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1/*
2 * bmap.h - NILFS block mapping.
3 *
4 * Copyright (C) 2006-2008 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 * Written by Koji Sato.
17 */
18
19#ifndef _NILFS_BMAP_H
20#define _NILFS_BMAP_H
21
22#include <linux/types.h>
23#include <linux/fs.h>
24#include <linux/buffer_head.h>
25#include <linux/nilfs2_ondisk.h> /* nilfs_binfo, nilfs_inode, etc */
26#include "alloc.h"
27#include "dat.h"
28
29#define NILFS_BMAP_INVALID_PTR 0
30
31#define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff))
32
33
34struct nilfs_bmap;
35
36/**
37 * union nilfs_bmap_ptr_req - request for bmap ptr
38 * @bpr_ptr: bmap pointer
39 * @bpr_req: request for persistent allocator
40 */
41union nilfs_bmap_ptr_req {
42 __u64 bpr_ptr;
43 struct nilfs_palloc_req bpr_req;
44};
45
46/**
47 * struct nilfs_bmap_stats - bmap statistics
48 * @bs_nblocks: number of blocks created or deleted
49 */
50struct nilfs_bmap_stats {
51 unsigned int bs_nblocks;
52};
53
54/**
55 * struct nilfs_bmap_operations - bmap operation table
56 */
57struct nilfs_bmap_operations {
58 int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
59 int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
60 unsigned int);
61 int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
62 int (*bop_delete)(struct nilfs_bmap *, __u64);
63 void (*bop_clear)(struct nilfs_bmap *);
64
65 int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
66 void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
67 struct list_head *);
68
69 int (*bop_assign)(struct nilfs_bmap *,
70 struct buffer_head **,
71 sector_t,
72 union nilfs_binfo *);
73 int (*bop_mark)(struct nilfs_bmap *, __u64, int);
74
75 int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
76 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
77
78 /* The following functions are internal use only. */
79 int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
80 int (*bop_check_delete)(struct nilfs_bmap *, __u64);
81 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
82};
83
84
85#define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
86#define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
87#define NILFS_BMAP_NEW_PTR_INIT \
88 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
89
90static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
91{
92 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
93}
94
95
96/**
97 * struct nilfs_bmap - bmap structure
98 * @b_u: raw data
99 * @b_sem: semaphore
100 * @b_inode: owner of bmap
101 * @b_ops: bmap operation table
102 * @b_last_allocated_key: last allocated key for data block
103 * @b_last_allocated_ptr: last allocated ptr for data block
104 * @b_ptr_type: pointer type
105 * @b_state: state
106 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
107 */
108struct nilfs_bmap {
109 union {
110 __u8 u_flags;
111 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
112 } b_u;
113 struct rw_semaphore b_sem;
114 struct inode *b_inode;
115 const struct nilfs_bmap_operations *b_ops;
116 __u64 b_last_allocated_key;
117 __u64 b_last_allocated_ptr;
118 int b_ptr_type;
119 int b_state;
120 __u16 b_nchildren_per_block;
121};
122
123/* pointer type */
124#define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
125#define NILFS_BMAP_PTR_VS 1 /*
126 * virtual block number (single
127 * version)
128 */
129#define NILFS_BMAP_PTR_VM 2 /*
130 * virtual block number (has multiple
131 * versions)
132 */
133#define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
134
135#define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
136
137/* state */
138#define NILFS_BMAP_DIRTY 0x00000001
139
140/**
141 * struct nilfs_bmap_store - shadow copy of bmap state
142 * @data: cached raw block mapping of on-disk inode
143 * @last_allocated_key: cached value of last allocated key for data block
144 * @last_allocated_ptr: cached value of last allocated ptr for data block
145 * @state: cached value of state field of bmap structure
146 */
147struct nilfs_bmap_store {
148 __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
149 __u64 last_allocated_key;
150 __u64 last_allocated_ptr;
151 int state;
152};
153
154int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
155int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
156void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
157int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
158int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
159int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
160int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
161int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
162int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
163void nilfs_bmap_clear(struct nilfs_bmap *);
164int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
165void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
166int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
167 unsigned long, union nilfs_binfo *);
168int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
169int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
170
171void nilfs_bmap_init_gc(struct nilfs_bmap *);
172
173void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
174void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
175
176static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
177 __u64 *ptr)
178{
179 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
180}
181
182/*
183 * Internal use only
184 */
185struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
186
187static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
188 union nilfs_bmap_ptr_req *req,
189 struct inode *dat)
190{
191 if (dat)
192 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
193 /* ignore target ptr */
194 req->bpr_ptr = bmap->b_last_allocated_ptr++;
195 return 0;
196}
197
198static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
199 union nilfs_bmap_ptr_req *req,
200 struct inode *dat)
201{
202 if (dat)
203 nilfs_dat_commit_alloc(dat, &req->bpr_req);
204}
205
206static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
207 union nilfs_bmap_ptr_req *req,
208 struct inode *dat)
209{
210 if (dat)
211 nilfs_dat_abort_alloc(dat, &req->bpr_req);
212 else
213 bmap->b_last_allocated_ptr--;
214}
215
216static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
217 union nilfs_bmap_ptr_req *req,
218 struct inode *dat)
219{
220 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
221}
222
223static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
224 union nilfs_bmap_ptr_req *req,
225 struct inode *dat)
226{
227 if (dat)
228 nilfs_dat_commit_end(dat, &req->bpr_req,
229 bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
230}
231
232static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
233 union nilfs_bmap_ptr_req *req,
234 struct inode *dat)
235{
236 if (dat)
237 nilfs_dat_abort_end(dat, &req->bpr_req);
238}
239
240static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
241 __u64 ptr)
242{
243 bmap->b_last_allocated_key = key;
244 bmap->b_last_allocated_ptr = ptr;
245}
246
247__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
248 const struct buffer_head *);
249
250__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
251__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
252
253
254/* Assume that bmap semaphore is locked. */
255static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
256{
257 return !!(bmap->b_state & NILFS_BMAP_DIRTY);
258}
259
260/* Assume that bmap semaphore is locked. */
261static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
262{
263 bmap->b_state |= NILFS_BMAP_DIRTY;
264}
265
266/* Assume that bmap semaphore is locked. */
267static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
268{
269 bmap->b_state &= ~NILFS_BMAP_DIRTY;
270}
271
272
273#define NILFS_BMAP_LARGE 0x1
274
275#define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
276#define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
277#define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
278#define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
279
280#endif /* _NILFS_BMAP_H */