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 "trace.h" 16 #include "block/blockjob_int.h" 17 #include "block/block_int.h" 18 #include "sysemu/block-backend.h" 19 #include "qapi/error.h" 20 #include "qapi/qmp/qerror.h" 21 #include "qemu/ratelimit.h" 22 #include "qemu/bitmap.h" 23 24 #define SLICE_TIME 100000000ULL /* ns */ 25 #define MAX_IN_FLIGHT 16 26 #define MAX_IO_SECTORS ((1 << 20) >> BDRV_SECTOR_BITS) /* 1 Mb */ 27 #define DEFAULT_MIRROR_BUF_SIZE \ 28 (MAX_IN_FLIGHT * MAX_IO_SECTORS * BDRV_SECTOR_SIZE) 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 sectors_in_flight; 70 int ret; 71 bool unmap; 72 bool waiting_for_io; 73 int target_cluster_sectors; 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 sector_num; 82 int nb_sectors; 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, sectors_per_chunk; 104 105 trace_mirror_iteration_done(s, op->sector_num, op->nb_sectors, ret); 106 107 s->in_flight--; 108 s->sectors_in_flight -= op->nb_sectors; 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 sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 117 chunk_num = op->sector_num / sectors_per_chunk; 118 nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk); 119 bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); 120 if (ret >= 0) { 121 if (s->cow_bitmap) { 122 bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); 123 } 124 if (!s->initial_zeroing_ongoing) { 125 s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE; 126 } 127 } 128 qemu_iovec_destroy(&op->qiov); 129 g_free(op); 130 131 if (s->waiting_for_io) { 132 qemu_coroutine_enter(s->common.co); 133 } 134 } 135 136 static void mirror_write_complete(void *opaque, int ret) 137 { 138 MirrorOp *op = opaque; 139 MirrorBlockJob *s = op->s; 140 141 aio_context_acquire(blk_get_aio_context(s->common.blk)); 142 if (ret < 0) { 143 BlockErrorAction action; 144 145 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); 146 action = mirror_error_action(s, false, -ret); 147 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 148 s->ret = ret; 149 } 150 } 151 mirror_iteration_done(op, ret); 152 aio_context_release(blk_get_aio_context(s->common.blk)); 153 } 154 155 static void mirror_read_complete(void *opaque, int ret) 156 { 157 MirrorOp *op = opaque; 158 MirrorBlockJob *s = op->s; 159 160 aio_context_acquire(blk_get_aio_context(s->common.blk)); 161 if (ret < 0) { 162 BlockErrorAction action; 163 164 bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); 165 action = mirror_error_action(s, true, -ret); 166 if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { 167 s->ret = ret; 168 } 169 170 mirror_iteration_done(op, ret); 171 } else { 172 blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov, 173 0, mirror_write_complete, op); 174 } 175 aio_context_release(blk_get_aio_context(s->common.blk)); 176 } 177 178 static inline void mirror_clip_sectors(MirrorBlockJob *s, 179 int64_t sector_num, 180 int *nb_sectors) 181 { 182 *nb_sectors = MIN(*nb_sectors, 183 s->bdev_length / BDRV_SECTOR_SIZE - sector_num); 184 } 185 186 /* Round sector_num and/or nb_sectors to target cluster if COW is needed, and 187 * return the offset of the adjusted tail sector against original. */ 188 static int mirror_cow_align(MirrorBlockJob *s, 189 int64_t *sector_num, 190 int *nb_sectors) 191 { 192 bool need_cow; 193 int ret = 0; 194 int chunk_sectors = s->granularity >> BDRV_SECTOR_BITS; 195 int64_t align_sector_num = *sector_num; 196 int align_nb_sectors = *nb_sectors; 197 int max_sectors = chunk_sectors * s->max_iov; 198 199 need_cow = !test_bit(*sector_num / chunk_sectors, s->cow_bitmap); 200 need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors, 201 s->cow_bitmap); 202 if (need_cow) { 203 bdrv_round_sectors_to_clusters(blk_bs(s->target), *sector_num, 204 *nb_sectors, &align_sector_num, 205 &align_nb_sectors); 206 } 207 208 if (align_nb_sectors > max_sectors) { 209 align_nb_sectors = max_sectors; 210 if (need_cow) { 211 align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors, 212 