README - external/git.kernel.org/fs/xfs/xfstests-dev - Git at Google

 _______________________
 BUILDING THE FSQA SUITE
 _______________________

 Ubuntu or Debian
 ----------------

 1. Make sure that package list is up-to-date and install all necessary packages:

    $ sudo apt-get update
    $ sudo apt-get install acl attr automake bc dbench dump e2fsprogs fio gawk \
         gcc git indent libacl1-dev libaio-dev libcap-dev libgdbm-dev libtool \
         libtool-bin liburing-dev libuuid1 lvm2 make psmisc python3 quota sed \
         uuid-dev uuid-runtime xfsprogs linux-headers-$(uname -r) sqlite3 \
         libgdbm-compat-dev

 2. Install packages for the filesystem(s) being tested:

    $ sudo apt-get install exfatprogs f2fs-tools ocfs2-tools udftools xfsdump \
         xfslibs-dev

 Fedora
 ------

 1. Install all necessary packages from standard repository:

    $ sudo yum install acl attr automake bc dbench dump e2fsprogs fio gawk gcc \
         gdbm-devel git indent kernel-devel libacl-devel libaio-devel \
         libcap-devel libtool liburing-devel libuuid-devel lvm2 make psmisc \
         python3 quota sed sqlite udftools  xfsprogs

 2. Install packages for the filesystem(s) being tested:

     $ sudo yum install btrfs-progs exfatprogs f2fs-tools ocfs2-tools xfsdump \
         xfsprogs-devel

 RHEL or CentOS
 --------------

 1. Enable EPEL repository:
     - see https://docs.fedoraproject.org/en-US/epel/#How_can_I_use_these_extra_packages.3F

 2. Install all necessary packages which are available from standard repository
    and EPEL:

    $ sudo yum install acl attr automake bc dbench dump e2fsprogs fio gawk gcc \
         gdbm-devel git indent kernel-devel libacl-devel libaio-devel \
         libcap-devel libtool libuuid-devel lvm2 make psmisc python3 quota sed \
         sqlite udftools xfsprogs

    Or, EPEL packages could be compiled from sources, see:
     - https://dbench.samba.org/web/download.html
     - https://www.gnu.org/software/indent/

 3. Build and install 'liburing':
     - see https://github.com/axboe/liburing.

 4. Install packages for the filesystem(s) being tested:

     For XFS install:
      $ sudo yum install xfsdump xfsprogs-devel

     For exfat install:
      $ sudo yum install exfatprogs

     For f2fs build and install:
      - see https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git/about/

     For ocfs2 build and install:
      - see https://github.com/markfasheh/ocfs2-tools

 SUSE Linux Enterprise or openSUSE
 ---------------------------------

 1. Install all necessary packages from standard repositories:

    $ sudo zypper install acct automake bc dbench duperemove dump fio gcc git \
         indent libacl-devel libaio-devel libattr-devel libcap libcap-devel \
         libtool liburing-devel libuuid-devel lvm2 make quota sqlite3 xfsprogs

 2. Install packages for the filesystem(s) being tested:

     For btrfs install:
      $ sudo zypper install btrfsprogs libbtrfs-devel

     For XFS install:
      $ sudo zypper install xfsdump xfsprogs-devel

 Build and install test, libs and utils
 --------------------------------------

 $ git clone git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git
 $ cd xfstests-dev
 $ make
 $ sudo make install

 Setup Environment
 -----------------

 1. Compile XFS/EXT4/BTRFS/etc. into your kernel or load as module. For example,
    for XFS, enable XFS_FS in your kernel configuration, or compile it as a
    module and load it with 'sudo modprobe xfs'. Most of the distributions will
    have these filesystems already in the kernel/as module.

 2. Create TEST device:
     - format as the filesystem type you wish to test.
     - should be at least 10GB in size.
     - optionally populate with destroyable data.
     - device contents may be destroyed.

 3. (optional) Create SCRATCH device.
     - many tests depend on the SCRATCH device existing.
     - not need to be formatted.
     - should be at least 10GB in size.
     - must be different to TEST device.
     - device contents will be destroyed.

