nilfs2: move parameters on nilfs_sb_info into nilfs object
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nilfs2 / the_nilfs.h
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1/*
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>
ba65ae47 29#include <linux/rbtree.h>
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30#include <linux/fs.h>
31#include <linux/blkdev.h>
32#include <linux/backing-dev.h>
5a0e3ad6 33#include <linux/slab.h>
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34#include "sb.h"
35
36/* the_nilfs struct */
37enum {
38 THE_NILFS_INIT = 0, /* Information from super_block is set */
65b4643d 39 THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
1cf58fa8 40 THE_NILFS_GC_RUNNING, /* gc process is running */
e605f0a7 41 THE_NILFS_SB_DIRTY, /* super block is dirty */
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42};
43
44/**
45 * struct the_nilfs - struct to supervise multiple nilfs mount points
46 * @ns_flags: flags
65b4643d 47 * @ns_bdev: block device
65b4643d 48 * @ns_sem: semaphore for shared states
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49 * @ns_sbh: buffer heads of on-disk super blocks
50 * @ns_sbp: pointers to super block data
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51 * @ns_sbwtime: previous write time of super block
52 * @ns_sbwcount: write count of super block
e339ad31 53 * @ns_sbsize: size of valid data in super block
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54 * @ns_seg_seq: segment sequence counter
55 * @ns_segnum: index number of the latest full segment.
56 * @ns_nextnum: index number of the full segment index to be used next
57 * @ns_pseg_offset: offset of next partial segment in the current full segment
58 * @ns_cno: next checkpoint number
59 * @ns_ctime: write time of the last segment
60 * @ns_nongc_ctime: write time of the last segment not for cleaner operation
61 * @ns_ndirtyblks: Number of dirty data blocks
62 * @ns_last_segment_lock: lock protecting fields for the latest segment
63 * @ns_last_pseg: start block number of the latest segment
64 * @ns_last_seq: sequence value of the latest segment
65 * @ns_last_cno: checkpoint number of the latest segment
2c2e52fc 66 * @ns_prot_seq: least sequence number of segments which must not be reclaimed
32502047 67 * @ns_prev_seq: base sequence number used to decide if advance log cursor
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68 * @ns_segctor_sem: segment constructor semaphore
69 * @ns_dat: DAT file inode
70 * @ns_cpfile: checkpoint file inode
71 * @ns_sufile: segusage file inode
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72 * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)
73 * @ns_cptree_lock: lock protecting @ns_cptree
65b4643d 74 * @ns_gc_inodes: dummy inodes to keep live blocks
3b2ce58b 75 * @ns_mount_opt: mount options
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76 * @ns_resuid: uid for reserved blocks
77 * @ns_resgid: gid for reserved blocks
78 * @ns_interval: checkpoint creation interval
79 * @ns_watermark: watermark for the number of dirty buffers
65b4643d 80 * @ns_blocksize_bits: bit length of block size
92c60cca 81 * @ns_blocksize: block size
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82 * @ns_nsegments: number of segments in filesystem
83 * @ns_blocks_per_segment: number of blocks per segment
84 * @ns_r_segments_percentage: reserved segments percentage
85 * @ns_nrsvsegs: number of reserved segments
86 * @ns_first_data_block: block number of first data block
87 * @ns_inode_size: size of on-disk inode
88 * @ns_first_ino: first not-special inode number
89 * @ns_crc_seed: seed value of CRC32 calculation
90 */
91struct the_nilfs {
92 unsigned long ns_flags;
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93
94 struct block_device *ns_bdev;
65b4643d 95 struct rw_semaphore ns_sem;
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96
97 /*
98 * used for
99 * - loading the latest checkpoint exclusively.
100 * - allocating a new full segment.
101 * - protecting s_dirt in the super_block struct
102 * (see nilfs_write_super) and the following fields.
103 */
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104 struct buffer_head *ns_sbh[2];
105 struct nilfs_super_block *ns_sbp[2];
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106 time_t ns_sbwtime;
107 unsigned ns_sbwcount;
e339ad31 108 unsigned ns_sbsize;
65b4643d 109 unsigned ns_mount_state;
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110
111 /*
112 * Following fields are dedicated to a writable FS-instance.
113 * Except for the period seeking checkpoint, code outside the segment
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114 * constructor must lock a segment semaphore while accessing these
115 * fields.
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116 * The writable FS-instance is sole during a lifetime of the_nilfs.
117 */
118 u64 ns_seg_seq;
119 __u64 ns_segnum;
120 __u64 ns_nextnum;
121 unsigned long ns_pseg_offset;
122 __u64 ns_cno;
123 time_t ns_ctime;
124 time_t ns_nongc_ctime;
125 atomic_t ns_ndirtyblks;
126
127 /*
128 * The following fields hold information on the latest partial segment
129 * written to disk with a super root. These fields are protected by
130 * ns_last_segment_lock.
131 */
132 spinlock_t ns_last_segment_lock;
133 sector_t ns_last_pseg;
134 u64 ns_last_seq;
135 __u64 ns_last_cno;
2c2e52fc 136 u64 ns_prot_seq;
32502047 137 u64 ns_prev_seq;
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138
139 struct rw_semaphore ns_segctor_sem;
140
141 /*
142 * Following fields are lock free except for the period before
143 * the_nilfs is initialized.
