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 "nilfs.h"
  31
  32 struct 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  */
  48 struct 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  */
  74 struct 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
  81 struct nilfs_segment_buffer;
  82
  83 struct 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_copied_buffers: List of copied buffers (buffer heads) to freeze data
  96  * @sc_freesegs: array of segment numbers to be freed
  97  * @sc_nfreesegs: number of segments on @sc_freesegs
  98  * @sc_dsync_inode: inode whose data pages are written for a sync operation
  99  * @sc_dsync_start: start byte offset of data pages
 100  * @sc_dsync_end: end byte offset of data pages (inclusive)
 101  * @sc_segbufs: List of segment buffers
 102  * @sc_write_logs: List of segment buffers to hold logs under writing
 103  * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
 104  * @sc_curseg: Current segment buffer
 105  * @sc_stage: Collection stage
 106  * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
 107  * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
 108  * @sc_blk_cnt: Block count of a file
 109  * @sc_datablk_cnt: Data block count of a file
 110  * @sc_nblk_this_inc: Number of blocks included in the current logical segment
 111  * @sc_seg_ctime: Creation time
 112  * @sc_cno: checkpoint number of current log
 113  * @sc_flags: Internal flags
 114  * @sc_state_lock: spinlock for sc_state and so on
 115  * @sc_state: Segctord state flags
 116  * @sc_flush_request: inode bitmap of metadata files to be flushed
 117  * @sc_wait_request: Client request queue
 118  * @sc_wait_daemon: Daemon wait queue
 119  * @sc_wait_task: Start/end wait queue to control segctord task
 120  * @sc_seq_request: Request counter
 121  * @sc_seq_accept: Accepted request count
 122  * @sc_seq_done: Completion counter
 123  * @sc_sync: Request of explicit sync operation
 124  * @sc_interval: Timeout value of background construction
 125  * @sc_mjcp_freq: Frequency of creating checkpoints
 126  * @sc_lseg_stime: Start time of the latest logical segment
 127  * @sc_watermark: Watermark for the number of dirty buffers
 128  * @sc_timer: Timer for segctord
 129  * @sc_task: current thread of segctord
 130  */
 131 struct nilfs_sc_info {
 132         struct super_block     *sc_super;
 133         struct nilfs_root      *sc_root;
 134
 135         unsigned long           sc_nblk_inc;
 136
 137         struct list_head        sc_dirty_files;
 138         struct list_head        sc_gc_inodes;
 139         struct list_head        sc_copied_buffers;
 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,   /* Requesting immediate flush without making a
 193                                    checkpoint */
 194         NILFS_SC_HAVE_DELTA,    /* Next checkpoint will have update of files
 195                                    other than DAT, cpfile, sufile, or files
 196                                    moved by GC */
 197 };
 198
 199 /* sc_state */
 200 #define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 201 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 202
 203 /*
 204  * Constant parameters
 205  */
 206 #define NILFS_SC_CLEANUP_RETRY      3  /* Retry count of construction when
 207                                           destroying segctord */
 208
 209 /*
 210  * Default values of timeout, in seconds.
 211  */
 212 #define NILFS_SC_DEFAULT_TIMEOUT    5   /* Timeout value of dirty blocks.
 213                                            It triggers construction of a
 214                                            logical segment with a super root */
 215 #define NILFS_SC_DEFAULT_SR_FREQ    30  /* Maximum frequency of super root
 216                                            creation */
 217
 218 /*
 219  * The default threshold amount of data, in block counts.
 220  */
 221 #define NILFS_SC_DEFAULT_WATERMARK  3600
 222
 223 /* super.c */
 224 extern struct kmem_cache *nilfs_transaction_cachep;
 225
 226 /* segment.c */
 227 extern void nilfs_relax_pressure_in_lock(struct super_block *);
 228
 229 extern int nilfs_construct_segment(struct super_block *);
 230 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 231                                          loff_t, loff_t);
 232 extern void nilfs_flush_segment(struct super_block *, ino_t);
 233 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 234                                 void **);
 235
 236 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 237 void nilfs_detach_log_writer(struct super_block *sb);
 238
 239 /* recovery.c */
 240 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 241                                        struct buffer_head **, int);
 242 extern int nilfs_search_super_root(struct the_nilfs *,
 243                                    struct nilfs_recovery_info *);
 244 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 245                               struct nilfs_recovery_info *ri);
 246 extern void nilfs_dispose_segment_list(struct list_head *);
 247
 248 #endif /* _NILFS_SEGMENT_H */