ioctl: Rearrange members in nvme_set_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_set_property_args {
        int                        args_size;            /*     0     4 */
        int                        fd;                   /*     4     4 */
        __u32 *                    result;               /*     8     8 */
        __u32                      timeout;              /*    16     4 */
        int                        offset;               /*    20     4 */
        __u64                      value;                /*    24     8 */

        /* size: 32, cachelines: 1, members: 6 */
        /* last cacheline: 32 bytes */
} __attribute__((__aligned__(8)));

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

Author: dwsuse

src/nvme/ioctl.h

@@ -3369,19 +3369,19 @@ int nvme_lockdown(struct nvme_lockdown_args *args);
 /**
  * nvme_set_property_args - Arguments for NVMe Set Property command
  * @fd:		File descriptor of nvme device
+ * @result:	The command completion result from CQE dword0
+ * @timeout:	Timeout in ms
  * @offset:	Property offset from the base to set
  * @value:	The value to set the property
- * @timeout:	Timeout in ms
- * @result:	The command completion result from CQE dword0
  */
 struct nvme_set_property_args {
 	int args_size;
 	int fd;
+	__u32 *result;
+	__u32 timeout;
 	int offset;
 	__u64 value;
-	__u32 timeout;
-	__u32 *result;
-};
+} __attribute__((packed, aligned(__alignof__(__u64))));
 
 /**
  * nvme_set_property() - Set controller property