diff options
Diffstat (limited to 'drivers/hv/channel_mgmt.c')
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 69 |
1 files changed, 53 insertions, 16 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 735f9363f2e4..0fabd410efd9 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -428,7 +428,6 @@ void vmbus_free_channels(void) { struct vmbus_channel *channel, *tmp; - mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, listentry) { /* hv_process_channel_removal() needs this */ @@ -436,7 +435,6 @@ void vmbus_free_channels(void) vmbus_device_unregister(channel->device_obj); } - mutex_unlock(&vmbus_connection.channel_mutex); } /* @@ -483,8 +481,10 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) list_add_tail(&newchannel->sc_list, &channel->sc_list); channel->num_sc++; spin_unlock_irqrestore(&channel->lock, flags); - } else + } else { + atomic_dec(&vmbus_connection.offer_in_progress); goto err_free_chan; + } } dev_type = hv_get_dev_type(newchannel); @@ -511,6 +511,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) if (!fnew) { if (channel->sc_creation_callback != NULL) channel->sc_creation_callback(newchannel); + atomic_dec(&vmbus_connection.offer_in_progress); return; } @@ -532,9 +533,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) * binding which eventually invokes the device driver's AddDevice() * method. */ - mutex_lock(&vmbus_connection.channel_mutex); ret = vmbus_device_register(newchannel->device_obj); - mutex_unlock(&vmbus_connection.channel_mutex); if (ret != 0) { pr_err("unable to add child device object (relid %d)\n", @@ -542,6 +541,8 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) kfree(newchannel->device_obj); goto err_deq_chan; } + + atomic_dec(&vmbus_connection.offer_in_progress); return; err_deq_chan: @@ -797,6 +798,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) newchannel = alloc_channel(); if (!newchannel) { vmbus_release_relid(offer->child_relid); + atomic_dec(&vmbus_connection.offer_in_progress); pr_err("Unable to allocate channel object\n"); return; } @@ -843,16 +845,38 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) rescind = (struct vmbus_channel_rescind_offer *)hdr; + /* + * The offer msg and the corresponding rescind msg + * from the host are guranteed to be ordered - + * offer comes in first and then the rescind. + * Since we process these events in work elements, + * and with preemption, we may end up processing + * the events out of order. Given that we handle these + * work elements on the same CPU, this is possible only + * in the case of preemption. In any case wait here + * until the offer processing has moved beyond the + * point where the channel is discoverable. + */ + + while (atomic_read(&vmbus_connection.offer_in_progress) != 0) { + /* + * We wait here until any channel offer is currently + * being processed. + */ + msleep(1); + } + mutex_lock(&vmbus_connection.channel_mutex); channel = relid2channel(rescind->child_relid); + mutex_unlock(&vmbus_connection.channel_mutex); if (channel == NULL) { /* - * This is very impossible, because in - * vmbus_process_offer(), we have already invoked - * vmbus_release_relid() on error. + * We failed in processing the offer message; + * we would have cleaned up the relid in that + * failure path. */ - goto out; + return; } spin_lock_irqsave(&channel->lock, flags); @@ -864,7 +888,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) if (channel->device_obj) { if (channel->chn_rescind_callback) { channel->chn_rescind_callback(channel); - goto out; + return; } /* * We will have to unregister this device from the @@ -875,13 +899,26 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) vmbus_device_unregister(channel->device_obj); put_device(dev); } - } else { - hv_process_channel_removal(channel, - channel->offermsg.child_relid); } - -out: - mutex_unlock(&vmbus_connection.channel_mutex); + if (channel->primary_channel != NULL) { + /* + * Sub-channel is being rescinded. Following is the channel + * close sequence when initiated from the driveri (refer to + * vmbus_close() for details): + * 1. Close all sub-channels first + * 2. Then close the primary channel. + */ + if (channel->state == CHANNEL_OPEN_STATE) { + /* + * The channel is currently not open; + * it is safe for us to cleanup the channel. + */ + mutex_lock(&vmbus_connection.channel_mutex); + hv_process_channel_removal(channel, + channel->offermsg.child_relid); + mutex_unlock(&vmbus_connection.channel_mutex); + } + } } void vmbus_hvsock_device_unregister(struct vmbus_channel *channel) |