ndctl/test: Exercise sub-section sized namespace creation/deletion

For kernels that have removed the section-aligned namespace constraint
validate that multiple namespaces can be created / deleted that collide
within a given section.

While this test acts on the ACPI.NFIT bus it is not marked "destructive"
because it only operates in available capacity and marks each namespace
created with a unique volume name ("subsection-test").

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

test/Makefile.am

@@ -25,7 +25,8 @@ TESTS =\
 	inject-smart.sh \
 	monitor.sh \
 	max_available_extent_ns.sh \
-	pfn-meta-errors.sh
+	pfn-meta-errors.sh \
+	sub-section.sh
 
 if ENABLE_KEYUTILS
 TESTS += security.sh

test/sub-section.sh

@@ -0,0 +1,78 @@
+#!/bin/bash -x
+
+# SPDX-License-Identifier: GPL-2.0
+# Copyright(c) 2015-2019 Intel Corporation. All rights reserved.
+
+set -e
+
+SKIP=77
+FAIL=1
+SUCCESS=0
+
+. ./common
+
+check_min_kver "5.2" || do_skip "may lack align sub-section hotplug support"
+
+MNT=test_dax_mnt
+mkdir -p $MNT
+
+TEST_SIZE=$((16<<20))
+MIN_AVAIL=$((TEST_SIZE*4))
+MAX_NS=10
+NAME="subsection-test"
+
+ndctl list -N | jq -r ".[] | select(.name==\"subsection-test\") | .dev"
+
+rc=$FAIL
+cleanup() {
+	if [ $rc -ne $SUCCESS ]; then
+		echo "test/sub-section.sh: failed at line $1"
+	fi
+	if mountpoint -q $MNT; then
+		umount $MNT
+	fi
+	rmdir $MNT
+	# opportunistic cleanup, not fatal if these fail
+	namespaces=$($NDCTL list -N | jq -r ".[] | select(.name==\"$NAME\") | .dev")
+	for i in $namespaces
+	do
+		if ! $NDCTL destroy-namespace -f $i; then
+			echo "test/sub-section.sh: cleanup() failed to destroy $i"
+		fi
+	done
+	exit $rc
+}
+
+trap 'err $LINENO cleanup' ERR
+
+json=$($NDCTL list -R -b ACPI.NFIT)
+region=$(echo $json | jq -r "[.[] | select(.available_size >= $MIN_AVAIL)][0].dev")
+avail=$(echo $json | jq -r "[.[] | select(.available_size >= $MIN_AVAIL)][0].available_size")
+if [ -z $region ]; then
+	exit $SKIP
+fi
+
+iter=$((avail/TEST_SIZE))
+if [ $iter -gt $MAX_NS ]; then
+	iter=$MAX_NS;
+fi
+
+for i in $(seq 1 $iter)
+do
+	json=$($NDCTL create-namespace -s $TEST_SIZE --no-autorecover -r $region -n "$NAME")
+	dev=$(echo $json | jq -r ".blockdev")
+	mkfs.ext4 -b 4096 /dev/$dev
+	mount -o dax /dev/$dev $MNT
+	umount $MNT
+done
+
+namespaces=$($NDCTL list -N | jq -r ".[] | select(.name==\"$NAME\") | .dev")
+for i in $namespaces
+do
+	$NDCTL disable-namespace $i
+	$NDCTL enable-namespace $i
+	$NDCTL destroy-namespace $i -f
+done
+
+rc=$SUCCESS
+cleanup $LINENO