From patchwork Fri Apr 18 09:38:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 14057114 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 9DBC320897F; Fri, 18 Apr 2025 09:45:38 +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=1744969540; cv=none; b=fwls1fP1OB845A7PGHYo2OiZgfLvYKZl5hPT8Dk1gAQgWzQuSqT1KIYov5ZKIlouUaVl29TYYik5Kl3i5nTxTqG2Nm5FnyT18lJlAqnXjOhGLymF46TURcYGcdYBya+aBeNimwdPNhtVslK+8rpjuUrpEOi/ndcP7yTIfUzPI4U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744969540; c=relaxed/simple; bh=Mck/DO6u1pZ0xBBp03punXg1wKhSA4AsVw2tCWvDC5E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=FiUHLu7RT6IRn1+FMEBJcdOEjeqXyA+D8tasibarlEqTf7+bvUESSAaHEyt8Ds/+Dw0Zxu3prITxMT97wQ9TzrS8Iz8hY7zNPf2kgJ+AcymVWWLFmmaeIMbRnTeaOAYmVCAEvZxxtVEp1v4U7qZQJwhcUO21Sh00uskMzq2MMZk= 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 [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Zf8xx68RVz4f3lDF; Fri, 18 Apr 2025 17:45:09 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 2E13E1A06DC; Fri, 18 Apr 2025 17:45:35 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgBHrGA6HwJozQ1aJw--.29179S9; Fri, 18 Apr 2025 17:45:34 +0800 (CST) From: Yu Kuai To: axboe@kernel.dk, kbusch@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH 5/5] brd: zero data for discard that is not aligned to page Date: Fri, 18 Apr 2025 17:38:26 +0800 Message-Id: <20250418093826.3149293-6-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250418093826.3149293-1-yukuai1@huaweicloud.com> References: <20250418093826.3149293-1-yukuai1@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgBHrGA6HwJozQ1aJw--.29179S9 X-Coremail-Antispam: 1UD129KBjvJXoW7urW5GF43uFWrAF1rAF43Jrb_yoW8Cw4DpF 4DJryIkrW5Kr17Kw13Jwn8ZFyFv34xGayrGay7u3909w1rGF9Fyas5t3WSqFy8GrWfWF13 Aan7tryF9r1kA3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP014x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY1x0262kKe7AKxVWUtV W8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJw CI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7VUbPC7UUU UUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ From: Yu Kuai Currently brd_do_discard() will just skip unaligned sectors, and in this case user will still get old data after discard. Fix this by writing zero data to unaligned sectors. Fixes: 9ead7efc6f3f ("brd: implement discard support") Signed-off-by: Yu Kuai --- drivers/block/brd.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index bf1e1b2a0d28..b5908703fb4b 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -224,6 +224,21 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page, return err; } +static void brd_zero_range(struct brd_device *brd, sector_t sector, u32 size) +{ + unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; + struct page *page; + void *dst; + + page = brd_lookup_page(brd, sector); + if (!page) + return; + + dst = kmap_local_page(page); + memset(dst + offset, 0, size); + kunmap_local(dst); +} + static void brd_free_one_page(struct rcu_head *head) { struct page *page = container_of(head, struct page, rcu_head); @@ -234,10 +249,17 @@ static void brd_free_one_page(struct rcu_head *head) static void brd_do_discard(struct brd_device *brd, sector_t sector, u32 size) { sector_t aligned_sector = round_up(sector, PAGE_SECTORS); - sector_t aligned_end = round_down(sector + (size >> SECTOR_SHIFT), - PAGE_SECTORS); + sector_t sector_end = sector + (size >> SECTOR_SHIFT); + sector_t aligned_end = round_down(sector_end, PAGE_SECTORS); struct page *page; + if (aligned_sector > sector) + brd_zero_range(brd, sector, + (aligned_sector - sector) << SECTOR_SHIFT); + if (aligned_end < sector_end) + brd_zero_range(brd, aligned_end, + (sector_end - aligned_end) << SECTOR_SHIFT); + if (aligned_end <= aligned_sector) return;