144 */
145 struct inode *ns_dat;
146 struct inode *ns_cpfile;
147 struct inode *ns_sufile;
65b4643d 148
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149 /* Checkpoint tree */
150 struct rb_root ns_cptree;
151 spinlock_t ns_cptree_lock;
152
263d90ce 153 /* GC inode list */
65b4643d 154 struct list_head ns_gc_inodes;
65b4643d 155
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156 /* Mount options */
157 unsigned long ns_mount_opt;
158
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159 uid_t ns_resuid;
160 gid_t ns_resgid;
161 unsigned long ns_interval;
162 unsigned long ns_watermark;
163
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164 /* Disk layout information (static) */
165 unsigned int ns_blocksize_bits;
92c60cca 166 unsigned int ns_blocksize;
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167 unsigned long ns_nsegments;
168 unsigned long ns_blocks_per_segment;
169 unsigned long ns_r_segments_percentage;
170 unsigned long ns_nrsvsegs;
171 unsigned long ns_first_data_block;
172 int ns_inode_size;
173 int ns_first_ino;
174 u32 ns_crc_seed;
175};
176
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177#define THE_NILFS_FNS(bit, name) \
178static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
179{ \
180 set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
181} \
182static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
183{ \
184 clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
185} \
186static inline int nilfs_##name(struct the_nilfs *nilfs) \
187{ \
188 return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
189}
190
191THE_NILFS_FNS(INIT, init)
65b4643d 192THE_NILFS_FNS(DISCONTINUED, discontinued)
1cf58fa8 193THE_NILFS_FNS(GC_RUNNING, gc_running)
e605f0a7 194THE_NILFS_FNS(SB_DIRTY, sb_dirty)
65b4643d 195
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196/*
197 * Mount option operations
198 */
199#define nilfs_clear_opt(nilfs, opt) \
200 do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0)
201#define nilfs_set_opt(nilfs, opt) \
202 do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0)
203#define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt)
204#define nilfs_write_opt(nilfs, mask, opt) \
205 do { (nilfs)->ns_mount_opt = \
206 (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \
207 NILFS_MOUNT_##opt); \
208 } while (0)
209
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210/**
211 * struct nilfs_root - nilfs root object
212 * @cno: checkpoint number
213 * @rb_node: red-black tree node
214 * @count: refcount of this structure
215 * @nilfs: nilfs object
216 * @ifile: inode file
217 * @root: root inode
218 * @inodes_count: number of inodes
219 * @blocks_count: number of blocks (Reserved)
220 */
221struct nilfs_root {
222 __u64 cno;
223 struct rb_node rb_node;
224
225 atomic_t count;
226 struct the_nilfs *nilfs;
227 struct inode *ifile;
228
229 atomic_t inodes_count;
230 atomic_t blocks_count;
231};
232
233/* Special checkpoint number */
234#define NILFS_CPTREE_CURRENT_CNO 0
235
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236/* Minimum interval of periodical update of superblocks (in seconds) */
237#define NILFS_SB_FREQ 10
e339ad31 238
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239static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
240{
241 u64 t = get_seconds();
b2ac86e1 242 return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ;
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243}
244
b2ac86e1 245static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)
79efdd94 246{
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247 int flip_bits = nilfs->ns_sbwcount & 0x0FL;
248 return (flip_bits != 0x08 && flip_bits != 0x0F);
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249}
250
65b4643d 251void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
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252struct the_nilfs *alloc_nilfs(struct block_device *bdev);
253void destroy_nilfs(struct the_nilfs *nilfs);
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254int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
255int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
e902ec99 256int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
65b4643d 257int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
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258struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno);
259struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,
260 __u64 cno);
261void nilfs_put_root(struct nilfs_root *root);
6dd47406 262struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
65b4643d 263int nilfs_near_disk_full(struct the_nilfs *);
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264void nilfs_fall_back_super_block(struct the_nilfs *);
265void nilfs_swap_super_block(struct the_nilfs *);
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266
267
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268static inline void nilfs_get_root(struct nilfs_root *root)
269{
270 atomic_inc(&root->count);
271}
272
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273static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
274{
275 unsigned valid_fs;
276
277 down_read(&nilfs->ns_sem);
278 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
279 up_read(&nilfs->ns_sem);
280 return valid_fs;
281}
282
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283static inline void
284nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
285 sector_t *seg_start, sector_t *seg_end)
286{
287 *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;
288 *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;
289 if (segnum == 0)
290 *seg_start = nilfs->ns_first_data_block;
291}
292
293static inline sector_t
294nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
295{
296 return (segnum == 0) ? nilfs->ns_first_data_block :
297 (sector_t)nilfs->ns_blocks_per_segment * segnum;
298}
299
300static inline __u64
301nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
302{
303 sector_t segnum = blocknr;
304
305 sector_div(segnum, nilfs->ns_blocks_per_segment);
306 return segnum;
307}
308
309static inline void
310nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
311 sector_t seg_end)
312{
313 /* terminate the current full segment (used in case of I/O-error) */
314 nilfs->ns_pseg_offset = seg_end - seg_start + 1;
315}
316
317static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
318{
319 /* move forward with a full segment */
320 nilfs->ns_segnum = nilfs->ns_nextnum;
321 nilfs->ns_pseg_offset = 0;
322 nilfs->ns_seg_seq++;
323}
324
325static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
326{
327 __u64 cno;
328
329 spin_lock(&nilfs->ns_last_segment_lock);
330 cno = nilfs->ns_last_cno;
331 spin_unlock(&nilfs->ns_last_segment_lock);
332 return cno;
333}
334
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335static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
336{
337 return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
338}
339
65b4643d 340#endif /* _THE_NILFS_H */