io-wq: wqe and worker locks no longer need to be IRQ safe

io_uring no longer queues async work off completion handlers that run in
hard or soft interrupt context, and that use case was the only reason that
io-wq had to use IRQ safe locks for wqe and worker locks.

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

diff --git a/fs/io-wq.c b/fs/io-wq.c
index da3ad45..13aeb48 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -178,7 +178,7 @@ static void io_worker_exit(struct io_worker *worker)
                complete(&worker->ref_done);
        wait_for_completion(&worker->ref_done);
 
-       raw_spin_lock_irq(&wqe->lock);
+       raw_spin_lock(&wqe->lock);
        if (worker->flags & IO_WORKER_F_FREE)
                hlist_nulls_del_rcu(&worker->nulls_node);
        list_del_rcu(&worker->all_list);
@@ -188,7 +188,7 @@ static void io_worker_exit(struct io_worker *worker)
        worker->flags = 0;
        current->flags &= ~PF_IO_WORKER;
        preempt_enable();
-       raw_spin_unlock_irq(&wqe->lock);
+       raw_spin_unlock(&wqe->lock);
 
        kfree_rcu(worker, rcu);
        io_worker_ref_put(wqe->wq);
@@ -254,14 +254,14 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
        if (!ret) {
                bool do_create = false, first = false;
 
-               raw_spin_lock_irq(&wqe->lock);
+               raw_spin_lock(&wqe->lock);
                if (acct->nr_workers < acct->max_workers) {
                        if (!acct->nr_workers)
                                first = true;
                        acct->nr_workers++;
                        do_create = true;
                }
-               raw_spin_unlock_irq(&wqe->lock);
+               raw_spin_unlock(&wqe->lock);
                if (do_create) {
                        atomic_inc(&acct->nr_running);
                        atomic_inc(&wqe->wq->worker_refs);
@@ -289,14 +289,14 @@ static void create_worker_cb(struct callback_head *cb)
        wqe = worker->wqe;
        wq = wqe->wq;
        acct = &wqe->acct[worker->create_index];
-       raw_spin_lock_irq(&wqe->lock);
+       raw_spin_lock(&wqe->lock);
        if (acct->nr_workers < acct->max_workers) {
                if (!acct->nr_workers)
                        first = true;
                acct->nr_workers++;
                do_create = true;
        }
-       raw_spin_unlock_irq(&wqe->lock);
+       raw_spin_unlock(&wqe->lock);
        if (do_create) {
                create_io_worker(wq, wqe, worker->create_index, first);
        } else {
@@ -510,9 +510,9 @@ static void io_assign_current_work(struct io_worker *worker,
                cond_resched();
        }
 
-       spin_lock_irq(&worker->lock);
+       spin_lock(&worker->lock);
        worker->cur_work = work;
-       spin_unlock_irq(&worker->lock);
+       spin_unlock(&worker->lock);
 }
 
 static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
@@ -542,7 +542,7 @@ get_next:
                else if (stalled)
                        wqe->flags |= IO_WQE_FLAG_STALLED;
 
-               raw_spin_unlock_irq(&wqe->lock);
+               raw_spin_unlock(&wqe->lock);
                if (!work)
                        break;
                io_assign_current_work(worker, work);
@@ -574,16 +574,16 @@ get_next:
                                clear_bit(hash, &wq->hash->map);
                                if (wq_has_sleeper(&wq->hash->wait))
                                        wake_up(&wq->hash->wait);
-                               raw_spin_lock_irq(&wqe->lock);
+                               raw_spin_lock(&wqe->lock);
                                wqe->flags &= ~IO_WQE_FLAG_STALLED;
                                /* skip unnecessary unlock-lock wqe->lock */
                                if (!work)
                                        goto get_next;
-                               raw_spin_unlock_irq(&wqe->lock);
+                               raw_spin_unlock(&wqe->lock);
                        }
                } while (work);
 
-               raw_spin_lock_irq(&wqe->lock);
+               raw_spin_lock(&wqe->lock);
        } while (1);
 }
 
@@ -604,13 +604,13 @@ static int io_wqe_worker(void *data)
 
                set_current_state(TASK_INTERRUPTIBLE);
 loop:
-               raw_spin_lock_irq(&wqe->lock);
+               raw_spin_lock(&wqe->lock);
                if (io_wqe_run_queue(wqe)) {
                        io_worker_handle_work(worker);
                        goto loop;
                }
                __io_worker_idle(wqe, worker);
-               raw_spin_unlock_irq(&wqe->lock);
+               raw_spin_unlock(&wqe->lock);
                if (io_flush_signals())
                        continue;
                ret = schedule_timeout(WORKER_IDLE_TIMEOUT);
@@ -629,7 +629,7 @@ loop:
        }
 
        if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-               raw_spin_lock_irq(&wqe->lock);
+               raw_spin_lock(&wqe->lock);
                io_worker_handle_work(worker);
        }
 
