discover-image: introduce per-user image directories

We nowadays support unprivileged invocation of systemd-nspawn +
systemd-vmspawn, but there was no support for discovering suitable disk
images (i.e. no per-user counterpart of /var/lib/machines). Add this
now, and hook it up everywhere.

Instead of hardcoding machined's, importd's, portabled's, sysupdated's
image discovery to RUNTIME_SCOPE_SYSTEM I introduced a field that make
the scope variable, even if this field is always initialized to
RUNTIME_SCOPE_SYSTEM for now. I think these four services should
eventually be updated to support a per-user concept too, this is
preparation for that, even though it doesn't outright add support for
this.

This is for the largest part not user visible, except for in nspawn,
vmspawn and the dissect tool. For the latter I added a pair of
--user/--system switches to select the discovery scope.

7 files changed, 19 insertions, 11 deletions

diff --git a/src/machine/image-dbus.c b/src/machine/image-dbus.c
index 8eca1e4c95..8f18e78c7d 100644
--- a/src/machine/image-dbus.c
+++ b/src/machine/image-dbus.c
@@ -178,7 +178,7 @@ int bus_image_method_clone(
                 return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
         if (r == 0) {
                 errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
-                r = image_clone(image, new_name, read_only);
+                r = image_clone(image, new_name, read_only, m->runtime_scope);
                 report_errno_and_exit(errno_pipe_fd[1], r);
         }
 
@@ -402,6 +402,7 @@ char* image_bus_path(const char *name) {
 static int image_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
         _cleanup_hashmap_free_ Hashmap *images = NULL;
         _cleanup_strv_free_ char **l = NULL;
+        Manager *m = ASSERT_PTR(userdata);
         Image *image;
         int r;
 
@@ -413,7 +414,7 @@ static int image_node_enumerator(sd_bus *bus, const char *path, void *userdata,
         if (!images)
                 return -ENOMEM;
 
-        r = image_discover(IMAGE_MACHINE, NULL, images);
+        r = image_discover(m->runtime_scope, IMAGE_MACHINE, NULL, images);
         if (r < 0)
                 return r;
 
diff --git a/src/machine/image-varlink.c b/src/machine/image-varlink.c
index 5eb636960d..1784de6146 100644
--- a/src/machine/image-varlink.c
+++ b/src/machine/image-varlink.c
@@ -148,7 +148,7 @@ int vl_method_clone_image(sd_varlink *link, sd_json_variant *parameters, sd_varl
                 return log_debug_errno(r, "Failed to fork: %m");
         if (r == 0) {
                 errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
-                r = image_clone(image, p.new_name, p.read_only > 0);
+                r = image_clone(image, p.new_name, p.read_only > 0, manager->runtime_scope);
                 report_errno_and_exit(errno_pipe_fd[1], r);
         }
 
diff --git a/src/machine/machined-core.c b/src/machine/machined-core.c
index b1468b62c6..52cb915c30 100644
--- a/src/machine/machined-core.c
+++ b/src/machine/machined-core.c
@@ -440,7 +440,7 @@ int manager_acquire_image(Manager *m, const char *name, Image **ret) {
                 return log_debug_errno(r, "Failed to enable source: %m") ;
 
         _cleanup_(image_unrefp) Image *image = NULL;
-        r = image_find(IMAGE_MACHINE, name, NULL, &image);
+        r = image_find(m->runtime_scope, IMAGE_MACHINE, name, NULL, &image);
         if (r < 0)
                 return log_debug_errno(r, "Failed to find image: %m");
 
@@ -467,7 +467,7 @@ int rename_image_and_update_cache(Manager *m, Image *image, const char* new_name
         /* The image is cached with its name, hence it is necessary to remove from the cache before renaming. */
         assert_se(hashmap_remove_value(m->image_cache, image->name, image));
 
-        r = image_rename(image, new_name);
+        r = image_rename(image, new_name, m->runtime_scope);
         if (r < 0) {
                 image = image_unref(image);
                 return r;
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index f4915f67da..fc50d3f147 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -123,7 +123,7 @@ static int method_get_image(sd_bus_message *message, void *userdata, sd_bus_erro
         if (r < 0)
                 return r;
 
