1 | #ifndef _VNETD_LIST_H_ |
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2 | #define _VNETD_LIST_H_ |
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3 | |
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4 | /* Taken from Linux kernel code, but de-kernelized for userspace. */ |
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5 | #include <stddef.h> |
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6 | |
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7 | /* |
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8 | * These are non-NULL pointers that will result in page faults |
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9 | * under normal circumstances, used to verify that nobody uses |
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10 | * non-initialized list entries. |
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11 | */ |
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12 | #define LIST_POISON1 ((void *) 0x00100100) |
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13 | #define LIST_POISON2 ((void *) 0x00200200) |
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14 | |
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15 | #define container_of(ptr, type, member) ({ \ |
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16 | const typeof( ((type *)0)->member ) *__mptr = (ptr); \ |
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17 | (type *)( (char *)__mptr - offsetof(type,member) );}) |
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18 | |
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19 | /* |
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20 | * Simple doubly linked list implementation. |
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21 | * |
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22 | * Some of the internal functions ("__xxx") are useful when |
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23 | * manipulating whole lists rather than single entries, as |
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24 | * sometimes we already know the next/prev entries and we can |
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25 | * generate better code by using them directly rather than |
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26 | * using the generic single-entry routines. |
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27 | */ |
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28 | |
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29 | struct list_head { |
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30 | struct list_head *next, *prev; |
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31 | }; |
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32 | |
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33 | #define LIST_HEAD_INIT(name) { &(name), &(name) } |
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34 | |
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35 | #define LIST_HEAD(name) \ |
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36 | struct list_head name = LIST_HEAD_INIT(name) |
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37 | |
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38 | #define INIT_LIST_HEAD(ptr) do { \ |
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39 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ |
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40 | } while (0) |
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41 | |
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42 | /* |
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43 | * Insert a new entry between two known consecutive entries. |
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44 | * |
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45 | * This is only for internal list manipulation where we know |
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46 | * the prev/next entries already! |
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47 | */ |
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48 | static inline void __list_add(struct list_head *new, |
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49 | struct list_head *prev, |
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50 | struct list_head *next) |
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51 | { |
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52 | next->prev = new; |
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53 | new->next = next; |
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54 | new->prev = prev; |
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55 | prev->next = new; |
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56 | } |
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57 | |
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58 | /** |
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59 | * list_add - add a new entry |
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60 | * @new: new entry to be added |
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61 | * @head: list head to add it after |
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62 | * |
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63 | * Insert a new entry after the specified head. |
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64 | * This is good for implementing stacks. |
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65 | */ |
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66 | static inline void list_add(struct list_head *new, struct list_head *head) |
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67 | { |
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68 | __list_add(new, head, head->next); |
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69 | } |
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70 | |
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71 | /** |
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72 | * list_add_tail - add a new entry |
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73 | * @new: new entry to be added |
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74 | * @head: list head to add it before |
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75 | * |
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76 | * Insert a new entry before the specified head. |
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77 | * This is useful for implementing queues. |
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78 | */ |
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79 | static inline void list_add_tail(struct list_head *new, struct list_head *head) |
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80 | { |
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81 | __list_add(new, head->prev, head); |
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82 | } |
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83 | |
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84 | /* |
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85 | * Delete a list entry by making the prev/next entries |
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86 | * point to each other. |
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87 | * |
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88 | * This is only for internal list manipulation where we know |
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89 | * the prev/next entries already! |
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90 | */ |
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91 | static inline void __list_del(struct list_head * prev, struct list_head * next) |
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92 | { |
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93 | next->prev = prev; |
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94 | prev->next = next; |
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95 | } |
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96 | |
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97 | /** |
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98 | * list_del - deletes entry from list. |
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99 | * @entry: the element to delete from the list. |
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100 | * Note: list_empty on entry does not return true after this, the entry is |
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101 | * in an undefined state. |
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102 | */ |
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103 | static inline void list_del(struct list_head *entry) |
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104 | { |
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105 | __list_del(entry->prev, entry->next); |
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106 | entry->next = LIST_POISON1; |
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107 | entry->prev = LIST_POISON2; |
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108 | } |
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109 | |
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110 | /** |
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111 | * list_del_rcu - deletes entry from list without re-initialization |
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112 | * @entry: the element to delete from the list. |
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113 | * |
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114 | * Note: list_empty on entry does not return true after this, |
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115 | * the entry is in an undefined state. It is useful for RCU based |
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116 | * lockfree traversal. |
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117 | * |
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118 | * In particular, it means that we can not poison the forward |
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119 | * pointers that may still be used for walking the list. |
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120 | */ |
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121 | static inline void list_del_rcu(struct list_head *entry) |
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122 | { |
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123 | __list_del(entry->prev, entry->next); |
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124 | entry->prev = LIST_POISON2; |
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125 | } |
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126 | |
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127 | /** |
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128 | * list_del_init - deletes entry from list and reinitialize it. |
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129 | * @entry: the element to delete from the list. |
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130 | */ |
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131 | static inline void list_del_init(struct list_head *entry) |
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132 | { |
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133 | __list_del(entry->prev, entry->next); |
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134 | INIT_LIST_HEAD(entry); |
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135 | } |
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136 | |
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137 | /** |
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138 | * list_move - delete from one list and add as another's head |
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139 | * @list: the entry to move |
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140 | * @head: the head that will precede our entry |
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141 | */ |
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142 | static inline void list_move(struct list_head *list, struct list_head *head) |
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143 | { |
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144 | __list_del(list->prev, list->next); |
