0006-scsi-target-core-Simplify-the-code-for-aborting-SCSI.patch

From 38da8b249f1708647ccc34cbbd0c58d7c65f236d Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 27 Nov 2018 15:52:01 -0800
Subject: [PATCH 6/8] 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>
---
 drivers/target/iscsi/iscsi_target_configfs.c |  2 ++
 drivers/target/target_core_transport.c       | 22 ++------------------
 include/target/target_core_fabric.h          |  7 +++++++
 3 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 95d0a22b2ad6..1a81386dd7f7 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1596,4 +1596,6 @@ 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 7c1c5f134ace..ae7f5182c2b3 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2592,7 +2592,8 @@ 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);
 
@@ -3305,25 +3306,6 @@ 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);
diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index eb9d0923c55c..6859277fc409 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h
@@ -101,6 +101,13 @@ struct target_core_fabric_ops {
 	struct configfs_attribute **tfc_tpg_nacl_attrib_attrs;
 	struct configfs_attribute **tfc_tpg_nacl_auth_attrs;
 	struct configfs_attribute **tfc_tpg_nacl_param_attrs;
+
+	/*
+	 * Set this member variable to true if the SCSI transport protocol
+	 * (e.g. iSCSI) requires that the Data-Out buffer is transferred in
+	 * its entirety before a command is aborted.
+	 */
+	bool write_pending_must_be_called;
 };
 
 int target_register_template(const struct target_core_fabric_ops *fo);
-- 
2.23.0