On Thu, Aug 13, 2020 at 12:48:10PM +0200, Dmitry Vyukov wrote:
> On Fri, Jun 5, 2020 at 6:44 PM Eric Dumazet <eric.duma...@gmail.com> wrote:
> >
> > On 6/5/20 5:00 AM, Matthew Wilcox wrote:
> > > From: "Matthew Wilcox (Oracle)" <wi...@infradead.org>
> > >
> > > The XArray interface is easier for this driver to use. Also fixes a
> > > bug reported by the improper use of GFP_ATOMIC.
> > >
> >
> > This does not look stable candidate.
> >
> > If you try to add a Fixes: tag, you might discover that this bug is old,
> > and I do not believe XArray has been backported to stable branches ?
> >
> >
> > Please submit a fix suitable for old kernels (as old as v4.7)
> >
> > Then when net-next is open in ~2 weeks, the Xarray stuff can be proposed.
> >
> > Thanks.
>
> Hello,
>
> What is the status of this patch? Was it merged/superseded by another patch?
> I don't see it in linux-next nor in net-net.
I don't know. I didn't understand Eric's response.
> Thanks
>
> > > Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
> > > ---
> > > net/qrtr/qrtr.c | 39 +++++++++++++--------------------------
> > > 1 file changed, 13 insertions(+), 26 deletions(-)
> > >
> > > diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> > > index 2d8d6131bc5f..488f8f326ee5 100644
> > > --- a/net/qrtr/qrtr.c
> > > +++ b/net/qrtr/qrtr.c
> > > @@ -20,6 +20,7 @@
> > > /* auto-bind range */
> > > #define QRTR_MIN_EPH_SOCKET 0x4000
> > > #define QRTR_MAX_EPH_SOCKET 0x7fff
> > > +#define QRTR_PORT_RANGE XA_LIMIT(QRTR_MIN_EPH_SOCKET,
> > > QRTR_MAX_EPH_SOCKET)
> > >
> > > /**
> > > * struct qrtr_hdr_v1 - (I|R)PCrouter packet header version 1
> > > @@ -106,8 +107,7 @@ static LIST_HEAD(qrtr_all_nodes);
> > > static DEFINE_MUTEX(qrtr_node_lock);
> > >
> > > /* local port allocation management */
> > > -static DEFINE_IDR(qrtr_ports);
> > > -static DEFINE_MUTEX(qrtr_port_lock);
> > > +static DEFINE_XARRAY_ALLOC(qrtr_ports);
> > >
> > > /**
> > > * struct qrtr_node - endpoint node
> > > @@ -623,7 +623,7 @@ static struct qrtr_sock *qrtr_port_lookup(int port)
> > > port = 0;
> > >
> > > rcu_read_lock();
> > > - ipc = idr_find(&qrtr_ports, port);
> > > + ipc = xa_load(&qrtr_ports, port);
> > > if (ipc)
> > > sock_hold(&ipc->sk);
> > > rcu_read_unlock();
> > > @@ -665,9 +665,7 @@ static void qrtr_port_remove(struct qrtr_sock *ipc)
> > >
> > > __sock_put(&ipc->sk);
> > >
> > > - mutex_lock(&qrtr_port_lock);
> > > - idr_remove(&qrtr_ports, port);
> > > - mutex_unlock(&qrtr_port_lock);
> > > + xa_erase(&qrtr_ports, port);
> > >
> > > /* Ensure that if qrtr_port_lookup() did enter the RCU read section
> > > we
> > > * wait for it to up increment the refcount */
> > > @@ -688,25 +686,18 @@ static int qrtr_port_assign(struct qrtr_sock *ipc,
> > > int *port)
> > > {
> > > int rc;
> > >
> > > - mutex_lock(&qrtr_port_lock);
> > > if (!*port) {
> > > - rc = idr_alloc(&qrtr_ports, ipc,
> > > - QRTR_MIN_EPH_SOCKET, QRTR_MAX_EPH_SOCKET + 1,
> > > - GFP_ATOMIC);
> > > - if (rc >= 0)
> > > - *port = rc;
> > > + rc = xa_alloc(&qrtr_ports, port, ipc, QRTR_PORT_RANGE,
> > > + GFP_KERNEL);
> > > } else if (*port < QRTR_MIN_EPH_SOCKET && !capable(CAP_NET_ADMIN)) {
> > > rc = -EACCES;
> > > } else if (*port == QRTR_PORT_CTRL) {
> > > - rc = idr_alloc(&qrtr_ports, ipc, 0, 1, GFP_ATOMIC);
> > > + rc = xa_insert(&qrtr_ports, 0, ipc, GFP_KERNEL);
> > > } else {
> > > - rc = idr_alloc(&qrtr_ports, ipc, *port, *port + 1,
> > > GFP_ATOMIC);
> > > - if (rc >= 0)
> > > - *port = rc;
> > > + rc = xa_insert(&qrtr_ports, *port, ipc, GFP_KERNEL);
> > > }
> > > - mutex_unlock(&qrtr_port_lock);
> > >
> > > - if (rc == -ENOSPC)
> > > + if (rc == -EBUSY)
> > > return -EADDRINUSE;
> > > else if (rc < 0)
> > > return rc;
> > > @@ -720,20 +711,16 @@ static int qrtr_port_assign(struct qrtr_sock *ipc,
> > > int *port)
> > > static void qrtr_reset_ports(void)
> > > {
> > > struct qrtr_sock *ipc;
> > > - int id;
> > > -
> > > - mutex_lock(&qrtr_port_lock);
> > > - idr_for_each_entry(&qrtr_ports, ipc, id) {
> > > - /* Don't reset control port */
> > > - if (id == 0)
> > > - continue;
> > > + unsigned long index;
> > >
> > > + rcu_read_lock();
> > > + xa_for_each_start(&qrtr_ports, index, ipc, 1) {
> > > sock_hold(&ipc->sk);
> > > ipc->sk.sk_err = ENETRESET;
> > > ipc->sk.sk_error_report(&ipc->sk);
> > > sock_put(&ipc->sk);
> > > }
> > > - mutex_unlock(&qrtr_port_lock);
> > > + rcu_read_unlock();
> > > }
> > >
> > > /* Bind socket to address.
> > >
