On Tue, May 23, 2017 at 12:20:59AM +0100, Marc Thomas wrote: > Hi All, > > Would you agree this is a bug? As I understand it, reading from an > "unpopulated" region of a sparse file should return all zeros - so the > md5sum should be the same before and after migration. I agree that sparse files should be properly handled after bmap2extent conversion. This code hasn't received that much use or testing, but I've tried to replicate the problem and I haven't succeeded. This script works for me: ----- cut here ----- #!/bin/bash rm -f /tmp/foo.img mke2fs -t ext3 -Fq /tmp/foo.img 65536 mount -o loop /tmp/foo.img /mnt dd if=/etc/motd of=/mnt/test bs=4k >& /dev/null dd if=/etc/motd of=/mnt/test conv=notrunc seek=32 bs=4k >& /dev/null dd if=/etc/motd of=/mnt/test2 bs=4k >& /dev/null dd if=/etc/motd of=/mnt/test2 conv=notrunc seek=1024 bs=4k >& /dev/null lsattr /mnt/test* md5sum /mnt/test* > /mnt/MD5SUMS umount /mnt e2fsck -fy -E bmap2extent /tmp/foo.img mount -o loop /tmp/foo.img /mnt md5sum -c /mnt/MD5SUMS lsattr /mnt/test* umount /mnt ----- cut here ----- Maybe you can come up with a simple repro case that fails for you? Thanks, - Ted
