[fs/lustre-release.git] / lustre / ptlrpc / layout.c

/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/ptlrpc/layout.c
 *
 * Lustre Metadata Target (mdt) request handler
 *
 * Author: Nikita Danilov <nikita@clusterfs.com>
 */
/*
 * This file contains the "capsule/pill" abstraction layered above PTLRPC.
 *
 * Every struct ptlrpc_request contains a "pill", which points to a description
 * of the format that the request conforms to.
 */

#if !defined(__REQ_LAYOUT_USER__)

#define DEBUG_SUBSYSTEM S_RPC

#ifdef __KERNEL__
#include <linux/module.h>
#else
# include <liblustre.h>
#endif

/* LUSTRE_VERSION_CODE */
#include <lustre_ver.h>

#include <obd_support.h>
/* lustre_swab_mdt_body */
#include <lustre/lustre_idl.h>
/* obd2cli_tgt() (required by DEBUG_REQ()) */
#include <obd.h>

/* __REQ_LAYOUT_USER__ */
#endif
/* struct ptlrpc_request, lustre_msg* */
#include <lustre_req_layout.h>
#include <lustre_update.h>
#include <lustre_acl.h>
#include <lustre_debug.h>

/*
 * RQFs (see below) refer to two struct req_msg_field arrays describing the
 * client request and server reply, respectively.
 */
/* empty set of fields... for suitable definition of emptiness. */
static const struct req_msg_field *empty[] = {
        &RMF_PTLRPC_BODY
};

static const struct req_msg_field *mgs_target_info_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MGS_TARGET_INFO
};

static const struct req_msg_field *mgs_set_info[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MGS_SEND_PARAM
};

static const struct req_msg_field *mgs_config_read_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MGS_CONFIG_BODY
};

static const struct req_msg_field *mgs_config_read_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MGS_CONFIG_RES
};

static const struct req_msg_field *log_cancel_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LOGCOOKIES
};

static const struct req_msg_field *mdt_body_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY
};

static const struct req_msg_field *mdt_body_capa[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_CAPA1
};

static const struct req_msg_field *quotactl_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OBD_QUOTACTL
};

static const struct req_msg_field *quota_body_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_QUOTA_BODY
};

static const struct req_msg_field *ldlm_intent_quota_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_QUOTA_BODY
};

static const struct req_msg_field *ldlm_intent_quota_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP,
        &RMF_DLM_LVB,
        &RMF_QUOTA_BODY
};

static const struct req_msg_field *mdt_close_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_EPOCH,
        &RMF_REC_REINT,
        &RMF_CAPA1
};

static const struct req_msg_field *obd_statfs_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OBD_STATFS
};

static const struct req_msg_field *seq_query_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_SEQ_OPC,
        &RMF_SEQ_RANGE
};

static const struct req_msg_field *seq_query_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_SEQ_RANGE
};

static const struct req_msg_field *fld_query_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_FLD_OPC,
        &RMF_FLD_MDFLD
};

static const struct req_msg_field *fld_query_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_FLD_MDFLD
};

static const struct req_msg_field *mds_getattr_name_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_CAPA1,
        &RMF_NAME
};

static const struct req_msg_field *mds_reint_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT
};

static const struct req_msg_field *mds_reint_create_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME
};

static const struct req_msg_field *mds_reint_create_slave_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_EADATA,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_create_rmt_acl_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_EADATA,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_create_sym_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_SYMTGT,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_open_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_CAPA2,
        &RMF_NAME,
        &RMF_EADATA
};

static const struct req_msg_field *mds_reint_open_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL,
        &RMF_CAPA1,
        &RMF_CAPA2
};

static const struct req_msg_field *mds_reint_unlink_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_link_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_CAPA2,
        &RMF_NAME,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_rename_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_CAPA2,
        &RMF_NAME,
        &RMF_SYMTGT,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_last_unlink_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_LOGCOOKIES,
        &RMF_CAPA1,
        &RMF_CAPA2
};

static const struct req_msg_field *mds_reint_setattr_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_MDT_EPOCH,
        &RMF_EADATA,
        &RMF_LOGCOOKIES,
        &RMF_DLM_REQ
};

static const struct req_msg_field *mds_reint_setxattr_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_REC_REINT,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_EADATA
};

static const struct req_msg_field *mdt_swap_layouts[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_SWAP_LAYOUTS,
        &RMF_CAPA1,
        &RMF_CAPA2,
        &RMF_DLM_REQ
};

static const struct req_msg_field *obd_connect_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_TGTUUID,
        &RMF_CLUUID,
        &RMF_CONN,
        &RMF_CONNECT_DATA
};

static const struct req_msg_field *obd_connect_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_CONNECT_DATA
};

static const struct req_msg_field *obd_set_info_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_SETINFO_KEY,
        &RMF_SETINFO_VAL
};

static const struct req_msg_field *ost_grant_shrink_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_SETINFO_KEY,
        &RMF_OST_BODY
};

static const struct req_msg_field *mds_getinfo_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_GETINFO_KEY,
        &RMF_GETINFO_VALLEN
};

static const struct req_msg_field *mds_getinfo_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_GETINFO_VAL,
};

static const struct req_msg_field *ldlm_enqueue_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ
};

static const struct req_msg_field *ldlm_enqueue_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP
};

static const struct req_msg_field *ldlm_enqueue_lvb_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP,
        &RMF_DLM_LVB
};

static const struct req_msg_field *ldlm_cp_callback_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_DLM_LVB
};

static const struct req_msg_field *ldlm_gl_callback_desc_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_DLM_GL_DESC
};

static const struct req_msg_field *ldlm_gl_callback_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_LVB
};

static const struct req_msg_field *ldlm_intent_basic_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
};

static const struct req_msg_field *ldlm_intent_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_REC_REINT
};

static const struct req_msg_field *ldlm_intent_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL
};

static const struct req_msg_field *ldlm_intent_layout_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_LAYOUT_INTENT,
        &RMF_EADATA /* for new layout to be set up */
};
static const struct req_msg_field *ldlm_intent_open_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL,
        &RMF_CAPA1,
        &RMF_CAPA2
};

static const struct req_msg_field *ldlm_intent_getattr_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_MDT_BODY,     /* coincides with mds_getattr_name_client[] */
        &RMF_CAPA1,
        &RMF_NAME
};

static const struct req_msg_field *ldlm_intent_getattr_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REP,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL,
        &RMF_CAPA1
};

static const struct req_msg_field *ldlm_intent_create_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_REC_REINT,    /* coincides with mds_reint_create_client[] */
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_EADATA
};

static const struct req_msg_field *ldlm_intent_open_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_REC_REINT,    /* coincides with mds_reint_open_client[] */
        &RMF_CAPA1,
        &RMF_CAPA2,
        &RMF_NAME,
        &RMF_EADATA
};

static const struct req_msg_field *ldlm_intent_unlink_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_DLM_REQ,
        &RMF_LDLM_INTENT,
        &RMF_REC_REINT,    /* coincides with mds_reint_unlink_client[] */
        &RMF_CAPA1,
        &RMF_NAME
};

static const struct req_msg_field *mds_getxattr_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_CAPA1,
        &RMF_NAME,
        &RMF_EADATA
};

static const struct req_msg_field *mds_getxattr_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_EADATA
};

static const struct req_msg_field *mds_getattr_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL,
        &RMF_CAPA1,
        &RMF_CAPA2
};

static const struct req_msg_field *mds_setattr_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_MDT_MD,
        &RMF_ACL,
        &RMF_CAPA1,
        &RMF_CAPA2
};

static const struct req_msg_field *mds_update_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_UPDATE,
};

static const struct req_msg_field *mds_update_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_UPDATE_REPLY,
};

static const struct req_msg_field *llog_origin_handle_create_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LLOGD_BODY,
        &RMF_NAME
};

static const struct req_msg_field *llogd_body_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LLOGD_BODY
};

static const struct req_msg_field *llog_log_hdr_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LLOG_LOG_HDR
};

static const struct req_msg_field *llogd_conn_body_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LLOGD_CONN_BODY
};

static const struct req_msg_field *llog_origin_handle_next_block_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_LLOGD_BODY,
        &RMF_EADATA
};

static const struct req_msg_field *obd_idx_read_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_IDX_INFO
};

static const struct req_msg_field *obd_idx_read_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_IDX_INFO
};

static const struct req_msg_field *ost_body_only[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY
};

static const struct req_msg_field *ost_body_capa[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY,
        &RMF_CAPA1
};

static const struct req_msg_field *ost_destroy_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY,
        &RMF_DLM_REQ,
        &RMF_CAPA1
};


static const struct req_msg_field *ost_brw_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY,
        &RMF_OBD_IOOBJ,
        &RMF_NIOBUF_REMOTE,
        &RMF_CAPA1
};

static const struct req_msg_field *ost_brw_read_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY
};

static const struct req_msg_field *ost_brw_write_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OST_BODY,
        &RMF_RCS
};

static const struct req_msg_field *ost_get_info_generic_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_GENERIC_DATA,
};

static const struct req_msg_field *ost_get_info_generic_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_SETINFO_KEY
};

static const struct req_msg_field *ost_get_last_id_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_OBD_ID
};

static const struct req_msg_field *ost_get_last_fid_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_FID
};

static const struct req_msg_field *ost_get_fiemap_client[] = {
        &RMF_PTLRPC_BODY,
        &RMF_FIEMAP_KEY,
        &RMF_FIEMAP_VAL
};

static const struct req_msg_field *ost_get_fiemap_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_FIEMAP_VAL
};

static const struct req_msg_field *mdt_hsm_progress[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDS_HSM_PROGRESS,
};

static const struct req_msg_field *mdt_hsm_ct_register[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDS_HSM_ARCHIVE,
};

static const struct req_msg_field *mdt_hsm_action_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDS_HSM_CURRENT_ACTION,
};

static const struct req_msg_field *mdt_hsm_state_get_server[] = {
        &RMF_PTLRPC_BODY,
        &RMF_HSM_USER_STATE,
};

static const struct req_msg_field *mdt_hsm_state_set[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_CAPA1,
        &RMF_HSM_STATE_SET,
};

static const struct req_msg_field *mdt_hsm_request[] = {
        &RMF_PTLRPC_BODY,
        &RMF_MDT_BODY,
        &RMF_MDS_HSM_REQUEST,
        &RMF_MDS_HSM_USER_ITEM,
        &RMF_GENERIC_DATA,
};

static struct req_format *req_formats[] = {
        &RQF_OBD_PING,
        &RQF_OBD_SET_INFO,
        &RQF_OBD_IDX_READ,
        &RQF_SEC_CTX,
        &RQF_MGS_TARGET_REG,
        &RQF_MGS_SET_INFO,
        &RQF_MGS_CONFIG_READ,
        &RQF_SEQ_QUERY,
        &RQF_FLD_QUERY,
        &RQF_MDS_CONNECT,
        &RQF_MDS_DISCONNECT,
        &RQF_MDS_GET_INFO,
        &RQF_MDS_GETSTATUS,
        &RQF_MDS_STATFS,
        &RQF_MDS_GETATTR,
        &RQF_MDS_GETATTR_NAME,
        &RQF_MDS_GETXATTR,
        &RQF_MDS_SYNC,
        &RQF_MDS_CLOSE,
        &RQF_MDS_PIN,
        &RQF_MDS_UNPIN,
        &RQF_MDS_READPAGE,
        &RQF_MDS_WRITEPAGE,
        &RQF_MDS_IS_SUBDIR,
        &RQF_MDS_DONE_WRITING,
        &RQF_MDS_REINT,
        &RQF_MDS_REINT_CREATE,
        &RQF_MDS_REINT_CREATE_RMT_ACL,
        &RQF_MDS_REINT_CREATE_SLAVE,
        &RQF_MDS_REINT_CREATE_SYM,
        &RQF_MDS_REINT_OPEN,
        &RQF_MDS_REINT_UNLINK,
        &RQF_MDS_REINT_LINK,
        &RQF_MDS_REINT_RENAME,
        &RQF_MDS_REINT_SETATTR,
        &RQF_MDS_REINT_SETXATTR,
        &RQF_MDS_QUOTACHECK,
        &RQF_MDS_QUOTACTL,
        &RQF_MDS_HSM_PROGRESS,
        &RQF_MDS_HSM_CT_REGISTER,
        &RQF_MDS_HSM_CT_UNREGISTER,
        &RQF_MDS_HSM_STATE_GET,
        &RQF_MDS_HSM_STATE_SET,
        &RQF_MDS_HSM_ACTION,
        &RQF_MDS_HSM_REQUEST,
        &RQF_MDS_SWAP_LAYOUTS,
        &RQF_UPDATE_OBJ,
        &RQF_QC_CALLBACK,
        &RQF_OST_CONNECT,
        &RQF_OST_DISCONNECT,
        &RQF_OST_QUOTACHECK,
        &RQF_OST_QUOTACTL,
        &RQF_OST_GETATTR,
        &RQF_OST_SETATTR,
        &RQF_OST_CREATE,
        &RQF_OST_PUNCH,
        &RQF_OST_SYNC,
        &RQF_OST_DESTROY,
        &RQF_OST_BRW_READ,
        &RQF_OST_BRW_WRITE,
        &RQF_OST_STATFS,
        &RQF_OST_SET_GRANT_INFO,
        &RQF_OST_GET_INFO_GENERIC,
        &RQF_OST_GET_INFO_LAST_ID,
        &RQF_OST_GET_INFO_LAST_FID,
        &RQF_OST_SET_INFO_LAST_FID,
        &RQF_OST_GET_INFO_FIEMAP,
        &RQF_LDLM_ENQUEUE,
        &RQF_LDLM_ENQUEUE_LVB,
        &RQF_LDLM_CONVERT,
        &RQF_LDLM_CANCEL,
        &RQF_LDLM_CALLBACK,
        &RQF_LDLM_CP_CALLBACK,
        &RQF_LDLM_BL_CALLBACK,
        &RQF_LDLM_GL_CALLBACK,
        &RQF_LDLM_GL_DESC_CALLBACK,
        &RQF_LDLM_INTENT,
        &RQF_LDLM_INTENT_BASIC,
        &RQF_LDLM_INTENT_LAYOUT,
        &RQF_LDLM_INTENT_GETATTR,
        &RQF_LDLM_INTENT_OPEN,
        &RQF_LDLM_INTENT_CREATE,
        &RQF_LDLM_INTENT_UNLINK,
        &RQF_LDLM_INTENT_QUOTA,
        &RQF_QUOTA_DQACQ,
        &RQF_LOG_CANCEL,
        &RQF_LLOG_ORIGIN_HANDLE_CREATE,
        &RQF_LLOG_ORIGIN_HANDLE_DESTROY,
        &RQF_LLOG_ORIGIN_HANDLE_NEXT_BLOCK,
        &RQF_LLOG_ORIGIN_HANDLE_PREV_BLOCK,
        &RQF_LLOG_ORIGIN_HANDLE_READ_HEADER,
        &RQF_LLOG_ORIGIN_CONNECT
};

struct req_msg_field {
        const __u32 rmf_flags;
        const char  *rmf_name;
        /**
         * Field length. (-1) means "variable length".  If the
         * \a RMF_F_STRUCT_ARRAY flag is set the field is also variable-length,
         * but the actual size must be a whole multiple of \a rmf_size.
         */
        const int   rmf_size;
        void        (*rmf_swabber)(void *);
        void        (*rmf_dumper)(void *);
        int         rmf_offset[ARRAY_SIZE(req_formats)][RCL_NR];
};

enum rmf_flags {
        /**
         * The field is a string, must be NUL-terminated.
         */
        RMF_F_STRING = 1 << 0,
        /**
         * The field's buffer size need not match the declared \a rmf_size.
         */
        RMF_F_NO_SIZE_CHECK = 1 << 1,
        /**
         * The field's buffer size must be a whole multiple of the declared \a
         * rmf_size and the \a rmf_swabber function must work on the declared \a
         * rmf_size worth of bytes.
         */
        RMF_F_STRUCT_ARRAY = 1 << 2
};

struct req_capsule;

/*
 * Request fields.
 */
#define DEFINE_MSGF(name, flags, size, swabber, dumper) {       \
        .rmf_name    = (name),                                  \
        .rmf_flags   = (flags),                                 \
        .rmf_size    = (size),                                  \
        .rmf_swabber = (void (*)(void*))(swabber),              \
        .rmf_dumper  = (void (*)(void*))(dumper)                \
}

struct req_msg_field RMF_GENERIC_DATA =
        DEFINE_MSGF("generic_data", 0,
                    -1, NULL, NULL);
EXPORT_SYMBOL(RMF_GENERIC_DATA);

struct req_msg_field RMF_MGS_TARGET_INFO =
        DEFINE_MSGF("mgs_target_info", 0,
                    sizeof(struct mgs_target_info),
                    lustre_swab_mgs_target_info, NULL);
EXPORT_SYMBOL(RMF_MGS_TARGET_INFO);

struct req_msg_field RMF_MGS_SEND_PARAM =
        DEFINE_MSGF("mgs_send_param", 0,
                    sizeof(struct mgs_send_param),
                    NULL, NULL);
EXPORT_SYMBOL(RMF_MGS_SEND_PARAM);

struct req_msg_field RMF_MGS_CONFIG_BODY =
        DEFINE_MSGF("mgs_config_read request", 0,
                    sizeof(struct mgs_config_body),
                    lustre_swab_mgs_config_body, NULL);
EXPORT_SYMBOL(RMF_MGS_CONFIG_BODY);

struct req_msg_field RMF_MGS_CONFIG_RES =
        DEFINE_MSGF("mgs_config_read reply ", 0,
                    sizeof(struct mgs_config_res),
                    lustre_swab_mgs_config_res, NULL);
EXPORT_SYMBOL(RMF_MGS_CONFIG_RES);

struct req_msg_field RMF_U32 =
        DEFINE_MSGF("generic u32", 0,
                    sizeof(__u32), lustre_swab_generic_32s, NULL);
EXPORT_SYMBOL(RMF_U32);

struct req_msg_field RMF_SETINFO_VAL =
        DEFINE_MSGF("setinfo_val", 0, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_SETINFO_VAL);

struct req_msg_field RMF_GETINFO_KEY =
        DEFINE_MSGF("getinfo_key", 0, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_GETINFO_KEY);

struct req_msg_field RMF_GETINFO_VALLEN =
        DEFINE_MSGF("getinfo_vallen", 0,
                    sizeof(__u32), lustre_swab_generic_32s, NULL);
EXPORT_SYMBOL(RMF_GETINFO_VALLEN);

struct req_msg_field RMF_GETINFO_VAL =
        DEFINE_MSGF("getinfo_val", 0, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_GETINFO_VAL);

struct req_msg_field RMF_SEQ_OPC =
        DEFINE_MSGF("seq_query_opc", 0,
                    sizeof(__u32), lustre_swab_generic_32s, NULL);
EXPORT_SYMBOL(RMF_SEQ_OPC);

struct req_msg_field RMF_SEQ_RANGE =
        DEFINE_MSGF("seq_query_range", 0,
                    sizeof(struct lu_seq_range),
                    lustre_swab_lu_seq_range, NULL);
EXPORT_SYMBOL(RMF_SEQ_RANGE);

struct req_msg_field RMF_FLD_OPC =
        DEFINE_MSGF("fld_query_opc", 0,
                    sizeof(__u32), lustre_swab_generic_32s, NULL);
EXPORT_SYMBOL(RMF_FLD_OPC);

struct req_msg_field RMF_FLD_MDFLD =
        DEFINE_MSGF("fld_query_mdfld", 0,
                    sizeof(struct lu_seq_range),
                    lustre_swab_lu_seq_range, NULL);
EXPORT_SYMBOL(RMF_FLD_MDFLD);

struct req_msg_field RMF_MDT_BODY =
        DEFINE_MSGF("mdt_body", 0,
                    sizeof(struct mdt_body), lustre_swab_mdt_body, NULL);
EXPORT_SYMBOL(RMF_MDT_BODY);

struct req_msg_field RMF_OBD_QUOTACTL =
        DEFINE_MSGF("obd_quotactl", 0,
                    sizeof(struct obd_quotactl),
                    lustre_swab_obd_quotactl, NULL);
EXPORT_SYMBOL(RMF_OBD_QUOTACTL);

struct req_msg_field RMF_QUOTA_BODY =
        DEFINE_MSGF("quota_body", 0,
                    sizeof(struct quota_body), lustre_swab_quota_body, NULL);
EXPORT_SYMBOL(RMF_QUOTA_BODY);

struct req_msg_field RMF_MDT_EPOCH =
        DEFINE_MSGF("mdt_ioepoch", 0,
                    sizeof(struct mdt_ioepoch), lustre_swab_mdt_ioepoch, NULL);
EXPORT_SYMBOL(RMF_MDT_EPOCH);

struct req_msg_field RMF_PTLRPC_BODY =
        DEFINE_MSGF("ptlrpc_body", 0,
                    sizeof(struct ptlrpc_body), lustre_swab_ptlrpc_body, NULL);
EXPORT_SYMBOL(RMF_PTLRPC_BODY);

struct req_msg_field RMF_OBD_STATFS =
        DEFINE_MSGF("obd_statfs", 0,
                    sizeof(struct obd_statfs), lustre_swab_obd_statfs, NULL);
EXPORT_SYMBOL(RMF_OBD_STATFS);

