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_BYTES (1 << 20) /* 1 Mb */ 28 #define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES) 29 30 /* The mirroring buffer is a list of granularity-sized chunks. 31 * Free chunks are organized in a list. 32 */ 33 typedef struct MirrorBuffer { 34 QSIMPLEQ_ENTRY(MirrorBuffer) next; 35 } MirrorBuffer; 36 37 typedef struct MirrorBlockJob { 38 BlockJob common; 39 RateLimit limit; 40 BlockBackend *target; 41 BlockDriverState *mirror_top_bs; 42 BlockDriverState *source; 43 BlockDriverState *base; 44 45 /* The name of the graph node to replace */ 46 char *replaces; 47 /* The BDS to replace */ 48 BlockDriverState *to_replace; 49 /* Used to block operations on the drive-mirror-replace target */ 50 Error *replace_blocker; 51 bool is_none_mode; 52 BlockMirrorBackingMode backing_mode; 53 BlockdevOnError on_source_error, on_target_error; 54 bool synced; 55 bool should_complete; 56 int64_t granularity; 57 size_t buf_size; 58 int64_t bdev_length; 59 unsigned long *cow_bitmap; 60 BdrvDirtyBitmap *dirty_bitmap; 61 BdrvDirtyBitmapIter *dbi; 62 uint8_t *buf; 63 QSIMPLEQ_HEAD(, MirrorBuffer) buf_free; 64 int buf_free_count; 65 66 uint64_t last_pause_ns; 67 unsigned long *in_flight_bitmap; 68 int in_flight; 69 int64_t bytes_in_flight; 70 int ret; 71 bool unmap; 72 bool waiting_for_io; 73 int target_cluster_size; 74 int max_iov; 75 bool initial_zeroing_ongoing; 76 } MirrorBlockJob; 77 78 typedef struct MirrorOp { 79 MirrorBlockJob *s; 80 QEMUIOVector qiov; 81 int64_t offset; 82 uint64_t bytes; 83 } MirrorOp; 84 85 static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, 86 int error) 87 { 88 s->synced = false; 89 if (read) { 90 return block_job_error_action(&s->common, s->on_source_error, 91 true, error); 92 } else { 93 return block_job_error_action(&s->common, s->on_target_error, 94 false, error); 95 } 96 } 97 98 static void mirror_iteration_done(MirrorOp *op, int ret) 99 { 100 MirrorBlockJob *s = op->s; 101 struct iovec *iov; 102 int64_t chunk_num; 103 int i, nb_chunks; 104 105 trace_mirror_iteration_done(s, op->offset, op->bytes, ret); 106 107 s->in_flight--; 108 s->bytes_in_flight -= op->bytes; 109 iov = op->qiov.iov; 110 for (i = 0; i < op->qiov.niov; i++) { 111 MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; 112 QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next); 113 s->buf_free_count++; 114 } 115 116 chunk_num = op->offset / s->granularity; 117 nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity); 118 bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); 119 if (ret >= 0) { 120 if (s->cow_bitmap) { 121 bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); 122 } 123 if (!s->initial_zeroing_ongoing) { 124 s->common.offset += op->bytes; 125 } 126 } 127 qemu_iovec_destroy(&op->qiov); 128 g_free(op); 129 130 if (s->waiting_for_io) { 131 qemu_coroutine_enter(s->common.co); 132 } 133 } 134 135 static void mirror_write_complete(void *opaque, int ret) 136 { 137 MirrorOp *op = opaque; 138 MirrorBlockJob *s = op->s; 139 140 aio_context_acquire(blk_get_aio_context(s->common.blk)); 141 if (ret < 0) { 142 BlockErrorAction action; 143 144 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes); 145 action = mirror_error_action(s, false, -ret); 146 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 147 s->ret = ret; 148 } 149 } 150 mirror_iteration_done(op, ret); 151 aio_context_release(blk_get_aio_context(s->common.blk)); 152 } 153 154 static void mirror_read_complete(void *opaque, int ret) 155 { 156 MirrorOp *op = opaque; 157 MirrorBlockJob *s = op->s; 158 159 aio_context_acquire(blk_get_aio_context(s->common.blk)); 160 if (ret < 0) { 161 BlockErrorAction action; 162 163 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset, op->bytes); 164 action = mirror_error_action(s, true, -ret); 165 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 166 s->ret = ret; 167 } 168 169 mirror_iteration_done(op, ret); 170 } else { 171 blk_aio_pwritev(s->target, op->offset, &op->qiov, 172 0, mirror_write_complete, op); 173 } 174 aio_context_release(blk_get_aio_context(s->common.blk)); 175 } 176 177 /* Clip bytes relative to offset to not exceed end-of-file */ 178 static inline int64_t mirror_clip_bytes(MirrorBlockJob *s, 179 int64_t offset, 180 int64_t bytes) 181 { 182 return MIN(bytes, s->bdev_length - offset); 183 } 184 185 /* Round offset and/or bytes to target cluster if COW is needed, and 186 * return the offset of the adjusted tail against original. */ 187 static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, 188 uint64_t *bytes) 189 { 190 bool need_cow; 191 int ret = 0; 192 int64_t align_offset = *offset; 193 int64_t align_bytes = *bytes; 194 int max_bytes = s->granularity * s->max_iov; 195 196 need_cow = !test_bit(*offset / s->granularity, s->cow_bitmap); 197 need_cow |= !test_bit((*offset + *bytes - 1) / s->granularity, 198 s->cow_bitmap); 199 if (need_cow) { 200 