From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from rcsinet15.oracle.com ([148.87.113.117]:32989 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753173Ab2INNBn (ORCPT ); Fri, 14 Sep 2012 09:01:43 -0400 Message-ID: <50532AB0.2020701@oracle.com> Date: Fri, 14 Sep 2012 21:01:36 +0800 From: Liu Bo MIME-Version: 1.0 To: Josef Bacik CC: "linux-btrfs@vger.kernel.org" Subject: Re: [PATCH 2/5] Btrfs: fix trans block rsv regression References: <1347613087-3489-1-git-send-email-bo.li.liu@oracle.com> <1347613087-3489-2-git-send-email-bo.li.liu@oracle.com> <20120914124159.GI12994@localhost.localdomain> In-Reply-To: <20120914124159.GI12994@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 09/14/2012 08:41 PM, Josef Bacik wrote: > On Fri, Sep 14, 2012 at 02:58:04AM -0600, Liu Bo wrote: >> In some workloads we have nested joining transaction operations, >> eg. >> run_delalloc_nocow >> btrfs_join_transaction >> cow_file_range >> btrfs_join_transaction >> >> it can be a serious bug since each trans handler has only two >> block_rsv, orig_rsv and block_rsv, which means we may lose our >> first block_rsv after two joining transaction operations: >> >> 1) btrfs_start_transaction >> trans->block_rsv = A >> >> 2) btrfs_join_transaction >> trans->orig_rsv = trans->block_rsv; ---> orig_rsv is now A >> trans->block_rsv = B >> >> 3) btrfs_join_transaction >> trans->orig_rsv = trans->block_rsv; ---> orig_rsv is now B >> trans->block_rsv = C >> ... >> > > I'd like to see the actual stack trace where this happens, because I don't think > it can happen. And if it is we need to look at that specific case and adjust it > as necessary and not add a bunch of kmallocs just to track the block_rsv, > because frankly it's not that big of a deal, it was just put into place in case > somebody wasn't expecting a call they made to start another transaction and > reset the block_rsv, which I don't actually think happens anywhere. So NAK on > this patch, give me more information so I can figure out the right way to deal > with this. Thanks, > Fine, please run xfstests 068 till it hits a BUG_ON inside either btrfs_delete_delayed_dir_index or btrfs_insert_delayed_dir_index. What I saw is that the orig_rsv and block_rsv is both delalloc_block_rsv, which is already lack of space. thanks, liubo > Josef > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >