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"
15 #include "qemu/cutils.h"
16 #include "qemu/coroutine.h"
17 #include "qemu/range.h"
19 #include "block/blockjob_int.h"
20 #include "block/block_int.h"
21 #include "sysemu/block-backend.h"
22 #include "qapi/error.h"
23 #include "qapi/qmp/qerror.h"
24 #include "qemu/ratelimit.h"
25 #include "qemu/bitmap.h"
27 #define MAX_IN_FLIGHT 16
28 #define MAX_IO_BYTES (1 << 20) /* 1 Mb */
29 #define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES)
31 /* The mirroring buffer is a list of granularity-sized chunks.
32 * Free chunks are organized in a list.
34 typedef struct MirrorBuffer
{
35 QSIMPLEQ_ENTRY(MirrorBuffer
) next
;
38 typedef struct MirrorOp MirrorOp
;
40 typedef struct MirrorBlockJob
{
43 BlockDriverState
*mirror_top_bs
;
44 BlockDriverState
*base
;
46 /* The name of the graph node to replace */
48 /* The BDS to replace */
49 BlockDriverState
*to_replace
;
50 /* Used to block operations on the drive-mirror-replace target */
51 Error
*replace_blocker
;
53 BlockMirrorBackingMode backing_mode
;
54 MirrorCopyMode copy_mode
;
55 BlockdevOnError on_source_error
, on_target_error
;
57 /* Set when the target is synced (dirty bitmap is clean, nothing
58 * in flight) and the job is running in active mode */
64 unsigned long *cow_bitmap
;
65 BdrvDirtyBitmap
*dirty_bitmap
;
66 BdrvDirtyBitmapIter
*dbi
;
68 QSIMPLEQ_HEAD(, MirrorBuffer
) buf_free
;
71 uint64_t last_pause_ns
;
72 unsigned long *in_flight_bitmap
;
74 int64_t bytes_in_flight
;
75 QTAILQ_HEAD(MirrorOpList
, MirrorOp
) ops_in_flight
;
78 int target_cluster_size
;
80 bool initial_zeroing_ongoing
;
81 int in_active_write_counter
;
85 typedef struct MirrorBDSOpaque
{
95 /* The pointee is set by mirror_co_read(), mirror_co_zero(), and
96 * mirror_co_discard() before yielding for the first time */
97 int64_t *bytes_handled
;
100 bool is_active_write
;
101 CoQueue waiting_requests
;
103 QTAILQ_ENTRY(MirrorOp
) next
;
106 typedef enum MirrorMethod
{
109 MIRROR_METHOD_DISCARD
,
112 static BlockErrorAction
mirror_error_action(MirrorBlockJob
*s
, bool read
,
116 s
->actively_synced
= false;
118 return block_job_error_action(&s
->common
, s
->on_source_error
,
121 return block_job_error_action(&s
->common
, s
->on_target_error
,
126 static void coroutine_fn
mirror_wait_on_conflicts(MirrorOp
*self
,
131 uint64_t self_start_chunk
= offset
/ s
->granularity
;
132 uint64_t self_end_chunk
= DIV_ROUND_UP(offset
+ bytes
, s
->granularity
);
133 uint64_t self_nb_chunks
= self_end_chunk
- self_start_chunk
;
135 while (find_next_bit(s
->in_flight_bitmap
, self_end_chunk
,
136 self_start_chunk
) < self_end_chunk
&&
141 QTAILQ_FOREACH(op
, &s
->ops_in_flight
, next
) {
142 uint64_t op_start_chunk
= op
->offset
/ s
->granularity
;
143 uint64_t op_nb_chunks
= DIV_ROUND_UP(op
->offset
+ op
->bytes
,
151 if (ranges_overlap(self_start_chunk
, self_nb_chunks
,
152 op_start_chunk
, op_nb_chunks
))
154 qemu_co_queue_wait(&op
->waiting_requests
, NULL
);
161 static void coroutine_fn
mirror_iteration_done(MirrorOp
*op
, int ret
)
163 MirrorBlockJob
*s
= op
->s
;
168 trace_mirror_iteration_done(s
, op
->offset
, op
->bytes
, ret
);
171 s
->bytes_in_flight
-= op
->bytes
;
173 for (i
= 0; i
< op
->qiov
.niov
; i
++) {
174 MirrorBuffer
*buf
= (MirrorBuffer
*) iov
[i
].iov_base
;
175 QSIMPLEQ_INSERT_TAIL(&s
->buf_free
, buf
, next
);
179 chunk_num
= op
->offset
/ s
->granularity
;
180 nb_chunks
= DIV_ROUND_UP(op
->bytes
, s
->granularity
);
182 bitmap_clear(s
->in_flight_bitmap
, chunk_num
, nb_chunks
);
183 QTAILQ_REMOVE(&s
->ops_in_flight
, op
, next
);
186 bitmap_set(s
->cow_bitmap
, chunk_num
, nb_chunks
);
188 if (!s
->initial_zeroing_ongoing
) {
189 job_progress_update(&s
->common
.job
, op
->bytes
);
192 qemu_iovec_destroy(&op
->qiov
);
194 qemu_co_queue_restart_all(&op
->waiting_requests
);
198 static void coroutine_fn
mirror_write_complete(MirrorOp
*op
, int ret
)
200 MirrorBlockJob
*s
= op
->s
;
203 BlockErrorAction action
;
205 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, op
->offset
, op
->bytes
);
206 action
= mirror_error_action(s
, false, -ret
);
207 if (action
== BLOCK_ERROR_ACTION_REPORT
&& s
->ret
>= 0) {
212 mirror_iteration_done(op
, ret
);
215 static void coroutine_fn
mirror_read_complete(MirrorOp
*op
, int ret
)
217 MirrorBlockJob
*s
= op
->s
;
220 BlockErrorAction action
;
222 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, op
->offset
, op
->bytes
);
223 action
= mirror_error_action(s
, true, -ret
);
224 if (action
== BLOCK_ERROR_ACTION_REPORT
&& s
->ret
>= 0) {
228 mirror_iteration_done(op
, ret
);
232 ret
= blk_co_pwritev(s
->target
, op
->offset
, op
->qiov
.size
, &op
->qiov
, 0);
233 mirror_write_complete(op
, ret
);
236 /* Clip bytes relative to offset to not exceed end-of-file */
237 static inline int64_t mirror_clip_bytes(MirrorBlockJob
*s
,
241 return MIN(bytes
, s
->bdev_length
- offset
);
244 /* Round offset and/or bytes to target cluster if COW is needed, and
245 * return the offset of the adjusted tail against original. */
246 static int mirror_cow_align(MirrorBlockJob
*s
, int64_t *offset
,
251 int64_t align_offset
= *offset
;
252 int64_t align_bytes
= *bytes
;
253 int max_bytes
= s
->granularity
* s
->max_iov
;
255 need_cow
= !test_bit(*offset
/ s
->granularity
, s
->cow_bitmap
);
256 need_cow
|= !test_bit((*offset
+ *bytes
- 1) / s
->granularity
,
259 bdrv_round_to_clusters(blk_bs(s
->target
), *offset
, *bytes
,
260 &align_offset
, &align_bytes
);
263 if (align_bytes
> max_bytes
) {
264 align_bytes
= max_bytes
;
266 align_bytes
= QEMU_ALIGN_DOWN(align_bytes
, s
->target_cluster_size
);
269 /* Clipping may result in align_bytes unaligned to chunk boundary, but
270 * that doesn't matter because it's already the end of source image. */
271 align_bytes
= mirror_clip_bytes(s
, align_offset
, align_bytes
);
273 ret
= align_offset
+ align_bytes
- (*offset
+ *bytes
);
274 *offset
= align_offset
;
275 *bytes
= align_bytes
;
280 static inline void mirror_wait_for_any_operation(MirrorBlockJob
*s
, bool active
)
284 QTAILQ_FOREACH(op
, &s
->ops_in_flight
, next
) {
285 /* Do not wait on pseudo ops, because it may in turn wait on
286 * some other operation to start, which may in fact be the
287 * caller of this function. Since there is only one pseudo op
288 * at any given time, we will always find some real operation
290 if (!op
->is_pseudo_op
&& op
->is_active_write
== active
) {
291 qemu_co_queue_wait(&op
->waiting_requests
, NULL
);
298 static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob
*s
)
300 /* Only non-active operations use up in-flight slots */
301 mirror_wait_for_any_operation(s
, false);
304 /* Perform a mirror copy operation.
