From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AF421C2A069 for ; Sun, 4 Jan 2026 18:54:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E0D8F6B009E; Sun, 4 Jan 2026 13:54:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DE4A06B009F; Sun, 4 Jan 2026 13:54:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1D2A6B00A0; Sun, 4 Jan 2026 13:54:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id BF7366B009E for ; Sun, 4 Jan 2026 13:54:39 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 53499161407 for ; Sun, 4 Jan 2026 18:54:39 +0000 (UTC) X-FDA: 84295182678.16.00D4796 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf26.hostedemail.com (Postfix) with ESMTP id 9C12E140007 for ; Sun, 4 Jan 2026 18:54:37 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=otFx3rCb; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf26.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1767552877; a=rsa-sha256; cv=none; b=mBJWw3kR538wRb853H7Sp4h3sP7B596tuB7eZF8mwMwSXJTk3qfRU2VN730/MENZIsxjmK yPvRbQHWV4Kr+pTxnW6dPmMWy21Tf5OQV7+dbMgo53K6w8GdCXyd3RqNlNc4vI3VtW4Oa2 t/vfEIAwZzUSUqKWm/yTC7aL26zoook= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=otFx3rCb; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf26.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767552877; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gaN7ORoI5WGBDDgDHPaIUghsOZoOq5cYVi0x3fGyaAY=; b=bFJLAKHLvWuuNu59T1fuH+EJh3fNJNM8CCD21tJEzTmOsVtdX0yWFBmc7yc6LpDPuIuXS2 8Fx4W7nVXoYL/xHUyMF5zC9G4FPdNLNQDpcG7hUerZvl761XLaaZuHYL3gs2d5ScwxcxEH carN5MWBXsGeckK2aRGcYbPE+5CmRXo= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 11B226000A; Sun, 4 Jan 2026 18:54:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DD5FC4CEF7; Sun, 4 Jan 2026 18:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767552876; bh=5ckW21cSSSQDwyPudbOFi8bdZ2K9Gm5VSRg9b0IN2z4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=otFx3rCbfqeWsQ/hkeCrE6l/4QCl2MKwjMNEHyGyX64T17Qd+sifh1TJmmKBHvYEC hflTn9bWskCb76Y0CLz7BPa72gSvtUl58oeghHQMrkS6AF9yrZbTmeLnQapyjyQZA0 0of++Cy/z6mKOJhFRTft2Yfx+tqhm3QK+0XdogprWkSKUHDLdyNRpNJ/O/DWNeGJSV cHNIqwE9klCdiH+oysrzU7qyVTfYUfkDv/Cj3Okmx7usCowXPpiYVamlLWWv09u2C4 xQKfLBiUksCjBTvyrZO5+R0TGIWkntMXfFhNwllqDyEPeYB3Hr4K7Y3vBIXNMVKKdT p+xKBzPKaKTIQ== Message-ID: <9f9343f6-c714-4d2f-985b-e832c6960360@kernel.org> Date: Sun, 4 Jan 2026 19:54:32 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/1] fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes() To: Andrew Morton , Joanne Koong Cc: miklos@szeredi.hu, linux-mm@kvack.org, athul.krishna.kr@protonmail.com, j.neuschaefer@gmx.net, carnil@debian.org, linux-fsdevel@vger.kernel.org, stable@vger.kernel.org References: <20251215030043.1431306-1-joannelkoong@gmail.com> <20251215030043.1431306-2-joannelkoong@gmail.com> <20260103100310.7181968cda53b14def0455b3@linux-foundation.org> From: "David Hildenbrand (Red Hat)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAa2VybmVsLm9yZz7CwY0EEwEIADcWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaKYhwAIbAwUJJlgIpAILCQQVCgkIAhYCAh4FAheAAAoJEE3eEPcA/4Naa5EP/3a1 9sgS9m7oiR0uenlj+C6kkIKlpWKRfGH/WvtFaHr/y06TKnWn6cMOZzJQ+8S39GOteyCCGADh 6ceBx1KPf6/AvMktnGETDTqZ0N9roR4/aEPSMt8kHu/GKR3gtPwzfosX2NgqXNmA7ErU4puf zica1DAmTvx44LOYjvBV24JQG99bZ5Bm2gTDjGXV15/X159CpS6Tc2e3KvYfnfRvezD+alhF XIym8OvvGMeo97BCHpX88pHVIfBg2g2JogR6f0PAJtHGYz6M/9YMxyUShJfo0Df1SOMAbU1Q Op0Ij4PlFCC64rovjH38ly0xfRZH37DZs6kP0jOj4QdExdaXcTILKJFIB3wWXWsqLbtJVgjR YhOrPokd6mDA3gAque7481KkpKM4JraOEELg8pF6eRb3KcAwPRekvf/nYVIbOVyT9lXD5mJn IZUY0LwZsFN0YhGhQJ8xronZy0A59faGBMuVnVb3oy2S0fO1y/r53IeUDTF1wCYF+fM5zo14 5L8mE1GsDJ7FNLj5eSDu/qdZIKqzfY0/l0SAUAAt5yYYejKuii4kfTyLDF/j4LyYZD1QzxLC MjQl36IEcmDTMznLf0/JvCHlxTYZsF0OjWWj1ATRMk41/Q+PX07XQlRCRcE13a8neEz3F6we 08oWh2DnC4AXKbP+kuD9ZP6+5+x1H1zEzsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCgh Cj/CA/lc/LMthqQ773gauB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseB fDXHA6m4B3mUTWo13nid0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts 6TZ+IrPOwT1hfB4WNC+X2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiu Qmt3yqrmN63V9wzaPhC+xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKB Tccu2AXJXWAE1Xjh6GOC8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvF FFyAS0Nk1q/7EChPcbRbhJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh 2YmnmLRTro6eZ/qYwWkCu8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRk F3TwgucpyPtcpmQtTkWSgDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0L LH63+BrrHasfJzxKXzqgrW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4v q7oFCPsOgwARAQABwsF8BBgBCAAmAhsMFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmic2qsF CSZYCKEACgkQTd4Q9wD/g1oq0xAAsAnw/OmsERdtdwRfAMpC74/++2wh9RvVQ0x8xXvoGJwZ rk0Jmck1ABIM//5sWDo7eDHk1uEcc95pbP9XGU6ZgeiQeh06+0vRYILwDk8Q/y06TrTb1n4n 7FRwyskKU1UWnNW86lvWUJuGPABXjrkfL41RJttSJHF3M1C0u2BnM5VnDuPFQKzhRRktBMK4 GkWBvXlsHFhn8Ev0xvPE/G99RAg9ufNAxyq2lSzbUIwrY918KHlziBKwNyLoPn9kgHD3hRBa Yakz87WKUZd17ZnPMZiXriCWZxwPx7zs6cSAqcfcVucmdPiIlyG1K/HIk2LX63T6oO2Libzz 7/0i4+oIpvpK2X6zZ2cu0k2uNcEYm2xAb+xGmqwnPnHX/ac8lJEyzH3lh+pt2slI4VcPNnz+ vzYeBAS1S+VJc1pcJr3l7PRSQ4bv5sObZvezRdqEFB4tUIfSbDdEBCCvvEMBgoisDB8ceYxO cFAM8nBWrEmNU2vvIGJzjJ/NVYYIY0TgOc5bS9wh6jKHL2+chrfDW5neLJjY2x3snF8q7U9G EIbBfNHDlOV8SyhEjtX0DyKxQKioTYPOHcW9gdV5fhSz5tEv+ipqt4kIgWqBgzK8ePtDTqRM qZq457g1/SXSoSQi4jN+gsneqvlTJdzaEu1bJP0iv6ViVf15+qHuY5iojCz8fa0= In-Reply-To: <20260103100310.7181968cda53b14def0455b3@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 9C12E140007 X-Stat-Signature: 1yyjgrstgsdy4xq4tq55wbzp3rtgn6dn X-Rspam-User: X-HE-Tag: 1767552877-619967 X-HE-Meta: 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 1GAns+sD 26qq+QUt68ewud0V9LVG3DrWRNOvcFz4tb20YsmOHoMLGx3HU+7HkAiCFMzk1DYCD0/AHZir2RF6WQUX/RXefd4Vk+5/fs5brkjGulx/S1ses/A910fS+dV+vULWxtTCNfAf+u+DAbeG+YEBHg5XBoX8WPkN1nrT2P+164KIaXPRsEkH3niiB/eaCiyd8jf9pD5EbBujHWVGTe5ZxzDRaivqZgtkujzibvIPZrYEmKyYX9CRhGMZcC6uMBWPiaq/7KwPYqDWaWWnKq4/tRcwkdWjOr1sNwLp1OsS/T+9ZNX00gbASwzzjaHRNiymirlvML7UfM06BMTLza3ErDHWEoNxyuuo09xY7N2wAtiTuO04Xc4uZ70W9ep+4lFo6gSfDg4pOwhAjuMZ7ky9D5Tx2BDdX85YKPPD47LQLIgHmbDFRHjbgsGg4Qu/6PABJkmxipTLHEPBn9YQGRb4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 1/3/26 19:03, Andrew Morton wrote: > On Sun, 14 Dec 2025 19:00:43 -0800 Joanne Koong wrote: > >> Skip waiting on writeback for inodes that belong to mappings that do not >> have data integrity guarantees (denoted by the AS_NO_DATA_INTEGRITY >> mapping flag). >> >> This restores fuse back to prior behavior where syncs are no-ops. This >> is needed because otherwise, if a system is running a faulty fuse >> server that does not reply to issued write requests, this will cause >> wait_sb_inodes() to wait forever. >> >> Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") >> Reported-by: Athul Krishna >> Reported-by: J. Neuschäfer >> Cc: stable@vger.kernel.org >> Signed-off-by: Joanne Koong >> >> .. >> >> --- a/fs/fs-writeback.c >> +++ b/fs/fs-writeback.c >> @@ -2751,7 +2751,8 @@ static void wait_sb_inodes(struct super_block *sb) >> * do not have the mapping lock. Skip it here, wb completion >> * will remove it. >> */ >> - if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) >> + if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK) || >> + mapping_no_data_integrity(mapping)) >> continue; > > It's not obvious why a no-data-integrity mapping would want to skip > writeback - what do these things have to do with each other? > > So can we please have a v2 which has a comment here explaining this to the > reader? Sorry for not replying earlier, I missed a couple of mails sent to my @redhat address due to @gmail being force-unsubscribed from linux-mm ... Probably sufficient to add at the beginning of the commit: "Above the while() loop in wait_sb_inodes(), we document that we must wait for all pages under writeback for data integrity. Consequently, if a mapping, like fuse, traditionally does not have data integrity semantics, there is no need to wait at all; we can simply skip these inodes. So skip ..." -- Cheers David