ZTS: add regression test for #17180

in #17180, we fixed an interesting bug that i believe i hit in one of my
pools, but as far as i can tell, there was no test for it.

this patch adds a regression test for #17180, minimised from my attempts
to reproduce the bug in a way that resembled the history of my pool.

Signed-off-by: delan azabani <dazabani@igalia.com>

Author: delan

tests/runfiles/common.run

@@ -82,7 +82,8 @@ tests = ['block_cloning_clone_mmap_cached',
     'block_cloning_copyfilerange_fallback_same_txg',
     'block_cloning_replay', 'block_cloning_replay_encrypted',
     'block_cloning_lwb_buffer_overflow', 'block_cloning_clone_mmap_write',
-    'block_cloning_rlimit_fsize', 'block_cloning_large_offset']
+    'block_cloning_rlimit_fsize', 'block_cloning_large_offset',
+    'block_cloning_after_device_removal_17180']
 tags = ['functional', 'block_cloning']
 
 [tests/functional/bootfs]

tests/zfs-tests/tests/Makefile.am

@@ -491,6 +491,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/block_cloning/block_cloning_lwb_buffer_overflow.ksh \
 	functional/block_cloning/block_cloning_rlimit_fsize.ksh \
 	functional/block_cloning/block_cloning_large_offset.ksh \
+	functional/block_cloning/block_cloning_after_device_removal_17180.ksh \
 	functional/bootfs/bootfs_001_pos.ksh \
 	functional/bootfs/bootfs_002_neg.ksh \
 	functional/bootfs/bootfs_003_pos.ksh \

tests/zfs-tests/tests/functional/block_cloning/block_cloning_after_device_removal_17180.ksh

@@ -0,0 +1,64 @@
+#!/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
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/block_cloning/block_cloning.kshlib
+
+#
+# DESCRIPTION:
+#	Verify that when modifying and freeing cloned blocks after a top-level
+#	vdev removal, there is no panic. This is a regression test for #17180.
+#
+
+verify_runnable "global"
+
+if is_linux && [[ $(linux_version) -lt $(linux_version "4.5") ]]; then
+  log_unsupported "copy_file_range not available before Linux 4.5"
+fi
+
+export VDIR=$TEST_BASE_DIR/disk-bclone
+export VDEV="$VDIR/0 $VDIR/1"
+log_must rm -rf $VDIR
+log_must mkdir -p $VDIR
+log_must truncate -s $MINVDEVSIZE $VDEV
+
+claim="No panic when destroying dataset with cloned blocks after top-level vdev removal"
+
+log_assert $claim
+
+function cleanup
+{
+	datasetexists $TESTPOOL && destroy_pool $TESTPOOL
+	rm -rf $TESTDIR $VDIR
+}
+
+log_onexit cleanup
+
+log_must zpool create -o feature@block_cloning=enabled $TESTPOOL $VDEV
+log_must dd if=/dev/urandom of=/$TESTPOOL/file bs=16M count=2
+log_must zpool remove -w $TESTPOOL $VDIR/1
+log_must zfs create $TESTPOOL/$TESTFS
+log_must cp /$TESTPOOL/file /$TESTPOOL/$TESTFS
+log_must dd if=/dev/urandom of=/$TESTPOOL/file bs=16M count=2
+log_must zfs destroy -r $TESTPOOL/$TESTFS
+
+log_pass $claim