[linux-2.6-block.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/rbtree.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/slab.h>

struct nilfs_sc_info;
struct nilfs_sysfs_dev_subgroups;

/* the_nilfs struct */
enum {
	THE_NILFS_INIT = 0,     /* Information from super_block is set */
	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_flushed_device: flag indicating if all volatile data was flushed
 * @ns_bdev: block device
 * @ns_sem: semaphore for shared states
 * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts
 * @ns_sbh: buffer heads of on-disk super blocks
 * @ns_sbp: pointers to super block data
 * @ns_sbwtime: previous write time of super block
 * @ns_sbwcount: write count of super block
 * @ns_sbsize: size of valid data in super block
 * @ns_mount_state: file system state
 * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds)
 * @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_prev_seq: base sequence number used to decide if advance log cursor
 * @ns_writer: log writer
 * @ns_segctor_sem: semaphore protecting log write
 * @ns_dat: DAT file inode
 * @ns_cpfile: checkpoint file inode
 * @ns_sufile: segusage file inode
 * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)
 * @ns_cptree_lock: lock protecting @ns_cptree
 * @ns_dirty_files: list of dirty files
 * @ns_inode_lock: lock protecting @ns_dirty_files
 * @ns_gc_inodes: dummy inodes to keep live blocks
 * @ns_next_generation: next generation number for inodes
 * @ns_next_gen_lock: lock protecting @ns_next_generation
 * @ns_mount_opt: mount options
 * @ns_resuid: uid for reserved blocks
 * @ns_resgid: gid for reserved blocks
 * @ns_interval: checkpoint creation interval
 * @ns_watermark: watermark for the number of dirty buffers
 * @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
 * @ns_dev_kobj: /sys/fs/<nilfs>/<device>
 * @ns_dev_kobj_unregister: completion state
 * @ns_dev_subgroups: <device> subgroups pointer
 */
struct the_nilfs {
	unsigned long		ns_flags;
	int			ns_flushed_device;

	struct block_device    *ns_bdev;
	struct rw_semaphore	ns_sem;
	struct mutex		ns_snapshot_mount_mutex;

	/*
	 * used for
	 * - loading the latest checkpoint exclusively.
	 * - allocating a new full segment.
	 */
	struct buffer_head     *ns_sbh[2];
	struct nilfs_super_block *ns_sbp[2];
	time_t			ns_sbwtime;
	unsigned		ns_sbwcount;
	unsigned		ns_sbsize;
	unsigned		ns_mount_state;
	unsigned		ns_sb_update_freq;

	/*
	 * 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;
	u64			ns_prev_seq;

	struct nilfs_sc_info   *ns_writer;
	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;

	/* Checkpoint tree */
	struct rb_root		ns_cptree;
	spinlock_t		ns_cptree_lock;

	/* Dirty inode list */
	struct list_head	ns_dirty_files;
	spinlock_t		ns_inode_lock;

	/* GC inode list */
	struct list_head	ns_gc_inodes;

	/* Inode allocator */
	u32			ns_next_generation;
	spinlock_t		ns_next_gen_lock;

	/* Mount options */
	unsigned long		ns_mount_opt;

	uid_t			ns_resuid;
	gid_t			ns_resgid;
	unsigned long		ns_interval;
	unsigned long		ns_watermark;

	/* 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;

	/* /sys/fs/<nilfs>/<device> */
	struct kobject ns_dev_kobj;
	struct completion ns_dev_kobj_unregister;
	struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups;
};

#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(DISCONTINUED, discontinued)
THE_NILFS_FNS(GC_RUNNING, gc_running)
THE_NILFS_FNS(SB_DIRTY, sb_dirty)

/*
 * Mount option operations
 */
#define nilfs_clear_opt(nilfs, opt)  \
	do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0)
#define nilfs_set_opt(nilfs, opt)  \
	do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0)
#define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt)
#define nilfs_write_opt(nilfs, mask, opt)				\
	do { (nilfs)->ns_mount_opt =					\
		(((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) |	\
		 NILFS_MOUNT_##opt);					\
	} while (0)

