xref: /openbmc/linux/fs/nilfs2/bmap.h (revision 82ced6fd)
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 
32 #define NILFS_BMAP_INVALID_PTR	0
33 
34 #define nilfs_bmap_dkey_to_key(dkey)	le64_to_cpu(dkey)
35 #define nilfs_bmap_key_to_dkey(key)	cpu_to_le64(key)
36 #define nilfs_bmap_dptr_to_ptr(dptr)	le64_to_cpu(dptr)
37 #define nilfs_bmap_ptr_to_dptr(ptr)	cpu_to_le64(ptr)
38 
39 #define nilfs_bmap_keydiff_abs(diff)	((diff) < 0 ? -(diff) : (diff))
40 
41 
42 struct nilfs_bmap;
43 
44 /**
45  * union nilfs_bmap_ptr_req - request for bmap ptr
46  * @bpr_ptr: bmap pointer
47  * @bpr_req: request for persistent allocator
48  */
49 union nilfs_bmap_ptr_req {
50 	__u64 bpr_ptr;
51 	struct nilfs_palloc_req bpr_req;
52 };
53 
54 /**
55  * struct nilfs_bmap_stats - bmap statistics
56  * @bs_nblocks: number of blocks created or deleted
57  */
58 struct nilfs_bmap_stats {
59 	unsigned int bs_nblocks;
60 };
61 
62 /**
63  * struct nilfs_bmap_operations - bmap operation table
64  */
65 struct nilfs_bmap_operations {
66 	int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
67 	int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
68 	int (*bop_delete)(struct nilfs_bmap *, __u64);
69 	void (*bop_clear)(struct nilfs_bmap *);
70 
71 	int (*bop_propagate)(const struct nilfs_bmap *, struct buffer_head *);
72 	void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
73 					 struct list_head *);
74 
75 	int (*bop_assign)(struct nilfs_bmap *,
76 			  struct buffer_head **,
77 			  sector_t,
78 			  union nilfs_binfo *);
79 	int (*bop_mark)(struct nilfs_bmap *, __u64, int);
80 
81 	/* The following functions are internal use only. */
82 	int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
83 	int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
84 	int (*bop_check_delete)(struct nilfs_bmap *, __u64);
85 	int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
86 };
87 
88 
89 /**
90  * struct nilfs_bmap_ptr_operations - bmap ptr operation table
91  */
92 struct nilfs_bmap_ptr_operations {
93 	int (*bpop_prepare_alloc_ptr)(struct nilfs_bmap *,
94 				      union nilfs_bmap_ptr_req *);
95 	void (*bpop_commit_alloc_ptr)(struct nilfs_bmap *,
96 				      union nilfs_bmap_ptr_req *);
97 	void (*bpop_abort_alloc_ptr)(struct nilfs_bmap *,
98 				     union nilfs_bmap_ptr_req *);
99 	int (*bpop_prepare_start_ptr)(struct nilfs_bmap *,
100 				      union nilfs_bmap_ptr_req *);
101 	void (*bpop_commit_start_ptr)(struct nilfs_bmap *,
102 				      union nilfs_bmap_ptr_req *,
103 				      sector_t);
104 	void (*bpop_abort_start_ptr)(struct nilfs_bmap *,
105 				     union nilfs_bmap_ptr_req *);
106 	int (*bpop_prepare_end_ptr)(struct nilfs_bmap *,
107 				    union nilfs_bmap_ptr_req *);
108 	void (*bpop_commit_end_ptr)(struct nilfs_bmap *,
109 				    union nilfs_bmap_ptr_req *);
110 	void (*bpop_abort_end_ptr)(struct nilfs_bmap *,
111 				   union nilfs_bmap_ptr_req *);
112 
113 	int (*bpop_translate)(const struct nilfs_bmap *, __u64, __u64 *);
114 };
115 
116 
117 #define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
118 #define NILFS_BMAP_KEY_BIT	(sizeof(unsigned long) * 8 /* CHAR_BIT */)
119 #define NILFS_BMAP_NEW_PTR_INIT	\
120 	(1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
121 
122 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
123 {
124 	return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
125 }
126 
127 
128 /**
129  * struct nilfs_bmap - bmap structure
130  * @b_u: raw data
131  * @b_sem: semaphore
132  * @b_inode: owner of bmap
133  * @b_ops: bmap operation table
134  * @b_pops: bmap ptr operation table
135  * @b_low: low watermark of conversion
136  * @b_high: high watermark of conversion
137  * @b_last_allocated_key: last allocated key for data block
