sunvdc: don't dereference port->disk before disk probe finishes

If the backing file for a vdisk is not present in the service domain an
ldc reset can occur during the initial port/disk probing. The ldc reset
logic was dereferencing port->disk, which may not have been setup yet.
Guard against this case.

Orabug: 20362258

Signed-off-by: Chris Hyser <chris.hyser@oracle.com>
Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
(cherry picked from commit cd6d3705da958b5db625272eb8733ab79a045f87)
(cherry picked from commit bee156ac9cad00f6a39417217c454085645c3d62)
(cherry picked from commit 476306db27c9a6bcd2e8012047ba06a0af16b734)
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 2c59f2778064f3a611aa9d95c9fd00ab2c0e2dbc..f1e3c5558053a5cffec11723ede15eb589b24717 100644 (file)
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -946,6 +946,8 @@ err_out_free_tx_ring:
        vdc_free_tx_ring(port);
 
 err_out_free_ldc:
+       flush_work(&port->ldc_reset_work);
+       del_timer_sync(&port->ldc_reset_timer);
        vio_ldc_free(&port->vio);
 
 err_out_free_port:
@@ -1025,6 +1027,9 @@ static void vdc_ldc_reset_timer(unsigned long _arg)
        struct vio_driver_state *vio = &port->vio;
        unsigned long flags;
 
+       if (!port->disk)
+               return;
+
        spin_lock_irqsave(&vio->lock, flags);
        if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
                pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
@@ -1056,6 +1061,9 @@ static void vdc_ldc_reset(struct vdc_port *port)
        assert_spin_locked(&port->vio.lock);
 
        pr_warn(PFX "%s ldc link reset\n", port->disk_name);
+       if (!port->disk)
+               return;
+
        blk_stop_queue(port->disk->queue);
        vdc_requeue_inflight(port);
        vdc_port_down(port);