tests: sparse-fiemap: with root/ext3, do not create an ext4 FS

* tests/cp/sparse-fiemap: When this test was run as root on an ext3
file system, (ext3 had known problems), it would trickily create and
mount a loopback ext4 file system and use that instead.  However, due
to a bug in 2.6.39-rc1..rc3, this loopback test (when run in another
loopback FS) exposed a bug with 1k-blocksize ext4 whereby non-NUL
data would be read from a hole.  For details, see this:
http://thread.gmane.org/gmane.comp.file-systems.ext4/24495

diff --git a/tests/cp/sparse-fiemap b/tests/cp/sparse-fiemap
index 2e8c95b..1394060 100755 (executable)
--- a/tests/cp/sparse-fiemap
+++ b/tests/cp/sparse-fiemap
@@ -26,6 +26,10 @@ touch fiemap_chk
 if fiemap_capable_ fiemap_chk && ! df -t ext3 . >/dev/null; then
   : # Current partition has working extents.  Good!
 else
+  # FIXME: temporarily(?) skip this variant, at least until after this bug
+  # is fixed: http://thread.gmane.org/gmane.comp.file-systems.ext4/24495
+  skip_test_ "current file system has insufficient FIEMAP support"
+
   # It's not;  we need to create one, hence we need root access.
   require_root_