[PATCH v2 1/6] Revert "qla2xxx: Make sure that aborted commands are freed"

[Bart Van Assche <bvanassche@xxxxxxx>]

Calling vha->hw->tgt.tgt_ops->free_cmd() from qlt_xmit_response() is wrong
since the command for which a response is sent must remain valid until the
SCSI target core calls .release_cmd(). It has been observed that the
following scenario triggers a kernel crash:
- qlt_xmit_response() calls qlt_check_reserve_free_req().
- qlt_check_reserve_free_req() returns -EAGAIN.
- qlt_xmit_response() calls vha->hw->tgt.tgt_ops->free_cmd(cmd).
- transport_handle_queue_full() tries to retransmit the response.

Fix this crash by reverting the patch that introduced it.

Fixes: 0dcec41acb85 ("scsi: qla2xxx: Make sure that aborted commands are freed")
Cc: Quinn Tran <qutran@xxxxxxxxxxx>
Cc: Mike Christie <michael.christie@xxxxxxxxxx>
Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 drivers/scsi/qla2xxx/qla_target.c  | 13 +++++--------
 drivers/scsi/qla2xxx/tcm_qla2xxx.c |  4 ----
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index d6366a46283e..5e8b2653e134 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3222,8 +3222,7 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 	if (!qpair->fw_started || (cmd->reset_count != qpair->chip_reset) ||
 	    (cmd->sess && cmd->sess->deleted)) {
 		cmd->state = QLA_TGT_STATE_PROCESSED;
-		res = 0;
-		goto free;
+		return 0;
 	}
 
 	ql_dbg_qp(ql_dbg_tgt, qpair, 0xe018,
@@ -3234,8 +3233,9 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 
 	res = qlt_pre_xmit_response(cmd, &prm, xmit_type, scsi_status,
 	    &full_req_cnt);
-	if (unlikely(res != 0))
-		goto free;
+	if (unlikely(res != 0)) {
+		return res;
+	}
 
 	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
 
@@ -3255,8 +3255,7 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 			vha->flags.online, qla2x00_reset_active(vha),
 			cmd->reset_count, qpair->chip_reset);
 		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
-		res = 0;
-		goto free;
+		return 0;
 	}
 
 	/* Does F/W have an IOCBs for this request */
@@ -3359,8 +3358,6 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 	qlt_unmap_sg(vha, cmd);
 	spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
 
-free:
-	vha->hw->tgt.tgt_ops->free_cmd(cmd);
 	return res;
 }
 EXPORT_SYMBOL(qlt_xmit_response);
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 30959f8da065..15650a0bde09 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -653,7 +653,6 @@ static int tcm_qla2xxx_queue_data_in(struct se_cmd *se_cmd)
 {
 	struct qla_tgt_cmd *cmd = container_of(se_cmd,
 				struct qla_tgt_cmd, se_cmd);
-	struct scsi_qla_host *vha = cmd->vha;
 
 	if (cmd->aborted) {
 		/* Cmd can loop during Q-full.  tcm_qla2xxx_aborted_task
@@ -666,7 +665,6 @@ static int tcm_qla2xxx_queue_data_in(struct se_cmd *se_cmd)
 			cmd->se_cmd.transport_state,
 			cmd->se_cmd.t_state,
 			cmd->se_cmd.se_cmd_flags);
-		vha->hw->tgt.tgt_ops->free_cmd(cmd);
 		return 0;
 	}
 
@@ -694,7 +692,6 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
 {
 	struct qla_tgt_cmd *cmd = container_of(se_cmd,
 				struct qla_tgt_cmd, se_cmd);
-	struct scsi_qla_host *vha = cmd->vha;
 	int xmit_type = QLA_TGT_XMIT_STATUS;
 
 	if (cmd->aborted) {
@@ -708,7 +705,6 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
 		    cmd, kref_read(&cmd->se_cmd.cmd_kref),
 		    cmd->se_cmd.transport_state, cmd->se_cmd.t_state,
 		    cmd->se_cmd.se_cmd_flags);
-		vha->hw->tgt.tgt_ops->free_cmd(cmd);
 		return 0;
 	}
 	cmd->bufflen = se_cmd->data_length;