From nobody Thu Oct 2 04:45:11 2025 Received: from mail-wm1-f48.google.com (mail-wm1-f48.google.com [209.85.128.48]) (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 26F26322740 for ; Tue, 23 Sep 2025 10:47:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.48 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758624457; cv=none; b=G36WD7LXb0CMTmQg7mtDx4wrlorlG9iZzpgTk6xpU11NXZGF8KYRyXwa4BtMfgiGkMfY3VFq3Dop3gsQV1akSA0oDz++/zYpeBrgB5prVOlAMk5pqr5HseBHpL1Orl/KIpcKXTMvqfwaPwz/yjeuIULwGCJ8BXtj/2Xyr2Xii4c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758624457; c=relaxed/simple; bh=ouMLdiYXJEV/tbThHG/kXZjFoWBywpLKJo/Paio0wwU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tZMI0ZGMtVABbJozoMwcljYQDVLJhzNaNiSKY0VViJXWU4lwgEylpwKJckVDsLz9/HlpUt4uO7wGq4KQzv4xiBsoATA9Z3WfZfJ1dC2CSNEy/mrJJ8otKBq1rsNGS6VnSKeDc8mw1whs3vS+aiESenEK6bf6CkVULho8gHg4oXE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=LhZGN+uX; arc=none smtp.client-ip=209.85.128.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LhZGN+uX" Received: by mail-wm1-f48.google.com with SMTP id 5b1f17b1804b1-46c889b310dso24389045e9.0 for ; Tue, 23 Sep 2025 03:47:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758624452; x=1759229252; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=UjQhtecysAf2+Tm/SiAxvWYNu2I/ZUKX2kulTrssyjQ=; b=LhZGN+uXvnRcZp/BkNSZYpY3HLnrF3MIXUHwRe5694SHPoiXPSjIF5o1Cx+hffoY2D wLQnIdbqbp35ju7NMkMmutMG6NxIK8kC9I0PKqjPRo3MlN6mwCJzofAiR4aChInAl7Dv uaazvsOcIgmaXfy/dWRVf/OhqHPCYnw40d9hV0nqJHuGnrYlHFvc4aKobLXWjPH/DEGO 5oFXfC+bDh/jOq/E0hzacTXcCu3dhKCjCeiUmPNy1FWresmWjR9SPuCx7AQWtSGJxaGZ jYjbsboNrycDe21fu6Ip2tQufSoGiGGCcxId78Js5h4L5suYrY2HneCBlUZX9HB6XZjW d+AA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758624452; x=1759229252; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=UjQhtecysAf2+Tm/SiAxvWYNu2I/ZUKX2kulTrssyjQ=; b=aoNfGuTjFSAu30KKSSj9Dgyl61ghWqth7uZM3plgr9HV4zQwcSbnb0hAAolo/vDgaE AqAXVVQ4sPER7uBx7Z4uB+phqeON392SqylHoqAxl4YuXB1Tv+6RKo5rxKu3SAimJZSk V30RXg0WWLAgLYTMbgxkvIlBgOYIWxLLT00AMsYEwlMZU/s9eLWH8IYN4fFDSeWakRL0 St4Yku6YXuur6SVhdAhJGlfnp/pWkJjVmqudqMtN4hKZs20qXzph+f0vzeAk1HfyciD+ ezdftRP+WjUmavVW5DAaSVfNkU9cC9wfBpnQaY3Er84PIKjApaDUAH7nYBCzgVXlS0zQ 9chQ== X-Forwarded-Encrypted: i=1; AJvYcCUP/wKmDIXl+oLUKBQp6DYQK+1TUEfj2LBBkXTPCO1PTh7A1jfsIowLe/989zhhtsCerSX5gNkUBta/IY8=@vger.kernel.org X-Gm-Message-State: AOJu0Yw1ydcB6yDPcDql+if3czdZ3a/ukYdfXn8LgzH7Q1MNeuXLG7ZH JsTXiRRfiTgJirR4ZUDQ8NqzI+Kwj7w4p/cFbcHig1Ve4xnx03zdvVK7 X-Gm-Gg: ASbGncvReN/dKodWW25Cz4x713VIxDcYJ24IR9T4CkPB2ddmtHq/BXhUY0QkUrZ5mL7 5Y2cvlgm7pULEFfbCxtJkurnzK3AA4HhxSllLzzR1PRo1XIV1iDHyNLr8Dp33hrr+5VhcHV3rpH E8ioHQJDRe93wQJuCFzgjChnWYYJbGc6BDM24ev4Gzf4oHka/5IM3Pi3h3fjIl7UC1CfQDvUzlW 29fcfX/iLXYUDf3VnCL+KmDMMxjAZ/nuYlY/cINCxA/67gDyq8TD/qTEpHTTTPd2a28rhmqC/2Y I/IiFcYONOwUrX87LO5kUygZ4qS9BRoOLZGiLnSX+qzBeDkC9BTRfCQ6dvzmZr7VoKRQQMLSjbn 2zOFVT1NJTGx4HKk1bVbOpVK788jsIBm/5QPpWM1TxOX4GhsPjigS5dDGoZXZiBe7L45zJyVLtz lJwgrw X-Google-Smtp-Source: AGHT+IEVb9i92+ZMOauFSkmxexkNVrc4dNm4CbgsPp4IcZSL124eR4borVyarFVwdram0vM+rxqviA== X-Received: by 2002:a05:600c:4685:b0:45c:b6d3:a11d with SMTP id 5b1f17b1804b1-46e1e1121edmr21348615e9.1.1758624451919; Tue, 23 Sep 2025 03:47:31 -0700 (PDT) Received: from f.. (cst-prg-21-74.cust.vodafone.cz. [46.135.21.74]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-46e23adce1bsm9710525e9.24.2025.09.23.03.47.