From 2432c8cf0a61be64094dae724638a9a081ee4bf9 Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Date: Thu, 27 Oct 2011 10:54:28 +0100
Subject: [PATCH] block: reinitialize across bdrv_close()/bdrv_open()
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Several BlockDriverState fields are not being reinitialized across
bdrv_close()/bdrv_open().  Make sure they are reset to their default
values.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 03f541bd6eacdc6c2893f72b975257c89cab2b74)

Signed-off-by: Bruce Rogers <brogers@suse.com>
[AF: backported]
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 block.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/block.c b/block.c
index 8d77746..1d6d26b 100644
--- a/block.c
+++ b/block.c
@@ -426,11 +426,14 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     bs->total_sectors = 0;
     bs->encrypted = 0;
     bs->valid_key = 0;
+    bs->sg = 0;
     bs->open_flags = flags;
+    bs->growable = 0;
     /* buffer_alignment defaulted to 512, drivers can change this value */
     bs->buffer_alignment = 512;
 
     pstrcpy(bs->filename, sizeof(bs->filename), filename);
+    bs->backing_file[0] = '\0';
 
     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
         return -ENOTSUP;
@@ -439,8 +442,7 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     bs->drv = drv;
     bs->opaque = qemu_mallocz(drv->instance_size);
 
-    if (flags & BDRV_O_CACHE_WB)
-        bs->enable_write_cache = 1;
+    bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
 
     /*
      * Clear flags that are internal to the block layer before opening the
-- 
1.7.11.2