releases/4.4.46/nfs-don-t-increment-lock-sequence-id-after-nfs4err_moved.patch

   1 From 059aa734824165507c65fd30a55ff000afd14983 Mon Sep 17 00:00:00 2001
   2 From: Chuck Lever <chuck.lever@oracle.com>
   3 Date: Sun, 22 Jan 2017 14:04:29 -0500
   4 Subject: nfs: Don't increment lock sequence ID after NFS4ERR_MOVED
   5
   6 From: Chuck Lever <chuck.lever@oracle.com>
   7
   8 commit 059aa734824165507c65fd30a55ff000afd14983 upstream.
   9
  10 Xuan Qi reports that the Linux NFSv4 client failed to lock a file
  11 that was migrated. The steps he observed on the wire:
  12
  13 1. The client sent a LOCK request to the source server
  14 2. The source server replied NFS4ERR_MOVED
  15 3. The client switched to the destination server
  16 4. The client sent the same LOCK request to the destination
  17    server with a bumped lock sequence ID
  18 5. The destination server rejected the LOCK request with
  19    NFS4ERR_BAD_SEQID
  20
  21 RFC 3530 section 8.1.5 provides a list of NFS errors which do not
  22 bump a lock sequence ID.
  23
  24 However, RFC 3530 is now obsoleted by RFC 7530. In RFC 7530 section
  25 9.1.7, this list has been updated by the addition of NFS4ERR_MOVED.
  26
  27 Reported-by: Xuan Qi <xuan.qi@oracle.com>
  28 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
  29 Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
  30 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  31
  32 ---
  33  include/linux/nfs4.h |    3 ++-
  34  1 file changed, 2 insertions(+), 1 deletion(-)
  35
  36 --- a/include/linux/nfs4.h
  37 +++ b/include/linux/nfs4.h
  38 @@ -266,7 +266,7 @@ enum nfsstat4 {
  39
  40  static inline bool seqid_mutating_err(u32 err)
  41  {
  42 -       /* rfc 3530 section 8.1.5: */
  43 +       /* See RFC 7530, section 9.1.7 */
  44         switch (err) {
  45         case NFS4ERR_STALE_CLIENTID:
  46         case NFS4ERR_STALE_STATEID:
  47 @@ -275,6 +275,7 @@ static inline bool seqid_mutating_err(u3
  48         case NFS4ERR_BADXDR:
  49         case NFS4ERR_RESOURCE:
  50         case NFS4ERR_NOFILEHANDLE:
  51 +       case NFS4ERR_MOVED:
  52                 return false;
  53         };
  54         return true;