generic/608: Remove drop cache and umount & mount cycle

[xfstests-dev.git] / README

_______________________
BUILDING THE FSQA SUITE
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- cd into the xfstests directory
- install prerequisite packages
  For example, for Ubuntu:
        sudo apt-get install xfslibs-dev uuid-dev libtool-bin \
        e2fsprogs automake gcc libuuid1 quota attr make \
        libacl1-dev libaio-dev xfsprogs libgdbm-dev gawk fio dbench \
        uuid-runtime python sqlite3 liburing-dev
  For Fedora, RHEL, or CentOS:
        yum install acl attr automake bc dbench dump e2fsprogs fio \
        gawk gcc indent libtool lvm2 make psmisc quota sed \
        xfsdump xfsprogs \
        libacl-devel libaio-devel libuuid-devel \
        xfsprogs-devel btrfs-progs-devel python sqlite liburing-devel
        (Older distributions may require xfsprogs-qa-devel as well.)
        (Note that for RHEL and CentOS, you may need the EPEL repo.)
- run make
- run make install
- create fsgqa test user ("sudo useradd -m fsgqa")
- create fsgqa group ("sudo groupadd fsgqa")
- create 123456-fsgqa test user ("sudo useradd 123456-fsgqa")
  this 2nd user creation step can be safely skipped if your system
  doesn't support names starting with digits, only a handful of tests
  require it.
- create fsgqa2 test user ("sudo useradd fsgqa2")

______________________
USING THE FSQA SUITE
______________________

Preparing system for tests:

    - compile XFS into your kernel or load XFS modules
    - install administrative tools specific to the filesystem you wish to test
    - If you wish to run the udf components of the suite install
      mkudffs. Also download and build the Philips UDF Verification Software
      from https://www.lscdweb.com/registered/udf_verifier.html, then copy the udf_test
      binary to xfstests/src/. If you wish to disable UDF verification test
      set the environment variable DISABLE_UDF_TEST to 1.

    - create one or two partitions to use for testing
        - one TEST partition
            - format as XFS, mount & optionally populate with
              NON-IMPORTANT stuff
        - one SCRATCH partition (optional)
            - leave empty and expect this partition to be clobbered
              by some tests.  If this is not provided, many tests will
              not be run.
              (SCRATCH and TEST must be two DIFFERENT partitions)
              OR
        - for btrfs only: some btrfs test cases will need 3 or more independent
              SCRATCH disks which should be set using SCRATCH_DEV_POOL (for eg:
              SCRATCH_DEV_POOL="/dev/sda /dev/sdb /dev/sdc") with which
              SCRATCH_DEV should be unused by the tester, and for the legacy
              support SCRATCH_DEV will be set to the first disk of the
              SCRATCH_DEV_POOL by xfstests script.

