The spinlock is (now) *not used to protect test-and-set accesses
to attributes of the structure or sc_list operations.
There is, AFAICT, a distinct lack of {WRITE,READ}_ONCE()s in the
handling of channel->state, but the changes below do not seem to
make things "worse". ;-)
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
---
drivers/hv/channel.c | 6 +-----
drivers/hv/channel_mgmt.c | 1 -
include/linux/hyperv.h | 6 ------
3 files changed, 1 insertion(+), 12 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 8848d1548b3f2..3ebda7707e46a 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -129,12 +129,8 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
send_pages = newchannel->ringbuffer_send_offset;
recv_pages = newchannel->ringbuffer_pagecount - send_pages;
- spin_lock_irqsave(&newchannel->lock, flags);
- if (newchannel->state != CHANNEL_OPEN_STATE) {
- spin_unlock_irqrestore(&newchannel->lock, flags);
+ if (newchannel->state != CHANNEL_OPEN_STATE)
return -EINVAL;
- }
- spin_unlock_irqrestore(&newchannel->lock, flags);
newchannel->state = CHANNEL_OPENING_STATE;
newchannel->onchannel_callback = onchannelcallback;
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 92f8bb2077a94..591106cf58fc0 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -317,7 +317,6 @@ static struct vmbus_channel *alloc_channel(void)
return NULL;
spin_lock_init(&channel->sched_lock);
- spin_lock_init(&channel->lock);
init_completion(&channel->rescind_event);
INIT_LIST_HEAD(&channel->sc_list);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 690394b79d727..38100e80360ac 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -840,12 +840,6 @@ struct vmbus_channel {
*/
void (*chn_rescind_callback)(struct vmbus_channel *channel);
- /*
- * The spinlock to protect the structure. It is being used to protect
- * test-and-set access to various attributes of the structure as well
- * as all sc_list operations.
- */
- spinlock_t lock;
/*
* All Sub-channels of a primary channel are linked here.
*/
--
2.25.1
