From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [PATCH] ext4: fix ext4_flush_completed_IO wait semantics Date: Fri, 5 Oct 2012 09:28:53 -0400 Message-ID: <20121005132853.GC21358@thunk.org> References: <1349289807-18811-1-git-send-email-dmonakhov@openvz.org> <20121005124027.GA21358@thunk.org> <87a9w1ax91.fsf@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, jack@suse.cz To: Dmitry Monakhov Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:53969 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932516Ab2JEN2z (ORCPT ); Fri, 5 Oct 2012 09:28:55 -0400 Content-Disposition: inline In-Reply-To: <87a9w1ax91.fsf@openvz.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Oct 05, 2012 at 05:01:30PM +0400, Dmitry Monakhov wrote: > > This WARN_ON is triggering on the truncate path... > Yeap, this is false positive one. We skip i_mutex on ext4_evict_inode > This is strange xfsstress 269'th should caught that for me. > I'll try to prepare workaround ASAP. This is the patch which I'm currently testing. If it passes I'll fold it into your patch. Anyone see any problems with it? - Ted diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f18e786..cd171dd 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -238,8 +238,10 @@ void ext4_evict_inode(struct inode *inode) * protection against it */ sb_start_intwrite(inode->i_sb); + mutex_lock(&inode->i_mutex); handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3); if (IS_ERR(handle)) { + mutex_unlock(&inode->i_mutex); ext4_std_error(inode->i_sb, PTR_ERR(handle)); /* * If we're going to skip the normal cleanup, we still need to @@ -256,12 +258,14 @@ void ext4_evict_inode(struct inode *inode) inode->i_size = 0; err = ext4_mark_inode_dirty(handle, inode); if (err) { + mutex_unlock(&inode->i_mutex); ext4_warning(inode->i_sb, "couldn't mark inode dirty (err %d)", err); goto stop_handle; } if (inode->i_blocks) ext4_truncate(inode); + mutex_unlock(&inode->i_mutex); /* * ext4_ext_truncate() doesn't reserve any slop when it