From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 4CA611E520 for ; Fri, 16 Aug 2024 14:26:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723818374; cv=none; b=i6N6+t1FrMAiPKvBiJIrtlQTXJFAjkGaMcS9uP7RWHq0VfEnhhZhVv46nkuKKb/tXM9Bn/aP1pq3XLMx4KDvqTQKG0g3/gjei8Jx4RAYxuDzHW3y1rDJrIqbBnky3xvC+FqyEcjHypqS+HrZLTl/6H+eLESWWL9xfrVOefR1rtE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723818374; c=relaxed/simple; bh=YlriYsXOqwiTgS6I2KpCXQbTpQsu2jOM4HwsURrgwvk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KphRAVUjyQ/P6tDOgsgdVhJTROjLsYZgsfII3VOmGCzuR8GkbDSEvd3UROZSc1uvu85Heu6rhPjqxwr7gXKj+169x5gKULV/T4MGvMeo0S8V7R8RsfOCgMRJbLwrksPbLoR3Z9q0lA/mbSb1JRVwVsV2NNjb000dDJsaXrPf9ng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=ZGVbDCMJ; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ZGVbDCMJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=YlriYsXOqwiTgS6I2KpCXQbTpQsu2jOM4HwsURrgwvk=; b=ZGVbDCMJ5EQ7fDp/OW1w/N7NOw 4t+UGUuzMVqEK9/1UpIg5LVG+0GmLRIQrnvLOOjD2AxfnJdrrhEqzr5VehqR6c/WWe4Q3PHQqzsHj f/x9rq1sXJN0QvuLCMVJSch8/gBas02AEufR03nbqbnPUGKg8d5QmzW0Te/lIzEkacXUNISSGeKwU 60rG7hv9cp+sos/3IXW0eY+GOTuZOuouu62pxF8Y4uz51gooHNqk2g/493D12BrNKUHv7fJxLTERT qF+qjvvfjj3EuugholQ1ggNpllxtTJBAjHQ6fmhY6AXsTS+bJztsBU3yi8o67zBw3RyA/LqexGukV WnT3W9JQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sexu2-0000000DCiv-3kjF; Fri, 16 Aug 2024 14:26:06 +0000 Date: Fri, 16 Aug 2024 07:26:06 -0700 From: Christoph Hellwig To: Michal Hocko Cc: Christoph Hellwig , Yafang Shao , Andrew Morton , viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, david@fromorbit.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Kent Overstreet Subject: Re: [PATCH] mm: document risk of PF_MEMALLOC_NORECLAIM Message-ID: References: Precedence: bulk X-Mailing-List: linux-fsdevel@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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Aug 16, 2024 at 10:54:37AM +0200, Michal Hocko wrote: > Yes, I think we should kill it before it spreads even more but I would > not like to make the existing user just broken. I have zero visibility > and understanding of the bcachefs code but from a quick look at __bch2_new_inode > it shouldn't be really terribly hard to push GFP_NOWAIT flag there > directly. It would require inode_init_always_gfp variant as well (to not > touch all existing callers that do not have any locking requirements but > I do not see any other nested allocations. I'll probably have to go down into security_inode_alloc as well. That being said there is no explanation for the behavior here in the commit logs or the code itself, so who knows.