s->target_cluster_sectors); 213 } 214 } 215 /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but 216 * that doesn't matter because it's already the end of source image. */ 217 mirror_clip_sectors(s, align_sector_num, &align_nb_sectors); 218 219 ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors); 220 *sector_num = align_sector_num; 221 *nb_sectors = align_nb_sectors; 222 assert(ret >= 0); 223 return ret; 224 } 225 226 static inline void mirror_wait_for_io(MirrorBlockJob *s) 227 { 228 assert(!s->waiting_for_io); 229 s->waiting_for_io = true; 230 qemu_coroutine_yield(); 231 s->waiting_for_io = false; 232 } 233 234 /* Submit async read while handling COW. 235 * Returns: The number of sectors copied after and including sector_num, 236 * excluding any sectors copied prior to sector_num due to alignment. 237 * This will be nb_sectors if no alignment is necessary, or 238 * (new_end - sector_num) if tail is rounded up or down due to 239 * alignment or buffer limit. 240 */ 241 static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, 242 int nb_sectors) 243 { 244 BlockBackend *source = s->common.blk; 245 int sectors_per_chunk, nb_chunks; 246 int ret; 247 MirrorOp *op; 248 int max_sectors; 249 250 sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 251 max_sectors = sectors_per_chunk * s->max_iov; 252 253 /* We can only handle as much as buf_size at a time. */ 254 nb_sectors = MIN(s->buf_size >> BDRV_SECTOR_BITS, nb_sectors); 255 nb_sectors = MIN(max_sectors, nb_sectors); 256 assert(nb_sectors); 257 ret = nb_sectors; 258 259 if (s->cow_bitmap) { 260 ret += mirror_cow_align(s, §or_num, &nb_sectors); 261 } 262 assert(nb_sectors << BDRV_SECTOR_BITS <= s->buf_size); 263 /* The sector range must meet granularity because: 264 * 1) Caller passes in aligned values; 265 * 2) mirror_cow_align is used only when target cluster is larger. */ 266 assert(!(sector_num % sectors_per_chunk)); 267 nb_chunks = DIV_ROUND_UP(nb_sectors, sectors_per_chunk); 268 269 while (s->buf_free_count < nb_chunks) { 270 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 271 mirror_wait_for_io(s); 272 } 273 274 /* Allocate a MirrorOp that is used as an AIO callback. */ 275 op = g_new(MirrorOp, 1); 276 op->s = s; 277 op->sector_num = sector_num; 278 op->nb_sectors = nb_sectors; 279 280 /* Now make a QEMUIOVector taking enough granularity-sized chunks 281 * from s->buf_free. 282 */ 283 qemu_iovec_init(&op->qiov, nb_chunks); 284 while (nb_chunks-- > 0) { 285 MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); 286 size_t remaining = nb_sectors * BDRV_SECTOR_SIZE - op->qiov.size; 287 288 QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); 289 s->buf_free_count--; 290 qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); 291 } 292 293 /* Copy the dirty cluster. */ 294 s->in_flight++; 295 s->sectors_in_flight += nb_sectors; 296 trace_mirror_one_iteration(s, sector_num, nb_sectors); 297 298 blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov, 0, 299 mirror_read_complete, op); 300 return ret; 301 } 302 303 static void mirror_do_zero_or_discard(MirrorBlockJob *s, 304 int64_t sector_num, 305 int nb_sectors, 306 bool is_discard) 307 { 308 MirrorOp *op; 309 310 /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed 311 * so the freeing in mirror_iteration_done is nop. */ 312 op = g_new0(MirrorOp, 1); 313 op->s = s; 314 op->sector_num = sector_num; 315 op->nb_sectors = nb_sectors; 316 317 s->in_flight++; 318 s->sectors_in_flight += nb_sectors; 319 if (is_discard) { 320 blk_aio_pdiscard(s->target, sector_num << BDRV_SECTOR_BITS, 321 op->nb_sectors << BDRV_SECTOR_BITS, 322 mirror_write_complete, op); 323 } else { 324 blk_aio_pwrite_zeroes(s->target, sector_num * BDRV_SECTOR_SIZE, 325 op->nb_sectors * BDRV_SECTOR_SIZE, 326 s->unmap ? BDRV_REQ_MAY_UNMAP : 0, 327 mirror_write_complete, op); 328 } 329 } 330 331 static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) 332 { 333 BlockDriverState *source = s->source; 334 int64_t sector_num, first_chunk; 335 uint64_t delay_ns = 0; 