throttle: add throttle_detach/attach_aio_context()
Block I/O throttling uses timers and currently always adds them to the
main loop. Throttling will break if bdrv_set_aio_context() is used to
move a BlockDriverState to a different AioContext.
This patch adds throttle_detach/attach_aio_context() interfaces so the
throttling timers and uses them to move timers to the new AioContext.
Note that bdrv_set_aio_context() already drains all requests so we're
sure no throttled requests are pending.
The test cases need to be updated since the throttle_init() interface
has changed.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
diff --git a/block.c b/block.c
index 1fd3815..17f763d 100644
--- a/block.c
+++ b/block.c
@@ -179,6 +179,7 @@
{
assert(!bs->io_limits_enabled);
throttle_init(&bs->throttle_state,
+ bdrv_get_aio_context(bs),
QEMU_CLOCK_VIRTUAL,
bdrv_throttle_read_timer_cb,
bdrv_throttle_write_timer_cb,
@@ -5671,6 +5672,9 @@
return;
}
+ if (bs->io_limits_enabled) {
+ throttle_detach_aio_context(&bs->throttle_state);
+ }
if (bs->drv->bdrv_detach_aio_context) {
bs->drv->bdrv_detach_aio_context(bs);
}
@@ -5702,6 +5706,9 @@
if (bs->drv->bdrv_attach_aio_context) {
bs->drv->bdrv_attach_aio_context(bs, new_context);
}
+ if (bs->io_limits_enabled) {
+ throttle_attach_aio_context(&bs->throttle_state, new_context);
+ }
}
void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
