[Qemu-stable] [BUGFIX][PATCH for 2.2 1/1] hw/ide/core.c: Prevent SIGSEGV during migration

[Don Slutz]

The other callers to blk_set_enable_write_cache() in this file
already check for s->blk == NULL.

Signed-off-by: Don Slutz <address@hidden>
---

I think this is a bugfix that should be back ported to stable
releases.

I also think this should be done in xen's copy of QEMU for 4.5 with
back port(s) to active stable releases.

Note: In 2.1 and earlier the routine is
bdrv_set_enable_write_cache(); variable is s->bs.

 hw/ide/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index 00e21cf..d4af5e2 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -2401,7 +2401,7 @@ static int ide_drive_post_load(void *opaque, int 
version_id)
 {
     IDEState *s = opaque;
 
-    if (s->identify_set) {
+    if (s->blk && s->identify_set) {
         blk_set_enable_write_cache(s->blk, !!(s->identify_data[85] & (1 << 
5)));
     }
     return 0;
-- 
1.8.4