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		   TESTING FOR REQUIREMENTS IN TEST SCRIPTS
		   ========================================

Test scripts need to indicate to the infrastructure what sorts of requirements
they have.  This is done with _require_<xxx> macros, which may take parameters.

 (1) General requirements.

	_require_command "$<NAME_PROG>" <name>
	_require_test
	_require_test_program <name>
	_require_xfs_io_command <name> [<switch>]

 (2) Filesystem capability requirements.

	_require_chattr <letters>
	_require_exportfs

 (3) System call requirements.

	_require_statx

 (4) Device mapper requirement.

	_require_dm_target
	_require_log_writes

====================
GENERAL REQUIREMENTS
====================

_require_command "$NAME_PROG" name

     The test requires an external command, called 'name' be present on the
     system and that '$VAR' should be set with the path to that command.  $VAR
     should then be used to refer to the command when executing it.  For
     example:

	_require_command "KILLALL_PROG" killall

     to locate the killall command and then:

	$KILLALL_PROG -q $FSSTRESS_PROG

     to make use of it.


_require_test

     The test requires that the block device specified by $TEST_DEV be mounted
     on $TEST_DIR.


_require_test_program <name>

     The test requires a program by the name of 'name' be present and built in
     the src/ directory.  For example:

	_require_test_program "stat_test"

     requires that src/stat_test be built.


_require_xfs_io_command <name> [<switch>]

     The test requires that the xfs_io command be available, that it supports
     command <name> and, optionally, that that command supports the specified
     switch.  For example:

	_require_xfs_io_command "falloc"
	_require_xfs_io_command "chattr" "+/-x"

     The first requires that xfs_io support the falloc command and the second
     that it supports the chattr command and that the chattr command supports
     the +x and -x arguments (DAX attribute).


==================================
FILESYSTEM CAPABILITY REQUIREMENTS
==================================

_require_chattr <letters>

     The test requires that the filesystem attribute set by the chattr command
     with +<letters> as an argument be available and supported by the $TEST_DEV
     filesystem.  No check is made of the scratch filesystem.  For example:

	_require_chattr ai

     tests to see if setting the append-only and immutable attributes on a file
     (chattr +a +i) is supported.

_require_exportfs

     The test requires that the $TEST_DEV filesystem supports NFS export.
     The test also requires the use of the open_by_handle_at() system call and
     will be skipped if it isn't available in the kernel.


========================
SYSTEM CALL REQUIREMENTS
========================

_require_statx

     The test requires the use of the statx() system call and will be skipped
     if it isn't available in the kernel.


==========================
DEVICE MAPPER REQUIREMENTS
==========================

_require_dm_target <name>

     The test requires the use of the device mapper target and will be skipped
     if it isn't available in the kernel.

_require_log_writes

     The test requires the use of the device mapper target log-writes.
     The test also requires the test program log-writes/replay-log is built
     and will be skipped if either isn't available.

======================
PERF TEST REQUIREMENTS
======================

_require_fio_results

     This test requires the supporting tools for saving and comparing fio based
     perf test results.
