r13482: Push the FAM notification file descriptor into the select

set to avoid unnecessary polling.

source/include/smb.h

@@ -1581,6 +1581,7 @@ struct cnotify_fns {
 	BOOL (*check_notify)(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *data, time_t t);
 	void (*remove_notify)(void *data);
 	int select_time;
+	int notification_fd;
 };
 
 #include "smb_macros.h"

source/smbd/notify.c

@@ -206,6 +206,15 @@ BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn,
 	return True;
 }
 
+int change_notify_fd(void)
+{
+	if (cnotify) {
+		return cnotify->notification_fd;
+	}
+
+	return -1;
+}
+
 /****************************************************************************
  Initialise the change notify subsystem.
 ****************************************************************************/

source/smbd/notify_fam.c

@@ -63,9 +63,30 @@ static int		global_fc_generation;
 #define FAM_TRACE	8
 #define FAM_TRACE_LOW	10
 
-#define FAM_NOTIFY_CHECK_TIMEOUT    1 /* secs */
 #define FAM_EVENT_DRAIN		    ((uint32_t)(-1))
 
+static void * fam_register_notify(connection_struct * conn,
+		    char *		path,
+		    uint32		flags);
+
+static BOOL fam_check_notify(connection_struct * conn,
+		 uint16_t		vuid,
+		 char *			path,
+		 uint32_t		flags,
+		 void *			data,
+		 time_t			when);
+
+static void fam_remove_notify(void * data)
+
+static struct cnotify_fns global_fam_notify =
+{
+    fam_register_notify,
+    fam_check_notify,
+    fam_remove_notify,
+    -1,
+    -1
+};
+
 /* Turn a FAM event code into a string. Don't rely on specific code values,
  * because that might not work across all flavours of FAM.
  */
@@ -110,6 +131,7 @@ fam_check_reconnect(void)
 	}
     }
 
+    global_fam_notify.notification_fd = FAMCONNECTION_GETFD(&global_fc);
     return(True);
 }
 
@@ -420,18 +442,6 @@ fam_remove_notify(void * data)
 
 struct cnotify_fns * fam_notify_init(void)
 {
-    static struct cnotify_fns global_fam_notify =
-    {
-	fam_register_notify,
-	fam_check_notify,
-	fam_remove_notify,
-	FAM_NOTIFY_CHECK_TIMEOUT
-    };
-
-    /* TODO: rather than relying on FAM_NOTIFY_CHECK_TIMEOUT, we should have an
-     * API to push the FAM fd into the global server fd set.
-     */
-
     FAMCONNECTION_GETFD(&global_fc) = -1;
 
     if (!fam_test_connection()) {

source/smbd/notify_hash.c

@@ -230,6 +230,7 @@ struct cnotify_fns *hash_notify_init(void)
 	cnotify.check_notify = hash_check_notify;
 	cnotify.remove_notify = hash_remove_notify;
 	cnotify.select_time = lp_change_notify_timeout();
+	cnotify.notification_fd = -1;
 
 	return &cnotify;
 }

source/smbd/notify_kernel.c

@@ -232,6 +232,7 @@ struct cnotify_fns *kernel_notify_init(void)
 	cnotify.check_notify = kernel_check_notify;
 	cnotify.remove_notify = kernel_remove_notify;
 	cnotify.select_time = -1;
+	cnotify.notification_fd = -1;
 
 	/* the signal can start off blocked due to a bug in bash */
 	BlockSignals(False, RT_SIGNAL_NOTIFY);

source/smbd/oplock.c

@@ -240,21 +240,16 @@ BOOL downgrade_oplock(files_struct *fsp)
 }
 
 /****************************************************************************
- Setup the listening set of file descriptors for an oplock break
- message either from the UDP socket or from the kernel. Returns the maximum
- fd used.
+ Return the fd (if any) used for receiving oplock notifications.
 ****************************************************************************/
 
-int setup_oplock_select_set( fd_set *fds)
+int oplock_notify_fd(void)
 {
-	int maxfd = 0;
-
-	if (koplocks && koplocks->notification_fd != -1) {
-		FD_SET(koplocks->notification_fd, fds);
-		maxfd = MAX(maxfd, koplocks->notification_fd);
+	if (koplocks) {
+		return koplocks->notification_fd;
 	}
 
-	return maxfd;
+	return -1;
 }
 
 /****************************************************************************

source/smbd/process.c

@@ -318,6 +318,20 @@ static void async_processing(void)
 	}
 }
 
+/****************************************************************************
+ Add a fd to the set we will be select(2)ing on.
+****************************************************************************/
+
+static int select_on_fd(int fd, int maxfd, fd_set *fds)
+{
+	if (fd != -1) {
+		FD_SET(fd, fds);
+		maxfd = MAX(maxfd, fd);
+	}
+
+	return maxfd;
+}
+
 /****************************************************************************
   Do a select on an two fd's - with timeout. 
 
@@ -344,7 +358,7 @@ static BOOL receive_message_or_smb(char *buffer, int buffer_len, int timeout)
 	fd_set fds;
 	int selrtn;
 	struct timeval to = timeval_set(SMBD_SELECT_TIMEOUT, 0);
-	int maxfd;
+	int maxfd = 0;
 
 	smb_read_error = 0;
 
@@ -437,10 +451,11 @@ static BOOL receive_message_or_smb(char *buffer, int buffer_len, int timeout)
 		}
 	}
 	
-	FD_SET(smbd_server_fd(),&fds);
-	maxfd = setup_oplock_select_set(&fds);
+	maxfd = select_on_fd(smbd_server_fd(), maxfd, &fds);
+	maxfd = select_on_fd(change_notify_fd(), maxfd, &fds);
+	maxfd = select_on_fd(oplock_notify_fd(), maxfd, &fds);
 
-	selrtn = sys_select(MAX(maxfd,smbd_server_fd())+1,&fds,NULL,NULL,&to);
+	selrtn = sys_select(maxfd+1,&fds,NULL,NULL,&to);
 
 	/* if we get EINTR then maybe we have received an oplock
 	   signal - treat this as select returning 1. This is ugly, but