[PATCH 0/5] Updates for tcm_loop

[PATCH 0/5] Updates for tcm_loop

[Hannes Reinecke]

Hi Nic,

here are some updates to tcm_loop I've done during ALUA testing.
I've implemented a 'transport_state' attribute to simulate
transport failure and added command abort callbacks.

Hannes Reinecke (5):
  tcm_loop: Check for valid hba in tcm_loop_drop_nexus()
  tcm_loop: Implement transport offline
  tcm_loop: separate out tcm_loop_issue_tmr
  tcm_loop: TCQ and command abort support
  tcm_loop: Implement target reset

 drivers/target/loopback/tcm_loop.c | 233 +++++++++++++++++++++++++++++++------
 drivers/target/loopback/tcm_loop.h |   6 +
 include/target/target_core_base.h  |   1 +
 3 files changed, 204 insertions(+), 36 deletions(-)

-- 
1.7.12.4

[PATCH 1/5] tcm_loop: Check for valid hba in tcm_loop_drop_nexus()

[Hannes Reinecke]

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/loopback/tcm_loop.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 0f6d69d..57d5a95 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -932,7 +932,10 @@ static int tcm_loop_drop_nexus(
 	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
 
-	tl_nexus = tpg->tl_hba->tl_nexus;
+	if (!tl_hba)
+		return -ENODEV;
+
+	tl_nexus = tl_hba->tl_nexus;
 	if (!tl_nexus)
 		return -ENODEV;
 
-- 
1.7.12.4

[PATCH 2/5] tcm_loop: Implement transport offline

[Hannes Reinecke]

Add attribute 'transport_status' to simulate link failure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/loopback/tcm_loop.c | 53 +++++++++++++++++++++++++++++++++++++-
 drivers/target/loopback/tcm_loop.h |  4 +++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 57d5a95..f81ebe4 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -178,7 +178,10 @@ static void tcm_loop_submission_work(struct work_struct *work)
 		set_host_byte(sc, DID_NO_CONNECT);
 		goto out_done;
 	}
-
+	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
+		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
+		goto out_done;
+	}
 	tl_nexus = tl_hba->tl_nexus;
 	if (!tl_nexus) {
 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
@@ -1064,8 +1067,56 @@ check_newline:
 
 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
 
+static ssize_t tcm_loop_tpg_show_transport_status(
+	struct se_portal_group *se_tpg,
+	char *page)
+{
+	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
+			struct tcm_loop_tpg, tl_se_tpg);
+	const char *status = NULL;
+	ssize_t ret = -EINVAL;
+
+	switch (tl_tpg->tl_transport_status) {
+	case TCM_TRANSPORT_ONLINE:
+		status = "online";
+		break;
+	case TCM_TRANSPORT_OFFLINE:
+		status = "offline";
+		break;
+	default:
+		break;
+	}
+
+	if (status)
+		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
+
+	return ret;
+}
+
+static ssize_t tcm_loop_tpg_store_transport_status(
+	struct se_portal_group *se_tpg,
+	const char *page,
+	size_t count)
+{
+	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
+			struct tcm_loop_tpg, tl_se_tpg);
+
+	if (!strncmp(page, "online", 6)) {
+		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
+		return count;
+	}
+	if (!strncmp(page, "offline", 7)) {
+		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
+		return count;
+	}
+	return -EINVAL;
+}
+
+TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
+
 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
 	&tcm_loop_tpg_nexus.attr,
+	&tcm_loop_tpg_transport_status.attr,
 	NULL,
 };
 
diff --git a/drivers/target/loopback/tcm_loop.h b/drivers/target/loopback/tcm_loop.h
index dd7a84e..56528f7 100644
--- a/drivers/target/loopback/tcm_loop.h
+++ b/drivers/target/loopback/tcm_loop.h
@@ -40,8 +40,12 @@ struct tcm_loop_nacl {
 	struct se_node_acl se_node_acl;
 };
 
+#define TCM_TRANSPORT_ONLINE 0
+#define TCM_TRANSPORT_OFFLINE 1
+
 struct tcm_loop_tpg {
 	unsigned short tl_tpgt;
+	unsigned short tl_transport_status;
 	atomic_t tl_tpg_port_count;
 	struct se_portal_group tl_se_tpg;
 	struct tcm_loop_hba *tl_hba;
-- 
1.7.12.4

[PATCH 3/5] tcm_loop: separate out tcm_loop_issue_tmr

[Hannes Reinecke]

No functional change.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/loopback/tcm_loop.c | 83 +++++++++++++++++++++++---------------
 include/target/target_core_base.h  |  1 +
 2 files changed, 51 insertions(+), 33 deletions(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index f81ebe4..7232976 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -245,41 +245,21 @@ static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
  * Called from SCSI EH process context to issue a LUN_RESET TMR
  * to struct scsi_device
  */
-static int tcm_loop_device_reset(struct scsi_cmnd *sc)
+static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
+			      struct tcm_loop_nexus *tl_nexus,
+			      int lun, enum tcm_tmreq_table tmr)
 {
 	struct se_cmd *se_cmd = NULL;
-	struct se_portal_group *se_tpg;
 	struct se_session *se_sess;
+	struct se_portal_group *se_tpg;
 	struct tcm_loop_cmd *tl_cmd = NULL;
-	struct tcm_loop_hba *tl_hba;
-	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_tmr *tl_tmr = NULL;
-	struct tcm_loop_tpg *tl_tpg;
-	int ret = FAILED, rc;
-	/*
-	 * Locate the tcm_loop_hba_t pointer
-	 */
-	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
-	/*
-	 * Locate the tl_nexus and se_sess pointers
-	 */
-	tl_nexus = tl_hba->tl_nexus;
-	if (!tl_nexus) {
-		pr_err("Unable to perform device reset without"
-				" active I_T Nexus\n");
-		return FAILED;
-	}
-	se_sess = tl_nexus->se_sess;
-	/*
-	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
-	 */
-	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
-	se_tpg = &tl_tpg->tl_se_tpg;
+	int ret = TMR_FUNCTION_FAILED, rc;
 
 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 	if (!tl_cmd) {
 		pr_err("Unable to allocate memory for tl_cmd\n");
-		return FAILED;
+		return ret;
 	}
 
 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
@@ -290,6 +270,8 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 
 	se_cmd = &tl_cmd->tl_se_cmd;
+	se_tpg = &tl_tpg->tl_se_tpg;
+	se_sess = tl_nexus->se_sess;
 	/*
 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 	 */
@@ -297,17 +279,20 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 				DMA_NONE, MSG_SIMPLE_TAG,
 				&tl_cmd->tl_sense_buf[0]);
 
-	rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
+	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
 	if (rc < 0)
 		goto release;
+
 	/*
-	 * Locate the underlying TCM struct se_lun from sc->device->lun
+	 * Locate the underlying TCM struct se_lun
 	 */
-	if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
+	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
+		ret = TMR_LUN_DOES_NOT_EXIST;
 		goto release;
+	}
 	/*
-	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
-	 * to wake us up.
+	 * Queue the TMR to TCM Core and sleep waiting for
+	 * tcm_loop_queue_tm_rsp() to wake us up.
 	 */
 	transport_generic_handle_tmr(se_cmd);
 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
@@ -315,8 +300,7 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	 * The TMR LUN_RESET has completed, check the response status and
 	 * then release allocations.
 	 */
-	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
-		SUCCESS : FAILED;
+	ret = se_cmd->se_tmr_req->response;
 release:
 	if (se_cmd)
 		transport_generic_free_cmd(se_cmd, 1);
@@ -326,6 +310,39 @@ release:
 	return ret;
 }
 
+/*
+ * Called from SCSI EH process context to issue a LUN_RESET TMR
+ * to struct scsi_device
+ */
+static int tcm_loop_device_reset(struct scsi_cmnd *sc)
+{
+	struct tcm_loop_hba *tl_hba;
+	struct tcm_loop_nexus *tl_nexus;
+	struct tcm_loop_tpg *tl_tpg;
+	int ret = FAILED;
+
+	/*
+	 * Locate the tcm_loop_hba_t pointer
+	 */
+	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
+	/*
+	 * Locate the tl_nexus and se_sess pointers
+	 */
+	tl_nexus = tl_hba->tl_nexus;
+	if (!tl_nexus) {
+		pr_err("Unable to perform device reset without"
+				" active I_T Nexus\n");
+		return FAILED;
+	}
+	/*
+	 * Locate the tl_tpg pointer from TargetID in sc->device->id
+	 */
+	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
+	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus,
+				 sc->device->lun, TMR_LUN_RESET);
+	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
+}
+
 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 {
 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 34181ad..637ea73 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -227,6 +227,7 @@ enum tcm_tmreq_table {
 
