PERFORCE change 81407 for review

[Robert Watson]

http://perforce.freebsd.org/chv.cgi?CH=81407

Change 81407 by rwatson at rwatson_zoo on 2005/08/03 16:48:09

	Mark in_multi_mtx as recursible instead of if_addr_mtx, that's
	what I meant to do before.  This is necessary because IGMP calls
	into ip_output() to send out packets while holding the
	in_multi_mtx, but ip_output() has to acquire it to perform
	address checks.  Really, this suggests IGMP shouldn't reenter
	the network code quite as much as it does.

Affected files ...

.. //depot/projects/netsmp/src/sys/net/if_var.h#8 edit
.. //depot/projects/netsmp/src/sys/netinet/in.c#5 edit

Differences ...

==== //depot/projects/netsmp/src/sys/net/if_var.h#8 (text+ko) ====

@@ -221,7 +221,7 @@
  * Locks for address lists on the network interface.
  */
 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
-				    "if_addr_mtx", NULL, MTX_DEF | MTX_RECURSE)
+				    "if_addr_mtx", NULL, MTX_DEF)
 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)

==== //depot/projects/netsmp/src/sys/netinet/in.c#5 (text+ko) ====

@@ -69,13 +69,15 @@
 	&subnetsarelocal, 0, "Treat all subnets as directly connected");
 
 /*
- * The IPv4 multicast list (in_multihead and associated structures)
- * are protected by the global in_multi_mtx.  See in_var.h for
- * more details.
+ * The IPv4 multicast list (in_multihead and associated structures) are
+ * protected by the global in_multi_mtx.  See in_var.h for more details.  For
+ * now, in_multi_mtx is marked as recursible due to IGMP's calling back into
+ * ip_output() to send IGMP packets while holding the lock; this probably is
+ * not quite desirable.
  */
 struct in_multihead in_multihead; /* XXX BSS initialization */
 struct mtx in_multi_mtx;
-MTX_SYSINIT(in_multi_mtx, &in_multi_mtx, "in_multi_mtx", MTX_DEF);
+MTX_SYSINIT(in_multi_mtx, &in_multi_mtx, "in_multi_mtx", MTX_DEF | MTX_RECURSE);
 
 extern struct inpcbinfo ripcbinfo;
 extern struct inpcbinfo udbinfo;