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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>
Ryusuke Konishiba65ae42010-08-14 12:59:15 +090029#include <linux/rbtree.h>
Ryusuke Konishi65b46432009-04-06 19:01:23 -070030#include <linux/fs.h>
31#include <linux/blkdev.h>
32#include <linux/backing-dev.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090033#include <linux/slab.h>
Ryusuke Konishi65b46432009-04-06 19:01:23 -070034#include "sb.h"
35
36/* the_nilfs struct */
37enum {
38 THE_NILFS_INIT = 0, /* Information from super_block is set */
39 THE_NILFS_LOADED, /* Roll-back/roll-forward has done and
40 the latest checkpoint was loaded */
41 THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
Jiro SEKIBA1cf58fa2009-09-03 22:24:17 +090042 THE_NILFS_GC_RUNNING, /* gc process is running */
Ryusuke Konishie605f0a2009-12-09 00:57:52 +090043 THE_NILFS_SB_DIRTY, /* super block is dirty */
Ryusuke Konishi65b46432009-04-06 19:01:23 -070044};
45
46/**
47 * struct the_nilfs - struct to supervise multiple nilfs mount points
48 * @ns_flags: flags
Ryusuke Konishi65b46432009-04-06 19:01:23 -070049 * @ns_bdev: block device
Ryusuke Konishi65b46432009-04-06 19:01:23 -070050 * @ns_sem: semaphore for shared states
Ryusuke Konishie339ad32009-04-06 19:01:59 -070051 * @ns_sbh: buffer heads of on-disk super blocks
52 * @ns_sbp: pointers to super block data
Jiro SEKIBAb2ac86e2010-06-28 17:49:33 +090053 * @ns_sbwtime: previous write time of super block
54 * @ns_sbwcount: write count of super block
Ryusuke Konishie339ad32009-04-06 19:01:59 -070055 * @ns_sbsize: size of valid data in super block
Ryusuke Konishi65b46432009-04-06 19:01:23 -070056 * @ns_seg_seq: segment sequence counter
57 * @ns_segnum: index number of the latest full segment.
58 * @ns_nextnum: index number of the full segment index to be used next
59 * @ns_pseg_offset: offset of next partial segment in the current full segment
60 * @ns_cno: next checkpoint number
61 * @ns_ctime: write time of the last segment
62 * @ns_nongc_ctime: write time of the last segment not for cleaner operation
63 * @ns_ndirtyblks: Number of dirty data blocks
64 * @ns_last_segment_lock: lock protecting fields for the latest segment
65 * @ns_last_pseg: start block number of the latest segment
66 * @ns_last_seq: sequence value of the latest segment
67 * @ns_last_cno: checkpoint number of the latest segment
Ryusuke Konishi2c2e52f2009-04-06 19:01:54 -070068 * @ns_prot_seq: least sequence number of segments which must not be reclaimed
Ryusuke Konishi32502042010-06-29 14:42:13 +090069 * @ns_prev_seq: base sequence number used to decide if advance log cursor
Ryusuke Konishi65b46432009-04-06 19:01:23 -070070 * @ns_segctor_sem: segment constructor semaphore
71 * @ns_dat: DAT file inode
72 * @ns_cpfile: checkpoint file inode
73 * @ns_sufile: segusage file inode
Ryusuke Konishiba65ae42010-08-14 12:59:15 +090074 * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)
75 * @ns_cptree_lock: lock protecting @ns_cptree
Ryusuke Konishi65b46432009-04-06 19:01:23 -070076 * @ns_gc_inodes: dummy inodes to keep live blocks
Ryusuke Konishi65b46432009-04-06 19:01:23 -070077 * @ns_blocksize_bits: bit length of block size
Ryusuke Konishi92c60cc2010-05-23 00:17:48 +090078 * @ns_blocksize: block size
Ryusuke Konishi65b46432009-04-06 19:01:23 -070079 * @ns_nsegments: number of segments in filesystem
80 * @ns_blocks_per_segment: number of blocks per segment
81 * @ns_r_segments_percentage: reserved segments percentage
82 * @ns_nrsvsegs: number of reserved segments
83 * @ns_first_data_block: block number of first data block
84 * @ns_inode_size: size of on-disk inode
85 * @ns_first_ino: first not-special inode number
86 * @ns_crc_seed: seed value of CRC32 calculation
87 */
88struct the_nilfs {
89 unsigned long ns_flags;
Ryusuke Konishi65b46432009-04-06 19:01:23 -070090
91 struct block_device *ns_bdev;
Ryusuke Konishi65b46432009-04-06 19:01:23 -070092 struct rw_semaphore ns_sem;
Ryusuke Konishi65b46432009-04-06 19:01:23 -070093
Ryusuke Konishie59399d2009-06-08 01:39:32 +090094 /*
Ryusuke Konishi65b46432009-04-06 19:01:23 -070095 * used for
96 * - loading the latest checkpoint exclusively.
