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From b461a24186f05d7adec265bd34f348f7b8f9569b Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Date: Thu, 27 Oct 2011 10:54:27 +0100
Subject: [PATCH] block: set bs->read_only before .bdrv_open()
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Several block drivers set bs->read_only in .bdrv_open() but
block.c:bdrv_open_common() clobbers its value.  Additionally, QED uses
bdrv_is_read_only() in .bdrv_open() to decide whether to perform
consistency checks.

The correct ordering is to initialize bs->read_only from the open flags
before calling .bdrv_open().  This way block drivers can override it if
necessary and can use bdrv_is_read_only() in .bdrv_open().

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit e7c637967e6aad195b5f30cfd995913c9e0b4666)

Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 block.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block.c b/block.c
index 4ebb18b..8d77746 100644
--- a/block.c
+++ b/block.c
@@ -455,6 +455,8 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
         open_flags |= BDRV_O_RDWR;
     }
 
+    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
+
     /* Open the image, either directly or using a protocol */
     if (drv->bdrv_file_open) {
         ret = drv->bdrv_file_open(bs, filename, open_flags);
@@ -469,8 +471,6 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
         goto free_and_fail;
     }
 
-    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
-
     ret = refresh_total_sectors(bs, bs->total_sectors);
     if (ret < 0) {
         goto free_and_fail;
-- 
1.7.11.2