use error to detect lockfile open failures vs. max connections reached

and report an appropriate error message

clientserver.c

@@ -132,9 +132,16 @@ static int rsync_module(int fd, int i)
 	}
 
 	if (!claim_connection(lp_lock_file(), lp_max_connections())) {
-		rprintf(FERROR,"max connections (%d) reached\n",
-			lp_max_connections());
-		io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections());
+		if (errno) {
+			rprintf(FERROR,"failed to open lock file %s : %s\n",
+				lp_lock_file(), strerror(errno));
+			io_printf(fd,"@ERROR: failed to open lock file %s : %s\n",
+				  lp_lock_file(), strerror(errno));
+		} else {
+			rprintf(FERROR,"max connections (%d) reached\n",
+				lp_max_connections());
+			io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections());
+		}
 		return -1;
 	}
 

connection.c

@@ -29,7 +29,7 @@ int claim_connection(char *fname,int max_connections)
 
 	if (max_connections <= 0)
 		return 1;
-	
+
 	fd = open(fname,O_RDWR|O_CREAT, 0600);
 
 	if (fd == -1) {
@@ -41,6 +41,9 @@ int claim_connection(char *fname,int max_connections)
 		if (lock_range(fd, i*4, 4)) return 1;
 	}		
 
+	/* only interested in open failures */
+	errno = 0;
+
 	close(fd);
 	return 0;
 }