/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
 */

#ifndef _ZFS_VFS_H
#define _ZFS_VFS_H

/*
 * 2.6.28 API change,
 * Added insert_inode_locked() helper function, prior to this most callers
 * used insert_inode_hash().  The older method doesn't check for collisions
 * in the inode_hashtable but it still acceptible for use.
 */
#ifndef HAVE_INSERT_INODE_LOCKED
static inline int
insert_inode_locked(struct inode *ip)
{
	insert_inode_hash(ip);
	return (0);
}
#endif /* HAVE_INSERT_INODE_LOCKED */

/*
 * 2.6.35 API change,
 * Add truncate_setsize() if it is not exported by the Linux kernel.
 *
 * Truncate the inode and pages associated with the inode. The pages are
 * unmapped and removed from cache.
 */
#ifndef HAVE_TRUNCATE_SETSIZE
static inline void
truncate_setsize(struct inode *ip, loff_t new)
{
	struct address_space *mapping = ip->i_mapping;

	i_size_write(ip, new);

	unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
	truncate_inode_pages(mapping, new);
	unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
}
#endif /* HAVE_TRUNCATE_SETSIZE */

#if defined(HAVE_BDI) && !defined(HAVE_BDI_SETUP_AND_REGISTER)
/*
 * 2.6.34 API change,
 * Add bdi_setup_and_register() function if not yet provided by kernel.
 * It is used to quickly initialize and register a BDI for the filesystem.
 */
extern atomic_long_t zfs_bdi_seq;

static inline int
bdi_setup_and_register(struct backing_dev_info *bdi,char *name,unsigned int cap)
{
	char tmp[32];
	int error;

	bdi->name = name;
	bdi->capabilities = cap;
	error = bdi_init(bdi);
	if (error)
		return (error);

	sprintf(tmp, "%.28s%s", name, "-%d");
	error = bdi_register(bdi, NULL, tmp,
	    atomic_long_inc_return(&zfs_bdi_seq));
	if (error) {
		bdi_destroy(bdi);
		return (error);
	}

	return (error);
}
#endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */

/*
 * 2.6.38 API change,
 * LOOKUP_RCU flag introduced to distinguish rcu-walk from ref-walk cases.
 */
#ifndef LOOKUP_RCU
#define LOOKUP_RCU      0x0
#endif /* LOOKUP_RCU */

/*
 * 3.2-rc1 API change,
 * Add set_nlink() if it is not exported by the Linux kernel.
 *
 * i_nlink is read-only in Linux 3.2, but it can be set directly in
 * earlier kernels.
 */
#ifndef HAVE_SET_NLINK
static inline void
set_nlink(struct inode *inode, unsigned int nlink)
{
	inode->i_nlink = nlink;
}
#endif /* HAVE_SET_NLINK */

/*
 * 3.3 API change,
 * The VFS .create, .mkdir and .mknod callbacks were updated to take a
 * umode_t type rather than an int.  To cleanly handle both definitions
 * the zpl_umode_t type is introduced and set accordingly.
 */
#ifdef HAVE_MKDIR_UMODE_T
typedef	umode_t		zpl_umode_t;
#else
typedef	int		zpl_umode_t;
#endif

/*
 * 3.5 API change,
 * The clear_inode() function replaces end_writeback() and introduces an
 * ordering change regarding when the inode_sync_wait() occurs.  See the
 * configure check in config/kernel-clear-inode.m4 for full details.
 */
#if defined(HAVE_EVICT_INODE) && !defined(HAVE_CLEAR_INODE)
#define clear_inode(ip)		end_writeback(ip)
#endif /* HAVE_EVICT_INODE && !HAVE_CLEAR_INODE */

/*
 * 3.6 API change,
 * The sget() helper function now takes the mount flags as an argument.
 */
#ifdef HAVE_5ARG_SGET
#define zpl_sget(type, cmp, set, fl, mtd)	sget(type, cmp, set, fl, mtd)
#else
#define zpl_sget(type, cmp, set, fl, mtd)	sget(type, cmp, set, mtd)
#endif /* HAVE_5ARG_SGET */

#define ZFS_IOC_GETFLAGS	FS_IOC_GETFLAGS
#define ZFS_IOC_SETFLAGS	FS_IOC_SETFLAGS

#endif /* _ZFS_VFS_H */