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			If io_uring.o is built with W=1, it triggers a warning:
io_uring/io_uring.c: In function ‘__io_submit_flush_completions’:
io_uring/io_uring.c:1502:40: warning: variable ‘prev’ set but not used [-Wunused-but-set-variable]
 1502 |         struct io_wq_work_node *node, *prev;
      |                                        ^~~~
which is due to the wq_list_for_each() iterator always keeping a 'prev'
variable. Most users need this to remove an entry from a list, for
example, but __io_submit_flush_completions() never does that.
Add a basic helper that doesn't track prev instead, and use that in
that function.
Reported-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
		
	
			
		
			
				
	
	
		
			119 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			119 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef INTERNAL_IO_SLIST_H
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| #define INTERNAL_IO_SLIST_H
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| 
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| #include <linux/io_uring_types.h>
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| 
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| #define __wq_list_for_each(pos, head)				\
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| 	for (pos = (head)->first; pos; pos = (pos)->next)
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| 
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| #define wq_list_for_each(pos, prv, head)			\
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| 	for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
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| 
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| #define wq_list_for_each_resume(pos, prv)			\
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| 	for (; pos; prv = pos, pos = (pos)->next)
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| 
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| #define wq_list_empty(list)	(READ_ONCE((list)->first) == NULL)
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| 
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| #define INIT_WQ_LIST(list)	do {				\
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| 	(list)->first = NULL;					\
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| } while (0)
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| 
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| static inline void wq_list_add_after(struct io_wq_work_node *node,
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| 				     struct io_wq_work_node *pos,
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| 				     struct io_wq_work_list *list)
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| {
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| 	struct io_wq_work_node *next = pos->next;
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| 
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| 	pos->next = node;
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| 	node->next = next;
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| 	if (!next)
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| 		list->last = node;
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| }
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| 
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| static inline void wq_list_add_tail(struct io_wq_work_node *node,
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| 				    struct io_wq_work_list *list)
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| {
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| 	node->next = NULL;
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| 	if (!list->first) {
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| 		list->last = node;
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| 		WRITE_ONCE(list->first, node);
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| 	} else {
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| 		list->last->next = node;
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| 		list->last = node;
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| 	}
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| }
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| 
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| static inline void wq_list_add_head(struct io_wq_work_node *node,
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| 				    struct io_wq_work_list *list)
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| {
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| 	node->next = list->first;
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| 	if (!node->next)
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| 		list->last = node;
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| 	WRITE_ONCE(list->first, node);
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| }
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| 
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| static inline void wq_list_cut(struct io_wq_work_list *list,
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| 			       struct io_wq_work_node *last,
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| 			       struct io_wq_work_node *prev)
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| {
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| 	/* first in the list, if prev==NULL */
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| 	if (!prev)
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| 		WRITE_ONCE(list->first, last->next);
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| 	else
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| 		prev->next = last->next;
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| 
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| 	if (last == list->last)
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| 		list->last = prev;
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| 	last->next = NULL;
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| }
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| 
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| static inline void __wq_list_splice(struct io_wq_work_list *list,
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| 				    struct io_wq_work_node *to)
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| {
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| 	list->last->next = to->next;
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| 	to->next = list->first;
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| 	INIT_WQ_LIST(list);
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| }
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| 
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| static inline bool wq_list_splice(struct io_wq_work_list *list,
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| 				  struct io_wq_work_node *to)
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| {
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| 	if (!wq_list_empty(list)) {
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| 		__wq_list_splice(list, to);
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| 		return true;
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| 	}
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| 	return false;
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| }
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| 
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| static inline void wq_stack_add_head(struct io_wq_work_node *node,
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| 				     struct io_wq_work_node *stack)
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| {
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| 	node->next = stack->next;
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| 	stack->next = node;
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| }
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| 
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| static inline void wq_list_del(struct io_wq_work_list *list,
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| 			       struct io_wq_work_node *node,
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| 			       struct io_wq_work_node *prev)
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| {
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| 	wq_list_cut(list, node, prev);
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| }
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| 
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| static inline
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| struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
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| {
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| 	struct io_wq_work_node *node = stack->next;
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| 
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| 	stack->next = node->next;
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| 	return node;
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| }
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| 
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| static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
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| {
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| 	if (!work->list.next)
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| 		return NULL;
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| 
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| 	return container_of(work->list.next, struct io_wq_work, list);
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| }
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| 
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| #endif // INTERNAL_IO_SLIST_H
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