336 /* At least the first dirty chunk is mirrored in one iteration. */ 337 int nb_chunks = 1; 338 int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; 339 int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; 340 bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); 341 int max_io_sectors = MAX((s->buf_size >> BDRV_SECTOR_BITS) / MAX_IN_FLIGHT, 342 MAX_IO_SECTORS); 343 344 sector_num = bdrv_dirty_iter_next(s->dbi); 345 if (sector_num < 0) { 346 bdrv_set_dirty_iter(s->dbi, 0); 347 sector_num = bdrv_dirty_iter_next(s->dbi); 348 trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); 349 assert(sector_num >= 0); 350 } 351 352 first_chunk = sector_num / sectors_per_chunk; 353 while (test_bit(first_chunk, s->in_flight_bitmap)) { 354 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 355 mirror_wait_for_io(s); 356 } 357 358 block_job_pause_point(&s->common); 359 360 /* Find the number of consective dirty chunks following the first dirty 361 * one, and wait for in flight requests in them. */ 362 while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { 363 int64_t next_dirty; 364 int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk; 365 int64_t next_chunk = next_sector / sectors_per_chunk; 366 if (next_sector >= end || 367 !bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) { 368 break; 369 } 370 if (test_bit(next_chunk, s->in_flight_bitmap)) { 371 break; 372 } 373 374 next_dirty = bdrv_dirty_iter_next(s->dbi); 375 if (next_dirty > next_sector || next_dirty < 0) { 376 /* The bitmap iterator's cache is stale, refresh it */ 377 bdrv_set_dirty_iter(s->dbi, next_sector); 378 next_dirty = bdrv_dirty_iter_next(s->dbi); 379 } 380 assert(next_dirty == next_sector); 381 nb_chunks++; 382 } 383 384 /* Clear dirty bits before querying the block status, because 385 * calling bdrv_get_block_status_above could yield - if some blocks are 386 * marked dirty in this window, we need to know. 387 */ 388 bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num, 389 nb_chunks * sectors_per_chunk); 390 bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks); 391 while (nb_chunks > 0 && sector_num < end) { 392 int64_t ret; 393 int io_sectors, io_sectors_acct; 394 BlockDriverState *file; 395 enum MirrorMethod { 396 MIRROR_METHOD_COPY, 397 MIRROR_METHOD_ZERO, 398 MIRROR_METHOD_DISCARD 399 } mirror_method = MIRROR_METHOD_COPY; 400 401 assert(!(sector_num % sectors_per_chunk)); 402 ret = bdrv_get_block_status_above(source, NULL, sector_num, 403 nb_chunks * sectors_per_chunk, 404 &io_sectors, &file); 405 if (ret < 0) { 406 io_sectors = MIN(nb_chunks * sectors_per_chunk, max_io_sectors); 407 } else if (ret & BDRV_BLOCK_DATA) { 408 io_sectors = MIN(io_sectors, max_io_sectors); 409 } 410 411 io_sectors -= io_sectors % sectors_per_chunk; 412 if (io_sectors < sectors_per_chunk) { 413 io_sectors = sectors_per_chunk; 414 } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { 415 int64_t target_sector_num; 416 int target_nb_sectors; 417 bdrv_round_sectors_to_clusters(blk_bs(s->target), sector_num, 418 io_sectors, &target_sector_num, 419 &target_nb_sectors); 420 if (target_sector_num == sector_num && 421 target_nb_sectors == io_sectors) { 422 mirror_method = ret & BDRV_BLOCK_ZERO ? 423 MIRROR_METHOD_ZERO : 424 MIRROR_METHOD_DISCARD; 425 } 426 } 427 428 while (s->in_flight >= MAX_IN_FLIGHT) { 429 trace_mirror_yield_in_flight(s, sector_num, s->in_flight); 430 mirror_wait_for_io(s); 431 } 432 433 if (s->ret < 0) { 434 return 0; 435 } 436 437 mirror_clip_sectors(s, sector_num, &io_sectors); 438 switch (mirror_method) { 439 case MIRROR_METHOD_COPY: 440 io_sectors = mirror_do_read(s, sector_num, io_sectors); 441 io_sectors_acct = io_sectors; 442 break; 443 case MIRROR_METHOD_ZERO: 444 case MIRROR_METHOD_DISCARD: 445 mirror_do_zero_or_discard(s, sector_num, io_sectors, 446 mirror_method == MIRROR_METHOD_DISCARD); 447 if (write_zeroes_ok) { 448 io_sectors_acct = 0; 449 } else { 450 io_sectors_acct = io_sectors; 451 } 452 break; 453 default: 454 abort(); 455 } 456 assert(io_sectors); 