selftest: add tests for debugging testing setup

Many people have developed infrastructure around xfstests. In order to
test a setup, it would be helpful to have dummy tests that have
consistent test outcomes. Add a new test folder with the following
tests:

selftest/001 pass
selftest/002 fail from output mismatch
selftest/003 fail via _fail
selftest/004 skip
selftest/005 crash
selftest/006 hang

Also, create two new groups: 'selftest' which includes tests 001-004 and
'dangerous_selftest' which includes tests 005-006. The selftests will
not run unless explicitly specified.

Signed-off-by: Leah Rumancik <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Reviewed-by: David Disseldorp <[email protected]>
Reviewed-by: Zorro Lang <[email protected]>
Signed-off-by: Zorro Lang <[email protected]>

Author: lrumancik

README.selftest

@@ -0,0 +1,29 @@
+Tests with consistent results are provided in the selftest folder.
+Since many people develop testing infrastructure around xfstests,
+these tests are helpful to confirm the testing setup is working as
+expected.
+
+The provided tests include:
+selftest/001 - pass
+selftest/002 - fail from output mismatch
+selftest/003 - fail via _fail
+selftest/004 - skip
+selftest/005 - crash
+selftest/006 - hang
+
+Two groups are used for these tests: selftest and dangerous_selftest.
+selftest/00[1-4] are in the selftest group and selftest/00[5-6] are
+in the dangerous_selftest group.
+
+The selftest will only be run if explicitly speficied. To run the
+selftest, you can specify individual tests, e.g.
+
+# ./check selftest/001
+
+or use the groups under selftest/, e.g.
+
+# ./check -g selftest/selftest
+# ./check -g selftest/dangerous_selftest
+
+Note, you cannot use the group names without including the folder name
+(ie. "-g selftest").

doc/group-names.txt

@@ -38,6 +38,7 @@ dangerous_fsstress_repair	race fsstress and xfs_scrub online repair
 dangerous_fsstress_scrub	race fsstress and xfs_scrub checking
 dangerous_repair	fuzzers to evaluate xfs_repair offline repair
 dangerous_scrub		fuzzers to evaluate xfs_scrub checking
+dangerous_selftest	selftests that crash/hang
 data			data loss checkers
 dax			direct access mode for persistent memory files
 db			xfs_db functional tests
@@ -111,6 +112,7 @@ samefs			overlayfs when all layers are on the same fs
 scrub			filesystem metadata scrubbers
 seed			btrfs seeded filesystems
 seek			llseek functionality
+selftest		tests with fixed results, used to validate testing setup
 send			btrfs send/receive
 shrinkfs		decreasing the size of a filesystem
 shutdown		FS_IOC_SHUTDOWN ioctl

tests/selftest/001

@@ -0,0 +1,13 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 001
+#
+# A test that should always pass
+#
+. ./common/preamble
+_begin_fstest selftest
+
+echo "Silence is golden"
+status=0
+exit

tests/selftest/001.out

@@ -0,0 +1,2 @@
+QA output created by 001
+Silence is golden

tests/selftest/002

@@ -0,0 +1,13 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 002
+#
+# A test that should always fail due to output mismatch
+#
+. ./common/preamble
+_begin_fstest selftest
+
+echo "I am intentionally broken"
+status=0
+exit

tests/selftest/002.out

@@ -0,0 +1,2 @@
+QA output created by 002
+Silence is golden

tests/selftest/003

@@ -0,0 +1,15 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 003
+#
+# A test that _fail's
+#
+
+. ./common/preamble
+_begin_fstest selftest
+
+_fail "I have _fail'ed"
+
+status=0
+exit

tests/selftest/003.out

@@ -0,0 +1,2 @@
+QA output created by 003
+Silence is golden

tests/selftest/004

@@ -0,0 +1,15 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 004
+#
+# A test that should always be skipped
+#
+. ./common/preamble
+_begin_fstest selftest
+
+_notrun "Always skip me"
+
+echo "I should be skipped"
+status=0
+exit

tests/selftest/004.out

@@ -0,0 +1,2 @@
+QA output created by 004
+Silence is golden

tests/selftest/005

@@ -0,0 +1,16 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 005
+#
+# A test that crashes
+#
+. ./common/preamble
+_begin_fstest dangerous_selftest
+
+echo 1 > /proc/sys/kernel/sysrq
+echo c > /proc/sysrq-trigger
+
+echo "I should have crashed by now"
+status=0
+exit

tests/selftest/005.out

@@ -0,0 +1,2 @@
+QA output created by 005
+Silence is golden

tests/selftest/006

@@ -0,0 +1,19 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 006
+#
+# A test that hangs
+#
+
+. ./common/preamble
+_begin_fstest dangerous_selftest
+
+while :
+do
+    sleep 1d
+done
+
+echo "I should still be sleeping"
+status=0
+exit

tests/selftest/006.out

@@ -0,0 +1,2 @@
+QA output created by 006
+Silence is golden

tests/selftest/Makefile

@@ -0,0 +1,24 @@
+#
+# Copyright (c) 2023 Google, Inc. All Rights Reserved.
+#
+
+TOPDIR = ../..
+include $(TOPDIR)/include/builddefs
+include $(TOPDIR)/include/buildgrouplist
+
+SELFTEST_DIR = selftest
+TARGET_DIR = $(PKG_LIB_DIR)/$(TESTS_DIR)/$(SELFTEST_DIR)
+DIRT = group.list
+
+default: $(DIRT)
+
+include $(BUILDRULES)
+
+install:
+	$(INSTALL) -m 755 -d $(TARGET_DIR)
+	$(INSTALL) -m 755 $(TESTS) $(TARGET_DIR)
+	$(INSTALL) -m 644 group.list $(TARGET_DIR)
+	$(INSTALL) -m 644 $(OUTFILES) $(TARGET_DIR)
+
+# Nothing.
+install-dev install-lib: