[net-next-2.6.git] / fs / nilfs2 / the_nilfs.h

/*
 * the_nilfs.h - the_nilfs shared structure.
 *
 * 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 Ryusuke Konishi <ryusuke@osrg.net>
 *
 */

#ifndef _THE_NILFS_H
#define _THE_NILFS_H

#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/slab.h>
#include "sb.h"

/* the_nilfs struct */
enum {
	THE_NILFS_INIT = 0,     /* Information from super_block is set */
	THE_NILFS_LOADED,       /* Roll-back/roll-forward has done and
				   the latest checkpoint was loaded */
	THE_NILFS_DISCONTINUED,	/* 'next' pointer chain has broken */
	THE_NILFS_GC_RUNNING,	/* gc process is running */
	THE_NILFS_SB_DIRTY,	/* super block is dirty */
};

/**
 * struct the_nilfs - struct to supervise multiple nilfs mount points
 * @ns_flags: flags
 * @ns_count: reference count
 * @ns_list: list head for nilfs_list
 * @ns_bdev: block device
 * @ns_bdi: backing dev info
 * @ns_writer: back pointer to writable nilfs_sb_info
 * @ns_sem: semaphore for shared states
 * @ns_super_sem: semaphore for global operations across super block instances
 * @ns_mount_mutex: mutex protecting mount process of nilfs
 * @ns_writer_sem: semaphore protecting ns_writer attach/detach
 * @ns_current: back pointer to current mount
 * @ns_sbh: buffer heads of on-disk super blocks
 * @ns_sbp: pointers to super block data
 * @ns_sbwtime: previous write time of super blocks
 * @ns_sbsize: size of valid data in super block
 * @ns_supers: list of nilfs super block structs
 * @ns_seg_seq: segment sequence counter
 * @ns_segnum: index number of the latest full segment.
 * @ns_nextnum: index number of the full segment index to be used next
 * @ns_pseg_offset: offset of next partial segment in the current full segment
 * @ns_cno: next checkpoint number
 * @ns_ctime: write time of the last segment
 * @ns_nongc_ctime: write time of the last segment not for cleaner operation
 * @ns_ndirtyblks: Number of dirty data blocks
 * @ns_last_segment_lock: lock protecting fields for the latest segment
 * @ns_last_pseg: start block number of the latest segment
 * @ns_last_seq: sequence value of the latest segment
 * @ns_last_cno: checkpoint number of the latest segment
 * @ns_prot_seq: least sequence number of segments which must not be reclaimed
 * @ns_segctor_sem: segment constructor semaphore
 * @ns_dat: DAT file inode
 * @ns_cpfile: checkpoint file inode
 * @ns_sufile: segusage file inode
 * @ns_gc_dat: shadow inode of the DAT file inode for GC
 * @ns_gc_inodes: dummy inodes to keep live blocks
 * @ns_gc_inodes_h: hash list to keep dummy inode holding live blocks
 * @ns_blocksize_bits: bit length of block size
 * @ns_blocksize: block size
 * @ns_nsegments: number of segments in filesystem
 * @ns_blocks_per_segment: number of blocks per segment
 * @ns_r_segments_percentage: reserved segments percentage
 * @ns_nrsvsegs: number of reserved segments
 * @ns_first_data_block: block number of first data block
 * @ns_inode_size: size of on-disk inode
 * @ns_first_ino: first not-special inode number
 * @ns_crc_seed: seed value of CRC32 calculation
 */
struct the_nilfs {
	unsigned long		ns_flags;
	atomic_t		ns_count;
	struct list_head	ns_list;

	struct block_device    *ns_bdev;
	struct backing_dev_info *ns_bdi;
	struct nilfs_sb_info   *ns_writer;
	struct rw_semaphore	ns_sem;
	struct rw_semaphore	ns_super_sem;
	struct mutex		ns_mount_mutex;
	struct rw_semaphore	ns_writer_sem;

	/*
	 * components protected by ns_super_sem
	 */
	struct nilfs_sb_info   *ns_current;
	struct list_head	ns_supers;

