Peter Rajnoha <prajnoha@redhat.com> on Mon, 2014/02/10 15:12: > On 02/10/2014 02:48 PM, Christian Hesse wrote: > > Zdenek Kabelac <zkabelac@redhat.com> on Mon, 2014/02/10 13:20: > >> Dne 10.2.2014 10:30, Christian Hesse napsal(a): > >>> Zdenek Kabelac <zkabelac@redhat.com> on Mon, 2014/02/10 09:33: > >>>> Dne 8.2.2014 00:55, Christian Hesse napsal(a): > >>>>> Christian Hesse <list@eworm.de> on Sat, 2014/02/08 00:36: > >>>>>> Hello everybody, > >>>>>> > >>>>>> I think I nailed it down with git bisect. My first bad commit is: > >>>>>> > >>>>>> 75628f341ad38b68aae33eae0b5700be2a6e5769 > >>>>>> configure: enable blkid_wiping by default if the blkid library is > >>>>>> present > >>>>>> > >>>>>> Looks like this wipes data that is still needed... Building a package > >>>>>> with '--disable-blkid_wipe' now to verify on another system. > >>>>> > >>>>> Uh, this only helps part of... > >>>>> > >>>>> I changed my test setup and used writable snapshots. After that I got: > >>>>> > >>>>> WARNING: DM_snapshot_cow signature detected on /dev/cvg/snap-home at > >>>>> offset 0. Wipe it? [y/n] > >>>>> > >>>>> (see https://bbs.archlinux.org/viewtopic.php?id=176504 for another > >>>>> report) > >>>>> > >>>>> Looks like disabling blkid_wiping fixes this. My snapshot corruption > >>>>> still occurs though. :-/ > >>>>> Bad thing about it is that the corruption does not occur reliable when > >>>>> doing simple tests in 'git bisect'... Out of ideas for now - Will go > >>>>> to bed now. > >>>> > >>>> Now this was helpful, I guess I think what is going on. > >>> > >>> Great! Waiting for patches then. :D > >>> > >>> I could provide some more information when needed: > >>> > >>> * This happens with read only snapshots only. > >>> * I could reproduce with commit eaa23d32732c9bc3dd4f948781b5764cf21d84ba > >>> (wiping: add support for blkid wiping), so it was introduced there or > >>> before. > >>> > >>> Should I investigate further or wait for something to test from you? > >> > >> Is the patch bellow fixing your problem ? > >> (It's still not final - but should help) > >> > >> Zdenek > >> > >> > >> diff --git a/tools/lvcreate.c b/tools/lvcreate.c > >> index 638a868..e8b1a7f 100644 > >> --- a/tools/lvcreate.c > >> +++ b/tools/lvcreate.c > >> @@ -772,7 +772,7 @@ static int _read_activation_params(struct > >> lvcreate_params *lp, LVM_READ | LVM_WRITE); > >> > >> /* Must not zero/wipe read only volume */ > >> - if (!(lp->permission & LVM_WRITE)) { > >> + if (!lp->snapshot && !(lp->permission & LVM_WRITE)) { > >> lp->zero = 0; > >> lp->wipe_signatures = 0; > >> } > > > > This looks good to me. I've made some backups now without any corruption. > > > > But with blkid_wiping enabled I do have this warning/question now for read > > only snapshots as well: > > > > WARNING: DM_snapshot_cow signature detected on /dev/cvg/snap-home > > at offset 0. Wipe it? [y/n] > > > > lvm works perfectly only with your patch applied and compiled with > > --disable-blkid_wiping. > > Also, try this patch in addition: > > https://git.fedorahosted.org/cgit/lvm2.git/commit/?id=ed166a3b1d3290ad887d8f83c24a8d8877713d3c That did the trick. Thanks a lot! If anybody is interested... These are the patches updated to apply against version 2.02.105: http://www.eworm.de/download/linux/lvm2-snapshot.patch http://www.eworm.de/download/linux/lvm2-snapshot-wiping.patch -- main(a){char*c=/* Schoene Gruesse */"B?IJj;MEH" "CX:;",b;for(a/* Chris get my mail address: */=0;b=c[a++];) putchar(b-1/(/* gcc -o sig sig.c && ./sig */b/42*2-3)*42);}
Attachment:
signature.asc
Description: PGP signature
_______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
