From: Eric Sandeen Subject: Re: Files full of zeros with coreutils-8.11 and xfs (FIEMAP related?) Date: Thu, 14 Apr 2011 10:50:10 -0500 Message-ID: <4DA717B2.3020305@sandeen.net> References: <20110414102608.GA1678@x4.trippels.de> <20110414120635.GB1678@x4.trippels.de> <20110414140222.GB1679@x4.trippels.de> <4DA70BD3.1070409@draigBrady.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, coreutils-mXXj517/zsQ@public.gmane.org, Markus Trippelsdorf , xfs-oss To: =?ISO-8859-1?Q?P=E1draig_Brady?= Return-path: In-Reply-To: <4DA70BD3.1070409-V8g9lnOeT5ydJdNcDFJN0w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: coreutils-bounces+gcgcg-coreutils=m.gmane.org-mXXj517/zsQ@public.gmane.org Sender: coreutils-bounces+gcgcg-coreutils=m.gmane.org-mXXj517/zsQ@public.gmane.org List-Id: linux-ext4.vger.kernel.org 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 = = =20 >>>> Filesystem type is: ef53 = = =20 >>>> File size of unwritten.withdata is 5120 (2 blocks, blocksize 4096) = = =20 >>>> ext logical physical expected length flags = = =20 >>>> 0 0 274432 2560 unwritten,eof = = =20 >>>> unwritten.withdata: 1 extent found >>>> >>>> Please notice that this also happens with ext4 on the same kernel.=20 >>>> Btrfs is fine. >>> >> `filefrag -vs` fixes the issue on both xfs and ext4. >=20 > So in summary, currently on (2.6.39-rc3), the following > will (usually?) report a single unwritten extent, > on both ext4 and xfs >=20 > fallocate -l 10MiB -n k > dd count=3D10 if=3D/dev/urandom conv=3Dnotrunc iflag=3Dfullblock of=3D= k > 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 destinat= ion 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 th= ink I started looking into it, but it's clearly still broken. Still, I don't know for sure what happened to Markus - did something prea= llocate, in his case? -Eric =20 > cheers, > P=E1draig. >=20 > _______________________________________________ > xfs mailing list > xfs-VZNHf3L845pBDgjK7y7TUQ@public.gmane.org > http://oss.sgi.com/mailman/listinfo/xfs >=20