tarfs: 'struct tarfs_fid': Switch 'gen' to 'u_int', avoid packing

As the 'gen' field in 'struct tarfs_node' (and then 'struct tarfs_fid')
is filled with arc4random() which returns an unsigned int, change its
type in both structures.  This allows reordering fields in 'struct
tarfs_fid' to reduce its size, finally avoiding the use of '__packed' to
ensure it fits into 'struct fid'.

While here, remove the 'data0' field which wasn't necessary from the
start.

Reviewed by:    markj, rmacklem, des
Approved by:    markj (mentor)
MFC after:      5 days
Differential Revision:  https://reviews.freebsd.org/D47954

1 files changed, 5 insertions, 6 deletions

diff --git a/sys/fs/tarfs/tarfs.h b/sys/fs/tarfs/tarfs.h
index ffb95d2c0ac5..46fa8b55b3ad 100644
--- a/sys/fs/tarfs/tarfs.h
+++ b/sys/fs/tarfs/tarfs.h
@@ -74,7 +74,7 @@ struct tarfs_node {
 	struct timespec		 mtime;
 	struct timespec		 ctime;
 	struct timespec		 birthtime;
-	unsigned long		 gen;
+	uint32_t		 gen;
 
 	/* Block map */
 	size_t			 nblk;
@@ -161,11 +161,10 @@ struct tarfs_zio {
 };
 
 struct tarfs_fid {
-	u_short			 len;	/* length of data in bytes */
-	u_short			 data0;	/* force alignment */
-	ino_t			 ino;
-	unsigned long		 gen;
-} __packed;
+	u_short		 len;	/* length of data in bytes */
+	uint32_t	 gen;
+	ino_t		 ino;
+};
 
 #define	TARFS_NODE_LOCK(tnp) \
 	mtx_lock(&(tnp)->lock)