dd a 24 bits wide ext_flags field to m_ext by reducing ext_type

to 8 bits.  ext_type is an enumerator and the number of types we
have is a mere dozen.

A couple of ext_types are renumbered to fit within 8 bits.

EXT_VENDOR[1-4] and EXT_EXP[1-4] types for vendor-internal and
experimental local mapping.

The ext_flags field is currently unused but has a couple of flags
already defined for future use.  Again vendor and experimental
flags are provided for local mapping.

EXT_FLAG_BITS is provided for the printf(9) %b identifier.

Initialize and copy ext_flags in the relevant mbuf functions.

Improve alignment and packing of struct m_ext on 32 and 64 archs
by carefully sorting the fields.

1 files changed, 3 insertions, 0 deletions

diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index 8395aacb86d7..f02e8cecbbd2 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -267,6 +267,7 @@ m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
 	mb->m_ext.ext_arg1 = arg1;
 	mb->m_ext.ext_arg2 = arg2;
 	mb->m_ext.ext_type = type;
+	mb->m_ext.ext_flags = 0;
 
 	return (0);
 }
@@ -342,6 +343,7 @@ mb_free_ext(struct mbuf *m)
 	m->m_ext.ref_cnt = NULL;
 	m->m_ext.ext_size = 0;
 	m->m_ext.ext_type = 0;
+	m->m_ext.ext_flags = 0;
 	m->m_flags &= ~M_EXT;
 	uma_zfree(zone_mbuf, m);
 }
@@ -368,6 +370,7 @@ mb_dupcl(struct mbuf *n, struct mbuf *m)
 	n->m_ext.ext_size = m->m_ext.ext_size;
 	n->m_ext.ref_cnt = m->m_ext.ref_cnt;
 	n->m_ext.ext_type = m->m_ext.ext_type;
+	n->m_ext.ext_flags = m->m_ext.ext_flags;
 	n->m_flags |= M_EXT;
 	n->m_flags |= m->m_flags & M_RDONLY;
 }