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 * Written by Koji Sato. 17 */ 18 19 #ifndef _NILFS_BMAP_H 20 #define _NILFS_BMAP_H 21 22 #include <linux/types.h> 23 #include <linux/fs.h> 24 #include <linux/buffer_head.h> 25 #include <linux/nilfs2_ondisk.h> /* nilfs_binfo, nilfs_inode, etc */ 26 #include "alloc.h" 27 #include "dat.h" 28 29 #define NILFS_BMAP_INVALID_PTR 0 30 31 #define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff)) 32 33 34 struct nilfs_bmap; 35 36 /** 37 * union nilfs_bmap_ptr_req - request for bmap ptr 38 * @bpr_ptr: bmap pointer 39 * @bpr_req: request for persistent allocator 40 */ 41 union nilfs_bmap_ptr_req { 42 __u64 bpr_ptr; 43 struct nilfs_palloc_req bpr_req; 44 }; 45 46 /** 47 * struct nilfs_bmap_stats - bmap statistics 48 * @bs_nblocks: number of blocks created or deleted 49 */ 50 struct nilfs_bmap_stats { 51 unsigned int bs_nblocks; 52 }; 53 54 /** 55 * struct nilfs_bmap_operations - bmap operation table 56 */ 57 struct nilfs_bmap_operations { 58 int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *); 59 int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *, 60 unsigned int); 61 int (*bop_insert)(struct nilfs_bmap *, __u64, __u64); 62 int (*bop_delete)(struct nilfs_bmap *, __u64); 63 void (*bop_clear)(struct nilfs_bmap *); 64 65 int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *); 66 void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *, 67 struct list_head *); 68 69 int (*bop_assign)(struct nilfs_bmap *, 70 struct buffer_head **, 71 sector_t, 72 union nilfs_binfo *); 73 int (*bop_mark)(struct nilfs_bmap *, __u64, int); 74 75 int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *); 76 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *); 77 78 /* The following functions are internal use only. */ 79 int (*bop_check_insert)(const struct nilfs_bmap *, __u64); 80 int (*bop_check_delete)(struct nilfs_bmap *, __u64); 81 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int); 82 }; 83 84 85 #define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64)) 86 #define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */) 87 #define NILFS_BMAP_NEW_PTR_INIT \ 88 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1)) 89 90 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr) 91 { 92 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT); 93 } 94 95 96 /** 97 * struct nilfs_bmap - bmap structure 98 * @b_u: raw data 99 * @b_sem: semaphore 100 * @b_inode: owner of bmap 101 * @b_ops: bmap operation table 102 * @b_last_allocated_key: last allocated key for data block 103 * @b_last_allocated_ptr: last allocated ptr for data block 104 * @b_ptr_type: pointer type 105 * @b_state: state 106 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes 107 */ 108 struct nilfs_bmap { 109 union { 110 __u8 u_flags; 111 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)]; 112 } b_u; 113 struct rw_semaphore b_sem; 114 struct inode *b_inode; 115 const struct nilfs_bmap_operations *b_ops; 116 __u64 b_last_allocated_key; 117 __u64 b_last_allocated_ptr; 118 int b_ptr_type; 119 int b_state; 120 __u16 b_nchildren_per_block; 121 }; 122 123 /* pointer type */ 124 #define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */ 125 #define NILFS_BMAP_PTR_VS 1 /* 126 * virtual block number (single 127 * version) 128 */ 129 #define NILFS_BMAP_PTR_VM 2 /* 130 * virtual block number (has multiple 131 * versions) 132 */ 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 */ 147 struct 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 }; 153 154 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *); 155 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *); 156 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *); 157 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int); 158 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec); 159 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key); 160 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp); 161 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp); 162 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key); 163 void nilfs_bmap_clear(struct nilfs_bmap *); 164 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *); 165 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *); 166 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **, 167 unsigned long, union nilfs_binfo *); 168 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *); 169 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int); 170 171 void nilfs_bmap_init_gc(struct nilfs_bmap *); 172 173 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *); 174 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *); 175 176 static 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 */ 185 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *); 186 187 static 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 } 197 198 static 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 } 205 206 static 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 } 215 216 static 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 } 222 223 static 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 } 231 232 static 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 } 239 240 static 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. */ 255 static 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. */ 261 static 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. */ 267 static 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