From nobody Fri Oct 3 13:27:18 2025 Received: from mail-ej1-f54.google.com (mail-ej1-f54.google.com [209.85.218.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2336A30DD0B for ; Mon, 1 Sep 2025 09:19:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756718375; cv=none; b=KUoRCpnAlmU0Yshq1hPhSS5nOpjKEGvQNrDvSxk4bCwOomR6pJb52v2eK0tX6/dvBEEm34TWQKiadx61tboQu2sg/GYmk/iZ6xj6J1JL/3HkGib0pL/7x6CW7sZsFgfWnxdwElbXxmhpTPtCmEzbEWRITiWWi1WHiPTyWzUUm3Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756718375; c=relaxed/simple; bh=fqMfYftVrFkOy3wbJRO7r0XLlbG/lU+7XLovauzZWxo=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dDbEOHwUn3tlvXFW6OjGTCKNi/NYsZJd7uJrrtoZErZGfNSWeEvjrBB2Qi3sUEogRKtSeX3WLkAqG1vUOwXzml+BEKr5+UsvvnjG/h78aSlTaFwozM/MwbojjY8WF+yARBl0cQRm7DY8tbYZo6NOCWD8eZbkw3dL20KxIUOmXH0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=ionos.com; spf=pass smtp.mailfrom=ionos.com; dkim=pass (2048-bit key) header.d=ionos.com header.i=@ionos.com header.b=Dl7V1wER; arc=none smtp.client-ip=209.85.218.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=ionos.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ionos.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ionos.com header.i=@ionos.com header.b="Dl7V1wER" Received: by mail-ej1-f54.google.com with SMTP id a640c23a62f3a-afede1b3d05so694639866b.2 for ; Mon, 01 Sep 2025 02:19:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ionos.com; s=google; t=1756718371; x=1757323171; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=8H3eprdm8oiBq+0anIaTODIO0eIcUyIWc/5jJ7tDkes=; b=Dl7V1wERFzMleKB/mcdbkOLSfivKh/0qTbbLHtW40hL12fF/PHC6FBC8qSvS+8F/AH 5823j13P3EjHQyBXddCElPlgiJAomY75h48tIKrF7Aiqehm9JKkfycrMNH8tpoI8wWhE 1kV99t9hXTKOXn52zT9HzwBCAp5xD3jTg0cA4HwqoPkGOq+MUNBgc4RNYD67veOaFXv5 yMZaKCwx/18ovZe7OG6CWpIBvjMi9DTLZhuoxCYTOkVPoG3Z2oVQNvrAnl7JC2RXUv/e CqNkBD/dICQCC+BKKzxrAq0FOGHnwGkJC+NZt0j7I/UEBoL31gvVNsHRUc9JZHTuF0S0 ksig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756718371; x=1757323171; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8H3eprdm8oiBq+0anIaTODIO0eIcUyIWc/5jJ7tDkes=; b=C0reoX9U9og6JFJmKUr0I4EMq8rNyiI2sv1fpnThwpaZiK7sVE6bA5UZMXIiqzv0vm hdQbHw80ZfcUzgTwYrWf/aFNTAaJxHhBGEvhpZWAFCEu71zkHz0cajWzZGTj+ky7n3CD YBi3jPx0oQ9A/xoqIyMD4Lo/3PyMqnitA9w38yti3J90+s+JSEJu0ykeV1wL72c2KumL KH6SI+n9LXJbDUt2QjHxf1DvSh22Y/9Ws5PDVxy8VEhxyvIfwi8TyYYDXWQ1GVH5JIzQ 7lze5CgCNBvpWDc/M8S3hhKNp//b6+uE9fIW/Ys0nAD9KqtmZGrUM7AnSmV3TJqsPL6Z WclQ== X-Forwarded-Encrypted: i=1; AJvYcCWXSdaTc7M7pmWIoghealKDBXdGVBG/J50fqOfkIL5moFsIURTkNb792XGDIyNNRTTaAOVSKI3hTZN3DiI=@vger.kernel.org X-Gm-Message-State: AOJu0YzY8MJ7TEcazV7/U7rGzz0o6XE+zL7+jBgEy9yZ2gjIW8PU82BV eC00bXtTJSI69/4AEspwK+kav+ASs/4isU22GIHB8c9Mk+QFvdCWSo+qN4HH791hHyM= X-Gm-Gg: ASbGncuKO9kwolW+dMXZJ73ic/+BZNAym0wgb27Y4+EYgaMnKHL59O3nNvy44/tkBxB AAND9NuF+1CCcA8i/fLOkcgQV7xVkZHmc/L5AUG6J8IE4GtHNB5oh/cF1PSh1pxUtWiS/1uofyH 5rKKEou5yWOxd02dpD0hqP8zf/N6Xs9L1o9Wx8ltjhi/NXBu1jqQMddV1JquE05Ji2MeqEGOZFo L8TGrzWscVKumnHe789/v5XNMiBjP9FEvX9wV48Wyyy4Pho8DtKgONaStjRuPX6kUWXkq7xR2pe sJ6cPkFrnjqzrg+yh5zif4/vWyjHDiMW7ej13uppY8K2yNPAPvELNRxMsQtOnF+Ucr5PAKAD+Om wJpVj9YjmNTFnM1wv4CMXVFv5ZEtzo+6l+gO9Tgu5gtqNoTbv18rlIaXPnt/jIrqF45J2wcBDZP DOGWy0EyhIczlt14pLmTWn7jCSZH+f0vGw X-Google-Smtp-Source: AGHT+IF3CGqBNxa77EXUE/Gi7n0PBGLpiMmjL4vqume2Hy8S1ALFuVUh9cDg4qepPIlJtHhtd6svhA== X-Received: by 2002:a17:907:7ea7:b0:b00:5399:f5c0 with SMTP id a640c23a62f3a-b01f20bfff5mr728590366b.62.1756718371341; Mon, 01 Sep 2025 02:19:31 -0700 (PDT) Received: from raven.intern.cm-ag (p200300dc6f1d0f00023064fffe740809.dip0.t-ipconnect.de. [2003:dc:6f1d:f00:230:64ff:fe74:809]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b01902d0e99sm541005766b.12.2025.09.01.02.19.