From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.3]) (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 5BC114749FC; Thu, 24 Sep 2026 11:06:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790247986; cv=none; b=XdDdAaveZ+cryZPOuCGKhA6WncSTDtqjo1TLUASCWtZRn+K4VpMFsJQELFo67+L826gIaea7UXzn3hXKAiBAQYAhiJwkIiX9bFQU6q4nUarq/5OLryYkMI1fKX6/WO/gFWNu34kS894FTBKe5rS8oXmWXbmLUiyMkZpZEp0ZUo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790247986; c=relaxed/simple; bh=5gW3H/1yVOxL00jh4JY44hYMcfiOVXML9SuZIS61MNk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jalExCKmMRVLijMU5+BAdwvFHMaFZ7afJx7Epx9opZSx+vxsKloeRjQKgkIM/+2UWW9SJkHf4DVV0fsnRvOu6IHW2khiSJl8rlMSsZpryVJ/iz2BaJpWCo2HR4j7stCJG1MSAOph+Vi3Ny6JyustqJ7oKK8hJQ1/ubUb/yTL5Rg= 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=FA5Gz0CO; arc=none smtp.client-ip=117.135.210.3 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="FA5Gz0CO" 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=2C SflERWiIEUtHIYwYt7AZ8Vjsf1CeCsPdvuomIllHU=; b=FA5Gz0COAgBSrDFqeE mx557yHlDT1xWLSeptLBqgN/xZFdKtdpGk1RluFFHFZsKcEWzyzz+iGxblajghdN WUw994pKSmYfNsrPNc9J6l/ObxUS6snYHSY5R1I9rTq4kWavMgI5XhHtoU4N4XUM VuetSygpUmpbKzp2FAVBfQYI8= Received: from pc.localdomain (unknown []) by gzga-smtp-mtada-g0-2 (Coremail) with SMTP id _____wD3N3wNBLVqE0AmAg--.64280S3; Thu, 24 Sep 2026 19:05:52 +0800 (CST) From: Jiale Yao To: 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 Cc: Jiale Yao Subject: [PATCH 1/3] ext2: drain in-flight DIO before buffered write fallback Date: Thu, 24 Sep 2026 19:05:42 +0800 Message-Id: <20260924110544.601390-2-yaojiale02@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260924110544.601390-1-yaojiale02@163.com> References: <20260924110544.601390-1-yaojiale02@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:_____wD3N3wNBLVqE0AmAg--.64280S3 X-Coremail-Antispam: 1Uf129KBjvJXoW7tFyUuryxtFyDXr47tF1DJrb_yoW8Zrykpr Z093W5JryqyrZ7Wwn7Wa18ur1fK398ArW3XrWvv3WDCry5Gws0gF4ktr1jvF1fGFsrJw4Y qan29r97u3W0yaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pMOJYwUUUUU= X-CM-SenderInfo: x1dryxhdohiji6rwjhhfrp/xtbCzRENR2q1BBFIDgAA3a 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, generic_perform_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. Ext2 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 generic_perform_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: fb5de4358e1a ("ext2: Move direct-io to use iomap") Link: https://lore.kernel.org/r/20260629113827.4074335-3-libaokun@linux.alibaba.com Signed-off-by: Jiale Yao --- fs/ext2/file.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ext2/file.c b/fs/ext2/file.c index b9020df7d89e..67fe423c3828 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -135,6 +135,13 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) int ret2; 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(inode); + pos = iocb->ki_pos; status = generic_perform_write(iocb, from); if (unlikely(status < 0)) { -- 2.34.1