lsns: disable netnsid column by default

Enable only when

* --type=net is given, or
* -o NETNSID is given.

Suggested by Karel Zak.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c
index 7ccc733a4b21bfe3ed35cd1211da32779faebb64..bb7d3956d83ea247c2c4efb5ad3233e0d7ccdabf 100644 (file)
--- a/sys-utils/lsns.c
+++ b/sys-utils/lsns.c
@@ -839,6 +839,7 @@ int main(int argc, char *argv[])
                { 0 }
        };
        int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
+       bool enabling_netnsid = false;
 
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
@@ -891,6 +892,8 @@ int main(int argc, char *argv[])
                                errx(EXIT_FAILURE, _("unknown namespace type: %s"), optarg);
                        ls.fltr_types[type] = 1;
                        ls.fltr_ntypes++;
+                       if (type == LSNS_ID_NET)
+                               enabling_netnsid = true;
                        break;
                }
                default:
@@ -900,6 +903,7 @@ int main(int argc, char *argv[])
 
        if (!ls.fltr_ntypes) {
                size_t i;
+
                for (i = 0; i < ARRAY_SIZE(ns_names); i++)
                        ls.fltr_types[i] = 1;
        }
@@ -924,14 +928,24 @@ int main(int argc, char *argv[])
                columns[ncolumns++] = COL_NPROCS;
                columns[ncolumns++] = COL_PID;
                columns[ncolumns++] = COL_USER;
-               columns[ncolumns++] = COL_NETNSID;
+               if (enabling_netnsid)
+                       columns[ncolumns++] = COL_NETNSID;
                columns[ncolumns++] = COL_COMMAND;
        }
 
-       if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
-                                        &ncolumns, column_name_to_id) < 0)
-               return EXIT_FAILURE;
+       if (outarg) {
+               size_t i;
 
+               if (string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
+                                         &ncolumns, column_name_to_id) < 0)
+                       return EXIT_FAILURE;
+               for (i = 0; i < ncolumns; i++) {
+                       if (columns[i] == COL_NETNSID) {
+                               enabling_netnsid = true;
+                               break;
+                       }
+               }
+       }
        scols_init_debug(0);
 
        uid_cache = new_idcache();
@@ -939,7 +953,8 @@ int main(int argc, char *argv[])
                err(EXIT_FAILURE, _("failed to allocate UID cache"));
 
 #ifdef HAVE_LINUX_NET_NAMESPACE_H
-       netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+       if (enabling_netnsid)
+               netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 #endif
        r = read_processes(&ls);
        if (!r)