block: Use writeback in .bdrv_create() implementations

There's no reason to use a writethrough cache mode while creating an
image.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/parallels.c

@@ -479,7 +479,8 @@ static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 
     file = NULL;
     ret = bdrv_open(&file, filename, NULL, NULL,
-                    BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
+                    &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         return ret;

block/qcow.c

@@ -798,7 +798,8 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
 
     qcow_bs = NULL;
     ret = bdrv_open(&qcow_bs, filename, NULL, NULL,
-                    BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
+                    &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto cleanup;

block/qcow2.c

@@ -2173,7 +2173,8 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     }
 
     bs = NULL;
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);

block/sheepdog.c

@@ -1645,7 +1645,8 @@ static int sd_prealloc(const char *filename, Error **errp)
     void *buf = NULL;
     int ret;
 
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     errp);
     if (ret < 0) {
         goto out_with_err_set;
@@ -1838,7 +1839,8 @@ static int sd_create(const char *filename, QemuOpts *opts,
         }
 
         bs = NULL;
-        ret = bdrv_open(&bs, backing_file, NULL, NULL, BDRV_O_PROTOCOL, errp);
+        ret = bdrv_open(&bs, backing_file, NULL, NULL,
+                        BDRV_O_PROTOCOL | BDRV_O_CACHE_WB, errp);
         if (ret < 0) {
             goto out;
         }

block/vdi.c

@@ -766,7 +766,8 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
         error_propagate(errp, local_err);
         goto exit;
     }
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);

block/vhdx.c

@@ -1838,7 +1838,8 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     bs = NULL;
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);

block/vmdk.c

@@ -1664,7 +1664,8 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
     }
 
     assert(bs == NULL);
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
@@ -1944,7 +1945,8 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
             ret = -ENOENT;
             goto exit;
         }
-        ret = bdrv_open(&bs, full_backing, NULL, NULL, BDRV_O_NO_BACKING, errp);
+        ret = bdrv_open(&bs, full_backing, NULL, NULL,
+                        BDRV_O_NO_BACKING | BDRV_O_CACHE_WB, errp);
         g_free(full_backing);
         if (ret != 0) {
             goto exit;
@@ -2015,7 +2017,8 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
     }
     assert(new_bs == NULL);
     ret = bdrv_open(&new_bs, filename, NULL, NULL,
-                    BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
+                    &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto exit;

block/vpc.c

@@ -886,7 +886,8 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
         error_propagate(errp, local_err);
         goto out;
     }
-    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+    ret = bdrv_open(&bs, filename, NULL, NULL,
+                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
                     &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);