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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 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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| 4581 | mejdrech | 42 | #include <fibril_sync.h> |
| 43 | #include <adt/hash_table.h> |
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| 44 | #include <adt/list.h> |
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| 3521 | jermar | 45 | |
| 3595 | jermar | 46 | /* |
| 47 | * Flags that can be used with block_get(). |
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| 48 | */ |
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| 49 | |||
| 50 | /** |
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| 51 | * This macro is a symbolic value for situations where no special flags are |
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| 52 | * needed. |
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| 53 | */ |
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| 54 | #define BLOCK_FLAGS_NONE 0 |
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| 55 | |||
| 56 | /** |
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| 57 | * When the client of block_get() intends to overwrite the current contents of |
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| 58 | * the block, this flag is used to avoid the unnecessary read. |
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| 59 | */ |
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| 60 | #define BLOCK_FLAGS_NOREAD 1 |
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| 61 | |||
| 3571 | jermar | 62 | typedef unsigned bn_t; /**< Block number type. */ |
| 63 | |||
| 3521 | jermar | 64 | typedef struct block { |
| 4581 | mejdrech | 65 | /** Mutex protecting the reference count. */ |
| 66 | fibril_mutex_t lock; |
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| 3527 | jermar | 67 | /** Number of references to the block_t structure. */ |
| 68 | unsigned refcnt; |
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| 69 | /** If true, the block needs to be written back to the block device. */ |
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| 70 | bool dirty; |
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| 71 | /** Readers / Writer lock protecting the contents of the block. */ |
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| 4581 | mejdrech | 72 | fibril_rwlock_t contents_lock; |
| 3527 | jermar | 73 | /** Handle of the device where the block resides. */ |
| 74 | dev_handle_t dev_handle; |
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| 75 | /** Block offset on the block device. Counted in 'size'-byte blocks. */ |
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| 3571 | jermar | 76 | bn_t boff; |
| 3527 | jermar | 77 | /** Size of the block. */ |
| 78 | size_t size; |
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| 79 | /** Link for placing the block into the free block list. */ |
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| 80 | link_t free_link; |
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| 81 | /** Link for placing the block into the block hash table. */ |
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| 82 | link_t hash_link; |
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| 83 | /** Buffer with the block data. */ |
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| 3521 | jermar | 84 | void *data; |
| 85 | } block_t; |
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| 86 | |||
| 4581 | mejdrech | 87 | /** Caching mode */ |
| 88 | enum cache_mode { |
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| 89 | /** Write-Through */ |
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| 90 | CACHE_MODE_WT, |
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| 91 | /** Write-Back */ |
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| 92 | CACHE_MODE_WB |
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| 93 | }; |
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| 94 | |||
| 3537 | jermar | 95 | extern int block_init(dev_handle_t, size_t); |
| 3530 | jermar | 96 | extern void block_fini(dev_handle_t); |
| 3537 | jermar | 97 | |
| 98 | extern int block_bb_read(dev_handle_t, off_t, size_t); |
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| 3530 | jermar | 99 | extern void *block_bb_get(dev_handle_t); |
| 3521 | jermar | 100 | |
| 4581 | mejdrech | 101 | extern int block_cache_init(dev_handle_t, size_t, unsigned, enum cache_mode); |
| 3539 | jermar | 102 | |
| 4718 | mejdrech | 103 | extern block_t *block_get(dev_handle_t, bn_t, int); |
| 3521 | jermar | 104 | extern void block_put(block_t *); |
| 105 | |||
| 4718 | mejdrech | 106 | extern int block_seqread(dev_handle_t, off_t *, size_t *, off_t *, void *, |
| 107 | size_t, size_t); |
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| 3521 | jermar | 108 | |
| 109 | #endif |
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| 110 | |||
| 111 | /** @} |
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| 112 | */ |
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| 113 |