	/*
	 * used for
	 * - loading the latest checkpoint exclusively.
	 * - allocating a new full segment.
	 * - protecting s_dirt in the super_block struct
	 *   (see nilfs_write_super) and the following fields.
	 */
	struct buffer_head     *ns_sbh[2];
	struct nilfs_super_block *ns_sbp[2];
	time_t			ns_sbwtime[2];
	unsigned		ns_sbsize;
	unsigned		ns_mount_state;

	/*
	 * Following fields are dedicated to a writable FS-instance.
	 * Except for the period seeking checkpoint, code outside the segment
	 * constructor must lock a segment semaphore while accessing these
	 * fields.
	 * The writable FS-instance is sole during a lifetime of the_nilfs.
	 */
	u64			ns_seg_seq;
	__u64			ns_segnum;
	__u64			ns_nextnum;
	unsigned long		ns_pseg_offset;
	__u64			ns_cno;
	time_t			ns_ctime;
	time_t			ns_nongc_ctime;
	atomic_t		ns_ndirtyblks;

	/*
	 * The following fields hold information on the latest partial segment
	 * written to disk with a super root.  These fields are protected by
	 * ns_last_segment_lock.
	 */
	spinlock_t		ns_last_segment_lock;
	sector_t		ns_last_pseg;
	u64			ns_last_seq;
	__u64			ns_last_cno;
	u64			ns_prot_seq;

	struct rw_semaphore	ns_segctor_sem;

	/*
	 * Following fields are lock free except for the period before
	 * the_nilfs is initialized.
	 */
	struct inode	       *ns_dat;
	struct inode	       *ns_cpfile;
	struct inode	       *ns_sufile;
	struct inode	       *ns_gc_dat;

	/* GC inode list and hash table head */
	struct list_head	ns_gc_inodes;
	struct hlist_head      *ns_gc_inodes_h;

	/* Disk layout information (static) */
	unsigned int		ns_blocksize_bits;
	unsigned int		ns_blocksize;
	unsigned long		ns_nsegments;
	unsigned long		ns_blocks_per_segment;
	unsigned long		ns_r_segments_percentage;
	unsigned long		ns_nrsvsegs;
	unsigned long		ns_first_data_block;
	int			ns_inode_size;
	int			ns_first_ino;
	u32			ns_crc_seed;
};

#define NILFS_GCINODE_HASH_BITS		8
#define NILFS_GCINODE_HASH_SIZE		(1<<NILFS_GCINODE_HASH_BITS)

#define THE_NILFS_FNS(bit, name)					\
static inline void set_nilfs_##name(struct the_nilfs *nilfs)		\
{									\
	set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags);			\
}									\
static inline void clear_nilfs_##name(struct the_nilfs *nilfs)		\
{									\
	clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags);			\
}									\
static inline int nilfs_##name(struct the_nilfs *nilfs)			\
{									\
	return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags);		\
}

THE_NILFS_FNS(INIT, init)
THE_NILFS_FNS(LOADED, loaded)
THE_NILFS_FNS(DISCONTINUED, discontinued)
THE_NILFS_FNS(GC_RUNNING, gc_running)
THE_NILFS_FNS(SB_DIRTY, sb_dirty)

/* Minimum interval of periodical update of superblocks (in seconds) */
#define NILFS_SB_FREQ		10
#define NILFS_ALTSB_FREQ	60  /* spare superblock */

static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
{
	u64 t = get_seconds();
	return t < nilfs->ns_sbwtime[0] ||
		 t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
}

static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
{
	u64 t = get_seconds();
	struct nilfs_super_block **sbp = nilfs->ns_sbp;
	return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
}

void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
struct the_nilfs *find_or_create_nilfs(struct block_device *);
void put_nilfs(struct the_nilfs *);
int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
int nilfs_near_disk_full(struct the_nilfs *);
void nilfs_fall_back_super_block(struct the_nilfs *);
void nilfs_swap_super_block(struct the_nilfs *);


