From 9af64492c3671825321409bdb6f68e3a359e594d Mon Sep 17 00:00:00 2001
From: Umer Saleem <usaleem@ixsystems.com>
Date: Sat, 9 Dec 2023 00:30:45 +0500
Subject: [PATCH] Test LWB buffer overflow

Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
---
 tests/runfiles/linux.run                      |  3 +-
 tests/test-runner/bin/zts-report.py.in        |  2 +
 tests/zfs-tests/tests/Makefile.am             |  1 +
 .../block_cloning_lwb_buffer_overflow.ksh     | 79 +++++++++++++++++++
 4 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 tests/zfs-tests/tests/functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh

diff --git a/tests/runfiles/linux.run b/tests/runfiles/linux.run
index fb78d96fb52d..444f5dfe616d 100644
--- a/tests/runfiles/linux.run
+++ b/tests/runfiles/linux.run
@@ -43,7 +43,8 @@ tests = ['block_cloning_copyfilerange', 'block_cloning_copyfilerange_partial',
     'block_cloning_disabled_ficlonerange',
     'block_cloning_copyfilerange_cross_dataset',
     'block_cloning_cross_enc_dataset',
-    'block_cloning_copyfilerange_fallback_same_txg']
+    'block_cloning_copyfilerange_fallback_same_txg',
+    'block_cloning_lwb_buffer_overflow']
 tags = ['functional', 'block_cloning']
 
 [tests/functional/chattr:Linux]
diff --git a/tests/test-runner/bin/zts-report.py.in b/tests/test-runner/bin/zts-report.py.in
index b188a101c257..02dc9d72d489 100755
--- a/tests/test-runner/bin/zts-report.py.in
+++ b/tests/test-runner/bin/zts-report.py.in
@@ -301,6 +301,8 @@ elif sys.platform.startswith('linux'):
             ['SKIP', cfr_reason],
         'block_cloning/block_cloning_copyfilerange_fallback':
             ['SKIP', cfr_reason],
+        'block_cloning/block_cloning_lwb_buffer_overflow':
+            ['SKIP', cfr_reason],
         'block_cloning/block_cloning_copyfilerange_cross_dataset':
             ['SKIP', cfr_cross_reason],
         'block_cloning/block_cloning_copyfilerange_fallback_same_txg':
diff --git a/tests/zfs-tests/tests/Makefile.am b/tests/zfs-tests/tests/Makefile.am
index 2d899e58bdbb..1a3e7bffb921 100644
--- a/tests/zfs-tests/tests/Makefile.am
+++ b/tests/zfs-tests/tests/Makefile.am
@@ -452,6 +452,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/block_cloning/block_cloning_ficlonerange.ksh \
 	functional/block_cloning/block_cloning_ficlonerange_partial.ksh \
 	functional/block_cloning/block_cloning_cross_enc_dataset.ksh \
+	functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh \
 	functional/bootfs/bootfs_001_pos.ksh \
 	functional/bootfs/bootfs_002_neg.ksh \
 	functional/bootfs/bootfs_003_pos.ksh \
diff --git a/tests/zfs-tests/tests/functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh b/tests/zfs-tests/tests/functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh
new file mode 100644
index 000000000000..4da3baf13939
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh
@@ -0,0 +1,79 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2023 by iXsystems, Inc. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/block_cloning/block_cloning.kshlib
+
+#
+# DESCRIPTION:
+#	Test for LWB buffer overflow with multiple VDEVs ZIL when 128KB
+#	block write is split into two 68KB ones, trying to write maximum
+#	sizes 128KB TX_CLONE_RANGE record with 1022 block pointers into
+#	68KB buffer.
+#
+# STRATEGY:
+#	1. Create a pool with multiple VDEVs ZIL
+#	2. Write maximum sizes TX_CLONE_RANGE record with 1022 block
+#	   pointers into 68KB buffer
+#	3. Sync TXG
+#	4. Clone the file
+#	5. Synchronize cached writes
+#
+
+verify_runnable "global"
+
+if [[ $(linux_version) -lt $(linux_version "4.5") ]]; then
+  log_unsupported "copy_file_range not available before Linux 4.5"
+fi
+
+VDIR=$TEST_BASE_DIR/disk-bclone
+VDEV="$VDIR/a $VDIR/b $VDIR/c"
+LDEV="$VDIR/e $VDIR/f"
+
+
+function cleanup
+{
+	datasetexists $TESTPOOL && destroy_pool $TESTPOOL
+	rm -rf $VDIR
+}
+
+log_assert "Test for LWB buffer overflow with multiple VDEVs ZIL"
+
+log_must rm -rf $VDIR
+log_must mkdir -p $VDIR
+log_must truncate -s $MINVDEVSIZE $VDEV $LDEV
+
+log_must zpool create -o feature@block_cloning=enabled $TESTPOOL $VDEV \
+	log mirror $LDEV
+log_must zfs create -o recordsize=32K $TESTPOOL/$TESTFS
+log_must dd if=/dev/urandom of=/testpool/testfs/file1 bs=32K count=1022 \
+	conv=fsync
+sync_pool $TESTPOOL
+log_must clonefile -c /testpool/testfs/file1 /testpool/testfs/file2
+log_must sync
+
+log_pass "LWB buffer overflow is not triggered with multiple VDEVs ZIL"
+