 /* fabric independent task management response values */
 enum tcm_tmrsp_table {
+	TMR_FUNCTION_FAILED		= 0,
 	TMR_FUNCTION_COMPLETE		= 1,
 	TMR_TASK_DOES_NOT_EXIST		= 2,
 	TMR_LUN_DOES_NOT_EXIST		= 3,
-- 
1.7.12.4

[PATCH 4/5] tcm_loop: TCQ and command abort support

[Hannes Reinecke]

Implement TCQ support, which enables us to do proper command
abort, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/loopback/tcm_loop.c | 71 +++++++++++++++++++++++++++++++++++---
 drivers/target/loopback/tcm_loop.h |  2 ++
 2 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 7232976..febe166 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -135,6 +135,21 @@ static int tcm_loop_change_queue_depth(
 	return sdev->queue_depth;
 }
 
+static int tcm_loop_change_queue_type(struct scsi_device *sdev, int tag)
+{
+	if (sdev->tagged_supported) {
+		scsi_set_tag_type(sdev, tag);
+
+		if (tag)
+			scsi_activate_tcq(sdev, sdev->queue_depth);
+		else
+			scsi_deactivate_tcq(sdev, sdev->queue_depth);
+	} else
+		tag = 0;
+
+	return tag;
+}
+
 /*
  * Locate the SAM Task Attr from struct scsi_cmnd *
  */
@@ -236,6 +251,7 @@ static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 	}
 
 	tl_cmd->sc = sc;
+	tl_cmd->sc_cmd_tag = sc->tag;
 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
 	return 0;
@@ -247,7 +263,7 @@ static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
  */
 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 			      struct tcm_loop_nexus *tl_nexus,
-			      int lun, enum tcm_tmreq_table tmr)
+			      int lun, int task, enum tcm_tmreq_table tmr)
 {
 	struct se_cmd *se_cmd = NULL;
 	struct se_session *se_sess;
@@ -283,6 +299,9 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 	if (rc < 0)
 		goto release;
 
+	if (tmr == TMR_ABORT_TASK)
+		se_cmd->se_tmr_req->ref_task_tag = task;
+
 	/*
 	 * Locate the underlying TCM struct se_lun
 	 */
@@ -310,6 +329,36 @@ release:
 	return ret;
 }
 
+static int tcm_loop_abort_task(struct scsi_cmnd *sc)
+{
+	struct tcm_loop_hba *tl_hba;
+	struct tcm_loop_nexus *tl_nexus;
+	struct tcm_loop_tpg *tl_tpg;
+	int ret = FAILED;
+
+	/*
+	 * Locate the tcm_loop_hba_t pointer
+	 */
+	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
+	/*
+	 * Locate the tl_nexus and se_sess pointers
+	 */
+	tl_nexus = tl_hba->tl_nexus;
+	if (!tl_nexus) {
+		pr_err("Unable to perform device reset without"
+				" active I_T Nexus\n");
+		return FAILED;
+	}
+
+	/*
+	 * Locate the tl_tpg pointer from TargetID in sc->device->id
+	 */
+	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
+	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
+				 sc->tag, TMR_ABORT_TASK);
+	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
+}
+
 /*
  * Called from SCSI EH process context to issue a LUN_RESET TMR
  * to struct scsi_device
@@ -338,8 +387,8 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
 	 */
 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
-	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus,
-				 sc->device->lun, TMR_LUN_RESET);
+	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
+				 0, TMR_LUN_RESET);
 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 }
 
@@ -351,6 +400,15 @@ static int tcm_loop_slave_alloc(struct scsi_device *sd)
 
 static int tcm_loop_slave_configure(struct scsi_device *sd)
 {
+	if (sd->tagged_supported) {
+		scsi_activate_tcq(sd, sd->queue_depth);
+		scsi_adjust_queue_depth(sd, MSG_SIMPLE_TAG,
+					sd->host->cmd_per_lun);
+	} else {
+		scsi_adjust_queue_depth(sd, 0,
+					sd->host->cmd_per_lun);
+	}
+
 	return 0;
 }
 
