linux/fs/nilfs2/segment.h
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   1/*
   2 * segment.h - NILFS Segment constructor prototypes and definitions
   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#ifndef _NILFS_SEGMENT_H
  24#define _NILFS_SEGMENT_H
  25
  26#include <linux/types.h>
  27#include <linux/fs.h>
  28#include <linux/buffer_head.h>
  29#include <linux/nilfs2_fs.h>
  30#include "nilfs.h"
  31
  32struct nilfs_root;
  33
  34/**
  35 * struct nilfs_recovery_info - Recovery information
  36 * @ri_need_recovery: Recovery status
  37 * @ri_super_root: Block number of the last super root
  38 * @ri_ri_cno: Number of the last checkpoint
  39 * @ri_lsegs_start: Region for roll-forwarding (start block number)
  40 * @ri_lsegs_end: Region for roll-forwarding (end block number)
  41 * @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start
  42 * @ri_used_segments: List of segments to be mark active
  43 * @ri_pseg_start: Block number of the last partial segment
  44 * @ri_seq: Sequence number on the last partial segment
  45 * @ri_segnum: Segment number on the last partial segment
  46 * @ri_nextnum: Next segment number on the last partial segment
  47 */
  48struct nilfs_recovery_info {
  49        int                     ri_need_recovery;
  50        sector_t                ri_super_root;
  51        __u64                   ri_cno;
  52
  53        sector_t                ri_lsegs_start;
  54        sector_t                ri_lsegs_end;
  55        u64                     ri_lsegs_start_seq;
  56        struct list_head        ri_used_segments;
  57        sector_t                ri_pseg_start;
  58        u64                     ri_seq;
  59        __u64                   ri_segnum;
  60        __u64                   ri_nextnum;
  61};
  62
  63/* ri_need_recovery */
  64#define NILFS_RECOVERY_SR_UPDATED        1  /* The super root was updated */
  65#define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */
  66
  67/**
  68 * struct nilfs_cstage - Context of collection stage
  69 * @scnt: Stage count
  70 * @flags: State flags
  71 * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
  72 * @gc_inode_ptr: Pointer on the list of gc-inodes
  73 */
  74struct nilfs_cstage {
  75        int                     scnt;
  76        unsigned                flags;
  77        struct nilfs_inode_info *dirty_file_ptr;
  78        struct nilfs_inode_info *gc_inode_ptr;
  79};
  80
  81struct nilfs_segment_buffer;
  82
  83struct nilfs_segsum_pointer {
  84        struct buffer_head     *bh;
  85        unsigned                offset; /* offset in bytes */
  86};
  87
  88/**
  89 * struct nilfs_sc_info - Segment constructor information
  90 * @sc_super: Back pointer to super_block struct
  91 * @sc_root: root object of the current filesystem tree
  92 * @sc_nblk_inc: Block count of current generation
  93 * @sc_dirty_files: List of files to be written
  94 * @sc_gc_inodes: List of GC inodes having blocks to be written
  95 * @sc_freesegs: array of segment numbers to be freed
  96 * @sc_nfreesegs: number of segments on @sc_freesegs
  97 * @sc_dsync_inode: inode whose data pages are written for a sync operation
  98 * @sc_dsync_start: start byte offset of data pages
  99 * @sc_dsync_end: end byte offset of data pages (inclusive)
 100 * @sc_segbufs: List of segment buffers
 101 * @sc_write_logs: List of segment buffers to hold logs under writing
 102 * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
 103 * @sc_curseg: Current segment buffer
 104 * @sc_stage: Collection stage
 105 * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
 106 * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
 107 * @sc_blk_cnt: Block count of a file
 108 * @sc_datablk_cnt: Data block count of a file
 109 * @sc_nblk_this_inc: Number of blocks included in the current logical segment
 110 * @sc_seg_ctime: Creation time
 111 * @sc_cno: checkpoint number of current log
 112 * @sc_flags: Internal flags
 113 * @sc_state_lock: spinlock for sc_state and so on
 114 * @sc_state: Segctord state flags
 115 * @sc_flush_request: inode bitmap of metadata files to be flushed
 116 * @sc_wait_request: Client request queue
 117 * @sc_wait_daemon: Daemon wait queue
 118 * @sc_wait_task: Start/end wait queue to control segctord task
 119 * @sc_seq_request: Request counter
 120 * @sc_seq_accept: Accepted request count
 121 * @sc_seq_done: Completion counter
 122 * @sc_sync: Request of explicit sync operation
 123 * @sc_interval: Timeout value of background construction
 124 * @sc_mjcp_freq: Frequency of creating checkpoints
 125 * @sc_lseg_stime: Start time of the latest logical segment
 126 * @sc_watermark: Watermark for the number of dirty buffers
 127 * @sc_timer: Timer for segctord
 128 * @sc_task: current thread of segctord
 129 */