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Sep 2025 02:19:31 -0700 (PDT) From: Max Kellermann To: akpm@linux-foundation.org, david@redhat.com, axelrasmussen@google.com, yuanchu@google.com, willy@infradead.org, hughd@google.com, mhocko@suse.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, vishal.moola@gmail.com, linux@armlinux.org.uk, James.Bottomley@HansenPartnership.com, deller@gmx.de, agordeev@linux.ibm.com, gerald.schaefer@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, davem@davemloft.net, andreas@gaisler.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, chris@zankel.net, jcmvbkbc@gmail.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, weixugc@google.com, baolin.wang@linux.alibaba.com, rientjes@google.com, shakeel.butt@linux.dev, max.kellermann@ionos.com, thuth@redhat.com, broonie@kernel.org, osalvador@suse.de, jfalempe@redhat.com, mpe@ellerman.id.au, nysal@linux.ibm.com, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v4 04/12] fs: add const to pointer parameters for improved const-correctness Date: Mon, 1 Sep 2025 11:19:07 +0200 Message-ID: <20250901091916.3002082-5-max.kellermann@ionos.com> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250901091916.3002082-1-max.kellermann@ionos.com> References: <20250901091916.3002082-1-max.kellermann@ionos.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 memory management (mm) subsystem is a fundamental low-level component of the Linux kernel. Establishing const-correctness at this foundational level enables higher-level subsystems, such as filesystems and drivers, to also adopt const-correctness in their interfaces. This patch lays the groundwork for broader const-correctness throughout the kernel by starting with the core mm subsystem. This patch adds const qualifiers to address_space pointer parameters in filesystem-related functions that do not modify the referenced memory, improving type safety and enabling compiler optimizations. Functions improved: - mapping_tagged() - mapping_mapped() - mapping_writably_mapped() Signed-off-by: Max Kellermann Reviewed-by: Vishal Moola (Oracle) --- include/linux/fs.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 3b9f54446db0..8dc46337467d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -537,7 +537,8 @@ struct address_space { /* * Returns true if any of the pages in the mapping are marked with the tag. */ -static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t= tag) +static inline bool mapping_tagged(const struct address_space *const mappin= g, + const xa_mark_t tag) { return xa_marked(&mapping->i_pages, tag); } @@ -585,7 +586,7 @@ static inline void i_mmap_assert_write_locked(struct ad= dress_space *mapping) /* * Might pages of this file be mapped into userspace? */ -static inline int mapping_mapped(struct address_space *mapping) +static inline int mapping_mapped(const struct address_space *const mapping) { return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root); } @@ -599,7 +600,7 @@ static inline int mapping_mapped(struct address_space *= mapping) * If i_mmap_writable is negative, no new writable mappings are allowed. Y= ou * can only deny writable mappings, if none exists right now. */ -static inline int mapping_writably_mapped(struct address_space *mapping) +static inline int mapping_writably_mapped(const struct address_space *cons= t mapping) { return atomic_read(&mapping->i_mmap_writable) > 0; } --=20 2.47.2