From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:53225 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755567AbaEPOnk (ORCPT ); Fri, 16 May 2014 10:43:40 -0400 Date: Fri, 16 May 2014 15:43:36 +0100 From: Hugo Mills To: dsterba@suse.cz, linux-btrfs@vger.kernel.org Subject: Re: [PATCH 3/3] btrfs check: Attempt to fix misordered keys with bitflips in them Message-ID: <20140516144336.GA2537@carfax.org.uk> References: <1399309671-9240-1-git-send-email-hugo@carfax.org.uk> <1399309671-9240-4-git-send-email-hugo@carfax.org.uk> <20140516142236.GW6917@twin.jikos.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bg08WKrSYDhXBjb5" In-Reply-To: <20140516142236.GW6917@twin.jikos.cz> Sender: linux-btrfs-owner@vger.kernel.org List-ID: --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, May 16, 2014 at 04:22:36PM +0200, David Sterba wrote: > On Mon, May 05, 2014 at 06:07:51PM +0100, Hugo Mills wrote: > > If precisely one of those bitflips puts the broken key back into order > > relative to its two neighbours, we probably have a fix for the bitflip, > > and so we write it back to the FS. > > This sounds safe enough to me. I'll add the patch to integration but > before I push it further upstream I'd really like to see the bitflip fix > in action, so if you already have testing images, please let me know. Here's the one I mostly used to test with -- it's a 32 GiB sparse full filesystem image, with a file full of zeroes in it. It has a single bitflip in the csum tree created by hand with a hex editor, and then the csum fixed up afterwards, again by hand. Hugo. [1] http://carfax.org.uk/files/temp/testfs.img.tar.gz -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- I don't care about "it works on my machine". We are not --- shipping your machine. --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBU3YkGFheFHXiqx3kAQJo6Q/+KMb/DL8ULr2O1LJitM4E6FRUXGOLsOB5 ba4/3TFZqaE4J+T9dOk0IIUUILdUxx83TIZ9UGlqgtMgtZkt3yVgiUzqPy8XpOKV PCtv4OyXGcpF1hWGFJe6XNIWOhqYJmIt2n2BW2VXBIGPZ/vDnr0PLKts9NplEUih Kr5fFT4FNwX73rxuQ1petlvm8d2ye7eAz0uitFTQovaBmUwIflaLhNssi/2rOeDi 07BU8btzoGSMax/5KLfg1N+6YW9GcvTpHrOWqLIwoCOFF6gNNWWQkA5SpPBOInBJ c8ThYSzMXL0fll2Exlrv0utCqDL7lR/HvviW2TLAwDJmOS+z8bokTuHwvc3U6pEs cvJsGkGwcGCLRTmNm6U6tPFTmq22dOG3GSH/myx5AHZwcJzWsnUiMXYCLB/HQGAt i+yp0qSmItEnlYEV5M8kcokQJQC1h9tf7YABreAdat57fi5j5YvCamKzhm86IAR2 mdFNOzc1q3UknXLe64Ge47nF710HPmEbYRIjpFQ4w0IT5cZDoVcE443kK9xtkFA9 CyrDViXmtX7B8SLllwbZouUfcKAA73S9x/mKfP0s4ujz/YgNcnUPl4spH2JtKxzh fP7RHqktpe4+4A8K2IFmp7JAbFgbUrlIW9drPCv2E5Bx8BMAFARLNN28uSgV2L6y 3OMFjRljXKE= =vlcy -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5--