LU-17218 ofd: improve filter_fid upgrade compatibility

[fs/lustre-release.git] / lustre / ofd / ofd_internal.h

diff --git a/lustre/ofd/ofd_internal.h b/lustre/ofd/ofd_internal.h
index 55e1639..688c332 100644 (file)
--- a/lustre/ofd/ofd_internal.h
+++ b/lustre/ofd/ofd_internal.h
@@ -179,6 +179,13 @@ static inline char *ofd_name(struct ofd_device *ofd)
        return ofd->ofd_dt_dev.dd_lu_dev.ld_obd->obd_name;
 }
 
+/**
+ * for compatibility, filter_fid could occupy more space in newer version and
+ * downgraded Lustre would fail reading it with -ERANGE, so it can read it
+ * again with more space to hold it.
+ */
+#define FILTER_FID_EXTRA_SIZE  32
+
 struct ofd_object {
        struct lu_object_header ofo_header;
        struct dt_object        ofo_obj;