From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) (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 F0D739460; Tue, 5 Mar 2024 20:29:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709670549; cv=none; b=Z0CxSkidmkdEWdtpF1x76f+/vr8Qbq+/hjy0lpegk5XJaBtqm22Czy4wSL4ecF9b0sYJ7FDo4HbjInNXq9nGV9XoIBiDmOWGBV+NPx+J4kZpLOkILDOuggkRuLKltix/7RmhhWiPSTRRn0v0kwiQsmt9mBXW7blopOMQ5Fhw944= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709670549; c=relaxed/simple; bh=oe2J97hfiCUqd8RBj/oWDlSveRaG9vwVNseRd0cTLKc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YN+8oNVtZOWeMbAWwxgszDETsbsNVLpzgbIR2yVRpb8vtAGsLF7KsJNuhxx1b/1ScedJZWpeWmPrHpp60GDUUD949PxzLiSOMgE1s+DB3rh/xavCmSz0Vx3RXKWuJvCFIPeqoKWV9JWWm//n4fJrOzqbte5CqtN275fGiGUlFvk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=acm.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-1dd01ea35b5so19716985ad.0; Tue, 05 Mar 2024 12:29:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709670547; x=1710275347; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=xXq7pFAKK69JkeekroRzoD2aGhQy0QdXJGytui7Sb+Q=; b=B1GBHJa4S2bBwfdALIiXMiM/5J3idVW/mX+3aQbz1FAgfb2MRNu8olvmgBEJvB862s LQbMGCu4JelFDBxANfMQkuO3JO693oKqfwwU0/LbgzTzSAK5K8Y/hX+auZDcyHMtQFrI Rs6kR03WqWxRnrcpH4/DZBksldxmyxwSjoe1e8R2Q4FZyhj5lAT7/NvT6eYIIQFrrhCZ N6kcOvhlmcilNVhXTg5fzu2bDaQmin2ZGU5to3B7B6/uDanayPZzYQjmKacUU9BwLh7A krPMak3xvAkKfZaLVOPxYJt9WKldRgzPlg5YZFHsATrK1FPX8JtDRRrsRdZ7dxLrXtkK 3QYg== X-Forwarded-Encrypted: i=1; AJvYcCX0YywZ6ZkDP7NC+jj8s8nCY3SSaWyDXtOfsb06rqR/1DsemxrEHbD0KroLXxLEYxPQ9A9dscE+hqPpEEG/aW2qqrDljblM X-Gm-Message-State: AOJu0Yx9pEOzKXQrHp3iFHocxIi9Nne/vxSuWFZIyalPd6EvgGmZ2MNJ bOUANJVAO4IRCKzrfF3V0HwM/oAV5EMbkGy0gTuGZNyH12L/GYt7icQ+mb4g X-Google-Smtp-Source: AGHT+IETxGKGf4oNCsiF0ugeq/oWFzeRGXyo+6AW6CukFPu5toWGC9tmAJCslyrUxa4UkmJCypV7bw== X-Received: by 2002:a17:902:8a83:b0:1d7:2e86:fb2a with SMTP id p3-20020a1709028a8300b001d72e86fb2amr2569921plo.65.1709670547210; Tue, 05 Mar 2024 12:29:07 -0800 (PST) Received: from ?IPV6:2620:0:1000:8411:3e11:2c1a:c1ee:7fe1? ([2620:0:1000:8411:3e11:2c1a:c1ee:7fe1]) by smtp.gmail.com with ESMTPSA id a6-20020a170902ecc600b001dcc2847655sm11005035plh.176.2024.03.05.12.29.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 05 Mar 2024 12:29:06 -0800 (PST) Message-ID: Date: Tue, 5 Mar 2024 12:29:05 -0800 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] Revert "fs/aio: Make io_cancel() generate completions again" Content-Language: en-US To: Christian Brauner , Eric Biggers Cc: linux-fsdevel@vger.kernel.org, Christoph Hellwig , Benjamin LaHaise , Avi Kivity , Sandeep Dhavale , Jens Axboe , Greg Kroah-Hartman , Kent Overstreet , stable@vger.kernel.org, syzbot+b91eb2ed18f599dd3c31@syzkaller.appspotmail.com References: <20240304182945.3646109-1-bvanassche@acm.org> <20240304193153.GC1195@sol.localdomain> <20240305-hinunter-atempause-5a3784811337@brauner> From: Bart Van Assche In-Reply-To: <20240305-hinunter-atempause-5a3784811337@brauner> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/5/24 00:50, Christian Brauner wrote: > We've been wrestling aio cancellations for a while now and aimed to > actually remove it but apparently it's used in the wild. I still very > much prefer if we could finally nuke this code. io_cancel() is being used by at least the Android user space code for cancelling pending USB writes. As far as I know we (Linux kernel developers) are not allowed to break existing user space code. See also: * https://android.googlesource.com/platform/frameworks/av/+/refs/heads/main/media/mtp/MtpFfsHandle.cpp * https://android.googlesource.com/platform/packages/modules/adb/+/refs/heads/main/daemon/usb.cpp Thanks, Bart.