nvme_fc: add module to ops template to allow module references
authorJames Smart <jsmart2021@gmail.com>
Thu, 14 Nov 2019 23:15:26 +0000 (15:15 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Jan 2020 09:17:50 +0000 (10:17 +0100)
[ Upstream commit 863fbae929c7a5b64e96b8a3ffb34a29eefb9f8f ]

In nvme-fc: it's possible to have connected active controllers
and as no references are taken on the LLDD, the LLDD can be
unloaded.  The controller would enter a reconnect state and as
long as the LLDD resumed within the reconnect timeout, the
controller would resume.  But if a namespace on the controller
is the root device, allowing the driver to unload can be problematic.
To reload the driver, it may require new io to the boot device,
and as it's no longer connected we get into a catch-22 that
eventually fails, and the system locks up.

Fix this issue by taking a module reference for every connected
controller (which is what the core layer did to the transport
module). Reference is cleared when the controller is removed.

Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/nvme/host/fc.c
drivers/nvme/target/fcloop.c
drivers/scsi/lpfc/lpfc_nvme.c
drivers/scsi/qla2xxx/qla_nvme.c
include/linux/nvme-fc-driver.h

index 058d542647dd5d1f6b8ba55b166c3a4cf03f89a4..9e4d2ecf736d563240aee9ca992359940a7a4709 100644 (file)
@@ -337,7 +337,8 @@ nvme_fc_register_localport(struct nvme_fc_port_info *pinfo,
            !template->ls_req || !template->fcp_io ||
            !template->ls_abort || !template->fcp_abort ||
            !template->max_hw_queues || !template->max_sgl_segments ||
-           !template->max_dif_sgl_segments || !template->dma_boundary) {
+           !template->max_dif_sgl_segments || !template->dma_boundary ||
+           !template->module) {
                ret = -EINVAL;
                goto out_reghost_failed;
        }
@@ -1762,6 +1763,7 @@ nvme_fc_ctrl_free(struct kref *ref)
 {
        struct nvme_fc_ctrl *ctrl =
                container_of(ref, struct nvme_fc_ctrl, ref);
+       struct nvme_fc_lport *lport = ctrl->lport;
        unsigned long flags;
 
        if (ctrl->ctrl.tagset) {
@@ -1787,6 +1789,7 @@ nvme_fc_ctrl_free(struct kref *ref)
        if (ctrl->ctrl.opts)
                nvmf_free_options(ctrl->ctrl.opts);
        kfree(ctrl);
+       module_put(lport->ops->module);
 }
 
 static void
@@ -2765,10 +2768,15 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
                goto out_fail;
        }
 
+       if (!try_module_get(lport->ops->module)) {
+               ret = -EUNATCH;
+               goto out_free_ctrl;
+       }
+
        idx = ida_simple_get(&nvme_fc_ctrl_cnt, 0, 0, GFP_KERNEL);
        if (idx < 0) {
                ret = -ENOSPC;
-               goto out_free_ctrl;
+               goto out_mod_put;
        }
 
        ctrl->ctrl.opts = opts;
@@ -2915,6 +2923,8 @@ out_free_queues:
 out_free_ida:
        put_device(ctrl->dev);
        ida_simple_remove(&nvme_fc_ctrl_cnt, ctrl->cnum);
+out_mod_put:
+       module_put(lport->ops->module);
 out_free_ctrl:
        kfree(ctrl);
 out_fail:
index 096523d8dd422b511c17290065dbaa290debd877..b8fe8702065bc1f88d26f8f292ef321412ab3b99 100644 (file)
@@ -693,6 +693,7 @@ fcloop_targetport_delete(struct nvmet_fc_target_port *targetport)
 #define FCLOOP_DMABOUND_4G             0xFFFFFFFF
 
 static struct nvme_fc_port_template fctemplate = {
+       .module                 = THIS_MODULE,
        .localport_delete       = fcloop_localport_delete,
        .remoteport_delete      = fcloop_remoteport_delete,
        .create_queue           = fcloop_create_queue,
index fcf4b4175d771a4711154f4c8ee55ba1f1fd2aeb..af937b91765e60d1cd8f1f8c9c18e4d5b2725b63 100644 (file)
@@ -1591,6 +1591,8 @@ lpfc_nvme_fcp_abort(struct nvme_fc_local_port *pnvme_lport,
 
 /* Declare and initialization an instance of the FC NVME template. */
 static struct nvme_fc_port_template lpfc_nvme_template = {
+       .module = THIS_MODULE,
+
        /* initiator-based functions */
        .localport_delete  = lpfc_nvme_localport_delete,
        .remoteport_delete = lpfc_nvme_remoteport_delete,
index 6b33a1f24f56169a3a17803e5a6952da2e6445a6..7dceed02123617a12bbf0de47e3517aed0087c55 100644 (file)
@@ -578,6 +578,7 @@ static void qla_nvme_remoteport_delete(struct nvme_fc_remote_port *rport)
 }
 
 static struct nvme_fc_port_template qla_nvme_fc_transport = {
+       .module = THIS_MODULE,
        .localport_delete = qla_nvme_localport_delete,
        .remoteport_delete = qla_nvme_remoteport_delete,
        .create_queue   = qla_nvme_alloc_queue,
index a726f96010d59d9d99eda4e6d5d5ea9776ebdd18..e9c3b98df3e256268d48c6d829fd1d8bd5346dc1 100644 (file)
@@ -279,6 +279,8 @@ struct nvme_fc_remote_port {
  *
  * Host/Initiator Transport Entrypoints/Parameters:
  *
+ * @module:  The LLDD module using the interface
+ *
  * @localport_delete:  The LLDD initiates deletion of a localport via
  *       nvme_fc_deregister_localport(). However, the teardown is
  *       asynchronous. This routine is called upon the completion of the
@@ -392,6 +394,8 @@ struct nvme_fc_remote_port {
  *       Value is Mandatory. Allowed to be zero.
  */
 struct nvme_fc_port_template {
+       struct module   *module;
+
        /* initiator-based functions */
        void    (*localport_delete)(struct nvme_fc_local_port *);
        void    (*remoteport_delete)(struct nvme_fc_remote_port *);