From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.2]) (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 C6BA12F8E8F for ; Sun, 20 Sep 2026 08:32:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.2 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789893139; cv=none; b=tPpMlCQ4JyNuRKhXtuFMb5XYbF61+RhI8hgS9REueOsNSddadTNXJBwlcc82M1CZXnF1ufNyjtSEgavBDVQU1+yZvwoKRk+Eo3NIaydBVeAEQQEnczPM+TSNEypDbLnfotrEWECE4ibet/hUTUzKNgqMIiLBHRul4rkFKHVkrko= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789893139; c=relaxed/simple; bh=hEj7I8IgfGqJ/cTL1OJazCZCq/g+2hBc263juLIj6/Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JAw2fir6rQXM0raI1Oq57cycWDjRHlcl4OzmnKKZU3IldIvOt2P5sMxf+u5CaDfbj7DvVO8FE6VGiKIuABX/9Lw5+bGKp4xg0jnzggm8+D3sjsVtxjjk/FaUKPSihcPpU5l5YNe6oZxe9fhRdiyRKxBljJcq8hY5PLL72XBn0d0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=SMytY0MS; arc=none smtp.client-ip=220.197.31.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="SMytY0MS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=0i phEToKxwJp7tGqiPSTQxmduIvvdFiWOZBziqAo1yc=; b=SMytY0MSI1SEczfIRU C71P34GIrUkrJL13jYOsqpzq1lOrbEbJT5lUovGavi8CogY/rKoS2HVXTpnpcnB2 ZWxKpDUDb3+IpDOQdbFpYnsJBNoOLScLcC6CIwXbpIOjXMkdx9CPENEb7wMfAv2Z XQiJpT5S4ZXEimmS6K4CpDTOM= Received: from liubaolin-ThinkPad-E15-Gen-2 (unknown []) by gzsmtp4 (Coremail) with SMTP id PygvCgB3m07lma9qs7GbAQ--.54162S11; Sun, 20 Sep 2026 16:31:52 +0800 (CST) From: Baolin Liu To: linkinjeon@kernel.org, hyc.lee@gmail.com Cc: ntfs@lists.linux.dev, linux-kernel@vger.kernel.org, chenxiaosong@chenxiaosong.com, Baolin Liu Subject: [PATCH v2 09/10] ntfs: persist append-only in the $LXFLAGS EA Date: Sun, 20 Sep 2026 16:31:30 +0800 Message-ID: <20260920083131.1880061-10-liubaolin12138@163.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260920083131.1880061-1-liubaolin12138@163.com> References: <20260920083131.1880061-1-liubaolin12138@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:PygvCgB3m07lma9qs7GbAQ--.54162S11 X-Coremail-Antispam: 1Uf129KBjvJXoWxCrW5Zw47KF18Jryxtw4kCrg_yoW7JF4xpF Z3JFyIg3yrWFyjgrZ2kF4q93WFvws3XF4UArWvgw18AasxJw1ftF1rtF4rGa48CryfC342 qF45trWUXrW3Z37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jU18PUUUUU= X-CM-SenderInfo: xolxutxrol0iasrtmqqrwthudrp/xtbCwRgr9WqvmfgMswAA3c From: Baolin Liu Extend the persistent fileattr interface to append-only using bit 1 of LXFLAGS. Restore S_APPEND on inode load and update it after successful EA writes. Include append in the known-bit mask while retaining all other unknown bits. Reuse the existing VFS capability checks and EA safeguards. Document append-only alongside immutable. Both flags now survive inode reclaim and remount without changing the NTFS attribute format. Signed-off-by: Baolin Liu --- Documentation/filesystems/ntfs.rst | 10 +++++----- fs/ntfs/ea.c | 2 ++ fs/ntfs/ea.h | 4 +++- fs/ntfs/file.c | 13 ++++++------- 4 files changed, 16 insertions(+), 13 deletions(-) diff --git a/Documentation/filesystems/ntfs.rst b/Documentation/filesystems/ntfs.rst index ced164216a5b..f00b618a3911 100644 --- a/Documentation/filesystems/ntfs.rst +++ b/Documentation/filesystems/ntfs.rst @@ -38,21 +38,21 @@ The project is available at: Linux file attributes ===================== -The driver supports lsattr(1) and setting immutable with chattr(1). -Immutable is stored in bit 0 of a private ``$LXFLAGS`` extended attribute +The driver supports lsattr(1) and setting immutable