From nobody Thu Apr 9 21:49:51 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 21FBA36C0BA; Thu, 5 Mar 2026 23:31:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772753472; cv=none; b=PMiqWys2CoYLrgJ287sJM8SAyTIYYM61ZAKvpfbSXkjzHG7qTVfrGKy6wEu21w/ZDUNHxcEeOyuYq/b/+m302cM4VInb+E/PgKursxCiv6H9iTzdBlH0uc8HPejmrPVlrhQEaVxFyl8dGrAxG718lwhsOT/uWVNin3KD04gUt4g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772753472; c=relaxed/simple; bh=LEkYCP2B26VM04U/Xfgf30JgLqLChdLWXV57GkA2dNs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=mVY4Q/eDSVjRcxjIbM42bmThly5bQiRHQX7MXvgvFObpX6qUUJ5bH3+tje0+yoJWkYRNLcnJ7EMLeTbfwRbrxSOBkvM23yXH8Kp8aWpwpmpyGjYDiEW2oui2eOfqnCPgKrlB2WKAq+FGXxGUiBDpUBgjJNO/9cTCNv3s1K7oC3I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KB1g9v7Y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KB1g9v7Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E557EC19423; Thu, 5 Mar 2026 23:31:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772753472; bh=LEkYCP2B26VM04U/Xfgf30JgLqLChdLWXV57GkA2dNs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=KB1g9v7YNo2cA5LeGftvekrvEjpF6FqnB/NDLsnF04wG4bVMhWyWdenXwEi8YzdTu Zzlqr2sA2PSNBJGSE2dO7HGMYE5QMCTdfM7l+Ys8wHsOXWf4n+uy7j+ysrNq9Ft12x E9E+1G84CYzF+0weUXpW3yrI2yHDUGsShw5bsSkVycnPjwS8mmBEM8BPhED1C9SH5B /noyRtjci8xfFDs+tElqlvDKZ8BSTXna1KOfugtOV89pbGA+vpqs9w6/vkIJoDwR/O PuCeFwWTaRRucpcVuEnupg7RdWnGZ963iBNYyC3GD9eSaC/gh8FhxIKiC5+nym62KS kHP4m0EuHuw0Q== From: Christian Brauner Date: Fri, 06 Mar 2026 00:30:23 +0100 Subject: [PATCH RFC v2 20/23] devtmpfs: create private mount namespace Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-work-kthread-nullfs-v2-20-ad1b4bed7d3e@kernel.org> References: <20260306-work-kthread-nullfs-v2-0-ad1b4bed7d3e@kernel.org> In-Reply-To: <20260306-work-kthread-nullfs-v2-0-ad1b4bed7d3e@kernel.org> To: linux-fsdevel@vger.kernel.org, Linus Torvalds Cc: linux-kernel@vger.kernel.org, Alexander Viro , Jens Axboe , Jan Kara , Tejun Heo , Jann Horn , Christian Brauner X-Mailer: b4 0.15-dev-47773 X-Developer-Signature: v=1; a=openpgp-sha256; l=792; i=brauner@kernel.org; h=from:subject:message-id; bh=LEkYCP2B26VM04U/Xfgf30JgLqLChdLWXV57GkA2dNs=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWSuEuJy3csm/W8Rm6p7/AmmpRdiQlncdVk1zu9vY5s+q b76wb6ZHaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABPJ/sjI0GGnvvropTn2jgrR Wb+PfNr4r5Mhdsq9g5VLnMykY7U3/GH4Z/Ql2HF5yPGL0r+05m77fWXG5zgLzq0e76cEmpcd0s9 MZQQA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Kernel threads are located in a completely isolated nullfs mount. Make it possible for a kthread to create a private mount namespace so it can mount private filesystem instances. This is only used by devtmpfs. Signed-off-by: Christian Brauner --- drivers/base/devtmpfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index b1c4ceb65026..246ac0b331fe 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -413,7 +413,7 @@ static noinline int __init devtmpfs_setup(void *p) { int err; =20 - err =3D ksys_unshare(CLONE_NEWNS); + err =3D kthread_mntns(); if (err) goto out; err =3D init_mount("devtmpfs", "/", "devtmpfs", DEVTMPFS_MFLAGS, NULL); --=20 2.47.3