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 */ 247