DAOS-18604 dfs: EC should not be used for directories

- if dir-oclass is set to EC on container create, use default instead.
- daos fs set-attr of an EC oclass on directory should apply only to
  files. directories will be create with the default in that case.
- fix daos fs get-attr to show such changes

Signed-off-by: Mohamad Chaarawi <mohamad.chaarawi@hpe.com>

Author: mchaarawi

src/client/dfs/common.c

@@ -1,5 +1,6 @@
 /**
  * (C) Copyright 2018-2024 Intel Corporation.
+ * (C) Copyright 2026 Hewlett Packard Enterprise Development LP
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -643,8 +644,15 @@ create_dir(dfs_t *dfs, dfs_obj_t *parent, daos_oclass_id_t cid, dfs_obj_t *dir)
 	if (cid == 0) {
 		if (parent->d.oclass == 0)
 			cid = dfs->attr.da_dir_oclass_id;
-		else
+		else {
 			cid = parent->d.oclass;
+			/*
+			 * If the parent oclass is EC, do not use that for a directory and use the
+			 * container default instead.
+			 */
+			if (daos_oid_is_ec(cid))
+				cid = dfs->attr.da_dir_oclass_id;
+		}
 	}
 
 	/** Allocate an OID for the dir - local operation */

src/client/dfs/cont.c

@@ -1,6 +1,6 @@
 /**
  * (C) Copyright 2018-2024 Intel Corporation.
- * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ * (C) Copyright 2025-2026 Hewlett Packard Enterprise Development LP
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -189,8 +189,14 @@ dfs_cont_create(daos_handle_t poh, uuid_t *cuuid, dfs_attr_t *attr, daos_handle_
 		}
 		if (attr->da_file_oclass_id)
 			dattr.da_file_oclass_id = attr->da_file_oclass_id;
-		if (attr->da_dir_oclass_id)
+		if (attr->da_dir_oclass_id) {
 			dattr.da_dir_oclass_id = attr->da_dir_oclass_id;
+			if (daos_oid_is_ec(dattr.da_dir_oclass_id)) {
+				D_WARN("EC object class for directories is not supported,"
+				       " reverting to use default");
+				dattr.da_dir_oclass_id = 0;
+			}
+		}
 
 		/** check non default mode */
 		if ((attr->da_mode & MODE_MASK) == DFS_RELAXED ||

src/client/dfs/obj.c

@@ -1,6 +1,6 @@
 /**
  * (C) Copyright 2018-2024 Intel Corporation.
- * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ * (C) Copyright 2025-2026 Hewlett Packard Enterprise Development LP
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -81,7 +81,16 @@ dfs_obj_get_info(dfs_t *dfs, dfs_obj_t *obj, dfs_obj_info_t *info)
 
 		/** what is the default oclass files and dirs will be created with in this dir */
 		if (obj->d.oclass) {
-			info->doi_dir_oclass_id  = obj->d.oclass;
+			/** if parent oclass is EC, dir would be chosen as container default */
+			if (!daos_oid_is_ec(obj->d.oclass)) {
+				info->doi_dir_oclass_id = obj->d.oclass;
+			} else {
+				if (dfs->attr.da_dir_oclass_id)
+					info->doi_dir_oclass_id = dfs->attr.da_dir_oclass_id;
+				else
+					rc = daos_obj_get_oclass(dfs->coh, DAOS_OT_MULTI_HASHED, 0,
+								 0, &info->doi_dir_oclass_id);
+			}
 			info->doi_file_oclass_id = obj->d.oclass;
 		} else {
 			if (dfs->attr.da_dir_oclass_id)

src/include/daos/object.h

@@ -1,6 +1,6 @@
 /**
  * (C) Copyright 2016-2023 Intel Corporation.
- * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ * (C) Copyright 2025-2026 Hewlett Packard Enterprise Development LP
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -404,6 +404,17 @@ daos_oclass_is_ec(struct daos_oclass_attr *oca)
 	return oca->ca_resil == DAOS_RES_EC;
 }
 
+static inline bool
+daos_oid_is_ec(daos_oclass_id_t cid)
+{
+	struct daos_oclass_attr *oca;
+
+	oca = daos_oclass_id2attr(cid, NULL);
+	if (oca == NULL)
+		return false;
+	return daos_oclass_is_ec(oca);
+}
+
 static inline void
 daos_obj_set_oid(daos_obj_id_t *oid, enum daos_otype_t type,
 		 enum daos_obj_redun ord, uint32_t nr_grps,