io_uring: clean up io_uring_cancel_files()

mainline inclusion
from mainline-5.5-rc1
commit 2f6d9b9d
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

We don't use the return value anymore, drop it. Also drop the
unecessary double cancel_req value check.
Signed-off-by: NBob Liu <bob.liu@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/io_uring.c

@@ -4319,7 +4319,6 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 	DEFINE_WAIT(wait);
 
 	while (!list_empty_careful(&ctx->inflight_list)) {
-		enum io_wq_cancel ret = IO_WQ_CANCEL_NOTFOUND;
 		struct io_kiocb *cancel_req = NULL;
 
 		spin_lock_irq(&ctx->inflight_lock);
@@ -4337,14 +4336,12 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 						TASK_UNINTERRUPTIBLE);
 		spin_unlock_irq(&ctx->inflight_lock);
 
-		if (cancel_req) {
-			ret = io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
-			io_put_req(cancel_req);
-		}
-
 		/* We need to keep going until we don't find a matching req */
 		if (!cancel_req)
 			break;
+
+		io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
+		io_put_req(cancel_req);
 		schedule();
 	}
 	finish_wait(&ctx->inflight_wait, &wait);