From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794065183; b=GWlJblyfOKg3E+uLQZnj1VEYF/zSW0XHIaYGAnuBhk4fvNBYUUW/03P3Bd6jhFOR8Srs V2qs72Y5V8tn5UZ0ABHwzlXhDD57Z4xyZxOghrKhaLCeqOHP3oFstYr1c6ngO5xOb7FpN wat5DdzJAmYIQpm42MCZzXj9IJN5txf2fyuFxDN+Cbg0rdnQDdNzvzJgNtoNrlIAIYjv4 FTQ8QKjeamlsm3pe59DMHNpk1uKle+SRyBTWZt2rSLcabV+qrt3Jbu5G+3y3ZxTm7TIs+ NB44M2IY/dbHrzht4kZ/vojB5ks1jCWkp5v50Db1r0JZMYyP679wzmujlpY2Y2GG5iA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794065183; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=2dx9471HhKEVi0TrX9Q0bSHhMOeMqrhpkv/PqAthfkA=; b=Bhv3eOAwE+f2LKcRDA/ysAGN8aUKSndlH8rsI+xRSuF5Km4d2OXKxGIbmmYK4ukjfOol j0wDxhORsVRcNjb4R1j9/s/ztEDygObo+W1xJ8+39pJ20+KhORa0zuxP8wIIrTxfDjXn4 wr/WP7qRtGhNp9oRvAA/H8sHqK2kwxniSYrT/z++hckkPTSBjcKgE0FyiUIxvfXvdTA/P T8QAWMktwBoZveCKhzyodi8FYZpnVjaayzDjmpdPfLM9WwGtDH720NxnJCf23MRy5PW9G evPvz9ybzqaEwwhW6V+7jBeu79LM0dKaW3NBcldWrJETIt2pFDZUAQJ/3FuVU7Iv6/g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FyJFoylD; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EC63606A32E; Sat, 7 Nov 2026 15:26:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FyJFoylD Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1EED1F0089F; Sat, 7 Nov 2026 15:26:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794065182; bh=2dx9471HhKEVi0TrX9Q0bSHhMOeMqrhpkv/PqAthfkA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FyJFoylDj6qMPZY77RSqVzBgg7cCxblgQP7nlahrXQ4xj0U7B+f9VGGjeEgcVtGy2 shoDWGmaIajrYU3IxF2Uf2YGl7Nv3j++XN6mblSPeh4AcwbDYUOEdcKAZNRmISCItM 1MpTXf6WxBPNy9rkz0xkTaw9UZjxyviiBx1Spa8c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiale Yao , Namjae Jeon , Sasha Levin Subject: [PATCH 7.3 0987/1257] exfat: drain in-flight DIO before buffered writes Date: Sat, 7 Nov 2026 08:54:43 -0500 Message-ID: <20261107135006.625749174@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiale Yao [ Upstream commit acea17f0f4c7742118375e96d3f876be34e449a5 ] An asynchronous direct write can remain in flight after the inode lock is released. If a buffered operation dirties page cache while the direct write is still pending, the direct write's post-I/O invalidation can find the dirty pages, report a page cache invalidation failure, and record -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. ExFAT does not drain in-flight DIO before a regular buffered write, the buffered fallback after iomap_dio_rw() returns -ENOTBLK or a short write, or the page-cache operations used to extend valid_size. Wait for in-flight DIO before these paths can dirty page cache. 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: 867b9c96dc83 ("exfat: add iomap direct I/O support") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20260629113827.4074335-3-libaokun@linux.alibaba.com Signed-off-by: Jiale Yao Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin --- fs/exfat/file.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/exfat/file.c b/fs/exfat/file.c index 89e2fdebcc2c1..d24f0650bfc88 100644 --- a/fs/exfat/file.c +++ b/fs/exfat/file.c @@ -706,6 +706,8 @@ static int exfat_extend_valid_size(struct inode *inode, loff_t new_valid_size) int ret = 0; if (old_valid_size < new_valid_size) { + inode_dio_wait(inode); + /* Do not re-zero blocks already covered by zeroed_size. */ loff_t gap_start = max(old_valid_size, exfat_get_zeroed_size(ei)); @@ -757,6 +759,8 @@ static ssize_t exfat_fallback_buffered_write(struct kiocb *iocb, iocb->ki_flags &= ~IOCB_DIRECT; + inode_dio_wait(file_inode(iocb->ki_filp)); + written = iomap_file_buffered_write(iocb, from, &exfat_write_iomap_ops, NULL, NULL); if (written < 0) @@ -840,11 +844,17 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) pos = valid_size; } - if (iocb->ki_flags & IOCB_DIRECT) + if (iocb->ki_flags & IOCB_DIRECT) { ret = exfat_dio_write_iter(iocb, iter); - else + } else { + /* + * 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); ret = iomap_file_buffered_write(iocb, iter, &exfat_write_iomap_ops, NULL, NULL); + } if (ret < 0) goto unlock; -- 2.53.0