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
  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  * @bop_lookup:               single block search operation
  48  * @bop_lookup_contig:        consecutive block search operation
  49  * @bop_insert:               block insertion operation
  50  * @bop_delete:               block delete operation
  51  * @bop_clear:                block mapping resource release operation
  52  * @bop_propagate:            operation to propagate dirty state towards the
  53  *                            mapping root
  54  * @bop_lookup_dirty_buffers: operation to collect dirty block buffers
  55  * @bop_assign:               disk block address assignment operation
  56  * @bop_mark:                 operation to mark in-use blocks as dirty for
  57  *                            relocation by GC
  58  * @bop_seek_key:             find valid block key operation
  59  * @bop_last_key:             find last valid block key operation
  60  */
  61 struct nilfs_bmap_operations {
  62         int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
  63         int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
  64                                  unsigned int);
  65         int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
  66         int (*bop_delete)(struct nilfs_bmap *, __u64);
  67         void (*bop_clear)(struct nilfs_bmap *);
  68
  69         int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
  70         void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
  71                                          struct list_head *);
  72
  73         int (*bop_assign)(struct nilfs_bmap *,
  74                           struct buffer_head **,
  75                           sector_t,
  76                           union nilfs_binfo *);
  77         int (*bop_mark)(struct nilfs_bmap *, __u64, int);
  78
  79         int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
  80         int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
  81
  82         /* private: internal use only */
  83         int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
  84         int (*bop_check_delete)(struct nilfs_bmap *, __u64);
  85         int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
  86 };
  87
  88
  89 #define NILFS_BMAP_SIZE         (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
  90 #define NILFS_BMAP_KEY_BIT      BITS_PER_LONG
  91 #define NILFS_BMAP_NEW_PTR_INIT (1UL << (BITS_PER_LONG - 1))
  92
  93 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
  94 {
  95         return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
  96 }
  97
  98
  99 /**
 100  * struct nilfs_bmap - bmap structure
 101  * @b_u: raw data
 102  * @b_sem: semaphore
 103  * @b_inode: owner of bmap
 104  * @b_ops: bmap operation table
 105  * @b_last_allocated_key: last allocated key for data block
 106  * @b_last_allocated_ptr: last allocated ptr for data block
 107  * @b_ptr_type: pointer type
 108  * @b_state: state
 109  * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
 110  */
 111 struct nilfs_bmap {
 112         union {
 113                 __u8 u_flags;
 114                 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
 115         } b_u;
 116         struct rw_semaphore b_sem;
 117         struct inode *b_inode;
 118         const struct nilfs_bmap_operations *b_ops;
 119         __u64 b_last_allocated_key;
 120         __u64 b_last_allocated_ptr;
 121         int b_ptr_type;
 122         int b_state;
 123         __u16 b_nchildren_per_block;
 124 };
 125
 126 /* pointer type */
 127 #define NILFS_BMAP_PTR_P        0       /* physical block number (i.e. LBN) */
 128 #define NILFS_BMAP_PTR_VS       1       /*
 129                                          * virtual block number (single
 130                                          * version)
 131                                          */
 132 #define NILFS_BMAP_PTR_VM       2       /*
 133                                          * virtual block number (has multiple
 134                                          * versions)
 135                                          */
 136 #define NILFS_BMAP_PTR_U        (-1)    /* never perform pointer operations */
 137
 138 #define NILFS_BMAP_USE_VBN(bmap)        ((bmap)->b_ptr_type > 0)
 139
 140 /* state */
 141 #define NILFS_BMAP_DIRTY        0x00000001
 142
 143 /**
 144  * struct nilfs_bmap_store - shadow copy of bmap state
 145  * @data: cached raw block mapping of on-disk inode
 146  * @last_allocated_key: cached value of last allocated key for data block
 147  * @last_allocated_ptr: cached value of last allocated ptr for data block
 148  * @state: cached value of state field of bmap structure
 149  */
 150 struct nilfs_bmap_store {
 151         __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
 152         __u64 last_allocated_key;
 153         __u64 last_allocated_ptr;
 154         int state;
 155 };
 156
 157 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
 158 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
 159 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
 160 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
 161 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
 162 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
 163 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
 164 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
 165 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
 166 void nilfs_bmap_clear(struct nilfs_bmap *);
 167 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
 168 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
 169 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
 170                       unsigned long, union nilfs_binfo *);
 171 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 172 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 173
 174 void nilfs_bmap_init_gc(struct nilfs_bmap *);
 175
 176 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
 177 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
 178
 179 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
 180                                     __u64 *ptr)
 181 {
 182         return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
 183 }
 184
 185 /*
 186  * Internal use only
 187  */
 188 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
 189
 190 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
 191                                                union nilfs_bmap_ptr_req *req,
 192                                                struct inode *dat)
 193 {
 194         if (dat)
 195                 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
 196         /* ignore target ptr */
 197         req->bpr_ptr = bmap->b_last_allocated_ptr++;
 198         return 0;
 199 }
 200
 201 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
 202                                                union nilfs_bmap_ptr_req *req,
 203                                                struct inode *dat)
 204 {
 205         if (dat)
 206                 nilfs_dat_commit_alloc(dat, &req->bpr_req);
 207 }
 208
 209 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
 210                                               union nilfs_bmap_ptr_req *req,
 211                                               struct inode *dat)
 212 {
 213         if (dat)
 214                 nilfs_dat_abort_alloc(dat, &req->bpr_req);
 215         else
 216                 bmap->b_last_allocated_ptr--;
 217 }
 218
 219 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
 220                                              union nilfs_bmap_ptr_req *req,
 221                                              struct inode *dat)
 222 {
 223         return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
 224 }
 225
 226 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
 227                                              union nilfs_bmap_ptr_req *req,
 228                                              struct inode *dat)
 229 {
 230         if (dat)
 231                 nilfs_dat_commit_end(dat, &req->bpr_req,
 232                                      bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 233 }
 234
 235 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
 236                                             union nilfs_bmap_ptr_req *req,
 237                                             struct inode *dat)
 238 {
 239         if (dat)
 240                 nilfs_dat_abort_end(dat, &req->bpr_req);
 241 }
 242
 243 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
 244                                            __u64 ptr)
 245 {
 246         bmap->b_last_allocated_key = key;
 247         bmap->b_last_allocated_ptr = ptr;
 248 }
 249
 250 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 251                               const struct buffer_head *);
 252
 253 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 254 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 255
 256
 257 /* Assume that bmap semaphore is locked. */
 258 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
 259 {
 260         return !!(bmap->b_state & NILFS_BMAP_DIRTY);
 261 }
 262
 263 /* Assume that bmap semaphore is locked. */
 264 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
 265 {
 266         bmap->b_state |= NILFS_BMAP_DIRTY;
 267 }
 268
 269 /* Assume that bmap semaphore is locked. */
 270 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
 271 {
 272         bmap->b_state &= ~NILFS_BMAP_DIRTY;
 273 }
 274
 275
 276 #define NILFS_BMAP_LARGE        0x1
 277
 278 #define NILFS_BMAP_SMALL_LOW    NILFS_DIRECT_KEY_MIN
 279 #define NILFS_BMAP_SMALL_HIGH   NILFS_DIRECT_KEY_MAX
 280 #define NILFS_BMAP_LARGE_LOW    NILFS_BTREE_ROOT_NCHILDREN_MAX
 281 #define NILFS_BMAP_LARGE_HIGH   NILFS_BTREE_KEY_MAX
 282
 283 #endif  /* _NILFS_BMAP_H */