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_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
  68                                  unsigned);
  69         int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
  70         int (*bop_delete)(struct nilfs_bmap *, __u64);
  71         void (*bop_clear)(struct nilfs_bmap *);
  72
  73         int (*bop_propagate)(const struct nilfs_bmap *, struct buffer_head *);
  74         void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
  75                                          struct list_head *);
  76
  77         int (*bop_assign)(struct nilfs_bmap *,
  78                           struct buffer_head **,
  79                           sector_t,
  80                           union nilfs_binfo *);
  81         int (*bop_mark)(struct nilfs_bmap *, __u64, int);
  82
  83         /* The following functions are internal use only. */
  84         int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
  85         int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
  86         int (*bop_check_delete)(struct nilfs_bmap *, __u64);
  87         int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
  88 };
  89
  90
  91 #define NILFS_BMAP_SIZE         (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
  92 #define NILFS_BMAP_KEY_BIT      (sizeof(unsigned long) * 8 /* CHAR_BIT */)
  93 #define NILFS_BMAP_NEW_PTR_INIT \
  94         (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
  95
  96 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
  97 {
  98         return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
  99 }
 100
 101
 102 /**
 103  * struct nilfs_bmap - bmap structure
 104  * @b_u: raw data
 105  * @b_sem: semaphore
 106  * @b_inode: owner of bmap
 107  * @b_ops: bmap operation table
 108  * @b_last_allocated_key: last allocated key for data block
 109  * @b_last_allocated_ptr: last allocated ptr for data block
 110  * @b_ptr_type: pointer type
 111  * @b_state: state
 112  */
 113 struct nilfs_bmap {
 114         union {
 115                 __u8 u_flags;
 116                 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
 117         } b_u;
 118         struct rw_semaphore b_sem;
 119         struct inode *b_inode;
 120         const struct nilfs_bmap_operations *b_ops;
 121         __u64 b_last_allocated_key;
 122         __u64 b_last_allocated_ptr;
 123         int b_ptr_type;
 124         int b_state;
 125 };
 126
 127 /* pointer type */
 128 #define NILFS_BMAP_PTR_P        0       /* physical block number (i.e. LBN) */
 129 #define NILFS_BMAP_PTR_VS       1       /* virtual block number (single
 130                                            version) */
 131 #define NILFS_BMAP_PTR_VM       2       /* virtual block number (has multiple
 132                                            versions) */
 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 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 142 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 143 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 144 int nilfs_bmap_lookup(struct nilfs_bmap *, unsigned long, unsigned long *);
 145 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
 146 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
 147 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
 148 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
 149 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
 150 void nilfs_bmap_clear(struct nilfs_bmap *);
 151 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 152 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 153 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 154                       unsigned long, union nilfs_binfo *);
 155 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 156 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 157
 158 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 159 void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 160 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 161
 162
 163 /*
 164  * Internal use only
 165  */
 166 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
 167 int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *,
 168                                union nilfs_bmap_ptr_req *);
 169 void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *,
 170                                union nilfs_bmap_ptr_req *);
 171 void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *,
 172                               union nilfs_bmap_ptr_req *);
 173
 174 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
 175                                                union nilfs_bmap_ptr_req *req)
 176 {
 177         if (NILFS_BMAP_USE_VBN(bmap))
 178                 return nilfs_bmap_prepare_alloc_v(bmap, req);
 179         /* ignore target ptr */
 180         req->bpr_ptr = bmap->b_last_allocated_ptr++;
 181         return 0;
 182 }
 183
 184 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
 185                                                union nilfs_bmap_ptr_req *req)
 186 {
 187         if (NILFS_BMAP_USE_VBN(bmap))
 188                 nilfs_bmap_commit_alloc_v(bmap, req);
 189 }
 190
 191 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
 192                                               union nilfs_bmap_ptr_req *req)
 193 {
 194         if (NILFS_BMAP_USE_VBN(bmap))
 195                 nilfs_bmap_abort_alloc_v(bmap, req);
 196         else
 197                 bmap->b_last_allocated_ptr--;
 198 }
 199
 200 int nilfs_bmap_prepare_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 201 void nilfs_bmap_commit_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 202 void nilfs_bmap_abort_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
 203
 204 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
 205                                              union nilfs_bmap_ptr_req *req)
 206 {
 207         return NILFS_BMAP_USE_VBN(bmap) ?
 208                 nilfs_bmap_prepare_end_v(bmap, req) : 0;
 209 }
 210
 211 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
 212                                              union nilfs_bmap_ptr_req *req)
 213 {
 214         if (NILFS_BMAP_USE_VBN(bmap))
 215                 nilfs_bmap_commit_end_v(bmap, req);
 216 }
 217
 218 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
 219                                             union nilfs_bmap_ptr_req *req)
 220 {
 221         if (NILFS_BMAP_USE_VBN(bmap))
 222                 nilfs_bmap_abort_end_v(bmap, req);
 223 }
 224
 225 int nilfs_bmap_start_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *,
 226                        sector_t);
 227 int nilfs_bmap_move_v(const struct nilfs_bmap *, __u64, sector_t);
 228 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *, __u64);
 229
 230
 231 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 232                               const struct buffer_head *);
 233
 234 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 235 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 236
 237 int nilfs_bmap_prepare_update_v(struct nilfs_bmap *,
 238                                 union nilfs_bmap_ptr_req *,
 239                                 union nilfs_bmap_ptr_req *);
 240 void nilfs_bmap_commit_update_v(struct nilfs_bmap *,
 241                                 union nilfs_bmap_ptr_req *,
 242                                 union nilfs_bmap_ptr_req *);
 243 void nilfs_bmap_abort_update_v(struct nilfs_bmap *,
 244                                union nilfs_bmap_ptr_req *,
 245                                union nilfs_bmap_ptr_req *);
 246
 247 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
 248 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
 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 */