linux/fs/nilfs2/segment.h
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   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * segment.h - NILFS Segment constructor prototypes and definitions
   4 *
   5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Written by Ryusuke Konishi.
   8 *
   9 */
  10#ifndef _NILFS_SEGMENT_H
  11#define _NILFS_SEGMENT_H
  12
  13#include <linux/types.h>
  14#include <linux/fs.h>
  15#include <linux/buffer_head.h>
  16#include <linux/workqueue.h>
  17#include "nilfs.h"
  18
  19struct nilfs_root;
  20
  21/**
  22 * struct nilfs_recovery_info - Recovery information
  23 * @ri_need_recovery: Recovery status
  24 * @ri_super_root: Block number of the last super root
  25 * @ri_ri_cno: Number of the last checkpoint
  26 * @ri_lsegs_start: Region for roll-forwarding (start block number)
  27 * @ri_lsegs_end: Region for roll-forwarding (end block number)
  28 * @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start
  29 * @ri_used_segments: List of segments to be mark active
  30 * @ri_pseg_start: Block number of the last partial segment
  31 * @ri_seq: Sequence number on the last partial segment
  32 * @ri_segnum: Segment number on the last partial segment
  33 * @ri_nextnum: Next segment number on the last partial segment
  34 */
  35struct nilfs_recovery_info {
  36        int                     ri_need_recovery;
  37        sector_t                ri_super_root;
  38        __u64                   ri_cno;
  39
  40        sector_t                ri_lsegs_start;
  41        sector_t                ri_lsegs_end;
  42        u64                     ri_lsegs_start_seq;
  43        struct list_head        ri_used_segments;
  44        sector_t                ri_pseg_start;
  45        u64                     ri_seq;
  46        __u64                   ri_segnum;
  47        __u64                   ri_nextnum;
  48};
  49
  50/* ri_need_recovery */
  51#define NILFS_RECOVERY_SR_UPDATED        1  /* The super root was updated */
  52#define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */
  53
  54/**
  55 * struct nilfs_cstage - Context of collection stage
  56 * @scnt: Stage count, must be accessed via wrappers:
  57 *        nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get()
  58 * @flags: State flags
  59 * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
  60 * @gc_inode_ptr: Pointer on the list of gc-inodes
  61 */
  62struct nilfs_cstage {
  63        int                     scnt;
  64        unsigned int            flags;
  65        struct nilfs_inode_info *dirty_file_ptr;
  66        struct nilfs_inode_info *gc_inode_ptr;
  67};
  68
  69struct nilfs_segment_buffer;
  70
  71struct nilfs_segsum_pointer {
  72        struct buffer_head     *bh;
  73        unsigned int            offset; /* offset in bytes */
  74};
  75
  76/**
  77 * struct nilfs_sc_info - Segment constructor information
  78 * @sc_super: Back pointer to super_block struct
  79 * @sc_root: root object of the current filesystem tree
  80 * @sc_nblk_inc: Block count of current generation
  81 * @sc_dirty_files: List of files to be written
  82 * @sc_gc_inodes: List of GC inodes having blocks to be written
  83 * @sc_iput_queue: list of inodes for which iput should be done
  84 * @sc_iput_work: work struct to defer iput call
  85 * @sc_freesegs: array of segment numbers to be freed
  86 * @sc_nfreesegs: number of segments on @sc_freesegs
  87 * @sc_dsync_inode: inode whose data pages are written for a sync operation
  88 * @sc_dsync_start: start byte offset of data pages
  89 * @sc_dsync_end: end byte offset of data pages (inclusive)
  90 * @sc_segbufs: List of segment buffers
  91 * @sc_write_logs: List of segment buffers to hold logs under writing
  92 * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
  93 * @sc_curseg: Current segment buffer
  94 * @sc_stage: Collection stage
  95 * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
  96 * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
  97 * @sc_blk_cnt: Block count of a file
  98 * @sc_datablk_cnt: Data block count of a file
  99 * @sc_nblk_this_inc: Number of blocks included in the current logical segment
 100 * @sc_seg_ctime: Creation time
 101 * @sc_cno: checkpoint number of current log
 102 * @sc_flags: Internal flags
 103 * @sc_state_lock: spinlock for sc_state and so on
 104 * @sc_state: Segctord state flags
 105 * @sc_flush_request: inode bitmap of metadata files to be flushed
 106 * @sc_wait_request: Client request queue
 107 * @sc_wait_daemon: Daemon wait queue
 108 * @sc_wait_task: Start/end wait queue to control segctord task
 109 * @sc_seq_request: Request counter
 110 * @sc_seq_accept: Accepted request count
 111 * @sc_seq_done: Completion counter
 112 * @sc_sync: Request of explicit sync operation
 113 * @sc_interval: Timeout value of background construction
 114 * @sc_mjcp_freq: Frequency of creating checkpoints
 115 * @sc_lseg_stime: Start time of the latest logical segment
 116 * @sc_watermark: Watermark for the number of dirty buffers
 117 * @sc_timer: Timer for segctord
 118 * @sc_task: current thread of segctord
 119 */
 120struct nilfs_sc_info {
 121        struct super_block     *sc_super;
 122        struct nilfs_root      *sc_root;
