[PATCH 3/6] Drivers: hv: vmbus: Handle both rescind and offer messages in the same context

[K. Y. Srinivasan]

Execute both ressind and offer messages in the same work context. This 
serializes these
operations and naturally addresses the various corner cases.

Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
---
 drivers/hv/channel_mgmt.c |   71 ++++++++++++--------------------------------
 1 files changed, 20 insertions(+), 51 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index b933891..af53168 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -244,29 +244,6 @@ void hv_process_channel_removal(struct vmbus_channel 
*channel, u32 relid)
        free_channel(channel);
 }
 
-/*
- * vmbus_process_rescind_offer -
- * Rescind the offer by initiating a device removal
- */
-static void vmbus_process_rescind_offer(struct work_struct *work)
-{
-       struct vmbus_channel *channel = container_of(work,
-                                                    struct vmbus_channel,
-                                                    work);
-       struct device *dev;
-
-       if (channel->device_obj) {
-               dev = get_device(&channel->device_obj->device);
-               if (dev) {
-                       vmbus_device_unregister(channel->device_obj);
-                       put_device(dev);
-               }
-       } else {
-               hv_process_channel_removal(channel,
-                                          channel->offermsg.child_relid);
-       }
-}
-
 void vmbus_free_channels(void)
 {
        struct vmbus_channel *channel;
@@ -281,11 +258,8 @@ void vmbus_free_channels(void)
  * vmbus_process_offer - Process the offer by creating a channel/device
  * associated with this offer
  */
-static void vmbus_process_offer(struct work_struct *work)
+static void vmbus_process_offer(struct vmbus_channel *newchannel)
 {
-       struct vmbus_channel *newchannel = container_of(work,
-                                                       struct vmbus_channel,
-                                                       work);
        struct vmbus_channel *channel;
        bool fnew = true;
        bool enq = false;
@@ -351,7 +325,7 @@ static void vmbus_process_offer(struct work_struct *work)
                        if (channel->sc_creation_callback != NULL)
                                channel->sc_creation_callback(newchannel);
 
-                       goto done_init_rescind;
+                       return;
                }
 
                goto err_free_chan;
@@ -392,15 +366,9 @@ static void vmbus_process_offer(struct work_struct *work)
                kfree(newchannel->device_obj);
                goto err_free_chan;
        }
-done_init_rescind:
-       spin_lock_irqsave(&newchannel->lock, flags);
-       /* The next possible work is rescind handling */
-       INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
-       /* Check if rescind offer was already received */
-       if (newchannel->rescind)
-               queue_work(newchannel->controlwq, &newchannel->work);
-       spin_unlock_irqrestore(&newchannel->lock, flags);
+
        return;
+
 err_free_chan:
        free_channel(newchannel);
 }
@@ -526,8 +494,7 @@ static void vmbus_onoffer(struct 
vmbus_channel_message_header *hdr)
        newchannel->monitor_grp = (u8)offer->monitorid / 32;
        newchannel->monitor_bit = (u8)offer->monitorid % 32;
 
-       INIT_WORK(&newchannel->work, vmbus_process_offer);
-       queue_work(newchannel->controlwq, &newchannel->work);
+       vmbus_process_offer(newchannel);
 }
 
 /*
@@ -540,28 +507,30 @@ static void vmbus_onoffer_rescind(struct 
vmbus_channel_message_header *hdr)
        struct vmbus_channel_rescind_offer *rescind;
        struct vmbus_channel *channel;
        unsigned long flags;
+       struct device *dev;
 
        rescind = (struct vmbus_channel_rescind_offer *)hdr;
        channel = relid2channel(rescind->child_relid);
 
-       if (channel == NULL)
-               /* Just return here, no channel found */
+       if (channel == NULL) {
+               hv_process_channel_removal(NULL, rescind->child_relid);
                return;
+       }
 
        spin_lock_irqsave(&channel->lock, flags);
        channel->rescind = true;
-       /*
-        * channel->work.func != vmbus_process_rescind_offer means we are still
-        * processing offer request and the rescind offer processing should be
-        * postponed. It will be done at the very end of vmbus_process_offer()
-        * as rescind flag is being checked there.
-        */
-       if (channel->work.func == vmbus_process_rescind_offer)
-               /* work is initialized for vmbus_process_rescind_offer() from
-                * vmbus_process_offer() where the channel got created */
-               queue_work(channel->controlwq, &channel->work);
-
        spin_unlock_irqrestore(&channel->lock, flags);
+
+       if (channel->device_obj) {
+               dev = get_device(&channel->device_obj->device);
+               if (dev) {
+                       vmbus_device_unregister(channel->device_obj);
+                       put_device(dev);
+               }
+       } else {
+               hv_process_channel_removal(channel,
+                                          channel->offermsg.child_relid);
+       }
 }
 
 /*
-- 
1.7.4.1

_______________________________________________
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel