/*
 * 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) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, 2013, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_MDC

#include <linux/module.h>
#include <linux/kernel.h>

#include <obd_class.h>
#include "mdc_internal.h"
#include <lustre_fid.h>

/* mdc_setattr does its own semaphore handling */
static int mdc_reint(struct ptlrpc_request *request,
                     struct mdc_rpc_lock *rpc_lock,
                     int level)
{
        int rc;

        request->rq_send_state = level;

        mdc_get_rpc_lock(rpc_lock, NULL);
        rc = ptlrpc_queue_wait(request);
        mdc_put_rpc_lock(rpc_lock, NULL);
        if (rc)
                CDEBUG(D_INFO, "error in handling %d\n", rc);
        else if (!req_capsule_server_get(&request->rq_pill, &RMF_MDT_BODY)) {
                rc = -EPROTO;
        }
        return rc;
}

/* Find and cancel locally locks matched by inode @bits & @mode in the resource
 * found by @fid. Found locks are added into @cancel list. Returns the amount of
 * locks added to @cancels list. */
int mdc_resource_get_unused(struct obd_export *exp, const struct lu_fid *fid,
			    struct list_head *cancels, ldlm_mode_t mode,
                            __u64 bits)
{
	struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
	ldlm_policy_data_t policy = { {0} };
	struct ldlm_res_id res_id;
	struct ldlm_resource *res;
	int count;
	ENTRY;

	/* Return, i.e. cancel nothing, only if ELC is supported (flag in
	 * export) but disabled through procfs (flag in NS).
	 *
	 * This distinguishes from a case when ELC is not supported originally,
	 * when we still want to cancel locks in advance and just cancel them
	 * locally, without sending any RPC. */
	if (exp_connect_cancelset(exp) && !ns_connect_cancelset(ns))
		RETURN(0);

	fid_build_reg_res_name(fid, &res_id);
	res = ldlm_resource_get(exp->exp_obd->obd_namespace,
				NULL, &res_id, 0, 0);
	if (IS_ERR(res))
		RETURN(0);
	LDLM_RESOURCE_ADDREF(res);
	/* Initialize ibits lock policy. */
	policy.l_inodebits.bits = bits;
	count = ldlm_cancel_resource_local(res, cancels, &policy,
					   mode, 0, 0, NULL);
	LDLM_RESOURCE_DELREF(res);
	ldlm_resource_putref(res);
	RETURN(count);
}

int mdc_setattr(struct obd_export *exp, struct md_op_data *op_data,
                void *ea, int ealen, void *ea2, int ea2len,
                struct ptlrpc_request **request, struct md_open_data **mod)
{
	struct list_head cancels = LIST_HEAD_INIT(cancels);
        struct ptlrpc_request *req;
        struct mdc_rpc_lock *rpc_lock;
        struct obd_device *obd = exp->exp_obd;
        int count = 0, rc;
        __u64 bits;
        ENTRY;

        LASSERT(op_data != NULL);

        bits = MDS_INODELOCK_UPDATE;
        if (op_data->op_attr.ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID))
                bits |= MDS_INODELOCK_LOOKUP;
	if ((op_data->op_flags & MF_MDC_CANCEL_FID1) &&
	    (fid_is_sane(&op_data->op_fid1)))
		count = mdc_resource_get_unused(exp, &op_data->op_fid1,
						&cancels, LCK_EX, bits);
        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_REINT_SETATTR);
        if (req == NULL) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                RETURN(-ENOMEM);
        }
        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        if ((op_data->op_flags & (MF_SOM_CHANGE | MF_EPOCH_OPEN)) == 0)
                req_capsule_set_size(&req->rq_pill, &RMF_MDT_EPOCH, RCL_CLIENT,
                                     0);
        req_capsule_set_size(&req->rq_pill, &RMF_EADATA, RCL_CLIENT, ealen);
        req_capsule_set_size(&req->rq_pill, &RMF_LOGCOOKIES, RCL_CLIENT,
                             ea2len);

	rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
	if (rc) {
		ptlrpc_request_free(req);
		RETURN(rc);
	}

        rpc_lock = obd->u.cli.cl_rpc_lock;

