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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6994BC001E0 for ; Thu, 10 Aug 2023 18:09:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235395AbjHJSJ6 (ORCPT ); Thu, 10 Aug 2023 14:09:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233399AbjHJSJz (ORCPT ); Thu, 10 Aug 2023 14:09:55 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89E3C1703 for ; Thu, 10 Aug 2023 11:09:52 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-51cff235226so2513984a12.0 for ; Thu, 10 Aug 2023 11:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; t=1691690991; x=1692295791; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=CdVO7LGdqPVywscLfXnXC7vbQR6Oxa8Ot+Ua+mHkMYE=; b=WzCIt8KVNJVdUdDcoICwW+y1kes2mDvZQAnTaZ6ICrlBFD2xuSWvx79+xCbSxwCNt5 0BZH4+mr4QPdacXjUPLHH+3Nkk6gDfHJWnBunWIQb+ByKli4xNSoMgz2mWMA/ZjNuv+2 ddxaQz7M3kybukD0yF8CCam9KHjAfVNNOtGyo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691690991; x=1692295791; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=CdVO7LGdqPVywscLfXnXC7vbQR6Oxa8Ot+Ua+mHkMYE=; b=Q7+UP0AQaQNePkEU58p0iSJAhXLU9s+9ohR3k6K8eCIL0e6avvoYOkS9nfkaIr0tAi tSZotlzfxGSAsz0qvkUsN1ykg82R9/AK0jDU8tvOODbOv52Q+o1L+3LlWaUIywyzGZYt XhsktmOZ+2kAWS93bwXBJIZNTOurBZ6Lt8rzQ14IOHeD3EpNcZM2JLevDMKjab2DYrIu YDc/6h4irBNiFVHZCqekO0TBkxied9NiMgj/sxkAxK4jOyFdhqSUPgaVgFbsOjOOzNlz rgtmcvisg1cvgykSGWONC2seRYsupT2PeipTfFJUzfgX4VpwwBFnTmDWpaEQXsue868z /37g== X-Gm-Message-State: AOJu0YyJO87WGzRkgaWlGAqhFFYMAQFE3HO4i+stRr6QPDvDpZm2aXi3 kkVIAusGNY8aDUfHOTq3F51Y5Z7phvQRV4Ut+IbNjPeG X-Google-Smtp-Source: AGHT+IGIsD9DhePdO/GdVWp97pzhAeeOlT2AsJgQ4Fsdf21e3OXZrlWi6wiHmEPi+tGp9gYXXufcGQ== X-Received: by 2002:aa7:d812:0:b0:521:728f:d84e with SMTP id v18-20020aa7d812000000b00521728fd84emr3715064edq.0.1691690990967; Thu, 10 Aug 2023 11:09:50 -0700 (PDT) Received: from mail-ed1-f49.google.com (mail-ed1-f49.google.com. [209.85.208.49]) by smtp.gmail.com with ESMTPSA id u14-20020aa7d98e000000b005231e3d89efsm1098889eds.31.2023.08.10.11.09.49 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Aug 2023 11:09:49 -0700 (PDT) Received: by mail-ed1-f49.google.com with SMTP id 4fb4d7f45d1cf-51cff235226so2513932a12.0 for ; Thu, 10 Aug 2023 11:09:49 -0700 (PDT) X-Received: by 2002:a05:6402:520a:b0:51e:5206:d69e with SMTP id s10-20020a056402520a00b0051e5206d69emr3555926edd.10.1691690989521; Thu, 10 Aug 2023 11:09:49 -0700 (PDT) MIME-Version: 1.0 References: <20230626214656.hcp4puionmtoloat@moria.home.lan> <20230706155602.mnhsylo3pnief2of@moria.home.lan> <20230712025459.dbzcjtkb4zem4pdn@moria.home.lan> <20230810155453.6xz2k7f632jypqyz@moria.home.lan> <20230810180244.cx3vouaqtisklttn@moria.home.lan> In-Reply-To: <20230810180244.cx3vouaqtisklttn@moria.home.lan> From: Linus Torvalds Date: Thu, 10 Aug 2023 11:09:31 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] bcachefs To: Kent Overstreet Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-bcachefs@vger.kernel.org, djwong@kernel.org, dchinner@redhat.com, sandeen@redhat.com, willy@infradead.org, josef@toxicpanda.com, tytso@mit.edu, bfoster@redhat.com, jack@suse.cz, andreas.gruenbacher@gmail.com, brauner@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, dhowells@redhat.com, snitzer@kernel.org, axboe@kernel.dk Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 10 Aug 2023 at 11:02, Kent Overstreet wrote: > > When using sget() in the conventional way it's not possible for > FMODE_EXCL to protect against concurrent opens scribbling over each > other because we open the block device before checking if it's already > mounted, and we expect that open to succeed. So? Read-only operations. Don't write to anything until after you then have verified your exclusive status. If you think you need to be exclusive to other people opening the device for other things, just stop expecting to control the whole world. Linus