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  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"
  42. #include <futex.h>
  43. #include <rwlock.h>
  44. #include <libadt/hash_table.h>
  45. #include <libadt/list.h>
  46.  
  47. typedef struct block {
  48.     /** Futex protecting the reference count. */
  49.     futex_t lock;
  50.     /** Number of references to the block_t structure. */
  51.     unsigned refcnt;
  52.     /** If true, the block needs to be written back to the block device. */
  53.     bool dirty;
  54.     /** Readers / Writer lock protecting the contents of the block. */
  55.     rwlock_t contents_lock;
  56.     /** Handle of the device where the block resides. */
  57.     dev_handle_t dev_handle;
  58.     /** Block offset on the block device. Counted in 'size'-byte blocks. */
  59.     off_t boff;
  60.     /** Size of the block. */
  61.     size_t size;
  62.     /** Link for placing the block into the free block list. */
  63.     link_t free_link;
  64.     /** Link for placing the block into the block hash table. */
  65.     link_t hash_link;
  66.     /** Buffer with the block data. */
  67.     void *data;
  68. } block_t;
  69.  
  70. extern int block_init(dev_handle_t, size_t, off_t, size_t);
  71. extern void block_fini(dev_handle_t);
  72. extern void *block_bb_get(dev_handle_t);
  73.  
  74. extern block_t *block_get(dev_handle_t, off_t, size_t);
  75. extern void block_put(block_t *);
  76.  
  77. extern bool block_read(int, off_t *, size_t *, off_t *, void *, size_t, size_t);
  78.  
  79. #endif
  80.  
  81. /** @}
  82.  */
  83.  
  84.