From nobody Thu Oct 2 18:15:48 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 B272F2FDC2C; Fri, 12 Sep 2025 11:00:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757674814; cv=none; b=nBy8Rh5GYIf97VKrJybnD/Q6wIDDZw1Tq8GgDjTPxFRbrv7GuGXB6dhjlrHLfUC9tCsa24s1lbObdF5zZdzCV2NFkAnC9JjktOYoHE+t/gTNTnnYLX02N33OoPM7arDrVce1+6GOCams6AuCLi0beeS/0XnN6jE4Pg9YkN+thIM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757674814; c=relaxed/simple; bh=SehddXTMIsz74GoDH6nj1R8W/jgXb6jePzjpjFOqgWk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=T1YsxjGtBoX2rRNmRxkMQPEEeKPN66VmtuOORiKRZCnZZfIAAeQ8wPFKmLt98XbUgqte4bhOJMWrn08AxXJK9xfbO8lofAHUUq4PWrm+SKvp0X9RLpdYw5PUNF6X+rftxpKR8BofC+DyayByMh6G9FQaKAtIAavbz0REI4crlRA= 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=45.249.212.51 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 [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cNWfW2hl0zYQvQs; Fri, 12 Sep 2025 19:00:03 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id E08A21A155E; Fri, 12 Sep 2025 19:00:01 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.85.155]) by APP4 (Coremail) with SMTP id gCh0CgCn8Y0r_cNoFHACCQ--.47583S4; Fri, 12 Sep 2025 19:00:01 +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, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, libaokun1@huawei.com, yukuai3@huawei.com, yangerkun@huawei.com Subject: [PATCH] ext4: fix an off-by-one issue during moving extents Date: Fri, 12 Sep 2025 18:58:41 +0800 Message-ID: <20250912105841.1886799-1-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.46.1 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: gCh0CgCn8Y0r_cNoFHACCQ--.47583S4 X-Coremail-Antispam: 1UD129KBjvJXoW7uw4rGFWktF4fJF1UWF1xZrb_yoW8JFW5p3 sIkay5KrW0qwnxCw4kW3Z7X3yUG34DKr47W34Fk3W7CFyay3409rWUK3Wq9a45tFWUJrWr XF4rKr15Za4UXaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9Y14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2 Y2ka0xkIwI1lc7CjxVAaw2AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x 0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2 zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF 4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWU CwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCT nIWIevJa73UjIFyTuYvjfUFg4SDUUUU X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ Content-Type: text/plain; charset="utf-8" From: Zhang Yi During the movement of a written extent, mext_page_mkuptodate() is called to read data in the range [from, to) into the page cache and to update the corresponding buffers. Therefore, we should not wait on any buffer whose start offset is >=3D 'to'. Otherwise, it will return -EIO and fail the extents movement. $ for i in `seq 3 -1 0`; \ do xfs_io -fs -c "pwrite -b 1024 $((i * 1024)) 1024" /mnt/foo; \ done $ umount /mnt && mount /dev/pmem1s /mnt # drop cache $ e4defrag /mnt/foo e4defrag 1.47.0 (5-Feb-2023) ext4 defragmentation for /mnt/foo [1/1]/mnt/foo: 0% [ NG ] Success: [0/1] Fixes: a40759fb16ae ("ext4: remove array of buffer_heads from mext_page_mku= ptodate()") Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/move_extent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index adae3caf175a..4b091c21908f 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -225,7 +225,7 @@ static int mext_page_mkuptodate(struct folio *folio, si= ze_t from, size_t to) do { if (bh_offset(bh) + blocksize <=3D from) continue; - if (bh_offset(bh) > to) + if (bh_offset(bh) >=3D to) break; wait_on_buffer(bh); if (buffer_uptodate(bh)) --=20 2.46.1