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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31C68C3ABDA for ; Wed, 14 May 2025 09:11:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4522A6B010D; Wed, 14 May 2025 05:11:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 402876B010F; Wed, 14 May 2025 05:11:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27CC66B0110; Wed, 14 May 2025 05:11:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 09BE56B010D for ; Wed, 14 May 2025 05:11:29 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 1D8C1BD2FC for ; Wed, 14 May 2025 09:11:30 +0000 (UTC) X-FDA: 83440945140.19.57C7E37 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf23.hostedemail.com (Postfix) with ESMTP id B268714000E for ; Wed, 14 May 2025 09:11:27 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ZPUJYg+R; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1747213888; 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=mbjkb6JTJAsuy38qD4oeTgqwyUosO6GgDAb+t/G8/WQ=; b=4qWmd2m+RR9zqKmGnHPCIPoqf9A1iJAswTL50HTixfv/EncgL10+Jql57f4+sPkbdw4WGq iUMO67i8T2E3QSInyjiwkNwT4C4N4AtR+BNqVFs2Y8W7bGpVIYyV1hMhgBG/qp/MRx9dai afdBjkM2DT8tHMGU8t1I4wa6zHtns1U= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ZPUJYg+R; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1747213888; a=rsa-sha256; cv=none; b=RgOnBShgTzdfXY48o6KmFNIY+9voE7bcWCMUOKtGZPLQCMbPbdWI39MqrDNU2Owty97BoK njXADsmOLsHtI+9HLVaax1mwGhnL8O43VWgModL0Mf0Q5Hm1FebPkYu+y1ssrCk1c5LQMR +CIZF1uwwpw+XIcs9MjnnSC0rsFYYik= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747213887; h=from:from: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:autocrypt:autocrypt; bh=mbjkb6JTJAsuy38qD4oeTgqwyUosO6GgDAb+t/G8/WQ=; b=ZPUJYg+RfJi7YUdp+BCS7E6eZ2oMePJ6nNRaA1lqvFPFRWBTo51nLJVV0Zt33YusZh9RLc U57kAKIBMMLXLmy2rNhwQErxSZQo88mgYzuB4ZhpiPa7xfjXqmcfTztOiplyADyml+Pd4t n5HJ4+Ir23qaTZJjhYkz5R036uqo6Uk= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-148-EjGoTSnPOCqthoY0SkXR2g-1; Wed, 14 May 2025 05:11:26 -0400 X-MC-Unique: EjGoTSnPOCqthoY0SkXR2g-1 X-Mimecast-MFC-AGG-ID: EjGoTSnPOCqthoY0SkXR2g_1747213885 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3a0ba24d233so2245591f8f.2 for ; Wed, 14 May 2025 02:11:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747213885; x=1747818685; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:references:cc:to:from:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=mbjkb6JTJAsuy38qD4oeTgqwyUosO6GgDAb+t/G8/WQ=; b=mzMyQx731U8amzi6Ovo4BrNVuj4iJx3cdtQ3xlVPNxitPHG00fZCpqCeX89oRcBHRO OuZBUJJSz9jfwAsgnviKAm3GjPVo6akb0Pc/7UUv03/SqUccaoqTMjhTMCfhbOB22EtI 4v35Z5v3HQqtmlFQAL2M3N7D62oo11cZFjJynYjG1RDsf5Y1hZ+ZBhk2WQz6y14KmxvV BshLF6+365ekZU608PIDGBFAlyNObPIfnSKJwYoApVs0prk4FHGJAH0/esLcjEk25Gn6 V5vxcrW+E+goUoSpGGAJwYnbiFSEROcGLvYGQ0k+AqXSv2u+ov5AO3/U0h/yyObVghP5 HOIA== X-Forwarded-Encrypted: i=1; AJvYcCVxrFYSg7klx//QBB79mSTQiaMGPSEOpkR7kq/KaUSDztx5dsp1PBUch7oz2ZZQ79YTdcAaxX7lhA==@kvack.org X-Gm-Message-State: AOJu0YwkmgpRDUxwQEvQ1rmutFnuzatOmZs4/8SOg0QgkqHjabt1ErQC EqINSdo/SfCzuLNbzatsIbcmjFjOEZ5frdyuSEBxgR/p7WNG490b4NpiHeLGtv2ODEur44JiGFK P8akYafuZKpSSvgVB3cZmcRFvgGLTN8fx1NOR1xGNhID1WxRo X-Gm-Gg: ASbGnct1NjTC2Ymgxc4YsMHH4AXj3Zq4mPqczQjY4M7db0pHR54INQ4Dd3Hvb7VbLb6 XMVuBY+cN9/K0PJoBUf0pdAdID1rF+rZ+2o/b5VvR2GqaAEtQtAjUQxgQTPf9PDa4S48rgG8sTP Sv9U5oaIaXtrdJEViThmorYtuAEYSA5oqzGgVEqysnL+LkIPMzsThp1W2NPDfs6dUBZkvPWoHT1 kTyTYsWGUn24FzCfse+YzamrPG6OqXL65UgNzQd5u8zvrewEfXk6t/SPTN0tI2GrcChvzEnTvUt EOJAfbtClRxYjlptQwDPGRlIf2YWOWqAiX51ZvQAi7Muj56QZpIQW6hQqVwCPN0SRekopCgfzFg Dy4LCTc883jxLzTF/8K5fJp35bTObgf3sWMwqgg4= X-Received: by 2002:a5d:5f91:0:b0:3a0:7017:61f6 with SMTP id ffacd0b85a97d-3a3496a40f6mr2274314f8f.14.1747213884691; Wed, 14 May 2025 02:11:24 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEzKwUpB8LZoEPItaEpiT42Rn95TAirv2fF/YHfvGZfDLHpm/T3BLxuSWtpEUruW+FjHC9Emg== X-Received: by 2002:a5d:5f91:0:b0:3a0:7017:61f6 with SMTP id ffacd0b85a97d-3a3496a40f6mr2274276f8f.14.1747213884315; Wed, 14 May 2025 02:11:24 -0700 (PDT) Received: from ?IPV6:2003:d8:2f15:6200:d485:1bcd:d708:f5df? (p200300d82f156200d4851bcdd708f5df.dip0.t-ipconnect.de. [2003:d8:2f15:6200:d485:1bcd:d708:f5df]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a1f58ec8f1sm18679910f8f.26.2025.05.14.02.11.