From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from victor.provo.novell.com ([137.65.250.26]:58149 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935994AbdJRIBJ (ORCPT ); Wed, 18 Oct 2017 04:01:09 -0400 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz Subject: [PATCH 3/5] btrfs-progs: mkfs: Error out gracefully for --rootdir Date: Wed, 18 Oct 2017 16:00:52 +0800 Message-Id: <20171018080054.25509-4-wqu@suse.com> In-Reply-To: <20171018080054.25509-1-wqu@suse.com> References: <20171018080054.25509-1-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 --- mkfs/main.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mkfs/main.c b/mkfs/main.c index 5817f114c1a1..8c332aa1e12a 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