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Ryusuke Konishi65b46432009-04-06 19:01:23 -07001/*
2 * the_nilfs.h - the_nilfs shared structure.
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
24#ifndef _THE_NILFS_H
25#define _THE_NILFS_H
26
27#include <linux/types.h>
28#include <linux/buffer_head.h>
29#include <linux/fs.h>
30#include <linux/blkdev.h>
31#include <linux/backing-dev.h>
32#include "sb.h"
33
34/* the_nilfs struct */
35enum {
36 THE_NILFS_INIT = 0, /* Information from super_block is set */
37 THE_NILFS_LOADED, /* Roll-back/roll-forward has done and
38 the latest checkpoint was loaded */
39 THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
Jiro SEKIBA1cf58fa2009-09-03 22:24:17 +090040 THE_NILFS_GC_RUNNING, /* gc process is running */
Ryusuke Konishie605f0a2009-12-09 00:57:52 +090041 THE_NILFS_SB_DIRTY, /* super block is dirty */
Ryusuke Konishi65b46432009-04-06 19:01:23 -070042};
43
44/**
45 * struct the_nilfs - struct to supervise multiple nilfs mount points
46 * @ns_flags: flags
47 * @ns_count: reference count
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090048 * @ns_list: list head for nilfs_list
Ryusuke Konishi65b46432009-04-06 19:01:23 -070049 * @ns_bdev: block device
50 * @ns_bdi: backing dev info
51 * @ns_writer: back pointer to writable nilfs_sb_info
52 * @ns_sem: semaphore for shared states
Ryusuke Konishie59399d2009-06-08 01:39:32 +090053 * @ns_super_sem: semaphore for global operations across super block instances
Ryusuke Konishiaa7dfb82009-06-08 01:39:33 +090054 * @ns_mount_mutex: mutex protecting mount process of nilfs
Ryusuke Konishi027d6402009-08-02 22:45:33 +090055 * @ns_writer_sem: semaphore protecting ns_writer attach/detach
Ryusuke Konishi3f82ff52009-06-08 01:39:30 +090056 * @ns_current: back pointer to current mount
Ryusuke Konishie339ad32009-04-06 19:01:59 -070057 * @ns_sbh: buffer heads of on-disk super blocks
58 * @ns_sbp: pointers to super block data
59 * @ns_sbwtime: previous write time of super blocks
60 * @ns_sbsize: size of valid data in super block
Ryusuke Konishi65b46432009-04-06 19:01:23 -070061 * @ns_supers: list of nilfs super block structs
62 * @ns_seg_seq: segment sequence counter
63 * @ns_segnum: index number of the latest full segment.
64 * @ns_nextnum: index number of the full segment index to be used next
65 * @ns_pseg_offset: offset of next partial segment in the current full segment
66 * @ns_cno: next checkpoint number
67 * @ns_ctime: write time of the last segment
68 * @ns_nongc_ctime: write time of the last segment not for cleaner operation
69 * @ns_ndirtyblks: Number of dirty data blocks
70 * @ns_last_segment_lock: lock protecting fields for the latest segment
71 * @ns_last_pseg: start block number of the latest segment
72 * @ns_last_seq: sequence value of the latest segment
73 * @ns_last_cno: checkpoint number of the latest segment
Ryusuke Konishi2c2e52f2009-04-06 19:01:54 -070074 * @ns_prot_seq: least sequence number of segments which must not be reclaimed
Ryusuke Konishi65b46432009-04-06 19:01:23 -070075 * @ns_free_segments_count: counter of free segments
76 * @ns_segctor_sem: segment constructor semaphore
77 * @ns_dat: DAT file inode
78 * @ns_cpfile: checkpoint file inode
79 * @ns_sufile: segusage file inode
80 * @ns_gc_dat: shadow inode of the DAT file inode for GC
81 * @ns_gc_inodes: dummy inodes to keep live blocks
82 * @ns_gc_inodes_h: hash list to keep dummy inode holding live blocks
Ryusuke Konishi65b46432009-04-06 19:01:23 -070083 * @ns_blocksize_bits: bit length of block size
84 * @ns_nsegments: number of segments in filesystem
85 * @ns_blocks_per_segment: number of blocks per segment
86 * @ns_r_segments_percentage: reserved segments percentage
87 * @ns_nrsvsegs: number of reserved segments
88 * @ns_first_data_block: block number of first data block
89 * @ns_inode_size: size of on-disk inode
90 * @ns_first_ino: first not-special inode number
91 * @ns_crc_seed: seed value of CRC32 calculation
92 */
93struct the_nilfs {
94 unsigned long ns_flags;
95 atomic_t ns_count;
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090096 struct list_head ns_list;
Ryusuke Konishi65b46432009-04-06 19:01:23 -070097
98 struct block_device *ns_bdev;
99 struct backing_dev_info *ns_bdi;
100 struct nilfs_sb_info *ns_writer;
101 struct rw_semaphore ns_sem;
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900102 struct rw_semaphore ns_super_sem;
Ryusuke Konishiaa7dfb82009-06-08 01:39:33 +0900103 struct mutex ns_mount_mutex;
Ryusuke Konishi027d6402009-08-02 22:45:33 +0900104 struct rw_semaphore ns_writer_sem;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700105
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900106 /*
107 * components protected by ns_super_sem
108 */
Ryusuke Konishi3f82ff52009-06-08 01:39:30 +0900109 struct nilfs_sb_info *ns_current;
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900110 struct list_head ns_supers;
Ryusuke Konishi3f82ff52009-06-08 01:39:30 +0900111
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700112 /*
113 * used for
114 * - loading the latest checkpoint exclusively.
