[e51bd96] | 1 | /* |
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| 2 | * Disk I/O buffering |
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| 3 | * Buffer managment |
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| 4 | * |
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| 5 | * Copyright (C) 2001 OKTET Ltd., St.-Peterburg, Russia |
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| 6 | * Author: Andrey G. Ivanov <Andrey.Ivanov@oktet.ru> |
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| 7 | * Victor V. Vengerov <vvv@oktet.ru> |
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[df6348bb] | 8 | * Alexander Kukuta <kam@oktet.ru> |
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[e51bd96] | 9 | * |
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| 10 | * @(#) $Id$ |
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| 11 | */ |
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| 12 | |
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[006fa1ef] | 13 | #if HAVE_CONFIG_H |
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| 14 | #include "config.h" |
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| 15 | #endif |
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| 16 | |
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[e51bd96] | 17 | #define __RTEMS_VIOLATE_KERNEL_VISIBILITY__ |
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| 18 | #include <rtems.h> |
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| 19 | #include <limits.h> |
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| 20 | #include <errno.h> |
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| 21 | #include <assert.h> |
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| 22 | |
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| 23 | #include "rtems/bdbuf.h" |
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| 24 | |
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| 25 | /* Fatal errors: */ |
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[c01d95b7] | 26 | #define BLKDEV_FATAL_ERROR(n) (((uint32_t)'B' << 24) | ((uint32_t)(n) & (uint32_t)0x00FFFFFF)) |
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[e51bd96] | 27 | #define BLKDEV_FATAL_BDBUF_CONSISTENCY BLKDEV_FATAL_ERROR(1) |
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| 28 | #define BLKDEV_FATAL_BDBUF_SWAPOUT BLKDEV_FATAL_ERROR(2) |
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| 29 | |
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| 30 | |
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| 31 | #define SWAPOUT_PRIORITY 15 |
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| 32 | #define SWAPOUT_STACK_SIZE (RTEMS_MINIMUM_STACK_SIZE * 2) |
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| 33 | |
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| 34 | static rtems_task bdbuf_swapout_task(rtems_task_argument unused); |
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| 35 | |
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| 36 | /* |
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| 37 | * The groups of the blocks with the same size are collected in the |
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| 38 | * bd_pool. Note that a several of the buffer's groups with the |
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| 39 | * same size can exists. |
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| 40 | */ |
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| 41 | typedef struct bdbuf_pool |
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| 42 | { |
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| 43 | bdbuf_buffer *tree; /* Buffer descriptor lookup AVL tree root */ |
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| 44 | |
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| 45 | Chain_Control free; /* Free buffers list */ |
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| 46 | Chain_Control lru; /* Last recently used list */ |
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| 47 | |
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| 48 | int blksize; /* The size of the blocks (in bytes) */ |
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| 49 | int nblks; /* Number of blocks in this pool */ |
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| 50 | rtems_id bufget_sema; /* Buffer obtain counting semaphore */ |
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| 51 | void *mallocd_bufs; /* Pointer to the malloc'd buffer memory, |
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| 52 | or NULL, if buffer memory provided in |
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| 53 | buffer configuration */ |
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| 54 | bdbuf_buffer *bdbufs; /* Pointer to table of buffer descriptors |
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| 55 | allocated for this buffer pool. */ |
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| 56 | } bdbuf_pool; |
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| 57 | |
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| 58 | /* Buffering layer context definition */ |
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| 59 | struct bdbuf_context { |
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| 60 | bdbuf_pool *pool; /* Table of buffer pools */ |
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| 61 | int npools; /* Number of entries in pool table */ |
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[048dcd2b] | 62 | |
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[e51bd96] | 63 | Chain_Control mod; /* Modified buffers list */ |
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[8b96149] | 64 | rtems_id flush_sema; /* Buffer flush semaphore; counting |
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[e51bd96] | 65 | semaphore; incremented when buffer |
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[8b96149] | 66 | flushed to the disk; decremented when |
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[e51bd96] | 67 | buffer modified */ |
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| 68 | rtems_id swapout_task; /* Swapout task ID */ |
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| 69 | }; |
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| 70 | |
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| 71 | /* Block device request with a single buffer provided */ |
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| 72 | typedef struct blkdev_request1 { |
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| 73 | blkdev_request req; |
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| 74 | blkdev_sg_buffer sg[1]; |
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| 75 | } blkdev_request1; |
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| 76 | |
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| 77 | /* The static context of buffering layer */ |
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| 78 | static struct bdbuf_context bd_ctx; |
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| 79 | |
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| 80 | #define SAFE |
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| 81 | #ifdef SAFE |
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| 82 | typedef rtems_mode preemption_key; |
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| 83 | |
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| 84 | #define DISABLE_PREEMPTION(key) \ |
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| 85 | do { \ |
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[828be6d] | 86 | rtems_task_mode(RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &(key)); \ |
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[e51bd96] | 87 | } while (0) |
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| 88 | |
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| 89 | #define ENABLE_PREEMPTION(key) \ |
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| 90 | do { \ |
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| 91 | rtems_mode temp; \ |
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[828be6d] | 92 | rtems_task_mode((key), RTEMS_PREEMPT_MASK, &temp); \ |
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[e51bd96] | 93 | } while (0) |
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| 94 | |
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| 95 | #else |
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[048dcd2b] | 96 | |
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[e51bd96] | 97 | typedef boolean preemption_key; |
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| 98 | |
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| 99 | #define DISABLE_PREEMPTION(key) \ |
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| 100 | do { \ |
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| 101 | (key) = _Thread_Executing->is_preemptible; \ |
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| 102 | _Thread_Executing->is_preemptible = 0; \ |
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| 103 | } while (0) |
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[048dcd2b] | 104 | |
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[e51bd96] | 105 | #define ENABLE_PREEMPTION(key) \ |
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| 106 | do { \ |
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| 107 | _Thread_Executing->is_preemptible = (key); \ |
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| 108 | if (_Thread_Evaluate_mode()) \ |
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| 109 | _Thread_Dispatch(); \ |
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| 110 | } while (0) |
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| 111 | |
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| 112 | #endif |
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| 113 | |
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| 114 | |
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| 115 | /* The default maximum height of 32 allows for AVL trees having |
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| 116 | between 5,704,880 and 4,294,967,295 nodes, depending on order of |
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| 117 | insertion. You may change this compile-time constant as you |
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| 118 | wish. */ |
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| 119 | #ifndef AVL_MAX_HEIGHT |
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| 120 | #define AVL_MAX_HEIGHT 32 |
