From patchwork Wed Sep 25 13:47:44 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miao Xie X-Patchwork-Id: 2942441 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1AE009F289 for ; Wed, 25 Sep 2013 13:47:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 90DF52041B for ; Wed, 25 Sep 2013 13:47:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FC032056A for ; Wed, 25 Sep 2013 13:47:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755613Ab3IYNr3 (ORCPT ); Wed, 25 Sep 2013 09:47:29 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:13618 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755591Ab3IYNr2 (ORCPT ); Wed, 25 Sep 2013 09:47:28 -0400 X-IronPort-AV: E=Sophos;i="4.90,978,1371052800"; d="scan'208";a="8618962" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 25 Sep 2013 21:44:10 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id r8PDlMZP026984 for ; Wed, 25 Sep 2013 21:47:23 +0800 Received: from miao.fnst.cn.fujitsu.com ([10.167.226.106]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2013092521454022-1781529 ; Wed, 25 Sep 2013 21:45:40 +0800 From: Miao Xie To: linux-btrfs@vger.kernel.org Subject: [PATCH 2/3] Btrfs: fix oops caused by the space balance and dead roots Date: Wed, 25 Sep 2013 21:47:44 +0800 Message-Id: <1380116865-23406-2-git-send-email-miaox@cn.fujitsu.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1380116865-23406-1-git-send-email-miaox@cn.fujitsu.com> References: <1380116865-23406-1-git-send-email-miaox@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/25 21:45:40, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/25 21:45:40, Serialize complete at 2013/09/25 21:45:40 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-8.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When doing space balance and subvolume destroy at the same time, we met the following oops: kernel BUG at fs/btrfs/relocation.c:2247! RIP: 0010: [] prepare_to_merge+0x154/0x1f0 [btrfs] Call Trace: [] relocate_block_group+0x466/0x4e6 [btrfs] [] btrfs_relocate_block_group+0x143/0x275 [btrfs] [] btrfs_relocate_chunk.isra.27+0x5c/0x5a2 [btrfs] [] ? btrfs_item_key_to_cpu+0x15/0x31 [btrfs] [] ? btrfs_get_token_64+0x7e/0xcd [btrfs] [] ? btrfs_tree_read_unlock_blocking+0xb2/0xb7 [btrfs] [] btrfs_balance+0x9c7/0xb6f [btrfs] [] btrfs_ioctl_balance+0x234/0x2ac [btrfs] [] btrfs_ioctl+0xd87/0x1ef9 [btrfs] [] ? path_openat+0x234/0x4db [] ? __do_page_fault+0x31d/0x391 [] ? vma_link+0x74/0x94 [] vfs_ioctl+0x1d/0x39 [] do_vfs_ioctl+0x32d/0x3e2 [] SyS_ioctl+0x57/0x83 [] ? do_page_fault+0xe/0x10 [] system_call_fastpath+0x16/0x1b It is because we returned the error number if the reference of the root was 0 when doing space relocation. It was not right here, because though the root was dead(refs == 0), but the space it held still need be relocated, or we could not remove the block group. So in this case, we should return the root no matter it is dead or not. Signed-off-by: Miao Xie --- fs/btrfs/disk-io.c | 9 +++++---- fs/btrfs/disk-io.h | 13 +++++++++++-- fs/btrfs/relocation.c | 2 +- 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4cbb00a..65eddf7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1560,8 +1560,9 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info, return ret; } -struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, - struct btrfs_key *location) +struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info, + struct btrfs_key *location, + bool check_ref) { struct btrfs_root *root; int ret; @@ -1585,7 +1586,7 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, again: root = btrfs_lookup_fs_root(fs_info, location->objectid); if (root) { - if (btrfs_root_refs(&root->root_item) == 0) + if (check_ref && btrfs_root_refs(&root->root_item) == 0) return ERR_PTR(-ENOENT); return root; } @@ -1594,7 +1595,7 @@ again: if (IS_ERR(root)) return root; - if (btrfs_root_refs(&root->root_item) == 0) { + if (check_ref && btrfs_root_refs(&root->root_item) == 0) { ret = -ENOENT; goto fail; } diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index b71acd6e..5ce2a7d 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -68,8 +68,17 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root, int btrfs_init_fs_root(struct btrfs_root *root); int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root); -struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, - struct btrfs_key *location); + +struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info, + struct btrfs_key *key, + bool check_ref); +static inline struct btrfs_root * +btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, + struct btrfs_key *location) +{ + return btrfs_get_fs_root(fs_info, location, true); +} + int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info); void btrfs_btree_balance_dirty(struct btrfs_root *root); void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root); diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index aacc212..1ba09d1 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -588,7 +588,7 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, else key.offset = (u64)-1; - return btrfs_read_fs_root_no_name(fs_info, &key); + return btrfs_get_fs_root(fs_info, &key, false); } #ifdef BTRFS_COMPAT_EXTENT_TREE_V0