[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 "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_free_segments_count: counter of free segments
 * @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_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;
	unsigned long		ns_free_segments_count;

	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 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>
	32	#include "sb.h"
	33
	34	/* the_nilfs struct */
	35	enum {
	36	THE_NILFS_INIT = 0, /* Information from super_block is set */
	37	THE_NILFS_LOADED, /* Roll-back/roll-forward has done and
	38	the latest checkpoint was loaded */
	39	THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
1cf58fa8	40	THE_NILFS_GC_RUNNING, /* gc process is running */
e605f0a7	41	THE_NILFS_SB_DIRTY, /* super block is dirty */
65b4643d RK	42	};
	43
	44	/**
	45	* struct the_nilfs - struct to supervise multiple nilfs mount points
	46	* @ns_flags: flags
	47	* @ns_count: reference count
33c8e57c	48	* @ns_list: list head for nilfs_list
65b4643d RK	49	* @ns_bdev: block device
	50	* @ns_bdi: backing dev info
	51	* @ns_writer: back pointer to writable nilfs_sb_info
	52	* @ns_sem: semaphore for shared states
e59399d0	53	* @ns_super_sem: semaphore for global operations across super block instances
aa7dfb89	54	* @ns_mount_mutex: mutex protecting mount process of nilfs
027d6404	55	* @ns_writer_sem: semaphore protecting ns_writer attach/detach
3f82ff55	56	* @ns_current: back pointer to current mount
e339ad31 RK	57	* @ns_sbh: buffer heads of on-disk super blocks
	58	* @ns_sbp: pointers to super block data
	59	* @ns_sbwtime: previous write time of super blocks
	60	* @ns_sbsize: size of valid data in super block
65b4643d RK	61	* @ns_supers: list of nilfs super block structs
	62	* @ns_seg_seq: segment sequence counter
	63	* @ns_segnum: index number of the latest full segment.
	64	* @ns_nextnum: index number of the full segment index to be used next
	65	* @ns_pseg_offset: offset of next partial segment in the current full segment
	66	* @ns_cno: next checkpoint number
	67	* @ns_ctime: write time of the last segment
	68	* @ns_nongc_ctime: write time of the last segment not for cleaner operation
	69	* @ns_ndirtyblks: Number of dirty data blocks
	70	* @ns_last_segment_lock: lock protecting fields for the latest segment
	71	* @ns_last_pseg: start block number of the latest segment
	72	* @ns_last_seq: sequence value of the latest segment
	73	* @ns_last_cno: checkpoint number of the latest segment
2c2e52fc	74	* @ns_prot_seq: least sequence number of segments which must not be reclaimed
65b4643d RK	75	* @ns_free_segments_count: counter of free segments
	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 RK	83	* @ns_blocksize_bits: bit length of block size
	84	* @ns_nsegments: number of segments in filesystem
	85	* @ns_blocks_per_segment: number of blocks per segment
	86	* @ns_r_segments_percentage: reserved segments percentage
	87	* @ns_nrsvsegs: number of reserved segments
	88	* @ns_first_data_block: block number of first data block
	89	* @ns_inode_size: size of on-disk inode
	90	* @ns_first_ino: first not-special inode number
	91	* @ns_crc_seed: seed value of CRC32 calculation
	92	*/
	93	struct the_nilfs {
	94	unsigned long ns_flags;
	95	atomic_t ns_count;
33c8e57c	96	struct list_head ns_list;
65b4643d RK	97
	98	struct block_device *ns_bdev;
	99	struct backing_dev_info *ns_bdi;
	100	struct nilfs_sb_info *ns_writer;
	101	struct rw_semaphore ns_sem;
e59399d0	102	struct rw_semaphore ns_super_sem;
aa7dfb89	103	struct mutex ns_mount_mutex;
027d6404	104	struct rw_semaphore ns_writer_sem;
65b4643d	105
e59399d0 RK	106	/*
	107	* components protected by ns_super_sem
	108	*/
3f82ff55	109	struct nilfs_sb_info *ns_current;
e59399d0	110	struct list_head ns_supers;
3f82ff55	111
65b4643d RK	112	/*
	113	* used for
	114	* - loading the latest checkpoint exclusively.
