From fea9277020e040a0be6d0c626262a2a2ff36a318 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Tue, 3 Apr 2018 16:22:31 -0400
Subject: [PATCH] switchroot: Don't log if running as pid1, minor code style
 cleanups

If we're running as pid1, avoid printing anything in the normal
success paths as we don't want to affect the physical console by
default; the device may be using a splash screen, etc.

Also cleanup the code a bit to use a single variable
`running_as_pid1`, declare-and-initialize, use the
`bool` type, etc.

Closes: #1531
Approved by: jlebon
---
 src/switchroot/ostree-prepare-root.c | 36 ++++++++++++++++++----------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/switchroot/ostree-prepare-root.c b/src/switchroot/ostree-prepare-root.c
index a5c3c785..5ed9b60f 100644
--- a/src/switchroot/ostree-prepare-root.c
+++ b/src/switchroot/ostree-prepare-root.c
@@ -39,6 +39,7 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -48,6 +49,9 @@
 
 #include "ostree-mount-util.h"
 
+/* Initialized early in main */
+static bool running_as_pid1;
+
 static char*
 resolve_deploy_path (const char * root_mountpoint)
 {
@@ -60,7 +64,6 @@ resolve_deploy_path (const char * root_mountpoint)
     errx (EXIT_FAILURE, "No OSTree target; expected ostree=/ostree/boot.N/...");
 
   snprintf (destpath, sizeof(destpath), "%s/%s", root_mountpoint, ostree_target);
-  printf ("Examining %s\n", destpath);
   if (lstat (destpath, &stbuf) < 0)
     err (EXIT_FAILURE, "Couldn't find specified OSTree root '%s'", destpath);
   if (!S_ISLNK (stbuf.st_mode))
@@ -68,7 +71,9 @@ resolve_deploy_path (const char * root_mountpoint)
   deploy_path = realpath (destpath, NULL);
   if (deploy_path == NULL)
     err (EXIT_FAILURE, "realpath(%s) failed", destpath);
-  printf ("Resolved OSTree target to: %s\n", deploy_path);
+  /* Quiet logs if there's no journal */
+  if (!running_as_pid1)
+    printf ("Resolved OSTree target to: %s\n", deploy_path);
   return deploy_path;
 }
 
@@ -81,13 +86,18 @@ pivot_root(const char * new_root, const char * put_old)
 int
 main(int argc, char *argv[])
 {
-  const char *root_mountpoint = NULL, *root_arg = NULL;
-  char *deploy_path = NULL;
-  char srcpath[PATH_MAX];
-  struct stat stbuf;
-  int we_mounted_proc = 0;
+  /* If we're pid 1, that means there's no initramfs; in this situation
+   * various defaults change:
+   *
+   * - Assume that the target root is /
+   * - Quiet logging as there's no journal
+   * etc.
+   */
+  running_as_pid1 = (getpid () == 1);
 
-  if (getpid() == 1)
+  const char *root_arg = NULL;
+  bool we_mounted_proc = false;
+  if (running_as_pid1)
     {
       root_arg = "/";
     }
@@ -98,6 +108,7 @@ main(int argc, char *argv[])
       root_arg = argv[1];
     }
 
+  struct stat stbuf;
   if (stat ("/proc/cmdline", &stbuf) < 0)
     {
       if (errno != ENOENT)
@@ -109,10 +120,10 @@ main(int argc, char *argv[])
       we_mounted_proc = 1;
     }
 
-  root_mountpoint = realpath (root_arg, NULL);
+  const char *root_mountpoint = realpath (root_arg, NULL);
   if (root_mountpoint == NULL)
     err (EXIT_FAILURE, "realpath(\"%s\")", root_arg);
-  deploy_path = resolve_deploy_path (root_mountpoint);
+  char *deploy_path = resolve_deploy_path (root_mountpoint);
 
   if (we_mounted_proc)
     {
@@ -147,6 +158,7 @@ main(int argc, char *argv[])
     err (EXIT_FAILURE, "failed to bind mount ../../var to var");
 #endif
 
+  char srcpath[PATH_MAX];
   /* If /boot is on the same partition, use a bind mount to make it visible
    * at /boot inside the deployment. */
   snprintf (srcpath, sizeof(srcpath), "%s/boot/loader", root_mountpoint);
@@ -193,7 +205,7 @@ main(int argc, char *argv[])
    * not pid 1.  Otherwise it's handled later via ostree-remount.service.
    * https://mail.gnome.org/archives/ostree-list/2018-March/msg00012.html
    */
-  if (getpid () != 1)
+  if (!running_as_pid1)
     touch_run_ostree ();
 
   if (strcmp(root_mountpoint, "/") == 0)
@@ -246,7 +258,7 @@ main(int argc, char *argv[])
   if (mount ("none", "sysroot", NULL, MS_PRIVATE, NULL) < 0)
     err (EXIT_FAILURE, "remounting 'sysroot' private");
 
-  if (getpid() == 1)
+  if (running_as_pid1)
     {
       execl ("/sbin/init", "/sbin/init", NULL);
       err (EXIT_FAILURE, "failed to exec init inside ostree");