[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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| 13 | #define __RTEMS_VIOLATE_KERNEL_VISIBILITY__ |
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| 14 | #include <rtems.h> |
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| 15 | #include <limits.h> |
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| 16 | #include <errno.h> |
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| 17 | #include <assert.h> |
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| 18 | |
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| 19 | #include "rtems/bdbuf.h" |
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| 20 | |
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| 21 | /* Fatal errors: */ |
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[25f37e8] | 22 | #define BLKDEV_FATAL_ERROR(n) (((unsigned32)'B' << 24) | ((unsigned32)(n) & (unsigned32)0x00FFFFFF)) |
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[e51bd96] | 23 | #define BLKDEV_FATAL_BDBUF_CONSISTENCY BLKDEV_FATAL_ERROR(1) |
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| 24 | #define BLKDEV_FATAL_BDBUF_SWAPOUT BLKDEV_FATAL_ERROR(2) |
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| 25 | |
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| 26 | |
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| 27 | #define SWAPOUT_PRIORITY 15 |
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| 28 | #define SWAPOUT_STACK_SIZE (RTEMS_MINIMUM_STACK_SIZE * 2) |
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| 29 | |
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| 30 | static rtems_task bdbuf_swapout_task(rtems_task_argument unused); |
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| 31 | |
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| 32 | /* |
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| 33 | * The groups of the blocks with the same size are collected in the |
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| 34 | * bd_pool. Note that a several of the buffer's groups with the |
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| 35 | * same size can exists. |
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| 36 | */ |
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| 37 | typedef struct bdbuf_pool |
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| 38 | { |
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| 39 | bdbuf_buffer *tree; /* Buffer descriptor lookup AVL tree root */ |
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| 40 | |
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| 41 | Chain_Control free; /* Free buffers list */ |
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| 42 | Chain_Control lru; /* Last recently used list */ |
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| 43 | |
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| 44 | int blksize; /* The size of the blocks (in bytes) */ |
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| 45 | int nblks; /* Number of blocks in this pool */ |
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| 46 | rtems_id bufget_sema; /* Buffer obtain counting semaphore */ |
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| 47 | void *mallocd_bufs; /* Pointer to the malloc'd buffer memory, |
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| 48 | or NULL, if buffer memory provided in |
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| 49 | buffer configuration */ |
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| 50 | bdbuf_buffer *bdbufs; /* Pointer to table of buffer descriptors |
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| 51 | allocated for this buffer pool. */ |
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| 52 | } bdbuf_pool; |
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| 53 | |
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| 54 | /* Buffering layer context definition */ |
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| 55 | struct bdbuf_context { |
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| 56 | bdbuf_pool *pool; /* Table of buffer pools */ |
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| 57 | int npools; /* Number of entries in pool table */ |
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| 58 | |
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| 59 | Chain_Control mod; /* Modified buffers list */ |
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| 60 | rtems_id flush_sema; /* Buffer flush semaphore; counting |
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| 61 | semaphore; incremented when buffer |
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| 62 | flushed to the disk; decremented when |
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| 63 | buffer modified */ |
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| 64 | rtems_id swapout_task; /* Swapout task ID */ |
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| 65 | }; |
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| 66 | |
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| 67 | /* Block device request with a single buffer provided */ |
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| 68 | typedef struct blkdev_request1 { |
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| 69 | blkdev_request req; |
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| 70 | blkdev_sg_buffer sg[1]; |
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| 71 | } blkdev_request1; |
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| 72 | |
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| 73 | /* The static context of buffering layer */ |
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| 74 | static struct bdbuf_context bd_ctx; |
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| 75 | |
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| 76 | #define SAFE |
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| 77 | #ifdef SAFE |
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| 78 | typedef rtems_mode preemption_key; |
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| 79 | |
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| 80 | #define DISABLE_PREEMPTION(key) \ |
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| 81 | do { \ |
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| 82 | rtems_task_mode(RTEMS_PREEMPT_MASK, RTEMS_NO_PREEMPT, &(key)); \ |
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| 83 | } while (0) |
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| 84 | |
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| 85 | #define ENABLE_PREEMPTION(key) \ |
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| 86 | do { \ |
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| 87 | rtems_mode temp; \ |
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| 88 | rtems_task_mode(RTEMS_PREEMPT_MASK, (key), &temp); \ |
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| 89 | } while (0) |
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| 90 | |
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| 91 | #else |
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| 92 | |
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| 93 | typedef boolean preemption_key; |
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| 94 | |
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| 95 | #define DISABLE_PREEMPTION(key) \ |
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| 96 | do { \ |
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| 97 | (key) = _Thread_Executing->is_preemptible; \ |
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| 98 | _Thread_Executing->is_preemptible = 0; \ |
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| 99 | } while (0) |
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| 100 | |
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| 101 | #define ENABLE_PREEMPTION(key) \ |
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| 102 | do { \ |
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| 103 | _Thread_Executing->is_preemptible = (key); \ |
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| 104 | if (_Thread_Evaluate_mode()) \ |
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| 105 | _Thread_Dispatch(); \ |
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| 106 | } while (0) |
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| 107 | |
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| 108 | #endif |
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| 109 | |
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| 110 | |
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| 111 | /* The default maximum height of 32 allows for AVL trees having |
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| 112 | between 5,704,880 and 4,294,967,295 nodes, depending on order of |
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| 113 | insertion. You may change this compile-time constant as you |
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| 114 | wish. */ |
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| 115 | #ifndef AVL_MAX_HEIGHT |
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| 116 | #define AVL_MAX_HEIGHT 32 |
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| 117 | #endif |
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| 118 | |
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| 119 | /* |
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| 120 | * avl_search -- |
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| 121 | * Searches for the node with specified dev/block. |
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| 122 | * |
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| 123 | * PARAMETERS: |
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| 124 | * root - pointer to the root node of the AVL-Tree. |
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| 125 | * dev, block - search key |
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| 126 | * |
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| 127 | * RETURNS: |
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| 128 | * NULL if node with specified dev/block not found |