/**
 * struct nilfs_root - nilfs root object
 * @cno: checkpoint number
 * @rb_node: red-black tree node
 * @count: refcount of this structure
 * @nilfs: nilfs object
 * @ifile: inode file
 * @inodes_count: number of inodes
 * @blocks_count: number of blocks
 * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot>
 * @snapshot_kobj_unregister: completion state for kernel object
 */
struct nilfs_root {
	__u64 cno;
	struct rb_node rb_node;

	atomic_t count;
	struct the_nilfs *nilfs;
	struct inode *ifile;

	atomic64_t inodes_count;
	atomic64_t blocks_count;

	/* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */
	struct kobject snapshot_kobj;
	struct completion snapshot_kobj_unregister;
};

/* Special checkpoint number */
#define NILFS_CPTREE_CURRENT_CNO	0

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

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

static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)
{
	int flip_bits = nilfs->ns_sbwcount & 0x0FL;
	return (flip_bits != 0x08 && flip_bits != 0x0F);
}

void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
struct the_nilfs *alloc_nilfs(struct block_device *bdev);
void destroy_nilfs(struct the_nilfs *nilfs);
int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data);
int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb);
unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs);
void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs);
int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno);
struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,
					     __u64 cno);
void nilfs_put_root(struct nilfs_root *root);
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 nilfs_get_root(struct nilfs_root *root)
{
	atomic_inc(&root->count);
}

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;
}

static inline int nilfs_flush_device(struct the_nilfs *nilfs)
{
	int err;

	if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device)
		return 0;

	nilfs->ns_flushed_device = 1;
	/*
	 * the store to ns_flushed_device must not be reordered after
	 * blkdev_issue_flush().
	 */
	smp_wmb();

	err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL);
	if (err != -EIO)
		err = 0;
	return err;
}