static inline void get_nilfs(struct the_nilfs *nilfs)
{
	/* Caller must have at least one reference of the_nilfs. */
	atomic_inc(&nilfs->ns_count);
}

static inline void
nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
	down_write(&nilfs->ns_writer_sem);
	nilfs->ns_writer = sbi;
	up_write(&nilfs->ns_writer_sem);
}

static inline void
nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
	down_write(&nilfs->ns_writer_sem);
	if (sbi == nilfs->ns_writer)
		nilfs->ns_writer = NULL;
	up_write(&nilfs->ns_writer_sem);
}

static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
{
	if (atomic_dec_and_test(&sbi->s_count))
		kfree(sbi);
}

static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
{
	unsigned valid_fs;

	down_read(&nilfs->ns_sem);
	valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
	up_read(&nilfs->ns_sem);
	return valid_fs;
}

static inline void
nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
			sector_t *seg_start, sector_t *seg_end)
{
	*seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;
	*seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;
	if (segnum == 0)
		*seg_start = nilfs->ns_first_data_block;
}

static inline sector_t
nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
{
	return (segnum == 0) ? nilfs->ns_first_data_block :
		(sector_t)nilfs->ns_blocks_per_segment * segnum;
}

static inline __u64
nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
{
	sector_t segnum = blocknr;

	sector_div(segnum, nilfs->ns_blocks_per_segment);
	return segnum;
}

static inline void
nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
			sector_t seg_end)
{
	/* terminate the current full segment (used in case of I/O-error) */
	nilfs->ns_pseg_offset = seg_end - seg_start + 1;
}

static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
{
	/* move forward with a full segment */
	nilfs->ns_segnum = nilfs->ns_nextnum;
	nilfs->ns_pseg_offset = 0;
	nilfs->ns_seg_seq++;
}

static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
{
	__u64 cno;

	spin_lock(&nilfs->ns_last_segment_lock);
	cno = nilfs->ns_last_cno;
	spin_unlock(&nilfs->ns_last_segment_lock);
	return cno;
}

static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
{
	return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
}

