scsi: qla2xxx: target: Fix offline port handling and host reset handling

Remove the function qlt_abort_cmd_on_host_reset() because it can do the
following, all of which can cause a kernel crash:

- DMA unmapping while DMA is in progress.
- Call target_execute_cmd() while DMA is in progress.
- Call transport_generic_free_cmd() while the LIO core owns a command.

Instead of trying to abort a command asynchronously, set the 'aborted' flag
and handle the abort after the hardware has passed control back to the
tcm_qla2xxx driver.

Cc: Arun Easi <arun.easi@qlogic.com>
Cc: Himanshu Madhani <hmadhani@marvell.com>
Cc: Giridhar Malavali <gmalavali@marvell.com>
Fixes: c0cb4496 ("qla2xxx: Add Host reset handling in target mode.") # v3.18.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_os.c

@@ -1837,15 +1837,10 @@ __qla2x00_abort_all_cmds(struct qla_qpair *qp, int res)
 					continue;
 				}
 				cmd = (struct qla_tgt_cmd *)sp;
-				qlt_abort_cmd_on_host_reset(cmd->vha, cmd);
+				cmd->aborted = 1;
 				break;
 			case TYPE_TGT_TMCMD:
-				/*
-				 * Currently, only ABTS response gets on the
-				 * outstanding_cmds[]
-				 */
-				ha->tgt.tgt_ops->free_mcmd(
-				   (struct qla_tgt_mgmt_cmd *)sp);
+				/* Skip task management functions. */
 				break;
 			default:
 				break;

drivers/scsi/qla2xxx/qla_target.c

@@ -3268,7 +3268,6 @@ 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;
-		qlt_abort_cmd_on_host_reset(cmd->vha, cmd);
 		return 0;
 	}
 
@@ -3297,7 +3296,6 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 		 * previous life, just abort the processing.
 		 */
 		cmd->state = QLA_TGT_STATE_PROCESSED;
-		qlt_abort_cmd_on_host_reset(cmd->vha, cmd);
 		ql_dbg_qp(ql_dbg_async, qpair, 0xe101,
 			"RESET-RSP online/active/old-count/new-count = %d/%d/%d/%d.\n",
 			vha->flags.online, qla2x00_reset_active(vha),
@@ -3438,8 +3436,10 @@ int qlt_rdy_to_xfer(struct qla_tgt_cmd *cmd)
 		 * Either the port is not online or this request was from
 		 * previous life, just abort the processing.
 		 */
-		cmd->state = QLA_TGT_STATE_NEED_DATA;
-		qlt_abort_cmd_on_host_reset(cmd->vha, cmd);
+		cmd->aborted = 1;
+		cmd->write_data_transferred = 0;
+		cmd->state = QLA_TGT_STATE_DATA_IN;
+		vha->hw->tgt.tgt_ops->handle_data(cmd);
 		ql_dbg_qp(ql_dbg_async, qpair, 0xe102,
 			"RESET-XFR online/active/old-count/new-count = %d/%d/%d/%d.\n",
 			vha->flags.online, qla2x00_reset_active(vha),
@@ -3961,39 +3961,6 @@ static void *qlt_ctio_to_cmd(struct scsi_qla_host *vha,
 	return cmd;
 }
 
-/* hardware_lock should be held by caller. */
-void
-qlt_abort_cmd_on_host_reset(struct scsi_qla_host *vha, struct qla_tgt_cmd *cmd)
-{
-	struct qla_hw_data *ha = vha->hw;
-
-	if (cmd->sg_mapped)
-		qlt_unmap_sg(vha, cmd);
-
-	/* TODO: fix debug message type and ids. */
-	if (cmd->state == QLA_TGT_STATE_PROCESSED) {
-		ql_dbg(ql_dbg_io, vha, 0xff00,
-		    "HOST-ABORT: state=PROCESSED.\n");
-	} else if (cmd->state == QLA_TGT_STATE_NEED_DATA) {
-		cmd->write_data_transferred = 0;
-		cmd->state = QLA_TGT_STATE_DATA_IN;
-
-		ql_dbg(ql_dbg_io, vha, 0xff01,
-		    "HOST-ABORT: state=DATA_IN.\n");
-
-		ha->tgt.tgt_ops->handle_data(cmd);
-		return;
-	} else {
-		ql_dbg(ql_dbg_io, vha, 0xff03,
-		    "HOST-ABORT: state=BAD(%d).\n",
-		    cmd->state);
-		dump_stack();
-	}
-
-	cmd->trc_flags |= TRC_FLUSH;
-	ha->tgt.tgt_ops->free_cmd(cmd);
-}
-
 /*
  * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
  */

drivers/scsi/qla2xxx/qla_target.h

@@ -889,9 +889,16 @@ struct qla_tgt_cmd {
 	unsigned int term_exchg:1;
 	unsigned int cmd_sent_to_fw:1;
 	unsigned int cmd_in_wq:1;
-	unsigned int aborted:1;
 	unsigned int released:1;
 
+	/*
+	 * This variable may be set from outside the LIO and I/O completion
+	 * callback functions. Do not declare this member variable as a
+	 * bitfield to avoid a read-modify-write operation when this variable
+	 * is set.
+	 */
+	unsigned int aborted;
+
 	struct scatterlist *sg;	/* cmd data buffer SG vector */
 	int sg_cnt;		/* SG segments count */
 	int bufflen;		/* cmd buffer length */
@@ -1101,7 +1108,5 @@ extern void qlt_do_generation_tick(struct scsi_qla_host *, int *);
 
 void qlt_send_resp_ctio(struct qla_qpair *, struct qla_tgt_cmd *, uint8_t,
     uint8_t, uint8_t, uint8_t);
-extern void qlt_abort_cmd_on_host_reset(struct scsi_qla_host *,
-    struct qla_tgt_cmd *);
 
 #endif /* __QLA_TARGET_H */

drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -504,7 +504,8 @@ static void tcm_qla2xxx_handle_data_work(struct work_struct *work)
 	if (cmd->aborted) {
 		spin_unlock_irqrestore(&cmd->cmd_lock, flags);
 
-		tcm_qla2xxx_free_cmd(cmd);
+		transport_generic_request_failure(&cmd->se_cmd,
+			TCM_CHECK_CONDITION_ABORT_CMD);
 		return;
 	}
 	spin_unlock_irqrestore(&cmd->cmd_lock, flags);