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| 129 | * non-NULL - pointer to the node with specified dev/block |
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| 130 | */ |
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| 131 | static bdbuf_buffer * |
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| 132 | avl_search(bdbuf_buffer **root, dev_t dev, blkdev_bnum block) |
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| 133 | { |
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| 134 | bdbuf_buffer *p = *root; |
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[df6348bb] | 135 | |
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[e51bd96] | 136 | while ((p != NULL) && ((p->dev != dev) || (p->block != block))) |
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| 137 | { |
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| 138 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[df6348bb] | 139 | { |
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| 140 | p = p->avl.right; |
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| 141 | } |
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[e51bd96] | 142 | else |
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[df6348bb] | 143 | { |
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| 144 | p = p->avl.left; |
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| 145 | } |
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[e51bd96] | 146 | } |
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[df6348bb] | 147 | |
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[e51bd96] | 148 | return p; |
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| 149 | } |
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| 150 | |
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[df6348bb] | 151 | |
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[e51bd96] | 152 | /* avl_search_for_sync -- |
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| 153 | * Search in AVL tree for first modified buffer belongs to specified |
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| 154 | * disk device. |
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| 155 | * |
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| 156 | * PARAMETERS: |
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| 157 | * root - pointer to tree root |
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| 158 | * dd - disk device descriptor |
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| 159 | * |
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| 160 | * RETURNS: |
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| 161 | * Block buffer, or NULL if no modified blocks on specified device |
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| 162 | * exists. |
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| 163 | */ |
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| 164 | static bdbuf_buffer * |
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| 165 | avl_search_for_sync(bdbuf_buffer **root, disk_device *dd) |
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| 166 | { |
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| 167 | dev_t dev = dd->phys_dev->dev; |
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[df6348bb] | 168 | blkdev_bnum block_start = dd->start; |
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| 169 | blkdev_bnum block_end = dd->start + dd->size - 1; |
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| 170 | |
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| 171 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 172 | bdbuf_buffer **buf_prev = buf_stack; |
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| 173 | bdbuf_buffer *p = *root; |
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| 174 | |
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[e51bd96] | 175 | while (p != NULL) |
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| 176 | { |
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[df6348bb] | 177 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block_start))) |
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| 178 | { |
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| 179 | p = p->avl.right; |
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| 180 | } |
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| 181 | else if ((p->dev > dev) || ((p->dev == dev) && (p->block > block_end))) |
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| 182 | { |
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| 183 | p = p->avl.left; |
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| 184 | } |
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[e51bd96] | 185 | else if (p->modified) |
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[df6348bb] | 186 | { |
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[e51bd96] | 187 | return p; |
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[df6348bb] | 188 | } |
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[e51bd96] | 189 | else |
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| 190 | { |
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[df6348bb] | 191 | if (p->avl.right != NULL) |
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| 192 | { |
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| 193 | *buf_prev++ = p->avl.right; |
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| 194 | } |
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| 195 | p = p->avl.left; |
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| 196 | } |
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| 197 | |
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| 198 | if ((p == NULL) && (buf_prev > buf_stack)) |
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| 199 | { |
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| 200 | p = *--buf_prev; |
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[e51bd96] | 201 | } |
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| 202 | } |
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[df6348bb] | 203 | |
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[e51bd96] | 204 | return p; |
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| 205 | } |
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| 206 | |
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| 207 | |
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| 208 | /* |
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| 209 | * avl_insert -- |
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| 210 | * Inserts the specified node to the AVl-Tree. |
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| 211 | * |
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| 212 | * PARAMETERS: |
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[df6348bb] | 213 | * root - Pointer to pointer to the root node |
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[e51bd96] | 214 | * node - Pointer to the node to add. |
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| 215 | * |
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| 216 | * RETURNS: |
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| 217 | * 0 - The node added successfully |
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| 218 | * -1 - An error occured |
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| 219 | */ |
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| 220 | static int |
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[df6348bb] | 221 | avl_insert(bdbuf_buffer **root, bdbuf_buffer *node) |
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[e51bd96] | 222 | { |
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[df6348bb] | 223 | dev_t dev = node->dev; |
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| 224 | blkdev_bnum block = node->block; |
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[e51bd96] | 225 | |
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[df6348bb] | 226 | bdbuf_buffer *p = *root; |
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| 227 | bdbuf_buffer *q, *p1, *p2; |
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| 228 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 229 | bdbuf_buffer **buf_prev = buf_stack; |
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[e51bd96] | 230 | |
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[df6348bb] | 231 | boolean modified = FALSE; |
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[e51bd96] | 232 | |
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[df6348bb] | 233 | if (p == NULL) |
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[e51bd96] | 234 | { |
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[df6348bb] | 235 | *root = node; |
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| 236 | node->avl.left = NULL; |
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| 237 | node->avl.right = NULL; |
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| 238 | node->avl.bal = 0; |
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[e51bd96] | 239 | return 0; |
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| 240 | } |
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| 241 | |
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[df6348bb] | 242 | while (p != NULL) |
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[e51bd96] | 243 | { |
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[df6348bb] | 244 | *buf_prev++ = p; |
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[e51bd96] | 245 | |
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[df6348bb] | 246 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[e51bd96] | 247 | { |
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[df6348bb] | 248 | p->avl.cache = 1; |
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| 249 | q = p->avl.right; |
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[e51bd96] | 250 | if (q == NULL) |
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| 251 | { |
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[df6348bb] | 252 | q = node; |
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| 253 | p->avl.right = q = node; |
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[e51bd96] | 254 | break; |
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| 255 | } |
