temporarily disable sanity 57b which lead to LBUG.

thanks tappro.

lustre/tests/sanity.sh

@@ -16,8 +16,11 @@ ONLY=${ONLY:-"$*"}
 #   configurations. Will be done in second phase of collibri.
 # - 71 mmap still not updated on HEAD
 # - 42b (current implementation of size-on-mds feature doesn't handle this)
+# - 57b direct access /proc/.../kbytesfree might directly call obd_statfs
+#   on mdc/osc (bypass lmv/lov), while the obd might still not connected yet.
+#   temporarily disable it.
 
-ALWAYS_EXCEPT=${ALWAYS_EXCEPT:-"24n 48a 51b 51c 65h 71 42b"}
+ALWAYS_EXCEPT=${ALWAYS_EXCEPT:-"24n 48a 51b 51c 65h 71 42b 57b"}
 # UPDATE THE COMMENT ABOVE WITH BUG NUMBERS WHEN CHANGING ALWAYS_EXCEPT!
 
 [ "$ALWAYS_EXCEPT$EXCEPT" ] && echo "Skipping tests: $ALWAYS_EXCEPT $EXCEPT"