From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Emanuele Giuseppe Esposito <eesposit@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>
Subject: [PATCH v3 5/5] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
Date: Tue, 8 Jun 2021 09:33:44 +0200 [thread overview]
Message-ID: <20210608073344.53637-6-eesposit@redhat.com> (raw)
In-Reply-To: <20210608073344.53637-1-eesposit@redhat.com>
By adding acquire/release pairs, we ensure that .ret and .error_is_read
fields are written by block_copy_dirty_clusters before .finished is true.
The atomic here are necessary because the fields are concurrently modified
also outside coroutines.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/block-copy.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
diff --git a/block/block-copy.c b/block/block-copy.c
index 56f62913e4..55b6ce6a57 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -56,11 +56,11 @@ typedef struct BlockCopyCallState {
QLIST_ENTRY(BlockCopyCallState) list;
/* State */
- bool finished;
+ bool finished; /* atomic */
QemuCoSleep sleep; /* TODO: protect API with a lock */
/* OUT parameters */
- bool cancelled;
+ bool cancelled; /* atomic */
/* Fields protected by lock in BlockCopyState */
bool error_is_read;
int ret;
@@ -648,7 +648,8 @@ block_copy_dirty_clusters(BlockCopyCallState *call_state)
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
assert(QEMU_IS_ALIGNED(bytes, s->cluster_size));
- while (bytes && aio_task_pool_status(aio) == 0 && !call_state->cancelled) {
+ while (bytes && aio_task_pool_status(aio) == 0 &&
+ !qatomic_read(&call_state->cancelled)) {
BlockCopyTask *task;
int64_t status_bytes;
@@ -758,7 +759,7 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state)
do {
ret = block_copy_dirty_clusters(call_state);
- if (ret == 0 && !call_state->cancelled) {
+ if (ret == 0 && !qatomic_read(&call_state->cancelled)) {
ret = block_copy_wait_one(call_state->s, call_state->offset,
call_state->bytes);
}
@@ -772,9 +773,9 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state)
* 2. We have waited for some intersecting block-copy request
* It may have failed and produced new dirty bits.
*/
- } while (ret > 0 && !call_state->cancelled);
+ } while (ret > 0 && !qatomic_read(&call_state->cancelled));
- call_state->finished = true;
+ qatomic_store_release(&call_state->finished, true);
if (call_state->cb) {
call_state->cb(call_state->cb_opaque);
@@ -837,35 +838,37 @@ void block_copy_call_free(BlockCopyCallState *call_state)
return;
}
- assert(call_state->finished);
+ assert(qatomic_load_acquire(&call_state->finished));
g_free(call_state);
}
bool block_copy_call_finished(BlockCopyCallState *call_state)
{
- return call_state->finished;
+ return qatomic_load_acquire(&call_state->finished);
}
bool block_copy_call_succeeded(BlockCopyCallState *call_state)
{
- return call_state->finished && !call_state->cancelled &&
- call_state->ret == 0;
+ return qatomic_load_acquire(&call_state->finished) &&
+ !qatomic_read(&call_state->cancelled) &&
+ call_state->ret == 0;
}
bool block_copy_call_failed(BlockCopyCallState *call_state)
{
- return call_state->finished && !call_state->cancelled &&
- call_state->ret < 0;
+ return qatomic_load_acquire(&call_state->finished) &&
+ !qatomic_read(&call_state->cancelled) &&
+ call_state->ret < 0;
}
bool block_copy_call_cancelled(BlockCopyCallState *call_state)
{
- return call_state->cancelled;
+ return qatomic_read(&call_state->cancelled);
}
int block_copy_call_status(BlockCopyCallState *call_state, bool *error_is_read)
{
- assert(call_state->finished);
+ assert(qatomic_load_acquire(&call_state->finished));
if (error_is_read) {
*error_is_read = call_state->error_is_read;
}
@@ -874,7 +877,7 @@ int block_copy_call_status(BlockCopyCallState *call_state, bool *error_is_read)
void block_copy_call_cancel(BlockCopyCallState *call_state)
{
- call_state->cancelled = true;
+ qatomic_set(&call_state->cancelled, true);
block_copy_kick(call_state);
}
--
2.30.2
prev parent reply other threads:[~2021-06-08 7:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-08 7:33 [PATCH v3 0/5] block-copy: protect block-copy internal structures Emanuele Giuseppe Esposito
2021-06-08 7:33 ` [PATCH v3 1/5] block-copy: streamline choice of copy_range vs. read/write Emanuele Giuseppe Esposito
2021-06-09 8:51 ` Vladimir Sementsov-Ogievskiy
2021-06-09 9:33 ` Paolo Bonzini
2021-06-09 10:09 ` Vladimir Sementsov-Ogievskiy
2021-06-09 10:54 ` Vladimir Sementsov-Ogievskiy
2021-06-08 7:33 ` [PATCH v3 2/5] block-copy: improve comments of BlockCopyTask and BlockCopyState types and functions Emanuele Giuseppe Esposito
2021-06-09 9:12 ` Vladimir Sementsov-Ogievskiy
2021-06-10 10:14 ` Emanuele Giuseppe Esposito
2021-06-10 10:27 ` Vladimir Sementsov-Ogievskiy
2021-06-10 10:46 ` Emanuele Giuseppe Esposito
2021-06-10 11:12 ` Vladimir Sementsov-Ogievskiy
2021-06-10 14:21 ` Emanuele Giuseppe Esposito
2021-06-10 15:05 ` Vladimir Sementsov-Ogievskiy
2021-06-08 7:33 ` [PATCH v3 3/5] block-copy: move progress_set_remaining in block_copy_task_end Emanuele Giuseppe Esposito
2021-06-08 7:33 ` [PATCH v3 4/5] block-copy: add a CoMutex Emanuele Giuseppe Esposito
2021-06-09 12:25 ` Vladimir Sementsov-Ogievskiy
2021-06-10 14:49 ` Emanuele Giuseppe Esposito
2021-06-08 7:33 ` Emanuele Giuseppe Esposito [this message]
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