4 * Copyright Red Hat, Inc. 2012
7 * Paolo Bonzini <pbonzini@redhat.com>
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.
14 #include "qemu/osdep.h"
16 #include "block/blockjob.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"
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)
30 /* The mirroring buffer is a list of granularity-sized chunks.
31 * Free chunks are organized in a list.
33 typedef struct MirrorBuffer
{
34 QSIMPLEQ_ENTRY(MirrorBuffer
) next
;
37 typedef struct MirrorBlockJob
{
41 BlockDriverState
*base
;
42 /* The name of the graph node to replace */
44 /* The BDS to replace */
45 BlockDriverState
*to_replace
;
46 /* Used to block operations on the drive-mirror-replace target */
47 Error
*replace_blocker
;
49 BlockMirrorBackingMode backing_mode
;
50 BlockdevOnError on_source_error
, on_target_error
;
56 unsigned long *cow_bitmap
;
57 BdrvDirtyBitmap
*dirty_bitmap
;
60 QSIMPLEQ_HEAD(, MirrorBuffer
) buf_free
;
63 uint64_t last_pause_ns
;
64 unsigned long *in_flight_bitmap
;
66 int64_t sectors_in_flight
;
70 int target_cluster_sectors
;
74 typedef struct MirrorOp
{
81 static BlockErrorAction
mirror_error_action(MirrorBlockJob
*s
, bool read
,
86 return block_job_error_action(&s
->common
, s
->on_source_error
,
89 return block_job_error_action(&s
->common
, s
->on_target_error
,
94 static void mirror_iteration_done(MirrorOp
*op
, int ret
)
96 MirrorBlockJob
*s
= op
->s
;
99 int i
, nb_chunks
, sectors_per_chunk
;
101 trace_mirror_iteration_done(s
, op
->sector_num
, op
->nb_sectors
, ret
);
104 s
->sectors_in_flight
-= op
->nb_sectors
;
106 for (i
= 0; i
< op
->qiov
.niov
; i
++) {
107 MirrorBuffer
*buf
= (MirrorBuffer
*) iov
[i
].iov_base
;
108 QSIMPLEQ_INSERT_TAIL(&s
->buf_free
, buf
, next
);
112 sectors_per_chunk
= s
->granularity
>> BDRV_SECTOR_BITS
;
113 chunk_num
= op
->sector_num
/ sectors_per_chunk
;
114 nb_chunks
= DIV_ROUND_UP(op
->nb_sectors
, sectors_per_chunk
);
115 bitmap_clear(s
->in_flight_bitmap
, chunk_num
, nb_chunks
);
118 bitmap_set(s
->cow_bitmap
, chunk_num
, nb_chunks
);
120 s
->common
.offset
+= (uint64_t)op
->nb_sectors
* BDRV_SECTOR_SIZE
;
123 qemu_iovec_destroy(&op
->qiov
);
126 if (s
->waiting_for_io
) {
127 qemu_coroutine_enter(s
->common
.co
);
131 static void mirror_write_complete(void *opaque
, int ret
)
133 MirrorOp
*op
= opaque
;
134 MirrorBlockJob
*s
= op
->s
;
136 BlockErrorAction action
;
138 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, op
->sector_num
, op
->nb_sectors
);
139 action
= mirror_error_action(s
, false, -ret
);
140 if (action
== BLOCK_ERROR_ACTION_REPORT
&& s
->ret
>= 0) {
144 mirror_iteration_done(op
, ret
);
147 static void mirror_read_complete(void *opaque
, int ret
)
149 MirrorOp
*op
= opaque
;
150 MirrorBlockJob
*s
= op
->s
;
152 BlockErrorAction action
;
154 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, op
->sector_num
, op
->nb_sectors
);
155 action
= mirror_error_action(s
, true, -ret
);
156 if (action
== BLOCK_ERROR_ACTION_REPORT
&& s
->ret
>= 0) {
160 mirror_iteration_done(op
, ret
);
163 blk_aio_pwritev(s
->target
, op
->sector_num
* BDRV_SECTOR_SIZE
, &op
->qiov
,
164 0, mirror_write_complete
, op
);
167 static inline void mirror_clip_sectors(MirrorBlockJob
