fs/nilfs2/bmap.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * bmap.h - NILFS block mapping.
   4  *
   5  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Written by Koji Sato.
   8  */
   9
  10 #ifndef _NILFS_BMAP_H
  11 #define _NILFS_BMAP_H
  12
  13 #include <linux/types.h>
  14 #include <linux/fs.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/nilfs2_ondisk.h>        /* nilfs_binfo, nilfs_inode, etc */
  17 #include "alloc.h"
  18 #include "dat.h"
  19
  20 #define NILFS_BMAP_INVALID_PTR  0
  21
  22 #define nilfs_bmap_keydiff_abs(diff)    ((diff) < 0 ? -(diff) : (diff))
  23
  24
  25 struct nilfs_bmap;
  26
  27 /**
  28  * union nilfs_bmap_ptr_req - request for bmap ptr
  29  * @bpr_ptr: bmap pointer
  30  * @bpr_req: request for persistent allocator
  31  */
  32 union nilfs_bmap_ptr_req {
  33         __u64 bpr_ptr;
  34         struct nilfs_palloc_req bpr_req;
  35 };
  36
  37 /**
  38  * struct nilfs_bmap_stats - bmap statistics
  39  * @bs_nblocks: number of blocks created or deleted
  40  */
  41 struct nilfs_bmap_stats {
  42         unsigned int bs_nblocks;
  43 };
  44
  45 /**
  46  * struct nilfs_bmap_operations - bmap operation table
  47  */
  48 struct nilfs_bmap_operations {
  49         int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
  50         int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
  51                                  unsigned int);
  52         int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
  53         int (*bop_delete)(struct nilfs_bmap *, __u64);
  54         void (*bop_clear)(struct nilfs_bmap *);
  55
  56         int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
  57         void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
  58                                          struct list_head *);
  59
  60         int (*bop_assign)(struct nilfs_bmap *,
  61                           struct buffer_head **,
  62                           sector_t,
  63                           union nilfs_binfo *);
  64         int (*bop_mark)(struct nilfs_bmap *, __u64, int);
  65
  66         int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
  67         int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
  68
  69         /* The following functions are internal use only. */
  70         int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
  71         int (*bop_check_delete)(struct nilfs_bmap *, __u64);
  72         int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
  73 };
  74
  75
  76 #define NILFS_BMAP_SIZE         (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
  77 #define NILFS_BMAP_KEY_BIT      (sizeof(unsigned long) * 8 /* CHAR_BIT */)
  78 #define NILFS_BMAP_NEW_PTR_INIT \
  79         (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
  80
  81 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
  82 {
  83         return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
  84 }
  85
  86
  87 /**
  88  * struct nilfs_bmap - bmap structure
  89  * @b_u: raw data
  90  * @b_sem: semaphore
  91  * @b_inode: owner of bmap
  92  * @b_ops: bmap operation table
  93  * @b_last_allocated_key: last allocated key for data block
  94  * @b_last_allocated_ptr: last allocated ptr for data block
  95  * @b_ptr_type: pointer type
  96  * @b_state: state
  97  * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
  98  */
  99 struct nilfs_bmap {
 100         union {
 101                 __u8 u_flags;
 102                 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
 103         } b_u;
 104         struct rw_semaphore b_sem;
 105         struct inode *b_inode;
 106         const struct nilfs_bmap_operations *b_ops;
 107         __u64 b_last_allocated_key;
 108         __u64 b_last_allocated_ptr;
 109         int b_ptr_type;
 110         int b_state;
 111         __u16 b_nchildren_per_block;
 112 };
 113
 114 /* pointer type */
 115 #define NILFS_BMAP_PTR_P        0       /* physical block number (i.e. LBN) */
 116 #define NILFS_BMAP_PTR_VS       1       /*
 117                                          * virtual block number (single
 118                                          * version)
 119                                          */
 120 #define NILFS_BMAP_PTR_VM       2       /*
 121                                          * virtual block number (has multiple
 122                                          * versions)
 123                                          */
 124 #define NILFS_BMAP_PTR_U        (-1)    /* never perform pointer operations */
 125
 126 #define NILFS_BMAP_USE_VBN(bmap)        ((bmap)->b_ptr_type > 0)
 127
 128 /* state */
 129 #define NILFS_BMAP_DIRTY        0x00000001
 130
 131 /**
 132  * struct nilfs_bmap_store - shadow copy of bmap state
 133  * @data: cached raw block mapping of on-disk inode
 134  * @last_allocated_key: cached value of last allocated key for data block
 135  * @last_allocated_ptr: cached value of last allocated ptr for data block
 136  * @state: cached value of state field of bmap structure
 137  */
 138 struct nilfs_bmap_store {
