Commit 4fa50799 authored Oct 13, 2016 by Jitendra Bhivare Committed by Martin K. Petersen Oct 17, 2016

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>

parent 8a4236a2

drivers/scsi/libiscsi.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}