*s
,
171 *nb_sectors
= MIN(*nb_sectors
,
172 s
->bdev_length
/ BDRV_SECTOR_SIZE
- sector_num
);
175 /* Round sector_num and/or nb_sectors to target cluster if COW is needed, and
176 * return the offset of the adjusted tail sector against original. */
177 static int mirror_cow_align(MirrorBlockJob
*s
,
183 int chunk_sectors
= s
->granularity
>> BDRV_SECTOR_BITS
;
184 int64_t align_sector_num
= *sector_num
;
185 int align_nb_sectors
= *nb_sectors
;
186 int max_sectors
= chunk_sectors
* s
->max_iov
;
188 need_cow
= !test_bit(*sector_num
/ chunk_sectors
, s
->cow_bitmap
);
189 need_cow
|= !test_bit((*sector_num
+ *nb_sectors
- 1) / chunk_sectors
,
192 bdrv_round_sectors_to_clusters(blk_bs(s
->target
), *sector_num
,
193 *nb_sectors
, &align_sector_num
,
197 if (align_nb_sectors
> max_sectors
) {
198 align_nb_sectors
= max_sectors
;
200 align_nb_sectors
= QEMU_ALIGN_DOWN(align_nb_sectors
,
201 s
->target_cluster_sectors
);
204 /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but
205 * that doesn't matter because it's already the end of source image. */
206 mirror_clip_sectors(s
, align_sector_num
, &align_nb_sectors
);
208 ret
= align_sector_num
+ align_nb_sectors
- (*sector_num
+ *nb_sectors
);
209 *sector_num
= align_sector_num
;
210 *nb_sectors
= align_nb_sectors
;
215 static inline void mirror_wait_for_io(MirrorBlockJob
*s
)
217 assert(!s
->waiting_for_io
);
218 s
->waiting_for_io
= true;
219 qemu_coroutine_yield();
220 s
->waiting_for_io
= false;
223 /* Submit async read while handling COW.
224 * Returns: The number of sectors copied after and including sector_num,
225 * excluding any sectors copied prior to sector_num due to alignment.
226 * This will be nb_sectors if no alignment is necessary, or
227 * (new_end - sector_num) if tail is rounded up or down due to
228 * alignment or buffer limit.
230 static int mirror_do_read(MirrorBlockJob
*s
, int64_t sector_num
,
233 BlockBackend
*source
= s
->common
.blk
;
234 int sectors_per_chunk
, nb_chunks
;
239 sectors_per_chunk
= s
->granularity
>> BDRV_SECTOR_BITS
;
240 max_sectors
= sectors_per_chunk
* s
->max_iov
;
242 /* We can only handle as much as buf_size at a time. */
243 nb_sectors
= MIN(s
->buf_size
>> BDRV_SECTOR_BITS
, nb_sectors
);
244 nb_sectors
= MIN(max_sectors
, nb_sectors
);
249 ret
+= mirror_cow_align(s
, §or_num
, &nb_sectors
);
251 assert(nb_sectors
<< BDRV_SECTOR_BITS
<= s
->buf_size
);
252 /* The sector range must meet granularity because:
253 * 1) Caller passes in aligned values;
254 * 2) mirror_cow_align is used only when target cluster is larger. */
255 assert(!(sector_num
% sectors_per_chunk
));
256 nb_chunks
= DIV_ROUND_UP(nb_sectors
, sectors_per_chunk
);
258 while (s
->buf_free_count
< nb_chunks
) {
259 trace_mirror_yield_in_flight(s
, sector_num
, s
->in_flight
);
260 mirror_wait_for_io(s
);
263 /* Allocate a MirrorOp that is used as an AIO callback. */
264 op
= g_new(MirrorOp
, 1);
266 op
->sector_num
= sector_num
;
267 op
->nb_sectors
= nb_sectors
;
269 /* Now make a QEMUIOVector taking enough granularity-sized chunks
272 qemu_iovec_init(&op
->qiov
, nb_chunks
);
273 while (nb_chunks
-- > 0) {
274 MirrorBuffer
*buf
= QSIMPLEQ_FIRST(&s
->buf_free
