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 38 struct 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 */ 45 union 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 */ 54 struct nilfs_bmap_stats { 55 unsigned int bs_nblocks; 56 }; 57 58 /** 59 * struct nilfs_bmap_operations - bmap operation table 60 */ 61 struct 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 /* The following functions are internal use only. */ 80 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *); 81 int (*bop_check_insert)(const struct nilfs_bmap *, __u64); 82 int (*bop_check_delete)(struct nilfs_bmap *, __u64); 83 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int); 84 }; 85 86 87 #define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64)) 88 #define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */) 89 #define NILFS_BMAP_NEW_PTR_INIT \ 90 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1)) 91 92 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr) 93 { 94 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT); 95 } 96 97 98 /** 99 * struct nilfs_bmap - bmap structure 100 * @b_u: raw data 101 * @b_sem: semaphore 102 * @b_inode: owner of bmap 103 * @b_ops: bmap operation table 104 * @b_last_allocated_key: last allocated key for data block 105 * @b_last_allocated_ptr: last allocated ptr for data block 106 * @b_ptr_type: pointer type 107 * @b_state: state 108 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes 109 */ 110 struct nilfs_bmap { 111 union { 112 __u8 u_flags; 113 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)]; 114 } b_u; 115 struct rw_semaphore b_sem; 116 struct inode *b_inode; 117 const struct nilfs_bmap_operations *b_ops; 118 __u64 b_last_allocated_key; 119 __u64 b_last_allocated_ptr; 120 int b_ptr_type; 121 int b_state; 122 __u16 b_nchildren_per_block; 123 }; 124 125 /* pointer type */ 126 #define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */ 127 #define NILFS_BMAP_PTR_VS 1 /* virtual block number (single 128 version) */ 129 #define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple 130 versions) */ 131 #define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */ 132 133 #define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0) 134 135 /* state */ 136 #define NILFS_BMAP_DIRTY 0x00000001 137 138 /** 139 * struct nilfs_bmap_store - shadow copy of bmap state 140 * @data: cached raw block mapping of on-disk inode 141 * @last_allocated_key: cached value of last allocated key for data block 142 * @last_allocated_ptr: cached value of last allocated ptr for data block 143 * @state: cached value of state field of bmap structure 144 */ 145 struct nilfs_bmap_store { 146 __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)]; 147 __u64 last_allocated_key; 148 __u64 last_allocated_ptr; 149 int state; 150 }; 151 152 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *); 153 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *); 154 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *); 155 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned); 156 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long); 157 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long); 158 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *); 159 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long); 160 void nilfs_bmap_clear(struct nilfs_bmap *); 161 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *); 162 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *); 163 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **, 164 unsigned long, union nilfs_binfo *); 165 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *); 166 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int); 167 168 void nilfs_bmap_init_gc(struct nilfs_bmap *); 169 170 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *); 171 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *); 172 173 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key, 174 __u64 *ptr) 175 { 176 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr); 177 } 178 179 /* 180 * Internal use only 181 */ 182 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *); 183 184 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap, 185 union nilfs_bmap_ptr_req *req, 186 struct inode *dat) 187 { 188 if (dat) 189 return nilfs_dat_prepare_alloc(dat, &req->bpr_req); 190 /* ignore target ptr */ 191 req->bpr_ptr = bmap->b_last_allocated_ptr++; 192 return 0; 193 } 194 195 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap, 196 union nilfs_bmap_ptr_req *req, 197 struct inode *dat) 198 { 199 if (dat) 200 nilfs_dat_commit_alloc(dat, &req->bpr_req); 201 } 202 203 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap, 204 union nilfs_bmap_ptr_req *req, 205 struct inode *dat) 206 { 207 if (dat) 208 nilfs_dat_abort_alloc(dat, &req->bpr_req); 209 else 210 bmap->b_last_allocated_ptr--; 211 } 212 213 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap, 214 union nilfs_bmap_ptr_req *req, 215 struct inode *dat) 216 { 217 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0; 218 } 219 220 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap, 221 union nilfs_bmap_ptr_req *req, 222 struct inode *dat) 223 { 224 if (dat) 225 nilfs_dat_commit_end(dat, &req->bpr_req, 226 bmap->b_ptr_type == NILFS_BMAP_PTR_VS); 227 } 228 229 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap, 230 union nilfs_bmap_ptr_req *req, 231 struct inode *dat) 232 { 233 if (dat) 234 nilfs_dat_abort_end(dat, &req->bpr_req); 235 } 236 237 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key, 238 __u64 ptr) 239 { 240 bmap->b_last_allocated_key = key; 241 bmap->b_last_allocated_ptr = ptr; 242 } 243 244 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *, 245 const struct buffer_head *); 246 247 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64); 248 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *); 249 250 251 /* Assume that bmap semaphore is locked. */ 252 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap) 253 { 254 return !!(bmap->b_state & NILFS_BMAP_DIRTY); 255 } 256 257 /* Assume that bmap semaphore is locked. */ 258 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap) 259 { 260 bmap->b_state |= NILFS_BMAP_DIRTY; 261 } 262 263 /* Assume that bmap semaphore is locked. */ 264 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap) 265 { 266 bmap->b_state &= ~NILFS_BMAP_DIRTY; 267 } 268 269 270 #define NILFS_BMAP_LARGE 0x1 271 272 #define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN 273 #define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX 274 #define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX 275 #define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX 276 277 #endif /* _NILFS_BMAP_H */ 278