diff options
Diffstat (limited to 'io_uring/eventfd.c')
-rw-r--r-- | io_uring/eventfd.c | 66 |
1 files changed, 14 insertions, 52 deletions
diff --git a/io_uring/eventfd.c b/io_uring/eventfd.c index 100d5da94cb9..78f8ab7db104 100644 --- a/io_uring/eventfd.c +++ b/io_uring/eventfd.c @@ -47,13 +47,6 @@ static void io_eventfd_do_signal(struct rcu_head *rcu) io_eventfd_put(ev_fd); } -static void io_eventfd_release(struct io_ev_fd *ev_fd, bool put_ref) -{ - if (put_ref) - io_eventfd_put(ev_fd); - rcu_read_unlock(); -} - /* * Returns true if the caller should put the ev_fd reference, false if not. */ @@ -72,63 +65,34 @@ static bool __io_eventfd_signal(struct io_ev_fd *ev_fd) /* * Trigger if eventfd_async isn't set, or if it's set and the caller is - * an async worker. If ev_fd isn't valid, obviously return false. + * an async worker. */ static bool io_eventfd_trigger(struct io_ev_fd *ev_fd) { - if (ev_fd) - return !ev_fd->eventfd_async || io_wq_current_is_worker(); - return false; + return !ev_fd->eventfd_async || io_wq_current_is_worker(); } -/* - * On success, returns with an ev_fd reference grabbed and the RCU read - * lock held. - */ -static struct io_ev_fd *io_eventfd_grab(struct io_ring_ctx *ctx) +void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event) { + bool skip = false; struct io_ev_fd *ev_fd; if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) - return NULL; - - rcu_read_lock(); + return; - /* - * rcu_dereference ctx->io_ev_fd once and use it for both for checking - * and eventfd_signal - */ + guard(rcu)(); ev_fd = rcu_dereference(ctx->io_ev_fd); - /* * Check again if ev_fd exists in case an io_eventfd_unregister call * completed between the NULL check of ctx->io_ev_fd at the start of * the function and rcu_read_lock. */ - if (io_eventfd_trigger(ev_fd) && refcount_inc_not_zero(&ev_fd->refs)) - return ev_fd; - - rcu_read_unlock(); - return NULL; -} - -void io_eventfd_signal(struct io_ring_ctx *ctx) -{ - struct io_ev_fd *ev_fd; - - ev_fd = io_eventfd_grab(ctx); - if (ev_fd) - io_eventfd_release(ev_fd, __io_eventfd_signal(ev_fd)); -} - -void io_eventfd_flush_signal(struct io_ring_ctx *ctx) -{ - struct io_ev_fd *ev_fd; - - ev_fd = io_eventfd_grab(ctx); - if (ev_fd) { - bool skip, put_ref = true; + if (!ev_fd) + return; + if (!io_eventfd_trigger(ev_fd) || !refcount_inc_not_zero(&ev_fd->refs)) + return; + if (cqe_event) { /* * Eventfd should only get triggered when at least one event * has been posted. Some applications rely on the eventfd @@ -142,12 +106,10 @@ void io_eventfd_flush_signal(struct io_ring_ctx *ctx) skip = ctx->cached_cq_tail == ev_fd->last_cq_tail; ev_fd->last_cq_tail = ctx->cached_cq_tail; spin_unlock(&ctx->completion_lock); - - if (!skip) - put_ref = __io_eventfd_signal(ev_fd); - - io_eventfd_release(ev_fd, put_ref); } + + if (skip || __io_eventfd_signal(ev_fd)) + io_eventfd_put(ev_fd); } int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg, |