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1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
2 | ||
3 | #ifndef __LXC_HLIST_H | |
4 | #define __LXC_HLIST_H | |
5 | ||
6 | struct list_head { | |
7 | struct list_head *next, *prev; | |
8 | }; | |
9 | ||
10 | struct hlist_head { | |
11 | struct hlist_node *first; | |
12 | }; | |
13 | ||
14 | struct hlist_node { | |
15 | struct hlist_node *next, **pprev; | |
16 | }; | |
17 | ||
18 | /* | |
19 | * These are non-NULL pointers that will result in page faults | |
20 | * under normal circumstances, used to verify that nobody uses | |
21 | * non-initialized list entries. | |
22 | */ | |
23 | #define LIST_POISON1 ((void *) 0x100) | |
24 | #define LIST_POISON2 ((void *) 0x122) | |
25 | ||
26 | /* | |
27 | * Circular doubly linked list implementation. | |
28 | * | |
29 | * Some of the internal functions ("__xxx") are useful when | |
30 | * manipulating whole lists rather than single entries, as | |
31 | * sometimes we already know the next/prev entries and we can | |
32 | * generate better code by using them directly rather than | |
33 | * using the generic single-entry routines. | |
34 | */ | |
35 | ||
36 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
37 | ||
38 | #define LIST_HEAD(name) \ | |
39 | struct list_head name = LIST_HEAD_INIT(name) | |
40 | ||
41 | /** | |
42 | * INIT_LIST_HEAD - Initialize a list_head structure | |
43 | * @list: list_head structure to be initialized. | |
44 | * | |
45 | * Initializes the list_head to point to itself. If it is a list header, | |
46 | * the result is an empty list. | |
47 | */ | |
48 | static inline void INIT_LIST_HEAD(struct list_head *list) | |
49 | { | |
50 | list->next = list; | |
51 | list->prev = list; | |
52 | } | |
53 | ||
54 | /* | |
55 | * Insert a new entry between two known consecutive entries. | |
56 | * | |
57 | * This is only for internal list manipulation where we know | |
58 | * the prev/next entries already! | |
59 | */ | |
60 | static inline void __list_add(struct list_head *new, | |
61 | struct list_head *prev, | |
62 | struct list_head *next) | |
63 | { | |
64 | next->prev = new; | |
65 | new->next = next; | |
66 | new->prev = prev; | |
67 | prev->next = new; | |
68 | } | |
69 | ||
70 | /** | |
71 | * list_add - add a new entry | |
72 | * @new: new entry to be added | |
73 | * @head: list head to add it after | |
74 | * | |
75 | * Insert a new entry after the specified head. | |
76 | * This is good for implementing stacks. | |
77 | */ | |
78 | static inline void list_add(struct list_head *new, struct list_head *head) | |
79 | { | |
80 | __list_add(new, head, head->next); | |
81 | } | |
82 | ||
83 | ||
84 | /** | |
85 | * list_add_tail - add a new entry | |
86 | * @new: new entry to be added | |
87 | * @head: list head to add it before | |
88 | * | |
89 | * Insert a new entry before the specified head. | |
90 | * This is useful for implementing queues. | |
91 | */ | |
92 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
93 | { | |
94 | __list_add(new, head->prev, head); | |
95 | } | |
96 | ||
97 | /* | |
98 | * Delete a list entry by making the prev/next entries | |
99 | * point to each other. | |
100 | * | |
101 | * This is only for internal list manipulation where we know | |
102 | * the prev/next entries already! | |
103 | */ | |
104 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
105 | { | |
106 | next->prev = prev; | |
107 | prev->next = next; | |
108 | } | |
109 | ||
110 | static inline void __list_del_entry(struct list_head *entry) | |
111 | { | |
112 | __list_del(entry->prev, entry->next); | |
113 | } | |
114 | ||
115 | /** | |
116 | * list_del - deletes entry from list. | |
117 | * @entry: the element to delete from the list. | |
118 | * Note: list_empty() on entry does not return true after this, the entry is | |
119 | * in an undefined state. | |
120 | */ | |
121 | static inline void list_del(struct list_head *entry) | |
122 | { | |
123 | __list_del_entry(entry); | |
124 | entry->next = LIST_POISON1; | |
125 | entry->prev = LIST_POISON2; | |
126 | } | |
127 | ||
128 | /** | |
129 | * list_replace - replace old entry by new one | |
130 | * @old : the element to be replaced | |
131 | * @new : the new element to insert | |
132 | * | |
133 | * If @old was empty, it will be overwritten. | |
134 | */ | |
135 | static inline void list_replace(struct list_head *old, | |
136 | struct list_head *new) | |
137 | { | |
138 | new->next = old->next; | |
139 | new->next->prev = new; | |
140 | new->prev = old->prev; | |