and append-only with chattr(1). +Immutable is stored in bit 0 and append-only in bit 1 of a private ``$LXFLAGS`` extended attribute within the standard NTFS ``$EA``/``$EA_INFORMATION`` attributes. Its value is a 32-bit little-endian bitmask. Unknown bits are preserved; the entry -is removed when the entire value becomes zero. The setting survives +is removed when the entire value becomes zero. These settings survive inode eviction, unmount and reboot. Direct writes or removal through xattr interfaces are rejected; use chattr(1) instead. System metadata files and files protected by ``sys_immutable`` cannot have their immutable protection cleared. Protection derived solely from -that policy is not stored in the EA. Compression, encryption, append-only +that policy is not stored in the EA. Compression, encryption and mount-wide case folding are reported but cannot be changed through chattr(1). -Windows does not enforce the Linux immutable flag stored in this EA. +Windows does not enforce the Linux immutable and append-only flags stored in this EA. Supported mount options ======================= diff --git a/fs/ntfs/ea.c b/fs/ntfs/ea.c index 1e9b66e88655..ddac912de78c 100644 --- a/fs/ntfs/ea.c +++ b/fs/ntfs/ea.c @@ -500,6 +500,8 @@ int ntfs_ea_get_lxflags(struct inode *inode) ni->lxflags = le32_to_cpu(value); if (ni->lxflags & NTFS_LXFLAGS_IMMUTABLE) inode->i_flags |= S_IMMUTABLE; + if (ni->lxflags & NTFS_LXFLAGS_APPEND) + inode->i_flags |= S_APPEND; return 0; } diff --git a/fs/ntfs/ea.h b/fs/ntfs/ea.h index 19aea162b909..eac5ab4da44a 100644 --- a/fs/ntfs/ea.h +++ b/fs/ntfs/ea.h @@ -9,7 +9,9 @@ /* $LXFLAGS stores these bits in a single little-endian 32-bit value. */ #define NTFS_LXFLAGS_IMMUTABLE BIT(0) -#define NTFS_LXFLAGS_MASK NTFS_LXFLAGS_IMMUTABLE +#define NTFS_LXFLAGS_APPEND BIT(1) +#define NTFS_LXFLAGS_MASK (NTFS_LXFLAGS_IMMUTABLE | \ + NTFS_LXFLAGS_APPEND) extern const struct xattr_handler *const ntfs_xattr_handlers[]; diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index 882d33b67560..5b2a31790275 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -190,7 +190,7 @@ int ntfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, { struct inode *vi = d_inode(dentry); struct ntfs_inode *ni = NTFS_I(vi); - u32 allowed = FS_IMMUTABLE_FL; + u32 allowed = FS_IMMUTABLE_FL | FS_APPEND_FL; u32 readonly = 0; u32 lxflags = ni->lxflags & ~NTFS_LXFLAGS_MASK; unsigned int new_fl = 0; @@ -203,11 +203,6 @@ int ntfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, if (fileattr_has_fsx(fa)) return -EOPNOTSUPP; - if ((fa->flags & FS_APPEND_FL) != - (IS_APPEND(vi) ? FS_APPEND_FL : 0)) - return -EOPNOTSUPP; - allowed |= fa->flags & FS_APPEND_FL; - /* chattr passes the unchanged read-only flags back to us too. */ if (NInoCompressed(ni) || NInoWofCompressed(ni)) readonly |= FS_COMPR_FL; @@ -234,6 +229,10 @@ int ntfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, (ni->lxflags & NTFS_LXFLAGS_IMMUTABLE)) lxflags |= NTFS_LXFLAGS_IMMUTABLE; } + if (fa->flags & FS_APPEND_FL) { + new_fl |= S_APPEND; + lxflags |= NTFS_LXFLAGS_APPEND; + } mutex_lock(&ni->mrec_lock); err = ntfs_ea_set_lxflags(vi, lxflags); @@ -241,7 +240,7 @@ int ntfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, if (err) return err; - inode_set_flags(vi, new_fl, S_IMMUTABLE); + inode_set_flags(vi, new_fl, S_IMMUTABLE | S_APPEND); inode_set_ctime_current(vi); mark_inode_dirty(vi); return 0; -- 2.51.0