xref: /linux/fs/nilfs2/segment.h (revision 7856a565416e0cf091f825b0e25c7a1b7abb650e)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * 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_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_lsegs_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_seq_request: Request counter
109  * @sc_seq_accepted: Accepted request count
110  * @sc_seq_done: Completion counter
111  * @sc_sync: Request of explicit sync operation
112  * @sc_interval: Timeout value of background construction
113  * @sc_mjcp_freq: Frequency of creating checkpoints
114  * @sc_lseg_stime: Start time of the latest logical segment
115  * @sc_watermark: Watermark for the number of dirty buffers
116  * @sc_timer: Timer for segctord
117  * @sc_task: current thread of segctord
118  */
119 struct nilfs_sc_info {
120 	struct super_block     *sc_super;
121 	struct nilfs_root      *sc_root;
122 
123 	unsigned long		sc_nblk_inc;
124 
125 	struct list_head	sc_dirty_files;
126 	struct list_head	sc_gc_inodes;
127 	struct list_head	sc_iput_queue;
128 	struct work_struct	sc_iput_work;
129 
130 	__u64		       *sc_freesegs;
131 	size_t			sc_nfreesegs;
132 
133 	struct nilfs_inode_info *sc_dsync_inode;
134 	loff_t			sc_dsync_start;
135 	loff_t			sc_dsync_end;
136 
137 	/* Segment buffers */
138 	struct list_head	sc_segbufs;
139 	struct list_head	sc_write_logs;
140 	unsigned long		sc_segbuf_nblocks;
141 	struct nilfs_segment_buffer *sc_curseg;
142 
143 	struct nilfs_cstage	sc_stage;
144 
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;
150 	time64_t		sc_seg_ctime;
151 	__u64			sc_cno;
152 	unsigned long		sc_flags;
153 
154 	spinlock_t		sc_state_lock;
155 	unsigned long		sc_state;
156 	unsigned long		sc_flush_request;
157 
158 	wait_queue_head_t	sc_wait_request;
159 	wait_queue_head_t	sc_wait_daemon;
160 
161 	__u32			sc_seq_request;
162 	__u32			sc_seq_accepted;
163 	__u32			sc_seq_done;
164 
165 	int			sc_sync;
166 	unsigned long		sc_interval;
167 	unsigned long		sc_mjcp_freq;
168 	unsigned long		sc_lseg_stime;	/* in 1/HZ seconds */
169 	unsigned long		sc_watermark;
170 
171 	struct timer_list	sc_timer;
172 	struct task_struct     *sc_task;
173 };
174 
175 /* sc_flags */
176 enum {
177 	NILFS_SC_DIRTY,		/* One or more dirty meta-data blocks exist */
178 	NILFS_SC_UNCLOSED,	/* Logical segment is not closed */
179 	NILFS_SC_SUPER_ROOT,	/* The latest segment has a super root */
180 	NILFS_SC_PRIOR_FLUSH,	/*
181 				 * Requesting immediate flush without making a
182 				 * checkpoint
183 				 */
184 	NILFS_SC_HAVE_DELTA,	/*
185 				 * Next checkpoint will have update of files
186 				 * other than DAT, cpfile, sufile, or files
187 				 * moved by GC.
188 				 */
189 };
190 
191 /* sc_state */
192 #define NILFS_SEGCTOR_COMMIT	    0x0004  /* committed transaction exists */
193 
194 /*
195  * Constant parameters
196  */
197 #define NILFS_SC_CLEANUP_RETRY	    3  /*
198 					* Retry count of construction when
199 					* destroying segctord
200 					*/
201 
202 /*
203  * Default values of timeout, in seconds.
204  */
205 #define NILFS_SC_DEFAULT_TIMEOUT    5   /*
206 					 * Timeout value of dirty blocks.
207 					 * It triggers construction of a
208 					 * logical segment with a super root.
209 					 */
210 #define NILFS_SC_DEFAULT_SR_FREQ    30  /*
211 					 * Maximum frequency of super root
212 					 * creation
213 					 */
214 
215 /*
216  * The default threshold amount of data, in block counts.
217  */
218 #define NILFS_SC_DEFAULT_WATERMARK  3600
219 
220 /* super.c */
221 extern struct kmem_cache *nilfs_transaction_cachep;
222 
223 /* segment.c */
224 extern void nilfs_relax_pressure_in_lock(struct super_block *);
225 
226 extern int nilfs_construct_segment(struct super_block *);
227 extern int nilfs_construct_dsync_segment(struct super_block *, struct inode *,
228 					 loff_t, loff_t);
229 extern void nilfs_flush_segment(struct super_block *, ino_t);
230 extern int nilfs_clean_segments(struct super_block *, struct nilfs_argv *,
231 				void **);
232 
233 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root);
234 void nilfs_detach_log_writer(struct super_block *sb);
235 
236 /* recovery.c */
237 extern int nilfs_read_super_root_block(struct the_nilfs *, sector_t,
238 				       struct buffer_head **, int);
239 extern int nilfs_search_super_root(struct the_nilfs *,
240 				   struct nilfs_recovery_info *);
241 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, struct super_block *sb,
242 			      struct nilfs_recovery_info *ri);
243 extern void nilfs_dispose_segment_list(struct list_head *);
244 
245 #endif /* _NILFS_SEGMENT_H */
246