drivers/staging/lustre/lustre/include/lustre_lite.h

/*
 * 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.
 */

#ifndef _LL_H
#define _LL_H

/** \defgroup lite lite
 *
 * @{
 */

#include "linux/lustre_lite.h"

#include "obd_class.h"
#include "lustre_net.h"
#include "lustre_mds.h"
#include "lustre_ha.h"

/* 4UL * 1024 * 1024 */
#define LL_MAX_BLKSIZE_BITS     (22)
#define LL_MAX_BLKSIZE	  (1UL<<LL_MAX_BLKSIZE_BITS)

#include "lustre/lustre_user.h"


struct lustre_rw_params {
	int		lrp_lock_mode;
	ldlm_policy_data_t lrp_policy;
	u32		lrp_brw_flags;
	int		lrp_ast_flags;
};

/*
 * XXX nikita: this function lives in the header because it is used by both
 * llite kernel module and liblustre library, and there is no (?) better place
 * to put it in.
 */
static inline void lustre_build_lock_params(int cmd, unsigned long open_flags,
					    __u64 connect_flags,
					    loff_t pos, ssize_t len,
					    struct lustre_rw_params *params)
{
	params->lrp_lock_mode = (cmd == OBD_BRW_READ) ? LCK_PR : LCK_PW;
	params->lrp_brw_flags = 0;

	params->lrp_policy.l_extent.start = pos;
	params->lrp_policy.l_extent.end = pos + len - 1;
	/*
	 * for now O_APPEND always takes local locks.
	 */
	if (cmd == OBD_BRW_WRITE && (open_flags & O_APPEND)) {
		params->lrp_policy.l_extent.start = 0;
		params->lrp_policy.l_extent.end   = OBD_OBJECT_EOF;
	} else if (LIBLUSTRE_CLIENT && (connect_flags & OBD_CONNECT_SRVLOCK)) {
		/*
		 * liblustre: OST-side locking for all non-O_APPEND
		 * reads/writes.
		 */
		params->lrp_lock_mode = LCK_NL;
		params->lrp_brw_flags = OBD_BRW_SRVLOCK;
	} else {
		/*
		 * nothing special for the kernel. In the future llite may use
		 * OST-side locks for small writes into highly contended
		 * files.
		 */
	}
	params->lrp_ast_flags = (open_flags & O_NONBLOCK) ?
		LDLM_FL_BLOCK_NOWAIT : 0;
}

/*
 * This is embedded into liblustre and llite super-blocks to keep track of
 * connect flags (capabilities) supported by all imports given mount is
 * connected to.
 */
struct lustre_client_ocd {
	/*
	 * This is conjunction of connect_flags across all imports (LOVs) this
	 * mount is connected to. This field is updated by cl_ocd_update()
	 * under ->lco_lock.
	 */
	__u64	      lco_flags;
	struct mutex	   lco_lock;
	struct obd_export *lco_md_exp;
	struct obd_export *lco_dt_exp;
};

/*
 * Chain of hash overflow pages.
 */
struct ll_dir_chain {
	/* XXX something. Later */
};

static inline void ll_dir_chain_init(struct ll_dir_chain *chain)
{
}

static inline void ll_dir_chain_fini(struct ll_dir_chain *chain)
{
}

static inline unsigned long hash_x_index(__u64 hash, int hash64)
{
	if (BITS_PER_LONG == 32 && hash64)
		hash >>= 32;
	/* save hash 0 as index 0 because otherwise we'll save it at
	 * page index end (~0UL) and it causes truncate_inode_pages_range()
	 * to loop forever.
	 */
	return ~0UL - (hash + !hash);
}

/** @} lite */

#endif