141 | new->prev->next = new; | |
142 | } | |
143 | ||
144 | /** | |
145 | * list_replace_init - replace old entry by new one and initialize the old one | |
146 | * @old : the element to be replaced | |
147 | * @new : the new element to insert | |
148 | * | |
149 | * If @old was empty, it will be overwritten. | |
150 | */ | |
151 | static inline void list_replace_init(struct list_head *old, | |
152 | struct list_head *new) | |
153 | { | |
154 | list_replace(old, new); | |
155 | INIT_LIST_HEAD(old); | |
156 | } | |
157 | ||
158 | /** | |
159 | * list_swap - replace entry1 with entry2 and re-add entry1 at entry2's position | |
160 | * @entry1: the location to place entry2 | |
161 | * @entry2: the location to place entry1 | |
162 | */ | |
163 | static inline void list_swap(struct list_head *entry1, | |
164 | struct list_head *entry2) | |
165 | { | |
166 | struct list_head *pos = entry2->prev; | |
167 | ||
168 | list_del(entry2); | |
169 | list_replace(entry1, entry2); | |
170 | if (pos == entry1) | |
171 | pos = entry2; | |
172 | list_add(entry1, pos); | |
173 | } | |
174 | ||
175 | /** | |
176 | * list_del_init - deletes entry from list and reinitialize it. | |
177 | * @entry: the element to delete from the list. | |
178 | */ | |
179 | static inline void list_del_init(struct list_head *entry) | |
180 | { | |
181 | __list_del_entry(entry); | |
182 | INIT_LIST_HEAD(entry); | |
183 | } | |
184 | ||
185 | /** | |
186 | * list_move - delete from one list and add as another's head | |
187 | * @list: the entry to move | |
188 | * @head: the head that will precede our entry | |
189 | */ | |
190 | static inline void list_move(struct list_head *list, struct list_head *head) | |
191 | { | |
192 | __list_del_entry(list); | |
193 | list_add(list, head); | |
194 | } | |
195 | ||
196 | /** | |
197 | * list_move_tail - delete from one list and add as another's tail | |
198 | * @list: the entry to move | |
199 | * @head: the head that will follow our entry | |
200 | */ | |
201 | static inline void list_move_tail(struct list_head *list, | |
202 | struct list_head *head) | |
203 | { | |
204 | __list_del_entry(list); | |
205 | list_add_tail(list, head); | |
206 | } | |
207 | ||
208 | /** | |
209 | * list_bulk_move_tail - move a subsection of a list to its tail | |
210 | * @head: the head that will follow our entry | |
211 | * @first: first entry to move | |
212 | * @last: last entry to move, can be the same as first | |
213 | * | |
214 | * Move all entries between @first and including @last before @head. | |
215 | * All three entries must belong to the same linked list. | |
216 | */ | |
217 | static inline void list_bulk_move_tail(struct list_head *head, | |
218 | struct list_head *first, | |
219 | struct list_head *last) | |
220 | { | |
221 | first->prev->next = last->next; | |
222 | last->next->prev = first->prev; | |
223 | ||
224 | head->prev->next = first; | |
225 | first->prev = head->prev; | |
226 | ||
227 | last->next = head; | |
228 | head->prev = last; | |
229 | } | |
230 | ||
231 | /** | |
232 | * list_is_first -- tests whether @list is the first entry in list @head | |
233 | * @list: the entry to test | |
234 | * @head: the head of the list | |
235 | */ | |
236 | static inline int list_is_first(const struct list_head *list, | |
237 | const struct list_head *head) | |
238 | { | |
239 | return list->prev == head; | |
240 | } | |
241 | ||
242 | /** | |
243 | * list_is_last - tests whether @list is the last entry in list @head | |
244 | * @list: the entry to test | |
245 | * @head: the head of the list | |
246 | */ | |
247 | static inline int list_is_last(const struct list_head *list, | |
248 | const struct list_head *head) | |
249 | { | |
250 | return list->next == head; | |
251 | } | |
252 | ||
253 | /** | |
254 | * list_empty - tests whether a list is empty | |
255 | * @head: the list to test. | |
256 | */ | |
257 | static inline int list_empty(const struct list_head *head) | |
258 | { | |
259 | return head->next == head; | |
260 | } | |
261 | ||
262 | /** | |
263 | * list_rotate_left - rotate the list to the left | |
264 | * @head: the head of the list | |
265 | */ | |
266 | static inline void list_rotate_left(struct list_head *head) | |
267 | { | |
268 | struct list_head *first; | |
269 | ||
270 | if (!list_empty(head)) { | |
271 | first = head->next; | |
272 | list_move_tail(first, head); | |
273 | } | |
274 | } | |
275 | ||
276 | /** | |
277 | * list_rotate_to_front() - Rotate list to specific item. | |
278 | * @list: The desired new front of the list. | |