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| 256 | } |
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[df6348bb] | 257 | else if ((p->dev != dev) || (p->block != block)) |
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| 258 | { |
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| 259 | p->avl.cache = -1; |
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| 260 | q = p->avl.left; |
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| 261 | if (q == NULL) |
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[e51bd96] | 262 | { |
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[df6348bb] | 263 | q = node; |
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| 264 | p->avl.left = q; |
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| 265 | break; |
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[e51bd96] | 266 | } |
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[df6348bb] | 267 | } |
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| 268 | else |
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[e51bd96] | 269 | { |
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[df6348bb] | 270 | return -1; |
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[e51bd96] | 271 | } |
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[df6348bb] | 272 | |
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[e51bd96] | 273 | p = q; |
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| 274 | } |
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| 275 | |
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[df6348bb] | 276 | q->avl.left = q->avl.right = NULL; |
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| 277 | q->avl.bal = 0; |
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| 278 | modified = TRUE; |
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| 279 | buf_prev--; |
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[e51bd96] | 280 | |
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[df6348bb] | 281 | while (modified) |
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[e51bd96] | 282 | { |
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[df6348bb] | 283 | if (p->avl.cache == -1) |
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[e51bd96] | 284 | { |
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[df6348bb] | 285 | switch (p->avl.bal) |
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| 286 | { |
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| 287 | case 1: |
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| 288 | p->avl.bal = 0; |
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| 289 | modified = FALSE; |
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| 290 | break; |
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| 291 | |
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| 292 | case 0: |
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| 293 | p->avl.bal = -1; |
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| 294 | break; |
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| 295 | |
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| 296 | case -1: |
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| 297 | p1 = p->avl.left; |
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| 298 | if (p1->avl.bal == -1) /* simple LL-turn */ |
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| 299 | { |
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| 300 | p->avl.left = p1->avl.right; |
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| 301 | p1->avl.right = p; |
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| 302 | p->avl.bal = 0; |
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| 303 | p = p1; |
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| 304 | } |
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| 305 | else /* double LR-turn */ |
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| 306 | { |
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| 307 | p2 = p1->avl.right; |
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| 308 | p1->avl.right = p2->avl.left; |
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| 309 | p2->avl.left = p1; |
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| 310 | p->avl.left = p2->avl.right; |
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| 311 | p2->avl.right = p; |
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| 312 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
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| 313 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
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| 314 | p = p2; |
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| 315 | } |
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| 316 | p->avl.bal = 0; |
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| 317 | modified = FALSE; |
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| 318 | break; |
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| 319 | |
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| 320 | default: |
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| 321 | break; |
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| 322 | } |
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[e51bd96] | 323 | } |
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| 324 | else |
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| 325 | { |
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[df6348bb] | 326 | switch (p->avl.bal) |
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[e51bd96] | 327 | { |
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[df6348bb] | 328 | case -1: |
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| 329 | p->avl.bal = 0; |
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| 330 | modified = FALSE; |
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| 331 | break; |
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| 332 | |
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| 333 | case 0: |
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| 334 | p->avl.bal = 1; |
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| 335 | break; |
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| 336 | |
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| 337 | case 1: |
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| 338 | p1 = p->avl.right; |
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| 339 | if (p1->avl.bal == 1) /* simple RR-turn */ |
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| 340 | { |
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| 341 | p->avl.right = p1->avl.left; |
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| 342 | p1->avl.left = p; |
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| 343 | p->avl.bal = 0; |
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| 344 | p = p1; |
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| 345 | } |
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| 346 | else /* double RL-turn */ |
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| 347 | { |
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| 348 | p2 = p1->avl.left; |
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| 349 | p1->avl.left = p2->avl.right; |
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| 350 | p2->avl.right = p1; |
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| 351 | p->avl.right = p2->avl.left; |
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| 352 | p2->avl.left = p; |
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| 353 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
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| 354 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
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| 355 | p = p2; |
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| 356 | } |
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| 357 | p->avl.bal = 0; |
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| 358 | modified = FALSE; |
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| 359 | break; |
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| 360 | |
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| 361 | default: |
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| 362 | break; |
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[e51bd96] | 363 | } |
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| 364 | } |
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[df6348bb] | 365 | q = p; |
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| 366 | if (buf_prev > buf_stack) |
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[e51bd96] | 367 | { |
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[df6348bb] | 368 | p = *--buf_prev; |
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[e51bd96] | 369 | |
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[df6348bb] | 370 | if (p->avl.cache == -1) |
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[e51bd96] | 371 | { |
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[df6348bb] | 372 | p->avl.left = q; |
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[e51bd96] | 373 | } |
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[df6348bb] | 374 | else |
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[e51bd96] | 375 | { |
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[df6348bb] | 376 | p->avl.right = q; |
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[e51bd96] | 377 | } |
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| 378 | } |
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| 379 | else |
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[df6348bb] | 380 | { |
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| 381 | *root = p; |
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| 382 | break; |
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| 383 | } |
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| 384 | }; |
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[e51bd96] | 385 | |
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| 386 | return 0; |
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| 387 | } |
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| 388 | |