 130struct nilfs_sc_info {
 131        struct super_block     *sc_super;
 132        struct nilfs_root      *sc_root;
 133
 134        unsigned long           sc_nblk_inc;
 135
 136        struct list_head        sc_dirty_files;
 137        struct list_head        sc_gc_inodes;
 138
 139        __u64                  *sc_freesegs;
 140        size_t                  sc_nfreesegs;
 141
 142        struct nilfs_inode_info *sc_dsync_inode;
 143        loff_t                  sc_dsync_start;
 144        loff_t                  sc_dsync_end;
 145
 146        /* Segment buffers */
 147        struct list_head        sc_segbufs;
 148        struct list_head        sc_write_logs;
 149        unsigned long           sc_segbuf_nblocks;
 150        struct nilfs_segment_buffer *sc_curseg;
 151
 152        struct nilfs_cstage     sc_stage;
 153
 154        struct nilfs_segsum_pointer sc_finfo_ptr;
 155        struct nilfs_segsum_pointer sc_binfo_ptr;
 156        unsigned long           sc_blk_cnt;
 157        unsigned long           sc_datablk_cnt;
 158        unsigned long           sc_nblk_this_inc;
 159        time_t                  sc_seg_ctime;
 160        __u64                   sc_cno;
 161        unsigned long           sc_flags;
 162
 163        spinlock_t              sc_state_lock;
 164        unsigned long           sc_state;
 165        unsigned long           sc_flush_request;
 166
 167        wait_queue_head_t       sc_wait_request;
 168        wait_queue_head_t       sc_wait_daemon;
 169        wait_queue_head_t       sc_wait_task;
 170
 171        __u32                   sc_seq_request;
 172        __u32                   sc_seq_accepted;
 173        __u32                   sc_seq_done;
 174
 175        int                     sc_sync;
 176        unsigned long           sc_interval;
 177        unsigned long           sc_mjcp_freq;
 178        unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 179        unsigned long           sc_watermark;
 180
 181        struct timer_list       sc_timer;
 182        struct task_struct     *sc_task;
 183};
 184
 185/* sc_flags */
 186enum {
 187        NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 188        NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 189        NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 190        NILFS_SC_PRIOR_FLUSH,   /* Requesting immediate flush without making a
 191                                   checkpoint */
 192        NILFS_SC_HAVE_DELTA,    /* Next checkpoint will have update of files
 193                                   other than DAT, cpfile, sufile, or files
 194                                   moved by GC */
 195};
 196
 197/* sc_state */
 198#define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 199#define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 200
 201/*
 202 * Constant parameters
 203 */
 204#define NILFS_SC_CLEANUP_RETRY      3  /* Retry count of construction when
 205                                          destroying segctord */
 206
 207/*
 208 * Default values of timeout, in seconds.
 209 */
 210#define NILFS_SC_DEFAULT_TIMEOUT    5   /* Timeout value of dirty blocks.
 211                                           It triggers construction of a
 212                                           logical segment with a super root */
 213#define NILFS_SC_DEFAULT_SR_FREQ    30  /* Maximum frequency of super root
 214                                           creation */
 215
 216/*
 217 * The default threshold amount of data, in block counts.
 218 */
 219#define NILFS_SC_DEFAULT_WATERMARK  3600
 220
 221/* super.c */
 222extern struct kmem_cache *nilfs_transaction_cachep;
 223
 224/* segment.c */
 225extern void nilfs_relax_pressure_in_lock(struct super_block *);
 226
 227extern int nilfs_construct_segment(struct super_block *);
 228extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 229                                         loff_t, loff_t);
 230extern void nilfs_flush_segment(struct super_block *, ino_t);
 231extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 232                                void **);
 233
 234int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 235void nilfs_detach_log_writer(struct super_block *sb);
 236
 237/* recovery.c */
 238extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 239                                       struct buffer_head **, int);
 240extern int nilfs_search_super_root(struct the_nilfs *,
 241                                   struct nilfs_recovery_info *);
 242int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 243                              struct nilfs_recovery_info *ri);
 244extern void nilfs_dispose_segment_list(struct list_head *);
 245
 246#endif /* _NILFS_SEGMENT_H */
 247
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