279 | * @head: The head of the list. | |
280 | * | |
281 | * Rotates list so that @list becomes the new front of the list. | |
282 | */ | |
283 | static inline void list_rotate_to_front(struct list_head *list, | |
284 | struct list_head *head) | |
285 | { | |
286 | /* | |
287 | * Deletes the list head from the list denoted by @head and | |
288 | * places it as the tail of @list, this effectively rotates the | |
289 | * list so that @list is at the front. | |
290 | */ | |
291 | list_move_tail(head, list); | |
292 | } | |
293 | ||
294 | /** | |
295 | * list_is_singular - tests whether a list has just one entry. | |
296 | * @head: the list to test. | |
297 | */ | |
298 | static inline int list_is_singular(const struct list_head *head) | |
299 | { | |
300 | return !list_empty(head) && (head->next == head->prev); | |
301 | } | |
302 | ||
303 | static inline void __list_cut_position(struct list_head *list, | |
304 | struct list_head *head, struct list_head *entry) | |
305 | { | |
306 | struct list_head *new_first = entry->next; | |
307 | list->next = head->next; | |
308 | list->next->prev = list; | |
309 | list->prev = entry; | |
310 | entry->next = list; | |
311 | head->next = new_first; | |
312 | new_first->prev = head; | |
313 | } | |
314 | ||
315 | /** | |
316 | * list_cut_position - cut a list into two | |
317 | * @list: a new list to add all removed entries | |
318 | * @head: a list with entries | |
319 | * @entry: an entry within head, could be the head itself | |
320 | * and if so we won't cut the list | |
321 | * | |
322 | * This helper moves the initial part of @head, up to and | |
323 | * including @entry, from @head to @list. You should | |
324 | * pass on @entry an element you know is on @head. @list | |
325 | * should be an empty list or a list you do not care about | |
326 | * losing its data. | |
327 | * | |
328 | */ | |
329 | static inline void list_cut_position(struct list_head *list, | |
330 | struct list_head *head, struct list_head *entry) | |
331 | { | |
332 | if (list_empty(head)) | |
333 | return; | |
334 | if (list_is_singular(head) && | |
335 | (head->next != entry && head != entry)) | |
336 | return; | |
337 | if (entry == head) | |
338 | INIT_LIST_HEAD(list); | |
339 | else | |
340 | __list_cut_position(list, head, entry); | |
341 | } | |
342 | ||
343 | /** | |
344 | * list_cut_before - cut a list into two, before given entry | |
345 | * @list: a new list to add all removed entries | |
346 | * @head: a list with entries | |
347 | * @entry: an entry within head, could be the head itself | |
348 | * | |
349 | * This helper moves the initial part of @head, up to but | |
350 | * excluding @entry, from @head to @list. You should pass | |
351 | * in @entry an element you know is on @head. @list should | |
352 | * be an empty list or a list you do not care about losing | |
353 | * its data. | |
354 | * If @entry == @head, all entries on @head are moved to | |
355 | * @list. | |
356 | */ | |
357 | static inline void list_cut_before(struct list_head *list, | |
358 | struct list_head *head, | |
359 | struct list_head *entry) | |
360 | { | |
361 | if (head->next == entry) { | |
362 | INIT_LIST_HEAD(list); | |
363 | return; | |
364 | } | |
365 | list->next = head->next; | |
366 | list->next->prev = list; | |
367 | list->prev = entry->prev; | |
368 | list->prev->next = list; | |
369 | head->next = entry; | |
370 | entry->prev = head; | |
371 | } | |
372 | ||
373 | static inline void __list_splice(const struct list_head *list, | |
374 | struct list_head *prev, | |
375 | struct list_head *next) | |
376 | { | |
377 | struct list_head *first = list->next; | |
378 | struct list_head *last = list->prev; | |
379 | ||
380 | first->prev = prev; | |
381 | prev->next = first; | |
382 | ||
383 | last->next = next; | |
384 | next->prev = last; | |
385 | } | |
386 | ||
387 | /** | |
388 | * list_splice - join two lists, this is designed for stacks | |
389 | * @list: the new list to add. | |
390 | * @head: the place to add it in the first list. | |
391 | */ | |
392 | static inline void list_splice(const struct list_head *list, | |
393 | struct list_head *head) | |
394 | { | |
395 | if (!list_empty(list)) | |
396 | __list_splice(list, head, head->next); | |
397 | } | |
398 | ||
399 | /** | |
400 | * list_splice_tail - join two lists, each list being a queue | |
401 | * @list: the new list to add. | |
402 | * @head: the place to add it in the first list. | |
403 | */ | |
404 | static inline void list_splice_tail(struct list_head *list, | |
