From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59747 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753126AbbHNCS3 (ORCPT ); Thu, 13 Aug 2015 22:18:29 -0400 Subject: Patch "ocfs2: fix BUG in ocfs2_downconvert_thread_do_work()" has been added to the 3.14-stable tree To: joseph.qi@huawei.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, jlbec@evilplan.org, mfasheh@suse.com, torvalds@linux-foundation.org Cc: , From: Date: Thu, 13 Aug 2015 19:18:29 -0700 Message-ID: <1439518709236181@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ocfs2-fix-bug-in-ocfs2_downconvert_thread_do_work.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 209f7512d007980fd111a74a064d70a3656079cf Mon Sep 17 00:00:00 2001 From: Joseph Qi Date: Thu, 6 Aug 2015 15:46:23 -0700 Subject: ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() From: Joseph Qi commit 209f7512d007980fd111a74a064d70a3656079cf upstream. The "BUG_ON(list_empty(&osb->blocked_lock_list))" in ocfs2_downconvert_thread_do_work can be triggered in the following case: ocfs2dc has firstly saved osb->blocked_lock_count to local varibale processed, and then processes the dentry lockres. During the dentry put, it calls iput and then deletes rw, inode and open lockres from blocked list in ocfs2_mark_lockres_freeing. And this causes the variable `processed' to not reflect the number of blocked lockres to be processed, which triggers the BUG. Signed-off-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/dlmglue.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -3973,9 +3973,13 @@ static void ocfs2_downconvert_thread_do_ osb->dc_work_sequence = osb->dc_wake_sequence; processed = osb->blocked_lock_count; - while (processed) { - BUG_ON(list_empty(&osb->blocked_lock_list)); - + /* + * blocked lock processing in this loop might call iput which can + * remove items off osb->blocked_lock_list. Downconvert up to + * 'processed' number of locks, but stop short if we had some + * removed in ocfs2_mark_lockres_freeing when downconverting. + */ + while (processed && !list_empty(&osb->blocked_lock_list)) { lockres = list_entry(osb->blocked_lock_list.next, struct ocfs2_lock_res, l_blocked_list); list_del_init(&lockres->l_blocked_list); Patches currently in stable-queue which might be from joseph.qi@huawei.com are queue-3.14/ocfs2-fix-bug-in-ocfs2_downconvert_thread_do_work.patch