smbd: some write time fixes

- only the first non truncating write causes
  the write time update with 2 seconds delay.
  It's not enough to check for an existing update event
  as it will be NULL after the event was triggered.

- SMBwrite truncates always update the write time
  unless the sticky write time is set.

- SMBwrite truncates don't trigger a write time update on close.

metze
(This used to be commit 3d17089b6d)

source3/include/smb.h

@@ -456,6 +456,7 @@ typedef struct files_struct {
 	uint32 access_mask;		/* NTCreateX access bits (FILE_READ_DATA etc.) */
 	uint32 share_access;		/* NTCreateX share constants (FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE). */
 
+	bool update_write_time_triggered;
 	struct timed_event *update_write_time_event;
 	bool update_write_time_on_close;
 	struct timespec close_write_time;

source3/smbd/fileio.c

@@ -202,12 +202,13 @@ void trigger_write_time_update(struct files_struct *fsp)
 		return;
 	}
 
-	if (fsp->update_write_time_event) {
+	if (fsp->update_write_time_triggered) {
 		/*
 		 * No point - an event is already scheduled.
 		 */
 		return;
 	}
+	fsp->update_write_time_triggered = true;
 
 	delay = lp_parm_int(SNUM(fsp->conn),
 			    "smbd", "writetimeupdatedelay",
@@ -232,14 +233,12 @@ void trigger_write_time_update_immediate(struct files_struct *fsp)
                 return;
         }
 
-        if (fsp->update_write_time_event) {
-		/*
-		 * No point - an event is already scheduled.
-		 */
-                return;
-        }
+	TALLOC_FREE(fsp->update_write_time_event);
+	DEBUG(5, ("Update write time immediate on %s\n", fsp->fsp_name));
 
-        fsp->update_write_time_on_close = true;
+	fsp->update_write_time_triggered = true;
+
+        fsp->update_write_time_on_close = false;
 	update_write_time(fsp);
 }