405 | struct list_head *head) | |
406 | { | |
407 | if (!list_empty(list)) | |
408 | __list_splice(list, head->prev, head); | |
409 | } | |
410 | ||
411 | /** | |
412 | * list_splice_init - join two lists and reinitialise the emptied list. | |
413 | * @list: the new list to add. | |
414 | * @head: the place to add it in the first list. | |
415 | * | |
416 | * The list at @list is reinitialised | |
417 | */ | |
418 | static inline void list_splice_init(struct list_head *list, | |
419 | struct list_head *head) | |
420 | { | |
421 | if (!list_empty(list)) { | |
422 | __list_splice(list, head, head->next); | |
423 | INIT_LIST_HEAD(list); | |
424 | } | |
425 | } | |
426 | ||
427 | /** | |
428 | * list_splice_tail_init - join two lists and reinitialise the emptied list | |
429 | * @list: the new list to add. | |
430 | * @head: the place to add it in the first list. | |
431 | * | |
432 | * Each of the lists is a queue. | |
433 | * The list at @list is reinitialised | |
434 | */ | |
435 | static inline void list_splice_tail_init(struct list_head *list, | |
436 | struct list_head *head) | |
437 | { | |
438 | if (!list_empty(list)) { | |
439 | __list_splice(list, head->prev, head); | |
440 | INIT_LIST_HEAD(list); | |
441 | } | |
442 | } | |
443 | ||
444 | /** | |
445 | * list_entry - get the struct for this entry | |
446 | * @ptr: the &struct list_head pointer. | |
447 | * @type: the type of the struct this is embedded in. | |
448 | * @member: the name of the list_head within the struct. | |
449 | */ | |
450 | #define list_entry(ptr, type, member) \ | |
451 | container_of(ptr, type, member) | |
452 | ||
453 | /** | |
454 | * list_first_entry - get the first element from a list | |
455 | * @ptr: the list head to take the element from. | |
456 | * @type: the type of the struct this is embedded in. | |
457 | * @member: the name of the list_head within the struct. | |
458 | * | |
459 | * Note, that list is expected to be not empty. | |
460 | */ | |
461 | #define list_first_entry(ptr, type, member) \ | |
462 | list_entry((ptr)->next, type, member) | |
463 | ||
464 | /** | |
465 | * list_last_entry - get the last element from a list | |
466 | * @ptr: the list head to take the element from. | |
467 | * @type: the type of the struct this is embedded in. | |
468 | * @member: the name of the list_head within the struct. | |
469 | * | |
470 | * Note, that list is expected to be not empty. | |
471 | */ | |
472 | #define list_last_entry(ptr, type, member) \ | |
473 | list_entry((ptr)->prev, type, member) | |
474 | ||
475 | /** | |
476 | * list_first_entry_or_null - get the first element from a list | |
477 | * @ptr: the list head to take the element from. | |
478 | * @type: the type of the struct this is embedded in. | |
479 | * @member: the name of the list_head within the struct. | |
480 | * | |
481 | * Note that if the list is empty, it returns NULL. | |
482 | */ | |
483 | #define list_first_entry_or_null(ptr, type, member) ({ \ | |
484 | struct list_head *head__ = (ptr); \ | |
485 | struct list_head *pos__ = head__->next; \ | |
486 | pos__ != head__ ? list_entry(pos__, type, member) : NULL; \ | |
487 | }) | |
488 | ||
489 | /** | |
490 | * list_next_entry - get the next element in list | |
491 | * @pos: the type * to cursor | |
492 | * @member: the name of the list_head within the struct. | |
493 | */ | |
494 | #define list_next_entry(pos, member) \ | |
495 | list_entry((pos)->member.next, typeof(*(pos)), member) | |
496 | ||
497 | /** | |
498 | * list_prev_entry - get the prev element in list | |
499 | * @pos: the type * to cursor | |
500 | * @member: the name of the list_head within the struct. | |
501 | */ | |
502 | #define list_prev_entry(pos, member) \ | |
503 | list_entry((pos)->member.prev, typeof(*(pos)), member) | |
504 | ||
505 | /** | |
506 | * list_for_each - iterate over a list | |
507 | * @pos: the &struct list_head to use as a loop cursor. | |
508 | * @head: the head for your list. | |
509 | */ | |
510 | #define list_for_each(pos, head) \ | |
511 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
512 | ||
513 | /** | |
514 | * list_for_each_continue - continue iteration over a list | |
515 | * @pos: the &struct list_head to use as a loop cursor. | |
516 | * @head: the head for your list. | |
517 | * | |
518 | * Continue to iterate over a list, continuing after the current position. | |
519 | */ | |
520 | #define list_for_each_continue(pos, head) \ | |
521 | for (pos = pos->next; pos != (head); pos = pos->next) | |
522 | ||
523 | /** | |