	115	* - allocating a new full segment.
	116	* - protecting s_dirt in the super_block struct
	117	* (see nilfs_write_super) and the following fields.
	118	*/
e339ad31 RK	119	struct buffer_head *ns_sbh[2];
	120	struct nilfs_super_block *ns_sbp[2];
	121	time_t ns_sbwtime[2];
	122	unsigned ns_sbsize;
65b4643d	123	unsigned ns_mount_state;
65b4643d RK	124
	125	/*
	126	* Following fields are dedicated to a writable FS-instance.
	127	* Except for the period seeking checkpoint, code outside the segment
47420c79 RK	128	* constructor must lock a segment semaphore while accessing these
47420c79 RK	129	* fields.
65b4643d RK	130	* The writable FS-instance is sole during a lifetime of the_nilfs.
	131	*/
	132	u64 ns_seg_seq;
	133	__u64 ns_segnum;
	134	__u64 ns_nextnum;
	135	unsigned long ns_pseg_offset;
	136	__u64 ns_cno;
	137	time_t ns_ctime;
	138	time_t ns_nongc_ctime;
	139	atomic_t ns_ndirtyblks;
	140
	141	/*
	142	* The following fields hold information on the latest partial segment
	143	* written to disk with a super root. These fields are protected by
	144	* ns_last_segment_lock.
	145	*/
	146	spinlock_t ns_last_segment_lock;
	147	sector_t ns_last_pseg;
	148	u64 ns_last_seq;
	149	__u64 ns_last_cno;
2c2e52fc	150	u64 ns_prot_seq;
65b4643d RK	151	unsigned long ns_free_segments_count;
	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) */
	169	unsigned int ns_blocksize_bits;
	170	unsigned long ns_nsegments;
	171	unsigned long ns_blocks_per_segment;
	172	unsigned long ns_r_segments_percentage;
	173	unsigned long ns_nrsvsegs;
	174	unsigned long ns_first_data_block;
	175	int ns_inode_size;
	176	int ns_first_ino;
	177	u32 ns_crc_seed;
	178	};
	179
	180	#define NILFS_GCINODE_HASH_BITS 8
	181	#define NILFS_GCINODE_HASH_SIZE (1<<NILFS_GCINODE_HASH_BITS)
	182
	183	#define THE_NILFS_FNS(bit, name) \
	184	static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
	185	{ \
	186	set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	187	} \
	188	static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
	189	{ \
	190	clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	191	} \
	192	static inline int nilfs_##name(struct the_nilfs *nilfs) \
	193	{ \
	194	return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	195	}
	196
	197	THE_NILFS_FNS(INIT, init)
	198	THE_NILFS_FNS(LOADED, loaded)
	199	THE_NILFS_FNS(DISCONTINUED, discontinued)
1cf58fa8	200	THE_NILFS_FNS(GC_RUNNING, gc_running)
e605f0a7	201	THE_NILFS_FNS(SB_DIRTY, sb_dirty)
65b4643d	202
e339ad31 RK	203	/* Minimum interval of periodical update of superblocks (in seconds) */
	204	#define NILFS_SB_FREQ 10
	205	#define NILFS_ALTSB_FREQ 60 /* spare superblock */
	206
79efdd94 JS	207	static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
	208	{
	209	u64 t = get_seconds();
	210	return t < nilfs->ns_sbwtime[0] \|\|
	211	t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
	212	}
	213
	214	static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
	215	{
	216	u64 t = get_seconds();
	217	struct nilfs_super_block **sbp = nilfs->ns_sbp;
	218	return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
	219	}
	220
65b4643d	221	void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
33c8e57c	222	struct the_nilfs find_or_create_nilfs(struct block_device );
65b4643d RK	223	void put_nilfs(struct the_nilfs *);
	224	int init_nilfs(struct the_nilfs , struct nilfs_sb_info , char *);
	225	int load_nilfs(struct the_nilfs , struct nilfs_sb_info );
