From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 114A920B806; Tue, 6 May 2025 17:51:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746553868; cv=none; b=O445Wwy5Y5PiluPR8k9zRLjft0Jspt2h5SnOhtuQaZt83vLn+nJi5dkZ4/nfv57KJP6c3zwE2kXs7xCyKV78rWjebM38txtG0QrfIiz22TXqO7qyO83OPUg9Tp43LZGjtAjSlKXJyzo7Aqq0dbPlPGdpu9Rdp3uuw6gzDD1pB78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746553868; c=relaxed/simple; bh=tNHkYVaPLR66Jwo6P/hAd7RGYTFoS8PrUrPK82+TRfE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NYsW/85O3CFNNRnOV5i+Mqs8plpTj/Bgku27A0wkKt9dbosFKBHmOG8JJEOEfFIpwg97AROnCSJNhovDV3v8BQGk9AcPkluFZjRY7c5I8P2HcSsq+JBbcte1fNNAGtPsGeOg5581u0saTDanFgH6ZCE5+vhID9avISTj8tnclzA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=b0P9HVbl; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="b0P9HVbl" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2btRWPwA9on4qXX8cdT3XjkC1igfIwg9iKd03qmtBNE=; b=b0P9HVblelra/46iw7YxdEPuLb DkqILc4752tu274SXheDygaSKYnxoFdPXkPvr88onFSIXKpxHZmFSD2ci3SBNjHiEOQMq2bw/hXmk nvIlxs+QGyRmuXn/FbN+A5zvYnSLBOXyNpk2OvFpldJUjVwGEFiVpEymMxVuS9O3ssWmkCym53gZU VnnBSVakpZJOt+ThOrYLLpj76064phvIct6YorBIlqO+f4hig+QYcoc7dfD061+/JRvP2WYhR778G njldhSlH/UsSgNAS1tuyDf7c5sjpTKoLK8rNfpl/L5GgTzs69GYSKQWI/FylHTbCAdnfClKhgO3G1 7Nl6/d8w==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uCMRc-0000000Brin-0Hnf; Tue, 06 May 2025 17:51:04 +0000 Date: Tue, 6 May 2025 18:51:04 +0100 From: Al Viro To: Klara Modin Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org Subject: Re: [RFC][PATCH] btrfs_get_tree_subvol(): switch from fc_mount() to vfs_create_mount() Message-ID: <20250506175104.GO2023217@ZenIV> References: <20250505030345.GD2023217@ZenIV> <3qdz7ntes5ufac7ldgfsrnvotk4izalmtdf7opqox5mk3kpxus@gabtxt27uwah> <20250506172539.GN2023217@ZenIV> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Al Viro On Tue, May 06, 2025 at 07:47:29PM +0200, Klara Modin wrote: > On 2025-05-06 18:25:39 +0100, Al Viro wrote: > > On Tue, May 06, 2025 at 03:36:03PM +0200, Klara Modin wrote: > > > > > 25: 49 8b 44 24 60 mov 0x60(%r12),%rax > > rax = fc->root > > > 2a:* 48 8b 78 68 mov 0x68(%rax),%rdi <-- trapping instruction > > rdi = rax->d_sb, hitting rax == 0 > > > > > > - mnt = fc_mount(dup_fc); > > > > - if (IS_ERR(mnt)) { > > > > - put_fs_context(dup_fc); > > > > - return PTR_ERR(mnt); > > > > + ret = vfs_get_tree(dup_fc); > > > > + if (!ret) { > > > > + ret = btrfs_reconfigure_for_mount(dup_fc); > > > > + up_write(&fc->root->d_sb->s_umount); > > > > ... here. D'oh... Should be dup_fc, obviously - fc->root hadn't been > > set yet. Make that line > > up_write(&dup_fc->root->d_sb->s_umount); > > and see if it helps. Sorry about the braino... > > Thanks, that fixes the oops for me. > > Though now I hit another issue which I don't know if it's related or > not. I'm using an overlay mount with squashfs as lower and btrfs as > upper. The mount fails with invalid argument and I see this in the log: > > overlayfs: failed to clone upperpath Seeing that you already have a kernel with that thing reverted, could you check if the problem exists there?