1 files changed, 6 insertions, 42 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 50a90e5581ed..0633cf3b325c 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -164,19 +164,6 @@ struct fsync_iocb {
 	bool			datasync;
 };
 
-/*
- * We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either
- * cancelled or completed (this makes a certain amount of sense because
- * successful cancellation - io_cancel() - does deliver the completion to
- * userspace).
- *
- * And since most things don't implement kiocb cancellation and we'd really like
- * kiocb completion to be lockless when possible, we use ki_cancel to
- * synchronize cancellation and completion - we only set it to KIOCB_CANCELLED
- * with xchg() or cmpxchg(), see batch_complete_aio() and kiocb_cancel().
- */
-#define KIOCB_CANCELLED		((void *) (~0ULL))
-
 struct aio_kiocb {
 	union {
 		struct kiocb		rw;
@@ -574,27 +561,6 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
 }
 EXPORT_SYMBOL(kiocb_set_cancel_fn);
 
-static int kiocb_cancel(struct aio_kiocb *kiocb)
-{
-	kiocb_cancel_fn *old, *cancel;
-
-	/*
-	 * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it
-	 * actually has a cancel function, hence the cmpxchg()
-	 */
-
-	cancel = READ_ONCE(kiocb->ki_cancel);
-	do {
-		if (!cancel || cancel == KIOCB_CANCELLED)
-			return -EINVAL;
-
-		old = cancel;
-		cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
-	} while (cancel != old);
-
-	return cancel(&kiocb->rw);
-}
-
 /*
  * free_ioctx() should be RCU delayed to synchronize against the RCU
  * protected lookup_ioctx() and also needs process context to call
@@ -641,7 +607,7 @@ static void free_ioctx_users(struct percpu_ref *ref)
 	while (!list_empty(&ctx->active_reqs)) {
 		req = list_first_entry(&ctx->active_reqs,
 				       struct aio_kiocb, ki_list);
-		kiocb_cancel(req);
+		req->ki_cancel(&req->rw);
 		list_del_init(&req->ki_list);
 	}
 
@@ -1842,8 +1808,8 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
 {
 	struct kioctx *ctx;
 	struct aio_kiocb *kiocb;
+	int ret = -EINVAL;
 	u32 key;
-	int ret;
 
 	if (unlikely(get_user(key, &iocb->aio_key)))
 		return -EFAULT;
@@ -1855,13 +1821,11 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
 		return -EINVAL;
 
 	spin_lock_irq(&ctx->ctx_lock);
-
 	kiocb = lookup_kiocb(ctx, iocb);
-	if (kiocb)
-		ret = kiocb_cancel(kiocb);
-	else
-		ret = -EINVAL;
-
+	if (kiocb) {
+		ret = kiocb->ki_cancel(&kiocb->rw);
+		list_del_init(&kiocb->ki_list);
+	}
 	spin_unlock_irq(&ctx->ctx_lock);
 
 	if (!ret) {