306 * *op->bytes_handled is set to the number of bytes copied after and
307 * including offset, excluding any bytes copied prior to offset due
308 * to alignment. This will be op->bytes if no alignment is necessary,
309 * or (new_end - op->offset) if the tail is rounded up or down due to
310 * alignment or buffer limit.
312 static void coroutine_fn
mirror_co_read(void *opaque
)
314 MirrorOp
*op
= opaque
;
315 MirrorBlockJob
*s
= op
->s
;
320 max_bytes
= s
->granularity
* s
->max_iov
;
322 /* We can only handle as much as buf_size at a time. */
323 op
->bytes
= MIN(s
->buf_size
, MIN(max_bytes
, op
->bytes
));
325 assert(op
->bytes
< BDRV_REQUEST_MAX_BYTES
);
326 *op
->bytes_handled
= op
->bytes
;
329 *op
->bytes_handled
+= mirror_cow_align(s
, &op
->offset
, &op
->bytes
);
331 /* Cannot exceed BDRV_REQUEST_MAX_BYTES + INT_MAX */
332 assert(*op
->bytes_handled
<= UINT_MAX
);
333 assert(op
->bytes
<= s
->buf_size
);
334 /* The offset is granularity-aligned because:
335 * 1) Caller passes in aligned values;
336 * 2) mirror_cow_align is used only when target cluster is larger. */
337 assert(QEMU_IS_ALIGNED(op
->offset
, s
->granularity
));
338 /* The range is sector-aligned, since bdrv_getlength() rounds up. */
339 assert(QEMU_IS_ALIGNED(op
->bytes
, BDRV_SECTOR_SIZE
));
340 nb_chunks
= DIV_ROUND_UP(op
->bytes
, s
->granularity
);
342 while (s
->buf_free_count
< nb_chunks
) {
343 trace_mirror_yield_in_flight(s
, op
->offset
, s
->in_flight
);
344 mirror_wait_for_free_in_flight_slot(s
);
347 /* Now make a QEMUIOVector taking enough granularity-sized chunks
350 qemu_iovec_init(&op
->qiov
, nb_chunks
);
351 while (nb_chunks
-- > 0) {
352 MirrorBuffer
*buf
= QSIMPLEQ_FIRST(&s
->buf_free
);
353 size_t remaining
= op
->bytes
- op
->qiov
.size
;
355 QSIMPLEQ_REMOVE_HEAD(&s
->buf_free
, next
);
357 qemu_iovec_add(&op
->qiov
, buf
, MIN(s
->granularity
, remaining
));
360 /* Copy the dirty cluster. */
362 s
->bytes_in_flight
+= op
->bytes
;
363 trace_mirror_one_iteration(s
, op
->offset
, op
->bytes
);
365 ret
= bdrv_co_preadv(s
->mirror_top_bs
->backing
, op
->offset
, op
->bytes
,
367 mirror_read_complete(op
, ret
);
370 static void coroutine_fn
mirror_co_zero(void *opaque
)
372 MirrorOp
*op
= opaque
;
376 op
->s
->bytes_in_flight
+= op
->bytes
;
377 *op
->bytes_handled
= op
->bytes
;
379 ret
= blk_co_pwrite_zeroes(op
->s
->target
, op
->offset
, op
->bytes
,
380 op
->s
->unmap
? BDRV_REQ_MAY_UNMAP
: 0);
381 mirror_write_complete(op
, ret
);
384 static void coroutine_fn
mirror_co_discard(void *opaque
)
386 MirrorOp
*op
= opaque
;
390 op
->s
->bytes_in_flight
+= op
->bytes
;
391 *op
->bytes_handled
= op
->bytes
;
393 ret
= blk_co_pdiscard(op
->s
->target
, op
->offset
, op
->bytes
);
394 mirror_write_complete(op
, ret
);
397 static unsigned mirror_perform(MirrorBlockJob
*s
, int64_t offset
,
398 unsigned bytes
, MirrorMethod mirror_method
)
402 int64_t bytes_handled
= -1;
404 op
= g_new(MirrorOp
, 1);
409 .bytes_handled
= &bytes_handled
,
411 qemu_co_queue_init(&op
->waiting_requests
);
413 switch (mirror_method
) {
414 case MIRROR_METHOD_COPY
:
415 co
= qemu_coroutine_create(mirror_co_read
, op
);
417 case MIRROR_METHOD_ZERO
:
418 co
= qemu_coroutine_create(mirror_co_zero
, op
);
420 case MIRROR_METHOD_DISCARD
:
421 co
= qemu_coroutine_create(mirror_co_discard
, op
);
427 QTAILQ_INSERT_TAIL(&s
->ops_in_flight
, op
, next
);
428 qemu_coroutine_enter(co
);
429 /* At this point, ownership of op has been moved to the coroutine
430 * and the object may already be freed */
432 /* Assert that this value has been set */
433 assert(bytes_handled
>= 0);
435 /* Same assertion as in mirror_co_read() (and for mirror_co_read()
436 * and mirror_co_discard(), bytes_handled == op->bytes, which
437 * is the @bytes parameter given to this function) */
438 assert(bytes_handled
<= UINT_MAX
);
439 return bytes_handled
;
442 static uint64_t coroutine_fn
mirror_iteration(MirrorBlockJob
*s
)
444 BlockDriverState
*source
= s
->mirror_top_bs
->backing
->bs
;
447 uint64_t delay_ns
= 0, ret
= 0;
448 /* At least the first dirty chunk is mirrored in one iteration. */
450 bool write_zeroes_ok
= bdrv_can_write_zeroes_with_unmap(blk_bs(s
->target
));
451 int max_io_bytes
= MAX(s
->buf_size
/ MAX_IN_FLIGHT
, MAX_IO_BYTES
);
453 bdrv_dirty_bitmap_lock(s
->dirty_bitmap
);
454 offset
= bdrv_dirty_iter_next(s
->dbi
);
456 bdrv_set_dirty_iter(s
->dbi
, 0);
457 offset
= bdrv_dirty_iter_next(s
->dbi
);
458 trace_mirror_restart_iter(s
, bdrv_get_dirty_count(s
->dirty_bitmap
));
461 bdrv_dirty_bitmap_unlock(s
->dirty_bitmap
);
463 mirror_wait_on_conflicts(NULL
, s
, offset
, 1);
465 job_pause_point(&s
->common
.job
);
467 /* Find the number of consective dirty chunks following the first dirty
468 * one, and wait for in flight requests in them. */
469 bdrv_dirty_bitmap_lock(s
->dirty_bitmap
);
470 while (nb_chunks
* s
->granularity
< s
->buf_size
) {
472 int64_t next_offset
= offset
+ nb_chunks
* s
->granularity
;
473 int64_t next_chunk
= next_offset
/ s
->granularity
;
474 if (next_offset
>= s
->bdev_length
||
475 !bdrv_get_dirty_locked(source
, s
->dirty_bitmap
, next_offset
)) {
478 if (test_bit(next_chunk
, s
->in_flight_bitmap
)) {
482 next_dirty
= bdrv_dirty_iter_next(s
->dbi
);
483 if (next_dirty
> next_offset
|| next_dirty
< 0) {
484 /* The bitmap iterator's cache is stale, refresh it */
485 bdrv_set_dirty_iter(s
->dbi
, next_offset
);
486 next_dirty
= bdrv_dirty_iter_next(s
->dbi
);
488 assert(next_dirty
== next_offset
);
492 /* Clear dirty bits before querying the block status, because
493 * calling bdrv_block_status_above could yield - if some blocks are
494 * marked dirty in this window, we need to know.
