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 "nilfs.h"
  27
  28 struct nilfs_root;
  29
  30 /**
  31  * struct nilfs_recovery_info - Recovery information
  32  * @ri_need_recovery: Recovery status
  33  * @ri_super_root: Block number of the last super root
  34  * @ri_ri_cno: Number of the last checkpoint
  35  * @ri_lsegs_start: Region for roll-forwarding (start block number)
  36  * @ri_lsegs_end: Region for roll-forwarding (end block number)
  37  * @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start
  38  * @ri_used_segments: List of segments to be mark active
  39  * @ri_pseg_start: Block number of the last partial segment
  40  * @ri_seq: Sequence number on the last partial segment
  41  * @ri_segnum: Segment number on the last partial segment
  42  * @ri_nextnum: Next segment number on the last partial segment
  43  */
  44 struct nilfs_recovery_info {
  45         int                     ri_need_recovery;
  46         sector_t                ri_super_root;
  47         __u64                   ri_cno;
  48
  49         sector_t                ri_lsegs_start;
  50         sector_t                ri_lsegs_end;
  51         u64                     ri_lsegs_start_seq;
  52         struct list_head        ri_used_segments;
  53         sector_t                ri_pseg_start;
  54         u64                     ri_seq;
  55         __u64                   ri_segnum;
  56         __u64                   ri_nextnum;
  57 };
  58
  59 /* ri_need_recovery */
  60 #define NILFS_RECOVERY_SR_UPDATED        1  /* The super root was updated */
  61 #define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */
  62
  63 /**
  64  * struct nilfs_cstage - Context of collection stage
  65  * @scnt: Stage count, must be accessed via wrappers:
  66  *        nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get()
  67  * @flags: State flags
  68  * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
  69  * @gc_inode_ptr: Pointer on the list of gc-inodes
  70  */
  71 struct nilfs_cstage {
  72         int                     scnt;
  73         unsigned int            flags;
  74         struct nilfs_inode_info *dirty_file_ptr;
  75         struct nilfs_inode_info *gc_inode_ptr;
  76 };
  77
  78 struct nilfs_segment_buffer;
  79
  80 struct nilfs_segsum_pointer {
  81         struct buffer_head     *bh;
  82         unsigned int            offset; /* offset in bytes */
  83 };
  84
  85 /**
  86  * struct nilfs_sc_info - Segment constructor information
  87  * @sc_super: Back pointer to super_block struct
  88  * @sc_root: root object of the current filesystem tree
  89  * @sc_nblk_inc: Block count of current generation
  90  * @sc_dirty_files: List of files to be written
  91  * @sc_gc_inodes: List of GC inodes having blocks to be written
  92  * @sc_iput_queue: list of inodes for which iput should be done
  93  * @sc_iput_work: work struct to defer iput call
  94  * @sc_freesegs: array of segment numbers to be freed
  95  * @sc_nfreesegs: number of segments on @sc_freesegs
  96  * @sc_dsync_inode: inode whose data pages are written for a sync operation
  97  * @sc_dsync_start: start byte offset of data pages
  98  * @sc_dsync_end: end byte offset of data pages (inclusive)
  99  * @sc_segbufs: List of segment buffers
 100  * @sc_write_logs: List of segment buffers to hold logs under writing
 101  * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
 102  * @sc_curseg: Current segment buffer
 103  * @sc_stage: Collection stage
 104  * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
 105  * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
 106  * @sc_blk_cnt: Block count of a file
 107  * @sc_datablk_cnt: Data block count of a file
 108  * @sc_nblk_this_inc: Number of blocks included in the current logical segment
 109  * @sc_seg_ctime: Creation time
 110  * @sc_cno: checkpoint number of current log
 111  * @sc_flags: Internal flags
 112  * @sc_state_lock: spinlock for sc_state and so on
 113  * @sc_state: Segctord state flags
 114  * @sc_flush_request: inode bitmap of metadata files to be flushed
 115  * @sc_wait_request: Client request queue
 116  * @sc_wait_daemon: Daemon wait queue
 117  * @sc_wait_task: Start/end wait queue to control segctord task
 118  * @sc_seq_request: Request counter
 119  * @sc_seq_accept: Accepted request count
 120  * @sc_seq_done: Completion counter
 121  * @sc_sync: Request of explicit sync operation
 122  * @sc_interval: Timeout value of background construction
 123  * @sc_mjcp_freq: Frequency of creating checkpoints
 124  * @sc_lseg_stime: Start time of the latest logical segment
 125  * @sc_watermark: Watermark for the number of dirty buffers
 126  * @sc_timer: Timer for segctord
 127  * @sc_task: current thread of segctord
 128  */
 129 struct nilfs_sc_info {
 130         struct super_block     *sc_super;
 131         struct nilfs_root      *sc_root;
 132
 133         unsigned long           sc_nblk_inc;
 134
 135         struct list_head        sc_dirty_files;
 136         struct list_head        sc_gc_inodes;
