In order to reduce use of M_EXT outside of the mbuf allocator and

socket-buffer implementations, introduce a return value for MCLGET()
(and m_cljget() that underlies it) to allow the caller to avoid testing
M_EXT itself.  Update all callers to use the return value.

With this change, very few network device drivers remain aware of
M_EXT; the primary exceptions lie in mbuf-chain pretty printers for
debugging, and in a few cases, custom mbuf and cluster allocation
implementations.

NB: This is a difficult-to-test change as it touches many drivers for
which I don't have physical devices.  Instead we've gone for intensive
review, but further post-commit review would definitely be appreciated
to spot errors where changes could not easily be made mechanically,
but were largely mechanical in nature.

Differential Revision:	https://reviews.freebsd.org/D1440
Reviewed by:	adrian, bz, gnn
Sponsored by:	EMC / Isilon Storage Division

1 files changed, 1 insertions, 2 deletions

diff --git a/sys/dev/pcn/if_pcn.c b/sys/dev/pcn/if_pcn.c
index d3121a1..d63d4aa 100644
--- a/sys/dev/pcn/if_pcn.c
+++ b/sys/dev/pcn/if_pcn.c
@@ -803,8 +803,7 @@ pcn_newbuf(sc, idx, m)
 		if (m_new == NULL)
 			return(ENOBUFS);
 
-		MCLGET(m_new, M_NOWAIT);
-		if (!(m_new->m_flags & M_EXT)) {
+		if (!(MCLGET(m_new, M_NOWAIT))) {
 			m_freem(m_new);
 			return(ENOBUFS);
 		}