 4. (optional) Create SCRATCH device pool.
     - needed for BTRFS testing
     - specifies 3 or more independent SCRATCH devices via the SCRATCH_DEV_POOL
       variable e.g SCRATCH_DEV_POOL="/dev/sda /dev/sdb /dev/sdc"
     - device contents will be destroyed.
     - SCRATCH device should be left unset, it will be overridden
       by the SCRATCH_DEV_POOL implementation.

 5. Copy local.config.example to local.config and edit as needed. The TEST_DEV
    and TEST_DIR are required.

 6. (optional) Create fsgqa test users and groups:

    $ sudo useradd -m fsgqa
    $ sudo useradd 123456-fsgqa
    $ sudo useradd fsgqa2
    $ sudo groupadd fsgqa

    The "123456-fsgqa" user creation step can be safely skipped if your system
    doesn't support names starting with digits, only a handful of tests require
    it.

 7. (optional) 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/.

 8. (optional) To do io_uring related testing, please make sure below 3 things:
      1) kernel is built with CONFIG_IO_URING=y
      2) sysctl -w kernel.io_uring_disabled=0 (or set it to 2 to disable io_uring
         testing dynamically if kernel supports)
      3) install liburing development package contains liburing.h before building
         fstests

 For example, to run the tests with loopback partitions:

     # xfs_io -f -c "falloc 0 10g" test.img
     # xfs_io -f -c "falloc 0 10g" scratch.img
     # mkfs.xfs test.img
     # losetup /dev/loop0 ./test.img
     # losetup /dev/loop1 ./scratch.img
     # mkdir -p /mnt/test && mount /dev/loop0 /mnt/test
     # mkdir -p /mnt/scratch

 The config for the setup above is:

     $ cat local.config
     export TEST_DEV=/dev/loop0
     export TEST_DIR=/mnt/test
     export SCRATCH_DEV=/dev/loop1
     export SCRATCH_MNT=/mnt/scratch

 From this point you can run some basic tests, see 'USING THE FSQA SUITE' below.

 Additional Setup
 ----------------

 Some tests require additional configuration in your local.config. Add these
 variables to a local.config and keep that file in your workarea. Or add a case
 to the switch in common/config assigning these variables based on the hostname
 of your test machine. Or use 'setenv' to set them.

 Extra TEST device specifications:
  - Set TEST_LOGDEV to "device for test-fs external log"
  - Set TEST_RTDEV to "device for test-fs realtime data"
  - If TEST_LOGDEV and/or TEST_RTDEV, these will always be used.
  - Set FSTYP to "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'

 Extra SCRATCH device specifications:
  - Set SCRATCH_LOGDEV to "device for scratch-fs external log"
  - Set SCRATCH_RTDEV to "device for scratch-fs realtime data"
  - If SCRATCH_LOGDEV and/or SCRATCH_RTDEV, the USE_EXTERNAL environment

 Tape device specification for xfsdump testing:
  - Set TAPE_DEV to "tape device for testing xfsdump".
  - Set RMT_TAPE_DEV to "remote tape device for testing xfsdump"
    variable set to "yes" will enable their use.
  - Note that if testing xfsdump, make sure the tape devices have a tape which
    can be overwritten.

 Extra XFS specification:
  - 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.
  - Set FORCE_XFS_CHECK_PROG=yes to have _check_xfs_filesystem run xfs_check
    to check the filesystem. As of August 2021, xfs_repair finds all
    filesystem corruptions found by xfs_check, and more, which means that
    xfs_check is no longer run by default.
  - Set TEST_XFS_SCRUB_REBUILD=1 to have _check_xfs_filesystem run xfs_scrub in
    "force_repair" mode to rebuild the filesystem; and xfs_repair -n 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.

 Tools specification:
  - dump:
     - Set DUMP_CORRUPT_FS=1 to record metadata dumps of XFS, ext* or
       btrfs 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.
  - dmesg:
     - Set KEEP_DMESG=yes to keep dmesg log after test
  - kmemleak:
     - Set USE_KMEMLEAK=yes to scan for memory leaks in the kernel after every
       test, if the kernel supports kmemleak.
  - fsstress:
     - Set 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.
  - core dumps:
     - Set COREDUMP_COMPRESSOR to a compression program to compress crash dumps.
       This program must accept '-f' and the name of a file to compress.  In
       other words, it must emulate gzip.

