From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 84F5B801 for ; Thu, 19 Dec 2024 13:05:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734613512; cv=none; b=ARfCp9uy6eefcsUGYKwyOr8SiashRp+xmCsvELViO3SH9hcKvlEF+QmMPLaGjdmcUay5PLohri9ezJpCEX3NbRKfSvU0lC3HC8/akM9UUrLgvEMerISTNzwtPZoKFb0raTlukwfNNuyWfWpXjE/oFU6QjmW+uBBl+8bWdxzflhA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734613512; c=relaxed/simple; bh=r1jCidUp+cvRhjuC2J6eG7t33CTSGGM8hB3Cq3HHWm0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AR6D2GKON8YMTa+cCMOXd60eSczKJ0z8wFXyieYHN3R8y0J0s0NKIlFsIo4yFMyzCQRuICDwUEu2zswLmVzwsjLmfmW6iJsQxUkdodGo7bCd5UxgTR6GLpMNWnGa/zEul/mKkb1dM+KUqAaCpoBvTgQDEjXiAG0vMViFkO1FxO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=U5lOBKa9; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U5lOBKa9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1734613509; 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=T5ScgxkNuZ1ybwXQme4UGRREuWyyWaRIhTG+vUuR3Xc=; b=U5lOBKa9m1OLePCruvB8yhAd2wpW0U+gT2kL7ctUtTT/zgiJHlwyiiIqdzX6NvUPIWJngK ZThgdFilHkFSarIQaCeDU4q4o7FK8h7wIYuPKUR2nnLt/AKG9U1rp3OL0Vj8yUkH66Rfx3 p8Iq4873WqCFbpRbGqcETjCPTYGTVso= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-607-AM-WnhsAMnGnQqrAc0tF8Q-1; Thu, 19 Dec 2024 08:05:08 -0500 X-MC-Unique: AM-WnhsAMnGnQqrAc0tF8Q-1 X-Mimecast-MFC-AGG-ID: AM-WnhsAMnGnQqrAc0tF8Q Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-385ed79291eso996870f8f.0 for ; Thu, 19 Dec 2024 05:05:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1734613507; x=1735218307; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from: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=T5ScgxkNuZ1ybwXQme4UGRREuWyyWaRIhTG+vUuR3Xc=; b=pY7iwQoUqeRE9CNgi90/aW1o7A9ERuUM5F0rXykDCqQxzOQokzLERVproIkyySJBH2 g/AHZNmn5Vbvq5BvD+SKFEGps+lWW5lP0Y8TVGq2/FTuRLiHEoonh2hpqxaNumCsD81T RwILf4kxYf1gJGZHoD8giHbDvWvqdEaMvpgGnUAgpbthGexkntm4oTzm9+0LitNqr7IW rNyU5mKBGKsRR22zvhsK2dUbSEM+1TcWIAY+Yf5d9p3uVRmLddh/aYnnMq392F26aeHy 9E1iNnrGHhFXDfo/MRKPuZOOekvp++c3CGO0CKMabSzG8v+T6q2IRp2d+I335CVYhfZP 3Daw== X-Forwarded-Encrypted: i=1; AJvYcCUExxeu5CsZMBwLtNsy+S2m8mYdSvr19HIgVu+n3sNm33DtXYqTxNM1m/lTkiywan3BlFUwpoMMN7/lz7ss@vger.kernel.org X-Gm-Message-State: AOJu0Yw/GZWhgmfLZX2SrQTlCLJC8rePq30xuaROaebcYr/eIZDlo8Gt TIMc72qO3sZOxnazB3Uj2WZKZHIBs+4SucwCFTbGphjTKR++G2ZclEACbdyRb9GRcCnavwIyQb3 DmqwBGZJIAwJ4VTeu1VSr8QTHgO2UYtCDrVwff+IcGuTojrISW54ihnaV8YxKn4k= X-Gm-Gg: ASbGncvktuQktUXndiJUYDSCEISvjRyRnFr8VwbtKgjzPM3gx9ZwnKq7+7xI35LwjAI FmjJ5+10RyaWtSbAd1NwVWzkCP5O//dX1eellG36U0UnHaRY7PNJdcu3hrtKomvX/LFNTnLxT9K 0G35osn/Kgh/stxt+91BpwvyTzNuN4R2AnsJv6gFOZa62gZ9FkKMZxBrmyDlTdGBv41E+dxWvQg /iYmMhxZ58TgNesUyC/VgQlaOdgCgOhfjmvQsuxyM7NHy3Osr+Bwi0TyFz01qvu3erV7vLNyKb7 