io-wq: remove unused busy list from io_sqe

Commit 5546fb621638 ("io-wq: ensure free/busy list browsing see all
items") added a list for io workers in addition to the free and busy
lists, not only making worker walk cleaner, but leaving the busy list
unused. Let's remove it.

Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 11e80b7252a82cefaf12d56e792f9b679e2f5a13..a1c85458f021ab94da9681632fac20f37b4ec529 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -92,7 +92,6 @@ struct io_wqe {
        struct io_wqe_acct acct[2];
 
        struct hlist_nulls_head free_list;
-       struct hlist_nulls_head busy_list;
        struct list_head all_list;
 
        struct io_wq *wq;
@@ -327,7 +326,6 @@ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
        if (worker->flags & IO_WORKER_F_FREE) {
                worker->flags &= ~IO_WORKER_F_FREE;
                hlist_nulls_del_init_rcu(&worker->nulls_node);
-               hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->busy_list);
        }
 
        /*
@@ -365,7 +363,6 @@ static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
 {
        if (!(worker->flags & IO_WORKER_F_FREE)) {
                worker->flags |= IO_WORKER_F_FREE;
-               hlist_nulls_del_init_rcu(&worker->nulls_node);
                hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
        }
 
@@ -798,10 +795,6 @@ void io_wq_cancel_all(struct io_wq *wq)
 
        set_bit(IO_WQ_BIT_CANCEL, &wq->state);
 
-       /*
-        * Browse both lists, as there's a gap between handing work off
-        * to a worker and the worker putting itself on the busy_list
-        */
        rcu_read_lock();
        for_each_node(node) {
                struct io_wqe *wqe = wq->wqes[node];
@@ -1049,7 +1042,6 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
                spin_lock_init(&wqe->lock);
                INIT_WQ_LIST(&wqe->work_list);
                INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
-               INIT_HLIST_NULLS_HEAD(&wqe->busy_list, 1);
                INIT_LIST_HEAD(&wqe->all_list);
        }