From nobody Sun Dec 17 02:39:35 2023 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4St6cB4GdRz53sdm; Sun, 17 Dec 2023 02:39:38 +0000 (UTC) (envelope-from kevans@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4St6cB3T5hz3W7g; Sun, 17 Dec 2023 02:39:38 +0000 (UTC) (envelope-from kevans@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1702780778; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RrYGUTZ8wcoobOy4eDRVcuAMxL4UAy+G4dwXOSU5UqU=; b=CaVPH7FGtzaFJH7tx+dTHIwDWeTcVVp8/5AYfBVN3LWbLM6bFsfK0GG0MuPJ2LI2QX2NGy dhPPpJ6H+nM+qfV22E490EUR7p24kRqvNEZM2DKpb+2h7rrb+f1bIoc75yRmnTVp3YW3DE q6RxxvKberMGBemw4uu92jViPYNBJ1iGCbyRbmtuxYQhGfVCDY/G5OdsPhDBmGiNxLP9gQ WfmX9sixZF+LHRx9KpdVQh0qKr84hkvZecAfXhaMb5KIrMurIEZZ/zZCXl4tvis81UrCsZ wCOJ6bAlP+PhleN1LDrNhQbrMUxmioWgv0JnpVDZweMP8tTwxhuG/AuR9MBZ1Q== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1702780778; a=rsa-sha256; cv=none; b=wOGhlamzZqNHRI0NN61ZZkc+uT1aipegqenyK96qhWZwY0BbjRX/NJgE0vP97wFAmhccZz 0JoVn3fv648AaFiOv683wGNEitTmzqYTUn9lX7hISi7ENF0BnjiSHz2RyX/DMEwtwEm9Zx cp3G3DGlZG69bAazPk51THQIMfBz7Knuj5ZBvXhEzkKsZz7EPwMb1yo8DJzdowb/sGuaZP JYUxbf1oN5rKRIy0X+d10ID44b55Y+UWz2/Qu4BVUSKuY4I65F1WxKfGMhsGSvFz44lmLH tzMXbqm9qdxTnpvqro9xEZlOrXEm+scfZiHYTis+q9eGi0EYJ3EJnM/s0EEmFQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1702780778; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RrYGUTZ8wcoobOy4eDRVcuAMxL4UAy+G4dwXOSU5UqU=; b=JrW2Nkzh+wbthQcQGhTvqmxtv/aaqgX/4YmZR7Czx24guD9nP0isg1yb1Dew/5of1mfQNb yL6KQ7jO89N9YkSC7/NvAT80sRHu3/YZgIOFKjfcNfJRaj8jwoVhb7Vw3IiNJ7HfVmGsin FRCJUST8uiTpbvsJDMNjW9FDFl7wHwIzErfA1k+O/WU+/7yeBK37G3QbQfw8xnMZUeoK94 ZCz4YK6J5W946UvDHO7I3Meg6ASrrjasjXHOhQT7RT7oEvm1STuHJ10OZ1iImqciULZ0Ds BzQai5LY2nrOYM+MNTtFaPBQTiVkPF1u0q/ROJx5b3Ou6Mix9cTOuieCyNZRXA== Received: from [10.9.4.95] (unknown [209.182.120.176]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: kevans/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 4St6c96Lhyzymj; Sun, 17 Dec 2023 02:39:37 +0000 (UTC) (envelope-from kevans@FreeBSD.org) Message-ID: <5ec2e86c-65c5-4733-b22a-443a9c103bde@FreeBSD.org> Date: Sat, 16 Dec 2023 20:39:35 -0600 List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: git: ca39f23347e1 - main - ufs: do not leave around empty buffers shadowing disk content Content-Language: en-US To: Konstantin Belousov , src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org References: <202312152209.3BFM9J2o038542@gitrepo.freebsd.org> From: Kyle Evans In-Reply-To: <202312152209.3BFM9J2o038542@gitrepo.freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/15/23 16:09, Konstantin Belousov wrote: > The branch main has been updated by kib: > > URL: https://cgit.FreeBSD.org/src/commit/?id=ca39f23347e1416a28dde13279bfe5841ad9a746 > > commit ca39f23347e1416a28dde13279bfe5841ad9a746 > Author: Konstantin Belousov > AuthorDate: 2023-12-11 22:57:28 +0000 > Commit: Konstantin Belousov > CommitDate: 2023-12-15 22:06:10 +0000 > > ufs: do not leave around empty buffers shadowing disk content > > If the ffs_write() operation specified to overwrite the whole buffer, > ffs tries to save the read by not validating allocated buffer. Then > uiommove() might fail with EFAULT, in which case pages are left zeroed > and marked valid but not read from the disk. Then vn_io_fault() logic > retries the write after holding the user pages to avoid EFAULTs. In > erronous case of really faulty buffer, or in contrived case of writing > from file to itself, we are left with zeroed buffer instead of valid > content written back to disk. > > Handle the situation by releasing non-cached buffer on fault, instead > of clearing it. Note that buffers with alive dependencies cannot be > released, but also either they cannot have valid content on the disk > because dependency on data buffer means that it was not yet written, or > they were reallocated by fragment extension or ffs_reallocbks(), and are > already fully valid. > > Reported by: kevans > Discussed with: mav > In collaboration with: pho > Sponsored by: The FreeBSD Foundation > MFC after: 1 week > Thanks!