);
275 size_t remaining
= nb_sectors
* BDRV_SECTOR_SIZE
- op
->qiov
.size
;
277 QSIMPLEQ_REMOVE_HEAD(&s
->buf_free
, next
);
279 qemu_iovec_add(&op
->qiov
, buf
, MIN(s
->granularity
, remaining
));
282 /* Copy the dirty cluster. */
284 s
->sectors_in_flight
+= nb_sectors
;
285 trace_mirror_one_iteration(s
, sector_num
, nb_sectors
);
287 blk_aio_preadv(source
, sector_num
* BDRV_SECTOR_SIZE
, &op
->qiov
, 0,
288 mirror_read_complete
, op
);
292 static void mirror_do_zero_or_discard(MirrorBlockJob
*s
,
299 /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed
300 * so the freeing in mirror_iteration_done is nop. */
301 op
= g_new0(MirrorOp
, 1);
303 op
->sector_num
= sector_num
;
304 op
->nb_sectors
= nb_sectors
;
307 s
->sectors_in_flight
+= nb_sectors
;
309 blk_aio_pdiscard(s
->target
, sector_num
<< BDRV_SECTOR_BITS
,
310 op
->nb_sectors
<< BDRV_SECTOR_BITS
,
311 mirror_write_complete
, op
);
313 blk_aio_pwrite_zeroes(s
->target
, sector_num
* BDRV_SECTOR_SIZE
,
314 op
->nb_sectors
* BDRV_SECTOR_SIZE
,
315 s
->unmap
? BDRV_REQ_MAY_UNMAP
: 0,
316 mirror_write_complete
, op
);
320 static uint64_t coroutine_fn
mirror_iteration(MirrorBlockJob
*s
)
322 BlockDriverState
*source
= blk_bs(s
->common
.blk
);
323 int64_t sector_num
, first_chunk
;
324 uint64_t delay_ns
= 0;
325 /* At least the first dirty chunk is mirrored in one iteration. */
327 int64_t end
= s
->bdev_length
/ BDRV_SECTOR_SIZE
;
328 int sectors_per_chunk
= s
->granularity
>> BDRV_SECTOR_BITS
;
329 bool write_zeroes_ok
= bdrv_can_write_zeroes_with_unmap(blk_bs(s
->target
));
330 int max_io_sectors
= MAX((s
->buf_size
>> BDRV_SECTOR_BITS
) / MAX_IN_FLIGHT
,
333 sector_num
= hbitmap_iter_next(&s
->hbi
);
334 if (sector_num
< 0) {
335 bdrv_dirty_iter_init(s
->dirty_bitmap
, &s
->hbi
);
336 sector_num
= hbitmap_iter_next(&s
->hbi
);
337 trace_mirror_restart_iter(s
, bdrv_get_dirty_count(s
->dirty_bitmap
));
338 assert(sector_num
>= 0);
341 first_chunk
= sector_num
/ sectors_per_chunk
;
342 while (test_bit(first_chunk
, s
->in_flight_bitmap
)) {
343 trace_mirror_yield_in_flight(s
, sector_num
, s
->in_flight
);
344 mirror_wait_for_io(s
);
347 block_job_pause_point(&s
->common
);
349 /* Find the number of consective dirty chunks following the first dirty
350 * one, and wait for in flight requests in them. */
351 while (nb_chunks
* sectors_per_chunk
< (s
->buf_size
>> BDRV_SECTOR_BITS
)) {
352 int64_t hbitmap_next
;
353 int64_t next_sector
= sector_num
+ nb_chunks
* sectors_per_chunk
;
354 int64_t next_chunk
= next_sector
/ sectors_per_chunk
;
355 if (next_sector
>= end
||
356 !bdrv_get_dirty(source
, s
->dirty_bitmap
, next_sector
)) {
359 if (test_bit(next_chunk
, s
->in_flight_bitmap
)) {
363 hbitmap_next
= hbitmap_iter_next(&s
->hbi
);
364 if (hbitmap_next
> next_sector
|| hbitmap_next
< 0) {
365 /* The bitmap iterator's cache is stale, refresh it */
366 bdrv_set_dirty_iter(&s
->hbi
, next_sector
);
367 hbitmap_next
= hbitmap_iter_next(&s
->hbi
);
369 assert(hbitmap_next
== next_sector
);
373 /* Clear dirty bits before querying the block status, because
374 * calling bdrv_get_block_status_above could yield - if some blocks are
375 * marked dirty in this window, we need to know.
