Byungchul Park <byungchul.p...@lge.com> writes: > Sometimes we have to dereference next field of llist node before entering > loop becasue the node might be deleted or the next field might be > modified within the loop. So this adds the safe version of llist_for_each, > that is, llist_for_each_safe. > > Signed-off-by: Byungchul Park <byungchul.p...@lge.com>
Reviewed-by: "Huang, Ying" <ying.hu...@intel.com> Best Regards, Huang, Ying > --- > include/linux/llist.h | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/include/linux/llist.h b/include/linux/llist.h > index fd4ca0b..b90c9f2 100644 > --- a/include/linux/llist.h > +++ b/include/linux/llist.h > @@ -105,6 +105,25 @@ static inline void init_llist_head(struct llist_head > *list) > for ((pos) = (node); pos; (pos) = (pos)->next) > > /** > + * llist_for_each_safe - iterate over some deleted entries of a lock-less > list > + * safe against removal of list entry > + * @pos: the &struct llist_node to use as a loop cursor > + * @n: another &struct llist_node to use as temporary storage > + * @node: the first entry of deleted list entries > + * > + * In general, some entries of the lock-less list can be traversed > + * safely only after being deleted from list, so start with an entry > + * instead of list head. > + * > + * If being used on entries deleted from lock-less list directly, the > + * traverse order is from the newest to the oldest added entry. If > + * you want to traverse from the oldest to the newest, you must > + * reverse the order by yourself before traversing. > + */ > +#define llist_for_each_safe(pos, n, node) \ > + for ((pos) = (node); (pos) && ((n) = (pos)->next, true); (pos) = (n)) > + > +/** > * llist_for_each_entry - iterate over some deleted entries of lock-less > list of given type > * @pos: the type * to use as a loop cursor. > * @node: the fist entry of deleted list entries.
