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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 * 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 Koji Sato <koji@osrg.net>.
21 */
22
23#ifndef _NILFS_BMAP_H
24#define _NILFS_BMAP_H
25
26#include <linux/types.h>
27#include <linux/fs.h>
28#include <linux/buffer_head.h>
29#include <linux/nilfs2_fs.h>
30#include "alloc.h"
31#include "dat.h"
32
33#define NILFS_BMAP_INVALID_PTR 0
34
35#define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff))
36
37
38struct nilfs_bmap;
39
40/**
41 * union nilfs_bmap_ptr_req - request for bmap ptr
42 * @bpr_ptr: bmap pointer
43 * @bpr_req: request for persistent allocator
44 */
45union nilfs_bmap_ptr_req {
46 __u64 bpr_ptr;
47 struct nilfs_palloc_req bpr_req;
48};
49
50/**
51 * struct nilfs_bmap_stats - bmap statistics
52 * @bs_nblocks: number of blocks created or deleted
53 */
54struct nilfs_bmap_stats {
55 unsigned int bs_nblocks;
56};
57
58/**
59 * struct nilfs_bmap_operations - bmap operation table
60 */
61struct nilfs_bmap_operations {
62 int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
63 int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
64 unsigned);
65 int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
66 int (*bop_delete)(struct nilfs_bmap *, __u64);
67 void (*bop_clear)(struct nilfs_bmap *);
68
69 int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
70 void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
71 struct list_head *);
72
73 int (*bop_assign)(struct nilfs_bmap *,
74 struct buffer_head **,
75 sector_t,
76 union nilfs_binfo *);
77 int (*bop_mark)(struct nilfs_bmap *, __u64, int);
78
79 /* The following functions are internal use only. */
80 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
81 int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
82 int (*bop_check_delete)(struct nilfs_bmap *, __u64);
83 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
84};
85
86
87#define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
88#define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
89#define NILFS_BMAP_NEW_PTR_INIT \
90 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
91
92static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
93{
94 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
95}
96
97
98/**
99 * struct nilfs_bmap - bmap structure
100 * @b_u: raw data
101 * @b_sem: semaphore
102 * @b_inode: owner of bmap
103 * @b_ops: bmap operation table
104 * @b_last_allocated_key: last allocated key for data block
105 * @b_last_allocated_ptr: last allocated ptr for data block
106 * @b_ptr_type: pointer type
107 * @b_state: state
108 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
109 */
110struct nilfs_bmap {
111 union {
112 __u8 u_flags;
113 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
114 } b_u;
115 struct rw_semaphore b_sem;
116 struct inode *b_inode;
117 const struct nilfs_bmap_operations *b_ops;
118 __u64 b_last_allocated_key;
119 __u64 b_last_allocated_ptr;
120 int b_ptr_type;
121 int b_state;
122 __u16 b_nchildren_per_block;
123};
124
125/* pointer type */
126#define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
127#define NILFS_BMAP_PTR_VS 1 /* virtual block number (single
128 version) */
129#define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple
130 versions) */
131#define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
132
133#define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
134
135/* state */
136#define NILFS_BMAP_DIRTY 0x00000001
137
138/**
139 * struct nilfs_bmap_store - shadow copy of bmap state
140 * @data: cached raw block mapping of on-disk inode
141 * @last_allocated_key: cached value of last allocated key for data block
142 * @last_allocated_ptr: cached value of last allocated ptr for data block
143 * @state: cached value of state field of bmap structure
144 */
145struct nilfs_bmap_store {
146 __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
147 __u64 last_allocated_key;
148 __u64 last_allocated_ptr;
149 int state;
150};
151
152int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
153int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
154void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
155int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
156int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
157int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
158int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
159int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
160void nilfs_bmap_clear(struct nilfs_bmap *);
161int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
162void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
163int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
164 unsigned long, union nilfs_binfo *);
165int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
166int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
167
168void nilfs_bmap_init_gc(struct nilfs_bmap *);
169
170void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
171void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
172
173static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
174 __u64 *ptr)
175{
176 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
177}
178
179/*
180 * Internal use only
181 */
182struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
183
184static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
185 union nilfs_bmap_ptr_req *req,
186 struct inode *dat)
187{
188 if (dat)
189 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
190 /* ignore target ptr */
191 req->bpr_ptr = bmap->b_last_allocated_ptr++;
192 return 0;
193}
194
195static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
196 union nilfs_bmap_ptr_req *req,
197 struct inode *dat)
198{
199 if (dat)
200 nilfs_dat_commit_alloc(dat, &req->bpr_req);
201}
202
203static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
204 union nilfs_bmap_ptr_req *req,
205 struct inode *dat)
206{
207 if (dat)
208 nilfs_dat_abort_alloc(dat, &req->bpr_req);
209 else
210 bmap->b_last_allocated_ptr--;
211}
212
213static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
214 union nilfs_bmap_ptr_req *req,
215 struct inode *dat)
216{
217 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
218}
219
220static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
221 union nilfs_bmap_ptr_req *req,
222 struct inode *dat)
223{
224 if (dat)
225 nilfs_dat_commit_end(dat, &req->bpr_req,
226 bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
227}
228
229static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
230 union nilfs_bmap_ptr_req *req,
231 struct inode *dat)
232{
233 if (dat)
234 nilfs_dat_abort_end(dat, &req->bpr_req);
235}
236
237static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
238 __u64 ptr)
239{
240 bmap->b_last_allocated_key = key;
241 bmap->b_last_allocated_ptr = ptr;
242}
243
244__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
245 const struct buffer_head *);
246
247__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
248__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
249
250
251/* Assume that bmap semaphore is locked. */
252static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
253{
254 return !!(bmap->b_state & NILFS_BMAP_DIRTY);
255}
256
257/* Assume that bmap semaphore is locked. */
258static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
259{
260 bmap->b_state |= NILFS_BMAP_DIRTY;
261}
262
263/* Assume that bmap semaphore is locked. */
264static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
265{
266 bmap->b_state &= ~NILFS_BMAP_DIRTY;
267}
268
269
270#define NILFS_BMAP_LARGE 0x1
271
272#define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
273#define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
274#define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
275#define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
276
277#endif /* _NILFS_BMAP_H */