On Wed, Nov 18, 2009 at 4:48 AM, Nuutti Kotivuori <na...@iki.fi> wrote: > Hello, > > I recently told here about a broken filesystem after btrfs-convert & > friends and I was informed that this was a known bug and fixed in later > releases. I should've reformatted the partition and copied in the files > anew, but I didn't, since this isn't a crucial production system for me. > > So, after a day or two, I got in a case where I had done a hibernate, > several suspend/resume cycles and exhausted the swap space so OOM killer > was running wild and stuff. > > And I managed to get an endless stream of errors to the system log that > looked more or less like this: > > parent transid verify failed on 39620608 wanted 5946 found 5944 > > I don't know if I'd be able to reproduce the problem, if spending a lot > of time on it, but atleast for now, this was just a one time off case. > > So I rebooted the machine, and got the same stream of errors upon > mounting the filesystem. 500 per second. So I tried fsck, and it gave > the same error and promptly segmentation faulted. btrfs-image did the > same I think (though I'm not sure about this one). > > Anyhow, I'd love to have a more reliable btrfsck, that is able to fix > all kinds of corruptions, even then ones that are "never supposed to > happen". So, personally, I'd like to work on this issue until btrfsck is > able to fix the filesystem in to perfect working order - or atleast in > such a good state, that files can be copied off from it. > > However, if you'd rather debug the mount problems, that can be done as > well - though that's more of a problem since I will have to do it in a > virtual machine as to not mess up my server. > > Anyhow, long story short, here's the error reported by btrfsck: > > --------------------------------------------------------------------------- > $ sudo ./btrfsck /dev/mapper/perspire-root > parent transid verify failed on 39620608 wanted 5946 found 5944 > Segmentation fault > --------------------------------------------------------------------------- > > And here's valgrind telling what goes awry: > > --------------------------------------------------------------------------- > parent transid verify failed on 39620608 wanted 5946 found 5944 > ==17536== Invalid read of size 4 > ==17536== at 0x40F9AB: btrfs_print_leaf (ctree.h:1411) > ==17536== by 0x40C066: btrfs_lookup_extent_info (extent-tree.c:1450) > ==17536== by 0x4023F2: check_extents (btrfsck.c:2509) > ==17536== by 0x405004: main (btrfsck.c:2829) > ==17536== Address 0xc4 is not stack'd, malloc'd or (recently) free'd > --------------------------------------------------------------------------- > > This is with the current head of btrfs-progs-unstable. >
You can try mounting the FS in read only mode and copying files out. If you still get that error, try making verify_parent_transid() in disk-io.c always return 0. These are all we can do now. Yan, Zheng -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
