fs/nilfs2/segment.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * NILFS Segment constructor prototypes and definitions
   4  *
   5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Written by Ryusuke Konishi.
   8  *
   9  */
  10 #ifndef _NILFS_SEGMENT_H
  11 #define _NILFS_SEGMENT_H
  12
  13 #include <linux/types.h>
  14 #include <linux/fs.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/workqueue.h>
  17 #include "nilfs.h"
  18
  19 struct nilfs_root;
  20
  21 /**
  22  * struct nilfs_recovery_info - Recovery information
  23  * @ri_need_recovery: Recovery status
  24  * @ri_super_root: Block number of the last super root
  25  * @ri_cno: Number of the last checkpoint
  26  * @ri_lsegs_start: Region for roll-forwarding (start block number)
  27  * @ri_lsegs_end: Region for roll-forwarding (end block number)
  28  * @ri_lsegs_start_seq: Sequence value of the segment at ri_lsegs_start
  29  * @ri_used_segments: List of segments to be mark active
  30  * @ri_pseg_start: Block number of the last partial segment
  31  * @ri_seq: Sequence number on the last partial segment
  32  * @ri_segnum: Segment number on the last partial segment
  33  * @ri_nextnum: Next segment number on the last partial segment
  34  */
  35 struct nilfs_recovery_info {
  36         int                     ri_need_recovery;
  37         sector_t                ri_super_root;
  38         __u64                   ri_cno;
  39
  40         sector_t                ri_lsegs_start;
  41         sector_t                ri_lsegs_end;
  42         u64                     ri_lsegs_start_seq;
  43         struct list_head        ri_used_segments;
  44         sector_t                ri_pseg_start;
  45         u64                     ri_seq;
  46         __u64                   ri_segnum;
  47         __u64                   ri_nextnum;
  48 };
  49
  50 /* ri_need_recovery */
  51 #define NILFS_RECOVERY_SR_UPDATED        1  /* The super root was updated */
  52 #define NILFS_RECOVERY_ROLLFORWARD_DONE  2  /* Rollforward was carried out */
  53
  54 /**
  55  * struct nilfs_cstage - Context of collection stage
  56  * @scnt: Stage count, must be accessed via wrappers:
  57  *        nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get()
  58  * @flags: State flags
  59  * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file
  60  * @gc_inode_ptr: Pointer on the list of gc-inodes
  61  */
  62 struct nilfs_cstage {
  63         int                     scnt;
  64         unsigned int            flags;
  65         struct nilfs_inode_info *dirty_file_ptr;
  66         struct nilfs_inode_info *gc_inode_ptr;
  67 };
  68
  69 struct nilfs_segment_buffer;
  70
  71 struct nilfs_segsum_pointer {
  72         struct buffer_head     *bh;
  73         unsigned int            offset; /* offset in bytes */
  74 };
  75
  76 /**
  77  * struct nilfs_sc_info - Segment constructor information
  78  * @sc_super: Back pointer to super_block struct
  79  * @sc_root: root object of the current filesystem tree
  80  * @sc_nblk_inc: Block count of current generation
  81  * @sc_dirty_files: List of files to be written
  82  * @sc_gc_inodes: List of GC inodes having blocks to be written
  83  * @sc_iput_queue: list of inodes for which iput should be done
  84  * @sc_iput_work: work struct to defer iput call
  85  * @sc_freesegs: array of segment numbers to be freed
  86  * @sc_nfreesegs: number of segments on @sc_freesegs
  87  * @sc_dsync_inode: inode whose data pages are written for a sync operation
  88  * @sc_dsync_start: start byte offset of data pages
  89  * @sc_dsync_end: end byte offset of data pages (inclusive)
  90  * @sc_segbufs: List of segment buffers
  91  * @sc_write_logs: List of segment buffers to hold logs under writing
  92  * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
  93  * @sc_curseg: Current segment buffer
  94  * @sc_stage: Collection stage
  95  * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
  96  * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
  97  * @sc_blk_cnt: Block count of a file
  98  * @sc_datablk_cnt: Data block count of a file
  99  * @sc_nblk_this_inc: Number of blocks included in the current logical segment
 100  * @sc_seg_ctime: Creation time
 101  * @sc_cno: checkpoint number of current log
 102  * @sc_flags: Internal flags
 103  * @sc_state_lock: spinlock for sc_state and so on
 104  * @sc_state: Segctord state flags
 105  * @sc_flush_request: inode bitmap of metadata files to be flushed
 106  * @sc_wait_request: Client request queue
 107  * @sc_wait_daemon: Daemon wait queue
 108  * @sc_seq_request: Request counter
 109  * @sc_seq_accepted: Accepted request count
 110  * @sc_seq_done: Completion counter
 111  * @sc_sync: Request of explicit sync operation
 112  * @sc_interval: Timeout value of background construction
 113  * @sc_mjcp_freq: Frequency of creating checkpoints
 114  * @sc_lseg_stime: Start time of the latest logical segment
 115  * @sc_watermark: Watermark for the number of dirty buffers
 116  * @sc_timer: Timer for segctord
 117  * @sc_task: current thread of segctord
 118  */
 119 struct nilfs_sc_info {
 120         struct super_block     *sc_super;
 121         struct nilfs_root      *sc_root;
 122
 123         unsigned long           sc_nblk_inc;
 124
 125         struct list_head        sc_dirty_files;
 126         struct list_head        sc_gc_inodes;
 127         struct list_head        sc_iput_queue;
 128         struct work_struct      sc_iput_work;
 129
 130         __u64                  *sc_freesegs;
 131         size_t                  sc_nfreesegs;
 132
 133         struct nilfs_inode_info *sc_dsync_inode;
 134         loff_t                  sc_dsync_start;
 135         loff_t                  sc_dsync_end;
 136
 137         /* Segment buffers */
 138         struct list_head        sc_segbufs;
 139         struct list_head        sc_write_logs;
 140         unsigned long           sc_segbuf_nblocks;
 141         struct nilfs_segment_buffer *sc_curseg;
 142
 143         struct nilfs_cstage     sc_stage;
 144
 145         struct nilfs_segsum_pointer sc_finfo_ptr;
 146         struct nilfs_segsum_pointer sc_binfo_ptr;
 147         unsigned long           sc_blk_cnt;
 148         unsigned long           sc_datablk_cnt;
 149         unsigned long           sc_nblk_this_inc;
 150         time64_t                sc_seg_ctime;
 151         __u64                   sc_cno;
 152         unsigned long           sc_flags;
 153
 154         spinlock_t              sc_state_lock;
 155         unsigned long           sc_state;
 156         unsigned long           sc_flush_request;
 157
 158         wait_queue_head_t       sc_wait_request;
 159         wait_queue_head_t       sc_wait_daemon;
 160
 161         __u32                   sc_seq_request;
 162         __u32                   sc_seq_accepted;
 163         __u32                   sc_seq_done;
 164
 165         int                     sc_sync;
 166         unsigned long           sc_interval;
 167         unsigned long           sc_mjcp_freq;
 168         unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
 169         unsigned long           sc_watermark;
 170
 171         struct timer_list       sc_timer;
 172         struct task_struct     *sc_task;
 173 };
 174
 175 /* sc_flags */
 176 enum {
 177         NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
 178         NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
 179         NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
 180         NILFS_SC_PRIOR_FLUSH,   /*
 181                                  * Requesting immediate flush without making a
 182                                  * checkpoint
 183                                  */
 184         NILFS_SC_HAVE_DELTA,    /*
 185                                  * Next checkpoint will have update of files
 186                                  * other than DAT, cpfile, sufile, or files
 187                                  * moved by GC.
 188                                  */
 189 };
 190
 191 /* sc_state */
 192 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
 193
 194 /*
 195  * Constant parameters
 196  */
 197 #define NILFS_SC_CLEANUP_RETRY      3  /*
 198                                         * Retry count of construction when
 199                                         * destroying segctord
 200                                         */
 201
 202 /*
 203  * Default values of timeout, in seconds.
 204  */
 205 #define NILFS_SC_DEFAULT_TIMEOUT    5   /*
 206                                          * Timeout value of dirty blocks.
 207                                          * It triggers construction of a
 208                                          * logical segment with a super root.
 209                                          */
 210 #define NILFS_SC_DEFAULT_SR_FREQ    30  /*
 211                                          * Maximum frequency of super root
 212                                          * creation
 213                                          */
 214
 215 /*
 216  * The default threshold amount of data, in block counts.
 217  */
 218 #define NILFS_SC_DEFAULT_WATERMARK  3600
 219
 220 /* super.c */
 221 extern struct kmem_cache *nilfs_transaction_cachep;
 222
 223 /* segment.c */
 224 extern void nilfs_relax_pressure_in_lock(struct super_block *);
 225
 226 extern int nilfs_construct_segment(struct super_block *);
 227 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
 228                                          loff_t, loff_t);
 229 extern void nilfs_flush_segment(struct super_block *, ino_t);
 230 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
 231                                 void **);
 232
 233 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
 234 void nilfs_detach_log_writer(struct super_block *sb);
 235
 236 /* recovery.c */
 237 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
 238                                        struct buffer_head **, int);
 239 extern int nilfs_search_super_root(struct the_nilfs *,
 240                                    struct nilfs_recovery_info *);
 241 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
 242                               struct nilfs_recovery_info *ri);
 243 extern void nilfs_dispose_segment_list(struct list_head *);
 244
 245 #endif /* _NILFS_SEGMENT_H */