fs/hfs/btree.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  *  linux/fs/hfs/btree.h
0004  *
0005  * Copyright (C) 2001
0006  * Brad Boyer (flar@allandria.com)
0007  * (C) 2003 Ardis Technologies <roman@ardistech.com>
0008  */
0009
0010 #include "hfs_fs.h"
0011
0012 typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
0013
0014 #define NODE_HASH_SIZE  256
0015
0016 /* B-tree mutex nested subclasses */
0017 enum hfs_btree_mutex_classes {
0018     CATALOG_BTREE_MUTEX,
0019     EXTENTS_BTREE_MUTEX,
0020     ATTR_BTREE_MUTEX,
0021 };
0022
0023 /* A HFS BTree held in memory */
0024 struct hfs_btree {
0025     struct super_block *sb;
0026     struct inode *inode;
0027     btree_keycmp keycmp;
0028
0029     u32 cnid;
0030     u32 root;
0031     u32 leaf_count;
0032     u32 leaf_head;
0033     u32 leaf_tail;
0034     u32 node_count;
0035     u32 free_nodes;
0036     u32 attributes;
0037
0038     unsigned int node_size;
0039     unsigned int node_size_shift;
0040     unsigned int max_key_len;
0041     unsigned int depth;
0042
0043     //unsigned int map1_size, map_size;
0044     struct mutex tree_lock;
0045
0046     unsigned int pages_per_bnode;
0047     spinlock_t hash_lock;
0048     struct hfs_bnode *node_hash[NODE_HASH_SIZE];
0049     int node_hash_cnt;
0050 };
0051
0052 /* A HFS BTree node in memory */
0053 struct hfs_bnode {
0054     struct hfs_btree *tree;
0055
0056     u32 prev;
0057     u32 this;
0058     u32 next;
0059     u32 parent;
0060
0061     u16 num_recs;
0062     u8 type;
0063     u8 height;
0064
0065     struct hfs_bnode *next_hash;
0066     unsigned long flags;
0067     wait_queue_head_t lock_wq;
0068     atomic_t refcnt;
0069     unsigned int page_offset;
0070     struct page *page[];
0071 };
0072
0073 #define HFS_BNODE_ERROR     0
0074 #define HFS_BNODE_NEW       1
0075 #define HFS_BNODE_DELETED   2
0076
0077 struct hfs_find_data {
0078     btree_key *key;
0079     btree_key *search_key;
0080     struct hfs_btree *tree;
0081     struct hfs_bnode *bnode;
0082     int record;
0083     int keyoffset, keylength;
0084     int entryoffset, entrylength;
0085 };
0086
0087
0088 /* btree.c */
0089 extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
0090 extern void hfs_btree_close(struct hfs_btree *);
0091 extern void hfs_btree_write(struct hfs_btree *);
0092 extern int hfs_bmap_reserve(struct hfs_btree *, int);
0093 extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
0094 extern void hfs_bmap_free(struct hfs_bnode *node);
0095
0096 /* bnode.c */
0097 extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
0098 extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
0099 extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
0100 extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
0101 extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
0102 extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
0103 extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
0104 extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
0105 extern void hfs_bnode_copy(struct hfs_bnode *, int,
0106                struct hfs_bnode *, int, int);
0107 extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
0108 extern void hfs_bnode_dump(struct hfs_bnode *);
0109 extern void hfs_bnode_unlink(struct hfs_bnode *);
0110 extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
0111 extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
0112 extern void hfs_bnode_unhash(struct hfs_bnode *);
0113 extern void hfs_bnode_free(struct hfs_bnode *);
0114 extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
0115 extern void hfs_bnode_get(struct hfs_bnode *);
0116 extern void hfs_bnode_put(struct hfs_bnode *);
0117
0118 /* brec.c */
0119 extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
0120 extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
0121 extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
0122 extern int hfs_brec_remove(struct hfs_find_data *);
0123
0124 /* bfind.c */
0125 extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
0126 extern void hfs_find_exit(struct hfs_find_data *);
0127 extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
0128 extern int hfs_brec_find(struct hfs_find_data *);
0129 extern int hfs_brec_read(struct hfs_find_data *, void *, int);
0130 extern int hfs_brec_goto(struct hfs_find_data *, int);
0131
0132
0133 struct hfs_bnode_desc {
0134     __be32 next;        /* (V) Number of the next node at this level */
0135     __be32 prev;        /* (V) Number of the prev node at this level */
0136     u8 type;        /* (F) The type of node */
0137     u8 height;      /* (F) The level of this node (leaves=1) */
0138     __be16 num_recs;    /* (V) The number of records in this node */
0139     u16 reserved;
0140 } __packed;
0141
0142 #define HFS_NODE_INDEX  0x00    /* An internal (index) node */
0143 #define HFS_NODE_HEADER 0x01    /* The tree header node (node 0) */
0144 #define HFS_NODE_MAP    0x02    /* Holds part of the bitmap of used nodes */
0145 #define HFS_NODE_LEAF   0xFF    /* A leaf (ndNHeight==1) node */
0146
0147 struct hfs_btree_header_rec {
0148     __be16 depth;       /* (V) The number of levels in this B-tree */
0149     __be32 root;        /* (V) The node number of the root node */
0150     __be32 leaf_count;  /* (V) The number of leaf records */
0151     __be32 leaf_head;   /* (V) The number of the first leaf node */
0152     __be32 leaf_tail;   /* (V) The number of the last leaf node */
0153     __be16 node_size;   /* (F) The number of bytes in a node (=512) */
0154     __be16 max_key_len; /* (F) The length of a key in an index node */
0155     __be32 node_count;  /* (V) The total number of nodes */
0156     __be32 free_nodes;  /* (V) The number of unused nodes */
0157     u16 reserved1;
0158     __be32 clump_size;  /* (F) clump size. not usually used. */
0159     u8 btree_type;      /* (F) BTree type */
0160     u8 reserved2;
0161     __be32 attributes;  /* (F) attributes */
0162     u32 reserved3[16];
0163 } __packed;
0164
0165 #define BTREE_ATTR_BADCLOSE 0x00000001  /* b-tree not closed properly. not
0166                            used by hfsplus. */
0167 #define HFS_TREE_BIGKEYS    0x00000002  /* key length is u16 instead of u8.
0168                            used by hfsplus. */
0169 #define HFS_TREE_VARIDXKEYS 0x00000004  /* variable key length instead of
0170                            max key length. use din catalog
0171                            b-tree but not in extents
0172                            b-tree (hfsplus). */