From nobody Sun Oct 5 10:47:04 2025 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [80.241.56.152]) (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 3E273213254; Wed, 6 Aug 2025 06:07:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.152 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754460447; cv=none; b=R4HRaHJnKQOIntS3En2pIyl05k9g7tI1e5q0XBj6IE9+x2D99PXqUXzVtuJDRaXGvnnoMu7n4uJrcrFCOhMLDVtkzzcfjWM/LB88SZUe7NjMZNOaOZPs/KbxLGFwxPZ4LPMOi5qKEGQECdWdWgD9lWLKsIV2eaXPEAKuLlEmabg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754460447; c=relaxed/simple; bh=4s8Gi1EenOHJaLb55g1juwsl7ZsPZjgWY4gDBSu2WAI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=KtFFDCDu1QUdvtPA0x+Ncn2C0365UJCgV/ixOzNRNw4idv1sbLu796OMgh3dI7LDtbiMdDpvksJFsOFsVlDUe+wQFEcLREZNIm17hcAK80CRxtnlLtK3BpO7a+bJnUb0eRhBtM8Iywact+0ZwTSXR1zPVefRroFv8WqaiHkbxLk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cyphar.com; spf=pass smtp.mailfrom=cyphar.com; dkim=pass (2048-bit key) header.d=cyphar.com header.i=@cyphar.com header.b=ADXrF2mq; arc=none smtp.client-ip=80.241.56.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cyphar.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cyphar.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cyphar.com header.i=@cyphar.com header.b="ADXrF2mq" Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4bxfvr4j5mz9tcl; Wed, 6 Aug 2025 08:07:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cyphar.com; s=MBO0001; t=1754460440; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yOE9waL0ew+X+ln2ytNi3KfwfeUFVHt9mFZ0tGiHb8c=; b=ADXrF2mqGhopMlhIOanMGYzWUQ1wtbPzl+gFMMbNzVNI5ezmijF7kTcBmi2kjSYv4CPvLO nVbZ1+AcM+xdMpICf2FmZAYqUIZ2OTMHAqG5LdF5forSKUgp9NusF6iq3Zpt4WoEYunu6A 83cLg3BVixa8LrEzac59d/0DquXiQGlhRkrtDd0xKHMtN7jhCnp88eKj/BgyU/WEJES9fm 6uXCFBY8kEEm/bKuECvcfUDb+KbZd7liSEhyiRgYTRdUJASlhu3+KI189cwNEewdyDXHPg rc6+j8X13ssp0c/ALLlCkvJzb4qiLzcIpmDf0AgHIp373KKnv6ffW1NiMc9LHQ== Authentication-Results: outgoing_mbo_mout; dkim=none; spf=pass (outgoing_mbo_mout: domain of cyphar@cyphar.com designates 2001:67c:2050:b231:465::102 as permitted sender) smtp.mailfrom=cyphar@cyphar.com From: Aleksa Sarai Date: Wed, 06 Aug 2025 16:07:05 +1000 Subject: [PATCH v2 1/2] fscontext: add custom-prefix log helpers 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: <20250806-errorfc-mount-too-revealing-v2-1-534b9b4d45bb@cyphar.com> References: <20250806-errorfc-mount-too-revealing-v2-0-534b9b4d45bb@cyphar.com> In-Reply-To: <20250806-errorfc-mount-too-revealing-v2-0-534b9b4d45bb@cyphar.com> To: Alexander Viro , Christian Brauner , Jan Kara Cc: David Howells , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Aleksa Sarai X-Developer-Signature: v=1; a=openpgp-sha256; l=3383; i=cyphar@cyphar.com; h=from:subject:message-id; bh=4s8Gi1EenOHJaLb55g1juwsl7ZsPZjgWY4gDBSu2WAI=; b=owGbwMvMwCWmMf3Xpe0vXfIZT6slMWRM+shv+dtntTbHe0WzBS52LzZk63wXurN6zQLJpY7+G 4X0pQ8JdJSyMIhxMciKKbJs8/MM3TR/8ZXkTyvZYOawMoEMYeDiFICJXMll+Ge1sefMKe6QYwF/ RLaJ+Et46kqvmp4Yxpv7bJL5vj+XZvox/GL2Wrm855Rf+qxtnq5TeU44JBXXOG+qaxFattkhclo XKx8A X-Developer-Key: i=cyphar@cyphar.com; a=openpgp; fpr=C9C370B246B09F6DBCFC744C34401015D1D2D386 X-Rspamd-Queue-Id: 4bxfvr4j5mz9tcl