[PATCH 06/15] hv: acquire vmbus_connection.channel_mutex in vmbus_free_channels()

From: kys
Date: Thu Dec 01 2016 - 10:36:09 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

"kernel BUG at drivers/hv/channel_mgmt.c:350!" is observed when hv_vmbus
module is unloaded. BUG_ON() was introduced in commit 85d9aa705184
("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()") as
vmbus_free_channels() codepath was apparently forgotten.

Fixes: 85d9aa705184 ("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()")
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/channel_mgmt.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index d83c1ac..e68f06c 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -390,6 +390,7 @@ 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 */
@@ -397,6 +398,7 @@ void vmbus_free_channels(void)

vmbus_device_unregister(channel->device_obj);
}
+ mutex_unlock(&vmbus_connection.channel_mutex);
}

/*
--
1.7.4.1