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| 389 | |
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| 390 | /* avl_remove -- |
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| 391 | * removes the node from the tree. |
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| 392 | * |
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| 393 | * PARAMETERS: |
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| 394 | * root_addr - Pointer to pointer to the root node |
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| 395 | * node - Pointer to the node to remove |
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| 396 | * |
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| 397 | * RETURNS: |
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| 398 | * 0 - Item removed |
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| 399 | * -1 - No such item found |
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| 400 | */ |
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| 401 | static int |
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[df6348bb] | 402 | avl_remove(bdbuf_buffer **root, const bdbuf_buffer *node) |
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[e51bd96] | 403 | { |
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[df6348bb] | 404 | dev_t dev = node->dev; |
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| 405 | blkdev_bnum block = node->block; |
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[e51bd96] | 406 | |
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[df6348bb] | 407 | bdbuf_buffer *p = *root; |
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| 408 | bdbuf_buffer *q, *r, *s, *p1, *p2; |
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| 409 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
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| 410 | bdbuf_buffer **buf_prev = buf_stack; |
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[e51bd96] | 411 | |
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[df6348bb] | 412 | boolean modified = FALSE; |
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[e51bd96] | 413 | |
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[df6348bb] | 414 | memset(buf_stack, 0, sizeof(buf_stack)); |
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[e51bd96] | 415 | |
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[df6348bb] | 416 | while (p != NULL) |
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[e51bd96] | 417 | { |
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[df6348bb] | 418 | *buf_prev++ = p; |
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[e51bd96] | 419 | |
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[df6348bb] | 420 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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| 421 | { |
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| 422 | p->avl.cache = 1; |
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| 423 | p = p->avl.right; |
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| 424 | } |
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| 425 | else if ((p->dev != dev) || (p->block != block)) |
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[e51bd96] | 426 | { |
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[df6348bb] | 427 | p->avl.cache = -1; |
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| 428 | p = p->avl.left; |
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[e51bd96] | 429 | } |
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[df6348bb] | 430 | else |
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[e51bd96] | 431 | { |
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[df6348bb] | 432 | /* node found */ |
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| 433 | break; |
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[e51bd96] | 434 | } |
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[df6348bb] | 435 | } |
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| 436 | |
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| 437 | if (p == NULL) |
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| 438 | { |
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| 439 | /* there is no such node */ |
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| 440 | return -1; |
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[e51bd96] | 441 | } |
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| 442 | |
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[df6348bb] | 443 | q = p; |
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| 444 | |
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| 445 | buf_prev--; |
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| 446 | if (buf_prev > buf_stack) |
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[e51bd96] | 447 | { |
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[df6348bb] | 448 | p = *(buf_prev - 1); |
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[e51bd96] | 449 | } |
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| 450 | else |
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| 451 | { |
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[df6348bb] | 452 | p = NULL; |
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[e51bd96] | 453 | } |
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[df6348bb] | 454 | |
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| 455 | /* at this moment q - is a node to delete, p is q's parent */ |
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| 456 | if (q->avl.right == NULL) |
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[e51bd96] | 457 | { |
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[df6348bb] | 458 | r = q->avl.left; |
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| 459 | if (r != NULL) |
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| 460 | { |
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| 461 | r->avl.bal = 0; |
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| 462 | } |
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| 463 | q = r; |
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[e51bd96] | 464 | } |
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| 465 | else |
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| 466 | { |
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[df6348bb] | 467 | bdbuf_buffer **t; |
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| 468 | |
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| 469 | r = q->avl.right; |
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| 470 | |
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| 471 | if (r->avl.left == NULL) |
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[e51bd96] | 472 | { |
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[df6348bb] | 473 | r->avl.left = q->avl.left; |
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| 474 | r->avl.bal = q->avl.bal; |
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| 475 | r->avl.cache = 1; |
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| 476 | *buf_prev++ = q = r; |
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[e51bd96] | 477 | } |
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| 478 | else |
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| 479 | { |
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[df6348bb] | 480 | t = buf_prev++; |
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| 481 | s = r; |
---|
[e51bd96] | 482 | |
---|
[df6348bb] | 483 | while (s->avl.left != NULL) |
---|
[e51bd96] | 484 | { |
---|
[df6348bb] | 485 | *buf_prev++ = r = s; |
---|
| 486 | s = r->avl.left; |
---|
| 487 | r->avl.cache = -1; |
---|
[e51bd96] | 488 | } |
---|
[df6348bb] | 489 | |
---|
| 490 | s->avl.left = q->avl.left; |
---|
| 491 | r->avl.left = s->avl.right; |
---|
| 492 | s->avl.right = q->avl.right; |
---|
| 493 | s->avl.bal = q->avl.bal; |
---|
| 494 | s->avl.cache = 1; |
---|
| 495 | |
---|
| 496 | *t = q = s; |
---|
[e51bd96] | 497 | } |
---|
| 498 | } |
---|
| 499 | |
---|
[df6348bb] | 500 | if (p != NULL) |
---|
[e51bd96] | 501 | { |
---|
[df6348bb] | 502 | if (p->avl.cache == -1) |
---|
[e51bd96] | 503 | { |
---|
[df6348bb] | 504 | p->avl.left = q; |
---|
| 505 | } |
---|
| 506 | else |
---|
| 507 | { |
---|
| 508 | p->avl.right = q; |
---|
| 509 | } |
---|
| 510 | } |
---|
| 511 | else |
---|
| 512 | { |
---|
| 513 | *root = q; |
---|
| 514 | } |
---|
[e51bd96] | 515 | |
---|
[df6348bb] | 516 | modified = TRUE; |
---|
[e51bd96] | 517 | |
---|
[df6348bb] | 518 | while (modified) |
---|
| 519 | { |
---|
| 520 | if (buf_prev > buf_stack) |
---|
| 521 | { |
---|
| 522 | p = *--buf_prev; |
---|
| 523 | } |
---|
| 524 | else |
---|
| 525 | { |
---|
| 526 | break; |
---|
| 527 | } |
---|
| 528 | |
---|
| 529 | if (p->avl.cache == -1) |
---|
| 530 | { |
---|
| 531 | /* rebalance left branch */ |
---|
| 532 | switch (p->avl.bal) |
---|
[e51bd96] | 533 | { |
---|
[df6348bb] | 534 | case -1: |
---|
[e51bd96] | 535 | p->avl.bal = 0; |
---|
[df6348bb] | 536 | break; |
---|
| 537 | case 0: |
---|
| 538 | p->avl.bal = 1; |
---|
| 539 | modified = FALSE; |
---|
| 540 | break; |
---|
| 541 | |
---|
| 542 | case +1: |
---|
| 543 | p1 = p->avl.right; |
---|
| 544 | |
---|
| 545 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
[e51bd96] | 546 | { |
---|
[df6348bb] | 547 | p->avl.right = p1->avl.left; |
---|
| 548 | p1->avl.left = p; |
---|
| 549 | |
---|
| 550 | if (p1->avl.bal == 0) |
---|
| 551 | { |
---|
| 552 | p1->avl.bal = -1; |
---|
| 553 | modified = FALSE; |
---|
| 554 | } |
---|
| 555 | else |
---|
| 556 | { |
---|
| 557 | p->avl.bal = 0; |
---|
| 558 | p1->avl.bal = 0; |
---|
| 559 | } |
---|
| 560 | p = p1; |
---|
[e51bd96] | 561 | } |
---|
[df6348bb] | 562 | else /* double RL-turn */ |
---|
[e51bd96] | 563 | { |
---|
[df6348bb] | 564 | p2 = p1->avl.left; |
---|
| 565 | |
---|
| 566 | p1->avl.left = p2->avl.right; |
---|
| 567 | p2->avl.right = p1; |
---|
| 568 | p->avl.right = p2->avl.left; |
---|
| 569 | p2->avl.left = p; |
---|
| 570 | |
---|
| 571 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
| 572 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
| 573 | |
---|
| 574 | p = p2; |
---|
| 575 | p2->avl.bal = 0; |