bdrv_round_to_clusters(blk_bs(s->target), *offset, *bytes, 201 &align_offset, &align_bytes); 202 } 203 204 if (align_bytes > max_bytes) { 205 align_bytes = max_bytes; 206 if (need_cow) { 207 align_bytes = QEMU_ALIGN_DOWN(align_bytes, s->target_cluster_size); 208 } 209 } 210 /* Clipping may result in align_bytes unaligned to chunk boundary, but 211 * that doesn't matter because it's already the end of source image. */ 212 align_bytes = mirror_clip_bytes(s, align_offset, align_bytes); 213 214 ret = align_offset + align_bytes - (*offset + *bytes); 215 *offset = align_offset; 216 *bytes = align_bytes; 217 assert(ret >= 0); 218 return ret; 219 } 220 221 static inline void mirror_wait_for_io(MirrorBlockJob *s) 222 { 223 assert(!s->waiting_for_io); 224 s->waiting_for_io = true; 225 qemu_coroutine_yield(); 226 s->waiting_for_io = false; 227 } 228 229 /* Submit async read while handling COW. 230 * Returns: The number of bytes copied after and including offset, 231 * excluding any bytes copied prior to offset due to alignment. 232 * This will be @bytes if no alignment is necessary, or 233 * (new_end - offset) if tail is rounded up or down due to 234 * alignment or buffer limit. 235 */ 236 static uint64_t mirror_do_read(MirrorBlockJob *s, int64_t offset, 237 uint64_t bytes) 238 { 239 BlockBackend *source = s->common.blk; 240 int nb_chunks; 241 uint64_t ret; 242 MirrorOp *op; 243 uint64_t max_bytes; 244 245 max_bytes = s->granularity * s->max_iov; 246 247 /* We can only handle as much as buf_size at a time. */ 248 bytes = MIN(s->buf_size, MIN(max_bytes, bytes)); 249 assert(bytes); 250 assert(bytes < BDRV_REQUEST_MAX_BYTES); 251 ret = bytes; 252 253 if (s->cow_bitmap) { 254 ret += mirror_cow_align(s, &offset, &bytes); 255 } 256 assert(bytes <= s->buf_size); 257 /* The offset is granularity-aligned because: 258 * 1) Caller passes in aligned values; 259 * 2) mirror_cow_align is used only when target cluster is larger. */ 260 assert(QEMU_IS_ALIGNED(offset, s->granularity)); 261 /* The range is sector-aligned, since bdrv_getlength() rounds up. */ 262 assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); 263 nb_chunks = DIV_ROUND_UP(bytes, s->granularity); 264 265 while (s->buf_free_count < nb_chunks) { 266 trace_mirror_yield_in_flight(s, offset, s->in_flight); 267 mirror_wait_for_io(s); 268 } 269 270 /* Allocate a MirrorOp that is used as an AIO callback. */ 271 op = g_new(MirrorOp, 1); 272 op->s = s; 273 op->offset = offset; 274 op->bytes = bytes; 275 276 /* Now make a QEMUIOVector taking enough granularity-sized chunks 277 * from s->buf_free. 278 */ 279 qemu_iovec_init(&op->qiov, nb_chunks); 280 while (nb_chunks-- > 0) { 281 MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); 282 size_t remaining = bytes - op->qiov.size; 283 284 QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); 285 s->buf_free_count--; 286 qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); 287 } 288 289 /* Copy the dirty cluster. */ 290 s->in_flight++; 291 s->bytes_in_flight += bytes; 292 trace_mirror_one_iteration(s, offset, bytes); 293 294 blk_aio_preadv(source, offset, &op->qiov, 0, mirror_read_complete, op); 295 return ret; 296 } 297 298 static void mirror_do_zero_or_discard(MirrorBlockJob *s, 299 int64_t offset, 300 uint64_t bytes, 301 bool is_discard) 302 { 303 MirrorOp *op; 304 305 /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed 306 * so the freeing in mirror_iteration_done is nop. */ 307 op = g_new0(MirrorOp, 1); 308 op->s = s; 309 op->offset = offset; 310 op->bytes = bytes; 311 312 s->in_flight++; 313 s->bytes_in_flight += bytes; 314 if (is_discard) { 315 blk_aio_pdiscard(s->target, offset, 316 op->bytes, mirror_write_complete, op); 317 } else { 318 blk_aio_pwrite_zeroes(s->target, offset, 319 op->bytes, s->unmap ? BDRV_REQ_MAY_UNMAP : 0, 320 mirror_write_complete, op); 321 } 322 } 323 324 static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) 325 { 326 BlockDriverState *source = s->source; 327 int64_t offset, first_chunk; 328 uint64_t delay_ns = 0; 329 /* At least the first dirty chunk is mirrored in one iteration. */ 330 int nb_chunks = 1; 331 bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); 332 int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES); 333 334 bdrv_dirty_bitmap_lock(s->dirty_bitmap); 335 offset = bdrv_dirty_iter_next(s->dbi); 336 if (offset < 0) { 337 bdrv_set_dirty_iter(s->dbi, 0); 338 offset = bdrv_dirty_iter_next(s->dbi); 339 trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); 340 assert(offset >= 0); 341 } 342 bdrv_dirty_bitmap_unlock(s->dirty_bitmap); 343 344 first_chunk = offset / s->granularity; 345 while (test_bit(first_chunk, s->in_flight_bitmap)) { 346 trace_mirror_yield_in_flight(s, offset, s->in_flight); 347 mirror_wait_for_io(s); 348 } 349 350 block_job_pause_point(&s->common); 351 352 /* Find the number of consective dirty chunks following the first dirty 353 * one, and wait for in