scsi: libiscsi: Fix locking in __iscsi_conn_send_pdu

The code at free_task label in __iscsi_conn_send_pdu can get executed
from blk_timeout_work which takes queue_lock using spin_lock_irq.
back_lock taken with spin_unlock_bh will cause WARN_ON_ONCE.  The code
gets executed either with bottom half or IRQ disabled hence using
spin_lock/spin_unlock for back_lock is safe.

Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index c051694bfcb0f42e1e983f409a581f1da5b344d2..f9b6fba689ffb41c6806cdabeb80debe38e25189 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -791,9 +791,9 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 
 free_task:
        /* regular RX path uses back_lock */
-       spin_lock_bh(&session->back_lock);
+       spin_lock(&session->back_lock);
        __iscsi_put_task(task);
-       spin_unlock_bh(&session->back_lock);
+       spin_unlock(&session->back_lock);
        return NULL;
 }