rculist: add list_for_each_entry_from_rcu()

list_for_each_entry_from_rcu() is an RCU version of
list_for_each_entry_from().  It walks a linked list under rcu
protection, from a given start point.

It is similar to list_for_each_entry_continue_rcu() but starts *at*
the given position rather than *after* it.

Naturally, the start point must be known to be in the list.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
NeilBrown 2018-04-30 14:31:30 +10:00 committed by Trond Myklebust
parent 3ca951b618
commit ead9ad7253

View File

@ -403,6 +403,19 @@ static inline void list_splice_tail_init_rcu(struct list_head *list,
&pos->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_from_rcu - iterate over a list from current point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_node within the struct.
*
* Iterate over the tail of a list starting from a given position,
* which must have been in the list when the RCU read lock was taken.
*/
#define list_for_each_entry_from_rcu(pos, head, member) \
for (; &(pos)->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*(pos)), member))
/**
* hlist_del_rcu - deletes entry from hash list without re-initialization
* @n: the element to delete from the hash list.