Commit a71a5dc7 authored Apr 11, 2017 by Nicholas Bellinger

target: Fix compare_and_write_callback handling for non GOOD status



Following the bugfix for handling non SAM_STAT_GOOD COMPARE_AND_WRITE
status during COMMIT phase in commit 9b2792c3, 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>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

parent fe25cc34

drivers/target/target_core_sbc.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -507,8 +507,11 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes
	* been failed with a non-zero SCSI status.		* been failed with a non-zero SCSI status.
	*/		*/
	if (cmd->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);		" 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;		goto out;
	}		}