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 int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *); 80 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *); 81 82 /* The following functions are 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 (sizeof(unsigned long) * 8 /* CHAR_BIT */) 91#define NILFS_BMAP_NEW_PTR_INIT \ 92 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1)) 93 94static inline int nilfs_bmap_is_new_ptr(unsigned long ptr) 95{ 96 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT); 97} 98 99 100/** 101 * struct nilfs_bmap - bmap structure 102 * @b_u: raw data 103 * @b_sem: semaphore 104 * @b_inode: owner of bmap 105 * @b_ops: bmap operation table 106 * @b_last_allocated_key: last allocated key for data block 107 * @b_last_allocated_ptr: last allocated ptr for data block 108 * @b_ptr_type: pointer type 109 * @b_state: state 110 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes 111 */ 112struct nilfs_bmap { 113 union { 114 __u8 u_flags; 115 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)]; 116 } b_u; 117 struct rw_semaphore b_sem; 118 struct inode *b_inode; 119 const struct nilfs_bmap_operations *b_ops; 120 __u64 b_last_allocated_key; 121 __u64 b_last_allocated_ptr; 122 int b_ptr_type; 123 int b_state; 124 __u16 b_nchildren_per_block; 125}; 126 127/* pointer type */ 128#define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */ 129#define NILFS_BMAP_PTR_VS 1 /* virtual block number (single 130 version) */ 131#define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple 132 versions) */ 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); 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 */ 281