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From: Dan Williams <dan.j.williams@intel.com>
To: linux-scsi@vger.kernel.org
Cc: linux-ide@vger.kernel.org, Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Subject: [PATCH 22/24] libsas: add mutex for SMP task execution
Date: Fri, 16 Dec 2011 18:35:02 -0800	[thread overview]
Message-ID: <20111217023502.15036.91063.stgit@localhost6.localdomain6> (raw)
In-Reply-To: <20111217022912.15036.85808.stgit@localhost6.localdomain6>

From: Jeff Skirvin <jeffrey.d.skirvin@intel.com>

SAS does not tag SMP requests, and at least one lldd (isci) does not permit
more than one in-flight request at a time.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/scsi/libsas/sas_discover.c |    1 +
 drivers/scsi/libsas/sas_expander.c |   29 ++++++++++++++++-------------
 include/scsi/libsas.h              |    2 ++
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 3f41ab7..e7837f9 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -43,6 +43,7 @@ void sas_init_dev(struct domain_device *dev)
         case EDGE_DEV:
         case FANOUT_DEV:
                 INIT_LIST_HEAD(&dev->ex_dev.children);
+		mutex_init(&dev->ex_dev.cmd_mutex);
                 break;
         case SATA_DEV:
         case SATA_PM:
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 9d2bb32..fd77ea3 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -72,11 +72,13 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 	struct sas_internal *i =
 		to_sas_internal(dev->port->ha->core.shost->transportt);
 
+	mutex_lock(&dev->ex_dev.cmd_mutex);
 	for (retry = 0; retry < 3; retry++) {
 		task = sas_alloc_task(GFP_KERNEL);
-		if (!task)
-			return -ENOMEM;
-
+		if (!task) {
+			res = -ENOMEM;
+			break;
+		}
 		task->dev = dev;
 		task->task_proto = dev->tproto;
 		sg_init_one(&task->smp_task.smp_req, req, req_size);
@@ -94,7 +96,7 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 		if (res) {
 			del_timer(&task->timer);
 			SAS_DPRINTK("executing SMP task failed:%d\n", res);
-			goto ex_err;
+			break;
 		}
 
 		wait_for_completion(&task->completion);
@@ -104,21 +106,23 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 			i->dft->lldd_abort_task(task);
 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
 				SAS_DPRINTK("SMP task aborted and not done\n");
-				goto ex_err;
+				break;
 			}
 		}
 		if (task->task_status.resp == SAS_TASK_COMPLETE &&
 		    task->task_status.stat == SAM_STAT_GOOD) {
 			res = 0;
 			break;
-		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
-		      task->task_status.stat == SAS_DATA_UNDERRUN) {
+		}
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == SAS_DATA_UNDERRUN) {
 			/* no error, but return the number of bytes of
 			 * underrun */
 			res = task->task_status.residual;
 			break;
-		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
-		      task->task_status.stat == SAS_DATA_OVERRUN) {
+		}
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == SAS_DATA_OVERRUN) {
 			res = -EMSGSIZE;
 			break;
 		} else {
@@ -131,11 +135,10 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 			task = NULL;
 		}
 	}
-ex_err:
+	mutex_unlock(&dev->ex_dev.cmd_mutex);
+
 	BUG_ON(retry == 3 && task != NULL);
-	if (task != NULL) {
-		sas_free_task(task);
-	}
+	sas_free_task(task);
 	return res;
 }
 
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 6e8f25d..a8159f9 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -152,6 +152,8 @@ struct expander_device {
 
 	struct ex_phy *ex_phy;
 	struct sas_port *parent_port;
+
+	struct mutex cmd_mutex;
 };
 
 /* ---------- SATA device ---------- */


  parent reply	other threads:[~2011-12-17  2:35 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-17  2:33 [PATCH 00/24] libsas: eh reworks (ata-eh vs discovery, races, ...) Dan Williams
2011-12-17  2:33 ` [PATCH 01/24] workqueue: promote workqueue_lock to hard-irq safe Dan Williams
2011-12-17  2:33 ` [PATCH 02/24] workqueue: defer work to a draining queue Dan Williams
2011-12-19 21:49   ` Tejun Heo
2011-12-19 22:01     ` Dan Williams
2011-12-19 22:08       ` Tejun Heo
2011-12-19 22:25         ` Williams, Dan J
2011-12-17  2:33 ` [PATCH 03/24] scsi: use drain_workqueue Dan Williams
2011-12-17  2:33 ` [PATCH 04/24] libsas: remove unused ata_task_resp fields Dan Williams
2011-12-17 12:51   ` Sergei Shtylyov
2011-12-19  1:38   ` Jack Wang
2011-12-17  2:33 ` [PATCH 05/24] libsas: kill sas_slave_destroy Dan Williams
2011-12-17  2:33 ` [PATCH 06/24] libsas: fix domain_device leak Dan Williams
2011-12-19  2:32   ` Jack Wang
2011-12-17  2:33 ` [PATCH 07/24] libsas: fix leak of dev->sata_dev.identify_[packet_]device Dan Williams
2011-12-19  2:38   ` Jack Wang
2011-12-17  2:33 ` [PATCH 08/24] libsas: replace event locks with atomic bitops Dan Williams
2011-12-17  2:33 ` [PATCH 09/24] libsas: remove ata_port.lock management duties from lldds Dan Williams
2011-12-17  2:33 ` [PATCH 10/24] libsas: prevent domain rediscovery competing with ata error handling Dan Williams
2011-12-17  2:34 ` [PATCH 11/24] libsas: use ->set_dmamode to notify lldds of NCQ parameters Dan Williams
2011-12-17  2:34 ` [PATCH 12/24] libsas: kill invocation of scsi_eh_finish_cmd from sas_ata_task_done Dan Williams
2011-12-17  2:34 ` [PATCH 13/24] libsas: close error handling vs sas_ata_task_done() race Dan Williams
2011-12-17  2:34 ` [PATCH 14/24] libsas: prevent double completion of scmds from eh Dan Williams
2011-12-17 13:08   ` Sergei Shtylyov
2011-12-18 19:19     ` Dan Williams
2011-12-17 13:13   ` Sergei Shtylyov
2011-12-18 19:24     ` Dan Williams
2011-12-17  2:34 ` [PATCH 15/24] libsas: fix timeout vs completion race Dan Williams
2011-12-17  2:34 ` [PATCH 16/24] libsas: let libata handle command timeouts Dan Williams
2011-12-17  2:34 ` [PATCH 17/24] libsas: defer SAS_TASK_NEED_DEV_RESET commands to libata Dan Williams
2011-12-17  2:34 ` [PATCH 18/24] libsas: use libata-eh-reset for sata rediscovery fis transmit failures Dan Williams
2011-12-17  2:34 ` [PATCH 19/24] libsas: execute transport link resets with libata-eh via host workqueue Dan Williams
2011-12-17  2:34 ` [PATCH 20/24] libsas: sas_phy_enable via transport_sas_phy_reset Dan Williams
2011-12-17  2:34 ` [PATCH 21/24] libsas: Remove redundant phy state notification calls Dan Williams
2011-12-17  2:35 ` Dan Williams [this message]
2011-12-17  2:35 ` [PATCH 23/24] libsas: async ata-eh Dan Williams
2011-12-17  2:35 ` [PATCH 24/24] libsas: poll for ata device readiness after reset Dan Williams
2011-12-20  6:18   ` Jack Wang
2011-12-20  7:08     ` Williams, Dan J

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