git: dadbc042500b - main - tcp: rack fails to send out a TLP after a MTU change

The branch main has been updated by rrs:

URL: https://cgit.FreeBSD.org/src/commit/?id=dadbc042500b57cb2ceb25bc0ec39583142e0c45

commit dadbc042500b57cb2ceb25bc0ec39583142e0c45
Author:     Randall Stewart <rrs@FreeBSD.org>
AuthorDate: 2021-12-06 14:56:09 +0000
Commit:     Randall Stewart <rrs@FreeBSD.org>
CommitDate: 2021-12-06 14:56:09 +0000

    tcp: rack fails to send out a TLP after a MTU change
    
    When rack sends out a TLP it sets up various state to make sure
    it avoids the cwnd (its been more than 1 RTT since our last send) and
    it may at times send new data. If an MTU change as occurred
    and our cwnd has collapsed we can have a situation where must_retran
    flag is set and we obey the cwnd thus never sending the TLP and then
    sitting stuck.
    
    This one line fix addresses that problem
    Reviewed by: Michael Tuexen
    Sponsored by: Netflix Inc.
    Differential Revision: https://reviews.freebsd.org/D33231
---
 sys/netinet/tcp_stacks/rack.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index 7391734a9786..16faa887530f 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -17139,6 +17139,7 @@ again:
 		len = cwin;
 	}
 	if (rack->r_must_retran &&
+	    (doing_tlp == 0) &&
 	    (rsm == NULL)) {
 		/*
 		 * Non-Sack and we had a RTO or Sack/non-Sack and a