mount: implement -O, --test-opts

--test-opts in combination with --all mounts only those filesystems
with options matching the given set of options.

Note that the semantic of the inverting "no" prefix differs from
--types: While --types=nonfs,ufs means neither nfs nor ufs,
--test-opts=nofoo,bar means not foo, but bar.

* utils/match-options.h: New file.
* utils/match-options.c: Likewise.
(test_opts): New variable.
(test_opts_len): Likewise.
(match_options): New function.
* utils/mount.c (parse_opt): Handle -O, --test-opts.
(main): Use match_options as filter.

1 files changed, 33 insertions, 0 deletions

diff --git a/utils/match-options.h b/utils/match-options.h
new file mode 100644
index 00000000..ea7ae70d
--- /dev/null
+++ b/utils/match-options.h
@@ -0,0 +1,33 @@
+/* Common functionality for the --test-opts flag of mount and umount.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   Written by Justus Winter <4winter@informatik.uni-hamburg.de>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include <mntent.h>
+
+extern char *test_opts;
+extern size_t test_opts_len;
+
+/* Check whether the given mount entry matches the given set of
+   options.
+
+   Returns 0 if foo is in the options vector but nofoo is in test_opts.
+   Returns 0 if foo is in test_opts but foo is not in the options vector. */
+int
+match_options (struct mntent *mntent);