scsi: qedi: Fix host removal with running sessions

qedi_clear_session_ctx() could race with the in-kernel or userspace driven
recovery/removal and we could access a NULL conn or do a double free.

We should be using iscsi_host_remove() to start the removal process from
the driver. It will start the in-kernel recovery and notify userspace that
the driver's scsi_hosts are being removed. iscsid will then drive the
session removal like is done when the logout command is run. When the
sessions are removed, iscsi_host_remove() will return so qedi can finish
knowing there are no running sessions and no new sessions will be allowed.

This also fixes an issue where we check for a NULL conn after already
accessing it introduced in commit 27e986289e73 ("scsi: iscsi: Drop suspend
calls from ep_disconnect") by just removing the function completely.

Link: https://lore.kernel.org/r/20210609192709.5094-1-michael.christie@oracle.com
Fixes: 27e986289e73 ("scsi: iscsi: Drop suspend calls from ep_disconnect")
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qedi/qedi_gbl.h b/drivers/scsi/qedi/qedi_gbl.h
index fb44a28..9f8e8ef 100644 (file)
--- a/drivers/scsi/qedi/qedi_gbl.h
+++ b/drivers/scsi/qedi/qedi_gbl.h
@@ -72,6 +72,5 @@ void qedi_remove_sysfs_ctx_attr(struct qedi_ctx *qedi);
 void qedi_clearsq(struct qedi_ctx *qedi,
                  struct qedi_conn *qedi_conn,
                  struct iscsi_task *task);
-void qedi_clear_session_ctx(struct iscsi_cls_session *cls_sess);
 
 #endif

diff --git a/drivers/scsi/qedi/qedi_iscsi.c b/drivers/scsi/qedi/qedi_iscsi.c
index bf581ec..97f8376 100644 (file)
--- a/drivers/scsi/qedi/qedi_iscsi.c
+++ b/drivers/scsi/qedi/qedi_iscsi.c
@@ -1659,23 +1659,6 @@ void qedi_process_iscsi_error(struct qedi_endpoint *ep,
                qedi_start_conn_recovery(qedi_conn->qedi, qedi_conn);
 }
 
-void qedi_clear_session_ctx(struct iscsi_cls_session *cls_sess)
-{
-       struct iscsi_session *session = cls_sess->dd_data;
-       struct iscsi_conn *conn = session->leadconn;
-       struct qedi_conn *qedi_conn = conn->dd_data;
-
-       if (iscsi_is_session_online(cls_sess)) {
-               if (conn)
-                       iscsi_suspend_queue(conn);
-               qedi_ep_disconnect(qedi_conn->iscsi_ep);
-       }
-
-       qedi_conn_destroy(qedi_conn->cls_conn);
-
-       qedi_session_destroy(cls_sess);
-}
-
 void qedi_process_tcp_error(struct qedi_endpoint *ep,
                            struct iscsi_eqe_data *data)
 {

diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index edf9154..0b0acb8 100644 (file)
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -2417,11 +2417,9 @@ static void __qedi_remove(struct pci_dev *pdev, int mode)
        int rval;
        u16 retry = 10;
 
-       if (mode == QEDI_MODE_SHUTDOWN)
-               iscsi_host_for_each_session(qedi->shost,
-                                           qedi_clear_session_ctx);
-
        if (mode == QEDI_MODE_NORMAL || mode == QEDI_MODE_SHUTDOWN) {
+               iscsi_host_remove(qedi->shost);
+
                if (qedi->tmf_thread) {
                        flush_workqueue(qedi->tmf_thread);
                        destroy_workqueue(qedi->tmf_thread);
@@ -2482,7 +2480,6 @@ static void __qedi_remove(struct pci_dev *pdev, int mode)
                if (qedi->boot_kset)
                        iscsi_boot_destroy_kset(qedi->boot_kset);
 
-               iscsi_host_remove(qedi->shost);
                iscsi_host_free(qedi->shost);
        }
 }