From 3cb3b0145ed8439eb604b43596e6456ed3292c46 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Sun, 21 Aug 2016 09:10:51 -0400

Subject: [PATCH] shared/install: do not enable masked instances (#4005)

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When told to enable a template unit, and the DefaultInstance specified in that

unit was masked, we would do this. Such a unit cannot be started or loaded, so

reporting successful enabling is misleading and unexpected.

$ systemctl mask getty@tty1

Created symlink /etc/systemd/system/getty@tty1.service → /dev/null.

$ systemctl --root=/ enable getty@tty1

(unchanged)

Failed to enable unit, unit /etc/systemd/system/getty@tty1.service is masked.

$ systemctl --root=/ enable getty@

(before)

Created symlink /etc/systemd/system/getty.target.wants/getty@tty1.service → /usr/lib/systemd/system/getty@.service.

(now)

Failed to enable unit, unit /etc/systemd/system/getty@tty1.service is masked.

The same error is emitted for enable and preset. And an error is emmited, not a

warning, so the failure to enable DefaultInstance is treated the same as if the

instance was specified on the command line. I think that this makes most sense,

for most template units.

Fixes #2513.

(cherry picked from commit 047d91f9c8cf1bcf5a30f428668babd619533944)

---

 src/shared/install.c | 35 ++++++++++++++++++++++++++++-------

 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/src/shared/install.c b/src/shared/install.c

index 9d9f4dff4f..cb2a2e7e0d 100644

--- a/src/shared/install.c

+++ b/src/shared/install.c

@@ -912,8 +912,8 @@ static int install_info_may_process(

         assert(i);

         assert(paths);

-        /* Checks whether the loaded unit file is one we should process, or is masked, transient or generated and thus

-         * not subject to enable/disable operations. */

+        /* Checks whether the loaded unit file is one we should process, or is masked,

+         * transient or generated and thus not subject to enable/disable operations. */

         if (i->type == UNIT_FILE_TYPE_MASKED) {

                 unit_file_changes_add(changes, n_changes, -ERFKILL, i->path, NULL);

@@ -1134,7 +1134,6 @@ static int unit_file_load(

         struct stat st;

         int r;

-        assert(c);

         assert(info);

         assert(path);

@@ -1163,6 +1162,9 @@ static int unit_file_load(

                 return 0;

         }

+        /* c is only needed if we actually load the file */

+        assert(c);

+

         fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

         if (fd < 0)

                 return -errno;

@@ -1275,7 +1277,6 @@ static int unit_file_search(

         char **p;

         int r;

-        assert(c);

         assert(info);

         assert(paths);

@@ -1546,7 +1547,14 @@ static int install_info_symlink_wants(

         assert(paths);

         assert(config_path);

+        if (strv_isempty(list))

+                return 0;

+

         if (unit_name_is_valid(i->name, UNIT_NAME_TEMPLATE)) {

+                UnitFileInstallInfo instance = {

+                        .type = _UNIT_FILE_TYPE_INVALID,

+                };

+                _cleanup_free_ char *path = NULL;

                 /* Don't install any symlink if there's no default

                  * instance configured */

@@ -1558,6 +1566,19 @@ static int install_info_symlink_wants(

                 if (r < 0)

                         return r;

+                instance.name = buf;

+                r = unit_file_search(NULL, &instance, paths, SEARCH_FOLLOW_CONFIG_SYMLINKS);

+                if (r < 0)

+                        return r;

+

+                path = instance.path;

+                instance.path = NULL;

+

+                if (instance.type == UNIT_FILE_TYPE_MASKED) {

+                        unit_file_changes_add(changes, n_changes, -ERFKILL, path, NULL);

+                        return -ERFKILL;

+                }

+

                 n = buf;

         } else

                 n = i->name;

@@ -1687,12 +1708,12 @@ static int install_context_apply(

                         return r;

                 /* We can attempt to process a masked unit when a different unit

-                 * that we were processing specifies it in DefaultInstance= or Also=. */

+                 * that we were processing specifies it in Also=. */

                 if (i->type == UNIT_FILE_TYPE_MASKED) {

                         unit_file_changes_add(changes, n_changes, UNIT_FILE_IS_MASKED, i->path, NULL);

                         if (r >= 0)

-                                /* Assume that some *could* have been enabled here, avoid

-                                 * "empty [Install] section" warning. */

+                                /* Assume that something *could* have been enabled here,

+                                 * avoid "empty [Install] section" warning. */

                                 r += 1;

                         continue;

                 }