/*
 * nilfs.h - NILFS local header file.
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <koji@osrg.net>
 *            Ryusuke Konishi <ryusuke@osrg.net>
 */

#ifndef _NILFS_H
#define _NILFS_H

#include <linux/kernel.h>
#include <linux/buffer_head.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/nilfs2_fs.h>
#include "the_nilfs.h"
#include "sb.h"
#include "bmap.h"
#include "bmap_union.h"

/*
 * nilfs inode data in memory
 */
struct nilfs_inode_info {
	__u32 i_flags;
	unsigned long  i_state;		/* Dynamic state flags */
	struct nilfs_bmap *i_bmap;
	union nilfs_bmap_union i_bmap_union;
	__u64 i_xattr;	/* sector_t ??? */
	__u32 i_dir_start_lookup;
	__u64 i_cno;		/* check point number for GC inode */
	struct address_space i_btnode_cache;
	struct list_head i_dirty;	/* List for connecting dirty files */

#ifdef CONFIG_NILFS_XATTR
	/*
	 * Extended attributes can be read independently of the main file
	 * data. Taking i_sem even when reading would cause contention
	 * between readers of EAs and writers of regular file data, so
	 * instead we synchronize on xattr_sem when reading or changing
	 * EAs.
	 */
	struct rw_semaphore xattr_sem;
#endif
	struct buffer_head *i_bh;	/* i_bh contains a new or dirty
					   disk inode */
	struct inode vfs_inode;
};

static inline struct nilfs_inode_info *NILFS_I(const struct inode *inode)
{
	return container_of(inode, struct nilfs_inode_info, vfs_inode);
}

static inline struct nilfs_inode_info *
NILFS_BMAP_I(const struct nilfs_bmap *bmap)
{
	return container_of((union nilfs_bmap_union *)bmap,
			    struct nilfs_inode_info,
			    i_bmap_union);
}

static inline struct inode *NILFS_BTNC_I(struct address_space *btnc)
{
	struct nilfs_inode_info *ii =
		container_of(btnc, struct nilfs_inode_info, i_btnode_cache);
	return &ii->vfs_inode;
}

static inline struct inode *NILFS_AS_I(struct address_space *mapping)
{
	return (mapping->host) ? :
		container_of(mapping, struct inode, i_data);
}

/*
 * Dynamic state flags of NILFS on-memory inode (i_state)
 */
enum {
	NILFS_I_NEW = 0,		/* Inode is newly created */
	NILFS_I_DIRTY,			/* The file is dirty */
	NILFS_I_QUEUED,			/* inode is in dirty_files list */
	NILFS_I_BUSY,			/* inode is grabbed by a segment
					   constructor */
	NILFS_I_COLLECTED,		/* All dirty blocks are collected */
	NILFS_I_UPDATED,		/* The file has been written back */
	NILFS_I_INODE_DIRTY,		/* write_inode is requested */
	NILFS_I_BMAP,			/* has bmap and btnode_cache */
	NILFS_I_GCINODE,		/* inode for GC, on memory only */
	NILFS_I_GCDAT,			/* shadow DAT, on memory only */
};

/*
 * Macros to check inode numbers
 */
#define NILFS_MDT_INO_BITS   \
  ((unsigned int)(1 << NILFS_DAT_INO | 1 << NILFS_CPFILE_INO |		\
		  1 << NILFS_SUFILE_INO | 1 << NILFS_IFILE_INO |	\
		  1 << NILFS_ATIME_INO | 1 << NILFS_SKETCH_INO))

#define NILFS_SYS_INO_BITS   \
  ((unsigned int)(1 << NILFS_ROOT_INO) | NILFS_MDT_INO_BITS)

#define NILFS_FIRST_INO(sb)  (NILFS_SB(sb)->s_nilfs->ns_first_ino)

#define NILFS_MDT_INODE(sb, ino) \
  ((ino) < NILFS_FIRST_INO(sb) && (NILFS_MDT_INO_BITS & (1 << (ino))))
#define NILFS_VALID_INODE(sb, ino) \
  ((ino) >= NILFS_FIRST_INO(sb) || (NILFS_SYS_INO_BITS & (1 << (ino))))

/**
 * struct nilfs_transaction_info: context information for synchronization
 * @ti_magic: Magic number
 * @ti_save: Backup of journal_info field of task_struct
 * @ti_flags: Flags
 * @ti_count: Nest level
 * @ti_garbage:	List of inode to be put when releasing semaphore
 */
struct nilfs_transaction_info {
	u32			ti_magic;
	void		       *ti_save;
				/* This should never used. If this happens,
				   one of other filesystems has a bug. */
	unsigned short		ti_flags;
	unsigned short		ti_count;
	struct list_head	ti_garbage;
};

/* ti_magic */
#define NILFS_TI_MAGIC		0xd9e392fb

/* ti_flags */
#define NILFS_TI_DYNAMIC_ALLOC	0x0001  /* Allocated from slab */
#define NILFS_TI_SYNC		0x0002	/* Force to construct segment at the
					   end of transaction. */
#define NILFS_TI_GC		0x0004	/* GC context */
#define NILFS_TI_COMMIT		0x0008	/* Change happened or not */
#define NILFS_TI_WRITER		0x0010	/* Constructor context */


int nilfs_transaction_begin(struct super_block *,
			    struct nilfs_transaction_info *, int);
int nilfs_transaction_commit(struct super_block *);
void nilfs_transaction_abort(struct super_block *);

static inline void nilfs_set_transaction_flag(unsigned int flag)
{
	struct nilfs_transaction_info *ti = current->journal_info;

	ti->ti_flags |= flag;
}

static inline int nilfs_test_transaction_flag(unsigned int flag)
{
	struct nilfs_transaction_info *ti = current->journal_info;

	if (ti == NULL || ti->ti_magic != NILFS_TI_MAGIC)
		return 0;
	return !!(ti->ti_flags & flag);
}

static inline int nilfs_doing_gc(void)
{
	return nilfs_test_transaction_flag(NILFS_TI_GC);
}

static inline int nilfs_doing_construction(void)
{
	return nilfs_test_transaction_flag(NILFS_TI_WRITER);
}

static inline struct inode *nilfs_dat_inode(const struct the_nilfs *nilfs)
{
	return nilfs_doing_gc() ? nilfs->ns_gc_dat : nilfs->ns_dat;
}

