ceph: provide seperate {inode,file}_operations for snapdir

remove all unsupported operations from {inode,file}_operations.
Signed-off-by: Yan, Zheng <zyan@redhat.com>

fs/ceph/dir.c

@@ -26,8 +26,6 @@
  * point by name.
  */
 
-const struct inode_operations ceph_dir_iops;
-const struct file_operations ceph_dir_fops;
 const struct dentry_operations ceph_dentry_ops;
 
 /*
@@ -1335,6 +1333,13 @@ const struct file_operations ceph_dir_fops = {
 	.fsync = ceph_dir_fsync,
 };
 
+const struct file_operations ceph_snapdir_fops = {
+	.iterate = ceph_readdir,
+	.llseek = ceph_dir_llseek,
+	.open = ceph_open,
+	.release = ceph_release,
+};
+
 const struct inode_operations ceph_dir_iops = {
 	.lookup = ceph_lookup,
 	.permission = ceph_permission,
@@ -1357,6 +1362,14 @@ const struct inode_operations ceph_dir_iops = {
 	.atomic_open = ceph_atomic_open,
 };
 
+const struct inode_operations ceph_snapdir_iops = {
+	.lookup = ceph_lookup,
+	.permission = ceph_permission,
+	.getattr = ceph_getattr,
+	.mkdir = ceph_mkdir,
+	.rmdir = ceph_unlink,
+};
+
 const struct dentry_operations ceph_dentry_ops = {
 	.d_revalidate = ceph_d_revalidate,
 	.d_release = ceph_d_release,

fs/ceph/inode.c

@@ -82,8 +82,8 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 	inode->i_mode = parent->i_mode;
 	inode->i_uid = parent->i_uid;
 	inode->i_gid = parent->i_gid;
-	inode->i_op = &ceph_dir_iops;
-	inode->i_fop = &ceph_dir_fops;
+	inode->i_op = &ceph_snapdir_iops;
+	inode->i_fop = &ceph_snapdir_fops;
 	ci->i_snap_caps = CEPH_CAP_PIN; /* so we can open */
 	ci->i_rbytes = 0;
 	return inode;

fs/ceph/super.h

@@ -893,7 +893,9 @@ extern void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
 int ceph_uninline_data(struct file *filp, struct page *locked_page);
 /* dir.c */
 extern const struct file_operations ceph_dir_fops;
+extern const struct file_operations ceph_snapdir_fops;
 extern const struct inode_operations ceph_dir_iops;
+extern const struct inode_operations ceph_snapdir_iops;
 extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
 	ceph_snapdir_dentry_ops;