/*
* 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.
*
* Written by Ryusuke Konishi.
*
*/
#ifndef _NILFS_SEGMENT_H
#define _NILFS_SEGMENT_H
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/workqueue.h>
#include "nilfs.h"
struct nilfs_root;
/**
* struct nilfs_recovery_info - Recovery information
* @ri_need_recovery: Recovery status
* @ri_super_root: Block number of the last super root
* @ri_ri_cno: Number of the last checkpoint
* @ri_lsegs_start: Region for roll-forwarding (start block number)
* @ri_lsegs_end: Region for roll-forwarding (end block number)
* @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start
* @ri_used_segments: List of segments to be mark active
* @ri_pseg_start: Block number of the last partial segment
* @ri_seq: Sequence number on the last partial segment
* @ri_segnum: Segment number on the last partial segment
* @ri_nextnum: Next segment number on the last partial segment
*/
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 - Context of collection stage
* @scnt: Stage count, must be accessed via wrappers:
* nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get()
* @flags: State flags
* @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
* @gc_inode_ptr: Pointer on the list of gc-inodes
*/
struct nilfs_cstage {
int scnt;
unsigned int 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 int offset; /* offset in bytes */
};
/**
* struct nilfs_sc_info - Segment constructor information
* @sc_super: Back pointer to super_block struct
* @sc_root: root object of the current filesystem tree
* @sc_nblk_inc: Block count of current generation
* @sc_dirty_files: List of files to be written
* @sc_gc_inodes: List of GC inodes having blocks to be written
* @sc_iput_queue: list of inodes for which iput should be done
* @sc_iput_work: work struct to defer iput call
* @sc_freesegs: array of segment numbers to be freed
* @sc_nfreesegs: number of segments on @sc_freesegs
* @sc_dsync_inode: inode whose data pages are written for a sync operation
* @sc_dsync_start: start byte offset of data pages
* @sc_dsync_end: end byte offset of data pages (inclusive)
* @sc_segbufs: List of segment buffers
* @sc_write_logs: List of segment buffers to hold logs under writing
* @sc_segbuf_nblocks: Number of available blocks in segment buffers.
* @sc_curseg: Current segment buffer
* @sc_stage: Collection stage
* @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
* @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
* @sc_blk_cnt: Block count of a file
* @sc_datablk_cnt: Data block count of a file
* @sc_nblk_this_inc: Number of blocks included in the current logical segment
* @sc_seg_ctime: Creation time
* @sc_cno: checkpoint number of current log
* @sc_flags: Internal flags
* @sc_state_lock: spinlock for sc_state and so on
* @sc_state: Segctord state flags
* @sc_flush_request: inode bitmap of metadata files to be flushed
* @sc_wait_request: Client request queue
* @sc_wait_daemon: Daemon wait queue
* @sc_wait_task: Start/end wait queue to control segctord task
* @sc_seq_request: Request counter
* @sc_seq_accept: Accepted request count
* @sc_seq_done: Completion counter
* @sc_sync: Request of explicit sync operation
* @sc_interval: Timeout value of background construction
* @sc_mjcp_freq: Frequency of creating checkpoints
* @sc_lseg_stime: Start time of the latest logical segment
* @sc_watermark: Watermark for the number of dirty buffers
* @sc_timer: Timer for segctord
* @sc_task: current thread of segctord
*/
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;
struct list_head sc_iput_queue;
struct work_struct sc_iput_work;
__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 */