[src/trunk]: src/sys/netsmb Send data for as long as there is new data availa...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0a68596f1544
branches:  trunk
changeset: 747155:0a68596f1544
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Sep 04 16:12:45 2009 +0000

description:
Send data for as long as there is new data available.  Otherwise
there was a danger of smb_iod_recvall() blocking, hence releasing
the kernel lock, new data creeping into the queue, and a wakeup
being missed (well, there's still a race, but since it's theoretical
enough for me to never have encountered it, I'll rather solve it
by periodic wakeups).

diffstat:

 sys/netsmb/smb_iod.c |  23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)

diffs (76 lines):

diff -r 83633c26cd1c -r 0a68596f1544 sys/netsmb/smb_iod.c
--- a/sys/netsmb/smb_iod.c      Fri Sep 04 14:23:24 2009 +0000
+++ b/sys/netsmb/smb_iod.c      Fri Sep 04 16:12:45 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: smb_iod.c,v 1.32 2009/07/06 11:46:49 njoly Exp $       */
+/*     $NetBSD: smb_iod.c,v 1.33 2009/09/04 16:12:45 pooka Exp $       */
 
 /*
  * Copyright (c) 2000-2001 Boris Popov
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: smb_iod.c,v 1.32 2009/07/06 11:46:49 njoly Exp $");
+__KERNEL_RCSID(0, "$NetBSD: smb_iod.c,v 1.33 2009/09/04 16:12:45 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -66,7 +66,7 @@
 
 static int smb_iod_next;
 
-static void smb_iod_sendall(struct smbiod *iod);
+static bool smb_iod_sendall(struct smbiod *iod);
 static int  smb_iod_disconnect(struct smbiod *iod);
 static void smb_iod_thread(void *);
 
@@ -555,11 +555,12 @@
 }
 
 
-static void
+static bool
 smb_iod_sendall(struct smbiod *iod)
 {
        struct smb_rq *rqp;
        int herror;
+       bool sentany = false;
 
        herror = 0;
        /*
@@ -580,11 +581,14 @@
 
                        if (__predict_false(herror != 0))
                                break;
+                       sentany = true;
                }
        }
        SMB_IOD_RQUNLOCK(iod);
        if (herror == ENOTCONN)
                smb_iod_dead(iod);
+
+       return sentany;
 }
 
 /*
@@ -647,8 +651,19 @@
                }
        }
 #endif
+
+       /*
+        * Do a send/receive cycle once and then as many times
+        * afterwards as we can send out new data.  This is to make
+        * sure we got all data sent which might have ended up in the
+        * queue during the receive phase (which might block releasing
+        * the kernel lock).
+        */
        smb_iod_sendall(iod);
        smb_iod_recvall(iod);
+       while (smb_iod_sendall(iod)) {
+               smb_iod_recvall(iod);
+       }
 }
 
 void