pnfs: layout roc code

A layout can request return-on-close.  How this interacts with the
forgetful model of never sending LAYOUTRETURNS is a bit ambiguous.
We forget any layouts marked roc, and wait for them to be completely
forgotten before continuing with the close.  In addition, to compensate
for races with any inflight LAYOUTGETs, and the fact that we do not get
any layout stateid back from the server, we set the barrier to the worst
case scenario of current_seqid + number of outstanding 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_fs_sb.h b/include/linux/nfs_fs_sb.h
index e93ada0565fc..7f20c0b47a91 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -149,6 +149,7 @@ struct nfs_server {
                                                    that are supported on this
                                                    filesystem */
         struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
+        struct rpc_wait_queue   roc_rpcwaitq;
 #endif
         void (*destroy)(struct nfs_server *);