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  * 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 */