flight requests in them. */ 354 bdrv_dirty_bitmap_lock(s->dirty_bitmap); 355 while (nb_chunks * s->granularity < s->buf_size) { 356 int64_t next_dirty; 357 int64_t next_offset = offset + nb_chunks * s->granularity; 358 int64_t next_chunk = next_offset / s->granularity; 359 if (next_offset >= s->bdev_length || 360 !bdrv_get_dirty_locked(source, s->dirty_bitmap, next_offset)) { 361 break; 362 } 363 if (test_bit(next_chunk, s->in_flight_bitmap)) { 364 break; 365 } 366 367 next_dirty = bdrv_dirty_iter_next(s->dbi); 368 if (next_dirty > next_offset || next_dirty < 0) { 369 /* The bitmap iterator's cache is stale, refresh it */ 370 bdrv_set_dirty_iter(s->dbi, next_offset); 371 next_dirty = bdrv_dirty_iter_next(s->dbi); 372 } 373 assert(next_dirty == next_offset); 374 nb_chunks++; 375 } 376 377 /* Clear dirty bits before querying the block status, because 378 * calling bdrv_block_status_above could yield - if some blocks are 379 * marked dirty in this window, we need to know. 380 */ 381 bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, offset, 382 nb_chunks * s->granularity); 383 bdrv_dirty_bitmap_unlock(s->dirty_bitmap); 384 385 bitmap_set(s->in_flight_bitmap, offset / s->granularity, nb_chunks); 386 while (nb_chunks > 0 && offset < s->bdev_length) { 387 int ret; 388 int64_t io_bytes; 389 int64_t io_bytes_acct; 390 enum MirrorMethod { 391 MIRROR_METHOD_COPY, 392 MIRROR_METHOD_ZERO, 393 MIRROR_METHOD_DISCARD 394 } mirror_method = MIRROR_METHOD_COPY; 395 396 assert(!(offset % s->granularity)); 397 ret = bdrv_block_status_above(source, NULL, offset, 398 nb_chunks * s->granularity, 399 &io_bytes, NULL, NULL); 400 if (ret < 0) { 401 io_bytes = MIN(nb_chunks * s->granularity, max_io_bytes); 402 } else if (ret & BDRV_BLOCK_DATA) { 403 io_bytes = MIN(io_bytes, max_io_bytes); 404 } 405 406 io_bytes -= io_bytes % s->granularity; 407 if (io_bytes < s->granularity) { 408 io_bytes = s->granularity; 409 } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { 410 int64_t target_offset; 411 int64_t target_bytes; 412 bdrv_round_to_clusters(blk_bs(s->target), offset, io_bytes, 413 &target_offset, &target_bytes); 414 if (target_offset == offset && 415 target_bytes == io_bytes) { 416 mirror_method = ret & BDRV_BLOCK_ZERO ? 417 MIRROR_METHOD_ZERO : 418 MIRROR_METHOD_DISCARD; 419 } 420 } 421 422 while (s->in_flight >= MAX_IN_FLIGHT) { 423 trace_mirror_yield_in_flight(s, offset, s->in_flight); 424 mirror_wait_for_io(s); 425 } 426 427 if (s->ret < 0) { 428 return 0; 429 } 430 431 io_bytes = mirror_clip_bytes(s, offset, io_bytes); 432 switch (mirror_method) { 433 case MIRROR_METHOD_COPY: 434 io_bytes = io_bytes_acct = mirror_do_read(s, offset, io_bytes); 435 break; 436 case MIRROR_METHOD_ZERO: 437 case MIRROR_METHOD_DISCARD: 438 mirror_do_zero_or_discard(s, offset, io_bytes, 439 mirror_method == MIRROR_METHOD_DISCARD); 440 if (write_zeroes_ok) { 441 io_bytes_acct = 0; 442 } else { 443 io_bytes_acct = io_bytes; 444 } 445 break; 446 default: 447 abort(); 448 } 449 assert(io_bytes); 450 offset += io_bytes; 451 nb_chunks -= DIV_ROUND_UP(io_bytes, s->granularity); 452 if (s->common.speed) { 453 delay_ns = ratelimit_calculate_delay(&s->limit, io_bytes_acct); 454 } 455 } 456 return delay_ns; 457 } 458 459 static void mirror_free_init(MirrorBlockJob *s) 460 { 461 int granularity = s->granularity; 462 size_t buf_size = s->buf_size; 463 uint8_t *buf = s->buf; 464 465 assert(s->buf_free_count == 0); 466 QSIMPLEQ_INIT(&s->buf_free); 467 while (buf_size != 0) { 468 MirrorBuffer *cur = (MirrorBuffer *)buf; 469 QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); 470 s->buf_free_count++; 471 buf_size -= granularity; 472 buf += granularity; 473 } 474 } 475 476 /* This is also used for the .pause callback. There is no matching 477 * mirror_resume() because mirror_run() will begin iterating again 478 * when the job is resumed. 479 */ 480 static void mirror_wait_for_all_io(MirrorBlockJob *s) 481 { 482 while (s->in_flight > 0) { 483 mirror_wait_for_io(s); 484 } 485 } 486 487 typedef struct { 488 int ret; 489 } MirrorExitData; 490 491 static void mirror_exit(BlockJob *job, void *opaque) 492 { 493 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 494 MirrorExitData *data = opaque; 495 AioContext *replace_aio_context = NULL; 496 BlockDriverState *src = s->source; 497 BlockDriverState *target_bs = blk_bs(s->target); 498 BlockDriverState *mirror_top_bs = s->mirror_top_bs; 499 Error *local_err = NULL; 500 501 bdrv_release_dirty_bitmap(src, s->dirty_bitmap); 502 503 /* Make sure that the source BDS doesn't go away before we called 504 * block_job_completed(). */ 505 bdrv_ref(src); 506 bdrv_ref(mirror_top_bs); 507 bdrv_ref(target_bs); 508 509 /* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before 510 * inserting target_bs at s->to_replace, where we might not be able to get 511 * these permissions. 