e902ec99	226	int nilfs_discard_segments(struct the_nilfs , __u64 , size_t);
65b4643d	227	int nilfs_count_free_blocks(struct the_nilfs , sector_t );
6dd47406	228	struct nilfs_sb_info nilfs_find_sbinfo(struct the_nilfs , int, __u64);
65b4643d RK	229	int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
65b4643d RK	230	int nilfs_near_disk_full(struct the_nilfs *);
e339ad31 RK	231	void nilfs_fall_back_super_block(struct the_nilfs *);
e339ad31 RK	232	void nilfs_swap_super_block(struct the_nilfs *);
65b4643d RK	233
	234
	235	static inline void get_nilfs(struct the_nilfs *nilfs)
	236	{
	237	/* Caller must have at least one reference of the_nilfs. */
	238	atomic_inc(&nilfs->ns_count);
	239	}
	240
65b4643d RK	241	static inline void
	242	nilfs_attach_writer(struct the_nilfs nilfs, struct nilfs_sb_info sbi)
	243	{
027d6404	244	down_write(&nilfs->ns_writer_sem);
65b4643d	245	nilfs->ns_writer = sbi;
027d6404	246	up_write(&nilfs->ns_writer_sem);
65b4643d RK	247	}
	248
	249	static inline void
	250	nilfs_detach_writer(struct the_nilfs nilfs, struct nilfs_sb_info sbi)
	251	{
027d6404	252	down_write(&nilfs->ns_writer_sem);
65b4643d RK	253	if (sbi == nilfs->ns_writer)
65b4643d RK	254	nilfs->ns_writer = NULL;
027d6404	255	up_write(&nilfs->ns_writer_sem);
65b4643d RK	256	}
65b4643d RK	257
6dd47406 RK	258	static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
6dd47406 RK	259	{
a9245860	260	if (atomic_dec_and_test(&sbi->s_count))
6dd47406 RK	261	kfree(sbi);
	262	}
	263
a057d2c0 RK	264	static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
	265	{
	266	unsigned valid_fs;
	267
	268	down_read(&nilfs->ns_sem);
	269	valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
	270	up_read(&nilfs->ns_sem);
	271	return valid_fs;
	272	}
	273
65b4643d RK	274	static inline void
	275	nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
	276	sector_t seg_start, sector_t seg_end)
	277	{
	278	seg_start = (sector_t)nilfs->ns_blocks_per_segment segnum;
	279	seg_end = seg_start + nilfs->ns_blocks_per_segment - 1;
	280	if (segnum == 0)
	281	*seg_start = nilfs->ns_first_data_block;
	282	}
	283
	284	static inline sector_t
	285	nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
	286	{
	287	return (segnum == 0) ? nilfs->ns_first_data_block :
	288	(sector_t)nilfs->ns_blocks_per_segment * segnum;
	289	}
	290
	291	static inline __u64
	292	nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
	293	{
	294	sector_t segnum = blocknr;
	295
	296	sector_div(segnum, nilfs->ns_blocks_per_segment);
	297	return segnum;
	298	}
	299
	300	static inline void
	301	nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
	302	sector_t seg_end)
	303	{
	304	/* terminate the current full segment (used in case of I/O-error) */
	305	nilfs->ns_pseg_offset = seg_end - seg_start + 1;
	306	}
	307
	308	static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
	309	{
	310	/* move forward with a full segment */
	311	nilfs->ns_segnum = nilfs->ns_nextnum;
	312	nilfs->ns_pseg_offset = 0;
	313	nilfs->ns_seg_seq++;
	314	}
	315
	316	static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
	317	{
	318	__u64 cno;
	319
	320	spin_lock(&nilfs->ns_last_segment_lock);
	321	cno = nilfs->ns_last_cno;
	322	spin_unlock(&nilfs->ns_last_segment_lock);
	323	return cno;
	324	}
	325
cece5520 RK	326	static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
	327	{
	328	return n == nilfs->ns_segnum \|\| n == nilfs->ns_nextnum;
	329	}
	330
65b4643d	331	#endif /* _THE_NILFS_H */