115 * - allocating a new full segment.
116 * - protecting s_dirt in the super_block struct
117 * (see nilfs_write_super) and the following fields.
118 */
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700119 struct buffer_head *ns_sbh[2];
120 struct nilfs_super_block *ns_sbp[2];
121 time_t ns_sbwtime[2];
122 unsigned ns_sbsize;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700123 unsigned ns_mount_state;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700124
125 /*
126 * Following fields are dedicated to a writable FS-instance.
127 * Except for the period seeking checkpoint, code outside the segment
Ryusuke Konishi47420c72009-04-06 19:01:45 -0700128 * constructor must lock a segment semaphore while accessing these
129 * fields.
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700130 * The writable FS-instance is sole during a lifetime of the_nilfs.
131 */
132 u64 ns_seg_seq;
133 __u64 ns_segnum;
134 __u64 ns_nextnum;
135 unsigned long ns_pseg_offset;
136 __u64 ns_cno;
137 time_t ns_ctime;
138 time_t ns_nongc_ctime;
139 atomic_t ns_ndirtyblks;
140
141 /*
142 * The following fields hold information on the latest partial segment
143 * written to disk with a super root. These fields are protected by
144 * ns_last_segment_lock.
145 */
146 spinlock_t ns_last_segment_lock;
147 sector_t ns_last_pseg;
148 u64 ns_last_seq;
149 __u64 ns_last_cno;
Ryusuke Konishi2c2e52f2009-04-06 19:01:54 -0700150 u64 ns_prot_seq;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700151 unsigned long ns_free_segments_count;
152
153 struct rw_semaphore ns_segctor_sem;
154
155 /*
156 * Following fields are lock free except for the period before
157 * the_nilfs is initialized.
158 */
159 struct inode *ns_dat;
160 struct inode *ns_cpfile;
161 struct inode *ns_sufile;
162 struct inode *ns_gc_dat;
163
164 /* GC inode list and hash table head */
165 struct list_head ns_gc_inodes;
166 struct hlist_head *ns_gc_inodes_h;
167
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700168 /* Disk layout information (static) */
169 unsigned int ns_blocksize_bits;
170 unsigned long ns_nsegments;
171 unsigned long ns_blocks_per_segment;
172 unsigned long ns_r_segments_percentage;
173 unsigned long ns_nrsvsegs;
174 unsigned long ns_first_data_block;
175 int ns_inode_size;
176 int ns_first_ino;
177 u32 ns_crc_seed;
178};
179
180#define NILFS_GCINODE_HASH_BITS 8
181#define NILFS_GCINODE_HASH_SIZE (1<<NILFS_GCINODE_HASH_BITS)
182
183#define THE_NILFS_FNS(bit, name) \
184static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
185{ \
186 set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
187} \
188static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
189{ \
190 clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
191} \
192static inline int nilfs_##name(struct the_nilfs *nilfs) \
193{ \
194 return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
195}
196
197THE_NILFS_FNS(INIT, init)
198THE_NILFS_FNS(LOADED, loaded)
199THE_NILFS_FNS(DISCONTINUED, discontinued)
Jiro SEKIBA1cf58fa2009-09-03 22:24:17 +0900200THE_NILFS_FNS(GC_RUNNING, gc_running)
Ryusuke Konishie605f0a2009-12-09 00:57:52 +0900201THE_NILFS_FNS(SB_DIRTY, sb_dirty)
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700202
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700203/* Minimum interval of periodical update of superblocks (in seconds) */
204#define NILFS_SB_FREQ 10
205#define NILFS_ALTSB_FREQ 60 /* spare superblock */
206
Jiro SEKIBA79efdd92009-07-23 01:26:34 +0900207static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
208{
209 u64 t = get_seconds();
210 return t < nilfs->ns_sbwtime[0] ||
211 t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
212}
213
214static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
215{
216 u64 t = get_seconds();
217 struct nilfs_super_block **sbp = nilfs->ns_sbp;
218 return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
219}
220
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700221void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
Ryusuke Konishi33c8e572009-06-08 01:39:29 +0900222struct the_nilfs *find_or_create_nilfs(struct block_device *);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700223void put_nilfs(struct the_nilfs *);
