[systemd-devel] [PATCH] nspawn: When exiting with an error, make the error code meaningful.

[Luke Shumaker]

This is accomplished by having wait_for_container() return a positive error
code when we would like that error code to make its way to the user.  This
is at odds with the CODING_STYLE rule that error codes should be returned
as negative values.
---
 src/nspawn/nspawn.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 0a8dc0c..42f939b 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -2645,12 +2645,17 @@ static int change_uid_gid(char **_home) {
 }
 
 /*
- * Return 0 in case the container is being rebooted, has been shut
- * down or exited successfully. On failures a negative value is
- * returned.
+ * Return values:
+ * < 0 : The container was terminated by a signal, or failed for an
+ *       unknown reason.  No change is made to the container argument.
+ * > 0 : The container terminated with an error code, which is the
+ *       return value.  No change is made to the container argument.
+ *   0 : The container is being rebooted, has been shut down or exited
+ *       successfully.  The container argument has been set to either
+ *       CONTAINER_TERMINATED or CONTAINER_REBOOTED.
  *
- * The status of the container "CONTAINER_TERMINATED" or
- * "CONTAINER_REBOOTED" will be saved in the container argument
+ * That is, success is indicated by a return value of zero, and an
+ * error is indicated by a non-zero value.
  */
 static int wait_for_container(pid_t pid, ContainerStatus *container) {
         int r;
@@ -2672,7 +2677,6 @@ static int wait_for_container(pid_t pid, ContainerStatus *container) {
                 } else {
                         log_error("Container %s failed with error code %i.",
                                   arg_machine, status.si_status);
-                        r = -1;
                 }
                 break;
 
@@ -3299,8 +3303,9 @@ check_container_status:
                 r = wait_for_container(pid, &container_status);
                 pid = 0;
 
-                if (r < 0) {
-                        r = EXIT_FAILURE;
+                if (r != 0) {
+                        if (r < 0)
+                                r = EXIT_FAILURE;
                         break;
                 } else if (container_status == CONTAINER_TERMINATED)
                         break;
-- 
2.0.1