 Kernel/Modules related configuration:
  - 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 MODPROBE_PATIENT_RM_TIMEOUT_SECONDS to specify the amount of time we
    should try a patient module remove. The default is 50 seconds. Set this
    to "forever" and we'll wait forever until the module is gone.
  - Set KCONFIG_PATH to specify your preferred location of kernel config
    file. The config is used by tests to check if kernel feature is enabled.
  - Set REPORT_GCOV to a directory path to make lcov and genhtml generate
    html reports from any gcov code coverage data collected by the kernel.
    If REPORT_GCOV is set to 1, the report will be written to $REPORT_DIR/gcov/.

 Test control:
  - Set LOAD_FACTOR to a nonzero positive integer to increase the amount of
    load applied to the system during a test by the specified multiple.
  - Set TIME_FACTOR to a nonzero positive integer to increase the amount of
    time that a test runs by the specified multiple.
  - For tests that are a member of the "soak" group, setting SOAK_DURATION
    allows the test runner to specify exactly how long the test should continue
    running.  This setting overrides TIME_FACTOR.  Floating point numbers are
    allowed, and the unit suffixes m(inutes), h(ours), d(ays), and w(eeks) are
    supported.

 Misc:
  - If you wish to disable UDF verification test set the environment variable
    DISABLE_UDF_TEST to 1.
  - Set LOGWRITES_DEV to a block device to use for power fail testing.
  - Set 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 MIN_FSSIZE to specify the minimal size (bytes) of a filesystem we
    can create. Setting this parameter will skip the tests creating a
    filesystem less than MIN_FSSIZE.
  - Set DIFF_LENGTH to "number of diff lines to print from a failed test",
    by default 10, set to 0 to print the full diff
  - set IDMAPPED_MOUNTS=true to run all tests on top of idmapped mounts. While
    this option is supported for all filesystems currently only -overlay is
    expected to run without issues. For other filesystems additional patches
    and fixes to the test suite might be needed.
  - Set REPORT_VARS_FILE to a file containing colon-separated name-value pairs
    that will be recorded in the test section report.  Names must be unique.
    Whitespace surrounding the colon will be removed.
  - set CANON_DEVS=yes to canonicalize device symlinks. This will let you
    for example use something like TEST_DEV/dev/disk/by-id/nvme-* so the
    device remains persistent between reboots. This is disabled by default.

 ______________________
 USING THE FSQA SUITE
 ______________________

 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 tests/*/group.list files after building xfstests to learn about
       each test's group memberships.
     - 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/AFS/CIFS/OVERLAY, otherwise
       the filesystem type will be autodetected from $TEST_DEV:
         - for running nfs tests: ./check -nfs [test(s)]
         - for running afs tests: ./check -afs [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/preamble" file has been
     sourced and the "_begin_fstest" function has been called.

      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.

      6. Test group membership: Each test can be associated with any number
 	of groups for convenient selection of subsets of tests.  Group names
 	must  be human readable using only characters in the set [:alnum:_-].

 	Test authors associate a test with groups by passing the names of those
 	groups as arguments to the _begin_fstest function. While _begin_fstests
 	is a shell function that must be called at the start of a test to
 	initialise the test environment correctly, the the build infrastructure
 	also scans the test files for _begin_fstests invocations. It does this
 	to compile the group lists that are used to determine which tests to run
 	when `check` is executed. In other words, test files files must call
 	_begin_fstest with their intended groups or they will not be run.

 	However, because the build infrastructure also uses _begin_fstests as
 	a defined keyword, addition restrictions are placed on how it must be
 	formatted:

 	(a) It must be a single line with no multi-line continuations.

 	(b) group names should be separated by spaces and not other whitespace

 	(c) A '#' placed anywhere in the list, even in the middle of a group
 	    name, will cause everything from the # to the end of the line to be
 	    ignored.

 	For example, the code:

 	_begin_fstest auto quick subvol snapshot # metadata

 	associates the current test with the "auto", "quick", "subvol", and
 	"snapshot" groups. Because "metadata" is after the "#" comment
 	delimiter, it is ignored by the build infrastructure and so it will not
 	be associated with that group.

 	It is not necessary to specify the "all" group in the list because that
 	group is always computed at run time from the group lists.