457 sector_num += io_sectors; 458 nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk); 459 if (s->common.speed) { 460 delay_ns = ratelimit_calculate_delay(&s->limit, io_sectors_acct); 461 } 462 } 463 return delay_ns; 464 } 465 466 static void mirror_free_init(MirrorBlockJob *s) 467 { 468 int granularity = s->granularity; 469 size_t buf_size = s->buf_size; 470 uint8_t *buf = s->buf; 471 472 assert(s->buf_free_count == 0); 473 QSIMPLEQ_INIT(&s->buf_free); 474 while (buf_size != 0) { 475 MirrorBuffer *cur = (MirrorBuffer *)buf; 476 QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); 477 s->buf_free_count++; 478 buf_size -= granularity; 479 buf += granularity; 480 } 481 } 482 483 /* This is also used for the .pause callback. There is no matching 484 * mirror_resume() because mirror_run() will begin iterating again 485 * when the job is resumed. 486 */ 487 static void mirror_wait_for_all_io(MirrorBlockJob *s) 488 { 489 while (s->in_flight > 0) { 490 mirror_wait_for_io(s); 491 } 492 } 493 494 typedef struct { 495 int ret; 496 } MirrorExitData; 497 498 static void mirror_exit(BlockJob *job, void *opaque) 499 { 500 MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); 501 MirrorExitData *data = opaque; 502 AioContext *replace_aio_context = NULL; 503 BlockDriverState *src = s->source; 504 BlockDriverState *target_bs = blk_bs(s->target); 505 BlockDriverState *mirror_top_bs = s->mirror_top_bs; 506 Error *local_err = NULL; 507 508 /* Make sure that the source BDS doesn't go away before we called 509 * block_job_completed(). */ 510 bdrv_ref(src); 511 bdrv_ref(mirror_top_bs); 512 bdrv_ref(target_bs); 513 514 /* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before 515 * inserting target_bs at s->to_replace, where we might not be able to get 516 * these permissions. */ 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_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL); 577 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 578 579 /* We just changed the BDS the job BB refers to (with either or both of the 580 * bdrv_replace_node() calls), so switch the BB back so the cleanup does 581 * the right thing. We don't need any permissions any more now. */ 582 blk_remove_bs(job->blk); 583 blk_set_perm(job->blk, 0, BLK_PERM_ALL, &error_abort); 584 blk_insert_bs(job->blk, mirror_top_bs, &error_abort); 585 586 block_job_completed(&s->common, data->ret); 587 588 g_free(data); 589 bdrv_drained_end(src); 590 bdrv_unref(mirror_top_bs); 591 bdrv_unref(src); 592 } 593 594 static void mirror_throttle(MirrorBlockJob *s) 595 { 596 int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 597 598 if (now - s->last_pause_ns > SLICE_TIME) { 599 s->last_pause_ns = now; 600 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); 601 } else { 602 block_job_pause_point(&s->common); 603 } 604 } 605 606 static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) 607 { 608 int64_t sector_num, end; 609 BlockDriverState *base = s->base; 610 BlockDriverState *bs = s->source; 611 BlockDriverState *target_bs = blk_bs(s->target); 612 int ret, n; 613 614 end = s->bdev_length / BDRV_SECTOR_SIZE; 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, end); 619 return 0; 620 } 621 622 s->initial_zeroing_ongoing = true; 623 for (sector_num = 0; sector_num < end; ) { 624 int nb_sectors = MIN(end - sector_num, 625 QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS); 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, s->in_flight, s->buf_free_count, -1); 636 mirror_wait_for_io(s); 637 continue; 638 } 639 640 mirror_do_zero_or_discard(s, sector_num, nb_sectors, false); 641 sector_num += nb_sectors; 642 } 643 644 mirror_wait_for_all_io(s); 645 s->initial_zeroing_ongoing = false; 646 } 647 648 /* First part, loop on the sectors and initialize the dirty bitmap. */ 649 for (sector_num = 0; sector_num < end; ) { 650 /* Just to make sure we are not exceeding int limit. */ 651 int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, 652 end - sector_num); 653 654 mirror_throttle(s); 655 656 if (block_job_is_cancelled(&s->common)) { 657 return 0; 658 } 659 660 ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n); 661 if (ret < 0) { 662 return ret; 663 } 664 665 assert(n > 0); 666 if (ret == 1) { 667 bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); 668 } 669 sector_num += n; 670 } 671 return 0; 672 } 673 674 /* Called when going out of the streaming phase to flush the bulk of the 675 * data to the medium, or just before completing. 