fs/nilfs2/bmap.h

   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
  32 #define NILFS_BMAP_INVALID_PTR  0
  33
  34 #define nilfs_bmap_dkey_to_key(dkey)    le64_to_cpu(dkey)
  35 #define nilfs_bmap_key_to_dkey(key)     cpu_to_le64(key)
  36 #define nilfs_bmap_dptr_to_ptr(dptr)    le64_to_cpu(dptr)
  37 #define nilfs_bmap_ptr_to_dptr(ptr)     cpu_to_le64(ptr)
  38
  39 #define nilfs_bmap_keydiff_abs(diff)    ((diff) < 0 ? -(diff) : (diff))
  40
  41
  42 struct nilfs_bmap;
  43
  44 /**
  45  * union nilfs_bmap_ptr_req - request for bmap ptr
  46  * @bpr_ptr: bmap pointer
  47  * @bpr_req: request for persistent allocator
  48  */
  49 union nilfs_bmap_ptr_req {
  50         __u64 bpr_ptr;
  51         struct nilfs_palloc_req bpr_req;
  52 };
  53
  54 /**
  55  * struct nilfs_bmap_stats - bmap statistics
  56  * @bs_nblocks: number of blocks created or deleted
  57  */
  58 struct nilfs_bmap_stats {
  59         unsigned int bs_nblocks;
  60 };
  61
  62 /**
  63  * struct nilfs_bmap_operations - bmap operation table
  64  */
  65 struct nilfs_bmap_operations {
  66         int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
  67         int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
  68         int (*bop_delete)(struct nilfs_bmap *, __u64);
  69         void (*bop_clear)(struct nilfs_bmap *);
  70
  71         int (*bop_propagate)(const struct nilfs_bmap *, struct buffer_head *);
  72         void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
  73                                          struct list_head *);
  74
  75         int (*bop_assign)(struct nilfs_bmap *,
  76                           struct buffer_head **,
  77                           sector_t,
  78                           union nilfs_binfo *);
  79         int (*bop_mark)(struct nilfs_bmap *, __u64, int);
  80
  81         /* The following functions are internal use only. */
  82         int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
  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
  94 static 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  */
 111 struct 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 };
 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 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 140 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 141 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 142 int nilfs_bmap_lookup(struct nilfs_bmap *, unsigned long, unsigned long *);
 143 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
 144 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
 145 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
 146 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
 147 void nilfs_bmap_clear(struct nilfs_bmap *);
 148 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 149 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 150 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 151                       unsigned long, union nilfs_binfo *);
 152 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 153 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 154
 155 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 156 void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 157 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 158
 159
 160 /*
 161  * Internal use only
 162  */
 163 int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *,
 164                                union nilfs_bmap_ptr_req *);
 165 void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *,
 166                                union nilfs_bmap_ptr_req *);
 167 void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *,
 168                               union nilfs_bmap_ptr_req *);
 169
 170 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
 171                                                union nilfs_bmap_ptr_req *req)
 172 {
 173         if (NILFS_BMAP_USE_VBN(bmap))
 174                 return nilfs_bmap_prepare_alloc_v(bmap, req);
 175         /* ignore target ptr */
 176         req->bpr_ptr = bmap->b_last_allocated_ptr++;
 177         return 0;
 178 }
 179
 180 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
 181                                                union nilfs_bmap_ptr_req *req)
 182 {
 183         if (NILFS_BMAP_USE_VBN(bmap))
 184                 nilfs_bmap_commit_alloc_v(bmap, req);
 185 }
 186
 187 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
 188                                               union nilfs_bmap_ptr_req *req)
 189 {
 190         if (NILFS_BMAP_USE_VBN(bmap))
 191                 nilfs_bmap_abort_alloc_v(bmap, req);
 192         else
 193                 bmap->b_last_allocated_ptr--;
 194 }
 195
 196 int nilfs_bmap_prepare_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 197 void nilfs_bmap_commit_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 198 void nilfs_bmap_abort_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 199
 200 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
 201                                              union nilfs_bmap_ptr_req *req)
 202 {
 203         return NILFS_BMAP_USE_VBN(bmap) ?
 204                 nilfs_bmap_prepare_end_v(bmap, req) : 0;
 205 }
 206
 207 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
 208                                              union nilfs_bmap_ptr_req *req)
 209 {
 210         if (NILFS_BMAP_USE_VBN(bmap))
 211                 nilfs_bmap_commit_end_v(bmap, req);
 212 }
 213
 214 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
 215                                             union nilfs_bmap_ptr_req *req)
 216 {
 217         if (NILFS_BMAP_USE_VBN(bmap))
 218                 nilfs_bmap_abort_end_v(bmap, req);
 219 }
 220
 221 int nilfs_bmap_start_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *,
 222                        sector_t);
 223 int nilfs_bmap_move_v(const struct nilfs_bmap *, __u64, sector_t);
 224 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *, __u64);
 225
 226
 227 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 228                               const struct buffer_head *);
 229
 230 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 231 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 232
 233 int nilfs_bmap_prepare_update_v(struct nilfs_bmap *,
 234                                 union nilfs_bmap_ptr_req *,
 235                                 union nilfs_bmap_ptr_req *);
 236 void nilfs_bmap_commit_update_v(struct nilfs_bmap *,
 237                                 union nilfs_bmap_ptr_req *,
 238                                 union nilfs_bmap_ptr_req *);
 239 void nilfs_bmap_abort_update_v(struct nilfs_bmap *,
 240                                union nilfs_bmap_ptr_req *,
 241                                union nilfs_bmap_ptr_req *);
 242
 243 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
 244 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
 245
 246
 247 /* Assume that bmap semaphore is locked. */
 248 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
 249 {
 250         return !!(bmap->b_state & NILFS_BMAP_DIRTY);
 251 }
 252
 253 /* Assume that bmap semaphore is locked. */
 254 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
 255 {
 256         bmap->b_state |= NILFS_BMAP_DIRTY;
 257 }
 258
 259 /* Assume that bmap semaphore is locked. */
 260 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
 261 {
 262         bmap->b_state &= ~NILFS_BMAP_DIRTY;
 263 }
 264
 265
 266 #define NILFS_BMAP_LARGE        0x1
 267
 268 #define NILFS_BMAP_SMALL_LOW    NILFS_DIRECT_KEY_MIN
 269 #define NILFS_BMAP_SMALL_HIGH   NILFS_DIRECT_KEY_MAX
 270 #define NILFS_BMAP_LARGE_LOW    NILFS_BTREE_ROOT_NCHILDREN_MAX
 271 #define NILFS_BMAP_LARGE_HIGH   NILFS_BTREE_KEY_MAX
 272
 273 #endif  /* _NILFS_BMAP_H */