ci: Load null_blk for I/O limit tests

Load the `null_blk` kernel module to have the `/dev/nullb0` device
available for the tests.

Signed-off-by: Giuseppe Scrivano <[email protected]>

Author: giuseppe

contrib/cirrus/setup_environment.sh

@@ -209,6 +209,12 @@ mount -t tmpfs -o size=75%,mode=0700 none /var/lib/containers
 showrun echo "Setting CI_DESIRED_STORAGE [=$CI_DESIRED_STORAGE] for *e2e* tests"
 echo "STORAGE_FS=$CI_DESIRED_STORAGE" >>/etc/ci_environment
 
+if ((CONTAINER==0)); then  # not yet inside a container
+    # Load null_blk to use /dev/nullb0 for testing block
+    # devices limits
+    modprobe null_blk nr_devices=1 || :
+fi
+
 # Required to be defined by caller: The environment where primary testing happens
 # shellcheck disable=SC2154
 showrun echo "about to set up for TEST_ENVIRON [=$TEST_ENVIRON]"