512 * 513 * Note that blk_unref() alone doesn't necessarily drop permissions because 514 * we might be running nested inside mirror_drain(), which takes an extra 515 * reference, so use an explicit blk_set_perm() first. */ 516 blk_set_perm(s->target, 0, BLK_PERM_ALL, &error_abort); 517 blk_unref(s->target); 518 s->target = NULL; 519 520 /* We don't access the source any more. Dropping any WRITE/RESIZE is 521 * required before it could become a backing file of target_bs. */ 522 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 523 &error_abort); 524 if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { 525 BlockDriverState *backing = s->is_none_mode ? src : s->base; 526 if (backing_bs(target_bs) != backing) { 527 bdrv_set_backing_hd(target_bs, backing, &local_err); 528 if (local_err) { 529 error_report_err(local_err); 530 data->ret = -EPERM; 531 } 532 } 533 } 534 535 if (s->to_replace) { 536 replace_aio_context = bdrv_get_aio_context(s->to_replace); 537 aio_context_acquire(replace_aio_context); 538 } 539 540 if (s->should_complete && data->ret == 0) { 541 BlockDriverState *to_replace = src; 542 if (s->to_replace) { 543 to_replace = s->to_replace; 544 } 545 546 if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) { 547 bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL); 548 } 549 550 /* The mirror job has no requests in flight any more, but we need to 551 * drain potential other users of the BDS before changing the graph. */ 552 bdrv_drained_begin(target_bs); 553 bdrv_replace_node(to_replace, target_bs, &local_err); 554 bdrv_drained_end(target_bs); 555 if (local_err) { 556 error_report_err(local_err); 557 data->ret = -EPERM; 558 } 559 } 560 if (s->to_replace) { 561 bdrv_op_unblock_all(s->to_replace, s->replace_blocker); 562 error_free(s->replace_blocker); 563 bdrv_unref(s->to_replace); 564 } 565 if (replace_aio_context) { 566 aio_context_release(replace_aio_context); 567 } 568 g_free(s->replaces); 569 bdrv_unref(target_bs); 570 571 /* Remove the mirror filter driver from the graph. Before this, get rid of 572 * the blockers on the intermediate nodes so that the resulting state is 573 * valid. Also give up permissions on mirror_top_bs->backing, which might 574 * block the removal. */ 575 block_job_remove_all_bdrv(job); 576 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 577 &error_abort); 578 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 579 580 /* We just changed the BDS the job BB refers to (with either or both of the 581 * bdrv_replace_node() calls), so switch the BB back so the cleanup does 582 * the right thing. We don't need any permissions any more now. */ 583 blk_remove_bs(job->blk); 584 blk_set_perm(job->blk, 0, BLK_PERM_ALL, &error_abort); 585 blk_insert_bs(job->blk, mirror_top_bs, &error_abort); 586 587 block_job_completed(&s->common, data->ret); 588 589 g_free(data); 590 bdrv_drained_end(src); 591 bdrv_unref(mirror_top_bs); 592 bdrv_unref(src); 593 } 594 595 static void mirror_throttle(MirrorBlockJob *s) 596 { 597 int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 598 599 if (now - s->last_pause_ns > SLICE_TIME) { 600 s->last_pause_ns = now; 601 block_job_sleep_ns(&s->common, 0); 602 } else { 603 block_job_pause_point(&s->common); 604 } 605 } 606 607 static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) 608 { 609 int64_t offset; 610 BlockDriverState *base = s->base; 611 BlockDriverState *bs = s->source; 612 BlockDriverState *target_bs = blk_bs(s->target); 613 int ret; 614 int64_t count; 615 616 if (base == NULL && !bdrv_has_zero_init(target_bs)) { 617 if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { 618 bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length); 619 return 0; 620 } 621 622 s->initial_zeroing_ongoing = true; 623 for (offset = 0; offset < s->bdev_length; ) { 624 int bytes = MIN(s->bdev_length - offset, 625 QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); 626 627 mirror_throttle(s); 628 629 if (block_job_is_cancelled(&s->common)) { 630 s->initial_zeroing_ongoing = false; 631 return 0; 632 } 633 634 if (s->in_flight >= MAX_IN_FLIGHT) { 635 trace_mirror_yield(s, UINT64_MAX, s->buf_free_count, 636 s->in_flight); 637 mirror_wait_for_io(s); 638 continue; 639 } 640 641 mirror_do_zero_or_discard(s, offset, bytes, false); 642 offset += bytes; 643 } 644 645 mirror_wait_for_all_io(s); 646 s->initial_zeroing_ongoing = false; 647 } 648 649 /* First part, loop on the sectors and initialize the dirty bitmap. */ 650 for (offset = 0; offset < s->bdev_length; ) { 651 /* Just to make sure we are not exceeding int limit. */ 652 int bytes = MIN(s->bdev_length - offset, 653 QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); 654 655 mirror_throttle(s); 656 657 if (block_job_is_cancelled(&s->common)) { 658 return 0; 659 } 660 661 ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count); 662 if (ret < 0) { 663 return ret; 664 } 665 666 assert(count); 667 if (ret == 1) { 668 bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count); 669 } 670 offset += count; 671 } 672 return 0; 673 } 674 675 /* Called when going out of the streaming phase to flush the bulk of the 676 * data to the medium, or just before completing. 