From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43987 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754469AbcIYSRV (ORCPT ); Sun, 25 Sep 2016 14:17:21 -0400 Subject: Patch "ocfs2/dlm: fix race between convert and migration" has been added to the 4.4-stable tree To: joseph.qi@huawei.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, jlbec@evilplan.org, junxiao.bi@oracle.com, mfasheh@suse.de, piaojun@huawei.com, torvalds@linux-foundation.org Cc: , From: Date: Sun, 25 Sep 2016 20:17:06 +0200 Message-ID: <147482742612207@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/dlm: fix race between convert and migration to the 4.4-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-dlm-fix-race-between-convert-and-migration.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From e6f0c6e6170fec175fe676495f29029aecdf486c Mon Sep 17 00:00:00 2001 From: Joseph Qi Date: Mon, 19 Sep 2016 14:43:55 -0700 Subject: ocfs2/dlm: fix race between convert and migration From: Joseph Qi commit e6f0c6e6170fec175fe676495f29029aecdf486c upstream. Commit ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery") checks if lockres master has changed to identify whether new master has finished recovery or not. This will introduce a race that right after old master does umount ( means master will change), a new convert request comes. In this case, it will reset lockres state to DLM_RECOVERING and then retry convert, and then fail with lockres->l_action being set to OCFS2_AST_INVALID, which will cause inconsistent lock level between ocfs2 and dlm, and then finally BUG. Since dlm recovery will clear lock->convert_pending in dlm_move_lockres_to_recovery_list, we can use it to correctly identify the race case between convert and recovery. So fix it. Fixes: ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery") Link: http://lkml.kernel.org/r/57CE1569.8010704@huawei.com Signed-off-by: Joseph Qi Signed-off-by: Jun Piao Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/dlm/dlmconvert.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/fs/ocfs2/dlm/dlmconvert.c +++ b/fs/ocfs2/dlm/dlmconvert.c @@ -262,7 +262,6 @@ enum dlm_status dlmconvert_remote(struct struct dlm_lock *lock, int flags, int type) { enum dlm_status status; - u8 old_owner = res->owner; mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type, lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS); @@ -329,7 +328,6 @@ enum dlm_status dlmconvert_remote(struct spin_lock(&res->spinlock); res->state &= ~DLM_LOCK_RES_IN_PROGRESS; - lock->convert_pending = 0; /* if it failed, move it back to granted queue. * if master returns DLM_NORMAL and then down before sending ast, * it may have already been moved to granted queue, reset to @@ -338,12 +336,14 @@ enum dlm_status dlmconvert_remote(struct if (status != DLM_NOTQUEUED) dlm_error(status); dlm_revert_pending_convert(res, lock); - } else if ((res->state & DLM_LOCK_RES_RECOVERING) || - (old_owner != res->owner)) { - mlog(0, "res %.*s is in recovering or has been recovered.\n", - res->lockname.len, res->lockname.name); + } else if (!lock->convert_pending) { + mlog(0, "%s: res %.*s, owner died and lock has been moved back " + "to granted list, retry convert.\n", + dlm->name, res->lockname.len, res->lockname.name); status = DLM_RECOVERING; } + + lock->convert_pending = 0; bail: spin_unlock(&res->spinlock); Patches currently in stable-queue which might be from joseph.qi@huawei.com are queue-4.4/ocfs2-fix-start-offset-to-ocfs2_zero_range_for_truncate.patch queue-4.4/ocfs2-dlm-fix-race-between-convert-and-migration.patch