-        r = image_find(IMAGE_MACHINE, name, NULL, NULL);
+        r = image_find(m->runtime_scope, IMAGE_MACHINE, name, NULL, NULL);
         if (r == -ENOENT)
                 return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_IMAGE, "No image '%s' known", name);
         if (r < 0)
@@ -476,7 +476,7 @@ static int method_list_images(sd_bus_message *message, void *userdata, sd_bus_er
         if (!images)
                 return -ENOMEM;
 
-        r = image_discover(IMAGE_MACHINE, NULL, images);
+        r = image_discover(m->runtime_scope, IMAGE_MACHINE, NULL, images);
         if (r < 0)
                 return r;
 
@@ -753,7 +753,7 @@ static int method_clean_pool(sd_bus_message *message, void *userdata, sd_bus_err
                         goto child_fail;
                 }
 
-                r = image_discover(IMAGE_MACHINE, NULL, images);
+                r = image_discover(m->runtime_scope, IMAGE_MACHINE, NULL, images);
                 if (r < 0)
                         goto child_fail;
 
diff --git a/src/machine/machined-varlink.c b/src/machine/machined-varlink.c
index e0e27c4496..104b841dd5 100644
--- a/src/machine/machined-varlink.c
+++ b/src/machine/machined-varlink.c
@@ -641,6 +641,7 @@ static int list_image_one_and_maybe_read_metadata(sd_varlink *link, Image *image
 }
 
 static int vl_method_list_images(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata) {
+        Manager *m = ASSERT_PTR(userdata);
         struct params {
                 const char *image_name;
                 AcquireMetadata acquire_metadata;
@@ -667,7 +668,7 @@ static int vl_method_list_images(sd_varlink *link, sd_json_variant *parameters,
                 if (!image_name_is_valid(p.image_name))
                         return sd_varlink_error_invalid_parameter_name(link, "name");
 
-                r = image_find(IMAGE_MACHINE, p.image_name, /* root = */ NULL, &found);
+                r = image_find(m->runtime_scope, IMAGE_MACHINE, p.image_name, /* root = */ NULL, &found);
                 if (r == -ENOENT)
                         return sd_varlink_error(link, "io.systemd.MachineImage.NoSuchImage", NULL);
                 if (r < 0)
@@ -683,7 +684,7 @@ static int vl_method_list_images(sd_varlink *link, sd_json_variant *parameters,
         if (!images)
                 return -ENOMEM;
 
-        r = image_discover(IMAGE_MACHINE, /* root = */ NULL, images);
+        r = image_discover(m->runtime_scope, IMAGE_MACHINE, /* root = */ NULL, images);
         if (r < 0)
                 return log_debug_errno(r, "Failed to discover images: %m");
 
diff --git a/src/machine/machined.c b/src/machine/machined.c
index a0c4ef751a..3a235aa0d4 100644
--- a/src/machine/machined.c
+++ b/src/machine/machined.c
@@ -40,10 +40,14 @@ static int manager_new(Manager **ret) {
 
         assert(ret);
 
-        m = new0(Manager, 1);
+        m = new(Manager, 1);
         if (!m)
                 return -ENOMEM;
 
+        *m = (Manager) {
+                .runtime_scope = RUNTIME_SCOPE_SYSTEM,
+        };
+
         m->machines = hashmap_new(&machine_hash_ops);
         if (!m->machines)
                 return -ENOMEM;
diff --git a/src/machine/machined.h b/src/machine/machined.h
index 3d1f502699..758678a205 100644
--- a/src/machine/machined.h
+++ b/src/machine/machined.h
@@ -42,6 +42,8 @@ struct Manager {
 
         sd_varlink_server *varlink_userdb_server;
         sd_varlink_server *varlink_machine_server;
+
+        RuntimeScope runtime_scope; /* for now: always RUNTIME_SCOPE_SYSTEM */
 };
 
 int manager_add_machine(Manager *m, const char *name, Machine **ret);