diff mbox

[1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex

Message ID 1476953642-2160-2-git-send-email-binoy.jayan@linaro.org
State New
Headers show

Commit Message

Binoy Jayan Oct. 20, 2016, 8:54 a.m. UTC 
Semaphores are going away in the future, so replace the semaphore
sync_request_sem with the a mutex lock. timeout_msecs is not used
for the lock sync_request_sem, so remove the timed locking too.

Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>

---
 drivers/scsi/smartpqi/smartpqi.h      |  4 +++-
 drivers/scsi/smartpqi/smartpqi_init.c | 31 ++++++-------------------------
 2 files changed, 9 insertions(+), 26 deletions(-)

-- 
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Comments

Arnd Bergmann Oct. 20, 2016, 9:06 a.m. UTC | #1 
On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote:
> Semaphores are going away in the future, so replace the semaphore

> sync_request_sem with the a mutex lock. timeout_msecs is not used

> for the lock sync_request_sem, so remove the timed locking too.

> 

> Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>


The patch looks correct to me, but I think if you remove the support
for handling timeouts, you should update the prototype of
pqi_submit_raid_request_synchronous to no longer pass the timeout
argument in the first place.

	Arnd
Arnd Bergmann Oct. 24, 2016, 10:10 a.m. UTC | #2 
On Monday, October 24, 2016 3:34:27 PM CEST Binoy Jayan wrote:
> Hi Arnd

> 

> On 20 October 2016 at 14:36, Arnd Bergmann <arnd@arndb.de> wrote:

> > On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote:

> >> Semaphores are going away in the future, so replace the semaphore

> >> sync_request_sem with the a mutex lock. timeout_msecs is not used

> >> for the lock sync_request_sem, so remove the timed locking too.

> >>

> >> Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>

> >

> > The patch looks correct to me, but I think if you remove the support

> > for handling timeouts, you should update the prototype of

> > pqi_submit_raid_request_synchronous to no longer pass the timeout

> > argument in the first place.

> 

> But we still need "timeout_msecs" in a call to

> pqi_submit_raid_request_synchronous_with_io_request()

> 

> drivers/scsi/smartpqi/smartpqi_init.c +3484


Why? If it's always zero, we can remove that too.

	Arnd
diff mbox

Patch

diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h
index 07b6444..b4559b1 100644
--- a/drivers/scsi/smartpqi/smartpqi.h
+++ b/drivers/scsi/smartpqi/smartpqi.h
@@ -19,6 +19,8 @@ 
 #if !defined(_SMARTPQI_H)
 #define _SMARTPQI_H
 
+#include <linux/mutex.h>
+
 #pragma pack(1)
 
 #define PQI_DEVICE_SIGNATURE	"PQI DREG"
@@ -961,7 +963,7 @@  struct pqi_ctrl_info {
 	unsigned int	num_heartbeats_requested;
 	struct timer_list heartbeat_timer;
 
-	struct semaphore sync_request_sem;
+	struct mutex sync_request_mutex;
 	struct semaphore lun_reset_sem;
 };
 
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index a535b26..4974f7e 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -3444,29 +3444,11 @@  static int pqi_submit_raid_request_synchronous(struct pqi_ctrl_info *ctrl_info,
 	unsigned long msecs_blocked;
 	size_t iu_length;
 
-	/*
-	 * Note that specifying PQI_SYNC_FLAGS_INTERRUPTABLE and a timeout value
-	 * are mutually exclusive.
-	 */
-
-	if (flags & PQI_SYNC_FLAGS_INTERRUPTABLE) {
-		if (down_interruptible(&ctrl_info->sync_request_sem))
+	if (flags & PQI_SYNC_FLAGS_INTERRUPTABLE)
+		if (mutex_lock_interruptible(&ctrl_info->sync_request_mutex))
 			return -ERESTARTSYS;
-	} else {
-		if (timeout_msecs == NO_TIMEOUT) {
-			down(&ctrl_info->sync_request_sem);
-		} else {
-			start_jiffies = jiffies;
-			if (down_timeout(&ctrl_info->sync_request_sem,
-				msecs_to_jiffies(timeout_msecs)))
-				return -ETIMEDOUT;
-			msecs_blocked =
-				jiffies_to_msecs(jiffies - start_jiffies);
-			if (msecs_blocked >= timeout_msecs)
-				return -ETIMEDOUT;
-			timeout_msecs -= msecs_blocked;
-		}
-	}
+	else
+		mutex_lock(&ctrl_info->sync_request_mutex);
 
 	io_request = pqi_alloc_io_request(ctrl_info);
 
@@ -3508,7 +3490,7 @@  static int pqi_submit_raid_request_synchronous(struct pqi_ctrl_info *ctrl_info,
 
 	pqi_free_io_request(io_request);
 
-	up(&ctrl_info->sync_request_sem);
+	mutex_unlock(&ctrl_info->sync_request_mutex);
 
 	return rc;
 }
@@ -5540,8 +5522,7 @@  static struct pqi_ctrl_info *pqi_alloc_ctrl_info(int numa_node)
 	INIT_DELAYED_WORK(&ctrl_info->rescan_work, pqi_rescan_worker);
 	INIT_DELAYED_WORK(&ctrl_info->update_time_work, pqi_update_time_worker);
 
-	sema_init(&ctrl_info->sync_request_sem,
-		PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS);
+	mutex_init(&ctrl_info->sync_request_mutex);
 	sema_init(&ctrl_info->lun_reset_sem, PQI_RESERVED_IO_SLOTS_LUN_RESET);
 
 	ctrl_info->ctrl_id = atomic_inc_return(&pqi_controller_count) - 1;