#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>
ba65ae47	29	#include <linux/rbtree.h>
65b4643d RK	30	#include <linux/fs.h>
	31	#include <linux/blkdev.h>
	32	#include <linux/backing-dev.h>
5a0e3ad6	33	#include <linux/slab.h>
65b4643d	34
3fd3fe5a	35	struct nilfs_sc_info;
caa05d49	36	struct nilfs_sysfs_dev_subgroups;
3fd3fe5a	37
65b4643d RK	38	/* the_nilfs struct */
	39	enum {
	40	THE_NILFS_INIT = 0, /* Information from super_block is set */
65b4643d	41	THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
1cf58fa8	42	THE_NILFS_GC_RUNNING, /* gc process is running */
e605f0a7	43	THE_NILFS_SB_DIRTY, /* super block is dirty */
65b4643d RK	44	};
	45
	46	/**
	47	* struct the_nilfs - struct to supervise multiple nilfs mount points
	48	* @ns_flags: flags
e2c7617a	49	* @ns_flushed_device: flag indicating if all volatile data was flushed
65b4643d	50	* @ns_bdev: block device
65b4643d	51	* @ns_sem: semaphore for shared states
572d8b39	52	* @ns_snapshot_mount_mutex: mutex to protect snapshot mounts
e339ad31 RK	53	* @ns_sbh: buffer heads of on-disk super blocks
e339ad31 RK	54	* @ns_sbp: pointers to super block data
b2ac86e1 JS	55	* @ns_sbwtime: previous write time of super block
b2ac86e1 JS	56	* @ns_sbwcount: write count of super block
e339ad31	57	* @ns_sbsize: size of valid data in super block
6b0f3393	58	* @ns_mount_state: file system state
caa05d49	59	* @ns_sb_update_freq: interval of periodical update of superblocks (in seconds)
65b4643d RK	60	* @ns_seg_seq: segment sequence counter
	61	* @ns_segnum: index number of the latest full segment.
	62	* @ns_nextnum: index number of the full segment index to be used next
	63	* @ns_pseg_offset: offset of next partial segment in the current full segment
	64	* @ns_cno: next checkpoint number
	65	* @ns_ctime: write time of the last segment
	66	* @ns_nongc_ctime: write time of the last segment not for cleaner operation
	67	* @ns_ndirtyblks: Number of dirty data blocks
	68	* @ns_last_segment_lock: lock protecting fields for the latest segment
	69	* @ns_last_pseg: start block number of the latest segment
	70	* @ns_last_seq: sequence value of the latest segment
	71	* @ns_last_cno: checkpoint number of the latest segment
2c2e52fc	72	* @ns_prot_seq: least sequence number of segments which must not be reclaimed
32502047	73	* @ns_prev_seq: base sequence number used to decide if advance log cursor
3fd3fe5a RK	74	* @ns_writer: log writer
3fd3fe5a RK	75	* @ns_segctor_sem: semaphore protecting log write
65b4643d RK	76	* @ns_dat: DAT file inode
	77	* @ns_cpfile: checkpoint file inode
	78	* @ns_sufile: segusage file inode
ba65ae47 RK	79	* @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)
ba65ae47 RK	80	* @ns_cptree_lock: lock protecting @ns_cptree
693dd321 RK	81	* @ns_dirty_files: list of dirty files
693dd321 RK	82	* @ns_inode_lock: lock protecting @ns_dirty_files
65b4643d	83	* @ns_gc_inodes: dummy inodes to keep live blocks
9b1fc4e4 RK	84	* @ns_next_generation: next generation number for inodes
9b1fc4e4 RK	85	* @ns_next_gen_lock: lock protecting @ns_next_generation
3b2ce58b	86	* @ns_mount_opt: mount options
574e6c31 RK	87	* @ns_resuid: uid for reserved blocks
	88	* @ns_resgid: gid for reserved blocks
	89	* @ns_interval: checkpoint creation interval
	90	* @ns_watermark: watermark for the number of dirty buffers
65b4643d	91	* @ns_blocksize_bits: bit length of block size
92c60cca	92	* @ns_blocksize: block size
65b4643d RK	93	* @ns_nsegments: number of segments in filesystem
	94	* @ns_blocks_per_segment: number of blocks per segment
	95	* @ns_r_segments_percentage: reserved segments percentage
	96	* @ns_nrsvsegs: number of reserved segments
	97	* @ns_first_data_block: block number of first data block
	98	* @ns_inode_size: size of on-disk inode
	99	* @ns_first_ino: first not-special inode number
	100	* @ns_crc_seed: seed value of CRC32 calculation
da7141fb VD	101	* @ns_dev_kobj: /sys/fs/<nilfs>/<device>
da7141fb VD	102	* @ns_dev_kobj_unregister: completion state
caa05d49	103	* @ns_dev_subgroups: <device> subgroups pointer
65b4643d RK	104	*/
	105	struct the_nilfs {
	106	unsigned long ns_flags;
e2c7617a	107	int ns_flushed_device;
65b4643d RK	108
65b4643d RK	109	struct block_device *ns_bdev;
65b4643d	110	struct rw_semaphore ns_sem;
572d8b39	111	struct mutex ns_snapshot_mount_mutex;
65b4643d RK	112
	113	/*
	114	* used for
