From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout03.his.huawei.com (canpmsgout03.his.huawei.com [113.46.200.218]) (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 4C399253B73 for ; Mon, 3 Aug 2026 01:48:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785721711; cv=none; b=WmjtkiQtsFJTW/cTIaUiR4Hl1zWkOpamfQKpFY1uMMhflgrxKSNtfGSFQ7Uqjh6ldrpAK2nS4CidZ6hSMqczwfNGunaWnd9RHX9xQ64rQ3fK1lrnwYiboTFuNx/gzD9AuuFtHZkeZQ0D+vTvLG9J3fV8iRec8gjJ+RsNjHVZTqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785721711; c=relaxed/simple; bh=E2DzJZp0aCm65tSSQTQQiN8uw56Lu4TexyYMUNz0Wto=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=tMw60ZMcWa8Fn1YLxIpht59SuKiaF1ePJqK+vExoAgpmVkyfGzTUc6PTrtvO9BLiPZMGRhJi/3H0WkSkIJxczeeB7NgCgaXi34PVzgJfe0TNoBWel7KMi/iimm/H+OaBFV2WhPG93VNQMymuzSBqa8bcOe036TTm3f1YxaWtkw0= 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=2U/zzGdN; arc=none smtp.client-ip=113.46.200.218 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="2U/zzGdN" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=uK86g8TYBAmGyyi9lNVOUbjU74cmwye+w4Dvmqke+1k=; b=2U/zzGdN9bGWPbn20lsgsih2CSLDAzJBx5cW5B1kuOauhV3zr7f0Mm/uyChNraVerARY3SP3M owYAm5IKHHL96ZII9ZhhQFjshJ7sL8KnxlgLM3HpdiozqJOoWZz7tuW5qmgiRQMG4OhzzGzWSyN 6FC0vEOwOJUn1RTXq4pLMLY= Received: from mail.maildlp.com (unknown [172.19.163.0]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4hCzq13YkxzpT0q; Mon, 3 Aug 2026 09:38:53 +0800 (CST) Received: from kwepemf100006.china.huawei.com (unknown [7.202.181.220]) by mail.maildlp.com (Postfix) with ESMTPS id 1872D40537; Mon, 3 Aug 2026 09:48:19 +0800 (CST) Received: from [10.174.176.240] (10.174.176.240) by kwepemf100006.china.huawei.com (7.202.181.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Mon, 3 Aug 2026 09:48:18 +0800 Message-ID: Date: Mon, 3 Aug 2026 09:48:17 +0800 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 5/8] nbd: skip queue freeze when setting size at device startup To: , , , CC: , , , , , , , , References: <20260730082046.3459239-1-yangerkun@huawei.com> <20260730082046.3459239-6-yangerkun@huawei.com> <75ff5ace-a4bb-4960-a992-dddb235fd2ca@fygo.io> From: yangerkun In-Reply-To: <75ff5ace-a4bb-4960-a992-dddb235fd2ca@fygo.io> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To kwepemf100006.china.huawei.com (7.202.181.220) 在 2026/8/2 19:45, yu kuai 写道: > Hi, > > 在 2026/7/30 16:20, Yang Erkun 写道: >> Commit 242a49e5c878 ("nbd: freeze the queue for queue limits updates") >> added the freeze to keep in-flight commands from seeing torn >> queue_limits. But at startup the capacity is still 0 >> (invalidate_disk cleared it) and the write cache is off (the previous >> patch cleared it on disconnect, and nbd_set_size sets it back only after >> the commit), so submit_bio_noacct() rejects any bio before it reaches >> the driver and no I/O is in flight. Drop the freeze there. >> >> Split nbd_set_size() with a bool: nbd_start_device() passes false, the >> runtime resize/reconfigure paths (ioctls and nbd_genl_size_set) keep >> passing true. nbd->pid is still 0 when nbd_genl_connect calls >> nbd_genl_size_set, so the early return in nbd_set_size keeps that path >> from applying limits before startup; the true covers the reconnect path >> on a live device. >> >> Signed-off-by: Yang Erkun >> --- >> drivers/block/nbd.c | 21 ++++++++++++++------- >> 1 file changed, 14 insertions(+), 7 deletions(-) > > Can you just checking if size is 0 and write cache is disabled first, and just > skip freeze in this case. I think this is simpler and straightforward, as you > don't have to modify all the callers. OK, it seems simple and clear, I will try it next version! > >> >> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c >> index ce25c254e5fb..3b7363b11d0b 100644 >> --- a/drivers/block/nbd.c >> +++ b/drivers/block/nbd.c >> @@ -331,7 +331,8 @@ static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock, >> nsock->sent = 0; >> } >> >> -static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, loff_t blksize) >> +static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, loff_t blksize, >> + bool freeze) >> { >> struct queue_limits lim; >> int error; >> @@ -371,7 +372,13 @@ static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, loff_t blksize) >> >> lim.logical_block_size = blksize; >> lim.physical_block_size = blksize; >> - error = queue_limits_commit_update_frozen(nbd->disk->queue, &lim); >> + >> + if (freeze) >> + error = queue_limits_commit_update_frozen(nbd->disk->queue, >> + &lim); >> + else >> + error = queue_limits_commit_update(nbd->disk->queue, &lim); >> + >> if (error) >> return error; >> >> @@ -1568,7 +1575,7 @@ static int nbd_start_device(struct nbd_device *nbd) >> args->index = i; >> queue_work(nbd->recv_workq, &args->work); >> } >> - return nbd_set_size(nbd, config->bytesize, nbd_blksize(config)); >> + return nbd_set_size(nbd, config->bytesize, nbd_blksize(config), false); >> } >> >> static int nbd_start_device_ioctl(struct nbd_device *nbd) >> @@ -1636,13 +1643,13 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, >> case NBD_SET_SOCK: >> return nbd_add_socket(nbd, arg, false); >> case NBD_SET_BLKSIZE: >> - return nbd_set_size(nbd, config->bytesize, arg); >> + return nbd_set_size(nbd, config->bytesize, arg, true); >> case NBD_SET_SIZE: >> - return nbd_set_size(nbd, arg, nbd_blksize(config)); >> + return nbd_set_size(nbd, arg, nbd_blksize(config), true); >> case NBD_SET_SIZE_BLOCKS: >> if (check_shl_overflow(arg, config->blksize_bits, &bytesize)) >> return -EINVAL; >> - return nbd_set_size(nbd, bytesize, nbd_blksize(config)); >> + return nbd_set_size(nbd, bytesize, nbd_blksize(config), true); >> case NBD_SET_TIMEOUT: >> nbd_set_cmd_timeout(nbd, arg); >> return 0; >> @@ -2097,7 +2104,7 @@ static int nbd_genl_size_set(struct genl_info *info, struct nbd_device *nbd) >> bsize = nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]); >> >> if (bytes != config->bytesize || bsize != nbd_blksize(config)) >> - return nbd_set_size(nbd, bytes, bsize); >> + return nbd_set_size(nbd, bytes, bsize, true); >> return 0; >> } >> >