377 bdrv_reset_dirty_bitmap(s
->dirty_bitmap
, sector_num
,
378 nb_chunks
* sectors_per_chunk
);
379 bitmap_set(s
->in_flight_bitmap
, sector_num
/ sectors_per_chunk
, nb_chunks
);
380 while (nb_chunks
> 0 && sector_num
< end
) {
382 int io_sectors
, io_sectors_acct
;
383 BlockDriverState
*file
;
387 MIRROR_METHOD_DISCARD
388 } mirror_method
= MIRROR_METHOD_COPY
;
390 assert(!(sector_num
% sectors_per_chunk
));
391 ret
= bdrv_get_block_status_above(source
, NULL
, sector_num
,
392 nb_chunks
* sectors_per_chunk
,
395 io_sectors
= MIN(nb_chunks
* sectors_per_chunk
, max_io_sectors
);
396 } else if (ret
& BDRV_BLOCK_DATA
) {
397 io_sectors
= MIN(io_sectors
, max_io_sectors
);
400 io_sectors
-= io_sectors
% sectors_per_chunk
;
401 if (io_sectors
< sectors_per_chunk
) {
402 io_sectors
= sectors_per_chunk
;
403 } else if (ret
>= 0 && !(ret
& BDRV_BLOCK_DATA
)) {
404 int64_t target_sector_num
;
405 int target_nb_sectors
;
406 bdrv_round_sectors_to_clusters(blk_bs(s
->target
), sector_num
,
407 io_sectors
, &target_sector_num
,
409 if (target_sector_num
== sector_num
&&
410 target_nb_sectors
== io_sectors
) {
411 mirror_method
= ret
& BDRV_BLOCK_ZERO
?
413 MIRROR_METHOD_DISCARD
;
417 while (s
->in_flight
>= MAX_IN_FLIGHT
) {
418 trace_mirror_yield_in_flight(s
, sector_num
, s
->in_flight
);
419 mirror_wait_for_io(s
);
422 mirror_clip_sectors(s
, sector_num
, &io_sectors
);
423 switch (mirror_method
) {
424 case MIRROR_METHOD_COPY
:
425 io_sectors
= mirror_do_read(s
, sector_num
, io_sectors
);
426 io_sectors_acct
= io_sectors
;
428 case MIRROR_METHOD_ZERO
:
429 case MIRROR_METHOD_DISCARD
:
430 mirror_do_zero_or_discard(s
, sector_num
, io_sectors
,
431 mirror_method
== MIRROR_METHOD_DISCARD
);
432 if (write_zeroes_ok
) {
435 io_sectors_acct
= io_sectors
;
442 sector_num
+= io_sectors
;
443 nb_chunks
-= DIV_ROUND_UP(io_sectors
, sectors_per_chunk
);
444 if (s
->common
.speed
) {
445 delay_ns
= ratelimit_calculate_delay(&s
->limit
, io_sectors_acct
);
451 static void mirror_free_init(MirrorBlockJob
*s
)
453 int granularity
= s
->granularity
;
454 size_t buf_size
= s
->buf_size
;
455 uint8_t *buf
= s
->buf
;
457 assert(s
->buf_free_count
== 0);
458 QSIMPLEQ_INIT(&s
->buf_free
);
459 while (buf_size
!= 0) {
460 MirrorBuffer
*cur
= (MirrorBuffer
*)buf
;
461 QSIMPLEQ_INSERT_TAIL(&s
->buf_free
, cur
, next
);
463 buf_size
-= granularity
;
468 static void mirror_drain(MirrorBlockJob
*s
)
470 while (s
->in_flight
> 0) {
471 mirror_wait_for_io(s
);
479 static void mirror_exit(BlockJob
*job
, void *opaque
)
481 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
482 MirrorExitData
*data
= opaque
;
483 AioContext
*replace_aio_context
= NULL
;
484 BlockDriverState
*src
= blk_bs(s
->common
.blk
);
485 BlockDriverState
*target_bs
= blk_bs(s
->target
);
487 /* Make sure that the source BDS doesn't go away before we called
488 * block_job_completed(). */
492 replace_aio_context
= bdrv_get_aio_context(s
->to_replace
);
493 aio_context_acquire(replace_aio_context
);
496 if (s
->should_complete
&& data
->ret
== 0) {
497 BlockDriverState
*to_replace
= src
;
499 to_replace
= s
->to_replace
;
502 if (bdrv_get_flags(target_bs
) != bdrv_get_flags(to_replace
)) {
503 bdrv_reopen(target_bs
, bdrv_get_flags(to_replace
), NULL
);
506 /* The mirror job has no requests in flight any more, but we need to
507 * drain potential other users of the BDS before changing the graph. */