224int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
225int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
Jiro SEKIBAe902ec92010-01-30 18:06:35 +0900226int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700227int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900228struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700229int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
230int nilfs_near_disk_full(struct the_nilfs *);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700231void nilfs_fall_back_super_block(struct the_nilfs *);
232void nilfs_swap_super_block(struct the_nilfs *);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700233
234
235static inline void get_nilfs(struct the_nilfs *nilfs)
236{
237 /* Caller must have at least one reference of the_nilfs. */
238 atomic_inc(&nilfs->ns_count);
239}
240
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700241static inline void
242nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
243{
Ryusuke Konishi027d6402009-08-02 22:45:33 +0900244 down_write(&nilfs->ns_writer_sem);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700245 nilfs->ns_writer = sbi;
Ryusuke Konishi027d6402009-08-02 22:45:33 +0900246 up_write(&nilfs->ns_writer_sem);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700247}
248
249static inline void
250nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
251{
Ryusuke Konishi027d6402009-08-02 22:45:33 +0900252 down_write(&nilfs->ns_writer_sem);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700253 if (sbi == nilfs->ns_writer)
254 nilfs->ns_writer = NULL;
Ryusuke Konishi027d6402009-08-02 22:45:33 +0900255 up_write(&nilfs->ns_writer_sem);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700256}
257
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900258static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
259{
Ryusuke Konishia9245862009-08-19 00:29:43 +0900260 if (atomic_dec_and_test(&sbi->s_count))
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900261 kfree(sbi);
262}
263
Ryusuke Konishia057d2c2009-11-19 19:58:46 +0900264static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
265{
266 unsigned valid_fs;
267
268 down_read(&nilfs->ns_sem);
269 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
270 up_read(&nilfs->ns_sem);
271 return valid_fs;
272}
273
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700274static inline void
275nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
276 sector_t *seg_start, sector_t *seg_end)
277{
278 *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;
279 *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;
280 if (segnum == 0)
281 *seg_start = nilfs->ns_first_data_block;
282}
283
284static inline sector_t
285nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
286{
287 return (segnum == 0) ? nilfs->ns_first_data_block :
288 (sector_t)nilfs->ns_blocks_per_segment * segnum;
289}
290
291static inline __u64
292nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
293{
294 sector_t segnum = blocknr;
295
296 sector_div(segnum, nilfs->ns_blocks_per_segment);
297 return segnum;
298}
299
300static inline void
301nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
302 sector_t seg_end)
303{
304 /* terminate the current full segment (used in case of I/O-error) */
305 nilfs->ns_pseg_offset = seg_end - seg_start + 1;
306}
307
308static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
309{
310 /* move forward with a full segment */
311 nilfs->ns_segnum = nilfs->ns_nextnum;
312 nilfs->ns_pseg_offset = 0;
313 nilfs->ns_seg_seq++;
314}
315
316static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
317{
318 __u64 cno;
319
320 spin_lock(&nilfs->ns_last_segment_lock);
321 cno = nilfs->ns_last_cno;
322 spin_unlock(&nilfs->ns_last_segment_lock);
323 return cno;
324}
325
Ryusuke Konishicece5522009-04-06 19:01:58 -0700326static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
327{
328 return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
329}
330
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700331#endif /* _THE_NILFS_H */