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Diffstat (limited to 'block/io.c')
-rw-r--r--block/io.c42
1 files changed, 33 insertions, 9 deletions
diff --git a/block/io.c b/block/io.c
index b413727..aece54c 100644
--- a/block/io.c
+++ b/block/io.c
@@ -149,6 +149,37 @@ bool bdrv_requests_pending(BlockDriverState *bs)
return false;
}
+typedef struct {
+ Coroutine *co;
+ BlockDriverState *bs;
+ bool done;
+} BdrvCoDrainData;
+
+static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
+{
+ BdrvCoDrainData *data = opaque;
+ BlockDriverState *bs = data->bs;
+
+ bs->drv->bdrv_co_drain(bs);
+
+ /* Set data->done before reading bs->wakeup. */
+ atomic_mb_set(&data->done, true);
+ bdrv_wakeup(bs);
+}
+
+static void bdrv_drain_invoke(BlockDriverState *bs)
+{
+ BdrvCoDrainData data = { .bs = bs, .done = false };
+
+ if (!bs->drv || !bs->drv->bdrv_co_drain) {
+ return;
+ }
+
+ data.co = qemu_coroutine_create(bdrv_drain_invoke_entry, &data);
+ bdrv_coroutine_enter(bs, data.co);
+ BDRV_POLL_WHILE(bs, !data.done);
+}
+
static bool bdrv_drain_recurse(BlockDriverState *bs)
{
BdrvChild *child, *tmp;
@@ -156,9 +187,8 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
- if (bs->drv && bs->drv->bdrv_drain) {
- bs->drv->bdrv_drain(bs);
- }
+ /* Ensure any pending metadata writes are submitted to bs->file. */
+ bdrv_drain_invoke(bs);
QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
BlockDriverState *bs = child->bs;
@@ -184,12 +214,6 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
return waited;
}
-typedef struct {
- Coroutine *co;
- BlockDriverState *bs;
- bool done;
-} BdrvCoDrainData;
-
static void bdrv_co_drain_bh_cb(void *opaque)
{
BdrvCoDrainData *data = opaque;