2019-06-27 10:16:11

by Ilya Maximets

Subject: [PATCH bpf v5 1/2] xdp: hold device for umem regardless of zero-copy mode

Device pointer stored in umem regardless of zero-copy mode,
so we heed to hold the device in all cases.

Fixes: c9b47cc1fabc ("xsk: fix bug when trying to use both copy and zero-copy on one queue id")
Signed-off-by: Ilya Maximets <[email protected]>
---
net/xdp/xdp_umem.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 9c6de4f114f8..267b82a4cbcf 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -105,6 +105,9 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,

umem->dev = dev;
umem->queue_id = queue_id;
+
+ dev_hold(dev);
+
if (force_copy)
/* For copy-mode, we are done. */
goto out_rtnl_unlock;
@@ -124,7 +127,6 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
goto err_unreg_umem;
rtnl_unlock();

- dev_hold(dev);
umem->zc = true;
return 0;

@@ -163,10 +165,9 @@ static void xdp_umem_clear_dev(struct xdp_umem *umem)
xdp_clear_umem_at_qid(umem->dev, umem->queue_id);
rtnl_unlock();

- if (umem->zc) {
- dev_put(umem->dev);
- umem->zc = false;
- }
+ dev_put(umem->dev);
+ umem->dev = NULL;
+ umem->zc = false;
}

static void xdp_umem_unpin_pages(struct xdp_umem *umem)
--
2.17.1

2019-06-27 22:05:01

by Jonathan Lemon

Subject: Re: [PATCH bpf v5 1/2] xdp: hold device for umem regardless of zero-copy mode

On 27 Jun 2019, at 3:15, Ilya Maximets wrote:

> Device pointer stored in umem regardless of zero-copy mode,
> so we heed to hold the device in all cases.
>
> Fixes: c9b47cc1fabc ("xsk: fix bug when trying to use both copy and
> zero-copy on one queue id")
> Signed-off-by: Ilya Maximets <[email protected]>

Acked-by: Jonathan Lemon <[email protected]>