/*
* 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 <fibril_sync.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 {
/** Mutex protecting the reference count. */
fibril_mutex_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. */
fibril_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;
/** Caching mode */
enum cache_mode {
/** Write-Through */
CACHE_MODE_WT,
/** Write-Back */
CACHE_MODE_WB
};
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, enum cache_mode);
extern block_t *block_get(dev_handle_t, bn_t, int);
extern void block_put(block_t *);
extern int block_seqread(dev_handle_t, off_t *, size_t *, off_t *, void *,
size_t, size_t);
#endif
/** @}
*/