524 | * list_for_each_prev - iterate over a list backwards | |
525 | * @pos: the &struct list_head to use as a loop cursor. | |
526 | * @head: the head for your list. | |
527 | */ | |
528 | #define list_for_each_prev(pos, head) \ | |
529 | for (pos = (head)->prev; pos != (head); pos = pos->prev) | |
530 | ||
531 | /** | |
532 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
533 | * @pos: the &struct list_head to use as a loop cursor. | |
534 | * @n: another &struct list_head to use as temporary storage | |
535 | * @head: the head for your list. | |
536 | */ | |
537 | #define list_for_each_safe(pos, n, head) \ | |
538 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
539 | pos = n, n = pos->next) | |
540 | ||
541 | /** | |
542 | * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry | |
543 | * @pos: the &struct list_head to use as a loop cursor. | |
544 | * @n: another &struct list_head to use as temporary storage | |
545 | * @head: the head for your list. | |
546 | */ | |
547 | #define list_for_each_prev_safe(pos, n, head) \ | |
548 | for (pos = (head)->prev, n = pos->prev; \ | |
549 | pos != (head); \ | |
550 | pos = n, n = pos->prev) | |
551 | ||
552 | /** | |
553 | * list_entry_is_head - test if the entry points to the head of the list | |
554 | * @pos: the type * to cursor | |
555 | * @head: the head for your list. | |
556 | * @member: the name of the list_head within the struct. | |
557 | */ | |
558 | #define list_entry_is_head(pos, head, member) \ | |
559 | (&pos->member == (head)) | |
560 | ||
561 | /** | |
562 | * list_for_each_entry - iterate over list of given type | |
563 | * @pos: the type * to use as a loop cursor. | |
564 | * @head: the head for your list. | |
565 | * @member: the name of the list_head within the struct. | |
566 | */ | |
567 | #define list_for_each_entry(pos, head, member) \ | |
568 | for (pos = list_first_entry(head, typeof(*pos), member); \ | |
569 | !list_entry_is_head(pos, head, member); \ | |
570 | pos = list_next_entry(pos, member)) | |
571 | ||
572 | /** | |
573 | * list_for_each_entry_reverse - iterate backwards over list of given type. | |
574 | * @pos: the type * to use as a loop cursor. | |
575 | * @head: the head for your list. | |
576 | * @member: the name of the list_head within the struct. | |
577 | */ | |
578 | #define list_for_each_entry_reverse(pos, head, member) \ | |
579 | for (pos = list_last_entry(head, typeof(*pos), member); \ | |
580 | !list_entry_is_head(pos, head, member); \ | |
581 | pos = list_prev_entry(pos, member)) | |
582 | ||
583 | /** | |
584 | * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() | |
585 | * @pos: the type * to use as a start point | |
586 | * @head: the head of the list | |
587 | * @member: the name of the list_head within the struct. | |
588 | * | |
589 | * Prepares a pos entry for use as a start point in list_for_each_entry_continue(). | |
590 | */ | |
591 | #define list_prepare_entry(pos, head, member) \ | |
592 | ((pos) ? : list_entry(head, typeof(*pos), member)) | |
593 | ||
594 | /** | |
595 | * list_for_each_entry_continue - continue iteration over list of given type | |
596 | * @pos: the type * to use as a loop cursor. | |
597 | * @head: the head for your list. | |
598 | * @member: the name of the list_head within the struct. | |
599 | * | |
600 | * Continue to iterate over list of given type, continuing after | |
601 | * the current position. | |
602 | */ | |
603 | #define list_for_each_entry_continue(pos, head, member) \ | |
604 | for (pos = list_next_entry(pos, member); \ | |
605 | !list_entry_is_head(pos, head, member); \ | |
606 | pos = list_next_entry(pos, member)) | |
607 | ||
608 | /** | |
609 | * list_for_each_entry_continue_reverse - iterate backwards from the given point | |
610 | * @pos: the type * to use as a loop cursor. | |
611 | * @head: the head for your list. | |
612 | * @member: the name of the list_head within the struct. | |
613 | * | |
614 | * Start to iterate over list of given type backwards, continuing after | |
615 | * the current position. | |
616 | */ | |
617 | #define list_for_each_entry_continue_reverse(pos, head, member) \ | |
618 | for (pos = list_prev_entry(pos, member); \ | |
619 | !list_entry_is_head(pos, head, member); \ | |
620 | pos = list_prev_entry(pos, member)) | |
621 | ||
622 | /** | |
623 | * list_for_each_entry_from - iterate over list of given type from the current point | |
624 | * @pos: the type * to use as a loop cursor. | |
625 | * @head: the head for your list. | |
626 | * @member: the name of the list_head within the struct. | |