508 bdrv_drained_begin(target_bs
);
509 bdrv_replace_in_backing_chain(to_replace
, target_bs
);
510 bdrv_drained_end(target_bs
);
512 /* We just changed the BDS the job BB refers to */
513 blk_remove_bs(job
->blk
);
514 blk_insert_bs(job
->blk
, src
);
517 bdrv_op_unblock_all(s
->to_replace
, s
->replace_blocker
);
518 error_free(s
->replace_blocker
);
519 bdrv_unref(s
->to_replace
);
521 if (replace_aio_context
) {
522 aio_context_release(replace_aio_context
);
525 bdrv_op_unblock_all(target_bs
, s
->common
.blocker
);
526 blk_unref(s
->target
);
527 block_job_completed(&s
->common
, data
->ret
);
529 bdrv_drained_end(src
);
533 static void mirror_throttle(MirrorBlockJob
*s
)
535 int64_t now
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
537 if (now
- s
->last_pause_ns
> SLICE_TIME
) {
538 s
->last_pause_ns
= now
;
539 block_job_sleep_ns(&s
->common
, QEMU_CLOCK_REALTIME
, 0);
541 block_job_pause_point(&s
->common
);
545 static int coroutine_fn
mirror_dirty_init(MirrorBlockJob
*s
)
547 int64_t sector_num
, end
;
548 BlockDriverState
*base
= s
->base
;
549 BlockDriverState
*bs
= blk_bs(s
->common
.blk
);
550 BlockDriverState
*target_bs
= blk_bs(s
->target
);
553 end
= s
->bdev_length
/ BDRV_SECTOR_SIZE
;
555 if (base
== NULL
&& !bdrv_has_zero_init(target_bs
)) {
556 if (!bdrv_can_write_zeroes_with_unmap(target_bs
)) {
557 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, 0, end
);
561 for (sector_num
= 0; sector_num
< end
; ) {
562 int nb_sectors
= MIN(end
- sector_num
,
563 QEMU_ALIGN_DOWN(INT_MAX
, s
->granularity
) >> BDRV_SECTOR_BITS
);
567 if (block_job_is_cancelled(&s
->common
)) {
571 if (s
->in_flight
>= MAX_IN_FLIGHT
) {
572 trace_mirror_yield(s
, s
->in_flight
, s
->buf_free_count
, -1);
573 mirror_wait_for_io(s
);
577 mirror_do_zero_or_discard(s
, sector_num
, nb_sectors
, false);
578 sector_num
+= nb_sectors
;
584 /* First part, loop on the sectors and initialize the dirty bitmap. */
585 for (sector_num
= 0; sector_num
< end
; ) {
586 /* Just to make sure we are not exceeding int limit. */
587 int nb_sectors
= MIN(INT_MAX
>> BDRV_SECTOR_BITS
,
592 if (block_job_is_cancelled(&s
->common
)) {
596 ret
= bdrv_is_allocated_above(bs
, base
, sector_num
, nb_sectors
, &n
);
603 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, sector_num
, n
);
610 static void coroutine_fn
mirror_run(void *opaque
)
612 MirrorBlockJob
*s
= opaque
;
613 MirrorExitData
*data
;
614 BlockDriverState
*bs
= blk_bs(s
->common
.blk
);
615 BlockDriverState
*target_bs
= blk_bs(s
->target
);
618 char backing_filename
[2]; /* we only need 2 characters because we are only
619 checking for a NULL string */
621 int target_cluster_size
= BDRV_SECTOR_SIZE
;
623 if (block_job_is_cancelled(&s
->common
)) {
627 s
->bdev_length
= bdrv_getlength(bs
);
628 if (s
->bdev_length
< 0) {
629 ret
= s
->bdev_length
;
631 } else if (s
->bdev_length
== 0) {
632 /* Report BLOCK_JOB_READY and wait for complete. */
633 block_job_event_ready(&s
->common
);
635 while (!block_job_is_cancelled(&s
->common
) && !s
->should_complete
) {
636 block_job_yield(&s
->common
);
638 s
->common
.cancelled
= false;
642 length
= DIV_ROUND_UP(s
->bdev_length
, s
->granularity
);
643 s
->in_flight_bitmap
= bitmap_new(length
);
645 /* If we have no backing file yet in the destination, we cannot let
646 * the destination do COW. Instead, we copy sectors around the
647 * dirty data if needed. We need a bitmap to do that.