struct req_msg_field RMF_SETINFO_KEY =
        DEFINE_MSGF("setinfo_key", 0, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_SETINFO_KEY);

struct req_msg_field RMF_NAME =
        DEFINE_MSGF("name", RMF_F_STRING, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_NAME);

struct req_msg_field RMF_SYMTGT =
        DEFINE_MSGF("symtgt", RMF_F_STRING, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_SYMTGT);

struct req_msg_field RMF_TGTUUID =
        DEFINE_MSGF("tgtuuid", RMF_F_STRING, sizeof(struct obd_uuid) - 1, NULL,
        NULL);
EXPORT_SYMBOL(RMF_TGTUUID);

struct req_msg_field RMF_CLUUID =
        DEFINE_MSGF("cluuid", RMF_F_STRING, sizeof(struct obd_uuid) - 1, NULL,
        NULL);
EXPORT_SYMBOL(RMF_CLUUID);

struct req_msg_field RMF_STRING =
        DEFINE_MSGF("string", RMF_F_STRING, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_STRING);

struct req_msg_field RMF_LLOGD_BODY =
        DEFINE_MSGF("llogd_body", 0,
                    sizeof(struct llogd_body), lustre_swab_llogd_body, NULL);
EXPORT_SYMBOL(RMF_LLOGD_BODY);

struct req_msg_field RMF_LLOG_LOG_HDR =
        DEFINE_MSGF("llog_log_hdr", 0,
                    sizeof(struct llog_log_hdr), lustre_swab_llog_hdr, NULL);
EXPORT_SYMBOL(RMF_LLOG_LOG_HDR);

struct req_msg_field RMF_LLOGD_CONN_BODY =
        DEFINE_MSGF("llogd_conn_body", 0,
                    sizeof(struct llogd_conn_body),
                    lustre_swab_llogd_conn_body, NULL);
EXPORT_SYMBOL(RMF_LLOGD_CONN_BODY);

/*
 * connection handle received in MDS_CONNECT request.
 *
 * No swabbing needed because struct lustre_handle contains only a 64-bit cookie
 * that the client does not interpret at all.
 */
struct req_msg_field RMF_CONN =
        DEFINE_MSGF("conn", 0, sizeof(struct lustre_handle), NULL, NULL);
EXPORT_SYMBOL(RMF_CONN);

struct req_msg_field RMF_CONNECT_DATA =
        DEFINE_MSGF("cdata",
                    RMF_F_NO_SIZE_CHECK /* we allow extra space for interop */,
#if LUSTRE_VERSION_CODE > OBD_OCD_VERSION(2, 7, 50, 0)
                    sizeof(struct obd_connect_data),
#else
/* For interoperability with 1.8 and 2.0 clients/servers.
 * The RPC verification code allows larger RPC buffers, but not
 * smaller buffers.  Until we no longer need to keep compatibility
 * with older servers/clients we can only check that the buffer
 * size is at least as large as obd_connect_data_v1.  That is not
 * not in itself harmful, since the chance of just corrupting this
 * field is low.  See JIRA LU-16 for details. */
                    sizeof(struct obd_connect_data_v1),
#endif
                    lustre_swab_connect, NULL);
EXPORT_SYMBOL(RMF_CONNECT_DATA);

struct req_msg_field RMF_DLM_REQ =
        DEFINE_MSGF("dlm_req", RMF_F_NO_SIZE_CHECK /* ldlm_request_bufsize */,
                    sizeof(struct ldlm_request),
                    lustre_swab_ldlm_request, NULL);
EXPORT_SYMBOL(RMF_DLM_REQ);

struct req_msg_field RMF_DLM_REP =
        DEFINE_MSGF("dlm_rep", 0,
                    sizeof(struct ldlm_reply), lustre_swab_ldlm_reply, NULL);
EXPORT_SYMBOL(RMF_DLM_REP);

struct req_msg_field RMF_LDLM_INTENT =
        DEFINE_MSGF("ldlm_intent", 0,
                    sizeof(struct ldlm_intent), lustre_swab_ldlm_intent, NULL);
EXPORT_SYMBOL(RMF_LDLM_INTENT);

struct req_msg_field RMF_DLM_LVB =
        DEFINE_MSGF("dlm_lvb", 0, -1, NULL, NULL);
EXPORT_SYMBOL(RMF_DLM_LVB);

struct req_msg_field RMF_DLM_GL_DESC =
        DEFINE_MSGF("dlm_gl_desc", 0, sizeof(union ldlm_gl_desc),
                    lustre_swab_gl_desc, NULL);
EXPORT_SYMBOL(RMF_DLM_GL_DESC);

struct req_msg_field RMF_MDT_MD =
        DEFINE_MSGF("mdt_md", RMF_F_NO_SIZE_CHECK, MIN_MD_SIZE, NULL, NULL);
EXPORT_SYMBOL(RMF_MDT_MD);

struct req_msg_field RMF_REC_REINT =
        DEFINE_MSGF("rec_reint", 0, sizeof(struct mdt_rec_reint),
                    lustre_swab_mdt_rec_reint, NULL);
EXPORT_SYMBOL(RMF_REC_REINT);

/* FIXME: this length should be defined as a macro */
struct req_msg_field RMF_EADATA = DEFINE_MSGF("eadata", 0, -1,
                                                    NULL, NULL);
EXPORT_SYMBOL(RMF_EADATA);

struct req_msg_field RMF_ACL =
        DEFINE_MSGF("acl", RMF_F_NO_SIZE_CHECK,
                    LUSTRE_POSIX_ACL_MAX_SIZE, NULL, NULL);
EXPORT_SYMBOL(RMF_ACL);

/* FIXME: this should be made to use RMF_F_STRUCT_ARRAY */
struct req_msg_field RMF_LOGCOOKIES =
        DEFINE_MSGF("logcookies", RMF_F_NO_SIZE_CHECK /* multiple cookies */,
                    sizeof(struct llog_cookie), NULL, NULL);
EXPORT_SYMBOL(RMF_LOGCOOKIES);

struct req_msg_field RMF_CAPA1 =
        DEFINE_MSGF("capa", 0, sizeof(struct lustre_capa),
                    lustre_swab_lustre_capa, NULL);
EXPORT_SYMBOL(RMF_CAPA1);

struct req_msg_field RMF_CAPA2 =
        DEFINE_MSGF("capa", 0, sizeof(struct lustre_capa),
                    lustre_swab_lustre_capa, NULL);
EXPORT_SYMBOL(RMF_CAPA2);

struct req_msg_field RMF_LAYOUT_INTENT =
        DEFINE_MSGF("layout_intent", 0,
                    sizeof(struct layout_intent), lustre_swab_layout_intent,
                    NULL);
EXPORT_SYMBOL(RMF_LAYOUT_INTENT);

/*
 * OST request field.
 */
struct req_msg_field RMF_OST_BODY =
        DEFINE_MSGF("ost_body", 0,
                    sizeof(struct ost_body), lustre_swab_ost_body, dump_ost_body);
EXPORT_SYMBOL(RMF_OST_BODY);

struct req_msg_field RMF_OBD_IOOBJ =
        DEFINE_MSGF("obd_ioobj", RMF_F_STRUCT_ARRAY,
                    sizeof(struct obd_ioobj), lustre_swab_obd_ioobj, dump_ioo);
EXPORT_SYMBOL(RMF_OBD_IOOBJ);

struct req_msg_field RMF_NIOBUF_REMOTE =
        DEFINE_MSGF("niobuf_remote", RMF_F_STRUCT_ARRAY,
                    sizeof(struct niobuf_remote), lustre_swab_niobuf_remote,
                    dump_rniobuf);
EXPORT_SYMBOL(RMF_NIOBUF_REMOTE);

struct req_msg_field RMF_RCS =
        DEFINE_MSGF("niobuf_remote", RMF_F_STRUCT_ARRAY, sizeof(__u32),
                    lustre_swab_generic_32s, dump_rcs);
EXPORT_SYMBOL(RMF_RCS);

struct req_msg_field RMF_OBD_ID =
        DEFINE_MSGF("obd_id", 0,
                    sizeof(obd_id), lustre_swab_ost_last_id, NULL);
EXPORT_SYMBOL(RMF_OBD_ID);

struct req_msg_field RMF_FID =
        DEFINE_MSGF("fid", 0,
                    sizeof(struct lu_fid), lustre_swab_lu_fid, NULL);
EXPORT_SYMBOL(RMF_FID);

struct req_msg_field RMF_FIEMAP_KEY =
        DEFINE_MSGF("fiemap", 0, sizeof(struct ll_fiemap_info_key),
                    lustre_swab_fiemap, NULL);
EXPORT_SYMBOL(RMF_FIEMAP_KEY);

struct req_msg_field RMF_FIEMAP_VAL =
        DEFINE_MSGF("fiemap", 0, -1, lustre_swab_fiemap, NULL);
EXPORT_SYMBOL(RMF_FIEMAP_VAL);

struct req_msg_field RMF_IDX_INFO =
        DEFINE_MSGF("idx_info", 0, sizeof(struct idx_info),
                    lustre_swab_idx_info, NULL);
EXPORT_SYMBOL(RMF_IDX_INFO);
struct req_msg_field RMF_HSM_USER_STATE =
        DEFINE_MSGF("hsm_user_state", 0, sizeof(struct hsm_user_state),
                    lustre_swab_hsm_user_state, NULL);
EXPORT_SYMBOL(RMF_HSM_USER_STATE);

struct req_msg_field RMF_HSM_STATE_SET =
        DEFINE_MSGF("hsm_state_set", 0, sizeof(struct hsm_state_set),
                    lustre_swab_hsm_state_set, NULL);
EXPORT_SYMBOL(RMF_HSM_STATE_SET);

struct req_msg_field RMF_MDS_HSM_PROGRESS =
        DEFINE_MSGF("hsm_progress", 0, sizeof(struct hsm_progress_kernel),
                    lustre_swab_hsm_progress_kernel, NULL);
EXPORT_SYMBOL(RMF_MDS_HSM_PROGRESS);

struct req_msg_field RMF_MDS_HSM_CURRENT_ACTION =
        DEFINE_MSGF("hsm_current_action", 0, sizeof(struct hsm_current_action),
                    lustre_swab_hsm_current_action, NULL);
EXPORT_SYMBOL(RMF_MDS_HSM_CURRENT_ACTION);

struct req_msg_field RMF_MDS_HSM_USER_ITEM =
        DEFINE_MSGF("hsm_user_item", RMF_F_STRUCT_ARRAY,
                    sizeof(struct hsm_user_item), lustre_swab_hsm_user_item,
                    NULL);
EXPORT_SYMBOL(RMF_MDS_HSM_USER_ITEM);

struct req_msg_field RMF_MDS_HSM_ARCHIVE =
        DEFINE_MSGF("hsm_archive", 0,
                    sizeof(__u32), lustre_swab_generic_32s, NULL);
EXPORT_SYMBOL(RMF_MDS_HSM_ARCHIVE);

struct req_msg_field RMF_MDS_HSM_REQUEST =
        DEFINE_MSGF("hsm_request", 0, sizeof(struct hsm_request),
                    lustre_swab_hsm_request, NULL);
EXPORT_SYMBOL(RMF_MDS_HSM_REQUEST);

struct req_msg_field RMF_UPDATE = DEFINE_MSGF("update", 0, -1,
                                              lustre_swab_update_buf, NULL);
EXPORT_SYMBOL(RMF_UPDATE);

struct req_msg_field RMF_UPDATE_REPLY = DEFINE_MSGF("update_reply", 0, -1,
                                                lustre_swab_update_reply_buf,
                                                    NULL);
EXPORT_SYMBOL(RMF_UPDATE_REPLY);

struct req_msg_field RMF_SWAP_LAYOUTS =
        DEFINE_MSGF("swap_layouts", 0, sizeof(struct  mdc_swap_layouts),
                    lustre_swab_swap_layouts, NULL);
EXPORT_SYMBOL(RMF_SWAP_LAYOUTS);
/*
 * Request formats.
 */

struct req_format {
        const char *rf_name;
        int         rf_idx;
        struct {
                int                          nr;
                const struct req_msg_field **d;
        } rf_fields[RCL_NR];
};

