From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f170.google.com (mail-pl1-f170.google.com [209.85.214.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9CD8714A82 for ; Thu, 23 May 2024 21:16:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716499005; cv=none; b=WYyxry3W8Q2V25bL/jgG7XTM60F/bP9/xGNpt2yVssSK0sY4zATxoaXHw5noHIkFq+JROcxEsBWvMJbbEun9Cqjl6EgPTaAEQkmfE7t1fndYGyfW/XnebJMoYQrsslmVLhXN5tT0kJTGTOTDDA+BKzHKAHdUPmLqr8Zo4SPeHRM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716499005; c=relaxed/simple; bh=UyvAR+rCqOFMlr/SS+1G6e+pvgKBDpk94OJDklZdVUE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=slt0Uvc07excorgbHSjSzrZnq6egjgXNHgDgKdA7HFsx1feTYYYoJ20Lm6olXQxBr36k/MFe8zghyjs7UA4qFY5I+gK6mGECFnTAAlt0sphPL0lWdEIABuMCzlt3sNiaBMdvup1Vn6uDcABqCPsB+nYME6oUoDnIvfoUxWQjXoo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=1cpAX/WT; arc=none smtp.client-ip=209.85.214.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="1cpAX/WT" Received: by mail-pl1-f170.google.com with SMTP id d9443c01a7336-1f33772fa90so1496395ad.0 for ; Thu, 23 May 2024 14:16:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1716499001; x=1717103801; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=dYKcD5IuchFm4IMrBOnq6lh3XNI0BhQKY7/Pq8Y41cA=; b=1cpAX/WTT+llFO04wUpvHFp4KZQDZVOU582pZ9oR8mGOBhcsAwKyHqr3mfDPVX/ynQ CXZoGJQFEpZ0MIlDWHem+rYrilyJHoM1fLQVuMLdYFdXFCszqF98nWWBVT+KhxF3mmRh aOe4Q0z+5yzOP8NO/7QL2dFO4ygvUS/iCAFOyrl1lTt+pAAaBCPJJBNtxtRt72XrtNoH MBdi84U8f7EgS+HMJI3qS7Uk4DNZXUMZBnn55Z76V8ny2cLFTnVzArduX2EjGwrebl4W 8HZu1PskH01AXn50nsUge0JsJUtjIcWW52sknSLyESCe8p3ayIUq0GQ4xcVtAzMom2lK Uw4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1716499001; x=1717103801; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=dYKcD5IuchFm4IMrBOnq6lh3XNI0BhQKY7/Pq8Y41cA=; b=Tefe3Gu9KRWXXfDfy7H+pJ/fXldlmyne5pwUmt8XEFXDtkwUFOVR0CxyocNBFx1ZGk PQrxGJgPzIN7T/sPpIpy+dXmJhZWvkxzJpTTRFXf4eR1Yrnwoy4S0KVeAoyMd2cZIWXp Tw8FFQq4FWotufKnpEoSBFIBdAU5QIXa40k9RaW3L8oHtHGqDMvKG1H1YsUIpBI8zZJD YTH+oRryoDXbxi7b83CTVz0nkAS8OBQC958zz/ZjYrwHx1B3tmr8QCriAvBocRjVuXhP XzNiqk0WOFc5ps4Lc0lQHjjPmv8Bd0LJMS5HZG1+fkp/yR+4hI/YTMJXpu7vNwBfBBuG kSZg== X-Forwarded-Encrypted: i=1; AJvYcCVKlIooDpdB/sydTexFRqxgGiDy0RGrpmPbwmUNULvEYh4PH0wyWcvi6r4ek5VExolwdZhrABAKUqbVyutAthG+tSYZ57NUEK36ULz6 X-Gm-Message-State: AOJu0YzsbtEYnHurofWf90X4u4hVsbUDTtAH4iz5d95mplSjf1MkLJmv QEkOSnZ61OLeW1vyVNYacEj30+d0zVshjjF8OYsr1JEq6Ueaew/f+mI9pwrYw28= X-Google-Smtp-Source: AGHT+IEuoEoQ/bJet1m7gQrg83v+8LU9LhdnXxXzTFJ+8azHok2UlXv7rYJvnuhuAuTOIbgYM9Cflg== X-Received: by 2002:a17:903:41c6:b0:1f2:f73c:c442 with SMTP id d9443c01a7336-1f4483e91a8mr6489475ad.0.1716499001521; Thu, 23 May 2024 14:16:41 -0700 (PDT) Received: from ?IPV6:2620:10d:c085:21c1::1060? ([2620:10d:c090:400::5:32c6]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1f44c79d046sm373525ad.72.2024.05.23.14.16.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 May 2024 14:16:40 -0700 (PDT) Message-ID: <024b9a30-ad3b-4063-b5c8-e6c948ad6b2e@kernel.dk> Date: Thu, 23 May 2024 15:16:38 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/filemap: invalidating pages is still necessary when io with IOCB_NOWAIT To: Matthew Wilcox , Liu Wei Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Goldwyn Rodrigues , Christoph Hellwig , Jan Kara , linux-fsdevel@vger.kernel.org References: <20240513132339.26269-1-liuwei09@cestc.cn> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/23/24 3:08 PM, Matthew Wilcox wrote: > 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. Yeah indeed... >> 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. -EAGAIN doesn't mean "just try again and it'll work". >> 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); >> + } I don't think WB_SYNC_NONE tells it not to block, it just says not to wait for it... So this won't work as-is. >> + 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 >> >> >> -- Jens Axboe