From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 540E74E533D for ; Thu, 17 Sep 2026 21:24:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789680269; cv=none; b=VVt2wed17wilXx5wlLnIW15K/Guv2DBLLI1cIfCb4BFwmX1mYhjWhlxq5V/WCEaTbnhjTqYbAgl83cSEIDwIGddigviKLsCcn0SAnzzljuvU+J27fe2VnJPD8CWVXCiSyKwzJf3Gp0PiqSPxCNNnHzGiIG88MchooxriWS/Oxq4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789680269; c=relaxed/simple; bh=H+rMQtT5fkiWfM9mSL8Pcff/AxQsQJ9rT4zKFbklWpw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FYq9oGiKbd+r717BrCCnF0sQSwdDw/ICUjrtpoI2qxeX58SDSU5w72ZnxDuGlLQuoA963pBvLaiDGI4ZPxYH/pDlPgPTKkxoYglmYbDDVhWJOIfpWRBJ8C1kUEM1IcyfXDrzguYk1/eiAFcfpaMxCpwUDd9KH47OJeI3uV55ffs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=arD5ID04; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="arD5ID04" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC1391F00899; Thu, 17 Sep 2026 21:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789680267; bh=8vtUfKdGbjKhAK5UY723TQqi1U3xgbEj9G5q6mV3yus=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=arD5ID04jxvjirYjxsFSsKfWuKvERKgH//ea9HMNtfR7CcC25qjOZxy1c0nU/JmQO Ee0+1mnGiRyz67vvaFXxBm0/iDwDWazVF3oJfwJ729pr3MIp5Ny2cqwG0efft9Tiee anxS2xaJkGzDAadibIIAiNoCaKLiJb5JtPQLZbeub3YD+lpPJSbCAPtz4rtCSXbQPq wu8GPIJSJVL8pvmdAuN7osRB2/sJP7iFo2jK1s5x1Ji5j5z3tlJa+WA+OMJktdJniw v9Z2LM7iZO1VlM9hpottfEK5O6eRGNLpB++PA/mWHgKv9EogMxGXh+9pPMwRHtUCW7 TIDXtS02bLNEQ== Date: Fri, 18 Sep 2026 07:24:19 +1000 From: Dave Chinner To: Shin'ichiro Kawasaki Cc: "linux-xfs@vger.kernel.org" , "Darrick J. Wong" , John Garry Subject: Re: [bug report] fstests generic/774 hang again Message-ID: References: Precedence: bulk X-Mailing-List: linux-xfs@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: On Thu, Sep 17, 2026 at 07:45:11PM +0900, Shin'ichiro Kawasaki wrote: > On Sep 17, 2026 / 15:52, Shin'ichiro Kawasaki wrote: > [...] > > As suggested, now I'm trying to increase the journal/log section size. > > I added the mkfs options below: > > > > MKFS_OPTIONS="-l size=128m" > > > > With this, I repeated the test case 30 times, and did not observe the hang. > > It looks like the log section size increase avoids the hang. I will keep it on > > running to see if the hang is observed after 100 times run. > > The test case did not hang all through the 100 times repeated runs. Then > expanding the log section from 64MiB to 128MiB avoided the hang. Ok, so the fix for the moment is to make the software COW path for atomic writes use IOLOCK_EXCL, rather than IOLOCK_SHARED. That will result in all the IO submission blocking on the IOLOCK with no other resources held rather than blocking on the ILOCK whilst holding an unreleasable transaction reservation. Cheers, Dave. -- Dave Chinner dgc@kernel.org