From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5DFCBE77188 for ; Mon, 6 Jan 2025 10:07:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3euJA8Ns15KPhEkUiWNhzNcQI81/iMSrckSXcWqOPgE=; b=1we3xC2upaCoWgzm/nwgI9p5Dq LzeXPbi4lllouJsubeW64NOthoQ/TOc5COUnarlBTxJTo3lRomHo4l4jlGTfYHj7wbHWtpPKGs289 CsmjgXf1gQz0GsqthwlRfa6EdJMBMyyUL2GnPsHUym+5JUy58a2SGdPBro2WYO4vWwaFM/svDAm+h Anj6HPnZ4NFYPNJVLzDyJ5GP7CO22f4KNQic2Qtuxeg3L+WZTGmKWlYKz49EFwVZlsZsWJE+vZMTD DvGUgctmEJ4Q2w1+Tyhx1EhbAPUZ3R8Q0f4wKRzdLe3A79Q/vhTlpmNm/kHVrG57LSFWgLpGuFqFD ZbztoOTg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tUk0v-00000000nkQ-44pu; Mon, 06 Jan 2025 10:07:13 +0000 Received: from 2a02-8389-2341-5b80-db6b-99e8-3feb-3b4e.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:db6b:99e8:3feb:3b4e] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tUk0t-00000000ng8-2TWU; Mon, 06 Jan 2025 10:07:12 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Damien Le Moal , Ming Lei , Nilay Shroff , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, nbd@other.debian.org, virtualization@lists.linux.dev, linux-scsi@vger.kernel.org, usb-storage@lists.one-eyed-alien.net Subject: [PATCH 09/10] loop: document why loop_clear_limits updates queue limits without freezing Date: Mon, 6 Jan 2025 11:06:22 +0100 Message-ID: <20250106100645.850445-10-hch@lst.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250106100645.850445-1-hch@lst.de> References: <20250106100645.850445-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Signed-off-by: Christoph Hellwig --- drivers/block/loop.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 836a53eef4b4..84b007b9c38c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -311,6 +311,13 @@ static void loop_clear_limits(struct loop_device *lo, int mode) lim.discard_granularity = 0; } + /* + * XXX: this updates the queue limits without freezing the queue, which + * is against the locking protocol and dangerous. But we can't just + * freeze the queue as we're inside the ->queue_rq method here. So this + * should move out into a workqueue unless we get the file operations to + * advertise if they support specific fallocate operations. + */ queue_limits_commit_update(lo->lo_queue, &lim); } -- 2.45.2