Commit 5f572526 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

qla2xxx: Fix incorrect tcm_qla2xxx_free_cmd use during TMR ABORT 



This patch drops two incorrect usages of tcm_qla2xxx_free_cmd()
during TMR ABORT within tcm_qla2xxx_handle_data_work() and
tcm_qla2xxx_aborted_task(), which where attempting to dispatch
into workqueue context to do tcm_qla2xxx_complete_free() and
subsequently invoke transport_generic_free_cmd().

This is incorrect because during TMR ABORT target-core will
drop the outstanding se_cmd->cmd_kref references once it has
quiesced the se_cmd via transport_wait_for_tasks(), and in
the case of qla2xxx it should not attempt to do it's own
transport_generic_free_cmd() once the abort has occured.

As reported by Pascal, this was originally manifesting as a
BUG_ON(cmd->cmd_in_wq) in qlt_free_cmd() during TMR ABORT,
with a LIO backend that had sufficently high enough WRITE
latency to trigger a host side TMR ABORT_TASK.

In addition, for the case in tcm_qla2xxx_write_pending_status()
and tcm_qla2xxx_handle_data_work() that waits for outstanding
FCP WRITE data transfer to complete before preceeding with a
TMR ABORT, avoid se_cmd->t_transport_stop_comp that is already
used by transport_wait_for_tasks() and use a qla2xxx internal
struct completion instead.

Reported-by: default avatarPascal de Bruijn <p.debruijn@unilogic.nl>
Tested-by: default avatarPascal de Bruijn <p.debruijn@unilogic.nl>
Acked-by: default avatarHimanshu Madhani <himanshu.madhani@cavium.com>
Cc: Quinn Tran <quinn.tran@cavium.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent fce50a2f

drivers/scsi/qla2xxx/qla_target.c

+4 −0
Original line number Diff line number Diff line
@@ -4079,6 +4079,8 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha, 
	cmd = &((struct qla_tgt_cmd *)se_sess->sess_cmd_map)[tag];

	memset(cmd, 0, sizeof(struct qla_tgt_cmd));



	init_completion(&cmd->write_pending_abort_comp);



	memcpy(&cmd->atio, atio, sizeof(*atio));

	cmd->state = QLA_TGT_STATE_NEW;

	cmd->tgt = vha->vha_tgt.qla_tgt;
@@ -5083,6 +5085,8 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha, 


	qlt_incr_num_pend_cmds(vha);

	INIT_LIST_HEAD(&cmd->cmd_list);

	init_completion(&cmd->write_pending_abort_comp);



	memcpy(&cmd->atio, atio, sizeof(*atio));



	cmd->tgt = vha->vha_tgt.qla_tgt;

drivers/scsi/qla2xxx/qla_target.h

+1 −0
Original line number Diff line number Diff line
@@ -868,6 +868,7 @@ struct qla_tgt_cmd { 
	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];



	spinlock_t cmd_lock;

	struct completion write_pending_abort_comp;

	/* to save extra sess dereferences */

	unsigned int conf_compl_supported:1;

	unsigned int sg_mapped:1;

drivers/scsi/qla2xxx/tcm_qla2xxx.c

+3 −33
Original line number Diff line number Diff line
@@ -415,6 +415,7 @@ static int tcm_qla2xxx_write_pending(struct se_cmd *se_cmd) 


static int tcm_qla2xxx_write_pending_status(struct se_cmd *se_cmd)

{

	struct qla_tgt_cmd *cmd = container_of(se_cmd, struct qla_tgt_cmd, se_cmd);

	unsigned long flags;

	/*

	 * Check for WRITE_PENDING status to determine if we need to wait for
@@ -424,8 +425,7 @@ static int tcm_qla2xxx_write_pending_status(struct se_cmd *se_cmd) 
	if (se_cmd->t_state == TRANSPORT_WRITE_PENDING ||

	    se_cmd->t_state == TRANSPORT_COMPLETE_QF_WP) {

		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);

		wait_for_completion_timeout(&se_cmd->t_transport_stop_comp,

						50);

		wait_for_completion(&cmd->write_pending_abort_comp);

		return 0;

	}

	spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
@@ -501,7 +501,6 @@ static int tcm_qla2xxx_handle_cmd(scsi_qla_host_t *vha, struct qla_tgt_cmd *cmd, 
static void tcm_qla2xxx_handle_data_work(struct work_struct *work)

{

	struct qla_tgt_cmd *cmd = container_of(work, struct qla_tgt_cmd, work);

	unsigned long flags;



	/*

	 * Ensure that the complete FCP WRITE payload has been received.
@@ -509,17 +508,6 @@ static void tcm_qla2xxx_handle_data_work(struct work_struct *work) 
	 */

	cmd->cmd_in_wq = 0;



	spin_lock_irqsave(&cmd->cmd_lock, flags);

	cmd->data_work = 1;

	if (cmd->aborted) {

		cmd->data_work_free = 1;

		spin_unlock_irqrestore(&cmd->cmd_lock, flags);



		tcm_qla2xxx_free_cmd(cmd);

		return;

	}

	spin_unlock_irqrestore(&cmd->cmd_lock, flags);



	cmd->vha->tgt_counters.qla_core_ret_ctio++;

	if (!cmd->write_data_transferred) {

		/*
@@ -527,7 +515,7 @@ static void tcm_qla2xxx_handle_data_work(struct work_struct *work) 
		 * waiting upon completion in tcm_qla2xxx_write_pending_status()

		 */

		if (cmd->se_cmd.transport_state & CMD_T_ABORTED) {

			complete(&cmd->se_cmd.t_transport_stop_comp);

			complete(&cmd->write_pending_abort_comp);

			return;

		}
@@ -753,31 +741,13 @@ static void tcm_qla2xxx_queue_tm_rsp(struct se_cmd *se_cmd) 
	qlt_xmit_tm_rsp(mcmd);

}



#define DATA_WORK_NOT_FREE(_cmd) (_cmd->data_work && !_cmd->data_work_free)

static void tcm_qla2xxx_aborted_task(struct se_cmd *se_cmd)

{

	struct qla_tgt_cmd *cmd = container_of(se_cmd,

				struct qla_tgt_cmd, se_cmd);

	unsigned long flags;



	if (qlt_abort_cmd(cmd))

		return;



	spin_lock_irqsave(&cmd->cmd_lock, flags);

	if ((cmd->state == QLA_TGT_STATE_NEW)||

	    ((cmd->state == QLA_TGT_STATE_DATA_IN) &&

		DATA_WORK_NOT_FREE(cmd))) {

		cmd->data_work_free = 1;

		spin_unlock_irqrestore(&cmd->cmd_lock, flags);

		/*

		 * cmd has not reached fw, Use this trigger to free it.

		 */

		tcm_qla2xxx_free_cmd(cmd);

		return;

	}

	spin_unlock_irqrestore(&cmd->cmd_lock, flags);

	return;



}



static void tcm_qla2xxx_clear_sess_lookup(struct tcm_qla2xxx_lport *,

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