@@ -671,9 +671,9 @@ void io_wq_worker_sleeping(struct task_struct *tsk)
 
        worker->flags &= ~IO_WORKER_F_RUNNING;
 
-       raw_spin_lock_irq(&worker->wqe->lock);
+       raw_spin_lock(&worker->wqe->lock);
        io_wqe_dec_running(worker);
-       raw_spin_unlock_irq(&worker->wqe->lock);
+       raw_spin_unlock(&worker->wqe->lock);
 }
 
 static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index, bool first)
@@ -699,9 +699,9 @@ static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index, bo
                kfree(worker);
 fail:
                atomic_dec(&acct->nr_running);
-               raw_spin_lock_irq(&wqe->lock);
+               raw_spin_lock(&wqe->lock);
                acct->nr_workers--;
-               raw_spin_unlock_irq(&wqe->lock);
+               raw_spin_unlock(&wqe->lock);
                io_worker_ref_put(wq);
                return;
        }
@@ -711,7 +711,7 @@ fail:
        set_cpus_allowed_ptr(tsk, wqe->cpu_mask);
        tsk->flags |= PF_NO_SETAFFINITY;
 
-       raw_spin_lock_irq(&wqe->lock);
+       raw_spin_lock(&wqe->lock);
        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;
@@ -719,7 +719,7 @@ fail:
                worker->flags |= IO_WORKER_F_BOUND;
        if (first && (worker->flags & IO_WORKER_F_BOUND))
                worker->flags |= IO_WORKER_F_FIXED;
-       raw_spin_unlock_irq(&wqe->lock);
+       raw_spin_unlock(&wqe->lock);
        wake_up_new_task(tsk);
 }
 
@@ -795,7 +795,6 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
 {
        struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
        int work_flags;
-       unsigned long flags;
 
        /*
         * If io-wq is exiting for this task, or if the request has explicitly
@@ -808,10 +807,10 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
        }
 
        work_flags = work->flags;
-       raw_spin_lock_irqsave(&wqe->lock, flags);
+       raw_spin_lock(&wqe->lock);
        io_wqe_insert_work(wqe, work);
        wqe->flags &= ~IO_WQE_FLAG_STALLED;
-       raw_spin_unlock_irqrestore(&wqe->lock, flags);
+       raw_spin_unlock(&wqe->lock);
 
        if ((work_flags & IO_WQ_WORK_CONCURRENT) ||
            !atomic_read(&acct->nr_running))
@@ -840,19 +839,18 @@ void io_wq_hash_work(struct io_wq_work *work, void *val)
 static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
 {
        struct io_cb_cancel_data *match = data;
-       unsigned long flags;
 
        /*
         * Hold the lock to avoid ->cur_work going out of scope, caller
         * may dereference the passed in work.
         */
-       spin_lock_irqsave(&worker->lock, flags);
+       spin_lock(&worker->lock);
        if (worker->cur_work &&
            match->fn(worker->cur_work, match->data)) {
                set_notify_signal(worker->task);
                match->nr_running++;
        }
-       spin_unlock_irqrestore(&worker->lock, flags);
+       spin_unlock(&worker->lock);
 
        return match->nr_running && !match->cancel_all;
 }
@@ -880,16 +878,15 @@ static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
 {
        struct io_wq_work_node *node, *prev;
        struct io_wq_work *work;
-       unsigned long flags;
 
 retry:
-       raw_spin_lock_irqsave(&wqe->lock, flags);
+       raw_spin_lock(&wqe->lock);
        wq_list_for_each(node, prev, &wqe->work_list) {
                work = container_of(node, struct io_wq_work, list);
                if (!match->fn(work, match->data))
                        continue;
                io_wqe_remove_pending(wqe, work, prev);
-               raw_spin_unlock_irqrestore(&wqe->lock, flags);
+               raw_spin_unlock(&wqe->lock);
                io_run_cancel(work, wqe);
                match->nr_pending++;
                if (!match->cancel_all)
@@ -898,7 +895,7 @@ retry:
                /* not safe to continue after unlock */
                goto retry;
        }
-       raw_spin_unlock_irqrestore(&wqe->lock, flags);
+       raw_spin_unlock(&wqe->lock);
 }
 
 static void io_wqe_cancel_running_work(struct io_wqe *wqe,