#endif /* _THE_NILFS_H */
Commit	Line	Data
65b4643d RK	1	/*
	2	* the_nilfs.h - the_nilfs shared structure.
	3	*
	4	* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*
	20	* Written by Ryusuke Konishi <ryusuke@osrg.net>
	21	*
	22	*/
	23
	24	#ifndef _THE_NILFS_H
	25	#define _THE_NILFS_H
	26
	27	#include <linux/types.h>
	28	#include <linux/buffer_head.h>
	29	#include <linux/fs.h>
	30	#include <linux/blkdev.h>
	31	#include <linux/backing-dev.h>
5a0e3ad6	32	#include <linux/slab.h>
65b4643d RK	33	#include "sb.h"
	34
	35	/* the_nilfs struct */
	36	enum {
	37	THE_NILFS_INIT = 0, /* Information from super_block is set */
	38	THE_NILFS_LOADED, /* Roll-back/roll-forward has done and
	39	the latest checkpoint was loaded */
	40	THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
1cf58fa8	41	THE_NILFS_GC_RUNNING, /* gc process is running */
e605f0a7	42	THE_NILFS_SB_DIRTY, /* super block is dirty */
65b4643d RK	43	};
	44
	45	/**
	46	* struct the_nilfs - struct to supervise multiple nilfs mount points
	47	* @ns_flags: flags
	48	* @ns_count: reference count
33c8e57c	49	* @ns_list: list head for nilfs_list
65b4643d RK	50	* @ns_bdev: block device
	51	* @ns_bdi: backing dev info
	52	* @ns_writer: back pointer to writable nilfs_sb_info
	53	* @ns_sem: semaphore for shared states
e59399d0	54	* @ns_super_sem: semaphore for global operations across super block instances
aa7dfb89	55	* @ns_mount_mutex: mutex protecting mount process of nilfs
027d6404	56	* @ns_writer_sem: semaphore protecting ns_writer attach/detach
3f82ff55	57	* @ns_current: back pointer to current mount
e339ad31 RK	58	* @ns_sbh: buffer heads of on-disk super blocks
	59	* @ns_sbp: pointers to super block data
	60	* @ns_sbwtime: previous write time of super blocks
	61	* @ns_sbsize: size of valid data in super block
65b4643d RK	62	* @ns_supers: list of nilfs super block structs
	63	* @ns_seg_seq: segment sequence counter
	64	* @ns_segnum: index number of the latest full segment.
	65	* @ns_nextnum: index number of the full segment index to be used next
	66	* @ns_pseg_offset: offset of next partial segment in the current full segment
	67	* @ns_cno: next checkpoint number
	68	* @ns_ctime: write time of the last segment
	69	* @ns_nongc_ctime: write time of the last segment not for cleaner operation
	70	* @ns_ndirtyblks: Number of dirty data blocks
	71	* @ns_last_segment_lock: lock protecting fields for the latest segment
	72	* @ns_last_pseg: start block number of the latest segment
	73	* @ns_last_seq: sequence value of the latest segment
	74	* @ns_last_cno: checkpoint number of the latest segment
2c2e52fc	75	* @ns_prot_seq: least sequence number of segments which must not be reclaimed
65b4643d RK	76	* @ns_segctor_sem: segment constructor semaphore
	77	* @ns_dat: DAT file inode
	78	* @ns_cpfile: checkpoint file inode
	79	* @ns_sufile: segusage file inode
	80	* @ns_gc_dat: shadow inode of the DAT file inode for GC
	81	* @ns_gc_inodes: dummy inodes to keep live blocks
	82	* @ns_gc_inodes_h: hash list to keep dummy inode holding live blocks
65b4643d	83	* @ns_blocksize_bits: bit length of block size
92c60cca	84	* @ns_blocksize: block size
65b4643d RK	85	* @ns_nsegments: number of segments in filesystem
	86	* @ns_blocks_per_segment: number of blocks per segment
	87	* @ns_r_segments_percentage: reserved segments percentage
	88	* @ns_nrsvsegs: number of reserved segments
	89	* @ns_first_data_block: block number of first data block
	90	* @ns_inode_size: size of on-disk inode
	91	* @ns_first_ino: first not-special inode number
	92	* @ns_crc_seed: seed value of CRC32 calculation
	93	*/
	94	struct the_nilfs {
	95	unsigned long ns_flags;
	96	atomic_t ns_count;
33c8e57c	97	struct list_head ns_list;
65b4643d RK	98
	99	struct block_device *ns_bdev;
	100	struct backing_dev_info *ns_bdi;
	101	struct nilfs_sb_info *ns_writer;
	102	struct rw_semaphore ns_sem;
