diff --git a/include/block/export.h b/include/block/export.h
index 5459f79469..597fc58245 100644
--- a/include/block/export.h
+++ b/include/block/export.h
@@ -20,7 +20,8 @@ typedef struct BlockExport BlockExport;
 
 typedef struct BlockExportDriver {
     BlockExportType type;
-    BlockExport *(*create)(BlockExportOptions *, Error **);
+    size_t instance_size;
+    int (*create)(BlockExport *, BlockExportOptions *, Error **);
     void (*delete)(BlockExport *);
 } BlockExportDriver;
 
diff --git a/include/block/nbd.h b/include/block/nbd.h
index af8509ab70..602536feb2 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -328,11 +328,12 @@ int nbd_errno_to_system_errno(int err);
 typedef struct NBDExport NBDExport;
 typedef struct NBDClient NBDClient;
 
-BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp);
-NBDExport *nbd_export_new(BlockDriverState *bs,
-                          const char *name, const char *desc,
-                          const char *bitmap, bool readonly, bool shared,
-                          bool writethrough, Error **errp);
+int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args,
+                      Error **errp);
+int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs,
+                   const char *name, const char *desc,
+                   const char *bitmap, bool readonly, bool shared,
+                   bool writethrough, Error **errp);
 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk);
 void nbd_export_close(NBDExport *exp);
 void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
diff --git a/block/export/export.c b/block/export/export.c
index ef86bf892b..9de108cbc1 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -39,6 +39,8 @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type)
 BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
 {
     const BlockExportDriver *drv;
+    BlockExport *exp;
+    int ret;
 
     drv = blk_exp_find_driver(export->type);
     if (!drv) {
@@ -46,7 +48,19 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
         return NULL;
     }
 
-    return drv->create(export, errp);
+    exp = g_malloc0(drv->instance_size);
+    *exp = (BlockExport) {
+        .drv        = &blk_exp_nbd,
+        .refcount   = 1,
+    };
+
+    ret = drv->create(exp, export, errp);
+    if (ret < 0) {
+        g_free(exp);
+        return NULL;
+    }
+
+    return exp;
 }
 
 void blk_exp_ref(BlockExport *exp)
@@ -60,6 +74,7 @@ void blk_exp_unref(BlockExport *exp)
     assert(exp->refcount > 0);
     if (--exp->refcount == 0) {
         exp->drv->delete(exp);
+        g_free(exp);
     }
 }
 
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 5e97975c80..f97deba424 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -173,18 +173,19 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
     qapi_free_SocketAddress(addr_flat);
 }
 
-BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp)
+int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args,
+                      Error **errp)
 {
     BlockExportOptionsNbd *arg = &exp_args->u.nbd;
     BlockDriverState *bs = NULL;
-    NBDExport *exp = NULL;
     AioContext *aio_context;
+    int ret;
 
     assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD);
 
     if (!nbd_server && !is_qemu_nbd) {
         error_setg(errp, "NBD server not running");
-        return NULL;
+        return -EINVAL;
     }
 
     if (!arg->has_name) {
@@ -193,22 +194,22 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp)
 
     if (strlen(arg->name) > NBD_MAX_STRING_SIZE) {
         error_setg(errp, "export name '%s' too long", arg->name);
-        return NULL;
+        return -EINVAL;
     }
 
     if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) {
         error_setg(errp, "description '%s' too long", arg->description);
-        return NULL;
+        return -EINVAL;
     }
 
     if (nbd_export_find(arg->name)) {
         error_setg(errp, "NBD server already has export named '%s'", arg->name);
-        return NULL;
+        return -EEXIST;
     }
 
     bs = bdrv_lookup_bs(exp_args->device, exp_args->device, errp);
     if (!bs) {
-        return NULL;
+        return -ENOENT;
     }
 
     aio_context = bdrv_get_aio_context(bs);
@@ -218,14 +219,15 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp)
         arg->writable = false;
     }
     if (bdrv_is_read_only(bs) && arg->writable) {
+        ret = -EINVAL;
         error_setg(errp, "Cannot export read-only node as writable");
         goto out;
     }
 
-    exp = nbd_export_new(bs, arg->name, arg->description, arg->bitmap,
+    ret = nbd_export_new(exp, bs, arg->name, arg->description, arg->bitmap,
                          !arg->writable, !arg->writable,
                          exp_args->writethrough, errp);
-    if (!exp) {
+    if (ret < 0) {
         goto out;
     }
 
@@ -234,10 +236,10 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp)
      * the strong reference that is @exp. */
     blk_exp_unref((BlockExport*) exp);
 
+    ret = 0;
  out:
     aio_context_release(aio_context);
-    /* TODO Remove the cast: Move to server.c which can access fields of exp */
-    return (BlockExport*) exp;
+    return ret;
 }
 
 void qmp_nbd_server_remove(const char *name,
diff --git a/nbd/server.c b/nbd/server.c
index b735a68429..6a58297557 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1513,14 +1513,14 @@ void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk)
     blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier);
 }
 
-NBDExport *nbd_export_new(BlockDriverState *bs,
-                          const char *name, const char *desc,
-                          const char *bitmap, bool readonly, bool shared,
-                          bool writethrough, Error **errp)
+int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs,
+                   const char *name, const char *desc,
+                   const char *bitmap, bool readonly, bool shared,
+                   bool writethrough, Error **errp)
 {
+    NBDExport *exp = container_of(blk_exp, NBDExport, common);
     AioContext *ctx;
     BlockBackend *blk;
-    NBDExport *exp;
     int64_t size;
     uint64_t perm;
     int ret;
@@ -1529,17 +1529,11 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
     if (size < 0) {
         error_setg_errno(errp, -size,
                          "Failed to determine the NBD export's length");
-        return NULL;
+        return size;
     }
 
     ctx = bdrv_get_aio_context(bs);
-
-    exp = g_new0(NBDExport, 1);
-    exp->common = (BlockExport) {
-        .drv        = &blk_exp_nbd,
-        .refcount   = 1,
-        .ctx        = ctx,
-    };
+    blk_exp->ctx = ctx;
 
     /*
      * NBD exports are used for non-shared storage migration.  Make sure
@@ -1599,16 +1593,19 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
         }
 
         if (bm == NULL) {
+            ret = -ENOENT;
             error_setg(errp, "Bitmap '%s' is not found", bitmap);
             goto fail;
         }
 
         if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) {
+            ret = -EINVAL;
             goto fail;
         }
 
         if (readonly && bdrv_is_writable(bs) &&
             bdrv_dirty_bitmap_enabled(bm)) {
+            ret = -EINVAL;
             error_setg(errp,
                        "Enabled bitmap '%s' incompatible with readonly export",
                        bitmap);
@@ -1628,14 +1625,13 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
     blk_exp_ref(&exp->common);
     QTAILQ_INSERT_TAIL(&exports, exp, next);
 
-    return exp;
+    return 0;
 
 fail:
     blk_unref(blk);
     g_free(exp->name);
     g_free(exp->description);
-    g_free(exp);
-    return NULL;
+    return ret;
 }
 
 NBDExport *nbd_export_find(const char *name)
@@ -1722,12 +1718,12 @@ static void nbd_export_delete(BlockExport *blk_exp)
     }
 
     QTAILQ_REMOVE(&closed_exports, exp, next);
-    g_free(exp);
     aio_wait_kick();
 }
 
 const BlockExportDriver blk_exp_nbd = {
     .type               = BLOCK_EXPORT_TYPE_NBD,
+    .instance_size      = sizeof(NBDExport),
     .create             = nbd_export_create,
     .delete             = nbd_export_delete,
 };