97 * - allocating a new full segment.
98 * - protecting s_dirt in the super_block struct
99 * (see nilfs_write_super) and the following fields.
100 */
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700101 struct buffer_head *ns_sbh[2];
102 struct nilfs_super_block *ns_sbp[2];
Jiro SEKIBAb2ac86e2010-06-28 17:49:33 +0900103 time_t ns_sbwtime;
104 unsigned ns_sbwcount;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700105 unsigned ns_sbsize;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700106 unsigned ns_mount_state;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700107
108 /*
109 * Following fields are dedicated to a writable FS-instance.
110 * Except for the period seeking checkpoint, code outside the segment
Ryusuke Konishi47420c72009-04-06 19:01:45 -0700111 * constructor must lock a segment semaphore while accessing these
112 * fields.
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700113 * The writable FS-instance is sole during a lifetime of the_nilfs.
114 */
115 u64 ns_seg_seq;
116 __u64 ns_segnum;
117 __u64 ns_nextnum;
118 unsigned long ns_pseg_offset;
119 __u64 ns_cno;
120 time_t ns_ctime;
121 time_t ns_nongc_ctime;
122 atomic_t ns_ndirtyblks;
123
124 /*
125 * The following fields hold information on the latest partial segment
126 * written to disk with a super root. These fields are protected by
127 * ns_last_segment_lock.
128 */
129 spinlock_t ns_last_segment_lock;
130 sector_t ns_last_pseg;
131 u64 ns_last_seq;
132 __u64 ns_last_cno;
Ryusuke Konishi2c2e52f2009-04-06 19:01:54 -0700133 u64 ns_prot_seq;
Ryusuke Konishi32502042010-06-29 14:42:13 +0900134 u64 ns_prev_seq;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700135
136 struct rw_semaphore ns_segctor_sem;
137
138 /*
139 * Following fields are lock free except for the period before
140 * the_nilfs is initialized.
141 */
142 struct inode *ns_dat;
143 struct inode *ns_cpfile;
144 struct inode *ns_sufile;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700145
Ryusuke Konishiba65ae42010-08-14 12:59:15 +0900146 /* Checkpoint tree */
147 struct rb_root ns_cptree;
148 spinlock_t ns_cptree_lock;
149
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900150 /* GC inode list */
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700151 struct list_head ns_gc_inodes;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700152
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700153 /* Disk layout information (static) */
154 unsigned int ns_blocksize_bits;
Ryusuke Konishi92c60cc2010-05-23 00:17:48 +0900155 unsigned int ns_blocksize;
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700156 unsigned long ns_nsegments;
157 unsigned long ns_blocks_per_segment;
158 unsigned long ns_r_segments_percentage;
159 unsigned long ns_nrsvsegs;
160 unsigned long ns_first_data_block;
161 int ns_inode_size;
162 int ns_first_ino;
163 u32 ns_crc_seed;
164};
165
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700166#define THE_NILFS_FNS(bit, name) \
167static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
168{ \
169 set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
170} \
171static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
172{ \
173 clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
174} \
175static inline int nilfs_##name(struct the_nilfs *nilfs) \
176{ \
177 return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
178}
179
180THE_NILFS_FNS(INIT, init)
181THE_NILFS_FNS(LOADED, loaded)
182THE_NILFS_FNS(DISCONTINUED, discontinued)
Jiro SEKIBA1cf58fa2009-09-03 22:24:17 +0900183THE_NILFS_FNS(GC_RUNNING, gc_running)
Ryusuke Konishie605f0a2009-12-09 00:57:52 +0900184THE_NILFS_FNS(SB_DIRTY, sb_dirty)
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700185
Ryusuke Konishiba65ae42010-08-14 12:59:15 +0900186/**
187 * struct nilfs_root - nilfs root object
188 * @cno: checkpoint number
189 * @rb_node: red-black tree node
190 * @count: refcount of this structure
191 * @nilfs: nilfs object
192 * @ifile: inode file
193 * @root: root inode
194 * @inodes_count: number of inodes
195 * @blocks_count: number of blocks (Reserved)
196 */
197struct nilfs_root {
198 __u64 cno;
199 struct rb_node rb_node;
200
201 atomic_t count;
202 struct the_nilfs *nilfs;
203 struct inode *ifile;
204
205 atomic_t inodes_count;
206 atomic_t blocks_count;
207};
208
209/* Special checkpoint number */