676 */ 677 static int mirror_flush(MirrorBlockJob *s) 678 { 679 int ret = blk_flush(s->target); 680 if (ret < 0) { 681 if (mirror_error_action(s, false, -ret) == BLOCK_ERROR_ACTION_REPORT) { 682 s->ret = ret; 683 } 684 } 685 return ret; 686 } 687 688 static void coroutine_fn mirror_run(void *opaque) 689 { 690 MirrorBlockJob *s = opaque; 691 MirrorExitData *data; 692 BlockDriverState *bs = s->source; 693 BlockDriverState *target_bs = blk_bs(s->target); 694 bool need_drain = true; 695 int64_t length; 696 BlockDriverInfo bdi; 697 char backing_filename[2]; /* we only need 2 characters because we are only 698 checking for a NULL string */ 699 int ret = 0; 700 int target_cluster_size = BDRV_SECTOR_SIZE; 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); 725 if (ret < 0) { 726 goto immediate_exit; 727 } 728 } 729 } 730 731 if (s->bdev_length == 0) { 732 /* Report BLOCK_JOB_READY and wait for complete. */ 733 block_job_event_ready(&s->common); 734 s->synced = true; 735 while (!block_job_is_cancelled(&s->common) && !s->should_complete) { 736 block_job_yield(&s->common); 737 } 738 s->common.cancelled = false; 739 goto immediate_exit; 740 } 741 742 length = DIV_ROUND_UP(s->bdev_length, s->granularity); 743 s->in_flight_bitmap = bitmap_new(length); 744 745 /* If we have no backing file yet in the destination, we cannot let 746 * the destination do COW. Instead, we copy sectors around the 747 * dirty data if needed. We need a bitmap to do that. 748 */ 749 bdrv_get_backing_filename(target_bs, backing_filename, 750 sizeof(backing_filename)); 751 if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) { 752 target_cluster_size = bdi.cluster_size; 753 } 754 if (backing_filename[0] && !target_bs->backing 755 && s->granularity < target_cluster_size) { 756 s->buf_size = MAX(s->buf_size, target_cluster_size); 757 s->cow_bitmap = bitmap_new(length); 758 } 759 s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS; 760 s->max_iov = MIN(bs->bl.max_iov, target_bs->bl.max_iov); 761 762 s->buf = qemu_try_blockalign(bs, s->buf_size); 763 if (s->buf == NULL) { 764 ret = -ENOMEM; 765 goto immediate_exit; 766 } 767 768 mirror_free_init(s); 769 770 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 771 if (!s->is_none_mode) { 772 ret = mirror_dirty_init(s); 773 if (ret < 0 || block_job_is_cancelled(&s->common)) { 774 goto immediate_exit; 775 } 776 } 777 778 assert(!s->dbi); 779 s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap, 0); 780 for (;;) { 781 uint64_t delay_ns = 0; 782 int64_t cnt, delta; 783 bool should_complete; 784 785 if (s->ret < 0) { 786 ret = s->ret; 787 goto immediate_exit; 788 } 789 790 block_job_pause_point(&s->common); 791 792 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 793 /* s->common.offset contains the number of bytes already processed so 794 * far, cnt is the number of dirty sectors remaining and 795 * s->sectors_in_flight is the number of sectors currently being 796 * processed; together those are the current total operation length */ 797 s->common.len = s->common.offset + 798 (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE; 799 800 /* Note that even when no rate limit is applied we need to yield 801 * periodically with no pending I/O so that bdrv_drain_all() returns. 802 * We do so every SLICE_TIME nanoseconds, or when there is an error, 803 * or when the source is clean, whichever comes first. 