Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752756AbdGRX12 (ORCPT ); Tue, 18 Jul 2017 19:27:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:58824 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751846AbdGRX11 (ORCPT ); Tue, 18 Jul 2017 19:27:27 -0400 From: NeilBrown To: Oleg Drokin , Greg Kroah-Hartman , Andreas Dilger Date: Wed, 19 Jul 2017 09:26:47 +1000 Subject: [PATCH 02/12] staging: lustre: llite: fix incorrect DCACHE_DISCONNECTED test Cc: Linux Kernel Mailing List , Lustre Development List Message-ID: <150042040741.20736.10796456139862947849.stgit@noble> In-Reply-To: <150041997277.20736.17112251996623587423.stgit@noble> References: <150041997277.20736.17112251996623587423.stgit@noble> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1533 Lines: 34 It is almost always wrong to test DCACHE_DISCONNECTED, except in "exportfs" code. The flag tells us that this dentry *might* not be connected to the root through a chain of d_parent links. Following the d_parent to an IS_ROOT() dentry *might* find one that is on the s_anon list rather than s_root. The code here need to know if it is safe to call __d_drop(), and the correct test is "!IS_ROOT(dentry)". If a dentry IS_ROOT(), then it might be the filesystem root, or it might be the root of a DCACHE_DISCONNECTED tree, and so be on the s_anon list. In these two cases it should not be __d_drop()ed. If !IS_ROOT(), then the dentry is attached to its parent through d_subdir, and can safely be unhashed. Signed-off-by: NeilBrown --- .../staging/lustre/lustre/llite/llite_internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h index cd3311abf999..4854985bf4d3 100644 --- a/drivers/staging/lustre/lustre/llite/llite_internal.h +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h @@ -1299,7 +1299,7 @@ static inline void d_lustre_invalidate(struct dentry *dentry, int nested) * If we unhashed such a dentry, unmount would not be able to find * it and busy inodes would be reported. */ - if (d_count(dentry) == 0 && !(dentry->d_flags & DCACHE_DISCONNECTED)) + if (d_count(dentry) == 0 && !IS_ROOT(dentry)) __d_drop(dentry); spin_unlock(&dentry->d_lock); }