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 /**
  90  * struct nilfs_bmap_ptr_operations - bmap ptr operation table
  91  */
  92 struct nilfs_bmap_ptr_operations {
  93         int (*bpop_prepare_alloc_ptr)(struct nilfs_bmap *,
  94                                       union nilfs_bmap_ptr_req *);
  95         void (*bpop_commit_alloc_ptr)(struct nilfs_bmap *,
  96                                       union nilfs_bmap_ptr_req *);
  97         void (*bpop_abort_alloc_ptr)(struct nilfs_bmap *,
  98                                      union nilfs_bmap_ptr_req *);
  99         int (*bpop_prepare_end_ptr)(struct nilfs_bmap *,
 100                                     union nilfs_bmap_ptr_req *);
 101         void (*bpop_commit_end_ptr)(struct nilfs_bmap *,
 102                                     union nilfs_bmap_ptr_req *);
 103         void (*bpop_abort_end_ptr)(struct nilfs_bmap *,
 104                                    union nilfs_bmap_ptr_req *);
 105
 106         int (*bpop_translate)(const struct nilfs_bmap *, __u64, __u64 *);
 107 };
 108
 109
 110 #define NILFS_BMAP_SIZE         (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
 111 #define NILFS_BMAP_KEY_BIT      (sizeof(unsigned long) * 8 /* CHAR_BIT */)
 112 #define NILFS_BMAP_NEW_PTR_INIT \
 113         (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
 114
 115 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
 116 {
 117         return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
 118 }
 119
 120
 121 /**
 122  * struct nilfs_bmap - bmap structure
 123  * @b_u: raw data
 124  * @b_sem: semaphore
 125  * @b_inode: owner of bmap
 126  * @b_ops: bmap operation table
 127  * @b_pops: bmap ptr operation table
 128  * @b_low: low watermark of conversion
 129  * @b_high: high watermark of conversion
 130  * @b_last_allocated_key: last allocated key for data block
 131  * @b_last_allocated_ptr: last allocated ptr for data block
 132  * @b_state: state
 133  */
 134 struct nilfs_bmap {
 135         union {
 136                 __u8 u_flags;
 137                 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
 138         } b_u;
 139         struct rw_semaphore b_sem;
 140         struct inode *b_inode;
 141         const struct nilfs_bmap_operations *b_ops;
 142         const struct nilfs_bmap_ptr_operations *b_pops;
 143         __u64 b_low;
 144         __u64 b_high;
 145         __u64 b_last_allocated_key;
 146         __u64 b_last_allocated_ptr;
 147         int b_state;
 148 };
 149
 150 /* state */
 151 #define NILFS_BMAP_DIRTY        0x00000001
 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(struct nilfs_bmap *, unsigned long, unsigned long *);
 158 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
 159 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
 160 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
 161 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
 162 void nilfs_bmap_clear(struct nilfs_bmap *);
 163 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 164 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 165 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 166                       unsigned long, union nilfs_binfo *);
 167 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 168 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 169
 170 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 171 void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 172 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 173
 174
 175 /*
 176  * Internal use only
 177  */
 178
 179 int nilfs_bmap_start_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *,
 180                        sector_t);
 181 int nilfs_bmap_move_v(const struct nilfs_bmap *, __u64, sector_t);
 182 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *, __u64);
 183
 184
 185 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 186                               const struct buffer_head *);
 187
 188 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 189 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 190
 191 int nilfs_bmap_prepare_update(struct nilfs_bmap *,
 192                               union nilfs_bmap_ptr_req *,
 193                               union nilfs_bmap_ptr_req *);
 194 void nilfs_bmap_commit_update(struct nilfs_bmap *,
 195                               union nilfs_bmap_ptr_req *,
 196                               union nilfs_bmap_ptr_req *);
 197 void nilfs_bmap_abort_update(struct nilfs_bmap *,
 198                              union nilfs_bmap_ptr_req *,
 199                              union nilfs_bmap_ptr_req *);
 200
 201 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
 202 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
 203
 204
 205 int nilfs_bmap_get_block(const struct nilfs_bmap *, __u64,
 206                          struct buffer_head **);
 207 void nilfs_bmap_put_block(const struct nilfs_bmap *, struct buffer_head *);
 208 int nilfs_bmap_get_new_block(const struct nilfs_bmap *, __u64,
 209                              struct buffer_head **);
 210 void nilfs_bmap_delete_block(const struct nilfs_bmap *, struct buffer_head *);
 211
 212
 213 /* Assume that bmap semaphore is locked. */
 214 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
 215 {
 216         return !!(bmap->b_state & NILFS_BMAP_DIRTY);
 217 }
 218
 219 /* Assume that bmap semaphore is locked. */
 220 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
 221 {
 222         bmap->b_state |= NILFS_BMAP_DIRTY;
 223 }
 224
 225 /* Assume that bmap semaphore is locked. */
 226 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
 227 {
 228         bmap->b_state &= ~NILFS_BMAP_DIRTY;
 229 }
 230
 231
 232 #define NILFS_BMAP_LARGE        0x1
 233
 234 #define NILFS_BMAP_SMALL_LOW    NILFS_DIRECT_KEY_MIN
 235 #define NILFS_BMAP_SMALL_HIGH   NILFS_DIRECT_KEY_MAX
 236 #define NILFS_BMAP_LARGE_LOW    NILFS_BTREE_ROOT_NCHILDREN_MAX
 237 #define NILFS_BMAP_LARGE_HIGH   NILFS_BTREE_KEY_MAX
 238
 239 #endif  /* _NILFS_BMAP_H */