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 #include "dat.h"
  32
  33 #define NILFS_BMAP_INVALID_PTR  0
  34
  35 #define nilfs_bmap_dkey_to_key(dkey)    le64_to_cpu(dkey)
  36 #define nilfs_bmap_key_to_dkey(key)     cpu_to_le64(key)
  37 #define nilfs_bmap_dptr_to_ptr(dptr)    le64_to_cpu(dptr)
  38 #define nilfs_bmap_ptr_to_dptr(ptr)     cpu_to_le64(ptr)
  39
  40 #define nilfs_bmap_keydiff_abs(diff)    ((diff) < 0 ? -(diff) : (diff))
  41
  42
  43 struct nilfs_bmap;
  44
  45 /**
  46  * union nilfs_bmap_ptr_req - request for bmap ptr
  47  * @bpr_ptr: bmap pointer
  48  * @bpr_req: request for persistent allocator
  49  */
  50 union nilfs_bmap_ptr_req {
  51         __u64 bpr_ptr;
  52         struct nilfs_palloc_req bpr_req;
  53 };
  54
  55 /**
  56  * struct nilfs_bmap_stats - bmap statistics
  57  * @bs_nblocks: number of blocks created or deleted
  58  */
  59 struct nilfs_bmap_stats {
  60         unsigned int bs_nblocks;
  61 };
  62
  63 /**
  64  * struct nilfs_bmap_operations - bmap operation table
  65  */
  66 struct nilfs_bmap_operations {
  67         int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
  68         int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
  69                                  unsigned);
  70         int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
  71         int (*bop_delete)(struct nilfs_bmap *, __u64);
  72         void (*bop_clear)(struct nilfs_bmap *);
  73
  74         int (*bop_propagate)(const struct nilfs_bmap *, struct buffer_head *);
  75         void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
  76                                          struct list_head *);
  77
  78         int (*bop_assign)(struct nilfs_bmap *,
  79                           struct buffer_head **,
  80                           sector_t,
  81                           union nilfs_binfo *);
  82         int (*bop_mark)(struct nilfs_bmap *, __u64, int);
  83
  84         /* The following functions are internal use only. */
  85         int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
  86         int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
  87         int (*bop_check_delete)(struct nilfs_bmap *, __u64);
  88         int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
  89 };
  90
  91
  92 #define NILFS_BMAP_SIZE         (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
  93 #define NILFS_BMAP_KEY_BIT      (sizeof(unsigned long) * 8 /* CHAR_BIT */)
  94 #define NILFS_BMAP_NEW_PTR_INIT \
  95         (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
  96
  97 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
  98 {
  99         return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
 100 }
 101
 102
 103 /**
 104  * struct nilfs_bmap - bmap structure
 105  * @b_u: raw data
 106  * @b_sem: semaphore
 107  * @b_inode: owner of bmap
 108  * @b_ops: bmap operation table
 109  * @b_last_allocated_key: last allocated key for data block
 110  * @b_last_allocated_ptr: last allocated ptr for data block
 111  * @b_ptr_type: pointer type
 112  * @b_state: state
 113  */
 114 struct nilfs_bmap {
 115         union {
 116                 __u8 u_flags;
 117                 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
 118         } b_u;
 119         struct rw_semaphore b_sem;
 120         struct inode *b_inode;
 121         const struct nilfs_bmap_operations *b_ops;
 122         __u64 b_last_allocated_key;
 123         __u64 b_last_allocated_ptr;
 124         int b_ptr_type;
 125         int b_state;
 126 };
 127
 128 /* pointer type */
 129 #define NILFS_BMAP_PTR_P        0       /* physical block number (i.e. LBN) */
 130 #define NILFS_BMAP_PTR_VS       1       /* virtual block number (single
 131                                            version) */
 132 #define NILFS_BMAP_PTR_VM       2       /* virtual block number (has multiple
 133                                            versions) */
 134 #define NILFS_BMAP_PTR_U        (-1)    /* never perform pointer operations */
 135
 136 #define NILFS_BMAP_USE_VBN(bmap)        ((bmap)->b_ptr_type > 0)
 137
 138 /* state */
 139 #define NILFS_BMAP_DIRTY        0x00000001
 140
 141
 142 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 143 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 144 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 145 int nilfs_bmap_lookup(struct nilfs_bmap *, unsigned long, unsigned long *);
 146 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
 147 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
 148 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
 149 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
 150 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
 151 void nilfs_bmap_clear(struct nilfs_bmap *);
 152 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 153 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 154 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 155                       unsigned long, union nilfs_binfo *);
 156 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 157 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 158
 159 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 160 void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 161 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 162
 163
 164 /*
 165  * Internal use only
 166  */
 167 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
 168
 169 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
 170                                                union nilfs_bmap_ptr_req *req,
 171                                                struct inode *dat)
 172 {
 173         if (dat)
 174                 return nilfs_dat_prepare_alloc(dat, &req->bpr_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                                                struct inode *dat)
 183 {
 184         if (dat)
 185                 nilfs_dat_commit_alloc(dat, &req->bpr_req);
 186 }
 187
 188 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
 189                                               union nilfs_bmap_ptr_req *req,
 190                                               struct inode *dat)
 191 {
 192         if (dat)
 193                 nilfs_dat_abort_alloc(dat, &req->bpr_req);
 194         else
 195                 bmap->b_last_allocated_ptr--;
 196 }
 197
 198 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
 199                                              union nilfs_bmap_ptr_req *req,
 200                                              struct inode *dat)
 201 {
 202         return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
 203 }
 204
 205 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
 206                                              union nilfs_bmap_ptr_req *req,
 207                                              struct inode *dat)
 208 {
 209         if (dat)
 210                 nilfs_dat_commit_end(dat, &req->bpr_req,
 211                                      bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 212 }
 213
 214 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
 215                                             union nilfs_bmap_ptr_req *req,
 216                                             struct inode *dat)
 217 {
 218         if (dat)
 219                 nilfs_dat_abort_end(dat, &req->bpr_req);
 220 }
 221
 222 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 223                               const struct buffer_head *);
 224
 225 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 226 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 227
 228 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
 229 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
 230
 231
 232 /* Assume that bmap semaphore is locked. */
 233 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
 234 {
 235         return !!(bmap->b_state & NILFS_BMAP_DIRTY);
 236 }
 237
 238 /* Assume that bmap semaphore is locked. */
 239 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
 240 {
 241         bmap->b_state |= NILFS_BMAP_DIRTY;
 242 }
 243
 244 /* Assume that bmap semaphore is locked. */
 245 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
 246 {
 247         bmap->b_state &= ~NILFS_BMAP_DIRTY;
 248 }
 249
 250
 251 #define NILFS_BMAP_LARGE        0x1
 252
 253 #define NILFS_BMAP_SMALL_LOW    NILFS_DIRECT_KEY_MIN
 254 #define NILFS_BMAP_SMALL_HIGH   NILFS_DIRECT_KEY_MAX
 255 #define NILFS_BMAP_LARGE_LOW    NILFS_BTREE_ROOT_NCHILDREN_MAX
 256 #define NILFS_BMAP_LARGE_HIGH   NILFS_BTREE_KEY_MAX
 257
 258 #endif  /* _NILFS_BMAP_H */