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/workqueue.h> 30 #include <linux/nilfs2_fs.h> 31 #include "nilfs.h" 32 33 struct nilfs_root; 34 35 /** 36 * struct nilfs_recovery_info - Recovery information 37 * @ri_need_recovery: Recovery status 38 * @ri_super_root: Block number of the last super root 39 * @ri_ri_cno: Number of the last checkpoint 40 * @ri_lsegs_start: Region for roll-forwarding (start block number) 41 * @ri_lsegs_end: Region for roll-forwarding (end block number) 42 * @ri_lseg_start_seq: Sequence value of the segment at ri_lsegs_start 43 * @ri_used_segments: List of segments to be mark active 44 * @ri_pseg_start: Block number of the last partial segment 45 * @ri_seq: Sequence number on the last partial segment 46 * @ri_segnum: Segment number on the last partial segment 47 * @ri_nextnum: Next segment number on the last partial segment 48 */ 49 struct nilfs_recovery_info { 50 int ri_need_recovery; 51 sector_t ri_super_root; 52 __u64 ri_cno; 53 54 sector_t ri_lsegs_start; 55 sector_t ri_lsegs_end; 56 u64 ri_lsegs_start_seq; 57 struct list_head ri_used_segments; 58 sector_t ri_pseg_start; 59 u64 ri_seq; 60 __u64 ri_segnum; 61 __u64 ri_nextnum; 62 }; 63 64 /* ri_need_recovery */ 65 #define NILFS_RECOVERY_SR_UPDATED 1 /* The super root was updated */ 66 #define NILFS_RECOVERY_ROLLFORWARD_DONE 2 /* Rollforward was carried out */ 67 68 /** 69 * struct nilfs_cstage - Context of collection stage 70 * @scnt: Stage count, must be accessed via wrappers: 71 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() 72 * @flags: State flags 73 * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file 74 * @gc_inode_ptr: Pointer on the list of gc-inodes 75 */ 76 struct nilfs_cstage { 77 int scnt; 78 unsigned flags; 79 struct nilfs_inode_info *dirty_file_ptr; 80 struct nilfs_inode_info *gc_inode_ptr; 81 }; 82 83 struct nilfs_segment_buffer; 84 85 struct nilfs_segsum_pointer { 86 struct buffer_head *bh; 87 unsigned offset; /* offset in bytes */ 88 }; 89 90 /** 91 * struct nilfs_sc_info - Segment constructor information 92 * @sc_super: Back pointer to super_block struct 93 * @sc_root: root object of the current filesystem tree 94 * @sc_nblk_inc: Block count of current generation 95 * @sc_dirty_files: List of files to be written 96 * @sc_gc_inodes: List of GC inodes having blocks to be written 97 * @sc_iput_queue: list of inodes for which iput should be done 98 * @sc_iput_work: work struct to defer iput call 99 * @sc_freesegs: array of segment numbers to be freed 100 * @sc_nfreesegs: number of segments on @sc_freesegs 101 * @sc_dsync_inode: inode whose data pages are written for a sync operation 102 * @sc_dsync_start: start byte offset of data pages 103 * @sc_dsync_end: end byte offset of data pages (inclusive) 104 * @sc_segbufs: List of segment buffers 105 * @sc_write_logs: List of segment buffers to hold logs under writing 106 * @sc_segbuf_nblocks: Number of available blocks in segment buffers. 107 * @sc_curseg: Current segment buffer 108 * @sc_stage: Collection stage 109 * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary 110 * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary 111 * @sc_blk_cnt: Block count of a file 112 * @sc_datablk_cnt: Data block count of a file 113 * @sc_nblk_this_inc: Number of blocks included in the current logical segment 114 * @sc_seg_ctime: Creation time 115 * @sc_cno: checkpoint number of current log 116 * @sc_flags: Internal flags 117 * @sc_state_lock: spinlock for sc_state and so on 118 * @sc_state: Segctord state flags 119 * @sc_flush_request: inode bitmap of metadata files to be flushed 120 * @sc_wait_request: Client request queue 121 * @sc_wait_daemon: Daemon wait queue 122 * @sc_wait_task: Start/end wait queue to control segctord task 123 * @sc_seq_request: Request counter 124 * @sc_seq_accept: Accepted request count 125 * @sc_seq_done: Completion counter 126 * @sc_sync: Request of explicit sync operation 127 * @sc_interval: Timeout