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145 | list_add(list, head); |
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146 | } |
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147 | |
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148 | /** |
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149 | * list_move_tail - delete from one list and add as another's tail |
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150 | * @list: the entry to move |
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151 | * @head: the head that will follow our entry |
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152 | */ |
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153 | static inline void list_move_tail(struct list_head *list, |
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154 | struct list_head *head) |
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155 | { |
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156 | __list_del(list->prev, list->next); |
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157 | list_add_tail(list, head); |
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158 | } |
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159 | |
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160 | /** |
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161 | * list_empty - tests whether a list is empty |
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162 | * @head: the list to test. |
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163 | */ |
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164 | static inline int list_empty(struct list_head *head) |
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165 | { |
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166 | return head->next == head; |
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167 | } |
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168 | |
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169 | static inline void __list_splice(struct list_head *list, |
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170 | struct list_head *head) |
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171 | { |
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172 | struct list_head *first = list->next; |
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173 | struct list_head *last = list->prev; |
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174 | struct list_head *at = head->next; |
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175 | |
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176 | first->prev = head; |
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177 | head->next = first; |
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178 | |
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179 | last->next = at; |
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180 | at->prev = last; |
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181 | } |
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182 | |
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183 | /** |
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184 | * list_splice - join two lists |
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185 | * @list: the new list to add. |
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186 | * @head: the place to add it in the first list. |
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187 | */ |
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188 | static inline void list_splice(struct list_head *list, struct list_head *head) |
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189 | { |
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190 | if (!list_empty(list)) |
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191 | __list_splice(list, head); |
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192 | } |
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193 | |
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194 | /** |
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195 | * list_splice_init - join two lists and reinitialise the emptied list. |
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196 | * @list: the new list to add. |
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197 | * @head: the place to add it in the first list. |
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198 | * |
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199 | * The list at @list is reinitialised |
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200 | */ |
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201 | static inline void list_splice_init(struct list_head *list, |
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202 | struct list_head *head) |
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203 | { |
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204 | if (!list_empty(list)) { |
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205 | __list_splice(list, head); |
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206 | INIT_LIST_HEAD(list); |
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207 | } |
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208 | } |
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209 | |
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210 | /** |
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211 | * list_entry - get the struct for this entry |
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212 | * @ptr: the &struct list_head pointer. |
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213 | * @type: the type of the struct this is embedded in. |
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214 | * @member: the name of the list_struct within the struct. |
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215 | */ |
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216 | #define list_entry(ptr, type, member) \ |
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217 | container_of(ptr, type, member) |
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218 | |
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219 | /** |
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220 | * list_for_each - iterate over a list |
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221 | * @pos: the &struct list_head to use as a loop counter. |
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222 | * @head: the head for your list. |
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223 | */ |
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224 | #define list_for_each(pos, head) \ |
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225 | for (pos = (head)->next; pos != (head); pos = pos->next) |
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226 | |
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227 | /** |
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228 | * list_for_each_prev - iterate over a list backwards |
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229 | * @pos: the &struct list_head to use as a loop counter. |
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230 | * @head: the head for your list. |
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231 | */ |
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232 | #define list_for_each_prev(pos, head) \ |
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233 | for (pos = (head)->prev; pos != (head); pos = pos->prev) |
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234 | |
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235 | /** |
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236 | * list_for_each_safe - iterate over a list safe against removal of list entry |
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237 | * @pos: the &struct list_head to use as a loop counter. |
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238 | * @n: another &struct list_head to use as temporary storage |
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239 | * @head: the head for your list. |
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240 | */ |
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241 | #define list_for_each_safe(pos, n, head) \ |
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242 | for (pos = (head)->next, n = pos->next; pos != (head); \ |
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243 | pos = n, n = pos->next) |
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244 | |
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245 | /** |
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246 | * list_for_each_entry - iterate over list of given type |
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247 | * @pos: the type * to use as a loop counter. |
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248 | * @head: the head for your list. |
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249 | * @member: the name of the list_struct within the struct. |
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250 | */ |
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251 | #define list_for_each_entry(pos, head, member) \ |
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252 | for (pos = list_entry((head)->next, typeof(*pos), member); \ |
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253 | &pos->member != (head); \ |
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254 | pos = list_entry(pos->member.next, typeof(*pos), member)) |
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255 | |
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256 | /** |
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257 | * list_for_each_entry_reverse - iterate backwards over list of given type. |
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258 | * @pos: the type * to use as a loop counter. |
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259 | * @head: the head for your list. |
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260 | * @member: the name of the list_struct within the struct. |
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261 | */ |
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262 | #define list_for_each_entry_reverse(pos, head, member) \ |
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263 | for (pos = list_entry((head)->prev, typeof(*pos), member); \ |
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264 | &pos->member != (head); \ |
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265 | pos = list_entry(pos->member.prev, typeof(*pos), member)) |
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266 | |
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267 | |
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268 | /** |
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269 | * list_for_each_entry_safe - iterate over list of given type safe against |
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270 | * removal of list entry |
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271 | * @pos: the type * to use as a loop counter. |
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272 | * @n: another type * to use as temporary storage |
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273 | * @head: the head for your list. |
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274 | * @member: the name of the list_struct within the struct. |
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275 | */ |
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276 | #define list_for_each_entry_safe(pos, n, head, member) \ |
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277 | for (pos = list_entry((head)->next, typeof(*pos), member), \ |
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278 | n = list_entry(pos->member.next, typeof(*pos), member); \ |
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279 | &pos->member != (head); \ |
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280 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) |
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281 | |
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282 | |
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283 | |
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284 | #endif /* _VNETD_LIST_H_ */ |
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