WebSVN – HelenOS – Diff – /branches/dd/uspace/lib/libblock/libblock.h


/*
 * Copyright (c) 2008 Jakub Jermar
 * Copyright (c) 2008 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup libblock
 * @{
 */
/**
 * @file
 */
 
#ifndef LIBBLOCK_LIBBLOCK_H_
#define LIBBLOCK_LIBBLOCK_H_ 
 
#include <stdint.h>
#include "../../srv/vfs/vfs.h"
#include <futex.h>
#include <rwlock.h>
#include <adt/hash_table.h>
#include <adt/list.h>
 
/*
 * Flags that can be used with block_get().
 */
 
/**
 * This macro is a symbolic value for situations where no special flags are
 * needed.
 */
#define BLOCK_FLAGS_NONE    0
 
/**
 * When the client of block_get() intends to overwrite the current contents of
 * the block, this flag is used to avoid the unnecessary read.
 */
#define BLOCK_FLAGS_NOREAD  1
 
typedef unsigned bn_t;  /**< Block number type. */
 
typedef struct block {
    /** Futex protecting the reference count. */
    futex_t lock;
    /** Number of references to the block_t structure. */
    unsigned refcnt;
    /** If true, the block needs to be written back to the block device. */
    bool dirty;
    /** Readers / Writer lock protecting the contents of the block. */
    rwlock_t contents_lock;
    /** Handle of the device where the block resides. */
    dev_handle_t dev_handle;
    /** Block offset on the block device. Counted in 'size'-byte blocks. */
    bn_t boff;
    /** Size of the block. */
    size_t size;
    /** Link for placing the block into the free block list. */
    link_t free_link;
    /** Link for placing the block into the block hash table. */
    link_t hash_link;
    /** Buffer with the block data. */
    void *data;
} block_t;
 
extern int block_init(dev_handle_t, size_t);
extern void block_fini(dev_handle_t);
 
extern int block_bb_read(dev_handle_t, off_t, size_t);
extern void *block_bb_get(dev_handle_t);
 
extern int block_cache_init(dev_handle_t, size_t, unsigned);
 
extern block_t *block_get(dev_handle_t, bn_t, int flags);
extern void block_put(block_t *);
 
extern int block_read(dev_handle_t, off_t *, size_t *, off_t *, void *, size_t,
    size_t);
 
#endif
 
/** @}
 */
 
 

Rev 4439	Rev 4537
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* Copyright (c) 2008 Martin Decky	3	* Copyright (c) 2008 Martin Decky
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	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	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.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	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	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	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	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	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	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.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	/** @addtogroup libblock	30	/** @addtogroup libblock
31	* @{	31	* @{
32	*/	32	*/
33	/**	33	/**
34	* @file	34	* @file
35	*/	35	*/
36		36
37	#ifndef LIBBLOCK_LIBBLOCK_H_	37	#ifndef LIBBLOCK_LIBBLOCK_H_
38	#define LIBBLOCK_LIBBLOCK_H_	38	#define LIBBLOCK_LIBBLOCK_H_
39		39
40	#include <stdint.h>	40	#include <stdint.h>
41	#include "../../srv/vfs/vfs.h"	41	#include "../../srv/vfs/vfs.h"
42	#include <futex.h>	42	#include <futex.h>
43	#include <rwlock.h>	43	#include <rwlock.h>
44	#include <libadt/hash_table.h>	44	#include <adt/hash_table.h>
45	#include <libadt/list.h>	45	#include <adt/list.h>
46		46
47	/*	47	/*
48	* Flags that can be used with block_get().	48	* Flags that can be used with block_get().
49	*/	49	*/
50		50
51	/**	51	/**
52	* This macro is a symbolic value for situations where no special flags are	52	* This macro is a symbolic value for situations where no special flags are
53	* needed.	53	* needed.
54	*/	54	*/
55	#define BLOCK_FLAGS_NONE 0	55	#define BLOCK_FLAGS_NONE 0
56		56
57	/**	57	/**
58	* When the client of block_get() intends to overwrite the current contents of	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.	59	* the block, this flag is used to avoid the unnecessary read.
60	*/	60	*/
61	#define BLOCK_FLAGS_NOREAD 1	61	#define BLOCK_FLAGS_NOREAD 1
62		62
63	typedef unsigned bn_t; /*< Block number type. /	63	typedef unsigned bn_t; /*< Block number type. /
64		64
65	typedef struct block {	65	typedef struct block {
66	/** Futex protecting the reference count. */	66	/** Futex protecting the reference count. */
67	futex_t lock;	67	futex_t lock;
68	/** Number of references to the block_t structure. */	68	/** Number of references to the block_t structure. */
69	unsigned refcnt;	69	unsigned refcnt;
70	/** If true, the block needs to be written back to the block device. */	70	/** If true, the block needs to be written back to the block device. */
71	bool dirty;	71	bool dirty;
72	/** Readers / Writer lock protecting the contents of the block. */	72	/** Readers / Writer lock protecting the contents of the block. */
73	rwlock_t contents_lock;	73	rwlock_t contents_lock;
74	/** Handle of the device where the block resides. */	74	/** Handle of the device where the block resides. */
75	dev_handle_t dev_handle;	75	dev_handle_t dev_handle;
76	/** Block offset on the block device. Counted in 'size'-byte blocks. */	76	/** Block offset on the block device. Counted in 'size'-byte blocks. */
77	bn_t boff;	77	bn_t boff;
78	/** Size of the block. */	78	/** Size of the block. */
79	size_t size;	79	size_t size;
80	/** Link for placing the block into the free block list. */	80	/** Link for placing the block into the free block list. */
81	link_t free_link;	81	link_t free_link;
82	/** Link for placing the block into the block hash table. */	82	/** Link for placing the block into the block hash table. */
83	link_t hash_link;	83	link_t hash_link;
84	/** Buffer with the block data. */	84	/** Buffer with the block data. */
85	void *data;	85	void *data;
86	} block_t;	86	} block_t;
87		87
88	extern int block_init(dev_handle_t, size_t);	88	extern int block_init(dev_handle_t, size_t);
89	extern void block_fini(dev_handle_t);	89	extern void block_fini(dev_handle_t);
90		90
91	extern int block_bb_read(dev_handle_t, off_t, size_t);	91	extern int block_bb_read(dev_handle_t, off_t, size_t);
92	extern void *block_bb_get(dev_handle_t);	92	extern void *block_bb_get(dev_handle_t);
93		93
94	extern int block_cache_init(dev_handle_t, size_t, unsigned);	94	extern int block_cache_init(dev_handle_t, size_t, unsigned);
95		95
96	extern block_t *block_get(dev_handle_t, bn_t, int flags);	96	extern block_t *block_get(dev_handle_t, bn_t, int flags);
97	extern void block_put(block_t *);	97	extern void block_put(block_t *);
98		98
99	extern int block_read(dev_handle_t, off_t , size_t , off_t , void , size_t,	99	extern int block_read(dev_handle_t, off_t , size_t , off_t , void , size_t,
100	size_t);	100	size_t);
101		101
102	#endif	102	#endif
103		103
104	/** @}	104	/** @}
105	*/	105	*/
106		106
107		107

Subversion Repositories HelenOS

(root)/branches/dd/uspace/lib/libblock/libblock.h – Rev 4439 → 4537