diff --git a/block.c b/block.c
index 3a32c37..432d659 100644
--- a/block.c
+++ b/block.c
@@ -953,9 +953,9 @@ free_and_fail:
  * after the call (even on failure), so if the caller intends to reuse the
  * dictionary, it needs to use QINCREF() before calling bdrv_file_open.
  */
-int bdrv_file_open(BlockDriverState **pbs, const char *filename,
-                   const char *reference, QDict *options, int flags,
-                   Error **errp)
+static int bdrv_file_open(BlockDriverState **pbs, const char *filename,
+                          const char *reference, QDict *options, int flags,
+                          Error **errp)
 {
     BlockDriverState *bs = NULL;
     BlockDriver *drv;
@@ -1201,8 +1201,9 @@ int bdrv_open_image(BlockDriverState **pbs, const char *filename,
 
         ret = bdrv_open(pbs, filename, NULL, image_options, flags, NULL, errp);
     } else {
-        ret = bdrv_file_open(pbs, filename, reference, image_options, flags,
-                             errp);
+        *pbs = NULL;
+        ret = bdrv_open(pbs, filename, reference, image_options,
+                        flags | BDRV_O_PROTOCOL, NULL, errp);
     }
 
 done:
@@ -1234,6 +1235,12 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
 
     assert(pbs);
 
+    if (flags & BDRV_O_PROTOCOL) {
+        assert(!drv);
+        return bdrv_file_open(pbs, filename, reference, options,
+                              flags & ~BDRV_O_PROTOCOL, errp);
+    }
+
     if (reference) {
         bool options_non_empty = options ? qdict_size(options) : false;
         QDECREF(options);
diff --git a/block/cow.c b/block/cow.c
index 7fc0b12..f0748a2 100644
--- a/block/cow.c
+++ b/block/cow.c
@@ -332,7 +332,7 @@ static int cow_create(const char *filename, QEMUOptionParameter *options,
     const char *image_filename = NULL;
     Error *local_err = NULL;
     int ret;
-    BlockDriverState *cow_bs;
+    BlockDriverState *cow_bs = NULL;
 
     /* Read out options */
     while (options && options->name) {
@@ -351,8 +351,8 @@ static int cow_create(const char *filename, QEMUOptionParameter *options,
         return ret;
     }
 
-    ret = bdrv_file_open(&cow_bs, filename, NULL, NULL, BDRV_O_RDWR,
-                         &local_err);
+    ret = bdrv_open(&cow_bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
     if (ret < 0) {
         qerror_report_err(local_err);
         error_free(local_err);
diff --git a/block/qcow.c b/block/qcow.c
index 948b0c5..4881d84 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -670,7 +670,7 @@ static int qcow_create(const char *filename, QEMUOptionParameter *options,
     int flags = 0;
     Error *local_err = NULL;
     int ret;
-    BlockDriverState *qcow_bs;
+    BlockDriverState *qcow_bs = NULL;
 
     /* Read out options */
     while (options && options->name) {
@@ -691,8 +691,8 @@ static int qcow_create(const char *filename, QEMUOptionParameter *options,
         return ret;
     }
 
-    ret = bdrv_file_open(&qcow_bs, filename, NULL, NULL, BDRV_O_RDWR,
-                         &local_err);
+    ret = bdrv_open(&qcow_bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
     if (ret < 0) {
         qerror_report_err(local_err);
         error_free(local_err);
diff --git a/block/qcow2.c b/block/qcow2.c
index 6996276..bd72172 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1481,7 +1481,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
      * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
      * size for any qcow2 image.
      */
-    BlockDriverState* bs;
+    BlockDriverState *bs = NULL;
     QCowHeader *header;
     uint8_t* refcount_table;
     Error *local_err = NULL;
@@ -1493,7 +1493,8 @@ static int qcow2_create2(const char *filename, int64_t total_size,
         return ret;
     }
 
-    ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
+    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+                    NULL, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         return ret;
diff --git a/block/qed.c b/block/qed.c
index b9ca7ac..33fbce1 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -571,8 +571,9 @@ static int qed_create(const char *filename, uint32_t cluster_size,
         return ret;
     }
 
