Commit 2b529089 authored by Cody P Schafer's avatar Cody P Schafer Committed by Linus Torvalds
Browse files

rbtree: add rbtree_postorder_for_each_entry_safe() helper 



Because deletion (of the entire tree) is a relatively common use of the
rbtree_postorder iteration, and because doing it safely means fiddling
with temporary storage, provide a helper to simplify postorder rbtree
iteration.

Signed-off-by: default avatarCody P Schafer <cody@linux.vnet.ibm.com>
Reviewed-by: default avatarSeth Jennings <sjenning@linux.vnet.ibm.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9dee5c51

include/linux/rbtree.h

+18 −0
Original line number Diff line number Diff line
@@ -85,4 +85,22 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, 
	*rb_link = node;

}



/**

 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of

 * given type safe against removal of rb_node entry

 *

 * @pos:	the 'type *' to use as a loop cursor.

 * @n:		another 'type *' to use as temporary storage

 * @root:	'rb_root *' of the rbtree.

 * @field:	the name of the rb_node field within 'type'.

 */

#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \

	for (pos = rb_entry(rb_first_postorder(root), typeof(*pos), field),\

		n = rb_entry(rb_next_postorder(&pos->field), \

			typeof(*pos), field); \

	     &pos->field; \

	     pos = n, \

		n = rb_entry(rb_next_postorder(&pos->field), \

			typeof(*pos), field))



#endif	/* _LINUX_RBTREE_H */