ceph: add get_name() NFS export callback

Use the newly introduced LOOKUPNAME MDS request to connect child
inode to its parent directory.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index eb66408ff236..00d6af6a32ec 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -202,9 +202,49 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb,
         return dentry;
 }
 
+static int ceph_get_name(struct dentry *parent, char *name,
+                         struct dentry *child)
+{
+        struct ceph_mds_client *mdsc;
+        struct ceph_mds_request *req;
+        int err;
+
+        mdsc = ceph_inode_to_client(child->d_inode)->mdsc;
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
+                                       USE_ANY_MDS);
+        if (IS_ERR(req))
+                return PTR_ERR(req);
+
+        mutex_lock(&parent->d_inode->i_mutex);
+
+        req->r_inode = child->d_inode;
+        ihold(child->d_inode);
+        req->r_ino2 = ceph_vino(parent->d_inode);
+        req->r_locked_dir = parent->d_inode;
+        req->r_num_caps = 2;
+        err = ceph_mdsc_do_request(mdsc, NULL, req);
+
+        mutex_unlock(&parent->d_inode->i_mutex);
+
+        if (!err) {
+                struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
+                memcpy(name, rinfo->dname, rinfo->dname_len);
+                name[rinfo->dname_len] = 0;
+                dout("get_name %p ino %llx.%llx name %s\n",
+                     child, ceph_vinop(child->d_inode), name);
+        } else {
+                dout("get_name %p ino %llx.%llx err %d\n",
+                     child, ceph_vinop(child->d_inode), err);
+        }
+
+        ceph_mdsc_put_request(req);
+        return err;
+}
+
 const struct export_operations ceph_export_ops = {
         .encode_fh = ceph_encode_fh,
         .fh_to_dentry = ceph_fh_to_dentry,
         .fh_to_parent = ceph_fh_to_parent,
         .get_parent = ceph_get_parent,
+        .get_name = ceph_get_name,
 };