segment.h

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/*
 * segment.h - NILFS Segment constructor prototypes and definitions
 *
 * 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 <[email protected]>
 *
 */
#ifndef _NILFS_SEGMENT_H
#define _NILFS_SEGMENT_H

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/nilfs2_fs.h>
#include "nilfs.h"

struct nilfs_root;

struct nilfs_recovery_info {
    int         ri_need_recovery;
    sector_t        ri_super_root;
    __u64           ri_cno;

    sector_t        ri_lsegs_start;
    sector_t        ri_lsegs_end;
    u64         ri_lsegs_start_seq;
    struct list_head    ri_used_segments;
    sector_t        ri_pseg_start;
    u64         ri_seq;
    __u64           ri_segnum;
    __u64           ri_nextnum;
};

/* ri_need_recovery */
#define NILFS_RECOVERY_SR_UPDATED    1  /* The super root was updated */
#define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */

struct nilfs_cstage {
    int         scnt;
    unsigned        flags;
    struct nilfs_inode_info *dirty_file_ptr;
    struct nilfs_inode_info *gc_inode_ptr;
};

struct nilfs_segment_buffer;

struct nilfs_segsum_pointer {
    struct buffer_head     *bh;
    unsigned        offset; /* offset in bytes */
};

struct nilfs_sc_info {
    struct super_block     *sc_super;
    struct nilfs_root      *sc_root;

    unsigned long       sc_nblk_inc;

    struct list_head    sc_dirty_files;
    struct list_head    sc_gc_inodes;

    __u64              *sc_freesegs;
    size_t          sc_nfreesegs;

    struct nilfs_inode_info *sc_dsync_inode;
    loff_t          sc_dsync_start;
    loff_t          sc_dsync_end;

    /* Segment buffers */
    struct list_head    sc_segbufs;
    struct list_head    sc_write_logs;
    unsigned long       sc_segbuf_nblocks;
    struct nilfs_segment_buffer *sc_curseg;

    struct nilfs_cstage sc_stage;

    struct nilfs_segsum_pointer sc_finfo_ptr;
    struct nilfs_segsum_pointer sc_binfo_ptr;
    unsigned long       sc_blk_cnt;
    unsigned long       sc_datablk_cnt;
    unsigned long       sc_nblk_this_inc;
    time_t          sc_seg_ctime;
    __u64           sc_cno;
    unsigned long       sc_flags;

    spinlock_t      sc_state_lock;
    unsigned long       sc_state;
    unsigned long       sc_flush_request;

    wait_queue_head_t   sc_wait_request;
    wait_queue_head_t   sc_wait_daemon;
    wait_queue_head_t   sc_wait_task;

    __u32           sc_seq_request;
    __u32           sc_seq_accepted;
    __u32           sc_seq_done;

    int         sc_sync;
    unsigned long       sc_interval;
    unsigned long       sc_mjcp_freq;
    unsigned long       sc_lseg_stime;  /* in 1/HZ seconds */
    unsigned long       sc_watermark;

    struct timer_list   sc_timer;
    struct task_struct     *sc_task;
};

/* sc_flags */
enum {
    NILFS_SC_DIRTY,     /* One or more dirty meta-data blocks exist */
    NILFS_SC_UNCLOSED,  /* Logical segment is not closed */
    NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
    NILFS_SC_PRIOR_FLUSH,   /* Requesting immediate flush without making a
                   checkpoint */
    NILFS_SC_HAVE_DELTA,    /* Next checkpoint will have update of files
                   other than DAT, cpfile, sufile, or files
                   moved by GC */
};

/* sc_state */
#define NILFS_SEGCTOR_QUIT      0x0001  /* segctord is being destroyed */
#define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */

/*
 * Constant parameters
 */
#define NILFS_SC_CLEANUP_RETRY      3  /* Retry count of construction when
                      destroying segctord */

/*
 * Default values of timeout, in seconds.
 */
#define NILFS_SC_DEFAULT_TIMEOUT    5   /* Timeout value of dirty blocks.
                       It triggers construction of a
                       logical segment with a super root */
#define NILFS_SC_DEFAULT_SR_FREQ    30  /* Maximum frequency of super root
                       creation */

/*
 * The default threshold amount of data, in block counts.
 */
#define NILFS_SC_DEFAULT_WATERMARK  3600

/* super.c */
extern struct kmem_cache *nilfs_transaction_cachep;

/* segment.c */
extern void nilfs_relax_pressure_in_lock(struct super_block *);

extern int nilfs_construct_segment(struct super_block *);
extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
                     loff_t, loff_t);
extern void nilfs_flush_segment(struct super_block *, ino_t);
extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
                void **);

int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
void nilfs_detach_log_writer(struct super_block *sb);

/* recovery.c */
extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
                       struct buffer_head **, int);
extern int nilfs_search_super_root(struct the_nilfs *,
                   struct nilfs_recovery_info *);
int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
                  struct nilfs_recovery_info *ri);
extern void nilfs_dispose_segment_list(struct list_head *);

#endif /* _NILFS_SEGMENT_H */