io_uring: minor io_cqring_wait() optimization

Move up the block manipulating the sig variable to execute code
that may encounter an error and exit first before continuing
executing the rest of the function and avoid useless computations

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Link: https://lore.kernel.org/r/84513f7cc1b1fb31d8f4cb910aee033391d036b4.1646777484.git.olivier@trillion01.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 36b001365a7972efe0d7419c9a114edf0733c6cf..3d2d47540e1b280b2bae7fef82013191c83abe9c 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7919,14 +7919,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
                        break;
        } while (1);
 
-       if (uts) {
-               struct timespec64 ts;
-
-               if (get_timespec64(&ts, uts))
-                       return -EFAULT;
-               timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
-       }
-
        if (sig) {
 #ifdef CONFIG_COMPAT
                if (in_compat_syscall())
@@ -7940,6 +7932,14 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
                        return ret;
        }
 
+       if (uts) {
+               struct timespec64 ts;
+
+               if (get_timespec64(&ts, uts))
+                       return -EFAULT;
+               timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
+       }
+
        init_waitqueue_func_entry(&iowq.wq, io_wake_function);
        iowq.wq.private = current;
        INIT_LIST_HEAD(&iowq.wq.entry);