From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , Chris Mason Subject: [PATCH 3.17 007/146] Btrfs: dont do async reclaim during log replay Date: Tue, 28 Oct 2014 11:32:29 +0800 Message-Id: <20141028033343.759096425@linuxfoundation.org> In-Reply-To: <20141028033343.441992423@linuxfoundation.org> References: <20141028033343.441992423@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik commit f6acfd50110b335c7af636cf1fc8e55319cae5fc upstream. Trying to reproduce a log enospc bug I hit a panic in the async reclaim code during log replay. This is because we use fs_info->fs_root as our root for shrinking and such. Technically we can use whatever root we want, but let's just not allow async reclaim while we're doing log replay. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4502,7 +4502,13 @@ again: space_info->flush = 1; } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { used += orig_bytes; - if (need_do_async_reclaim(space_info, root->fs_info, used) && + /* + * We will do the space reservation dance during log replay, + * which means we won't have fs_info->fs_root set, so don't do + * the async reclaim as we will panic. + */ + if (!root->fs_info->log_root_recovering && + need_do_async_reclaim(space_info, root->fs_info, used) && !work_busy(&root->fs_info->async_reclaim_work)) queue_work(system_unbound_wq, &root->fs_info->async_reclaim_work);