block: introduce rq_list_for_each_safe macro

While iterating a list, a particular request may need to be removed for
special handling. Provide an iterator that can safely handle that.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220105170518.3181469-3-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch 2022-01-05 09:05:16 -08:00 committed by Jens Axboe
parent edce22e19b
commit 3764fd05e1
1 changed files with 4 additions and 0 deletions

View File

@ -242,6 +242,10 @@ static inline unsigned short req_get_ioprio(struct request *req)
#define rq_list_for_each(listptr, pos) \
for (pos = rq_list_peek((listptr)); pos; pos = rq_list_next(pos))
#define rq_list_for_each_safe(listptr, pos, nxt) \
for (pos = rq_list_peek((listptr)), nxt = rq_list_next(pos); \
pos; pos = nxt, nxt = pos ? rq_list_next(pos) : NULL)
#define rq_list_next(rq) (rq)->rq_next
#define rq_list_empty(list) ((list) == (struct request *) NULL)