ZTS: Fix summary page creation

There are cases, where some needed files for the summary page aren't
created. Currently the whole Summary Page creation will fail then.
Sample run: https://github.com/openzfs/zfs/actions/runs/11148248072/job/30999748588

Fix this, by properly checking for existence of the needed files.

Reviewed-by: Tony Hutter <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Rob Norris <[email protected]>
Signed-off-by: Tino Reichardt <[email protected]>
Closes openzfs#16599

.github/workflows/scripts/qemu-6-tests.sh

@@ -85,15 +85,28 @@ case "$1" in
     sudo mv -f /tmp/*.txt /var/tmp
     sudo -E modprobe zfs
     TDIR="/usr/share/zfs"
+
+    # Enable swap to mitigate some OOM conditions like:
+    # https://github.com/openzfs/zfs/issues/16566
+    #
+    # Directions for setting up swap on btrfs (Fedora) from:
+    # https://btrfs.readthedocs.io/en/latest/Swapfile.html
+    sudo truncate -s 0 /swapfile
+    sudo chattr +C /swapfile
+    sudo fallocate -l 16G /swapfile
+    sudo chmod 0600 /swapfile
+    sudo mkswap /swapfile
+    sudo swapon /swapfile
     ;;
 esac
 
 # run functional testings and save exitcode
 cd /var/tmp
-TAGS=$2/$3
+# TAGS=$2/$3
 if [ "$4" == "quick" ]; then
   export RUNFILES="sanity.run"
 fi
+TAGS=raidz
 sudo dmesg -c > dmesg-prerun.txt
 mount > mount.txt
 df -h > df-prerun.txt

.github/workflows/scripts/qemu-9-summary-page.sh

@@ -11,10 +11,12 @@ function output() {
 }
 
 function outfile() {
+  test -s "$1" || return
   cat "$1" >> "out-$logfile.md"
 }
 
 function outfile_plain() {
+  test -s "$1" || return
   output "<pre>"
   cat "$1" >> "out-$logfile.md"
   output "</pre>"