On Mon, 2013-08-05 at 13:37 -0400, Jeff Layton wrote:
> On Mon, 5 Aug 2013 16:15:01 +0000
> "Myklebust, Trond" <Trond.Myklebust@xxxxxxxxxx> wrote:
>
> > From 3c50ba80105464a28d456d9a1e0f1d81d4af92a8 Mon Sep 17 00:00:00 2001
> > From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> > Date: Mon, 5 Aug 2013 12:06:12 -0400
> > Subject: [PATCH] LOCKD: Don't call utsname()->nodename from
> > nlmclnt_setlockargs
> > MIME-Version: 1.0
> > Content-Type: text/plain; charset=UTF-8
> > Content-Transfer-Encoding: 8bit
> >
> > Firstly, nlmclnt_setlockargs can be called from a reclaimer thread, in
> > which case we're in entirely the wrong namespace.
> > Secondly, commit 8aac62706adaaf0fab02c4327761561c8bda9448 (move
> > exit_task_namespaces() outside of exit_notify()) now means that
> > exit_task_work() is called after exit_task_namespaces(), which
> > triggers an Oops when we're freeing up the locks.
> >
> > Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> > Cc: Toralf Förster <toralf.foerster@xxxxxx>
> > Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> > Cc: Nix <nix@xxxxxxxxxxxxx>
> > Cc: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > fs/lockd/clntproc.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
> > index 9760ecb..acd3947 100644
> > --- a/fs/lockd/clntproc.c
> > +++ b/fs/lockd/clntproc.c
> > @@ -125,14 +125,15 @@ static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
> > {
> > struct nlm_args *argp = &req->a_args;
> > struct nlm_lock *lock = &argp->lock;
> > + char *nodename = req->a_host->h_rpcclnt->cl_nodename;
> >
> > nlmclnt_next_cookie(&argp->cookie);
> > memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh));
> > - lock->caller = utsname()->nodename;
> > + lock->caller = nodename;
> > lock->oh.data = req->a_owner;
> > lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
> > (unsigned int)fl->fl_u.nfs_fl.owner->pid,
> > - utsname()->nodename);
> > + nodename);
> > lock->svid = fl->fl_u.nfs_fl.owner->pid;
> > lock->fl.fl_start = fl->fl_start;
> > lock->fl.fl_end = fl->fl_end;
>
> Looks good to me...
>
> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
>
> Trond, any thoughts on the other oops that Nix posted? The issue there
> seems to be that we're trying to do the pathwalk to the rpcbind unix
> socket from exit_task_work(), but that's happening after we've already
> called exit_fs().
>
> The trivial answer seems to be to simply call exit_task_work() before
> exit_fs() there, but it seems like we ought to be doing the upcall to
> rpcbind in a mount namespace from which we know we can reach the
> socket...
Isn't it enough to just do the same thing as we did for gss proxy? i.e.
set the RPC_CLNT_CREATE_NO_IDLE_TIMEOUT flag.
See attachment.
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
From ab56d77893815b1b9f0aaa7a89cee7c832a31cff Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Date: Mon, 5 Aug 2013 14:10:43 -0400
Subject: [PATCH] SUNRPC: Don't auto-disconnect from the local rpcbind socket
There is no need for the kernel to time out the AF_LOCAL connection to
the rpcbind socket, and doing so is problematic because when it is
time to reconnect, our process may no longer be using the same mount
namespace.
Reported-by: Nix <nix@xxxxxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 3.9.x
---
net/sunrpc/rpcb_clnt.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 3df764d..4b00555 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -238,6 +238,15 @@ static int rpcb_create_local_unix(struct net *net)
.program = &rpcb_program,
.version = RPCBVERS_2,
.authflavor = RPC_AUTH_NULL,
+ /*
+ * We turn off the idle timeout to prevent the kernel
+ * from automatically disconnecting the socket.
+ * Otherwise, we'd have to cache the mount namespace
+ * of the caller and somehow pass that to the socket
+ * reconnect code.
+ */
+ .flags = RPC_CLNT_CREATE_NOPING |
+ RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
};
struct rpc_clnt *clnt, *clnt4;
int result = 0;
--
1.8.3.1
