ext4: do not delete unlinked inode from orphan list on failed truncate

It is possible that unlinked inode enters ext4_setattr() (e.g. if
somebody calls ftruncate(2) on unlinked but still open file). In such
case we should not delete the inode from the orphan list if truncate
fails. Note that this is mostly a theoretical concern as filesystem is
corrupted if we reach this path anyway but let's be consistent in our
orphan handling.
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

fs/ext4/inode.c

@@ -5625,7 +5625,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			up_write(&EXT4_I(inode)->i_data_sem);
 			ext4_journal_stop(handle);
 			if (error) {
-				if (orphan)
+				if (orphan && inode->i_nlink)
 					ext4_orphan_del(NULL, inode);
 				goto err_out;
 			}