From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7E9A43BADA5; Mon, 1 Jun 2026 13:57:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780322239; cv=none; b=iD4W1FvvOUyEm+s5rpHA2TaMzbq96SFEPkwkG9V/h6iuO8uL0vA9G/85o/Ib8v9L8bjEuvgMvOxGIgOYbz7YKJ9VfLuYtXZK9jPACbGe2PwO7fTdT4RIXlCUDbm91iVJqjLLw0KmsI4cR9Mc8DfUZZxOrTfxvx63k19QDzN7UpM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780322239; c=relaxed/simple; bh=piQMn1e6FaWg5N5YyNpDLQ+CLvrL1afyXNBbQ5NJvPc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jodfAZBfZNsfee2sS7A5HQ7PjeZl5svbKM1rv5DgRZXvqMi1NgNyrvFXolyNnVZbLarPd6q8tC0Z7Q/KU9ZlA6XdZ2FOXBqBEnqW3k9jFsF2BoSzb65uXVHDq9h5dRmXi3QjEa8QqC54/yipm0uEDTQCi0dEkGa+hFhIIirMuCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dBO+ATgg; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dBO+ATgg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F5051F00893; Mon, 1 Jun 2026 13:57:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780322238; bh=lP8OEgQM5WpZ3TOFDqqMlVW2UDNnbc/Kdkkhd8jbQeM=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=dBO+ATggiG7i6Gqbs4BC2koSaI34cjBXvAaePvMFxmzJDmwclb3yQlmZtV13NuEKq rravWdbKT3aYxi0/kkJX9p7MDQXSMOu5F+ViO81FATVMmdQhqBfxtD/vgKP4FtAooU KIJlgWE9ysv75AqLQ7SENGy4cHS5B9icRHNqkZo0e07g2KeoZcT9vUmKGitQCbTghv l0pW0zF5Fr60q2Zlb5GwgSajNc4shHrzCpybbo35z0MCemyTKmSkzyuqwKqNbzNyxp XYm4qxV4KJvaJxm/BApCsMShaH4IQiSnwk8ZhsxaJIp5TSCCIDyi905rMZZ5/3KiZ0 Or3a92+NzjDFw== From: Christian Brauner Date: Mon, 01 Jun 2026 15:56:43 +0200 Subject: [PATCH RFC v4 10/25] btrfs: use scoped_with_init_fs() for update_dev_time() 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: 8bit Message-Id: <20260601-work-kthread-nullfs-v4-10-77ee053060e0@kernel.org> References: <20260601-work-kthread-nullfs-v4-0-77ee053060e0@kernel.org> In-Reply-To: <20260601-work-kthread-nullfs-v4-0-77ee053060e0@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Alexander Viro , Jan Kara , Jann Horn , "Christian Brauner (Amutable)" X-Mailer: b4 0.16-dev-fffa9 X-Developer-Signature: v=1; a=openpgp-sha256; l=1471; i=brauner@kernel.org; h=from:subject:message-id; bh=piQMn1e6FaWg5N5YyNpDLQ+CLvrL1afyXNBbQ5NJvPc=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWTJ9i8zPL7G/nBPgmPz5Y+37+lJ21duublV8pVQwrXt7 EHORcmrO0pZGMS4GGTFFFkc2k3C5ZbzVGw2ytSAmcPKBDKEgYtTACYyOYLhn13SnR398sf7K3W1 C3jKd2XP87eX0un8lymTsvtQ7BoeY0aGid6ryjklZ87geH/5BZfKGd55Z/avf1PWfnfTyrTcRW4 nmAA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 update_dev_time() can be called from both kthread and process context. Use scoped_with_init_fs() to temporarily override current->fs for the kern_path() call when running in kthread context so the path lookup happens in init's filesystem context. update_dev_time() ← btrfs_scratch_superblocks() ← btrfs_dev_replace_finishing() ← btrfs_dev_replace_kthread() ← kthread (kthread_run) Also called from ioctl (user process). Signed-off-by: Christian Brauner (Amutable) --- fs/btrfs/volumes.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a88e68f90564..967a1fab5c96 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "misc.h" #include "disk-io.h" #include "extent-tree.h" @@ -2120,8 +2121,16 @@ static int btrfs_add_dev_item(struct btrfs_trans_handle *trans, static void update_dev_time(const char *device_path) { struct path path; + int err; - if (!kern_path(device_path, LOOKUP_FOLLOW, &path)) { + if (tsk_is_kthread(current)) { + scoped_with_init_fs() + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } else { + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } + + if (!err) { vfs_utimes(&path, NULL); path_put(&path); } -- 2.47.3