From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:49368 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733175AbeKLIVl (ORCPT ); Mon, 12 Nov 2018 03:21:41 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Mahoney , David Sterba Subject: [PATCH 4.18 321/350] btrfs: fix error handling in btrfs_dev_replace_start Date: Sun, 11 Nov 2018 14:23:05 -0800 Message-Id: <20181111221721.495847126@linuxfoundation.org> In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Mahoney commit 5c06147128fbbdf7a84232c5f0d808f53153defe upstream. When we fail to start a transaction in btrfs_dev_replace_start, we leave dev_replace->replace_start set to STARTED but clear ->srcdev and ->tgtdev. Later, that can result in an Oops in btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED implies that ->srcdev is valid. Also fix error handling when the state is already STARTED or SUSPENDED while starting. That, too, will clear ->srcdev and ->tgtdev even though it doesn't own them. This should be an impossible case to hit since we should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an ASSERT there while we're at it. Fixes: e93c89c1aaaaa (Btrfs: add new sources for device replace code) CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/dev-replace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -445,6 +445,7 @@ int btrfs_dev_replace_start(struct btrfs break; case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + ASSERT(0); ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; goto leave; } @@ -487,6 +488,10 @@ int btrfs_dev_replace_start(struct btrfs if (IS_ERR(trans)) { ret = PTR_ERR(trans); btrfs_dev_replace_write_lock(dev_replace); + dev_replace->replace_state = + BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; + dev_replace->srcdev = NULL; + dev_replace->tgtdev = NULL; goto leave; } @@ -508,8 +513,6 @@ int btrfs_dev_replace_start(struct btrfs return ret; leave: - dev_replace->srcdev = NULL; - dev_replace->tgtdev = NULL; btrfs_dev_replace_write_unlock(dev_replace); btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); return ret;