 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
 __________________

 Send patches to the fstests mailing list at fstests@vger.kernel.org.
	_______________________
	BUILDING THE FSQA SUITE
	_______________________

	Ubuntu or Debian
	----------------

	1. Make sure that package list is up-to-date and install all necessary packages:

	$ sudo apt-get update
	$ sudo apt-get install acl attr automake bc dbench dump e2fsprogs fio gawk \
	gcc git indent libacl1-dev libaio-dev libcap-dev libgdbm-dev libtool \
	libtool-bin liburing-dev libuuid1 lvm2 make psmisc python3 quota sed \
	uuid-dev uuid-runtime xfsprogs linux-headers-$(uname -r) sqlite3 \
	libgdbm-compat-dev

	2. Install packages for the filesystem(s) being tested:

	$ sudo apt-get install exfatprogs f2fs-tools ocfs2-tools udftools xfsdump \
	xfslibs-dev

	Fedora
	------

	1. Install all necessary packages from standard repository:

	$ sudo yum install acl attr automake bc dbench dump e2fsprogs fio gawk gcc \
	gdbm-devel git indent kernel-devel libacl-devel libaio-devel \
	libcap-devel libtool liburing-devel libuuid-devel lvm2 make psmisc \
	python3 quota sed sqlite udftools xfsprogs

	2. Install packages for the filesystem(s) being tested:

	$ sudo yum install btrfs-progs exfatprogs f2fs-tools ocfs2-tools xfsdump \
	xfsprogs-devel

	RHEL or CentOS
	--------------

	1. Enable EPEL repository:
	- see https://docs.fedoraproject.org/en-US/epel/#How_can_I_use_these_extra_packages.3F

	2. Install all necessary packages which are available from standard repository
	and EPEL:

	$ sudo yum install acl attr automake bc dbench dump e2fsprogs fio gawk gcc \
	gdbm-devel git indent kernel-devel libacl-devel libaio-devel \
	libcap-devel libtool libuuid-devel lvm2 make psmisc python3 quota sed \
	sqlite udftools xfsprogs

	Or, EPEL packages could be compiled from sources, see:
	- https://dbench.samba.org/web/download.html
	- https://www.gnu.org/software/indent/

	3. Build and install 'liburing':
	- see https://github.com/axboe/liburing.

	4. Install packages for the filesystem(s) being tested:

	For XFS install:
	$ sudo yum install xfsdump xfsprogs-devel

	For exfat install:
	$ sudo yum install exfatprogs

	For f2fs build and install:
	- see https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git/about/

	For ocfs2 build and install:
	- see https://github.com/markfasheh/ocfs2-tools

	SUSE Linux Enterprise or openSUSE
	---------------------------------

	1. Install all necessary packages from standard repositories:

	$ sudo zypper install acct automake bc dbench duperemove dump fio gcc git \
	indent libacl-devel libaio-devel libattr-devel libcap libcap-devel \
	libtool liburing-devel libuuid-devel lvm2 make quota sqlite3 xfsprogs

	2. Install packages for the filesystem(s) being tested:

	For btrfs install:
	$ sudo zypper install btrfsprogs libbtrfs-devel

	For XFS install:
	$ sudo zypper install xfsdump xfsprogs-devel

	Build and install test, libs and utils
	--------------------------------------

	$ git clone git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git
	$ cd xfstests-dev
	$ make
	$ sudo make install

	Setup Environment
	-----------------

	1. Compile XFS/EXT4/BTRFS/etc. into your kernel or load as module. For example,
	for XFS, enable XFS_FS in your kernel configuration, or compile it as a
	module and load it with 'sudo modprobe xfs'. Most of the distributions will
	have these filesystems already in the kernel/as module.

	2. Create TEST device:
	- format as the filesystem type you wish to test.
	- should be at least 10GB in size.
	- optionally populate with destroyable data.
	- device contents may be destroyed.

	3. (optional) Create SCRATCH device.
	- many tests depend on the SCRATCH device existing.
	- not need to be formatted.
	- should be at least 10GB in size.
	- must be different to TEST device.
	- device contents will be destroyed.

