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 EC3D1C5AD5A for ; Wed, 12 Aug 2026 11:06:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EFE626B00E8; Wed, 12 Aug 2026 07:06:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ED5336B00EA; Wed, 12 Aug 2026 07:06:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DC4926B00EB; Wed, 12 Aug 2026 07:06:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id B1F816B00E8 for ; Wed, 12 Aug 2026 07:06:12 -0400 (EDT) Received: from smtpin17.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 4D307160246 for ; Wed, 12 Aug 2026 11:06:12 +0000 (UTC) X-FDA: 85092338184.17.6DD0E68 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf17.hostedemail.com (Postfix) with ESMTP id 99E4D40007 for ; Wed, 12 Aug 2026 11:06:10 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=dwSyVabW; spf=pass (imf17.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786532770; 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=HDzCYichzDSEcw3dqF/NDMA9kt8syQtQ95yT2do8fzk=; b=1I7/Xg6fcZSOnFMq662t9nn0wkhsBDO1NvwFYmKehLr6bXcZ5E3/cn3TI81TWWEj/3rbrO VaWBTt6wr9dcnCyGRcy2uJ/U9IcCihAL/sqD3e96XRAdw58UQ7jDGBP3eLgIZd3Az0Jt5z jL88taPf9X1/fNaGD0K8dpEn6tj1ZNA= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786532770; b=GZULyjb/aRTfHa4cJmKIRu7gAUvTsqU1jYxMwpXzAMg9W8TpwvCkwlQb1rIqG1ZmFu8zgf IAyb1CNIXbWE0yGEOVy3wkoHDhX34uYo/yeqTBlfP19N+STcgF7vkaQPS290VvL2p+2YCr 6RVarmJlxCvWP4Nfd02IMwnluPBsLZQ= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=dwSyVabW; spf=pass (imf17.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 2774F600E2; Wed, 12 Aug 2026 11:06:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C3071F000E9; Wed, 12 Aug 2026 11:06:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786532769; bh=HDzCYichzDSEcw3dqF/NDMA9kt8syQtQ95yT2do8fzk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=dwSyVabWR6PJJ4qz5yJ+EsK9GBIq2itvgzG6L0XS3n2UcUg4s5bKtQD7XBlFhVUwr IKJUuHLRqgrJ9vrNJknI/ms+csBFrkPR9JjFPEH8hDpmFAFyOBXKLw3UTOznSBNG+V 5NdQG6AFIhb1XbdDCgRphAq83MLD6OYyCKIRzUXu5AgeXzKA+vkK+rP1j/IVYM3sBX 6K1LTweVvEKFyaoWWfhm6NRWAjtpf//iiek30y2yytEyU9fTdOLg6y68bQQ9atRgkA IKZa4GrgHDHt5dTblJE4oZHCfhw4I43VhnOIFZ0LH3z/ly5ibt8ETM4XGtzCQin9TB YtsKKPyerErQw== Message-ID: Date: Wed, 12 Aug 2026 13:06:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] mm, swap: distinguish a malformed swap entry from a dying device To: Pedro Falcato , Breno Leitao Cc: Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Hugh Dickins , Baolin Wang , Peter Xu , Johannes Weiner , Yosry Ahmed , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com References: <20260810-swap-v1-0-375ef0767206@debian.org> <20260810-swap-v1-2-375ef0767206@debian.org> From: "David Hildenbrand (Arm)" 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: 4eir15j7c19f8nufbifjzr5774dyb57h X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 99E4D40007 X-HE-Tag: 1786532770-582127 X-HE-Meta: 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 6/aOkaDH kki4H9XBbDhIKf47w0/oUg4k37Jr9Kp0y5XS1MTsyjxZC+TRFZCMeiJ+XP50WLAkAFMMlbu0OUe5ydshfDAzSwHxOvd3aDOAvmZ8E9i3t7M/fLBjVH/Akuojm7N+kmUXBX+50/6DysdiI5K5pp1deJCwbMnlfboASASuCfajxZaN6k8s3OteauIoKiTQlxt2GPd7Ge7U0fJPE/dG2aoNZKwxCW926+kiOsjJbqnmxiF4x4q0adN90SKntH3N5pInz5Aj4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/12/26 13:02, Pedro Falcato wrote: > On Wed, Aug 12, 2026 at 03:48:56AM -0700, Breno Leitao wrote: >> Hello David, >> >> On Tue, Aug 11, 2026 at 05:36:31PM +0200, David Hildenbrand (Arm) wrote: >>> >>> Is -EINVAL really the logical right return value? Running into bad swap entries >>> sounds more serious to me than "-EINVAL" :) >> >> Good point, maybe we need a strong drug here, what about -EIO? >> >> I picked -EINVAL because it is what the swap code already returns for >> this exact condition. >> >> >> * Returns -EINVAL if the swap entry is invalid, which might >> * occur if a page table entry has got corrupted. >> */ >> int swap_dup_entry_direct(swp_entry_t entry) >> { >> si = swap_entry_to_info(entry); >> if (WARN_ON_ONCE(!si)) { >> pr_err("%s%08lx\n", Bad_file, entry.val); >> return -EINVAL; >> >> But, I do agree -EINVAL is too soft given the situation we are in. >> >> I will return -EIO in the next version, if I don't hear any concern. > > Perhaps -EUCLEAN would be a more fitting error. It's generally what > filesystems use, at least (EFSCORRUPTED = EUCLEAN). Not a big fan of EUCLEAN for the use case here. The details don't really matter, but EINVAL just looked rather odd. -- Cheers, David