From nobody Fri Jan 9 00:52:57 2026 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 CCF6725771; Mon, 5 Jan 2026 01:48:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767577727; cv=none; b=bJ5Tgz4Vi4UjH83An/WYKmvMFEQWns3cQGI2eDt6Abg4o30KNh0OUGd8rQC25NOi0hV7jN2Vqopj4dVLm1bJ4/r8ImwA0AdFHq8iJZNtnAkw5EAAnVbabOndRwBIinfGjjVLci4ssVROlWdCsEquUmCqU4d+kVQoVRWAfioZCDg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767577727; c=relaxed/simple; bh=lyqJr2AL6pJI07G3sWFtV9DhqLLWFZmbQX/2gYl7RM0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MKJ87KNB5XwJHYUcDLH/HKi09rKDYXTyEm7xqygVRQH+2XZyyfunR4RgveJgX6hFMXoxu8nCXUgzRtyrzORjlKesCvx4y5vNq6E656XKCxIDPSv8/LIjxZ0nEGZJGMO4LohFNjkyz4apmlORs30tqzu9v4GR7UnWaCFw8hWSxZM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.170]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4dkxyY3ZQSzKHMb2; Mon, 5 Jan 2026 09:48:05 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 0506B40571; Mon, 5 Jan 2026 09:48:43 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.85.155]) by APP4 (Coremail) with SMTP id gCh0CgBHp_dpGFtppFisCg--.42376S10; Mon, 05 Jan 2026 09:48:42 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ojaswin@linux.ibm.com, ritesh.list@gmail.com, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, yizhang089@gmail.com, libaokun1@huawei.com, yangerkun@huawei.com, yukuai@fnnas.com Subject: [PATCH -next v3 6/7] ext4: simplify the mapping query logic in ext4_iomap_begin() Date: Mon, 5 Jan 2026 09:45:21 +0800 Message-ID: <20260105014522.1937690-7-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260105014522.1937690-1-yi.zhang@huaweicloud.com> References: <20260105014522.1937690-1-yi.zhang@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgBHp_dpGFtppFisCg--.42376S10 X-Coremail-Antispam: 1UD129KBjvJXoW7CFWUCFW7Cw1fWFW8tFWrXwb_yoW8Ww18pa 93Ka95GFn5Xr1UurZavF93XrWUKa1xKw4UZFWfGry5Wr90gr10gr4YgF1Yqr18JrWxArWF gFW0yr18u3WUZFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Baokun Li Reviewed-by: Ojaswin Mujoo --- 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, lo= ff_t offset, loff_t length, if (offset + length <=3D i_size_read(inode)) { ret =3D 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 >=3D orig_mlen)) + /* + * For atomic writes the entire requested + * length should be mapped. + */ + if (ret =3D=3D orig_mlen || + (!(flags & IOMAP_ATOMIC) && ret > 0)) goto out; } map.m_len =3D orig_mlen; --=20 2.52.0