From c235b26103e8846ae956922a8c14be91f3208d69 Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@suse.com>
Date: Tue, 8 Sep 2020 11:32:02 +0100
Subject: [PATCH] generic: add test for zero range over a file range with many
 small extents

Test a fallocate() zero range operation against a large file range for which
there are many small extents allocated. Verify the operation does not fail
and the respective range return zeroes on subsequent reads.

This test is motivated by a bug found on btrfs. The patch that fixes the
bug on btrfs has the following subject:

 "btrfs: fix metadata reservation for fallocate that leads to transaction aborts"

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
---
 tests/generic/610     | 61 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/610.out |  5 ++++
 tests/generic/group   |  1 +
 3 files changed, 67 insertions(+)
 create mode 100755 tests/generic/610
 create mode 100644 tests/generic/610.out

diff --git a/tests/generic/610 b/tests/generic/610
new file mode 100755
index 00000000..0b9e7322
--- /dev/null
+++ b/tests/generic/610
@@ -0,0 +1,61 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
+#
+# FS QA Test No. 610
+#
+# Test a fallocate() zero range operation against a large file range for which
+# there are many small extents allocated. Verify the operation does not fail
+# and the respective range return zeroes on subsequent reads.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+_require_xfs_io_command "fzero"
+_require_xfs_io_command "fpunch"
+_require_test_program "punch-alternating"
+
+rm -f $seqres.full
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+# Create a file with many small extents. To speed up file creation, do
+# buffered writes and then punch a hole on every other block.
+$XFS_IO_PROG -f -c "pwrite -S 0xab -b 10M 0 100M" \
+	$SCRATCH_MNT/foobar >>$seqres.full
+$here/src/punch-alternating $SCRATCH_MNT/foobar >>$seqres.full
+
+# For btrfs, trigger a transaction commit to force metadata COW for the
+# following fallocate zero range operation.
+sync
+
+$XFS_IO_PROG -c "fzero 0 100M" $SCRATCH_MNT/foobar
+
+# Check the file content after umounting and mounting again the fs, to verify
+# everything was persisted.
+_scratch_cycle_mount
+
+echo "File content after zero range operation:"
+od -A d -t x1 $SCRATCH_MNT/foobar
+
+status=0
+exit
diff --git a/tests/generic/610.out b/tests/generic/610.out
new file mode 100644
index 00000000..96f8d135
--- /dev/null
+++ b/tests/generic/610.out
@@ -0,0 +1,5 @@
+QA output created by 610
+File content after zero range operation:
+0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+104857600
diff --git a/tests/generic/group b/tests/generic/group
index 2c704266..8eba6c98 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -612,3 +612,4 @@
 607 auto attr quick dax
 608 auto attr quick dax
 609 auto quick rw
+610 auto quick prealloc zero
-- 
2.39.5