From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout09.his.huawei.com (canpmsgout09.his.huawei.com [113.46.200.224]) (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 DF7692AE70; Wed, 31 Dec 2025 07:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.224 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767167188; cv=none; b=julOi0zUQDfFVMuuDSxbiV26+L4JlQZnVdYFDUiFD8gWHi9r2/6bMB8UHwIDcclKuqZYPnLO+7rV9yiPN9+BS2SF3krCeA9wNWw/458HoFNAUQnHg19rGKbx0KboMwJMNUmVWXPmT69czmFOzo/wsUpZ/UmOEO0rocke2GbVDs4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767167188; c=relaxed/simple; bh=iBkZD85chhanwQQuFMd9eUoiCLSqRMuvLdnJo9O3Ers=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=g4KgRToX8GlsOHisR5NL7UOj45+43PbxD6nbVqKJ7r2JsJ0QGgOeJYTsXMh3lkg/RNBbjL6H/mdnsmNmwt5abVV47aBdV1HNXpCIdSkWPEia/8XTcMGezSD3/eAujGUISU452mmZdKIsMj9yl6bKBZ8eK0CO5LPoV9m6H63BRkk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=Pi9XuF0c; arc=none smtp.client-ip=113.46.200.224 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="Pi9XuF0c" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=Pee7Hdi+CKtfsyuR4wU0ELvYZgSYce+bDuxyAadhdbQ=; b=Pi9XuF0c64/Bth/M6Z/sQMUrmuddu9FxT5m0qUfXrXWrlU9Pty4d4aXtswOKdglcDJqy/JRRU 00dhfRjdBE+WW8GKGcTl3omeHnJumKZM14/SOghtD1pO/aben3EDZAKBjlXyc3TWrtE06uODrVF XQ4bvQxDhjXmAfraIyv67E4= Received: from mail.maildlp.com (unknown [172.19.163.163]) by canpmsgout09.his.huawei.com (SkyGuard) with ESMTPS id 4dh24V1BHWz1cySN; Wed, 31 Dec 2025 15:43:06 +0800 (CST) Received: from dggpemf500013.china.huawei.com (unknown [7.185.36.188]) by mail.maildlp.com (Postfix) with ESMTPS id C9CE640538; Wed, 31 Dec 2025 15:46:16 +0800 (CST) Received: from [127.0.0.1] (10.174.178.254) by dggpemf500013.china.huawei.com (7.185.36.188) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 31 Dec 2025 15:46:15 +0800 Message-ID: <65ffdc21-1f94-428c-be06-f81c87f019bc@huawei.com> Date: Wed, 31 Dec 2025 15:46:14 +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 -next v2 6/7] ext4: simply the mapping query logic in ext4_iomap_begin() Content-Language: en-GB To: Zhang Yi , CC: , , , , , , , , , , References: <20251223011802.31238-1-yi.zhang@huaweicloud.com> <20251223011802.31238-7-yi.zhang@huaweicloud.com> From: Baokun Li In-Reply-To: <20251223011802.31238-7-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To dggpemf500013.china.huawei.com (7.185.36.188) On 2025-12-23 09:18, Zhang Yi wrote: > From: Zhang Yi > > In the write path mapping check of ext4_iomap_begin(), the return value > 'ret' should never greater than orig_mlen. If 'ret' equals 'orig_mlen', > it can be returned directly without checking IOMAP_ATOMIC. > > Signed-off-by: Zhang Yi > Reviewed-by: Jan Kara Looks good. Feel free to add: Reviewed-by: Baokun Li > --- > fs/ext4/inode.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index b84a2a10dfb8..67fe7d0f47e3 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3816,17 +3816,19 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > if (offset + length <= i_size_read(inode)) { > ret = ext4_map_blocks(NULL, inode, &map, 0); > /* > - * For atomic writes the entire requested length should > - * be mapped. For DAX we convert extents to initialized > - * ones before copying the data, otherwise we do it > - * after I/O so there's no need to call into > - * ext4_iomap_alloc(). > + * For DAX we convert extents to initialized ones before > + * copying the data, otherwise we do it after I/O so > + * there's no need to call into ext4_iomap_alloc(). > */ > if ((map.m_flags & EXT4_MAP_MAPPED) || > (!(flags & IOMAP_DAX) && > (map.m_flags & EXT4_MAP_UNWRITTEN))) { > - if ((!(flags & IOMAP_ATOMIC) && ret > 0) || > - (flags & IOMAP_ATOMIC && ret >= orig_mlen)) > + /* > + * For atomic writes the entire requested > + * length should be mapped. > + */ > + if (ret == orig_mlen || > + (!(flags & IOMAP_ATOMIC) && ret > 0)) > goto out; > } > map.m_len = orig_mlen;