Comment "Called only on full-dirty region" without corresponding
assertion is a very unsafe thing. Adding assertion means call
bdrv_dirty_bitmap_next_zero twice. Instead, let's move
bdrv_dirty_bitmap_next_zero call to block_copy_task_create. It also
allows to drop cur_bytes variable which partly duplicate task->bytes.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
block/block-copy.c | 42 +++++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 21 deletions(-)
diff --git a/block/block-copy.c b/block/block-copy.c
index 7652b4afc5..0525a9fcd5 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -111,12 +111,23 @@ static bool coroutine_fn
block_copy_wait_one(BlockCopyState *s, int64_t start,
return true;
}
-/* Called only on full-dirty region */
static BlockCopyTask *block_copy_task_create(BlockCopyState *s,
int64_t offset, int64_t bytes)
{
+ int64_t next_zero;
BlockCopyTask *task = g_new(BlockCopyTask, 1);
+ assert(bdrv_dirty_bitmap_get(s->copy_bitmap, offset));
+
+ bytes = MIN(bytes, s->copy_size);
+ next_zero = bdrv_dirty_bitmap_next_zero(s->copy_bitmap, offset, bytes);
+ if (next_zero >= 0) {
+ assert(next_zero > offset); /* offset is dirty */
+ assert(next_zero < offset + bytes); /* no need to do MIN() */
+ bytes = next_zero - offset;
+ }
+
+ /* region is dirty, so no existent tasks possible in it */
assert(!block_copy_find_task(s, offset, bytes));
bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
@@ -461,7 +472,7 @@ static int coroutine_fn
block_copy_dirty_clusters(BlockCopyState *s,
while (bytes) {
g_autofree BlockCopyTask *task = NULL;
- int64_t next_zero, cur_bytes, status_bytes;
+ int64_t status_bytes;
if (!bdrv_dirty_bitmap_get(s->copy_bitmap, offset)) {
trace_block_copy_skip(s, offset);
@@ -472,18 +483,9 @@ static int coroutine_fn
block_copy_dirty_clusters(BlockCopyState *s,
found_dirty = true;
- cur_bytes = MIN(bytes, s->copy_size);
+ task = block_copy_task_create(s, offset, bytes);
- next_zero = bdrv_dirty_bitmap_next_zero(s->copy_bitmap, offset,
- cur_bytes);
- if (next_zero >= 0) {
- assert(next_zero > offset); /* offset is dirty */
- assert(next_zero < offset + cur_bytes); /* no need to do MIN() */
- cur_bytes = next_zero - offset;
- }
- task = block_copy_task_create(s, offset, cur_bytes);
-
- ret = block_copy_block_status(s, offset, cur_bytes, &status_bytes);
+ ret = block_copy_block_status(s, offset, task->bytes, &status_bytes);
block_copy_task_shrink(task, status_bytes);
if (s->skip_unallocated && !(ret & BDRV_BLOCK_ALLOCATED)) {
block_copy_task_end(task, 0);
@@ -494,22 +496,20 @@ static int coroutine_fn
block_copy_dirty_clusters(BlockCopyState *s,
continue;
}
- cur_bytes = MIN(cur_bytes, status_bytes);
-
trace_block_copy_process(s, offset);
- co_get_from_shres(s->mem, cur_bytes);
- ret = block_copy_do_copy(s, offset, cur_bytes, ret & BDRV_BLOCK_ZERO,
+ co_get_from_shres(s->mem, task->bytes);
+ ret = block_copy_do_copy(s, offset, task->bytes, ret & BDRV_BLOCK_ZERO,
error_is_read);
- co_put_to_shres(s->mem, cur_bytes);
+ co_put_to_shres(s->mem, task->bytes);
block_copy_task_end(task, ret);
if (ret < 0) {
return ret;
}
- s->progress_bytes_callback(cur_bytes, s->progress_opaque);
- offset += cur_bytes;
- bytes -= cur_bytes;
+ s->progress_bytes_callback(task->bytes, s->progress_opaque);
+ offset += task->bytes;
+ bytes -= task->bytes;
}
return found_dirty;
--
2.21.0
