Subversion Repositories HelenOS

Rev

Rev 3571 | Rev 4435 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
3521 jermar 1
/*
2
 * Copyright (c) 2008 Jakub Jermar
3
 * Copyright (c) 2008 Martin Decky
4
 * All rights reserved.
5
 *
6
 * Redistribution and use in source and binary forms, with or without
7
 * modification, are permitted provided that the following conditions
8
 * are met:
9
 *
10
 * - Redistributions of source code must retain the above copyright
11
 *   notice, this list of conditions and the following disclaimer.
12
 * - Redistributions in binary form must reproduce the above copyright
13
 *   notice, this list of conditions and the following disclaimer in the
14
 *   documentation and/or other materials provided with the distribution.
15
 * - The name of the author may not be used to endorse or promote products
16
 *   derived from this software without specific prior written permission.
17
 *
18
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
 */
29
 
30
/** @addtogroup libblock
31
 * @{
32
 */
33
/**
34
 * @file
35
 */
36
 
37
#ifndef LIBBLOCK_LIBBLOCK_H_
38
#define LIBBLOCK_LIBBLOCK_H_ 
39
 
40
#include <stdint.h>
41
#include "../../srv/vfs/vfs.h"
3527 jermar 42
#include <futex.h>
43
#include <rwlock.h>
44
#include <libadt/hash_table.h>
45
#include <libadt/list.h>
3521 jermar 46
 
3595 jermar 47
/*
48
 * Flags that can be used with block_get().
49
 */
50
 
51
/**
52
 * This macro is a symbolic value for situations where no special flags are
53
 * needed.
54
 */
55
#define BLOCK_FLAGS_NONE    0
56
 
57
/**
58
 * When the client of block_get() intends to overwrite the current contents of
59
 * the block, this flag is used to avoid the unnecessary read.
60
 */
61
#define BLOCK_FLAGS_NOREAD  1
62
 
3571 jermar 63
typedef unsigned bn_t;  /**< Block number type. */
64
 
3521 jermar 65
typedef struct block {
3527 jermar 66
    /** Futex protecting the reference count. */
67
    futex_t lock;
68
    /** Number of references to the block_t structure. */
69
    unsigned refcnt;
70
    /** If true, the block needs to be written back to the block device. */
71
    bool dirty;
72
    /** Readers / Writer lock protecting the contents of the block. */
73
    rwlock_t contents_lock;
74
    /** Handle of the device where the block resides. */
75
    dev_handle_t dev_handle;
76
    /** Block offset on the block device. Counted in 'size'-byte blocks. */
3571 jermar 77
    bn_t boff;
3527 jermar 78
    /** Size of the block. */
79
    size_t size;
80
    /** Link for placing the block into the free block list. */
81
    link_t free_link;
82
    /** Link for placing the block into the block hash table. */
83
    link_t hash_link;
84
    /** Buffer with the block data. */
3521 jermar 85
    void *data;
86
} block_t;
87
 
3537 jermar 88
extern int block_init(dev_handle_t, size_t);
3530 jermar 89
extern void block_fini(dev_handle_t);
3537 jermar 90
 
91
extern int block_bb_read(dev_handle_t, off_t, size_t);
3530 jermar 92
extern void *block_bb_get(dev_handle_t);
3521 jermar 93
 
3539 jermar 94
extern int block_cache_init(dev_handle_t, size_t, unsigned);
95
 
3595 jermar 96
extern block_t *block_get(dev_handle_t, bn_t, int flags);
3521 jermar 97
extern void block_put(block_t *);
98
 
3538 jermar 99
extern int block_read(int, off_t *, size_t *, off_t *, void *, size_t, size_t);
3521 jermar 100
 
101
#endif
102
 
103
/** @}
104
 */
105