From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793372274; b=jdtEc+lQX20lAbJDeZN5x8bNQFjfM6JbCSe16HltlCmRLjLYfkSQGJzrk79JS0KXYuF+ YS4KelECqdg631X8bckLm0o1SEIM9zSLHZiSwzi42//pB6a+DHcwybpUNP9oruzc3JbK7 GJoNAxLUFTIDoS4wCP9P7T+RqwfC4EGkl8T81P/8+zKlUatmgtaDSiBzksxZOpkO1LrHA W6NEiuof5Rv21sYveztz8mI5ZxfioSAjy1+hf0InQwMg+9iyDgBm1vrmllAADMjjUVlYp j/P4utFz74fzBlEH2piXMtYDLL0zAXc7jDStQgSV7XOnEXYRUUz4J4p46Ugrp6TuUBw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793372274; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=jdzo/JB3v48SeneKPfJ1gOvJLI6gIMIp+FynceKuycM=; b=GmjCuaaPc4/yMDnjInyFQ3w44RCO41Jm3IupPzjTBQEiPO8DLTMORfOeG7976n1oOB4x w1BpNGbRLK48pcSx9gykRj/YDtXn781uPzh3M6DLzJLntHBmH08/0XEXXo9cjfVicB6X9 LqiPk8ix0OThF8muD7jL4n067gOo+HqJPsC59IFI3EHvEx2maVMnA91hWUJ69OLlYP8nb iA1wk4nO753GDk0IPGCjUPLWlFsNMtvj7wr9sEaA0PPtDCei+Mw3lhMV665lL3uaR3ab+ QrzQQ7Wz7jyamUqK4GiVeR1KKUlEOxjfhYoGDPNWc6lQq9WxeVFIDjnMfXzv37wqIug== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KDtmM5U9; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 28B0E606A31A; Fri, 30 Oct 2026 14:57:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KDtmM5U9 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B83CE1F000C1; Fri, 30 Oct 2026 14:57:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793372273; bh=jdzo/JB3v48SeneKPfJ1gOvJLI6gIMIp+FynceKuycM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=KDtmM5U9/nlLDrvkYK477BJ6l62T7j3Tq61FVrN1RPIoswoDY6osdmLedz7FG7ZNz nyKKOYYn7v0PDdl6GhDXOCSvt0PDLyL6tg6tdB2J8v8QCFzgrPkU6o9H5JEhhSLjq3 qEPMg5AR1UnOY2EszabX7fOmdau0IquNp4c3/hNhhh8vu85TGAKqd/uURl1ccD47Oe lruFjzGdBGLjW9RxSgppdcv2Cd0Zo2npHfpgHJSMNhacNU/sMyqZ6QoUnx2QnBpqu1 4yWH1v7l/hy8f84veiUbdKCIV3ieDDy082/rpdBxoAPQeKnIZ/wyiF/M2KTDZIhGGn 7PZf9dTpmujSg== Date: Fri, 30 Oct 2026 15:57:49 +0100 From: Christian Brauner To: Edvard Conrad , Amir Goldstein Cc: Miklos Szeredi , Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3] fs: let backing files inherit FMODE_NONOTIFY from the user file Message-ID: <20261030-welpen-anbinden-nullen-b2432cee1d10@brauner> References: X-Mailing-List: linux-kernel@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=utf-8 Content-Disposition: inline In-Reply-To: On Thu, Oct 29, 2026 at 10:18:40PM +0100, Edvard Conrad wrote: > Make a backing file inherit FMODE_NONOTIFY when the user file it is > opened for must not generate events. This restores the pre-6.14 > behaviour for the fds that fanotify creates (and for any other > FMODE_NONOTIFY file), while ordinary opens through a stacked filesystem > keep generating events on the real path, as intended by bc2473c90fca. Looks good to me. I'll take this via vfs.fixes and fix up the subject to use the "backing-file:" prefix while applying. Amir, note that the same deadlock is still there for directories. ovl_dir_open_realfile() goes through ovl_path_open() -> dentry_open() and not through backing_file_open(). So a FAN_OPEN_PERM|FAN_ONDIR listener that opens an overlay directory through the fd fanotify handed it wedges the same way. That needs to be fixed on the overlayfs side.