NFS: re-add readdir plus

This patch adds readdir plus support to the cache array.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 33b0ce7a97be..fd30f185ec01 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -370,6 +370,71 @@ int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, __be32 *
         return 0;
 }
 
+static
+int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
+{
+        struct nfs_inode *node;
+        if (dentry->d_inode == NULL)
+                goto different;
+        node = NFS_I(dentry->d_inode);
+        if (node->fh.size != entry->fh->size)
+                goto different;
+        if (strncmp(node->fh.data, entry->fh->data, node->fh.size) != 0)
+                goto different;
+        return 1;
+different:
+        return 0;
+}
+
+static
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
+{
+        struct qstr filename;
+        struct dentry *dentry = NULL;
+        struct dentry *alias = NULL;
+        struct inode *dir = parent->d_inode;
+        struct inode *inode;
+
+        nfs_readdir_make_qstr(&filename, entry->name, entry->len);
+        if (filename.len == 1 && filename.name[0] == '.')
+                dentry = dget(parent);
+        else if (filename.len == 2 && filename.name[0] == '.'
+                                   && filename.name[1] == '.')
+                dentry = dget_parent(parent);
+        else
+                dentry = d_lookup(parent, &filename);
+
+        if (dentry != NULL) {
+                if (nfs_same_file(dentry, entry)) {
+                        nfs_refresh_inode(dentry->d_inode, entry->fattr);
+                        goto out;
+                } else {
+                        d_drop(dentry);
+                        dput(dentry);
+                }
+        }
+
+        dentry = d_alloc(parent, &filename);
+        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+        inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
+        if (IS_ERR(inode))
+                goto out;
+
+        alias = d_materialise_unique(dentry, inode);
+        if (IS_ERR(alias))
+                goto out;
+        else if (alias) {
+                nfs_set_verifier(alias, nfs_save_change_attribute(dir));
+                dput(alias);
+        } else
+                nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+
+out:
+        dput(dentry);
+        kfree(filename.name);
+        return;
+}
+
 /* Perform conversion from xdr to cache array */
 static
 void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
@@ -379,6 +444,8 @@ void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *e
         while (xdr_decode(desc, entry, &ptr) == 0) {
                 if (nfs_readdir_add_to_array(entry, page) == -1)
                         break;
+                if (desc->plus == 1)
+                        nfs_prime_dcache(desc->file->f_path.dentry, entry);
         }
         kunmap(xdr_page);
 }