496 bdrv_reset_dirty_bitmap_locked(s
->dirty_bitmap
, offset
,
497 nb_chunks
* s
->granularity
);
498 bdrv_dirty_bitmap_unlock(s
->dirty_bitmap
);
500 /* Before claiming an area in the in-flight bitmap, we have to
501 * create a MirrorOp for it so that conflicting requests can wait
502 * for it. mirror_perform() will create the real MirrorOps later,
503 * for now we just create a pseudo operation that will wake up all
504 * conflicting requests once all real operations have been
506 pseudo_op
= g_new(MirrorOp
, 1);
507 *pseudo_op
= (MirrorOp
){
509 .bytes
= nb_chunks
* s
->granularity
,
510 .is_pseudo_op
= true,
512 qemu_co_queue_init(&pseudo_op
->waiting_requests
);
513 QTAILQ_INSERT_TAIL(&s
->ops_in_flight
, pseudo_op
, next
);
515 bitmap_set(s
->in_flight_bitmap
, offset
/ s
->granularity
, nb_chunks
);
516 while (nb_chunks
> 0 && offset
< s
->bdev_length
) {
519 int64_t io_bytes_acct
;
520 MirrorMethod mirror_method
= MIRROR_METHOD_COPY
;
522 assert(!(offset
% s
->granularity
));
523 ret
= bdrv_block_status_above(source
, NULL
, offset
,
524 nb_chunks
* s
->granularity
,
525 &io_bytes
, NULL
, NULL
);
527 io_bytes
= MIN(nb_chunks
* s
->granularity
, max_io_bytes
);
528 } else if (ret
& BDRV_BLOCK_DATA
) {
529 io_bytes
= MIN(io_bytes
, max_io_bytes
);
532 io_bytes
-= io_bytes
% s
->granularity
;
533 if (io_bytes
< s
->granularity
) {
534 io_bytes
= s
->granularity
;
535 } else if (ret
>= 0 && !(ret
& BDRV_BLOCK_DATA
)) {
536 int64_t target_offset
;
537 int64_t target_bytes
;
538 bdrv_round_to_clusters(blk_bs(s
->target
), offset
, io_bytes
,
539 &target_offset
, &target_bytes
);
540 if (target_offset
== offset
&&
541 target_bytes
== io_bytes
) {
542 mirror_method
= ret
& BDRV_BLOCK_ZERO
?
544 MIRROR_METHOD_DISCARD
;
548 while (s
->in_flight
>= MAX_IN_FLIGHT
) {
549 trace_mirror_yield_in_flight(s
, offset
, s
->in_flight
);
550 mirror_wait_for_free_in_flight_slot(s
);
558 io_bytes
= mirror_clip_bytes(s
, offset
, io_bytes
);
559 io_bytes
= mirror_perform(s
, offset
, io_bytes
, mirror_method
);
560 if (mirror_method
!= MIRROR_METHOD_COPY
&& write_zeroes_ok
) {
563 io_bytes_acct
= io_bytes
;
567 nb_chunks
-= DIV_ROUND_UP(io_bytes
, s
->granularity
);
568 delay_ns
= block_job_ratelimit_get_delay(&s
->common
, io_bytes_acct
);
573 QTAILQ_REMOVE(&s
->ops_in_flight
, pseudo_op
, next
);
574 qemu_co_queue_restart_all(&pseudo_op
->waiting_requests
);
580 static void mirror_free_init(MirrorBlockJob
*s
)
582 int granularity
= s
->granularity
;
583 size_t buf_size
= s
->buf_size
;
584 uint8_t *buf
= s
->buf
;
586 assert(s
->buf_free_count
== 0);
587 QSIMPLEQ_INIT(&s
->buf_free
);
588 while (buf_size
!= 0) {
589 MirrorBuffer
*cur
= (MirrorBuffer
*)buf
;
590 QSIMPLEQ_INSERT_TAIL(&s
->buf_free
, cur
, next
);
592 buf_size
-= granularity
;
597 /* This is also used for the .pause callback. There is no matching
598 * mirror_resume() because mirror_run() will begin iterating again
599 * when the job is resumed.
601 static void mirror_wait_for_all_io(MirrorBlockJob
*s
)
603 while (s
->in_flight
> 0) {
604 mirror_wait_for_free_in_flight_slot(s
);
609 * mirror_exit_common: handle both abort() and prepare() cases.
610 * for .prepare, returns 0 on success and -errno on failure.
611 * for .abort cases, denoted by abort = true, MUST return 0.
