From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Tue, 11 Apr 2017 23:24:16 +0000 (-0700)
Subject: target: Fix compare_and_write_callback handling for non GOOD status
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~8^2~54
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a1c2b01c310afa6490db8a7f704b8fe77f7107fd;p=firefly-linux-kernel-4.4.55.git

target: Fix compare_and_write_callback handling for non GOOD status

commit a71a5dc7f833943998e97ca8fa6a4c708a0ed1a9 upstream.

Following the bugfix for handling non SAM_STAT_GOOD COMPARE_AND_WRITE
status during COMMIT phase in commit 9b2792c3da1, the same bug exists
for the READ phase as well.

This would manifest first as a lost SCSI response, and eventual
hung task during fabric driver logout or re-login, as existing
shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref
to reach zero.

To address this bug, compare_and_write_callback() has been changed
to set post_ret = 1 and return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
as necessary to signal failure status.

Reported-by: Bill Borsari <wgb@datera.io>
Cc: Bill Borsari <wgb@datera.io>
Tested-by: Gary Guo <ghg@datera.io>
Cc: Gary Guo <ghg@datera.io>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 90c5dffc9fa4..608117819366 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -498,8 +498,11 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes
 	 * been failed with a non-zero SCSI status.
 	 */
 	if (cmd->scsi_status) {
-		pr_err("compare_and_write_callback: non zero scsi_status:"
+		pr_debug("compare_and_write_callback: non zero scsi_status:"
 			" 0x%02x\n", cmd->scsi_status);
+		*post_ret = 1;
+		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
+			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 		goto out;
 	}