[PATCH 1/2] Handle NFS4ERR_WRONGSEC outside of nfs4_handle_exception()

[PATCH 1/2] Handle NFS4ERR_WRONGSEC outside of nfs4_handle_exception()

[bjschuma]

From: Bryan Schumaker <bjschuma@netapp.com>

I only want to try other secflavors during an initial mount if
NFS4ERR_WRONGSEC is returned.  nfs4_handle_exception() could
potentially map other errors to EPERM, so we should handle this
error specially for correctness.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>

---
 fs/nfs/nfs4proc.c |   17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b8e1ac6..152e0eb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2186,9 +2186,14 @@ static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
 	struct nfs4_exception exception = { };
 	int err;
 	do {
-		err = nfs4_handle_exception(server,
-				_nfs4_lookup_root(server, fhandle, info),
-				&exception);
+		err = _nfs4_lookup_root(server, fhandle, info);
+		switch (err) {
+		case 0:
+		case -NFS4ERR_WRONGSEC:
+			break;
+		default:
+			err = nfs4_handle_exception(server, err, &exception);
+		}
 	} while (exception.retry);
 	return err;
 }
@@ -2221,10 +2226,12 @@ static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
 
 	for (i = 0; i < len; i++) {
 		status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]);
-		if (status == -EPERM || status == -EACCES)
+		if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
 			continue;
 		break;
 	}
+	if (status == -EACCES)
+		status = -EPERM;
 	return status;
 }
 
@@ -2235,7 +2242,7 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
 			      struct nfs_fsinfo *info)
 {
 	int status = nfs4_lookup_root(server, fhandle, info);
-	if ((status == -EPERM) && !(server->flags & NFS_MOUNT_SECFLAVOUR))
+	if ((status == -NFS4ERR_WRONGSEC) && !(server->flags & NFS_MOUNT_SECFLAVOUR))
 		status = nfs4_find_root_sec(server, fhandle, info);
 	if (status == 0)
 		status = nfs4_server_capabilities(server, fhandle);
-- 
1.7.4.4

[PATCH 2/2] Don't update sequence number if rpc_task is not sent

[bjschuma]

From: Bryan Schumaker <bjschuma@netapp.com>

If we fail to contact the gss upcall program, then no message will
be sent to the server.  The client still updated the sequence number,
however, and this lead to NFS4ERR_SEQ_MISMATCH for the next several
RPC calls.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>

---
 fs/nfs/nfs4proc.c            |    4 ++--
 include/linux/sunrpc/sched.h |    2 ++
 net/sunrpc/xprt.c            |    1 +
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 152e0eb..869caf5 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -444,8 +444,8 @@ static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *
 	if (res->sr_status == 1)
 		res->sr_status = NFS_OK;
 
-	/* -ERESTARTSYS can result in skipping nfs41_sequence_setup */
-	if (!res->sr_slot)
+	/* don't increment the sequence number if the task wasn't sent */
+	if (!RPC_WAS_SENT(task))
 		goto out;
 
 	/* Check the SEQUENCE operation status */
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index d81db80..3b94f80 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -127,6 +127,7 @@ struct rpc_task_setup {
 #define RPC_TASK_KILLED		0x0100		/* task was killed */
 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
+#define RPC_TASK_SENT		0x0800		/* message was sent */
 
 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
@@ -134,6 +135,7 @@ struct rpc_task_setup {
 #define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
 #define RPC_IS_SOFT(t)		((t)->tk_flags & RPC_TASK_SOFT)
 #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
+#define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
 
 #define RPC_TASK_RUNNING	0
 #define RPC_TASK_QUEUED		1
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 9494c37..ce5eb68 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -906,6 +906,7 @@ void xprt_transmit(struct rpc_task *task)
 	}
 
 	dprintk("RPC: %5u xmit complete\n", task->tk_pid);
+	task->tk_flags |= RPC_TASK_SENT;
 	spin_lock_bh(&xprt->transport_lock);
 
 	xprt->ops->set_retrans_timeout(task);
-- 
1.7.4.4

Re: [PATCH 1/2] Handle NFS4ERR_WRONGSEC outside of nfs4_handle_exception()

[Trond Myklebust]

On Mon, 2011-04-18 at 15:57 -0400, bjschuma@netapp.com wrote:
> From: Bryan Schumaker <bjschuma@netapp.com>
> 
> I only want to try other secflavors during an initial mount if
> NFS4ERR_WRONGSEC is returned.  nfs4_handle_exception() could
> potentially map other errors to EPERM, so we should handle this
> error specially for correctness.
> 
> Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
> 
> ---
>  fs/nfs/nfs4proc.c |   17 ++++++++++++-----
>  1 files changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index b8e1ac6..152e0eb 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -2186,9 +2186,14 @@ static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
>  	struct nfs4_exception exception = { };
>  	int err;
>  	do {
> -		err = nfs4_handle_exception(server,
> -				_nfs4_lookup_root(server, fhandle, info),
> -				&exception);
> +		err = _nfs4_lookup_root(server, fhandle, info);
> +		switch (err) {
> +		case 0:
> +		case -NFS4ERR_WRONGSEC:
> +			break;
> +		default:
> +			err = nfs4_handle_exception(server, err, &exception);
> +		}
>  	} while (exception.retry);
>  	return err;
>  }
> @@ -2221,10 +2226,12 @@ static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
>  
>  	for (i = 0; i < len; i++) {
>  		status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]);
> -		if (status == -EPERM || status == -EACCES)
> +		if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
>  			continue;
>  		break;
>  	}
> +	if (status == -EACCES)
> +		status = -EPERM;

Won't this leak -NFS4ERR_WRONGSEC errors to the user? I think you need
to handle both errors above by mapping them into EPERM.

>  	return status;
>  }
>  
> @@ -2235,7 +2242,7 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
>  			      struct nfs_fsinfo *info)
>  {
>  	int status = nfs4_lookup_root(server, fhandle, info);
> -	if ((status == -EPERM) && !(server->flags & NFS_MOUNT_SECFLAVOUR))
> +	if ((status == -NFS4ERR_WRONGSEC) && !(server->flags & NFS_MOUNT_SECFLAVOUR))
>  		status = nfs4_find_root_sec(server, fhandle, info);
>  	if (status == 0)
>  		status = nfs4_server_capabilities(server, fhandle);

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com