804 */ 805 delta = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->last_pause_ns; 806 if (delta < SLICE_TIME && 807 s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 808 if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || 809 (cnt == 0 && s->in_flight > 0)) { 810 trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt); 811 mirror_wait_for_io(s); 812 continue; 813 } else if (cnt != 0) { 814 delay_ns = mirror_iteration(s); 815 } 816 } 817 818 should_complete = false; 819 if (s->in_flight == 0 && cnt == 0) { 820 trace_mirror_before_flush(s); 821 if (!s->synced) { 822 if (mirror_flush(s) < 0) { 823 /* Go check s->ret. */ 824 continue; 825 } 826 /* We're out of the streaming phase. From now on, if the job 827 * is cancelled we will actually complete all pending I/O and 828 * report completion. This way, block-job-cancel will leave 829 * the target in a consistent state. 830 */ 831 block_job_event_ready(&s->common); 832 s->synced = true; 833 } 834 835 should_complete = s->should_complete || 836 block_job_is_cancelled(&s->common); 837 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 838 } 839 840 if (cnt == 0 && should_complete) { 841 /* The dirty bitmap is not updated while operations are pending. 842 * If we're about to exit, wait for pending operations before 843 * calling bdrv_get_dirty_count(bs), or we may exit while the 844 * source has dirty data to copy! 845 * 846 * Note that I/O can be submitted by the guest while 847 * mirror_populate runs, so pause it now. Before deciding 848 * whether to switch to target check one last time if I/O has 849 * come in the meanwhile, and if not flush the data to disk. 850 */ 851 trace_mirror_before_drain(s, cnt); 852 853 bdrv_drained_begin(bs); 854 cnt = bdrv_get_dirty_count(s->dirty_bitmap); 855 if (cnt > 0 || mirror_flush(s) < 0) { 856 bdrv_drained_end(bs); 857 continue; 858 } 859 860 /* The two disks are in sync. Exit and report successful 861 * completion. 862 */ 863 assert(QLIST_EMPTY(&bs->tracked_requests)); 864 s->common.cancelled = false; 865 need_drain = false; 866 break; 867 } 868 869 ret = 0; 870 trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); 871 if (!s->synced) { 872 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 873 if (block_job_is_cancelled(&s->common)) { 874 break; 875 } 876 } else if (!should_complete) { 877 delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0); 878 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 879 } 880 s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); 881 } 882 883 immediate_exit: 884 if (s->in_flight > 0) { 885 /* We get here only if something went wrong. Either the job failed, 886 * or it was cancelled prematurely so that we do not guarantee that 887 * the target is a copy of the source. 888 */ 889 assert(ret < 0 || (!s->synced && block_job_is_cancelled(&s->common))); 890 assert(need_drain); 891 mirror_wait_for_all_io(s); 892 } 893 894 assert(s->in_flight == 0); 895 qemu_vfree(s->buf); 896 g_free(s->cow_bitmap); 897 g_free(s->in_flight_bitmap); 898 bdrv_dirty_iter_free(s->dbi); 899 bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); 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 / BDRV_SECTOR_SIZE, 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 return bdrv_co_flush(bs->backing->bs); 1039 } 1040 1041 static int64_t coroutine_fn bdrv_mirror_top_get_block_status( 1042 BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum, 1043 BlockDriverState **file) 1044 { 1045 *pnum = nb_sectors; 1046 *file = bs->backing->bs; 1047 return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | 1048 (sector_num << BDRV_SECTOR_BITS); 1049 } 1050 1051 static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, 1052 int64_t offset, int count, BdrvRequestFlags flags) 1053 { 1054 return bdrv_co_pwrite_zeroes(bs->backing, offset, count, flags); 1055 } 1056 1057 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, 1058 int64_t offset, int count) 1059 { 1060 return bdrv_co_pdiscard(bs->backing->bs, offset, count); 1061 } 1062 1063 static void bdrv_mirror_top_close(BlockDriverState *bs) 1064 { 1065 } 1066 1067 static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c, 1068 const