From 6af40160209f579997e4adb05648813a717caab6 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 8 Mar 2016 15:57:05 +0100
Subject: [PATCH] qcow: Use BB functions in .bdrv_create()

All users of the block layers are supposed to go through a BlockBackend.
The .bdrv_create() implementation is one such user, so this patch
converts it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/block/qcow.c b/block/qcow.c
index c46810c56b..2fd5ee65d4 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -24,6 +24,7 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "block/block_int.h"
+#include "sysemu/block-backend.h"
 #include "qemu/module.h"
 #include <zlib.h>
 #include "qapi/qmp/qerror.h"
@@ -780,7 +781,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     int flags = 0;
     Error *local_err = NULL;
     int ret;
-    BlockDriverState *qcow_bs;
+    BlockBackend *qcow_blk;
 
     /* Read out options */
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
@@ -796,16 +797,18 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
         goto cleanup;
     }
 
-    qcow_bs = NULL;
-    ret = bdrv_open(&qcow_bs, filename, NULL, NULL,
-                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                    &local_err);
-    if (ret < 0) {
+    qcow_blk = blk_new_open("image", filename, NULL, NULL,
+                            BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
+                            &local_err);
+    if (qcow_blk == NULL) {
         error_propagate(errp, local_err);
+        ret = -EIO;
         goto cleanup;
     }
 
-    ret = bdrv_truncate(qcow_bs, 0);
+    blk_set_allow_write_beyond_eof(qcow_blk, true);
+
+    ret = blk_truncate(qcow_blk, 0);
     if (ret < 0) {
         goto exit;
     }
@@ -845,13 +848,13 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     /* write all the data */
-    ret = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header));
+    ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header));
     if (ret != sizeof(header)) {
         goto exit;
     }
 
     if (backing_file) {
-        ret = bdrv_pwrite(qcow_bs, sizeof(header),
+        ret = blk_pwrite(qcow_blk, sizeof(header),
             backing_file, backing_filename_len);
         if (ret != backing_filename_len) {
             goto exit;
@@ -861,7 +864,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     tmp = g_malloc0(BDRV_SECTOR_SIZE);
     for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/
         BDRV_SECTOR_SIZE); i++) {
-        ret = bdrv_pwrite(qcow_bs, header_size +
+        ret = blk_pwrite(qcow_blk, header_size +
             BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE);
         if (ret != BDRV_SECTOR_SIZE) {
             g_free(tmp);
@@ -872,7 +875,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     g_free(tmp);
     ret = 0;
 exit:
-    bdrv_unref(qcow_bs);
+    blk_unref(qcow_blk);
 cleanup:
     g_free(backing_file);
     return ret;