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| 121 | #endif |
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| 122 | |
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| 123 | /* |
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| 124 | * avl_search -- |
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| 125 | * Searches for the node with specified dev/block. |
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| 126 | * |
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| 127 | * PARAMETERS: |
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| 128 | * root - pointer to the root node of the AVL-Tree. |
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| 129 | * dev, block - search key |
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| 130 | * |
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| 131 | * RETURNS: |
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| 132 | * NULL if node with specified dev/block not found |
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| 133 | * non-NULL - pointer to the node with specified dev/block |
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| 134 | */ |
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| 135 | static bdbuf_buffer * |
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| 136 | avl_search(bdbuf_buffer **root, dev_t dev, blkdev_bnum block) |
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| 137 | { |
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| 138 | bdbuf_buffer *p = *root; |
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[df6348bb] | 139 | |
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[e51bd96] | 140 | while ((p != NULL) && ((p->dev != dev) || (p->block != block))) |
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| 141 | { |
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| 142 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[df6348bb] | 143 | { |
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| 144 | p = p->avl.right; |
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| 145 | } |
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[e51bd96] | 146 | else |
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[df6348bb] | 147 | { |
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| 148 | p = p->avl.left; |
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| 149 | } |
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[e51bd96] | 150 | } |
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[048dcd2b] | 151 | |
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[e51bd96] | 152 | return p; |
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| 153 | } |
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| 154 | |
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[df6348bb] | 155 | |
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[e51bd96] | 156 | /* avl_search_for_sync -- |
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| 157 | * Search in AVL tree for first modified buffer belongs to specified |
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| 158 | * disk device. |
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| 159 | * |
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| 160 | * PARAMETERS: |
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| 161 | * root - pointer to tree root |
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| 162 | * dd - disk device descriptor |
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| 163 | * |
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| 164 | * RETURNS: |
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| 165 | * Block buffer, or NULL if no modified blocks on specified device |
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| 166 | * exists. |
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| 167 | */ |
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| 168 | static bdbuf_buffer * |
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| 169 | avl_search_for_sync(bdbuf_buffer **root, disk_device *dd) |
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| 170 | { |
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| 171 | dev_t dev = dd->phys_dev->dev; |
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[df6348bb] | 172 | blkdev_bnum block_start = dd->start; |
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| 173 | blkdev_bnum block_end = dd->start + dd->size - 1; |
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| 174 | |
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| 175 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 176 | bdbuf_buffer **buf_prev = buf_stack; |
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| 177 | bdbuf_buffer *p = *root; |
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| 178 | |
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[e51bd96] | 179 | while (p != NULL) |
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| 180 | { |
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[df6348bb] | 181 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block_start))) |
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| 182 | { |
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| 183 | p = p->avl.right; |
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| 184 | } |
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| 185 | else if ((p->dev > dev) || ((p->dev == dev) && (p->block > block_end))) |
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| 186 | { |
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| 187 | p = p->avl.left; |
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| 188 | } |
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[e51bd96] | 189 | else if (p->modified) |
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[df6348bb] | 190 | { |
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[e51bd96] | 191 | return p; |
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[df6348bb] | 192 | } |
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[e51bd96] | 193 | else |
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| 194 | { |
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[df6348bb] | 195 | if (p->avl.right != NULL) |
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| 196 | { |
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| 197 | *buf_prev++ = p->avl.right; |
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| 198 | } |
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| 199 | p = p->avl.left; |
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| 200 | } |
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| 201 | |
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| 202 | if ((p == NULL) && (buf_prev > buf_stack)) |
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| 203 | { |
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| 204 | p = *--buf_prev; |
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[e51bd96] | 205 | } |
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| 206 | } |
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[df6348bb] | 207 | |
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[e51bd96] | 208 | return p; |
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| 209 | } |
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| 210 | |
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| 211 | |
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| 212 | /* |
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| 213 | * avl_insert -- |
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| 214 | * Inserts the specified node to the AVl-Tree. |
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| 215 | * |
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| 216 | * PARAMETERS: |
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[df6348bb] | 217 | * root - Pointer to pointer to the root node |
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[e51bd96] | 218 | * node - Pointer to the node to add. |
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| 219 | * |
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| 220 | * RETURNS: |
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| 221 | * 0 - The node added successfully |
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| 222 | * -1 - An error occured |
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| 223 | */ |
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| 224 | static int |
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[df6348bb] | 225 | avl_insert(bdbuf_buffer **root, bdbuf_buffer *node) |
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[e51bd96] | 226 | { |
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[df6348bb] | 227 | dev_t dev = node->dev; |
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| 228 | blkdev_bnum block = node->block; |
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[e51bd96] | 229 | |
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[df6348bb] | 230 | bdbuf_buffer *p = *root; |
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[120b59e] | 231 | bdbuf_buffer *q = NULL; |
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| 232 | bdbuf_buffer *p1, *p2; |
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[df6348bb] | 233 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 234 | bdbuf_buffer **buf_prev = buf_stack; |
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[e51bd96] | 235 | |
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[df6348bb] | 236 | boolean modified = FALSE; |
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[e51bd96] | 237 | |
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[df6348bb] | 238 | if (p == NULL) |
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[e51bd96] | 239 | { |
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[df6348bb] | 240 | *root = node; |
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| 241 | node->avl.left = NULL; |
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| 242 | node->avl.right = NULL; |
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| 243 | node->avl.bal = 0; |
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[e51bd96] | 244 | return 0; |
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| 245 | } |
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| 246 | |
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[df6348bb] | 247 | while (p != NULL) |
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[e51bd96] | 248 | { |
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[df6348bb] | 249 | *buf_prev++ = p; |
