/*
 * 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.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, 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 "../include/obd_class.h"
#include "mdc_internal.h"
#include "../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, enum ldlm_mode mode,
			    __u64 bits)
{
	struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
	ldlm_policy_data_t policy = {};
	struct ldlm_res_id res_id;
	struct ldlm_resource *res;
	int count;

	/* 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, size_t ealen, void *ea2, size_t ea2len,
		struct ptlrpc_request **request, struct md_open_data **mod)
{
	LIST_HEAD(cancels);
	struct ptlrpc_request *req;
	struct mdc_rpc_lock *rpc_lock;
	struct obd_device *obd = exp->exp_obd;
	int count = 0, rc;
	__u64 bits;

	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) {
		ldlm_lock_list_put(&cancels, l_bl_ast, count);
		return -ENOMEM;
	}
	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 %ld, ctime %ld\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);

		*mod = obd_mod_alloc();
		if (!*mod) {
			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);
		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 && *mod)
			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, size_t datalen, umode_t mode,
	       uid_t uid, gid_t 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;
	LIST_HEAD(cancels);

	/* 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_ACL);
	if (!req) {
		ldlm_lock_list_put(&cancels, l_bl_ast, count);
		return -ENOMEM;
	}
	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 = ktime_get_real_seconds() + 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;
		}
	}

	*request = req;
	return rc;
}

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

	LASSERT(!req);

	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) {
		ldlm_lock_list_put(&cancels, l_bl_ast, count);
		return -ENOMEM;
	}
	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)
{
	LIST_HEAD(cancels);
	struct obd_device *obd = exp->exp_obd;
	struct ptlrpc_request *req;
	int count = 0, rc;

	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) {
		ldlm_lock_list_put(&cancels, l_bl_ast, count);
		return -ENOMEM;
	}
	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, size_t oldlen, const char *new, size_t newlen,
	       struct ptlrpc_request **request)
{
	LIST_HEAD(cancels);
	struct obd_device *obd = exp->exp_obd;
	struct ptlrpc_request *req;
	int count = 0, rc;

	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) {
		ldlm_lock_list_put(&cancels, l_bl_ast, count);
		return -ENOMEM;
	}

	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;
}