Y574+3MQmt1UNreqZS4hqPh+5RJAVUiAvryvsdcPeLOtk+cduNQzLtuCPwZSnUbqhoefEm2rvul gghQwRA== X-Received: by 2002:a05:6000:1863:b0:386:3bde:9849 with SMTP id ffacd0b85a97d-38a1a20f407mr2696274f8f.12.1734613507023; Thu, 19 Dec 2024 05:05:07 -0800 (PST) X-Google-Smtp-Source: AGHT+IGZxd5/mfBE4XH/PDfC5RZrYtRzsU+3d1fLOzHQbPbIWfr4ljQziLuWO40YIOgGa7NxCDTgAg== X-Received: by 2002:a05:6000:1863:b0:386:3bde:9849 with SMTP id ffacd0b85a97d-38a1a20f407mr2696219f8f.12.1734613506515; Thu, 19 Dec 2024 05:05:06 -0800 (PST) Received: from ?IPV6:2003:cb:c749:6600:b73a:466c:e610:686? (p200300cbc7496600b73a466ce6100686.dip0.t-ipconnect.de. [2003:cb:c749:6600:b73a:466c:e610:686]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4366127c639sm17416435e9.31.2024.12.19.05.05.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Dec 2024 05:05:05 -0800 (PST) Message-ID: Date: Thu, 19 Dec 2024 14:05:04 +0100 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 4/5] mm/migrate: skip migrating folios under writeback with AS_WRITEBACK_INDETERMINATE mappings To: Joanne Koong , miklos@szeredi.hu, linux-fsdevel@vger.kernel.org Cc: shakeel.butt@linux.dev, jefflexu@linux.alibaba.com, josef@toxicpanda.com, bernd.schubert@fastmail.fm, linux-mm@kvack.org, kernel-team@meta.com, Matthew Wilcox , Zi Yan , Oscar Salvador , Michal Hocko References: <20241122232359.429647-1-joannelkoong@gmail.com> <20241122232359.429647-5-joannelkoong@gmail.com> From: David Hildenbrand Content-Language: en-US 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: <20241122232359.429647-5-joannelkoong@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 23.11.24 00:23, Joanne Koong wrote: > For migrations called in MIGRATE_SYNC mode, skip migrating the folio if > it is under writeback and has the AS_WRITEBACK_INDETERMINATE flag set on its > mapping. If the AS_WRITEBACK_INDETERMINATE flag is set on the mapping, the > writeback may take an indeterminate amount of time to complete, and > waits may get stuck. > > Signed-off-by: Joanne Koong > Reviewed-by: Shakeel Butt > --- > mm/migrate.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index df91248755e4..fe73284e5246 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1260,7 +1260,10 @@ static int migrate_folio_unmap(new_folio_t get_new_folio, > */ > switch (mode) { > case MIGRATE_SYNC: > - break; > + if (!src->mapping || > + !mapping_writeback_indeterminate(src->mapping)) > + break; > + fallthrough; > default: > rc = -EBUSY; > goto out; Ehm, doesn't this mean that any fuse user can essentially completely block CMA allocations, memory compaction, memory hotunplug, memory poisoning... ?! That sounds very bad. -- Cheers, David / dhildenb