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[e51bd96] | 250 | |
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[df6348bb] | 251 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[e51bd96] | 252 | { |
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[df6348bb] | 253 | p->avl.cache = 1; |
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| 254 | q = p->avl.right; |
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[e51bd96] | 255 | if (q == NULL) |
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| 256 | { |
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[df6348bb] | 257 | q = node; |
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| 258 | p->avl.right = q = node; |
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[e51bd96] | 259 | break; |
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| 260 | } |
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| 261 | } |
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[df6348bb] | 262 | else if ((p->dev != dev) || (p->block != block)) |
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| 263 | { |
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| 264 | p->avl.cache = -1; |
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| 265 | q = p->avl.left; |
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| 266 | if (q == NULL) |
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[e51bd96] | 267 | { |
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[df6348bb] | 268 | q = node; |
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| 269 | p->avl.left = q; |
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| 270 | break; |
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[e51bd96] | 271 | } |
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[df6348bb] | 272 | } |
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| 273 | else |
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[e51bd96] | 274 | { |
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[df6348bb] | 275 | return -1; |
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[e51bd96] | 276 | } |
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[df6348bb] | 277 | |
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[e51bd96] | 278 | p = q; |
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| 279 | } |
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| 280 | |
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[df6348bb] | 281 | q->avl.left = q->avl.right = NULL; |
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| 282 | q->avl.bal = 0; |
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| 283 | modified = TRUE; |
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| 284 | buf_prev--; |
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[e51bd96] | 285 | |
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[df6348bb] | 286 | while (modified) |
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[e51bd96] | 287 | { |
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[df6348bb] | 288 | if (p->avl.cache == -1) |
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[e51bd96] | 289 | { |
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[df6348bb] | 290 | switch (p->avl.bal) |
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| 291 | { |
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| 292 | case 1: |
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| 293 | p->avl.bal = 0; |
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| 294 | modified = FALSE; |
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| 295 | break; |
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| 296 | |
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| 297 | case 0: |
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| 298 | p->avl.bal = -1; |
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| 299 | break; |
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| 300 | |
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| 301 | case -1: |
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| 302 | p1 = p->avl.left; |
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| 303 | if (p1->avl.bal == -1) /* simple LL-turn */ |
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| 304 | { |
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| 305 | p->avl.left = p1->avl.right; |
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| 306 | p1->avl.right = p; |
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| 307 | p->avl.bal = 0; |
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| 308 | p = p1; |
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| 309 | } |
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| 310 | else /* double LR-turn */ |
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| 311 | { |
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| 312 | p2 = p1->avl.right; |
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| 313 | p1->avl.right = p2->avl.left; |
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| 314 | p2->avl.left = p1; |
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| 315 | p->avl.left = p2->avl.right; |
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| 316 | p2->avl.right = p; |
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| 317 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
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| 318 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
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| 319 | p = p2; |
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| 320 | } |
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| 321 | p->avl.bal = 0; |
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| 322 | modified = FALSE; |
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| 323 | break; |
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| 324 | |
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| 325 | default: |
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| 326 | break; |
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| 327 | } |
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[e51bd96] | 328 | } |
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| 329 | else |
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| 330 | { |
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[df6348bb] | 331 | switch (p->avl.bal) |
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[e51bd96] | 332 | { |
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[df6348bb] | 333 | case -1: |
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| 334 | p->avl.bal = 0; |
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| 335 | modified = FALSE; |
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| 336 | break; |
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| 337 | |
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| 338 | case 0: |
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| 339 | p->avl.bal = 1; |
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| 340 | break; |
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| 341 | |
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| 342 | case 1: |
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| 343 | p1 = p->avl.right; |
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| 344 | if (p1->avl.bal == 1) /* simple RR-turn */ |
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| 345 | { |
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| 346 | p->avl.right = p1->avl.left; |
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| 347 | p1->avl.left = p; |
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| 348 | p->avl.bal = 0; |
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| 349 | p = p1; |
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| 350 | } |
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| 351 | else /* double RL-turn */ |
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| 352 | { |
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| 353 | p2 = p1->avl.left; |
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| 354 | p1->avl.left = p2->avl.right; |
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| 355 | p2->avl.right = p1; |
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| 356 | p->avl.right = p2->avl.left; |
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| 357 | p2->avl.left = p; |
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| 358 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
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| 359 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
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| 360 | p = p2; |
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| 361 | } |
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| 362 | p->avl.bal = 0; |
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| 363 | modified = FALSE; |
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| 364 | break; |
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| 365 | |
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| 366 | default: |
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| 367 | break; |
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[e51bd96] | 368 | } |
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| 369 | } |
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[df6348bb] | 370 | q = p; |
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| 371 | if (buf_prev > buf_stack) |
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[e51bd96] | 372 | { |
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[df6348bb] | 373 | p = *--buf_prev; |
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[e51bd96] | 374 | |
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[df6348bb] | 375 | if (p->avl.cache == -1) |
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[e51bd96] | 376 | { |
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[df6348bb] | 377 | p->avl.left = q; |
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[e51bd96] | 378 | } |
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[df6348bb] | 379 | else |
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[e51bd96] | 380 | { |
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[df6348bb] | 381 | p->avl.right = q; |
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[e51bd96] | 382 | } |
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| 383 | } |
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| 384 | else |
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[df6348bb] | 385 | { |