677 */ 678 static int mirror_flush(MirrorBlockJob *s) 679 { 680 int ret = blk_flush(s->target); 681 if (ret < 0) { 682 if (mirror_error_action(s, false, -ret) == BLOCK_ERROR_ACTION_REPORT) { 683 s->ret = ret; 684 } 685 } 686 return ret; 687 } 688 689 static void coroutine_fn mirror_run(void *opaque) 690 { 691 MirrorBlockJob *s = opaque; 692 MirrorExitData *data; 693 BlockDriverState *bs = s->source; 694 BlockDriverState *target_bs = blk_bs(s->target); 695 bool need_drain = true; 696 int64_t length; 697 BlockDriverInfo bdi; 698 char backing_filename[2]; /* we only need 2 characters because we are only 699 checking for a NULL string */ 700 int ret = 0; 701 702 if (block_job_is_cancelled(&s->common)) { 703 goto immediate_exit; 704 } 705 706 s->bdev_length = bdrv_getlength(bs); 707 if (s->bdev_length < 0) { 708 ret = s->bdev_length; 709 goto immediate_exit; 710 } 711 712 /* Active commit must resize the base image if its size differs from the 713 * active layer. */ 714 if (s->base == blk_bs(s->target)) { 715 int64_t base_length; 716 717 base_length = blk_getlength(s->target); 718 if (base_length < 0) { 719 ret = base_length; 720 goto immediate_exit; 721 } 722 723 if (s->bdev_length > base_length) { 724 ret = blk_truncate(s->target, s->bdev_length, PREALLOC_MODE_OFF, 725 NULL); 726 if (ret < 0) { 727 goto immediate_exit; 728 } 729 } 730 } 731 732 if (s->bdev_length == 0) { 733 /* Report BLOCK_JOB_READY and wait for complete. */ 734 block_job_event_ready(&s->common); 735 s->synced = true; 736 while (!block_job_is_cancelled(&s->common) && !s->should_complete) { 737 block_job_yield(&s->common); 738 } 739 s->common.cancelled = false; 740 goto immediate_exit; 741 } 742 743 length = DIV_ROUND_UP(s->bdev_length, s->granularity); 744 s->in_flight_bitmap = bitmap_new(length); 745 746 /* If we have no backing file yet in the destination, we cannot let 747 * the destination do COW. Instead, we copy sectors around the 748 * dirty data if needed. We need a bitmap to do that. 749 */ 750 bdrv_get_backing_filename(target_bs, backing_filename, 751 sizeof(backing_filename)); 752 if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) { 753 s->target_cluster_size = bdi.cluster_size; 754 } else { 755 s->target_cluster_size = BDRV_SECTOR_SIZE; 756 } 757 if (backing_filename[0] && !target_bs->backing && 758 s->granularity < s->target_cluster_size) { 759 s->buf_size = MAX(s->buf_size, s->target_cluster_size); 760 s->cow_bitmap = bitmap_new(length); 761 } 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); 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 bytes remaining and 797 * s->bytes_in_flight is the number of bytes currently being 798 * processed; together those are the current total operation length */ 799 s->common.len = s->common.offset + s->bytes_in_flight + cnt; 800 801 /* Note that even when no rate limit is applied we need to yield 802 * periodically with no pending I/O so that bdrv_drain_all() returns. 803 * We do so every SLICE_TIME nanoseconds, or when there is an error, 804 * or when the source is clean, whichever comes first. 805 */ 806 delta = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->last_pause_ns; 807 if (delta < SLICE_TIME && 808 s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 809 if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || 810 (cnt == 0 && s->in_flight > 0)) { 811 trace_mirror_yield(s, cnt, s->buf_free_count, s->in_flight); 812 mirror_wait_for_io(s); 813 continue; 814 } else if (cnt != 0) { 815 delay_ns = mirror_iteration(s); 816 } 817 } 818 819 should_complete = false; 820 if (s->in_flight == 0 && cnt == 0) { 821 trace_mirror_before_flush(s); 822 if (!s->synced) { 823 if (mirror_flush(s) < 0) { 824 /* Go check s->ret. */ 825 continue; 826 } 827 /* We're out of the streaming phase. From now on, if the job 828 * is cancelled we will actually complete all pending I/O and 829 * report completion. This way, block-job-cancel will leave 830 * the target in a consistent state. 831 */ 832 block_job_event_ready(&s->common); 833 s->synced = true; 834 } 835 836 should_complete = s->should_complete || 837 block_job_is_cancelled(&s->common); 838 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 839 } 840 841 if (cnt == 0 && should_complete) { 842 /* The dirty bitmap is not updated while operations are pending. 843 * If we're about to exit, wait for pending operations before 844 * calling bdrv_get_dirty_count(bs), or we may exit while the 845 * source has dirty data to copy! 846 * 847 * Note that I/O can be submitted by the guest while 848 * mirror_populate runs, so pause it now. Before deciding 849 * whether to switch to target check one last time if I/O has 850 * come in the meanwhile, and if not flush the data to disk. 851 */ 852 trace_mirror_before_drain(s, cnt); 853 854 bdrv_drained_begin(bs); 855 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 856 if (cnt > 0 || mirror_flush(s) < 0) { 857 bdrv_drained_end(bs); 858 continue; 859 } 860 861 /* The two disks are in sync. Exit and report successful 862 * completion. 