From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from prv3-mh.provo.novell.com ([137.65.250.26]:58204 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751466AbdJSFmA (ORCPT ); Thu, 19 Oct 2017 01:42:00 -0400 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz, nborisov@suse.com Subject: [PATCH v2 4/6] btrfs-progs: mkfs: Error out gracefully for --rootdir Date: Thu, 19 Oct 2017 13:41:36 +0800 Message-Id: <20171019054138.13965-5-wqu@suse.com> In-Reply-To: <20171019054138.13965-1-wqu@suse.com> References: <20171019054138.13965-1-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: --rootdir option will start a transaction to fill the fs, however if something goes wrong, from ENOSPC to lack of permission, we won't commit transaction and cause BUG_ON trigger by uncommitted transaction: ------ extent buffer leak: start 29392896 len 16384 extent_io.c:579: free_extent_buffer: BUG_ON `eb->flags & EXTENT_DIRTY` triggered, value 1 ------ The root fix is to introduce btrfs_abort_transaction() in btrfs-progs, however in this particular case, we can workaround it by force committing the transaction. Since during mkfs, the magic of btrfs is set to an invalid one, without setting fs_info->finalize_on_close() the fs is never able to be mounted. So even we force to commit wrong transaction we won't screw up things worse. Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov --- mkfs/main.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mkfs/main.c b/mkfs/main.c index 60250c011ac3..358a046f1cf2 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -1073,6 +1073,19 @@ static int make_image(const char *source_dir, struct btrfs_root *root) printf("Making image is completed.\n"); return 0; fail: + /* + * Since we don't have btrfs_abort_transaction() yet, uncommitted trans + * will trigger a BUG_ON(). + * + * However before mkfs is fully finished, the magic number is invalid, + * so even we commit transaction here, the fs still can't be mounted. + * + * To do a graceful error out, here we commit transaction as a + * workaround. + * Since we have already hit some problem, the return value doesn't + * matter now. + */ + btrfs_commit_transaction(trans, root); while (!list_empty(&dir_head.list)) { dir_entry = list_entry(dir_head.list.next, struct directory_name_entry, list); -- 2.14.2