From a680beb2fe912aadcddd3855d130e10a36e574d7 Mon Sep 17 00:00:00 2001
From: Alexey Bogdanenko <alexey@bogdanenko.com>
Date: Tue, 11 Dec 2018 16:55:34 +0300
Subject: [PATCH 1/2] udev-test: add message to show why test-udev failed

Before:

    Assertion 'mknod(devname, mode, devnum) == 0' failed at ../src/test/test-udev.c:116, function run(). Aborting.
    Assertion 'unlink(devname) == 0' failed at ../src/test/test-udev.c:118, function run(). Aborting.

After:

    mknod() failed for '/dev/sda': Operation not permitted
    unlink('/dev/sda') failed: No such file or directory
---
 src/test/test-udev.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/test/test-udev.c b/src/test/test-udev.c
index b5d3eb7bc4..281dbb51f2 100644
--- a/src/test/test-udev.c
+++ b/src/test/test-udev.c
@@ -113,9 +113,11 @@ static int run(int argc, char *argv[]) {
 
                         (void) mkdir_parents_label(devname, 0755);
                         (void) sd_device_get_devnum(dev, &devnum);
-                        assert_se(mknod(devname, mode, devnum) == 0);
+                        if (mknod(devname, mode, devnum) < 0)
+                                return log_error_errno(errno, "mknod() failed for '%s': %m", devname);
                 } else {
-                        assert_se(unlink(devname) == 0);
+                        if (unlink(devname) < 0)
+                                return log_error_errno(errno, "unlink('%s') failed: %m", devname);
                         (void) rmdir_parents(devname, "/");
                 }
         }

From dbfbc6c4e34366033cb340e8b0c3cbca683ff6f5 Mon Sep 17 00:00:00 2001
From: Alexey Bogdanenko <alexey@bogdanenko.com>
Date: Tue, 11 Dec 2018 16:55:34 +0300
Subject: [PATCH 2/2] udev-test: check if permitted to create block device
 nodes

---
 test/udev-test.pl | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/udev-test.pl b/test/udev-test.pl
index eb76ebd72e..957cda541c 100755
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -1554,6 +1554,14 @@ sub udev_setup {
                 return 0;
         }
 
+        # check if we are permitted to create block device nodes
+        my $block_device_filename = $udev_dev . "/sda";
+        if (system("mknod", $block_device_filename, "b", "8", "0")) {
+                warn "unable to create $block_device_filename";
+                return 0;
+        }
+        unlink $block_device_filename;
+
         system("cp", "-r", "test/sys/", $udev_sys) && die "unable to copy test/sys";
 
         system("rm", "-rf", "$udev_run");