On Mon, Feb 13, 2017 at 03:36:33PM +0800, Huang, Ying wrote: > 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> > > --- > > include/linux/llist.h | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/include/linux/llist.h b/include/linux/llist.h > > index fd4ca0b..4c508a5 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 type * to use as temporary storage > > s/type */&struct llist_node/
Yes. > > > + * @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)) > > + > > Following the style of other xxx_for_each_safe, > > #define llist_for_each_safe(pos, n, node) \ > for (pos = (node), (pos && (n = pos->next)); pos; pos = n, n = > pos->next) Do you think it should be modified? I think mine is simpler. No? > > Best Regards, > Huang, Ying > > > +/** > > * 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.
