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, 50 insertions, 1 deletions

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 8bf2384bd42..91d6c9d49e3 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1044,10 +1044,59 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 					 session, req->r_request_started, -1,
 					 &req->r_caps_reservation);
 			if (err < 0)
-				return err;
+				goto done;
 		} else {
 			WARN_ON_ONCE(1);
 		}
+
+		if (dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME) {
+			struct qstr dname;
+			struct dentry *dn, *parent;
+
+			BUG_ON(!rinfo->head->is_target);
+			BUG_ON(req->r_dentry);
+
+			parent = d_find_any_alias(dir);
+			BUG_ON(!parent);
+
+			dname.name = rinfo->dname;
+			dname.len = rinfo->dname_len;
+			dname.hash = full_name_hash(dname.name, dname.len);
+			vino.ino = le64_to_cpu(rinfo->targeti.in->ino);
+			vino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
+retry_lookup:
+			dn = d_lookup(parent, &dname);
+			dout("d_lookup on parent=%p name=%.*s got %p\n",
+			     parent, dname.len, dname.name, dn);
+
+			if (!dn) {
+				dn = d_alloc(parent, &dname);
+				dout("d_alloc %p '%.*s' = %p\n", parent,
+				     dname.len, dname.name, dn);
+				if (dn == NULL) {
+					dput(parent);
+					err = -ENOMEM;
+					goto done;
+				}
+				err = ceph_init_dentry(dn);
+				if (err < 0) {
+					dput(dn);
+					dput(parent);
+					goto done;
+				}
+			} else if (dn->d_inode &&
+				   (ceph_ino(dn->d_inode) != vino.ino ||
+				    ceph_snap(dn->d_inode) != vino.snap)) {
+				dout(" dn %p points to wrong inode %p\n",
+				     dn, dn->d_inode);
+				d_delete(dn);
+				dput(dn);
+				goto retry_lookup;
+			}
+
+			req->r_dentry = dn;
+			dput(parent);
+		}
 	}
 
 	if (rinfo->head->is_target) {