btrfs-progs/tests/README.md

Btrfs-progs tests

Run the tests from the top directory:

$ make test
$ make test-fsck
$ make test-convert

or selectively from the tests/ directory:

$ ./fsck-tests.sh
$ ./misc-tests.sh

The verbose output of the tests is logged into a file named after the test category, eg. fsck-tests-results.txt.

Selective testing

The test are prefixed by a number for ordering and uniquenes. To run a particular test use:

$ make TEST=MASK test

where MASK is a glob expression that will execute only tests that match the MASK. Here the test number comes handy:

$ make TEST=001\* test-fsck
$ TEST=001\* ./fsck-tests.sh

will run the first test in fsck-tests subdirectory.

Test structure

tests/fsck-tests/:

• tests targeted at bugs that are fixable by fsck

tests/convert-tests/:

• coverage tests of ext2/3/4 and btrfs-convert options

tests/fuzz-tests/:

• collection of fuzzed or crafted images
• tests that are supposed to run various utilities on the images and not crash

tests/misc-tests/:

• anything that does not fit to the above, the test driver script will only execute ./test.sh in the test directory

tests/common:

• script with helpers

tests/test.img:

• default testing image, the file is never deleted by the scripts but truncated to 0 bytes, so it keeps it's permissions. It's eg. possible to host it on NFS, make it chmod a+w for root.

Other tuning, environment variables

Instrumentation

It's possible to wrap the tested commands to utilities that might do more checking or catch failures at runtime. This can be done by setting the INSTRUMENT environment variable:

INSTRUMENT=valgrind ./fuzz-tests.sh    # in tests/
make INSTRUMENT=valgrind test-fuzz     # in the top directory

The variable is prepended to the command unquoted, all sorts of shell tricks are possible.

Note: instrumentation is not applied to privileged commands (anything that uses the root helper).

Verbosity

Setting the variable TEST_LOG=tty will print all commands executed by some of the wrappers (run_check etc), other commands are silent.

Permissions

Some commands require root privileges (to mount/umount, access loop devices). It is assumed that sudo will work in some way (no password, password asked and cached). Note that instrumentation is not applied in this case, for safety reasons. You need to modify the test script instead.

Cleanup

The tests are supposed to cleanup after themselves if they pass. In case of failure, the rest of the tests are skipped and intermediate files, mounts and loop devices are kept. This should help to investigate the test failure but at least the mounts and loop devices need to be cleaned before the next run.

This is partially done by the script clean-tests.sh, you may want to check the loop devices as they are managed on a per-test basis.

New test

1. Pick the category for the new test or fallback to misc-tests if not sure. For an easy start copy an existing test.sh script from some test that might be close to the purpose of your new test.

• Use the highest unused number in the sequence, write a short descriptive title and join by dashes -.

• Write a short description of the bug and how it's teste to the comment at the begining of test.sh.

• Write the test commands, comment anything that's not obvious.

• Test your test. Use the TEST variable to jump right to your test:

$ make TEST=012\* tests-misc           # from top directory
$ TEST=012\* ./misc-tests.sh           # from tests/

• The commit changelog should reference a commit that either introduced or fixed the bug (or both). Subject line of the shall mention the name of the new directory for ease of search, eg. btrfs-progs: tests: add 012-subvolume-sync-must-wait