ioctl: Rearrange members in nvme_get_property_args

Avoid any holes in the struct by rearranging the members. Also add the
attribute packed to struct definition to reduce ABI breakage.

struct nvme_get_property_args {
        int                        args_size;            /*     0     4 */
        int                        fd;                   /*     4     4 */
        __u64 *                    value;                /*     8     8 */
        __u32                      timeout;              /*    16     4 */
        int                        offset;               /*    20     4 */

       /* size: 24, cachelines: 1, members: 5 */
        /* last cacheline: 24 bytes */
} __attribute__((__aligned__(8)));

Signed-off-by: Daniel Wagner <[email protected]>

Author: dwsuse

src/nvme/ioctl.h

@@ -3398,17 +3398,17 @@ int nvme_set_property(struct nvme_set_property_args *args);
 /**
  * nvme_get_property_args - Arguments for NVMe Get Property command
  * @fd:		File descriptor of nvme device
- * @offset:	Property offset from the base to retrieve
  * @value:	Where the property's value will be stored on success
+ * @offset:	Property offset from the base to retrieve
  * @timeout:	Timeout in ms
  */
 struct nvme_get_property_args {
 	int args_size;
 	int fd;
-	int offset;
 	__u64 *value;
 	__u32 timeout;
-};
+	int offset;
+} __attribute__((packed, aligned(__alignof__(__u64*))));
 
 /**
  * nvme_get_property() - Get a controller property