From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from len.romanrm.net ([91.121.75.85]:45294 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750763AbdHAGEN (ORCPT ); Tue, 1 Aug 2017 02:04:13 -0400 Date: Tue, 1 Aug 2017 11:04:10 +0500 From: Roman Mamedov To: Liu Bo Cc: "marcel.cochem" , linux-btrfs@vger.kernel.org Subject: Re: BTRFS error: bad tree block start 0 623771648 Message-ID: <20170801110410.0813a03a@natsu> In-Reply-To: <20170731181200.GA3459@lim.localdomain> References: <20170731181200.GA3459@lim.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, 31 Jul 2017 11:12:01 -0700 Liu Bo wrote: > Superblock and chunk tree root is OK, looks like the header part of > the tree root is now all-zero, but I'm unable to think of a btrfs bug > which can lead to that (if there is, it is a serious enough one) I see that the FS is being mounted with "discard". So maybe it was a TRIM gone bad (wrong location or in a wrong sequence). Generally it appears to be not recommended to use "discard" by now (because of its performance impact, and maybe possible issues like this), instead schedule to call "fstrim " once a day or so, and/or on boot-up. > on ssd like disks, by default there is only one copy for metadata. Time and time again, the default of "single" metadata for SSD is a terrible idea. Most likely DUP metadata would save the FS in this case. -- With respect, Roman