138  * @b_last_allocated_ptr: last allocated ptr for data block
139  * @b_state: state
140  */
141 struct nilfs_bmap {
142 	union {
143 		__u8 u_flags;
144 		__le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
145 	} b_u;
146 	struct rw_semaphore b_sem;
147 	struct inode *b_inode;
148 	const struct nilfs_bmap_operations *b_ops;
149 	const struct nilfs_bmap_ptr_operations *b_pops;
150 	__u64 b_low;
151 	__u64 b_high;
152 	__u64 b_last_allocated_key;
153 	__u64 b_last_allocated_ptr;
154 	int b_state;
155 };
156 
157 /* state */
158 #define NILFS_BMAP_DIRTY	0x00000001
159 
160 
161 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
162 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
163 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
164 int nilfs_bmap_lookup(struct nilfs_bmap *, unsigned long, unsigned long *);
165 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
166 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
167 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
168 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
169 void nilfs_bmap_clear(struct nilfs_bmap *);
170 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
171 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
172 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
173 		      unsigned long, union nilfs_binfo *);
174 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
175 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
176 
177 void nilfs_bmap_init_gc(struct nilfs_bmap *);
178 void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
179 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
180 
181 
182 /*
183  * Internal use only
184  */
185 
186 int nilfs_bmap_move_v(const struct nilfs_bmap *, __u64, sector_t);
187 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *, __u64);
188 
189 
190 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
191 			      const struct buffer_head *);
192 
193 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
194 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
195 
196 int nilfs_bmap_prepare_update(struct nilfs_bmap *,
197 			      union nilfs_bmap_ptr_req *,
198 			      union nilfs_bmap_ptr_req *);
199 void nilfs_bmap_commit_update(struct nilfs_bmap *,
200 			      union nilfs_bmap_ptr_req *,
201 			      union nilfs_bmap_ptr_req *);
202 void nilfs_bmap_abort_update(struct nilfs_bmap *,
203 			     union nilfs_bmap_ptr_req *,
204 			     union nilfs_bmap_ptr_req *);
205 
206 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
207 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
208 
209 
210 int nilfs_bmap_get_block(const struct nilfs_bmap *, __u64,
211 			 struct buffer_head **);
212 void nilfs_bmap_put_block(const struct nilfs_bmap *, struct buffer_head *);
213 int nilfs_bmap_get_new_block(const struct nilfs_bmap *, __u64,
214 			     struct buffer_head **);
215 void nilfs_bmap_delete_block(const struct nilfs_bmap *, struct buffer_head *);
216 
217 
218 /* Assume that bmap semaphore is locked. */
219 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
220 {
221 	return !!(bmap->b_state & NILFS_BMAP_DIRTY);
222 }
223 
224 /* Assume that bmap semaphore is locked. */
225 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
226 {
227 	bmap->b_state |= NILFS_BMAP_DIRTY;
228 }
229 
230 /* Assume that bmap semaphore is locked. */
231 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
232 {
233 	bmap->b_state &= ~NILFS_BMAP_DIRTY;
234 }
235 
236 
237 #define NILFS_BMAP_LARGE	0x1
238 
239 #define NILFS_BMAP_SMALL_LOW	NILFS_DIRECT_KEY_MIN
240 #define NILFS_BMAP_SMALL_HIGH	NILFS_DIRECT_KEY_MAX
241 #define NILFS_BMAP_LARGE_LOW	NILFS_BTREE_ROOT_NCHILDREN_MAX
242 #define NILFS_BMAP_LARGE_HIGH	NILFS_BTREE_KEY_MAX
243 
244 #endif	/* _NILFS_BMAP_H */
245