[SCSI] iscsi: fix run list corruption

from davidw@netapp.com:

We must grab the session lock when modifying the running lists.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 963002598995..a223413e1564 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -552,8 +552,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
         if (unlikely(__kfifo_len(conn->immqueue))) {
                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
                                    sizeof(void*))) {
+                        spin_lock_bh(&conn->session->lock);
                         list_add_tail(&conn->mtask->running,
                                       &conn->mgmt_run_list);
+                        spin_unlock_bh(&conn->session->lock);
                         if (tt->xmit_mgmt_task(conn, conn->mtask))
                                 goto again;
                 }
@@ -568,8 +570,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
                  * iscsi tcp may readd the task to the xmitqueue to send
                  * write data
                  */
+                spin_lock_bh(&conn->session->lock);
                 if (list_empty(&conn->ctask->running))
                         list_add_tail(&conn->ctask->running, &conn->run_list);
+                spin_unlock_bh(&conn->session->lock);
                 if (tt->xmit_cmd_task(conn, conn->ctask))
                         goto again;
         }
@@ -580,8 +584,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
                                    sizeof(void*))) {
+                        spin_lock_bh(&conn->session->lock);
                         list_add_tail(&conn->mtask->running,
                                       &conn->mgmt_run_list);
+                        spin_unlock_bh(&conn->session->lock);
                         if (tt->xmit_mgmt_task(conn, conn->mtask))
                                 goto again;
                 }