value of background construction 128 * @sc_mjcp_freq: Frequency of creating checkpoints 129 * @sc_lseg_stime: Start time of the latest logical segment 130 * @sc_watermark: Watermark for the number of dirty buffers 131 * @sc_timer: Timer for segctord 132 * @sc_task: current thread of segctord 133 */ 134 struct nilfs_sc_info { 135 struct super_block *sc_super; 136 struct nilfs_root *sc_root; 137 138 unsigned long sc_nblk_inc; 139 140 struct list_head sc_dirty_files; 141 struct list_head sc_gc_inodes; 142 struct list_head sc_iput_queue; 143 struct work_struct sc_iput_work; 144 145 __u64 *sc_freesegs; 146 size_t sc_nfreesegs; 147 148 struct nilfs_inode_info *sc_dsync_inode; 149 loff_t sc_dsync_start; 150 loff_t sc_dsync_end; 151 152 /* Segment buffers */ 153 struct list_head sc_segbufs; 154 struct list_head sc_write_logs; 155 unsigned long sc_segbuf_nblocks; 156 struct nilfs_segment_buffer *sc_curseg; 157 158 struct nilfs_cstage sc_stage; 159 160 struct nilfs_segsum_pointer sc_finfo_ptr; 161 struct nilfs_segsum_pointer sc_binfo_ptr; 162 unsigned long sc_blk_cnt; 163 unsigned long sc_datablk_cnt; 164 unsigned long sc_nblk_this_inc; 165 time_t sc_seg_ctime; 166 __u64 sc_cno; 167 unsigned long sc_flags; 168 169 spinlock_t sc_state_lock; 170 unsigned long sc_state; 171 unsigned long sc_flush_request; 172 173 wait_queue_head_t sc_wait_request; 174 wait_queue_head_t sc_wait_daemon; 175 wait_queue_head_t sc_wait_task; 176 177 __u32 sc_seq_request; 178 __u32 sc_seq_accepted; 179 __u32 sc_seq_done; 180 181 int sc_sync; 182 unsigned long sc_interval; 183 unsigned long sc_mjcp_freq; 184 unsigned long sc_lseg_stime; /* in 1/HZ seconds */ 185 unsigned long sc_watermark; 186 187 struct timer_list sc_timer; 188 struct task_struct *sc_task; 189 }; 190 191 /* sc_flags */ 192 enum { 193 NILFS_SC_DIRTY, /* One or more dirty meta-data blocks exist */ 194 NILFS_SC_UNCLOSED, /* Logical segment is not closed */ 195 NILFS_SC_SUPER_ROOT, /* The latest segment has a super root */ 196 NILFS_SC_PRIOR_FLUSH, /* Requesting immediate flush without making a 197 checkpoint */ 198 NILFS_SC_HAVE_DELTA, /* Next checkpoint will have update of files 199 other than DAT, cpfile, sufile, or files 200 moved by GC */ 201 }; 202 203 /* sc_state */ 204 #define NILFS_SEGCTOR_QUIT 0x0001 /* segctord is being destroyed */ 205 #define NILFS_SEGCTOR_COMMIT 0x0004 /* committed transaction exists */ 206 207 /* 208 * Constant parameters 209 */ 210 #define NILFS_SC_CLEANUP_RETRY 3 /* Retry count of construction when 211 destroying segctord */ 212 213 /* 214 * Default values of timeout, in seconds. 215 */ 216 #define NILFS_SC_DEFAULT_TIMEOUT 5 /* Timeout value of dirty blocks. 217 It triggers construction of a 218 logical segment with a super root */ 219 #define NILFS_SC_DEFAULT_SR_FREQ 30 /* Maximum frequency of super root 220 creation */ 221 222 /* 223 * The default threshold amount of data, in block counts. 224 */ 225 #define NILFS_SC_DEFAULT_WATERMARK 3600 226 227 /* super.c */ 228 extern struct kmem_cache *nilfs_transaction_cachep; 229 230 /* segment.c */ 231 extern void nilfs_relax_pressure_in_lock(struct super_block *); 232 233 extern int nilfs_construct_segment(struct super_block *); 234 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *, 235 loff_t, loff_t); 236 extern void nilfs_flush_segment(struct super_block *, ino_t); 237 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *, 238 void **); 239 240 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root); 241 void nilfs_detach_log_writer(struct super_block *sb); 242 243 /* recovery.c */ 244 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t, 245 struct buffer_head **, int); 246 extern int nilfs_search_super_root(struct the_nilfs *, 247 struct nilfs_recovery_info *); 248 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb, 249 struct nilfs_recovery_info *ri); 250 extern void nilfs_dispose_segment_list(struct list_head *); 251 252 #endif /* _NILFS_SEGMENT_H */ 253