---|
[e51bd96] | 576 | } |
---|
[df6348bb] | 577 | break; |
---|
| 578 | |
---|
| 579 | default: |
---|
| 580 | break; |
---|
| 581 | } |
---|
[e51bd96] | 582 | } |
---|
| 583 | else |
---|
| 584 | { |
---|
[df6348bb] | 585 | /* rebalance right branch */ |
---|
| 586 | switch (p->avl.bal) |
---|
[e51bd96] | 587 | { |
---|
[df6348bb] | 588 | case +1: |
---|
| 589 | p->avl.bal = 0; |
---|
[e51bd96] | 590 | break; |
---|
| 591 | |
---|
[df6348bb] | 592 | case 0: |
---|
| 593 | p->avl.bal = -1; |
---|
| 594 | modified = FALSE; |
---|
| 595 | break; |
---|
[e51bd96] | 596 | |
---|
[df6348bb] | 597 | case -1: |
---|
| 598 | p1 = p->avl.left; |
---|
[e51bd96] | 599 | |
---|
[df6348bb] | 600 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
[e51bd96] | 601 | { |
---|
[df6348bb] | 602 | p->avl.left = p1->avl.right; |
---|
| 603 | p1->avl.right = p; |
---|
| 604 | if (p1->avl.bal == 0) |
---|
[e51bd96] | 605 | { |
---|
[df6348bb] | 606 | p1->avl.bal = 1; |
---|
| 607 | modified = FALSE; |
---|
[e51bd96] | 608 | } |
---|
| 609 | else |
---|
| 610 | { |
---|
[df6348bb] | 611 | p->avl.bal = 0; |
---|
| 612 | p1->avl.bal = 0; |
---|
[e51bd96] | 613 | } |
---|
[df6348bb] | 614 | p = p1; |
---|
| 615 | } |
---|
| 616 | else /* double LR-turn */ |
---|
| 617 | { |
---|
| 618 | p2 = p1->avl.right; |
---|
| 619 | |
---|
| 620 | p1->avl.right = p2->avl.left; |
---|
| 621 | p2->avl.left = p1; |
---|
| 622 | p->avl.left = p2->avl.right; |
---|
| 623 | p2->avl.right = p; |
---|
| 624 | |
---|
| 625 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
| 626 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
| 627 | |
---|
| 628 | p = p2; |
---|
| 629 | p2->avl.bal = 0; |
---|
[e51bd96] | 630 | } |
---|
[df6348bb] | 631 | break; |
---|
| 632 | |
---|
| 633 | default: |
---|
| 634 | break; |
---|
| 635 | } |
---|
[e51bd96] | 636 | } |
---|
| 637 | |
---|
[df6348bb] | 638 | if (buf_prev > buf_stack) |
---|
| 639 | { |
---|
| 640 | q = *(buf_prev - 1); |
---|
| 641 | |
---|
| 642 | if (q->avl.cache == -1) |
---|
| 643 | { |
---|
| 644 | q->avl.left = p; |
---|
| 645 | } |
---|
| 646 | else |
---|
| 647 | { |
---|
| 648 | q->avl.right = p; |
---|
| 649 | } |
---|
| 650 | } |
---|
| 651 | else |
---|
| 652 | { |
---|
| 653 | *root = p; |
---|
| 654 | break; |
---|
| 655 | } |
---|
| 656 | |
---|
| 657 | } |
---|
| 658 | |
---|
[e51bd96] | 659 | return 0; |
---|
| 660 | } |
---|
| 661 | |
---|
| 662 | /* bdbuf_initialize_pool -- |
---|
| 663 | * Initialize single buffer pool. |
---|
| 664 | * |
---|
| 665 | * PARAMETERS: |
---|
| 666 | * config - buffer pool configuration |
---|
| 667 | * pool - pool number |
---|
| 668 | * |
---|
| 669 | * RETURNS: |
---|
| 670 | * RTEMS_SUCCESSFUL, if buffer pool initialized successfully, or error |
---|
| 671 | * code if error occured. |
---|
| 672 | */ |
---|
| 673 | static rtems_status_code |
---|
| 674 | bdbuf_initialize_pool(rtems_bdbuf_config *config, int pool) |
---|
| 675 | { |
---|
| 676 | bdbuf_pool *p = bd_ctx.pool + pool; |
---|
| 677 | unsigned char *bufs; |
---|
| 678 | bdbuf_buffer *b; |
---|
| 679 | rtems_status_code rc; |
---|
| 680 | int i; |
---|
| 681 | |
---|
| 682 | p->blksize = config->size; |
---|
| 683 | p->nblks = config->num; |
---|
| 684 | p->tree = NULL; |
---|
| 685 | |
---|
| 686 | Chain_Initialize_empty(&p->free); |
---|
| 687 | Chain_Initialize_empty(&p->lru); |
---|
| 688 | |
---|
| 689 | /* Allocate memory for buffer descriptors */ |
---|
| 690 | p->bdbufs = calloc(config->num, sizeof(bdbuf_buffer)); |
---|
| 691 | if (p->bdbufs == NULL) |
---|
| 692 | { |
---|
| 693 | return RTEMS_NO_MEMORY; |
---|
| 694 | } |
---|
| 695 | |
---|
| 696 | /* Allocate memory for buffers if required */ |
---|
| 697 | if (config->mem_area == NULL) |
---|
| 698 | { |
---|
| 699 | bufs = p->mallocd_bufs = malloc(config->num * config->size); |
---|
| 700 | if (bufs == NULL) |
---|
| 701 | { |
---|
| 702 | free(p->bdbufs); |
---|
| 703 | return RTEMS_NO_MEMORY; |
---|
| 704 | } |
---|
| 705 | } |
---|
| 706 | else |
---|
| 707 | { |
---|
| 708 | bufs = config->mem_area; |
---|
| 709 | p->mallocd_bufs = NULL; |
---|
| 710 | } |
---|
| 711 | |
---|
| 712 | for (i = 0, b = p->bdbufs; i < p->nblks; i++, b++, bufs += p->blksize) |
---|
| 713 | { |
---|
| 714 | b->dev = -1; b->block = 0; |
---|
| 715 | b->buffer = bufs; |
---|
| 716 | b->actual = b->modified = b->in_progress = FALSE; |
---|
| 717 | b->use_count = 0; |
---|
| 718 | b->pool = pool; |
---|
| 719 | _Chain_Append(&p->free, &b->link); |
---|
| 720 | } |
---|
| 721 | |
---|
| 722 | rc = rtems_semaphore_create( |
---|
| 723 | rtems_build_name('B', 'U', 'F', 'G'), |
---|
| 724 | p->nblks, |
---|
| 725 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
| 726 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, |
---|
| 727 | 0, |
---|
| 728 | &p->bufget_sema); |
---|
| 729 | |
---|
| 730 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 731 | { |
---|
| 732 | free(p->bdbufs); |
---|
| 733 | free(p->mallocd_bufs); |
---|
| 734 | return rc; |
---|
| 735 | } |
---|
| 736 | |
---|
| 737 | return RTEMS_SUCCESSFUL; |
---|
| 738 | } |
---|
| 739 | |
---|
| 740 | /* bdbuf_release_pool -- |
---|
| 741 | * Free resources allocated for buffer pool with specified number. |
---|
| 742 | * |
---|
| 743 | * PARAMETERS: |
---|
| 744 | * pool - buffer pool number |
---|
| 745 | * |
---|
| 746 | * RETURNS: |
---|
| 747 | * RTEMS_SUCCESSFUL |
---|
| 748 | */ |
---|
| 749 | static rtems_status_code |
---|
| 750 | bdbuf_release_pool(rtems_bdpool_id pool) |
---|
| 751 | { |
---|
| 752 | bdbuf_pool *p = bd_ctx.pool + pool; |
---|
| 753 | rtems_semaphore_delete(p->bufget_sema); |
---|
| 754 | free(p->bdbufs); |
---|
| 755 | free(p->mallocd_bufs); |
---|
| 756 | return RTEMS_SUCCESSFUL; |
---|
| 757 | } |
---|
| 758 | |
---|
| 759 | /* rtems_bdbuf_init -- |
---|
| 760 | * Prepare buffering layer to work - initialize buffer descritors |
---|
| 761 | * and (if it is neccessary)buffers. Buffers will be allocated accoriding |
---|
| 762 | * to the configuration table, each entry describes kind of block and |
---|
| 763 | * amount requested. After initialization all blocks is placed into |
---|
| 764 | * free elements lists. |
---|
| 765 | * |
---|
| 766 | * PARAMETERS: |
---|
| 767 | * conf_table - pointer to the buffers configuration table |
---|
| 768 | * size - number of entries in configuration table |
---|
| 769 | * |
---|
| 770 | * RETURNS: |
---|
| 771 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 772 | * or error code if error is occured) |
---|
| 773 | */ |
---|
| 774 | rtems_status_code |
---|
| 775 | rtems_bdbuf_init(rtems_bdbuf_config *conf_table, int size) |
---|
| 776 | { |
---|
| 777 | rtems_bdpool_id i; |
---|
| 778 | rtems_status_code rc; |
---|
| 779 | |
---|
| 780 | if (size <= 0) |
---|
| 781 | return RTEMS_INVALID_SIZE; |
---|
| 782 | |
---|
| 783 | bd_ctx.npools = size; |
---|
| 784 | |
---|
| 785 | /* |
---|
| 786 | * Allocate memory for buffer pool descriptors |
---|
| 787 | */ |
---|
| 788 | bd_ctx.pool = calloc(size, sizeof(bdbuf_pool)); |
---|
| 789 | if (bd_ctx.pool == NULL) |
---|
| 790 | { |
---|
| 791 | return RTEMS_NO_MEMORY; |
---|
| 792 | } |
---|
| 793 | |
---|
| 794 | Chain_Initialize_empty(&bd_ctx.mod); |
---|
| 795 | |
---|
| 796 | /* Initialize buffer pools and roll out if something failed */ |
---|
| 797 | for (i = 0; i < size; i++) |
---|
| 798 | { |
---|
| 799 | rc = bdbuf_initialize_pool(conf_table + i, i); |
---|
| 800 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 801 | { |
---|
| 802 | rtems_bdpool_id j; |
---|
| 803 | for (j = 0; j < i - 1; j++) |
---|
| 804 | { |
---|
| 805 | bdbuf_release_pool(j); |
---|
| 806 | } |
---|
| 807 | return rc; |
---|
| 808 | } |
---|
| 809 | } |
---|
| 810 | |
---|
| 811 | /* Create buffer flush semaphore */ |
---|
| 812 | rc = rtems_semaphore_create( |
---|
| 813 | rtems_build_name('B', 'F', 'L', 'U'), 0, |
---|
| 814 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
| 815 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, 0, |
---|
| 816 | &bd_ctx.flush_sema); |
---|
| 817 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 818 | { |
---|
| 819 | for (i = 0; i < size; i++) |
---|
| 820 | bdbuf_release_pool(i); |
---|
| 821 | free(bd_ctx.pool); |
---|
| 822 | return rc; |
---|
| 823 | } |
---|
| 824 | |
---|
| 825 | /* Create and start swapout task */ |
---|
| 826 | rc = rtems_task_create( |
---|
| 827 | rtems_build_name('B', 'S', 'W', 'P'), |
---|
| 828 | SWAPOUT_PRIORITY, |
---|
| 829 | SWAPOUT_STACK_SIZE, |
---|
| 830 | RTEMS_DEFAULT_MODES | RTEMS_NO_PREEMPT, |
---|
| 831 | RTEMS_DEFAULT_ATTRIBUTES, |
---|
| 832 | &bd_ctx.swapout_task); |
---|
| 833 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 834 | { |
---|
| 835 | rtems_semaphore_delete(bd_ctx.flush_sema); |
---|
| 836 | for (i = 0; i < size; i++) |
---|
| 837 | bdbuf_release_pool(i); |
---|
| 838 | free(bd_ctx.pool); |
---|
| 839 | return rc; |
---|
| 840 | } |
---|
| 841 | |
---|
| 842 | rc = rtems_task_start(bd_ctx.swapout_task, bdbuf_swapout_task, 0); |
---|
| 843 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 844 | { |
---|
| 845 | rtems_task_delete(bd_ctx.swapout_task); |
---|
| 846 | rtems_semaphore_delete(bd_ctx.flush_sema); |
---|
| 847 | for (i = 0; i < size; i++) |
---|
| 848 | bdbuf_release_pool(i); |
---|
| 849 | free(bd_ctx.pool); |
---|
| 850 | return rc; |
---|
| 851 | } |
---|
| 852 | |
---|
| 853 | return RTEMS_SUCCESSFUL; |
---|
| 854 | } |
---|
| 855 | |
---|
| 856 | /* find_or_assign_buffer -- |
---|
| 857 | * Looks for buffer already assigned for this dev/block. If one is found |
---|
| 858 | * obtain block buffer. If specified block already cached (i.e. there's |
---|
| 859 | * block in the _modified_, or _recently_used_), return address |
---|
| 860 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
| 861 | * If block is not cached, allocate new buffer and return it. Data |
---|
| 862 | * shouldn't be read to the buffer from media; buffer contains arbitrary |
---|
| 863 | * data. This primitive may be blocked if there are no free buffer |
---|
| 864 | * descriptors available and there are no unused non-modified (or |
---|
| 865 | * synchronized with media) buffers available. |
---|
| 866 | * |
---|
| 867 | * PARAMETERS: |
---|
| 868 | * device - device number (constructed of major and minor device number |
