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