e59399d0	103	struct rw_semaphore ns_super_sem;
aa7dfb89	104	struct mutex ns_mount_mutex;
027d6404	105	struct rw_semaphore ns_writer_sem;
65b4643d	106
e59399d0 RK	107	/*
	108	* components protected by ns_super_sem
	109	*/
3f82ff55	110	struct nilfs_sb_info *ns_current;
e59399d0	111	struct list_head ns_supers;
3f82ff55	112
65b4643d RK	113	/*
	114	* used for
	115	* - loading the latest checkpoint exclusively.
	116	* - allocating a new full segment.
	117	* - protecting s_dirt in the super_block struct
	118	* (see nilfs_write_super) and the following fields.
	119	*/
e339ad31 RK	120	struct buffer_head *ns_sbh[2];
	121	struct nilfs_super_block *ns_sbp[2];
	122	time_t ns_sbwtime[2];
	123	unsigned ns_sbsize;
65b4643d	124	unsigned ns_mount_state;
65b4643d RK	125
	126	/*
	127	* Following fields are dedicated to a writable FS-instance.
	128	* Except for the period seeking checkpoint, code outside the segment
47420c79 RK	129	* constructor must lock a segment semaphore while accessing these
47420c79 RK	130	* fields.
65b4643d RK	131	* The writable FS-instance is sole during a lifetime of the_nilfs.
	132	*/
	133	u64 ns_seg_seq;
	134	__u64 ns_segnum;
	135	__u64 ns_nextnum;
	136	unsigned long ns_pseg_offset;
	137	__u64 ns_cno;
	138	time_t ns_ctime;
	139	time_t ns_nongc_ctime;
	140	atomic_t ns_ndirtyblks;
	141
	142	/*
	143	* The following fields hold information on the latest partial segment
	144	* written to disk with a super root. These fields are protected by
	145	* ns_last_segment_lock.
	146	*/
	147	spinlock_t ns_last_segment_lock;
	148	sector_t ns_last_pseg;
	149	u64 ns_last_seq;
	150	__u64 ns_last_cno;
2c2e52fc	151	u64 ns_prot_seq;
65b4643d RK	152
	153	struct rw_semaphore ns_segctor_sem;
	154
	155	/*
	156	* Following fields are lock free except for the period before
	157	* the_nilfs is initialized.
	158	*/
	159	struct inode *ns_dat;
	160	struct inode *ns_cpfile;
	161	struct inode *ns_sufile;
	162	struct inode *ns_gc_dat;
	163
	164	/* GC inode list and hash table head */
	165	struct list_head ns_gc_inodes;
	166	struct hlist_head *ns_gc_inodes_h;
	167
65b4643d RK	168	/* Disk layout information (static) */
65b4643d RK	169	unsigned int ns_blocksize_bits;
92c60cca	170	unsigned int ns_blocksize;
65b4643d RK	171	unsigned long ns_nsegments;
	172	unsigned long ns_blocks_per_segment;
	173	unsigned long ns_r_segments_percentage;
	174	unsigned long ns_nrsvsegs;
	175	unsigned long ns_first_data_block;
	176	int ns_inode_size;
	177	int ns_first_ino;
	178	u32 ns_crc_seed;
	179	};
	180
	181	#define NILFS_GCINODE_HASH_BITS 8
	182	#define NILFS_GCINODE_HASH_SIZE (1<<NILFS_GCINODE_HASH_BITS)
	183
	184	#define THE_NILFS_FNS(bit, name) \
	185	static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
	186	{ \
	187	set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	188	} \
	189	static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
	190	{ \
	191	clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	192	} \
	193	static inline int nilfs_##name(struct the_nilfs *nilfs) \
	194	{ \
	195	return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	196	}
	197
	198	THE_NILFS_FNS(INIT, init)
	199	THE_NILFS_FNS(LOADED, loaded)
	200	THE_NILFS_FNS(DISCONTINUED, discontinued)
1cf58fa8	201	THE_NILFS_FNS(GC_RUNNING, gc_running)
e605f0a7	202	THE_NILFS_FNS(SB_DIRTY, sb_dirty)
65b4643d	203
e339ad31 RK	204	/* Minimum interval of periodical update of superblocks (in seconds) */
	205	#define NILFS_SB_FREQ 10
	206	#define NILFS_ALTSB_FREQ 60 /* spare superblock */
	207
79efdd94 JS	208	static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
	209	{
	210	u64 t = get_seconds();
	211	return t < nilfs->ns_sbwtime[0] \|\|
	212	t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
	213	}
	214
	215	static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
	216	{
	217	u64 t = get_seconds();
	218	struct nilfs_super_block **sbp = nilfs->ns_sbp;
