fs/nilfs2/segment.h

   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  * Written by Ryusuke Konishi.
  17  *
  18  */
  19 #ifndef _NILFS_SEGMENT_H
  20 #define _NILFS_SEGMENT_H
  21
  22 #include <linux/types.h>
  23 #include <linux/fs.h>
  24 #include <linux/buffer_head.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/nilfs2_fs.h>
  27 #include "nilfs.h"
  28
  29 struct nilfs_root;
  30
  31 /**
  32  * struct nilfs_recovery_info - Recovery information
  33  * @ri_need_recovery: Recovery status
  34  * @ri_super_root: Block number of the last super root
  35  * @ri_ri_cno: Number of the last checkpoint
  36  * @ri_lsegs_start: Region for roll-forwarding (start block number)
  37  * @ri_lsegs_end: Region for roll-forwarding (end block number)
  38  * @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start
  39  * @ri_used_segments: List of segments to be mark active
  40  * @ri_pseg_start: Block number of the last partial segment
  41  * @ri_seq: Sequence number on the last partial segment
  42  * @ri_segnum: Segment number on the last partial segment
  43  * @ri_nextnum: Next segment number on the last partial segment
  44  */
  45 struct nilfs_recovery_info {
  46         int                     ri_need_recovery;
  47         sector_t                ri_super_root;
  48         __u64                   ri_cno;
  49
  50         sector_t                ri_lsegs_start;
  51         sector_t                ri_lsegs_end;
  52         u64                     ri_lsegs_start_seq;
  53         struct list_head        ri_used_segments;
  54         sector_t                ri_pseg_start;
  55         u64                     ri_seq;
  56         __u64                   ri_segnum;
  57         __u64                   ri_nextnum;
  58 };
  59
  60 /* ri_need_recovery */
  61 #define NILFS_RECOVERY_SR_UPDATED        1  /* The super root was updated */
  62 #define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */
  63
  64 /**
  65  * struct nilfs_cstage - Context of collection stage
  66  * @scnt: Stage count, must be accessed via wrappers:
  67  *        nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get()
  68  * @flags: State flags
  69  * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
  70  * @gc_inode_ptr: Pointer on the list of gc-inodes
  71  */
  72 struct nilfs_cstage {
  73         int                     scnt;
  74         unsigned int            flags;
  75         struct nilfs_inode_info *dirty_file_ptr;
  76         struct nilfs_inode_info *gc_inode_ptr;
  77 };
  78
  79 struct nilfs_segment_buffer;
  80
  81 struct nilfs_segsum_pointer {
  82         struct buffer_head     *bh;
  83         unsigned int            offset; /* offset in bytes */
  84 };
  85
  86 /**
  87  * struct nilfs_sc_info - Segment constructor information
  88  * @sc_super: Back pointer to super_block struct
  89  * @sc_root: root object of the current filesystem tree
  90  * @sc_nblk_inc: Block count of current generation
  91  * @sc_dirty_files: List of files to be written
  92  * @sc_gc_inodes: List of GC inodes having blocks to be written
  93  * @sc_iput_queue: list of inodes for which iput should be done
  94  * @sc_iput_work: work struct to defer iput call
  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  */
 130 struct 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         struct list_head        sc_iput_queue;
 139         struct work_struct      sc_iput_work;
 140
 141         __u64                  *sc_freesegs;
 142         size_t                  sc_nfreesegs;
 143
 144         struct nilfs_inode_info *sc_dsync_inode;
 145         loff_t                  sc_dsync_start;
 146         loff_t                  sc_dsync_end;
 147
 148         /* Segment buffers */
 149         struct list_head        sc_segbufs;
 150         struct list_head        sc_write_logs;
 151         unsigned long           sc_segbuf_nblocks;
 152         struct nilfs_segment_buffer *sc_curseg;
 153
 154         struct nilfs_cstage     sc_stage;
 155
 156         struct nilfs_segsum_pointer sc_finfo_ptr;
 157         struct nilfs_segsum_pointer sc_binfo_ptr;
 158         unsigned long           sc_blk_cnt;
 159         unsigned long           sc_datablk_cnt;
 160         unsigned long           sc_nblk_this_inc;
 161         time_t                  sc_seg_ctime;
 162         __u64                   sc_cno;
 163         unsigned long           sc_flags;
 164
 165         spinlock_t              sc_state_lock;
 166         unsigned long           sc_state;
 167         unsigned long           sc_flush_request;
 168
 169         wait_queue_head_t       sc_wait_request;
 170         wait_queue_head_t       sc_wait_daemon;
 171         wait_queue_head_t       sc_wait_task;
 172
 173         __u32                   sc_seq_request;
 174         __u32                   sc_seq_accepted;
 175         __u32                   sc_seq_done;
 176
 177         int                     sc_sync;
 178         unsigned long           sc_interval;
 179         unsigned long           sc_mjcp_freq;
 180         unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 181         unsigned long           sc_watermark;
 182
 183         struct timer_list       sc_timer;
 184         struct task_struct     *sc_task;
 185 };
 186
 187 /* sc_flags */
 188 enum {
 189         NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 190         NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 191         NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 192         NILFS_SC_PRIOR_FLUSH,   /*
 193                                  * Requesting immediate flush without making a
 194                                  * checkpoint
 195                                  */
 196         NILFS_SC_HAVE_DELTA,    /*
 197                                  * Next checkpoint will have update of files
 198                                  * other than DAT, cpfile, sufile, or files
 199                                  * moved by GC.
 200                                  */
 201 };
 202
 203 /* sc_state */
 204 #define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 205 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 206
 207 /*
 208  * Constant parameters
 209  */
 210 #define NILFS_SC_CLEANUP_RETRY      3  /*
 211                                         * Retry count of construction when
 212                                         * destroying segctord
 213                                         */
 214
 215 /*
 216  * Default values of timeout, in seconds.
 217  */
 218 #define NILFS_SC_DEFAULT_TIMEOUT    5   /*
 219                                          * Timeout value of dirty blocks.
 220                                          * It triggers construction of a
 221                                          * logical segment with a super root.
 222                                          */
 223 #define NILFS_SC_DEFAULT_SR_FREQ    30  /*
 224                                          * Maximum frequency of super root
 225                                          * creation
 226                                          */
 227
 228 /*
 229  * The default threshold amount of data, in block counts.
 230  */
 231 #define NILFS_SC_DEFAULT_WATERMARK  3600
 232
 233 /* super.c */
 234 extern struct kmem_cache *nilfs_transaction_cachep;
 235
 236 /* segment.c */
 237 extern void nilfs_relax_pressure_in_lock(struct super_block *);
 238
 239 extern int nilfs_construct_segment(struct super_block *);
 240 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 241                                          loff_t, loff_t);
 242 extern void nilfs_flush_segment(struct super_block *, ino_t);
 243 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 244                                 void **);
 245
 246 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 247 void nilfs_detach_log_writer(struct super_block *sb);
 248
 249 /* recovery.c */
 250 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 251                                        struct buffer_head **, int);
 252 extern int nilfs_search_super_root(struct the_nilfs *,
 253                                    struct nilfs_recovery_info *);
 254 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 255                               struct nilfs_recovery_info *ri);
 256 extern void nilfs_dispose_segment_list(struct list_head *);
 257
 258 #endif /* _NILFS_SEGMENT_H */