863 */ 864 assert(QLIST_EMPTY(&bs->tracked_requests)); 865 s->common.cancelled = false; 866 need_drain = false; 867 break; 868 } 869 870 ret = 0; 871 trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); 872 if (!s->synced) { 873 block_job_sleep_ns(&s->common, delay_ns); 874 if (block_job_is_cancelled(&s->common)) { 875 break; 876 } 877 } else if (!should_complete) { 878 delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0); 879 block_job_sleep_ns(&s->common, delay_ns); 880 } 881 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 882 } 883 884 immediate_exit: 885 if (s->in_flight > 0) { 886 /* We get here only if something went wrong. Either the job failed, 887 * or it was cancelled prematurely so that we do not guarantee that 888 * the target is a copy of the source. 889 */ 890 assert(ret < 0 || (!s->synced && block_job_is_cancelled(&s->common))); 891 assert(need_drain); 892 mirror_wait_for_all_io(s); 893 } 894 895 assert(s->in_flight == 0); 896 qemu_vfree(s->buf); 897 g_free(s->cow_bitmap); 898 g_free(s->in_flight_bitmap); 899 bdrv_dirty_iter_free(s->dbi); 900 901 data = g_malloc(sizeof(*data)); 902 data->ret = ret; 903 904 if (need_drain) { 905 bdrv_drained_begin(bs); 906 } 907 block_job_defer_to_main_loop(&s->common, mirror_exit, data); 908 } 909 910 static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp) 911 { 912 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 913 914 if (speed < 0) { 915 error_setg(errp, QERR_INVALID_PARAMETER, "speed"); 916 return; 917 } 918 ratelimit_set_speed(&s->limit, speed, SLICE_TIME); 919 } 920 921 static void mirror_complete(BlockJob *job, Error **errp) 922 { 923 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 924 BlockDriverState *target; 925 926 target = blk_bs(s->target); 927 928 if (!s->synced) { 929 error_setg(errp, "The active block job '%s' cannot be completed", 930 job->id); 931 return; 932 } 933 934 if (s->backing_mode == MIRROR_OPEN_BACKING_CHAIN) { 935 int ret; 936 937 assert(!target->backing); 938 ret = bdrv_open_backing_file(target, NULL, "backing", errp); 939 if (ret < 0) { 940 return; 941 } 942 } 943 944 /* block all operations on to_replace bs */ 945 if (s->replaces) { 946 AioContext *replace_aio_context; 947 948 s->to_replace = bdrv_find_node(s->replaces); 949 if (!s->to_replace) { 950 error_setg(errp, "Node name '%s' not found", s->replaces); 951 return; 952 } 953 954 replace_aio_context = bdrv_get_aio_context(s->to_replace); 955 aio_context_acquire(replace_aio_context); 956 957 /* TODO Translate this into permission system. Current definition of 958 * GRAPH_MOD would require to request it for the parents; they might 959 * not even be BlockDriverStates, however, so a BdrvChild can't address 960 * them. May need redefinition of GRAPH_MOD. */ 961 error_setg(&s->replace_blocker, 962 "block device is in use by block-job-complete"); 963 bdrv_op_block_all(s->to_replace, s->replace_blocker); 964 bdrv_ref(s->to_replace); 965 966 aio_context_release(replace_aio_context); 967 } 968 969 s->should_complete = true; 970 block_job_enter(&s->common); 971 } 972 973 static void mirror_pause(BlockJob *job) 974 { 975 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 976 977 mirror_wait_for_all_io(s); 978 } 979 980 static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context) 981 { 982 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 983 984 blk_set_aio_context(s->target, new_context); 985 } 986 987 static void mirror_drain(BlockJob *job) 988 { 989 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 990 991 /* Need to keep a reference in case blk_drain triggers execution 992 * of mirror_complete... 993 */ 994 if (s->target) { 995 BlockBackend *target = s->target; 996 blk_ref(target); 997 blk_drain(target); 998 blk_unref(target); 999 } 1000 } 1001 1002 static const BlockJobDriver mirror_job_driver = { 1003 .instance_size = sizeof(MirrorBlockJob), 1004 .job_type = BLOCK_JOB_TYPE_MIRROR, 1005 .set_speed = mirror_set_speed, 1006 .start = mirror_run, 1007 .complete = mirror_complete, 1008 .pause = mirror_pause, 1009 .attached_aio_context = mirror_attached_aio_context, 1010 .drain = mirror_drain, 1011 }; 1012 1013 static const BlockJobDriver commit_active_job_driver = { 1014 .instance_size = sizeof(MirrorBlockJob), 1015 .job_type = BLOCK_JOB_TYPE_COMMIT, 1016 .set_speed = mirror_set_speed, 1017 .start = mirror_run, 1018 .complete = mirror_complete, 1019 .pause = mirror_pause, 1020 .attached_aio_context = mirror_attached_aio_context, 1021 .drain = mirror_drain, 1022 }; 1023 1024 static int coroutine_fn bdrv_mirror_top_preadv(BlockDriverState *bs, 1025 