From 84bdf21f97e670d61615d44a95d2f33b41f849b1 Mon Sep 17 00:00:00 2001
From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Date: Mon, 28 Nov 2022 09:23:30 -0500
Subject: [PATCH] block: distinguish between bdrv_create running in coroutine
 and not

Call two different functions depending on whether bdrv_create
is in coroutine or not, following the same pattern as
generated_co_wrapper functions.

This allows to also call the coroutine function directly,
without using CreateCo or relying in bdrv_create().

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-8-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 71 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 35 insertions(+), 36 deletions(-)

diff --git a/block.c b/block.c
index 9d77ec8818..0a1d484a27 100644
--- a/block.c
+++ b/block.c
@@ -526,63 +526,62 @@ typedef struct CreateCo {
     Error *err;
 } CreateCo;
 
+static int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
+                                       QemuOpts *opts, Error **errp)
+{
+    int ret;
+    GLOBAL_STATE_CODE();
+    ERRP_GUARD();
+
+    if (!drv->bdrv_co_create_opts) {
+        error_setg(errp, "Driver '%s' does not support image creation",
+                   drv->format_name);
+        return -ENOTSUP;
+    }
+
+    ret = drv->bdrv_co_create_opts(drv, filename, opts, errp);
+    if (ret < 0 && !*errp) {
+        error_setg_errno(errp, -ret, "Could not create image");
+    }
+
+    return ret;
+}
+
 static void coroutine_fn bdrv_create_co_entry(void *opaque)
 {
-    Error *local_err = NULL;
-    int ret;
-
     CreateCo *cco = opaque;
-    assert(cco->drv);
     GLOBAL_STATE_CODE();
 
-    ret = cco->drv->bdrv_co_create_opts(cco->drv,
-                                        cco->filename, cco->opts, &local_err);
-    error_propagate(&cco->err, local_err);
-    cco->ret = ret;
+    cco->ret = bdrv_co_create(cco->drv, cco->filename, cco->opts, &cco->err);
+    aio_wait_kick();
 }
 
 int bdrv_create(BlockDriver *drv, const char* filename,
                 QemuOpts *opts, Error **errp)
 {
-    int ret;
-
     GLOBAL_STATE_CODE();
 
-    Coroutine *co;
-    CreateCo cco = {
-        .drv = drv,
-        .filename = filename,
-        .opts = opts,
-        .ret = NOT_DONE,
-        .err = NULL,
-    };
-
-    if (!drv->bdrv_co_create_opts) {
-        error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
-        return -ENOTSUP;
-    }
-
     if (qemu_in_coroutine()) {
         /* Fast-path if already in coroutine context */
-        bdrv_create_co_entry(&cco);
+        return bdrv_co_create(drv, filename, opts, errp);
     } else {
+        Coroutine *co;
+        CreateCo cco = {
+            .drv = drv,
+            .filename = filename,
+            .opts = opts,
+            .ret = NOT_DONE,
+            .err = NULL,
+        };
+
         co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
         qemu_coroutine_enter(co);
         while (cco.ret == NOT_DONE) {
             aio_poll(qemu_get_aio_context(), true);
         }
+        error_propagate(errp, cco.err);
+        return cco.ret;
     }
-
-    ret = cco.ret;
-    if (ret < 0) {
-        if (cco.err) {
-            error_propagate(errp, cco.err);
-        } else {
-            error_setg_errno(errp, -ret, "Could not create image");
-        }
-    }
-
-    return ret;
 }
 
 /**