| Message ID | 20191015154927.GL18794@devbig004.ftw2.facebook.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [block/for-linus] blk-rq-qos: fix first node deletion of rq_qos_del() | expand |
On 10/15/19 9:49 AM, Tejun Heo wrote: > rq_qos_del() incorrectly assigns the node being deleted to the head if > it was the first on the list in the !prev path. Fix it by iterating > with ** instead. Well, that's unfortunate... Applied.
--- a/block/blk-rq-qos.h +++ b/block/blk-rq-qos.h @@ -108,16 +108,13 @@ static inline void rq_qos_add(struct req static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) { - struct rq_qos *cur, *prev = NULL; - for (cur = q->rq_qos; cur; cur = cur->next) { - if (cur == rqos) { - if (prev) - prev->next = rqos->next; - else - q->rq_qos = cur; + struct rq_qos **cur; + + for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { + if (*cur == rqos) { + *cur = rqos->next; break; } - prev = cur; } blk_mq_debugfs_unregister_rqos(rqos);
rq_qos_del() incorrectly assigns the node being deleted to the head if it was the first on the list in the !prev path. Fix it by iterating with ** instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org # v4.19+ --- block/blk-rq-qos.h | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)