/*
 * function prototype
 */
#ifdef CONFIG_NILFS_POSIX_ACL
#error "NILFS: not yet supported POSIX ACL"
extern int nilfs_permission(struct inode *, int, struct nameidata *);
extern int nilfs_acl_chmod(struct inode *);
extern int nilfs_init_acl(struct inode *, struct inode *);
#else
#define nilfs_permission   NULL

static inline int nilfs_acl_chmod(struct inode *inode)
{
	return 0;
}

static inline int nilfs_init_acl(struct inode *inode, struct inode *dir)
{
	inode->i_mode &= ~current_umask();
	return 0;
}
#endif

#define NILFS_ATIME_DISABLE

/* dir.c */
extern int nilfs_add_link(struct dentry *, struct inode *);
extern ino_t nilfs_inode_by_name(struct inode *, const struct qstr *);
extern int nilfs_make_empty(struct inode *, struct inode *);
extern struct nilfs_dir_entry *
nilfs_find_entry(struct inode *, const struct qstr *, struct page **);
extern int nilfs_delete_entry(struct nilfs_dir_entry *, struct page *);
extern int nilfs_empty_dir(struct inode *);
extern struct nilfs_dir_entry *nilfs_dotdot(struct inode *, struct page **);
extern void nilfs_set_link(struct inode *, struct nilfs_dir_entry *,
			   struct page *, struct inode *);

/* file.c */
extern int nilfs_sync_file(struct file *, int);

/* ioctl.c */
long nilfs_ioctl(struct file *, unsigned int, unsigned long);
int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *, struct nilfs_argv *,
				       void **);

/* inode.c */
extern struct inode *nilfs_new_inode(struct inode *, int);
extern void nilfs_free_inode(struct inode *);
extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern void nilfs_set_inode_flags(struct inode *);
extern int nilfs_read_inode_common(struct inode *, struct nilfs_inode *);
extern void nilfs_write_inode_common(struct inode *, struct nilfs_inode *, int);
extern struct inode *nilfs_iget(struct super_block *, unsigned long);
extern void nilfs_update_inode(struct inode *, struct buffer_head *);
extern void nilfs_truncate(struct inode *);
extern void nilfs_evict_inode(struct inode *);
extern int nilfs_setattr(struct dentry *, struct iattr *);
extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *,
				  struct buffer_head **);
extern int nilfs_inode_dirty(struct inode *);
extern int nilfs_set_file_dirty(struct nilfs_sb_info *, struct inode *,
				unsigned);
extern int nilfs_mark_inode_dirty(struct inode *);
extern void nilfs_dirty_inode(struct inode *);

/* namei.c */
extern struct dentry *nilfs_get_parent(struct dentry *);

/* super.c */
extern struct inode *nilfs_alloc_inode_common(struct the_nilfs *);
extern struct inode *nilfs_alloc_inode(struct super_block *);
extern void nilfs_destroy_inode(struct inode *);
extern void nilfs_error(struct super_block *, const char *, const char *, ...)
	__attribute__ ((format (printf, 3, 4)));
extern void nilfs_warning(struct super_block *, const char *, const char *, ...)
       __attribute__ ((format (printf, 3, 4)));
extern struct nilfs_super_block *
nilfs_read_super_block(struct super_block *, u64, int, struct buffer_head **);
extern int nilfs_store_magic_and_option(struct super_block *,
					struct nilfs_super_block *, char *);
extern int nilfs_commit_super(struct nilfs_sb_info *, int);
extern int nilfs_attach_checkpoint(struct nilfs_sb_info *, __u64);
extern void nilfs_detach_checkpoint(struct nilfs_sb_info *);

/* gcinode.c */
int nilfs_gccache_submit_read_data(struct inode *, sector_t, sector_t, __u64,
				   struct buffer_head **);
int nilfs_gccache_submit_read_node(struct inode *, sector_t, __u64,
				   struct buffer_head **);
int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *);
int nilfs_init_gccache(struct the_nilfs *);
void nilfs_destroy_gccache(struct the_nilfs *);
void nilfs_clear_gcinode(struct inode *);
struct inode *nilfs_gc_iget(struct the_nilfs *, ino_t, __u64);
void nilfs_remove_all_gcinode(struct the_nilfs *);

/* gcdat.c */
int nilfs_init_gcdat_inode(struct the_nilfs *);
void nilfs_commit_gcdat_inode(struct the_nilfs *);
void nilfs_clear_gcdat_inode(struct the_nilfs *);

/*
 * Inodes and files operations
 */
extern const struct file_operations nilfs_dir_operations;
extern const struct inode_operations nilfs_file_inode_operations;
extern const struct file_operations nilfs_file_operations;
extern const struct address_space_operations nilfs_aops;
extern const struct inode_operations nilfs_dir_inode_operations;
extern const struct inode_operations nilfs_special_inode_operations;
extern const struct inode_operations nilfs_symlink_inode_operations;

/*
 * filesystem type
 */
extern struct file_system_type nilfs_fs_type;


#endif	/* _NILFS_H */