	115	* - loading the latest checkpoint exclusively.
	116	* - allocating a new full segment.
65b4643d	117	*/
e339ad31 RK	118	struct buffer_head *ns_sbh[2];
e339ad31 RK	119	struct nilfs_super_block *ns_sbp[2];
b2ac86e1 JS	120	time_t ns_sbwtime;
b2ac86e1 JS	121	unsigned ns_sbwcount;
e339ad31	122	unsigned ns_sbsize;
65b4643d	123	unsigned ns_mount_state;
caa05d49	124	unsigned ns_sb_update_freq;
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;
32502047	152	u64 ns_prev_seq;
65b4643d	153
3fd3fe5a	154	struct nilfs_sc_info *ns_writer;
65b4643d RK	155	struct rw_semaphore ns_segctor_sem;
	156
	157	/*
	158	* Following fields are lock free except for the period before
	159	* the_nilfs is initialized.
	160	*/
	161	struct inode *ns_dat;
	162	struct inode *ns_cpfile;
	163	struct inode *ns_sufile;
65b4643d	164
ba65ae47 RK	165	/* Checkpoint tree */
	166	struct rb_root ns_cptree;
	167	spinlock_t ns_cptree_lock;
	168
693dd321 RK	169	/* Dirty inode list */
	170	struct list_head ns_dirty_files;
	171	spinlock_t ns_inode_lock;
	172
263d90ce	173	/* GC inode list */
65b4643d	174	struct list_head ns_gc_inodes;
65b4643d	175
9b1fc4e4 RK	176	/* Inode allocator */
	177	u32 ns_next_generation;
	178	spinlock_t ns_next_gen_lock;
	179
3b2ce58b RK	180	/* Mount options */
	181	unsigned long ns_mount_opt;
	182
574e6c31 RK	183	uid_t ns_resuid;
	184	gid_t ns_resgid;
	185	unsigned long ns_interval;
	186	unsigned long ns_watermark;
	187
65b4643d RK	188	/* Disk layout information (static) */
65b4643d RK	189	unsigned int ns_blocksize_bits;
92c60cca	190	unsigned int ns_blocksize;
65b4643d RK	191	unsigned long ns_nsegments;
	192	unsigned long ns_blocks_per_segment;
	193	unsigned long ns_r_segments_percentage;
	194	unsigned long ns_nrsvsegs;
	195	unsigned long ns_first_data_block;
	196	int ns_inode_size;
	197	int ns_first_ino;
	198	u32 ns_crc_seed;
da7141fb VD	199
	200	/* /sys/fs/<nilfs>/<device> */
	201	struct kobject ns_dev_kobj;
	202	struct completion ns_dev_kobj_unregister;
caa05d49	203	struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups;
65b4643d RK	204	};
65b4643d RK	205
65b4643d RK	206	#define THE_NILFS_FNS(bit, name) \
	207	static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
	208	{ \
	209	set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	210	} \
	211	static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
	212	{ \
	213	clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	214	} \
	215	static inline int nilfs_##name(struct the_nilfs *nilfs) \
	216	{ \
	217	return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
	218	}
	219
	220	THE_NILFS_FNS(INIT, init)
65b4643d	221	THE_NILFS_FNS(DISCONTINUED, discontinued)
1cf58fa8	222	THE_NILFS_FNS(GC_RUNNING, gc_running)
e605f0a7	223	THE_NILFS_FNS(SB_DIRTY, sb_dirty)
65b4643d	224
3b2ce58b RK	225	/*
	226	* Mount option operations
	227	*/
	228	#define nilfs_clear_opt(nilfs, opt) \
	229	do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0)
	230	#define nilfs_set_opt(nilfs, opt) \
	231	do { (nilfs)->ns_mount_opt \|= NILFS_MOUNT_##opt; } while (0)
	232	#define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt)
	233	#define nilfs_write_opt(nilfs, mask, opt) \
	234	do { (nilfs)->ns_mount_opt = \
	235	(((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) \| \
	236	NILFS_MOUNT_##opt); \
	237	} while (0)
	238
ba65ae47 RK	239	/**
	240	* struct nilfs_root - nilfs root object
	241	* @cno: checkpoint number
	242	* @rb_node: red-black tree node
	243	* @count: refcount of this structure
	244	* @nilfs: nilfs object
	245	* @ifile: inode file
ba65ae47	246	* @inodes_count: number of inodes
f5974c8f	247	* @blocks_count: number of blocks
a5a7332a VD	248	* @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot>
a5a7332a VD	249	* @snapshot_kobj_unregister: completion state for kernel object
ba65ae47 RK	250	*/
	251	struct nilfs_root {
	252	__u64 cno;
	253	struct rb_node rb_node;
	254
	255	atomic_t count;
	256	struct the_nilfs *nilfs;
	257	struct inode *ifile;
	258
e5f7f848 VD	259	atomic64_t inodes_count;
e5f7f848 VD	260	atomic64_t blocks_count;
a5a7332a VD	261
	262	/* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */
	263	struct kobject snapshot_kobj;
	264	struct completion snapshot_kobj_unregister;
ba65ae47 RK	265	};
	266
	267	/* Special checkpoint number */
	268	#define NILFS_CPTREE_CURRENT_CNO 0
	269
e339ad31 RK	270	/* Minimum interval of periodical update of superblocks (in seconds) */
