+/**
+ * FLR: verify the layout version of object.
+ *
+ * \param[in] env execution environment
+ * \param[in] fo OFD object
+ * \param[in] oa OBDO structure with layout version
+ *
+ * \retval 0 on successful verification
+ * \retval -EINPROGRESS layout version is in transfer
+ * \retval -ESTALE the layout version on client is stale
+ */
+int ofd_verify_layout_version(const struct lu_env *env,
+ struct ofd_object *fo, const struct obdo *oa)
+{
+ __u32 layout_version;
+ int rc;
+ ENTRY;
+
+ if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_OST_SKIP_LV_CHECK)))
+ GOTO(out, rc = 0);
+
+ rc = ofd_object_ff_load(env, fo);
+ if (rc < 0) {
+ if (rc == -ENODATA)
+ rc = -EINPROGRESS;
+ GOTO(out, rc);
+ }
+
+ layout_version = fo->ofo_ff.ff_layout_version;
+ if (oa->o_layout_version >= layout_version &&
+ oa->o_layout_version <= layout_version + fo->ofo_ff.ff_range)
+ GOTO(out, rc = 0);
+
+ /* normal traffic, decide if to return ESTALE or EINPROGRESS */
+ layout_version &= ~LU_LAYOUT_RESYNC;
+
+ /* this update is not legitimate */
+ if ((oa->o_layout_version & ~LU_LAYOUT_RESYNC) <= layout_version)
+ GOTO(out, rc = -ESTALE);
+
+ /* layout version may not be transmitted yet */
+ if ((oa->o_layout_version & ~LU_LAYOUT_RESYNC) > layout_version)
+ GOTO(out, rc = -EINPROGRESS);
+
+ EXIT;
+
+out:
+ CDEBUG(D_INODE, DFID " verify layout version: %u vs. %u/%u, rc: %d\n",
+ PFID(lu_object_fid(&fo->ofo_obj.do_lu)),
+ oa->o_layout_version, fo->ofo_ff.ff_layout_version,
+ fo->ofo_ff.ff_range, rc);
+ return rc;
+
+}
+
+/**
+ * Prepare buffers for read request processing.
+ *
+ * This function converts remote buffers from client to local buffers
+ * and prepares the latter.
+ *
+ * \param[in] env execution environment
+ * \param[in] exp OBD export of client
+ * \param[in] ofd OFD device
+ * \param[in] fid FID of object
+ * \param[in] la object attributes
+ * \param[in] oa OBDO structure from client
+ * \param[in] niocount number of remote buffers
+ * \param[in] rnb remote buffers
+ * \param[in] nr_local number of local buffers
+ * \param[in] lnb local buffers
+ * \param[in] jobid job ID name
+ *
+ * \retval 0 on successful prepare
+ * \retval negative value on error
+ */