io-wq: remove now redundant struct io_wq_nulls_list

Since we don't iterate these lists anymore after commit:

e61df66c69b1 ("io-wq: ensure free/busy list browsing see all items")

we don't need to retain the nulls value we use for them. That means it's
pretty pointless to wrap the hlist_nulls_head in a structure, so get rid
of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io-wq.c b/fs/io-wq.c
index fcb6c74209dafa6230ba34f1ac03109945a1698f..9174007ce107b6ff9034e44001e1b89c14c22c5b 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -59,11 +59,6 @@ struct io_worker {
        struct files_struct *restore_files;
 };
 
-struct io_wq_nulls_list {
-       struct hlist_nulls_head head;
-       unsigned long nulls;
-};
-
 #if BITS_PER_LONG == 64
 #define IO_WQ_HASH_ORDER       6
 #else
@@ -95,8 +90,8 @@ struct io_wqe {
        int node;
        struct io_wqe_acct acct[2];
 
-       struct io_wq_nulls_list free_list;
-       struct io_wq_nulls_list busy_list;
+       struct hlist_nulls_head free_list;
+       struct hlist_nulls_head busy_list;
        struct list_head all_list;
 
        struct io_wq *wq;
@@ -249,7 +244,7 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
        struct hlist_nulls_node *n;
        struct io_worker *worker;
 
-       n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list.head));
+       n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list));
        if (is_a_nulls(n))
                return false;
 
@@ -325,8 +320,7 @@ 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.head);
+               hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->busy_list);
        }
 
        /*
@@ -365,8 +359,7 @@ 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.head);
+               hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
        }
 
        return __io_worker_unuse(wqe, worker);
@@ -592,7 +585,7 @@ static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
        }
 
        spin_lock_irq(&wqe->lock);
-       hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list.head);
+       hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
        list_add_tail_rcu(&worker->all_list, &wqe->all_list);
        worker->flags |= IO_WORKER_F_FREE;
        if (index == IO_WQ_ACCT_BOUND)
@@ -617,7 +610,7 @@ static inline bool io_wqe_need_worker(struct io_wqe *wqe, int index)
        if (index == IO_WQ_ACCT_BOUND && !acct->nr_workers)
                return true;
        /* if we have available workers or no work, no need */
-       if (!hlist_nulls_empty(&wqe->free_list.head) || !io_wqe_run_queue(wqe))
+       if (!hlist_nulls_empty(&wqe->free_list) || !io_wqe_run_queue(wqe))
                return false;
        return acct->nr_workers < acct->max_workers;
 }
@@ -665,7 +658,7 @@ static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct,
                return true;
 
        rcu_read_lock();
-       free_worker = !hlist_nulls_empty(&wqe->free_list.head);
+       free_worker = !hlist_nulls_empty(&wqe->free_list);
        rcu_read_unlock();
        if (free_worker)
                return true;
@@ -1009,10 +1002,8 @@ struct io_wq *io_wq_create(unsigned bounded, struct mm_struct *mm,
                wqe->wq = wq;
                spin_lock_init(&wqe->lock);
                INIT_LIST_HEAD(&wqe->work_list);
-               INIT_HLIST_NULLS_HEAD(&wqe->free_list.head, 0);
-               wqe->free_list.nulls = 0;
-               INIT_HLIST_NULLS_HEAD(&wqe->busy_list.head, 1);
-               wqe->busy_list.nulls = 1;
+               INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
+               INIT_HLIST_NULLS_HEAD(&wqe->busy_list, 1);
                INIT_LIST_HEAD(&wqe->all_list);
 
                i++;