627 | * | |
628 | * Iterate over list of given type, continuing from current position. | |
629 | */ | |
630 | #define list_for_each_entry_from(pos, head, member) \ | |
631 | for (; !list_entry_is_head(pos, head, member); \ | |
632 | pos = list_next_entry(pos, member)) | |
633 | ||
634 | /** | |
635 | * list_for_each_entry_from_reverse - iterate backwards over list of given type | |
636 | * from the current point | |
637 | * @pos: the type * to use as a loop cursor. | |
638 | * @head: the head for your list. | |
639 | * @member: the name of the list_head within the struct. | |
640 | * | |
641 | * Iterate backwards over list of given type, continuing from current position. | |
642 | */ | |
643 | #define list_for_each_entry_from_reverse(pos, head, member) \ | |
644 | for (; !list_entry_is_head(pos, head, member); \ | |
645 | pos = list_prev_entry(pos, member)) | |
646 | ||
647 | /** | |
648 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
649 | * @pos: the type * to use as a loop cursor. | |
650 | * @n: another type * to use as temporary storage | |
651 | * @head: the head for your list. | |
652 | * @member: the name of the list_head within the struct. | |
653 | */ | |
654 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
655 | for (pos = list_first_entry(head, typeof(*pos), member), \ | |
656 | n = list_next_entry(pos, member); \ | |
657 | !list_entry_is_head(pos, head, member); \ | |
658 | pos = n, n = list_next_entry(n, member)) | |
659 | ||
660 | /** | |
661 | * list_for_each_entry_safe_continue - continue list iteration safe against removal | |
662 | * @pos: the type * to use as a loop cursor. | |
663 | * @n: another type * to use as temporary storage | |
664 | * @head: the head for your list. | |
665 | * @member: the name of the list_head within the struct. | |
666 | * | |
667 | * Iterate over list of given type, continuing after current point, | |
668 | * safe against removal of list entry. | |
669 | */ | |
670 | #define list_for_each_entry_safe_continue(pos, n, head, member) \ | |
671 | for (pos = list_next_entry(pos, member), \ | |
672 | n = list_next_entry(pos, member); \ | |
673 | !list_entry_is_head(pos, head, member); \ | |
674 | pos = n, n = list_next_entry(n, member)) | |
675 | ||
676 | /** | |
677 | * list_for_each_entry_safe_from - iterate over list from current point safe against removal | |
678 | * @pos: the type * to use as a loop cursor. | |
679 | * @n: another type * to use as temporary storage | |
680 | * @head: the head for your list. | |
681 | * @member: the name of the list_head within the struct. | |
682 | * | |
683 | * Iterate over list of given type from current point, safe against | |
684 | * removal of list entry. | |
685 | */ | |
686 | #define list_for_each_entry_safe_from(pos, n, head, member) \ | |
687 | for (n = list_next_entry(pos, member); \ | |
688 | !list_entry_is_head(pos, head, member); \ | |
689 | pos = n, n = list_next_entry(n, member)) | |
690 | ||
691 | /** | |
692 | * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal | |
693 | * @pos: the type * to use as a loop cursor. | |
694 | * @n: another type * to use as temporary storage | |
695 | * @head: the head for your list. | |
696 | * @member: the name of the list_head within the struct. | |
697 | * | |
698 | * Iterate backwards over list of given type, safe against removal | |
699 | * of list entry. | |
700 | */ | |
701 | #define list_for_each_entry_safe_reverse(pos, n, head, member) \ | |
702 | for (pos = list_last_entry(head, typeof(*pos), member), \ | |
703 | n = list_prev_entry(pos, member); \ | |
704 | !list_entry_is_head(pos, head, member); \ | |
705 | pos = n, n = list_prev_entry(n, member)) | |
706 | ||
707 | /** | |
708 | * list_safe_reset_next - reset a stale list_for_each_entry_safe loop | |
709 | * @pos: the loop cursor used in the list_for_each_entry_safe loop | |
710 | * @n: temporary storage used in list_for_each_entry_safe | |
711 | * @member: the name of the list_head within the struct. | |
712 | * | |
713 | * list_safe_reset_next is not safe to use in general if the list may be | |
714 | * modified concurrently (eg. the lock is dropped in the loop body). An | |
715 | * exception to this is if the cursor element (pos) is pinned in the list, | |
716 | * and list_safe_reset_next is called after re-taking the lock and before | |
717 | * completing the current iteration of the loop body. | |
718 | */ | |
719 | #define list_safe_reset_next(pos, n, member) \ | |
720 | n = list_next_entry(pos, member) | |
721 | ||
722 | /* | |
723 | * Double linked lists with a single pointer list head. | |
724 | * Mostly useful for hash tables where the two pointer list head is | |
725 | * too wasteful. | |
726 | * You lose the ability to access the tail in O(1). | |
727 | */ | |
728 | ||
729 | #define HLIST_HEAD_INIT { .first = NULL } | |
730 | #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } | |
731 | #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) | |
732 | static inline void INIT_HLIST_NODE(struct hlist_node *h) | |
733 | { | |
734 | h->next = NULL; | |
735 | h->pprev = NULL; | |
736 | } | |
737 | ||
738 | /** | |
739 | * hlist_unhashed - Has node been removed from list and reinitialized? | |
740 | * @h: Node to be checked | |
741 | * | |
742 | * Not that not all removal functions will leave a node in unhashed | |
743 | * state. For example, hlist_nulls_del_init_rcu() does leave the | |
744 | * node in unhashed state, but hlist_nulls_del() does not. | |
745 | */ | |
746 | static inline int hlist_unhashed(const struct hlist_node *h) | |
747 | { | |
748 | return !h->pprev; | |
749 | } | |
750 | ||
751 | /** | |
752 | * hlist_unhashed_lockless - Version of hlist_unhashed for lockless use | |
753 | * @h: Node to be checked | |
754 | */ | |
755 | static inline int hlist_unhashed_lockless(const struct hlist_node *h) | |
756 | { | |
757 | return !h->pprev; | |
758 | } | |
759 | ||
760 | /** | |
761 | * hlist_empty - Is the specified hlist_head structure an empty hlist? | |
762 | * @h: Structure to check. | |
763 | */ | |
764 | static inline int hlist_empty(const struct hlist_head *h) | |
765 | { | |
766 | return !h->first; | |
767 | } | |
768 | ||
769 | static inline void __hlist_del(struct hlist_node *n) | |
770 | { | |
771 | struct hlist_node *next = n->next; | |
772 | struct hlist_node **pprev = n->pprev; | |
773 | ||
774 | *pprev = next; | |
775 | if (next) | |
776 | next->pprev = pprev; | |
777 | } | |
778 | ||
779 | /** | |
780 | * hlist_del - Delete the specified hlist_node from its list | |
781 | * @n: Node to delete. | |
782 | * | |
783 | * Note that this function leaves the node in hashed state. Use | |
784 | * hlist_del_init() or similar instead to unhash @n. | |
785 | */ | |
786 | static inline void hlist_del(struct hlist_node *n) | |
787 | { | |
788 | __hlist_del(n); | |
789 | n->next = LIST_POISON1; | |
790 | n->pprev = LIST_POISON2; | |
791 | } | |
792 | ||
793 | /** | |
794 | * hlist_del_init - Delete the specified hlist_node from its list and initialize | |
795 | * @n: Node to delete. | |
796 | * | |
797 | * Note that this function leaves the node in unhashed state. | |
798 | */ | |
799 | static inline void hlist_del_init(struct hlist_node *n) | |
800 | { | |
801 | if (!hlist_unhashed(n)) { | |
802 | __hlist_del(n); | |
803 | INIT_HLIST_NODE(n); | |
804 | } | |
805 | } | |
806 | ||
807 | /** | |
808 | * hlist_add_head - add a new entry at the beginning of the hlist | |
809 | * @n: new entry to be added | |
810 | * @h: hlist head to add it after | |
811 | * | |
812 | * Insert a new entry after the specified head. | |
813 | * This is good for implementing stacks. | |
814 | */ | |
815 | static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) | |
816 | { | |
817 | struct hlist_node *first = h->first; | |
818 | n->next = first; | |
819 | if (first) | |
820 | first->pprev = &n->next; | |
821 | h->first = n; | |
822 | n->pprev = &h->first; | |
823 | } | |
824 | ||
825 | /** | |
826 | * hlist_add_before - add a new entry before the one specified | |
827 | * @n: new entry to be added | |
828 | * @next: hlist node to add it before, which must be non-NULL | |
829 | */ | |
830 | static inline void hlist_add_before(struct hlist_node *n, | |
831 | struct hlist_node *next) | |
832 | { | |
833 | n->pprev = next->pprev; | |
834 | n->next = next; | |
835 | next->pprev = &n->next; | |
836 | *(n->pprev) = n; | |
837 | } | |
838 | ||
839 | /** | |
840 | * hlist_add_behind - add a new entry after the one specified | |
841 | * @n: new entry to be added | |
842 | * @prev: hlist node to add it after, which must be non-NULL | |
843 | */ | |
844 | static inline void hlist_add_behind(struct hlist_node *n, | |
845 | struct hlist_node *prev) | |
846 | { | |
847 | n->next = prev->next; | |
848 | prev->next = n; | |
849 | n->pprev = &prev->next; | |
850 | ||
851 | if (n->next) | |
852 | n->next->pprev = &n->next; | |
853 | } | |
854 | ||
855 | /** | |
856 | * hlist_add_fake - create a fake hlist consisting of a single headless node | |
857 | * @n: Node to make a fake list out of | |