---|
| 869 | * block - linear media block number |
---|
| 870 | * ret_buf - address of the variable to store address of found descriptor |
---|
| 871 | * |
---|
| 872 | * RETURNS: |
---|
| 873 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 874 | * or error code if error is occured) |
---|
| 875 | * |
---|
| 876 | * SIDE EFFEECTS: |
---|
| 877 | * bufget_sema may be obtained by this primitive |
---|
| 878 | * |
---|
| 879 | * NOTE: |
---|
| 880 | * It is assumed that primitive invoked when thread preemption is disabled. |
---|
| 881 | */ |
---|
| 882 | static rtems_status_code |
---|
| 883 | find_or_assign_buffer(disk_device *dd, |
---|
| 884 | blkdev_bnum block, |
---|
| 885 | bdbuf_buffer **ret_buf) |
---|
| 886 | { |
---|
| 887 | bdbuf_buffer *bd_buf; |
---|
| 888 | bdbuf_pool *bd_pool; |
---|
| 889 | rtems_status_code rc; |
---|
| 890 | dev_t device; |
---|
| 891 | ISR_Level level; |
---|
| 892 | |
---|
| 893 | int blksize; |
---|
| 894 | |
---|
| 895 | device = dd->dev; |
---|
| 896 | bd_pool = bd_ctx.pool + dd->pool; |
---|
| 897 | blksize = dd->block_size; |
---|
| 898 | |
---|
| 899 | again: |
---|
| 900 | /* Looking for buffer descriptor used for this dev/block. */ |
---|
| 901 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
| 902 | |
---|
| 903 | if (bd_buf == NULL) |
---|
| 904 | { |
---|
| 905 | /* Try to obtain semaphore without waiting first. It is the most |
---|
| 906 | frequent case when reasonable number of buffers configured. If |
---|
| 907 | it is failed, obtain semaphore blocking on it. In this case |
---|
| 908 | it should be checked that appropriate buffer hasn't been loaded |
---|
| 909 | by another thread, because this thread is preempted */ |
---|
| 910 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, RTEMS_NO_WAIT, 0); |
---|
| 911 | if (rc == RTEMS_UNSATISFIED) |
---|
| 912 | { |
---|
| 913 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
| 914 | RTEMS_WAIT, RTEMS_NO_TIMEOUT); |
---|
| 915 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
| 916 | if (bd_buf != NULL) |
---|
| 917 | rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 918 | } |
---|
| 919 | } |
---|
| 920 | |
---|
| 921 | if (bd_buf == NULL) |
---|
| 922 | { |
---|
| 923 | /* Assign new buffer descriptor */ |
---|
| 924 | if (_Chain_Is_empty(&bd_pool->free)) |
---|
| 925 | { |
---|
| 926 | bd_buf = (bdbuf_buffer *)Chain_Get(&bd_pool->lru); |
---|
| 927 | if (bd_buf != NULL) |
---|
| 928 | { |
---|
| 929 | int avl_result; |
---|
| 930 | avl_result = avl_remove(&bd_pool->tree, bd_buf); |
---|
| 931 | if (avl_result != 0) |
---|
| 932 | { |
---|
| 933 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 934 | return RTEMS_INTERNAL_ERROR; |
---|
| 935 | } |
---|
| 936 | } |
---|
| 937 | } |
---|
| 938 | else |
---|
| 939 | { |
---|
| 940 | bd_buf = (bdbuf_buffer *)Chain_Get(&(bd_pool->free)); |
---|
| 941 | } |
---|
| 942 | |
---|
| 943 | if (bd_buf == NULL) |
---|
| 944 | { |
---|
| 945 | goto again; |
---|
| 946 | } |
---|
| 947 | else |
---|
| 948 | { |
---|
| 949 | bd_buf->dev = device; |
---|
| 950 | bd_buf->block = block; |
---|
[df6348bb] | 951 | #ifdef AVL_GPL |
---|
[e51bd96] | 952 | bd_buf->avl.link[0] = NULL; |
---|
| 953 | bd_buf->avl.link[1] = NULL; |
---|
[df6348bb] | 954 | #else |
---|
| 955 | bd_buf->avl.left = NULL; |
---|
| 956 | bd_buf->avl.right = NULL; |
---|
[e51bd96] | 957 | #endif |
---|
| 958 | bd_buf->use_count = 1; |
---|
| 959 | bd_buf->modified = bd_buf->actual = bd_buf->in_progress = FALSE; |
---|
| 960 | bd_buf->status = RTEMS_SUCCESSFUL; |
---|
| 961 | |
---|
| 962 | if (avl_insert(&bd_pool->tree, bd_buf) != 0) |
---|
| 963 | { |
---|
| 964 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 965 | return RTEMS_INTERNAL_ERROR; |
---|
| 966 | } |
---|
| 967 | |
---|
| 968 | *ret_buf = bd_buf; |
---|
| 969 | |
---|
| 970 | return RTEMS_SUCCESSFUL; |
---|
| 971 | } |
---|
| 972 | } |
---|
| 973 | else |
---|
| 974 | { |
---|
| 975 | /* Buffer descriptor already assigned for this dev/block */ |
---|
| 976 | if (bd_buf->use_count == 0) |
---|
| 977 | { |
---|
| 978 | /* If we are removing from lru list, obtain the bufget_sema |
---|
| 979 | * first. If we are removing from mod list, obtain flush sema. |
---|
| 980 | * It should be obtained without blocking because we know |
---|
| 981 | * that our buffer descriptor is in the list. */ |
---|
| 982 | if (bd_buf->modified) |
---|
| 983 | { |
---|
| 984 | rc = rtems_semaphore_obtain(bd_ctx.flush_sema, |
---|
| 985 | RTEMS_NO_WAIT, 0); |
---|
| 986 | } |
---|
| 987 | else |
---|
| 988 | { |
---|
| 989 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
| 990 | RTEMS_NO_WAIT, 0); |
---|
| 991 | } |
---|
| 992 | /* It is possible that we couldn't obtain flush or bufget sema |
---|
| 993 | * although buffer in the appropriate chain is available: |
---|
| 994 | * semaphore may be released to swapout task, but this task |
---|
| 995 | * actually did not start to process it. */ |
---|
| 996 | if (rc == RTEMS_UNSATISFIED) |
---|
| 997 | rc = RTEMS_SUCCESSFUL; |
---|
| 998 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 999 | { |
---|
| 1000 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
| 1001 | return RTEMS_INTERNAL_ERROR; |
---|
| 1002 | } |
---|
| 1003 | |
---|
| 1004 | /* Buffer descriptor is linked to the lru or mod chain. Remove |
---|
| 1005 | it from there. */ |
---|
| 1006 | Chain_Extract(&bd_buf->link); |
---|
| 1007 | } |
---|
| 1008 | bd_buf->use_count++; |
---|
| 1009 | while (bd_buf->in_progress != 0) |
---|
| 1010 | { |
---|
[df6348bb] | 1011 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1012 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1013 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1014 | } |
---|
| 1015 | |
---|
| 1016 | *ret_buf = bd_buf; |
---|
| 1017 | return RTEMS_SUCCESSFUL; |
---|
| 1018 | } |
---|
| 1019 | } |
---|
| 1020 | |
---|
| 1021 | /* rtems_bdbuf_get -- |
---|
| 1022 | * Obtain block buffer. If specified block already cached (i.e. there's |
---|
| 1023 | * block in the _modified_, or _recently_used_), return address |
---|
| 1024 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
| 1025 | * If block is not cached, allocate new buffer and return it. Data |
---|
| 1026 | * shouldn't be read to the buffer from media; buffer may contains |
---|
| 1027 | * arbitrary data. This primitive may be blocked if there are no free |
---|
| 1028 | * buffer descriptors available and there are no unused non-modified |
---|
| 1029 | * (or synchronized with media) buffers available. |
---|
| 1030 | * |
---|
| 1031 | * PARAMETERS: |
---|
| 1032 | * device - device number (constructed of major and minor device number) |
---|
| 1033 | * block - linear media block number |
---|
| 1034 | * bd - address of variable to store pointer to the buffer descriptor |
---|
| 1035 | * |
---|
| 1036 | * RETURNS: |
---|
| 1037 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1038 | * or error code if error is occured) |
---|
| 1039 | * |
---|
| 1040 | * SIDE EFFECTS: |
---|
| 1041 | * bufget_sema semaphore obtained by this primitive. |
---|
| 1042 | */ |
---|
| 1043 | rtems_status_code |
---|
| 1044 | rtems_bdbuf_get(dev_t device, blkdev_bnum block, bdbuf_buffer **bd) |
---|
| 1045 | { |
---|
| 1046 | rtems_status_code rc; |
---|
| 1047 | disk_device *dd; |
---|
| 1048 | disk_device *pdd; |
---|
| 1049 | preemption_key key; |
---|
| 1050 | |
---|
| 1051 | /* |
---|
| 1052 | * Convert logical dev/block to physical one |
---|
| 1053 | */ |
---|
| 1054 | dd = rtems_disk_lookup(device); |
---|
| 1055 | if (dd == NULL) |
---|
| 1056 | return RTEMS_INVALID_ID; |
---|
| 1057 | |
---|
| 1058 | if (block >= dd->size) |
---|
| 1059 | { |
---|
| 1060 | rtems_disk_release(dd); |
---|
| 1061 | return RTEMS_INVALID_NUMBER; |
---|
| 1062 | } |
---|
| 1063 | |
---|
| 1064 | pdd = dd->phys_dev; |
---|
| 1065 | block += dd->start; |
---|
| 1066 | rtems_disk_release(dd); |
---|
| 1067 | |
---|
| 1068 | DISABLE_PREEMPTION(key); |
---|
| 1069 | rc = find_or_assign_buffer(pdd, block, bd); |
---|
| 1070 | ENABLE_PREEMPTION(key); |
---|
| 1071 | |
---|
| 1072 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1073 | return rc; |
---|
| 1074 | |
---|
| 1075 | return RTEMS_SUCCESSFUL; |
---|
| 1076 | } |
---|
| 1077 | |
---|
| 1078 | /* bdbuf_initialize_transfer_sema -- |
---|
| 1079 | * Initialize transfer_sema mutex semaphore associated with buffer |
---|
| 1080 | * descriptor. |
---|
| 1081 | */ |
---|
| 1082 | static inline void |
---|
| 1083 | bdbuf_initialize_transfer_sema(bdbuf_buffer *bd_buf) |
---|
| 1084 | { |
---|
| 1085 | CORE_mutex_Attributes mutex_attr; |
---|
| 1086 | mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS; |
---|
| 1087 | mutex_attr.only_owner_release = FALSE; |
---|
| 1088 | mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_FIFO; |
---|
| 1089 | mutex_attr.priority_ceiling = 0; |
---|
| 1090 | |
---|
[87da638] | 1091 | _CORE_mutex_Initialize(&bd_buf->transfer_sema, |
---|
| 1092 | &mutex_attr, CORE_MUTEX_LOCKED); |
---|
[e51bd96] | 1093 | } |
---|
| 1094 | |
---|
| 1095 | /* bdbuf_write_transfer_done -- |
---|
| 1096 | * Callout function. Invoked by block device driver when data transfer |
---|
| 1097 | * to device (write) is completed. This function may be invoked from |
---|
| 1098 | * interrupt handler. |
---|
| 1099 | * |
---|
| 1100 | * PARAMETERS: |
---|
| 1101 | * arg - arbitrary argument specified in block device request |
---|
| 1102 | * structure (in this case - pointer to the appropriate |
---|
| 1103 | * bdbuf_buffer buffer descriptor structure). |
---|
| 1104 | * status - I/O completion status |
---|
| 1105 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
| 1106 | * |
---|
| 1107 | * RETURNS: |
---|
| 1108 | * none |
---|
| 1109 | */ |
---|
| 1110 | static void |
---|
| 1111 | bdbuf_write_transfer_done(void *arg, rtems_status_code status, int error) |
---|
| 1112 | { |
---|
| 1113 | bdbuf_buffer *bd_buf = arg; |
---|
| 1114 | bd_buf->status = status; |
---|
[662814d] | 1115 | bd_buf->error = RTEMS_IO_ERROR; |
---|
[e51bd96] | 1116 | bd_buf->in_progress = bd_buf->modified = FALSE; |
---|
| 1117 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
| 1118 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
| 1119 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1120 | } |
---|
| 1121 | |
