scsi: target/core: Simplify the code for aborting SCSI commands

Instead of allowing the code that aborts a SCSI command to finish before
all iSCSI data frames have been received, make that code wait until all
iSCSI data frames have been received. Introduce a new member variable in
the target driver template to communicate that information from the iSCSI
target driver to the target core. This change allows to leave out the check
whether or not it is already safe to send the TASK_ABORTED reply from
transport_send_task_abort().

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 4 insertions, 20 deletions

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 39a700a41f6e..a5481dfeae8d 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1591,4 +1591,6 @@ const struct target_core_fabric_ops iscsi_ops = {
 	.tfc_tpg_nacl_attrib_attrs	= lio_target_nacl_attrib_attrs,
 	.tfc_tpg_nacl_auth_attrs	= lio_target_nacl_auth_attrs,
 	.tfc_tpg_nacl_param_attrs	= lio_target_nacl_param_attrs,
+
+	.write_pending_must_be_called	= true,
 };
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index caeedb112a85..868ee9c28c9a 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2584,7 +2584,8 @@ transport_generic_new_cmd(struct se_cmd *cmd)
 	 * Determine if frontend context caller is requesting the stopping of
 	 * this command for frontend exceptions.
 	 */
-	if (cmd->transport_state & CMD_T_STOP) {
+	if (cmd->transport_state & CMD_T_STOP &&
+	    !cmd->se_tfo->write_pending_must_be_called) {
 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 			 __func__, __LINE__, cmd->tag);
 
@@ -3297,25 +3298,6 @@ void transport_send_task_abort(struct se_cmd *cmd)
 	}
 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
-	/*
-	 * If there are still expected incoming fabric WRITEs, we wait
-	 * until until they have completed before sending a TASK_ABORTED
-	 * response.  This response with TASK_ABORTED status will be
-	 * queued back to fabric module by transport_check_aborted_status().
-	 */
-	if (cmd->data_direction == DMA_TO_DEVICE) {
-		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
-			spin_lock_irqsave(&cmd->t_state_lock, flags);
-			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
-				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-				goto send_abort;
-			}
-			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
-			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-			return;
-		}
-	}
-send_abort:
 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
 
 	transport_lun_remove_cmd(cmd);