bmap.h

  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 * @bop_lookup:               single block search operation
 48 * @bop_lookup_contig:        consecutive block search operation
 49 * @bop_insert:               block insertion operation
 50 * @bop_delete:               block delete operation
 51 * @bop_clear:                block mapping resource release operation
 52 * @bop_propagate:            operation to propagate dirty state towards the
 53 *                            mapping root
 54 * @bop_lookup_dirty_buffers: operation to collect dirty block buffers
 55 * @bop_assign:               disk block address assignment operation
 56 * @bop_mark:                 operation to mark in-use blocks as dirty for
 57 *                            relocation by GC
 58 * @bop_seek_key:             find valid block key operation
 59 * @bop_last_key:             find last valid block key operation
 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 int);
 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	int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
 80	int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
 81
 82	/* private: internal use only */
 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#define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
 90#define NILFS_BMAP_KEY_BIT	BITS_PER_LONG
 91#define NILFS_BMAP_NEW_PTR_INIT	(1UL << (BITS_PER_LONG - 1))
 92
 93static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
 94{
 95	return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
 96}
 97
 98
 99/**
100 * struct nilfs_bmap - bmap structure
101 * @b_u: raw data
102 * @b_sem: semaphore
103 * @b_inode: owner of bmap
104 * @b_ops: bmap operation table
105 * @b_last_allocated_key: last allocated key for data block
106 * @b_last_allocated_ptr: last allocated ptr for data block
107 * @b_ptr_type: pointer type
108 * @b_state: state
109 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
110 */
111struct nilfs_bmap {
112	union {
113		__u8 u_flags;
114		__le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
115	} b_u;
116	struct rw_semaphore b_sem;
117	struct inode *b_inode;
118	const struct nilfs_bmap_operations *b_ops;
119	__u64 b_last_allocated_key;
120	__u64 b_last_allocated_ptr;
121	int b_ptr_type;
122	int b_state;
123	__u16 b_nchildren_per_block;
124};
125
126/* pointer type */
127#define NILFS_BMAP_PTR_P	0	/* physical block number (i.e. LBN) */
128#define NILFS_BMAP_PTR_VS	1	/*
129					 * virtual block number (single
130					 * version)
131					 */
132#define NILFS_BMAP_PTR_VM	2	/*
133					 * virtual block number (has multiple
134					 * versions)
135					 */
136#define NILFS_BMAP_PTR_U	(-1)	/* never perform pointer operations */
137
138#define NILFS_BMAP_USE_VBN(bmap)	((bmap)->b_ptr_type > 0)
139
140/* state */
141#define NILFS_BMAP_DIRTY	0x00000001
142
143/**
144 * struct nilfs_bmap_store - shadow copy of bmap state
145 * @data: cached raw block mapping of on-disk inode
146 * @last_allocated_key: cached value of last allocated key for data block
147 * @last_allocated_ptr: cached value of last allocated ptr for data block
148 * @state: cached value of state field of bmap structure
149 */
150struct nilfs_bmap_store {
151	__le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
152	__u64 last_allocated_key;
153	__u64 last_allocated_ptr;
154	int state;
155};
156
157int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
158int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
159void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
160int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
161int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
162int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
163int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
164int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
165int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
166void nilfs_bmap_clear(struct nilfs_bmap *);
167int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
168void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
169int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
170		      unsigned long, union nilfs_binfo *);
171int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
172int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
173
174void nilfs_bmap_init_gc(struct nilfs_bmap *);
175
176void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
177void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
178
179static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
180				    __u64 *ptr)
181{
182	return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
183}
184
185/*
186 * Internal use only
187 */
188struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
189
190static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
191					       union nilfs_bmap_ptr_req *req,
192					       struct inode *dat)
193{
194	if (dat)
195		return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
196	/* ignore target ptr */
197	req->bpr_ptr = bmap->b_last_allocated_ptr++;
198	return 0;
199}
200
201static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
202					       union nilfs_bmap_ptr_req *req,
203					       struct inode *dat)
204{
205	if (dat)
206		nilfs_dat_commit_alloc(dat, &req->bpr_req);
207}
208
209static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
210					      union nilfs_bmap_ptr_req *req,
211					      struct inode *dat)
212{
213	if (dat)
214		nilfs_dat_abort_alloc(dat, &req->bpr_req);
215	else
216		bmap->b_last_allocated_ptr--;
217}
218
219static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
220					     union nilfs_bmap_ptr_req *req,
221					     struct inode *dat)
222{
223	return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
224}
225
226static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
227					     union nilfs_bmap_ptr_req *req,
228					     struct inode *dat)
229{
230	if (dat)
231		nilfs_dat_commit_end(dat, &req->bpr_req,
232				     bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
233}
234
235static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
236					    union nilfs_bmap_ptr_req *req,
237					    struct inode *dat)
238{
239	if (dat)
240		nilfs_dat_abort_end(dat, &req->bpr_req);
241}
242
243static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
244					   __u64 ptr)
245{
246	bmap->b_last_allocated_key = key;
247	bmap->b_last_allocated_ptr = ptr;
248}
249
250__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
251			      const struct buffer_head *);
252
253__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
254__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
255
256
257/* Assume that bmap semaphore is locked. */
258static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
259{
260	return !!(bmap->b_state & NILFS_BMAP_DIRTY);
261}
262
263/* Assume that bmap semaphore is locked. */
264static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
265{
266	bmap->b_state |= NILFS_BMAP_DIRTY;
267}
268
269/* Assume that bmap semaphore is locked. */
270static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
271{
272	bmap->b_state &= ~NILFS_BMAP_DIRTY;
273}
274
275
276#define NILFS_BMAP_LARGE	0x1
277
278#define NILFS_BMAP_SMALL_LOW	NILFS_DIRECT_KEY_MIN
279#define NILFS_BMAP_SMALL_HIGH	NILFS_DIRECT_KEY_MAX
280#define NILFS_BMAP_LARGE_LOW	NILFS_BTREE_ROOT_NCHILDREN_MAX
281#define NILFS_BMAP_LARGE_HIGH	NILFS_BTREE_KEY_MAX
282
283#endif	/* _NILFS_BMAP_H */