	4. (optional) Create SCRATCH device pool.
	- needed for BTRFS testing
	- specifies 3 or more independent SCRATCH devices via the SCRATCH_DEV_POOL
	variable e.g SCRATCH_DEV_POOL="/dev/sda /dev/sdb /dev/sdc"
	- device contents will be destroyed.
	- SCRATCH device should be left unset, it will be overridden
	by the SCRATCH_DEV_POOL implementation.

	5. Copy local.config.example to local.config and edit as needed. The TEST_DEV
	and TEST_DIR are required.

	6. (optional) Create fsgqa test users and groups:

	$ sudo useradd -m fsgqa
	$ sudo useradd 123456-fsgqa
	$ sudo useradd fsgqa2
	$ sudo groupadd fsgqa

	The "123456-fsgqa" user creation step can be safely skipped if your system
	doesn't support names starting with digits, only a handful of tests require
	it.

	7. (optional) 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/.

	8. (optional) To do io_uring related testing, please make sure below 3 things:
	1) kernel is built with CONFIG_IO_URING=y
	2) sysctl -w kernel.io_uring_disabled=0 (or set it to 2 to disable io_uring
	testing dynamically if kernel supports)
	3) install liburing development package contains liburing.h before building
	fstests

	For example, to run the tests with loopback partitions:

	# xfs_io -f -c "falloc 0 10g" test.img
	# xfs_io -f -c "falloc 0 10g" scratch.img
	# mkfs.xfs test.img
	# losetup /dev/loop0 ./test.img
	# losetup /dev/loop1 ./scratch.img
	# mkdir -p /mnt/test && mount /dev/loop0 /mnt/test
	# mkdir -p /mnt/scratch

	The config for the setup above is:

	$ cat local.config
	export TEST_DEV=/dev/loop0
	export TEST_DIR=/mnt/test
	export SCRATCH_DEV=/dev/loop1
	export SCRATCH_MNT=/mnt/scratch

	From this point you can run some basic tests, see 'USING THE FSQA SUITE' below.

	Additional Setup
	----------------

	Some tests require additional configuration in your local.config. Add these
	variables to a local.config and keep that file in your workarea. Or add a case
	to the switch in common/config assigning these variables based on the hostname
	of your test machine. Or use 'setenv' to set them.

	Extra TEST device specifications:
	- Set TEST_LOGDEV to "device for test-fs external log"
	- Set TEST_RTDEV to "device for test-fs realtime data"
	- If TEST_LOGDEV and/or TEST_RTDEV, these will always be used.
	- Set FSTYP to "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'

	Extra SCRATCH device specifications:
	- Set SCRATCH_LOGDEV to "device for scratch-fs external log"
	- Set SCRATCH_RTDEV to "device for scratch-fs realtime data"
	- If SCRATCH_LOGDEV and/or SCRATCH_RTDEV, the USE_EXTERNAL environment

	Tape device specification for xfsdump testing:
	- Set TAPE_DEV to "tape device for testing xfsdump".
	- Set RMT_TAPE_DEV to "remote tape device for testing xfsdump"
	variable set to "yes" will enable their use.
	- Note that if testing xfsdump, make sure the tape devices have a tape which
	can be overwritten.

	Extra XFS specification:
	- 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.
	- Set FORCE_XFS_CHECK_PROG=yes to have _check_xfs_filesystem run xfs_check
	to check the filesystem. As of August 2021, xfs_repair finds all
	filesystem corruptions found by xfs_check, and more, which means that
	xfs_check is no longer run by default.
	- Set TEST_XFS_SCRUB_REBUILD=1 to have _check_xfs_filesystem run xfs_scrub in
	"force_repair" mode to rebuild the filesystem; and xfs_repair -n 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.

	Tools specification:
	- dump:
	- Set DUMP_CORRUPT_FS=1 to record metadata dumps of XFS, ext* or
	btrfs 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.
	- dmesg:
	- Set KEEP_DMESG=yes to keep dmesg log after test
	- kmemleak:
	- Set USE_KMEMLEAK=yes to scan for memory leaks in the kernel after every
	test, if the kernel supports kmemleak.
	- fsstress:
	- Set 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.
	- core dumps:
	- Set COREDUMP_COMPRESSOR to a compression program to compress crash dumps.
	This program must accept '-f' and the name of a file to compress. In
	other words, it must emulate gzip.

