From c6accdaa7b2a4cf991bf13c77ae2c1158cefbb2e Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Sun, 22 Apr 2012 01:59:11 +0200
Subject: [PATCH] util: fix tty_is_vc_resolve() in a container where
 /sys/class/tty/console/active is misleading (cherry picked
 from commit 3d9a412243035beeaaf3465a62065444a5adf21c)

Conflicts:

	TODO
---
 src/core/condition.c |   10 ++--------
 src/shared/util.c    |   18 ++++++++++++++++--
 src/shared/util.h    |    1 +
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/core/condition.c b/src/core/condition.c
index 4ed4eee..3ee9944 100644
--- a/src/core/condition.c
+++ b/src/core/condition.c
@@ -223,14 +223,8 @@ bool condition_test(Condition *c) {
         case CONDITION_PATH_IS_MOUNT_POINT:
                 return (path_is_mount_point(c->parameter, true) > 0) == !c->negate;
 
-        case CONDITION_PATH_IS_READ_WRITE: {
-                struct statvfs st;
-
-                if (statvfs(c->parameter, &st) < 0)
-                        return c->negate;
-
-                return !(st.f_flag & ST_RDONLY) == !c->negate;
-        }
+        case CONDITION_PATH_IS_READ_WRITE:
+                return (path_is_read_only_fs(c->parameter) > 0) == c->negate;
 
         case CONDITION_DIRECTORY_NOT_EMPTY: {
                 int k;
diff --git a/src/shared/util.c b/src/shared/util.c
index e82a336..6d12766 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -56,6 +56,7 @@
 #include <glob.h>
 #include <grp.h>
 #include <sys/mman.h>
+#include <sys/statvfs.h>
 
 #include "macro.h"
 #include "util.h"
@@ -4319,8 +4320,10 @@ bool tty_is_vc_resolve(const char *tty) {
         if (startswith(tty, "/dev/"))
                 tty += 5;
 
-        /* Resolve where /dev/console is pointing to */
-        if (streq(tty, "console"))
+        /* Resolve where /dev/console is pointing to, if /sys is
+         * actually ours (i.e. not read-only-mounted which is a sign
+         * for container setups) */
+        if (streq(tty, "console") && path_is_read_only_fs("/sys") <= 0)
                 if (read_one_line_file("/sys/class/tty/console/active", &active) >= 0) {
                         /* If multiple log outputs are configured the
                          * last one is what /dev/console points to */
@@ -6145,3 +6148,14 @@ int setrlimit_closest(int resource, const struct rlimit *rlim) {
 
         return 0;
 }
+
+int path_is_read_only_fs(const char *path) {
+        struct statvfs st;
+
+        assert(path);
+
+        if (statvfs(path, &st) < 0)
+                return -errno;
+
+        return !!(st.f_flag & ST_RDONLY);
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index d4932eb..aaa0426 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -350,6 +350,7 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll);
 ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll);
 
 int path_is_mount_point(const char *path, bool allow_symlink);
+int path_is_read_only_fs(const char *path);
 
 bool is_device_path(const char *path);