@@ -360,6 +418,8 @@ static struct scsi_host_template tcm_loop_driver_template = {
 	.name			= "TCM_Loopback",
 	.queuecommand		= tcm_loop_queuecommand,
 	.change_queue_depth	= tcm_loop_change_queue_depth,
+	.change_queue_type	= tcm_loop_change_queue_type,
+	.eh_abort_handler = tcm_loop_abort_task,
 	.eh_device_reset_handler = tcm_loop_device_reset,
 	.can_queue		= 1024,
 	.this_id		= -1,
@@ -719,7 +779,10 @@ static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 
 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 {
-	return 1;
+	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
+			struct tcm_loop_cmd, tl_se_cmd);
+
+	return tl_cmd->sc_cmd_tag;
 }
 
 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
diff --git a/drivers/target/loopback/tcm_loop.h b/drivers/target/loopback/tcm_loop.h
index 56528f7..54c59d0 100644
--- a/drivers/target/loopback/tcm_loop.h
+++ b/drivers/target/loopback/tcm_loop.h
@@ -10,6 +10,8 @@
 struct tcm_loop_cmd {
 	/* State of Linux/SCSI CDB+Data descriptor */
 	u32 sc_cmd_state;
+	/* Tagged command queueing */
+	u32 sc_cmd_tag;
 	/* Pointer to the CDB+Data descriptor from Linux/SCSI subsystem */
 	struct scsi_cmnd *sc;
 	/* The TCM I/O descriptor that is accessed via container_of() */
-- 
1.7.12.4

[PATCH 5/5] tcm_loop: Implement target reset

[Hannes Reinecke]

Implement target reset by resetting the transport status.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/loopback/tcm_loop.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index febe166..d52c0aa 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -392,6 +392,32 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 }
 
+static int tcm_loop_target_reset(struct scsi_cmnd *sc)
+{
+	struct tcm_loop_hba *tl_hba;
+	struct tcm_loop_tpg *tl_tpg;
+	int ret = FAILED;
+
+	/*
+	 * Locate the tcm_loop_hba_t pointer
+	 */
+	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
+	if (!tl_hba) {
+		pr_err("Unable to perform device reset without"
+				" active I_T Nexus\n");
+		return FAILED;
+	}
+	/*
+	 * Locate the tl_tpg pointer from TargetID in sc->device->id
+	 */
+	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
+	if (tl_tpg) {
+		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
+		return SUCCESS;
+	}
+	return FAILED;
+}
+
 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 {
 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
@@ -421,6 +447,7 @@ static struct scsi_host_template tcm_loop_driver_template = {
 	.change_queue_type	= tcm_loop_change_queue_type,
 	.eh_abort_handler = tcm_loop_abort_task,
 	.eh_device_reset_handler = tcm_loop_device_reset,
+	.eh_target_reset_handler = tcm_loop_target_reset,
 	.can_queue		= 1024,
 	.this_id		= -1,
 	.sg_tablesize		= 256,
-- 
1.7.12.4

Re: [PATCH 0/5] Updates for tcm_loop

[Nicholas A. Bellinger]

On Wed, 2013-10-16 at 09:12 +0200, Hannes Reinecke wrote:
> Hi Nic,
> 
> here are some updates to tcm_loop I've done during ALUA testing.
> I've implemented a 'transport_state' attribute to simulate
> transport failure and added command abort callbacks.
> 
> Hannes Reinecke (5):
>   tcm_loop: Check for valid hba in tcm_loop_drop_nexus()
>   tcm_loop: Implement transport offline
>   tcm_loop: separate out tcm_loop_issue_tmr
>   tcm_loop: TCQ and command abort support
>   tcm_loop: Implement target reset
> 
>  drivers/target/loopback/tcm_loop.c | 233 +++++++++++++++++++++++++++++++------
>  drivers/target/loopback/tcm_loop.h |   6 +
>  include/target/target_core_base.h  |   1 +
>  3 files changed, 204 insertions(+), 36 deletions(-)
> 

Everything looks reasonable to me..  Applied to target-pending/for-next.

Thanks Hannes!

--nab