2 * segment.h - NILFS Segment constructor prototypes and definitions
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
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
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
23 #ifndef _NILFS_SEGMENT_H
24 #define _NILFS_SEGMENT_H
26 #include <linux/types.h>
28 #include <linux/buffer_head.h>
29 #include <linux/nilfs2_fs.h>
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
46 struct nilfs_recovery_info {
48 sector_t ri_super_root;
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;
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 */
66 * struct nilfs_cstage - Context of collection stage
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
75 struct nilfs_inode_info *dirty_file_ptr;
76 struct nilfs_inode_info *gc_inode_ptr;
79 struct nilfs_segment_buffer;
81 struct nilfs_segsum_pointer {
82 struct buffer_head *bh;
83 unsigned offset; /* offset in bytes */
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_active_segments: List of active segments that were already written out
94 * @sc_cleaning_segments: List of segments to be freed through construction
95 * @sc_copied_buffers: List of copied buffers (buffer heads) to freeze data
96 * @sc_segbufs: List of segment buffers
97 * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
98 * @sc_curseg: Current segment buffer
99 * @sc_super_root: Pointer to the super root buffer
100 * @sc_stage: Collection stage
101 * @sc_finfo_ptr: pointer to the current finfo struct in the segment summary
102 * @sc_binfo_ptr: pointer to the current binfo struct in the segment summary
103 * @sc_blk_cnt: Block count of a file
104 * @sc_datablk_cnt: Data block count of a file
105 * @sc_nblk_this_inc: Number of blocks included in the current logical segment
106 * @sc_seg_ctime: Creation time
107 * @sc_flags: Internal flags
108 * @sc_sketch_inode: Inode of the sketch file
109 * @sc_state_lock: spinlock for sc_state and so on
110 * @sc_state: Segctord state flags
111 * @sc_flush_request: inode bitmap of metadata files to be flushed
112 * @sc_wait_request: Client request queue
113 * @sc_wait_daemon: Daemon wait queue
114 * @sc_wait_task: Start/end wait queue to control segctord task
115 * @sc_seq_request: Request counter
116 * @sc_seq_done: Completion counter
117 * @sc_sync: Request of explicit sync operation
118 * @sc_interval: Timeout value of background construction
119 * @sc_mjcp_freq: Frequency of creating checkpoints
120 * @sc_lseg_stime: Start time of the latest logical segment
121 * @sc_watermark: Watermark for the number of dirty buffers
122 * @sc_timer: Timer for segctord
123 * @sc_task: current thread of segctord
125 struct nilfs_sc_info {
126 struct super_block *sc_super;
127 struct nilfs_sb_info *sc_sbi;
129 unsigned long sc_nblk_inc;
131 struct list_head sc_dirty_files;
132 struct list_head sc_gc_inodes;
133 struct list_head sc_active_segments;
134 struct list_head sc_cleaning_segments;
135 struct list_head sc_copied_buffers;
137 /* Segment buffers */
138 struct list_head sc_segbufs;
139 unsigned long sc_segbuf_nblocks;
140 struct nilfs_segment_buffer *sc_curseg;
141 struct buffer_head *sc_super_root;
143 struct nilfs_cstage sc_stage;
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;
152 unsigned long sc_flags;
155 * Pointer to an inode of the sketch.
156 * This pointer is kept only while it contains data.
157 * We protect it with a semaphore of the segment constructor.
159 struct inode *sc_sketch_inode;
161 spinlock_t sc_state_lock;
162 unsigned long sc_state;
163 unsigned long sc_flush_request;
165 wait_queue_head_t sc_wait_request;
166 wait_queue_head_t sc_wait_daemon;
167 wait_queue_head_t sc_wait_task;
169 __u32 sc_seq_request;
173 unsigned long sc_interval;
174 unsigned long sc_mjcp_freq;
175 unsigned long sc_lseg_stime; /* in 1/HZ seconds */
176 unsigned long sc_watermark;
178 struct timer_list *sc_timer;
179 struct task_struct *sc_task;
184 NILFS_SC_DIRTY, /* One or more dirty meta-data blocks exist */
185 NILFS_SC_UNCLOSED, /* Logical segment is not closed */
186 NILFS_SC_SUPER_ROOT, /* The latest segment has a super root */
187 NILFS_SC_PRIOR_FLUSH, /* Requesting immediate flush without making a
192 #define NILFS_SEGCTOR_QUIT 0x0001 /* segctord is being destroyed */
193 #define NILFS_SEGCTOR_COMMIT 0x0004 /* committed transaction exists */
196 * Constant parameters
198 #define NILFS_SC_CLEANUP_RETRY 3 /* Retry count of construction when
199 destroying segctord */
202 * Default values of timeout, in seconds.
204 #define NILFS_SC_DEFAULT_TIMEOUT 5 /* Timeout value of dirty blocks.
205 It triggers construction of a
206 logical segment with a super root */
207 #define NILFS_SC_DEFAULT_SR_FREQ 30 /* Maximum frequency of super root
209 #define NILFS_SC_DEFAULT_SB_FREQ 30 /* Minimum interval of periodical
210 update of superblock (reserved) */
213 * The default threshold amount of data, in block counts.
215 #define NILFS_SC_DEFAULT_WATERMARK 3600
219 extern int nilfs_init_transaction_cache(void);
220 extern void nilfs_destroy_transaction_cache(void);
221 extern void nilfs_relax_pressure_in_lock(struct super_block *);
223 extern int nilfs_construct_segment(struct super_block *);
224 extern int nilfs_construct_dsync_segment(struct super_block *,
226 extern void nilfs_flush_segment(struct super_block *, ino_t);
227 extern int nilfs_clean_segments(struct super_block *, void __user *);
229 extern int nilfs_segctor_add_segments_to_be_freed(struct nilfs_sc_info *,
231 extern void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *);
233 extern int nilfs_attach_segment_constructor(struct nilfs_sb_info *,
234 struct nilfs_recovery_info *);
235 extern void nilfs_detach_segment_constructor(struct nilfs_sb_info *);
238 extern int nilfs_read_super_root_block(struct super_block *, sector_t,
239 struct buffer_head **, int);
240 extern int nilfs_search_super_root(struct the_nilfs *, struct nilfs_sb_info *,
241 struct nilfs_recovery_info *);
242 extern int nilfs_recover_logical_segments(struct the_nilfs *,
243 struct nilfs_sb_info *,
244 struct nilfs_recovery_info *);
246 #endif /* _NILFS_SEGMENT_H */