Currently, when a test case has callback functions for fallback device,
the fallback device is created in run_test(). Meanwhile,
_unload_module() is called in _call_test(). Then,
cleanup_fallback_device() is called after _unload_module().

  _run_test
    fallback_device
      _check_and_call_test_device
        _call_test
          _unload_modules
    cleanup_fallback_device

This is not desired since module unload can affect
cleanup_fallback_device(). For example, scsi_debug is used as a fallback
device, _unload_modules() can unload scsi_debug before calling
cleanup_fallback_device().

To resolve this, make two changes. The first change is to move fallback
operations from _run_test() to _check_and_call_test_device(). This
commit does it. After this commit, the call chain will be as follows.

  _run_test
    _check_and_call_test_device
      fallback_device
        _call_test
          _unload_modules
      cleanup_fallback_device

As the second change, the following commit will move the
_unload_modules() call.

While at this change, rename the local variable FALLBACK_DEVICE to
'fallback', since capital letters imply that the variable would be
a global variable.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
---
 check | 57 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 28 insertions(+), 29 deletions(-)

diff --git a/check b/check
index f170458..3fa3e97 100755
--- a/check
+++ b/check
@@ -716,14 +716,34 @@ _check_and_call_test() {
 _check_and_call_test_device() {
 	local postfix
 	local unset_skip_reason
-	local ret
+	local ret=0
+	local fallback=0
 
 	if declare -fF requires >/dev/null; then
 		requires
 	fi
 
+	if [[ ${#TEST_DEVS[@]} -eq 0 ]] && \
+		   declare -fF fallback_device >/dev/null; then
+		TEST_DEVS[0]=fallback
+	fi
+
 	[[ -n $COND_DESC ]] && postfix=_${COND_DESC//[ =]/_}
 	for TEST_DEV in "${TEST_DEVS[@]}"; do
+		if [[ $TEST_DEV == fallback ]]; then
+			if ! TEST_DEV=$(fallback_device); then
+				_warning "$TEST_NAME: fallback_device call failure"
+				return 0
+			fi
+
+			if ! _find_sysfs_dirs "$TEST_DEV"; then
+				_warning "$TEST_NAME: could not find sysfs directory for ${TEST_DEV}"
+				cleanup_fallback_device
+				return 0
+			fi
+			fallback=1
+		fi
+
 		TEST_DEV_SYSFS="${TEST_DEV_SYSFS_DIRS["$TEST_DEV"]}"
 		TEST_DEV_PART_SYSFS="${TEST_DEV_PART_SYSFS_DIRS["$TEST_DEV"]}"
 
@@ -744,6 +764,13 @@ _check_and_call_test_device() {
 		if (( unset_skip_reason )); then
 			unset SKIP_REASONS
 		fi
+
+		if (( fallback )); then
+			cleanup_fallback_device
+			unset "TEST_DEV_SYSFS_DIRS[${TEST_DEV}]]"
+			unset "TEST_DEV_PART_SYSFS_DIRS[${TEST_DEV}]"
+			TEST_DEVS=()
+		fi
 	done
 
 	return $ret
@@ -825,7 +852,6 @@ _run_test() {
 	DMESG_FILTER="cat"
 	RUN_FOR_ZONED=0
 	COND_DESC=""
-	FALLBACK_DEVICE=0
 	MODULES_TO_UNLOAD=()
 
 	local nr_conds cond_i
@@ -855,26 +881,6 @@ _run_test() {
 			ret=$?
 		fi
 	elif declare -fF test_device >/dev/null; then
-		if [[ ${#TEST_DEVS[@]} -eq 0 ]] && \
-			declare -fF fallback_device >/dev/null; then
-			if ! test_dev=$(fallback_device); then
-				_warning "$TEST_NAME: fallback_device call failure"
-				return 0
-			fi
-
-			if ! _find_sysfs_dirs "$test_dev"; then
-				_warning "$TEST_NAME: could not find sysfs directory for ${test_dev}"
-				cleanup_fallback_device
-				return 0
-			fi
-			TEST_DEVS=( "${test_dev}" )
-			FALLBACK_DEVICE=1
-		fi
-
-		if [[ ${#TEST_DEVS[@]} -eq 0 ]]; then
-			return 0
-		fi
-
 		if declare -fF set_conditions >/dev/null; then
 			nr_conds=$(set_conditions)
 			for ((cond_i = 0; cond_i < nr_conds; cond_i++)); do
@@ -887,13 +893,6 @@ _run_test() {
 			_check_and_call_test_device
 			ret=$?
 		fi
-
-		if (( FALLBACK_DEVICE )); then
-			cleanup_fallback_device
-			unset "TEST_DEV_SYSFS_DIRS[${TEST_DEVS[0]}]"
-			unset "TEST_DEV_PART_SYSFS_DIRS[${TEST_DEVS[0]}]"
-			TEST_DEVS=()
-		fi
 	else
 		_check_and_call_test_device_array
 		ret=$?
-- 
2.49.0