NFSv4.1: Optimise layout return-on-close

Optimise the layout return on close code by ensuring that

1) Add a check for whether we hold a layout before taking any spinlocks
2) Only take the spin lock once
3) Use nfs_state->state to speed up open file checks

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 9ae5b765b073..a98d8fd9637f 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -275,6 +275,11 @@ void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
 bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
 
+static inline bool nfs_have_layout(struct inode *inode)
+{
+	return NFS_I(inode)->layout != NULL;
+}
+
 static inline struct nfs4_deviceid_node *
 nfs4_get_deviceid(struct nfs4_deviceid_node *d)
 {
@@ -427,6 +432,11 @@ static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
 #endif /* NFS_DEBUG */
 #else  /* CONFIG_NFS_V4_1 */
 
+static inline bool nfs_have_layout(struct inode *inode)
+{
+	return false;
+}
+
 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 {
 }