[PATCH 4.14 164/246] scsi: qedf: Set the UNLOADING flag when removing a vport

From: Greg Kroah-Hartman
Date: Wed Aug 01 2018 - 13:19:58 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chad Dupuis <chad.dupuis@xxxxxxxxxx>

[ Upstream commit 4f4616ceebaf045c59e8a6aa01f08826d18d5c63 ]

Similar to what we do when we remove a PCI function, set the
QEDF_UNLOADING flag to prevent any requests from being queued while a
vport is being deleted. This prevents any requests from getting stuck
in limbo when the vport is unloaded or deleted.

Fixes the crash:

PID: 106676 TASK: ffff9a436aa90000 CPU: 12 COMMAND: "multipathd"
#0 [ffff9a43567d3550] machine_kexec+522 at ffffffffaca60b2a
#1 [ffff9a43567d35b0] __crash_kexec+114 at ffffffffacb13512
#2 [ffff9a43567d3680] crash_kexec+48 at ffffffffacb13600
#3 [ffff9a43567d3698] oops_end+168 at ffffffffad117768
#4 [ffff9a43567d36c0] no_context+645 at ffffffffad106f52
#5 [ffff9a43567d3710] __bad_area_nosemaphore+116 at ffffffffad106fe9
#6 [ffff9a43567d3760] bad_area+70 at ffffffffad107379
#7 [ffff9a43567d3788] __do_page_fault+1247 at ffffffffad11a8cf
#8 [ffff9a43567d37f0] do_page_fault+53 at ffffffffad11a915
#9 [ffff9a43567d3820] page_fault+40 at ffffffffad116768
[exception RIP: qedf_init_task+61]
RIP: ffffffffc0e13c2d RSP: ffff9a43567d38d0 RFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffbe920472c738 RCX: ffff9a434fa0e3e8
RDX: ffff9a434f695280 RSI: ffffbe920472c738 RDI: ffff9a43aa359c80
RBP: ffff9a43567d3950 R8: 0000000000000c15 R9: ffff9a3fb09b9880
R10: ffff9a434fa0e3e8 R11: ffff9a43567d35ce R12: 0000000000000000
R13: ffff9a434f695280 R14: ffff9a43aa359c80 R15: ffff9a3fb9e005c0
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

Signed-off-by: Chad Dupuis <chad.dupuis@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/qedf/qedf_main.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/scsi/qedf/qedf_main.c
+++ b/drivers/scsi/qedf/qedf_main.c
@@ -1649,6 +1649,15 @@ static int qedf_vport_destroy(struct fc_
struct Scsi_Host *shost = vport_to_shost(vport);
struct fc_lport *n_port = shost_priv(shost);
struct fc_lport *vn_port = vport->dd_data;
+ struct qedf_ctx *qedf = lport_priv(vn_port);
+
+ if (!qedf) {
+ QEDF_ERR(NULL, "qedf is NULL.\n");
+ goto out;
+ }
+
+ /* Set unloading bit on vport qedf_ctx to prevent more I/O */
+ set_bit(QEDF_UNLOADING, &qedf->flags);

mutex_lock(&n_port->lp_mutex);
list_del(&vn_port->list);
@@ -1675,6 +1684,7 @@ static int qedf_vport_destroy(struct fc_
if (vn_port->host)
scsi_host_put(vn_port->host);

+out:
return 0;
}