Index: head/sys/geom/geom_io.c
===================================================================
--- head/sys/geom/geom_io.c
+++ head/sys/geom/geom_io.c
@@ -504,11 +504,11 @@
 	cmd = bp->bio_cmd;
 	if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) {
 		KASSERT(bp->bio_data != NULL,
-		    ("NULL bp->data in g_io_request(cmd=%hhu)", bp->bio_cmd));
+		    ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd));
 	}
 	if (cmd == BIO_DELETE || cmd == BIO_FLUSH) {
 		KASSERT(bp->bio_data == NULL,
-		    ("non-NULL bp->data in g_io_request(cmd=%hhu)",
+		    ("non-NULL bp->data in g_io_request(cmd=%hu)",
 		    bp->bio_cmd));
 	}
 	if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) {
Index: head/sys/geom/geom_subr.c
===================================================================
--- head/sys/geom/geom_subr.c
+++ head/sys/geom/geom_subr.c
@@ -1508,8 +1508,8 @@
 		db_printf("BIO %p\n", bp);
 		db_print_bio_cmd(bp);
 		db_print_bio_flags(bp);
-		db_printf("  cflags: 0x%hhx\n", bp->bio_cflags);
-		db_printf("  pflags: 0x%hhx\n", bp->bio_pflags);
+		db_printf("  cflags: 0x%hx\n", bp->bio_cflags);
+		db_printf("  pflags: 0x%hx\n", bp->bio_pflags);
 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
 		db_printf("  bcount: %ld\n", bp->bio_bcount);
Index: head/sys/geom/mirror/g_mirror.c
===================================================================
--- head/sys/geom/mirror/g_mirror.c
+++ head/sys/geom/mirror/g_mirror.c
@@ -1905,7 +1905,7 @@
 				g_mirror_sync_request(bp);	/* WRITE */
 			else {
 				KASSERT(0,
-				    ("Invalid request cflags=0x%hhx to=%s.",
+				    ("Invalid request cflags=0x%hx to=%s.",
 				    bp->bio_cflags, bp->bio_to->name));
 			}
 		} else {
Index: head/sys/geom/raid3/g_raid3.c
===================================================================
--- head/sys/geom/raid3/g_raid3.c
+++ head/sys/geom/raid3/g_raid3.c
@@ -2127,7 +2127,7 @@
 				g_raid3_sync_request(bp);	/* WRITE */
 			else {
 				KASSERT(0,
-				    ("Invalid request cflags=0x%hhx to=%s.",
+				    ("Invalid request cflags=0x%hx to=%s.",
 				    bp->bio_cflags, bp->bio_to->name));
 			}
 		} else if (g_raid3_register_request(bp) != 0) {
Index: head/sys/sys/bio.h
===================================================================
--- head/sys/sys/bio.h
+++ head/sys/sys/bio.h
@@ -77,10 +77,10 @@
  * The bio structure describes an I/O operation in the kernel.
  */
 struct bio {
-	uint8_t	bio_cmd;		/* I/O operation. */
-	uint8_t	bio_flags;		/* General flags. */
-	uint8_t	bio_cflags;		/* Private use by the consumer. */
-	uint8_t	bio_pflags;		/* Private use by the provider. */
+	uint16_t bio_cmd;		/* I/O operation. */
+	uint16_t bio_flags;		/* General flags. */
+	uint16_t bio_cflags;		/* Private use by the consumer. */
+	uint16_t bio_pflags;		/* Private use by the provider. */
 	struct cdev *bio_dev;		/* Device to do I/O on. */
 	struct disk *bio_disk;		/* Valid below geom_disk.c only */
 	off_t	bio_offset;		/* Offset into file. */
Index: head/sys/sys/buf.h
===================================================================
--- head/sys/sys/buf.h
+++ head/sys/sys/buf.h
@@ -98,8 +98,8 @@
 	void		*b_caller1;
 	caddr_t		b_data;
 	int		b_error;
-	uint8_t		b_iocmd;	/* BIO_* bio_cmd from bio.h */
-	uint8_t		b_ioflags;	/* BIO_* bio_flags from bio.h */
+	uint16_t	b_iocmd;	/* BIO_* bio_cmd from bio.h */
+	uint16_t	b_ioflags;	/* BIO_* bio_flags from bio.h */
 	off_t		b_iooffset;
 	long		b_resid;
 	void	(*b_iodone)(struct buf *);