mainline inclusion
from mainline-v5.2-rc1
commit 0688e64b
category: bugfix
bugzilla: NA
CVE: NA

--------------------------------

If the server is unable to immediately execute an RPC call, and returns
an NFS4ERR_DELAY then we can assume it is safe to interrupt the operation
in order to handle ordinary signals. This allows the application to
service timer interrupts that would otherwise have to wait until the
server is again able to respond.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>