diff mbox

[PATCH-v2,1/2] target: Avoid DataIN transfers for non-GOOD SAM status

Message ID 1457161634-15756-1-git-send-email-nab@daterainc.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Nicholas A. Bellinger March 5, 2016, 7:07 a.m. UTC 
From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch modifies existing transport_complete_*() code
to avoid invoking target_core_fabric_ops->queue_data_in()
driver callbacks for I/O READs with non-GOOD SAM status.

Some initiators expect GOOD status when a DATA-IN payload
transfer is involved, so to be safe go ahead and always
invoke target_core_fabric_ops->queue_status() to generate
fabric responses instead.

Note this is a prerequisite for IBLOCK supporting retriable
status, so SAM_STAT_BUSY + SAM_STAT_TASK_SET_FULL always
generates fabric driver responses instead of initiating
DataIN payload transfer when non-GOOD status is present

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_transport.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Christoph Hellwig March 5, 2016, 9:01 p.m. UTC | #1 
Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>
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diff mbox

Patch

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index f5ad9e0..784dd22 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1997,6 +1997,9 @@  static void transport_complete_qf(struct se_cmd *cmd)
 
 	switch (cmd->data_direction) {
 	case DMA_FROM_DEVICE:
+		if (cmd->scsi_status)
+			goto queue_status;
+
 		trace_target_cmd_complete(cmd);
 		ret = cmd->se_tfo->queue_data_in(cmd);
 		break;
@@ -2007,6 +2010,7 @@  static void transport_complete_qf(struct se_cmd *cmd)
 		}
 		/* Fall through for DMA_TO_DEVICE */
 	case DMA_NONE:
+queue_status:
 		trace_target_cmd_complete(cmd);
 		ret = cmd->se_tfo->queue_status(cmd);
 		break;
@@ -2128,6 +2132,9 @@  static void target_complete_ok_work(struct work_struct *work)
 queue_rsp:
 	switch (cmd->data_direction) {
 	case DMA_FROM_DEVICE:
+		if (cmd->scsi_status)
+			goto queue_status;
+
 		atomic_long_add(cmd->data_length,
 				&cmd->se_lun->lun_stats.tx_data_octets);
 		/*
@@ -2167,6 +2174,7 @@  queue_rsp:
 		}
 		/* Fall through for DMA_TO_DEVICE */
 	case DMA_NONE:
+queue_status:
 		trace_target_cmd_complete(cmd);
 		ret = cmd->se_tfo->queue_status(cmd);
 		if (ret == -EAGAIN || ret == -ENOMEM)