210#define NILFS_CPTREE_CURRENT_CNO 0
211
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700212/* Minimum interval of periodical update of superblocks (in seconds) */
213#define NILFS_SB_FREQ 10
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700214
Jiro SEKIBA79efdd92009-07-23 01:26:34 +0900215static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
216{
217 u64 t = get_seconds();
Jiro SEKIBAb2ac86e2010-06-28 17:49:33 +0900218 return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ;
Jiro SEKIBA79efdd92009-07-23 01:26:34 +0900219}
220
Jiro SEKIBAb2ac86e2010-06-28 17:49:33 +0900221static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)
Jiro SEKIBA79efdd92009-07-23 01:26:34 +0900222{
Jiro SEKIBAb2ac86e2010-06-28 17:49:33 +0900223 int flip_bits = nilfs->ns_sbwcount & 0x0FL;
224 return (flip_bits != 0x08 && flip_bits != 0x0F);
Jiro SEKIBA79efdd92009-07-23 01:26:34 +0900225}
226
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700227void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
Ryusuke Konishi348fe8d2010-09-09 02:07:56 +0900228struct the_nilfs *alloc_nilfs(struct block_device *bdev);
229void destroy_nilfs(struct the_nilfs *nilfs);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700230int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
231int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
Jiro SEKIBAe902ec92010-01-30 18:06:35 +0900232int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700233int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
Ryusuke Konishiba65ae42010-08-14 12:59:15 +0900234struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno);
235struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,
236 __u64 cno);
237void nilfs_put_root(struct nilfs_root *root);
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900238struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700239int nilfs_near_disk_full(struct the_nilfs *);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700240void nilfs_fall_back_super_block(struct the_nilfs *);
241void nilfs_swap_super_block(struct the_nilfs *);
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700242
243
Ryusuke Konishiba65ae42010-08-14 12:59:15 +0900244static inline void nilfs_get_root(struct nilfs_root *root)
245{
246 atomic_inc(&root->count);
247}
248
Ryusuke Konishia057d2c2009-11-19 19:58:46 +0900249static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
250{
251 unsigned valid_fs;
252
253 down_read(&nilfs->ns_sem);
254 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
255 up_read(&nilfs->ns_sem);
256 return valid_fs;
257}
258
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700259static inline void
260nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
261 sector_t *seg_start, sector_t *seg_end)
262{
263 *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;
264 *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;
265 if (segnum == 0)
266 *seg_start = nilfs->ns_first_data_block;
267}
268
269static inline sector_t
270nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
271{
272 return (segnum == 0) ? nilfs->ns_first_data_block :
273 (sector_t)nilfs->ns_blocks_per_segment * segnum;
274}
275
276static inline __u64
277nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
278{
279 sector_t segnum = blocknr;
280
281 sector_div(segnum, nilfs->ns_blocks_per_segment);
282 return segnum;
283}
284
285static inline void
286nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
287 sector_t seg_end)
288{
289 /* terminate the current full segment (used in case of I/O-error) */
290 nilfs->ns_pseg_offset = seg_end - seg_start + 1;
291}
292
293static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
294{
295 /* move forward with a full segment */
296 nilfs->ns_segnum = nilfs->ns_nextnum;
297 nilfs->ns_pseg_offset = 0;
298 nilfs->ns_seg_seq++;
299}
300
301static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
302{
303 __u64 cno;
304
305 spin_lock(&nilfs->ns_last_segment_lock);
306 cno = nilfs->ns_last_cno;
307 spin_unlock(&nilfs->ns_last_segment_lock);
308 return cno;
309}
310
Ryusuke Konishicece5522009-04-06 19:01:58 -0700311static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
312{
313 return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
314}
315
Ryusuke Konishi65b46432009-04-06 19:01:23 -0700316#endif /* _THE_NILFS_H */