---|
| 1122 | /* bdbuf_read_transfer_done -- |
---|
| 1123 | * Callout function. Invoked by block device driver when data transfer |
---|
| 1124 | * from device (read) is completed. This function may be invoked from |
---|
| 1125 | * interrupt handler. |
---|
| 1126 | * |
---|
| 1127 | * PARAMETERS: |
---|
| 1128 | * arg - arbitrary argument specified in block device request |
---|
| 1129 | * structure (in this case - pointer to the appropriate |
---|
| 1130 | * bdbuf_buffer buffer descriptor structure). |
---|
| 1131 | * status - I/O completion status |
---|
| 1132 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
| 1133 | * |
---|
| 1134 | * RETURNS: |
---|
| 1135 | * none |
---|
| 1136 | */ |
---|
| 1137 | static void |
---|
| 1138 | bdbuf_read_transfer_done(void *arg, rtems_status_code status, int error) |
---|
| 1139 | { |
---|
| 1140 | bdbuf_buffer *bd_buf = arg; |
---|
| 1141 | bd_buf->status = status; |
---|
[662814d] | 1142 | bd_buf->error = RTEMS_IO_ERROR; |
---|
[e51bd96] | 1143 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
| 1144 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
| 1145 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1146 | } |
---|
| 1147 | |
---|
| 1148 | /* rtems_bdbuf_read -- |
---|
| 1149 | * (Similar to the rtems_bdbuf_get, except reading data from media) |
---|
| 1150 | * Obtain block buffer. If specified block already cached, return address |
---|
| 1151 | * of appropriate buffer and increment reference counter to 1. If block is |
---|
| 1152 | * not cached, allocate new buffer and read data to it from the media. |
---|
| 1153 | * This primitive may be blocked on waiting until data to be read from |
---|
| 1154 | * media, if there are no free buffer descriptors available and there are |
---|
| 1155 | * no unused non-modified (or synchronized with media) buffers available. |
---|
| 1156 | * |
---|
| 1157 | * PARAMETERS: |
---|
| 1158 | * device - device number (consists of major and minor device number) |
---|
| 1159 | * block - linear media block number |
---|
| 1160 | * bd - address of variable to store pointer to the buffer descriptor |
---|
| 1161 | * |
---|
| 1162 | * RETURNS: |
---|
| 1163 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1164 | * or error code if error is occured) |
---|
| 1165 | * |
---|
| 1166 | * SIDE EFFECTS: |
---|
| 1167 | * bufget_sema and transfer_sema semaphores obtained by this primitive. |
---|
| 1168 | */ |
---|
| 1169 | rtems_status_code |
---|
| 1170 | rtems_bdbuf_read(dev_t device, |
---|
| 1171 | blkdev_bnum block, |
---|
| 1172 | bdbuf_buffer **bd) |
---|
| 1173 | { |
---|
| 1174 | preemption_key key; |
---|
| 1175 | ISR_Level level; |
---|
| 1176 | |
---|
| 1177 | bdbuf_buffer *bd_buf; |
---|
| 1178 | rtems_status_code rc; |
---|
| 1179 | int result; |
---|
| 1180 | disk_device *dd; |
---|
| 1181 | disk_device *pdd; |
---|
| 1182 | blkdev_request1 req; |
---|
| 1183 | |
---|
| 1184 | dd = rtems_disk_lookup(device); |
---|
| 1185 | if (dd == NULL) |
---|
| 1186 | return RTEMS_INVALID_ID; |
---|
| 1187 | |
---|
| 1188 | if (block >= dd->size) |
---|
| 1189 | { |
---|
| 1190 | rtems_disk_release(dd); |
---|
| 1191 | return RTEMS_INVALID_NUMBER; |
---|
| 1192 | } |
---|
| 1193 | |
---|
| 1194 | pdd = dd->phys_dev; |
---|
| 1195 | block += dd->start; |
---|
| 1196 | |
---|
| 1197 | DISABLE_PREEMPTION(key); |
---|
| 1198 | rc = find_or_assign_buffer(pdd, block, &bd_buf); |
---|
| 1199 | |
---|
| 1200 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1201 | { |
---|
| 1202 | ENABLE_PREEMPTION(key); |
---|
| 1203 | rtems_disk_release(dd); |
---|
| 1204 | return rc; |
---|
| 1205 | } |
---|
| 1206 | |
---|
| 1207 | if (!bd_buf->actual) |
---|
| 1208 | { |
---|
| 1209 | bd_buf->in_progress = 1; |
---|
| 1210 | |
---|
| 1211 | req.req.req = BLKDEV_REQ_READ; |
---|
| 1212 | req.req.req_done = bdbuf_read_transfer_done; |
---|
| 1213 | req.req.done_arg = bd_buf; |
---|
| 1214 | req.req.start = block; |
---|
| 1215 | req.req.count = 1; |
---|
| 1216 | req.req.bufnum = 1; |
---|
| 1217 | req.req.bufs[0].length = dd->block_size; |
---|
| 1218 | req.req.bufs[0].buffer = bd_buf->buffer; |
---|
| 1219 | |
---|
| 1220 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
[662814d] | 1221 | result = dd->ioctl(pdd->dev, BLKIO_REQUEST, &req); |
---|
[e51bd96] | 1222 | if (result == -1) |
---|
| 1223 | { |
---|
| 1224 | bd_buf->status = RTEMS_IO_ERROR; |
---|
| 1225 | bd_buf->error = errno; |
---|
| 1226 | bd_buf->actual = FALSE; |
---|
| 1227 | } |
---|
| 1228 | else |
---|
| 1229 | { |
---|
[df6348bb] | 1230 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1231 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1232 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1233 | bd_buf->actual = TRUE; |
---|
| 1234 | } |
---|
| 1235 | bd_buf->in_progress = FALSE; |
---|
| 1236 | } |
---|
| 1237 | rtems_disk_release(dd); |
---|
| 1238 | |
---|
| 1239 | ENABLE_PREEMPTION(key); |
---|
| 1240 | |
---|
| 1241 | *bd = bd_buf; |
---|
| 1242 | |
---|
| 1243 | return RTEMS_SUCCESSFUL; |
---|
| 1244 | } |
---|
| 1245 | |
---|
| 1246 | |
---|
| 1247 | /* bdbuf_release -- |
---|
| 1248 | * Release buffer. Decrease buffer usage counter. If it is zero, further |
---|
| 1249 | * processing depends on modified attribute. If buffer was modified, it |
---|
| 1250 | * is inserted into mod chain and swapout task waken up. If buffer was |
---|
| 1251 | * not modified, it is returned to the end of lru chain making it available |
---|
| 1252 | * for further use. |
---|
| 1253 | * |
---|
| 1254 | * PARAMETERS: |
---|
| 1255 | * bd_buf - pointer to the released buffer descriptor. |
---|
| 1256 | * |
---|
| 1257 | * RETURNS: |
---|
| 1258 | * RTEMS_SUCCESSFUL if buffer released successfully, or error code if |
---|
| 1259 | * error occured. |
---|
| 1260 | * |
---|
| 1261 | * NOTE: |
---|
| 1262 | * This is internal function. It is assumed that task made non-preemptive |
---|
| 1263 | * before its invocation. |
---|
| 1264 | */ |
---|
| 1265 | static rtems_status_code |
---|
| 1266 | bdbuf_release(bdbuf_buffer *bd_buf) |
---|
| 1267 | { |
---|
| 1268 | bdbuf_pool *bd_pool; |
---|
| 1269 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1270 | |
---|
| 1271 | if (bd_buf->use_count <= 0) |
---|
| 1272 | return RTEMS_INTERNAL_ERROR; |
---|
| 1273 | |
---|
| 1274 | bd_pool = bd_ctx.pool + bd_buf->pool; |
---|
| 1275 | |
---|
| 1276 | bd_buf->use_count--; |
---|
| 1277 | |
---|
| 1278 | if (bd_buf->use_count == 0) |
---|
| 1279 | { |
---|
| 1280 | if (bd_buf->modified) |
---|
| 1281 | { |
---|
| 1282 | |
---|
| 1283 | /* Buffer was modified. Insert buffer to the modified buffers |
---|
| 1284 | * list and initiate flushing. */ |
---|
| 1285 | Chain_Append(&bd_ctx.mod, &bd_buf->link); |
---|
| 1286 | |
---|
| 1287 | /* Release the flush_sema */ |
---|
| 1288 | rc = rtems_semaphore_release(bd_ctx.flush_sema); |
---|
| 1289 | } |
---|
| 1290 | else |
---|
| 1291 | { |
---|
| 1292 | /* Buffer was not modified. Add this descriptor to the |
---|
| 1293 | * end of lru chain and make it available for reuse. */ |
---|
| 1294 | Chain_Append(&bd_pool->lru, &bd_buf->link); |
---|
| 1295 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 1296 | } |
---|
| 1297 | } |
---|
| 1298 | return rc; |
---|
| 1299 | } |
---|
| 1300 | |
---|
| 1301 | |
---|
| 1302 | /* rtems_bdbuf_release -- |
---|
| 1303 | * Release buffer allocated before. This primitive decrease the |
---|
| 1304 | * usage counter. If it is zero, further destiny of buffer depends on |
---|
| 1305 | * 'modified' status. If buffer was modified, it is placed to the end of |
---|
| 1306 | * mod list and flush task waken up. If buffer was not modified, |
---|
| 1307 | * it is placed to the end of lru list, and bufget_sema released, allowing |
---|
| 1308 | * to reuse this buffer. |
---|
| 1309 | * |
---|
| 1310 | * PARAMETERS: |
---|
| 1311 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
| 1312 | * get/read primitive. |
---|
| 1313 | * |
---|
| 1314 | * RETURNS: |
---|
| 1315 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1316 | * or error code if error is occured) |
---|
| 1317 | * |
---|
| 1318 | * SIDE EFFECTS: |
---|
| 1319 | * flush_sema and bufget_sema semaphores may be released by this primitive. |
---|
| 1320 | */ |
---|
| 1321 | rtems_status_code |
---|
| 1322 | rtems_bdbuf_release(bdbuf_buffer *bd_buf) |
---|
| 1323 | { |
---|
| 1324 | preemption_key key; |
---|
| 1325 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1326 | |
---|
| 1327 | if (bd_buf == NULL) |
---|
| 1328 | return RTEMS_INVALID_ADDRESS; |
---|
| 1329 | |
---|
| 1330 | DISABLE_PREEMPTION(key); |
---|
| 1331 | |
---|
| 1332 | rc = bdbuf_release(bd_buf); |
---|
| 1333 | |
---|
| 1334 | ENABLE_PREEMPTION(key); |
---|
| 1335 | |
---|
| 1336 | return rc; |
---|
| 1337 | } |
---|
| 1338 | |
---|
| 1339 | /* rtems_bdbuf_release_modified -- |
---|
| 1340 | * Release buffer allocated before, assuming that it is _modified_ by |
---|
| 1341 | * it's owner. This primitive decrease usage counter for buffer, mark |
---|
| 1342 | * buffer descriptor as modified. If usage counter is 0, insert it at |
---|
| 1343 | * end of mod chain and release flush_sema semaphore to activate the |
---|
| 1344 | * flush task. |
---|
| 1345 | * |
---|
| 1346 | * PARAMETERS: |
---|
| 1347 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
| 1348 | * get/read primitive. |
---|
| 1349 | * |
---|
| 1350 | * RETURNS: |
---|
| 1351 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1352 | * or error code if error is occured) |
---|
| 1353 | * |
---|
| 1354 | * SIDE EFFECTS: |
---|
| 1355 | * flush_sema semaphore may be released by this primitive. |
---|
| 1356 | */ |
---|
| 1357 | rtems_status_code |
---|
| 1358 | rtems_bdbuf_release_modified(bdbuf_buffer *bd_buf) |
---|
| 1359 | { |
---|
| 1360 | preemption_key key; |
---|
| 1361 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1362 | |
---|
| 1363 | if (bd_buf == NULL) |
---|
| 1364 | return RTEMS_INVALID_ADDRESS; |
---|
| 1365 | |
---|
| 1366 | DISABLE_PREEMPTION(key); |
---|
| 1367 | |
---|
| 1368 | if (!bd_buf->modified) |
---|
| 1369 | { |
---|
| 1370 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
| 1371 | } |
---|
| 1372 | bd_buf->modified = TRUE; |
---|
| 1373 | bd_buf->actual = TRUE; |
---|
| 1374 | rc = bdbuf_release(bd_buf); |
---|