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| 386 | *root = p; |
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| 387 | break; |
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| 388 | } |
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| 389 | }; |
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[e51bd96] | 390 | |
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| 391 | return 0; |
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| 392 | } |
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| 393 | |
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| 394 | |
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| 395 | /* avl_remove -- |
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| 396 | * removes the node from the tree. |
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| 397 | * |
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| 398 | * PARAMETERS: |
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| 399 | * root_addr - Pointer to pointer to the root node |
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| 400 | * node - Pointer to the node to remove |
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| 401 | * |
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| 402 | * RETURNS: |
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| 403 | * 0 - Item removed |
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| 404 | * -1 - No such item found |
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| 405 | */ |
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| 406 | static int |
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[df6348bb] | 407 | avl_remove(bdbuf_buffer **root, const bdbuf_buffer *node) |
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[e51bd96] | 408 | { |
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[df6348bb] | 409 | dev_t dev = node->dev; |
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| 410 | blkdev_bnum block = node->block; |
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[e51bd96] | 411 | |
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[df6348bb] | 412 | bdbuf_buffer *p = *root; |
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| 413 | bdbuf_buffer *q, *r, *s, *p1, *p2; |
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| 414 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 415 | bdbuf_buffer **buf_prev = buf_stack; |
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[e51bd96] | 416 | |
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[df6348bb] | 417 | boolean modified = FALSE; |
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[e51bd96] | 418 | |
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[df6348bb] | 419 | memset(buf_stack, 0, sizeof(buf_stack)); |
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[e51bd96] | 420 | |
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[df6348bb] | 421 | while (p != NULL) |
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[e51bd96] | 422 | { |
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[df6348bb] | 423 | *buf_prev++ = p; |
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[e51bd96] | 424 | |
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[df6348bb] | 425 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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| 426 | { |
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| 427 | p->avl.cache = 1; |
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| 428 | p = p->avl.right; |
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| 429 | } |
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| 430 | else if ((p->dev != dev) || (p->block != block)) |
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[e51bd96] | 431 | { |
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[df6348bb] | 432 | p->avl.cache = -1; |
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| 433 | p = p->avl.left; |
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[e51bd96] | 434 | } |
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[df6348bb] | 435 | else |
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[e51bd96] | 436 | { |
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[df6348bb] | 437 | /* node found */ |
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| 438 | break; |
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[e51bd96] | 439 | } |
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[df6348bb] | 440 | } |
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[048dcd2b] | 441 | |
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[df6348bb] | 442 | if (p == NULL) |
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| 443 | { |
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| 444 | /* there is no such node */ |
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| 445 | return -1; |
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[e51bd96] | 446 | } |
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| 447 | |
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[df6348bb] | 448 | q = p; |
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| 449 | |
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| 450 | buf_prev--; |
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| 451 | if (buf_prev > buf_stack) |
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[e51bd96] | 452 | { |
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[df6348bb] | 453 | p = *(buf_prev - 1); |
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[e51bd96] | 454 | } |
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| 455 | else |
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| 456 | { |
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[df6348bb] | 457 | p = NULL; |
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[e51bd96] | 458 | } |
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[df6348bb] | 459 | |
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| 460 | /* at this moment q - is a node to delete, p is q's parent */ |
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| 461 | if (q->avl.right == NULL) |
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[e51bd96] | 462 | { |
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[df6348bb] | 463 | r = q->avl.left; |
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| 464 | if (r != NULL) |
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[8b96149] | 465 | { |
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[df6348bb] | 466 | r->avl.bal = 0; |
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| 467 | } |
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| 468 | q = r; |
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[e51bd96] | 469 | } |
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| 470 | else |
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| 471 | { |
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[df6348bb] | 472 | bdbuf_buffer **t; |
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| 473 | |
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| 474 | r = q->avl.right; |
---|
| 475 | |
---|
| 476 | if (r->avl.left == NULL) |
---|
[e51bd96] | 477 | { |
---|
[df6348bb] | 478 | r->avl.left = q->avl.left; |
---|
| 479 | r->avl.bal = q->avl.bal; |
---|
| 480 | r->avl.cache = 1; |
---|
| 481 | *buf_prev++ = q = r; |
---|
[e51bd96] | 482 | } |
---|
| 483 | else |
---|
| 484 | { |
---|
[df6348bb] | 485 | t = buf_prev++; |
---|
| 486 | s = r; |
---|
[048dcd2b] | 487 | |
---|
[df6348bb] | 488 | while (s->avl.left != NULL) |
---|
[e51bd96] | 489 | { |
---|
[df6348bb] | 490 | *buf_prev++ = r = s; |
---|
| 491 | s = r->avl.left; |
---|
| 492 | r->avl.cache = -1; |
---|
[e51bd96] | 493 | } |
---|
[048dcd2b] | 494 | |
---|
[df6348bb] | 495 | s->avl.left = q->avl.left; |
---|
| 496 | r->avl.left = s->avl.right; |
---|
| 497 | s->avl.right = q->avl.right; |
---|
| 498 | s->avl.bal = q->avl.bal; |
---|
| 499 | s->avl.cache = 1; |
---|
[048dcd2b] | 500 | |
---|
[df6348bb] | 501 | *t = q = s; |
---|
[e51bd96] | 502 | } |
---|
| 503 | } |
---|
| 504 | |
---|
[df6348bb] | 505 | if (p != NULL) |
---|
[e51bd96] | 506 | { |
---|
[df6348bb] | 507 | if (p->avl.cache == -1) |
---|
[e51bd96] | 508 | { |
---|
[df6348bb] | 509 | p->avl.left = q; |
---|
| 510 | } |
---|
| 511 | else |
---|
| 512 | { |
---|
| 513 | p->avl.right = q; |
---|
| 514 | } |
---|
| 515 | } |
---|
| 516 | else |
---|
| 517 | { |
---|
| 518 | *root = q; |
---|
| 519 | } |
---|
[e51bd96] | 520 | |
---|
[df6348bb] | 521 | modified = TRUE; |
---|
[e51bd96] | 522 | |
---|
[df6348bb] | 523 | while (modified) |
---|
| 524 | { |
---|
| 525 | if (buf_prev > buf_stack) |
---|
| 526 | { |
---|
| 527 | p = *--buf_prev; |
---|
| 528 | } |
---|
| 529 | else |
---|
| 530 | { |
---|
| 531 | break; |
---|
| 532 | } |
---|
[048dcd2b] | 533 | |
---|
[df6348bb] | 534 | if (p->avl.cache == -1) |
---|
| 535 | { |
---|
| 536 | /* rebalance left branch */ |
---|
| 537 | switch (p->avl.bal) |
---|
[e51bd96] | 538 | { |
---|
[df6348bb] | 539 | case -1: |
---|
[e51bd96] | 540 | p->avl.bal = 0; |
---|
[df6348bb] | 541 | break; |
---|
| 542 | case 0: |
---|
| 543 | p->avl.bal = 1; |
---|
| 544 | modified = FALSE; |
---|
| 545 | break; |
---|
| 546 | |
---|
| 547 | case +1: |
---|
| 548 | p1 = p->avl.right; |
---|
| 549 | |
---|
| 550 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
[e51bd96] | 551 | { |
---|
[df6348bb] | 552 | p->avl.right = p1->avl.left; |
---|
| 553 | p1->avl.left = p; |
---|
| 554 | |
---|
| 555 | if (p1->avl.bal == 0) |
---|
| 556 | { |
---|
| 557 | p1->avl.bal = -1; |
---|
| 558 | modified = FALSE; |
---|
| 559 | } |
---|
| 560 | else |
---|
| 561 | { |
---|
| 562 | p->avl.bal = 0; |
---|
| 563 | p1->avl.bal = 0; |
---|
| 564 | } |
---|
| 565 | p = p1; |
---|
[e51bd96] | 566 | } |
---|
[df6348bb] | 567 | else /* double RL-turn */ |
---|
[e51bd96] | 568 | { |
---|
[df6348bb] | 569 | p2 = p1->avl.left; |
---|
| 570 | |
---|
| 571 | p1->avl.left = p2->avl.right; |
---|
| 572 | p2->avl.right = p1; |
---|
| 573 | p->avl.right = p2->avl.left; |
---|
| 574 | p2->avl.left = p; |
---|
[048dcd2b] | 575 | |
---|
[df6348bb] | 576 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
| 577 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
[048dcd2b] | 578 | |
---|
[df6348bb] | 579 | p = p2; |
---|
| 580 | p2->avl.bal = 0; |
---|
[e51bd96] | 581 | } |
---|
[df6348bb] | 582 | break; |
---|
| 583 | |
---|
| 584 | default: |
---|
| 585 | break; |
---|
| 586 | } |
---|
[e51bd96] | 587 | } |
---|
| 588 | else |
---|
| 589 | { |
---|
[df6348bb] | 590 | /* rebalance right branch */ |
