 1288 base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; 1289 mirror_start_job(job_id, bs, JOB_DEFAULT, target, replaces, 1290 speed, granularity, buf_size, backing_mode, 1291 on_source_error, on_target_error, unmap, NULL, NULL, 1292 &mirror_job_driver, is_none_mode, base, false, 1293 filter_node_name, true, errp); 1294 } 1295 1296 void commit_active_start(const char *job_id, BlockDriverState *bs, 1297 BlockDriverState *base, int creation_flags, 1298 int64_t speed, BlockdevOnError on_error, 1299 const char *filter_node_name, 1300 BlockCompletionFunc *cb, void *opaque, 1301 bool auto_complete, Error **errp) 1302 { 1303 int orig_base_flags; 1304 Error *local_err = NULL; 1305 1306 orig_base_flags = bdrv_get_flags(base); 1307 1308 if (bdrv_reopen(base, bs->open_flags, errp)) { 1309 return; 1310 } 1311 1312 mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0, 1313 MIRROR_LEAVE_BACKING_CHAIN, 1314 on_error, on_error, true, cb, opaque, 1315 &commit_active_job_driver, false, base, auto_complete, 1316 filter_node_name, false, &local_err); 1317 if (local_err) { 1318 error_propagate(errp, local_err); 1319 goto error_restore_flags; 1320 } 1321 1322 return; 1323 1324 error_restore_flags: 1325 /* ignore error and errp for bdrv_reopen, because we want to propagate 1326 * the original error */ 1327 bdrv_reopen(base, orig_base_flags, NULL); 1328 return; 1329 } 1330