+ * Merge layouts to form a mirrored file.
+ */
+static int lod_declare_layout_merge(const struct lu_env *env,
+ struct dt_object *dt, const struct lu_buf *mbuf,
+ struct thandle *th)
+{
+ struct lod_thread_info *info = lod_env_info(env);
+ struct lu_buf *buf = &info->lti_buf;
+ struct lod_object *lo = lod_dt_obj(dt);
+ struct lov_comp_md_v1 *lcm;
+ struct lov_comp_md_v1 *cur_lcm;
+ struct lov_comp_md_v1 *merge_lcm;
+ struct lov_comp_md_entry_v1 *lcme;
+ size_t size = 0;
+ size_t offset;
+ __u16 cur_entry_count;
+ __u16 merge_entry_count;
+ __u32 id = 0;
+ __u16 mirror_id = 0;
+ __u32 mirror_count;
+ int rc, i;
+ ENTRY;
+
+ merge_lcm = mbuf->lb_buf;
+ if (mbuf->lb_len < sizeof(*merge_lcm))
+ RETURN(-EINVAL);
+
+ /* must be an existing layout from disk */
+ if (le32_to_cpu(merge_lcm->lcm_magic) != LOV_MAGIC_COMP_V1)
+ RETURN(-EINVAL);
+
+ merge_entry_count = le16_to_cpu(merge_lcm->lcm_entry_count);
+
+ /* do not allow to merge two mirrored files */
+ if (le16_to_cpu(merge_lcm->lcm_mirror_count))
+ RETURN(-EBUSY);
+
+ /* verify the target buffer */
+ rc = lod_get_lov_ea(env, lo);
+ if (rc <= 0)
+ RETURN(rc ? : -ENODATA);
+
+ cur_lcm = info->lti_ea_store;
+ if (le32_to_cpu(cur_lcm->lcm_magic) != LOV_MAGIC_COMP_V1)
+ RETURN(-EINVAL);
+
+ cur_entry_count = le16_to_cpu(cur_lcm->lcm_entry_count);
+
+ /* 'lcm_mirror_count + 1' is the current # of mirrors the file has */
+ mirror_count = le16_to_cpu(cur_lcm->lcm_mirror_count) + 1;
+ if (mirror_count + 1 > LUSTRE_MIRROR_COUNT_MAX)
+ RETURN(-ERANGE);
+
+ /* size of new layout */
+ size = le32_to_cpu(cur_lcm->lcm_size) +
+ le32_to_cpu(merge_lcm->lcm_size) - sizeof(*cur_lcm);
+
+ memset(buf, 0, sizeof(*buf));
+ lu_buf_alloc(buf, size);
+ if (buf->lb_buf == NULL)
+ RETURN(-ENOMEM);
+
+ lcm = buf->lb_buf;
+ memcpy(lcm, cur_lcm, sizeof(*lcm) + cur_entry_count * sizeof(*lcme));
+
+ offset = sizeof(*lcm) +
+ sizeof(*lcme) * (cur_entry_count + merge_entry_count);
+ for (i = 0; i < cur_entry_count; i++) {
+ struct lov_comp_md_entry_v1 *cur_lcme;
+
+ lcme = &lcm->lcm_entries[i];
+ cur_lcme = &cur_lcm->lcm_entries[i];
+
+ lcme->lcme_offset = cpu_to_le32(offset);
+ memcpy((char *)lcm + offset,
+ (char *)cur_lcm + le32_to_cpu(cur_lcme->lcme_offset),
+ le32_to_cpu(lcme->lcme_size));
+
+ offset += le32_to_cpu(lcme->lcme_size);
+
+ if (mirror_count == 1) {
+ /* new mirrored file, create new mirror ID */
+ id = pflr_id(1, i + 1);
+ lcme->lcme_id = cpu_to_le32(id);
+ }
+
+ id = MAX(le32_to_cpu(lcme->lcme_id), id);
+ }
+
+ mirror_id = mirror_id_of(id) + 1;
+ for (i = 0; i < merge_entry_count; i++) {
+ struct lov_comp_md_entry_v1 *merge_lcme;
+
+ merge_lcme = &merge_lcm->lcm_entries[i];
+ lcme = &lcm->lcm_entries[cur_entry_count + i];
+
+ *lcme = *merge_lcme;
+ lcme->lcme_offset = cpu_to_le32(offset);
+
+ id = pflr_id(mirror_id, i + 1);
+ lcme->lcme_id = cpu_to_le32(id);
+
+ memcpy((char *)lcm + offset,
+ (char *)merge_lcm + le32_to_cpu(merge_lcme->lcme_offset),
+ le32_to_cpu(lcme->lcme_size));
+
+ offset += le32_to_cpu(lcme->lcme_size);
+ }
+
+ /* fixup layout information */
+ lod_obj_inc_layout_gen(lo);
+ lcm->lcm_layout_gen = cpu_to_le32(lo->ldo_layout_gen);
+ lcm->lcm_size = cpu_to_le32(size);
+ lcm->lcm_entry_count = cpu_to_le16(cur_entry_count + merge_entry_count);
+ lcm->lcm_mirror_count = cpu_to_le16(mirror_count);
+ if ((le16_to_cpu(lcm->lcm_flags) & LCM_FL_FLR_MASK) == LCM_FL_NOT_FLR)
+ lcm->lcm_flags = cpu_to_le32(LCM_FL_RDONLY);
+
+ LASSERT(dt_write_locked(env, dt_object_child(dt)));
+ lod_object_free_striping(env, lo);
+ rc = lod_parse_striping(env, lo, buf);
+ if (rc)
+ GOTO(out, rc);
+
+ rc = lod_sub_declare_xattr_set(env, dt_object_child(dt), buf,
+ XATTR_NAME_LOV, LU_XATTR_REPLACE, th);
+
+out:
+ lu_buf_free(buf);
+ RETURN(rc);
+}
+
+/**