qcow1: Make padding in the header explicit
We were relying on all compilers inserting the same padding in the
header struct that is used for the on-disk format. Let's not do that.
Mark the struct as packed and insert an explicit padding field for
compatibility.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
diff --git a/block/qcow.c b/block/qcow.c
index 937dd6d..3684794 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -48,9 +48,10 @@
uint64_t size; /* in bytes */
uint8_t cluster_bits;
uint8_t l2_bits;
+ uint16_t padding;
uint32_t crypt_method;
uint64_t l1_table_offset;
-} QCowHeader;
+} QEMU_PACKED QCowHeader;
#define L2_CACHE_SIZE 16
