[run-virt] check for /tmp/virt not in RAM

to cater for usecases where /tmp is in RAM but /tmp/virt is backed by,
e.g., an NFS (Ramboz)

3 files changed, 27 insertions, 8 deletions

diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/init_core.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/init_core.inc
index b3bc1cdf..00211c94 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/init_core.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/init_core.inc
@@ -31,14 +31,15 @@ if check_dep mkdir && ! mkdir -p "$TMPDIR"; then
 	EXIT_TYPE="internal" EXIT_REASON="Konnte kein Arbeitsverzeichnis für die VM-Sitzung anlegen." cleanexit 1
 fi
 
-# Determine if /tmp resides on the hdd
-# This variable is empty (but set!) if no hard drive was mounted on /tmp
+# Check that /tmp/virt is not in RAM.
+# Either mounted directly (e.g. NFS) or backed by hdd mounted /tmp.
+# This variable is empty (but set!) if /tmp/virt isn't backed at all
 # else it will be non-empty (check with helper function 'notempty').
-declare -g TMP_ON_HDD=
-if ! grep -q -E '\s+/tmp\s+tmpfs\s+' '/proc/mounts'; then
-	writelog "Hard drive partition mounted on /tmp"
-	TMP_ON_HDD=1
-	readonly TMP_ON_HDD
+declare -g TMPDIR_NOT_RAM=
+if ! dir_on_tmpfs /tmp/virt ; then
+	writelog "/tmp/virt is not in RAM, will allocate more RAM to VMs."
+	TMPDIR_NOT_RAM=1
+	readonly TMPDIR_NOT_RAM
 fi
 
 # Get a unique VM_ID for the current invocation
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/set_runvirt_hardware_variables.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/set_runvirt_hardware_variables.inc
index 04f3b22e..c59a82b0 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/set_runvirt_hardware_variables.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/set_runvirt_hardware_variables.inc
@@ -34,7 +34,7 @@ set_virt_memory() {
 	# Amount of memory for the VM. Be generous if diff is written to HDD
 	local min=768
 	local reserve max
-	if notempty TMP_ON_HDD; then
+	if notempty TMPDIR_NOT_RAM; then
 		if lsmod | grep -q '^nvidia'; then
 			max=2800
 			reserve=28
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
index 30676152..2336718a 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
@@ -468,3 +468,21 @@ clean_string() {
 		tr '[A-Z]' '[a-z]' | tr -d -c '[a-z0-9\-]'
 	fi
 }
+
+# Helper to check whether given directory resides in RAM, either
+# by being mounted as tmpfs or not mounted at all in which case
+# we assume the same. Returns 0 if so, 1 otherwise.
+dir_on_tmpfs() {
+	local current_dir="$1"
+	while [ -n "$current_dir" ]; do
+		local mount_line="$(awk -v dir="$current_dir" '$2 == dir' /proc/mounts)"
+		if [ -z "$mount_line" ]; then
+			# check its parent directory
+			current_dir="${current_dir%/*}"
+			continue
+		fi
+		[ "x$(cut -d' ' -f3 <<< ${mount_line})" == "xtmpfs" ]
+		return $?
+	done
+	return 0
+}