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 13A5ACCF9F8 for ; Fri, 7 Nov 2025 12:11:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5C08A8E0010; Fri, 7 Nov 2025 07:11:02 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 570CE8E0002; Fri, 7 Nov 2025 07:11:02 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 486848E0010; Fri, 7 Nov 2025 07:11:02 -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 333C08E0002 for ; Fri, 7 Nov 2025 07:11:02 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id F36C4140455 for ; Fri, 7 Nov 2025 12:11:01 +0000 (UTC) X-FDA: 84083695122.18.8A80D7D Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf05.hostedemail.com (Postfix) with ESMTP id 5566A10000A for ; Fri, 7 Nov 2025 12:11:00 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=pass (policy=none) header.from=lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762517460; 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: in-reply-to:in-reply-to:references:references; bh=WHMcTbA2Qmp+ikXo6uXrRBMFP0WlUljXRCgUWUmqtJU=; b=QTVhVzy6/jTYw5kQNqGV2tEyk0AomjoEdT004MZgmpXbVUSYdWb0VjQfccEBa6tnuBpzL3 dKGt8a+xv96JaAldXqv+SXkoR3/KO0ymlEtfDBXBv3/27pevgYyKe9BebrzwTVp+ZGBB2d wFC4+UyW+jHSc74+dmDprm3SjxVJUHg= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=pass (policy=none) header.from=lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762517460; a=rsa-sha256; cv=none; b=OSP0H1pfa8/MltUc6YHbbkrclQkHnrDZMdmVqArHe8D37W9VcqllhOdAzNbuwJzTtZv07H trA5kLFHoXL7iexEgA+1pik8K2/daWG+SPsi4YDmVl2GAWY3vT9JzwA6GfEEBAKt9K36ev 8RzT9nLdYl65oMphaIgzdKa+4Y54fKs= Received: by verein.lst.de (Postfix, from userid 2407) id 678C4227AAE; Fri, 7 Nov 2025 13:10:56 +0100 (CET) Date: Fri, 7 Nov 2025 13:10:56 +0100 From: Christoph Hellwig To: Eric Biggers Cc: Christoph Hellwig , Jens Axboe , Vlastimil Babka , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 8/9] blk-crypto: use on-stack skciphers for fallback en/decryption Message-ID: <20251107121056.GF30551@lst.de> References: <20251031093517.1603379-1-hch@lst.de> <20251031093517.1603379-9-hch@lst.de> <20251107041859.GD47797@sol> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251107041859.GD47797@sol> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5566A10000A X-Stat-Signature: sni1b8mni1x53fazgz6y78czk3co74zo X-Rspam-User: X-HE-Tag: 1762517460-876105 X-HE-Meta: U2FsdGVkX19B05c5ASGooW4arK3kz9zKuLxnjJv+LR4DjIGbCzckyWL5Ptv54BUBct3RDmOu7ygB8U0QfIyUdA6CqrlwkL3H82GNlsmC1qr5IMrioThDfT5CF3Z0jYKBM/Nk4Uf5dTXOc+vW7msWtfPZ6Z2FA2v7ikxHuCzJT/Et6ha1t1mtY/byPoUucjIAjoG39NqZ3nK6B69+agpQQxkxdqKIlpFdLXJuZUba+GTqhyfXPT39XNXFC1qDCxw5daawKoFzWenPKCaqDWhD3FmYZ05Yv0iJ/PPFVXDcM6dgkNtj/toDIbDuwxDBGkWWg8RGv1UgTT9QdiLph5MDWRm0f5kRb4xNdmGLU6Wsi197hYZkskyFrMm0HPOea2WpZ3/w6DyatUm6fKr9RkxK4JQRq9fzBEhiLO08d2ONJh+y2DZ3ZEOtnkT7PXIRgNWL1kkOoZ92/vlZ8KMBoxsqTDGdZDpMd3oZn9RskuzX50WwRpUdUaikL9Wao/ytJROen0hKzEdz9VtWyi+G/Vzc0XEp50oCkGnNzjvrPp/mT21anLkP9RIE/atRhYDG10AClCntjes5gPPuLSPPf8pdNf18LldFgHtymIrW7Tu5QtIDTN/eJ74uHnW9MRw7/YuJWwWcp5wVgvQb/lkM1pUPeYEHkmVliYIP17ZIMh6fF8EilvVFtKgVwAy0eay8A0TQaXX4nKQYrReaMrxrjD63xxiPw2TCM7bEyfklnlptvel+mnmHxX5A8uZIMik/6nMfG6JoBJXd00PKPAVoQkhkyRtlGPx2Qva+lcdrQqD2xt7Oy9kfNBgA4oe6BZwMKGksg257Fmd9WxPvBbiYslfMha8vGuJPz4BfksdSou+oOxItxXy5fEH/As0kVqTHEExkZVkYHYe/WpAR1pmAbTZ0SBm3ozDviuZVlCceXYvZO/coua3JEpJfB7cONenDIAqUt+1gZ5d88v6lpQEoHWs CO01IQW+ soLYyzWTCLfLtIuRL6jsc9h3JtPk9Ku730BCIhtCOpZq01vw0Bl4d6Lh0fJ4V/78zu9dKB5bsuvkDilQb9YUUvwzlPLvR5Zf+gc7m 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 Thu, Nov 06, 2025 at 08:18:59PM -0800, Eric Biggers wrote: > On Fri, Oct 31, 2025 at 10:34:38AM +0100, Christoph Hellwig wrote: > > Allocating a skcipher dynamically can deadlock or cause unexpected > > I/O failures when called from writeback context. Sidestep the > > allocation by using on-stack skciphers, similar to what the non > > blk-crypto fscrypt already does. > > > > Signed-off-by: Christoph Hellwig > > It might be worth leaving a note in the commit message that this also > drops the incomplete support for asynchronous algorithms. ("Incomplete" > in the sense that they could be used, but only synchronously.) sure. > Also note that with asynchronous algorithms no being longer supported, > the code can actually be simplified further because the > DECLARE_CRYPTO_WAIT(wait) objects are no longer necessary. The sequence > of crypto_sync_skcipher calls that is used should be similar to what > fscrypt_crypt_data_unit() does. Ok.