scsi: Revert "qla2xxx: Make sure that aborted commands are freed"

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.

Link: https://lore.kernel.org/r/20210320232359.941-2-bvanassche@acm.org
Fixes: 0dcec41acb85 ("scsi: qla2xxx: Make sure that aborted commands are freed")
Cc: Quinn Tran <qutran@marvell.com>
Cc: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index c48daf5..480e7d2 100644 (file)
--- 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 @@ out_unmap_unlock:
        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 b55fc76..8b4890c 100644 (file)
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -644,7 +644,6 @@ 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
@@ -657,7 +656,6 @@ 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;
        }
 
@@ -685,7 +683,6 @@ 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) {
@@ -699,7 +696,6 @@ 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;