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/ex/if_ex.c b/sys/dev/ex/if_ex.c
index 4072351..5832168 100644
--- a/sys/dev/ex/if_ex.c
+++ b/sys/dev/ex/if_ex.c
@@ -745,8 +745,7 @@ ex_rx_intr(struct ex_softc *sc)
 
 				while (pkt_len > 0) {
 					if (pkt_len >= MINCLSIZE) {
-						MCLGET(m, M_NOWAIT);
-						if (m->m_flags & M_EXT) {
+						if (MCLGET(m, M_NOWAIT)) {
 							m->m_len = MCLBYTES;
 						} else {
 							m_freem(ipkt);