613 static int mirror_exit_common(Job
*job
)
615 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
.job
);
616 BlockJob
*bjob
= &s
->common
;
617 MirrorBDSOpaque
*bs_opaque
= s
->mirror_top_bs
->opaque
;
618 AioContext
*replace_aio_context
= NULL
;
619 BlockDriverState
*src
= s
->mirror_top_bs
->backing
->bs
;
620 BlockDriverState
*target_bs
= blk_bs(s
->target
);
621 BlockDriverState
*mirror_top_bs
= s
->mirror_top_bs
;
622 Error
*local_err
= NULL
;
623 bool abort
= job
->ret
< 0;
631 bdrv_release_dirty_bitmap(src
, s
->dirty_bitmap
);
633 /* Make sure that the source BDS doesn't go away during bdrv_replace_node,
634 * before we can call bdrv_drained_end */
636 bdrv_ref(mirror_top_bs
);
639 /* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before
640 * inserting target_bs at s->to_replace, where we might not be able to get
643 * Note that blk_unref() alone doesn't necessarily drop permissions because
644 * we might be running nested inside mirror_drain(), which takes an extra
645 * reference, so use an explicit blk_set_perm() first. */
646 blk_set_perm(s
->target
, 0, BLK_PERM_ALL
, &error_abort
);
647 blk_unref(s
->target
);
650 /* We don't access the source any more. Dropping any WRITE/RESIZE is
651 * required before it could become a backing file of target_bs. */
652 bdrv_child_try_set_perm(mirror_top_bs
->backing
, 0, BLK_PERM_ALL
,
654 if (!abort
&& s
->backing_mode
== MIRROR_SOURCE_BACKING_CHAIN
) {
655 BlockDriverState
*backing
= s
->is_none_mode
? src
: s
->base
;
656 if (backing_bs(target_bs
) != backing
) {
657 bdrv_set_backing_hd(target_bs
, backing
, &local_err
);
659 error_report_err(local_err
);
666 replace_aio_context
= bdrv_get_aio_context(s
->to_replace
);
667 aio_context_acquire(replace_aio_context
);
670 if (s
->should_complete
&& !abort
) {
671 BlockDriverState
*to_replace
= s
->to_replace
?: src
;
673 if (bdrv_get_flags(target_bs
) != bdrv_get_flags(to_replace
)) {
674 bdrv_reopen(target_bs
, bdrv_get_flags(to_replace
), NULL
);
677 /* The mirror job has no requests in flight any more, but we need to
678 * drain potential other users of the BDS before changing the graph. */
679 bdrv_drained_begin(target_bs
);
680 bdrv_replace_node(to_replace
, target_bs
, &local_err
);
681 bdrv_drained_end(target_bs
);
683 error_report_err(local_err
);
688 bdrv_op_unblock_all(s
->to_replace
, s
->replace_blocker
);
689 error_free(s
->replace_blocker
);
690 bdrv_unref(s
->to_replace
);
692 if (replace_aio_context
) {
693 aio_context_release(replace_aio_context
);
696 bdrv_unref(target_bs
);
698 /* Remove the mirror filter driver from the graph. Before this, get rid of
699 * the blockers on the intermediate nodes so that the resulting state is
700 * valid. Also give up permissions on mirror_top_bs->backing, which might
701 * block the removal. */
702 block_job_remove_all_bdrv(bjob
);
703 bdrv_child_try_set_perm(mirror_top_bs
->backing
, 0, BLK_PERM_ALL
,
705 bdrv_replace_node(mirror_top_bs
, backing_bs(mirror_top_bs
), &error_abort
);
707 /* We just changed the BDS the job BB refers to (with either or both of the
708 * bdrv_replace_node() calls), so switch the BB back so the cleanup does
709 * the right thing. We don't need any permissions any more now. */
710 blk_remove_bs(bjob
->blk
);
711 blk_set_perm(bjob
->blk
, 0, BLK_PERM_ALL
, &error_abort
);
712 blk_insert_bs(bjob
->blk
, mirror_top_bs
, &error_abort
);
714 bs_opaque
->job
= NULL
;
716 bdrv_drained_end(src
);
717 bdrv_unref(mirror_top_bs
);
723 static int mirror_prepare(Job
*job
)
725 return mirror_exit_common(job
);
728 static void mirror_abort(Job
*job
)
730 int ret
= mirror_exit_common(job
);
734 static void mirror_throttle(MirrorBlockJob
*s
)
736 int64_t now
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
738 if (now
- s
->last_pause_ns
> BLOCK_JOB_SLICE_TIME
) {
739 s
->last_pause_ns
= now
;
740 job_sleep_ns(&s
->common
.job
, 0);
742 job_pause_point(&s
->common
.job
);
746 static int coroutine_fn
mirror_dirty_init(MirrorBlockJob
*s
)
749 BlockDriverState
*base
= s
->base
;
750 BlockDriverState
*bs
= s
->mirror_top_bs
->backing
->bs
;
751 BlockDriverState
*target_bs
= blk_bs(s
->target
);
755 if (base
== NULL
&& !bdrv_has_zero_init(target_bs
)) {
756 if (!bdrv_can_write_zeroes_with_unmap(target_bs
)) {
757 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, 0, s
->bdev_length
);
761 s
->initial_zeroing_ongoing
= true;
762 for (offset
= 0; offset
< s
->bdev_length
; ) {
763 int bytes
= MIN(s
->bdev_length
- offset
,
764 QEMU_ALIGN_DOWN(INT_MAX
, s
->granularity
));
768 if (job_is_cancelled(&s
->common
.job
)) {
769 s
->initial_zeroing_ongoing
= false;
773 if (s
->in_flight
>= MAX_IN_FLIGHT
) {
774 trace_mirror_yield(s
, UINT64_MAX
, s
->buf_free_count
,
776 mirror_wait_for_free_in_flight_slot(s
);
780 mirror_perform(s
, offset
, bytes
, MIRROR_METHOD_ZERO
);
784 mirror_wait_for_all_io(s
);
785 s
->initial_zeroing_ongoing
= false;
788 /* First part, loop on the sectors and initialize the dirty bitmap. */
789 for (offset
= 0; offset
< s
->bdev_length
; ) {
790 /* Just to make sure we are not exceeding int limit. */
791 int bytes
= MIN(s
->bdev_length
- offset
,
792 QEMU_ALIGN_DOWN(INT_MAX
, s
->granularity
));
796 if (job_is_cancelled(&s
->common
.job
)) {
800 ret
= bdrv_is_allocated_above(bs
, base
, offset
, bytes
, &count
);
807 bdrv_set_dirty_bitmap(s
->dirty_bitmap
, offset
, count
);
814 /* Called when going out of the streaming phase to flush the bulk of the
815 * data to the medium, or just before completing.
817 static int mirror_flush(MirrorBlockJob
*s
)
819 int ret
= blk_flush(s
->target
);
821 if (mirror_error_action(s
, false, -ret
) == BLOCK_ERROR_ACTION_REPORT
) {
828 static int coroutine_fn
mirror_run(Job
*job
, Error
**errp
)
830 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
.job
);
831 BlockDriverState
*bs
= s
->mirror_top_bs
->backing
->bs
;
832 BlockDriverState
*target_bs
= blk_bs(s
->target
);
833 bool need_drain
= true;
836 char backing_filename
[2]; /* we only need 2 characters because we are only
837 checking for a NULL string */
840 if (job_is_cancelled(&s
->common
.job
)) {
844 s
->bdev_length
= bdrv_getlength(bs
);
845 if (s
->bdev_length
< 0) {
846 ret
= s
->bdev_length
;
850 /* Active commit must resize the base image if its size differs from the
852 if (s
->base
== blk_bs(s
->target
)) {
855 base_length
= blk_getlength(s
->target
);
856 if (base_length
< 0) {
861 if (s
->bdev_length
> base_length
) {
862 ret
= blk_truncate(s
->target
, s
->bdev_length
, PREALLOC_MODE_OFF
,
870 if (s
->bdev_length
== 0) {
871 /* Transition to the READY state and wait for complete. */
872 job_transition_to_ready(&s
->common
.job
);
874 s
->actively_synced
= true;
875 while (!job_is_cancelled(&s
->common
.job
) && !s
->should_complete
) {
876 job_yield(&s
->common
.job
);
878 s
->common
.job
.cancelled
= false;
882 length
= DIV_ROUND_UP(s
->bdev_length
, s
->granularity
);
883 s
->in_flight_bitmap
= bitmap_new(length
);
885 /* If we have no backing file yet in the destination, we cannot let
886 * the destination do COW. Instead, we copy sectors around the
887 * dirty data if needed. We need a bitmap to do that.