BdrvChildRole *role, 1069 uint64_t perm, uint64_t shared, 1070 uint64_t *nperm, uint64_t *nshared) 1071 { 1072 /* Must be able to forward guest writes to the real image */ 1073 *nperm = 0; 1074 if (perm & BLK_PERM_WRITE) { 1075 *nperm |= BLK_PERM_WRITE; 1076 } 1077 1078 *nshared = BLK_PERM_ALL; 1079 } 1080 1081 /* Dummy node that provides consistent read to its users without requiring it 1082 * from its backing file and that allows writes on the backing file chain. */ 1083 static BlockDriver bdrv_mirror_top = { 1084 .format_name = "mirror_top", 1085 .bdrv_co_preadv = bdrv_mirror_top_preadv, 1086 .bdrv_co_pwritev = bdrv_mirror_top_pwritev, 1087 .bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes, 1088 .bdrv_co_pdiscard = bdrv_mirror_top_pdiscard, 1089 .bdrv_co_flush = bdrv_mirror_top_flush, 1090 .bdrv_co_get_block_status = bdrv_mirror_top_get_block_status, 1091 .bdrv_close = bdrv_mirror_top_close, 1092 .bdrv_child_perm = bdrv_mirror_top_child_perm, 1093 }; 1094 1095 static void mirror_start_job(const char *job_id, BlockDriverState *bs, 1096 int creation_flags, BlockDriverState *target, 1097 const char *replaces, int64_t speed, 1098 uint32_t granularity, int64_t buf_size, 1099 BlockMirrorBackingMode backing_mode, 1100 BlockdevOnError on_source_error, 1101 BlockdevOnError on_target_error, 1102 bool unmap, 1103 BlockCompletionFunc *cb, 1104 void *opaque, Error **errp, 1105 const BlockJobDriver *driver, 1106 bool is_none_mode, BlockDriverState *base, 1107 bool auto_complete, const char *filter_node_name) 1108 { 1109 MirrorBlockJob *s; 1110 BlockDriverState *mirror_top_bs; 1111 bool target_graph_mod; 1112 bool target_is_backing; 1113 Error *local_err = NULL; 1114 int ret; 1115 1116 if (granularity == 0) { 1117 granularity = bdrv_get_default_bitmap_granularity(target); 1118 } 1119 1120 assert ((granularity & (granularity - 1)) == 0); 1121 1122 if (buf_size < 0) { 1123 error_setg(errp, "Invalid parameter 'buf-size'"); 1124 return; 1125 } 1126 1127 if (buf_size == 0) { 1128 buf_size = DEFAULT_MIRROR_BUF_SIZE; 1129 } 1130 1131 /* In the case of active commit, add dummy driver to provide consistent 1132 * reads on the top, while disabling it in the intermediate nodes, and make 1133 * the backing chain writable. */ 1134 mirror_top_bs = bdrv_new_open_driver(&bdrv_mirror_top, filter_node_name, 1135 BDRV_O_RDWR, errp); 1136 if (mirror_top_bs == NULL) { 1137 return; 1138 } 1139 mirror_top_bs->total_sectors = bs->total_sectors; 1140 1141 /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep 1142 * it alive until block_job_create() even if bs has no parent. */ 1143 bdrv_ref(mirror_top_bs); 1144 bdrv_drained_begin(bs); 1145 bdrv_append(mirror_top_bs, bs, &local_err); 1146 bdrv_drained_end(bs); 1147 1148 if (local_err) { 1149 bdrv_unref(mirror_top_bs); 1150 error_propagate(errp, local_err); 1151 return; 1152 } 1153 1154 /* Make sure that the source is not resized while the job is running */ 1155 s = block_job_create(job_id, driver, mirror_top_bs, 1156 BLK_PERM_CONSISTENT_READ, 1157 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED | 1158 BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD, speed, 1159 creation_flags, cb, opaque, errp); 1160 bdrv_unref(mirror_top_bs); 1161 if (!s) { 1162 goto fail; 1163 } 1164 s->source = bs; 1165 s->mirror_top_bs = mirror_top_bs; 1166 1167 /* No resize for the target either; while the mirror is still running, a 1168 * consistent read isn't necessarily possible. We could possibly allow 1169 * writes and graph modifications, though it would likely defeat the 1170 * purpose of a mirror, so leave them blocked for now. 1171 * 1172 * In the case of active commit, things look a bit different, though, 1173 * because the target is an already populated backing file in active use. 1174 * We can allow anything except resize there.