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sunvnet: improve error handling when a remote crashes

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If a remote machine crashes while there are pending transmit buffers, the
sunvnet driver reallocates the ring descriptors giving us enries that have
state VIO_DESC_FREE but also an allocated skb. This results in a BUG_ON()
call when the remote reboots and we reach that point in the ring.

This patch:

1) clears pending tx packets in the ring on port reset
2) changes a BUG_ON() to a pr_warn() when a remote host has given us an invalid
	descriptor state
3) collapses multiple active buffer frees in a ring to a single message per
	ring and adds the device name and remote MAC address

This fixes the particular problem of not cleaning up pending buffers on a
reset, but also prevents us from crashing if the remote handles descriptors
out of order or sets an unexpected state for a descriptor.

Signed-off-by: David L Stevens <david.stevens@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David L Stevens 2015-01-26 15:54:27 -05:00 committed by David S. Miller
parent 07ac3e7099
commit 8e2b60cd18
1 changed files with 35 additions and 29 deletions
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64
drivers/net/ethernet/sun/sunvnet.c
View file

@ -50,6 +50,7 @@ MODULE_VERSION(DRV_MODULE_VERSION);
#define VNET_MAX_RETRIES 10
static int __vnet_tx_trigger(struct vnet_port *port, u32 start);
static void vnet_port_reset(struct vnet_port *port);
/* Ordered from largest major to lowest */
static struct vio_version vnet_versions[] = {
@ -736,9 +737,7 @@ static int vnet_event_napi(struct vnet_port *port, int budget)
vio_link_state_change(vio, event);
if (event == LDC_EVENT_RESET) {
port->rmtu = 0;
port->tso = true;
port->tsolen = 0;
vnet_port_reset(port);
vio_port_up(vio);
}
port->rx_event = 0;
@ -934,36 +933,36 @@ static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
*pending = 0;
txi = dr->prod-1;
if (txi < 0)
txi = VNET_TX_RING_SIZE-1;
txi = dr->prod;
for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
struct vio_net_desc *d;
d = vio_dring_entry(dr, txi);
if (d->hdr.state == VIO_DESC_DONE) {
if (port->tx_bufs[txi].skb) {
BUG_ON(port->tx_bufs[txi].skb->next);
port->tx_bufs[txi].skb->next = skb;
skb = port->tx_bufs[txi].skb;
port->tx_bufs[txi].skb = NULL;
ldc_unmap(port->vio.lp,
port->tx_bufs[txi].cookies,
port->tx_bufs[txi].ncookies);
}
d->hdr.state = VIO_DESC_FREE;
} else if (d->hdr.state == VIO_DESC_READY) {
(*pending)++;
} else if (d->hdr.state == VIO_DESC_FREE) {
break;
}
--txi;
if (txi < 0)
txi = VNET_TX_RING_SIZE-1;
d = vio_dring_entry(dr, txi);
if (d->hdr.state == VIO_DESC_READY) {
(*pending)++;
continue;
}
if (port->tx_bufs[txi].skb) {
if (d->hdr.state != VIO_DESC_DONE)
pr_notice("invalid ring buffer state %d\n",
d->hdr.state);
BUG_ON(port->tx_bufs[txi].skb->next);
port->tx_bufs[txi].skb->next = skb;
skb = port->tx_bufs[txi].skb;
port->tx_bufs[txi].skb = NULL;
ldc_unmap(port->vio.lp,
port->tx_bufs[txi].cookies,
port->tx_bufs[txi].ncookies);
} else if (d->hdr.state == VIO_DESC_FREE)
break;
d->hdr.state = VIO_DESC_FREE;
}
return skb;
}
@ -1649,8 +1648,6 @@ static void vnet_port_free_tx_bufs(struct vnet_port *port)
continue;
d = vio_dring_entry(dr, i);
if (d->hdr.state == VIO_DESC_READY)
pr_warn("active transmit buffers freed\n");
ldc_unmap(port->vio.lp,
port->tx_bufs[i].cookies,
@ -1669,6 +1666,15 @@ static void vnet_port_free_tx_bufs(struct vnet_port *port)
dr->ncookies = 0;
}
static void vnet_port_reset(struct vnet_port *port)
{
del_timer(&port->clean_timer);
vnet_port_free_tx_bufs(port);
port->rmtu = 0;
port->tso = true;
port->tsolen = 0;
}
static int vnet_port_alloc_tx_ring(struct vnet_port *port)
{
struct vio_dring_state *dr;