-    ret = bdrv_file_open(&bs, filename, NULL, NULL,
-                         BDRV_O_RDWR | BDRV_O_CACHE_WB, &local_err);
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL, NULL,
+                    &local_err);
     if (ret < 0) {
         qerror_report_err(local_err);
         error_free(local_err);
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 672b9c9..6f2ec57 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1534,7 +1534,8 @@ static int sd_prealloc(const char *filename)
     Error *local_err = NULL;
     int ret;
 
-    ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
+    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+                    NULL, &local_err);
     if (ret < 0) {
         qerror_report_err(local_err);
         error_free(local_err);
@@ -1683,7 +1684,7 @@ static int sd_create(const char *filename, QEMUOptionParameter *options,
     }
 
     if (backing_file) {
-        BlockDriverState *bs;
+        BlockDriverState *bs = NULL;
         BDRVSheepdogState *base;
         BlockDriver *drv;
 
@@ -1695,7 +1696,8 @@ static int sd_create(const char *filename, QEMUOptionParameter *options,
             goto out;
         }
 
-        ret = bdrv_file_open(&bs, backing_file, NULL, NULL, 0, &local_err);
+        ret = bdrv_open(&bs, backing_file, NULL, NULL, BDRV_O_PROTOCOL, NULL,
+                        &local_err);
         if (ret < 0) {
             qerror_report_err(local_err);
             error_free(local_err);
diff --git a/block/vhdx.c b/block/vhdx.c
index 55689cf..38d949c 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1724,7 +1724,7 @@ static int vhdx_create(const char *filename, QEMUOptionParameter *options,
 
     gunichar2 *creator = NULL;
     glong creator_items;
-    BlockDriverState *bs;
+    BlockDriverState *bs = NULL;
     const char *type = NULL;
     VHDXImageType image_type;
     Error *local_err = NULL;
@@ -1797,7 +1797,8 @@ static int vhdx_create(const char *filename, QEMUOptionParameter *options,
         goto exit;
     }
 
-    ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
+    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+                    NULL, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto exit;
diff --git a/block/vmdk.c b/block/vmdk.c
index e007793..70bf011 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -776,8 +776,9 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
 
         path_combine(extent_path, sizeof(extent_path),
                 desc_file_path, fname);
-        ret = bdrv_file_open(&extent_file, extent_path, NULL, NULL,
-                             bs->open_flags, errp);
+        extent_file = NULL;
+        ret = bdrv_open(&extent_file, extent_path, NULL, NULL,
+                        bs->open_flags | BDRV_O_PROTOCOL, NULL, errp);
         if (ret) {
             return ret;
         }
@@ -1493,7 +1494,8 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
         goto exit;
     }
 
-    ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
+    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+                    NULL, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto exit;
@@ -1831,7 +1833,8 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options,
             goto exit;
         }
     }
-    ret = bdrv_file_open(&new_bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
+    ret = bdrv_open(&new_bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Could not write description");
         goto exit;
diff --git a/include/block/block.h b/include/block/block.h
index a421041..bf78db5 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -102,6 +102,9 @@ typedef enum {
 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
+#define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
+                                      select an appropriate protocol driver,
+                                      ignoring the format layer */
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
 
@@ -183,9 +186,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old);
 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
 int bdrv_parse_cache_flags(const char *mode, int *flags);
 int bdrv_parse_discard_flags(const char *mode, int *flags);
-int bdrv_file_open(BlockDriverState **pbs, const char *filename,
-                   const char *reference, QDict *options, int flags,
-                   Error **errp);
 int bdrv_open_image(BlockDriverState **pbs, const char *filename,
                     QDict *options, const char *bdref_key, int flags,
                     bool force_raw, bool allow_none, Error **errp);
diff --git a/qemu-io.c b/qemu-io.c
index 61d54c0..71d7806 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -59,7 +59,9 @@ static int openfile(char *name, int flags, int growable, QDict *opts)
     }
 
     if (growable) {
-        if (bdrv_file_open(&qemuio_bs, name, NULL, opts, flags, &local_err)) {
+        if (bdrv_open(&qemuio_bs, name, NULL, opts, flags | BDRV_O_PROTOCOL,
+                      NULL, &local_err))
+        {
             fprintf(stderr, "%s: can't open device %s: %s\n", progname, name,
                     error_get_pretty(local_err));
             error_free(local_err);
