From patchwork Thu Aug 2 04:39:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miao Xie X-Patchwork-Id: 1266161 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id DB97BDF223 for ; Thu, 2 Aug 2012 04:41:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750884Ab2HBEk0 (ORCPT ); Thu, 2 Aug 2012 00:40:26 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:31533 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750786Ab2HBEkZ (ORCPT ); Thu, 2 Aug 2012 00:40:25 -0400 X-IronPort-AV: E=Sophos;i="4.77,697,1336320000"; d="scan'208";a="5533585" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 02 Aug 2012 12:39:25 +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 q724eKPS005003; Thu, 2 Aug 2012 12:40:21 +0800 Received: from [10.167.225.199] ([10.167.225.199]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012080212405141-77032 ; Thu, 2 Aug 2012 12:40:51 +0800 Message-ID: <501A047F.5030103@cn.fujitsu.com> Date: Thu, 02 Aug 2012 12:39:27 +0800 From: Miao Xie Reply-To: miaox@cn.fujitsu.com User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: Linux Btrfs CC: Josef Bacik , Wu Fengguang , Seto Hidetoshi , David Sterba Subject: [PATCH V3 1/2] Btrfs: fix error path in create_pending_snapshot() X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/02 12:40:51, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/02 12:40:55, Serialize complete at 2012/08/02 12:40:55 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This patch fixes the following problem: - If we failed to deal with the delayed dir items, we should abort transaction, just as its comment said. Fix it. - If root reference or root back reference insertion failed, we should abort transaction. Fix it. - Fix the double free problem of pending->inherit. - Do not restore the trans->rsv if we doesn't change it. - make the error path more clearly. Signed-off-by: Miao Xie --- Changelog v2 -> v3: - rebase on the latest for-linus branch - fix double free problem of pending->inherit Changelog v1 -> v2: - fix double dput() when aborting transaction. In the previous version of the patches, this problem was fixed in the second patch, it is not good because this problem is the bug of the patch in fact. --- fs/btrfs/transaction.c | 40 +++++++++++++++++----------------------- 1 files changed, 17 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 7ac7cdc..4e9c106 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -962,18 +962,16 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, u64 root_flags; uuid_le new_uuid; - rsv = trans->block_rsv; - new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); if (!new_root_item) { ret = pending->error = -ENOMEM; - goto fail; + goto root_item_alloc_fail; } ret = btrfs_find_free_objectid(tree_root, &objectid); if (ret) { pending->error = ret; - goto fail; + goto no_free_objectid; } btrfs_reloc_pre_snapshot(trans, pending, &to_reserve); @@ -983,22 +981,22 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, to_reserve); if (ret) { pending->error = ret; - goto fail; + goto no_free_objectid; } } ret = btrfs_qgroup_inherit(trans, fs_info, root->root_key.objectid, objectid, pending->inherit); - kfree(pending->inherit); if (ret) { pending->error = ret; - goto fail; + goto no_free_objectid; } key.objectid = objectid; key.offset = (u64)-1; key.type = BTRFS_ROOT_ITEM_KEY; + rsv = trans->block_rsv; trans->block_rsv = &pending->block_rsv; dentry = pending->dentry; @@ -1018,17 +1016,16 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, BTRFS_FT_DIR, index); if (ret == -EEXIST) { pending->error = -EEXIST; - dput(parent); goto fail; } else if (ret) { - goto abort_trans_dput; + goto abort_trans; } btrfs_i_size_write(parent_inode, parent_inode->i_size + dentry->d_name.len * 2); ret = btrfs_update_inode(trans, parent_root, parent_inode); if (ret) - goto abort_trans_dput; + goto abort_trans; /* * pull in the delayed directory update @@ -1037,10 +1034,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, * snapshot */ ret = btrfs_run_delayed_items(trans, root); - if (ret) { /* Transaction aborted */ - dput(parent); - goto fail; - } + if (ret) /* Transaction aborted */ + goto abort_trans; record_root_in_trans(trans, root); btrfs_set_root_last_snapshot(&root->root_item, trans->transid); @@ -1073,7 +1068,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, if (ret) { btrfs_tree_unlock(old); free_extent_buffer(old); - goto abort_trans_dput; + goto abort_trans; } btrfs_set_lock_blocking(old); @@ -1083,7 +1078,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_tree_unlock(old); free_extent_buffer(old); if (ret) - goto abort_trans_dput; + goto abort_trans; /* see comments in should_cow_block() */ root->force_cow = 1; @@ -1096,7 +1091,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_tree_unlock(tmp); free_extent_buffer(tmp); if (ret) - goto abort_trans_dput; + goto abort_trans; /* * insert root back/forward references @@ -1105,9 +1100,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, parent_root->root_key.objectid, btrfs_ino(parent_inode), index, dentry->d_name.name, dentry->d_name.len); - dput(parent); if (ret) - goto fail; + goto abort_trans; key.offset = (u64)-1; pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); @@ -1119,15 +1113,15 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, ret = btrfs_reloc_post_snapshot(trans, pending); if (ret) goto abort_trans; - ret = 0; fail: - kfree(new_root_item); + dput(parent); trans->block_rsv = rsv; +no_free_objectid: + kfree(new_root_item); +root_item_alloc_fail: btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1); return ret; -abort_trans_dput: - dput(parent); abort_trans: btrfs_abort_transaction(trans, root, ret); goto fail;