Commit b681a1c7 authored by Benoît Canet's avatar Benoît Canet Committed by Stefan Hajnoczi
Browse files

block: Repair the throttling code.

The throttling code was segfaulting since commit
02ffb504

 because some qemu_co_queue_next caller
does not run in a coroutine.
qemu_co_queue_do_restart assume that the caller is a coroutinne.
As suggested by Stefan fix this by entering the coroutine directly.
Also make sure like suggested that qemu_co_queue_next() and
qemu_co_queue_restart_all() can be called only in coroutines.
Signed-off-by: default avatarBenoit Canet <benoit@irqsave.net>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 42ec24e2
......@@ -127,7 +127,7 @@ void bdrv_io_limits_disable(BlockDriverState *bs)
{
bs->io_limits_enabled = false;
while (qemu_co_queue_next(&bs->throttled_reqs));
do {} while (qemu_co_enter_next(&bs->throttled_reqs));
if (bs->block_timer) {
qemu_del_timer(bs->block_timer);
......@@ -143,7 +143,7 @@ static void bdrv_block_timer(void *opaque)
{
BlockDriverState *bs = opaque;
qemu_co_queue_next(&bs->throttled_reqs);
qemu_co_enter_next(&bs->throttled_reqs);
}
void bdrv_io_limits_enable(BlockDriverState *bs)
......@@ -1452,8 +1452,7 @@ void bdrv_drain_all(void)
* a busy wait.
*/
QTAILQ_FOREACH(bs, &bdrv_states, list) {
if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
qemu_co_queue_restart_all(&bs->throttled_reqs);
while (qemu_co_enter_next(&bs->throttled_reqs)) {
busy = true;
}
}
......
......@@ -130,12 +130,17 @@ void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue);
*
* Returns true if a coroutine was restarted, false if the queue is empty.
*/
bool qemu_co_queue_next(CoQueue *queue);
bool coroutine_fn qemu_co_queue_next(CoQueue *queue);
/**
* Restarts all coroutines in the CoQueue and leaves the queue empty.
*/
void qemu_co_queue_restart_all(CoQueue *queue);
void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue);
/**
* Enter the next coroutine in the queue
*/
bool qemu_co_enter_next(CoQueue *queue);
/**
* Checks if the CoQueue is empty.
......
......@@ -88,16 +88,32 @@ static bool qemu_co_queue_do_restart(CoQueue *queue, bool single)
return true;
}
bool qemu_co_queue_next(CoQueue *queue)
bool coroutine_fn qemu_co_queue_next(CoQueue *queue)
{
assert(qemu_in_coroutine());
return qemu_co_queue_do_restart(queue, true);
}
void qemu_co_queue_restart_all(CoQueue *queue)
void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue)
{
assert(qemu_in_coroutine());
qemu_co_queue_do_restart(queue, false);
}
bool qemu_co_enter_next(CoQueue *queue)
{
Coroutine *next;
next = QTAILQ_FIRST(&queue->entries);
if (!next) {
return false;
}
QTAILQ_REMOVE(&queue->entries, next, co_queue_next);
qemu_coroutine_enter(next, NULL);
return true;
}
bool qemu_co_queue_empty(CoQueue *queue)
{
return (QTAILQ_FIRST(&queue->entries) == NULL);
......
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