GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / nilfs2 / segment.h
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * segment.h - 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_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_lseg_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_wait_task: Start/end wait queue to control segctord task
109  * @sc_seq_request: Request counter
110  * @sc_seq_accept: Accepted request count
111  * @sc_seq_done: Completion counter
112  * @sc_sync: Request of explicit sync operation
113  * @sc_interval: Timeout value of background construction
114  * @sc_mjcp_freq: Frequency of creating checkpoints
115  * @sc_lseg_stime: Start time of the latest logical segment
116  * @sc_watermark: Watermark for the number of dirty buffers
117  * @sc_timer: Timer for segctord
118  * @sc_task: current thread of segctord
119  */
120 struct nilfs_sc_info {
121         struct super_block     *sc_super;
122         struct nilfs_root      *sc_root;
123
124         unsigned long           sc_nblk_inc;
125
126         struct list_head        sc_dirty_files;
127         struct list_head        sc_gc_inodes;
128         struct list_head        sc_iput_queue;
129         struct work_struct      sc_iput_work;
130
131         __u64                  *sc_freesegs;
132         size_t                  sc_nfreesegs;
133
134         struct nilfs_inode_info *sc_dsync_inode;
135         loff_t                  sc_dsync_start;
136         loff_t                  sc_dsync_end;
137
138         /* Segment buffers */
139         struct list_head        sc_segbufs;
140         struct list_head        sc_write_logs;
141         unsigned long           sc_segbuf_nblocks;
142         struct nilfs_segment_buffer *sc_curseg;
143
144         struct nilfs_cstage     sc_stage;
145
146         struct nilfs_segsum_pointer sc_finfo_ptr;
147         struct nilfs_segsum_pointer sc_binfo_ptr;
148         unsigned long           sc_blk_cnt;
149         unsigned long           sc_datablk_cnt;
150         unsigned long           sc_nblk_this_inc;
151         time64_t                sc_seg_ctime;
152         __u64                   sc_cno;
153         unsigned long           sc_flags;
154
155         spinlock_t              sc_state_lock;
156         unsigned long           sc_state;
157         unsigned long           sc_flush_request;
158
159         wait_queue_head_t       sc_wait_request;
160         wait_queue_head_t       sc_wait_daemon;
161         wait_queue_head_t       sc_wait_task;
162
163         __u32                   sc_seq_request;
164         __u32                   sc_seq_accepted;
165         __u32                   sc_seq_done;
166
167         int                     sc_sync;
168         unsigned long           sc_interval;
169         unsigned long           sc_mjcp_freq;
170         unsigned long           sc_lseg_stime;  /* in 1/HZ seconds */
171         unsigned long           sc_watermark;
172
173         struct timer_list       sc_timer;
174         struct task_struct     *sc_timer_task;
175         struct task_struct     *sc_task;
176 };
177
178 /* sc_flags */
179 enum {
180         NILFS_SC_DIRTY,         /* One or more dirty meta-data blocks exist */
181         NILFS_SC_UNCLOSED,      /* Logical segment is not closed */
182         NILFS_SC_SUPER_ROOT,    /* The latest segment has a super root */
183         NILFS_SC_PRIOR_FLUSH,   /*
184                                  * Requesting immediate flush without making a
185                                  * checkpoint
186                                  */
187         NILFS_SC_HAVE_DELTA,    /*
188                                  * Next checkpoint will have update of files
189                                  * other than DAT, cpfile, sufile, or files
190                                  * moved by GC.
191                                  */
192 };
193
194 /* sc_state */
195 #define NILFS_SEGCTOR_QUIT          0x0001  /* segctord is being destroyed */
196 #define NILFS_SEGCTOR_COMMIT        0x0004  /* committed transaction exists */
197
198 /*
199  * Constant parameters
200  */
201 #define NILFS_SC_CLEANUP_RETRY      3  /*
202                                         * Retry count of construction when
203                                         * destroying segctord
204                                         */
205
206 /*
207  * Default values of timeout, in seconds.
208  */
209 #define NILFS_SC_DEFAULT_TIMEOUT    5   /*
210                                          * Timeout value of dirty blocks.
211                                          * It triggers construction of a
212                                          * logical segment with a super root.
213                                          */
214 #define NILFS_SC_DEFAULT_SR_FREQ    30  /*
215                                          * Maximum frequency of super root
216                                          * creation
217                                          */
218
219 /*
220  * The default threshold amount of data, in block counts.
221  */
222 #define NILFS_SC_DEFAULT_WATERMARK  3600
223
224 /* super.c */
225 extern struct kmem_cache *nilfs_transaction_cachep;
226
227 /* segment.c */
228 extern void nilfs_relax_pressure_in_lock(struct super_block *);
229
230 extern int nilfs_construct_segment(struct super_block *);
231 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
232                                          loff_t, loff_t);
233 extern void nilfs_flush_segment(struct super_block *, ino_t);
234 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
235                                 void **);
236
237 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
238 void nilfs_detach_log_writer(struct super_block *sb);
239
240 /* recovery.c */
241 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
242                                        struct buffer_head **, int);
243 extern int nilfs_search_super_root(struct the_nilfs *,
244                                    struct nilfs_recovery_info *);
245 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
246                               struct nilfs_recovery_info *ri);
247 extern void nilfs_dispose_segment_list(struct list_head *);
248
249 #endif /* _NILFS_SEGMENT_H */