block: convert bdrv_check callback to coroutine_fn

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 40 insertions, 3 deletions

diff --git a/block.c b/block.c
index 603befb325..8f1c43d037 100644
--- a/block.c
+++ b/block.c
@@ -3455,17 +3455,54 @@ static void bdrv_delete(BlockDriverState *bs)
  * free of errors) or -errno when an internal error occurred. The results of the
  * check are stored in res.
  */
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
+static int coroutine_fn bdrv_co_check(BlockDriverState *bs,
+                                      BdrvCheckResult *res, BdrvCheckMode fix)
 {
     if (bs->drv == NULL) {
         return -ENOMEDIUM;
     }
-    if (bs->drv->bdrv_check == NULL) {
+    if (bs->drv->bdrv_co_check == NULL) {
         return -ENOTSUP;
     }
 
     memset(res, 0, sizeof(*res));
-    return bs->drv->bdrv_check(bs, res, fix);
+    return bs->drv->bdrv_co_check(bs, res, fix);
+}
+
+typedef struct CheckCo {
+    BlockDriverState *bs;
+    BdrvCheckResult *res;
+    BdrvCheckMode fix;
+    int ret;
+} CheckCo;
+
+static void bdrv_check_co_entry(void *opaque)
+{
+    CheckCo *cco = opaque;
+    cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
+}
+
+int bdrv_check(BlockDriverState *bs,
+               BdrvCheckResult *res, BdrvCheckMode fix)
+{
+    Coroutine *co;
+    CheckCo cco = {
+        .bs = bs,
+        .res = res,
+        .ret = -EINPROGRESS,
+        .fix = fix,
+    };
+
+    if (qemu_in_coroutine()) {
+        /* Fast-path if already in coroutine context */
+        bdrv_check_co_entry(&cco);
+    } else {
+        co = qemu_coroutine_create(bdrv_check_co_entry, &cco);
+        qemu_coroutine_enter(co);
+        BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS);
+    }
+
+    return cco.ret;
 }
 
 /*