#define DEFINE_REQ_FMT(name, client, client_nr, server, server_nr) {    \
        .rf_name   = name,                                              \
        .rf_fields = {                                                  \
                [RCL_CLIENT] = {                                        \
                        .nr = client_nr,                                \
                        .d  = client                                    \
                },                                                      \
                [RCL_SERVER] = {                                        \
                        .nr = server_nr,                                \
                        .d  = server                                    \
                }                                                       \
        }                                                               \
}

#define DEFINE_REQ_FMT0(name, client, server)                                  \
DEFINE_REQ_FMT(name, client, ARRAY_SIZE(client), server, ARRAY_SIZE(server))

struct req_format RQF_OBD_PING =
        DEFINE_REQ_FMT0("OBD_PING", empty, empty);
EXPORT_SYMBOL(RQF_OBD_PING);

struct req_format RQF_OBD_SET_INFO =
        DEFINE_REQ_FMT0("OBD_SET_INFO", obd_set_info_client, empty);
EXPORT_SYMBOL(RQF_OBD_SET_INFO);

/* Read index file through the network */
struct req_format RQF_OBD_IDX_READ =
        DEFINE_REQ_FMT0("OBD_IDX_READ",
                        obd_idx_read_client, obd_idx_read_server);
EXPORT_SYMBOL(RQF_OBD_IDX_READ);

struct req_format RQF_SEC_CTX =
        DEFINE_REQ_FMT0("SEC_CTX", empty, empty);
EXPORT_SYMBOL(RQF_SEC_CTX);

struct req_format RQF_MGS_TARGET_REG =
        DEFINE_REQ_FMT0("MGS_TARGET_REG", mgs_target_info_only,
                         mgs_target_info_only);
EXPORT_SYMBOL(RQF_MGS_TARGET_REG);

struct req_format RQF_MGS_SET_INFO =
        DEFINE_REQ_FMT0("MGS_SET_INFO", mgs_set_info,
                         mgs_set_info);
EXPORT_SYMBOL(RQF_MGS_SET_INFO);

struct req_format RQF_MGS_CONFIG_READ =
        DEFINE_REQ_FMT0("MGS_CONFIG_READ", mgs_config_read_client,
                         mgs_config_read_server);
EXPORT_SYMBOL(RQF_MGS_CONFIG_READ);

struct req_format RQF_SEQ_QUERY =
        DEFINE_REQ_FMT0("SEQ_QUERY", seq_query_client, seq_query_server);
EXPORT_SYMBOL(RQF_SEQ_QUERY);

struct req_format RQF_FLD_QUERY =
        DEFINE_REQ_FMT0("FLD_QUERY", fld_query_client, fld_query_server);
EXPORT_SYMBOL(RQF_FLD_QUERY);

struct req_format RQF_LOG_CANCEL =
        DEFINE_REQ_FMT0("OBD_LOG_CANCEL", log_cancel_client, empty);
EXPORT_SYMBOL(RQF_LOG_CANCEL);

struct req_format RQF_MDS_QUOTACHECK =
        DEFINE_REQ_FMT0("MDS_QUOTACHECK", quotactl_only, empty);
EXPORT_SYMBOL(RQF_MDS_QUOTACHECK);

struct req_format RQF_OST_QUOTACHECK =
        DEFINE_REQ_FMT0("OST_QUOTACHECK", quotactl_only, empty);
EXPORT_SYMBOL(RQF_OST_QUOTACHECK);

struct req_format RQF_MDS_QUOTACTL =
        DEFINE_REQ_FMT0("MDS_QUOTACTL", quotactl_only, quotactl_only);
EXPORT_SYMBOL(RQF_MDS_QUOTACTL);

struct req_format RQF_OST_QUOTACTL =
        DEFINE_REQ_FMT0("OST_QUOTACTL", quotactl_only, quotactl_only);
EXPORT_SYMBOL(RQF_OST_QUOTACTL);

struct req_format RQF_QC_CALLBACK =
        DEFINE_REQ_FMT0("QC_CALLBACK", quotactl_only, empty);
EXPORT_SYMBOL(RQF_QC_CALLBACK);

struct req_format RQF_QUOTA_DQACQ =
        DEFINE_REQ_FMT0("QUOTA_DQACQ", quota_body_only, quota_body_only);
EXPORT_SYMBOL(RQF_QUOTA_DQACQ);

struct req_format RQF_LDLM_INTENT_QUOTA =
        DEFINE_REQ_FMT0("LDLM_INTENT_QUOTA",
                        ldlm_intent_quota_client,
                        ldlm_intent_quota_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_QUOTA);

struct req_format RQF_MDS_GETSTATUS =
        DEFINE_REQ_FMT0("MDS_GETSTATUS", mdt_body_only, mdt_body_capa);
EXPORT_SYMBOL(RQF_MDS_GETSTATUS);

struct req_format RQF_MDS_STATFS =
        DEFINE_REQ_FMT0("MDS_STATFS", empty, obd_statfs_server);
EXPORT_SYMBOL(RQF_MDS_STATFS);

struct req_format RQF_MDS_SYNC =
        DEFINE_REQ_FMT0("MDS_SYNC", mdt_body_capa, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_SYNC);

struct req_format RQF_MDS_GETATTR =
        DEFINE_REQ_FMT0("MDS_GETATTR", mdt_body_capa, mds_getattr_server);
EXPORT_SYMBOL(RQF_MDS_GETATTR);

struct req_format RQF_MDS_GETXATTR =
        DEFINE_REQ_FMT0("MDS_GETXATTR",
                        mds_getxattr_client, mds_getxattr_server);
EXPORT_SYMBOL(RQF_MDS_GETXATTR);

struct req_format RQF_MDS_GETATTR_NAME =
        DEFINE_REQ_FMT0("MDS_GETATTR_NAME",
                        mds_getattr_name_client, mds_getattr_server);
EXPORT_SYMBOL(RQF_MDS_GETATTR_NAME);

struct req_format RQF_MDS_REINT =
        DEFINE_REQ_FMT0("MDS_REINT", mds_reint_client, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_REINT);

struct req_format RQF_MDS_REINT_CREATE =
        DEFINE_REQ_FMT0("MDS_REINT_CREATE",
                        mds_reint_create_client, mdt_body_capa);
EXPORT_SYMBOL(RQF_MDS_REINT_CREATE);

struct req_format RQF_MDS_REINT_CREATE_RMT_ACL =
        DEFINE_REQ_FMT0("MDS_REINT_CREATE_RMT_ACL",
                        mds_reint_create_rmt_acl_client, mdt_body_capa);
EXPORT_SYMBOL(RQF_MDS_REINT_CREATE_RMT_ACL);

struct req_format RQF_MDS_REINT_CREATE_SLAVE =
        DEFINE_REQ_FMT0("MDS_REINT_CREATE_EA",
                        mds_reint_create_slave_client, mdt_body_capa);
EXPORT_SYMBOL(RQF_MDS_REINT_CREATE_SLAVE);

struct req_format RQF_MDS_REINT_CREATE_SYM =
        DEFINE_REQ_FMT0("MDS_REINT_CREATE_SYM",
                        mds_reint_create_sym_client, mdt_body_capa);
EXPORT_SYMBOL(RQF_MDS_REINT_CREATE_SYM);

struct req_format RQF_MDS_REINT_OPEN =
        DEFINE_REQ_FMT0("MDS_REINT_OPEN",
                        mds_reint_open_client, mds_reint_open_server);
EXPORT_SYMBOL(RQF_MDS_REINT_OPEN);

struct req_format RQF_MDS_REINT_UNLINK =
        DEFINE_REQ_FMT0("MDS_REINT_UNLINK", mds_reint_unlink_client,
                        mds_last_unlink_server);
EXPORT_SYMBOL(RQF_MDS_REINT_UNLINK);

struct req_format RQF_MDS_REINT_LINK =
        DEFINE_REQ_FMT0("MDS_REINT_LINK",
                        mds_reint_link_client, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_REINT_LINK);

struct req_format RQF_MDS_REINT_RENAME =
        DEFINE_REQ_FMT0("MDS_REINT_RENAME", mds_reint_rename_client,
                        mds_last_unlink_server);
EXPORT_SYMBOL(RQF_MDS_REINT_RENAME);

struct req_format RQF_MDS_REINT_SETATTR =
        DEFINE_REQ_FMT0("MDS_REINT_SETATTR",
                        mds_reint_setattr_client, mds_setattr_server);
EXPORT_SYMBOL(RQF_MDS_REINT_SETATTR);

struct req_format RQF_MDS_REINT_SETXATTR =
        DEFINE_REQ_FMT0("MDS_REINT_SETXATTR",
                        mds_reint_setxattr_client, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_REINT_SETXATTR);

struct req_format RQF_MDS_CONNECT =
        DEFINE_REQ_FMT0("MDS_CONNECT",
                        obd_connect_client, obd_connect_server);
EXPORT_SYMBOL(RQF_MDS_CONNECT);

struct req_format RQF_MDS_DISCONNECT =
        DEFINE_REQ_FMT0("MDS_DISCONNECT", empty, empty);
EXPORT_SYMBOL(RQF_MDS_DISCONNECT);

