struct objlayout *objlay = OBJLAYOUT(state->lseg->pls_layout);
 
                spin_lock(&objlay->lock);
+               objlay->delta_space_valid = OBJ_DSU_INVALID;
                list_add(&objlay->err_list, &state->err_list);
                spin_unlock(&objlay->lock);
        }
        return PNFS_ATTEMPTED;
 }
 
+void
+objlayout_encode_layoutcommit(struct pnfs_layout_hdr *pnfslay,
+                             struct xdr_stream *xdr,
+                             const struct nfs4_layoutcommit_args *args)
+{
+       struct objlayout *objlay = OBJLAYOUT(pnfslay);
+       struct pnfs_osd_layoutupdate lou;
+       __be32 *start;
+
+       dprintk("%s: Begin\n", __func__);
+
+       spin_lock(&objlay->lock);
+       lou.dsu_valid = (objlay->delta_space_valid == OBJ_DSU_VALID);
+       lou.dsu_delta = objlay->delta_space_used;
+       objlay->delta_space_used = 0;
+       objlay->delta_space_valid = OBJ_DSU_INIT;
+       lou.olu_ioerr_flag = !list_empty(&objlay->err_list);
+       spin_unlock(&objlay->lock);
+
+       start = xdr_reserve_space(xdr, 4);
+
+       BUG_ON(pnfs_osd_xdr_encode_layoutupdate(xdr, &lou));
+
+       *start = cpu_to_be32((xdr->p - start - 1) * 4);
+
+       dprintk("%s: Return delta_space_used %lld err %d\n", __func__,
+               lou.dsu_delta, lou.olu_ioerr_flag);
+}
+
 static int
 err_prio(u32 oer_errno)
 {
 
 struct objlayout {
        struct pnfs_layout_hdr pnfs_layout;
 
+        /* for layout_commit */
+       enum osd_delta_space_valid_enum {
+               OBJ_DSU_INIT = 0,
+               OBJ_DSU_VALID,
+               OBJ_DSU_INVALID,
+       } delta_space_valid;
+       s64 delta_space_used;  /* consumed by write ops */
+
         /* for layout_return */
        spinlock_t lock;
        struct list_head err_list;
                        unsigned index, struct pnfs_osd_objid *pooid,
                        int osd_error, u64 offset, u64 length, bool is_write);
 
+static inline void
+objlayout_add_delta_space_used(struct objlayout_io_state *state, s64 space_used)
+{
+       struct objlayout *objlay = OBJLAYOUT(state->lseg->pls_layout);
+
+       /* If one of the I/Os errored out and the delta_space_used was
+        * invalid we render the complete report as invalid. Protocol mandate
+        * the DSU be accurate or not reported.
+        */
+       spin_lock(&objlay->lock);
+       if (objlay->delta_space_valid != OBJ_DSU_INVALID) {
+               objlay->delta_space_valid = OBJ_DSU_VALID;
+               objlay->delta_space_used += space_used;
+       }
+       spin_unlock(&objlay->lock);
+}
+
 extern void objlayout_read_done(struct objlayout_io_state *state,
                                ssize_t status, bool sync);
 extern void objlayout_write_done(struct objlayout_io_state *state,
        struct nfs_write_data *,
        int how);
 
+extern void objlayout_encode_layoutcommit(
+       struct pnfs_layout_hdr *,
+       struct xdr_stream *,
+       const struct nfs4_layoutcommit_args *);
+
 extern void objlayout_encode_layoutreturn(
        struct pnfs_layout_hdr *,
        struct xdr_stream *,