    - setup your environment
        Quick start:
        - copy local.config.example to local.config and edit as needed
        Or:
        - setenv TEST_DEV "device containing TEST PARTITION"
        - setenv TEST_DIR "mount point of TEST PARTITION"
        - optionally:
             - setenv SCRATCH_DEV "device containing SCRATCH PARTITION" OR
               (btrfs only) setenv SCRATCH_DEV_POOL "to 3 or more SCRATCH disks for
               testing btrfs raid concepts"
             - setenv SCRATCH_MNT "mount point for SCRATCH PARTITION"
             - setenv TAPE_DEV "tape device for testing xfsdump"
             - setenv RMT_TAPE_DEV "remote tape device for testing xfsdump"
             - setenv RMT_IRIXTAPE_DEV "remote IRIX tape device for testing xfsdump"
             - setenv SCRATCH_LOGDEV "device for scratch-fs external log"
             - setenv SCRATCH_RTDEV "device for scratch-fs realtime data"
             - setenv TEST_LOGDEV "device for test-fs external log"
             - setenv TEST_RTDEV "device for test-fs realtime data"
             - if TEST_LOGDEV and/or TEST_RTDEV, these will always be used.
             - if SCRATCH_LOGDEV and/or SCRATCH_RTDEV, the USE_EXTERNAL
               environment variable set to "yes" will enable their use.
             - setenv DIFF_LENGTH "number of diff lines to print from a failed test",
               by default 10, set to 0 to print the full diff
             - setenv FSTYP "the filesystem you want to test", the filesystem
               type is devised from the TEST_DEV device, but you may want to
               override it; if unset, the default is 'xfs'
             - setenv FSSTRESS_AVOID and/or FSX_AVOID, which contain options
               added to the end of fsstresss and fsx invocations, respectively,
               in case you wish to exclude certain operational modes from these
               tests.
             - set TEST_XFS_REPAIR_REBUILD=1 to have _check_xfs_filesystem
               run xfs_repair -n to check the filesystem; xfs_repair to rebuild
               metadata indexes; and xfs_repair -n (a third time) to check the
               results of the rebuilding.
             - xfs_scrub, if present, will always check the test and scratch
               filesystems if they are still online at the end of the test.
               It is no longer necessary to set TEST_XFS_SCRUB.
             - setenv LOGWRITES_DEV to a block device to use for power fail
               testing.
             - setenv PERF_CONFIGNAME to a arbitrary string to be used for
               identifying the test setup for running perf tests.  This should
               be different for each type of performance test you wish to run so
               that relevant results are compared.  For example 'spinningrust'
               for configurations that use spinning disks and 'nvme' for tests
               using nvme drives.
             - set USE_KMEMLEAK=yes to scan for memory leaks in the kernel
               after every test, if the kernel supports kmemleak.
             - set KEEP_DMESG=yes to keep dmesg log after test
             - Set TEST_FS_MODULE_RELOAD=1 to unload the module and reload
               it between test invocations.  This assumes that the name of
               the module is the same as FSTYP.
             - Set DUMP_CORRUPT_FS=1 to record metadata dumps of XFS or ext*
               filesystems if a filesystem check fails.
             - Set DUMP_COMPRESSOR to a compression program to compress
               metadumps of filesystems.  This program must accept '-f' and the
               name of a file to compress; and it must accept '-d -f -k' and
               the name of a file to decompress.  In other words, it must
               emulate gzip.

        - or add a case to the switch in common/config assigning
          these variables based on the hostname of your test
          machine
        - or add these variables to a file called local.config and keep that
          file in your workarea.

    - if testing xfsdump, make sure the tape devices have a
      tape which can be overwritten.

    - make sure $TEST_DEV is a mounted XFS partition
    - make sure that $SCRATCH_DEV or $SCRATCH_DEV_POOL contains nothing useful

Running tests:

    - cd xfstests
    - By default the tests suite will run all the tests in the auto group. These
      are the tests that are expected to function correctly as regression tests,
      and it excludes tests that exercise conditions known to cause machine
      failures (i.e. the "dangerous" tests).
    - ./check '*/001' '*/002' '*/003'
    - ./check '*/06?'
    - Groups of tests maybe ran by: ./check -g [group(s)]
      See the 'group' file for details on groups
    - If you want to run all tests regardless of what group they are in
      (including dangerous tests), use the "all" group: ./check -g all
    - To randomize test order: ./check -r [test(s)]
    - You can explicitly specify NFS/CIFS/OVERLAY, otherwise
      the filesystem type will be autodetected from $TEST_DEV:
        - for running nfs tests: ./check -nfs [test(s)]
        - for running cifs/smb3 tests: ./check -cifs [test(s)]
        - for overlay tests: ./check -overlay [test(s)]
          The TEST and SCRATCH partitions should be pre-formatted
          with another base fs, where the overlay dirs will be created


    The check script tests the return value of each script, and
    compares the output against the expected output. If the output
    is not as expected, a diff will be output and an .out.bad file
    will be produced for the failing test.

    Unexpected console messages, crashes and hangs may be considered
    to be failures but are not necessarily detected by the QA system.

__________________________
ADDING TO THE FSQA SUITE
__________________________


Creating new tests scripts:

    Use the "new" script.

Test script environment:

    When developing a new test script keep the following things in
    mind.  All of the environment variables and shell procedures are
    available to the script once the "common/rc" file has been
    sourced.

