2 files changed, 31 insertions, 4 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 82b42e2ea65..d0884c0d946 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -475,6 +475,29 @@ different:
 }
 
 static
+bool nfs_use_readdirplus(struct inode *dir, struct file *filp)
+{
+        if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
+                return false;
+        if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
+                return true;
+        if (filp->f_pos == 0)
+                return true;
+        return false;
+}
+
+/*
+ * This function is called by the lookup code to request the use of
+ * readdirplus to accelerate any future lookups in the same
+ * directory.
+ */
+static
+void nfs_advise_use_readdirplus(struct inode *dir)
+{
+        set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
+}
+
+static
 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 {
         struct qstr filename = {
@@ -874,7 +897,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         desc->file = filp;
         desc->dir_cookie = &dir_ctx->dir_cookie;
         desc->decode = NFS_PROTO(inode)->decode_dirent;
-        desc->plus = NFS_USE_READDIRPLUS(inode);
+        desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0;
 
         nfs_block_sillyrename(dentry);
         res = nfs_revalidate_mapping(inode, filp->f_mapping);
@@ -1114,7 +1137,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
         if (!inode) {
                 if (nfs_neg_need_reval(dir, dentry, nd))
                         goto out_bad;
-                goto out_valid;
+                goto out_valid_noent;
         }
 
         if (is_bad_inode(inode)) {
@@ -1156,6 +1179,9 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 out_set_verifier:
         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  out_valid:
+        /* Success: notify readdir to use READDIRPLUS */
+        nfs_advise_use_readdirplus(dir);
+ out_valid_noent:
         dput(parent);
         dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
                         __func__, dentry->d_parent->d_name.name,
@@ -1311,6 +1337,9 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
         if (IS_ERR(res))
                 goto out_unblock_sillyrename;
 
+        /* Success: notify readdir to use READDIRPLUS */
+        nfs_advise_use_readdirplus(dir);
+
 no_entry:
         res = d_materialise_unique(dentry, inode);
         if (res != NULL) {
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 0d53113207e..9f17cd19e71 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -298,8 +298,6 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
                         inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
                         inode->i_fop = &nfs_dir_operations;
                         inode->i_data.a_ops = &nfs_dir_aops;
-                        if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS))
-                                set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
                         /* Deal with crossing mountpoints */
                         if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
                                         fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {