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_copied_buffers: List of copied buffers (buffer heads) to freeze data 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_super_root: Pointer to the super root 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_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_sb_info *sc_sbi; 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_copied_buffers; 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 struct buffer_head *sc_super_root; 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; 161 162 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, /* Requesting immediate flush without making a 192 checkpoint */ 193 NILFS_SC_HAVE_DELTA, /* Next checkpoint will have update of files 194 other than DAT, cpfile, sufile, or files 195 moved by GC */ 196 }; 197 198 /* sc_state */ 199 #define NILFS_SEGCTOR_QUIT 0x0001 /* segctord is being destroyed */ 200 #define NILFS_SEGCTOR_COMMIT 0x0004 /* committed transaction exists */ 201 202 /* 203 * Constant parameters 204 */ 205 #define NILFS_SC_CLEANUP_RETRY 3 /* Retry count of construction when 206 destroying segctord */ 207 208 /* 209 * Default values of timeout, in seconds. 210 */ 211 #define NILFS_SC_DEFAULT_TIMEOUT 5 /* Timeout value of dirty blocks. 212 It triggers construction of a 213 logical segment with a super root */ 214 #define NILFS_SC_DEFAULT_SR_FREQ 30 /* Maximum frequency of super root 215 creation */ 216 217 /* 218 * The default threshold amount of data, in block counts. 219 */ 220 #define NILFS_SC_DEFAULT_WATERMARK 3600 221 222 223 /* segment.c */ 224 extern int nilfs_init_transaction_cache(void); 225 extern void nilfs_destroy_transaction_cache(void); 226 extern void nilfs_relax_pressure_in_lock(struct super_block *); 227 228 extern int nilfs_construct_segment(struct super_block *); 229 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *, 230 loff_t, loff_t); 231 extern void nilfs_flush_segment(struct super_block *, ino_t); 232 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *, 233 void **); 234 235 extern int nilfs_attach_segment_constructor(struct nilfs_sb_info *); 236 extern void nilfs_detach_segment_constructor(struct nilfs_sb_info *); 237 238 /* recovery.c */ 239 extern int nilfs_read_super_root_block(struct super_block *, sector_t, 240 struct buffer_head **, int); 241 extern int nilfs_search_super_root(struct the_nilfs *, struct nilfs_sb_info *, 242 struct nilfs_recovery_info *); 243 extern int nilfs_recover_logical_segments(struct the_nilfs *, 244 struct nilfs_sb_info *, 245 struct nilfs_recovery_info *); 246 extern void nilfs_dispose_segment_list(struct list_head *); 247 248 #endif /* _NILFS_SEGMENT_H */ 249