| 0,0 → 1,105 |
|---|
| /* |
| * 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 <libadt/hash_table.h> |
| #include <libadt/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(int, off_t *, size_t *, off_t *, void *, size_t, size_t); |
| |
| #endif |
| |
| /** @} |
| */ |
| |