---|
| 591 | switch (p->avl.bal) |
---|
[e51bd96] | 592 | { |
---|
[df6348bb] | 593 | case +1: |
---|
| 594 | p->avl.bal = 0; |
---|
[e51bd96] | 595 | break; |
---|
| 596 | |
---|
[df6348bb] | 597 | case 0: |
---|
| 598 | p->avl.bal = -1; |
---|
| 599 | modified = FALSE; |
---|
| 600 | break; |
---|
[e51bd96] | 601 | |
---|
[df6348bb] | 602 | case -1: |
---|
| 603 | p1 = p->avl.left; |
---|
[e51bd96] | 604 | |
---|
[df6348bb] | 605 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
[e51bd96] | 606 | { |
---|
[df6348bb] | 607 | p->avl.left = p1->avl.right; |
---|
| 608 | p1->avl.right = p; |
---|
| 609 | if (p1->avl.bal == 0) |
---|
[e51bd96] | 610 | { |
---|
[df6348bb] | 611 | p1->avl.bal = 1; |
---|
| 612 | modified = FALSE; |
---|
[e51bd96] | 613 | } |
---|
| 614 | else |
---|
| 615 | { |
---|
[df6348bb] | 616 | p->avl.bal = 0; |
---|
| 617 | p1->avl.bal = 0; |
---|
[e51bd96] | 618 | } |
---|
[df6348bb] | 619 | p = p1; |
---|
| 620 | } |
---|
| 621 | else /* double LR-turn */ |
---|
| 622 | { |
---|
| 623 | p2 = p1->avl.right; |
---|
| 624 | |
---|
| 625 | p1->avl.right = p2->avl.left; |
---|
| 626 | p2->avl.left = p1; |
---|
| 627 | p->avl.left = p2->avl.right; |
---|
| 628 | p2->avl.right = p; |
---|
[048dcd2b] | 629 | |
---|
[df6348bb] | 630 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
| 631 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
| 632 | |
---|
| 633 | p = p2; |
---|
| 634 | p2->avl.bal = 0; |
---|
[e51bd96] | 635 | } |
---|
[df6348bb] | 636 | break; |
---|
| 637 | |
---|
| 638 | default: |
---|
| 639 | break; |
---|
| 640 | } |
---|
[e51bd96] | 641 | } |
---|
| 642 | |
---|
[df6348bb] | 643 | if (buf_prev > buf_stack) |
---|
| 644 | { |
---|
| 645 | q = *(buf_prev - 1); |
---|
[048dcd2b] | 646 | |
---|
[df6348bb] | 647 | if (q->avl.cache == -1) |
---|
| 648 | { |
---|
| 649 | q->avl.left = p; |
---|
| 650 | } |
---|
| 651 | else |
---|
| 652 | { |
---|
| 653 | q->avl.right = p; |
---|
| 654 | } |
---|
| 655 | } |
---|
| 656 | else |
---|
| 657 | { |
---|
| 658 | *root = p; |
---|
| 659 | break; |
---|
| 660 | } |
---|
| 661 | |
---|
| 662 | } |
---|
[048dcd2b] | 663 | |
---|
[e51bd96] | 664 | return 0; |
---|
| 665 | } |
---|
| 666 | |
---|
| 667 | /* bdbuf_initialize_pool -- |
---|
| 668 | * Initialize single buffer pool. |
---|
| 669 | * |
---|
| 670 | * PARAMETERS: |
---|
| 671 | * config - buffer pool configuration |
---|
| 672 | * pool - pool number |
---|
| 673 | * |
---|
| 674 | * RETURNS: |
---|
| 675 | * RTEMS_SUCCESSFUL, if buffer pool initialized successfully, or error |
---|
| 676 | * code if error occured. |
---|
| 677 | */ |
---|
| 678 | static rtems_status_code |
---|
| 679 | bdbuf_initialize_pool(rtems_bdbuf_config *config, int pool) |
---|
| 680 | { |
---|
| 681 | bdbuf_pool *p = bd_ctx.pool + pool; |
---|
| 682 | unsigned char *bufs; |
---|
| 683 | bdbuf_buffer *b; |
---|
| 684 | rtems_status_code rc; |
---|
| 685 | int i; |
---|
[048dcd2b] | 686 | |
---|
[e51bd96] | 687 | p->blksize = config->size; |
---|
| 688 | p->nblks = config->num; |
---|
| 689 | p->tree = NULL; |
---|
[048dcd2b] | 690 | |
---|
[e51bd96] | 691 | Chain_Initialize_empty(&p->free); |
---|
| 692 | Chain_Initialize_empty(&p->lru); |
---|
[048dcd2b] | 693 | |
---|
[e51bd96] | 694 | /* Allocate memory for buffer descriptors */ |
---|
| 695 | p->bdbufs = calloc(config->num, sizeof(bdbuf_buffer)); |
---|
| 696 | if (p->bdbufs == NULL) |
---|
| 697 | { |
---|
| 698 | return RTEMS_NO_MEMORY; |
---|
| 699 | } |
---|
[048dcd2b] | 700 | |
---|
[e51bd96] | 701 | /* Allocate memory for buffers if required */ |
---|
| 702 | if (config->mem_area == NULL) |
---|
| 703 | { |
---|
| 704 | bufs = p->mallocd_bufs = malloc(config->num * config->size); |
---|
| 705 | if (bufs == NULL) |
---|
| 706 | { |
---|
| 707 | free(p->bdbufs); |
---|
| 708 | return RTEMS_NO_MEMORY; |
---|
| 709 | } |
---|
| 710 | } |
---|
| 711 | else |
---|
| 712 | { |
---|
| 713 | bufs = config->mem_area; |
---|
| 714 | p->mallocd_bufs = NULL; |
---|
| 715 | } |
---|
[048dcd2b] | 716 | |
---|
[e51bd96] | 717 | for (i = 0, b = p->bdbufs; i < p->nblks; i++, b++, bufs += p->blksize) |
---|
| 718 | { |
---|
| 719 | b->dev = -1; b->block = 0; |
---|
| 720 | b->buffer = bufs; |
---|
| 721 | b->actual = b->modified = b->in_progress = FALSE; |
---|
| 722 | b->use_count = 0; |
---|
| 723 | b->pool = pool; |
---|
| 724 | _Chain_Append(&p->free, &b->link); |
---|
| 725 | } |
---|
[048dcd2b] | 726 | |
---|
[e51bd96] | 727 | rc = rtems_semaphore_create( |
---|
| 728 | rtems_build_name('B', 'U', 'F', 'G'), |
---|
| 729 | p->nblks, |
---|
| 730 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
| 731 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, |
---|
| 732 | 0, |
---|
| 733 | &p->bufget_sema); |
---|
[048dcd2b] | 734 | |
---|
[e51bd96] | 735 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 736 | { |
---|
| 737 | free(p->bdbufs); |
---|
| 738 | free(p->mallocd_bufs); |
---|
| 739 | return rc; |
---|
| 740 | } |
---|
[048dcd2b] | 741 | |
---|
[e51bd96] | 742 | return RTEMS_SUCCESSFUL; |
---|
| 743 | } |
---|
| 744 | |
---|
| 745 | /* bdbuf_release_pool -- |
---|
| 746 | * Free resources allocated for buffer pool with specified number. |
---|
| 747 | * |
---|
| 748 | * PARAMETERS: |
---|
| 749 | * pool - buffer pool number |
---|
| 750 | * |
---|
| 751 | * RETURNS: |
---|
| 752 | * RTEMS_SUCCESSFUL |
---|
| 753 | */ |
---|
| 754 | static rtems_status_code |
---|
| 755 | bdbuf_release_pool(rtems_bdpool_id pool) |
---|
| 756 | { |
---|
| 757 | bdbuf_pool *p = bd_ctx.pool + pool; |
---|
| 758 | rtems_semaphore_delete(p->bufget_sema); |
---|
| 759 | free(p->bdbufs); |
---|
| 760 | free(p->mallocd_bufs); |
---|
| 761 | return RTEMS_SUCCESSFUL; |
---|
| 762 | } |
---|
| 763 | |
---|
| 764 | /* rtems_bdbuf_init -- |
---|
[8b96149] | 765 | * Prepare buffering layer to work - initialize buffer descritors |
---|
[e51bd96] | 766 | * and (if it is neccessary)buffers. Buffers will be allocated accoriding |
---|
[8b96149] | 767 | * to the configuration table, each entry describes kind of block and |
---|
[e51bd96] | 768 | * amount requested. After initialization all blocks is placed into |
---|
| 769 | * free elements lists. |
---|
| 770 | * |
---|
| 771 | * PARAMETERS: |
---|
| 772 | * conf_table - pointer to the buffers configuration table |
---|
| 773 | * size - number of entries in configuration table |
---|
| 774 | * |
---|
| 775 | * RETURNS: |
---|
| 776 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 777 | * or error code if error is occured) |
---|
| 778 | */ |
---|
| 779 | rtems_status_code |
---|
| 780 | rtems_bdbuf_init(rtems_bdbuf_config *conf_table, int size) |
---|
| 781 | { |
---|
| 782 | rtems_bdpool_id i; |
---|
| 783 | rtems_status_code rc; |
---|
| 784 | |
---|
| 785 | if (size <= 0) |
---|
| 786 | return RTEMS_INVALID_SIZE; |
---|
[048dcd2b] | 787 | |
---|
[e51bd96] | 788 | bd_ctx.npools = size; |
---|
| 789 | |
---|
| 790 | /* |
---|
| 791 | * Allocate memory for buffer pool descriptors |
---|
| 792 | */ |
---|
| 793 | bd_ctx.pool = calloc(size, sizeof(bdbuf_pool)); |
---|
| 794 | if (bd_ctx.pool == NULL) |
---|
| 795 | { |
---|
| 796 | return RTEMS_NO_MEMORY; |
---|
| 797 | } |
---|
| 798 | |
---|
| 799 | Chain_Initialize_empty(&bd_ctx.mod); |
---|
[048dcd2b] | 800 | |
---|
[e51bd96] | 801 | /* Initialize buffer pools and roll out if something failed */ |
---|
| 802 | for (i = 0; i < size; i++) |
---|
| 803 | { |
---|
| 804 | rc = bdbuf_initialize_pool(conf_table + i, i); |
---|
| 805 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 806 | { |
---|
| 807 | rtems_bdpool_id j; |
---|
| 808 | for (j = 0; j < i - 1; j++) |
---|
| 809 | { |
---|
| 810 | bdbuf_release_pool(j); |
---|
| 811 | } |
---|
| 812 | return rc; |
---|
| 813 | } |
---|
| 814 | } |
---|
| 815 | |
---|
| 816 | /* Create buffer flush semaphore */ |
---|
| 817 | rc = rtems_semaphore_create( |
---|
| 818 | rtems_build_name('B', 'F', 'L', 'U'), 0, |
---|
| 819 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
| 820 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, 0, |
---|
| 821 | &bd_ctx.flush_sema); |
---|
| 822 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 823 | { |
---|
| 824 | for (i = 0; i < size; i++) |
---|
| 825 | bdbuf_release_pool(i); |
---|
| 826 | free(bd_ctx.pool); |
---|
| 827 | return rc; |
---|
| 828 | } |
---|
[048dcd2b] | 829 | |
---|
[e51bd96] | 830 | /* Create and start swapout task */ |
---|
| 831 | rc = rtems_task_create( |
---|
| 832 | rtems_build_name('B', 'S', 'W', 'P'), |
---|
| 833 | SWAPOUT_PRIORITY, |
---|
[8b96149] | 834 | SWAPOUT_STACK_SIZE, |
---|
[e51bd96] | 835 | RTEMS_DEFAULT_MODES | RTEMS_NO_PREEMPT, |
---|
| 836 | RTEMS_DEFAULT_ATTRIBUTES, |
---|
| 837 | &bd_ctx.swapout_task); |
---|
| 838 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 839 | { |
---|
| 840 | rtems_semaphore_delete(bd_ctx.flush_sema); |
---|
| 841 | for (i = 0; i < size; i++) |
---|
| 842 | bdbuf_release_pool(i); |
---|
| 843 | free(bd_ctx.pool); |
---|
| 844 | return rc; |
---|
| 845 | } |
---|
| 846 | |
---|
| 847 | rc = rtems_task_start(bd_ctx.swapout_task, bdbuf_swapout_task, 0); |
---|
| 848 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 849 | { |
---|
| 850 | rtems_task_delete(bd_ctx.swapout_task); |
---|
| 851 | rtems_semaphore_delete(bd_ctx.flush_sema); |
---|
| 852 | for (i = 0; i < size; i++) |
---|
| 853 | bdbuf_release_pool(i); |
---|
| 854 | free(bd_ctx.pool); |
---|
| 855 | return rc; |
---|
| 856 | } |
---|
| 857 | |
---|
| 858 | return RTEMS_SUCCESSFUL; |
---|
| 859 | } |
---|
| 860 | |
---|
| 861 | /* find_or_assign_buffer -- |
---|
| 862 | * Looks for buffer already assigned for this dev/block. If one is found |
---|
| 863 | * obtain block buffer. If specified block already cached (i.e. there's |
---|
| 864 | * block in the _modified_, or _recently_used_), return address |
---|
[8b96149] | 865 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
| 866 | * If block is not cached, allocate new buffer and return it. Data |
---|
| 867 | * shouldn't be read to the buffer from media; buffer contains arbitrary |
---|
| 868 | * data. This primitive may be blocked if there are no free buffer |
---|
| 869 | * descriptors available and there are no unused non-modified (or |
---|
[e51bd96] | 870 | * synchronized with media) buffers available. |
---|
| 871 | * |
---|
| 872 | * PARAMETERS: |
---|
| 873 | * device - device number (constructed of major and minor device number |
---|
| 874 | * block - linear media block number |
---|
| 875 | * ret_buf - address of the variable to store address of found descriptor |
---|
| 876 | * |
---|
| 877 | * RETURNS: |
---|
