fs/nilfs2/btree.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * NILFS B-tree.
   4  *
   5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Written by Koji Sato.
   8  */
   9
  10 #ifndef _NILFS_BTREE_H
  11 #define _NILFS_BTREE_H
  12
  13 #include <linux/types.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/list.h>
  16 #include <linux/nilfs2_ondisk.h>        /* nilfs_btree_node */
  17 #include "btnode.h"
  18 #include "bmap.h"
  19
  20 /**
  21  * struct nilfs_btree_path - A path on which B-tree operations are executed
  22  * @bp_bh: buffer head of node block
  23  * @bp_sib_bh: buffer head of sibling node block
  24  * @bp_index: index of child node
  25  * @bp_oldreq: ptr end request for old ptr
  26  * @bp_newreq: ptr alloc request for new ptr
  27  * @bp_ctxt: context information for changing the key of a b-tree node block
  28  * @bp_op: rebalance operation
  29  */
  30 struct nilfs_btree_path {
  31         struct buffer_head *bp_bh;
  32         struct buffer_head *bp_sib_bh;
  33         int bp_index;
  34         union nilfs_bmap_ptr_req bp_oldreq;
  35         union nilfs_bmap_ptr_req bp_newreq;
  36         struct nilfs_btnode_chkey_ctxt bp_ctxt;
  37         void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
  38                       int, __u64 *, __u64 *);
  39 };
  40
  41 #define NILFS_BTREE_ROOT_SIZE           NILFS_BMAP_SIZE
  42 #define NILFS_BTREE_ROOT_NCHILDREN_MAX                                  \
  43         ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /    \
  44          (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  45 #define NILFS_BTREE_ROOT_NCHILDREN_MIN  0
  46 #define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64))
  47 #define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)                        \
  48         (((nodesize) - sizeof(struct nilfs_btree_node) -                \
  49                 NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /                      \
  50          (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  51 #define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)                        \
  52         ((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
  53 #define NILFS_BTREE_KEY_MIN     ((__u64)0)
  54 #define NILFS_BTREE_KEY_MAX     (~(__u64)0)
  55
  56 extern struct kmem_cache *nilfs_btree_path_cache;
  57
  58 int nilfs_btree_init(struct nilfs_bmap *);
  59 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
  60                                    const __u64 *, const __u64 *, int);
  61 void nilfs_btree_init_gc(struct nilfs_bmap *);
  62
  63 int nilfs_btree_broken_node_block(struct buffer_head *bh);
  64
  65 #endif  /* _NILFS_BTREE_H */