889 bdrv_get_backing_filename(target_bs
, backing_filename
,
890 sizeof(backing_filename
));
891 if (!bdrv_get_info(target_bs
, &bdi
) && bdi
.cluster_size
) {
892 s
->target_cluster_size
= bdi
.cluster_size
;
894 s
->target_cluster_size
= BDRV_SECTOR_SIZE
;
896 if (backing_filename
[0] && !target_bs
->backing
&&
897 s
->granularity
< s
->target_cluster_size
) {
898 s
->buf_size
= MAX(s
->buf_size
, s
->target_cluster_size
);
899 s
->cow_bitmap
= bitmap_new(length
);
901 s
->max_iov
= MIN(bs
->bl
.max_iov
, target_bs
->bl
.max_iov
);
903 s
->buf
= qemu_try_blockalign(bs
, s
->buf_size
);
904 if (s
->buf
== NULL
) {
911 s
->last_pause_ns
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
912 if (!s
->is_none_mode
) {
913 ret
= mirror_dirty_init(s
);
914 if (ret
< 0 || job_is_cancelled(&s
->common
.job
)) {
920 s
->dbi
= bdrv_dirty_iter_new(s
->dirty_bitmap
);
922 uint64_t delay_ns
= 0;
924 bool should_complete
;
926 /* Do not start passive operations while there are active
927 * writes in progress */
928 while (s
->in_active_write_counter
) {
929 mirror_wait_for_any_operation(s
, true);
937 job_pause_point(&s
->common
.job
);
939 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
940 /* cnt is the number of dirty bytes remaining and s->bytes_in_flight is
941 * the number of bytes currently being processed; together those are
942 * the current remaining operation length */
943 job_progress_set_remaining(&s
->common
.job
, s
->bytes_in_flight
+ cnt
);
945 /* Note that even when no rate limit is applied we need to yield
946 * periodically with no pending I/O so that bdrv_drain_all() returns.
947 * We do so every BLKOCK_JOB_SLICE_TIME nanoseconds, or when there is
948 * an error, or when the source is clean, whichever comes first. */
949 delta
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
) - s
->last_pause_ns
;
950 if (delta
< BLOCK_JOB_SLICE_TIME
&&
951 s
->common
.iostatus
== BLOCK_DEVICE_IO_STATUS_OK
) {
952 if (s
->in_flight
>= MAX_IN_FLIGHT
|| s
->buf_free_count
== 0 ||
953 (cnt
== 0 && s
->in_flight
> 0)) {
954 trace_mirror_yield(s
, cnt
, s
->buf_free_count
, s
->in_flight
);
955 mirror_wait_for_free_in_flight_slot(s
);
957 } else if (cnt
!= 0) {
958 delay_ns
= mirror_iteration(s
);
962 should_complete
= false;
963 if (s
->in_flight
== 0 && cnt
== 0) {
964 trace_mirror_before_flush(s
);
966 if (mirror_flush(s
) < 0) {
967 /* Go check s->ret. */
970 /* We're out of the streaming phase. From now on, if the job
971 * is cancelled we will actually complete all pending I/O and
972 * report completion. This way, block-job-cancel will leave
973 * the target in a consistent state.
975 job_transition_to_ready(&s
->common
.job
);
977 if (s
->copy_mode
!= MIRROR_COPY_MODE_BACKGROUND
) {
978 s
->actively_synced
= true;
982 should_complete
= s
->should_complete
||
983 job_is_cancelled(&s
->common
.job
);
984 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
987 if (cnt
== 0 && should_complete
) {
988 /* The dirty bitmap is not updated while operations are pending.
989 * If we're about to exit, wait for pending operations before
990 * calling bdrv_get_dirty_count(bs), or we may exit while the
991 * source has dirty data to copy!
993 * Note that I/O can be submitted by the guest while
994 * mirror_populate runs, so pause it now. Before deciding
995 * whether to switch to target check one last time if I/O has
996 * come in the meanwhile, and if not flush the data to disk.
998 trace_mirror_before_drain(s
, cnt
);
1000 bdrv_drained_begin(bs
);
1001 cnt
= bdrv_get_dirty_count(s
->dirty_bitmap
);
1002 if (cnt
> 0 || mirror_flush(s
) < 0) {
1003 bdrv_drained_end(bs
);
1007 /* The two disks are in sync. Exit and report successful
1010 assert(QLIST_EMPTY(&bs
->tracked_requests
));
1011 s
->common
.job
.cancelled
= false;
1018 if (s
->synced
&& !should_complete
) {
1019 delay_ns
= (s
->in_flight
== 0 &&
1020 cnt
== 0 ? BLOCK_JOB_SLICE_TIME
: 0);
1022 trace_mirror_before_sleep(s
, cnt
, s
->synced
, delay_ns
);
1023 job_sleep_ns(&s
->common
.job
, delay_ns
);
1024 if (job_is_cancelled(&s
->common
.job
) &&
1025 (!s
->synced
|| s
->common
.job
.force_cancel
))
1029 s
->last_pause_ns
= qemu_clock_get_ns(QEMU_CLOCK_REALTIME
);
1033 if (s
->in_flight
> 0) {
1034 /* We get here only if something went wrong. Either the job failed,
1035 * or it was cancelled prematurely so that we do not guarantee that
1036 * the target is a copy of the source.
1038 assert(ret
< 0 || ((s
->common
.job
.force_cancel
|| !s
->synced
) &&
1039 job_is_cancelled(&s
->common
.job
)));
1041 mirror_wait_for_all_io(s
);
1044 assert(s
->in_flight
== 0);
1046 g_free(s
->cow_bitmap
);
1047 g_free(s
->in_flight_bitmap
);
1048 bdrv_dirty_iter_free(s
->dbi
);
1051 bdrv_drained_begin(bs
);
1057 static void mirror_complete(Job
*job
, Error
**errp
)
1059 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
.job
);
1060 BlockDriverState
*target
;
1062 target
= blk_bs(s
->target
);
1065 error_setg(errp
, "The active block job '%s' cannot be completed",
1070 if (s
->backing_mode
== MIRROR_OPEN_BACKING_CHAIN
) {
1073 assert(!target
->backing
);
1074 ret
= bdrv_open_backing_file(target
, NULL
, "backing", errp
);
1080 /* block all operations on to_replace bs */
1082 AioContext
*replace_aio_context
;
1084 s
->to_replace
= bdrv_find_node(s
->replaces
);
1085 if (!s
->to_replace
) {
1086 error_setg(errp
, "Node name '%s' not found", s
->replaces
);
1090 replace_aio_context
= bdrv_get_aio_context(s
->to_replace
);
1091 aio_context_acquire(replace_aio_context
);
1093 /* TODO Translate this into permission system. Current definition of
1094 * GRAPH_MOD would require to request it for the parents; they might
1095 * not even be BlockDriverStates, however, so a BdrvChild can't address
1096 * them. May need redefinition of GRAPH_MOD. */
1097 error_setg(&s
->replace_blocker
,
1098 "block device is in use by block-job-complete");
1099 bdrv_op_block_all(s
->to_replace
, s
->replace_blocker
);
1100 bdrv_ref(s
->to_replace
);
1102 aio_context_release(replace_aio_context
);
1105 s
->should_complete
= true;
1109 static void mirror_pause(Job
*job
)
1111 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
.job
);
1113 mirror_wait_for_all_io(s
);
1116 static bool mirror_drained_poll(BlockJob
*job
)
1118 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
1119 return !!s
->in_flight
;
1122 static void mirror_attached_aio_context(BlockJob
*job
, AioContext
*new_context
)
1124 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
1126 blk_set_aio_context(s
->target
, new_context
);
1129 static void mirror_drain(BlockJob
*job
)
1131 MirrorBlockJob
*s
= container_of(job
, MirrorBlockJob
, common
);
1133 /* Need to keep a reference in case blk_drain triggers execution
1134 * of mirror_complete...
