From 402242c904432207515e3ccb4126ff0dcfba89ca Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Wed, 31 May 2017 15:52:43 -0500 Subject: [PATCH] target: fix SAM_STAT_BUSY/TASK_SET_FULL handling If the scsi status was not SAM_STAT_GOOD or there was no transport sense, we would ignore the scsi status and do a generic not ready LUN communication failure check condition failure. The problem is that LUN COMM failure is treated as a hard error sometimes and will cause apps to get IO errors instead of the OS's SCSI layer retrying. For example, the tcmu daemon will return SAM_STAT_QUEUE_FULL when memory runs low and can still make progress but wants the initiator to reduce the work load. Windows will fail this error directly the app instead of retrying. This patch is based on Nick's "target/iblock: Use -EAGAIN/-ENOMEM to propigate SAM BUSY/TASK_SET_FULL" patch here: http://comments.gmane.org/gmane.linux.scsi.target.devel/11301 but instead of only setting SAM_STAT_GOOD, SAM_STAT_TASK_SET_FULL and SAM_STAT_BUSY as success, it sets all non check condition status as success so they are passed back to the initiator, so passthrough type backends can return all SCSI status codes. Since only passthrough uses this, I was not sure if we wanted to add checks for non-passthrough and specific codes. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index b9122a5..8735243 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -725,15 +725,23 @@ EXPORT_SYMBOL(transport_copy_sense_to_cmd); void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status) { struct se_device *dev = cmd->se_dev; - int success = scsi_status == GOOD; + int success; unsigned long flags; cmd->scsi_status = scsi_status; - spin_lock_irqsave(&cmd->t_state_lock, flags); - if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) + switch (cmd->scsi_status) { + case SAM_STAT_CHECK_CONDITION: + if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) + success = 1; + else + success = 0; + break; + default: success = 1; + break; + } /* * Check for case where an explicit ABORT_TASK has been received -- 2.7.4