From: Stephen Hemminger <stephen@networkplumber.org>
Date: Thu, 18 May 2017 09:18:12 -0700
Patch-mainline: v4.13-rc1
Subject: scsi: storvsc: remove unnecessary channel inbound lock
Git-commit: 2371cd90abe3fa1b88e15111abf2cc0a26db6e52
References: fate#323887
In storvsc driver, inbound messages do not go through inbound lock. The
only effect of this lock was is to provide a barrier for connect and
remove logic.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Olaf Hering <ohering@suse.de>
---
drivers/hv/channel_mgmt.c | 1 -
drivers/scsi/storvsc_drv.c | 8 +++-----
include/linux/hyperv.h | 1 -
3 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -332,7 +332,6 @@ static struct vmbus_channel *alloc_channel(void)
if (!channel)
return NULL;
- spin_lock_init(&channel->inbound_lock);
spin_lock_init(&channel->lock);
INIT_LIST_HEAD(&channel->sc_list);
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1206,13 +1206,13 @@ static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
static int storvsc_dev_remove(struct hv_device *device)
{
struct storvsc_device *stor_device;
- unsigned long flags;
stor_device = hv_get_drvdata(device);
- spin_lock_irqsave(&device->channel->inbound_lock, flags);
stor_device->destroy = true;
- spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+ /* Make sure flag is set before waiting */
+ wmb();
/*
* At this point, all outbound traffic should be disable. We
@@ -1229,9 +1229,7 @@ static int storvsc_dev_remove(struct hv_device *device)
* we have drained - to drain the outgoing packets, we need to
* allow incoming packets.
*/
- spin_lock_irqsave(&device->channel->inbound_lock, flags);
hv_set_drvdata(device, NULL);
- spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
/* Close the channel */
vmbus_close(device->channel);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -744,7 +744,6 @@ struct vmbus_channel {
u32 ringbuffer_pagecount;
struct hv_ring_buffer_info outbound; /* send to parent */
struct hv_ring_buffer_info inbound; /* receive from parent */
- spinlock_t inbound_lock;
struct vmbus_close_msg close_msg;