LXR linux/fs/nilfs2/bmap.h

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * 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
  25struct 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 */
  32union 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 */
  41struct nilfs_bmap_stats {
  42        unsigned int bs_nblocks;
  43};
  44
  45/**
  46 * struct nilfs_bmap_operations - bmap operation table
  47 */
  48struct 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
  81static 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 */
  99struct 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 */
 138struct 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
 145int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 146int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 147void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 148int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
 149int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
 150int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
 151int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
 152int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
 153int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
 154void nilfs_bmap_clear(struct nilfs_bmap *);
 155int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 156void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 157int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 158                      unsigned long, union nilfs_binfo *);
 159int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 160int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 161
 162void nilfs_bmap_init_gc(struct nilfs_bmap *);
 163
 164void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
 165void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
 166
 167static 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 */
 176struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
 177
 178static 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
 189static 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
 197static 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
 207static 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
 214static 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
 223static 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
 231static 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. */
 246static 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. */
 252static 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. */
 258static 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 */
 272