From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with SMTP id p3EFqu2v003391 for ; Thu, 14 Apr 2011 10:52:56 -0500 Received: from mail.sandeen.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with SMTP id BF53D3E1621 for ; Thu, 14 Apr 2011 08:56:17 -0700 (PDT) Received: from mail.sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with SMTP id FcgaDR0ApcqrTZIF for ; Thu, 14 Apr 2011 08:56:17 -0700 (PDT) Message-ID: <4DA71920.9@sandeen.net> Date: Thu, 14 Apr 2011 10:56:16 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: Files full of zeros with coreutils-8.11 and xfs (FIEMAP related?) References: <20110414102608.GA1678@x4.trippels.de> <20110414120635.GB1678@x4.trippels.de> <20110414140222.GB1679@x4.trippels.de> <4DA70BD3.1070409@draigBrady.com> <4DA717B2.3020305@sandeen.net> <4DA7182B.8050409@draigBrady.com> In-Reply-To: <4DA7182B.8050409@draigBrady.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: =?ISO-8859-1?Q?P=E1draig_Brady?= Cc: linux-ext4@vger.kernel.org, coreutils@gnu.org, Markus Trippelsdorf , xfs-oss On 4/14/11 10:52 AM, P=E1draig Brady wrote: > On 14/04/11 16:50, Eric Sandeen wrote: >> On 4/14/11 9:59 AM, P=E1draig Brady wrote: >>> On 14/04/11 15:02, Markus Trippelsdorf wrote: >>>>>> Hi P=E1draig, >>>>>> >>>>>> here you go: >>>>>> + filefrag -v unwritten.withdata = = = >>>>>> Filesystem type is: ef53 = = = >>>>>> File size of unwritten.withdata is 5120 (2 blocks, blocksize 4096) = = = >>>>>> ext logical physical expected length flags = = = >>>>>> 0 0 274432 2560 unwritten,eof = = = >>>>>> unwritten.withdata: 1 extent found >>>>>> >>>>>> Please notice that this also happens with ext4 on the same kernel. = >>>>>> Btrfs is fine. >>>>> >>>> `filefrag -vs` fixes the issue on both xfs and ext4. >>> >>> So in summary, currently on (2.6.39-rc3), the following >>> will (usually?) report a single unwritten extent, >>> on both ext4 and xfs >>> >>> fallocate -l 10MiB -n k >>> dd count=3D10 if=3D/dev/urandom conv=3Dnotrunc iflag=3Dfullblock of= =3Dk >>> filefrag -v k # grep for an extent without unwritten || fail >> >> right, that's what I see too in testing. >> >> But would the coreutils install have done a preallocation of the destina= tion file? >> >> Otherwise this looks like a different bug... >> >>> This particular issue has been discussed so far at: >>> http://debbugs.gnu.org/cgi/bugreport.cgi?bug=3D8411 >>> Note there it was stated there that ext4 had this >>> fixed as of 2.6.39-rc1, so maybe there is something lurking? >> >> ext4 got a fix, but not xfs, I guess. My poor brain can't remember, I t= hink I started looking into it, but it's clearly still broken. >> >> Still, I don't know for sure what happened to Markus - did something pre= allocate, in his case? > = > Well that preallocate test is failing for him > when the source file is either on ext4 or xfs. > He noticed the issue initially on XFS when copying > none preallocated files, so XFS probably just has > the general issue of needing a sync before fiemap, > where as EXT4 just has this preallocate one > (though I've not seen it myself). > = > cheers, > P=E1draig. > = well, if I simply take the preallocation step out of the testcase, it works= fine on xfs without a sync. So I still don't know what Markus hit... -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs