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 85A7B84D04; Thu, 23 May 2024 21:09:04 +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=1716498547; cv=none; b=iGPMLIRVqxK69h8geOiezgMrndccsY2wrbhEq+9jYnBg9JIrm2wHFKsmXlZKmilcgdY0HvdXid3ZaANt8r67AqOdPqunDr2GfbgS1nJEvWcb2qQZEULdFvPU34RfrSQOQh3LDTnPfu6mkepX3tmx/tNvXPf6oZvpoEi9Qkw0kbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716498547; c=relaxed/simple; bh=CuLd6TYGiS2+rBvn4z08Wn3+YNLIR/6ODCNpJdMqEg4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gMltebJN6H63TqZTl/xP3hBF/LP+2zMS1/2sp1+vKGj5FQQDtmLHnaI5LIp17w03F8gzcPZndBCYgjJBt6nwNT9x85RFApTOO7qR/ZxnTGOqj1m0N1o1tu30AdKAqAOo3yFNuPSFDndIAeboalh0uuhZ39NtrMLNMY9wCREXipQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=rMjxjrtH; arc=none smtp.client-ip=90.155.50.34 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=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="rMjxjrtH" 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=kfXLI35AfLCSFV6qQpB+s4UJzywNe6zaOkdmoMWLhoA=; b=rMjxjrtHoKYBcGVQ1mLGX02Da9 MhBSwsAUQz8UyEwOojru4LeYNEf9ECbRJHigOYDGFkoOutPwb5OD7MzcAH0D/wRqzwmQ6ZC4znrAY BsqS4JEms1QSmWH+SHakY/tLJjsKiLFL1ruP/8BTGu+tjyVi8wGgNUbxGODtUvxPQzggDDM9I/UC6 783sO5NBSp44JcRpEpq34873WCE0VME4hQqZW9RXBXSi/EcCwlItSaPkjoPTy7HQncXWcJwM0N2oi iWFUAKV1hXtWwuog8XFzgRfMb7hPHCH2+2nZmpJ9pkrCrhjRamU06UWQd3jaiZpqximFG34AuMiE0 /t/t7t8g==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sAFgJ-00000002690-3zOP; Thu, 23 May 2024 21:09:00 +0000 Date: Thu, 23 May 2024 22:08:59 +0100 From: Matthew Wilcox To: Liu Wei Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Goldwyn Rodrigues , Christoph Hellwig , Jan Kara , Jens Axboe , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] mm/filemap: invalidating pages is still necessary when io with IOCB_NOWAIT Message-ID: References: <20240513132339.26269-1-liuwei09@cestc.cn> 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: <20240513132339.26269-1-liuwei09@cestc.cn> On Mon, May 13, 2024 at 09:23:39PM +0800, Liu Wei wrote: > After commit (6be96d3ad3 fs: return if direct I/O will trigger writeback), If you're reporting problems with a particular commit, it's good form to cc the people who actually wrote that commit. > when we issuing AIO with direct I/O and IOCB_NOWAIT on a block device, the > process context will not be blocked. > > However, if the device already has page cache in memory, EAGAIN will be > returned. And even when trying to reissue the AIO with direct I/O and > IOCB_NOWAIT again, we consistently receive EAGAIN. > > Maybe a better way to deal with it: filemap_fdatawrite_range dirty pages > with WB_SYNC_NONE flag, and invalidate_mapping_pages unmapped pages at > the same time. > > Signed-off-by: Liu Wei > --- > mm/filemap.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 30de18c4fd28..1852a00caf31 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2697,8 +2697,15 @@ int kiocb_invalidate_pages(struct kiocb *iocb, size_t count) > > if (iocb->ki_flags & IOCB_NOWAIT) { > /* we could block if there are any pages in the range */ > - if (filemap_range_has_page(mapping, pos, end)) > + if (filemap_range_has_page(mapping, pos, end)) { > + if (mapping_needs_writeback(mapping)) { > + __filemap_fdatawrite_range(mapping, > + pos, end, WB_SYNC_NONE); > + } > + invalidate_mapping_pages(mapping, > + pos >> PAGE_SHIFT, end >> PAGE_SHIFT); > return -EAGAIN; > + } > } else { > ret = filemap_write_and_wait_range(mapping, pos, end); > if (ret) > -- > 2.42.1 > > >