        if (op_data->op_attr.ia_valid & (ATTR_MTIME | ATTR_CTIME))
                CDEBUG(D_INODE, "setting mtime "CFS_TIME_T
                       ", ctime "CFS_TIME_T"\n",
                       LTIME_S(op_data->op_attr.ia_mtime),
                       LTIME_S(op_data->op_attr.ia_ctime));
        mdc_setattr_pack(req, op_data, ea, ealen, ea2, ea2len);

        ptlrpc_request_set_replen(req);
        if (mod && (op_data->op_flags & MF_EPOCH_OPEN) &&
            req->rq_import->imp_replayable)
        {
                LASSERT(*mod == NULL);

                *mod = obd_mod_alloc();
                if (*mod == NULL) {
                        DEBUG_REQ(D_ERROR, req, "Can't allocate "
                                  "md_open_data");
                } else {
                        req->rq_replay = 1;
                        req->rq_cb_data = *mod;
                        (*mod)->mod_open_req = req;
                        req->rq_commit_cb = mdc_commit_open;
			(*mod)->mod_is_create = true;
                        /**
                         * Take an extra reference on \var mod, it protects \var
                         * mod from being freed on eviction (commit callback is
                         * called despite rq_replay flag).
                         * Will be put on mdc_done_writing().
                         */
                        obd_mod_get(*mod);
                }
        }

        rc = mdc_reint(req, rpc_lock, LUSTRE_IMP_FULL);

        /* Save the obtained info in the original RPC for the replay case. */
        if (rc == 0 && (op_data->op_flags & MF_EPOCH_OPEN)) {
                struct mdt_ioepoch *epoch;
                struct mdt_body  *body;

                epoch = req_capsule_client_get(&req->rq_pill, &RMF_MDT_EPOCH);
                body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
                LASSERT(epoch != NULL);
                LASSERT(body != NULL);
		epoch->handle = body->mbo_handle;
		epoch->ioepoch = body->mbo_ioepoch;
                req->rq_replay_cb = mdc_replay_open;
        /** bug 3633, open may be committed and estale answer is not error */
        } else if (rc == -ESTALE && (op_data->op_flags & MF_SOM_CHANGE)) {
                rc = 0;
        } else if (rc == -ERESTARTSYS) {
                rc = 0;
        }
        *request = req;
	if (rc && req->rq_commit_cb) {
		/* Put an extra reference on \var mod on error case. */
		if (mod != NULL && *mod != NULL)
			obd_mod_put(*mod);
		req->rq_commit_cb(req);
	}
	RETURN(rc);
}

int mdc_create(struct obd_export *exp, struct md_op_data *op_data,
               const void *data, int datalen, int mode, __u32 uid, __u32 gid,
               cfs_cap_t cap_effective, __u64 rdev,
               struct ptlrpc_request **request)
{
        struct ptlrpc_request *req;
        int level, rc;
        int count, resends = 0;
        struct obd_import *import = exp->exp_obd->u.cli.cl_import;
        int generation = import->imp_generation;
	struct list_head cancels = LIST_HEAD_INIT(cancels);
        ENTRY;

	/* For case if upper layer did not alloc fid, do it now. */
	if (!fid_is_sane(&op_data->op_fid2)) {
		/*
		 * mdc_fid_alloc() may return errno 1 in case of switch to new
		 * sequence, handle this.
		 */
		rc = mdc_fid_alloc(NULL, exp, &op_data->op_fid2, op_data);
		if (rc < 0)
			RETURN(rc);
	}

rebuild:
        count = 0;
        if ((op_data->op_flags & MF_MDC_CANCEL_FID1) &&
            (fid_is_sane(&op_data->op_fid1)))
                count = mdc_resource_get_unused(exp, &op_data->op_fid1,
                                                &cancels, LCK_EX,
                                                MDS_INODELOCK_UPDATE);

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_REINT_CREATE_RMT_ACL);
        if (req == NULL) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                RETURN(-ENOMEM);
        }
        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT,
                             op_data->op_namelen + 1);
        req_capsule_set_size(&req->rq_pill, &RMF_EADATA, RCL_CLIENT,
                             data && datalen ? datalen : 0);

	rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
	if (rc) {
		ptlrpc_request_free(req);
		RETURN(rc);
	}

