From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:44337 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752172AbcG2QyT (ORCPT ); Fri, 29 Jul 2016 12:54:19 -0400 Date: Fri, 29 Jul 2016 18:53:57 +0200 From: David Sterba To: Liu Bo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v3] Btrfs: remove BUG() in raid56 Message-ID: <20160729165357.GD30795@suse.cz> Reply-To: dsterba@suse.cz References: <1467248276-12310-1-git-send-email-bo.li.liu@oracle.com> <1469645807-16370-1-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1469645807-16370-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, Jul 27, 2016 at 11:56:47AM -0700, Liu Bo wrote: > This BUG() has been triggered by a fuzz testing image, which contains > an invalid chunk type, ie. a single stripe chunk has the raid6 type. > > Btrfs can handle this gracefully by returning -EIO, so besides using > btrfs_warn to give us more debugging information rather than a single > BUG(), we can return error properly. > > Signed-off-by: Liu Bo > --- > v2: use btrfs_warn with more debugging information instead of WARN_ONCE. > v3: - give a short summary about what happens when the error occurs. > - add a ASSERT() which only takes effect for developers. > > fs/btrfs/raid56.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c > index f8b6d41..6f8addf 100644 > --- a/fs/btrfs/raid56.c > +++ b/fs/btrfs/raid56.c > @@ -2139,7 +2139,11 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio, > > rbio->faila = find_logical_bio_stripe(rbio, bio); > if (rbio->faila == -1) { > - BUG(); > + btrfs_warn(root->fs_info, > + "%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)", > + __func__, (u64)bio->bi_iter.bi_sector << 9, > + (u64)bio->bi_iter.bi_size, bbio->map_type); > + ASSERT(0); Why is this here? Say we'll test a fuzzed image, this would stop any further testing. The message and EIO should be fine. > if (generic_io) > btrfs_put_bbio(bbio); > kfree(rbio); > -- > 2.5.5 >