| 878 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 879 | * or error code if error is occured) |
---|
| 880 | * |
---|
| 881 | * SIDE EFFEECTS: |
---|
| 882 | * bufget_sema may be obtained by this primitive |
---|
| 883 | * |
---|
| 884 | * NOTE: |
---|
| 885 | * It is assumed that primitive invoked when thread preemption is disabled. |
---|
| 886 | */ |
---|
| 887 | static rtems_status_code |
---|
| 888 | find_or_assign_buffer(disk_device *dd, |
---|
[8b96149] | 889 | blkdev_bnum block, |
---|
[e51bd96] | 890 | bdbuf_buffer **ret_buf) |
---|
| 891 | { |
---|
| 892 | bdbuf_buffer *bd_buf; |
---|
| 893 | bdbuf_pool *bd_pool; |
---|
| 894 | rtems_status_code rc; |
---|
| 895 | dev_t device; |
---|
| 896 | ISR_Level level; |
---|
| 897 | |
---|
| 898 | int blksize; |
---|
| 899 | |
---|
| 900 | device = dd->dev; |
---|
| 901 | bd_pool = bd_ctx.pool + dd->pool; |
---|
| 902 | blksize = dd->block_size; |
---|
| 903 | |
---|
| 904 | again: |
---|
| 905 | /* Looking for buffer descriptor used for this dev/block. */ |
---|
| 906 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
| 907 | |
---|
| 908 | if (bd_buf == NULL) |
---|
| 909 | { |
---|
| 910 | /* Try to obtain semaphore without waiting first. It is the most |
---|
[8b96149] | 911 | frequent case when reasonable number of buffers configured. If |
---|
| 912 | it is failed, obtain semaphore blocking on it. In this case |
---|
| 913 | it should be checked that appropriate buffer hasn't been loaded |
---|
[e51bd96] | 914 | by another thread, because this thread is preempted */ |
---|
| 915 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, RTEMS_NO_WAIT, 0); |
---|
| 916 | if (rc == RTEMS_UNSATISFIED) |
---|
| 917 | { |
---|
| 918 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
| 919 | RTEMS_WAIT, RTEMS_NO_TIMEOUT); |
---|
| 920 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
| 921 | if (bd_buf != NULL) |
---|
| 922 | rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 923 | } |
---|
| 924 | } |
---|
[048dcd2b] | 925 | |
---|
[e51bd96] | 926 | if (bd_buf == NULL) |
---|
| 927 | { |
---|
| 928 | /* Assign new buffer descriptor */ |
---|
| 929 | if (_Chain_Is_empty(&bd_pool->free)) |
---|
| 930 | { |
---|
| 931 | bd_buf = (bdbuf_buffer *)Chain_Get(&bd_pool->lru); |
---|
| 932 | if (bd_buf != NULL) |
---|
| 933 | { |
---|
[8b96149] | 934 | int avl_result; |
---|
[e51bd96] | 935 | avl_result = avl_remove(&bd_pool->tree, bd_buf); |
---|
| 936 | if (avl_result != 0) |
---|
| 937 | { |
---|
| 938 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 939 | return RTEMS_INTERNAL_ERROR; |
---|
| 940 | } |
---|
| 941 | } |
---|
| 942 | } |
---|
| 943 | else |
---|
| 944 | { |
---|
| 945 | bd_buf = (bdbuf_buffer *)Chain_Get(&(bd_pool->free)); |
---|
| 946 | } |
---|
| 947 | |
---|
| 948 | if (bd_buf == NULL) |
---|
| 949 | { |
---|
| 950 | goto again; |
---|
| 951 | } |
---|
| 952 | else |
---|
| 953 | { |
---|
| 954 | bd_buf->dev = device; |
---|
| 955 | bd_buf->block = block; |
---|
[df6348bb] | 956 | #ifdef AVL_GPL |
---|
[e51bd96] | 957 | bd_buf->avl.link[0] = NULL; |
---|
| 958 | bd_buf->avl.link[1] = NULL; |
---|
[df6348bb] | 959 | #else |
---|
| 960 | bd_buf->avl.left = NULL; |
---|
| 961 | bd_buf->avl.right = NULL; |
---|
[e51bd96] | 962 | #endif |
---|
| 963 | bd_buf->use_count = 1; |
---|
| 964 | bd_buf->modified = bd_buf->actual = bd_buf->in_progress = FALSE; |
---|
| 965 | bd_buf->status = RTEMS_SUCCESSFUL; |
---|
| 966 | |
---|
| 967 | if (avl_insert(&bd_pool->tree, bd_buf) != 0) |
---|
| 968 | { |
---|
| 969 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 970 | return RTEMS_INTERNAL_ERROR; |
---|
| 971 | } |
---|
| 972 | |
---|
| 973 | *ret_buf = bd_buf; |
---|
| 974 | |
---|
| 975 | return RTEMS_SUCCESSFUL; |
---|
| 976 | } |
---|
| 977 | } |
---|
| 978 | else |
---|
| 979 | { |
---|
| 980 | /* Buffer descriptor already assigned for this dev/block */ |
---|
| 981 | if (bd_buf->use_count == 0) |
---|
| 982 | { |
---|
| 983 | /* If we are removing from lru list, obtain the bufget_sema |
---|
| 984 | * first. If we are removing from mod list, obtain flush sema. |
---|
| 985 | * It should be obtained without blocking because we know |
---|
| 986 | * that our buffer descriptor is in the list. */ |
---|
| 987 | if (bd_buf->modified) |
---|
| 988 | { |
---|
[8b96149] | 989 | rc = rtems_semaphore_obtain(bd_ctx.flush_sema, |
---|
[e51bd96] | 990 | RTEMS_NO_WAIT, 0); |
---|
| 991 | } |
---|
| 992 | else |
---|
| 993 | { |
---|
[8b96149] | 994 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
[e51bd96] | 995 | RTEMS_NO_WAIT, 0); |
---|
| 996 | } |
---|
[8b96149] | 997 | /* It is possible that we couldn't obtain flush or bufget sema |
---|
[e51bd96] | 998 | * although buffer in the appropriate chain is available: |
---|
[8b96149] | 999 | * semaphore may be released to swapout task, but this task |
---|
[e51bd96] | 1000 | * actually did not start to process it. */ |
---|
| 1001 | if (rc == RTEMS_UNSATISFIED) |
---|
| 1002 | rc = RTEMS_SUCCESSFUL; |
---|
| 1003 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1004 | { |
---|
| 1005 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 1006 | return RTEMS_INTERNAL_ERROR; |
---|
| 1007 | } |
---|
| 1008 | |
---|
| 1009 | /* Buffer descriptor is linked to the lru or mod chain. Remove |
---|
| 1010 | it from there. */ |
---|
| 1011 | Chain_Extract(&bd_buf->link); |
---|
| 1012 | } |
---|
| 1013 | bd_buf->use_count++; |
---|
| 1014 | while (bd_buf->in_progress != 0) |
---|
| 1015 | { |
---|
[df6348bb] | 1016 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1017 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1018 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1019 | } |
---|
[048dcd2b] | 1020 | |
---|
[e51bd96] | 1021 | *ret_buf = bd_buf; |
---|
| 1022 | return RTEMS_SUCCESSFUL; |
---|
| 1023 | } |
---|
| 1024 | } |
---|
| 1025 | |
---|
| 1026 | /* rtems_bdbuf_get -- |
---|
| 1027 | * Obtain block buffer. If specified block already cached (i.e. there's |
---|
| 1028 | * block in the _modified_, or _recently_used_), return address |
---|
[8b96149] | 1029 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
| 1030 | * If block is not cached, allocate new buffer and return it. Data |
---|
| 1031 | * shouldn't be read to the buffer from media; buffer may contains |
---|
| 1032 | * arbitrary data. This primitive may be blocked if there are no free |
---|
| 1033 | * buffer descriptors available and there are no unused non-modified |
---|
[e51bd96] | 1034 | * (or synchronized with media) buffers available. |
---|
| 1035 | * |
---|
| 1036 | * PARAMETERS: |
---|
| 1037 | * device - device number (constructed of major and minor device number) |
---|
| 1038 | * block - linear media block number |
---|
| 1039 | * bd - address of variable to store pointer to the buffer descriptor |
---|
| 1040 | * |
---|
| 1041 | * RETURNS: |
---|
| 1042 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1043 | * or error code if error is occured) |
---|
| 1044 | * |
---|
| 1045 | * SIDE EFFECTS: |
---|
| 1046 | * bufget_sema semaphore obtained by this primitive. |
---|
| 1047 | */ |
---|
| 1048 | rtems_status_code |
---|
| 1049 | rtems_bdbuf_get(dev_t device, blkdev_bnum block, bdbuf_buffer **bd) |
---|
| 1050 | { |
---|
| 1051 | rtems_status_code rc; |
---|
| 1052 | disk_device *dd; |
---|
| 1053 | disk_device *pdd; |
---|
| 1054 | preemption_key key; |
---|
| 1055 | |
---|
| 1056 | /* |
---|
| 1057 | * Convert logical dev/block to physical one |
---|
| 1058 | */ |
---|
| 1059 | dd = rtems_disk_lookup(device); |
---|
| 1060 | if (dd == NULL) |
---|
| 1061 | return RTEMS_INVALID_ID; |
---|
[048dcd2b] | 1062 | |
---|
[e51bd96] | 1063 | if (block >= dd->size) |
---|
| 1064 | { |
---|
| 1065 | rtems_disk_release(dd); |
---|
| 1066 | return RTEMS_INVALID_NUMBER; |
---|
| 1067 | } |
---|
[048dcd2b] | 1068 | |
---|
[e51bd96] | 1069 | pdd = dd->phys_dev; |
---|
| 1070 | block += dd->start; |
---|
| 1071 | rtems_disk_release(dd); |
---|
| 1072 | |
---|
| 1073 | DISABLE_PREEMPTION(key); |
---|
| 1074 | rc = find_or_assign_buffer(pdd, block, bd); |
---|
| 1075 | ENABLE_PREEMPTION(key); |
---|
| 1076 | |
---|
| 1077 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1078 | return rc; |
---|
| 1079 | |
---|
| 1080 | return RTEMS_SUCCESSFUL; |
---|
| 1081 | } |
---|
| 1082 | |
---|
| 1083 | /* bdbuf_initialize_transfer_sema -- |
---|
| 1084 | * Initialize transfer_sema mutex semaphore associated with buffer |
---|
| 1085 | * descriptor. |
---|
| 1086 | */ |
---|
| 1087 | static inline void |
---|
| 1088 | bdbuf_initialize_transfer_sema(bdbuf_buffer *bd_buf) |
---|
| 1089 | { |
---|
| 1090 | CORE_mutex_Attributes mutex_attr; |
---|
| 1091 | mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS; |
---|
| 1092 | mutex_attr.only_owner_release = FALSE; |
---|
| 1093 | mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_FIFO; |
---|
| 1094 | mutex_attr.priority_ceiling = 0; |
---|
| 1095 | |
---|
[8b96149] | 1096 | _CORE_mutex_Initialize(&bd_buf->transfer_sema, |
---|
[87da638] | 1097 | &mutex_attr, CORE_MUTEX_LOCKED); |
---|
[e51bd96] | 1098 | } |
---|
| 1099 | |
---|
| 1100 | /* bdbuf_write_transfer_done -- |
---|
| 1101 | * Callout function. Invoked by block device driver when data transfer |
---|
| 1102 | * to device (write) is completed. This function may be invoked from |
---|
| 1103 | * interrupt handler. |
---|
| 1104 | * |
---|
| 1105 | * PARAMETERS: |
---|
| 1106 | * arg - arbitrary argument specified in block device request |
---|
| 1107 | * structure (in this case - pointer to the appropriate |
---|
| 1108 | * bdbuf_buffer buffer descriptor structure). |
---|
| 1109 | * status - I/O completion status |
---|
| 1110 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
| 1111 | * |
---|
| 1112 | * RETURNS: |
---|
| 1113 | * none |
---|
| 1114 | */ |
---|
| 1115 | static void |
---|
| 1116 | bdbuf_write_transfer_done(void *arg, rtems_status_code status, int error) |
---|
| 1117 | { |
---|
| 1118 | bdbuf_buffer *bd_buf = arg; |
---|
| 1119 | bd_buf->status = status; |
---|
[662814d] | 1120 | bd_buf->error = RTEMS_IO_ERROR; |
---|
[e51bd96] | 1121 | bd_buf->in_progress = bd_buf->modified = FALSE; |
---|
| 1122 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
[8b96149] | 1123 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
[e51bd96] | 1124 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1125 | } |
---|
| 1126 | |
---|
| 1127 | /* bdbuf_read_transfer_done -- |
---|
| 1128 | * Callout function. Invoked by block device driver when data transfer |
---|
| 1129 | * from device (read) is completed. This function may be invoked from |
---|