 139         __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
 140         __u64 last_allocated_key;
 141         __u64 last_allocated_ptr;
 142         int state;
 143 };
 144
 145 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 146 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 147 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 148 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
 149 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
 150 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
 151 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
 152 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
 153 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
 154 void nilfs_bmap_clear(struct nilfs_bmap *);
 155 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 156 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 157 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 158                       unsigned long, union nilfs_binfo *);
 159 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 160 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 161
 162 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 163
 164 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
 165 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
 166
 167 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
 168                                     __u64 *ptr)
 169 {
 170         return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
 171 }
 172
 173 /*
 174  * Internal use only
 175  */
 176 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
 177
 178 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
 179                                                union nilfs_bmap_ptr_req *req,
 180                                                struct inode *dat)
 181 {
 182         if (dat)
 183                 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
 184         /* ignore target ptr */
 185         req->bpr_ptr = bmap->b_last_allocated_ptr++;
 186         return 0;
 187 }
 188
 189 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
 190                                                union nilfs_bmap_ptr_req *req,
 191                                                struct inode *dat)
 192 {
 193         if (dat)
 194                 nilfs_dat_commit_alloc(dat, &req->bpr_req);
 195 }
 196
 197 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
 198                                               union nilfs_bmap_ptr_req *req,
 199                                               struct inode *dat)
 200 {
 201         if (dat)
 202                 nilfs_dat_abort_alloc(dat, &req->bpr_req);
 203         else
 204                 bmap->b_last_allocated_ptr--;
 205 }
 206
 207 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
 208                                              union nilfs_bmap_ptr_req *req,
 209                                              struct inode *dat)
 210 {
 211         return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
 212 }
 213
 214 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
 215                                              union nilfs_bmap_ptr_req *req,
 216                                              struct inode *dat)
 217 {
 218         if (dat)
 219                 nilfs_dat_commit_end(dat, &req->bpr_req,
 220                                      bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 221 }
 222
 223 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
 224                                             union nilfs_bmap_ptr_req *req,
 225                                             struct inode *dat)
 226 {
 227         if (dat)
 228                 nilfs_dat_abort_end(dat, &req->bpr_req);
 229 }
 230
 231 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
 232                                            __u64 ptr)
 233 {
 234         bmap->b_last_allocated_key = key;
 235         bmap->b_last_allocated_ptr = ptr;
 236 }
 237
 238 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 239                               const struct buffer_head *);
 240
 241 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 242 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 243
 244
 245 /* Assume that bmap semaphore is locked. */
 246 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
 247 {
 248         return !!(bmap->b_state & NILFS_BMAP_DIRTY);
 249 }
 250
 251 /* Assume that bmap semaphore is locked. */
 252 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
 253 {
 254         bmap->b_state |= NILFS_BMAP_DIRTY;
 255 }
 256
 257 /* Assume that bmap semaphore is locked. */
 258 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
 259 {
 260         bmap->b_state &= ~NILFS_BMAP_DIRTY;
 261 }
 262
 263
 264 #define NILFS_BMAP_LARGE        0x1
 265
 266 #define NILFS_BMAP_SMALL_LOW    NILFS_DIRECT_KEY_MIN
 267 #define NILFS_BMAP_SMALL_HIGH   NILFS_DIRECT_KEY_MAX
 268 #define NILFS_BMAP_LARGE_LOW    NILFS_BTREE_ROOT_NCHILDREN_MAX
 269 #define NILFS_BMAP_LARGE_HIGH   NILFS_BTREE_KEY_MAX
 270
 271 #endif  /* _NILFS_BMAP_H */