All the way back in 2013, the linux kernel updated the four
hlist_for_each_entry* iterators to require one less auxiliary
variable:
commit b67bfe0d42cac56c512dd5da4b1b347a23f4b70a
Author: Sasha Levin <sasha.le...@oracle.com>
Date: Wed Feb 27 17:06:00 2013 -0800
hlist: drop the node parameter from iterators
Currently, there is only one "user" of any of these, namely in
fs/ubifs/super.c, but that actually uses the "new-style" form, and
is (obviously, or it wouldn't have built) inside #ifndef __UBOOT__.
Before adding actual users of these, import the version as of linux
v6.1-rc1, including the hlist_entry_safe() helper used by the new
versions.
Signed-off-by: Rasmus Villemoes <rasmus.villem...@prevas.dk>
---
include/linux/list.h | 53 +++++++++++++++++++++-----------------------
1 file changed, 25 insertions(+), 28 deletions(-)
diff --git a/include/linux/list.h b/include/linux/list.h
index 3eacf68e3a..6910721c00 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -646,54 +646,51 @@ static inline void hlist_add_after(struct hlist_node *n,
for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
pos = n)
+#define hlist_entry_safe(ptr, type, member) \
+ ({ typeof(ptr) ____ptr = (ptr); \
+ ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
+ })
+
/**
* hlist_for_each_entry - iterate over list of given type
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry(tpos, pos, head, member) \
- for (pos = (head)->first; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry(pos, head, member)
\
+ for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
+ pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_continue - iterate over a hlist continuing after
current point
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_continue(tpos, pos, member) \
- for (pos = (pos)->next; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry_continue(pos, member) \
+ for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)),
member);\
+ pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_from - iterate over a hlist continuing from current
point
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_from(tpos, pos, member) \
- for (; pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry_from(pos, member) \
+ for (; pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_safe - iterate over list of given type safe against
removal of list entry
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
- * @n: another &struct hlist_node to use as temporary storage
+ * @pos: the type * to use as a loop cursor.
+ * @n: a &struct hlist_node to use as temporary storage
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
- for (pos = (head)->first; \
- pos && ({ n = pos->next; 1; }) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = n)
+#define hlist_for_each_entry_safe(pos, n, head, member) \
+ for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
+ pos && ({ n = pos->member.next; 1; }); \
+ pos = hlist_entry_safe(n, typeof(*pos), member))
#endif