struct req_format RQF_MDS_GET_INFO =
        DEFINE_REQ_FMT0("MDS_GET_INFO", mds_getinfo_client,
                        mds_getinfo_server);
EXPORT_SYMBOL(RQF_MDS_GET_INFO);

struct req_format RQF_UPDATE_OBJ =
        DEFINE_REQ_FMT0("OBJECT_UPDATE_OBJ", mds_update_client,
                        mds_update_server);
EXPORT_SYMBOL(RQF_UPDATE_OBJ);

struct req_format RQF_LDLM_ENQUEUE =
        DEFINE_REQ_FMT0("LDLM_ENQUEUE",
                        ldlm_enqueue_client, ldlm_enqueue_lvb_server);
EXPORT_SYMBOL(RQF_LDLM_ENQUEUE);

struct req_format RQF_LDLM_ENQUEUE_LVB =
        DEFINE_REQ_FMT0("LDLM_ENQUEUE_LVB",
                        ldlm_enqueue_client, ldlm_enqueue_lvb_server);
EXPORT_SYMBOL(RQF_LDLM_ENQUEUE_LVB);

struct req_format RQF_LDLM_CONVERT =
        DEFINE_REQ_FMT0("LDLM_CONVERT",
                        ldlm_enqueue_client, ldlm_enqueue_server);
EXPORT_SYMBOL(RQF_LDLM_CONVERT);

struct req_format RQF_LDLM_CANCEL =
        DEFINE_REQ_FMT0("LDLM_CANCEL", ldlm_enqueue_client, empty);
EXPORT_SYMBOL(RQF_LDLM_CANCEL);

struct req_format RQF_LDLM_CALLBACK =
        DEFINE_REQ_FMT0("LDLM_CALLBACK", ldlm_enqueue_client, empty);
EXPORT_SYMBOL(RQF_LDLM_CALLBACK);

struct req_format RQF_LDLM_CP_CALLBACK =
        DEFINE_REQ_FMT0("LDLM_CP_CALLBACK", ldlm_cp_callback_client, empty);
EXPORT_SYMBOL(RQF_LDLM_CP_CALLBACK);

struct req_format RQF_LDLM_BL_CALLBACK =
        DEFINE_REQ_FMT0("LDLM_BL_CALLBACK", ldlm_enqueue_client, empty);
EXPORT_SYMBOL(RQF_LDLM_BL_CALLBACK);

struct req_format RQF_LDLM_GL_CALLBACK =
        DEFINE_REQ_FMT0("LDLM_GL_CALLBACK", ldlm_enqueue_client,
                        ldlm_gl_callback_server);
EXPORT_SYMBOL(RQF_LDLM_GL_CALLBACK);

struct req_format RQF_LDLM_GL_DESC_CALLBACK =
        DEFINE_REQ_FMT0("LDLM_GL_CALLBACK", ldlm_gl_callback_desc_client,
                        ldlm_gl_callback_server);
EXPORT_SYMBOL(RQF_LDLM_GL_DESC_CALLBACK);

struct req_format RQF_LDLM_INTENT_BASIC =
        DEFINE_REQ_FMT0("LDLM_INTENT_BASIC",
                        ldlm_intent_basic_client, ldlm_enqueue_lvb_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_BASIC);

struct req_format RQF_LDLM_INTENT =
        DEFINE_REQ_FMT0("LDLM_INTENT",
                        ldlm_intent_client, ldlm_intent_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT);

struct req_format RQF_LDLM_INTENT_LAYOUT =
        DEFINE_REQ_FMT0("LDLM_INTENT_LAYOUT ",
                        ldlm_intent_layout_client, ldlm_enqueue_lvb_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_LAYOUT);

struct req_format RQF_LDLM_INTENT_GETATTR =
        DEFINE_REQ_FMT0("LDLM_INTENT_GETATTR",
                        ldlm_intent_getattr_client, ldlm_intent_getattr_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_GETATTR);

struct req_format RQF_LDLM_INTENT_OPEN =
        DEFINE_REQ_FMT0("LDLM_INTENT_OPEN",
                        ldlm_intent_open_client, ldlm_intent_open_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_OPEN);

struct req_format RQF_LDLM_INTENT_CREATE =
        DEFINE_REQ_FMT0("LDLM_INTENT_CREATE",
                        ldlm_intent_create_client, ldlm_intent_getattr_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_CREATE);

struct req_format RQF_LDLM_INTENT_UNLINK =
        DEFINE_REQ_FMT0("LDLM_INTENT_UNLINK",
                        ldlm_intent_unlink_client, ldlm_intent_server);
EXPORT_SYMBOL(RQF_LDLM_INTENT_UNLINK);

struct req_format RQF_MDS_CLOSE =
        DEFINE_REQ_FMT0("MDS_CLOSE",
                        mdt_close_client, mds_last_unlink_server);
EXPORT_SYMBOL(RQF_MDS_CLOSE);

struct req_format RQF_MDS_PIN =
        DEFINE_REQ_FMT0("MDS_PIN",
                        mdt_body_capa, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_PIN);

struct req_format RQF_MDS_UNPIN =
        DEFINE_REQ_FMT0("MDS_UNPIN", mdt_body_only, empty);
EXPORT_SYMBOL(RQF_MDS_UNPIN);

struct req_format RQF_MDS_DONE_WRITING =
        DEFINE_REQ_FMT0("MDS_DONE_WRITING",
                        mdt_close_client, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_DONE_WRITING);

struct req_format RQF_MDS_READPAGE =
        DEFINE_REQ_FMT0("MDS_READPAGE",
                        mdt_body_capa, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_READPAGE);

struct req_format RQF_MDS_HSM_ACTION =
        DEFINE_REQ_FMT0("MDS_HSM_ACTION", mdt_body_capa, mdt_hsm_action_server);
EXPORT_SYMBOL(RQF_MDS_HSM_ACTION);

struct req_format RQF_MDS_HSM_PROGRESS =
        DEFINE_REQ_FMT0("MDS_HSM_PROGRESS", mdt_hsm_progress, empty);
EXPORT_SYMBOL(RQF_MDS_HSM_PROGRESS);

struct req_format RQF_MDS_HSM_CT_REGISTER =
        DEFINE_REQ_FMT0("MDS_HSM_CT_REGISTER", mdt_hsm_ct_register, empty);
EXPORT_SYMBOL(RQF_MDS_HSM_CT_REGISTER);

struct req_format RQF_MDS_HSM_CT_UNREGISTER =
        DEFINE_REQ_FMT0("MDS_HSM_CT_UNREGISTER", empty, empty);
EXPORT_SYMBOL(RQF_MDS_HSM_CT_UNREGISTER);

struct req_format RQF_MDS_HSM_STATE_GET =
        DEFINE_REQ_FMT0("MDS_HSM_STATE_GET",
                        mdt_body_capa, mdt_hsm_state_get_server);
EXPORT_SYMBOL(RQF_MDS_HSM_STATE_GET);

struct req_format RQF_MDS_HSM_STATE_SET =
        DEFINE_REQ_FMT0("MDS_HSM_STATE_SET", mdt_hsm_state_set, empty);
EXPORT_SYMBOL(RQF_MDS_HSM_STATE_SET);

struct req_format RQF_MDS_HSM_REQUEST =
        DEFINE_REQ_FMT0("MDS_HSM_REQUEST", mdt_hsm_request, empty);
EXPORT_SYMBOL(RQF_MDS_HSM_REQUEST);

struct req_format RQF_MDS_SWAP_LAYOUTS =
        DEFINE_REQ_FMT0("MDS_SWAP_LAYOUTS",
                        mdt_swap_layouts, empty);
EXPORT_SYMBOL(RQF_MDS_SWAP_LAYOUTS);

/* This is for split */
struct req_format RQF_MDS_WRITEPAGE =
        DEFINE_REQ_FMT0("MDS_WRITEPAGE",
                        mdt_body_capa, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_WRITEPAGE);

struct req_format RQF_MDS_IS_SUBDIR =
        DEFINE_REQ_FMT0("MDS_IS_SUBDIR",
                        mdt_body_only, mdt_body_only);
EXPORT_SYMBOL(RQF_MDS_IS_SUBDIR);

struct req_format RQF_LLOG_ORIGIN_HANDLE_CREATE =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_HANDLE_CREATE",
                        llog_origin_handle_create_client, llogd_body_only);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_HANDLE_CREATE);

struct req_format RQF_LLOG_ORIGIN_HANDLE_DESTROY =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_HANDLE_DESTROY",
                        llogd_body_only, llogd_body_only);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_HANDLE_DESTROY);

struct req_format RQF_LLOG_ORIGIN_HANDLE_NEXT_BLOCK =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_HANDLE_NEXT_BLOCK",
                        llogd_body_only, llog_origin_handle_next_block_server);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_HANDLE_NEXT_BLOCK);

struct req_format RQF_LLOG_ORIGIN_HANDLE_PREV_BLOCK =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_HANDLE_PREV_BLOCK",
                        llogd_body_only, llog_origin_handle_next_block_server);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_HANDLE_PREV_BLOCK);

struct req_format RQF_LLOG_ORIGIN_HANDLE_READ_HEADER =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_HANDLE_READ_HEADER",
                        llogd_body_only, llog_log_hdr_only);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_HANDLE_READ_HEADER);

struct req_format RQF_LLOG_ORIGIN_CONNECT =
        DEFINE_REQ_FMT0("LLOG_ORIGIN_CONNECT", llogd_conn_body_only, empty);
EXPORT_SYMBOL(RQF_LLOG_ORIGIN_CONNECT);

struct req_format RQF_OST_CONNECT =
        DEFINE_REQ_FMT0("OST_CONNECT",
                        obd_connect_client, obd_connect_server);
EXPORT_SYMBOL(RQF_OST_CONNECT);

struct req_format RQF_OST_DISCONNECT =
        DEFINE_REQ_FMT0("OST_DISCONNECT", empty, empty);
EXPORT_SYMBOL(RQF_OST_DISCONNECT);

struct req_format RQF_OST_GETATTR =
        DEFINE_REQ_FMT0("OST_GETATTR", ost_body_capa, ost_body_only);
EXPORT_SYMBOL(RQF_OST_GETATTR);

struct req_format RQF_OST_SETATTR =
        DEFINE_REQ_FMT0("OST_SETATTR", ost_body_capa, ost_body_only);
EXPORT_SYMBOL(RQF_OST_SETATTR);

struct req_format RQF_OST_CREATE =
        DEFINE_REQ_FMT0("OST_CREATE", ost_body_only, ost_body_only);
EXPORT_SYMBOL(RQF_OST_CREATE);

struct req_format RQF_OST_PUNCH =
        DEFINE_REQ_FMT0("OST_PUNCH", ost_body_capa, ost_body_only);
EXPORT_SYMBOL(RQF_OST_PUNCH);

struct req_format RQF_OST_SYNC =
        DEFINE_REQ_FMT0("OST_SYNC", ost_body_capa, ost_body_only);
EXPORT_SYMBOL(RQF_OST_SYNC);

struct req_format RQF_OST_DESTROY =
        DEFINE_REQ_FMT0("OST_DESTROY", ost_destroy_client, ost_body_only);
EXPORT_SYMBOL(RQF_OST_DESTROY);

struct req_format RQF_OST_BRW_READ =
        DEFINE_REQ_FMT0("OST_BRW_READ", ost_brw_client, ost_brw_read_server);
EXPORT_SYMBOL(RQF_OST_BRW_READ);

struct req_format RQF_OST_BRW_WRITE =
        DEFINE_REQ_FMT0("OST_BRW_WRITE", ost_brw_client, ost_brw_write_server);
EXPORT_SYMBOL(RQF_OST_BRW_WRITE);

struct req_format RQF_OST_STATFS =
        DEFINE_REQ_FMT0("OST_STATFS", empty, obd_statfs_server);
EXPORT_SYMBOL(RQF_OST_STATFS);

struct req_format RQF_OST_SET_GRANT_INFO =
        DEFINE_REQ_FMT0("OST_SET_GRANT_INFO", ost_grant_shrink_client,
                         ost_body_only);
EXPORT_SYMBOL(RQF_OST_SET_GRANT_INFO);

struct req_format RQF_OST_GET_INFO_GENERIC =
        DEFINE_REQ_FMT0("OST_GET_INFO", ost_get_info_generic_client,
                                        ost_get_info_generic_server);
EXPORT_SYMBOL(RQF_OST_GET_INFO_GENERIC);

struct req_format RQF_OST_GET_INFO_LAST_ID =
        DEFINE_REQ_FMT0("OST_GET_INFO_LAST_ID", ost_get_info_generic_client,
                                                ost_get_last_id_server);
EXPORT_SYMBOL(RQF_OST_GET_INFO_LAST_ID);

struct req_format RQF_OST_GET_INFO_LAST_FID =
        DEFINE_REQ_FMT0("OST_GET_INFO_LAST_FID", obd_set_info_client,
                                                 ost_get_last_fid_server);
EXPORT_SYMBOL(RQF_OST_GET_INFO_LAST_FID);

struct req_format RQF_OST_SET_INFO_LAST_FID =
        DEFINE_REQ_FMT0("OST_SET_INFO_LAST_FID", obd_set_info_client,
                                                 empty);
EXPORT_SYMBOL(RQF_OST_SET_INFO_LAST_FID);

struct req_format RQF_OST_GET_INFO_FIEMAP =
        DEFINE_REQ_FMT0("OST_GET_INFO_FIEMAP", ost_get_fiemap_client,
                                               ost_get_fiemap_server);
EXPORT_SYMBOL(RQF_OST_GET_INFO_FIEMAP);

#if !defined(__REQ_LAYOUT_USER__)

/* Convenience macro */
#define FMT_FIELD(fmt, i, j) (fmt)->rf_fields[(i)].d[(j)]

/**
 * Initializes the capsule abstraction by computing and setting the \a rf_idx
 * field of RQFs and the \a rmf_offset field of RMFs.
 */
int req_layout_init(void)
{
        int i;
        int j;
        int k;
        struct req_format *rf = NULL;

        for (i = 0; i < ARRAY_SIZE(req_formats); ++i) {
                rf = req_formats[i];
                rf->rf_idx = i;
                for (j = 0; j < RCL_NR; ++j) {
                        LASSERT(rf->rf_fields[j].nr <= REQ_MAX_FIELD_NR);
                        for (k = 0; k < rf->rf_fields[j].nr; ++k) {
                                struct req_msg_field *field;

                                field = (typeof(field))rf->rf_fields[j].d[k];
                                LASSERT(!(field->rmf_flags & RMF_F_STRUCT_ARRAY)
                                        || field->rmf_size > 0);
                                LASSERT(field->rmf_offset[i][j] == 0);
                                /*
                                 * k + 1 to detect unused format/field
                                 * combinations.
                                 */
                                field->rmf_offset[i][j] = k + 1;
                        }
                }
        }
        return 0;
}
EXPORT_SYMBOL(req_layout_init);

void req_layout_fini(void)
{
}
EXPORT_SYMBOL(req_layout_fini);

/**
 * Initializes the expected sizes of each RMF in a \a pill (\a rc_area) to -1.
 *
 * Actual/expected field sizes are set elsewhere in functions in this file:
 * req_capsule_init(), req_capsule_server_pack(), req_capsule_set_size() and
 * req_capsule_msg_size().  The \a rc_area information is used by.
 * ptlrpc_request_set_replen().
 */
void req_capsule_init_area(struct req_capsule *pill)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(pill->rc_area[RCL_CLIENT]); i++) {
                pill->rc_area[RCL_CLIENT][i] = -1;
                pill->rc_area[RCL_SERVER][i] = -1;
        }
}
EXPORT_SYMBOL(req_capsule_init_area);

/**
 * Initialize a pill.
 *
 * The \a location indicates whether the caller is executing on the client side
 * (RCL_CLIENT) or server side (RCL_SERVER)..
 */
void req_capsule_init(struct req_capsule *pill,
                      struct ptlrpc_request *req,
                      enum req_location location)
{
        LASSERT(location == RCL_SERVER || location == RCL_CLIENT);

        /*
         * Today all capsules are embedded in ptlrpc_request structs,
         * but just in case that ever isn't the case, we don't reach
         * into req unless req != NULL and pill is the one embedded in
         * the req.
         *
         * The req->rq_pill_init flag makes it safe to initialize a pill
         * twice, which might happen in the OST paths as a result of the
         * high-priority RPC queue getting peeked at before ost_handle()
         * handles an OST RPC.
         */
        if (req != NULL && pill == &req->rq_pill && req->rq_pill_init)
                return;

        memset(pill, 0, sizeof *pill);
        pill->rc_req = req;
        pill->rc_loc = location;
        req_capsule_init_area(pill);

        if (req != NULL && pill == &req->rq_pill)
                req->rq_pill_init = 1;
}
EXPORT_SYMBOL(req_capsule_init);

void req_capsule_fini(struct req_capsule *pill)
{
}
EXPORT_SYMBOL(req_capsule_fini);

static int __req_format_is_sane(const struct req_format *fmt)
{
        return
                0 <= fmt->rf_idx && fmt->rf_idx < ARRAY_SIZE(req_formats) &&
                req_formats[fmt->rf_idx] == fmt;
}

static struct lustre_msg *__req_msg(const struct req_capsule *pill,
                                    enum req_location loc)
{
        struct ptlrpc_request *req;

        req = pill->rc_req;
        return loc == RCL_CLIENT ? req->rq_reqmsg : req->rq_repmsg;
}

/**
 * Set the format (\a fmt) of a \a pill; format changes are not allowed here
 * (see req_capsule_extend()).
 */
void req_capsule_set(struct req_capsule *pill, const struct req_format *fmt)
{
        LASSERT(pill->rc_fmt == NULL || pill->rc_fmt == fmt);
        LASSERT(__req_format_is_sane(fmt));

        pill->rc_fmt = fmt;
}
EXPORT_SYMBOL(req_capsule_set);

/**
 * Fills in any parts of the \a rc_area of a \a pill that haven't been filled in
 * yet.

 * \a rc_area is an array of REQ_MAX_FIELD_NR elements, used to store sizes of
 * variable-sized fields.  The field sizes come from the declared \a rmf_size
 * field of a \a pill's \a rc_fmt's RMF's.
 */
int req_capsule_filled_sizes(struct req_capsule *pill,
                           enum req_location loc)
{
        const struct req_format *fmt = pill->rc_fmt;
        int                      i;

        LASSERT(fmt != NULL);

        for (i = 0; i < fmt->rf_fields[loc].nr; ++i) {
                if (pill->rc_area[loc][i] == -1) {
                        pill->rc_area[loc][i] =
                                            fmt->rf_fields[loc].d[i]->rmf_size;
                        if (pill->rc_area[loc][i] == -1) {
                                /*
                                 * Skip the following fields.
                                 *
                                 * If this LASSERT() trips then you're missing a
                                 * call to req_capsule_set_size().
                                 */
                                LASSERT(loc != RCL_SERVER);
                                break;
                        }
                }
        }
        return i;
}
EXPORT_SYMBOL(req_capsule_filled_sizes);

/**
 * Capsule equivalent of lustre_pack_request() and lustre_pack_reply().
 *
 * This function uses the \a pill's \a rc_area as filled in by
 * req_capsule_set_size() or req_capsule_filled_sizes() (the latter is called by
 * this function).
 */
int req_capsule_server_pack(struct req_capsule *pill)
{
        const struct req_format *fmt;
        int                      count;
        int                      rc;

        LASSERT(pill->rc_loc == RCL_SERVER);
        fmt = pill->rc_fmt;
        LASSERT(fmt != NULL);

        count = req_capsule_filled_sizes(pill, RCL_SERVER);
        rc = lustre_pack_reply(pill->rc_req, count,
                               pill->rc_area[RCL_SERVER], NULL);
        if (rc != 0) {
                DEBUG_REQ(D_ERROR, pill->rc_req,
                       "Cannot pack %d fields in format `%s': ",
                       count, fmt->rf_name);
        }
        return rc;
}
EXPORT_SYMBOL(req_capsule_server_pack);

/**
 * Returns the PTLRPC request or reply (\a loc) buffer offset of a \a pill
 * corresponding to the given RMF (\a field).
 */
static int __req_capsule_offset(const struct req_capsule *pill,
                                const struct req_msg_field *field,
                                enum req_location loc)
{
        int offset;

        offset = field->rmf_offset[pill->rc_fmt->rf_idx][loc];
        LASSERTF(offset > 0, "%s:%s, off=%d, loc=%d\n",
                            pill->rc_fmt->rf_name,
                            field->rmf_name, offset, loc);
        offset --;