649 bdrv_get_backing_filename(target_bs
, backing_filename
,
650 sizeof(backing_filename
));
651 if (!bdrv_get_info(target_bs
, &bdi
) && bdi
.cluster_size
) {
652 target_cluster_size
= bdi
.cluster_size
;
654 if (backing_filename
[0] && !target_bs
->backing
655 && s
->granularity
< target_cluster_size
) {
656 s
->buf_size
= MAX(s
->buf_size
, target_cluster_size
);
657 s
->cow_bitmap
= bitmap_new(length
);
659 s
->target_cluster_sectors
= target_cluster_size
>> BDRV_SECTOR_BITS
;
660 s
->max_iov
= MIN(bs
->bl
.max_iov
, target_bs
->bl
.max_iov
);
662 s
->buf
= qemu_try_blockalign(bs
, s
->buf_size
);
663 if (s
->buf
== NULL
) {
670 s
->last_pause_ns
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
671 if (!s
->is_none_mode
) {
672 ret
= mirror_dirty_init(s
);
673 if (ret
< 0 || block_job_is_cancelled(&s
->common
)) {
678 bdrv_dirty_iter_init(s
->dirty_bitmap
, &s
->hbi
);
680 uint64_t delay_ns
= 0;
682 bool should_complete
;
689 block_job_pause_point(&s
->common
);
691 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
692 /* s->common.offset contains the number of bytes already processed so
693 * far, cnt is the number of dirty sectors remaining and
694 * s->sectors_in_flight is the number of sectors currently being
695 * processed; together those are the current total operation length */
696 s
->common
.len
= s
->common
.offset
+
697 (cnt
+ s
->sectors_in_flight
) * BDRV_SECTOR_SIZE
;
699 /* Note that even when no rate limit is applied we need to yield
700 * periodically with no pending I/O so that bdrv_drain_all() returns.
701 * We do so every SLICE_TIME nanoseconds, or when there is an error,
702 * or when the source is clean, whichever comes first.
704 delta
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
) - s
->last_pause_ns
;
705 if (delta
< SLICE_TIME
&&
706 s
->common
.iostatus
== BLOCK_DEVICE_IO_STATUS_OK
) {
707 if (s
->in_flight
>= MAX_IN_FLIGHT
|| s
->buf_free_count
== 0 ||
708 (cnt
== 0 && s
->in_flight
> 0)) {
709 trace_mirror_yield(s
, s
->in_flight
, s
->buf_free_count
, cnt
);
710 mirror_wait_for_io(s
);
712 } else if (cnt
!= 0) {
713 delay_ns
= mirror_iteration(s
);
717 should_complete
= false;
718 if (s
->in_flight
== 0 && cnt
== 0) {
719 trace_mirror_before_flush(s
);
720 ret
= blk_flush(s
->target
);
722 if (mirror_error_action(s
, false, -ret
) ==
723 BLOCK_ERROR_ACTION_REPORT
) {
727 /* We're out of the streaming phase. From now on, if the job
728 * is cancelled we will actually complete all pending I/O and
729 * report completion. This way, block-job-cancel will leave
730 * the target in a consistent state.
733 block_job_event_ready(&s
->common
);
737 should_complete
= s
->should_complete
||
738 block_job_is_cancelled(&s
->common
);
739 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
743 if (cnt
== 0 && should_complete
) {
744 /* The dirty bitmap is not updated while operations are pending.
745 * If we're about to exit, wait for pending operations before
746 * calling bdrv_get_dirty_count(bs), or we may exit while the
747 * source has dirty data to copy!
749 * Note that I/O can be submitted by the guest while
750 * mirror_populate runs.
752 trace_mirror_before_drain(s
, cnt
);
754 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
758 trace_mirror_before_sleep(s
, cnt
, s
->synced
, delay_ns
);
760 block_job_sleep_ns(&s
->common
, QEMU_CLOCK_REALTIME
, delay_ns
);
761 if (block_job_is_cancelled(&s
->common
)) {
764 } else if (!should_complete
) {
765 delay_ns
= (s
->in_flight
== 0 && cnt
== 0 ? SLICE_TIME
: 0);
766 block_job_sleep_ns(&s
->common
, QEMU_CLOCK_REALTIME
, delay_ns
);
767 } else if (cnt
== 0) {
768 /* The two disks are in sync. Exit and report successful
771 assert(QLIST_EMPTY(&bs
->tracked_requests
));
772 s
->common
.cancelled
= false;
775 s
->last_pause_ns
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
779 if (s
->in_flight
> 0) {
780 /* We get here only if something went wrong. Either the job failed,
781 * or it was cancelled prematurely so that we do not guarantee that
782 * the target is a copy of the source.