858 | * | |
859 | * This makes @n appear to be its own predecessor on a headless hlist. | |
860 | * The point of this is to allow things like hlist_del() to work correctly | |
861 | * in cases where there is no list. | |
862 | */ | |
863 | static inline void hlist_add_fake(struct hlist_node *n) | |
864 | { | |
865 | n->pprev = &n->next; | |
866 | } | |
867 | ||
868 | /** | |
869 | * hlist_fake: Is this node a fake hlist? | |
870 | * @h: Node to check for being a self-referential fake hlist. | |
871 | */ | |
872 | static inline bool hlist_fake(struct hlist_node *h) | |
873 | { | |
874 | return h->pprev == &h->next; | |
875 | } | |
876 | ||
877 | /** | |
878 | * hlist_is_singular_node - is node the only element of the specified hlist? | |
879 | * @n: Node to check for singularity. | |
880 | * @h: Header for potentially singular list. | |
881 | * | |
882 | * Check whether the node is the only node of the head without | |
883 | * accessing head, thus avoiding unnecessary cache misses. | |
884 | */ | |
885 | static inline bool | |
886 | hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h) | |
887 | { | |
888 | return !n->next && n->pprev == &h->first; | |
889 | } | |
890 | ||
891 | /** | |
892 | * hlist_move_list - Move an hlist | |
893 | * @old: hlist_head for old list. | |
894 | * @new: hlist_head for new list. | |
895 | * | |
896 | * Move a list from one list head to another. Fixup the pprev | |
897 | * reference of the first entry if it exists. | |
898 | */ | |
899 | static inline void hlist_move_list(struct hlist_head *old, | |
900 | struct hlist_head *new) | |
901 | { | |
902 | new->first = old->first; | |
903 | if (new->first) | |
904 | new->first->pprev = &new->first; | |
905 | old->first = NULL; | |
906 | } | |
907 | ||
908 | #define hlist_entry(ptr, type, member) container_of(ptr,type,member) | |
909 | ||
910 | #define hlist_for_each(pos, head) \ | |
911 | for (pos = (head)->first; pos ; pos = pos->next) | |
912 | ||
913 | #define hlist_for_each_safe(pos, n, head) \ | |
914 | for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ | |
915 | pos = n) | |
916 | ||
917 | #define hlist_entry_safe(ptr, type, member) \ | |
918 | ({ typeof(ptr) ____ptr = (ptr); \ | |
919 | ____ptr ? hlist_entry(____ptr, type, member) : NULL; \ | |
920 | }) | |
921 | ||
922 | /** | |
923 | * hlist_for_each_entry - iterate over list of given type | |
924 | * @pos: the type * to use as a loop cursor. | |
925 | * @head: the head for your list. | |
926 | * @member: the name of the hlist_node within the struct. | |
927 | */ | |
928 | #define hlist_for_each_entry(pos, head, member) \ | |
929 | for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\ | |
930 | pos; \ | |
931 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
932 | ||
933 | /** | |
934 | * hlist_for_each_entry_continue - iterate over a hlist continuing after current point | |
935 | * @pos: the type * to use as a loop cursor. | |
936 | * @member: the name of the hlist_node within the struct. | |
937 | */ | |
938 | #define hlist_for_each_entry_continue(pos, member) \ | |
939 | for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\ | |
940 | pos; \ | |
941 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
942 | ||
943 | /** | |
944 | * hlist_for_each_entry_from - iterate over a hlist continuing from current point | |
945 | * @pos: the type * to use as a loop cursor. | |
946 | * @member: the name of the hlist_node within the struct. | |
947 | */ | |
948 | #define hlist_for_each_entry_from(pos, member) \ | |
949 | for (; pos; \ | |
950 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
951 | ||
952 | /** | |
953 | * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
954 | * @pos: the type * to use as a loop cursor. | |
955 | * @n: a &struct hlist_node to use as temporary storage | |
956 | * @head: the head for your list. | |
957 | * @member: the name of the hlist_node within the struct. | |
958 | */ | |
959 | #define hlist_for_each_entry_safe(pos, n, head, member) \ | |
960 | for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\ | |
961 | pos && ({ n = pos->member.next; 1; }); \ | |
962 | pos = hlist_entry_safe(n, typeof(*pos), member)) | |
963 | ||
d696c45e CB |
964 | #define list_len(pos, head, member) \ |
965 | ({ \ | |
966 | size_t __list_len__ = 0; \ | |
967 | \ | |
968 | list_for_each_entry(pos, head, member) { \ | |
969 | (__list_len__)++; \ | |
970 | } \ | |
971 | \ | |
972 | __list_len__; \ | |
973 | }) | |
87d0990c | 974 | |
4780b5e7 | 975 | #endif /* __LXC_HLIST_H */ |