        /*
         * mdc_create_pack() fills msg->bufs[1] with name and msg->bufs[2] with
         * tgt, for symlinks or lov MD data.
         */
        mdc_create_pack(req, op_data, data, datalen, mode, uid,
                        gid, cap_effective, rdev);

        ptlrpc_request_set_replen(req);

	/* ask ptlrpc not to resend on EINPROGRESS since we have our own retry
	 * logic here */
	req->rq_no_retry_einprogress = 1;

        if (resends) {
                req->rq_generation_set = 1;
                req->rq_import_generation = generation;
                req->rq_sent = cfs_time_current_sec() + resends;
        }
        level = LUSTRE_IMP_FULL;
 resend:
        rc = mdc_reint(req, exp->exp_obd->u.cli.cl_rpc_lock, level);

        /* Resend if we were told to. */
        if (rc == -ERESTARTSYS) {
                level = LUSTRE_IMP_RECOVER;
                goto resend;
        } else if (rc == -EINPROGRESS) {
                /* Retry create infinitely until succeed or get other
                 * error code. */
                ptlrpc_req_finished(req);
                resends++;

                CDEBUG(D_HA, "%s: resend:%d create on "DFID"/"DFID"\n",
                       exp->exp_obd->obd_name, resends,
                       PFID(&op_data->op_fid1), PFID(&op_data->op_fid2));

                if (generation == import->imp_generation) {
                        goto rebuild;
                } else {
                        CDEBUG(D_HA, "resend cross eviction\n");
                        RETURN(-EIO);
                }
        } else if (rc == 0) {
                struct mdt_body *body;
                struct lustre_capa *capa;

                body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
                LASSERT(body);
		if (body->mbo_valid & OBD_MD_FLMDSCAPA) {
                        capa = req_capsule_server_get(&req->rq_pill,
                                                      &RMF_CAPA1);
                        if (capa == NULL)
                                rc = -EPROTO;
                }
        }

        *request = req;
        RETURN(rc);
}

int mdc_unlink(struct obd_export *exp, struct md_op_data *op_data,
               struct ptlrpc_request **request)
{
	struct list_head cancels = LIST_HEAD_INIT(cancels);
        struct obd_device *obd = class_exp2obd(exp);
        struct ptlrpc_request *req = *request;
        int count = 0, rc;
        ENTRY;

        LASSERT(req == NULL);

	if ((op_data->op_flags & MF_MDC_CANCEL_FID1) &&
	    (fid_is_sane(&op_data->op_fid1)))
		count = mdc_resource_get_unused(exp, &op_data->op_fid1,
						&cancels, LCK_EX,
						MDS_INODELOCK_UPDATE);
	if ((op_data->op_flags & MF_MDC_CANCEL_FID3) &&
	    (fid_is_sane(&op_data->op_fid3)))
		count += mdc_resource_get_unused(exp, &op_data->op_fid3,
						 &cancels, LCK_EX,
						 MDS_INODELOCK_FULL);
        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_REINT_UNLINK);
        if (req == NULL) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                RETURN(-ENOMEM);
        }
        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT,
                             op_data->op_namelen + 1);

	rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
	if (rc) {
		ptlrpc_request_free(req);
		RETURN(rc);
	}

	mdc_unlink_pack(req, op_data);

	req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
			     obd->u.cli.cl_default_mds_easize);
	req_capsule_set_size(&req->rq_pill, &RMF_LOGCOOKIES, RCL_SERVER,
			     obd->u.cli.cl_default_mds_cookiesize);
	ptlrpc_request_set_replen(req);