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1026 { 1027 return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); 1028 } 1029 1030 static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs, 1031 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) 1032 { 1033 return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); 1034 } 1035 1036 static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) 1037 { 1038 if (bs->backing == NULL) { 1039 /* we can be here after failed bdrv_append in mirror_start_job */ 1040 return 0; 1041 } 1042 return bdrv_co_flush(bs->backing->bs); 1043 } 1044 1045 static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, 1046 int64_t offset, int bytes, BdrvRequestFlags flags) 1047 { 1048 return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags); 1049 } 1050 1051 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, 1052 int64_t offset, int bytes) 1053 { 1054 return bdrv_co_pdiscard(bs->backing->bs, offset, bytes); 1055 } 1056 1057 static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts) 1058 { 1059 if (bs->backing == NULL) { 1060 /* we can be here after failed bdrv_attach_child in 1061 * bdrv_set_backing_hd */ 1062 return; 1063 } 1064 bdrv_refresh_filename(bs->backing->bs); 1065 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), 1066 bs->backing->bs->filename); 1067 } 1068 1069 static void bdrv_mirror_top_close(BlockDriverState *bs) 1070 { 1071 } 1072 1073 static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c, 1074 const BdrvChildRole *role, 1075 BlockReopenQueue *reopen_queue, 1076 uint64_t perm, uint64_t shared, 1077 uint64_t *nperm, uint64_t *nshared) 1078 { 1079 /* Must be able to forward guest writes to the real image */ 1080 *nperm = 0; 1081 if (perm & BLK_PERM_WRITE) { 1082 *nperm |= BLK_PERM_WRITE; 1083 } 1084 1085 *nshared = BLK_PERM_ALL; 1086 } 1087 1088 /* Dummy node that provides consistent read to its users without requiring it 1089 * from its backing file and that allows writes on the backing file chain. */ 1090 static BlockDriver bdrv_mirror_top = { 1091 .format_name = "mirror_top", 1092 .bdrv_co_preadv = bdrv_mirror_top_preadv, 1093 .bdrv_co_pwritev = bdrv_mirror_top_pwritev, 1094 .bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes, 1095 .bdrv_co_pdiscard = bdrv_mirror_top_pdiscard, 1096 .bdrv_co_flush = bdrv_mirror_top_flush, 1097 .bdrv_co_get_block_status = bdrv_co_get_block_status_from_backing, 1098 .bdrv_refresh_filename = bdrv_mirror_top_refresh_filename, 1099 .bdrv_close = bdrv_mirror_top_close, 1100 .bdrv_child_perm = bdrv_mirror_top_child_perm, 1101 }; 1102 1103 static void mirror_start_job(const char *job_id, BlockDriverState *bs, 1104 int creation_flags, BlockDriverState *target, 1105 const char *replaces, int64_t speed, 1106 uint32_t granularity, int64_t buf_size, 1107 BlockMirrorBackingMode backing_mode, 1108 BlockdevOnError on_source_error, 1109 BlockdevOnError on_target_error, 1110 bool unmap, 1111 BlockCompletionFunc *cb, 1112 void *opaque, 1113 const BlockJobDriver *driver, 1114 bool is_none_mode, BlockDriverState *base, 1115 bool auto_complete, const char *filter_node_name, 1116 bool is_mirror, 1117 Error **errp) 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(is_power_of_2(granularity)); 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 if (!filter_node_name) { 1150 mirror_top_bs->implicit = true; 1151 } 1152 mirror_top_bs->total_sectors = bs->total_sectors; 1153 bdrv_set_aio_context(mirror_top_bs, bdrv_get_aio_context(bs)); 1154 1155 /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep 1156 * it alive until block_job_create() succeeds even if bs has no parent. */ 1157 bdrv_ref(mirror_top_bs); 1158 bdrv_drained_begin(bs); 1159 bdrv_append(mirror_top_bs, bs, &local_err); 1160 bdrv_drained_end(bs); 1161 1162 if (local_err) { 1163 bdrv_unref(mirror_top_bs); 1164 error_propagate(errp, local_err); 1165 return; 1166 } 1167 1168 /* Make sure that the source is not resized while the job is running */ 1169 s = block_job_create(job_id, driver, mirror_top_bs, 1170 BLK_PERM_CONSISTENT_READ, 1171 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED | 1172 BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD, speed, 1173 creation_flags, cb, opaque, errp); 1174 if (!s) { 1175 goto fail; 1176 } 1177 /* The block job now has a reference to this node */ 1178 bdrv_unref(mirror_top_bs); 1179 1180 s->source = bs; 1181 s->mirror_top_bs = mirror_top_bs; 1182 1183 /* No resize for the target either; while the mirror is still running, a 1184 * consistent read isn't necessarily possible. We could possibly allow 1185 * writes and graph modifications, though it would likely defeat the 1186 * purpose of a mirror, so leave them blocked for now. 1187 * 1188 * In the case of active commit, things look a bit different, though, 1189 * because the target is an already populated backing file in active use. 1190 * We can allow anything except resize there.