btrfs-progs: tests: detecting compressed extent without csum

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/fsck-tests/040-compressed-nodatasum/test.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+#
+# Verify that check can detect compressed extent without csum as an error
+#
+# There is report about nodatasum inode which has compressed extent, and when
+# its compressed data is corrupted, decompress screws up the whole kernel.
+#
+# While btrfs(5) shows that nodatasum will disable data CoW and compression,
+# there was bug in kernel that allowed this combination.  And in above case,
+# lzo problem can lead to more serious kernel memory corruption since btrfs
+# completely depends its csum to prevent corruption.
+#
+# So btrfs check should report such compressed extent without csum as error.
+
+source "$TEST_TOP/common"
+
+check_prereq btrfs
+
+check_image() {
+	run_mustfail "compressed extent with csum not detected" \
+		"$TOP/btrfs" check "$1"
+}
+
+check_all_images