| 1375 | |
---|
| 1376 | ENABLE_PREEMPTION(key); |
---|
| 1377 | |
---|
| 1378 | return rc; |
---|
| 1379 | } |
---|
| 1380 | |
---|
| 1381 | /* rtems_bdbuf_sync -- |
---|
| 1382 | * Wait until specified buffer synchronized with disk. Invoked on exchanges |
---|
| 1383 | * critical for data consistency on the media. This primitive mark owned |
---|
| 1384 | * block as modified, decrease usage counter. If usage counter is 0, |
---|
| 1385 | * block inserted to the mod chain and flush_sema semaphore released. |
---|
| 1386 | * Finally, primitives blocked on transfer_sema semaphore. |
---|
| 1387 | * |
---|
| 1388 | * PARAMETERS: |
---|
| 1389 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
| 1390 | * get/read primitive. |
---|
| 1391 | * |
---|
| 1392 | * RETURNS: |
---|
| 1393 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1394 | * or error code if error is occured) |
---|
| 1395 | * |
---|
| 1396 | * SIDE EFFECTS: |
---|
| 1397 | * Primitive may be blocked on transfer_sema semaphore. |
---|
| 1398 | */ |
---|
| 1399 | rtems_status_code |
---|
| 1400 | rtems_bdbuf_sync(bdbuf_buffer *bd_buf) |
---|
| 1401 | { |
---|
| 1402 | preemption_key key; |
---|
| 1403 | ISR_Level level; |
---|
| 1404 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
| 1405 | |
---|
| 1406 | if (bd_buf == NULL) |
---|
| 1407 | return RTEMS_INVALID_ADDRESS; |
---|
| 1408 | |
---|
| 1409 | DISABLE_PREEMPTION(key); |
---|
| 1410 | |
---|
| 1411 | if (!bd_buf->modified) |
---|
| 1412 | { |
---|
| 1413 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
| 1414 | } |
---|
| 1415 | bd_buf->modified = TRUE; |
---|
| 1416 | bd_buf->actual = TRUE; |
---|
| 1417 | |
---|
| 1418 | rc = bdbuf_release(bd_buf); |
---|
| 1419 | |
---|
| 1420 | if (rc == RTEMS_SUCCESSFUL) |
---|
| 1421 | { |
---|
[df6348bb] | 1422 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1423 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1424 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1425 | } |
---|
| 1426 | |
---|
| 1427 | ENABLE_PREEMPTION(key); |
---|
| 1428 | |
---|
| 1429 | return rc; |
---|
| 1430 | } |
---|
| 1431 | |
---|
| 1432 | /* rtems_bdbuf_syncdev -- |
---|
| 1433 | * Synchronize with disk all buffers containing the blocks belonging to |
---|
| 1434 | * specified device. |
---|
| 1435 | * |
---|
| 1436 | * PARAMETERS: |
---|
| 1437 | * dev - block device number |
---|
| 1438 | * |
---|
| 1439 | * RETURNS: |
---|
| 1440 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
| 1441 | * or error code if error is occured) |
---|
| 1442 | */ |
---|
| 1443 | rtems_status_code |
---|
| 1444 | rtems_bdbuf_syncdev(dev_t dev) |
---|
| 1445 | { |
---|
| 1446 | preemption_key key; |
---|
| 1447 | ISR_Level level; |
---|
| 1448 | |
---|
| 1449 | bdbuf_buffer *bd_buf; |
---|
| 1450 | disk_device *dd; |
---|
| 1451 | bdbuf_pool *pool; |
---|
| 1452 | |
---|
| 1453 | dd = rtems_disk_lookup(dev); |
---|
| 1454 | if (dd == NULL) |
---|
| 1455 | return RTEMS_INVALID_ID; |
---|
| 1456 | |
---|
| 1457 | pool = bd_ctx.pool + dd->pool; |
---|
| 1458 | |
---|
| 1459 | DISABLE_PREEMPTION(key); |
---|
| 1460 | do { |
---|
| 1461 | bd_buf = avl_search_for_sync(&pool->tree, dd); |
---|
| 1462 | if (bd_buf != NULL /* && bd_buf->modified */) |
---|
| 1463 | { |
---|
[df6348bb] | 1464 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1465 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
| 1466 | WATCHDOG_NO_TIMEOUT, level); |
---|
| 1467 | } |
---|
| 1468 | } while (bd_buf != NULL); |
---|
| 1469 | ENABLE_PREEMPTION(key); |
---|
| 1470 | return rtems_disk_release(dd); |
---|
| 1471 | } |
---|
| 1472 | |
---|
| 1473 | /* bdbuf_swapout_task -- |
---|
| 1474 | * Body of task which take care on flushing modified buffers to the |
---|
| 1475 | * disk. |
---|
| 1476 | */ |
---|
| 1477 | static rtems_task |
---|
| 1478 | bdbuf_swapout_task(rtems_task_argument unused) |
---|
| 1479 | { |
---|
| 1480 | rtems_status_code rc; |
---|
| 1481 | int result; |
---|
| 1482 | ISR_Level level; |
---|
| 1483 | bdbuf_buffer *bd_buf; |
---|
| 1484 | bdbuf_pool *bd_pool; |
---|
| 1485 | disk_device *dd; |
---|
| 1486 | blkdev_request1 req; |
---|
| 1487 | |
---|
| 1488 | while (1) |
---|
| 1489 | { |
---|
| 1490 | rc = rtems_semaphore_obtain(bd_ctx.flush_sema, RTEMS_WAIT, 0); |
---|
| 1491 | if (rc != RTEMS_SUCCESSFUL) |
---|
| 1492 | { |
---|
| 1493 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_SWAPOUT); |
---|
| 1494 | } |
---|
| 1495 | |
---|
| 1496 | bd_buf = (bdbuf_buffer *)Chain_Get(&bd_ctx.mod); |
---|
| 1497 | if (bd_buf == NULL) |
---|
| 1498 | { |
---|
| 1499 | /* It is possible that flush_sema semaphore will be released, but |
---|
| 1500 | * buffer to be removed from mod chain before swapout task start |
---|
| 1501 | * its processing. */ |
---|
| 1502 | continue; |
---|
| 1503 | } |
---|
| 1504 | |
---|
| 1505 | bd_buf->in_progress = TRUE; |
---|
| 1506 | bd_buf->use_count++; |
---|
| 1507 | bd_pool = bd_ctx.pool + bd_buf->pool; |
---|
| 1508 | dd = rtems_disk_lookup(bd_buf->dev); |
---|
| 1509 | |
---|
| 1510 | req.req.req = BLKDEV_REQ_WRITE; |
---|
| 1511 | req.req.req_done = bdbuf_write_transfer_done; |
---|
| 1512 | req.req.done_arg = bd_buf; |
---|
| 1513 | req.req.start = bd_buf->block + dd->start; |
---|
| 1514 | req.req.count = 1; |
---|
| 1515 | req.req.bufnum = 1; |
---|
| 1516 | req.req.bufs[0].length = dd->block_size; |
---|
| 1517 | req.req.bufs[0].buffer = bd_buf->buffer; |
---|
| 1518 | |
---|
| 1519 | /* transfer_sema initialized when bd_buf inserted in the mod chain |
---|
| 1520 | first time */ |
---|
| 1521 | result = dd->ioctl(dd->phys_dev->dev, BLKIO_REQUEST, &req); |
---|
| 1522 | |
---|
| 1523 | rtems_disk_release(dd); |
---|
| 1524 | |
---|
| 1525 | if (result == -1) |
---|
| 1526 | { |
---|
| 1527 | bd_buf->status = RTEMS_IO_ERROR; |
---|
| 1528 | bd_buf->error = errno; |
---|
| 1529 | /* Release tasks waiting on syncing this buffer */ |
---|
| 1530 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
| 1531 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
| 1532 | } |
---|
| 1533 | else |
---|
| 1534 | { |
---|
| 1535 | if (bd_buf->in_progress) |
---|
| 1536 | { |
---|
[df6348bb] | 1537 | rtems_interrupt_disable(level); |
---|
[e51bd96] | 1538 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, 0, level); |
---|
| 1539 | } |
---|
| 1540 | } |
---|
| 1541 | bd_buf->use_count--; |
---|
| 1542 | |
---|
| 1543 | /* Another task have chance to use this buffer, or even |
---|
| 1544 | * modify it. If buffer is not in use, insert it in appropriate chain |
---|
| 1545 | * and release semaphore */ |
---|
| 1546 | if (bd_buf->use_count == 0) |
---|
| 1547 | { |
---|
| 1548 | if (bd_buf->modified) |
---|
| 1549 | { |
---|
| 1550 | Chain_Append(&bd_ctx.mod, &bd_buf->link); |
---|
| 1551 | rc = rtems_semaphore_release(bd_ctx.flush_sema); |
---|
| 1552 | } |
---|
| 1553 | else |
---|
| 1554 | { |
---|
| 1555 | Chain_Append(&bd_pool->lru, &bd_buf->link); |
---|
| 1556 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
| 1557 | } |
---|
| 1558 | } |
---|
| 1559 | } |
---|
| 1560 | } |
---|
| 1561 | |
---|
| 1562 | /* rtems_bdbuf_find_pool -- |
---|
| 1563 | * Find first appropriate buffer pool. This primitive returns the index |
---|
| 1564 | * of first buffer pool which block size is greater than or equal to |
---|
| 1565 | * specified size. |
---|
| 1566 | * |
---|
| 1567 | * PARAMETERS: |
---|
| 1568 | * block_size - requested block size |
---|
| 1569 | * pool - placeholder for result |
---|
| 1570 | * |
---|
| 1571 | * RETURNS: |
---|
| 1572 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
| 1573 | * RTEMS_INVALID_SIZE if specified block size is invalid (not a power |
---|
| 1574 | * of 2), RTEMS_NOT_DEFINED if buffer pool for this or greater block size |
---|
| 1575 | * is not configured. |
---|
| 1576 | */ |
---|
| 1577 | rtems_status_code |
---|
| 1578 | rtems_bdbuf_find_pool(int block_size, rtems_bdpool_id *pool) |
---|
| 1579 | { |
---|
| 1580 | rtems_bdpool_id i; |
---|
| 1581 | bdbuf_pool *p; |
---|
| 1582 | int cursize = INT_MAX; |
---|
| 1583 | rtems_bdpool_id curid = -1; |
---|
| 1584 | rtems_boolean found = FALSE; |
---|
| 1585 | int j; |
---|
| 1586 | |
---|
| 1587 | for (j = block_size; (j != 0) && ((j & 1) == 0); j >>= 1); |
---|
| 1588 | if (j != 1) |
---|
| 1589 | return RTEMS_INVALID_SIZE; |
---|
| 1590 | |
---|
| 1591 | for (i = 0, p = bd_ctx.pool; i < bd_ctx.npools; i++, p++) |
---|
| 1592 | { |
---|
| 1593 | if ((p->blksize >= block_size) && |
---|
| 1594 | (p->blksize < cursize)) |
---|
| 1595 | { |
---|
| 1596 | curid = i; |
---|
| 1597 | cursize = p->blksize; |
---|
| 1598 | found = TRUE; |
---|
| 1599 | } |
---|
| 1600 | } |
---|
| 1601 | |
---|
| 1602 | if (found) |
---|
| 1603 | { |
---|
| 1604 | if (pool != NULL) |
---|
| 1605 | *pool = curid; |
---|
| 1606 | return RTEMS_SUCCESSFUL; |
---|
| 1607 | } |
---|
| 1608 | else |
---|
| 1609 | { |
---|
| 1610 | return RTEMS_NOT_DEFINED; |
---|
| 1611 | } |
---|
| 1612 | } |
---|
| 1613 | |
---|
| 1614 | /* rtems_bdbuf_get_pool_info -- |
---|
| 1615 | * Obtain characteristics of buffer pool with specified number. |
---|
| 1616 | * |
---|
| 1617 | * PARAMETERS: |
---|
| 1618 | * pool - buffer pool number |
---|
| 1619 | * block_size - block size for which buffer pool is configured returned |
---|
| 1620 | * there |
---|
| 1621 | * blocks - number of buffers in buffer pool returned there |
---|
| 1622 | * |
---|
| 1623 | * RETURNS: |
---|
| 1624 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
| 1625 | * RTEMS_INVALID_NUMBER if appropriate buffer pool is not configured. |
---|
| 1626 | * |
---|
| 1627 | * NOTE: |
---|
| 1628 | * Buffer pools enumerated contiguously starting from 0. |
---|
| 1629 | */ |
---|
| 1630 | rtems_status_code |
---|
| 1631 | rtems_bdbuf_get_pool_info(rtems_bdpool_id pool, int *block_size, |
---|
| 1632 | int *blocks) |
---|
| 1633 | { |
---|
| 1634 | if (pool >= bd_ctx.npools) |
---|
| 1635 | return RTEMS_INVALID_NUMBER; |
---|
| 1636 | |
---|
| 1637 | if (block_size != NULL) |
---|
| 1638 | { |
---|
| 1639 | *block_size = bd_ctx.pool[pool].blksize; |
---|
| 1640 | } |
---|
| 1641 | |
---|
| 1642 | if (blocks != NULL) |
---|
| 1643 | { |
---|
| 1644 | *blocks = bd_ctx.pool[pool].nblks; |
---|
| 1645 | } |
---|
| 1646 | |
---|
| 1647 | return RTEMS_SUCCESSFUL; |
---|
| 1648 | } |
---|