Re: PROBLEM: NFS client IO fails with ERESTARTSYS when another mount point with the same export is unmounted with force [NFS] [SUNRPC]

[Jeff Layton]

On Wed, 2024-02-21 at 13:48 +0000, Trond Myklebust wrote:
> On Wed, 2024-02-21 at 16:20 +0800, Zhitao Li wrote:
> > [You don't often get email from zhitao.li@xxxxxxxxxx. Learn why this
> > is important at https://aka.ms/LearnAboutSenderIdentification ;]
> > 
> > Hi, everyone,
> > 
> > - Facts:
> > I have a remote NFS export and I mount the same export on two
> > different directories in my OS with the same options. There is an
> > inflight IO under one mounted directory. And then I unmount another
> > mounted directory with force. The inflight IO ends up with "Unknown
> > error 512", which is ERESTARTSYS.
> > 
> 
> All of the above is well known. That's because forced umount affects
> the entire filesystem. Why are you using it here in the first place? It
> is not intended for casual use.
> 

While I agree Trond's above statement, the kernel is not supposed to
leak error codes that high into userland. Are you seeing ERESTARTSYS
being returned to system calls? If so, which ones?
-- 
Jeff Layton <jlayton@xxxxxxxxxx>