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.levin@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.villemoes@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