FAILED: patch "[PATCH] Drivers: hv: vmbus: Fix a rescind handling bug" failed to apply to 4.4-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
Quoted 1 line
From
ccb61f8a99e6c29df4fb96a65dad4fad740d5be9Mon Sep 17 00:00:00 2001
From: "K. Y. Srinivasan" <[email protected]>
Date: Thu, 22 Dec 2016 16:54:00 -0800
Subject: [PATCH] Drivers: hv: vmbus: Fix a rescind handling bug
The host can rescind a channel that has been offered to the guest and once the channel is rescinded, the host does not respond to any requests on that channel. Deal with the case where the guest may be blocked waiting for a response from the host.
drivers/hv/channel.c +18 -0
@@ -157,6 +157,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, }init_completion (&open_info->waitevent); + open_info->waiting_channel = newchannel; open_msg = (struct vmbus_channel_open_channel *)open_info->msg; open_msg->header.msgtype =CHANNELMSG_OPENCHANNEL ;
@@ -194,6 +195,11 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,list_del (&open_info->msglistentry);spin_unlock_irqrestore (&vmbus_connection.channelmsg_lock, flags); +if (newchannel->rescind) { + err = -ENODEV ; + goto error_free_gpadl; + } +if (open_info->response.open_result.status) { err = -EAGAIN ; goto error_free_gpadl;
@@ -405,6 +411,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,return ret;init_completion (&msginfo->waitevent); + msginfo->waiting_channel = channel; gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; gpadlmsg->header.msgtype =CHANNELMSG_GPADL_HEADER ;
@@ -441,6 +448,11 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, }wait_for_completion (&msginfo->waitevent); +if (channel->rescind) { + ret = -ENODEV ; + goto cleanup; + } +/* At this point, we received the gpadl created msg */ *gpadl_handle = gpadlmsg->gpadl;
@@ -474,6 +486,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)return -ENOMEM ;init_completion (&info->waitevent); + info->waiting_channel = channel; msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
@@ -493,6 +506,11 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)wait_for_completion (&info->waitevent); +if (channel->rescind) { + ret = -ENODEV ; + goto post_msg_err; + } + post_msg_err:spin_lock_irqsave (&vmbus_connection.channelmsg_lock, flags);list_del (&info->msglistentry);
drivers/hv/channel_mgmt.c +25 -0
@@ -147,6 +147,29 @@ static const struct { { HV_RDV_GUID }, }; +/* +* The rescinded channel may be blocked waiting for a response from the host; +* take care of that. +*/ +static void vmbus_rescind_cleanup (struct vmbus_channel *channel) +{ +struct vmbus_channel_msginfo *msginfo; +unsigned long flags; + + +spin_lock_irqsave (&vmbus_connection.channelmsg_lock, flags); + +list_for_each_entry (msginfo, &vmbus_connection.chn_msg_list, + msglistentry) { + +if (msginfo->waiting_channel == channel) { +complete (&msginfo->waitevent); +break ; + } + } +spin_unlock_irqrestore (&vmbus_connection.channelmsg_lock, flags); +} +static bool is_unsupported_vmbus_devs (const uuid_le *guid) {int i;
@@ -825,6 +848,8 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) channel->rescind = true;spin_unlock_irqrestore (&channel->lock, flags); +vmbus_rescind_cleanup (channel); +if (channel->device_obj) {if (channel->chn_rescind_callback) { channel->chn_rescind_callback (channel);
include/linux/hyperv.h +1 -0
@@ -627,6 +627,7 @@ struct vmbus_channel_msginfo {/* Synchronize the request/response if needed */ struct completion waitevent; +struct vmbus_channel *waiting_channel;union {struct vmbus_channel_version_supported version_supported;struct vmbus_channel_open_result open_result;