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block/block-copy: fix progress calculation

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Assume we have two regions, A and B, and region B is in-flight now,
region A is not yet touched, but it is unallocated and should be
skipped.

Correspondingly, as progress we have

  total = A + B
  current = 0

If we reset unallocated region A and call progress_reset_callback,
it will calculate 0 bytes dirty in the bitmap and call
job_progress_set_remaining, which will set

   total = current + 0 = 0 + 0 = 0

So, B bytes are actually removed from total accounting. When job
finishes we'll have

   total = 0
   current = B

, which doesn't sound good.

This is because we didn't considered in-flight bytes, actually when
calculating remaining, we should have set (in_flight + dirty_bytes)
as remaining, not only dirty_bytes.

To fix it, let's refactor progress calculation, moving it to block-copy
itself instead of fixing callback. And, of course, track in_flight
bytes count.

We still have to keep one callback, to maintain backup job bytes_read
calculation, but it will go on soon, when we turn the whole backup
process into one block_copy call.

Cc: qemu-stable@nongnu.org
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-Id: <20200311103004.7649-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2020-03-11 13:29:57 +03:00 committed by Max Reitz
parent 01fe1ca945
commit d0ebeca14a
3 changed files with 19 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
block/backup.c
View file

@ -57,15 +57,6 @@ static void backup_progress_bytes_callback(int64_t bytes, void *opaque)
BackupBlockJob *s = opaque;
s->bytes_read += bytes;
job_progress_update(&s->common.job, bytes);
}
static void backup_progress_reset_callback(void *opaque)
{
BackupBlockJob *s = opaque;
uint64_t estimate = bdrv_get_dirty_count(s->bcs->copy_bitmap);
job_progress_set_remaining(&s->common.job, estimate);
}
static int coroutine_fn backup_do_cow(BackupBlockJob *job,
@ -464,8 +455,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
job->cluster_size = cluster_size;
job->len = len;
block_copy_set_callbacks(bcs, backup_progress_bytes_callback,
backup_progress_reset_callback, job);
block_copy_set_progress_callback(bcs, backup_progress_bytes_callback, job);
block_copy_set_progress_meter(bcs, &job->common.job.progress);
/* Required permissions are already taken by backup-top target */
block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,

16
block/block-copy.c
View file

@ -127,17 +127,20 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
return s;
}
void block_copy_set_callbacks(
void block_copy_set_progress_callback(
BlockCopyState *s,
ProgressBytesCallbackFunc progress_bytes_callback,
ProgressResetCallbackFunc progress_reset_callback,
void *progress_opaque)
{
s->progress_bytes_callback = progress_bytes_callback;
s->progress_reset_callback = progress_reset_callback;
s->progress_opaque = progress_opaque;
}
void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm)
{
s->progress = pm;
}
/*
* block_copy_do_copy
*
@ -269,7 +272,9 @@ int64_t block_copy_reset_unallocated(BlockCopyState *s,
if (!ret) {
bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
s->progress_reset_callback(s->progress_opaque);
progress_set_remaining(s->progress,
bdrv_get_dirty_count(s->copy_bitmap) +
s->in_flight_bytes);
}
*count = bytes;
@ -331,15 +336,18 @@ int coroutine_fn block_copy(BlockCopyState *s,
trace_block_copy_process(s, start);
bdrv_reset_dirty_bitmap(s->copy_bitmap, start, chunk_end - start);
s->in_flight_bytes += chunk_end - start;
co_get_from_shres(s->mem, chunk_end - start);
ret = block_copy_do_copy(s, start, chunk_end, error_is_read);
co_put_to_shres(s->mem, chunk_end - start);
s->in_flight_bytes -= chunk_end - start;
if (ret < 0) {
bdrv_set_dirty_bitmap(s->copy_bitmap, start, chunk_end - start);
break;
}
progress_work_done(s->progress, chunk_end - start);
s->progress_bytes_callback(chunk_end - start, s->progress_opaque);
start = chunk_end;
ret = 0;

15
include/block/block-copy.h
View file

@ -26,7 +26,6 @@ typedef struct BlockCopyInFlightReq {
} BlockCopyInFlightReq;
typedef void (*ProgressBytesCallbackFunc)(int64_t bytes, void *opaque);
typedef void (*ProgressResetCallbackFunc)(void *opaque);
typedef struct BlockCopyState {
/*
* BdrvChild objects are not owned or managed by block-copy. They are
@ -36,6 +35,7 @@ typedef struct BlockCopyState {
BdrvChild *source;
BdrvChild *target;
BdrvDirtyBitmap *copy_bitmap;
int64_t in_flight_bytes;
int64_t cluster_size;
bool use_copy_range;
int64_t copy_size;
@ -60,15 +60,9 @@ typedef struct BlockCopyState {
*/
bool skip_unallocated;
ProgressMeter *progress;
/* progress_bytes_callback: called when some copying progress is done. */
ProgressBytesCallbackFunc progress_bytes_callback;
/*
* progress_reset_callback: called when some bytes reset from copy_bitmap
* (see @skip_unallocated above). The callee is assumed to recalculate how
* many bytes remain based on the dirty bit count of copy_bitmap.
*/
ProgressResetCallbackFunc progress_reset_callback;
void *progress_opaque;
SharedResource *mem;
@ -79,12 +73,13 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
BdrvRequestFlags write_flags,
Error **errp);
void block_copy_set_callbacks(
void block_copy_set_progress_callback(
BlockCopyState *s,
ProgressBytesCallbackFunc progress_bytes_callback,
ProgressResetCallbackFunc progress_reset_callback,
void *progress_opaque);
void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm);
void block_copy_state_free(BlockCopyState *s);
int64_t block_copy_reset_unallocated(BlockCopyState *s,