ceph: do not chain inode updates to parent fsync

The fsync(dirfd) only covers namespace operations, not inode updates.
We do not need to cover setattr variants or O_TRUNC.

Reported-by: Al Viro <viro@xeniv.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index a55ec37..2dbd668 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -842,7 +842,6 @@
 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 	struct inode *inode = dentry->d_inode;
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct inode *parent_inode;
 	struct ceph_mds_request *req;
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	int err;
@@ -893,9 +892,7 @@
 	req->r_data_len = size;
 
 	dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
-	parent_inode = ceph_get_dentry_parent_inode(dentry);
-	err = ceph_mdsc_do_request(mdsc, parent_inode, req);
-	iput(parent_inode);
+	err = ceph_mdsc_do_request(mdsc, NULL, req);
 	ceph_mdsc_put_request(req);
 	dout("xattr.ver (after): %lld\n", ci->i_xattrs.version);
 
@@ -1019,7 +1016,6 @@
 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	struct inode *inode = dentry->d_inode;
-	struct inode *parent_inode;
 	struct ceph_mds_request *req;
 	int err;
 
@@ -1033,9 +1029,7 @@
 	req->r_num_caps = 1;
 	req->r_path2 = kstrdup(name, GFP_NOFS);
 
-	parent_inode = ceph_get_dentry_parent_inode(dentry);
-	err = ceph_mdsc_do_request(mdsc, parent_inode, req);
-	iput(parent_inode);
+	err = ceph_mdsc_do_request(mdsc, NULL, req);
 	ceph_mdsc_put_request(req);
 	return err;
 }