        LASSERT(0 <= offset && offset < REQ_MAX_FIELD_NR);
        return offset;
}

/**
 * Helper for __req_capsule_get(); swabs value / array of values and/or dumps
 * them if desired.
 */
static
void
swabber_dumper_helper(struct req_capsule *pill,
                      const struct req_msg_field *field,
                      enum req_location loc,
                      int offset,
                      void *value, int len, int dump, void (*swabber)( void *))
{
        void    *p;
        int     i;
        int     n;
        int     do_swab;
        int     inout = loc == RCL_CLIENT;

        swabber = swabber ?: field->rmf_swabber;

        if (ptlrpc_buf_need_swab(pill->rc_req, inout, offset) &&
            swabber != NULL && value != NULL)
                do_swab = 1;
        else
                do_swab = 0;

        if (!(field->rmf_flags & RMF_F_STRUCT_ARRAY)) {
                if (dump && field->rmf_dumper) {
                        CDEBUG(D_RPCTRACE, "Dump of %sfield %s follows\n",
                               do_swab ? "unswabbed " : "", field->rmf_name);
                        field->rmf_dumper(value);
                }
                if (!do_swab)
                        return;
                swabber(value);
                ptlrpc_buf_set_swabbed(pill->rc_req, inout, offset);
                if (dump) {
                        CDEBUG(D_RPCTRACE, "Dump of swabbed field %s "
                               "follows\n", field->rmf_name);
                        field->rmf_dumper(value);
                }

                return;
        }

        /*
         * We're swabbing an array; swabber() swabs a single array element, so
         * swab every element.
         */
        LASSERT((len % field->rmf_size) == 0);
        for (p = value, i = 0, n = len / field->rmf_size;
             i < n;
             i++, p += field->rmf_size) {
                if (dump && field->rmf_dumper) {
                        CDEBUG(D_RPCTRACE, "Dump of %sarray field %s, "
                               "element %d follows\n",
                               do_swab ? "unswabbed " : "", field->rmf_name, i);
                        field->rmf_dumper(p);
                }
                if (!do_swab)
                        continue;
                swabber(p);
                if (dump && field->rmf_dumper) {
                        CDEBUG(D_RPCTRACE, "Dump of swabbed array field %s, "
                               "element %d follows\n", field->rmf_name, i);
                        field->rmf_dumper(value);
                }
        }
        if (do_swab)
                ptlrpc_buf_set_swabbed(pill->rc_req, inout, offset);
}

/**
 * Returns the pointer to a PTLRPC request or reply (\a loc) buffer of a \a pill
 * corresponding to the given RMF (\a field).
 *
 * The buffer will be swabbed using the given \a swabber.  If \a swabber == NULL
 * then the \a rmf_swabber from the RMF will be used.  Soon there will be no
 * calls to __req_capsule_get() with a non-NULL \a swabber; \a swabber will then
 * be removed.  Fields with the \a RMF_F_STRUCT_ARRAY flag set will have each
 * element of the array swabbed.
 */
static void *__req_capsule_get(struct req_capsule *pill,
                               const struct req_msg_field *field,
                               enum req_location loc,
                               void (*swabber)( void *),
                               int dump)
{
        const struct req_format *fmt;
        struct lustre_msg       *msg;
        void                    *value;
        int                      len;
        int                      offset;

        void *(*getter)(struct lustre_msg *m, int n, int minlen);

        static const char *rcl_names[RCL_NR] = {
                [RCL_CLIENT] = "client",
                [RCL_SERVER] = "server"
        };

        LASSERT(pill != NULL);
        LASSERT(pill != LP_POISON);
        fmt = pill->rc_fmt;
        LASSERT(fmt != NULL);
        LASSERT(fmt != LP_POISON);
        LASSERT(__req_format_is_sane(fmt));

        offset = __req_capsule_offset(pill, field, loc);

        msg = __req_msg(pill, loc);
        LASSERT(msg != NULL);

        getter = (field->rmf_flags & RMF_F_STRING) ?
                (typeof(getter))lustre_msg_string : lustre_msg_buf;

        if (field->rmf_flags & RMF_F_STRUCT_ARRAY) {
                /*
                 * We've already asserted that field->rmf_size > 0 in
                 * req_layout_init().
                 */
                len = lustre_msg_buflen(msg, offset);
                if ((len % field->rmf_size) != 0) {
                        CERROR("%s: array field size mismatch "
                               "%d modulo %d != 0 (%d)\n",
                               field->rmf_name, len, field->rmf_size, loc);
                        return NULL;
                }
        } else if (pill->rc_area[loc][offset] != -1) {
                len = pill->rc_area[loc][offset];
        } else {
                len = max(field->rmf_size, 0);
        }
        value = getter(msg, offset, len);

        if (value == NULL) {
                DEBUG_REQ(D_ERROR, pill->rc_req,
                          "Wrong buffer for field `%s' (%d of %d) "
                          "in format `%s': %d vs. %d (%s)\n",
                          field->rmf_name, offset, lustre_msg_bufcount(msg),
                          fmt->rf_name, lustre_msg_buflen(msg, offset), len,
                          rcl_names[loc]);
        } else {
                swabber_dumper_helper(pill, field, loc, offset, value, len,
                                      dump, swabber);
        }

        return value;
}

/**
 * Dump a request and/or reply
 */
void __req_capsule_dump(struct req_capsule *pill, enum req_location loc)
{
        const struct    req_format *fmt;
        const struct    req_msg_field *field;
        int             len;
        int             i;

        fmt = pill->rc_fmt;

        DEBUG_REQ(D_RPCTRACE, pill->rc_req, "BEGIN REQ CAPSULE DUMP\n");
        for (i = 0; i < fmt->rf_fields[loc].nr; ++i) {
                field = FMT_FIELD(fmt, loc, i);
                if (field->rmf_dumper == NULL) {
                        /*
                         * FIXME Add a default hex dumper for fields that don't
                         * have a specific dumper
                         */
                        len = req_capsule_get_size(pill, field, loc);
                        CDEBUG(D_RPCTRACE, "Field %s has no dumper function;"
                               "field size is %d\n", field->rmf_name, len);
                } else {
                        /* It's the dumping side-effect that we're interested in */
                        (void) __req_capsule_get(pill, field, loc, NULL, 1);
                }
        }
        CDEBUG(D_RPCTRACE, "END REQ CAPSULE DUMP\n");
}

/**
 * Dump a request.
 */
void req_capsule_client_dump(struct req_capsule *pill)
{
        __req_capsule_dump(pill, RCL_CLIENT);
}
EXPORT_SYMBOL(req_capsule_client_dump);

/**
 * Dump a reply
 */
void req_capsule_server_dump(struct req_capsule *pill)
{
        __req_capsule_dump(pill, RCL_SERVER);
}
EXPORT_SYMBOL(req_capsule_server_dump);

/**
 * Trivial wrapper around __req_capsule_get(), that returns the PTLRPC request
 * buffer corresponding to the given RMF (\a field) of a \a pill.
 */
void *req_capsule_client_get(struct req_capsule *pill,
                             const struct req_msg_field *field)
{
        return __req_capsule_get(pill, field, RCL_CLIENT, NULL, 0);
}
EXPORT_SYMBOL(req_capsule_client_get);

/**
 * Same as req_capsule_client_get(), but with a \a swabber argument.
 *
 * Currently unused; will be removed when req_capsule_server_swab_get() is
 * unused too.
 */
void *req_capsule_client_swab_get(struct req_capsule *pill,
                                  const struct req_msg_field *field,
                                  void *swabber)
{
        return __req_capsule_get(pill, field, RCL_CLIENT, swabber, 0);
}
EXPORT_SYMBOL(req_capsule_client_swab_get);

/**
 * Utility that combines req_capsule_set_size() and req_capsule_client_get().
 *
 * First the \a pill's request \a field's size is set (\a rc_area) using
 * req_capsule_set_size() with the given \a len.  Then the actual buffer is
 * returned.
 */
void *req_capsule_client_sized_get(struct req_capsule *pill,
                                   const struct req_msg_field *field,
                                   int len)
{
        req_capsule_set_size(pill, field, RCL_CLIENT, len);
        return __req_capsule_get(pill, field, RCL_CLIENT, NULL, 0);
}
EXPORT_SYMBOL(req_capsule_client_sized_get);

/**
 * Trivial wrapper around __req_capsule_get(), that returns the PTLRPC reply
 * buffer corresponding to the given RMF (\a field) of a \a pill.
 */
void *req_capsule_server_get(struct req_capsule *pill,
                             const struct req_msg_field *field)
{
        return __req_capsule_get(pill, field, RCL_SERVER, NULL, 0);
}
EXPORT_SYMBOL(req_capsule_server_get);

/**
 * Same as req_capsule_server_get(), but with a \a swabber argument.
 *
 * Ideally all swabbing should be done pursuant to RMF definitions, with no
 * swabbing done outside this capsule abstraction.
 */
void *req_capsule_server_swab_get(struct req_capsule *pill,
                                  const struct req_msg_field *field,
                                  void *swabber)
{
        return __req_capsule_get(pill, field, RCL_SERVER, swabber, 0);
}
EXPORT_SYMBOL(req_capsule_server_swab_get);

/**
 * Utility that combines req_capsule_set_size() and req_capsule_server_get().
 *
 * First the \a pill's request \a field's size is set (\a rc_area) using
 * req_capsule_set_size() with the given \a len.  Then the actual buffer is
 * returned.
 */
void *req_capsule_server_sized_get(struct req_capsule *pill,
                                   const struct req_msg_field *field,
                                   int len)
{
        req_capsule_set_size(pill, field, RCL_SERVER, len);
        return __req_capsule_get(pill, field, RCL_SERVER, NULL, 0);
}
EXPORT_SYMBOL(req_capsule_server_sized_get);

void *req_capsule_server_sized_swab_get(struct req_capsule *pill,
                                        const struct req_msg_field *field,
                                        int len, void *swabber)
{
        req_capsule_set_size(pill, field, RCL_SERVER, len);
        return __req_capsule_get(pill, field, RCL_SERVER, swabber, 0);
}
EXPORT_SYMBOL(req_capsule_server_sized_swab_get);

/**
 * Returns the buffer of a \a pill corresponding to the given \a field from the
 * request (if the caller is executing on the server-side) or reply (if the
 * caller is executing on the client-side).
 *
 * This function convienient for use is code that could be executed on the
 * client and server alike.
 */
const void *req_capsule_other_get(struct req_capsule *pill,
                                  const struct req_msg_field *field)
{
        return __req_capsule_get(pill, field, pill->rc_loc ^ 1, NULL, 0);
}
EXPORT_SYMBOL(req_capsule_other_get);

/**
 * Set the size of the PTLRPC request/reply (\a loc) buffer for the given \a
 * field of the given \a pill.
 *
 * This function must be used when constructing variable sized fields of a
 * request or reply.
 */
void req_capsule_set_size(struct req_capsule *pill,
                          const struct req_msg_field *field,
                          enum req_location loc, int size)
{
        LASSERT(loc == RCL_SERVER || loc == RCL_CLIENT);

        if ((size != field->rmf_size) &&
            (field->rmf_size != -1) &&
            !(field->rmf_flags & RMF_F_NO_SIZE_CHECK) &&
            (size > 0)) {
                if ((field->rmf_flags & RMF_F_STRUCT_ARRAY) &&
                    (size % field->rmf_size != 0)) {
                        CERROR("%s: array field size mismatch "
                               "%d %% %d != 0 (%d)\n",
                               field->rmf_name, size, field->rmf_size, loc);
                        LBUG();
                } else if (!(field->rmf_flags & RMF_F_STRUCT_ARRAY) &&
                    size < field->rmf_size) {
                        CERROR("%s: field size mismatch %d != %d (%d)\n",
                               field->rmf_name, size, field->rmf_size, loc);
                        LBUG();
                }
        }

        pill->rc_area[loc][__req_capsule_offset(pill, field, loc)] = size;
}
EXPORT_SYMBOL(req_capsule_set_size);

