From d9420445fe0b78de91dc8615a61b973ed64e4f78 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 9 Sep 2013 14:27:57 +0200
Subject: [PATCH 06/38] blockdev: drop redundant proto_drv check

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1378736903-18489-7-git-send-email-kwolf@redhat.com>
Patchwork-id: 54193
O-Subject: [RHEL-7.0 qemu-kvm PATCH 06/32] blockdev: drop redundant proto_drv check
Bugzilla: 1005818
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Stefan Hajnoczi <stefanha@redhat.com>

Bugzilla: 1005818

It is not necessary to check that we can find a protocol block driver
since we create or open the image file.  This produces the error that we
need anyway.

Besides, the QERR_INVALID_BLOCK_FORMAT is inappropriate since the
protocol is incorrect rather than the format.

Also drop an empty line between bdrv_open() and checking its return
value.  This may be due to copy-pasting from earlier code that performed
other operations before handling errors.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit cb78466ef60ccf707a6f38a1294c435b65a828e0)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c | 15 ---------------
 1 file changed, 15 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 blockdev.c |   15 ---------------
 1 files changed, 0 insertions(+), 15 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index b8521c7..1f405c9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -818,7 +818,6 @@ typedef struct ExternalSnapshotStates {
 static void external_snapshot_prepare(BlkTransactionStates *common,
                                       Error **errp)
 {
-    BlockDriver *proto_drv;
     BlockDriver *drv;
     int flags, ret;
     Error *local_err = NULL;
@@ -874,12 +873,6 @@ static void external_snapshot_prepare(BlkTransactionStates *common,
 
     flags = states->old_bs->open_flags;
 
-    proto_drv = bdrv_find_protocol(new_image_file);
-    if (!proto_drv) {
-        error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
-        return;
-    }
-
     /* create new image w/backing file */
     if (mode != NEW_IMAGE_MODE_EXISTING) {
         bdrv_img_create(new_image_file, format,
@@ -1372,7 +1365,6 @@ void qmp_drive_mirror(const char *device, const char *target,
 {
     BlockDriverState *bs;
     BlockDriverState *source, *target_bs;
-    BlockDriver *proto_drv;
     BlockDriver *drv = NULL;
     Error *local_err = NULL;
     int flags;
@@ -1440,12 +1432,6 @@ void qmp_drive_mirror(const char *device, const char *target,
         sync = MIRROR_SYNC_MODE_FULL;
     }
 
-    proto_drv = bdrv_find_protocol(target);
-    if (!proto_drv) {
-        error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
-        return;
-    }
-
     bdrv_get_geometry(bs, &size);
     size *= 512;
     if (sync == MIRROR_SYNC_MODE_FULL && mode != NEW_IMAGE_MODE_EXISTING) {
@@ -1480,7 +1466,6 @@ void qmp_drive_mirror(const char *device, const char *target,
      */
     target_bs = bdrv_new("");
     ret = bdrv_open(target_bs, target, NULL, flags | BDRV_O_NO_BACKING, drv);
-
     if (ret < 0) {
         bdrv_delete(target_bs);
         error_set(errp, QERR_OPEN_FILE_FAILED, target);
-- 
1.7.1