 137         struct list_head        sc_iput_queue;
 138         struct work_struct      sc_iput_work;
 139
 140         __u64                  *sc_freesegs;
 141         size_t                  sc_nfreesegs;
 142
 143         struct nilfs_inode_info *sc_dsync_inode;
 144         loff_t                  sc_dsync_start;
 145         loff_t                  sc_dsync_end;
 146
 147         /* Segment buffers */
 148         struct list_head        sc_segbufs;
 149         struct list_head        sc_write_logs;
 150         unsigned long           sc_segbuf_nblocks;
 151         struct nilfs_segment_buffer *sc_curseg;
 152
 153         struct nilfs_cstage     sc_stage;
 154
 155         struct nilfs_segsum_pointer sc_finfo_ptr;
 156         struct nilfs_segsum_pointer sc_binfo_ptr;
 157         unsigned long           sc_blk_cnt;
 158         unsigned long           sc_datablk_cnt;
 159         unsigned long           sc_nblk_this_inc;
 160         time_t                  sc_seg_ctime;
 161         __u64                   sc_cno;
 162         unsigned long           sc_flags;
 163
 164         spinlock_t              sc_state_lock;
 165         unsigned long           sc_state;
 166         unsigned long           sc_flush_request;
 167
 168         wait_queue_head_t       sc_wait_request;
 169         wait_queue_head_t       sc_wait_daemon;
 170         wait_queue_head_t       sc_wait_task;
 171
 172         __u32                   sc_seq_request;
 173         __u32                   sc_seq_accepted;
 174         __u32                   sc_seq_done;
 175
 176         int                     sc_sync;
 177         unsigned long           sc_interval;
 178         unsigned long           sc_mjcp_freq;
 179         unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 180         unsigned long           sc_watermark;
 181
 182         struct timer_list       sc_timer;
 183         struct task_struct     *sc_task;
 184 };
 185
 186 /* sc_flags */
 187 enum {
 188         NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 189         NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 190         NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 191         NILFS_SC_PRIOR_FLUSH,   /*
 192                                  * Requesting immediate flush without making a
 193                                  * checkpoint
 194                                  */
 195         NILFS_SC_HAVE_DELTA,    /*
 196                                  * Next checkpoint will have update of files
 197                                  * other than DAT, cpfile, sufile, or files
 198                                  * moved by GC.
 199                                  */
 200 };
 201
 202 /* sc_state */
 203 #define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 204 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 205
 206 /*
 207  * Constant parameters
 208  */
 209 #define NILFS_SC_CLEANUP_RETRY      3  /*
 210                                         * Retry count of construction when
 211                                         * destroying segctord
 212                                         */
 213
 214 /*
 215  * Default values of timeout, in seconds.
 216  */
 217 #define NILFS_SC_DEFAULT_TIMEOUT    5   /*
 218                                          * Timeout value of dirty blocks.
 219                                          * It triggers construction of a
 220                                          * logical segment with a super root.
 221                                          */
 222 #define NILFS_SC_DEFAULT_SR_FREQ    30  /*
 223                                          * Maximum frequency of super root
 224                                          * creation
 225                                          */
 226
 227 /*
 228  * The default threshold amount of data, in block counts.
 229  */
 230 #define NILFS_SC_DEFAULT_WATERMARK  3600
 231
 232 /* super.c */
 233 extern struct kmem_cache *nilfs_transaction_cachep;
 234
 235 /* segment.c */
 236 extern void nilfs_relax_pressure_in_lock(struct super_block *);
 237
 238 extern int nilfs_construct_segment(struct super_block *);
 239 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 240                                          loff_t, loff_t);
 241 extern void nilfs_flush_segment(struct super_block *, ino_t);
 242 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 243                                 void **);
 244
 245 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 246 void nilfs_detach_log_writer(struct super_block *sb);
 247
 248 /* recovery.c */
 249 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 250                                        struct buffer_head **, int);
 251 extern int nilfs_search_super_root(struct the_nilfs *,
 252                                    struct nilfs_recovery_info *);
 253 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 254                               struct nilfs_recovery_info *ri);
 255 extern void nilfs_dispose_segment_list(struct list_head *);
 256
 257 #endif /* _NILFS_SEGMENT_H */