device: do not merge devices

Don't try to merge devices that have been created via dependencies when
they appear in the system and can be recognized as the same.  Instead,
simply continue to maintain them independently of each other, however
with the same state cycle. Why? Because otherwise we'd have a hard time
to seperate the dependencies after the devices are unplugged again and
we hence cannot be sure anymore that next time the device is plugged in
it will carry the same names.

Example: if one depndency refers to dev-sda.device and another one to
dev-by-id-xxxyyy.device we only learn at time of plug in of the device
that it is actually the same device that was ment. In the moment the
device is unplugged again we won't know anymore their relation to each
other and the next time the harddisk is plugged it might even appear as
dev-by-id-xxxyyy.device and dev-sdb.service. To ensure the dependencies
continue to have the meaning they were intended to have let's hence keep
the .device objects seperate all the time, even when they are plugged
in.

This patch also introduces a new Following= property which points from
the various .device units of a specific device to the main .device unit
for it. This can be used by the client side to figure out the relation
of the .device units to each other and even filter units from display.

1 files changed, 11 insertions, 8 deletions

diff --git a/src/service.h b/src/service.h
index d254044316..0ddaaa4c2d 100644
--- a/src/service.h
+++ b/src/service.h
@@ -90,8 +90,6 @@ struct Service {
         ServiceType type;
         ServiceRestart restart;
 
-        NotifyAccess notify_access;
-
         /* If set we'll read the main daemon PID from this file */
         char *pid_file;
 
@@ -101,10 +99,6 @@ struct Service {
         ExecCommand* exec_command[_SERVICE_EXEC_COMMAND_MAX];
         ExecContext exec_context;
 
-        bool permissions_start_only;
-        bool root_directory_start_only;
-        bool valid_no_process;
-
         ServiceState state, deserialized_state;
 
         ExecStatus main_exec_status;
@@ -112,6 +106,11 @@ struct Service {
         ExecCommand *control_command;
         ServiceExecCommand control_command_id;
         pid_t main_pid, control_pid;
+
+        bool permissions_start_only;
+        bool root_directory_start_only;
+        bool valid_no_process;
+
         bool main_pid_known:1;
 
         /* If we shut down, remember why */
@@ -124,8 +123,11 @@ struct Service {
         bool got_socket_fd:1;
 
         bool sysv_has_lsb:1;
-        char *sysv_path;
+
+        int socket_fd;
         int sysv_start_priority;
+
+        char *sysv_path;
         char *sysv_runlevels;
 
         char *bus_name;
@@ -134,10 +136,11 @@ struct Service {
 
         RateLimit ratelimit;
 
-        int socket_fd;
         struct Socket *socket;
 
         Watch timer_watch;
+
+        NotifyAccess notify_access;
 };
 
 extern const UnitVTable service_vtable;