net: xsk: don't return frames via the allocator on error

xdp_return_buff() is used when frame has been successfully
handled (transmitted) or if an error occurred during delayed
processing and there is no way to report it back to
xdp_do_redirect().

In case of __xsk_rcv_zc() error is propagated all the way
back to the driver, so there is no need to call
xdp_return_buff().  Driver will recycle the frame anyway
after seeing that error happened.

Fixes: 173d3adb6f43 ("xsk: add zero-copy support for Rx")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 72335c2e8108996d07702086f1f1391faa33fd7d..4e937cd7c17dc6b4b617f463336e9a8d2867ed6d 100644 (file)
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -84,10 +84,8 @@ static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
 {
        int err = xskq_produce_batch_desc(xs->rx, (u64)xdp->handle, len);
 
-       if (err) {
-               xdp_return_buff(xdp);
+       if (err)
                xs->rx_dropped++;
-       }
 
        return err;
 }