1137 BlockBackend
*target
= s
->target
;
1144 static const BlockJobDriver mirror_job_driver
= {
1146 .instance_size
= sizeof(MirrorBlockJob
),
1147 .job_type
= JOB_TYPE_MIRROR
,
1148 .free
= block_job_free
,
1149 .user_resume
= block_job_user_resume
,
1150 .drain
= block_job_drain
,
1152 .prepare
= mirror_prepare
,
1153 .abort
= mirror_abort
,
1154 .pause
= mirror_pause
,
1155 .complete
= mirror_complete
,
1157 .drained_poll
= mirror_drained_poll
,
1158 .attached_aio_context
= mirror_attached_aio_context
,
1159 .drain
= mirror_drain
,
1162 static const BlockJobDriver commit_active_job_driver
= {
1164 .instance_size
= sizeof(MirrorBlockJob
),
1165 .job_type
= JOB_TYPE_COMMIT
,
1166 .free
= block_job_free
,
1167 .user_resume
= block_job_user_resume
,
1168 .drain
= block_job_drain
,
1170 .prepare
= mirror_prepare
,
1171 .abort
= mirror_abort
,
1172 .pause
= mirror_pause
,
1173 .complete
= mirror_complete
,
1175 .drained_poll
= mirror_drained_poll
,
1176 .attached_aio_context
= mirror_attached_aio_context
,
1177 .drain
= mirror_drain
,
1180 static void do_sync_target_write(MirrorBlockJob
*job
, MirrorMethod method
,
1181 uint64_t offset
, uint64_t bytes
,
1182 QEMUIOVector
*qiov
, int flags
)
1184 BdrvDirtyBitmapIter
*iter
;
1185 QEMUIOVector target_qiov
;
1186 uint64_t dirty_offset
;
1190 qemu_iovec_init(&target_qiov
, qiov
->niov
);
1193 iter
= bdrv_dirty_iter_new(job
->dirty_bitmap
);
1194 bdrv_set_dirty_iter(iter
, offset
);
1200 bdrv_dirty_bitmap_lock(job
->dirty_bitmap
);
1201 valid_area
= bdrv_dirty_iter_next_area(iter
, offset
+ bytes
,
1202 &dirty_offset
, &dirty_bytes
);
1204 bdrv_dirty_bitmap_unlock(job
->dirty_bitmap
);
1208 bdrv_reset_dirty_bitmap_locked(job
->dirty_bitmap
,
1209 dirty_offset
, dirty_bytes
);
1210 bdrv_dirty_bitmap_unlock(job
->dirty_bitmap
);
1212 job_progress_increase_remaining(&job
->common
.job
, dirty_bytes
);
1214 assert(dirty_offset
- offset
<= SIZE_MAX
);
1216 qemu_iovec_reset(&target_qiov
);
1217 qemu_iovec_concat(&target_qiov
, qiov
,
1218 dirty_offset
- offset
, dirty_bytes
);
1222 case MIRROR_METHOD_COPY
:
1223 ret
= blk_co_pwritev(job
->target
, dirty_offset
, dirty_bytes
,
1224 qiov
? &target_qiov
: NULL
, flags
);
1227 case MIRROR_METHOD_ZERO
:
1229 ret
= blk_co_pwrite_zeroes(job
->target
, dirty_offset
, dirty_bytes
,
1233 case MIRROR_METHOD_DISCARD
:
1235 ret
= blk_co_pdiscard(job
->target
, dirty_offset
, dirty_bytes
);
1243 job_progress_update(&job
->common
.job
, dirty_bytes
);
1245 BlockErrorAction action
;
1247 bdrv_set_dirty_bitmap(job
->dirty_bitmap
, dirty_offset
, dirty_bytes
);
1248 job
->actively_synced
= false;
1250 action
= mirror_error_action(job
, false, -ret
);
1251 if (action
== BLOCK_ERROR_ACTION_REPORT
) {
1260 bdrv_dirty_iter_free(iter
);
1262 qemu_iovec_destroy(&target_qiov
);
1266 static MirrorOp
*coroutine_fn
active_write_prepare(MirrorBlockJob
*s
,
1271 uint64_t start_chunk
= offset
/ s
->granularity
;
1272 uint64_t end_chunk
= DIV_ROUND_UP(offset
+ bytes
, s
->granularity
);
1274 op
= g_new(MirrorOp
, 1);
1279 .is_active_write
= true,
1281 qemu_co_queue_init(&op
->waiting_requests
);
1282 QTAILQ_INSERT_TAIL(&s
->ops_in_flight
, op
, next
);
1284 s
->in_active_write_counter
++;
1286 mirror_wait_on_conflicts(op
, s
, offset
, bytes
);
1288 bitmap_set(s
->in_flight_bitmap
, start_chunk
, end_chunk
- start_chunk
);
1293 static void coroutine_fn
active_write_settle(MirrorOp
*op
)
1295 uint64_t start_chunk
= op
->offset
/ op
->s
->granularity
;
1296 uint64_t end_chunk
= DIV_ROUND_UP(op
->offset
+ op
->bytes
,
1297 op
->s
->granularity
);
1299 if (!--op
->s
->in_active_write_counter
&& op
->s
->actively_synced
) {
1300 BdrvChild
*source
= op
->s
->mirror_top_bs
->backing
;
1302 if (QLIST_FIRST(&source
->bs
->parents
) == source
&&
1303 QLIST_NEXT(source
, next_parent
) == NULL
)
1305 /* Assert that we are back in sync once all active write
1306 * operations are settled.
