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_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
 139         __u64                  *sc_freesegs;
 140         size_t                  sc_nfreesegs;
 141
 142         struct nilfs_inode_info *sc_dsync_inode;
 143         loff_t                  sc_dsync_start;
 144         loff_t                  sc_dsync_end;
 145
 146         /* Segment buffers */
 147         struct list_head        sc_segbufs;
 148         struct list_head        sc_write_logs;
 149         unsigned long           sc_segbuf_nblocks;
 150         struct nilfs_segment_buffer *sc_curseg;
 151
 152         struct nilfs_cstage     sc_stage;
 153
 154         struct nilfs_segsum_pointer sc_finfo_ptr;
 155         struct nilfs_segsum_pointer sc_binfo_ptr;
 156         unsigned long           sc_blk_cnt;
 157         unsigned long           sc_datablk_cnt;
 158         unsigned long           sc_nblk_this_inc;
 159         time_t                  sc_seg_ctime;
 160         __u64                   sc_cno;
 161         unsigned long           sc_flags;
 162
 163         spinlock_t              sc_state_lock;
 164         unsigned long           sc_state;
 165         unsigned long           sc_flush_request;
 166
 167         wait_queue_head_t       sc_wait_request;
 168         wait_queue_head_t       sc_wait_daemon;
 169         wait_queue_head_t       sc_wait_task;
 170
 171         __u32                   sc_seq_request;
 172         __u32                   sc_seq_accepted;
 173         __u32                   sc_seq_done;
 174
 175         int                     sc_sync;
 176         unsigned long           sc_interval;
 177         unsigned long           sc_mjcp_freq;
 178         unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 179         unsigned long           sc_watermark;
 180
 181         struct timer_list       sc_timer;
 182         struct task_struct     *sc_task;
 183 };
 184
 185 /* sc_flags */
 186 enum {
 187         NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 188         NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 189         NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 190         NILFS_SC_PRIOR_FLUSH,   /* Requesting immediate flush without making a
 191                                    checkpoint */
 192         NILFS_SC_HAVE_DELTA,    /* Next checkpoint will have update of files
 193                                    other than DAT, cpfile, sufile, or files
 194                                    moved by GC */
 195 };
 196
 197 /* sc_state */
 198 #define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
 199 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 200
 201 /*
 202  * Constant parameters
 203  */
 204 #define NILFS_SC_CLEANUP_RETRY      3  /* Retry count of construction when
 205                                           destroying segctord */
 206
 207 /*
 208  * Default values of timeout, in seconds.
 209  */
 210 #define NILFS_SC_DEFAULT_TIMEOUT    5   /* Timeout value of dirty blocks.
 211                                            It triggers construction of a
 212                                            logical segment with a super root */
 213 #define NILFS_SC_DEFAULT_SR_FREQ    30  /* Maximum frequency of super root
 214                                            creation */
 215
 216 /*
 217  * The default threshold amount of data, in block counts.
 218  */
 219 #define NILFS_SC_DEFAULT_WATERMARK  3600
 220
 221 /* super.c */
 222 extern struct kmem_cache *nilfs_transaction_cachep;
 223
 224 /* segment.c */
 225 extern void nilfs_relax_pressure_in_lock(struct super_block *);
 226
 227 extern int nilfs_construct_segment(struct super_block *);
 228 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 229                                          loff_t, loff_t);
 230 extern void nilfs_flush_segment(struct super_block *, ino_t);
 231 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 232                                 void **);
 233
 234 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 235 void nilfs_detach_log_writer(struct super_block *sb);
 236
 237 /* recovery.c */
 238 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 239                                        struct buffer_head **, int);
 240 extern int nilfs_search_super_root(struct the_nilfs *,
 241                                    struct nilfs_recovery_info *);
 242 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 243                               struct nilfs_recovery_info *ri);
 244 extern void nilfs_dispose_segment_list(struct list_head *);
 245
 246 #endif /* _NILFS_SEGMENT_H */