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| Rev | Author | Line No. | Line |
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| 3521 | jermar | 1 | /* |
| 2 | * Copyright (c) 2008 Jakub Jermar |
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| 3 | * Copyright (c) 2008 Martin Decky |
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| 4 | * All rights reserved. |
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| 5 | * |
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| 6 | * Redistribution and use in source and binary forms, with or without |
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| 7 | * modification, are permitted provided that the following conditions |
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| 8 | * are met: |
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| 9 | * |
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| 10 | * - Redistributions of source code must retain the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer. |
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| 12 | * - Redistributions in binary form must reproduce the above copyright |
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| 13 | * notice, this list of conditions and the following disclaimer in the |
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| 14 | * documentation and/or other materials provided with the distribution. |
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| 15 | * - The name of the author may not be used to endorse or promote products |
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| 16 | * derived from this software without specific prior written permission. |
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| 17 | * |
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| 18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 28 | */ |
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| 29 | |||
| 30 | /** @addtogroup libblock |
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| 31 | * @{ |
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| 32 | */ |
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| 33 | /** |
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| 34 | * @file |
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| 35 | */ |
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| 36 | |||
| 37 | #ifndef LIBBLOCK_LIBBLOCK_H_ |
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| 38 | #define LIBBLOCK_LIBBLOCK_H_ |
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| 39 | |||
| 40 | #include <stdint.h> |
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| 41 | #include "../../srv/vfs/vfs.h" |
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| 3527 | jermar | 42 | #include <futex.h> |
| 43 | #include <rwlock.h> |
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| 44 | #include <libadt/hash_table.h> |
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| 45 | #include <libadt/list.h> |
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| 3521 | jermar | 46 | |
| 3598 | svoboda | 47 | /* |
| 48 | * Flags that can be used with block_get(). |
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| 49 | */ |
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| 50 | |||
| 51 | /** |
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| 52 | * This macro is a symbolic value for situations where no special flags are |
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| 53 | * needed. |
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| 54 | */ |
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| 55 | #define BLOCK_FLAGS_NONE 0 |
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| 56 | |||
| 57 | /** |
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| 58 | * When the client of block_get() intends to overwrite the current contents of |
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| 59 | * the block, this flag is used to avoid the unnecessary read. |
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| 60 | */ |
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| 61 | #define BLOCK_FLAGS_NOREAD 1 |
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| 62 | |||
| 3588 | svoboda | 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; |
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| 68 | /** Number of references to the block_t structure. */ |
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| 69 | unsigned refcnt; |
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| 70 | /** If true, the block needs to be written back to the block device. */ |
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| 71 | bool dirty; |
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| 72 | /** Readers / Writer lock protecting the contents of the block. */ |
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| 73 | rwlock_t contents_lock; |
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| 74 | /** Handle of the device where the block resides. */ |
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| 75 | dev_handle_t dev_handle; |
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| 76 | /** Block offset on the block device. Counted in 'size'-byte blocks. */ |
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| 3588 | svoboda | 77 | bn_t boff; |
| 3527 | jermar | 78 | /** Size of the block. */ |
| 79 | size_t size; |
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| 80 | /** Link for placing the block into the free block list. */ |
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| 81 | link_t free_link; |
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| 82 | /** Link for placing the block into the block hash table. */ |
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| 83 | link_t hash_link; |
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| 84 | /** Buffer with the block data. */ |
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| 3521 | jermar | 85 | void *data; |
| 86 | } block_t; |
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| 87 | |||
| 3561 | svoboda | 88 | extern int block_init(dev_handle_t, size_t); |
| 3530 | jermar | 89 | extern void block_fini(dev_handle_t); |
| 3561 | svoboda | 90 | |
| 91 | extern int block_bb_read(dev_handle_t, off_t, size_t); |
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| 3530 | jermar | 92 | extern void *block_bb_get(dev_handle_t); |
| 3521 | jermar | 93 | |
| 3561 | svoboda | 94 | extern int block_cache_init(dev_handle_t, size_t, unsigned); |
| 95 | |||
| 3598 | svoboda | 96 | extern block_t *block_get(dev_handle_t, bn_t, int flags); |
| 3521 | jermar | 97 | extern void block_put(block_t *); |
| 98 | |||
| 3561 | svoboda | 99 | extern int block_read(int, off_t *, size_t *, off_t *, void *, size_t, size_t); |
| 3521 | jermar | 100 | |
| 101 | #endif |
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| 102 | |||
| 103 | /** @} |
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| 104 | */ |
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| 105 |