[Qemu-devel] [PATCH 1/2] block: make bdrv_create adopt coroutine

[zwu.kernel@gmail.com]

From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
 block.c |   48 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 47 insertions(+), 1 deletions(-)

diff --git a/block.c b/block.c
index 43c794c..3ff78c5 100644
--- a/block.c
+++ b/block.c
@@ -341,13 +341,59 @@ BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
     return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
 }
 
+typedef struct CreateCo {
+    BlockDriver *drv;
+    const char *filename;
+    QEMUOptionParameter *options;
+    int ret;
+} CreateCo;
+
+static void coroutine_fn bdrv_create_co_entry(void *opaque)
+{
+    CreateCo *cco = opaque;
+    assert(cco->drv);
+
+    cco->ret = cco->drv->bdrv_create(cco->filename, cco->options);
+}
+
+static int bdrv_create_co(BlockDriver *drv,
+                          const char *filename,
+                          QEMUOptionParameter *options)
+{
+    int ret;
+
+    Coroutine *co;
+    CreateCo cco = {
+        .drv = drv,
+        .filename = g_strdup(filename),
+        .options = options,
+        .ret = NOT_DONE,
+    };
+
+    if (qemu_in_coroutine()) {
+        /* Fast-path if already in coroutine context */
+        bdrv_create_co_entry(&cco);
+    } else {
+        co = qemu_coroutine_create(bdrv_create_co_entry);
+        qemu_coroutine_enter(co, &cco);
+        while (cco.ret == NOT_DONE) {
+            qemu_aio_wait();
+        }
+    }
+
+    ret = cco.ret;
+    g_free(cco.filename);
+
+    return ret;
+}
+
 int bdrv_create(BlockDriver *drv, const char* filename,
     QEMUOptionParameter *options)
 {
     if (!drv->bdrv_create)
         return -ENOTSUP;
 
-    return drv->bdrv_create(filename, options);
+    return bdrv_create_co(drv, filename, options);
 }
 
 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
-- 
1.7.6