[PATCH] Add list_for_each_entry_safe_reverse()

Add list_for_each_entry_safe_reverse() to linux/list.h

This is needed by unmerged cachefs and be an as-yet-unreviewed
device_shutdown() fix.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index 8e3388284530..945daa1f13dd 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -436,6 +436,20 @@ static inline void list_splice_init(struct list_head *list,
              pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
+ * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against
+ *                                    removal of list entry
+ * @pos:        the type * to use as a loop counter.
+ * @n:          another type * to use as temporary storage
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe_reverse(pos, n, head, member)          \
+        for (pos = list_entry((head)->prev, typeof(*pos), member),      \
+                n = list_entry(pos->member.prev, typeof(*pos), member); \
+             &pos->member != (head);                                    \
+             pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+
+/**
  * list_for_each_rcu    -       iterate over an rcu-protected list
  * @pos:        the &struct list_head to use as a loop counter.
  * @head:       the head for your list.