784 assert(ret
< 0 || (!s
->synced
&& block_job_is_cancelled(&s
->common
)));
788 assert(s
->in_flight
== 0);
790 g_free(s
->cow_bitmap
);
791 g_free(s
->in_flight_bitmap
);
792 bdrv_release_dirty_bitmap(bs
, s
->dirty_bitmap
);
794 data
= g_malloc(sizeof(*data
));
796 /* Before we switch to target in mirror_exit, make sure data doesn't
798 bdrv_drained_begin(bs
);
799 block_job_defer_to_main_loop(&s
->common
, mirror_exit
, data
);
802 static void mirror_set_speed(BlockJob
*job
, int64_t speed
, Error
**errp
)
804 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
807 error_setg(errp
, QERR_INVALID_PARAMETER
, "speed");
810 ratelimit_set_speed(&s
->limit
, speed
/ BDRV_SECTOR_SIZE
, SLICE_TIME
);
813 static void mirror_complete(BlockJob
*job
, Error
**errp
)
815 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
816 BlockDriverState
*src
, *target
;
818 src
= blk_bs(job
->blk
);
819 target
= blk_bs(s
->target
);
822 error_setg(errp
, "The active block job '%s' cannot be completed",
827 if (s
->backing_mode
== MIRROR_OPEN_BACKING_CHAIN
) {
830 assert(!target
->backing
);
831 ret
= bdrv_open_backing_file(target
, NULL
, "backing", errp
);
837 /* block all operations on to_replace bs */
839 AioContext
*replace_aio_context
;
841 s
->to_replace
= bdrv_find_node(s
->replaces
);
842 if (!s
->to_replace
) {
843 error_setg(errp
, "Node name '%s' not found", s
->replaces
);
847 replace_aio_context
= bdrv_get_aio_context(s
->to_replace
);
848 aio_context_acquire(replace_aio_context
);
850 error_setg(&s
->replace_blocker
,
851 "block device is in use by block-job-complete");
852 bdrv_op_block_all(s
->to_replace
, s
->replace_blocker
);
853 bdrv_ref(s
->to_replace
);
855 aio_context_release(replace_aio_context
);
858 if (s
->backing_mode
== MIRROR_SOURCE_BACKING_CHAIN
) {
859 BlockDriverState
*backing
= s
->is_none_mode
? src
: s
->base
;
860 if (backing_bs(target
) != backing
) {
861 bdrv_set_backing_hd(target
, backing
);
865 s
->should_complete
= true;
866 block_job_enter(&s
->common
);
869 /* There is no matching mirror_resume() because mirror_run() will begin
870 * iterating again when the job is resumed.
872 static void coroutine_fn
mirror_pause(BlockJob
*job
)
874 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
879 static void mirror_attached_aio_context(BlockJob
*job
, AioContext
*new_context
)
881 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
883 blk_set_aio_context(s
->target
, new_context
);
886 static const BlockJobDriver mirror_job_driver
= {
887 .instance_size
= sizeof(MirrorBlockJob
),
888 .job_type
= BLOCK_JOB_TYPE_MIRROR
,
889 .set_speed
= mirror_set_speed
,
890 .complete
= mirror_complete
,
891 .pause
= mirror_pause
,
892 .attached_aio_context
= mirror_attached_aio_context
,
895 static const BlockJobDriver commit_active_job_driver
= {
896 .instance_size
= sizeof(MirrorBlockJob
),
897 .job_type
= BLOCK_JOB_TYPE_COMMIT
,
898 .set_speed
= mirror_set_speed
,
899 .complete
= mirror_complete
,
900 .pause
= mirror_pause
,
901 .attached_aio_context
= mirror_attached_aio_context
,
904 static void mirror_start_job(const char *job_id
, BlockDriverState
*bs
,
905 BlockDriverState
*target
, const char *replaces
,
906 int64_t speed
, uint32_t granularity
,
908 BlockMirrorBackingMode backing_mode
,
909 BlockdevOnError on_source_error
,
910 BlockdevOnError on_target_error
,
912 BlockCompletionFunc
*cb
,
913 void *opaque
, Error
**errp
,
914 const BlockJobDriver
*driver
,
915 bool is_none_mode
