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 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>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index f9250b3c3fd411a07567b893263c5f1f527013fb..a0ad618f1b1ada886058322a0224b26b0f74ccb0 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -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.
         */
        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;
        }