> -----Original Message-----
> From: Leon Romanovsky <leon@xxxxxxxxxx>
> Sent: Thursday, December 6, 2018 12:48 PM
> To: Doug Ledford <dledford@xxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>; Mark Zhang
> <markz@xxxxxxxxxxxx>; RDMA mailing list <linux-rdma@xxxxxxxxxxxxxxx>;
> Parav Pandit <parav@xxxxxxxxxxxx>
> Subject: Re: [PATCH rdma-rc] IB/core: Don't match bond master filter for
> closed slaves
>
> On Thu, Dec 06, 2018 at 12:19:30PM -0500, Doug Ledford wrote:
> > On Wed, 2018-12-05 at 15:50 +0200, Leon Romanovsky wrote:
> > > From: Mark Zhang <markz@xxxxxxxxxxxx>
> > >
> > > The "modprobe -r mlx4_en" will close bond slaves and in such case
> > > the rdma_dev would be NULL, so no match should be returned.
> >
> > I'm not groking your commit message. What happens without this patch?
>
> We will see calltrace due to the fact that NULL is passed down the stack
> through rdma_is_upper_dev_rcu() upto netdev_walk_all_upper_dev_rcu().
>
I see this patch being sent for -rc which I was not sure when I reviewed.
Commit message needs to change as below.
When mlx4_en driver is unloaded, and configured to use bond devices, get_netdev() callback returns NULL because associated netdev is unregistered.
Therefore, similar to other filter() routines, fix is_upper_ndev_bond_master_filter() to handle NULL netdev.
Without this check, a call trace is observed.
> > > Fixes: 408f1242d940 ("IB/core: Delete lower netdevice default GID
> > > entries in bonding scenario")
> > > Signed-off-by: Mark Zhang <markz@xxxxxxxxxxxx>
> > > Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
> > > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> > > ---
> > > drivers/infiniband/core/roce_gid_mgmt.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/infiniband/core/roce_gid_mgmt.c
> > > b/drivers/infiniband/core/roce_gid_mgmt.c
> > > index 25d43c8f1c2a..558de0b9895c 100644
> > > --- a/drivers/infiniband/core/roce_gid_mgmt.c
> > > +++ b/drivers/infiniband/core/roce_gid_mgmt.c
> > > @@ -267,6 +267,9 @@ is_upper_ndev_bond_master_filter(struct
> ib_device *ib_dev, u8 port,
> > > struct net_device *cookie_ndev = cookie;
> > > bool match = false;
> > >
> > > + if (!rdma_ndev)
> > > + return false;
> > > +
> > > rcu_read_lock();
> > > if (netif_is_bond_master(cookie_ndev) &&
> > > rdma_is_upper_dev_rcu(rdma_ndev, cookie_ndev))
> >
> > --
> > Doug Ledford <dledford@xxxxxxxxxx>
> > GPG KeyID: B826A3330E572FDD
> > Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57
> > 2FDD
>