/**
 * Return the actual PTLRPC buffer length of a request or reply (\a loc)
 * for the given \a pill's given \a field.
 *
 * NB: this function doesn't correspond with req_capsule_set_size(), which
 * actually sets the size in pill.rc_area[loc][offset], but this function
 * returns the message buflen[offset], maybe we should use another name.
 */
int req_capsule_get_size(const struct req_capsule *pill,
                         const struct req_msg_field *field,
                         enum req_location loc)
{
        LASSERT(loc == RCL_SERVER || loc == RCL_CLIENT);

        return lustre_msg_buflen(__req_msg(pill, loc),
                                 __req_capsule_offset(pill, field, loc));
}
EXPORT_SYMBOL(req_capsule_get_size);

/**
 * Wrapper around lustre_msg_size() that returns the PTLRPC size needed for the
 * given \a pill's request or reply (\a loc) given the field size recorded in
 * the \a pill's rc_area.
 *
 * See also req_capsule_set_size().
 */
int req_capsule_msg_size(struct req_capsule *pill, enum req_location loc)
{
        return lustre_msg_size(pill->rc_req->rq_import->imp_msg_magic,
                               pill->rc_fmt->rf_fields[loc].nr,
                               pill->rc_area[loc]);
}

/**
 * While req_capsule_msg_size() computes the size of a PTLRPC request or reply
 * (\a loc) given a \a pill's \a rc_area, this function computes the size of a
 * PTLRPC request or reply given only an RQF (\a fmt).
 *
 * This function should not be used for formats which contain variable size
 * fields.
 */
int req_capsule_fmt_size(__u32 magic, const struct req_format *fmt,
                         enum req_location loc)
{
        int size, i = 0;

        /*
         * This function should probably LASSERT() that fmt has no fields with
         * RMF_F_STRUCT_ARRAY in rmf_flags, since we can't know here how many
         * elements in the array there will ultimately be, but then, we could
         * assume that there will be at least one element, and that's just what
         * we do.
         */
        size = lustre_msg_hdr_size(magic, fmt->rf_fields[loc].nr);
        if (size < 0)
                return size;

        for (; i < fmt->rf_fields[loc].nr; ++i)
                if (fmt->rf_fields[loc].d[i]->rmf_size != -1)
                        size += cfs_size_round(fmt->rf_fields[loc].d[i]->
                                               rmf_size);
        return size;
}

/**
 * Changes the format of an RPC.
 *
 * The pill must already have been initialized, which means that it already has
 * a request format.  The new format \a fmt must be an extension of the pill's
 * old format.  Specifically: the new format must have as many request and reply
 * fields as the old one, and all fields shared by the old and new format must
 * be at least as large in the new format.
 *
 * The new format's fields may be of different "type" than the old format, but
 * only for fields that are "opaque" blobs: fields which have a) have no
 * \a rmf_swabber, b) \a rmf_flags == 0 or RMF_F_NO_SIZE_CHECK, and c) \a
 * rmf_size == -1 or \a rmf_flags == RMF_F_NO_SIZE_CHECK.  For example,
 * OBD_SET_INFO has a key field and an opaque value field that gets interpreted
 * according to the key field.  When the value, according to the key, contains a
 * structure (or array thereof) to be swabbed, the format should be changed to
 * one where the value field has \a rmf_size/rmf_flags/rmf_swabber set
 * accordingly.
 */
void req_capsule_extend(struct req_capsule *pill, const struct req_format *fmt)
{
        int i;
        int j;

        const struct req_format *old;

        LASSERT(pill->rc_fmt != NULL);
        LASSERT(__req_format_is_sane(fmt));

        old = pill->rc_fmt;
        /*
         * Sanity checking...
         */
        for (i = 0; i < RCL_NR; ++i) {
                LASSERT(fmt->rf_fields[i].nr >= old->rf_fields[i].nr);
                for (j = 0; j < old->rf_fields[i].nr - 1; ++j) {
                        const struct req_msg_field *ofield = FMT_FIELD(old, i, j);

                        /* "opaque" fields can be transmogrified */
                        if (ofield->rmf_swabber == NULL &&
                            (ofield->rmf_flags & ~RMF_F_NO_SIZE_CHECK) == 0 &&
                            (ofield->rmf_size == -1 ||
                            ofield->rmf_flags == RMF_F_NO_SIZE_CHECK))
                                continue;
                        LASSERT(FMT_FIELD(fmt, i, j) == FMT_FIELD(old, i, j));
                }
                /*
                 * Last field in old format can be shorter than in new.
                 */
                LASSERT(FMT_FIELD(fmt, i, j)->rmf_size >=
                        FMT_FIELD(old, i, j)->rmf_size);
        }

        pill->rc_fmt = fmt;
}
EXPORT_SYMBOL(req_capsule_extend);

/**
 * This function returns a non-zero value if the given \a field is present in
 * the format (\a rc_fmt) of \a pill's PTLRPC request or reply (\a loc), else it
 * returns 0.
 */
int req_capsule_has_field(const struct req_capsule *pill,
                          const struct req_msg_field *field,
                          enum req_location loc)
{
        LASSERT(loc == RCL_SERVER || loc == RCL_CLIENT);

        return field->rmf_offset[pill->rc_fmt->rf_idx][loc];
}
EXPORT_SYMBOL(req_capsule_has_field);

/**
 * Returns a non-zero value if the given \a field is present in the given \a
 * pill's PTLRPC request or reply (\a loc), else it returns 0.
 */
int req_capsule_field_present(const struct req_capsule *pill,
                              const struct req_msg_field *field,
                              enum req_location loc)
{
        int offset;

        LASSERT(loc == RCL_SERVER || loc == RCL_CLIENT);
        LASSERT(req_capsule_has_field(pill, field, loc));

        offset = __req_capsule_offset(pill, field, loc);
        return lustre_msg_bufcount(__req_msg(pill, loc)) > offset;
}
EXPORT_SYMBOL(req_capsule_field_present);

/**
 * This function shrinks the size of the _buffer_ of the \a pill's PTLRPC
 * request or reply (\a loc).
 *
 * This is not the opposite of req_capsule_extend().
 */
void req_capsule_shrink(struct req_capsule *pill,
                        const struct req_msg_field *field,
                        unsigned int newlen,
                        enum req_location loc)
{
        const struct req_format *fmt;
        struct lustre_msg       *msg;
        int                      len;
        int                      offset;

        fmt = pill->rc_fmt;
        LASSERT(fmt != NULL);
        LASSERT(__req_format_is_sane(fmt));
        LASSERT(req_capsule_has_field(pill, field, loc));
        LASSERT(req_capsule_field_present(pill, field, loc));

        offset = __req_capsule_offset(pill, field, loc);

        msg = __req_msg(pill, loc);
        len = lustre_msg_buflen(msg, offset);
        LASSERTF(newlen <= len, "%s:%s, oldlen=%d, newlen=%d\n",
                                fmt->rf_name, field->rmf_name, len, newlen);

        if (loc == RCL_CLIENT)
                pill->rc_req->rq_reqlen = lustre_shrink_msg(msg, offset, newlen,
                                                            1);
        else
                pill->rc_req->rq_replen = lustre_shrink_msg(msg, offset, newlen,
                                                            1);
}
EXPORT_SYMBOL(req_capsule_shrink);

int req_capsule_server_grow(struct req_capsule *pill,
                            const struct req_msg_field *field,
                            unsigned int newlen)
{
        struct ptlrpc_reply_state *rs = pill->rc_req->rq_reply_state, *nrs;
        char *from, *to;
        int offset, len, rc;

        LASSERT(pill->rc_fmt != NULL);
        LASSERT(__req_format_is_sane(pill->rc_fmt));
        LASSERT(req_capsule_has_field(pill, field, RCL_SERVER));
        LASSERT(req_capsule_field_present(pill, field, RCL_SERVER));

        len = req_capsule_get_size(pill, field, RCL_SERVER);
        offset = __req_capsule_offset(pill, field, RCL_SERVER);
        if (pill->rc_req->rq_repbuf_len >=
            lustre_packed_msg_size(pill->rc_req->rq_repmsg) - len + newlen)
                CERROR("Inplace repack might be done\n");

        pill->rc_req->rq_reply_state = NULL;
        req_capsule_set_size(pill, field, RCL_SERVER, newlen);
        rc = req_capsule_server_pack(pill);
        if (rc) {
                /* put old rs back, the caller will decide what to do */
                pill->rc_req->rq_reply_state = rs;
                return rc;
        }
        nrs = pill->rc_req->rq_reply_state;
        /* Now we need only buffers, copy first chunk */
        to = lustre_msg_buf(nrs->rs_msg, 0, 0);
        from = lustre_msg_buf(rs->rs_msg, 0, 0);
        len = (char *)lustre_msg_buf(rs->rs_msg, offset, 0) - from;
        memcpy(to, from, len);
        /* check if we have tail and copy it too */
        if (rs->rs_msg->lm_bufcount > offset + 1) {
                to = lustre_msg_buf(nrs->rs_msg, offset + 1, 0);
                from = lustre_msg_buf(rs->rs_msg, offset + 1, 0);
                offset = rs->rs_msg->lm_bufcount - 1;
                len = (char *)lustre_msg_buf(rs->rs_msg, offset, 0) +
                      cfs_size_round(rs->rs_msg->lm_buflens[offset]) - from;
                memcpy(to, from, len);
        }
        /* drop old reply if everything is fine */
        if (rs->rs_difficult) {
                /* copy rs data */
                int i;

                nrs->rs_difficult = 1;
                nrs->rs_no_ack = rs->rs_no_ack;
                for (i = 0; i < rs->rs_nlocks; i++) {
                        nrs->rs_locks[i] = rs->rs_locks[i];
                        nrs->rs_modes[i] = rs->rs_modes[i];
                        nrs->rs_nlocks++;
                }
                rs->rs_nlocks = 0;
                rs->rs_difficult = 0;
                rs->rs_no_ack = 0;
        }
        ptlrpc_rs_decref(rs);
        return 0;
}
EXPORT_SYMBOL(req_capsule_server_grow);
/* __REQ_LAYOUT_USER__ */
#endif