From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 48CD21D27A9; Fri, 11 Oct 2024 23:11:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728688311; cv=none; b=hZRK5tqr3zMMzpTL+IYZoA7fpmZNh3MD7y4YXW/yx4ooOBkFcdHdEO+9BIUNy03FGbulIBV52WHcSe0SPv/GMlnHm3ojmzQUl1eODABzUymEBqxaWhTcEktOMI7Y2KrMFnraxDhcX6MDTMTk1GehOx+ebLEzKmnTcC4CtHWAA3g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728688311; c=relaxed/simple; bh=iVJ74e4tA1WxfHXS2xP4RqS7VvfQLdtn7Zy1xtIgh5A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jtzn6bBBnEacnYghEb/bNNaU85KV8uWOt1v9xiziLT+dV/weXr8J1brl91rA9vGvMamG6p/zcoh2ACyLXkrCAbuJq3Aa/tvqWq7c/lbDnta+MeuEgkfhz9bMZiCLPHwrJy2UcbmDlDeKOtMx2y1og5O23m++Tg1VeAjlcHlupjU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R6Ym6KJO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R6Ym6KJO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D19CC4CEC3; Fri, 11 Oct 2024 23:11:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728688310; bh=iVJ74e4tA1WxfHXS2xP4RqS7VvfQLdtn7Zy1xtIgh5A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R6Ym6KJOF6tfls3kP0ehEPQZxEZLje3eMQHOk+Cd/nR4ws/cIVbd6MA5SeVoVQmKK mxx5dNMw/481In9ovH50xCEVB6pP31MVQ47e2nYl3C2Oxsuauy29+O1peg0N9/xmbq F180EP5MTAbYcFwxk9baCTKhQp6OkU2jX/OWDYssXq7xfX8l7jg6+ZhNT+sY/xZhdi II6Ij98DGQ7smljfSzMGiRKX/PseqCew3FmMuE0rE1HUkLnNWA3KbFktOSDp6z6euh WvKHXPhyfD2yFHIyQ5QYFySsVXz118y+VowWBAQhzm2diBIvUbczSC4jjVNi6WDHjk QWA7uI9pVYXzA== Date: Fri, 11 Oct 2024 16:11:49 -0700 From: Luis Chamberlain To: "Maciej S. Szmigiero" , "Darrick J. Wong" Cc: "Rafael J. Wysocki" , Len Brown , Pavel Machek , linux-pm , linux-kernel@vger.kernel.org, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, Russ Weight , Danilo Krummrich Subject: Re: Root filesystem read access for firmware load during hibernation image writing Message-ID: References: <3c95fb54-9cac-4b4f-8e1b-84ca041b57cb@maciej.szmigiero.name> <413b1e99-8cfe-4018-9ef3-2f3e21806bad@maciej.szmigiero.name> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <413b1e99-8cfe-4018-9ef3-2f3e21806bad@maciej.szmigiero.name> On Sat, Oct 05, 2024 at 03:16:27PM +0200, Maciej S. Szmigiero wrote: > The issue below still happens on kernel version 6.11.1. > > Created a kernel bugzilla entry for it: > https://bugzilla.kernel.org/show_bug.cgi?id=219353 > > It would be nice to at least know whether the filesystem read access supposed is > to be working normally at PMSG_THAW hibernation stage to assign the issue accordingly. No, there are races possible if you trigger IO to a fs before a suspend is going on. If you have *more* IO ongoing, then you are likely to stall suspend and not be able to recover. > CC: request_firmware() maintainers If IO is ongoing suspend is broken today because of the kthread freezer which puts kthreads which should sleep idle, but if IO is ongoing we can stall. This is work which we've been working to remove for years and after its removal we can gracefully freeze filesystems [0] [1] properly on suspend. Other than that, obviously upon resume we want firmware to be present, and to prevent races on resume we have a firmware cache. So on suspend we cache used firmware so its available in cache on resume. See device_cache_fw_images(). So.. we just now gotta respin the latest effort. I had stopped because I know Darrick had some changes which he needed to get in sooner but since this is low hanging fruit I never got around to it. So someone just needs to respin the series. [0] https://lwn.net/Articles/752588/ [1] https://lwn.net/Articles/935602/ Luis