From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 C44553431FD; Fri, 6 Mar 2026 18:41:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772822477; cv=none; b=bm/K0o8rxxgcA7JVvUOasKbcPV+n4dg4ipUNW2qvCsMCnSMcYU9dH3ic4uhZmV5LGKZIvzqtnFO0U1D8+27ss+n4nmRvTvt56SaS5wtVwZDe1FkYUGFRt1IBSVzRMH790MxQnLMh/n5hlleeKXGEDrpcEZ4xWUpTVfb3xGIDHic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772822477; c=relaxed/simple; bh=pVQX8UbFQFuwDfMZUkbjtXBKe6Lw0V+LZTPRaPnqEoY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QX+Q0ILwEA3QLYlVgfqMGmscV6c4LWMu7bcpAGSFUIojBPHmXMwI3OtBU+jpEOe6UvpM8cA93Dgs9AJhibFKHwAdOYV70v1KYKOCkBwVSSMl0aykDH3xdzFVaLpk/aYGxtGnDrstfwbJZH8LW8YTQ05gCwTU26IBhdym8qWR304= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Wg/i8/QW; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Wg/i8/QW" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=VM5um0Un0dBqpJi9mEsTrBTXwrxc0DE4YjAakbTEyXQ=; b=Wg/i8/QWd4Ak3VOJCLKU4dOiuQ xhhympkoBIIrndvU9oNWzizRvbkRQ3jezMSezju9eBLweSBuzsBZdBVnJOYqnOrHMvr5SmlnVP7Rg Ng7hBgG47iGveYVWERXxjBdpvNRmq5AUyqBbP+7Nd6VQdOMNY/jUo+w/KgoQdH47g2HRf2TYFAWfw CCM7PTZXAotdCUsSZQMpGSkloS/Q2nDnr0/Aq9/YgBeRNfhWNv8pPcEzDkNj6deFHagI4erqIHgJp eteoq5s9zoTi8qpjjo0mqYvWpKAt2FdK+b+ImQ30AyTXD4aDaJV9zgu+yWXF0XFKvpq91UIqEg4U3 Eoj2sqbg==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vya6m-0000000H9Eb-2cL2; Fri, 06 Mar 2026 18:41:08 +0000 Date: Fri, 6 Mar 2026 18:41:08 +0000 From: Matthew Wilcox To: Kiryl Shutsemau Cc: Chris J Arges , akpm@linux-foundation.org, william.kucharski@oracle.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@cloudflare.com Subject: Re: [PATCH RFC 1/1] mm/filemap: handle large folio split race in page cache lookups Message-ID: References: <20260305183438.1062312-1-carges@cloudflare.com> <20260305183438.1062312-2-carges@cloudflare.com> 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: On Fri, Mar 06, 2026 at 06:36:30PM +0000, Kiryl Shutsemau wrote: > The proposed change doesn't fix anything, but hides the problem. > It would be better to downgrade the VM_BUG_ON_FOLIO() to a warning + > retry. The trouble is that a retry only happens to work in ... whatever scenario this is. If there's a persistent corruption of the radix tree, a retry might be an infinite loop which isn't terribly helpful.