From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (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 548CD478870; Thu, 24 Sep 2026 12:04:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790251497; cv=none; b=kznndfzzNFLuBXge8384BP33iWR8p/F+cA+TfWfIQBfsmY0DhzrTjlqGFRSI06JKjEEC0pP/eOYorQZMzAoBSsH1Kxwf/pYAIbaoBvD4pmE0ygP7JVHBpHuQgmf44xpzLVNgPTsT2RlHYkEqi4fLvF2qIyAjzS4ndxn36VmAogM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790251497; c=relaxed/simple; bh=Wb9UfTdAfRe3M7usASG3pV8I28E3o5494Kjit7FKro8=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=rcs4s0ZKoJKOnCc1YO9cE1Wc9Dq6D1gou5ZcNPYPDl0S1JdmpAwjP6Zh1e6crDcS1V18NTZ6AkBY6RVWGJs1qYH32CuKVWKBxchVLT3nfiCMeIdQxK0fZnKWowB/T16ZdLjtDD1PLUGfY8dw+5RgXsMcXpMkC7RqDZocT8b4y/w= 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=mEaC849y; arc=none smtp.client-ip=220.197.31.5 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="mEaC849y" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=BHGkzVj7YVTIwQWSxeG5FamHMAQuS8AgVPjPclOktEs=; b=mEaC849yZzIANJfxqgtQ0/Jrm6BZuParKlK8S6ZUAZmhhAjjF3wO+t1u0+dMGT +eojw893NVAbotH0Kl9UY/WNjxCTQi9A52z3Sy7WYar7MvUtmsXKfLjbL8/UtimP oZ8hG91LR5Wr4aGwRUBXkKJ7iMolLeRnSRo3trqrw/SsY= Message-ID: Date: Thu, 24 Sep 2026 20:04:14 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] ntfs: drain in-flight DIO before buffered write fallback To: Jiale Yao , Namjae Jeon , Sungjong Seo , Yuezhang Mo , Jan Kara , Hyunchul Lee , "Ritesh Harjani (IBM)" , "Darrick J. Wong" , exfat@lists.linux.dev, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, ntfs@lists.linux.dev References: <20260924110544.601390-1-yaojiale02@163.com> <20260924110544.601390-3-yaojiale02@163.com> Content-Language: en-US From: liubaolin In-Reply-To: <20260924110544.601390-3-yaojiale02@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:PCgvCgBHFBW+EbVq9SEGBA--.9703S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxWrWDZryfZF47Zr1xJw13urg_yoW5Gw17pr ZakFy5Jr9FyrWIq3Z7GF4rWF1Fg397JrWa9rWkWw1UC3y8Gr4vgF40kr1jvr4rAFsrJr42 qa109rykZryjvaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07U5CztUUUUU= X-CM-SenderInfo: xolxutxrol0iasrtmqqrwthudrp/xtbC6gF8R2q1EcEEMwAA3o 在 2026/9/24 19:05, Jiale Yao 写道: > An asynchronous direct write can remain in flight after the inode lock is > released. If another direct write falls back to buffered I/O while the > first write is still pending, iomap_file_buffered_write() can dirty pages > before the first write completes its post-I/O page cache invalidation. > The invalidation then finds dirty pages, reports a page cache invalidation > failure, and records -EIO in the mapping error sequence. A later fsync() > therefore returns -EIO. > > Commit 15cdefd0c0522f9d5e12d947fa04f4c11649b699 ("ext4: drain > in-flight DIO before buffered write fallback") fixed the same race in > ext4. NTFS has an equivalent fallback after iomap_dio_rw() returns > -ENOTBLK or a short write, but does not drain other in-flight DIO before > dirtying the page cache. > > Wait for in-flight DIO before calling iomap_file_buffered_write() in the > fallback path. > > A reproducer using concurrent AIO direct writes and buffered fallback > triggered the following warning and made a subsequent fsync() return > -EIO: > > Page cache invalidation failure on direct I/O. Possible data corruption > due to collision with buffered I/O! > > Fixes: 9c87959601e8 ("ntfs: update file operations") > Link: https://lore.kernel.org/r/20260629113827.4074335-3-libaokun@linux.alibaba.com > Signed-off-by: Jiale Yao > --- > fs/ntfs/file.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c > index 007d1614b9ac..2fc2ffde3846 100644 > --- a/fs/ntfs/file.c > +++ b/fs/ntfs/file.c > @@ -527,6 +527,13 @@ static ssize_t ntfs_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) > > offset = iocb->ki_pos; > iocb->ki_flags &= ~IOCB_DIRECT; > + > + /* > + * Prevent concurrent direct I/O and buffered I/O to the same file > + * range. Wait for in-flight DIO to finish before dirtying pages. > + */ > + inode_dio_wait(file_inode(iocb->ki_filp)); Hi Jiale, This fallback path can still have IOCB_NOWAIT set, but inode_dio_wait() blocks when there is outstanding DIO. Clearing IOCB_DIRECT does not clear IOCB_NOWAIT. In comparison, ext4_buffered_write_iter() rejects NOWAIT requests before reaching the wait. Could we also handle IOCB_NOWAIT before entering this potentially blocking fallback? If no bytes have been written, we can return -EAGAIN; if some DIO has already completed, we should preserve the positive short-write result. Thanks, Baolin. > + > written = iomap_file_buffered_write(iocb, from, > &ntfs_write_iomap_ops, &ntfs_iomap_folio_ops, > NULL);