Nailed the "oplock hang" problem. Found the logic bug. It was an

optimisation someone... :-) added to process an incoming smbd if both the oplock
fd and server fd because active simultaneously. This of course is
wrong as processing the oplock break message can involve I/O on
the server fd which makes the stored FD_SET state completely bogus.
Also added debug 10 messages I will remove once Gerry has confirmed
the fix.
Jeremy.

1 files changed, 27 insertions, 1 deletions

diff --git a/source/smbd/process.c b/source/smbd/process.c
index e67d8728b1a..3e795d0e30f 100644
--- a/source/smbd/process.c
+++ b/source/smbd/process.c
@@ -115,11 +115,17 @@ oplock messages, change notify events etc.
 ****************************************************************************/
 static void async_processing(fd_set *fds, char *buffer, int buffer_len)
 {
+	/* JRATEMP */
+	DEBUG(10,("async_processing: doing async_processing...\n"));
+
 	/* check for oplock messages (both UDP and kernel) */
 	if (receive_local_message(fds, buffer, buffer_len, 0)) {
 		process_local_message(buffer, buffer_len);
 	}
 
+	/* JRATEMP */
+	DEBUG(10,("async_processing: doing pending_change_notify_queue...\n"));
+
 	/* check for async change notify events */
 	process_pending_change_notify_queue(0);
 
@@ -130,6 +136,9 @@ static void async_processing(fd_set *fds, char *buffer, int buffer_len)
 		reload_services(False);
 		reload_after_sighup = False;
 	}
+
+	/* JRATEMP */
+	DEBUG(10,("async_processing: end async_processing...\n"));
 }
 
 /****************************************************************************
@@ -199,14 +208,25 @@ static BOOL receive_message_or_smb(char *buffer, int buffer_len, int timeout)
 	to.tv_sec = timeout / 1000;
 	to.tv_usec = (timeout % 1000) * 1000;
 
+	/* JRATEMP */
+	DEBUG(10,("receive_message_or_smb: Entering main select with maxfd = %d\n", maxfd));
+
 	selrtn = sys_select(MAX(maxfd,smbd_server_fd())+1,&fds,timeout>0?&to:NULL);
 
+	/* JRATEMP */
+	DEBUG(10,("receive_message_or_smb: exited main select with return = %d\n", selrtn ));
+
 	/* if we get EINTR then maybe we have received an oplock
 	   signal - treat this as select returning 1. This is ugly, but
 	   is the best we can do until the oplock code knows more about
 	   signals */
 	if (selrtn == -1 && errno == EINTR) {
 		async_processing(&fds, buffer, buffer_len);
+		/*
+		 * After async processing we must go and do the select again, as
+		 * the state of the flag in fds for the server file descriptor is
+		 * indeterminate - we may have done I/O on it in the oplock processing. JRA.
+		 */
 		goto again;
 	}
 
@@ -230,8 +250,14 @@ static BOOL receive_message_or_smb(char *buffer, int buffer_len, int timeout)
 	 */
 
 	if (oplock_message_waiting(&fds)) {
+		DEBUG(10,("receive_message_or_smb: oplock_message is waiting.\n"));
 		async_processing(&fds, buffer, buffer_len);
-		if (!FD_ISSET(smbd_server_fd(),&fds)) goto again;
+		/*
+		 * After async processing we must go and do the select again, as
+		 * the state of the flag in fds for the server file descriptor is
+		 * indeterminate - we may have done I/O on it in the oplock processing. JRA.
+		 */
+		goto again;
 	}
 	
 	return receive_smb(smbd_server_fd(), buffer, 0);