diff --git a/fs/io-wq.c b/fs/io-wq.c index bb7f161bb19c..9595616ccaa3 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -76,6 +76,7 @@ struct io_wqe_acct { unsigned max_workers; int index; atomic_t nr_running; + raw_spinlock_t lock; struct io_wq_work_list work_list; unsigned long flags; }; @@ -224,12 +225,12 @@ static void io_worker_exit(struct io_worker *worker) if (worker->flags & IO_WORKER_F_FREE) hlist_nulls_del_rcu(&worker->nulls_node); list_del_rcu(&worker->all_list); - preempt_disable(); + raw_spin_unlock(&wqe->lock); io_wqe_dec_running(worker); worker->flags = 0; + preempt_disable(); current->flags &= ~PF_IO_WORKER; preempt_enable(); - raw_spin_unlock(&wqe->lock); kfree_rcu(worker, rcu); io_worker_ref_put(wqe->wq); @@ -385,7 +386,6 @@ fail: } static void io_wqe_dec_running(struct io_worker *worker) - __must_hold(wqe->lock) { struct io_wqe_acct *acct = io_wqe_get_acct(worker); struct io_wqe *wqe = worker->wqe; @@ -393,13 +393,18 @@ static void io_wqe_dec_running(struct io_worker *worker) if (!(worker->flags & IO_WORKER_F_UP)) return; - if (atomic_dec_and_test(&acct->nr_running) && io_acct_run_queue(acct)) { - atomic_inc(&acct->nr_running); - atomic_inc(&wqe->wq->worker_refs); + if (!atomic_dec_and_test(&acct->nr_running)) + return; + raw_spin_lock(&wqe->lock); + if (!io_acct_run_queue(acct)) { raw_spin_unlock(&wqe->lock); - io_queue_worker_create(worker, acct, create_worker_cb); - raw_spin_lock(&wqe->lock); + return; } + + raw_spin_unlock(&wqe->lock); + atomic_inc(&acct->nr_running); + atomic_inc(&wqe->wq->worker_refs); + io_queue_worker_create(worker, acct, create_worker_cb); } /* @@ -407,11 +412,12 @@ static void io_wqe_dec_running(struct io_worker *worker) * it's currently on the freelist */ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker) - __must_hold(wqe->lock) { if (worker->flags & IO_WORKER_F_FREE) { worker->flags &= ~IO_WORKER_F_FREE; + raw_spin_lock(&wqe->lock); hlist_nulls_del_init_rcu(&worker->nulls_node); + raw_spin_unlock(&wqe->lock); } } @@ -456,7 +462,7 @@ static bool io_wait_on_hash(struct io_wqe *wqe, unsigned int hash) static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, struct io_worker *worker) - __must_hold(wqe->lock) + __must_hold(acct->lock) { struct io_wq_work_node *node, *prev; struct io_wq_work *work, *tail; @@ -498,9 +504,9 @@ static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, * work being added and clearing the stalled bit. */ set_bit(IO_ACCT_STALLED_BIT, &acct->flags); - raw_spin_unlock(&wqe->lock); + raw_spin_unlock(&acct->lock); unstalled = io_wait_on_hash(wqe, stall_hash); - raw_spin_lock(&wqe->lock); + raw_spin_lock(&acct->lock); if (unstalled) { clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); if (wq_has_sleeper(&wqe->wq->hash->wait)) @@ -538,7 +544,7 @@ static void io_assign_current_work(struct io_worker *worker, static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work); static void io_worker_handle_work(struct io_worker *worker) - __releases(wqe->lock) + __releases(acct->lock) { struct io_wqe_acct *acct = io_wqe_get_acct(worker); struct io_wqe *wqe = worker->wqe; @@ -556,6 +562,7 @@ static void io_worker_handle_work(struct io_worker *worker) * clear the stalled flag. */ work = io_get_next_work(acct, worker); + raw_spin_unlock(&acct->lock); if (work) { __io_worker_busy(wqe, worker); @@ -569,10 +576,9 @@ static void io_worker_handle_work(struct io_worker *worker) raw_spin_lock(&worker->lock); worker->next_work = work; raw_spin_unlock(&worker->lock); - } - raw_spin_unlock(&wqe->lock); - if (!work) + } else { break; + } io_assign_current_work(worker, work); __set_current_state(TASK_RUNNING); @@ -609,7 +615,7 @@ static void io_worker_handle_work(struct io_worker *worker) } } while (work); - raw_spin_lock(&wqe->lock); + raw_spin_lock(&acct->lock); } while (1); } @@ -634,11 +640,14 @@ static int io_wqe_worker(void *data) set_current_state(TASK_INTERRUPTIBLE); loop: - raw_spin_lock(&wqe->lock); + raw_spin_lock(&acct->lock); if (io_acct_run_queue(acct)) { io_worker_handle_work(worker); goto loop; + } else { + raw_spin_unlock(&acct->lock); } + raw_spin_lock(&wqe->lock); /* timed out, exit unless we're the last worker */ if (last_timeout && acct->nr_workers > 1) { acct->nr_workers--; @@ -663,7 +672,7 @@ loop: } if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) { - raw_spin_lock(&wqe->lock); + raw_spin_lock(&acct->lock); io_worker_handle_work(worker); } @@ -705,10 +714,7 @@ void io_wq_worker_sleeping(struct task_struct *tsk) return; worker->flags &= ~IO_WORKER_F_RUNNING; - - raw_spin_lock(&worker->wqe->lock); io_wqe_dec_running(worker); - raw_spin_unlock(&worker->wqe->lock); } static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker, @@ -778,10 +784,12 @@ static void create_worker_cont(struct callback_head *cb) .cancel_all = true, }; + raw_spin_unlock(&wqe->lock); while (io_acct_cancel_pending_work(wqe, acct, &match)) - raw_spin_lock(&wqe->lock); + ; + } else { + raw_spin_unlock(&wqe->lock); } - raw_spin_unlock(&wqe->lock); io_worker_ref_put(wqe->wq); kfree(worker); return; @@ -914,6 +922,7 @@ static bool io_wq_work_match_item(struct io_wq_work *work, void *data) 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); + struct io_cb_cancel_data match; unsigned work_flags = work->flags; bool do_create; @@ -927,10 +936,12 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; } - raw_spin_lock(&wqe->lock); + raw_spin_lock(&acct->lock); io_wqe_insert_work(wqe, work); clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + raw_spin_unlock(&acct->lock); + raw_spin_lock(&wqe->lock); rcu_read_lock(); do_create = !io_wqe_activate_free_worker(wqe, acct); rcu_read_unlock(); @@ -946,18 +957,18 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; raw_spin_lock(&wqe->lock); - /* fatal condition, failed to create the first worker */ - if (!acct->nr_workers) { - struct io_cb_cancel_data match = { - .fn = io_wq_work_match_item, - .data = work, - .cancel_all = false, - }; - - if (io_acct_cancel_pending_work(wqe, acct, &match)) - raw_spin_lock(&wqe->lock); + if (acct->nr_workers) { + raw_spin_unlock(&wqe->lock); + return; } raw_spin_unlock(&wqe->lock); + + /* fatal condition, failed to create the first worker */ + match.fn = io_wq_work_match_item, + match.data = work, + match.cancel_all = false, + + io_acct_cancel_pending_work(wqe, acct, &match); } } @@ -1032,22 +1043,23 @@ static inline void io_wqe_remove_pending(struct io_wqe *wqe, static bool io_acct_cancel_pending_work(struct io_wqe *wqe, struct io_wqe_acct *acct, struct io_cb_cancel_data *match) - __releases(wqe->lock) { struct io_wq_work_node *node, *prev; struct io_wq_work *work; + raw_spin_lock(&acct->lock); wq_list_for_each(node, prev, &acct->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(&wqe->lock); + raw_spin_unlock(&acct->lock); io_run_cancel(work, wqe); match->nr_pending++; /* not safe to continue after unlock */ return true; } + raw_spin_unlock(&acct->lock); return false; } @@ -1061,7 +1073,6 @@ retry: struct io_wqe_acct *acct = io_get_acct(wqe, i == 0); if (io_acct_cancel_pending_work(wqe, acct, match)) { - raw_spin_lock(&wqe->lock); if (match->cancel_all) goto retry; break; @@ -1103,13 +1114,11 @@ enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, for_each_node(node) { struct io_wqe *wqe = wq->wqes[node]; - raw_spin_lock(&wqe->lock); io_wqe_cancel_pending_work(wqe, &match); - if (match.nr_pending && !match.cancel_all) { - raw_spin_unlock(&wqe->lock); + if (match.nr_pending && !match.cancel_all) return IO_WQ_CANCEL_OK; - } + raw_spin_lock(&wqe->lock); io_wqe_cancel_running_work(wqe, &match); raw_spin_unlock(&wqe->lock); if (match.nr_running && !match.cancel_all) @@ -1190,6 +1199,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) acct->index = i; atomic_set(&acct->nr_running, 0); INIT_WQ_LIST(&acct->work_list); + raw_spin_lock_init(&acct->lock); } wqe->wq = wq; raw_spin_lock_init(&wqe->lock); @@ -1282,9 +1292,7 @@ static void io_wq_destroy(struct io_wq *wq) .fn = io_wq_work_match_all, .cancel_all = true, }; - raw_spin_lock(&wqe->lock); io_wqe_cancel_pending_work(wqe, &match); - raw_spin_unlock(&wqe->lock); free_cpumask_var(wqe->cpu_mask); kfree(wqe); }