     1. The tests are run from an arbitrary directory.  If you want to
        do operations on an XFS filesystem (good idea, eh?), then do
        one of the following:

        (a) Create directories and files at will in the directory
            $TEST_DIR ... this is within an XFS filesystem and world
            writeable.  You should cleanup when your test is done,
            e.g. use a _cleanup shell procedure in the trap ... see
            001 for an example.  If you need to know, the $TEST_DIR
            directory is within the filesystem on the block device
            $TEST_DEV.

        (b) mkfs a new XFS filesystem on $SCRATCH_DEV, and mount this
            on $SCRATCH_MNT. Call the the _require_scratch function
            on startup if you require use of the scratch partition.
            _require_scratch does some checks on $SCRATCH_DEV &
            $SCRATCH_MNT and makes sure they're unmounted. You should
            cleanup when your test is done, and in particular unmount
            $SCRATCH_MNT.
            Tests can make use of $SCRATCH_LOGDEV and $SCRATCH_RTDEV
            for testing external log and realtime volumes - however,
            these tests need to simply "pass" (e.g. cat $seq.out; exit
            - or default to an internal log) in the common case where
            these variables are not set.

     2. You can safely create temporary files that are not part of the
        filesystem tests (e.g. to catch output, prepare lists of things
        to do, etc.) in files named $tmp.<anything>.  The standard test
        script framework created by "new" will initialize $tmp and
        cleanup on exit.

     3. By default, tests are run as the same uid as the person
        executing the control script "check" that runs the test scripts.

     4. Some other useful shell procedures:

        _get_fqdn               - echo the host's fully qualified
                                  domain name

        _get_pids_by_name       - one argument is a process name, and
                                  return all of the matching pids on
                                  standard output

        _within_tolerance       - fancy numerical "close enough is good
                                  enough" filter for deterministic
                                  output ... see comments in
                                  common/filter for an explanation

        _filter_date            - turn ctime(3) format dates into the
                                  string DATE for deterministic
                                  output

        _cat_passwd,            - dump the content of the password
        _cat_group                or group file (both the local file
                                  and the content of the NIS database
                                  if it is likely to be present)

     5. General recommendations, usage conventions, etc.:
        - When the content of the password or group file is
          required, get it using the _cat_passwd and _cat_group
          functions, to ensure NIS information is included if NIS
          is active.
        - When calling getfacl in a test, pass the "-n" argument so
          that numeric rather than symbolic identifiers are used in
          the output.
        - When creating a new test, it is possible to enter a custom name
          for the file. Filenames are in form NNN-custom-name, where NNN
          is automatically added by the ./new script as an unique ID,
          and "custom-name" is the optional string entered into a prompt
          in the ./new script. It can contain only alphanumeric characters
          and dash. Note the "NNN-" part is added automatically.

Verified output:

    Each test script has a name, e.g. 007, and an associated
    verified output, e.g. 007.out.

    It is important that the verified output is deterministic, and
    part of the job of the test script is to filter the output to
    make this so.  Examples of the sort of things that need filtering:

    - dates
    - pids
    - hostnames
    - filesystem names
    - timezones
    - variable directory contents
    - imprecise numbers, especially sizes and times

Pass/failure:

    The script "check" may be used to run one or more tests.

    Test number $seq is deemed to "pass" when:
    (a) no "core" file is created,
    (b) the file $seq.notrun is not created,
    (c) the exit status is 0, and
    (d) the output matches the verified output.

    In the "not run" case (b), the $seq.notrun file should contain a
    short one-line summary of why the test was not run.  The standard
    output is not checked, so this can be used for a more verbose
    explanation and to provide feedback when the QA test is run
    interactively.


    To force a non-zero exit status use:
        status=1
        exit

    Note that:
        exit 1
    won't have the desired effect because of the way the exit trap
    works.

    The recent pass/fail history is maintained in the file "check.log".
    The elapsed time for the most recent pass for each test is kept
    in "check.time".

    The compare-failures script in tools/ may be used to compare failures
    across multiple runs, given files containing stdout from those runs.

__________________
SUBMITTING PATCHES
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