Sometimes, errors associated with an fscontext come from the VFS or otherwise outside of the filesystem driver itself. However, the default logging of errorfc will always prefix the message with the filesystem name. So, add some *fcp() wrappers that allow for custom prefixes to be used when emitting information to the fscontext log. Signed-off-by: Aleksa Sarai --- include/linux/fs_context.h | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h index 7773eb870039..671f031be173 100644 --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -186,10 +186,12 @@ struct fc_log { extern __attribute__((format(printf, 4, 5))) void logfc(struct fc_log *log, const char *prefix, char level, const char = *fmt, ...); =20 -#define __logfc(fc, l, fmt, ...) logfc((fc)->log.log, NULL, \ - l, fmt, ## __VA_ARGS__) -#define __plog(p, l, fmt, ...) logfc((p)->log, (p)->prefix, \ - l, fmt, ## __VA_ARGS__) +#define __logfc(fc, l, fmt, ...) \ + logfc((fc)->log.log, NULL, (l), (fmt), ## __VA_ARGS__) +#define __plogp(p, prefix, l, fmt, ...) \ + logfc((p)->log, (prefix), (l), (fmt), ## __VA_ARGS__) +#define __plog(p, l, fmt, ...) __plogp(p, (p)->prefix, l, fmt, ## __VA_ARG= S__) + /** * infof - Store supplementary informational message * @fc: The context in which to log the informational message @@ -201,6 +203,8 @@ void logfc(struct fc_log *log, const char *prefix, char= level, const char *fmt, #define infof(fc, fmt, ...) __logfc(fc, 'i', fmt, ## __VA_ARGS__) #define info_plog(p, fmt, ...) __plog(p, 'i', fmt, ## __VA_ARGS__) #define infofc(fc, fmt, ...) __plog((&(fc)->log), 'i', fmt, ## __VA_ARGS__) +#define infofcp(fc, prefix, fmt, ...) \ + __plogp((&(fc)->log), prefix, 'i', fmt, ## __VA_ARGS__) =20 /** * warnf - Store supplementary warning message @@ -213,6 +217,8 @@ void logfc(struct fc_log *log, const char *prefix, char= level, const char *fmt, #define warnf(fc, fmt, ...) __logfc(fc, 'w', fmt, ## __VA_ARGS__) #define warn_plog(p, fmt, ...) __plog(p, 'w', fmt, ## __VA_ARGS__) #define warnfc(fc, fmt, ...) __plog((&(fc)->log), 'w', fmt, ## __VA_ARGS__) +#define warnfcp(fc, prefix, fmt, ...) \ + __plogp((&(fc)->log), prefix, 'w', fmt, ## __VA_ARGS__) =20 /** * errorf - Store supplementary error message @@ -225,6 +231,8 @@ void logfc(struct fc_log *log, const char *prefix, char= level, const char *fmt, #define errorf(fc, fmt, ...) __logfc(fc, 'e', fmt, ## __VA_ARGS__) #define error_plog(p, fmt, ...) __plog(p, 'e', fmt, ## __VA_ARGS__) #define errorfc(fc, fmt, ...) __plog((&(fc)->log), 'e', fmt, ## __VA_ARGS_= _) +#define errorfcp(fc, prefix, fmt, ...) \ + __plogp((&(fc)->log), prefix, 'e', fmt, ## __VA_ARGS__) =20 /** * invalf - Store supplementary invalid argument error message @@ -237,5 +245,7 @@ void logfc(struct fc_log *log, const char *prefix, char= level, const char *fmt, #define invalf(fc, fmt, ...) (errorf(fc, fmt, ## __VA_ARGS__), -EINVAL) #define inval_plog(p, fmt, ...) (error_plog(p, fmt, ## __VA_ARGS__), -EINV= AL) #define invalfc(fc, fmt, ...) (errorfc(fc, fmt, ## __VA_ARGS__), -EINVAL) +#define invalfcp(fc, prefix, fmt, ...) \ + (errorfcp(fc, prefix, fmt, ## __VA_ARGS__), -EINVAL) =20 #endif /* _LINUX_FS_CONTEXT_H */ --=20 2.50.1