[PATCH v5 2/2] generic: test i_blocks for truncated large files

[Pavel Reichl <preichl@redhat.com>]

This is a regression test for an incorrect computation of i_blocks for
truncated files larger than 4 GiB. Bug was filed for exFAT.

Test is based on reproducer provied by Christophe Vu-Brugier as part
of kernel patch-fix submission.

Signed-off-by: Pavel Reichl <preichl@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
 tests/generic/698     | 51 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/698.out |  2 ++
 2 files changed, 53 insertions(+)
 create mode 100755 tests/generic/698
 create mode 100644 tests/generic/698.out

diff --git a/tests/generic/698 b/tests/generic/698
new file mode 100755
index 00000000..6aeea64e
--- /dev/null
+++ b/tests/generic/698
@@ -0,0 +1,51 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022  Red Hat Inc. All Rights Reserved.
+#
+# FS QA Test 698
+#
+# Verify that i_blocks for truncated files larger than 4 GiB have correct
+# values.
+#
+# This test verifies the problem fixed in kernel with commit
+# 92fba084b79e exfat: fix i_blocks for files truncated over 4 GiB
+#
+. ./common/preamble
+. ./common/filter
+
+_begin_fstest auto
+
+# Override the default cleanup function.
+_cleanup()
+{
+	cd /
+	rm -r -f $tmp.* $junk_dir
+}
+
+_supported_fs generic
+_fixed_by_kernel_commit 92fba084b79e \
+	"exfat: fix i_blocks for files truncated over 4 GiB"
+
+_require_test
+_require_fs_space $TEST_DIR $((5 * 1024 * 1024)) #kB
+
+junk_dir=$TEST_DIR/$seq
+junk_file=$junk_dir/junk
+mkdir -p $junk_dir
+
+_create_file_sized 5G $junk_file
+if [ $? -ne 0 ]; then
+	echo "Could not create 5G test file"
+fi
+
+truncate -s 4G $junk_file
+
+block_size=`stat -c '%B' $junk_file`
+iblocks_after_truncate=`stat -c '%b' $junk_file`
+iblocks_expected=$((4 * 1024 * 1024 * 1024 / $block_size))
+
+_within_tolerance "Number of allocated blocks after truncate" $iblocks_after_truncate $iblocks_expected 1% -v
+
+status=0
+
+exit
diff --git a/tests/generic/698.out b/tests/generic/698.out
new file mode 100644
index 00000000..cbb02d37
--- /dev/null
+++ b/tests/generic/698.out
@@ -0,0 +1,2 @@
+QA output created by 698
+Number of allocated blocks after truncate is in range
-- 
2.37.3