Rev 4055 | Rev 4537 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 3521 | jermar | 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" |
||
| 3527 | jermar | 42 | #include <futex.h> |
| 43 | #include <rwlock.h> |
||
| 44 | #include <libadt/hash_table.h> |
||
| 45 | #include <libadt/list.h> |
||
| 3521 | jermar | 46 | |
| 3595 | jermar | 47 | /* |
| 48 | * Flags that can be used with block_get(). |
||
| 49 | */ |
||
| 50 | |||
| 51 | /** |
||
| 52 | * This macro is a symbolic value for situations where no special flags are |
||
| 53 | * needed. |
||
| 54 | */ |
||
| 55 | #define BLOCK_FLAGS_NONE 0 |
||
| 56 | |||
| 57 | /** |
||
| 58 | * When the client of block_get() intends to overwrite the current contents of |
||
| 59 | * the block, this flag is used to avoid the unnecessary read. |
||
| 60 | */ |
||
| 61 | #define BLOCK_FLAGS_NOREAD 1 |
||
| 62 | |||
| 3571 | jermar | 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; |
||
| 68 | /** Number of references to the block_t structure. */ |
||
| 69 | unsigned refcnt; |
||
| 70 | /** If true, the block needs to be written back to the block device. */ |
||
| 71 | bool dirty; |
||
| 72 | /** Readers / Writer lock protecting the contents of the block. */ |
||
| 73 | rwlock_t contents_lock; |
||
| 74 | /** Handle of the device where the block resides. */ |
||
| 75 | dev_handle_t dev_handle; |
||
| 76 | /** Block offset on the block device. Counted in 'size'-byte blocks. */ |
||
| 3571 | jermar | 77 | bn_t boff; |
| 3527 | jermar | 78 | /** Size of the block. */ |
| 79 | size_t size; |
||
| 80 | /** Link for placing the block into the free block list. */ |
||
| 81 | link_t free_link; |
||
| 82 | /** Link for placing the block into the block hash table. */ |
||
| 83 | link_t hash_link; |
||
| 84 | /** Buffer with the block data. */ |
||
| 3521 | jermar | 85 | void *data; |
| 86 | } block_t; |
||
| 87 | |||
| 3537 | jermar | 88 | extern int block_init(dev_handle_t, size_t); |
| 3530 | jermar | 89 | extern void block_fini(dev_handle_t); |
| 3537 | jermar | 90 | |
| 91 | extern int block_bb_read(dev_handle_t, off_t, size_t); |
||
| 3530 | jermar | 92 | extern void *block_bb_get(dev_handle_t); |
| 3521 | jermar | 93 | |
| 3539 | jermar | 94 | extern int block_cache_init(dev_handle_t, size_t, unsigned); |
| 95 | |||
| 3595 | jermar | 96 | extern block_t *block_get(dev_handle_t, bn_t, int flags); |
| 3521 | jermar | 97 | extern void block_put(block_t *); |
| 98 | |||
| 4439 | trochtova | 99 | extern int block_read(dev_handle_t, off_t *, size_t *, off_t *, void *, size_t, |
| 100 | size_t); |
||
| 3521 | jermar | 101 | |
| 102 | #endif |
||
| 103 | |||
| 104 | /** @} |
||
| 105 | */ |
||
| 106 |