From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1F6602D7D2F; Wed, 29 Oct 2025 01:05:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761699950; cv=none; b=Mk1wIdnP8bpZeG+8JRn496hV1DEcAQDFhj3bdqWmoLs5j9PLm/5rz0xqUubPx2PqOgEsUWYEacwRbTVwAnEkJhr67mZAYzQ0U49YV5Hjk+zC48zRaEukbXQLa6JOkHlGn/Y5D6oNBullzTZH/fadkzUgju9v1jRD48tWNMoeQII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761699950; c=relaxed/simple; bh=KnPW33uEVVBJJatHIwC617mAd1OFFENhGGqQbFR/YF4=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aPjpeHg4obn6RucXWFUR59IWgy3i7Hothh1jVNYFGhES5S6wjwweQFUgmDS/4fD9esVjxlnMdmAtvwuhgA5vE3K6xDK9aRCEbFaW4TkyRQwzJ9QIRzMil7DMDv9Z7XSb+JD4J+UcmonVGJiXHgkqSBcZ2VbdzyVSLt1TAHeKPrY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EHe22hmH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EHe22hmH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9C08C4CEE7; Wed, 29 Oct 2025 01:05:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761699950; bh=KnPW33uEVVBJJatHIwC617mAd1OFFENhGGqQbFR/YF4=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=EHe22hmHJjvuESbAGFy4CEffAloh/h/z2QUOdRyGq5XHzStSa34NuuphU/JSr1s5H w5Fetv2/bOgcDParTKj7xiH2JebzGbe56kmiaNsdfoqb8OXzKFudJ5TXPXpIzRNPYl jMRSm74T6AhBsSR2ZOz9G1WD7tissBSS+zo9FTcVrDx/Rh1aEAeMN1dQc9sW1klhdu 8kkZIIPWcJBiKshlRQ7stBryJCLxun2vunONbydZJLKV23w7a7RXj+Z0nUYcci/RaP ooIQXi9WXsFq9iCkxPcSOylvK+O0M/xG2VBzG7zV9aS5vPD/2cpkgbrTm9Jb7t/AJj u7S9HZy6RDKYQ== Date: Tue, 28 Oct 2025 18:05:49 -0700 Subject: [PATCH 2/4] libfuse: set sync, immutable, and append when loading files From: "Darrick J. Wong" To: djwong@kernel.org, bschubert@ddn.com Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, bernd@bsbernd.com, miklos@szeredi.hu, joannelkoong@gmail.com, neal@gompa.dev Message-ID: <176169814355.1428390.16043068248654100347.stgit@frogsfrogsfrogs> In-Reply-To: <176169814307.1428390.11550104537543281678.stgit@frogsfrogsfrogs> References: <176169814307.1428390.11550104537543281678.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit From: Darrick J. Wong Add these three fuse_attr::flags bits so that servers can mark a file as immutable or append-only and have the kernel advertise and enforce that. Signed-off-by: "Darrick J. Wong" --- include/fuse_common.h | 6 ++++++ include/fuse_kernel.h | 8 ++++++++ lib/fuse_lowlevel.c | 6 ++++++ 3 files changed, 20 insertions(+) diff --git a/include/fuse_common.h b/include/fuse_common.h index 83ab3f54f54a2e..5df95ba35ce341 100644 --- a/include/fuse_common.h +++ b/include/fuse_common.h @@ -1241,6 +1241,12 @@ static inline bool fuse_iomap_need_write_allocate(unsigned int opflags, #define FUSE_IFLAG_IOMAP (1U << 1) /* enable untorn writes */ #define FUSE_IFLAG_ATOMIC (1U << 2) +/* file writes are synchronous */ +#define FUSE_IFLAG_SYNC (1U << 3) +/* file is immutable */ +#define FUSE_IFLAG_IMMUTABLE (1U << 4) +/* file is append only */ +#define FUSE_IFLAG_APPEND (1U << 5) /* Which fields are set in fuse_iomap_config_out? */ #define FUSE_IOMAP_CONFIG_SID (1 << 0ULL) diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h index 37e5eb8c65f206..6fd0397b758eae 100644 --- a/include/fuse_kernel.h +++ b/include/fuse_kernel.h @@ -246,6 +246,8 @@ * - add FUSE_IOMAP_CONFIG so the fuse server can configure more fs geometry * - add FUSE_NOTIFY_IOMAP_DEV_INVAL to invalidate iomap bdev ranges * - add FUSE_ATTR_ATOMIC for single-fsblock atomic write support + * - add FUSE_ATTR_{SYNC,IMMUTABLE,APPEND} for VFS enforcement of file + * attributes */ #ifndef _LINUX_FUSE_H @@ -588,11 +590,17 @@ struct fuse_file_lock { * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode * FUSE_ATTR_IOMAP: Use iomap for this inode * FUSE_ATTR_ATOMIC: Enable untorn writes + * FUSE_ATTR_SYNC: File writes are always synchronous + * FUSE_ATTR_IMMUTABLE: File is immutable + * FUSE_ATTR_APPEND: File is append-only */ #define FUSE_ATTR_SUBMOUNT (1 << 0) #define FUSE_ATTR_DAX (1 << 1) #define FUSE_ATTR_IOMAP (1 << 2) #define FUSE_ATTR_ATOMIC (1 << 3) +#define FUSE_ATTR_SYNC (1 << 4) +#define FUSE_ATTR_IMMUTABLE (1 << 5) +#define FUSE_ATTR_APPEND (1 << 6) /** * Open flags diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c index 728a6b635471c7..3ab4a532b4edbb 100644 --- a/lib/fuse_lowlevel.c +++ b/lib/fuse_lowlevel.c @@ -129,6 +129,12 @@ static void convert_stat(const struct stat *stbuf, struct fuse_attr *attr, attr->flags |= FUSE_ATTR_IOMAP; if (iflags & FUSE_IFLAG_ATOMIC) attr->flags |= FUSE_ATTR_ATOMIC; + if (iflags & FUSE_IFLAG_SYNC) + attr->flags |= FUSE_ATTR_SYNC; + if (iflags & FUSE_IFLAG_IMMUTABLE) + attr->flags |= FUSE_ATTR_IMMUTABLE; + if (iflags & FUSE_IFLAG_APPEND) + attr->flags |= FUSE_ATTR_APPEND; } static void convert_attr(const struct fuse_setattr_in *attr, struct stat *stbuf)