netvsc: fix deadlock betwen link status and removal
authorstephen hemminger <stephen@networkplumber.org>
Thu, 24 Aug 2017 23:49:16 +0000 (16:49 -0700)
committerDavid S. Miller <davem@davemloft.net>
Fri, 25 Aug 2017 04:59:08 +0000 (21:59 -0700)
commit9b4e946ce14e20d7addbfb7d9139e604f9fda107
tree0175bcaad416e1b058108ea515878d40ab63663c
parentc3d8d60e1efe5432dc4905646481f460795fac4e
netvsc: fix deadlock betwen link status and removal

There is a deadlock possible when canceling the link status
delayed work queue. The removal process is run with RTNL held,
and the link status callback is acquring RTNL.

Resolve the issue by using trylock and rescheduling.
If cancel is in process, that block it from happening.

Fixes: 122a5f6410f4 ("staging: hv: use delayed_work for netvsc_send_garp()")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/hyperv/netvsc_drv.c