Re: [PATCH v2 06/17] tcm_qla2xxx: Do not allow aborted cmd to advance.

[Bart Van Assche]

On Tue, 2017-05-30 at 10:54 -0700, Himanshu Madhani wrote:
> From: Quinn Tran 
> 
> In case of hardware queue full, commands can loop between
> TCM stack and tcm_qla2xx shim layers for retry. While command
> is waiting for retry, task mgmt can get ahead and abort the
> cmmand that encountered queue full condition. Fix this by
> dropping the command, if task mgmt has already started the
> command free process.

Although I think this is a check that should be performed by the target core
instead of each target driver:

Reviewed-by: Bart Van Assche 

[PATCH v2 06/17] tcm_qla2xxx: Do not allow aborted cmd to advance.

[Himanshu Madhani]

From: Quinn Tran 

In case of hardware queue full, commands can loop between
TCM stack and tcm_qla2xx shim layers for retry. While command
is waiting for retry, task mgmt can get ahead and abort the
cmmand that encountered queue full condition. Fix this by
dropping the command, if task mgmt has already started the
command free process.

Acked-by: Nicholas Bellinger 
Signed-off-by: Quinn Tran 
Signed-off-by: Himanshu Madhani 
---
 drivers/scsi/qla2xxx/tcm_qla2xxx.c | 13 +
 1 file changed, 13 insertions(+)

diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c 
b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 7443e4efa3ae..1131fe8e2dd2 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -686,6 +686,19 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
struct qla_tgt_cmd, se_cmd);
int xmit_type = QLA_TGT_XMIT_STATUS;
 
+   if (cmd->aborted) {
+   /*
+* Cmd can loop during Q-full. tcm_qla2xxx_aborted_task
+* can get ahead of this cmd. tcm_qla2xxx_aborted_task
+* already kick start the free.
+*/
+   pr_debug(
+   "queue_data_in aborted cmd[%p] refcount %d transport_state 
%x, t_state %x, se_cmd_flags %x\n",
+   cmd, kref_read(&cmd->se_cmd.cmd_kref),
+   cmd->se_cmd.transport_state, cmd->se_cmd.t_state,
+   cmd->se_cmd.se_cmd_flags);
+   return 0;
+   }
cmd->bufflen = se_cmd->data_length;
cmd->sg = NULL;
cmd->sg_cnt = 0;
-- 
2.12.0