*/ 1175 target_is_backing = bdrv_chain_contains(bs, target); 1176 target_graph_mod = (backing_mode != MIRROR_LEAVE_BACKING_CHAIN); 1177 s->target = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE | 1178 (target_graph_mod ? BLK_PERM_GRAPH_MOD : 0), 1179 BLK_PERM_WRITE_UNCHANGED | 1180 (target_is_backing ? BLK_PERM_CONSISTENT_READ | 1181 BLK_PERM_WRITE | 1182 BLK_PERM_GRAPH_MOD : 0)); 1183 ret = blk_insert_bs(s->target, target, errp); 1184 if (ret < 0) { 1185 goto fail; 1186 } 1187 1188 s->replaces = g_strdup(replaces); 1189 s->on_source_error = on_source_error; 1190 s->on_target_error = on_target_error; 1191 s->is_none_mode = is_none_mode; 1192 s->backing_mode = backing_mode; 1193 s->base = base; 1194 s->granularity = granularity; 1195 s->buf_size = ROUND_UP(buf_size, granularity); 1196 s->unmap = unmap; 1197 if (auto_complete) { 1198 s->should_complete = true; 1199 } 1200 1201 s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); 1202 if (!s->dirty_bitmap) { 1203 goto fail; 1204 } 1205 1206 /* Required permissions are already taken with blk_new() */ 1207 block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL, 1208 &error_abort); 1209 1210 /* In commit_active_start() all intermediate nodes disappear, so 1211 * any jobs in them must be blocked */ 1212 if (target_is_backing) { 1213 BlockDriverState *iter; 1214 for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) { 1215 /* XXX BLK_PERM_WRITE needs to be allowed so we don't block 1216 * ourselves at s->base (if writes are blocked for a node, they are 1217 * also blocked for its backing file). The other options would be a 1218 * second filter driver above s->base (== target). */ 1219 ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, 1220 BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, 1221 errp); 1222 if (ret < 0) { 1223 goto fail; 1224 } 1225 } 1226 } 1227 1228 trace_mirror_start(bs, s, opaque); 1229 block_job_start(&s->common); 1230 return; 1231 1232 fail: 1233 if (s) { 1234 g_free(s->replaces); 1235 blk_unref(s->target); 1236 block_job_unref(&s->common); 1237 } 1238 1239 bdrv_child_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL); 1240 bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort); 1241 } 1242 1243 void mirror_start(const char *job_id, BlockDriverState *bs, 1244 BlockDriverState *target, const char *replaces, 1245 int64_t speed, uint32_t granularity, int64_t buf_size, 1246 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, 1247 BlockdevOnError on_source_error, 1248 BlockdevOnError on_target_error, 1249 bool unmap, const char *filter_node_name, Error **errp) 1250 { 1251 bool is_none_mode; 1252 BlockDriverState *base; 1253 1254 if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { 1255 error_setg(errp, "Sync mode 'incremental' not supported"); 1256 return; 1257 } 1258 is_none_mode = mode == MIRROR_SYNC_MODE_NONE; 1259 base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; 1260 mirror_start_job(job_id, bs, BLOCK_JOB_DEFAULT, target, replaces, 1261 speed, granularity, buf_size, backing_mode, 1262 on_source_error, on_target_error, unmap, NULL, NULL, errp, 1263 &mirror_job_driver, is_none_mode, base, false, 1264 filter_node_name); 1265 } 1266 1267 void commit_active_start(const char *job_id, BlockDriverState *bs, 1268 BlockDriverState *base, int creation_flags, 1269 int64_t speed, BlockdevOnError on_error, 1270 const char *filter_node_name, 1271 BlockCompletionFunc *cb, void *opaque, Error **errp, 1272 bool auto_complete) 1273 { 1274 int orig_base_flags; 1275 Error *local_err = NULL; 1276 1277 orig_base_flags = bdrv_get_flags(base); 1278 1279 if (bdrv_reopen(base, bs->open_flags, errp)) { 1280 return; 1281 } 1282 1283 mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0, 1284 MIRROR_LEAVE_BACKING_CHAIN, 1285 on_error, on_error, true, cb, opaque, &local_err, 1286 &commit_active_job_driver, false, base, auto_complete, 1287 filter_node_name); 1288 if (local_err) { 1289 error_propagate(errp, local_err); 1290 goto error_restore_flags; 1291 } 1292 1293 return; 1294 1295 error_restore_flags: 1296 /* ignore error and errp for bdrv_reopen, because we want to propagate 1297 * the original error */ 1298 bdrv_reopen(base, orig_base_flags, NULL); 1299 return; 1300 } 1301