e339ad31 RK	271	#define NILFS_SB_FREQ 10
e339ad31	272
79efdd94 JS	273	static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
	274	{
	275	u64 t = get_seconds();
caa05d49 VD	276	return t < nilfs->ns_sbwtime \|\|
caa05d49 VD	277	t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq;
79efdd94 JS	278	}
79efdd94 JS	279
b2ac86e1	280	static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)
79efdd94	281	{
b2ac86e1 JS	282	int flip_bits = nilfs->ns_sbwcount & 0x0FL;
b2ac86e1 JS	283	return (flip_bits != 0x08 && flip_bits != 0x0F);
79efdd94 JS	284	}
79efdd94 JS	285
65b4643d	286	void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
348fe8da RK	287	struct the_nilfs alloc_nilfs(struct block_device bdev);
348fe8da RK	288	void destroy_nilfs(struct the_nilfs *nilfs);
f7545144 RK	289	int init_nilfs(struct the_nilfs nilfs, struct super_block sb, char *data);
f7545144 RK	290	int load_nilfs(struct the_nilfs nilfs, struct super_block sb);
4e33f9ea RK	291	unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs);
4e33f9ea RK	292	void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs);
e902ec99	293	int nilfs_discard_segments(struct the_nilfs , __u64 , size_t);
65b4643d	294	int nilfs_count_free_blocks(struct the_nilfs , sector_t );
ba65ae47 RK	295	struct nilfs_root nilfs_lookup_root(struct the_nilfs nilfs, __u64 cno);
	296	struct nilfs_root nilfs_find_or_create_root(struct the_nilfs nilfs,
	297	__u64 cno);
	298	void nilfs_put_root(struct nilfs_root *root);
65b4643d	299	int nilfs_near_disk_full(struct the_nilfs *);
e339ad31 RK	300	void nilfs_fall_back_super_block(struct the_nilfs *);
e339ad31 RK	301	void nilfs_swap_super_block(struct the_nilfs *);
65b4643d RK	302
65b4643d RK	303
ba65ae47 RK	304	static inline void nilfs_get_root(struct nilfs_root *root)
	305	{
	306	atomic_inc(&root->count);
	307	}
	308
a057d2c0 RK	309	static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
	310	{
	311	unsigned valid_fs;
	312
	313	down_read(&nilfs->ns_sem);
	314	valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
	315	up_read(&nilfs->ns_sem);
	316	return valid_fs;
	317	}
	318
65b4643d RK	319	static inline void
	320	nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
	321	sector_t seg_start, sector_t seg_end)
	322	{
	323	seg_start = (sector_t)nilfs->ns_blocks_per_segment segnum;
	324	seg_end = seg_start + nilfs->ns_blocks_per_segment - 1;
	325	if (segnum == 0)
	326	*seg_start = nilfs->ns_first_data_block;
	327	}
	328
	329	static inline sector_t
	330	nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
	331	{
	332	return (segnum == 0) ? nilfs->ns_first_data_block :
	333	(sector_t)nilfs->ns_blocks_per_segment * segnum;
	334	}
	335
	336	static inline __u64
	337	nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
	338	{
	339	sector_t segnum = blocknr;
	340
	341	sector_div(segnum, nilfs->ns_blocks_per_segment);
	342	return segnum;
	343	}
	344
	345	static inline void
	346	nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
	347	sector_t seg_end)
	348	{
	349	/* terminate the current full segment (used in case of I/O-error) */
	350	nilfs->ns_pseg_offset = seg_end - seg_start + 1;
	351	}
	352
	353	static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
	354	{
	355	/* move forward with a full segment */
	356	nilfs->ns_segnum = nilfs->ns_nextnum;
	357	nilfs->ns_pseg_offset = 0;
	358	nilfs->ns_seg_seq++;
	359	}
	360
	361	static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
	362	{
	363	__u64 cno;
	364
	365	spin_lock(&nilfs->ns_last_segment_lock);
	366	cno = nilfs->ns_last_cno;
	367	spin_unlock(&nilfs->ns_last_segment_lock);
	368	return cno;
	369	}
	370
cece5520 RK	371	static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
	372	{
	373	return n == nilfs->ns_segnum \|\| n == nilfs->ns_nextnum;
	374	}
	375
e2c7617a AR	376	static inline int nilfs_flush_device(struct the_nilfs *nilfs)
	377	{
	378	int err;
	379
	380	if (!nilfs_test_opt(nilfs, BARRIER) \|\| nilfs->ns_flushed_device)
	381	return 0;
	382
	383	nilfs->ns_flushed_device = 1;
	384	/*
	385	* the store to ns_flushed_device must not be reordered after
	386	* blkdev_issue_flush().
	387	*/
	388	smp_wmb();
	389
	390	err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL);
	391	if (err != -EIO)
	392	err = 0;
	393	return err;
	394	}
	395
65b4643d	396	#endif /* _THE_NILFS_H */