[Qemu-devel] [PATCH stable-0.15 23/36] block: set bs->read_only before .bdrv_open()

[Andreas Färber]

From: Stefan Hajnoczi <address@hidden>

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 <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
(cherry picked from commit e7c637967e6aad195b5f30cfd995913c9e0b4666)

Signed-off-by: Bruce Rogers <address@hidden>
Signed-off-by: Andreas Färber <address@hidden>
---
 block.c |    4 ++--
 1 files 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;
-- 
1.7.7