| 1130 | * interrupt handler. |
---|
| 1131 | * |
---|
| 1132 | * PARAMETERS: |
---|
| 1133 | * arg - arbitrary argument specified in block device request |
---|
| 1134 | * structure (in this case - pointer to the appropriate |
---|
| 1135 | * bdbuf_buffer buffer descriptor structure). |
---|
| 1136 | * status - I/O completion status |
---|
| 1137 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
| 1138 | * |
---|
| 1139 | * RETURNS: |
---|
| 1140 | * none |
---|
| 1141 | */ |
---|
| 1142 | static void |
---|
| 1143 | bdbuf_read_transfer_done(void *arg, rtems_status_code status, int error) |
---|
| 1144 | { |
---|
| 1145 | bdbuf_buffer *bd_buf = arg; |
---|
| 1146 | bd_buf->status = status; |
---|
[662814d] | 1147 | bd_buf->error = RTEMS_IO_ERROR; |
---|
[e51bd96] | 1148 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
[8b96149] | 1149 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
[e51bd96] | 1150 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1151 | } |
---|
| 1152 | |
---|
| 1153 | /* rtems_bdbuf_read -- |
---|
| 1154 | * (Similar to the rtems_bdbuf_get, except reading data from media) |
---|
| 1155 | * Obtain block buffer. If specified block already cached, return address |
---|
| 1156 | * of appropriate buffer and increment reference counter to 1. If block is |
---|
| 1157 | * not cached, allocate new buffer and read data to it from the media. |
---|
| 1158 | * This primitive may be blocked on waiting until data to be read from |
---|
| 1159 | * media, if there are no free buffer descriptors available and there are |
---|
| 1160 | * no unused non-modified (or synchronized with media) buffers available. |
---|
| 1161 | * |
---|
| 1162 | * PARAMETERS: |
---|
| 1163 | * device - device number (consists of major and minor device number) |
---|
| 1164 | * block - linear media block number |
---|
| 1165 | * bd - address of variable to store pointer to the buffer descriptor |
---|
| 1166 | * |
---|
| 1167 | * RETURNS: |
---|
| 1168 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1169 | * or error code if error is occured) |
---|
| 1170 | * |
---|
| 1171 | * SIDE EFFECTS: |
---|
| 1172 | * bufget_sema and transfer_sema semaphores obtained by this primitive. |
---|
| 1173 | */ |
---|
| 1174 | rtems_status_code |
---|
[8b96149] | 1175 | rtems_bdbuf_read(dev_t device, |
---|
[e51bd96] | 1176 | blkdev_bnum block, |
---|
| 1177 | bdbuf_buffer **bd) |
---|
| 1178 | { |
---|
| 1179 | preemption_key key; |
---|
| 1180 | ISR_Level level; |
---|
[048dcd2b] | 1181 | |
---|
[e51bd96] | 1182 | bdbuf_buffer *bd_buf; |
---|
| 1183 | rtems_status_code rc; |
---|
| 1184 | int result; |
---|
| 1185 | disk_device *dd; |
---|
| 1186 | disk_device *pdd; |
---|
| 1187 | blkdev_request1 req; |
---|
| 1188 | |
---|
| 1189 | dd = rtems_disk_lookup(device); |
---|
| 1190 | if (dd == NULL) |
---|
| 1191 | return RTEMS_INVALID_ID; |
---|
[048dcd2b] | 1192 | |
---|
[e51bd96] | 1193 | if (block >= dd->size) |
---|
| 1194 | { |
---|
| 1195 | rtems_disk_release(dd); |
---|
| 1196 | return RTEMS_INVALID_NUMBER; |
---|
| 1197 | } |
---|
[048dcd2b] | 1198 | |
---|
[e51bd96] | 1199 | pdd = dd->phys_dev; |
---|
| 1200 | block += dd->start; |
---|
| 1201 | |
---|
| 1202 | DISABLE_PREEMPTION(key); |
---|
| 1203 | rc = find_or_assign_buffer(pdd, block, &bd_buf); |
---|
| 1204 | |
---|
| 1205 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1206 | { |
---|
| 1207 | ENABLE_PREEMPTION(key); |
---|
| 1208 | rtems_disk_release(dd); |
---|
| 1209 | return rc; |
---|
| 1210 | } |
---|
| 1211 | |
---|
| 1212 | if (!bd_buf->actual) |
---|
| 1213 | { |
---|
| 1214 | bd_buf->in_progress = 1; |
---|
| 1215 | |
---|
| 1216 | req.req.req = BLKDEV_REQ_READ; |
---|
| 1217 | req.req.req_done = bdbuf_read_transfer_done; |
---|
| 1218 | req.req.done_arg = bd_buf; |
---|
| 1219 | req.req.start = block; |
---|
| 1220 | req.req.count = 1; |
---|
| 1221 | req.req.bufnum = 1; |
---|
| 1222 | req.req.bufs[0].length = dd->block_size; |
---|
| 1223 | req.req.bufs[0].buffer = bd_buf->buffer; |
---|
[048dcd2b] | 1224 | |
---|
[e51bd96] | 1225 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
[662814d] | 1226 | result = dd->ioctl(pdd->dev, BLKIO_REQUEST, &req); |
---|
[e51bd96] | 1227 | if (result == -1) |
---|
| 1228 | { |
---|
| 1229 | bd_buf->status = RTEMS_IO_ERROR; |
---|
| 1230 | bd_buf->error = errno; |
---|
| 1231 | bd_buf->actual = FALSE; |
---|
| 1232 | } |
---|
| 1233 | else |
---|
| 1234 | { |
---|
[df6348bb] | 1235 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1236 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1237 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1238 | bd_buf->actual = TRUE; |
---|
| 1239 | } |
---|
| 1240 | bd_buf->in_progress = FALSE; |
---|
| 1241 | } |
---|
| 1242 | rtems_disk_release(dd); |
---|
[048dcd2b] | 1243 | |
---|
[e51bd96] | 1244 | ENABLE_PREEMPTION(key); |
---|
| 1245 | |
---|
| 1246 | *bd = bd_buf; |
---|
[048dcd2b] | 1247 | |
---|
[e51bd96] | 1248 | return RTEMS_SUCCESSFUL; |
---|
| 1249 | } |
---|
| 1250 | |
---|
| 1251 | |
---|
| 1252 | /* bdbuf_release -- |
---|
| 1253 | * Release buffer. Decrease buffer usage counter. If it is zero, further |
---|
| 1254 | * processing depends on modified attribute. If buffer was modified, it |
---|
| 1255 | * is inserted into mod chain and swapout task waken up. If buffer was |
---|
| 1256 | * not modified, it is returned to the end of lru chain making it available |
---|
| 1257 | * for further use. |
---|
| 1258 | * |
---|
| 1259 | * PARAMETERS: |
---|
| 1260 | * bd_buf - pointer to the released buffer descriptor. |
---|
| 1261 | * |
---|
| 1262 | * RETURNS: |
---|
| 1263 | * RTEMS_SUCCESSFUL if buffer released successfully, or error code if |
---|
| 1264 | * error occured. |
---|
| 1265 | * |
---|
| 1266 | * NOTE: |
---|
| 1267 | * This is internal function. It is assumed that task made non-preemptive |
---|
| 1268 | * before its invocation. |
---|
| 1269 | */ |
---|
| 1270 | static rtems_status_code |
---|
| 1271 | bdbuf_release(bdbuf_buffer *bd_buf) |
---|
| 1272 | { |
---|
| 1273 | bdbuf_pool *bd_pool; |
---|
| 1274 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1275 | |
---|
| 1276 | if (bd_buf->use_count <= 0) |
---|
| 1277 | return RTEMS_INTERNAL_ERROR; |
---|
[048dcd2b] | 1278 | |
---|
[e51bd96] | 1279 | bd_pool = bd_ctx.pool + bd_buf->pool; |
---|
| 1280 | |
---|
| 1281 | bd_buf->use_count--; |
---|
| 1282 | |
---|
| 1283 | if (bd_buf->use_count == 0) |
---|
| 1284 | { |
---|
| 1285 | if (bd_buf->modified) |
---|
| 1286 | { |
---|
[048dcd2b] | 1287 | |
---|
[e51bd96] | 1288 | /* Buffer was modified. Insert buffer to the modified buffers |
---|
| 1289 | * list and initiate flushing. */ |
---|
| 1290 | Chain_Append(&bd_ctx.mod, &bd_buf->link); |
---|
| 1291 | |
---|
| 1292 | /* Release the flush_sema */ |
---|
| 1293 | rc = rtems_semaphore_release(bd_ctx.flush_sema); |
---|
| 1294 | } |
---|
| 1295 | else |
---|
| 1296 | { |
---|
[8b96149] | 1297 | /* Buffer was not modified. Add this descriptor to the |
---|
[e51bd96] | 1298 | * end of lru chain and make it available for reuse. */ |
---|
| 1299 | Chain_Append(&bd_pool->lru, &bd_buf->link); |
---|
| 1300 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 1301 | } |
---|
| 1302 | } |
---|
| 1303 | return rc; |
---|
| 1304 | } |
---|
| 1305 | |
---|
| 1306 | |
---|
| 1307 | /* rtems_bdbuf_release -- |
---|
| 1308 | * Release buffer allocated before. This primitive decrease the |
---|
| 1309 | * usage counter. If it is zero, further destiny of buffer depends on |
---|
| 1310 | * 'modified' status. If buffer was modified, it is placed to the end of |
---|
| 1311 | * mod list and flush task waken up. If buffer was not modified, |
---|
| 1312 | * it is placed to the end of lru list, and bufget_sema released, allowing |
---|
| 1313 | * to reuse this buffer. |
---|
| 1314 | * |
---|
| 1315 | * PARAMETERS: |
---|
| 1316 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
[8b96149] | 1317 | * get/read primitive. |
---|
[e51bd96] | 1318 | * |
---|
| 1319 | * RETURNS: |
---|
| 1320 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1321 | * or error code if error is occured) |
---|
| 1322 | * |
---|
| 1323 | * SIDE EFFECTS: |
---|
| 1324 | * flush_sema and bufget_sema semaphores may be released by this primitive. |
---|
| 1325 | */ |
---|
| 1326 | rtems_status_code |
---|
| 1327 | rtems_bdbuf_release(bdbuf_buffer *bd_buf) |
---|
| 1328 | { |
---|
| 1329 | preemption_key key; |
---|
| 1330 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1331 | |
---|
| 1332 | if (bd_buf == NULL) |
---|
| 1333 | return RTEMS_INVALID_ADDRESS; |
---|
[048dcd2b] | 1334 | |
---|
[e51bd96] | 1335 | DISABLE_PREEMPTION(key); |
---|
[048dcd2b] | 1336 | |
---|
[e51bd96] | 1337 | rc = bdbuf_release(bd_buf); |
---|
[048dcd2b] | 1338 | |
---|
[e51bd96] | 1339 | ENABLE_PREEMPTION(key); |
---|
[048dcd2b] | 1340 | |
---|
[e51bd96] | 1341 | return rc; |
---|
| 1342 | } |
---|
| 1343 | |
---|
| 1344 | /* rtems_bdbuf_release_modified -- |
---|
| 1345 | * Release buffer allocated before, assuming that it is _modified_ by |
---|
[8b96149] | 1346 | * it's owner. This primitive decrease usage counter for buffer, mark |
---|
[e51bd96] | 1347 | * buffer descriptor as modified. If usage counter is 0, insert it at |
---|
| 1348 | * end of mod chain and release flush_sema semaphore to activate the |
---|
| 1349 | * flush task. |
---|
| 1350 | * |
---|
| 1351 | * PARAMETERS: |
---|
| 1352 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
| 1353 | * get/read primitive. |
---|
| 1354 | * |
---|
| 1355 | * RETURNS: |
---|
| 1356 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1357 | * or error code if error is occured) |
---|
| 1358 | * |
---|
| 1359 | * SIDE EFFECTS: |
---|
| 1360 | * flush_sema semaphore may be released by this primitive. |
---|
| 1361 | */ |
---|
| 1362 | rtems_status_code |
---|
| 1363 | rtems_bdbuf_release_modified(bdbuf_buffer *bd_buf) |
---|
| 1364 | { |
---|
| 1365 | preemption_key key; |
---|
| 1366 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1367 | |
---|
| 1368 | if (bd_buf == NULL) |
---|
| 1369 | return RTEMS_INVALID_ADDRESS; |
---|
[048dcd2b] | 1370 | |
---|
[e51bd96] | 1371 | DISABLE_PREEMPTION(key); |
---|
| 1372 | |
---|
| 1373 | if (!bd_buf->modified) |
---|
| 1374 | { |
---|
| 1375 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
| 1376 | } |
---|
| 1377 | bd_buf->modified = TRUE; |
---|
| 1378 | bd_buf->actual = TRUE; |
---|
[8b96149] | 1379 | rc = bdbuf_release(bd_buf); |
---|
[048dcd2b] | 1380 | |
---|
[e51bd96] | 1381 | ENABLE_PREEMPTION(key); |
---|
[048dcd2b] | 1382 | |
---|
[e51bd96] | 1383 | return rc; |
---|
| 1384 | } |
---|
| 1385 | |
