git: 46f38a6dedb1 - main - netgraph: Exit the net epoch to handle control messages

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=46f38a6dedb1b474f04b7c2b072825fda5d7bd5a

commit 46f38a6dedb1b474f04b7c2b072825fda5d7bd5a
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2024-11-21 18:55:35 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2024-11-21 18:55:35 +0000

    netgraph: Exit the net epoch to handle control messages
    
    In general, in the direct dispatch case netgraph only enters the net
    epoch to send data messages, but this was inconsistent with the netgraph
    thread, which also entered the net epoch to send fn and fn2 messages to
    nodes.  Some handlers, e.g., ng_bridge_newhook(), may sleep, and so
    cannot be called in epoch context; the netgraph tests occasionally panic
    due to this problem.
    
    Make ngthread() consistent with the direct dispatch path.
    
    Discussed with: afedorov (in D44615)
    MFC after:      2 weeks
    Sponsored by:   Klara, Inc.
---
 sys/netgraph/ng_base.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/sys/netgraph/ng_base.c b/sys/netgraph/ng_base.c
index 5bff0663e03e..77c7cb0d3c00 100644
--- a/sys/netgraph/ng_base.c
+++ b/sys/netgraph/ng_base.c
@@ -3440,10 +3440,13 @@ ngthread(void *arg)
 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
 				NGI_GET_NODE(item, node); /* zaps stored node */
 
-				if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {
+				if ((item->el_flags & NGQF_TYPE) != NGQF_DATA) {
 					/*
-					 * NGQF_MESG items should never be processed in
-					 * NET_EPOCH context. So, temporary exit from EPOCH.
+					 * NGQF_MESG, NGQF_FN and NGQF_FN2 items
+					 * should never be processed in
+					 * NET_EPOCH context; they generally
+					 * require heavier synchronization and
+					 * may sleep. So, temporarily exit.
 					 */
 					NET_EPOCH_EXIT(et);
 					ng_apply_item(node, item, rw);