xfs: test attr_list_by_handle cursor iteration

Apparently the XFS attr_list_by_handle ioctl has never actually
copied the cursor contents back to user space, which means that
iteration has never worked.  Add a test case for this and see

"xfs: in _attrlist_by_handle, copy the cursor back to userspace".

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/xfs/269

@@ -0,0 +1,64 @@
+#! /bin/bash
+# FS QA Test No. 269
+#
+# Check that attr_list_by_handle copies the cursor back to userspace.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2016, Oracle and/or its affiliates.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+
+seq=`basename "$0"`
+seqres="$RESULT_DIR/$seq"
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1    # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -rf "$tmp".* $TEST_DIR/fsmap $TEST_DIR/testout
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/attr
+. ./common/populate
+
+# real QA test starts here
+_supported_os Linux
+_require_scratch
+_require_test_program "attr-list-by-handle-cursor-test"
+
+rm -f "$seqres.full"
+
+echo "Format and mount"
+_scratch_mkfs > "$seqres.full" 2>&1
+_scratch_mount
+
+echo "Stuff file with xattrs"
+mkdir $SCRATCH_MNT/foo
+__populate_create_attr $SCRATCH_MNT/foo 100
+
+echo "Run test program"
+./src/attr-list-by-handle-cursor-test $SCRATCH_MNT/foo
+
+# success, all done
+status=0
+exit

tests/xfs/269.out

@@ -0,0 +1,5 @@
+QA output created by 269
+Format and mount
+Stuff file with xattrs
+Run test program
+Test passes.

tests/xfs/group

@@ -264,6 +264,7 @@
 266 dump ioctl auto quick
 267 dump ioctl tape
 268 dump ioctl tape
+269 auto quick ioctl
 278 repair auto
 279 auto mkfs
 281 dump ioctl auto quick