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 14 May 2025 02:11:23 -0700 (PDT) Message-ID: <8d11bb04-2feb-4189-adbd-5f27819d2095@redhat.com> Date: Wed, 14 May 2025 11:11:22 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: remove WARN_ON_ONCE() in file_has_valid_mmap_hooks() From: David Hildenbrand To: Lorenzo Stoakes Cc: Andrew Morton , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Viro , Christian Brauner , Jan Kara , Matthew Wilcox References: <20250514084024.29148-1-lorenzo.stoakes@oracle.com> <357de3b3-6f70-49c4-87d4-f6e38e7bec11@redhat.com> Autocrypt: addr=david@redhat.com; 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: KoXfftcgzINbLl5MoakKJ2056qDkoZjkE6KahqKnIhk_1747213885 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Stat-Signature: fayetadzig6677xukn76sgrer86q9hky X-Rspamd-Queue-Id: B268714000E X-Rspam-User: X-HE-Tag: 1747213887-463410 X-HE-Meta: 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 ScjPDV70 7ysORax01yBAv8M1Liuhk6cZMu7qwo8d/Kn92lnStw3FEpC12LAf7/vU1mfVtOdp1v9N6Wju4vMVeXQzYwcHghERLnHb5qS7yG7ecHwzdA5wina09vOvvLM2To0CYcVsQD963 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 14.05.25 11:10, David Hildenbrand wrote: > On 14.05.25 10:56, Lorenzo Stoakes wrote: >> On Wed, May 14, 2025 at 10:49:57AM +0200, David Hildenbrand wrote: >>> On 14.05.25 10:40, Lorenzo Stoakes wrote: >>>> Having encountered a trinity report in linux-next (Linked in the 'Closes' >>>> tag) it appears that there are legitimate situations where a file-backed >>>> mapping can be acquired but no file->f_op->mmap or file->f_op->mmap_prepare >>>> is set, at which point do_mmap() should simply error out with -ENODEV. >>>> >>>> Since previously we did not warn in this scenario and it appears we rely >>>> upon this, restore this situation, while retaining a WARN_ON_ONCE() for the >>>> case where both are set, which is absolutely incorrect and must be >>>> addressed and thus always requires a warning. >>>> >>>> If further work is required to chase down precisely what is causing this, >>>> then we can later restore this, but it makes no sense to hold up this >>>> series to do so, as this is existing and apparently expected behaviour. >>>> >>>> Reported-by: kernel test robot >>>> Closes: https://lore.kernel.org/oe-lkp/202505141434.96ce5e5d-lkp@intel.com >>>> Signed-off-by: Lorenzo Stoakes >>>> --- >>>> >>>> Andrew - >>>> >>>> Since this series is in mm-stable we should take this fix there asap (and >>>> certainly get it to -next to fix any further error reports). I didn't know >>>> whether it was best for it to be a fix-patch or not, so have sent >>>> separately so you can best determine what to do with it :) >>> >>> A couple more days in mm-unstable probably wouldn't have hurt here, >>> especially given that I recall reviewing + seeing review yesterday? >>> >> >> We're coming close to end of cycle, and the review commentary is essentially >> style stuff or follow up stuff, and also the series has a ton of tags now, so I >> - respectfully (you know I love you man :>) - disagree with this assessment :) >> >> This situation that arose here is just extremely weird, there's really no reason >> anybody should rely on this scenario (yes we should probably try and chase this >> down actually, perhaps though a driver somehow sets f_op->mmap to NULL somewhere >> in some situation?) >> >> So I think this (easily fixed) situation doesn't argue _too_ much against that >> :) > > Again, I am talking about a couple more days, not weeks or months ;) > > At least looking at the report it sounds like something the test bots > would usually find given a bit more time on -next. I might be wrong. > > next-20250500 had the old version without WARN ^ for completeness, next-20250509 -- Cheers, David / dhildenb