From 5b204a113c89e1e881a115db9ecbe0ac9f9b460c Mon Sep 17 00:00:00 2001
From: Kip Macy <kmacy@FreeBSD.org>
Date: Fri, 19 Jun 2009 21:14:39 +0000
Subject: [PATCH] define helper routines for deferred mbuf initialization

---
 sys/kern/kern_mbuf.c | 26 ++++++++++++++++++++++++++
 sys/sys/mbuf.h       | 30 ++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
index 80274edb7f48..67c955c101be 100644
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -645,6 +645,32 @@ mb_ctor_pack(void *mem, int size, void *arg, int how)
 	return (0);
 }
 
+int
+m_pkthdr_init(struct mbuf *m, int how)
+{
+#ifdef MAC
+	int error;
+#endif
+	m->m_data = m->m_pktdat;
+	SLIST_INIT(&m->m_pkthdr.tags);
+	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.header = NULL;
+	m->m_pkthdr.len = 0;
+	m->m_pkthdr.flowid = 0;
+	m->m_pkthdr.csum_flags = 0;
+	m->m_pkthdr.csum_data = 0;
+	m->m_pkthdr.tso_segsz = 0;
+	m->m_pkthdr.ether_vtag = 0;
+#ifdef MAC
+	/* If the label init fails, fail the alloc */
+	error = mac_mbuf_init(m, how);
+	if (error)
+		return (error);
+#endif
+
+	return (0);
+}
+
 /*
  * This is the protocol drain routine.
  *
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 18b14887184f..43126887d277 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -366,12 +366,15 @@ static __inline struct mbuf	*m_gethdr(int how, short type);
 static __inline struct mbuf	*m_getjcl(int how, short type, int flags,
 				    int size);
 static __inline struct mbuf	*m_getclr(int how, short type);	/* XXX */
+static __inline int		 m_init(struct mbuf *m, uma_zone_t zone,
+				    int size, int how, short type, int flags);
 static __inline struct mbuf	*m_free(struct mbuf *m);
 static __inline void		 m_clget(struct mbuf *m, int how);
 static __inline void		*m_cljget(struct mbuf *m, int how, int size);
 static __inline void		 m_chtype(struct mbuf *m, short new_type);
 void				 mb_free_ext(struct mbuf *);
 static __inline struct mbuf	*m_last(struct mbuf *m);
+int				 m_pkthdr_init(struct mbuf *m, int how);
 
 static __inline int
 m_gettype(int size)
@@ -433,6 +436,33 @@ m_getzone(int size)
 	return (zone);
 }
 
+/*
+ * Initialize an mbuf with linear storage.
+ *
+ * Inline because the consumer text overhead will be roughly the same to
+ * initialize or call a function with this many parameters and M_PKTHDR
+ * should go away with constant propagation for !MGETHDR.
+ */
+static __inline int
+m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
+    int flags)
+{
+	int error;
+
+	m->m_next = NULL;
+	m->m_nextpkt = NULL;
+	m->m_data = m->m_dat;
+	m->m_len = 0;
+	m->m_flags = flags;
+	m->m_type = type;
+	if (flags & M_PKTHDR) {
+		if ((error = m_pkthdr_init(m, how)) != 0)
+			return (error);
+	}
+
+	return (0);
+}
+
 static __inline struct mbuf *
 m_get(int how, short type)
 {