, BlockDriverState
*base
)
919 if (granularity
== 0) {
920 granularity
= bdrv_get_default_bitmap_granularity(target
);
923 assert ((granularity
& (granularity
- 1)) == 0);
926 error_setg(errp
, "Invalid parameter 'buf-size'");
931 buf_size
= DEFAULT_MIRROR_BUF_SIZE
;
934 s
= block_job_create(job_id
, driver
, bs
, speed
, cb
, opaque
, errp
);
939 s
->target
= blk_new();
940 blk_insert_bs(s
->target
, target
);
942 s
->replaces
= g_strdup(replaces
);
943 s
->on_source_error
= on_source_error
;
944 s
->on_target_error
= on_target_error
;
945 s
->is_none_mode
= is_none_mode
;
946 s
->backing_mode
= backing_mode
;
948 s
->granularity
= granularity
;
949 s
->buf_size
= ROUND_UP(buf_size
, granularity
);
952 s
->dirty_bitmap
= bdrv_create_dirty_bitmap(bs
, granularity
, NULL
, errp
);
953 if (!s
->dirty_bitmap
) {
955 blk_unref(s
->target
);
956 block_job_unref(&s
->common
);
960 bdrv_op_block_all(target
, s
->common
.blocker
);
962 s
->common
.co
= qemu_coroutine_create(mirror_run
, s
);
963 trace_mirror_start(bs
, s
, s
->common
.co
, opaque
);
964 qemu_coroutine_enter(s
->common
.co
);
967 void mirror_start(const char *job_id
, BlockDriverState
*bs
,
968 BlockDriverState
*target
, const char *replaces
,
969 int64_t speed
, uint32_t granularity
, int64_t buf_size
,
970 MirrorSyncMode mode
, BlockMirrorBackingMode backing_mode
,
971 BlockdevOnError on_source_error
,
972 BlockdevOnError on_target_error
,
974 BlockCompletionFunc
*cb
,
975 void *opaque
, Error
**errp
)
978 BlockDriverState
*base
;
980 if (mode
== MIRROR_SYNC_MODE_INCREMENTAL
) {
981 error_setg(errp
, "Sync mode 'incremental' not supported");
984 is_none_mode
= mode
== MIRROR_SYNC_MODE_NONE
;
985 base
= mode
== MIRROR_SYNC_MODE_TOP
? backing_bs(bs
) : NULL
;
986 mirror_start_job(job_id
, bs
, target
, replaces
,
987 speed
, granularity
, buf_size
, backing_mode
,
988 on_source_error
, on_target_error
, unmap
, cb
, opaque
, errp
,
989 &mirror_job_driver
, is_none_mode
, base
);
992 void commit_active_start(const char *job_id
, BlockDriverState
*bs
,
993 BlockDriverState
*base
, int64_t speed
,
994 BlockdevOnError on_error
,
995 BlockCompletionFunc
*cb
,
996 void *opaque
, Error
**errp
)
998 int64_t length
, base_length
;
1001 Error
*local_err
= NULL
;
1003 orig_base_flags
= bdrv_get_flags(base
);
1005 if (bdrv_reopen(base
, bs
->open_flags
, errp
)) {
1009 length
= bdrv_getlength(bs
);
1011 error_setg_errno(errp
, -length
,
1012 "Unable to determine length of %s", bs
->filename
);
1013 goto error_restore_flags
;
1016 base_length
= bdrv_getlength(base
);
1017 if (base_length
< 0) {
1018 error_setg_errno(errp
, -base_length
,
1019 "Unable to determine length of %s", base
->filename
);
1020 goto error_restore_flags
;
1023 if (length
> base_length
) {
1024 ret
= bdrv_truncate(base
, length
);
1026 error_setg_errno(errp
, -ret
,
1027 "Top image %s is larger than base image %s, and "
1028 "resize of base image failed",
1029 bs
->filename
, base
->filename
);
1030 goto error_restore_flags
;
1034 mirror_start_job(job_id
, bs
, base
, NULL
, speed
, 0, 0,
1035 MIRROR_LEAVE_BACKING_CHAIN
,
1036 on_error
, on_error
, false, cb
, opaque
, &local_err
,
1037 &commit_active_job_driver
, false, base
);
1039 error_propagate(errp
, local_err
);
1040 goto error_restore_flags
;
1045 error_restore_flags
:
1046 /* ignore error and errp for bdrv_reopen, because we want to propagate
1047 * the original error */
1048 bdrv_reopen(base
, orig_base_flags
, NULL
);