svn commit: r308283 - stable/10/sys/dev/cxgbe/tom

[John Baldwin]

Author: jhb
Date: Fri Nov  4 04:01:59 2016
New Revision: 308283
URL: https://svnweb.freebsd.org/changeset/base/308283

Log:
  MFC 301932: Use sbused() instead of sbspace() to avoid signed issues.
  
  Inserting a full mbuf with an external cluster into the socket buffer
  resulted in sbspace() returning -MLEN.  However, since sb_hiwat is
  unsigned, the -MLEN value was converted to unsigned in comparisons.  As a
  result, the socket buffer was never autosized.  Note that sb_lowat is signed
  to permit direct comparisons with sbspace(), but sb_hiwat is unsigned.
  Follow suit with what tcp_output() does and compare the value of sbused()
  with sb_hiwat instead.
  
  Note: Since stable/10 does not include sbused(), this uses sb->sb_cc
  instead.
  
  Sponsored by:	Chelsio Communications

Modified:
  stable/10/sys/dev/cxgbe/tom/t4_cpl_io.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/cxgbe/tom/t4_cpl_io.c
==============================================================================
--- stable/10/sys/dev/cxgbe/tom/t4_cpl_io.c	Fri Nov  4 03:49:53 2016	(r308282)
+++ stable/10/sys/dev/cxgbe/tom/t4_cpl_io.c	Fri Nov  4 04:01:59 2016	(r308283)
@@ -606,7 +606,7 @@ t4_push_frames(struct adapter *sc, struc
 	struct tcpcb *tp = intotcpcb(inp);
 	struct socket *so = inp->inp_socket;
 	struct sockbuf *sb = &so->so_snd;
-	int tx_credits, shove, compl, space, sowwakeup;
+	int tx_credits, shove, compl, sowwakeup;
 	struct ofld_tx_sdesc *txsd = &toep->txsd[toep->txsd_pidx];
 
 	INP_WLOCK_ASSERT(inp);
@@ -678,9 +678,7 @@ t4_push_frames(struct adapter *sc, struc
 			}
 		}
 
-		space = sbspace(sb);
-
-		if (space <= sb->sb_hiwat * 3 / 8 &&
+		if (sb->sb_cc > sb->sb_hiwat * 5 / 8 &&
 		    toep->plen_nocompl + plen >= sb->sb_hiwat / 4)
 			compl = 1;
 		else
@@ -689,7 +687,7 @@ t4_push_frames(struct adapter *sc, struc
 		if (sb->sb_flags & SB_AUTOSIZE &&
 		    V_tcp_do_autosndbuf &&
 		    sb->sb_hiwat < V_tcp_autosndbuf_max &&
-		    space < sb->sb_hiwat / 8) {
+		    sb->sb_cc >= sb->sb_hiwat * 7 / 8) {
 			int newsize = min(sb->sb_hiwat + V_tcp_autosndbuf_inc,
 			    V_tcp_autosndbuf_max);