Tests for btree implementation used by range trees

Additional test cases for the btree implementation, see #9181.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Kennedy <john.kennedy@delphix.com>
Closes #9717

tests/zfs-tests/tests/functional/btree/Makefile.am

@@ -0,0 +1,20 @@
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2019 by Delphix. All rights reserved.
+#
+
+pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/btree
+
+dist_pkgdata_SCRIPTS = \
+	btree_positive.ksh \
+	btree_negative.ksh

tests/zfs-tests/tests/functional/btree/btree_negative.ksh

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+#!/usr/bin/ksh -p
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2019 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# Description:
+# Verify that the btree functions don't allow bad inputs
+#
+# insert_duplicate - Callers may not add values that are already in the tree
+# remove_missing   - Callers may not remove values that are not in the tree
+#
+# Note: These invocations cause btree_test to crash, but the program disables
+# core dumps first. As such, we can't use log_mustnot because it explicitly
+# looks for return values that correspond to a core dump and cause a test
+# failure.
+
+btree_test -n insert_duplicate
+[[ $? -eq 0 ]] && log_fail "Failure from insert_duplicate"
+
+btree_test -n remove_missing
+[[ $? -eq 0 ]] && log_fail "Failure from remove_missing"
+
+log_pass "Btree negative tests passed"

tests/zfs-tests/tests/functional/btree/btree_positive.ksh

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+#!/usr/bin/ksh -p
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2019 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# Description:
+# The `btree_test` binary runs a series of positive tests when called
+# without arguments.
+#
+# insert_find_remove - Basic functionality test
+# find_without_index - Using the find function with a NULL argument
+# drain_tree         - Fill the tree then empty it using the first and last
+#                      functions
+# stress_tree        - Allow the tree to have items added and removed for a
+#                      given amount of time
+#
+
+log_must btree_test
+
+log_pass "Btree positive tests passed"