reflink: don't test disjoint block sharing sets

Unlike xfs/btrfs which store refcounting information as part of the
space metadata, ocfs2 implements block sharing (reflink) by creating
refcount btrees that are shared between subsets of files.  Effectively,
this means that a ocfs2 can have multiple disjoint sets of files that
share blocks, which also means that blocks cannot be reflinked between
two disjoint refcounted-file-sets.  generic/119 tests the ability to do
this, so we cannot run it for ocfs2.  Create a _require helper to check
for this.

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>

common/reflink

@@ -28,6 +28,15 @@ _require_cp_reflink()
                _notrun "This test requires a cp with --reflink support."
 }
 
+# Can we reflink between arbitrary file sets?
+# i.e. if we reflink a->b and c->d, can we later share
+# blocks between b & c?
+_require_arbitrary_fileset_reflink()
+{
+	test "$FSTYP" = "ocfs2" && \
+		_notrun "reflink between arbitrary file groups not supported in $FSTYP"
+}
+
 # Given 2 files, verify that they have the same mapping but different
 # inodes - i.e. an undisturbed reflink
 # Silent if so, make noise if not

tests/generic/119

@@ -47,6 +47,7 @@ _cleanup()
 # real QA test starts here
 _supported_os Linux
 _require_test_reflink
+_require_arbitrary_fileset_reflink
 
 rm -f $seqres.full