 123
 124        unsigned long           sc_nblk_inc;
 125
 126        struct list_head        sc_dirty_files;
 127        struct list_head        sc_gc_inodes;
 128        struct list_head        sc_iput_queue;
 129        struct work_struct      sc_iput_work;
 130
 131        __u64                  *sc_freesegs;
 132        size_t                  sc_nfreesegs;
 133
 134        struct nilfs_inode_info *sc_dsync_inode;
 135        loff_t                  sc_dsync_start;
 136        loff_t                  sc_dsync_end;
 137
 138        /* Segment buffers */
 139        struct list_head        sc_segbufs;
 140        struct list_head        sc_write_logs;
 141        unsigned long           sc_segbuf_nblocks;
 142        struct nilfs_segment_buffer *sc_curseg;
 143
 144        struct nilfs_cstage     sc_stage;
 145
 146        struct nilfs_segsum_pointer sc_finfo_ptr;
 147        struct nilfs_segsum_pointer sc_binfo_ptr;
 148        unsigned long           sc_blk_cnt;
 149        unsigned long           sc_datablk_cnt;
 150        unsigned long           sc_nblk_this_inc;
 151        time64_t                sc_seg_ctime;
 152        __u64                   sc_cno;
 153        unsigned long           sc_flags;
 154
 155        spinlock_t              sc_state_lock;
 156        unsigned long           sc_state;
 157        unsigned long           sc_flush_request;
 158
 159        wait_queue_head_t       sc_wait_request;
 160        wait_queue_head_t       sc_wait_daemon;
 161        wait_queue_head_t       sc_wait_task;
 162
 163        __u32                   sc_seq_request;
 164        __u32                   sc_seq_accepted;
 165        __u32                   sc_seq_done;
 166
 167        int                     sc_sync;
 168        unsigned long           sc_interval;
 169        unsigned long           sc_mjcp_freq;
 170        unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 171        unsigned long           sc_watermark;
 172
 173        struct timer_list       sc_timer;
 174        struct task_struct     *sc_timer_task;
 175        struct task_struct     *sc_task;
 176};
 177
 178/* sc_flags */
 179enum {
 180        NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 181        NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 182        NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 183        NILFS_SC_PRIOR_FLUSH,   /*
 184                                 * Requesting immediate flush without making a
 185                                 * checkpoint
 186                                 */
 187        NILFS_SC_HAVE_DELTA,    /*
 188                                 * Next checkpoint will have update of files
 189                                 * other than DAT, cpfile, sufile, or files
 190                                 * moved by GC.
 191                                 */
 192};
 193
 194/* sc_state */
 195#define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 196#define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 197
 198/*
 199 * Constant parameters
 200 */
 201#define NILFS_SC_CLEANUP_RETRY      3  /*
 202                                        * Retry count of construction when
 203                                        * destroying segctord
 204                                        */
 205
 206/*
 207 * Default values of timeout, in seconds.
 208 */
 209#define NILFS_SC_DEFAULT_TIMEOUT    5   /*
 210                                         * Timeout value of dirty blocks.
 211                                         * It triggers construction of a
 212                                         * logical segment with a super root.
 213                                         */
 214#define NILFS_SC_DEFAULT_SR_FREQ    30  /*
 215                                         * Maximum frequency of super root
 216                                         * creation
 217                                         */
 218
 219/*
 220 * The default threshold amount of data, in block counts.
 221 */
 222#define NILFS_SC_DEFAULT_WATERMARK  3600
 223
 224/* super.c */
 225extern struct kmem_cache *nilfs_transaction_cachep;
 226
 227/* segment.c */
 228extern void nilfs_relax_pressure_in_lock(struct super_block *);
 229
 230extern int nilfs_construct_segment(struct super_block *);
 231extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 232                                         loff_t, loff_t);
 233extern void nilfs_flush_segment(struct super_block *, ino_t);
 234extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 235                                void **);
 236
 237int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 238void nilfs_detach_log_writer(struct super_block *sb);
 239
 240/* recovery.c */
 241extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 242                                       struct buffer_head **, int);
 243extern int nilfs_search_super_root(struct the_nilfs *,
 244                                   struct nilfs_recovery_info *);
 245int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 246                              struct nilfs_recovery_info *ri);
 247extern void nilfs_dispose_segment_list(struct list_head *);
 248
 249#endif /* _NILFS_SEGMENT_H */
 250