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.

4 files changed, 121 insertions, 4 deletions

diff --git a/utils/Makefile b/utils/Makefile
index e3bed0bf..6975fb59 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -28,7 +28,8 @@ SRCS = shd.c ps.c settrans.c syncfs.c showtrans.c addauth.c rmauth.c \
 	uptime.sh psout.c ids.c vmstat.c portinfo.c devprobe.c vminfo.c \
 	parse.c frobauth.c frobauth-mod.c setauth.c pids.c nonsugid.c \
 	unsu.c ftpcp.c ftpdir.c storeread.c storecat.c msgport.c \
-	rpctrace.c mount.c gcore.c fakeauth.c fakeroot.sh remap.sh
+	rpctrace.c mount.c gcore.c fakeauth.c fakeroot.sh remap.sh \
+	match-options.c
 
 OBJS = $(filter-out %.sh,$(SRCS:.c=.o))
 HURDLIBS = ps ihash store fshelp ports ftpconn shouldbeinlibc
@@ -72,7 +73,7 @@ fakeauth-CPPFLAGS = -I$(srcdir)/../auth
 authServer-CPPFLAGS = -I$(srcdir)/../auth
 auth_requestUser-CPPFLAGS = -I$(srcdir)/../auth
 
-mount: ../sutils/fstab.o ../sutils/clookup.o \
+mount: ../sutils/fstab.o ../sutils/clookup.o match-options.o \
        $(foreach L,fshelp ports,../lib$L/lib$L.a)
 ../sutils/fstab.o ../sutils/clookup.o: FORCE
 	$(MAKE) -C $(@D) $(@F)
diff --git a/utils/match-options.c b/utils/match-options.c
new file mode 100644
index 00000000..11fc9dcb
--- /dev/null
+++ b/utils/match-options.c
@@ -0,0 +1,68 @@
+/* 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 <argz.h>
+#include <error.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "match-options.h"
+
+char *test_opts;
+size_t test_opts_len;
+
+int
+match_options (struct mntent *mntent)
+{
+  char *opts;
+  size_t opts_len;
+
+  error_t err = argz_create_sep (mntent->mnt_opts, ',', &opts, &opts_len);
+  if (err)
+    error (3, err, "parsing mount options failed");
+
+  for (char *test = test_opts;
+       test; test = argz_next (test_opts, test_opts_len, test))
+    {
+      char *needle = test;
+      int inverse = strncmp("no", needle, 2) == 0;
+      if (inverse)
+        needle += 2;
+
+      int match = 0;
+      for (char *opt = opts; opt; opt = argz_next (opts, opts_len, opt))
+        {
+          if (strcmp (opt, needle) == 0) {
+            if (inverse)
+              return 0; /* foo in opts, nofoo in test_opts. */
+
+            /* foo in opts, foo in test_opts, record match. */
+            match = 1;
+          }
+        }
+
+      if (! inverse && ! match)
+        return 0; /* No foo in opts, but foo in test_opts. */
+    }
+
+  /* If no conflicting test_opt was encountered, return success. */
+  return 1;
+}
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);
diff --git a/utils/mount.c b/utils/mount.c
index f8928f1c..73a75391 100644
--- a/utils/mount.c
+++ b/utils/mount.c
@@ -29,6 +29,8 @@
 #include <hurd/fshelp.h>
 #include <hurd/paths.h>
 
+#include "match-options.h"
+
 #define SEARCH_FMTS	_HURD "%sfs\0" _HURD "%s"
 #define DEFAULT_FSTYPE	"ext2"
 
@@ -57,6 +59,8 @@ static const struct argp_option argp_opts[] =
   {"remount", 0, 0, OPTION_ALIAS},
   {"verbose", 'v', 0, 0, "Give more detailed information"},
   {"no-mtab", 'n', 0, 0, "Do not update /etc/mtab"},
+  {"test-opts", 'O', "OPTIONS", 0,
+   "Only mount fstab entries matching the given set of options"},
   {"fake", 'f', 0, 0, "Do not actually mount, just pretend"},
   {0, 0}
 };
@@ -122,6 +126,12 @@ parse_opt (int key, char *arg, struct argp_state *state)
       fake = 1;
       break;
 
+    case 'O':
+      err = argz_create_sep (arg, ',', &test_opts, &test_opts_len);
+      if (err)
+	argp_failure (state, 100, ENOMEM, "%s", arg);
+      break;
+
     case ARGP_KEY_ARG:
       if (mountpoint == 0)	/* One arg: mountpoint */
 	mountpoint = arg;
@@ -615,8 +625,13 @@ main (int argc, char **argv)
       case mount:
 	for (fs = fstab->entries; fs; fs = fs->next)
 	  {
-	    if (fstab_params.do_all && hasmntopt (&fs->mntent, MNTOPT_NOAUTO))
-	      continue;
+	    if (fstab_params.do_all) {
+              if (hasmntopt (&fs->mntent, MNTOPT_NOAUTO))
+                continue;
+
+              if (! match_options (&fs->mntent))
+                continue;
+            }
 	    err |= do_mount (fs, remount);
 	  }
 	break;