From nobody Fri Oct 3 10:15:34 2025 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (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 2FFB128489B; Tue, 2 Sep 2025 15:22:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756826570; cv=none; b=plUpk+3nXYDZUWmPiUuJgmOPXdTvAQ174lTV7TnOVV5u4mT4z5BcqOLiRAIbEgH+HJHWmTrDwDDyR1WyxPOqYj4rBIfveAF636a0aTAvQw5pBNuw7ZzEysvQ8Y2o6ECxmW3HR4liYxDmXr9pH2A277cjrjLmgtgXGl71O+uzfRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756826570; c=relaxed/simple; bh=HaUYGzzb/C0ZDIqppBt972XneJxjm2FpucYUwJY3Mq0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kOoLk7b3XPvOfrmMg5w0/a/krP3tfW0Ciwv5ufYEvCOFnKVE6fZdy5uzl35VGK9PbOVnV4PYh1bq1T3L4Q81DuGTcrNXvWOIy5seYZO0dCPJ1N+PZgGwVxGWBCLVkemOfBh9YOJXOlkz6XUoobc3MJPq6068dLaJZbAcdjpL/4g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=AnLLyO9V; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="AnLLyO9V" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject: Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=U0gQV6ybTFZGuryr56vx/u+MpC/277rOqkaUQrD8Who=; b=AnLLyO9VMFwCr2es3/frbxHCBC JjlPP7n5z9ULDCVWr5AQzJ2l+5q8UR66ExwbJHr6BkB1jeIzNQMrNOxqEIPvli742kjWtQgd2zzCY vMFTibF3LJcdJwQVNj22JNPUIL6brEeMOevh2LnJ3Fla/R2w5OyaEhlk8ekLJHdo9l4t0Gx5d9Qpt wNMbh5xJ2zU7tA0gctkcN5r3o3ZtkeDmFSF1c196PEPJ1+SPEOHBPfKAB6q5WmO0HRoA5UMPeoaM2 cdJeEn7Q/ObGevUCQaRo+XaSlU61ZAy2B3RQbAmsUz/YQSV3qHJ55gQdj4H3qjFyKYnNPxsY187/W SMJSM2hg==; Received: from bl17-145-117.dsl.telepac.pt ([188.82.145.117] helo=localhost) by fanzine2.igalia.com with utf8esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1utSqH-005lLV-MA; Tue, 02 Sep 2025 17:22:41 +0200 From: Luis Henriques To: Miklos Szeredi , Joanne Koong Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Luis Henriques Subject: [PATCH] fuse: remove WARN_ON_ONCE() from fuse_iomap_writeback_{range,submit}() Date: Tue, 2 Sep 2025 16:22:34 +0100 Message-ID: <20250902152234.35173-1-luis@igalia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The usage of WARN_ON_ONCE doesn't seem to be necessary in these functions. All fuse_iomap_writeback_submit() call sites already ensure that wpc->wb_ctx contains a valid fuse_fill_wb_data. Function fuse_iomap_writeback_range() also seems to always be called with a valid value. But even if this wasn't the case, there would be a crash before this WARN_ON_ONCE() because ->wpa is being accessed before it. Signed-off-by: Luis Henriques --- As I'm saying above, I _think_ there's no need for these WARN_ON_ONCE(). However, if I'm wrong and they are required, I believe there's a need for a different patch (I can send one) to actually prevent a kernel crash. fs/fuse/file.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 5525a4520b0f..fac52f9fb333 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -2142,8 +2142,6 @@ static ssize_t fuse_iomap_writeback_range(struct ioma= p_writepage_ctx *wpc, struct fuse_conn *fc =3D get_fuse_conn(inode); loff_t offset =3D offset_in_folio(folio, pos); =20 - WARN_ON_ONCE(!data); - if (!data->ff) { data->ff =3D fuse_write_file_get(fi); if (!data->ff) @@ -2182,8 +2180,6 @@ static int fuse_iomap_writeback_submit(struct iomap_w= ritepage_ctx *wpc, { struct fuse_fill_wb_data *data =3D wpc->wb_ctx; =20 - WARN_ON_ONCE(!data); - if (data->wpa) { WARN_ON(!data->wpa->ia.ap.num_folios); fuse_writepages_send(wpc->inode, data);