git: cdb8017d0bb1 - stable/13 - cxgbe tom: Account for pre-iSCSI mode data on suspended connections.

The branch stable/13 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=cdb8017d0bb1e6cdf28555108b86968e17d0178b

commit cdb8017d0bb1e6cdf28555108b86968e17d0178b
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2021-05-14 19:17:02 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2021-10-29 22:48:44 +0000

    cxgbe tom: Account for pre-iSCSI mode data on suspended connections.
    
    Sponsored by:   Chelsio Communications
    Differential Revision:  https://reviews.freebsd.org/D29907
    
    (cherry picked from commit 23b209ee885b7891f806ecfe1bb944e40b3b4728)
---
 sys/dev/cxgbe/tom/t4_cpl_io.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/sys/dev/cxgbe/tom/t4_cpl_io.c b/sys/dev/cxgbe/tom/t4_cpl_io.c
index 0d37804c4f8e..acb2d3408244 100644
--- a/sys/dev/cxgbe/tom/t4_cpl_io.c
+++ b/sys/dev/cxgbe/tom/t4_cpl_io.c
@@ -1058,9 +1058,7 @@ t4_push_pdus(struct adapter *sc, struct toepcb *toep, int drop)
 	struct fw_wr_hdr *wrhdr;
 	struct wrqe *wr;
 	u_int plen, credits;
-#ifdef INVARIANTS
 	struct inpcb *inp = toep->inp;
-#endif
 	struct ofld_tx_sdesc *txsd = &toep->txsd[toep->txsd_pidx];
 	struct mbufq *pduq = &toep->ulp_pduq;
 
@@ -1083,8 +1081,34 @@ t4_push_pdus(struct adapter *sc, struct toepcb *toep, int drop)
 		return;
 	}
 
-	if (drop)
+	if (drop) {
+		struct socket *so = inp->inp_socket;
+		struct sockbuf *sb = &so->so_snd;
+		int sbu;
+
+		/*
+		 * An unlocked read is ok here as the data should only
+		 * transition from a non-zero value to either another
+		 * non-zero value or zero.  Once it is zero it should
+		 * stay zero.
+		 */
+		if (__predict_false(sbused(sb)) > 0) {
+			SOCKBUF_LOCK(sb);
+			sbu = sbused(sb);
+			if (sbu > 0) {
+				/*
+				 * The data transmitted before the
+				 * tid's ULP mode changed to ISCSI is
+				 * still in so_snd.  Incoming credits
+				 * should account for so_snd first.
+				 */
+				sbdrop_locked(sb, min(sbu, drop));
+				drop -= min(sbu, drop);
+			}
+			sowwakeup_locked(so);	/* unlocks so_snd */
+		}
 		rqdrop_locked(&toep->ulp_pdu_reclaimq, drop);
+	}
 
 	while ((sndptr = mbufq_first(pduq)) != NULL) {
 		wr = write_iscsi_mbuf_wr(toep, sndptr);