pnfs: serialize LAYOUTGET(openstateid)

We shouldn't send a LAYOUTGET(openstateid) unless all outstanding RPCs
using the previous stateid are completed.  This requires choosing the
stateid to encode earlier, so we can abort if one is not available (we
want to use the open stateid, but a LAYOUTGET is already out using
it), and adding a count of the number of outstanding rpc calls using
layout state (which for now consist solely of LAYOUTGETs).

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 8fcc54267bba..83d36d3a12e6 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -208,6 +208,7 @@ struct nfs4_layoutget_args {
         struct inode *inode;
         struct nfs_open_context *ctx;
         struct nfs4_sequence_args seq_args;
+        nfs4_stateid stateid;
 };
 
 struct nfs4_layoutget_res {