*/ 1191 target_is_backing = bdrv_chain_contains(bs, target); 1192 target_graph_mod = (backing_mode != MIRROR_LEAVE_BACKING_CHAIN); 1193 s->target = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE | 1194 (target_graph_mod ? BLK_PERM_GRAPH_MOD : 0), 1195 BLK_PERM_WRITE_UNCHANGED | 1196 (target_is_backing ? BLK_PERM_CONSISTENT_READ | 1197 BLK_PERM_WRITE | 1198 BLK_PERM_GRAPH_MOD : 0)); 1199 ret = blk_insert_bs(s->target, target, errp); 1200 if (ret < 0) { 1201 goto fail; 1202 } 1203 if (is_mirror) { 1204 /* XXX: Mirror target could be a NBD server of target QEMU in the case 1205 * of non-shared block migration. To allow migration completion, we 1206 * have to allow "inactivate" of the target BB. When that happens, we 1207 * know the job is drained, and the vcpus are stopped, so no write 1208 * operation will be performed. Block layer already has assertions to 1209 * ensure that. */ 1210 blk_set_force_allow_inactivate(s->target); 1211 } 1212 1213 s->replaces = g_strdup(replaces); 1214 s->on_source_error = on_source_error; 1215 s->on_target_error = on_target_error; 1216 s->is_none_mode = is_none_mode; 1217 s->backing_mode = backing_mode; 1218 s->base = base; 1219 s->granularity = granularity; 1220 s->buf_size = ROUND_UP(buf_size, granularity); 1221 s->unmap = unmap; 1222 if (auto_complete) { 1223 s->should_complete = true; 1224 } 1225 1226 s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); 1227 if (!s->dirty_bitmap) { 1228 goto fail; 1229 } 1230 1231 /* Required permissions are already taken with blk_new() */ 1232 block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL, 1233 &error_abort); 1234 1235 /* In commit_active_start() all intermediate nodes disappear, so 1236 * any jobs in them must be blocked */ 1237 if (target_is_backing) { 1238 BlockDriverState *iter; 1239 for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) { 1240 /* XXX BLK_PERM_WRITE needs to be allowed so we don't block 1241 * ourselves at s->base (if writes are blocked for a node, they are 1242 * also blocked for its backing file). The other options would be a 1243 * second filter driver above s->base (== target). */ 1244 ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, 1245 BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, 1246 errp); 1247 if (ret < 0) { 1248 goto fail; 1249 } 1250 } 1251 } 1252 1253 trace_mirror_start(bs, s, opaque); 1254 block_job_start(&s->common); 1255 return; 1256 1257 fail: 1258 if (s) { 1259 /* Make sure this BDS does not go away until we have completed the graph 1260 * changes below */ 1261 bdrv_ref(mirror_top_bs); 1262 1263 g_free(s->replaces); 1264 blk_unref(s->target); 1265 block_job_early_fail(&s->common); 1266 } 1267 1268 bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, 1269 &error_abort); 1270 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 1271 1272 bdrv_unref(mirror_top_bs); 1273 } 1274 1275 void mirror_start(const char *job_id, BlockDriverState *bs, 1276 BlockDriverState *target, const char *replaces, 1277 int64_t speed, uint32_t granularity, int64_t buf_size, 1278 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, 1279 BlockdevOnError on_source_error, 1280 BlockdevOnError on_target_error, 1281 bool unmap, const char *filter_node_name, Error **errp) 1282 { 1283 bool is_none_mode; 1284 BlockDriverState *base; 1285 1286 if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { 1287 error_setg(errp, "Sync mode 'incremental' not supported"); 1288 return; 1289 } 1290 is_none_mode = mode == MIRROR_SYNC_MODE_NONE; 1291 base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; 1292 mirror_start_job(job_id, bs, BLOCK_JOB_DEFAULT, target, replaces, 1293 speed, granularity, buf_size, backing_mode, 1294 on_source_error, on_target_error, unmap, NULL, NULL, 1295 &mirror_job_driver, is_none_mode, base, false, 1296 filter_node_name, true, errp); 1297 } 1298 1299 void commit_active_start(const char *job_id, BlockDriverState *bs, 1300 BlockDriverState *base, int creation_flags, 1301 int64_t speed, BlockdevOnError on_error, 1302 const char *filter_node_name, 1303 BlockCompletionFunc *cb, void *opaque, 1304 bool auto_complete, Error **errp) 1305 { 1306 int orig_base_flags; 1307 Error *local_err = NULL; 1308 1309 orig_base_flags = bdrv_get_flags(base); 1310 1311 if (bdrv_reopen(base, bs->open_flags, errp)) { 1312 return; 1313 } 1314 1315 mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0, 1316 MIRROR_LEAVE_BACKING_CHAIN, 1317 on_error, on_error, true, cb, opaque, 1318 &commit_active_job_driver, false, base, auto_complete, 1319 filter_node_name, false, &local_err); 1320 if (local_err) { 1321 error_propagate(errp, local_err); 1322 goto error_restore_flags; 1323 } 1324 1325 return; 1326 1327 error_restore_flags: 1328 /* ignore error and errp for bdrv_reopen, because we want to propagate 1329 * the original error */ 1330 bdrv_reopen(base, orig_base_flags, NULL); 1331 return; 1332 } 1333