NFS: Be more aggressive in using readdirplus for 'ls -l' situations

Try to detect 'ls -l' by having nfs_getattr() look at whether or not
there is an opendir() file descriptor for the parent directory.
If so, then assume that we want to force use of readdirplus in order
to avoid the multiple GETATTR calls over the wire.

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

1 files changed, 27 insertions, 7 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 360114ae8b8..9dbef878a2b 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -588,6 +588,25 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
 }
 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
 
+static void nfs_request_parent_use_readdirplus(struct dentry *dentry)
+{
+	struct dentry *parent;
+
+	parent = dget_parent(dentry);
+	nfs_force_use_readdirplus(parent->d_inode);
+	dput(parent);
+}
+
+static bool nfs_need_revalidate_inode(struct inode *inode)
+{
+	if (NFS_I(inode)->cache_validity &
+			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
+		return true;
+	if (nfs_attribute_cache_expired(inode))
+		return true;
+	return false;
+}
+
 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
 	struct inode *inode = dentry->d_inode;
@@ -616,10 +635,13 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
  	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
 		need_atime = 0;
 
-	if (need_atime)
-		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
-	else
-		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (need_atime || nfs_need_revalidate_inode(inode)) {
+		struct nfs_server *server = NFS_SERVER(inode);
+
+		if (server->caps & NFS_CAP_READDIRPLUS)
+			nfs_request_parent_use_readdirplus(dentry);
+		err = __nfs_revalidate_inode(server, inode);
+	}
 	if (!err) {
 		generic_fillattr(inode, stat);
 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
@@ -961,9 +983,7 @@ int nfs_attribute_cache_expired(struct inode *inode)
  */
 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
 {
-	if (!(NFS_I(inode)->cache_validity &
-			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
-			&& !nfs_attribute_cache_expired(inode))
+	if (!nfs_need_revalidate_inode(inode))
 		return NFS_STALE(inode) ? -ESTALE : 0;
 	return __nfs_revalidate_inode(server, inode);
 }