20.04.2021 15:51, Emanuele Giuseppe Esposito wrote:
On 20/04/2021 14:03, Vladimir Sementsov-Ogievskiy wrote:
20.04.2021 13:04, Emanuele Giuseppe Esposito wrote:
As done in BlockCopyCallState, categorize BlockCopyTask
in IN, State and OUT fields. This is just to understand
which field has to be protected with a lock.
Also add coroutine_fn attribute to block_copy_task_create,
because it is only usedn block_copy_dirty_clusters, a coroutine
function itself.
Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
---
block/block-copy.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/block/block-copy.c b/block/block-copy.c
index 39ae481c8b..03df50a354 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -48,25 +48,32 @@ typedef struct BlockCopyCallState {
QLIST_ENTRY(BlockCopyCallState) list;
/* State */
- int ret;
bool finished;
QemuCoSleepState *sleep_state;
bool cancelled;
/* OUT parameters */
+ int ret;
Hmm. Somehow, ret may be considered is part of state too.. But I don't really
care. Here it looks not bad. Will see how and what you are going protect by new
lock.
Note, that ret is concurently set in block_copy_task_entry..
It is set but as far as I understood it contains the result of the operation
(thus OUT), correct?
Yes. I just mean, that ret should be protected too. If block_copy_task_entry()
called concurently from different threads, we'll check-and-set ret concurently.
bool error_is_read;
} BlockCopyCallState;
typedef struct BlockCopyTask {
+ /* IN parameters. Initialized in block_copy_task_create()
+ * and never changed.
+ */
It's wrong about task field, as it has "ret" inside.
Not sure I understand what you mean here.
task.ret it not an "IN" parameter
AioTask task;
-
BlockCopyState *s;
BlockCopyCallState *call_state;
+
+ /* State */
int64_t offset;
I think, offset is never changed after block_copy_task_create()..
right, will revert that for offset
int64_t bytes;
bool zeroes;
- QLIST_ENTRY(BlockCopyTask) list;
CoQueue wait_queue; /* coroutines blocked on this task */
+
+ /* To reference all call states from BlockCopyTask */
Amm.. Actually,
To reference all tasks from BlockCopyState
right, agree, thanks
+ QLIST_ENTRY(BlockCopyTask) list;
+
} BlockCopyTask;
static int64_t task_end(BlockCopyTask *task)
@@ -153,7 +160,7 @@ static bool coroutine_fn block_copy_wait_one(BlockCopyState
*s, int64_t offset,
* Search for the first dirty area in offset/bytes range and create task at
* the beginning of it.
*/
-static BlockCopyTask *block_copy_task_create(BlockCopyState *s,
+static BlockCopyTask *coroutine_fn block_copy_task_create(BlockCopyState *s,
BlockCopyCallState *call_state,
int64_t offset, int64_t bytes)
{
We mark by "coroutine_fn" functions that can be called _only_ from coroutine context.
In my opinion, block_copy_task_create is a static function and it's called only
by another coroutine_fn, block_copy_dirty_clusters, so it matches what you just
wrote above.
"coroutine_fn" is restriction. block_copy_task_create doesn't need this
restriction. It may be safely called from non-coroutine context. So, no reason to add the
restriction.
block_copy_task_create() may be called from any context, both coroutine and
non-coroutine. So, it shouldn't have this mark.
Thank you,
Emanuele
--
Best regards,
Vladimir
