From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=213.95.11.211 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793203171; b=hliwI0jY0Cej23Gsn/PkbMyP4Mczyt9ET05lmhorG61I5RP2xeowap/2ci12txruvXc/ xMDMGif0FyHs+xUMu0L8/uI6sqReUGDN10xdJsAYLUujNZ/jAsGEMKBW/WdhTm2MdnrSr cZXZQoHGd0s7xQ0rWDhrwUKdtcTf3kpvgpWy3jpyrXHZlVhdRtmsCeEjZk83S4XbI0QP4 +YzCnz5Kfjp7dMR1AtHDHgLl7iBe9y92JkL8pmPFU/BRAreTURwQ80RmH6X78MLf9nSd9 fWxYfDaJhoZVDiuTPeIdMpaj7KTY5+CJ7TqTBANw6qu3BVR+KtA1p7eLB2PeYrvbfwg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793203171; h=DMARC-Filter:Received:Date:From:To:Cc:Subject:Message-ID:References: MIME-Version:Content-Type:Content-Disposition:In-Reply-To:User-Agent; bh=tPemWb2rCPGtbEKexorlNRNCXDQ/EWhUdVHMfdkbSJM=; b=Eq7NzkjsTkTpdK85kFHd2fBx+VGnxrgWqNyv/5BjjdCF4rtdbufX3Q3Smg3zOzCGJ5UZ 1gK1F0RUtdpzdvFURflZSbLseOEwGbc/ps4KFLF/XC+wbochRg1Ru5UIqut+UuGlreJDn +S8yD0kBJzun1anUUECjHnM3TOvbat1CtBD1haOfEpysVTe8r9g0LhwQ3rz3rIuocFb+5 hskhLWeXduwgcbaIZOAG9SoHH9L1bx2lKqJFfsU07TR1TBwndGA25+x0XbjZpr0hLfh9Q PV8PPKEAQ0PQZPxmikPk2/y3VbyQqlGp3LhR+ydy/oEwGp45c2xu5Cjej2Hi79LSypg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.remote-ip=213.95.11.211 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C617F606A321; Wed, 28 Oct 2026 15:59:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C617F606A321 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 8A55068AFE; Wed, 28 Oct 2026 16:59:26 +0100 (CET) Date: Wed, 28 Oct 2026 16:59:26 +0100 From: Christoph Hellwig To: Amir Goldstein Cc: Zorro Lang , Miklos Szeredi , Christian Brauner , Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH v2] src/vfs: skip whiteout-device fixtures on overlayfs Message-ID: <20261028155926.GA20501@lst.de> References: <20261017092841.2364286-1-amir73il@gmail.com> X-Mailing-List: fstests@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261017092841.2364286-1-amir73il@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) On Sat, Oct 17, 2026 at 11:28:40AM +0200, Amir Goldstein wrote: > From: Christian Brauner > > The idmapped mount tests create a whiteout device, > mknod(S_IFCHR, makedev(0, 0)), as a fixture: a whiteout device is the > only character device an unprivileged caller may create, since it is > exempt from the CAP_MKNOD check. overlayfs reserves a 0:0 character > device as its on-disk whiteout marker, so ovl_mknod() returns -EPERM > and the fixture cannot be created, failing generic/633, generic/696 and > generic/697 on overlayfs. > > Add a whiteout_device_supported() helper and skip the whiteout-device > fixtures and the checks that depend on them on overlayfs. The > makedev(5, 1) "creation must fail" probes are unaffected and keep > running. No-op on every other filesystem. Looks fine: Reviewed-by: Christoph Hellwig