ksmbd: lazy v2 lease break on smb2_write()

Don't immediately send directory lease break notification on smb2_write().
Instead, It postpones it until smb2_close().
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/server/oplock.c

@@ -396,8 +396,8 @@ void close_id_del_oplock(struct ksmbd_file *fp)
 {
 	struct oplock_info *opinfo;
 
-	if (S_ISDIR(file_inode(fp->filp)->i_mode))
-		return;
+	if (fp->reserve_lease_break)
+		smb_lazy_parent_lease_break_close(fp);
 
 	opinfo = opinfo_get(fp);
 	if (!opinfo)
@@ -1127,6 +1127,47 @@ void smb_send_parent_lease_break_noti(struct ksmbd_file *fp,
 	ksmbd_inode_put(p_ci);
 }
 
+void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp)
+{
+	struct oplock_info *opinfo;
+	struct ksmbd_inode *p_ci = NULL;
+
+	rcu_read_lock();
+	opinfo = rcu_dereference(fp->f_opinfo);
+	rcu_read_unlock();
+
+	if (!opinfo->is_lease || opinfo->o_lease->version != 2)
+		return;
+
+	p_ci = ksmbd_inode_lookup_lock(fp->filp->f_path.dentry->d_parent);
+	if (!p_ci)
+		return;
+
+	read_lock(&p_ci->m_lock);
+	list_for_each_entry(opinfo, &p_ci->m_op_list, op_entry) {
+		if (!opinfo->is_lease)
+			continue;
+
+		if (opinfo->o_lease->state != SMB2_OPLOCK_LEVEL_NONE) {
+			if (!atomic_inc_not_zero(&opinfo->refcount))
+				continue;
+
+			atomic_inc(&opinfo->conn->r_count);
+			if (ksmbd_conn_releasing(opinfo->conn)) {
+				atomic_dec(&opinfo->conn->r_count);
+				continue;
+			}
+			read_unlock(&p_ci->m_lock);
+			oplock_break(opinfo, SMB2_OPLOCK_LEVEL_NONE);
+			opinfo_conn_put(opinfo);
+			read_lock(&p_ci->m_lock);
+		}
+	}
+	read_unlock(&p_ci->m_lock);
+
+	ksmbd_inode_put(p_ci);
+}
+
 /**
  * smb_grant_oplock() - handle oplock/lease request on file open
  * @work:		smb work

fs/smb/server/oplock.h

@@ -129,4 +129,5 @@ int find_same_lease_key(struct ksmbd_session *sess, struct ksmbd_inode *ci,
 void destroy_lease_table(struct ksmbd_conn *conn);
 void smb_send_parent_lease_break_noti(struct ksmbd_file *fp,
 				      struct lease_ctx_info *lctx);
+void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp);
 #endif /* __KSMBD_OPLOCK_H */

fs/smb/server/vfs.c

@@ -517,6 +517,9 @@ int ksmbd_vfs_write(struct ksmbd_work *work, struct ksmbd_file *fp,
 		}
 	}
 
+	/* Reserve lease break for parent dir at closing time */
+	fp->reserve_lease_break = true;
+
 	/* Do we need to break any of a levelII oplock? */
 	smb_break_all_levII_oplock(work, fp, 1);
 

fs/smb/server/vfs_cache.h

@@ -105,6 +105,7 @@ struct ksmbd_file {
 	struct ksmbd_readdir_data	readdir_data;
 	int				dot_dotdot[2];
 	unsigned int			f_state;
+	bool				reserve_lease_break;
 };
 
 static inline void set_ctx_actor(struct dir_context *ctx,