1307 * Note that we can only assert this if the mirror node
1308 * is the source node's only parent. */
1309 assert(!bdrv_get_dirty_count(op
->s
->dirty_bitmap
));
1312 bitmap_clear(op
->s
->in_flight_bitmap
, start_chunk
, end_chunk
- start_chunk
);
1313 QTAILQ_REMOVE(&op
->s
->ops_in_flight
, op
, next
);
1314 qemu_co_queue_restart_all(&op
->waiting_requests
);
1318 static int coroutine_fn
bdrv_mirror_top_preadv(BlockDriverState
*bs
,
1319 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
)
1321 return bdrv_co_preadv(bs
->backing
, offset
, bytes
, qiov
, flags
);
1324 static int coroutine_fn
bdrv_mirror_top_do_write(BlockDriverState
*bs
,
1325 MirrorMethod method
, uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
,
1328 MirrorOp
*op
= NULL
;
1329 MirrorBDSOpaque
*s
= bs
->opaque
;
1331 bool copy_to_target
;
1333 copy_to_target
= s
->job
->ret
>= 0 &&
1334 s
->job
->copy_mode
== MIRROR_COPY_MODE_WRITE_BLOCKING
;
1336 if (copy_to_target
) {
1337 op
= active_write_prepare(s
->job
, offset
, bytes
);
1341 case MIRROR_METHOD_COPY
:
1342 ret
= bdrv_co_pwritev(bs
->backing
, offset
, bytes
, qiov
, flags
);
1345 case MIRROR_METHOD_ZERO
:
1346 ret
= bdrv_co_pwrite_zeroes(bs
->backing
, offset
, bytes
, flags
);
1349 case MIRROR_METHOD_DISCARD
:
1350 ret
= bdrv_co_pdiscard(bs
->backing
, offset
, bytes
);
1361 if (copy_to_target
) {
1362 do_sync_target_write(s
->job
, method
, offset
, bytes
, qiov
, flags
);
1366 if (copy_to_target
) {
1367 active_write_settle(op
);
1372 static int coroutine_fn
bdrv_mirror_top_pwritev(BlockDriverState
*bs
,
1373 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
)
1375 MirrorBDSOpaque
*s
= bs
->opaque
;
1376 QEMUIOVector bounce_qiov
;
1379 bool copy_to_target
;
1381 copy_to_target
= s
->job
->ret
>= 0 &&
1382 s
->job
->copy_mode
== MIRROR_COPY_MODE_WRITE_BLOCKING
;
1384 if (copy_to_target
) {
1385 /* The guest might concurrently modify the data to write; but
1386 * the data on source and destination must match, so we have
1387 * to use a bounce buffer if we are going to write to the
1389 bounce_buf
= qemu_blockalign(bs
, bytes
);
1390 iov_to_buf_full(qiov
->iov
, qiov
->niov
, 0, bounce_buf
, bytes
);
1392 qemu_iovec_init(&bounce_qiov
, 1);
1393 qemu_iovec_add(&bounce_qiov
, bounce_buf
, bytes
);
1394 qiov
= &bounce_qiov
;
1397 ret
= bdrv_mirror_top_do_write(bs
, MIRROR_METHOD_COPY
, offset
, bytes
, qiov
,
1400 if (copy_to_target
) {
1401 qemu_iovec_destroy(&bounce_qiov
);
1402 qemu_vfree(bounce_buf
);
1408 static int coroutine_fn
bdrv_mirror_top_flush(BlockDriverState
*bs
)
1410 if (bs
->backing
== NULL
) {
1411 /* we can be here after failed bdrv_append in mirror_start_job */
1414 return bdrv_co_flush(bs
->backing
->bs
);
1417 static int coroutine_fn
bdrv_mirror_top_pwrite_zeroes(BlockDriverState
*bs
,
1418 int64_t offset
, int bytes
, BdrvRequestFlags flags
)
1420 return bdrv_mirror_top_do_write(bs
, MIRROR_METHOD_ZERO
, offset
, bytes
, NULL
,
1424 static int coroutine_fn
bdrv_mirror_top_pdiscard(BlockDriverState
*bs
,
1425 int64_t offset
, int bytes
)
1427 return bdrv_mirror_top_do_write(bs
, MIRROR_METHOD_DISCARD
, offset
, bytes
,
1431 static void bdrv_mirror_top_refresh_filename(BlockDriverState
*bs
, QDict
*opts
)
1433 if (bs
->backing
== NULL
) {
1434 /* we can be here after failed bdrv_attach_child in
1435 * bdrv_set_backing_hd */
1438 bdrv_refresh_filename(bs
->backing
->bs
);
1439 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
),
1440 bs
->backing
->bs
->filename
);
1443 static void bdrv_mirror_top_child_perm(BlockDriverState
*bs
, BdrvChild
*c
,
1444 const BdrvChildRole
*role
,
1445 BlockReopenQueue
*reopen_queue
,
1446 uint64_t perm
, uint64_t shared
,
1447 uint64_t *nperm
, uint64_t *nshared
)
1449 /* Must be able to forward guest writes to the real image */
1451 if (perm
& BLK_PERM_WRITE
) {
1452 *nperm
|= BLK_PERM_WRITE
;
1455 *nshared
= BLK_PERM_ALL
;
1458 /* Dummy node that provides consistent read to its users without requiring it
1459 * from its backing file and that allows writes on the backing file chain. */
1460 static BlockDriver bdrv_mirror_top
= {
1461 .format_name
= "mirror_top",
1462 .bdrv_co_preadv
= bdrv_mirror_top_preadv
,
1463 .bdrv_co_pwritev
= bdrv_mirror_top_pwritev
,
1464 .bdrv_co_pwrite_zeroes
= bdrv_mirror_top_pwrite_zeroes
,
1465 .bdrv_co_pdiscard
= bdrv_mirror_top_pdiscard
,
1466 .bdrv_co_flush
= bdrv_mirror_top_flush
,
1467 .bdrv_co_block_status
= bdrv_co_block_status_from_backing
,
1468 .bdrv_refresh_filename
= bdrv_mirror_top_refresh_filename
,
1469 .bdrv_child_perm
= bdrv_mirror_top_child_perm
,
1472 static void mirror_start_job(const char *job_id
, BlockDriverState
*bs
,
1473 int creation_flags
, BlockDriverState
*target
,
1474 const char *replaces
, int64_t speed
,
1475 uint32_t granularity
, int64_t buf_size
,
1476 BlockMirrorBackingMode backing_mode
,
1477 BlockdevOnError on_source_error
,
1478 BlockdevOnError on_target_error
,
1480 BlockCompletionFunc
*cb
,
1482 const BlockJobDriver
*driver
,
1483 bool is_none_mode
, BlockDriverState
*base
,
1484 bool auto_complete
, const char *filter_node_name
,
1485 bool is_mirror
, MirrorCopyMode copy_mode
,
1489 MirrorBDSOpaque
*bs_opaque
;
1490 BlockDriverState
*mirror_top_bs
;
1491 bool target_graph_mod
;
1492 bool target_is_backing
;
1493 Error
*local_err
= NULL
;
1496 if (granularity
== 0) {
1497 granularity
= bdrv_get_default_bitmap_granularity(target
);
1500 assert(is_power_of_2(granularity
));
1503 error_setg(errp
, "Invalid parameter 'buf-size'");
1507 if (buf_size
== 0) {
1508 buf_size
= DEFAULT_MIRROR_BUF_SIZE
;
1512 error_setg(errp
, "Can't mirror node into itself");
1516 /* In the case of active commit, add dummy driver to provide consistent
1517 * reads on the top, while disabling it in the intermediate nodes, and make
1518 * the backing chain writable. */
1519 mirror_top_bs
= bdrv_new_open_driver(&bdrv_mirror_top
, filter_node_name
,
1521 if (mirror_top_bs
== NULL
) {
1524 if (!filter_node_name
) {
1525 mirror_top_bs
->implicit
= true;
1527 mirror_top_bs
->total_sectors
= bs
->total_sectors
;
1528 mirror_top_bs
->supported_write_flags
= BDRV_REQ_WRITE_UNCHANGED
;
1529 mirror_top_bs
->supported_zero_flags
= BDRV_REQ_WRITE_UNCHANGED
;
1530 bs_opaque
= g_new0(MirrorBDSOpaque
, 1);
1531 mirror_top_bs
->opaque
= bs_opaque
;
1532 bdrv_set_aio_context(mirror_top_bs
, bdrv_get_aio_context(bs
));
1534 /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep
1535 * it alive until block_job_create() succeeds even if bs has no parent. */
1536 bdrv_ref(mirror_top_bs
);
1537 bdrv_drained_begin(bs
);
1538 bdrv_append(mirror_top_bs
, bs
, &local_err
);
1539 bdrv_drained_end(bs
);
1542 bdrv_unref(mirror_top_bs
);
1543 error_propagate(errp
, local_err
);
1547 /* Make sure that the source is not resized while the job is running */
1548 s
= block_job_create(job_id
, driver
, NULL
, mirror_top_bs
,
1549 BLK_PERM_CONSISTENT_READ
,
1550 BLK_PERM_CONSISTENT_READ
| BLK_PERM_WRITE_UNCHANGED
|
1551 BLK_PERM_WRITE
| BLK_PERM_GRAPH_MOD
, speed
,
1552 creation_flags
, cb
, opaque
, errp
);
1558 /* The block job now has a reference to this node */
1559 bdrv_unref(mirror_top_bs
);
1561 s
->mirror_top_bs
= mirror_top_bs
;
1563 /* No resize for the target either; while the mirror is still running, a
1564 * consistent read isn't necessarily possible. We could possibly allow
1565 * writes and graph modifications, though it would likely defeat the
1566 * purpose of a mirror, so leave them blocked for now.
1568 * In the case of active commit, things look a bit different, though,
1569 * because the target is an already populated backing file in active use.
1570 * We can allow anything except resize there.*/
1571 target_is_backing
= bdrv_chain_contains(bs
, target
);
1572 target_graph_mod
= (backing_mode
!= MIRROR_LEAVE_BACKING_CHAIN
);
1573 s
->target
= blk_new(BLK_PERM_WRITE
| BLK_PERM_RESIZE
|
1574 (target_graph_mod
? BLK_PERM_GRAPH_MOD
: 0),
1575 BLK_PERM_WRITE_UNCHANGED
|
1576 (target_is_backing
? BLK_PERM_CONSISTENT_READ
|
1578 BLK_PERM_GRAPH_MOD
: 0));
1579 ret
= blk_insert_bs(s
->target
, target
, errp
);
1584 /* XXX: Mirror target could be a NBD server of target QEMU in the case
1585 * of non-shared block migration. To allow migration completion, we
1586 * have to allow "inactivate" of the target BB. When that happens, we
1587 * know the job is drained, and the vcpus are stopped, so no write
1588 * operation will be performed. Block layer already has assertions to
1590 blk_set_force_allow_inactivate(s
->target
);
1593 s
->replaces
= g_strdup(replaces
);
1594 s
->on_source_error
= on_source_error
;
1595 s
->on_target_error
= on_target_error
;
1596 s
->is_none_mode
= is_none_mode
;
1597 s
->backing_mode
= backing_mode
;
1598 s
->copy_mode
= copy_mode
;
1600 s
->granularity
= granularity
;
1601 s
->buf_size
= ROUND_UP(buf_size
, granularity
);
1603 if (auto_complete
) {
1604 s
->should_complete
= true;
1607 s
->dirty_bitmap
= bdrv_create_dirty_bitmap(bs
, granularity
, NULL
, errp
);
1608 if (!s
->dirty_bitmap
) {
1612 /* Required permissions are already taken with blk_new() */
1613 block_job_add_bdrv(&s
->common
, "target", target
, 0, BLK_PERM_ALL
,
1616 /* In commit_active_start() all intermediate nodes disappear, so
1617 * any jobs in them must be blocked */
1618 if (target_is_backing
) {
1619 BlockDriverState
*iter
;
1620 for (iter
= backing_bs(bs
); iter
!= target
; iter
= backing_bs(iter
)) {
1621 /* XXX BLK_PERM_WRITE needs to be allowed so we don't block
1622 * ourselves at s->base (if writes are blocked for a node, they are
1623 * also blocked for its backing file). The other options would be a
1624 * second filter driver above s->base (== target). */
1625 ret
= block_job_add_bdrv(&s
->common
, "intermediate node", iter
, 0,
1626 BLK_PERM_WRITE_UNCHANGED
| BLK_PERM_WRITE
,
1634 QTAILQ_INIT(&s
->ops_in_flight
);
1636 trace_mirror_start(bs
, s
, opaque
);
1637 job_start(&s
->common
.job
);
1642 /* Make sure this BDS does not go away until we have completed the graph
1644 bdrv_ref(mirror_top_bs
);
1646 g_free(s
->replaces
);
1647 blk_unref(s
->target
);
1648 bs_opaque
->job
= NULL
;
1649 job_early_fail(&s
->common
.job
);
1652 bdrv_child_try_set_perm(mirror_top_bs
->backing
, 0, BLK_PERM_ALL
,
1654 bdrv_replace_node(mirror_top_bs
, backing_bs(mirror_top_bs
), &error_abort
);
1656 bdrv_unref(mirror_top_bs
);
1659 void mirror_start(const char *job_id
, BlockDriverState
*bs
,
1660 BlockDriverState
*target
, const char *replaces
,
1661 int creation_flags
, int64_t speed
,
1662 uint32_t granularity
, int64_t buf_size
,
1663 MirrorSyncMode mode
, BlockMirrorBackingMode backing_mode
,
1664 BlockdevOnError on_source_error
,
1665 BlockdevOnError on_target_error
,
1666 bool unmap
, const char *filter_node_name
,
1667 MirrorCopyMode copy_mode
, Error
**errp
)
1670 BlockDriverState
*base
;
1672 if (mode
== MIRROR_SYNC_MODE_INCREMENTAL
) {
1673 error_setg(errp
, "Sync mode 'incremental' not supported");
1676 is_none_mode
= mode
== MIRROR_SYNC_MODE_NONE
;
1677 base
= mode
== MIRROR_SYNC_MODE_TOP
? backing_bs(bs
) : NULL
;
1678 mirror_start_job(job_id
, bs
, creation_flags
, target
, replaces
,
1679 speed
, granularity
, buf_size
, backing_mode
,
1680 on_source_error
, on_target_error
, unmap
, NULL
, NULL
,
1681 &mirror_job_driver
, is_none_mode
, base
, false,
1682 filter_node_name
, true, copy_mode
, errp
);
1685 void commit_active_start(const char *job_id
, BlockDriverState
*bs
,
1686 BlockDriverState
*base
, int creation_flags
,
1687 int64_t speed
, BlockdevOnError on_error
,
1688 const char *filter_node_name
,
1689 BlockCompletionFunc
*cb
, void *opaque
,
1690 bool auto_complete
, Error
**errp
)
1692 int orig_base_flags
;
1693 Error
*local_err
= NULL
;
1695 orig_base_flags
= bdrv_get_flags(base
);
1697 if (bdrv_reopen(base
, bs
->open_flags
, errp
)) {
1701 mirror_start_job(job_id
, bs
, creation_flags
, base
, NULL
, speed
, 0, 0,
1702 MIRROR_LEAVE_BACKING_CHAIN
,
1703 on_error
, on_error
, true, cb
, opaque
,
1704 &commit_active_job_driver
, false, base
, auto_complete
,
1705 filter_node_name
, false, MIRROR_COPY_MODE_BACKGROUND
,
1708 error_propagate(errp
, local_err
);
1709 goto error_restore_flags
;
1714 error_restore_flags
:
1715 /* ignore error and errp for bdrv_reopen, because we want to propagate
1716 * the original error */
1717 bdrv_reopen(base
, orig_base_flags
, NULL
);