	219	return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
	220	}
	221
65b4643d	222	void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
33c8e57c	223	struct the_nilfs find_or_create_nilfs(struct block_device );
65b4643d RK	224	void put_nilfs(struct the_nilfs *);
	225	int init_nilfs(struct the_nilfs , struct nilfs_sb_info , char *);
	226	int load_nilfs(struct the_nilfs , struct nilfs_sb_info );
e902ec99	227	int nilfs_discard_segments(struct the_nilfs , __u64 , size_t);
65b4643d	228	int nilfs_count_free_blocks(struct the_nilfs , sector_t );
6dd47406	229	struct nilfs_sb_info nilfs_find_sbinfo(struct the_nilfs , int, __u64);
65b4643d RK	230	int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
65b4643d RK	231	int nilfs_near_disk_full(struct the_nilfs *);
e339ad31 RK	232	void nilfs_fall_back_super_block(struct the_nilfs *);
e339ad31 RK	233	void nilfs_swap_super_block(struct the_nilfs *);
65b4643d RK	234
	235
	236	static inline void get_nilfs(struct the_nilfs *nilfs)
	237	{
	238	/* Caller must have at least one reference of the_nilfs. */
	239	atomic_inc(&nilfs->ns_count);
	240	}
	241
65b4643d RK	242	static inline void
	243	nilfs_attach_writer(struct the_nilfs nilfs, struct nilfs_sb_info sbi)
	244	{
027d6404	245	down_write(&nilfs->ns_writer_sem);
65b4643d	246	nilfs->ns_writer = sbi;
027d6404	247	up_write(&nilfs->ns_writer_sem);
65b4643d RK	248	}
	249
	250	static inline void
	251	nilfs_detach_writer(struct the_nilfs nilfs, struct nilfs_sb_info sbi)
	252	{
027d6404	253	down_write(&nilfs->ns_writer_sem);
65b4643d RK	254	if (sbi == nilfs->ns_writer)
65b4643d RK	255	nilfs->ns_writer = NULL;
027d6404	256	up_write(&nilfs->ns_writer_sem);
65b4643d RK	257	}
65b4643d RK	258
6dd47406 RK	259	static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
6dd47406 RK	260	{
a9245860	261	if (atomic_dec_and_test(&sbi->s_count))
6dd47406 RK	262	kfree(sbi);
	263	}
	264
a057d2c0 RK	265	static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
	266	{
	267	unsigned valid_fs;
	268
	269	down_read(&nilfs->ns_sem);
	270	valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
	271	up_read(&nilfs->ns_sem);
	272	return valid_fs;
	273	}
	274
65b4643d RK	275	static inline void
	276	nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
	277	sector_t seg_start, sector_t seg_end)
	278	{
	279	seg_start = (sector_t)nilfs->ns_blocks_per_segment segnum;
	280	seg_end = seg_start + nilfs->ns_blocks_per_segment - 1;
	281	if (segnum == 0)
	282	*seg_start = nilfs->ns_first_data_block;
	283	}
	284
	285	static inline sector_t
	286	nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
	287	{
	288	return (segnum == 0) ? nilfs->ns_first_data_block :
	289	(sector_t)nilfs->ns_blocks_per_segment * segnum;
	290	}
	291
	292	static inline __u64
	293	nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
	294	{
	295	sector_t segnum = blocknr;
	296
	297	sector_div(segnum, nilfs->ns_blocks_per_segment);
	298	return segnum;
	299	}
	300
	301	static inline void
	302	nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
	303	sector_t seg_end)
	304	{
	305	/* terminate the current full segment (used in case of I/O-error) */
	306	nilfs->ns_pseg_offset = seg_end - seg_start + 1;
	307	}
	308
	309	static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
	310	{
	311	/* move forward with a full segment */
	312	nilfs->ns_segnum = nilfs->ns_nextnum;
	313	nilfs->ns_pseg_offset = 0;
	314	nilfs->ns_seg_seq++;
	315	}
	316
	317	static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
	318	{
	319	__u64 cno;
	320
	321	spin_lock(&nilfs->ns_last_segment_lock);
	322	cno = nilfs->ns_last_cno;
	323	spin_unlock(&nilfs->ns_last_segment_lock);
	324	return cno;
	325	}
	326
cece5520 RK	327	static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
	328	{
	329	return n == nilfs->ns_segnum \|\| n == nilfs->ns_nextnum;
	330	}
	331
65b4643d	332	#endif /* _THE_NILFS_H */