Patch "nfs: Don't increment lock sequence ID after NFS4ERR_MOVED" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    nfs: Don't increment lock sequence ID after NFS4ERR_MOVED

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfs-don-t-increment-lock-sequence-id-after-nfs4err_moved.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 059aa734824165507c65fd30a55ff000afd14983 Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever@oracle.com>
Date: Sun, 22 Jan 2017 14:04:29 -0500
Subject: nfs: Don't increment lock sequence ID after NFS4ERR_MOVED

From: Chuck Lever <chuck.lever@oracle.com>

commit 059aa734824165507c65fd30a55ff000afd14983 upstream.

Xuan Qi reports that the Linux NFSv4 client failed to lock a file
that was migrated. The steps he observed on the wire:

1. The client sent a LOCK request to the source server
2. The source server replied NFS4ERR_MOVED
3. The client switched to the destination server
4. The client sent the same LOCK request to the destination
   server with a bumped lock sequence ID
5. The destination server rejected the LOCK request with
   NFS4ERR_BAD_SEQID

RFC 3530 section 8.1.5 provides a list of NFS errors which do not
bump a lock sequence ID.

However, RFC 3530 is now obsoleted by RFC 7530. In RFC 7530 section
9.1.7, this list has been updated by the addition of NFS4ERR_MOVED.

Reported-by: Xuan Qi <xuan.qi@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/nfs4.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -282,7 +282,7 @@ enum nfsstat4 {
 
 static inline bool seqid_mutating_err(u32 err)
 {
-	/* rfc 3530 section 8.1.5: */
+	/* See RFC 7530, section 9.1.7 */
 	switch (err) {
 	case NFS4ERR_STALE_CLIENTID:
 	case NFS4ERR_STALE_STATEID:
@@ -291,6 +291,7 @@ static inline bool seqid_mutating_err(u3
 	case NFS4ERR_BADXDR:
 	case NFS4ERR_RESOURCE:
 	case NFS4ERR_NOFILEHANDLE:
+	case NFS4ERR_MOVED:
 		return false;
 	};
 	return true;


Patches currently in stable-queue which might be from chuck.lever@oracle.com are

queue-4.9/nfs-don-t-increment-lock-sequence-id-after-nfs4err_moved.patch