---|
| 1386 | /* rtems_bdbuf_sync -- |
---|
| 1387 | * Wait until specified buffer synchronized with disk. Invoked on exchanges |
---|
| 1388 | * critical for data consistency on the media. This primitive mark owned |
---|
| 1389 | * block as modified, decrease usage counter. If usage counter is 0, |
---|
| 1390 | * block inserted to the mod chain and flush_sema semaphore released. |
---|
| 1391 | * Finally, primitives blocked on transfer_sema semaphore. |
---|
| 1392 | * |
---|
| 1393 | * PARAMETERS: |
---|
| 1394 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
| 1395 | * get/read primitive. |
---|
| 1396 | * |
---|
| 1397 | * RETURNS: |
---|
| 1398 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1399 | * or error code if error is occured) |
---|
| 1400 | * |
---|
| 1401 | * SIDE EFFECTS: |
---|
| 1402 | * Primitive may be blocked on transfer_sema semaphore. |
---|
| 1403 | */ |
---|
| 1404 | rtems_status_code |
---|
| 1405 | rtems_bdbuf_sync(bdbuf_buffer *bd_buf) |
---|
| 1406 | { |
---|
| 1407 | preemption_key key; |
---|
| 1408 | ISR_Level level; |
---|
| 1409 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1410 | |
---|
| 1411 | if (bd_buf == NULL) |
---|
| 1412 | return RTEMS_INVALID_ADDRESS; |
---|
[048dcd2b] | 1413 | |
---|
[e51bd96] | 1414 | DISABLE_PREEMPTION(key); |
---|
| 1415 | |
---|
| 1416 | if (!bd_buf->modified) |
---|
| 1417 | { |
---|
| 1418 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
| 1419 | } |
---|
| 1420 | bd_buf->modified = TRUE; |
---|
| 1421 | bd_buf->actual = TRUE; |
---|
| 1422 | |
---|
| 1423 | rc = bdbuf_release(bd_buf); |
---|
| 1424 | |
---|
| 1425 | if (rc == RTEMS_SUCCESSFUL) |
---|
| 1426 | { |
---|
[df6348bb] | 1427 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1428 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1429 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1430 | } |
---|
[048dcd2b] | 1431 | |
---|
[e51bd96] | 1432 | ENABLE_PREEMPTION(key); |
---|
[048dcd2b] | 1433 | |
---|
[e51bd96] | 1434 | return rc; |
---|
| 1435 | } |
---|
| 1436 | |
---|
| 1437 | /* rtems_bdbuf_syncdev -- |
---|
| 1438 | * Synchronize with disk all buffers containing the blocks belonging to |
---|
| 1439 | * specified device. |
---|
| 1440 | * |
---|
| 1441 | * PARAMETERS: |
---|
| 1442 | * dev - block device number |
---|
| 1443 | * |
---|
| 1444 | * RETURNS: |
---|
| 1445 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1446 | * or error code if error is occured) |
---|
| 1447 | */ |
---|
| 1448 | rtems_status_code |
---|
| 1449 | rtems_bdbuf_syncdev(dev_t dev) |
---|
| 1450 | { |
---|
| 1451 | preemption_key key; |
---|
| 1452 | ISR_Level level; |
---|
[048dcd2b] | 1453 | |
---|
[e51bd96] | 1454 | bdbuf_buffer *bd_buf; |
---|
| 1455 | disk_device *dd; |
---|
| 1456 | bdbuf_pool *pool; |
---|
[048dcd2b] | 1457 | |
---|
[e51bd96] | 1458 | dd = rtems_disk_lookup(dev); |
---|
| 1459 | if (dd == NULL) |
---|
| 1460 | return RTEMS_INVALID_ID; |
---|
[048dcd2b] | 1461 | |
---|
[e51bd96] | 1462 | pool = bd_ctx.pool + dd->pool; |
---|
[048dcd2b] | 1463 | |
---|
[e51bd96] | 1464 | DISABLE_PREEMPTION(key); |
---|
| 1465 | do { |
---|
| 1466 | bd_buf = avl_search_for_sync(&pool->tree, dd); |
---|
| 1467 | if (bd_buf != NULL /* && bd_buf->modified */) |
---|
| 1468 | { |
---|
[df6348bb] | 1469 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1470 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1471 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1472 | } |
---|
| 1473 | } while (bd_buf != NULL); |
---|
| 1474 | ENABLE_PREEMPTION(key); |
---|
| 1475 | return rtems_disk_release(dd); |
---|
| 1476 | } |
---|
| 1477 | |
---|
| 1478 | /* bdbuf_swapout_task -- |
---|
| 1479 | * Body of task which take care on flushing modified buffers to the |
---|
| 1480 | * disk. |
---|
| 1481 | */ |
---|
[8b96149] | 1482 | static rtems_task |
---|
[e51bd96] | 1483 | bdbuf_swapout_task(rtems_task_argument unused) |
---|
| 1484 | { |
---|
| 1485 | rtems_status_code rc; |
---|
| 1486 | int result; |
---|
| 1487 | ISR_Level level; |
---|
| 1488 | bdbuf_buffer *bd_buf; |
---|
| 1489 | bdbuf_pool *bd_pool; |
---|
| 1490 | disk_device *dd; |
---|
| 1491 | blkdev_request1 req; |
---|
| 1492 | |
---|
| 1493 | while (1) |
---|
| 1494 | { |
---|
| 1495 | rc = rtems_semaphore_obtain(bd_ctx.flush_sema, RTEMS_WAIT, 0); |
---|
| 1496 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1497 | { |
---|
| 1498 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_SWAPOUT); |
---|
| 1499 | } |
---|
[048dcd2b] | 1500 | |
---|
[e51bd96] | 1501 | bd_buf = (bdbuf_buffer *)Chain_Get(&bd_ctx.mod); |
---|
| 1502 | if (bd_buf == NULL) |
---|
| 1503 | { |
---|
| 1504 | /* It is possible that flush_sema semaphore will be released, but |
---|
| 1505 | * buffer to be removed from mod chain before swapout task start |
---|
| 1506 | * its processing. */ |
---|
| 1507 | continue; |
---|
| 1508 | } |
---|
| 1509 | |
---|
| 1510 | bd_buf->in_progress = TRUE; |
---|
| 1511 | bd_buf->use_count++; |
---|
| 1512 | bd_pool = bd_ctx.pool + bd_buf->pool; |
---|
| 1513 | dd = rtems_disk_lookup(bd_buf->dev); |
---|
| 1514 | |
---|
| 1515 | req.req.req = BLKDEV_REQ_WRITE; |
---|
| 1516 | req.req.req_done = bdbuf_write_transfer_done; |
---|
| 1517 | req.req.done_arg = bd_buf; |
---|
| 1518 | req.req.start = bd_buf->block + dd->start; |
---|
| 1519 | req.req.count = 1; |
---|
| 1520 | req.req.bufnum = 1; |
---|
| 1521 | req.req.bufs[0].length = dd->block_size; |
---|
| 1522 | req.req.bufs[0].buffer = bd_buf->buffer; |
---|
| 1523 | |
---|
[8b96149] | 1524 | /* transfer_sema initialized when bd_buf inserted in the mod chain |
---|
[e51bd96] | 1525 | first time */ |
---|
| 1526 | result = dd->ioctl(dd->phys_dev->dev, BLKIO_REQUEST, &req); |
---|
[048dcd2b] | 1527 | |
---|
[e51bd96] | 1528 | rtems_disk_release(dd); |
---|
[048dcd2b] | 1529 | |
---|
[e51bd96] | 1530 | if (result == -1) |
---|
| 1531 | { |
---|
| 1532 | bd_buf->status = RTEMS_IO_ERROR; |
---|
| 1533 | bd_buf->error = errno; |
---|
| 1534 | /* Release tasks waiting on syncing this buffer */ |
---|
| 1535 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
| 1536 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1537 | } |
---|
| 1538 | else |
---|
| 1539 | { |
---|
| 1540 | if (bd_buf->in_progress) |
---|
| 1541 | { |
---|
[df6348bb] | 1542 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1543 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, 0, level); |
---|
| 1544 | } |
---|
| 1545 | } |
---|
| 1546 | bd_buf->use_count--; |
---|
| 1547 | |
---|
| 1548 | /* Another task have chance to use this buffer, or even |
---|
| 1549 | * modify it. If buffer is not in use, insert it in appropriate chain |
---|
| 1550 | * and release semaphore */ |
---|
| 1551 | if (bd_buf->use_count == 0) |
---|
| 1552 | { |
---|
| 1553 | if (bd_buf->modified) |
---|
| 1554 | { |
---|
| 1555 | Chain_Append(&bd_ctx.mod, &bd_buf->link); |
---|
| 1556 | rc = rtems_semaphore_release(bd_ctx.flush_sema); |
---|
| 1557 | } |
---|
| 1558 | else |
---|
| 1559 | { |
---|
| 1560 | Chain_Append(&bd_pool->lru, &bd_buf->link); |
---|
| 1561 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 1562 | } |
---|
| 1563 | } |
---|
| 1564 | } |
---|
| 1565 | } |
---|
| 1566 | |
---|
| 1567 | /* rtems_bdbuf_find_pool -- |
---|
| 1568 | * Find first appropriate buffer pool. This primitive returns the index |
---|
| 1569 | * of first buffer pool which block size is greater than or equal to |
---|
| 1570 | * specified size. |
---|
| 1571 | * |
---|
| 1572 | * PARAMETERS: |
---|
| 1573 | * block_size - requested block size |
---|
| 1574 | * pool - placeholder for result |
---|
| 1575 | * |
---|
| 1576 | * RETURNS: |
---|
| 1577 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
[8b96149] | 1578 | * RTEMS_INVALID_SIZE if specified block size is invalid (not a power |
---|
[e51bd96] | 1579 | * of 2), RTEMS_NOT_DEFINED if buffer pool for this or greater block size |
---|
| 1580 | * is not configured. |
---|
| 1581 | */ |
---|
| 1582 | rtems_status_code |
---|
| 1583 | rtems_bdbuf_find_pool(int block_size, rtems_bdpool_id *pool) |
---|
| 1584 | { |
---|
| 1585 | rtems_bdpool_id i; |
---|
| 1586 | bdbuf_pool *p; |
---|
| 1587 | int cursize = INT_MAX; |
---|
| 1588 | rtems_bdpool_id curid = -1; |
---|
| 1589 | rtems_boolean found = FALSE; |
---|
| 1590 | int j; |
---|
[048dcd2b] | 1591 | |
---|
[e51bd96] | 1592 | for (j = block_size; (j != 0) && ((j & 1) == 0); j >>= 1); |
---|
| 1593 | if (j != 1) |
---|
| 1594 | return RTEMS_INVALID_SIZE; |
---|
[048dcd2b] | 1595 | |
---|
[e51bd96] | 1596 | for (i = 0, p = bd_ctx.pool; i < bd_ctx.npools; i++, p++) |
---|
| 1597 | { |
---|
| 1598 | if ((p->blksize >= block_size) && |
---|
| 1599 | (p->blksize < cursize)) |
---|
| 1600 | { |
---|
| 1601 | curid = i; |
---|
| 1602 | cursize = p->blksize; |
---|
| 1603 | found = TRUE; |
---|
| 1604 | } |
---|
| 1605 | } |
---|
[048dcd2b] | 1606 | |
---|
[e51bd96] | 1607 | if (found) |
---|
| 1608 | { |
---|
| 1609 | if (pool != NULL) |
---|
| 1610 | *pool = curid; |
---|
| 1611 | return RTEMS_SUCCESSFUL; |
---|
| 1612 | } |
---|
| 1613 | else |
---|
| 1614 | { |
---|
| 1615 | return RTEMS_NOT_DEFINED; |
---|
| 1616 | } |
---|
| 1617 | } |
---|
| 1618 | |
---|
| 1619 | /* rtems_bdbuf_get_pool_info -- |
---|
| 1620 | * Obtain characteristics of buffer pool with specified number. |
---|
| 1621 | * |
---|
| 1622 | * PARAMETERS: |
---|
| 1623 | * pool - buffer pool number |
---|
| 1624 | * block_size - block size for which buffer pool is configured returned |
---|
| 1625 | * there |
---|
[8b96149] | 1626 | * blocks - number of buffers in buffer pool returned there |
---|
[e51bd96] | 1627 | * |
---|
| 1628 | * RETURNS: |
---|
| 1629 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
| 1630 | * RTEMS_INVALID_NUMBER if appropriate buffer pool is not configured. |
---|
| 1631 | * |
---|
| 1632 | * NOTE: |
---|
| 1633 | * Buffer pools enumerated contiguously starting from 0. |
---|
| 1634 | */ |
---|
| 1635 | rtems_status_code |
---|
| 1636 | rtems_bdbuf_get_pool_info(rtems_bdpool_id pool, int *block_size, |
---|
| 1637 | int *blocks) |
---|
| 1638 | { |
---|
| 1639 | if (pool >= bd_ctx.npools) |
---|
| 1640 | return RTEMS_INVALID_NUMBER; |
---|
[048dcd2b] | 1641 | |
---|
[e51bd96] | 1642 | if (block_size != NULL) |
---|
| 1643 | { |
---|
| 1644 | *block_size = bd_ctx.pool[pool].blksize; |
---|
| 1645 | } |
---|
[048dcd2b] | 1646 | |
---|
[e51bd96] | 1647 | if (blocks != NULL) |
---|
| 1648 | { |
---|
| 1649 | *blocks = bd_ctx.pool[pool].nblks; |
---|
| 1650 | } |
---|
[048dcd2b] | 1651 | |
---|
[e51bd96] | 1652 | return RTEMS_SUCCESSFUL; |
---|
| 1653 | } |
---|