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Sep 2025 03:47:31 -0700 (PDT) From: Mateusz Guzik To: brauner@kernel.org Cc: viro@zeniv.linux.org.uk, jack@suse.cz, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, josef@toxicpanda.com, kernel-team@fb.com, amir73il@gmail.com, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-unionfs@vger.kernel.org, Mateusz Guzik Subject: [PATCH v6 4/4] fs: make plain ->i_state access fail to compile Date: Tue, 23 Sep 2025 12:47:10 +0200 Message-ID: <20250923104710.2973493-5-mjguzik@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250923104710.2973493-1-mjguzik@gmail.com> References: <20250923104710.2973493-1-mjguzik@gmail.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" ... to make sure all accesses are properly validated. Merely renaming the var to __i_state still lets the compiler make the following suggestion: error: 'struct inode' has no member named 'i_state'; did you mean '__i_stat= e'? Unfortunately some people will add the __'s and call it a day. In order to make it harder to mess up in this way, hide it behind a struct. The resulting error message should be convincing in terms of checking what to do: error: invalid operands to binary & (have 'struct inode_state_flags' and 'i= nt') Of course people determined to do a plain access can still do it, but nothing can be done for that case. Signed-off-by: Mateusz Guzik --- include/linux/fs.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 73f3ce5add6b..caf438d56f88 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -782,6 +782,13 @@ enum inode_state_flags_enum { #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME) =20 +/* + * Use inode_state_read() & friends to access. + */ +struct inode_state_flags { + enum inode_state_flags_enum __state; +}; + /* * Keep mostly read-only and often accessed (especially for * the RCU path lookup and 'stat' data) fields at the beginning @@ -840,7 +847,7 @@ struct inode { #endif =20 /* Misc */ - enum inode_state_flags_enum i_state; + struct inode_state_flags i_state; /* 32-bit hole */ struct rw_semaphore i_rwsem; =20 @@ -906,26 +913,26 @@ struct inode { */ static inline enum inode_state_flags_enum inode_state_read(struct inode *i= node) { - return READ_ONCE(inode->i_state); + return READ_ONCE(inode->i_state.__state); } =20 static inline void inode_state_set(struct inode *inode, enum inode_state_flags_enum flags) { - WRITE_ONCE(inode->i_state, inode->i_state | flags); + WRITE_ONCE(inode->i_state.__state, inode->i_state.__state | flags); } =20 static inline void inode_state_clear(struct inode *inode, enum inode_state_flags_enum flags) { - WRITE_ONCE(inode->i_state, inode->i_state & ~flags); + WRITE_ONCE(inode->i_state.__state, inode->i_state.__state & ~flags); =20 } =20 static inline void inode_state_assign(struct inode *inode, enum inode_state_flags_enum flags) { - WRITE_ONCE(inode->i_state, flags); + WRITE_ONCE(inode->i_state.__state, flags); } =20 static inline void inode_set_cached_link(struct inode *inode, char *link, = int linklen) --=20 2.43.0