linux/fs/hfs/btree.h
Gustavo A. R. Silva 5e01fdff04 fs: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00

166 lines
5.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/fs/hfs/btree.h
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*/
#include "hfs_fs.h"
typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
#define NODE_HASH_SIZE 256
/* A HFS BTree held in memory */
struct hfs_btree {
struct super_block *sb;
struct inode *inode;
btree_keycmp keycmp;
u32 cnid;
u32 root;
u32 leaf_count;
u32 leaf_head;
u32 leaf_tail;
u32 node_count;
u32 free_nodes;
u32 attributes;
unsigned int node_size;
unsigned int node_size_shift;
unsigned int max_key_len;
unsigned int depth;
//unsigned int map1_size, map_size;
struct mutex tree_lock;
unsigned int pages_per_bnode;
spinlock_t hash_lock;
struct hfs_bnode *node_hash[NODE_HASH_SIZE];
int node_hash_cnt;
};
/* A HFS BTree node in memory */
struct hfs_bnode {
struct hfs_btree *tree;
u32 prev;
u32 this;
u32 next;
u32 parent;
u16 num_recs;
u8 type;
u8 height;
struct hfs_bnode *next_hash;
unsigned long flags;
wait_queue_head_t lock_wq;
atomic_t refcnt;
unsigned int page_offset;
struct page *page[];
};
#define HFS_BNODE_ERROR 0
#define HFS_BNODE_NEW 1
#define HFS_BNODE_DELETED 2
struct hfs_find_data {
btree_key *key;
btree_key *search_key;
struct hfs_btree *tree;
struct hfs_bnode *bnode;
int record;
int keyoffset, keylength;
int entryoffset, entrylength;
};
/* btree.c */
extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
extern void hfs_btree_close(struct hfs_btree *);
extern void hfs_btree_write(struct hfs_btree *);
extern int hfs_bmap_reserve(struct hfs_btree *, int);
extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
extern void hfs_bmap_free(struct hfs_bnode *node);
/* bnode.c */
extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
extern void hfs_bnode_copy(struct hfs_bnode *, int,
struct hfs_bnode *, int, int);
extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
extern void hfs_bnode_dump(struct hfs_bnode *);
extern void hfs_bnode_unlink(struct hfs_bnode *);
extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
extern void hfs_bnode_unhash(struct hfs_bnode *);
extern void hfs_bnode_free(struct hfs_bnode *);
extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
extern void hfs_bnode_get(struct hfs_bnode *);
extern void hfs_bnode_put(struct hfs_bnode *);
/* brec.c */
extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
extern int hfs_brec_remove(struct hfs_find_data *);
/* bfind.c */
extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
extern void hfs_find_exit(struct hfs_find_data *);
extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
extern int hfs_brec_find(struct hfs_find_data *);
extern int hfs_brec_read(struct hfs_find_data *, void *, int);
extern int hfs_brec_goto(struct hfs_find_data *, int);
struct hfs_bnode_desc {
__be32 next; /* (V) Number of the next node at this level */
__be32 prev; /* (V) Number of the prev node at this level */
u8 type; /* (F) The type of node */
u8 height; /* (F) The level of this node (leaves=1) */
__be16 num_recs; /* (V) The number of records in this node */
u16 reserved;
} __packed;
#define HFS_NODE_INDEX 0x00 /* An internal (index) node */
#define HFS_NODE_HEADER 0x01 /* The tree header node (node 0) */
#define HFS_NODE_MAP 0x02 /* Holds part of the bitmap of used nodes */
#define HFS_NODE_LEAF 0xFF /* A leaf (ndNHeight==1) node */
struct hfs_btree_header_rec {
__be16 depth; /* (V) The number of levels in this B-tree */
__be32 root; /* (V) The node number of the root node */
__be32 leaf_count; /* (V) The number of leaf records */
__be32 leaf_head; /* (V) The number of the first leaf node */
__be32 leaf_tail; /* (V) The number of the last leaf node */
__be16 node_size; /* (F) The number of bytes in a node (=512) */
__be16 max_key_len; /* (F) The length of a key in an index node */
__be32 node_count; /* (V) The total number of nodes */
__be32 free_nodes; /* (V) The number of unused nodes */
u16 reserved1;
__be32 clump_size; /* (F) clump size. not usually used. */
u8 btree_type; /* (F) BTree type */
u8 reserved2;
__be32 attributes; /* (F) attributes */
u32 reserved3[16];
} __packed;
#define BTREE_ATTR_BADCLOSE 0x00000001 /* b-tree not closed properly. not
used by hfsplus. */
#define HFS_TREE_BIGKEYS 0x00000002 /* key length is u16 instead of u8.
used by hfsplus. */
#define HFS_TREE_VARIDXKEYS 0x00000004 /* variable key length instead of
max key length. use din catalog
b-tree but not in extents
b-tree (hfsplus). */