        *request = req;

        rc = mdc_reint(req, obd->u.cli.cl_rpc_lock, LUSTRE_IMP_FULL);
        if (rc == -ERESTARTSYS)
                rc = 0;
        RETURN(rc);
}

int mdc_link(struct obd_export *exp, struct md_op_data *op_data,
             struct ptlrpc_request **request)
{
	struct list_head cancels = LIST_HEAD_INIT(cancels);
        struct obd_device *obd = exp->exp_obd;
        struct ptlrpc_request *req;
        int count = 0, rc;
        ENTRY;

        if ((op_data->op_flags & MF_MDC_CANCEL_FID2) &&
            (fid_is_sane(&op_data->op_fid2)))
                count = mdc_resource_get_unused(exp, &op_data->op_fid2,
                                                &cancels, LCK_EX,
                                                MDS_INODELOCK_UPDATE);
        if ((op_data->op_flags & MF_MDC_CANCEL_FID1) &&
            (fid_is_sane(&op_data->op_fid1)))
                count += mdc_resource_get_unused(exp, &op_data->op_fid1,
                                                 &cancels, LCK_EX,
                                                 MDS_INODELOCK_UPDATE);

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_REINT_LINK);
        if (req == NULL) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                RETURN(-ENOMEM);
        }
        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        mdc_set_capa_size(req, &RMF_CAPA2, op_data->op_capa2);
        req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT,
                             op_data->op_namelen + 1);

	rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
	if (rc) {
		ptlrpc_request_free(req);
		RETURN(rc);
	}

        mdc_link_pack(req, op_data);
        ptlrpc_request_set_replen(req);

        rc = mdc_reint(req, obd->u.cli.cl_rpc_lock, LUSTRE_IMP_FULL);
        *request = req;
        if (rc == -ERESTARTSYS)
                rc = 0;

        RETURN(rc);
}

int mdc_rename(struct obd_export *exp, struct md_op_data *op_data,
               const char *old, int oldlen, const char *new, int newlen,
               struct ptlrpc_request **request)
{
	struct list_head cancels = LIST_HEAD_INIT(cancels);
        struct obd_device *obd = exp->exp_obd;
        struct ptlrpc_request *req;
        int count = 0, rc;
        ENTRY;

        if ((op_data->op_flags & MF_MDC_CANCEL_FID1) &&
            (fid_is_sane(&op_data->op_fid1)))
                count = mdc_resource_get_unused(exp, &op_data->op_fid1,
                                                &cancels, LCK_EX,
                                                MDS_INODELOCK_UPDATE);
        if ((op_data->op_flags & MF_MDC_CANCEL_FID2) &&
            (fid_is_sane(&op_data->op_fid2)))
                count += mdc_resource_get_unused(exp, &op_data->op_fid2,
                                                 &cancels, LCK_EX,
                                                 MDS_INODELOCK_UPDATE);
        if ((op_data->op_flags & MF_MDC_CANCEL_FID3) &&
            (fid_is_sane(&op_data->op_fid3)))
                count += mdc_resource_get_unused(exp, &op_data->op_fid3,
                                                 &cancels, LCK_EX,
                                                 MDS_INODELOCK_LOOKUP);
        if ((op_data->op_flags & MF_MDC_CANCEL_FID4) &&
             (fid_is_sane(&op_data->op_fid4)))
                count += mdc_resource_get_unused(exp, &op_data->op_fid4,
                                                 &cancels, LCK_EX,
                                                 MDS_INODELOCK_FULL);

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_REINT_RENAME);
        if (req == NULL) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                RETURN(-ENOMEM);
        }

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        mdc_set_capa_size(req, &RMF_CAPA2, op_data->op_capa2);
        req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT, oldlen + 1);
        req_capsule_set_size(&req->rq_pill, &RMF_SYMTGT, RCL_CLIENT, newlen+1);

	rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
	if (rc) {
		ptlrpc_request_free(req);
		RETURN(rc);
	}

        if (exp_connect_cancelset(exp) && req)
                ldlm_cli_cancel_list(&cancels, count, req, 0);

        mdc_rename_pack(req, op_data, old, oldlen, new, newlen);

	req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
			     obd->u.cli.cl_default_mds_easize);
	req_capsule_set_size(&req->rq_pill, &RMF_LOGCOOKIES, RCL_SERVER,
			     obd->u.cli.cl_default_mds_cookiesize);
	ptlrpc_request_set_replen(req);

        rc = mdc_reint(req, obd->u.cli.cl_rpc_lock, LUSTRE_IMP_FULL);
        *request = req;
        if (rc == -ERESTARTSYS)
                rc = 0;

        RETURN(rc);
}