	Kernel/Modules related configuration:
	- 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 MODPROBE_PATIENT_RM_TIMEOUT_SECONDS to specify the amount of time we
	should try a patient module remove. The default is 50 seconds. Set this
	to "forever" and we'll wait forever until the module is gone.
	- Set KCONFIG_PATH to specify your preferred location of kernel config
	file. The config is used by tests to check if kernel feature is enabled.
	- Set REPORT_GCOV to a directory path to make lcov and genhtml generate
	html reports from any gcov code coverage data collected by the kernel.
	If REPORT_GCOV is set to 1, the report will be written to $REPORT_DIR/gcov/.

	Test control:
	- Set LOAD_FACTOR to a nonzero positive integer to increase the amount of
	load applied to the system during a test by the specified multiple.
	- Set TIME_FACTOR to a nonzero positive integer to increase the amount of
	time that a test runs by the specified multiple.
	- For tests that are a member of the "soak" group, setting SOAK_DURATION
	allows the test runner to specify exactly how long the test should continue
	running. This setting overrides TIME_FACTOR. Floating point numbers are
	allowed, and the unit suffixes m(inutes), h(ours), d(ays), and w(eeks) are
	supported.

	Misc:
	- If you wish to disable UDF verification test set the environment variable
	DISABLE_UDF_TEST to 1.
	- Set LOGWRITES_DEV to a block device to use for power fail testing.
	- Set 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 MIN_FSSIZE to specify the minimal size (bytes) of a filesystem we
	can create. Setting this parameter will skip the tests creating a
	filesystem less than MIN_FSSIZE.
	- Set DIFF_LENGTH to "number of diff lines to print from a failed test",
	by default 10, set to 0 to print the full diff
	- set IDMAPPED_MOUNTS=true to run all tests on top of idmapped mounts. While
	this option is supported for all filesystems currently only -overlay is
	expected to run without issues. For other filesystems additional patches
	and fixes to the test suite might be needed.
	- Set REPORT_VARS_FILE to a file containing colon-separated name-value pairs
	that will be recorded in the test section report. Names must be unique.
	Whitespace surrounding the colon will be removed.
	- set CANON_DEVS=yes to canonicalize device symlinks. This will let you
	for example use something like TEST_DEV/dev/disk/by-id/nvme-* so the
	device remains persistent between reboots. This is disabled by default.

	______________________
	USING THE FSQA SUITE
	______________________

	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 tests/*/group.list files after building xfstests to learn about
	each test's group memberships.
	- 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/AFS/CIFS/OVERLAY, otherwise
	the filesystem type will be autodetected from $TEST_DEV:
	- for running nfs tests: ./check -nfs [test(s)]
	- for running afs tests: ./check -afs [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/preamble" file has been
	sourced and the "_begin_fstest" function has been called.

	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.

	6. Test group membership: Each test can be associated with any number
	of groups for convenient selection of subsets of tests. Group names
	must be human readable using only characters in the set [:alnum:_-].

	Test authors associate a test with groups by passing the names of those
	groups as arguments to the _begin_fstest function. While _begin_fstests
	is a shell function that must be called at the start of a test to
	initialise the test environment correctly, the the build infrastructure
	also scans the test files for _begin_fstests invocations. It does this
	to compile the group lists that are used to determine which tests to run
	when `check` is executed. In other words, test files files must call
	_begin_fstest with their intended groups or they will not be run.

	However, because the build infrastructure also uses _begin_fstests as
	a defined keyword, addition restrictions are placed on how it must be
	formatted:

	(a) It must be a single line with no multi-line continuations.

	(b) group names should be separated by spaces and not other whitespace

	(c) A '#' placed anywhere in the list, even in the middle of a group
	name, will cause everything from the # to the end of the line to be
	ignored.

	For example, the code:

	_begin_fstest auto quick subvol snapshot # metadata

	associates the current test with the "auto", "quick", "subvol", and
	"snapshot" groups. Because "metadata" is after the "#" comment
	delimiter, it is ignored by the build infrastructure and so it will not
	be associated with that group.

	It is not necessary to specify the "all" group in the list because that
	group is always computed at run time from the group lists.


	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
	__________________

	Send patches to the fstests mailing list at fstests@vger.kernel.org.