1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * NILFS block mapping.
4 *
5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Koji Sato.
8 */
9
10#ifndef _NILFS_BMAP_H
11#define _NILFS_BMAP_H
12
13#include <linux/types.h>
14#include <linux/fs.h>
15#include <linux/buffer_head.h>
16#include <linux/nilfs2_ondisk.h>	/* nilfs_binfo, nilfs_inode, etc */
17#include "alloc.h"
18#include "dat.h"
19
20#define NILFS_BMAP_INVALID_PTR	0
21
22#define nilfs_bmap_keydiff_abs(diff)	((diff) < 0 ? -(diff) : (diff))
23
24
25struct nilfs_bmap;
26
27/**
28 * union nilfs_bmap_ptr_req - request for bmap ptr
29 * @bpr_ptr: bmap pointer
30 * @bpr_req: request for persistent allocator
31 */
32union nilfs_bmap_ptr_req {
33	__u64 bpr_ptr;
34	struct nilfs_palloc_req bpr_req;
35};
36
37/**
38 * struct nilfs_bmap_stats - bmap statistics
39 * @bs_nblocks: number of blocks created or deleted
40 */
41struct nilfs_bmap_stats {
42	unsigned int bs_nblocks;
43};
44
45/**
46 * struct nilfs_bmap_operations - bmap operation table
47 */
48struct nilfs_bmap_operations {
49	int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
50	int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
51				 unsigned int);
52	int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
53	int (*bop_delete)(struct nilfs_bmap *, __u64);
54	void (*bop_clear)(struct nilfs_bmap *);
55
56	int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
57	void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
58					 struct list_head *);
59
60	int (*bop_assign)(struct nilfs_bmap *,
61			  struct buffer_head **,
62			  sector_t,
63			  union nilfs_binfo *);
64	int (*bop_mark)(struct nilfs_bmap *, __u64, int);
65
66	int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
67	int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
68
69	/* The following functions are internal use only. */
70	int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
71	int (*bop_check_delete)(struct nilfs_bmap *, __u64);
72	int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
73};
74
75
76#define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
77#define NILFS_BMAP_KEY_BIT	(sizeof(unsigned long) * 8 /* CHAR_BIT */)
78#define NILFS_BMAP_NEW_PTR_INIT	\
79	(1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
80
81static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
82{
83	return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
84}
85
86
87/**
88 * struct nilfs_bmap - bmap structure
89 * @b_u: raw data
90 * @b_sem: semaphore
91 * @b_inode: owner of bmap
92 * @b_ops: bmap operation table
93 * @b_last_allocated_key: last allocated key for data block
94 * @b_last_allocated_ptr: last allocated ptr for data block
95 * @b_ptr_type: pointer type
96 * @b_state: state
97 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
98 */
99struct nilfs_bmap {
100	union {
101		__u8 u_flags;
102		__le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
103	} b_u;
104	struct rw_semaphore b_sem;
105	struct inode *b_inode;
106	const struct nilfs_bmap_operations *b_ops;
107	__u64 b_last_allocated_key;
108	__u64 b_last_allocated_ptr;
109	int b_ptr_type;
110	int b_state;
111	__u16 b_nchildren_per_block;
112};
113
114/* pointer type */
115#define NILFS_BMAP_PTR_P	0	/* physical block number (i.e. LBN) */
116#define NILFS_BMAP_PTR_VS	1	/*
117					 * virtual block number (single
118					 * version)
119					 */
120#define NILFS_BMAP_PTR_VM	2	/*
121					 * virtual block number (has multiple
122					 * versions)
123					 */
124#define NILFS_BMAP_PTR_U	(-1)	/* never perform pointer operations */
125
126#define NILFS_BMAP_USE_VBN(bmap)	((bmap)->b_ptr_type > 0)
127
128/* state */
129#define NILFS_BMAP_DIRTY	0x00000001
130
131/**
132 * struct nilfs_bmap_store - shadow copy of bmap state
133 * @data: cached raw block mapping of on-disk inode
134 * @last_allocated_key: cached value of last allocated key for data block
135 * @last_allocated_ptr: cached value of last allocated ptr for data block
136 * @state: cached value of state field of bmap structure
137 */
138struct nilfs_bmap_store {
139	__le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
140	__u64 last_allocated_key;
141	__u64 last_allocated_ptr;
142	int state;
143};
144
145int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
146int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
147void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
148int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
149int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
150int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
151int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
152int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
153int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
154void nilfs_bmap_clear(struct nilfs_bmap *);
155int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
156void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
157int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
158		      unsigned long, union nilfs_binfo *);
159int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
160int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
161
162void nilfs_bmap_init_gc(struct nilfs_bmap *);
163
164void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
165void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
166
167static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
168				    __u64 *ptr)
169{
170	return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
171}
172
173/*
174 * Internal use only
175 */
176struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
177
178static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
179					       union nilfs_bmap_ptr_req *req,
180					       struct inode *dat)
181{
182	if (dat)
183		return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
184	/* ignore target ptr */
185	req->bpr_ptr = bmap->b_last_allocated_ptr++;
186	return 0;
187}
188
189static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
190					       union nilfs_bmap_ptr_req *req,
191					       struct inode *dat)
192{
193	if (dat)
194		nilfs_dat_commit_alloc(dat, &req->bpr_req);
195}
196
197static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
198					      union nilfs_bmap_ptr_req *req,
199					      struct inode *dat)
200{
201	if (dat)
202		nilfs_dat_abort_alloc(dat, &req->bpr_req);
203	else
204		bmap->b_last_allocated_ptr--;
205}
206
207static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
208					     union nilfs_bmap_ptr_req *req,
209					     struct inode *dat)
210{
211	return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
212}
213
214static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
215					     union nilfs_bmap_ptr_req *req,
216					     struct inode *dat)
217{
218	if (dat)
219		nilfs_dat_commit_end(dat, &req->bpr_req,
220				     bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
221}
222
223static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
224					    union nilfs_bmap_ptr_req *req,
225					    struct inode *dat)
226{
227	if (dat)
228		nilfs_dat_abort_end(dat, &req->bpr_req);
229}
230
231static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
232					   __u64 ptr)
233{
234	bmap->b_last_allocated_key = key;
235	bmap->b_last_allocated_ptr = ptr;
236}
237
238__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
239			      const struct buffer_head *);
240
241__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
242__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
243
244
245/* Assume that bmap semaphore is locked. */
246static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
247{
248	return !!(bmap->b_state & NILFS_BMAP_DIRTY);
249}
250
251/* Assume that bmap semaphore is locked. */
252static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
253{
254	bmap->b_state |= NILFS_BMAP_DIRTY;
255}
256
257/* Assume that bmap semaphore is locked. */
258static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
259{
260	bmap->b_state &= ~NILFS_BMAP_DIRTY;
261}
262
263
264#define NILFS_BMAP_LARGE	0x1
265
266#define NILFS_BMAP_SMALL_LOW	NILFS_DIRECT_KEY_MIN
267#define NILFS_BMAP_SMALL_HIGH	NILFS_DIRECT_KEY_MAX
268#define NILFS_BMAP_LARGE_LOW	NILFS_BTREE_ROOT_NCHILDREN_MAX
269#define NILFS_BMAP_LARGE_HIGH	NILFS_BTREE_KEY_MAX
270
271#endif	/* _NILFS_BMAP_H */
272